National Library of Energy BETA

Sample records for hor se trap

  1. Barrier to Trap Filling CuIn1-xGaxSe2: Preprint

    SciTech Connect (OSTI)

    Young, D. L.; Ramanathan, K.; Contreras, M.; Abushama, J.; Crandall, R. S.

    2003-04-01

    Voltage pulses of variable length were applied to CuIn1-xGaxSe2/CdS (0< x< 1) junction solar cells. The resulting transient capacitance emission signal was recorded for several minutes. The amplitude of the capacitance emission signal increased linearly with the log of pulse time. These data do not follow the standard model for trap capture and emission of carriers. Instead they follow a simple electrostatic model based on electrostatic charging of traps.

  2. Charge trapping and de-trapping in isolated CdSe/ZnS nanocrystals under an external electric field: Indirect evidence for a permanent dipole moment

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

    Zang, Huidong; Cristea, Mihail; Shen, Xuan; Liu, Mingzhao; Camino, Fernando; Cotlet, Mircea

    2015-08-05

    Single nanoparticle studies of charge trapping and de-trapping in core/shell CdSe/ZnS nanocrystals incorporated into an insulating matrix and subjected to an external electric field demonstrate the ability to reversibly modulate the exciton dynamics and photoluminescence blinking while providing indirect evidence for the existence of a permanent ground state dipole moment in such nanocrystals. A model assuming the presence of energetically deep charge traps physically aligned along the direction of the permanent dipole is proposed in order to explain the dynamics of nanocrystal blinking in the presence of a permanent dipole moment.

  3. Gate-modulated weak anti-localization and carrier trapping in individual Bi{sub 2}Se{sub 3} nanoribbons

    SciTech Connect (OSTI)

    Wang, Li-Xian; Yan, Yuan; Liao, Zhi-Min Yu, Da-Peng

    2015-02-09

    We report a gate-voltage modulation on the weak anti-localization of individual topological insulator Bi{sub 2}Se{sub 3} nanoribbons. The phase coherence length decreases with decreasing the carrier density of the surface states on the bottom surface of the Bi{sub 2}Se{sub 3} nanoribbon as tuning the gate voltage from 0 to −100 V, indicating that the electron-electron interaction dominates the decoherence at low carrier density. Furthermore, we observe an abnormal conductance decline at positive gate voltage regime, which is ascribed to the capture of surface carriers by the trapping centers in the surface oxidation layer.

  4. Recombination luminescence and trap levels in undoped and Al-doped ZnO thin films on quartz and GaSe (0 0 0 1) substrates

    SciTech Connect (OSTI)

    Evtodiev, I.; Caraman, I.; Leontie, L.; Rusu, D.-I.; Dafinei, A.; Nedeff, V.; Lazar, G.

    2012-03-15

    Highlights: Black-Right-Pointing-Pointer ZnO films on GaSe create electron trapping states and PL recombination levels. Black-Right-Pointing-Pointer Zn and Al diffusion in GaSe produces low-energy widening of its PL emission. Black-Right-Pointing-Pointer ZnO:Al films on GaSe lamellas are suitable for gas-discharge lamp applications. -- Abstract: Photoluminescence spectra of ZnO and ZnO:Al (1.00, 2.00 and 5.00 at.%) films on GaSe (0 0 0 1) lamellas and amorphous quartz substrates, obtained by annealing, at 700 K, of undoped and Al-doped metal films, are investigated. For all samples, the nonequilibrium charge carriers recombine by radiative band-to-band transitions with energy of 3.27 eV, via recombination levels created by the monoionized oxygen atoms, forming the impurity band laying in the region 2.00 - 2.70 eV. Al doping induces an additional recombination level at 1.13 eV above the top of the valence band of ZnO films on GaSe substrates. As a result of thermal diffusion of Zn and Al into the GaSe interface layer from ZnO:Al/GaSe heterojunction, electron trap levels located at 0.22 eV and 0.26 eV below the conduction band edge of GaSe, as well as a deep recombination level, responsible for the luminescent emission in the region 1.10 - 1.40 eV, are created.

  5. COLD TRAPS

    DOE Patents [OSTI]

    Thompson, W.I.

    1958-09-30

    A cold trap is presented for removing a condensable component from a gas mixture by cooling. It consists of a shell, the exterior surface of which is chilled by a refrigerant, and conductive fins welded inside the shell to condense the gas, and distribute the condensate evenly throughout the length of the trap, so that the trap may function until it becomes completely filled with the condensed solid. The contents may then be removed as either a gas or as a liquid by heating the trap. This device has particuinr use as a means for removing uranium hexafluoride from the gaseous diffusion separation process during equipment breakdown and repair periods.

  6. TRAP) K. S. Marble

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

    The trap's electric quadrupole field is provided by a SHIP TRAPS RF electronic circuit to the four segmented electrodes at the center of the trap while the trap's 7 Tesla magnetic ...

  7. VACUUM TRAP

    DOE Patents [OSTI]

    Gordon, H.S.

    1959-09-15

    An improved adsorption vacuum trap for use in vacuum systems was designed. The distinguishing feature is the placement of a plurality of torsionally deformed metallic fins within a vacuum jacket extending from the walls to the central axis so that substantially all gas molecules pass through the jacket will impinge upon the fin surfaces. T fins are heated by direct metallic conduction, thereby ol taining a uniform temperature at the adeorbing surfaces so that essentially all of the condensible impurities from the evacuating gas are removed from the vacuum system.

  8. COLD TRAP

    DOE Patents [OSTI]

    Milleron, N.

    1963-03-12

    An improved linear-flow cold trap is designed for highvacuum applications such as mitigating back migration of diffusion pump oil moiecules. A central pot of liquid nitrogen is nested within and supported by a surrounding, vertical, helical coil of metai sheet, all enveloped by a larger, upright, cylindrical, vacuum vessel. The vertical interstices between successive turns of the coil afford lineal, axial, high-vacuum passages between open mouths at top and bottom of said vessel, while the coil, being cold by virtue of thermal contact of its innermost turn with the nitrogen pot, affords expansive proximate condensation surfaces. (AEC)

  9. Microfabricated ion trap array

    DOE Patents [OSTI]

    Blain, Matthew G.; Fleming, James G.

    2006-12-26

    A microfabricated ion trap array, comprising a plurality of ion traps having an inner radius of order one micron, can be fabricated using surface micromachining techniques and materials known to the integrated circuits manufacturing and microelectromechanical systems industries. Micromachining methods enable batch fabrication, reduced manufacturing costs, dimensional and positional precision, and monolithic integration of massive arrays of ion traps with microscale ion generation and detection devices. Massive arraying enables the microscale ion traps to retain the resolution, sensitivity, and mass range advantages necessary for high chemical selectivity. The reduced electrode voltage enables integration of the microfabricated ion trap array with on-chip circuit-based rf operation and detection electronics (i.e., cell phone electronics). Therefore, the full performance advantages of the microfabricated ion trap array can be realized in truly field portable, handheld microanalysis systems.

  10. Simplifying steam trap selection

    SciTech Connect (OSTI)

    Debat, R.J. )

    1994-01-01

    In the current economic world order, there is an obligation to eliminate waste and conserve economic and natural resources. One trap blowing 100-lb of steam through a 1/4-in. orifice can cost more than $12,000 a year in wasted energy. Richard J. Debat of Armstrong International, Inc. explains the operating principles of the four basic types of steam traps as the first step in simplifying the selection process so the right trap can be specified for a given application.

  11. Greenpower Trap Mufflerl System

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

    Water GREENPOWER TRAP-MUFFLER(tm) System (US Patent 6892531, 5085049, PCT, others pending) www.dieselnet.comdr.rim CatalystDPF EGR Accumulator Air Intake Filter Turbo Charger ...

  12. Steam trap monitor

    DOE Patents [OSTI]

    Ryan, M.J.

    1987-05-04

    A steam trap monitor positioned downstream of a steam trap in a closed steam system includes a first sensor (a hot finger) for measuring the energy of condensate and a second sensor (a cold finger) for measuring the total energy of condensate and steam in the line. The hot finger includes one or more thermocouples for detecting condensate level and energy, while the cold finger contains a liquid with a lower boiling temperature than that of water. Vapor pressure from the liquid is used to do work such as displacing a piston or bellow in providing an indication of total energy (steam + condensate) of the system. Processing means coupled to and responsive to outputs from the hot and cold fingers subtracts the former from the latter to provide an indication of the presence of steam downstream from the trap indicating that the steam trap is malfunctioning. 2 figs.

  13. Microfabricated cylindrical ion trap

    DOE Patents [OSTI]

    Blain, Matthew G.

    2005-03-22

    A microscale cylindrical ion trap, having an inner radius of order one micron, can be fabricated using surface micromachining techniques and materials known to the integrated circuits manufacturing and microelectromechanical systems industries. Micromachining methods enable batch fabrication, reduced manufacturing costs, dimensional and positional precision, and monolithic integration of massive arrays of ion traps with microscale ion generation and detection devices. Massive arraying enables the microscale cylindrical ion trap to retain the resolution, sensitivity, and mass range advantages necessary for high chemical selectivity. The microscale CIT has a reduced ion mean free path, allowing operation at higher pressures with less expensive and less bulky vacuum pumping system, and with lower battery power than conventional- and miniature-sized ion traps. The reduced electrode voltage enables integration of the microscale cylindrical ion trap with on-chip integrated circuit-based rf operation and detection electronics (i.e., cell phone electronics). Therefore, the full performance advantages of microscale cylindrical ion traps can be realized in truly field portable, handheld microanalysis systems.

  14. Thermoelectrically cooled water trap

    DOE Patents [OSTI]

    Micheels, Ronald H.

    2006-02-21

    A water trap system based on a thermoelectric cooling device is employed to remove a major fraction of the water from air samples, prior to analysis of these samples for chemical composition, by a variety of analytical techniques where water vapor interferes with the measurement process. These analytical techniques include infrared spectroscopy, mass spectrometry, ion mobility spectrometry and gas chromatography. The thermoelectric system for trapping water present in air samples can substantially improve detection sensitivity in these analytical techniques when it is necessary to measure trace analytes with concentrations in the ppm (parts per million) or ppb (parts per billion) partial pressure range. The thermoelectric trap design is compact and amenable to use in a portable gas monitoring instrumentation.

  15. Asymmetric ion trap

    DOE Patents [OSTI]

    Barlow, S.E.; Alexander, M.L.; Follansbee, J.C.

    1997-12-02

    An ion trap having two end cap electrodes disposed asymmetrically about a center of a ring electrode is disclosed. The inner surface of the end cap electrodes are conformed to an asymmetric pair of equipotential lines of the harmonic formed by the application of voltages to the electrodes. The asymmetry of the end cap electrodes allows ejection of charged species through the closer of the two electrodes which in turn allows for simultaneously detecting anions and cations expelled from the ion trap through the use of two detectors charged with opposite polarity. 4 figs.

  16. Asymmetric ion trap

    DOE Patents [OSTI]

    Barlow, Stephan E.; Alexander, Michael L.; Follansbee, James C.

    1997-01-01

    An ion trap having two end cap electrodes disposed asymmetrically about a center of a ring electrode. The inner surface of the end cap electrodes are conformed to an asymmetric pair of equipotential lines of the harmonic formed by the application of voltages to the electrodes. The asymmetry of the end cap electrodes allows ejection of charged species through the closer of the two electrodes which in turn allows for simultaneously detecting anions and cations expelled from the ion trap through the use of two detectors charged with opposite polarity.

  17. Steam trap monitor

    DOE Patents [OSTI]

    Ryan, Michael J. (Plainfield, IL)

    1988-01-01

    A steam trap monitor positioned downstream of a steam trap in a closed steam system includes a first sensor (the combination of a hot finger and thermocouple well) for measuring the energy of condensate and a second sensor (a cold finger) for measuring the total energy of condensate and steam in the line. The hot finger includes one or more thermocouples for detecting condensate level and energy, while the cold finger contains a liquid with a lower boiling temperature than that of water. Vapor pressure from the liquid is used to do work such as displacing a piston or bellows in providing an indication of total energy (steam+condensate) of the system. Processing means coupled to and responsive to outputs from the thermocouple well hot and cold fingers subtracts the condensate energy as measured by the hot finger and thermocouple well from the total energy as measured by the cold finger to provide an indication of the presence of steam downstream from the trap indicating that the steam trap is malfunctioning.

  18. WATER-TRAPPED WORLDS

    SciTech Connect (OSTI)

    Menou, Kristen [Department of Astronomy, Columbia University, 550 West 120th Street, New York, NY 10027 (United States)

    2013-09-01

    Although tidally locked habitable planets orbiting nearby M-dwarf stars are among the best astronomical targets to search for extrasolar life, they may also be deficient in volatiles and water. Climate models for this class of planets show atmospheric transport of water from the dayside to the nightside, where it is precipitated as snow and trapped as ice. Since ice only slowly flows back to the dayside upon accumulation, the resulting hydrological cycle can trap a large amount of water in the form of nightside ice. Using ice sheet dynamical and thermodynamical constraints, I illustrate how planets with less than about a quarter the Earth's oceans could trap most of their surface water on the nightside. This would leave their dayside, where habitable conditions are met, potentially dry. The amount and distribution of residual liquid water on the dayside depend on a variety of geophysical factors, including the efficiency of rock weathering at regulating atmospheric CO{sub 2} as dayside ocean basins dry up. Water-trapped worlds with dry daysides may offer similar advantages as land planets for habitability, by contrast with worlds where more abundant water freely flows around the globe.

  19. Radial cold trap

    DOE Patents [OSTI]

    Grundy, Brian R.

    1981-01-01

    The radial cold trap comprises a housing having a plurality of mesh bands disposed therein. The mesh bands comprise concentrically arranged bands of mesh with the mesh specific surface area of each band increasing from the outermost mesh band to the innermost mesh band. An inlet nozzle is attached to the outside section of the housing while an outlet nozzle is attached to the inner portion of the housing so as to be concentrically connected to the innermost mesh band. An inlet baffle having orifices therein may be disposed around the outermost mesh band and within the housing for directing the flow of the fluid from the inlet nozzle to the outermost mesh band in a uniform manner. The flow of fluid passes through each consecutive mesh band and into the outlet nozzle. The circular pattern of the symmetrically arranged mesh packing allows for better utilization of the entire cold trap volume.

  20. Radial cold trap

    DOE Patents [OSTI]

    Grundy, B.R.

    1981-09-29

    The radial cold trap comprises a housing having a plurality of mesh bands disposed therein. The mesh bands comprise concentrically arranged bands of mesh with the mesh specific surface area of each band increasing from the outermost mesh band to the innermost mesh band. An inlet nozzle is attached to the outside section of the housing while an outlet nozzle is attached to the inner portion of the housing so as to be concentrically connected to the innermost mesh band. An inlet baffle having orifices therein may be disposed around the outermost mesh band and within the housing for directing the flow of the fluid from the inlet nozzle to the outermost mesh band in a uniform manner. The flow of fluid passes through each consecutive mesh band and into the outlet nozzle. The circular pattern of the symmetrically arranged mesh packing allows for better utilization of the entire cold trap volume. 2 figs.

  1. Filter vapor trap

    DOE Patents [OSTI]

    Guon, Jerold

    1976-04-13

    A sintered filter trap is adapted for insertion in a gas stream of sodium vapor to condense and deposit sodium thereon. The filter is heated and operated above the melting temperature of sodium, resulting in a more efficient means to remove sodium particulates from the effluent inert gas emanating from the surface of a liquid sodium pool. Preferably the filter leaves are precoated with a natrophobic coating such as tetracosane.

  2. Gated charged-particle trap

    DOE Patents [OSTI]

    Benner, W. Henry

    1999-01-01

    The design and operation of a new type of charged-particle trap provides simultaneous measurements of mass, charge, and velocity of large electrospray ions. The trap consists of a detector tube mounted between two sets of center-bored trapping plates. Voltages applied to the trapping plates define symmetrically-opposing potential valleys which guide axially-injected ions to cycle back and forth through the charge-detection tube. A low noise charge-sensitive amplifier, connected to the tube, reproduces the image charge of individual ions as they pass through the detector tube. Ion mass is calculated from measurement of ion charge and velocity following each passage through the detector.

  3. Electron Trapping by Molecular Vibration

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

    Electron Trapping by Molecular Vibration Print In photoelectron spectroscopy experiments performed at the ALS, a group of researchers has found that electronic transitions normally...

  4. CNEEC - Nanophotonic Light Trapping Tutorial by Shanhui Fan

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

    Nanophotonic Light Trapping for Solar Cells

  5. Audit unto others hor ellipsis

    SciTech Connect (OSTI)

    Maday, J.H. Jr.

    1992-05-01

    My first encounter with a quality assurance auditor is reminiscent of an old Dodge commercial. You remember The old sheriff, masked in mirrored sunglasses, paunch hanging over his gun belt, prophesying, You're in a heap o' trouble boy '' Well, my auditor could have been kin to the sheriff; they had the same posture, attitude, and mirrored sunglasses. Plus, my auditor wore a black leather vest and sported a Buffalo Bill'' goatee. While certainly memorable, both gentlemen were far from pleasant. I'm fairly certain that the compliance auditor of old deserved this perceived association with his law enforcement counterpart. Both believed in enforcing the letter of the law, or their interpretations of it. Neither seemed capable of exercising interpretive powers, but instead relied on winning through intimidation, possibly with an eye toward claiming some version of a monthly Quota Award. Is the auditor of today any better perceived Because this first encounter of the worst kind'' made a lasting impression on me, I have dedicated considerable time and effort trying to avoid being perceived as another sheriff when I conduct audits. In my auditing career, I am determined to capitalize on each opportunity to turn negative situations, as experienced by the auditee, into meaningful opportunities for improved performance. I want to treat the auditee the way I want to be treated when I am being audited. (author)

  6. Thermostatic steam trap

    SciTech Connect (OSTI)

    Anderson, A.H.; Mac Nicol, A.E.

    1987-03-03

    A thermostatic trap is described for a heating system having a feed pipe connected to a source of steam and a discharge pipe for discharge of condensate and comprising: housing means defining a volume and comprising a bowl shaped body, a removable cover therefor, a housing inlet pipe portion projecting from a side wall portion of the body and adapted for connection to the discharge pipe. A housing outlet pipe portion projects from a bottom wall portion of the body, and an outlet orifice defined by the bottom wall portion and extends between the volume and the outlet pipe portion; a valve body means retained within the volume and comprising an end wall, a side wall and a retaining ring portion that together define a valve chamber. The end wall defines a valve inlet opening communicating with the chamber and an annular valve seat within the chamber and encircling the valve inlet opening. The valve body means comprises a valve outlet pipe that defines a valve outlet opening axially aligned with the valve inlet opening and communicating with the chamber, the outlet pipe being fixed in the outlet orifice; a resilient, annular seal means disposed within the valve chamber and encircling the valve inlet opening; and a bi-metallic disc disposed within the valve chamber between the annular seal means and the outlet opening and having an outer peripheral portion retained by the retaining ring portion of the valve body means.

  7. Protection #2: Trap and Remove Sediment

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

    Trap and Remove Sediment Protection 2: Trap and Remove Sediment The 3 Protections Defense in Depth August 1, 2013 Sediment behind LA Canyon weir is sampled and excavated...

  8. Fundamental Electroweak Studies using Trapped Ions & Atoms

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

    collaboration performs fundamental electroweak studies on trapped ions & atoms. We use neutral atom and ion trapping techniques at radioactive ion beam facilities here and...

  9. Gated charged-particle trap

    DOE Patents [OSTI]

    Benner, W.H.

    1999-03-09

    The design and operation of a new type of charged-particle trap provides simultaneous measurements of mass, charge, and velocity of large electrospray ions. The trap consists of a detector tube mounted between two sets of center-bored trapping plates. Voltages applied to the trapping plates define symmetrically-opposing potential valleys which guide axially-injected ions to cycle back and forth through the charge-detection tube. A low noise charge-sensitive amplifier, connected to the tube, reproduces the image charge of individual ions as they pass through the detector tube. Ion mass is calculated from measurement of ion charge and velocity following each passage through the detector. 5 figs.

  10. Hydrodynamic enhanced dielectrophoretic particle trapping

    DOE Patents [OSTI]

    Miles, Robin R.

    2003-12-09

    Hydrodynamic enhanced dielectrophoretic particle trapping carried out by introducing a side stream into the main stream to squeeze the fluid containing particles close to the electrodes producing the dielelectrophoretic forces. The region of most effective or the strongest forces in the manipulating fields of the electrodes producing the dielectrophoretic forces is close to the electrodes, within 100 .mu.m from the electrodes. The particle trapping arrangement uses a series of electrodes with an AC field placed between pairs of electrodes, which causes trapping of particles along the edges of the electrodes. By forcing an incoming flow stream containing cells and DNA, for example, close to the electrodes using another flow stream improves the efficiency of the DNA trapping.

  11. Inspect and Repair Steam Traps

    SciTech Connect (OSTI)

    Not Available

    2006-01-01

    This revised ITP tip sheet on inspecting and repairing steam traps provide how-to advice for improving industrial steam systems using low-cost, proven practices and technologies.

  12. Mini ion trap mass spectrometer

    DOE Patents [OSTI]

    Dietrich, Daniel D.; Keville, Robert F.

    1995-01-01

    An ion trap which operates in the regime between research ion traps which can detect ions with a mass resolution of better than 1:10.sup.9 and commercial mass spectrometers requiring 10.sup.4 ions with resolutions of a few hundred. The power consumption is kept to a minimum by the use of permanent magnets and a novel electron gun design. By Fourier analyzing the ion cyclotron resonance signals induced in the trap electrodes, a complete mass spectra in a single combined structure can be detected. An attribute of the ion trap mass spectrometer is that overall system size is drastically reduced due to combining a unique electron source and mass analyzer/detector in a single device. This enables portable low power mass spectrometers for the detection of environmental pollutants or illicit substances, as well as sensors for on board diagnostics to monitor engine performance or for active feedback in any process involving exhausting waste products.

  13. Mini ion trap mass spectrometer

    DOE Patents [OSTI]

    Dietrich, D.D.; Keville, R.F.

    1995-09-19

    An ion trap is described which operates in the regime between research ion traps which can detect ions with a mass resolution of better than 1:10{sup 9} and commercial mass spectrometers requiring 10{sup 4} ions with resolutions of a few hundred. The power consumption is kept to a minimum by the use of permanent magnets and a novel electron gun design. By Fourier analyzing the ion cyclotron resonance signals induced in the trap electrodes, a complete mass spectra in a single combined structure can be detected. An attribute of the ion trap mass spectrometer is that overall system size is drastically reduced due to combining a unique electron source and mass analyzer/detector in a single device. This enables portable low power mass spectrometers for the detection of environmental pollutants or illicit substances, as well as sensors for on board diagnostics to monitor engine performance or for active feedback in any process involving exhausting waste products. 10 figs.

  14. Electron Trapping by Molecular Vibration

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

    Electron Trapping by Molecular Vibration Print In photoelectron spectroscopy experiments performed at the ALS, a group of researchers has found that electronic transitions normally thought to be forbidden can in fact be excited in conjunction with certain types of molecular vibrations. Specifically, they found that when the symmetry of a linear triatomic molecule is broken by asymmetric vibrational modes, photoelectrons can become temporarily trapped by the molecule before ultimately escaping,

  15. Electron Trapping by Molecular Vibration

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

    Electron Trapping by Molecular Vibration Print In photoelectron spectroscopy experiments performed at the ALS, a group of researchers has found that electronic transitions normally thought to be forbidden can in fact be excited in conjunction with certain types of molecular vibrations. Specifically, they found that when the symmetry of a linear triatomic molecule is broken by asymmetric vibrational modes, photoelectrons can become temporarily trapped by the molecule before ultimately escaping,

  16. Electron Trapping by Molecular Vibration

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

    Electron Trapping by Molecular Vibration Print In photoelectron spectroscopy experiments performed at the ALS, a group of researchers has found that electronic transitions normally thought to be forbidden can in fact be excited in conjunction with certain types of molecular vibrations. Specifically, they found that when the symmetry of a linear triatomic molecule is broken by asymmetric vibrational modes, photoelectrons can become temporarily trapped by the molecule before ultimately escaping,

  17. Electron Trapping by Molecular Vibration

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

    Electron Trapping by Molecular Vibration Print In photoelectron spectroscopy experiments performed at the ALS, a group of researchers has found that electronic transitions normally thought to be forbidden can in fact be excited in conjunction with certain types of molecular vibrations. Specifically, they found that when the symmetry of a linear triatomic molecule is broken by asymmetric vibrational modes, photoelectrons can become temporarily trapped by the molecule before ultimately escaping,

  18. Electron Trapping by Molecular Vibration

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

    Electron Trapping by Molecular Vibration Electron Trapping by Molecular Vibration Print Wednesday, 27 April 2005 00:00 In photoelectron spectroscopy experiments performed at the ALS, a group of researchers has found that electronic transitions normally thought to be forbidden can in fact be excited in conjunction with certain types of molecular vibrations. Specifically, they found that when the symmetry of a linear triatomic molecule is broken by asymmetric vibrational modes, photoelectrons can

  19. Universal collisional activation ion trap mass spectrometry

    DOE Patents [OSTI]

    McLuckey, Scott A.; Goeringer, Douglas E.; Glish, Gary L.

    1993-01-01

    A universal collisional activation ion trap comprises an ion trapping means containing a bath gas and having connected thereto a noise signal generator. A method of operating a universal collisional activation ion trap comprises the steps of: providing an ion trapping means; introducing into the ion trapping means a bath gas; and, generating a noise signal within the ion trapping means; introducing into the ion trapping means a substance that, when acted upon by the noise signal, undergoes collisional activation to form product ions.

  20. Universal collisional activation ion trap mass spectrometry

    DOE Patents [OSTI]

    McLuckey, S.A.; Goeringer, D.E.; Glish, G.L.

    1993-04-27

    A universal collisional activation ion trap comprises an ion trapping means containing a bath gas and having connected thereto a noise signal generator. A method of operating a universal collisional activation ion trap comprises the steps of: providing an ion trapping means; introducing into the ion trapping means a bath gas; and, generating a noise signal within the ion trapping means; introducing into the ion trapping means a substance that, when acted upon by the noise signal, undergoes collisional activation to form product ions.

  1. Microfabricated linear Paul-Straubel ion trap

    DOE Patents [OSTI]

    Mangan, Michael A.; Blain, Matthew G.; Tigges, Chris P.; Linker, Kevin L.

    2011-04-19

    An array of microfabricated linear Paul-Straubel ion traps can be used for mass spectrometric applications. Each ion trap comprises two parallel inner RF electrodes and two parallel outer DC control electrodes symmetric about a central trap axis and suspended over an opening in a substrate. Neighboring ion traps in the array can share a common outer DC control electrode. The ions confined transversely by an RF quadrupole electric field potential well on the ion trap axis. The array can trap a wide array of ions.

  2. VACUUM TRAP AND VALVE COMBINATION

    DOE Patents [OSTI]

    Milleron, N.; Levenson, L.

    1963-02-19

    This patent relates to a vacuum trap and valve combination suitable for use in large ultra-high vacuum systems. The vacuum trap is a chamber having an inlet and outlet opening which may be made to communicate with a chamber to be evacuated and a diffusion pump, respectively. A valve is designed to hermeticaliy seal with inlet opening and, when opened, block the line-of- sight'' between the inlet and outlet openings, while allowing a large flow path between the opened vaive and the side walls of the trap. The interior of the trap and the side of the valve facing the inlet opening are covered with an impurity absorbent, such as Zeolite or activated aluminum. Besides the advantage of combining two components of a vacuum system into one, the present invention removes the need for a baffle between the pump and the chamber to be evacuated. In one use of a specific embodiment of this invention, the transmission probability was 45 and the partial pressure of the pump fluid vapor in the vacuum chamber was at least 100 times lower than its vapor pressure. (AEC)

  3. Ion temperature gradient driven turbulence with strong trapped...

    Office of Scientific and Technical Information (OSTI)

    driven turbulence with strong trapped ion resonance is presented. The role of trapped ion granulations, clusters of trapped ions correlated by precession resonance, is the focus. ...

  4. Guide to Orifice Plate Steam Traps

    SciTech Connect (OSTI)

    Oland, C.B.

    2001-01-11

    This guide was prepared to serve as a foundation for making informed decisions about when orifice plate steam traps should be considered for use in new or existing steam systems. It presents background information about different types of steam traps and defines their unique functional and operational characteristics. The advantages and disadvantages associated with using orifice plate steam traps are provided to highlight their capabilities and limitations. Finally, recommendations for using orifice plate steam traps are presented, and possible applications are identified.

  5. Microscale ion trap mass spectrometer

    DOE Patents [OSTI]

    Ramsey, J. Michael; Witten, William B.; Kornienko, Oleg

    2002-01-01

    An ion trap for mass spectrometric chemical analysis of ions is delineated. The ion trap includes a central electrode having an aperture; a pair of insulators, each having an aperture; a pair of end cap electrodes, each having an aperture; a first electronic signal source coupled to the central electrode; a second electronic signal source coupled to the end cap electrodes. The central electrode, insulators, and end cap electrodes are united in a sandwich construction where their respective apertures are coaxially aligned and symmetric about an axis to form a partially enclosed cavity having an effective radius r.sub.0 and an effective length 2z.sub.0, wherein r.sub.0 and/or z.sub.0 are less than 1.0 mm, and a ratio z.sub.0 /r.sub.0 is greater than 0.83.

  6. Ion traps fabricated in a CMOS foundry

    SciTech Connect (OSTI)

    Mehta, K. K.; Ram, R. J.; Eltony, A. M.; Chuang, I. L.; Bruzewicz, C. D.; Sage, J. M. Chiaverini, J.

    2014-07-28

    We demonstrate trapping in a surface-electrode ion trap fabricated in a 90-nm CMOS (complementary metal-oxide-semiconductor) foundry process utilizing the top metal layer of the process for the trap electrodes. The process includes doped active regions and metal interconnect layers, allowing for co-fabrication of standard CMOS circuitry as well as devices for optical control and measurement. With one of the interconnect layers defining a ground plane between the trap electrode layer and the p-type doped silicon substrate, ion loading is robust and trapping is stable. We measure a motional heating rate comparable to those seen in surface-electrode traps of similar size. This demonstration of scalable quantum computing hardware utilizing a commercial CMOS process opens the door to integration and co-fabrication of electronics and photonics for large-scale quantum processing in trapped-ion arrays.

  7. Electrostatic particle trap for ion beam sputter deposition ...

    Office of Scientific and Technical Information (OSTI)

    The electrostatic particle trap consists of an array of electrode surfaces, each ... particle; trap; consists; array; electrode; surfaces; maintained; electrostatic; ...

  8. Thermal stability and photoconductive properties of photosensors with an alternating multilayer structure of amorphous Se and As{sub x}Se{sub 1−x}

    SciTech Connect (OSTI)

    Yu, Tung-Yuan; Pan, Fu-Ming Chang, Cheng-Yi; Lin, Jian-Siang; Huang, Wen-Hsien

    2015-07-28

    In this study, we fabricated a-Se based photosensors with an alternating multilayer structure of a-Se and As{sub x}Se{sub 1−x} by rotational thermal evaporation deposition. During the deposition of the amorphous As{sub x}Se{sub 1−x} layers, As diffuses into the underlying a-Se component layers, thereby improving the thermal stability of the multilayer photosensor and thus increasing the breakdown electric field. Although the As doping introduces carrier traps in the a-Se layers, the multilayer photosensors demonstrate an effective quantum efficiency comparable to the single-layered a-Se sensor under the blue light illumination but are with a lower dark current density by two orders of magnitude. In addition to the top As{sub x}Se{sub 1−x} layer being functioning as an electron blocking layer, carrier traps present in the multilayer structure may decrease the drift mobility of charge carriers and disturb electric field distribution in the photosensors, thereby suppressing the dark current.

  9. About-PHaSe-EFRC

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

    LGRT Conte Buildings The University of Massachusetts Amherst Energy Frontier Research Center (EFRC) - Polymer-Based Materials for Harvesting Solar Energy, PHaSE - was one of 46 ...

  10. Solon SE | Open Energy Information

    Open Energy Info (EERE)

    to: navigation, search Name: Solon SE Place: Berlin, Berlin, Germany Zip: D-12489 Sector: Solar Product: Manufacturer of PV modules and tracking systems, and integrator of solar...

  11. Trapping of intense light in hollow shell

    SciTech Connect (OSTI)

    Luan, Shixia; Yu, Wei; Yu, M. Y.; Weng, Suming; Wang, Jingwei; Xu, Han; Zhuo, Hongbin; Wong, A. Y.

    2015-09-15

    A small hollow shell for trapping laser light is proposed. Two-dimensional particle-in-cell simulation shows that under appropriate laser and plasma conditions a part of the radiation fields of an intense short laser pulse can enter the cavity of a small shell through an over-critical density plasma in an adjacent guide channel and become trapped. The trapped light evolves into a circulating radial wave pattern until its energy is dissipated.

  12. Measurements of PM Traps | Department of Energy

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

    Measurements of PM Traps 2004 Diesel Engine Emissions Reduction (DEER) Conference Presentantion: West Virginia University PDF icon 2004deerclark.pdf More Documents & Publications ...

  13. Shale gas is natural gas trapped inside

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

    Shale gas is natural gas trapped inside formations of shale - fine grained sedimentary ... Fossil Energy Research Benefits FE's early investments in shale research in the 1970s ...

  14. Cavity sideband cooling of trapped molecules

    SciTech Connect (OSTI)

    Kowalewski, Markus; Vivie-Riedle, Regina de [Department of Chemistry, Ludwig-Maximilian-Universitaet, D-81377 Munich (Germany); Morigi, Giovanna [Departament de Fisica, Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain); Theoretische Physik, Universitaet des Saarlandes, D-66041 Saarbruecken (Germany); Pinkse, Pepijn W. H. [MESA Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500AE Enschede (Netherlands)

    2011-09-15

    The efficiency of cavity sideband cooling of trapped molecules is theoretically investigated for the case in which the infrared transition between two rovibrational states is used as a cycling transition. The molecules are assumed to be trapped either by a radiofrequency or optical trapping potential, depending on whether they are charged or neutral, and confined inside a high-finesse optical resonator that enhances radiative emission into the cavity mode. Using realistic experimental parameters and COS as a representative molecular example, we show that in this setup, cooling to the trap ground state is feasible.

  15. The Paul Trap Simulator Experiment (PTSX) | Princeton Plasma...

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

    The Paul Trap Simulator Experiment (PTSX) The Paul Trap Simulator Experiment (PTSX) at the U.S. Department of Energy's Princeton Plasma Physics Laboratory doesn't trap people named...

  16. Transient and steady state photoelectronic analysis in TlInSe{sub 2} crystals

    SciTech Connect (OSTI)

    Qasrawi, A.F.; Gasanly, N.M.

    2011-08-15

    Highlights: {yields} The steady state and time dependent photoconductivity kinetics of the TlInSe{sub 2} crystals are investigated in the temperature region of 100-350 K. {yields} The photocurrent of the sample exhibited linear, sublinear, and supralinear recombination mechanisms, at, above and below 160 K, respectively. {yields} Steady state photoconductivity revealed two recombination centres located at 234 and 94 meV. {yields} The transient photoconductivity is limited by a trapping center located at 173 meV. {yields} The capture coefficient of the trap for holes was determined as 3.11 x 10{sup -22} cm{sup -2}. -- Abstract: The temperature and illumination effects on the transient and steady state photoconductivities of TlInSe{sub 2} crystals have been studied. Namely, two recombination centres located at 234 and at 94 meV and one trap center located at 173 meV were determined from the temperature-dependent steady state and transient photoconductivities, respectively. The illumination dependence of photoconductivity indicated the domination of sublinear and supralinear recombination mechanisms above and below 160 K, respectively. The change in the recombination mechanism is attributed to the exchange of roles between the linear recombination at the surface and trapping centres in the crystal, which become dominant as temperature decreases. The transient photoconductivity measurement allowed the determination of the capture coefficient of traps for holes as 3.11 x 10{sup -22} cm{sup -2}.

  17. Production and Trapping of Ultracold Polar Molecules

    SciTech Connect (OSTI)

    David, DeMille

    2015-04-21

    We report a set of experiments aimed at the production and trapping of ultracold polar molecules. We begin with samples of laser-cooled and trapped Rb and Cs atoms, and bind them together to form polar RbCs molecules. The binding is accomplished via photoassociation, which uses a laser to catalyze the sticking process. We report results from investigation of a new pathway for photoassociation that can produce molecules in their absolute ground state of vibrational and rotational motion. We also report preliminary observations of collisions between these ground-state molecules and co-trapped atoms.

  18. NAC 503 - Hunting, Fishing and Trapping | Open Energy Information

    Open Energy Info (EERE)

    Fishing and TrappingLegal Abstract These code sections outline the protective measures and restrictions on hunting, fishing, and trapping in the state of Nevada. Published...

  19. Requirements-Driven Diesel Catalyzed Particulate Trap Design...

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

    Requirements-Driven Diesel Catalyzed Particulate Trap Design and Optimization Requirements-Driven Diesel Catalyzed Particulate Trap Design and Optimization 2005 Diesel Engine ...

  20. Bear Trap Hot Spring Pool & Spa Low Temperature Geothermal Facility...

    Open Energy Info (EERE)

    Trap Hot Spring Pool & Spa Low Temperature Geothermal Facility Jump to: navigation, search Name Bear Trap Hot Spring Pool & Spa Low Temperature Geothermal Facility Facility Bear...

  1. Inspect and Repair Steam Traps, Energy Tips: STEAM, Steam Tip...

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

    ... There are four basic ways to test steam traps: temperature, sound, visual, and electronic. Recommended Steam Trap Testing Intervals * High-Pressure (150 psig and above): Weekly to ...

  2. Resources-PHaSe-EFRC

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

    Resources This webpage is provided for legacy archive purposes only, as of 30 April 2015. However, the facilities and resources created under PHaSE (thanks to the support of the U.S. Department of Energy) remain available for their original purpose of investigating organic-based electronic materials. Resources As a national and regional center of excellence for energy research, PHaSE has access to many resources linked from the Department of Energy and the greater UMass Amherst campus, as well

  3. Trapped Ion Optical Clocks at NPL

    SciTech Connect (OSTI)

    Margolis, H. S.; Barwood, G. P.; Hosaka, K.; Klein, H. A.; Lea, S. N.; Walton, B. R.; Webster, S. A.; Gill, P.; Huang, G.; Stannard, A.

    2006-11-07

    Forbidden transitions in single laser-cooled trapped ions provide highly stable and accurate references for optical frequency standards. This paper describes recent progress on strontium and ytterbium ion optical frequency standards under development at NPL.

  4. Protection #2: Trap and Remove Sediment

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

    Trap and Remove Sediment Protection #2: Trap and Remove Sediment The 3 Protections = Defense in Depth August 1, 2013 Sediment behind LA Canyon weir is sampled and excavated regularly. As of 2012, no sediment required disposal as hazardous or radioactive waste. Sediment behind LA Canyon weir is sampled and excavated regularly. As of 2012, no sediment required disposal as hazardous or radioactive waste. The 3 Protections Protection #1: Remove the source of contamination Protection #2: Stabilize,

  5. News-PHaSe-EFRC

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

    News and Highlights Saxony This page shows highlights and news items about PHaSE activities, research achievements, and people; archived items can be accessed by year at the menu to the left. If you have questions about any items, or want to know more, please contact either Tom Russell or D. Venkataraman. Final archive date: 26 April

  6. Antihydrogen Trapped in the ALPHA Experiment

    ScienceCinema (OSTI)

    None

    2011-04-25

    In 2010 the ALPHA collaboration succeeded in trapping antihydrogen atoms for the first time.[i]  Stored antihydrogen promises to be a unique tool for making high precision measurements of the structure of this first anti-atom. Achieving this milestone presented several substantial experimental challenges and this talk will describe how they were overcome.   The unique design features of the ALPHA apparatus will be explained.[ii]  These allow a high intensity positron source and an antiproton imaging detector similar to the one used in the ATHENA[iii] experiment to be combined with an innovative magnet design of the anti-atom trap. This seeks to minimise the perturbations to trapped charged particles which may cause particle loss and heating[iv].   The diagnostic techniques used to measure the diameter, number, density, and temperatures of both plasmas will be presented as will the methods developed to actively compress and cool of both plasma species to sizes and temperatures [v],[vi], [vii] where trapping attempts with a reasonable chance of success can be tried.   The results of the successful trapping experiments will be outlined as well as some subsequent experiments to improve the trapping rate and storage time. [i] 'Trapped antihydrogen' G.B. Andresen et al., Nature 468, 673 (2010) [ii]'A Magnetic Trap for Antihydrogen Confinement' W. Bertsche et al., Nucl. Instr. Meth. Phys. Res. A566, 746 (2006) [iii] Production and detection of cold antihydrogen atoms M.Amoretti et al., Nature 419, 456 (2002). [iv]' Antihydrogen formation dynamics in a multipolar neutral anti-atom trap' G.B. Andresen et al., Phys. Lett. B 685, 141 (2010) [v]' Evaporative Cooling of Antiprotons to Cryogenic Temperatures',                                   G.B. Andresen et al. Phys. Rev. Lett 105, 013003 (2010) [vi]'Compression of Antiproton Clouds for Antihydrogen Trapping' G. B. Andresen et al. Phys. Rev. Lett 100, 203401 (2008) [vii]  'Autoresonant

  7. Audit unto others{hor_ellipsis}

    SciTech Connect (OSTI)

    Maday, J.H. Jr.

    1992-05-01

    My first encounter with a quality assurance auditor is reminiscent of an old Dodge commercial. You remember? The old sheriff, masked in mirrored sunglasses, paunch hanging over his gun belt, prophesying, ``You`re in a heap o` trouble boy!`` Well, my auditor could have been kin to the sheriff; they had the same posture, attitude, and mirrored sunglasses. Plus, my auditor wore a black leather vest and sported a ``Buffalo Bill`` goatee. While certainly memorable, both gentlemen were far from pleasant. I`m fairly certain that the compliance auditor of old deserved this perceived association with his law enforcement counterpart. Both believed in enforcing the letter of the law, or their interpretations of it. Neither seemed capable of exercising interpretive powers, but instead relied on winning through intimidation, possibly with an eye toward claiming some version of a monthly Quota Award. Is the auditor of today any better perceived? Because this ``first encounter of the worst kind`` made a lasting impression on me, I have dedicated considerable time and effort trying to avoid being perceived as another sheriff when I conduct audits. In my auditing career, I am determined to capitalize on each opportunity to turn negative situations, as experienced by the auditee, into meaningful opportunities for improved performance. I want to treat the auditee the way I want to be treated when I am being audited. (author)

  8. Review of Orifice Plate Steam Traps | Department of Energy

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

    Orifice Plate Steam Traps Review of Orifice Plate Steam Traps This guide was prepared to serve as a foundation for making informed decisions about when orifice plate steam traps should be considered for use in new or existing steam systems. It presents background information about different types of steam traps and defines their unique functional and operational characteristics. The advantages and disadvantages associated with using orifice plate steam traps are provided to highlight their

  9. Barron: Noncompliance Determination (2013-SE-5402) | Department...

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

    Noncompliance Determination (2013-SE-5402) Barron: Noncompliance Determination (2013-SE-5402) December 17, 2015 DOE issued a Notice of Noncompliance Determination to Barron ...

  10. Shandong Hongtai: Noncompliance Determination (2016-SE-42010...

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

    Noncompliance Determination (2016-SE-42010) Shandong Hongtai: Noncompliance Determination (2016-SE-42010) January 6, 2016 DOE issued a Notice of Noncompliance Determination to ...

  11. SE Project Srl | Open Energy Information

    Open Energy Info (EERE)

    search Name: SE Project Srl Place: San Pietro, Italy Zip: 35010 Sector: Solar Product: Italian manufacturer and supplier of solar modules and solar technology. References: SE...

  12. I2SE | Open Energy Information

    Open Energy Info (EERE)

    I2SE Jump to: navigation, search Name: I2SE Place: Leipzig, Germany Zip: 4103 Sector: Efficiency Product: IT company providing solutions for energy efficiency and data...

  13. Ion funnel ion trap and process

    DOE Patents [OSTI]

    Belov, Mikhail E [Richland, WA; Ibrahim, Yehia M [Richland, WA; Clowers, Biran H [West Richland, WA; Prior, David C [Hermiston, OR; Smith, Richard D [Richland, WA

    2011-02-15

    An ion funnel trap is described that includes a inlet portion, a trapping portion, and a outlet portion that couples, in normal operation, with an ion funnel. The ion trap operates efficiently at a pressure of .about.1 Torr and provides for: 1) removal of low mass-to-charge (m/z) ion species, 2) ion accumulation efficiency of up to 80%, 3) charge capacity of .about.10,000,000 elementary charges, 4) ion ejection time of 40 to 200 .mu.s, and 5) optimized variable ion accumulation times. Ion accumulation with low concentration peptide mixtures has shown an increase in analyte signal-to-noise ratios (SNR) of a factor of 30, and a greater than 10-fold improvement in SNR for multiply charged analytes.

  14. Signal enhancement using a switchable magnetic trap

    DOE Patents [OSTI]

    Beer, Neil Reginald

    2012-05-29

    A system for analyzing a sample including providing a microchannel flow channel; associating the sample with magnetic nanoparticles or magnetic polystyrene-coated beads; moving the sample with said magnetic nanoparticles or magnetic polystyrene-coated beads in the microchannel flow channel; holding the sample with the magnetic nanoparticles or magnetic polystyrene-coated beads in a magnetic trap in the microchannel flow channel; and analyzing the sample obtaining an enhanced analysis signal. An apparatus for analysis of a sample includes magnetic particles connected to the sample, a microchip, a flow channel in the microchip, a source of carrier fluid connected to the flow channel for moving the sample in the flow channel, an electromagnet trap connected to the flow line for selectively magnetically trapping the sample and the magnetic particles, and an analyzer for analyzing the sample.

  15. Screening the Hanford tanks for trapped gas

    SciTech Connect (OSTI)

    Whitney, P.

    1995-10-01

    The Hanford Site is home to 177 large, underground nuclear waste storage tanks. Hydrogen gas is generated within the waste in these tanks. This document presents the results of a screening of Hanford`s nuclear waste storage tanks for the presence of gas trapped in the waste. The method used for the screening is to look for an inverse correlation between waste level measurements and ambient atmospheric pressure. If the waste level in a tank decreases with an increase in ambient atmospheric pressure, then the compressibility may be attributed to gas trapped within the waste. In this report, this methodology is not used to estimate the volume of gas trapped in the waste. The waste level measurements used in this study were made primarily to monitor the tanks for leaks and intrusions. Four measurement devices are widely used in these tanks. Three of these measure the level of the waste surface. The remaining device measures from within a well embedded in the waste, thereby monitoring the liquid level even if the liquid level is below a dry waste crust. In the past, a steady rise in waste level has been taken as an indicator of trapped gas. This indicator is not part of the screening calculation described in this report; however, a possible explanation for the rise is given by the mathematical relation between atmospheric pressure and waste level used to support the screening calculation. The screening was applied to data from each measurement device in each tank. If any of these data for a single tank indicated trapped gas, that tank was flagged by this screening process. A total of 58 of the 177 Hanford tanks were flagged as containing trapped gas, including 21 of the 25 tanks currently on the flammable gas watch list.

  16. Entanglement generation in planar Penning traps

    SciTech Connect (OSTI)

    Martins, Ana M.; Mendonca, J. T.; Guerreiro, A.; Vieira, V. R.

    2010-07-15

    We investigate the generation of entanglement between the axial degrees of freedom of electrons confined in separated locations in planar Penning traps. We show that there are two different sources of entanglement: one is related with the mechanism of switching on and off the electrical coupling between the two electrons, and the other is due to the two-quanta-transition term of the coupling interaction. We show that the degree of entanglement can be controlled by adjusting the strength of the coupling between the traps and the time of interaction. We show that the coupled electrons behave as a temporal active interferometer.

  17. Thermal electric vapor trap arrangement and method

    DOE Patents [OSTI]

    Alger, Terry (Tracy, CA)

    1988-01-01

    A technique for trapping vapor within a section of a tube is disclosed herein. This technique utilizes a conventional, readily providable thermal electric device having a hot side and a cold side and means for powering the device to accomplish this. The cold side of this device is positioned sufficiently close to a predetermined section of the tube and is made sufficiently cold so that any condensable vapor passing through the predetermined tube section is condensed and trapped, preferably within the predetermined tube section itself.

  18. Thermal electric vapor trap arrangement and method

    DOE Patents [OSTI]

    Alger, T.

    1988-03-15

    A technique for trapping vapor within a section of a tube is disclosed herein. This technique utilizes a conventional, readily providable thermal electric device having a hot side and a cold side and means for powering the device to accomplish this. The cold side of this device is positioned sufficiently close to a predetermined section of the tube and is made sufficiently cold so that any condensable vapor passing through the predetermined tube section is condensed and trapped, preferably within the predetermined tube section itself. 4 figs.

  19. Analysis of a magnetically trapped atom clock

    SciTech Connect (OSTI)

    Kadio, D.; Band, Y. B.

    2006-11-15

    We consider optimization of a rubidium atom clock that uses magnetically trapped Bose condensed atoms in a highly elongated trap, and determine the optimal conditions for minimum Allan variance of the clock using microwave Ramsey fringe spectroscopy. Elimination of magnetic field shifts and collisional shifts are considered. The effects of spin-dipolar relaxation are addressed in the optimization of the clock. We find that for the interstate interaction strength equal to or larger than the intrastate interaction strengths, a modulational instability results in phase separation and symmetry breaking of the two-component condensate composed of the ground and excited hyperfine clock levels, and this mechanism limits the clock accuracy.

  20. Entanglement of trapped-ion clock states

    SciTech Connect (OSTI)

    Haljan, P. C.; Lee, P. J.; Brickman, K-A.; Acton, M.; Deslauriers, L.; Monroe, C.

    2005-12-15

    A Moelmer-Soerensen entangling gate is realized for pairs of trapped {sup 111}Cd{sup +} ions using magnetic-field insensitive 'clock' states and an implementation offering reduced sensitivity to optical phase drifts. The gate is used to generate the complete set of four entangled states, which are reconstructed and evaluated with quantum-state tomography. An average target-state fidelity of 0.79 is achieved, limited by available laser power and technical noise. The tomographic reconstruction of entangled states demonstrates universal quantum control of two ion qubits, which through multiplexing can provide a route to scalable architectures for trapped-ion quantum computing.

  1. Ball-grid array architecture for microfabricated ion traps

    SciTech Connect (OSTI)

    Guise, Nicholas D. Fallek, Spencer D.; Stevens, Kelly E.; Brown, K. R.; Volin, Curtis; Harter, Alexa W.; Amini, Jason M.; Higashi, Robert E.; Lu, Son Thai; Chanhvongsak, Helen M.; Nguyen, Thi A.; Marcus, Matthew S.; Ohnstein, Thomas R.; Youngner, Daniel W.

    2015-05-07

    State-of-the-art microfabricated ion traps for quantum information research are approaching nearly one hundred control electrodes. We report here on the development and testing of a new architecture for microfabricated ion traps, built around ball-grid array (BGA) connections, that is suitable for increasingly complex trap designs. In the BGA trap, through-substrate vias bring electrical signals from the back side of the trap die to the surface trap structure on the top side. Gold-ball bump bonds connect the back side of the trap die to an interposer for signal routing from the carrier. Trench capacitors fabricated into the trap die replace area-intensive surface or edge capacitors. Wirebonds in the BGA architecture are moved to the interposer. These last two features allow the trap die to be reduced to only the area required to produce trapping fields. The smaller trap dimensions allow tight focusing of an addressing laser beam for fast single-qubit rotations. Performance of the BGA trap as characterized with {sup 40}Ca{sup +} ions is comparable to previous surface-electrode traps in terms of ion heating rate, mode frequency stability, and storage lifetime. We demonstrate two-qubit entanglement operations with {sup 171}Yb{sup +} ions in a second BGA trap.

  2. Bucket-type steam traps removed in $82K retrofit

    SciTech Connect (OSTI)

    Poplett, J.

    1985-08-19

    A retrofit of 481 mostly failed steam traps at Martin Marietta's Aerospace Division should reduce steam costs by $70,000 and require little or no maintenance. Payback should occur within 14 months. The new traps include orifice, bellow-type thermostatic, and float-type traps that have few or no moving parts. Lack of maintenance was responsible for the poor performance of the bucket traps that were replaced, although manufacturers of the bucket traps disagree that replacement of certain parts is necessary every six months. The author describes the design and operation of each type of trap.

  3. RYPOS Trap Field Demonstrations Part 1 | Department of Energy

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

    1 RYPOS Trap Field Demonstrations Part 1 2002 DEER Conference Presentation: RYPOS Inc. 2002_deer_depetrillo1.pdf (812.87 KB) More Documents & Publications RYPOS Trap Field Demonstrations Part 2

  4. RYPOS Trap Field Demonstrations Part 2 | Department of Energy

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

    2 RYPOS Trap Field Demonstrations Part 2 2002 DEER Conference Presentation: RYPOS Inc. 2002_deer_depetrillo2.pdf (1016 KB) More Documents & Publications RYPOS Trap Field Demonstrations Part 1

  5. Review of Orifice Plate Steam Traps | Department of Energy

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

    Review of Orifice Plate Steam Traps Review of Orifice Plate Steam Traps This guide was prepared to serve as a foundation for making informed decisions about when orifice plate...

  6. Thermal Deactivation Mechanisms of Fully-Formed Lean NOx Trap...

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

    Duty Linehaul Platform Project Update Effect of Thermal Aging on NO oxidation and NOx storage in a Fully-Formulated Lean NOx Trap Pt-free, Perovskite-based Lean NOx Trap Catalysts

  7. November 18, 2010: Antimatter Trapped and Stored | Department of Energy

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

    8, 2010: Antimatter Trapped and Stored November 18, 2010: Antimatter Trapped and Stored November 18, 2010: Antimatter Trapped and Stored November 18, 2010 The Department's Lawrence Berkeley National Laboratory (LBNL) announces that atoms of antimatter have been trapped and stored for the first time in a magnetic bottle-like device by the ALPHA collaboration, an international team of scientists working at CERN, the European Organization for Nuclear Research near Geneva, Switzerland. Scientists

  8. Trapping and Measuring Charged Particles in Liquids - Energy Innovation

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

    Portal Advanced Materials Advanced Materials Find More Like This Return to Search Trapping and Measuring Charged Particles in Liquids Oak Ridge National Laboratory Contact ORNL About This Technology Publications: PDF Document Publication Printable fact sheet (552 KB) Planar aqueous Paul trap (PAPT) devices and experimental platform Planar aqueous Paul trap (PAPT) devices and experimental platform Technology Marketing SummaryA nanoscale version of the Paul ion trap was developed by

  9. Inspect and Repair Steam Traps | Department of Energy

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

    Inspect and Repair Steam Traps Inspect and Repair Steam Traps This tip sheet on inspecting and repairing steam traps provides how-to advice for improving industrial steam systems using low-cost, proven practices and technologies. STEAM TIP SHEET #1 Inspect and Repair Steam Traps (January 2012) (393.77 KB) More Documents & Publications Flash High-Pressure Condensate to Regenerate Low-Pressure Steam Steam Pressure Reduction: Opportunities and Issues Use Steam Jet Ejectors or Thermocompressors

  10. High voltage gas insulated transmission line with continuous particle trapping

    DOE Patents [OSTI]

    Cookson, Alan H. (Pittsburgh, PA); Dale, Steinar J. (Monroeville, PA)

    1983-01-01

    This invention provides a novel high voltage gas insulated transmission line utilizing insulating supports spaced at intervals with snap-in means for supporting a continuous trapping apparatus and said trapping apparatus having perforations and cutouts to facilitate trapping of contaminating particles and system flexibility.

  11. Non-vanishing ponderomotive AC electrophoretic effect for particle trapping

    SciTech Connect (OSTI)

    Guan, Weihau; Park, Jae Hyun nmn; Krstic, Predrag S; Reed, Mark A

    2011-01-01

    We present here a study on overlooked aspects of alternating current (AC) electrokinetics AC electrophoretic (ACEP) phenomena. The dynamics of a particle with both polarizability and net charges in a non-uniform AC electric trapping field is investigated. It is found that either electrophoretic (EP) or dielectrophoretic (DEP) effects can dominate the trapping dynamics, depending on experimental conditions. A dimensionless parameter gamma is developed to predict the relative strength of EP and DEP effects in a quadrupole AC field. An ACEP trap is feasible for charged particles in salt-free or low salt concentration solutions. In contrast to DEP traps, an ACEP trap favors the downscaling of the particle size.

  12. Zinc-oxide charge trapping memory cell with ultra-thin chromium-oxide trapping layer

    SciTech Connect (OSTI)

    El-Atab, Nazek; Rizk, Ayman; Nayfeh, Ammar; Okyay, Ali K.; UNAM-National Nanotechnology Research Center and Institute of Materials Science and Nanotechnology, Bilkent University, 06800 Ankara

    2013-11-15

    A functional zinc-oxide based SONOS memory cell with ultra-thin chromium oxide trapping layer was fabricated. A 5 nm CrO{sub 2} layer is deposited between Atomic Layer Deposition (ALD) steps. A threshold voltage (V{sub t}) shift of 2.6V was achieved with a 10V programming voltage. Also for a 2V V{sub t} shift, the memory with CrO{sub 2} layer has a low programming voltage of 7.2V. Moreover, the deep trapping levels in CrO{sub 2} layer allows for additional scaling of the tunnel oxide due to an increase in the retention time. In addition, the structure was simulated using Physics Based TCAD. The results of the simulation fit very well with the experimental results providing an understanding of the charge trapping and tunneling physics.

  13. Sales lag sparks steam trap diversity

    SciTech Connect (OSTI)

    Crawford, E.

    1980-03-03

    Competing manufacturers have broadened their product range and customer services in an effort to survive a tightened market and the introduction of unconventional devices. Users and vendors agree that rising energy costs now give inspection and maintenance of steam traps top priority. New products on the market are described. Competition has led to some questionable advertising and legal action. Fixed orifice and temperature-actuated valves are among the alternative products offered. Models of the major manufacturers are compared by type, pressure and condensate load range, primary use, and price.

  14. Gas turbine engines with particle traps

    DOE Patents [OSTI]

    Boyd, Gary L.; Sumner, D. Warren; Sheoran, Yogendra; Judd, Z. Daniel

    1992-01-01

    A gas turbine engine (10) incorporates a particle trap (46) that forms an entrapment region (73) in a plenum (24) which extends from within the combustor (18) to the inlet (32) of a radial-inflow turbine (52, 54). The engine (10) is thereby adapted to entrap particles that originate downstream from the compressor (14) and are otherwise propelled by combustion gas (22) into the turbine (52, 54). Carbonaceous particles that are dislodged from the inner wall (50) of the combustor (18) are incinerated within the entrapment region (73) during operation of the engine (10).

  15. Isotopic abundance in atom trap trace analysis

    DOE Patents [OSTI]

    Lu, Zheng-Tian; Hu, Shiu-Ming; Jiang, Wei; Mueller, Peter

    2014-03-18

    A method and system for detecting ratios and amounts of isotopes of noble gases. The method and system is constructed to be able to measure noble gas isotopes in water and ice, which helps reveal the geological age of the samples and understand their movements. The method and system uses a combination of a cooled discharge source, a beam collimator, a beam slower and magneto-optic trap with a laser to apply resonance frequency energy to the noble gas to be quenched and detected.

  16. Oxidation of ultrathin GaSe

    SciTech Connect (OSTI)

    Thomas Edwin Beechem; McDonald, Anthony E.; Ohta, Taisuke; Howell, Stephen W.; Kalugin, Nikolai G.; Kowalski, Brian M.; Brumbach, Michael T.; Spataru, Catalin D.; Pask, Jesse A.

    2015-10-26

    Oxidation of exfoliated gallium selenide (GaSe) is investigated through Raman, photoluminescence, Auger, and X-ray photoelectron spectroscopies. Photoluminescence and Raman intensity reductions associated with spectral features of GaSe are shown to coincide with the emergence of signatures emanating from the by-products of the oxidation reaction, namely, Ga2Se3 and amorphous Se. Furthermore, photoinduced oxidation is initiated over a portion of a flake highlighting the potential for laser based patterning of two-dimensional heterostructures via selective oxidation.

  17. Q Cells SE | Open Energy Information

    Open Energy Info (EERE)

    Name: Q-Cells SE Place: Thalheim, Brandenburg, Germany Zip: 6766 Product: German PV cell manufacturer; also makes strategic venture capital and corporate investments....

  18. Li2Se as a Neutron Scintillator

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

    Du, Mao-Hua; Shi, Hongliang; Singh, David J.

    2015-06-23

    We show that Li2Se:Te is a potential neutron scintillator material based on density functional calculations. Li2Se exhibits a number of properties favorable for efficient neutron detection, such as a high Li concentration for neutron absorption, a small effective atomic mass and a low density for reduced sensitivity to background gamma rays, and a small band gap for a high light yield. Our calculations show that Te doping should lead to the formation of deep acceptor complex VLi-TeSe, which can facilitate efficient light emission, similar to the emission activation in Te doped ZnSe.

  19. Oxidation of ultrathin GaSe

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

    Thomas Edwin Beechem; McDonald, Anthony E.; Ohta, Taisuke; Howell, Stephen W.; Kalugin, Nikolai G.; Kowalski, Brian M.; Brumbach, Michael T.; Spataru, Catalin D.; Pask, Jesse A.

    2015-10-26

    Oxidation of exfoliated gallium selenide (GaSe) is investigated through Raman, photoluminescence, Auger, and X-ray photoelectron spectroscopies. Photoluminescence and Raman intensity reductions associated with spectral features of GaSe are shown to coincide with the emergence of signatures emanating from the by-products of the oxidation reaction, namely, Ga2Se3 and amorphous Se. Furthermore, photoinduced oxidation is initiated over a portion of a flake highlighting the potential for laser based patterning of two-dimensional heterostructures via selective oxidation.

  20. Templates-Resources-PHaSe-EFRC

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

    templates 36 inch high by 48 inch wide, landscape poster template with PHaSE acknowledgements (PPT file download) 36 inch high by 48 inch wide, landscape poster template with PHaSE acknowledgements, 12-panel layout (typical pattern used by UMass PSE) (PPT file download) 42 inch high by 48 inch wide, landscape poster template with PHaSE acknowledgements (PPT file download) 36 inch high by 48 inch wide, portrait poster template with PHaSE acknowledgements (PPT file download) 16:9 Slide Templates

  1. Mesoscopic supersolid of dipoles in a trap

    SciTech Connect (OSTI)

    Golomedov, A. E.; Astrakharchik, G. E.; Lozovik, Yu. E.

    2011-09-15

    A mesoscopic system of dipolar bosons trapped by a harmonic potential is considered. The system has a number of physical realizations including dipole excitons, atoms with large dipolar moment, polar molecules, and Rydberg atoms in inhomogeneous electric field. We carry out a diffusion Monte Carlo simulation to define the quantum properties of a two-dimensional system of trapped dipoles at zero temperature. In dimensionless units the system is described by two control parameters, namely, the number of particles and the strength of the interparticle interaction. We have shown that when the interparticle interaction is strong enough a mesoscopic crystal is formed. As the strength of interactions is decreased a multistage melting takes place. Off-diagonal order in the system is tested using natural-orbitals analysis. We have found that the system might be Bose condensed even in the case of strong interparticle interactions. There is a set of parameters for which a spatially ordered structure is formed while simultaneously the fraction of Bose-condensed particles is nonzero. This might be considered as a realization of a mesoscopic supersolid.

  2. Identification of microscopic hole-trapping mechanisms in nitride semiconductors

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

    John L. Lyons; Krishnaswamy, Karthik; Luke Gordon; Van de Walle, Chris G.; Anderson, Janotti

    2015-12-17

    Hole trapping has been observed in nitride heterostructure devices, where the Fermi level is in the vicinity of the valence-band maximum. Using hybrid density functional calculations, we examine microscopic mechanisms for hole trapping in GaN and AlN. In a defect-free material, hole trapping does not spontaneously occur, but trapping can occur in the vicinity of impurities, such as C-a common unintentional impurity in nitrides. As a result, using Schrödinger-Poisson simulations, we assess the effects of C-derived hole traps on N-face high-electron mobility transistors, which we find to be more detrimental than the previously proposed interface traps.

  3. Investigation of long lifetimes in Cu(In,Ga)Se{sub 2} by time-resolved photoluminescence

    SciTech Connect (OSTI)

    Maiberg, Matthias; Hölscher, Torsten; Zahedi-Azad, Setareh; Fränzel, Wolfgang; Scheer, Roland

    2015-09-21

    The main objective of time-resolved photoluminescence (TRPL) is to characterize minority carrier recombination in semiconductors. However, trap states in the band gap can lead to artificially long decay times thus distorting the measured minority carrier lifetime. In this work, we propose to measure TRPL under elevated temperature and excitation in order to reduce minority carrier trapping. Taking three Cu(In,Ga)Se{sub 2} layers as examples, we show that the decay time decreases with increasing temperature—in accordance with simulations. Under increasing excitation, the decay time can become smaller due to trap saturation but also can become larger due to asymmetric hole and electron lifetimes. By comparison of simulation and experiment, we can find the energy, the density, and the electron capture cross-section of the trap which in the present example of Cu(In,Ga)Se{sub 2} films gives values of ∼200 meV, ∼10{sup 15 }cm{sup −3}, and ∼10{sup −13} cm{sup 2}, respectively.

  4. Requirements-Driven Diesel Catalyzed Particulate Trap Design and

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

    Optimization | Department of Energy Requirements-Driven Diesel Catalyzed Particulate Trap Design and Optimization Requirements-Driven Diesel Catalyzed Particulate Trap Design and Optimization 2005 Diesel Engine Emissions Reduction (DEER) Conference Presentations and Posters 2005_deer_harris.pdf (388.49 KB) More Documents & Publications Diesel Emission Control Technology Review Investigation of Aging Mechanisms in Lean NOx Traps Diesel Particulate Filters: Market Introducution in Euro

  5. Gas insulated transmission line having tapered particle trapping ring

    DOE Patents [OSTI]

    Cookson, Alan H.

    1982-01-01

    A gas-insulated transmission line includes an outer sheath, an inner conductor, insulating supports and an insulating gas. A particle-trapping ring is secured to each insulating support, and it is comprised of a central portion and two tapered end portions. The ends of the particle trapping ring have a smaller diameter than the central portion of the ring, so as to enable the use of the particle trapping ring in a curved transmission line.

  6. Steam trap maintenance management saves $180,000 annually

    SciTech Connect (OSTI)

    Franks, F.C.; Wickersham, C.

    1985-12-01

    The Reichhold Chemical plant is located in Elizabeth, NJ. At this location, the cost of steam had skyrocketed to $5.30 per million Btu. The plant has 600 steam traps manufactured by ten different companies. Some 17 different models of traps are used with 33 piping configurations. There are five different operating pressures throughout the plant ranging from 15-175 psig, including 30, 65, and 120 psig. Five different applications of steam usage can be broken down as follows: steam tracing (56%); drip (21%); comfort heating (18%); tank coil (4%); and process (1%). In the fall of 1983, the annual yearly inspection of steam traps was supplanted with an independent trap survey service, specializing in detecting the malfunctioning of various types of steam traps. The basic program included location and tagging of all steam traps; survey and inspection of steam trap population; development of a trap map; and full computer analysis of collected data. It was determined that approximately 3919 lb/hr of steam could be saved by repairing the failed open traps and implementing the report's recommendations. There were also benefits from fixing the failed closed traps which were out of service at the time of the survey. These traps do not allow the flow of steam or condensate to pass through the orifice. This condition causes condensate to back up and reduce efficiency. The maintenance management has been pleased with the results and recommendations of the program. It has provided them with a complete inventory and status report of the 600 traps plantwide. It saved $180,000 over the previous year in energy expenditures. This was the most important contribution in lowering the plant energy costs.

  7. Thermostatic/orifice trap reduces fuel, repair costs

    SciTech Connect (OSTI)

    Not Available

    1982-11-01

    This article is an evaluation of a steam trap that combines the continuous drain oriface with a thermostatically controlled trap oriface to efficiently remove condensate from virtually any steam system within its operating limits. This trap effectively reduces fuel and repair costs and has a capacity of 6000 il/hr, handles various pressures up to 600 psig, and operates against back pressures up to 90% of inlet pressure.

  8. Particle trapping: A key requisite of structure formation and...

    Office of Scientific and Technical Information (OSTI)

    Particle trapping is shown to control the existence of ... Journal Volume: 22; Journal Issue: 4; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International ...

  9. Biogas Purifications for Fuel Cells: SulfaTrap Sorbents

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

    Biogas Purifications for Fuel Cells SulfaTrap TM Sorbents Gökhan Alptekin, PhD Vice President, Technology Tel: 303 940 2349 galptekin@tda.com DOE Workshop on Gas Clean-up for Fuel Cell Applications Argonne National Laboratory March 7, 2014 TDA Research Inc. * Wheat Ridge, CO 80033 * www.tda.com Background - SulfaTrap TM Sorbents Bio-ethanol desulfurizer SulfaTrap TM sorbents for stationary/mobile fuel cell applications * Fundamental work started at TDA Research in 2002 * SulfaTrap LLC was

  10. Lean NOx Traps - Microstructural Studies of Real World and Model...

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

    KB) More Documents & Publications Low Temperature Emission Control Pre-Competitive Catalysis Research: Fundamental SulfationDesulfation Studies of Lean NOx Traps Investigation ...

  11. Light Trapping, Absorption and Solar Energy Harvesting by Artificial...

    Office of Scientific and Technical Information (OSTI)

    Energy Harvesting by Artificial Materials Citation Details In-Document Search Title: Light Trapping, Absorption and Solar Energy Harvesting by Artificial Materials We provide ...

  12. Ball-grid array architecture for microfabricated ion traps (Journal...

    Office of Scientific and Technical Information (OSTI)

    Ball-grid array architecture for microfabricated ion traps Citation Details In-Document ... Country of Publication: United States Language: English Subject: 71 CLASSICAL AND QUANTUM ...

  13. On the Equivalence of Trapped Colloids, Pinned Vortices, and...

    Office of Scientific and Technical Information (OSTI)

    Title: On the Equivalence of Trapped Colloids, Pinned Vortices, and Spin Ice We investigate the recently reported analogies between pinned vortices in nano-structured ...

  14. Lean NOx Trap Regeneration Selectivity Towards N2O -- Similarities...

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

    Lean NOx Trap Regeneration Selectivity Towards N2O -- Similarities and Differences Between ... More Documents & Publications Spatiotemporal Distribution of NOx Storage: a Factor ...

  15. Stable metal-organic frameworks containing single-molecule traps...

    Office of Scientific and Technical Information (OSTI)

    Title: Stable metal-organic frameworks containing single-molecule traps for enzyme encapsulation Authors: Feng, Dawei ; Liu, Tian-Fu ; Su, Jie ; Bosch, Mathieu ; Wei, Zhangwen ; ...

  16. Wolf Trap, Virginia: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    Bureau 2005 Place to 2006 CBSA Retrieved from "http:en.openei.orgwindex.php?titleWolfTrap,Virginia&oldid253815" Feedback Contact needs updating Image needs updating...

  17. H2-Assisted NOx Traps: Test Cell Results Vehicle Installations...

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

    H2-Assisted NOx Traps: Test Cell Results Vehicle Installations 2003 DEER Conference Presentation: ArvinMeritor 2003deercrane.pdf (630.37 KB) More Documents & Publications ...

  18. A Sub-Millimeter Solenoid Device for Trapping Paramagnetic Microbeads...

    Office of Scientific and Technical Information (OSTI)

    a paramagnetic microsphere trapping and separation device consisting of a copper solenoid ... to the design of magnetic-based separation devices because the ...

  19. Contaminant trap for gas-insulated apparatus

    DOE Patents [OSTI]

    Adcock, James L.; Pace, Marshall O.; Christophorou, Loucas G.

    1984-01-01

    A contaminant trap for a gas-insulated electrical conductor is provided. A resinous dielectric body such as Kel-F wax, grease or other sticky polymeric or oligomeric compound is disposed on the inside wall of the outer housing for the conductor. The resinous body is sufficiently sticky at ambient temperatures to immobilize contaminant particles in the insulating gas on the exposed surfaces thereof. An electric resistance heating element is disposed in the resinous body to selectively raise the temperature of the resinous body to a molten state so that the contaminant particles collected on the surface of the body sink into the body so that the surface of the resinous body is renewed to a particle-less condition and, when cooled, returns to a sticky collecting surface.

  20. Production of Ultracold Trapped Molecular Hydrogen Ions

    SciTech Connect (OSTI)

    Blythe, P.; Roth, B.; Froehlich, U.; Wenz, H.; Schiller, S.

    2005-10-28

    We have cooled ensembles of the molecular hydrogen ions H{sub 2}{sup +}, H{sub 3}{sup +}, and all their deuterated variants to temperatures of a few mK in a radio frequency trap, by sympathetic cooling with laser-cooled beryllium ions. The molecular ions are embedded in the central regions of Coulomb crystals. Mass spectroscopy and molecular dynamics simulations were used to accurately characterize the properties of the ultracold multispecies crystals. We demonstrate species-selective purification of multispecies ensembles. These molecules are of fundamental importance as the simplest of all molecules, and have the potential to be used for precision tests of molecular structure theory, tests of Lorentz invariance, and measurements of electron to nuclear mass ratios and their time variation.

  1. Debris trap in a turbine cooling system

    DOE Patents [OSTI]

    Wilson, Ian David

    2002-01-01

    In a turbine having a rotor and a plurality of stages, each stage comprising a row of buckets mounted on the rotor for rotation therewith; and wherein the buckets of at least one of the stages are cooled by steam, the improvement comprising at least one axially extending cooling steam supply conduit communicating with an at least partially annular steam supply manifold; one or more axially extending cooling steam feed tubes connected to the manifold at a location radially outwardly of the cooling steam supply conduit, the feed tubes arranged to supply cooling steam to the buckets of at least one of the plurality of stages; the manifold extending radially beyond the feed tubes to thereby create a debris trap region for collecting debris under centrifugal loading caused by rotation of the rotor.

  2. Penning trap mass measurements on nobelium isotopes

    SciTech Connect (OSTI)

    Dworschak, M.; Block, M.; Ackermann, D.; Herfurth, F.; Hessberger, F. P.; Hofmann, S.; Vorobyev, G. K.; Audi, G.; Blaum, K.; Droese, C.; Marx, G.; Schweikhard, L.; Eliseev, S.; Ketter, J.; Fleckenstein, T.; Haettner, E.; Plass, W. R.; Scheidenberger, C.; Ketelaer, J.; Kluge, H.-J.

    2010-06-15

    The Penning trap mass spectrometer SHIPTRAP at GSI Darmstadt allows accurate mass measurements of radionuclides, produced in fusion-evaporation reactions and separated by the velocity filter SHIP from the primary beam. Recently, the masses of the three nobelium isotopes {sup 252-254}No were determined. These are the first direct mass measurements of transuranium elements, which provide new anchor points in this region. The heavy nuclides were produced in cold-fusion reactions by irradiating a PbS target with a {sup 48}Ca beam, resulting in production rates of the nuclei of interest of about one atom per second. In combination with data from decay spectroscopy our results are used to perform a new atomic-mass evaluation in this region.

  3. Charge Trapping in High Efficiency Alternating Copolymers: Implications in

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

    Organic Photovoltaic Device Efficiency | ANSER Center | Argonne-Northwestern National Laboratory Charge Trapping in High Efficiency Alternating Copolymers: Implications in Organic Photovoltaic Device Efficiency Home > Research > ANSER Research Highlights > Charge Trapping in High Efficiency Alternating Copolymers: Implications in Organic Photovoltaic Device Efficiency

  4. Quantum chaos of an ion trapped in a linear ion trap

    SciTech Connect (OSTI)

    Berman, Gennady P. [Theoretical Division T-13, and CNLS, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Theoretical Division T-13, and CNLS, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); James, Daniel F. V. [Theoretical Division T-4, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Theoretical Division T-4, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Kamenev, Dimitri I. [Theoretical Division T-13, and CNLS, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States) [Theoretical Division T-13, and CNLS, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Nizhny Novgorod State University, Nizhny Novgorod, 603600, Russia (Russian Federation)

    2000-06-01

    We describe the transition to quantum chaos of an ion trapped in a linear ion trap and interacting with two laser fields. Under the conditions of adiabatic illumination of the upper level of the ion, and when the frequencies of the two laser beams are slightly different, the system is reduced to a quantum linear oscillator interacting with a monochromatic wave. The property of localization over the quantum resonance cells is proposed to exploit in order to facilitate the process of measurement of the probability distribution of an ion on the vibrational levels. In the regime of strong chaos the time-averaged values of the energy and dispersion of energy are computed and compared with the corresponding classical quantities for different values of the perturbation amplitude. In the exact resonance case, the classical analog of the system possesses an infinite inhomogeneous stochastic web. We analyze the quantum dynamics inside the inhomogeneous web. It is shown that the quantum system mimics on average the dynamics of the corresponding classical system. Formation of the quantum resonance cells is illustrated in the case of a finite detuning from the exact resonance, and under increasing of the wave amplitude. The parameters of the model and the initial conditions are close to the real physical situation which can be realized in the system of cold trapped ion perturbed by two lasers fields with close frequencies. (c) 2000 American Institute of Physics.

  5. Facilities-Resources-PHaSe-EFRC

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

    Various PHaSE EFRC equipment may be accessed by making arrangments for training and acceptance to the list of registered users. Access to the facility rooms requires a password ...

  6. SE Drive Technik | Open Energy Information

    Open Energy Info (EERE)

    Drive Technik Jump to: navigation, search Name: SE Drive Technik Place: Bochum, Germany Zip: 44791 Product: Germany-based R&D subsidiary of Indian turbine maker Suzlon. References:...

  7. 2013 Archives-News-PHaSe-EFRC

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

    3 Archives Volodimyr Duzhko photo Volodimyr Duzhko promoted to (extension) Assistant Professor of Polymer Science & Engineering. PHaSE is pleased to announce that Facility Director Dr. Volodimyr Duzhko has been promoted to extension Assistant Professor of Polymer Science & Engineering. Volodimyr is a semiconductor physicist with considerable experience in polymer materials. Since joining PHaSE, he has trained over 70 people to use 10 instruments in the Photovoltaic & Optical

  8. Electrostatic particle trap for ion beam sputter deposition

    DOE Patents [OSTI]

    Vernon, Stephen P.; Burkhart, Scott C.

    2002-01-01

    A method and apparatus for the interception and trapping of or reflection of charged particulate matter generated in ion beam sputter deposition. The apparatus involves an electrostatic particle trap which generates electrostatic fields in the vicinity of the substrate on which target material is being deposited. The electrostatic particle trap consists of an array of electrode surfaces, each maintained at an electrostatic potential, and with their surfaces parallel or perpendicular to the surface of the substrate. The method involves interception and trapping of or reflection of charged particles achieved by generating electrostatic fields in the vicinity of the substrate, and configuring the fields to force the charged particulate material away from the substrate. The electrostatic charged particle trap enables prevention of charged particles from being deposited on the substrate thereby enabling the deposition of extremely low defect density films, such as required for reflective masks of an extreme ultraviolet lithography (EUVL) system.

  9. A Pneumatic Actuated Microfluidic Beads-Trapping Device

    SciTech Connect (OSTI)

    Shao, Guocheng; Cai, Ziliang; Wang, Jun; Wang, Wanjun; Lin, Yuehe

    2011-08-20

    The development of a polydimethylsiloxane (PDMS) microfluidic microbeads trapping device is reported in this paper. Besides fluid channels, the proposed device includes a pneumatic control chamber and a beads-trapping chamber with a filter array structure. The pneumatic flow control chamber and the beads-trapping chamber are vertically stacked and separated by a thin membrane. By adjusting the pressure in the pneumatic control chamber, the membrane can either be pushed against the filter array to set the device in trapping mode or be released to set the device in releasing mode. In this paper, a computational fluid dynamics simulation was conducted to optimize the geometry design of the filter array structure; the device fabrication was also carried out. The prototype device was tested and the preliminary experimental results showed that it can be used as a beads-trapping unit for various biochemistry and analytical chemistry applications, especially for flow injection analysis systems.

  10. Ionization-Induced Electron Trapping inUltrarelativistic Plasma Wakes

    SciTech Connect (OSTI)

    Oz, E.; Deng, S.; Katsouleas, T.; Muggli, P.; Barnes, C.D.; Blumenfeld, I.; Decker, F.J.; Emma, P.; Hogan, M.J.; Ischebeck, R.; Iverson, R.H.; Kirby, N.; Krejcik, P.; O'Connell, C.; Siemann, R.H.; Walz, D.; Auerbach, D.; Clayton, C.E.; Huang, C.; Johnson, D.K.; Joshi, C.; /UCLA

    2007-04-06

    The onset of trapping of electrons born inside a highly relativistic, 3D beam-driven plasma wake is investigated. Trapping occurs in the transition regions of a Li plasma confined by He gas. Li plasma electrons support the wake, and higher ionization potential He atoms are ionized as the beam is focused by Li ions and can be trapped. As the wake amplitude is increased, the onset of trapping is observed. Some electrons gain up to 7.6 GeV in a 30.5 cm plasma. The experimentally inferred trapping threshold is at a wake amplitude of 36 GV/m, in good agreement with an analytical model and PIC simulations.

  11. Optical trapping apparatus, methods and applications using photonic crystal resonators

    DOE Patents [OSTI]

    Erickson, David; Chen, Yih-Fan

    2015-06-16

    A plurality of photonic crystal resonator optical trapping apparatuses and a plurality optical trapping methods using the plurality of photonic crystal resonator optical trapping apparatuses include located and formed over a substrate a photonic waveguide that is coupled (i.e., either separately coupled or integrally coupled) with a photonic crystal resonator. In a particular embodiment, the photonic waveguide and the photonic crystal resonator comprise a monocrystalline silicon (or other) photonic material absent any chemical functionalization. In another particular embodiment, the photonic waveguide and the photonic crystal resonator comprise a silicon nitride material which when actuating the photonic crystal resonator optical trapping apparatus with a 1064 nanometer resonant photonic radiation wavelength (or other resonant photonic radiation wavelength in a range from about 700 to about 1200 nanometers) provides no appreciable heating of an aqueous sample fluid that is analyzed by the photonic crystal resonator optical trapping apparatus.

  12. A transferable force field for CdS-CdSe-PbS-PbSe solid systems

    SciTech Connect (OSTI)

    Fan, Zhaochuan; Vlugt, Thijs J. H.; Koster, Rik S.; Fang, Changming; Huis, Marijn A. van; Wang, Shuaiwei; Yalcin, Anil O.; Tichelaar, Frans D.; Zandbergen, Henny W.

    2014-12-28

    A transferable force field for the PbSe-CdSe solid system using the partially charged rigid ion model has been successfully developed and was used to study the cation exchange in PbSe-CdSe heteronanocrystals [A. O. Yalcin et al., “Atomic resolution monitoring of cation exchange in CdSe-PbSe heteronanocrystals during epitaxial solid-solid-vapor growth,” Nano Lett. 14, 3661–3667 (2014)]. In this work, we extend this force field by including another two important binary semiconductors, PbS and CdS, and provide detailed information on the validation of this force field. The parameterization combines Bader charge analysis, empirical fitting, and ab initio energy surface fitting. When compared with experimental data and density functional theory calculations, it is shown that a wide range of physical properties of bulk PbS, PbSe, CdS, CdSe, and their mixed phases can be accurately reproduced using this force field. The choice of functional forms and parameterization strategy is demonstrated to be rational and effective. This transferable force field can be used in various studies on II-VI and IV-VI semiconductor materials consisting of CdS, CdSe, PbS, and PbSe. Here, we demonstrate the applicability of the force field model by molecular dynamics simulations whereby transformations are initiated by cation exchange.

  13. Cast-to-shape electrokinetic trapping medium

    DOE Patents [OSTI]

    Shepodd, Timothy J.; Franklin, Elizabeth; Prickett, Zane T.; Artau, Alexander

    2004-08-03

    A three-dimensional microporous polymer network material, or monolith, cast-to-shape in a microchannel. The polymer monolith, produced by a phase separation process, is capable of trapping and retaining charged protein species from a mixture of charged and uncharged species under the influence of an applied electric field. The retained charged protein species are released from the porous polymer monolith by a pressure driven flow in the substantial absence of the electric field. The pressure driven flow is independent of direction and thus neither means to reverse fluid flow nor a multi-directional flow field is required, a single flow through the porous polymer monolith can be employed, in contrast to prior art systems. The monolithic polymer material produced by the invention can function as a chromatographic medium. Moreover, by virtue of its ability to retain charged protein species and quantitatively release the retained species the porous polymer monolith can serve as a means for concentrating charged protein species from, for example, a dilute solution.

  14. Cast-to-shape electrokinetic trapping medium

    DOE Patents [OSTI]

    Shepodd, Timothy J.; Franklin, Elizabeth; Prickett, Zane T.; Artau, Alexander

    2006-05-30

    A three-dimensional microporous polymer network material, or monolith, cast-to-shape in a microchannel. The polymer monolith, produced by a phase separation process, is capable of trapping and retaining charged protein species from a mixture of charged and uncharged species under the influence of an applied electric field. The retained charged protein species are released from the porous polymer monolith by a pressure driven flow in the substantial absence of the electric field. The pressure driven flow is independent of direction and thus neither means to reverse fluid flow nor a multi-directional flow field is required, a single flow through the porous polymer monolith can be employed, in contrast to prior art systems. The monolithic polymer material produced by the invention can function as a chromatographic medium. Moreover, by virtue of its ability to retain charged protein species and quantitatively release the retained species the porous polymer monolith can serve as a means for concentrating charged protein species from, for example, a dilute solution.

  15. Hydrogen isotope trapping in Al-Cu binary alloys

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

    Chao, Paul; Karnesky, Richard A.

    2016-01-01

    In this study, the trapping mechanisms for hydrogen isotopes in Al–X Cu (0.0 at. % < X < 3.5 at. %) alloys were investigated using thermal desorption spectroscopy (TDS), electrical conductivity, and differential scanning calorimetry. Constant heating rate TDS was used to determine microstructural trap energies and occupancies. In addition to the trapping states in pure Al reported in the literature (interstitial lattice sites, dislocations, and vacancies), a trap site due to Al–Cu intermetallic precipitates is observed. The binding energy of this precipitate trap is (18 ± 3) kJ•mol–1 (0.19 ± 0.03 eV). Typical occupancy of this trap is high;more » for Al–2.6 at. % Cu (a Cu composition comparable to that in AA2219) charged at 200 °C with 130 MPa D2 for 68 days, there is ca. there is 3.15×10–7 mol D bound to the precipitate trap per mol of Al, accounting for a third of the D in the charged sample.« less

  16. Hydrogen isotope trapping in Al-Cu binary alloys

    SciTech Connect (OSTI)

    Chao, Paul; Karnesky, Richard A.

    2016-01-01

    In this study, the trapping mechanisms for hydrogen isotopes in Al–X Cu (0.0 at. % < X < 3.5 at. %) alloys were investigated using thermal desorption spectroscopy (TDS), electrical conductivity, and differential scanning calorimetry. Constant heating rate TDS was used to determine microstructural trap energies and occupancies. In addition to the trapping states in pure Al reported in the literature (interstitial lattice sites, dislocations, and vacancies), a trap site due to Al–Cu intermetallic precipitates is observed. The binding energy of this precipitate trap is (18 ± 3) kJ•mol–1 (0.19 ± 0.03 eV). Typical occupancy of this trap is high; for Al–2.6 at. % Cu (a Cu composition comparable to that in AA2219) charged at 200 °C with 130 MPa D2 for 68 days, there is ca. there is 3.15×10–7 mol D bound to the precipitate trap per mol of Al, accounting for a third of the D in the charged sample.

  17. Using malaise traps to sample ground beetles (Coleoptera. Carabidae)

    SciTech Connect (OSTI)

    Ulyshen, Michael D.; Hanula, James L.; Horn, Scott

    2012-04-02

    Pitfall traps provide an easy and inexpensive way to sample ground-dwelling arthropods (Spence and Niemela 1994; Spence et al. 1997; Abildsnes and Tommeras 2000) and have been used exclusively in many studies of the abundance and diversity of ground beetles (Coleoptera: Carabidae). Despite the popularity of this trapping technique, pitfall traps have many disadvantages. For example, they often fail to collect both small (Spence and Niemela 1994) and trap-shy species (Benest 1989), eventually deplete the local carabid population (Digweed et al. 1995), require a species to be ground-dwelling in order to be captured (Liebherr and Mahar 1979), and produce different results depending on trap diameter and material, type of preservative used, and trap placement (Greenslade 1964; Luff 1975; Work et al. 2002). Further complications arise from seasonal patterns of movement among the beetles themselves (Maelfait and Desender 1990), as well as numerous climatic factors, differences in plant cover, and variable surface conditions (Adis 1979). Because of these limitations, pitfall trap data give an incomplete picture of the carabid community and should be interpreted carefully. Additional methods, such as use of Berlese funnels and litter washing (Spence and Niemela 1994), collection from lights (Usis and MacLean 1998), and deployment of flight intercept devices (Liebherr and Mahar 1979; Paarmann and Stork 1987), should be incorporated in surveys to better ascertain the species composition and relative numbers of ground beetles. Flight intercept devices, like pitfall traps, have the advantage of being easy to use and replicate, but their value to carabid surveys is largely unknown. Here we demonstrate the effectiveness of Malaise traps for sampling ground beetles in a bottomland hardwood forest.

  18. Using malaise traps to sample ground beetles (Coleoptera: Carabidae).

    SciTech Connect (OSTI)

    Ulyshen, Michael D., James L. Hanula, and Scott Horn

    2005-01-01

    Pitfall traps provide an easy and inexpensive way to sample ground-dwelling arthropods (Spence and Niemela 1994; Spence et al. 1997; Abildsnes and Tommeras 2000) and have been used exclusively in many studies of the abundance and diversity of ground beetles (Coleoptera: Carabidae). Despite the popularity of this trapping technique, pitfall traps have many disadvantages. For example, they often fail to collect both small (Spence and Niemela 1994) and ? ????trap-shy?¢??? species (Benest 1989), eventually deplete the local carabid population (Digweed et al. 1995), require a species to be ground-dwelling in order to be captured (Liebherr and Mahar 1979), and produce different results depending on trap diameter and material, type of preservative used, and trap placement (Greenslade 1964; Luff 1975; Work et al. 2002). Further complications arise from seasonal patterns of movement among the beetles themselves (Maelfait and Desender 1990), as well as numerous climatic factors, differences in plant cover, and variable surface conditions (Adis 1979). Because of these limitations, pitfall trap data give an incomplete picture of the carabid community and should be interpreted carefully. Additional methods, such as use of Berlese funnels and litter washing (Spence and Niemela 1994), collection from lights (Usis and MacLean 1998), and deployment of flight intercept devices (Liebherr and Mahar 1979; Paarmann and Stork 1987), should be incorporated in surveys to better ascertain the species composition and relative numbers of ground beetles. Flight intercept devices, like pitfall traps, have the advantage of being easy to use and replicate, but their value to carabid surveys is largely unknown. Here we demonstrate the effectiveness of Malaise traps for sampling ground beetles in a bottomland hardwood forest.

  19. Power-Amplified Predatory Strikes in Trap-Jaw Spiders

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

    Power-Amplified Predatory Strikes in Trap-Jaw Spiders Power-Amplified Predatory Strikes in Trap-Jaw Spiders Print Friday, 10 June 2016 13:23 "Trap-jaw" spiders are tiny (about 2 mm), ground-dwelling spiders that rely on hunting rather than web-building to capture prey. Hannah Wood, curator of spiders at the Smithsonian's National Museum of Natural History, was curious as to why these spiders' carapaces (their front sections) seemed almost neck-like and their chelicerae (mandibles or

  20. Scalable error correction in distributed ion trap computers

    SciTech Connect (OSTI)

    Oi, Daniel K. L.; Devitt, Simon J.; Hollenberg, Lloyd C. L.

    2006-11-15

    A major challenge for quantum computation in ion trap systems is scalable integration of error correction and fault tolerance. We analyze a distributed architecture with rapid high-fidelity local control within nodes and entangled links between nodes alleviating long-distance transport. We demonstrate fault-tolerant operator measurements which are used for error correction and nonlocal gates. This scheme is readily applied to linear ion traps which cannot be scaled up beyond a few ions per individual trap but which have access to a probabilistic entanglement mechanism. A proof-of-concept system is presented which is within the reach of current experiment.

  1. Movement of particles using sequentially activated dielectrophoretic particle trapping

    DOE Patents [OSTI]

    Miles, Robin R.

    2004-02-03

    Manipulation of DNA and cells/spores using dielectrophoretic (DEP) forces to perform sample preparation protocols for polymerized chain reaction (PCR) based assays for various applications. This is accomplished by movement of particles using sequentially activated dielectrophoretic particle trapping. DEP forces induce a dipole in particles, and these particles can be trapped in non-uniform fields. The particles can be trapped in the high field strength region of one set of electrodes. By switching off this field and switching on an adjacent electrodes, particles can be moved down a channel with little or no flow.

  2. Modeling the Regeneration Chemistry of Lean NOx Traps | Department of

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

    Energy the Regeneration Chemistry of Lean NOx Traps Modeling the Regeneration Chemistry of Lean NOx Traps Presentation given at DEER 2006, August 20-24, 2006, Detroit, Michigan. Sponsored by the U.S. DOE's EERE FreedomCar and Fuel Partnership and 21st Century Truck Programs. 2006_deer_larson.pdf (637.26 KB) More Documents & Publications Kinetic and Performance Studies of the Regeneration Phase of Model Pt/Rh/Ba NOx Traps for Design and Optimization Production, Storage, and FC Analysis

  3. Trap seal for open circuit liquid cooled turbines

    DOE Patents [OSTI]

    Grondahl, Clayton M.; Germain, Malcolm R.

    1980-01-01

    An improved trap seal for open circuit liquid cooled turbines is disclosed. The trap seal of the present invention includes an annular recess formed in the supply conduit of cooling channels formed in the airfoil of the turbine buckets. A cylindrical insert is located in the annular recesses and has a plurality of axial grooves formed along the outer periphery thereof and a central recess formed in one end thereof. The axial grooves and central recess formed in the cylindrical insert cooperate with the annular recess to define a plurality of S-shaped trap seals which permit the passage of liquid coolant but prohibit passage of gaseous coolant.

  4. Synergies of High-Efficiency Clean Combustion and Lean NOx Trap...

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

    Synergies of High-Efficiency Clean Combustion and Lean NOx Trap Catalysts Synergies of High-Efficiency Clean Combustion and Lean NOx Trap Catalysts investigation of potential ...

  5. Nitrogen Oxides as a Chemistry Trap in Detonating Oxygen-Rich...

    Office of Scientific and Technical Information (OSTI)

    Conference: Nitrogen Oxides as a Chemistry Trap in Detonating Oxygen-Rich Materials Citation Details In-Document Search Title: Nitrogen Oxides as a Chemistry Trap in Detonating ...

  6. 2011 Archives-News-PHaSe-EFRC

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

    1 Archives solar cells video clip Solar Cells from Plastics? Mission Possible at the PHaSE energy research center, UMass Amherst!, a YouTube video about work at PHaSE, debuted on 24 March 2011. This video is part of our center's contributions to the Energy Frontier Research Centers Summit & Forum on 25-27 May 2011, which is further described below. Many thanks to Harihara Venkatraman (DV group, ERG 1) and Dr. Emily Pentzer (Emrick group, ERG 1) for starring in the video clip, along with

  7. Single-step in-situ synthesis and optical properties of ZnSe nanostructured dielectric nanocomposites

    SciTech Connect (OSTI)

    Dey, Chirantan; Rahaman Molla, Atiar; Tarafder, Anal; Karmakar, Basudeb; Kr Mishra, Manish; De, Goutam; Goswami, Madhumita; Kothiyal, G. P.

    2014-04-07

    This work provides the evidence of visible red photoluminescent light emission from ZnSe nanocrystals (NCs) grown within a dielectric (borosilicate glass) matrix synthesized by a single step in-situ technique for the first time and the NC sizes were controlled by varying only the concentration of ZnSe in glass matrix. The ZnSe NCs were investigated by UV-Vis optical absorption spectroscopy, Raman spectroscopy, and transmission electron microscopy (TEM). The sizes of the ZnSe NCs estimated from the TEM images are found to alter in the range of 2–53 nm. Their smaller sizes of the NCs were also calculated by using the optical absorption spectra and the effective mass approximation model. The band gap enlargements both for carrier and exciton confinements were evaluated and found to be changed in the range of 0–1.0 eV. The Raman spectroscopic studies showed blue shifted Raman peaks of ZnSe at 295 and 315 cm{sup −1} indicating phonon confinement effect as well as compressive stress effect on the surface atoms of the NCs. Red photoluminescence in ZnSe-glass nanocomposite reveals a broad multiple-peak structure due to overlapping of emission from NC size related electron-hole recombination (∼707 nm) and emissions from defects to traps, which were formed due to Se and Zn vacancies signifying potential application in photonics.

  8. Fuel traps: mapping stability via water association.

    SciTech Connect (OSTI)

    Rempe, Susan L.; Clawson, Jacalyn S.; Greathouse, Jeffery A.; Alam, Todd M; Leung, Kevin; Varma, Sameer; Sabo, Dubravko; Martin, Marcus Gary; Cygan, Randall Timothy

    2007-03-01

    Hydrogen storage is a key enabling technology required for attaining a hydrogen-based economy. Fundamental research can reveal the underlying principles controlling hydrogen uptake and release by storage materials, and also aid in characterizing and designing novel storage materials. New ideas for hydrogen storage materials come from exploiting the properties of hydrophobic hydration, which refers to water s ability to stabilize, by its mode of association, specific structures under specific conditions. Although hydrogen was always considered too small to support the formation of solid clathrate hydrate structures, exciting new experiments show that water traps hydrogen molecules at conditions of low temperatures and moderate pressures. Hydrogen release is accomplished by simple warming. While these experiments lend credibility to the idea that water could form an environmentally attractive alternative storage compound for hydrogen fuel, which would advance our nation s goals of attaining a hydrogen-based economy, much work is yet required to understand and realize the full potential of clathrate hydrates for hydrogen storage. Here we undertake theoretical studies of hydrogen in water to establish a firm foundation for predictive work on clathrate hydrate H{sub 2} storage capabilities. Using molecular simulation and statistical mechanical theories based in part on quantum mechanical descriptions of molecular interactions, we characterize the interactions between hydrogen and liquid water in terms of structural and thermodynamic properties. In the process we validate classical force field models of hydrogen in water and discover new features of hydrophobic hydration that impact problems in both energy technology and biology. Finally, we predict hydrogen occupancy in the small and large cages of hydrogen clathrate hydrates, a property unresolved by previous experimental and theoretical work.

  9. Evolution of Electronic Properties of (Cu(In,Ga)Se2 (CIGS)-Based Solar Cells During a 3-Stage Growth Process: Preprint

    SciTech Connect (OSTI)

    AbuShama, J. A.; Johnston, S.; Ahrenkiel, R.; Crandall, R.; Young, D.; Noufi, R.

    2003-04-01

    We investigated the electronic properties of ZnO/CdS/CIGS /Mo/SLG polycrystalline thin-film solar cells with compositions ranging from Cu-rich to In(Ga)-rich by deep-level transient spectroscopy (DLTS) and capacitance-voltage (C-V) measurements. This compositional change represents the evolution of the film during growth by the 3-stage process. Two sets (four samples each) of CIGS thin films were prepared with Ga/(In+Ga) ratios of~0.3 (low Ga) and~0.6 (high Ga). The Cu/(In+Ga) ratio ranges from 1.24 (Cu-rich) to 0.88 (In(Ga)-rich). The films were treated with NaCN to remove the Cu2-xSe phase where needed. Key results include: (1) For low-Ga devices, DLTS data show that acceptor-like traps dominate in samples where CIGS grains do not go through the Cu-rich to In(Ga)-rich transition, whereas donor-like traps dominate in In(Ga)-rich samples. Therefore, we see a clear transformation of defects from acceptor-like to donor-like traps. The activation energies of these traps range from 0.12 to 0.63 eV. We also observed that NaCN treatment eliminates a deep minority trap in the In(Ga)-rich devices, (2) For high-Ga devices, only majority-carrier traps were detected. These traps again range from shallow to deep, (3) The carrier concentration around the junction and the density of traps decrease as the CIGS becomes more In(Ga)-rich.

  10. Light Trapping, Absorption and Solar Energy Harvesting by Artificial Materials

    SciTech Connect (OSTI)

    John, Sajeev

    2014-08-15

    We provide designs of thin-film solar cells utilizing optimized photonic-crystal light-trapping and numerical simulations of their solar-to-electrical power conversion efficiencies.

  11. Stories of Discovery & Innovation: Trapping the Light Fantastic...

    Office of Science (SC) Website

    Trapping the Light Fantastic Energy Frontier Research Centers (EFRCs) EFRCs Home Centers ... Print Text Size: A A A Subscribe FeedbackShare Page New solar cell design uses advanced ...

  12. Laser-driven Sisyphus cooling in an optical dipole trap

    SciTech Connect (OSTI)

    Ivanov, Vladyslav V.; Gupta, Subhadeep

    2011-12-15

    We propose a laser-driven Sisyphus-cooling scheme for atoms confined in a far-off resonance optical dipole trap. Utilizing the differential trap-induced ac Stark shift, two electronic levels of the atom are resonantly coupled by a cooling laser preferentially near the trap bottom. After absorption of a cooling photon, the atom loses energy by climbing the steeper potential, and then spontaneously decays preferentially away from the trap bottom. The proposed method is particularly suited to cooling alkaline-earth-metal-like atoms where two-level systems with narrow electronic transitions are present. Numerical simulations for the cases of {sup 88}Sr and {sup 174}Yb demonstrate the expected recoil and Doppler temperature limits. The method requires a relatively small number of scattered photons and can potentially lead to phase-space densities approaching quantum degeneracy in subsecond time scales.

  13. DOE - NNSA/NFO -- News & Views Accident Trap

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

    Accident Traps Four Workers 1,800 Feet below Ground Photo - rescue from 1,800 feet below ... Thousands of workers have completed millions of accident-free hours at this heavy industry ...

  14. Stable Metal-Organic Frameworks Containing Single-Molecule Traps...

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

    Stable Metal-Organic Frameworks Containing Single-Molecule Traps for Enzyme Encapsulation Previous Next List Dawei Feng, Tian-Fu Liu, Jie Su, Mathieu Bosch, Zhangwen Wei, Wei Wan,...

  15. Inspect and Repair Steam Traps - Steam Tip Sheet #1

    SciTech Connect (OSTI)

    2012-01-31

    This revised AMO tip sheet on inspecting and repairing steam traps provides how-to advice for improving industrial steam systems using low-cost, proven practices and technologies.

  16. Electron source for a mini ion trap mass spectrometer

    DOE Patents [OSTI]

    Dietrich, Daniel D.; Keville, Robert F.

    1995-01-01

    An ion trap which operates in the regime between research ion traps which can detect ions with a mass resolution of better than 1:10.sup.9 and commercial mass spectrometers requiring 10.sup.4 ions with resolutions of a few hundred. The power consumption is kept to a minimum by the use of permanent magnets and a novel electron gun design. By Fourier analyzing the ion cyclotron resonance signals induced in the trap electrodes, a complete mass spectra in a single combined structure can be detected. An attribute of the ion trap mass spectrometer is that overall system size is drastically reduced due to combining a unique electron source and mass analyzer/detector in a single device. This enables portable low power mass spectrometers for the detection of environmental pollutants or illicit substances, as well as sensors for on board diagnostics to monitor engine performance or for active feedback in any process involving exhausting waste products.

  17. Electron source for a mini ion trap mass spectrometer

    DOE Patents [OSTI]

    Dietrich, D.D.; Keville, R.F.

    1995-12-19

    An ion trap is described which operates in the regime between research ion traps which can detect ions with a mass resolution of better than 1:10{sup 9} and commercial mass spectrometers requiring 10{sup 4} ions with resolutions of a few hundred. The power consumption is kept to a minimum by the use of permanent magnets and a novel electron gun design. By Fourier analyzing the ion cyclotron resonance signals induced in the trap electrodes, a complete mass spectra in a single combined structure can be detected. An attribute of the ion trap mass spectrometer is that overall system size is drastically reduced due to combining a unique electron source and mass analyzer/detector in a single device. This enables portable low power mass spectrometers for the detection of environmental pollutants or illicit substances, as well as sensors for on board diagnostics to monitor engine performance or for active feedback in any process involving exhausting waste products. 10 figs.

  18. Catch and Release: Reaction Dynamics from a Freed "Tension Trapped...

    Office of Scientific and Technical Information (OSTI)

    Title: Catch and Release: Reaction Dynamics from a Freed "Tension Trapped Transition State" Authors: Wang, J ; Ong, M T ; Kouznetsova, T B ; Lenhardt, J M ; Martinez, T J ; Craig, ...

  19. Electrostatic ion beam trap for electron collision studies

    SciTech Connect (OSTI)

    Heber, O.; Witte, P.D.; Diner, A.; Bhushan, K.G.; Strasser, D.; Toker, Y.; Rappaport, M.L.; Ben-Itzhak, I.; Altstein, N.; Schwalm, D.; Wolf, A.; Zajfman, D.

    2005-01-01

    We describe a system combining an ion beam trap and a low energy electron target in which the interaction between electrons and vibrationally cold molecular ions and clusters can be studied. The entire system uses only electrostatic fields for both trapping and focusing, thus being able to store particles without a mass limit. Preliminary results for the electron impact neutralization of C{sub 2}{sup -} ions and aluminum clusters are presented.

  20. Grooved impactor and inertial trap for sampling inhalable particulate matter

    DOE Patents [OSTI]

    Loo, Billy W.

    1984-01-01

    An inertial trap and grooved impactor for providing a sharp cutoff for particles over 15 microns from entering an inhalable particulate sampler. The impactor head has a tapered surface and is provided with V-shaped grooves. The tapered surface functions for reducing particle blow-off or reentrainment while the grooves prevent particle bounce. Water droplets and any resuspended material over the 15 micron size are collected by the inertial trap and deposited in a reservoir associated with the impactor.

  1. PowerTrap: Ultrafine PM Control without Performance Penalties | Department

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

    of Energy PowerTrap: Ultrafine PM Control without Performance Penalties PowerTrap: Ultrafine PM Control without Performance Penalties 2003 DEER Conference Presentation: Per-Tec Ltd, University of Manchester 2003_deer_kukla.pdf (693.04 KB) More Documents & Publications Plasmatron Fuel Reformer Development and Internal Combustion Engine Vehicle Applications Review of Diesel Emission Control Technology Active Soot Filter Regeneration

  2. Anisotropy in CdSe quantum rods

    SciTech Connect (OSTI)

    Li, Liang-shi

    2003-09-01

    The size-dependent optical and electronic properties of semiconductor nanocrystals have drawn much attention in the past decade, and have been very well understood for spherical ones. The advent of the synthetic methods to make rod-like CdSe nanocrystals with wurtzite structure has offered us a new opportunity to study their properties as functions of their shape. This dissertation includes three main parts: synthesis of CdSe nanorods with tightly controlled widths and lengths, their optical and dielectric properties, and their large-scale assembly, all of which are either directly or indirectly caused by the uniaxial crystallographic structure of wurtzite CdSe. The hexagonal wurtzite structure is believed to be the primary reason for the growth of CdSe nanorods. It represents itself in the kinetic stabilization of the rod-like particles over the spherical ones in the presence of phosphonic acids. By varying the composition of the surfactant mixture used for synthesis we have achieved tight control of the widths and lengths of the nanorods. The synthesis of monodisperse CdSe nanorods enables us to systematically study their size-dependent properties. For example, room temperature single particle fluorescence spectroscopy has shown that nanorods emit linearly polarized photoluminescence. Theoretical calculations have shown that it is due to the crossing between the two highest occupied electronic levels with increasing aspect ratio. We also measured the permanent electric dipole moment of the nanorods with transient electric birefringence technique. Experimental results on nanorods with different sizes show that the dipole moment is linear to the particle volume, indicating that it originates from the non-centrosymmetric hexagonal lattice. The elongation of the nanocrystals also results in the anisotropic inter-particle interaction. One of the consequences is the formation of liquid crystalline phases when the nanorods are dispersed in solvent to a high enough

  3. Applications of Admittance Spectroscopy in Photovoltaic Devices Beyond Majority-Carrier Trapping Defects

    SciTech Connect (OSTI)

    Li, J. V.; Crandall, R. S.; Repins, I. L.; Nardes, A. M.; Levi, D. H.

    2011-01-01

    Admittance spectroscopy is commonly used to characterize majority-carrier trapping defects. In today's practical photovoltaic devices, however, a number of other physical mechanisms may contribute to the admittance measurement and interfere with the data interpretation. Such challenges arise due to the violation of basic assumptions of conventional admittance spectroscopy such as single-junction, ohmic contact, highly conductive absorbers, and measurement in reverse bias. We exploit such violations to devise admittance spectroscopy-based methods for studying the respective origins of 'interference': majority-carrier mobility, non-ohmic contact potential barrier, minority-carrier inversion at heterointerface, and minority-carrier lifetime in a device environment. These methods are applied to a variety of photovoltaic technologies: CdTe, Cu(In, Ga)Se{sub 2}, Si HIT cells, and organic photovoltaic materials.

  4. Applications of Admittance Spectroscopy in Photovoltaic Devices Beyond Majority Carrier Trapping Defects: Preprint

    SciTech Connect (OSTI)

    Li, J. V.; Crandall, R. S.; Repins, I. L.; Nardes, A. M.; Levi, D. H.; Sulima, O.

    2011-07-01

    Admittance spectroscopy is commonly used to characterize majority-carrier trapping defects. In today's practical photovoltaic devices, however, a number of other physical mechanisms may contribute to the admittance measurement and interfere with the data interpretation. Such challenges arise due to the violation of basic assumptions of conventional admittance spectroscopy such as single-junction, ohmic contact, highly conductive absorbers, and measurement in reverse bias. We exploit such violations to devise admittance spectroscopy-based methods for studying the respective origins of 'interference': majority-carrier mobility, non-ohmic contact potential barrier, minority-carrier inversion at hetero-interface, and minority-carrier lifetime in a device environment. These methods are applied to a variety of photovoltaic technologies: CdTe, Cu(In,Ga)Se2, Si HIT cells, and organic photovoltaic materials.

  5. Organization-About-PHaSe-EFRC

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

    About Mission Statement (PDF) Organization Contact Us organization This webpage is provided for legacy archive purposes only, as of 30 April 2015. The day to day operations of the University of Massachusetts Amherst PHaSE EFRC are administered by co-directors. Russell is the Samuel Conte Distingushed Professor of Polymer Science and Engineering, with years of previous experience at IBM Research, over 620 publications and 21 patents for polymer chemistry and physics. Lahti has over 29 years at

  6. SE Great Basin Play Fairway Analysis

    SciTech Connect (OSTI)

    Adam Brandt

    2015-11-15

    This submission includes a Na/K geothermometer probability greater than 200 deg C map, as well as two play fairway analysis (PFA) models. The probability map acts as a composite risk segment for the PFA models. The PFA models differ in their application of magnetotelluric conductors as composite risk segments. These PFA models map out the geothermal potential in the region of SE Great Basin, Utah.

  7. UMass-Resources-PHaSe-EFRC

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

    UMass Resources UMass logo The following links provide information about important local (UMass Amherst) campus and departmental offices and resources, including major interdepartmental research centers that pursue work closely akin to research that was initiated or expanded under PHaSE. The last four links go to sites with energy or research news of potential interest to scientists interested in organic electronic materails. Major UMass User Facilities Vice-Chancellor for Research UMass

  8. 2010 Archives-News-PHaSe-EFRC

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

    0 Archives PHaSE welcomes Dr. Lawrence Friedman as our new Managing Director. Larry comes to us with strong backgrounds in both academic and industrial experience. He is well acquainted with UMass Amherst from his time at Bayer Materials Science, where he was much involved in doctoral level recruiting and in academic/industrial liaison work as Head of University Relations. Before this, he was at Polaroid doing work in flims research as a manager and senior scientist. His academic credentials

  9. 2013 Archives-News-PHaSe-EFRC

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

    4 Archives PHaSE EFRC work was featured in an MRS-TV video production, UMASS Amherst -- Optimal Design: Interdisciplinary Teamwork from Synthesis to Production, that was highlighted on electronic signage throughout the Fall 2014 Boston Materials Research Society meeting. Major vignettes were shown from Maroudas group, DV group, Emrick group. Both faculty and undergraduates/graduates/postdocs described EFRC work and work being carried out by closely allied groups interested in energy-related

  10. SeQuential Pacific Biodiesel LLC | Open Energy Information

    Open Energy Info (EERE)

    Pacific Biodiesel LLC Jump to: navigation, search Name: SeQuential-Pacific Biodiesel LLC Place: Oregon Sector: Biofuels Product: JV between SeQuential Biofuels, Pacific Biodiesel,...

  11. AeroSys: Noncompliance Determination (2010-SE-0302) | Department...

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

    Noncompliance Determination (2010-SE-0302) AeroSys: Noncompliance Determination (2010-SE-0302) April 13, 2010 DOE issued a Notice of Noncompliance Determination to AeroSys, Inc. ...

  12. System and method for trapping and measuring a charged particle in a liquid

    DOE Patents [OSTI]

    Reed, Mark A; Krstic, Predrag S; Guan, Weihua; Zhao, Xiongce

    2013-07-23

    A system and method for trapping a charged particle is disclosed. A time-varying periodic multipole electric potential is generated in a trapping volume. A charged particle under the influence of the multipole electric field is confined to the trapping volume. A three electrode configuration giving rise to a 3D Paul trap and a four planar electrode configuration giving rise to a 2D Paul trap are disclosed.

  13. System and method for trapping and measuring a charged particle in a liquid

    DOE Patents [OSTI]

    Reed, Mark A; Krstic, Predrag S; Guan, Weihua; Zhao, Xiongce

    2012-10-23

    A system and method for trapping a charged particle is disclosed. A time-varying periodic multipole electric potential is generated in a trapping volume. A charged particle under the influence of the multipole electric field is confined to the trapping volume. A three electrode configuration giving rise to a 3D Paul trap and a four planar electrode configuration giving rise to a 2D Paul trap are disclosed.

  14. Photoinduced Surface Oxidation and Its Effect on the Exciton Dynamics of CdSe Quantum Dots

    SciTech Connect (OSTI)

    Hines, Douglas A.; Becker, Matthew A.; Kamat, Prashant V.

    2012-11-14

    With increased interest in semiconductor nanoparticles for use in quantum dot solar cells there comes a need to understand the long-term photostability of such materials. Colloidal CdSe quantum dots (QDs) were suspended in toluene and stored in combinations of light/dark and N{sub 2}/O{sub 2} to simulate four possible benchtop storage environments. CdSe QDs stored in a dark, oxygen-free environment were observed to better retain their optical properties over the course of 90 days. The excited state lifetimes, determined through femtosecond transient absorption spectroscopy, of air-equilibrated samples exposed to light exhibit a decrease in average lifetime (0.81 ns) when compared to samples stored in a nitrogen/dark environment (8.3 ns). A photoetching technique commonly used for controlled reduction of QD size was found to induce energetic trap states to CdSe QDs and accelerate the rate of electron-hole recombination. X-ray absorption near edge structure (XANES) analysis confirms surface oxidation, the extent of which is shown to be dependent on the thickness of the ligand shell.

  15. 2009 Archives-News-PHaSe-EFRC

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

    09 Archives U.S. DOE Announces Energy Frontier Research Centers (08/2009) UMass Amherst EFRC Proposal (08/2009) EFRC Funding Distributed to Successful Centers (08/2009) PHaSE co-director Paul Lahti led off a set of presentations organized by the UMass Amherst Research & Liaison office to meet with a delegation of scientists from various technical research centers of the Gipuzkoa province in the Basque region of northern Spain. The delegation was organized through the Tecnalia Corporation,

  16. 2012 Archives-News-PHaSe-EFRC

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

    2 Archives Tom Russell photo Joint work by Tom Russell, Alex Briseno, and coworkers describes fabrication and a significant degree of device optimization of a low band polymer pDPP/PCBM solar cell, in an article published in Advanced Materials. Photoconversion efficiency up to 5.6% with a fill factor of 60% were obtained. Morphology control based on solvent mixture tuning was critically important for best electrical output. [read more] PHaSE members D. Venkataraman and Tom Russell have edited a

  17. Computer analysis of sodium cold trap design and performance. [LMFBR

    SciTech Connect (OSTI)

    McPheeters, C.C.; Raue, D.J.

    1983-11-01

    Normal steam-side corrosion of steam-generator tubes in Liquid Metal Fast Breeder Reactors (LMFBRs) results in liberation of hydrogen, and most of this hydrogen diffuses through the tubes into the heat-transfer sodium and must be removed by the purification system. Cold traps are normally used to purify sodium, and they operate by cooling the sodium to temperatures near the melting point, where soluble impurities including hydrogen and oxygen precipitate as NaH and Na/sub 2/O, respectively. A computer model was developed to simulate the processes that occur in sodium cold traps. The Model for Analyzing Sodium Cold Traps (MASCOT) simulates any desired configuration of mesh arrangements and dimensions and calculates pressure drops and flow distributions, temperature profiles, impurity concentration profiles, and impurity mass distributions.

  18. Recent progress in tailoring trap-based positron beams

    SciTech Connect (OSTI)

    Natisin, M. R.; Hurst, N. C.; Danielson, J. R.; Surko, C. M.

    2013-03-19

    Recent progress is described to implement two approaches to specially tailor trap-based positron beams. Experiments and simulations are presented to understand the limits on the energy spread and pulse duration of positron beams extracted from a Penning-Malmberg (PM) trap after the particles have been buffer-gas cooled (or heated) in the range of temperatures 1000 {>=} T {>=} 300 K. These simulations are also used to predict beam performance for cryogenically cooled positrons. Experiments and simulations are also presented to understand the properties of beams formed when plasmas are tailored in a PM trap in a 5 tesla magnetic field, then non-adiabatically extracted from the field using a specially designed high-permeability grid to create a new class of electrostatically guided beams.

  19. Optical lattice clock with atoms confined in a shallow trap

    SciTech Connect (OSTI)

    Lemonde, Pierre; Wolf, Peter

    2005-09-15

    We study the trap depth requirement for the realization of an optical clock using atoms confined in a lattice. We show that site-to-site tunneling leads to a residual sensitivity to the atom dynamics hence requiring large depths [(50-100)E{sub r} for Sr] to avoid any frequency shift or line broadening of the atomic transition at the 10{sup -17}-10{sup -18} level. Such large depths and the corresponding laser power may, however, lead to difficulties (e.g., higher-order light shifts, two-photon ionization, technical difficulties) and therefore one would like to operate the clock in much shallower traps. To circumvent this problem we propose the use of an accelerated lattice. Acceleration lifts the degeneracy between adjacents potential wells which strongly inhibits tunneling. We show that using the Earth's gravity, much shallower traps (down to 5E{sub r} for Sr) can be used for the same accuracy goal.

  20. Synthesis and optical study of green light emitting polymer coated CdSe/ZnSe core/shell nanocrystals

    SciTech Connect (OSTI)

    Tripathi, S.K.; Sharma, Mamta

    2013-05-15

    Highlights: ► Synthesis of Polymer coated core CdSe and CdSe/ZnSe core/shell NCs. ► From TEM image, the spherical nature of CdSe and CdSe/ZnSe is obtained. ► Exhibiting green band photoemission peak at 541 nm and 549 nm for CdSe core and CdSe/ZnSe core/shell NCs. ► The shell thickness has been calculated by using superposition of quantum confinement energy model. - Abstract: CdSe/ZnSe Core/Shell NCs dispersed in PVA are synthesized by chemical method at room temperature. This is characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), UV/Vis spectra and photoluminescence spectroscopy (PL). TEM image shows the spherical nature of CdSe/ZnSe core/shell NCs. The red shift of absorption and emission peak of CdSe/ZnSe core/shell NCs as compared to CdSe core confirmed the formation of core/shell. The superposition of quantum confinement energy model is used for calculation of thickness of ZnSe shell.

  1. Photo-instability of CdSe/ZnS quantum dots in poly(methylmethacrylate) film

    SciTech Connect (OSTI)

    Zhang, Hongyi; Liu, Yu; Ye, Xiaoling; Chen, Yonghai

    2013-12-28

    The photo-instability of CdSe/ZnS quantum dots (QDs) has been studied under varied conditions. We discussed the main features of the evolution of photoluminescence (PL) intensity and energy at different laser powers, which showed critical dependences on the environment. The PL red shift in a vacuum showed strong temperature dependence, from which we concluded that the thermal activation energy for trapping states of the charge carriers was about 14.7 meV. Furthermore, the PL spectra showed asymmetric evolution during the laser irradiation, for which two possible explanations were discussed. Those results provided a comprehensive picture for the photo-instability of the colloidal QDs under different conditions.

  2. Three dimensional separation trap based on dielectrophoresis and use thereof

    DOE Patents [OSTI]

    Mariella, Jr., Raymond P.

    2004-05-04

    An apparatus is adapted to separate target materials from other materials in a flow containing the target materials and other materials. A dielectrophoretic trap is adapted to receive the target materials and the other materials. At least one electrode system is provided in the trap. The electrode system has a three-dimensional configuration. The electrode system includes a first electrode and a second electrode that are shaped and positioned relative to each such that application of an electrical voltage to the first electrode and the second electrode creates a dielectrophoretic force and said dielectrophoretic force does not reach zero between the first electrode and the second electrode.

  3. Electron beam ion source and electron beam ion trap (invited)

    SciTech Connect (OSTI)

    Becker, Reinard [Scientific Software Service, Kapellenweg 2a, D-63571 Gelnhausen (Germany); Kester, Oliver [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824 (United States)

    2010-02-15

    The electron beam ion source (EBIS) and its trap variant [electron beam ion trap (EBIT)] celebrated their 40th and 20th anniversary, respectively, at the EBIS/T Symposium 2007 in Heidelberg. These technologically challenging sources of highly charged ions have seen a broad development in many countries over the last decades. In contrast to most other ion sources the recipe of improvement was not ''sorcery'' but a clear understanding of the physical laws and obeying the technological constraints. This review will report important achievements of the past as well as promising developments in the future.

  4. Theory of magic optical traps for Zeeman-insensitive clock transitions in alkali-metal atoms

    SciTech Connect (OSTI)

    Derevianko, Andrei

    2010-05-15

    Precision measurements and quantum-information processing with cold atoms may benefit from trapping atoms with specially engineered, 'magic' optical fields. At the magic trapping conditions, the relevant atomic properties remain immune to strong perturbations by the trapping fields. Here we develop a theoretical analysis of magic trapping for especially valuable Zeeman-insensitive clock transitions in alkali-metal atoms. The involved mechanism relies on applying a magic bias B field along a circularly polarized trapping laser field. We map out these B fields as a function of trapping laser wavelength for all commonly used alkalis. We also highlight a common error in evaluating Stark shifts of hyperfine manifolds.

  5. Differentially pumped dual linear quadrupole ion trap mass spectrometer

    DOE Patents [OSTI]

    Owen, Benjamin C.; Kenttamaa, Hilkka I.

    2015-10-20

    The present disclosure provides a new tandem mass spectrometer and methods of using the same for analyzing charged particles. The differentially pumped dual linear quadrupole ion trap mass spectrometer of the present disclose includes a combination of two linear quadrupole (LQIT) mass spectrometers with differentially pumped vacuum chambers.

  6. Single particle density of trapped interacting quantum gases

    SciTech Connect (OSTI)

    Bala, Renu; Bosse, J.; Pathak, K. N.

    2015-05-15

    An expression for single particle density for trapped interacting gases has been obtained in first order of interaction using Greens function method. Results are easily simplified for homogeneous quantum gases and are found to agree with famous results obtained by Huang-Yang-Luttinger and Lee-Yang.

  7. An extension of the multiple-trapping model

    SciTech Connect (OSTI)

    Shkilev, V. P.

    2012-07-15

    The hopping charge transport in disordered semiconductors is considered. Using the concept of the transport energy level, macroscopic equations are derived that extend a multiple-trapping model to the case of semiconductors with both energy and spatial disorders. It is shown that, although both types of disorder can cause dispersive transport, the frequency dependence of conductivity is determined exclusively by the spatial disorder.

  8. Intra-catalyst Reductant Chemistry in Lean NOx Traps: A Study...

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

    Intra-catalyst Reductant Chemistry in Lean NOx Traps: A Study on Sulfur Effects Intra-catalyst Reductant Chemistry in Lean NOx Traps: A Study on Sulfur Effects Presentation given ...

  9. SulfaTrap(tm): Novel Sorbent to Clean Biogas for Fuel Cell Combined...

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

    SulfaTrap(tm): Novel Sorbent to Clean Biogas for Fuel Cell Combined Heat and Power SulfaTrap(tm): Novel Sorbent to Clean Biogas for Fuel Cell Combined Heat and Power Improving ...

  10. SE-MA-NO Electric Coop | Open Energy Information

    Open Energy Info (EERE)

    SE-MA-NO Electric Coop Jump to: navigation, search Name: SE-MA-NO Electric Coop Place: Missouri Phone Number: (417) 924-3291 Website: www.semano.com Facebook: https:...

  11. MgSe/ZnSe/CdSe coupled quantum wells grown on InP substrate with intersubband absorption covering 1.55??m

    SciTech Connect (OSTI)

    Chen, Guopeng; Shen, Aidong; De Jesus, Joel; Tamargo, Maria C.

    2014-12-08

    The authors report the observation of intersubband (ISB) transitions in the optical communication wavelength region in MgSe/ZnSe/CdSe coupled quantum wells (QWs). The coupled QWs were grown on InP substrates by molecular beam epitaxy. By inserting ZnSe layers to compensate the strain, samples with high structural quality were obtained, as indicated by well resolved satellite peaks in high-resolution x-ray diffraction. The observed ISB transition energies agree well with the calculated values.

  12. Goodman Manufacturing: Order (2011-SE-4301) | Department of Energy

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

    Goodman Manufacturing: Order (2011-SE-4301) Goodman Manufacturing: Order (2011-SE-4301) March 2, 2012 DOE ordered Goodman Manufacturing Company, L.P., to pay a $14,800 civil penalty after finding Goodman had manufactured and distributed in commerce in the U.S. at least 74 units of commercial package air conditioner basic model CPC180*. Goodman Manufacturing: Order (2011-SE-4301) (131.78 KB) More Documents & Publications Goodman Manufacturing: Proposed Penalty (2011-SE-4301) Goodman

  13. Barron: Order (2013-SE-5402) | Department of Energy

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

    Order (2013-SE-5402) Barron: Order (2013-SE-5402) March 22, 2016 DOE ordered Barron Lighting Group, Inc. to pay a $22,849 civil penalty after finding Barron had manufactured and distributed in commerce in the U.S. 429 units of various noncompliant metal halide lamp fixtures. The Order adopted a Compromise Agreement, which reflected settlement terms between DOE and Barron. Barron: Order (2013-SE-5402) (19.24 KB) More Documents & Publications Barron: Noncompliance Determination (2013-SE-5402)

  14. Probing Interfacial Electronic States in CdSe Quantum Dots using Second Harmonic Generation Spectroscopy

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

    Doughty, Benjamin L.; Ma, Yingzhong; Shaw, Robert W

    2015-01-07

    Understanding and rationally controlling the properties of nanomaterial surfaces is a rapidly expanding field of research due to the dramatic role they play on the optical and electronic properties vital to light harvesting, emitting and detection technologies. This information is essential to the continued development of synthetic approaches designed to tailor interfaces for optimal nanomaterial based device performance. In this work, closely spaced electronic excited states in model CdSe quantum dots (QDs) are resolved using second harmonic generation (SHG) spectroscopy, and the corresponding contributions from surface species to these states are assessed. Two distinct spectral features are observed in themore » SHG spectra, which are not readily identified in linear absorption and photoluminescence excitation spectra. These features include a weak band at 395 6 nm, which coincides with transitions to the 2S1/2 1Se state, and a much more pronounced band at 423 4 nm arising from electronic transitions to the 1P3/2 1Pe state. Chemical modification of the QD surfaces through oxidation resulted in disappearance of the SHG band corresponding to the 1P3/2 1Pe state, indicating prominent surface contributions. Signatures of deep trap states localized on the surfaces of the QDs are also observed. We further find that the SHG signal intensities depend strongly on the electronic states being probed and their relative surface contributions, thereby offering additional insight into the surface specificity of SHG signals from QDs.« less

  15. The role of ligands in the optical and electronic spectra of CdSe nanoclusters

    SciTech Connect (OSTI)

    Kilina, Svletana; Sergei, Ivanov A; Victor, Klimov I; Sergei, Tretiak

    2008-01-01

    We investigate the impact of ligands on morphology, electronic structure, and optical response of the Cd33Se33 cluster, which already overlapps in size with the smallest synthesized CdSe quantum dots (QDs). Our Density Functional Theory (DFT) calculations demonstrate significant surface reorganization both for the bare cluster and for the cluster capped by amine and phosphine oxide ligand models. We observe strong surface-ligand interactions leading to substantial charge redistribution and polarization effects on the surface. This effect results in the appearance of hybridized states, where the electronic density is spread over the cluster and the ligands. Neither the ligand's nor hybridized molecular orbitals appear as trap states inside or near the band gap of the QD. Instead, being optically dark, dense hybridized states from the edges of the valence and the conduction bands could open new relaxation channels for high energy photoexcitations. Comparing quantum dots passivated by different ligands, we found that hybridized states are denser in at the edge of the conduction band of the cluster ligated with phosphine oxide molecules than that with primary amines. Such a different manifestation of ligand binding may potentially lead to the faster electron relaxation in dots passivated by phosphine oxide than by amine ligands, which is in agreement with experimental data.

  16. SE-72/AS-72 generator system based on Se extraction/ As reextraction

    DOE Patents [OSTI]

    Fassbender, Michael Ernst; Ballard, Beau D

    2013-09-10

    The preparation of a .sup.72Se/.sup.72As radioisotope generator involves forming an acidic aqueous solution of an irradiated alkali bromide target such as a NaBr target, oxidizing soluble bromide in the solution to elemental bromine, removing the elemental bromine, evaporating the resulting solution to a residue, removing hydrogen chloride from the residue, forming an acidic aqueous solution of the residue, adding a chelator that selectively forms a chelation complex with selenium, and extracting the chelation complex from the acidic aqueous solution into an organic phase. As the .sup.72Se generates .sup.72As in the organic phase, the .sup.72As may be extracted repeatedly from the organic phase with an aqueous acid solution.

  17. Bose gas in a single-beam optical dipole trap

    SciTech Connect (OSTI)

    Simon, Lena; Strunz, Walter T.

    2010-06-15

    We study an ultracold Bose gas in an optical dipole trap consisting of one single focused laser beam. An analytical expression for the corresponding density of states beyond the usual harmonic approximation is obtained. We are thus able to discuss the existence of a critical temperature for Bose-Einstein condensation and find that the phase transition must be enabled by a cutoff near the threshold. Moreover, we study the dynamics of evaporative cooling and observe significant deviations from the findings for the well-established harmonic approximation. Furthermore, we investigate Bose-Einstein condensates in such a trap in Thomas-Fermi approximation and determine analytical expressions for chemical potential, internal energy, and Thomas-Fermi radii beyond the usual harmonic approximation.

  18. Real-time calibration of a feedback trap

    SciTech Connect (OSTI)

    Gavrilov, Momčilo; Jun, Yonggun; Bechhoefer, John

    2014-09-15

    Feedback traps use closed-loop control to trap or manipulate small particles and molecules in solution. They have been applied to the measurement of physical and chemical properties of particles and to explore fundamental questions in the non-equilibrium statistical mechanics of small systems. These applications have been hampered by drifts in the electric forces used to manipulate the particles. Although the drifts are small for measurements on the order of seconds, they dominate on time scales of minutes or slower. Here, we show that a recursive maximum likelihood (RML) algorithm can allow real-time measurement and control of electric and stochastic forces over time scales of hours. Simulations show that the RML algorithm recovers known parameters accurately. Experimental estimates of diffusion coefficients are also consistent with expected physical properties.

  19. Dipole Excitation With A Paul Ion Trap Mass Spectrometer

    SciTech Connect (OSTI)

    MacAskill, J. A.; Madzunkov, S. M.; Chutjian, A.

    2011-06-01

    Preliminary results are presented for the use of an auxiliary radiofrequency (rf) excitation voltage in combination with a high purity, high voltage rf generator to perform dipole excitation within a high precision Paul ion trap. These results show the effects of the excitation frequency over a continuous frequency range on the resultant mass spectra from the Paul trap with particular emphasis on ion ejection times, ion signal intensity, and peak shapes. Ion ejection times are found to decrease continuously with variations in dipole frequency about several resonant values and show remarkable symmetries. Signal intensities vary in a complex fashion with numerous resonant features and are driven to zero at specific frequency values. Observed intensity variations depict dipole excitations that target ions of all masses as well as individual masses. Substantial increases in mass resolution are obtained with resolving powers for nitrogen increasing from 114 to 325.

  20. Constructive polarization modulation for coherent population trapping clock

    SciTech Connect (OSTI)

    Yun, Peter Danet, Jean-Marie; Holleville, David; Clercq, Emeric de; Guérandel, Stéphane

    2014-12-08

    We propose a constructive polarization modulation scheme for atomic clocks based on coherent population trapping (CPT). In this scheme, the polarization of a bichromatic laser beam is modulated between two opposite circular polarizations to avoid trapping the atomic populations in the extreme Zeeman sublevels. We show that if an appropriate phase modulation between the two optical components of the bichromatic laser is applied synchronously, the two CPT dark states which are produced successively by the alternate polarizations add constructively. Measured CPT resonance contrasts up to 20% in one-pulse CPT and 12% in two-pulse Ramsey-CPT experiments are reported, demonstrating the potential of this scheme for applications to high performance atomic clocks.

  1. Trapping of dust and dust acoustic waves in laboratory plasmas

    SciTech Connect (OSTI)

    Prabhakara, H.R.; Tanna, V.L. [Institute for Plasma Research, Bhat, Gandhinagar 382 424 (India)] [Institute for Plasma Research, Bhat, Gandhinagar 382 424 (India)

    1996-08-01

    Trapping of negatively charged dust particles is observed in a hot cathode plasma discharge when a layer of dust is exposed to the plasma. The particles are visible in the scattered He{endash}Ne laser light. The trajectories of individual particles have been photographed. The dust particles are excluded from the sheath region of any object in the plasma. The intensity of scattered light as well as the potential on a floating Langmuir probe show coherent fluctuations in the frequency range 1{endash}15 Hz. After several hours of exposure to the plasma, the dust layer develops striations similar to those on sand dunes. Trapping of dust particles by the plasma and the possible identification of the observed low-frequency fluctuations with dust acoustic waves are discussed. {copyright} {ital 1996 American Institute of Physics.}

  2. Two-dimensional GaSe/MoSe2 misfit bilayer heterojunctions by van der Waals epitaxy

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

    Li, Xufan; Lin, Ming-Wei; Lin, Junhao; Huang, Bing; Puretzky, Alexander A.; Ma, Cheng; Wang, Kai; Zhou, Wu; Pantelides, Sokrates T.; Chi, Miaofang; et al

    2016-04-01

    Two-dimensional (2D) heterostructures hold the promise for future atomically-thin electronics and optoelectronics due to their diverse functionalities. While heterostructures consisting of different transition metal dichacolgenide monolayers with well-matched lattices and novel physical properties have been successfully fabricated via van der Waals (vdW) or edge epitaxy, constructing heterostructures from monolayers of layered semiconductors with large lattice misfits still remains challenging. Here, we report the growth of monolayer GaSe/MoSe2 heterostructures with large lattice misfit by two-step chemical vapor deposition (CVD). Both vertically stacked and lateral heterostructures are demonstrated. The vertically stacked GaSe/MoSe2 heterostructures exhibit vdW epitaxy with well-aligned lattice orientation between themore » two layers, forming an incommensurate vdW heterostructure. However, the lateral heterostructures exhibit no lateral epitaxial alignment at the interface between GaSe and MoSe2 crystalline domains. Instead of a direct lateral connection at the boundary region where the same lattice orientation is observed between GaSe and MoSe2 monolayer domains in lateral GaSe/MoSe2 heterostructures, GaSe monolayers are found to overgrow MoSe2 during CVD, forming a stripe of vertically stacked vdW heterostructure at the crystal interface. Such vertically-stacked vdW GaSe/MoSe2 heterostructures are shown to form p-n junctions with effective transport and separation of photo-generated charge carriers between layers, resulting in a gate-tunable photovoltaic response. In conclusion, these GaSe/MoSe2 vdW heterostructures should have applications as gate-tunable field-effect transistors, photodetectors, and solar cells.« less

  3. Spectral photoresponse of ZnSe/GaAs(001) heterostructures with CdSe ultra-thin quantum well insertions

    SciTech Connect (OSTI)

    Valverde-Chvez, D. A.; Sutara, F.; Hernndez-Caldern, I.

    2014-05-15

    We present a study of the spectral photoresponse (SPR) of ZnSe/GaAs(001) heterostructures for different ZnSe film thickness with and without CdSe ultra-thin quantum well (UTQW) insertions. We observe a significant increase of the SPR of heterostructures containing 3 monolayer thick CdSe UTQW insertions; these results encourage their use in photodetectors and solar cells.

  4. Hydrogen trapping, diffusion, and recombination in austenitic stainless steels

    SciTech Connect (OSTI)

    Langley, R.A.

    1984-01-01

    Trapping, diffusion, and recombination of hydrogen in austenitic stainless steels are reviewed. It is suggested that since all of these processes are strongly interdependent and since the measured recombination rates are found to vary four orders of magnitude at any temperature, the data analysis techniques used to date are insufficient. A two-region diffusion model with surface recombination is proposed in which the surface layer is characterized by a smaller diffusion coefficient than the bulk.

  5. Qualitative analysis of trapped Dirac fermions in graphene

    SciTech Connect (OSTI)

    Jakubsk, Vt Krej?i?k, David

    2014-10-15

    We study the confinement of Dirac fermions in graphene and in carbon nanotubes by an external magnetic field, mechanical deformations or inhomogeneities in the substrate. By applying variational principles to the square of the Dirac operator, we obtain sufficient and necessary conditions for confinement of the quasi-particles. The rigorous theoretical results are illustrated on the realistic examples of the three classes of traps.

  6. Twinning effect on photoluminescence spectra of ZnSe nanowires

    SciTech Connect (OSTI)

    Xu, Jing; Wang, Chunrui Wu, Binhe; Xu, Xiaofeng; Chen, Xiaoshuang; Oh, Hongseok; Baek, Hyeonjun; Yi, Gyu-Chul

    2014-11-07

    Bandgap engineering in a single material along the axial length of nanowires may be realized by arranging periodic twinning, whose twin plane is vertical to the axial length of nanowires. In this paper, we report the effect of twin on photoluminescence of ZnSe nanowires, which refers to the bandgap of it. The exciton-related emission peaks of transverse twinning ZnSe nanowires manifest a 10-meV-blue-shift in comparison with those of longitudinal twinning ZnSe nanowires. The blue-shift is attributed to quantum confinement effect, which is influenced severely by the proportion of wurtzite ZnSe layers in ZnSe nanowires.

  7. Observation of cold Rb{sub 2} molecules trapped in an optical dipole trap using a laser-pulse-train technique

    SciTech Connect (OSTI)

    Menegatti, Carlos R.; Marangoni, Bruno S.; Marcassa, Luis G.

    2011-11-15

    In this work, we have developed and characterized a laser-pulse-train technique to observe cold Rb{sub 2} molecules trapped in an optical dipole trap. The molecules are produced in a magneto-optical trap, and then loaded into a crossed optical dipole trap. The time evolution of the molecular population is obtained by applying a laser pulse train, which photoionizes the ground-state molecules through intermediate molecular bands. Our results show that this technique allows us to obtain a faster data acquisition rate of the time evolution of the molecule population than other techniques.

  8. WATER TRAPPING ON TIDALLY LOCKED TERRESTRIAL PLANETS REQUIRES SPECIAL CONDITIONS

    SciTech Connect (OSTI)

    Yang, Jun; Abbot, Dorian S.; Liu, Yonggang; Hu, Yongyun

    2014-12-01

    Surface liquid water is essential for standard planetary habitability. Calculations of atmospheric circulation on tidally locked planets around M stars suggest that this peculiar orbital configuration lends itself to the trapping of large amounts of water in kilometers-thick ice on the night side, potentially removing all liquid water from the day side where photosynthesis is possible. We study this problem using a global climate model including coupled atmosphere, ocean, land, and sea ice components as well as a continental ice sheet model driven by the climate model output. For a waterworld, we find that surface winds transport sea ice toward the day side and the ocean carries heat toward the night side. As a result, nightside sea ice remains O(10m) thick and nightside water trapping is insignificant. If a planet has large continents on its night side, they can grow ice sheets O(1000m) thick if the geothermal heat flux is similar to Earth's or smaller. Planets with a water complement similar to Earth's would therefore experience a large decrease in sea level when plate tectonics drives their continents onto the night side, but would not experience complete dayside dessiccation. Only planets with a geothermal heat flux lower than Earth's, much of their surface covered by continents, and a surface water reservoir O(10%) of Earth's would be susceptible to complete water trapping.

  9. Single microbe trap and release in sub-microfluidics

    SciTech Connect (OSTI)

    Vasdekis, Andreas E.

    2013-05-08

    Lab-on-a-chip systems have substantially impacted the way life-sciences are explored; life on earth, however, comprises mostly of microbes, which due to their sub-micron dimensions and high mobility are more challenging to dynamically manipulate on-a-chip. To address this challenge, we developed a high resolution microfluidic system (submicrofluidics) fabricated by direct electron beam lithography that is capable of trapping single microbes and releasing them upon demand. The fabrication method enabled the integration of sub-micron indentations (400 nm) with millimetre-scale fluidic channels rapidly in a single processing step. The larger channels deliver the cell suspension and reagents, while the sub-micron indentations immobilize the cells by locally increasing the hydrodynamic resistance. By volume exclusion, single cell trapping was possible in this system without any surface treatment. By increasing the flow rate, the microbes overcome the trap barrier and pass through the narrow indentation without undergoing lysis with kinetics that depend on their size. The fabrication method and its performance are described, along with microbial characterisations using E. coli.

  10. X-ray irradiation induced changes in electron transport in stabilized a-Se photoconductors

    SciTech Connect (OSTI)

    Walornyj, M.; Kasap, S. O.

    2013-12-07

    We have examined the effect of high-dose x-ray irradiation on electron transport in stabilized amorphous selenium (a-Se) x-ray photoconductive films (of the type used in x-ray image detectors) by measuring the electron lifetime ?{sub e} through interrupted-field time-of-flight experiments. X-ray induced effects have been examined through two types of experiments. In recovery experiments, the a-Se was preirradiated with and without an applied field (5 V/?m) during irradiation with sufficient dose (typically ?20 Gy at 21 C) to significantly reduce the electron lifetime by ?50%, and then the recovery of the lifetime was monitored as a function of time at three different temperatures, 10 C, 21 C, and 35 C. The lifetime recovery kinetics was exponential with a relaxation time ?{sub r} that is thermally activated with an activation energy of 1.66 eV. ?{sub r} is a few hours at 21 C and only a few minutes at 35 C. In experiments examining the irradiation induced effects, the a-Se film was repeatedly exposed to x-ray radiation and the changes in the drift mobility and lifetime were monitored as a function of accumulated dose D. There was no observable change in the drift mobility. At 21 C, the concentration of x-ray induced deep traps (or capture centers), N{sub d}, increases linearly with D (N{sub d} ? D) whereas at 35 C, the recovery process prevents a linear increase in N{sub d} with D, and N{sub d} saturates. In all cases, even under high dose irradiation (?50 Gy), the lifetime was recoverable to its original equilibrium (pre-exposure) value within a few relaxation times.

  11. Ion Trap Array-Based Systems And Methods For Chemical Analysis

    DOE Patents [OSTI]

    Whitten, William B [Oak Ridge, TN; Ramsey, J Michael [Knoxville, TN

    2005-08-23

    An ion trap-based system for chemical analysis includes an ion trap array. The ion trap array includes a plurality of ion traps arranged in a 2-dimensional array for initially confining ions. Each of the ion traps comprise a central electrode having an aperture, a first and second insulator each having an aperture sandwiching the central electrode, and first and second end cap electrodes each having an aperture sandwiching the first and second insulator. A structure for simultaneously directing a plurality of different species of ions out from the ion traps is provided. A spectrometer including a detector receives and identifies the ions. The trap array can be used with spectrometers including time-of-flight mass spectrometers and ion mobility spectrometers.

  12. Cesium trapping characteristics on fly ash filter according to different carrier gases

    SciTech Connect (OSTI)

    Shin, Jin-Myeong; Park, Jang-Jin; Song, Kee-Chan

    2007-07-01

    Fly ash, which is a kind of waste from a coal fired power plant, has been used as a trapping material because it contains silica and alumina suitable for forming pollucite (CsAlSi{sub 2}O{sub 6}). Fly ash is sintered in order to fabricate it into a self-standing filter. The effect of a carrier gas on a cesium trapping quantity is investigated to analyze the cesium trapping characteristics by the fly ash filter in a lab-scale experimental apparatus. The chemical form of the cesium trapped on the filter after trapping cesium is identified to be a pollucite phase regardless of the type of carrier gas. The trapping efficiency of cesium by the fly ash filter under the air and NO{sub x}/air conditions is up to 99.0 %. However, the trapping efficiency of the cesium under the SO{sub x} condition was decreased to 80.0 %. (authors)

  13. Imaging electronic trap states in perovskite thin films with combined fluorescence and femtosecond transient absorption microscopy

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

    Xiao, Kai; Ma, Ying -Zhong; Simpson, Mary Jane; Doughty, Benjamin; Yang, Bin

    2016-04-22

    Charge carrier trapping degrades the performance of organometallic halide perovskite solar cells. To characterize the locations of electronic trap states in a heterogeneous photoactive layer, a spatially resolved approach is essential. Here, we report a comparative study on methylammonium lead tri-iodide perovskite thin films subject to different thermal annealing times using a combined photoluminescence (PL) and femtosecond transient absorption microscopy (TAM) approach to spatially map trap states. This approach coregisters the initially populated electronic excited states with the regions that recombine radiatively. Although the TAM images are relatively homogeneous for both samples, the corresponding PL images are highly structured. Themore » remarkable variation in the PL intensities as compared to transient absorption signal amplitude suggests spatially dependent PL quantum efficiency, indicative of trapping events. Furthermore, detailed analysis enables identification of two trapping regimes: a densely packed trapping region and a sparse trapping area that appear as unique spatial features in scaled PL maps.« less

  14. Thermoelectric transport of Se-rich Ag{sub 2}Se in normal phases and phase transitions

    SciTech Connect (OSTI)

    Mi, Wenlong; Lv, Yanhong; Qiu, Pengfei; Shi, Xun E-mail: cld@mail.sic.ac.cn; Chen, Lidong E-mail: cld@mail.sic.ac.cn; Zhang, Tiansong

    2014-03-31

    Small amount of Se atoms are used to tune the carrier concentrations (n{sub H}) and electrical transport in Ag{sub 2}Se. Significant enhancements in power factor and thermoelectric figure of merit (zT) are observed in the compositions of Ag{sub 2}Se{sub 1.06} and Ag{sub 2}Se{sub 1.08}. The excessive Se atoms do not change the intrinsically electron-conducting character in Ag{sub 2}Se. The detailed analysis reveals the experiment optimum carrier concentration in Ag{sub 2}Se is around 5??10{sup 18}?cm{sup ?3}. We also investigate the temperature of maximum zT and the thermoelectric transport during the first order phase transitions using the recently developed measurement system.

  15. Confined lattice dynamics of single and quadruple SnSe bilayers in [(SnSe) 1.04 ] m [MoSe 2 ] n ferecrystals

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

    Klobes, Benedikt; Hu, Michael Y.; Beekman, Matt; Johnson, David C.; Hermann, Raphaël P.

    2015-11-30

    The Sn specific densities of phonon states in the SnSe subunits of [(SnSe)1.04]m[MoSe2]n ferecrystals with (m,n) = (1,1), (4,1) and in bulk SnSe were derived from nuclear inelastic scattering by the 119Sn M ssbauer resonance. When using different measurement configurations, phonons with polarization parallel and perpendicular to the ferecrystal plane were specifically probed. Vibrational properties and phonon spectral weight are found to strongly depend on the phonon polarization and layer count m. Moreover, a highly peculiar feature of these ferecrystal densities of phonon states is the emergence of rather sharp high energy vibrational modes polarized perpendicular to the ferecrystal plane,more » which contrasts with usual findings in thin layered structures and nanostructured materials in general, and a depletion of modes with a gap appearing between acoustic and high energy modes. The spectral weight of these phonons depends on the overall SnSe content, m, but cannot be unambiguously attributed to SnSe MoSe2 interfaces. Considering the low energy part of lattice dynamics, ferecrystals exhibit rather low average phonon group velocities as compared to the speed of sound in the long wavelength limit. For the (1,1) ferecrystal, this effect is most pronounced for vibrations polarized in the ferecrystal plane. Therefore, an experimental microscopic origin for the vibrational and bonding anisotropy in subunits of ferecrystals is provided.« less

  16. CuInSe/sub 2/-based photoelectrochemical cells: their use in characterization of thin CuInSe/sub 2/ films, and as photovoltaic cells per se

    SciTech Connect (OSTI)

    Cahen, D.; Chen, Y.W.; Ireland, P.J.; Noufi, R.; Turner, J.A.; Rincon, C.; Bachmann, K.J.

    1984-05-01

    Photoelectrochemistry has been employed to characterize the p-CuInSe/sub 2/ component of the CdS/CuInSe/sub 2/ on-metal and a nonaqueous electrolyte containing a redox couple not specifically adsorbed onto the semiconductor, we can test the films for photovoltaic activity and obtain effective electronic properties of them, before CdS deposition, in a nondestructive manner. Electrochemical decomposition of CuInSe/sub 2/ was investigated in acetonitrile solutions to determine the mechanism of decomposition (n and p) in the dark and under illumination. Electrochemical, solution chemical and surface analyses confirmed at the light-assisted decomposition of CuInSe/sub 2/ resulted in metal ions and elemental chalcogen. On the basis of the results from the electrochemical decomposition, and studies on the solid state chemistry of the (Cu/sub 2/Se)/sub x/(In/sub 2/Se/sub 3/)/sub 1-x/ system and surface analyses, the CuInSe/sub 2//polyiodide interface was stabilized and up to 11.7% conversion efficiencies were obtained.

  17. Influence of local capillary trapping on containment system effectiveness

    SciTech Connect (OSTI)

    Bryant, Steven

    2014-03-31

    Immobilization of CO2 injected into deep subsurface storage reservoirs is a critical component of risk assessment for geologic CO2 storage (GCS). Local capillary trapping (LCT) is a recently established mode of immobilization that arises when CO2 migrates due to buoyancy through heterogeneous storage reservoirs. This project sought to assess the amount and extent of LCT expected in storage formations under a range of injection conditions, and to confirm the persistence of LCT if the seal overlying the reservoir were to lose its integrity. Numerical simulation using commercial reservoir simulation software was conducted to assess the influence of injection. Laboratory experiments, modeling and numerical simulation were conducted to assess the effect of compromised seal integrity. Bench-scale (0.6 m by 0.6 m by 0.03 m) experiments with surrogate fluids provided the first empirical confirmation of the key concepts underlying LCT: accumulation of buoyant nonwetting phase at above residual saturations beneath capillary barriers in a variety of structures, which remains immobile under normal capillary pressure gradients. Immobilization of above-residual saturations is a critical distinction between LCT and the more familiar “residual saturation trapping.” To estimate the possible extent of LCT in a storage reservoir an algorithm was developed to identify all potential local traps, given the spatial distribution of capillary entry pressure in the reservoir. The algorithm assumes that the driving force for CO2 migration can be represented as a single value of “critical capillary entry pressure” Pc,entrycrit, such that cells with capillary entry pressure greater/less than Pc,entrycrit act as barriers/potential traps during CO2 migration. At intermediate values of Pc,entrycrit, the barrier regions become more laterally extensive in the reservoir

  18. Point defects in CdTexSe1-x crystals grown from a Te-rich solution for applications in detecting radiation

    SciTech Connect (OSTI)

    Gul, R.; Roy, U. N.; Bolotnikov, A. E.; Camarda, G. S.; Cui, Y.; Hossain, A.; Lee, W.; Yang, G.; Burger, A.; James, R. B.; Cui, Y.

    2015-04-15

    We investigated cadmium telluride selenide (CdTeSe) crystals, newly grown by the Traveling Heater Method (THM), for the presence and abundance of point defects. Deep Level Transient spectroscopy (I-DLTS) was used to determine the energies of the traps, their capture cross sections, and densities. The bias across the detectors was varied from (1–30) V. Four types of point defects were identified, ranging from 10 meV to 0.35 eV. Two dominant traps at energies of 0.18 eV and 0.14 eV were studied in depth. Cd vacancies are found at lower concentrations than other point defects present in the material.

  19. Point defects in CdTexSe1-x crystals grown from a Te-rich solution for applications in detecting radiation

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

    Gul, R.; Roy, U. N.; Bolotnikov, A. E.; Camarda, G. S.; Cui, Y.; Hossain, A.; Lee, W.; Yang, G.; Burger, A.; James, R. B.; et al

    2015-04-15

    We investigated cadmium telluride selenide (CdTeSe) crystals, newly grown by the Traveling Heater Method (THM), for the presence and abundance of point defects. Deep Level Transient spectroscopy (I-DLTS) was used to determine the energies of the traps, their capture cross sections, and densities. The bias across the detectors was varied from (1–30) V. Four types of point defects were identified, ranging from 10 meV to 0.35 eV. Two dominant traps at energies of 0.18 eV and 0.14 eV were studied in depth. Cd vacancies are found at lower concentrations than other point defects present in the material.

  20. Perlick: Agreement (2010-SE-0109) | Department of Energy

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

    Perlick: Agreement (2010-SE-0109) Perlick: Agreement (2010-SE-0109) February 7, 2011 DOE and Perlick Residential & Hospitality Products entered into a Compromise Agreement in which Perlick agreed to pay a $5,000 civil penalty after DOE found that Perlick had manufactured and distributed in commerce in the U.S. model HP72ROO-S, a noncompliant refrigerator. The Compromise Agreement reflected the settlement terms between DOE and Perlick. Perlick: Agreement (2010-SE-0109) (240.67 KB) More

  1. Research Forum Schedule-Research-PHaSe-EFRC

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

    Research Forum Schedule PHaSE Research Fora and Talks This webpage is provided for legacy archive purposes only, as of 30 April 2015.

  2. SE Idaho Load Service Update - June 10, 2015

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

    SE-Idaho-Load-Service-Update---June-10,-2015 Sign In About | Careers | Contact | Investors | bpa.gov Search Doing Business Expand Doing Business Customer Involvement Expand...

  3. U-105:Oracle Java SE Critical Patch Update Advisory

    Broader source: Energy.gov [DOE]

    Multiple vulnerabilities were reported in Oracle Java SE. A remote user can execute arbitrary code on the target system. A remote user can cause denial of service conditions.

  4. SeQuential Biofuels LLC | Open Energy Information

    Open Energy Info (EERE)

    Biofuels LLC Jump to: navigation, search Name: SeQuential Biofuels LLC Place: Portland, Oregon Zip: 97231 Sector: Biofuels Product: A biofuels marketing and distribution company...

  5. Photovoltaic cell with light trapping for enhanced efficiency

    DOE Patents [OSTI]

    Brener, Igal; Fofang, Nche Tumasang; Luk, Ting S.

    2015-11-19

    The efficiency of a photovoltaic cell is enhanced by light trapping using Mie-scattering nanostructures. In one embodiment, an array of nanocylinders is formed on the front surface of a silicon film to enhance forward scattering into the film, and an array of nanocylinders is formed on the back surface to enhance backscattering so that more light is absorbed within the silicon film. In an alternate embodiment, a mirror layer is formed on the back surface of the silicon film to reflect light within the film back toward the front-surface nanocylinder array.

  6. Nonideal fishbone instability excited by trapped energetic electrons

    SciTech Connect (OSTI)

    Liu, Y.; Tang, C. J.; Wang, Z. T.; Long, Y. X.; Dong, J. Q.

    2013-03-15

    It is shown that trapped energetic electrons can resonate with the collisionless m = 1 nonideal kink mode, therefore exciting the nonideal e-fishbone, which would often lead to a drop in soft x-ray emissivity and frequency chirping. The theory predictions agree well with the experimental observations of e-fishbone on HL-2A. It is also found that the effects of MHD energy of background plasma might be the reason for the observed phenomena: frequency chirping up and down, and V-font-style sweeping.

  7. Selective interactions in trapped ions: State reconstruction and quantum logic

    SciTech Connect (OSTI)

    Solano, E.

    2005-01-01

    We propose the implementation of selective interactions of atom-motion subspaces in trapped ions. These interactions yield resonant exchange of population inside a selected subspace, leaving the others in a highly dispersive regime. Selectivity allows us to generate motional Fock (and other nonclassical) states with high purity out of a wide class of initial states, and becomes an unconventional cooling mechanism when the ground state is chosen. Individual population of number states can be distinctively measured, as well as the motional Wigner function. Furthermore, a protocol for implementing quantum logic through a suitable control of selective subspaces is presented.

  8. Selective control of the symmetric Dicke subspace in trapped ions

    SciTech Connect (OSTI)

    Lopez, C. E.; Retamal, J. C.; Solano, E.

    2007-09-15

    We propose a method of manipulating selectively the symmetric Dicke subspace in the internal degrees of freedom of N trapped ions. We show that the direct access to ionic-motional subspaces, based on a suitable tuning of motion-dependent ac Stark shifts, induces a two-level dynamics involving previously selected ionic Dicke states. In this manner, it is possible to produce, sequentially and unitarily, ionic Dicke states with increasing excitation number. Moreover, we propose a probabilistic technique to produce directly any ionic Dicke state assuming suitable initial conditions.

  9. Rovibrational spectroscopy of trapped molecular hydrogen ions at millikelvin temperatures

    SciTech Connect (OSTI)

    Roth, B.; Koelemeij, J. C. J.; Daerr, H.; Schiller, S.

    2006-10-15

    We report a high-resolution spectroscopic study of molecular ions at millikelvin temperatures. We measured several rovibrational infrared transitions in HD{sup +} molecular ions, stored in a radio-frequency trap and sympathetically cooled to {approx_equal}20 mK by laser-cooled Be{sup +} ions. We observed hyperfine splitting of the lines, in good agreement with theoretical predictions. The transitions were detected by monitoring the decrease in ion number after selective photodissociation of HD{sup +} ions in the upper vibrational state. The method described here is expected to be generally applicable.

  10. Confocal shift interferometry of coherent emission from trapped dipolar excitons

    SciTech Connect (OSTI)

    Repp, J.; Schinner, G. J.; Schubert, E.; Rai, A. K.; Wieck, A. D.; Reuter, D.; Wurstbauer, U.; Holleitner, A. W.; and others

    2014-12-15

    We introduce a confocal shift-interferometer based on optical fibers. The presented spectroscopy allows measuring coherence maps of luminescent samples with a high spatial resolution even at cryogenic temperatures. We apply the spectroscopy onto electrostatically trapped, dipolar excitons in a semiconductor double quantum well. We find that the measured spatial coherence length of the excitonic emission coincides with the point spread function of the confocal setup. The results are consistent with a temporal coherence of the excitonic emission down to temperatures of 250 mK.

  11. Atomic clock based on transient coherent population trapping

    SciTech Connect (OSTI)

    Guo Tao; Deng Ke; Chen Xuzong; Wang Zhong

    2009-04-13

    We proposed a scheme to implement coherent population trapping (CPT) atomic clock based on the transient CPT phenomenon. We proved that the transient transmitted laser power in a typical {lambda} system near CPT resonance features as a damping oscillation. Also, the oscillating frequency is exactly equal to the frequency detuning from the atomic hyperfine splitting. Therefore, we can directly measure the frequency detuning and then compensated to the output frequency of microwave oscillator to get the standard frequency. By this method, we can further simplify the structure of CPT atomic clock, and make it easier to be digitized and miniaturized.

  12. Charge transfer fluorescence and 34 nm exciton diffusion length in polymers with electron acceptor end traps

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

    Zaikowski, Lori; Mauro, Gina; Bird, Matthew; Karten, Brianne; Asaoka, Sadayuki; Wu, Qin; Cook, Andrew R.; Miller, John R.

    2014-12-22

    Photoexcitation of conjugated poly-2,7-(9,9-dihexylfluorene) polyfluorenes with naphthylimide (NI) and anthraquinone (AQ) electron-acceptor end traps produces excitons that form charge transfer states at the end traps. Intramolecular singlet exciton transport to end traps was examined by steady state fluorescence for polyfluorenes of 17 to 127 repeat units in chloroform, dimethylformamide (DMF), tetrahydrofuran (THF), and p-xylene. End traps capture excitons and form charge transfer (CT) states at all polymer lengths and in all solvents. The CT nature of the end-trapped states is confirmed by their fluorescence spectra, solvent and trap group dependence and DFT descriptions. Quantum yields of CT fluorescence are asmore » large as 46%. This strong CT emission is understood in terms of intensity borrowing. Energies of the CT states from onsets of the fluorescence spectra give the depths of the traps which vary with solvent polarity. For NI end traps the trap depths are 0.06 (p-xylene), 0.13 (THF) and 0.19 eV (CHCl3). For AQ, CT fluorescence could be observed only in p-xylene where the trap depth is 0.27 eV. Quantum yields, emission energies, charge transfer energies, solvent reorganization and vibrational energies were calculated. Fluorescence measurements on chains >100 repeat units indicate that end traps capture ~50% of the excitons, and that the exciton diffusion length LD =34 nm, which is much larger than diffusion lengths reported in polymer films or than previously known for diffusion along isolated chains. As a result, the efficiency of exciton capture depends on chain length, but not on trap depth, solvent polarity or which trap group is present.« less

  13. Charge Transfer Fluorescence and 34 nm Exciton Diffusion Length in Polymers with Electron Acceptor End Traps

    SciTech Connect (OSTI)

    Zaikowski, L.; Mauro, G.; Bird, M.; Karten, B.; Asaoka, S.; Wu, Q.; Cook, A. R.; Miller, J.

    2014-12-22

    Photoexcitation of conjugated poly-2,7-(9,9-dihexylfluorene) polyfluorenes with naphthylimide (NI) and anthraquinone (AQ) electron-acceptor end traps produces excitons that form charge transfer states at the end traps. Intramolecular singlet exciton transport to end traps was examined by steady state fluorescence for polyfluorenes of 17 to 127 repeat units in chloroform, dimethylformamide (DMF), tetrahydrofuran (THF), and p-xylene. End traps capture excitons and form charge transfer (CT) states at all polymer lengths and in all solvents. The CT nature of the end-trapped states is confirmed by their fluorescence spectra, solvent and trap group dependence and DFT descriptions. Quantum yields of CT fluorescence are as large as 46%. This strong CT emission is understood in terms of intensity borrowing. Energies of the CT states from onsets of the fluorescence spectra give the depths of the traps which vary with solvent polarity. For NI end traps the trap depths are 0.06 (p-xylene), 0.13 (THF) and 0.19 eV (CHCl3). For AQ, CT fluorescence could be observed only in p-xylene where the trap depth is 0.27 eV. Quantum yields, emission energies, charge transfer energies, solvent reorganization and vibrational energies were calculated. Fluorescence measurements on chains >100 repeat units indicate that end traps capture ~50% of the excitons, and that the exciton diffusion length LD =34 nm, which is much larger than diffusion lengths reported in polymer films or than previously known for diffusion along isolated chains. The efficiency of exciton capture depends on chain length, but not on trap depth, solvent polarity or which trap group is present.

  14. CdSe self-assembled quantum dots with ZnCdMgSe barriers emitting throughout the visible spectrum

    SciTech Connect (OSTI)

    Perez-Paz, M. Noemi; Zhou Xuecong; Munoz, Martin; Lu Hong; Sohel, Mohammad; Tamargo, Maria C.; Jean-Mary, Fleumingue; Akins, Daniel L.

    2004-12-27

    Self-assembled quantum dots of CdSe with ZnCdMgSe barriers have been grown by molecular beam epitaxy on InP substrates. The optical and microstructural properties were investigated using photoluminescence (PL) and atomic force microscopy (AFM) measurements. Control and reproducibility of the quantum dot (QD) size leading to light emission throughout the entire visible spectrum range has been obtained by varying the CdSe deposition time. Longer CdSe deposition times result in a redshift of the PL peaks as a consequence of an increase of QD size. AFM studies demonstrate the presence of QDs in uncapped structures. A comparison of this QD system with CdSe/ZnSe shows that not only the strain but also the chemical properties of the system play an important role in QD formation.

  15. Project Closeout Report Francium trapping facility at Triumf

    SciTech Connect (OSTI)

    Orozco, Luis A

    2014-09-30

    This is a report of the construction of a Francium Trapping Facility (FTF) at the Isotope Separator and Accelerator (ISAC) of TRIUMF in Vancouver, Canada, where the Francium Parity Non Conservation (FrPNC) international collaboration has its home. This facility will be used to study fundamental symmetries with high-resolution atomic spectroscopy. The primary scientific objective of the program is a measurement of the anapole moment of francium in a chain of isotopes by observing the parity violation induced by the weak interaction. The anapole moment of francium and associated signal are expected to be ten times larger than in cesium, the only element in which an anapole moment has been observed. The measurement will provide crucial information for better understanding weak hadronic interactions in the context of Quantum Chromodynamics (QCD). The methodology combines nuclear and particle physics techniques for the production of francium with precision measurements based on laser cooling and trapping and microwave spectroscopy. The program builds on an initial series of atomic spectroscopy measurements of the nuclear structure of francium, based on isotope shifts and hyperfine anomalies, before conducting the anapole moment measurements, these measurements performed during commissioning runs help understand the atomic and nuclear structure of Fr.

  16. Trapping ultracold gases near cryogenic materials with rapid reconfigurability

    SciTech Connect (OSTI)

    Naides, Matthew A.; Turner, Richard W.; Lai, Ruby A.; DiSciacca, Jack M.; Lev, Benjamin L.

    2013-12-16

    We demonstrate an atom chip trapping system that allows the placement and high-resolution imaging of ultracold atoms within microns from any ?100??m-thin, UHV-compatible material, while also allowing sample exchange with minimal experimental downtime. The sample is not connected to the atom chip, allowing rapid exchange without perturbing the atom chip or laser cooling apparatus. Exchange of the sample and retrapping of atoms has been performed within a week turnaround, limited only by chamber baking. Moreover, the decoupling of sample and atom chip provides the ability to independently tune the sample temperature and its position with respect to the trapped ultracold gas, which itself may remain in the focus of a high-resolution imaging system. As a first demonstration of this system, we have confined a 700-nK cloud of 8??10{sup 4} {sup 87}Rb atoms within 100??m of a gold-mirrored 100-?m-thick silicon substrate. The substrate was cooled to 35?K without use of a heat shield, while the atom chip, 120??m away, remained at room temperature. Atoms may be imaged and retrapped every 16?s, allowing rapid data collection.

  17. Have the best available trap on the job, check design, installation, and maintenance

    SciTech Connect (OSTI)

    Spires, F.; Toy, D.A.

    1986-12-01

    Industrial and commercial installations can have much more efficient steam systems with properly designed, installed, and maintained steam traps. Thirty years ago, steam trap maintenance did not have near the significance it does today; fuel costs have risen from about $0.30 per 1000 lb of steam to over 25 times that a few years ago to about 15 times that cost today. Worn or otherwise malfunctioning steam traps can take quite a toll on the energy bill, especially since most traps are designed to fail in the open position. Failure of just one steam trap with a 1/2'' diameter orifice in the open position can cost $45,090 a year. This article gives guidelines for the prevention of steam trap failures.

  18. Polarization-dependent atomic dipole traps behind a circular aperture for neutral-atom quantum computing

    SciTech Connect (OSTI)

    Gillen-Christandl, Katharina; Copsey, Bert D.

    2011-02-15

    The neutral-atom quantum computing community has successfully implemented almost all necessary steps for constructing a neutral-atom quantum computer. We present computational results of a study aimed at solving the remaining problem of creating a quantum memory with individually addressable sites for quantum computing. The basis of this quantum memory is the diffraction pattern formed by laser light incident on a circular aperture. Very close to the aperture, the diffraction pattern has localized bright and dark spots that can serve as red-detuned or blue-detuned atomic dipole traps. These traps are suitable for quantum computing even for moderate laser powers. In particular, for moderate laser intensities ({approx}100 W/cm{sup 2}) and comparatively small detunings ({approx}1000-10 000 linewidths), trap depths of {approx}1 mK and trap frequencies of several to tens of kilohertz are achieved. Our results indicate that these dipole traps can be moved by tilting the incident laser beams without significantly changing the trap properties. We also explored the polarization dependence of these dipole traps. We developed a code that calculates the trapping potential energy for any magnetic substate of any hyperfine ground state of any alkali-metal atom for any laser detuning much smaller than the fine-structure splitting for any given electric field distribution. We describe details of our calculations and include a summary of different notations and conventions for the reduced matrix element and how to convert it to SI units. We applied this code to these traps and found a method for bringing two traps together and apart controllably without expelling the atoms from the trap and without significant tunneling probability between the traps. This approach can be scaled up to a two-dimensional array of many pinholes, forming a quantum memory with single-site addressability, in which pairs of atoms can be brought together and apart for two-qubit gates for quantum computing.

  19. DYNAMICAL STABILITY AND QUANTUM CHAOS OF IONS IN A LINEAR TRAP (1999002ER).

    Office of Scientific and Technical Information (OSTI)

    (Technical Report) | SciTech Connect Technical Report: DYNAMICAL STABILITY AND QUANTUM CHAOS OF IONS IN A LINEAR TRAP (1999002ER). Citation Details In-Document Search Title: DYNAMICAL STABILITY AND QUANTUM CHAOS OF IONS IN A LINEAR TRAP (1999002ER). The realization of a paradigm chaotic system, namely the harmonically driven oscillator, in the quantum domain using cold trapped ions driven by lasers is theoretically investigated. The simplest characteristics of regular and chaotic dynamics

  20. GreenPower Trap Water-Muffler System | Department of Energy

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

    GreenPower Trap Water-Muffler System GreenPower Trap Water-Muffler System This hydrated EGR system reduces NOx and enhances fuel efficiency, and the DPF is catalyzed by the fuel-borne catalyst generated by the oil-borne catalyst system deer09_rim.pdf (118.32 KB) More Documents & Publications DPF -"Hydrated EGR" Fuel Saver System GreenPowerTM Trap-Muffler

  1. Ionization of polarized 3He+ ions in EBIS trap with slanted electrostatic mirror.

    SciTech Connect (OSTI)

    Pikin,A.; Zelenski, A.; Kponou, A.; Alessi, J.; Beebe, E.; Prelee, K.; Raparia, D.

    2007-09-10

    Methods of producing the nuclear polarized {sup 3}He{sup +} ions and their ionization to {sup 3}H{sup ++} in ion trap of the electron Beam Ion Source (EBIS) are discussed. Computer simulations show that injection and accumulation of {sup 3}He{sup +} ions in the EBIS trap with slanted electrostatic mirror can be very effective for injection times longer than the ion traversal time through the trap.

  2. Using impedance measurements for detecting pathogens trapped in an electric field

    DOE Patents [OSTI]

    Miles, Robin R.

    2004-07-20

    Impedance measurements between the electrodes in an electric field is utilized to detect the presence of pathogens trapped in the electric field. Since particles trapped in a field using the dielectiphoretic force changes the impedance between the electrodes by changing the dielectric material between the electrodes, the degree of particle trapping can be determined by measuring the impedance. This measurement is used to determine if sufficient pathogen have been collected to analyze further or potentially to identify the pathogen.

  3. Lean NOx Trap Formulation Effect on Performance with In-Cylinder...

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

    Lean NOx Trap Formulation Effect on Performance with In-Cylinder Regeneration Strategies Poster presentation at the 2007 Diesel Engine-Efficiency & Emissions Research Conference ...

  4. Subtask 4.27 - Evaluation of the Multielement Sorbent Trap (MEST...

    Office of Scientific and Technical Information (OSTI)

    As a possible alternative to the EPA methods, the Energy & Environmental Research Center (EERC) has developed a novel multielement sorbent trap (MEST) method to be used to sample ...

  5. Combining Low-Temperature Combustion with Lean-NOx Trap Yields...

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

    More Documents & Publications Intra-catalyst Reductant Chemistry in Lean NOx Traps: A Study on Sulfur Effects Reductant Utilization in a LNT + SCR System Synergies of ...

  6. Modeling Drift Loss Cone Effects on the Trapping of an Artificial...

    Office of Scientific and Technical Information (OSTI)

    Conference: Modeling Drift Loss Cone Effects on the Trapping of an Artificial Radiation Belt Citation Details In-Document Search Title: Modeling Drift Loss Cone Effects on the ...

  7. Lean NOx Trap Catalysis for Lean Natural Gas Engine Applications

    SciTech Connect (OSTI)

    Parks, II, James E; Storey, John Morse; Theiss, Timothy J; Ponnusamy, Senthil; Ferguson, Harley Douglas; Williams, Aaron M; Tassitano, James B

    2007-09-01

    efficiency and emissions of natural gas reciprocating engines are being pursued. Approaches include: stoichiometric engine operation with exhaust gas recirculation and three-way catalysis, advanced combustion modes such as homogeneous charge compression ignition, and extension of the lean combustion limit with advanced ignition concepts and/or hydrogen mixing. The research presented here addresses the technical approach of combining efficient lean spark-ignited natural gas combustion with low emissions obtained from a lean NOx trap catalyst aftertreatment system. This approach can be applied to current lean engine technology or advanced lean engines that may result from related efforts in lean limit extension. Furthermore, the lean NOx trap technology has synergy with hydrogen-assisted lean limit extension since hydrogen is produced from natural gas during the lean NOx trap catalyst system process. The approach is also applicable to other lean engines such as diesel engines, natural gas turbines, and lean gasoline engines; other research activities have focused on those applications. Some commercialization of the technology has occurred for automotive applications (both diesel and lean gasoline engine vehicles) and natural gas turbines for stationary power. The research here specifically addresses barriers to commercialization of the technology for large lean natural gas reciprocating engines for stationary power. The report presented here is a comprehensive collection of research conducted by Oak Ridge National Laboratory (ORNL) on lean NOx trap catalysis for lean natural gas reciprocating engines. The research was performed in the Department of Energy's ARES program from 2003 to 2007 and covers several aspects of the technology. All studies were conducted at ORNL on a Cummins C8.3G+ natural gas engine chosen based on industry input to simulate large lean natural gas engines. Specific technical areas addressed by the research include: NOx reduction efficiency, partial

  8. CdSe/ZnSe quantum dot structures grown by molecular beam epitaxy with a CdTe submonolayer stressor

    SciTech Connect (OSTI)

    Sedova, I. V. Lyublinskaya, O. G.; Sorokin, S. V.; Sitnikova, A. A.; Toropov, A. A.; Donatini, F.; Dang, Si Le; Ivanov, S. V.

    2007-11-15

    A procedure for formation of CdSe quantum dots (QDs) in a ZnSe matrix is suggested. The procedure is based on the introduction of a CdTe submonolayer stressor deposited on the matrix surface just before deposition of the material of the QDs. (For CdTe/ZnSe structure, the relative lattice mismatch is {delta}a/a {approx} 14%.) The stressor forms small strained islands at the ZnSe surface, thus producing local fields of high elastic stresses controlling the process of the self-assembling of the QDs. According to the data of transmission electron microscopy, this procedure allows a considerable increase in the surface density of QDs, with a certain decrease in their lateral dimensions (down to 4.5 {+-} 1.5 nm). In the photoluminescence spectra, a noticeable ({approx}150 meV) shift of the peak to longer wavelengths from the position of the reference CdSe/ZnSe QD structure is observed. The shift is due to some transformation of the morphology of the QDs and an increase in the Cd content in the QDs. Comprehensive studies of the nanostructures by recording and analyzing the excitation spectra of photoluminescence, the time-resolved photoluminescence spectra, and the cathodoluminescence spectra show that the emission spectra involve two types of optical transitions, namely, the type-I transitions in the CdSeTe/ZnSe QDs and the type-II transitions caused mainly by the low cadmium content (Zn,Cd)(Se,Te)/ZnSe layer formed between the QDs.

  9. AHT: Order (2015-SE-42031) | Department of Energy

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

    Order (2015-SE-42031) AHT: Order (2015-SE-42031) March 9, 2016 DOE ordered AHT Cooling Systems, Inc. to pay a $179,040 civil penalty after finding AHT had manufactured and distributed in commerce in the U.S. at least 1,032 units of commercial refrigeration equipment model RIO S 68 L F, a noncompliant product. The Order adopted a Compromise Agreement, which reflected settlement terms between DOE and AHT. AHT: Order (2015-SE-42031) (66.05 KB) More Documents & Publications AHT: Proposed Penalty

  10. Optical Probing of metamagnetic phases in epitaxial EuSe

    SciTech Connect (OSTI)

    Galgano, G. D.; Henriques, A. B.; Bauer, G.; Springholz, G.

    2011-12-23

    EuSe is a wide gap magnetic semiconductors with a potential for applications in proof-of-concept spintronic devices. When the temperature is lowered, EuSe goes through sharp transitions between a variety of magnetic phases and is thus described as metamagnetic. The purpose of the present investigation is to correlate the magnetic order to the sharp dichroic doublet, discovered recently in high quality thin epitaxial layers of EuSe, grown by molecular beam epitaxy. We report detailed measurements of the doublet positions and intensities as a function of magnetic field in low temperatures, covering several magnetic phases.

  11. Bu Sung: Order (2015-SE-42007) | Department of Energy

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

    Order (2015-SE-42007) Bu Sung: Order (2015-SE-42007) October 13, 2015 DOE ordered Bu Sung America Corporation to pay a $71,480 civil penalty after finding Bu Sung had manufactured and distributed in commerce in the U.S. at least 361 units of basic model ESRF2, a noncompliant commercial refrigerator-freezer. The Order adopted a Compromise Agreement, which reflected settlement terms between DOE and Bu Sung. Bu Sung: Order (2015-SE-42007) (123.64 KB) More Documents & Publications Bu Sung:

  12. Victory: Order (2015-SE-42033) | Department of Energy

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

    Order (2015-SE-42033) Victory: Order (2015-SE-42033) October 27, 2015 DOE ordered Victory Refrigeration to pay a $1,600 civil penalty after finding Victory had manufactured and distributed in commerce in the U.S. at least 8 units of commercial refrigerator-freezer basic model RFS-1D-S1-EW-PT-HD, a noncompliant product. The Order adopted a Compromise Agreement, which reflected settlement terms between DOE and Victory. Victory: Order (2015-SE-42033) (21.59 KB) More Documents & Publications

  13. Analysis of electron dynamics in non-ideal Penning traps

    SciTech Connect (OSTI)

    Coppa, G.; Mulas, R.; D'Angola, A.

    2012-06-15

    Penning traps that are used for particular applications, such as in ion pump technology, Larmor, bouncing, and diocotron frequencies, can be of the same order of magnitude. The paper deals with the dynamics of electrons confined in such devices starting from the study of the properties of the trajectories. In cases of interest, in which electron-neutral collision frequency is much smaller with respect to the characteristic frequencies of the motion, suitable time averages of the trajectories are introduced in order to simplify the analysis of the problem. In the work, time averages have been calculated in a simple way by using an approximate r-z decoupling of the effective potential. Results obtained with the method are presented and discussed in both linear and nonlinear regimes.

  14. Trapping and aerogelation of nanoparticles in negative gravity hydrocarbon flames

    SciTech Connect (OSTI)

    Chakrabarty, Rajan K.; Novosselov, Igor V.; Beres, Nicholas D.; Moosmller, Hans; Sorensen, Christopher M.; Stipe, Christopher B.

    2014-06-16

    We report the experimental realization of continuous carbon aerogel production using a flame aerosol reactor by operating it in negative gravity (?g; up-side-down configuration). Buoyancy opposes the fuel and air flow forces in ?g, which eliminates convectional outflow of nanoparticles from the flame and traps them in a distinctive non-tipping, flicker-free, cylindrical flame body, where they grow to millimeter-size aerogel particles and gravitationally fall out. Computational fluid dynamics simulations show that a closed-loop recirculation zone is set up in ?g flames, which reduces the time to gel for nanoparticles by ?10{sup 6}?s, compared to positive gravity (upward rising) flames. Our results open up new possibilities of one-step gas-phase synthesis of a wide variety of aerogels on an industrial scale.

  15. Nonclassical imaging for a quantum search of trapped ions

    SciTech Connect (OSTI)

    Agarwal, G.S.; Ariunbold, G.O.; Zanthier, J. von; Walther, H.

    2004-12-01

    We discuss a simple search problem which can be pursued with different methods, either on a classical or on a quantum basis. The system is represented by a chain of trapped ions. The ion to be searched for is a member of that chain, consisting, however, of an isotopic species different from the others. It is shown that classical imaging may lead to the final result as fast as quantum imaging. However, for the discussed case the quantum method gives more flexibility and higher precision when the number of ions considered in the chain increases. In addition, interferences are observable even when the distances between the ions are smaller than half a wavelength of the incident light.

  16. Lean Gasoline Engine Reductant Chemistry During Lean NOx Trap Regeneration

    SciTech Connect (OSTI)

    Choi, Jae-Soon; Prikhodko, Vitaly Y; Partridge Jr, William P; Parks, II, James E; Norman, Kevin M; Huff, Shean P; Chambon, Paul H; Thomas, John F

    2010-01-01

    Lean NOx Trap (LNT) catalysts can effectively reduce NOx from lean engine exhaust. Significant research for LNTs in diesel engine applications has been performed and has led to commercialization of the technology. For lean gasoline engine applications, advanced direct injection engines have led to a renewed interest in the potential for lean gasoline vehicles and, thereby, a renewed demand for lean NOx control. To understand the gasoline-based reductant chemistry during regeneration, a BMW lean gasoline vehicle has been studied on a chassis dynamometer. Exhaust samples were collected and analyzed for key reductant species such as H2, CO, NH3, and hydrocarbons during transient drive cycles. The relation of the reductant species to LNT performance will be discussed. Furthermore, the challenges of NOx storage in the lean gasoline application are reviewed.

  17. Gas turbine engine combustor can with trapped vortex cavity

    DOE Patents [OSTI]

    Burrus, David Louis; Joshi, Narendra Digamber; Haynes, Joel Meier; Feitelberg, Alan S.

    2005-10-04

    A gas turbine engine combustor can downstream of a pre-mixer has a pre-mixer flowpath therein and circumferentially spaced apart swirling vanes disposed across the pre-mixer flowpath. A primary fuel injector is positioned for injecting fuel into the pre-mixer flowpath. A combustion chamber surrounded by an annular combustor liner disposed in supply flow communication with the pre-mixer. An annular trapped dual vortex cavity located at an upstream end of the combustor liner is defined between an annular aft wall, an annular forward wall, and a circular radially outer wall formed therebetween. A cavity opening at a radially inner end of the cavity is spaced apart from the radially outer wall. Air injection first holes are disposed through the forward wall and air injection second holes are disposed through the aft wall. Fuel injection holes are disposed through at least one of the forward and aft walls.

  18. Optical Properties of CdSe Nanoparticle Assemblies

    SciTech Connect (OSTI)

    Huser, T; Gerion, D; Zaitseva, N; Krol, D M; Leon, F R

    2003-11-24

    We report on three-dimensional fluorescence imaging of micron-size faceted crystals precipitated from solutions of CdSe nanocrystals. Such crystals have previously been suggested to be superlattices of CdSe quantum dots [1,2]. Possible applications for these materials include their use in optical and optoelectronic devices. The micron-size crystals were grown by slow evaporation from toluene solutions of CdSe nanocrystals in the range of 3-6 nm, produced by traditional wet-chemistry techniques. By using a confocal microscope with laser illumination, three-dimensional raster-scanning and synchronized hyper-spectral detection, we have generated spatial profiles of the fluorescence emission intensity and spectrum. The fluorescence data of the micro-crystals were compared with spectra of individual nanocrystals obtained from the same solution. The results do not support the assertion that these microcrystals consist of CdSe superlattices.

  19. Synthesis and properties of new CdSe-AgI-As{sub 2}Se{sub 3} chalcogenide glasses

    SciTech Connect (OSTI)

    Kassem, M.; ULCO, LPCA, EAC CNRS 4493 F-59140 Dunkerque ; Le Coq, D.; Fourmentin, M.; Hindle, F.; Bokova, M.; Cuisset, A.; Masselin, P.; Bychkov, E.; ULCO, LPCA, EAC CNRS 4493 F-59140 Dunkerque

    2011-02-15

    Research highlights: {yields} Determination of the glass-forming region in the pseudo-ternary CdSe-AgI-As{sub 2}Se{sub 3} system. {yields} Characterization of macroscopic properties of the new CdSe-AgI-As{sub 2}Se{sub 3} glasses. {yields} Far infrared transmission of chalcogenide glasses. {yields} Characterization of the total conductivity of CdSe-AgI-As{sub 2}Se{sub 3} glasses. -- Abstract: The glass-forming region in the pseudo-ternary CdSe-AgI-As{sub 2}Se{sub 3} system was determined. Measurements including differential scanning calorimetry (DSC), density, and X-ray diffraction were performed. The effect resulting from the addition of CdSe or AgI has been highlighted by examining three series of different base glasses. The characteristic temperatures of the glass samples, including glass transition (T{sub g}), crystallisation (T{sub x}), and melting (T{sub m}) temperatures are reported and used to calculate their {Delta}T = T{sub x} - T{sub g} and their Hruby, H{sub r} = (T{sub x} - T{sub g})/(T{sub m} - T{sub x}), criteria. Evolution of the total electrical conductivity {sigma} and the room temperature conductivity {sigma}{sub 298} was also studied. The terahertz transparency domain in the 50-600 cm{sup -1} region was pointed for different chalcogenide glasses (ChGs) and the potential of the THz spectroscopy was suggested to obtain structural information on ChGs.

  20. Haier: Compromise Agreement (2011-SE-1428) | Department of Energy

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

    Compromise Agreement (2011-SE-1428) Haier: Compromise Agreement (2011-SE-1428) April 23, 2013 DOE and Haier America Trading, LLC entered into a Compromise Agreement to resolve a case involving the distribution in commerce of residential freezers that did not meet the applicable energy conservation performance standard. Haier agreed to ensure that no additional units of the noncompliant freezers will be distributed in commerce in the U.S. and not to use the same model numbers in the future.

  1. Bu Sung: Proposed Penalty (2015-SE-42007) | Department of Energy

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

    Proposed Penalty (2015-SE-42007) Bu Sung: Proposed Penalty (2015-SE-42007) September 29, 2015 DOE alleged in a Notice of Proposed Civil Penalty that Bu Sung America Corporation d/b/a Everest Refrigeration manufactured and distributed noncompliant commercial refrigerator-freezers in the U.S. Federal law subjects manufacturers and private labelers to civil penalties if those parties distribute in the U.S. products that do not meet applicable energy conservation standards. This civil penalty notice

  2. True: Order (2015-SE-42049) | Department of Energy

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

    True: Order (2015-SE-42049) True: Order (2015-SE-42049) February 4, 2016 DOE ordered True Manufacturing Co., Inc., to pay a $36,400 civil penalty after finding True had manufactured and distributed in commerce in the U.S. 182 units of True commercial refrigerator basic models TCGG-72 and TCGG-72-S, which did not meet the application energy conservation standard. The Order adopted a Compromise Agreement, which reflected settlement terms between DOE and True. Federal law subjects manufacturers and

  3. Utility: Noncompliance Determination (2016-SE-42003) | Department of Energy

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

    Noncompliance Determination (2016-SE-42003) Utility: Noncompliance Determination (2016-SE-42003) December 30, 2015 DOE issued a Notice of Noncompliance Determination to Utility Refrigerator finding that commercial refrigeration equipment basic model number PT-R-75-SS-3S-3S-N does not comport with the energy conservation standards. DOE determined the product was noncompliant based on DOE testing. Utility must immediately notify each person (or company) to whom Utility distributed the noncompliant

  4. Victory: Noncompliance Determination (2015-SE-42033) | Department of Energy

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

    Noncompliance Determination (2015-SE-42033) Victory: Noncompliance Determination (2015-SE-42033) August 18, 2015 DOE issued a Notice of Noncompliance Determination to Victory Refrigeration finding that commercial refrigeration equipment basic model number RFS-1D-S1-EW-PT-HD (including each individual model within the basic model) does not comport with the energy conservation standards. DOE determined the product was noncompliant based on DOE testing. Victory must immediately notify each person

  5. Victory: Proposed Penalty (2015-SE-42033) | Department of Energy

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

    Proposed Penalty (2015-SE-42033) Victory: Proposed Penalty (2015-SE-42033) September 25, 2015 DOE alleged in a Notice of Proposed Civil Penalty that Victory Refrigeration manufactured and distributed noncompliant commercial refrigerator-freezer model RFS-1D-S1-EW-PT-HD in the U.S. Federal law subjects manufacturers and private labelers to civil penalties if those parties distribute in the U.S. products that do not meet applicable energy conservation standards. This civil penalty notice advises

  6. Characterization of a state-insensitive dipole trap for cesium atoms

    SciTech Connect (OSTI)

    Phoonthong, P.; Douglas, P.; Wickenbrock, A.; Renzoni, F.

    2010-07-15

    In this work we characterize a state-insensitive dipole trap for cold cesium atoms, as realized by tightly focusing a single running laser beam at the magic wavelength. The use of trapping light at the magic wavelength of 935.6 nm resulted in the same ac Stark shift for the {sup 6}S{sub 1/2} ground state and the {sup 6}P{sub 3/2} excited state. A complete characterization of the trap is given, which includes the dependence of the lifetime on the trap depth, an analysis of the important role played by a depumper beam, and a comparison with dipole trapping at different (nonmagic) wavelengths. In particular, we measured the differential light shift of the relevant optical transition as a function of the trapping light wavelength, and showed that it becomes zero at the magic wavelength. Our results are compared to previous realizations of state-insensitive dipole traps for cesium atoms. We also discuss the possible role of the state-insensitive trap, its limitations, and possible developments for the study of ground-state quantum coherence phenomena and related applications.

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

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

    Sulfur Dioxide on Lean NOx Trap Catalysts Impact of Sulfur Dioxide on Lean NOx Trap Catalysts 2004 Diesel Engine Emissions Reduction (DEER) Conference Presentation: University of New Mexico 2004_deer_hammache.pdf (249.2 KB) More Documents & Publications CLEERS Aftertreatment Modeling and Analysis CLEERS Aftertreatment Modeling and Analysis An Improvement of Diesel PM and NOx Reduction System

  8. Scattering of a tightly focused beam by an optically trapped particle

    SciTech Connect (OSTI)

    Lock, James A.; Wrbanek, Susan Y.; Weiland, Kenneth E

    2006-05-20

    Near-forward scattering of an optically trapped 5-{mu}m-radius polystyrene latex sphere by the trapping beam was examined both theoretically and experimentally. Since the trapping beam is tightly focused, the beam fields superpose and interfere with the scattered fields in the forward hemisphere. The observed light intensity consists of a series of concentric bright and dark fringes centered about the forward-scattering direction. Both the number of fringes and their contrast depend on the position of the trapping beam focal waist with respect to the sphere. The fringes are caused by diffraction that is due to the truncation of the tail of the trapping beam as the beam is transmitted through the sphere.

  9. Hydride vapor phase GaN films with reduced density of residual electrons and deep traps

    SciTech Connect (OSTI)

    Polyakov, A. Y.; Smirnov, N. B.; Govorkov, A. V.; Yugova, T. G.; Cox, H.; Helava, H.; Makarov, Yu.; Usikov, A. S.

    2014-05-14

    Electrical properties and deep electron and hole traps spectra are compared for undoped n-GaN films grown by hydride vapor phase epitaxy (HVPE) in the regular process (standard HVPE samples) and in HVPE process optimized for decreasing the concentration of residual donor impurities (improved HVPE samples). It is shown that the residual donor density can be reduced by optimization from ?10{sup 17}?cm{sup ?3} to (25)??10{sup 14}?cm{sup ?3}. The density of deep hole traps and deep electron traps decreases with decreased donor density, so that the concentration of deep hole traps in the improved samples is reduced to ?5??10{sup 13}?cm{sup ?3} versus 2.9??10{sup 16}?cm{sup ?3} in the standard samples, with a similar decrease in the electron traps concentration.

  10. Simultaneous magneto-optical trapping of bosonic and fermionic chromium atoms

    SciTech Connect (OSTI)

    Chicireanu, R.; Pouderous, A.; Barbe, R.; Laburthe-Tolra, B.; Marechal, E.; Vernac, L.; Keller, J.-C.; Gorceix, O.

    2006-05-15

    We report on magneto-optical trapping of fermionic {sup 53}Cr atoms. A Zeeman-slowed atomic beam provides loading rates up to 3x10{sup 6} s{sup -1}. We present systematic characterization of the magneto-optical trap (MOT). We obtain up to 5x10{sup 5} atoms in the steady-state MOT. The atoms radiatively decay from the excited P state into metastable D states, and, due to the large dipolar magnetic moment of chromium atoms in these states, they can remain magnetically trapped in the quadrupole field gradient of the MOT. We study the accumulation of metastable {sup 53}Cr atoms in this magnetic trap. We also report on the simultaneous magneto-optical trapping of bosonic {sup 52}Cr and fermionic {sup 53}Cr atoms. Finally, we characterize the light-assisted collision losses in this Bose-Fermi cold mixture.

  11. Adiabatic electron response and solitary wave generation by trapped particle nonlinearity in a hydrogen plasma

    SciTech Connect (OSTI)

    Mandal, Debraj; Sharma, Devendra

    2014-10-15

    The finite amplitude ion acoustic waves that trap electrons modify the structure of the evolving nonlinear soliton solutions. In the numerical simulations, self-consistently generated solitary waves are studied that emerge as a result of a current driven microinstability growing the ion acoustic mode in a collisionless Vlasov plasma. The growth saturates as a result of nonlinear effects governed by a combination of nonlinearities originating from the hydrodynamic model and kinetic particle trapping effects. The resulting solitary waves also coexist with a finite current and an electron plasma wave capable of perturbing the trapping potential. The results of multiscale simulation are analyzed and characterized following the kinetic prescription of undamped trapped particle mode in the form of phase space vortex solutions that are generalized form of Sagdeev's solitons and obey the solutions of a modified Korteweg-de Vries equation, accounting for a stronger nonlinearity originating from the electron trapping.

  12. Hybrid particle traps and conditioning procedure for gas insulated transmission lines

    DOE Patents [OSTI]

    Dale, Steinar J.; Cookson, Alan H.

    1982-01-01

    A gas insulated transmission line includes an outer sheath, an inner condor within the outer sheath, insulating supports supporting the inner conductor within the outer sheath, and an insulating gas electrically insulating the inner conductor from the outer sheath. An apertured particle trapping ring is disposed within the outer sheath, and the trapping ring has a pair of dielectric members secured at each longitudinal end thereof, with the dielectric members extending outwardly from the trapping ring along an arc. A support sheet having an adhesive coating thereon is secured to the trapping ring and disposed on the outer sheath within the low field region formed between the trapping ring and the outer sheath. A conditioning method used to condition the transmission line prior to activation in service comprises applying an AC voltage to the inner conductor in a plurality of voltage-time steps, with the voltage-time steps increasing in voltage magnitude while decreasing in time duration.

  13. The Role of Electron Transport and Trapping in MOS Total-Dose Modeling

    SciTech Connect (OSTI)

    Fleetwood, D.M.; Winokur, P.S.; Riewe, L.C.; Flament, O.; Paillet, P.; Leray, J.L.

    1999-07-19

    Radiation-induced hole and electron transport and trapping are fundamental to MOS total-dose models. Here we separate the effects of electron-hole annihilation and electron trapping on the neutralization of radiation-induced charge during switched-bias irradiation for hard and soft oxides, via combined thermally stimulated current (TSC) and capacitance-voltage measurements. We also show that present total-dose models cannot account for the thermal stability of deeply trapped electrons near the Si/SiO{sub 2} interface, or the inability of electrons in deep or shallow traps to contribute to TSC at positive bias following (1) room-temperature, (2) high-temperature, or (3) switched-bias irradiation. These results require revisions of modeling parameters and boundary conditions for hole and electron transport in SiO{sub 2}. The nature of deep and shallow electron traps in the near-interfacial SiO{sub 2} is discussed.

  14. The influence of interfaces on properties of thin-film inorganic structural isomers containing SnSeNbSe? Subunits

    SciTech Connect (OSTI)

    Alemayehu, Matti B.; Falmbigl, Matthias; Ta, Kim; Johnson, David C.

    2015-08-28

    Inorganic isomers ([SnSe]1+?)m(NbSe?)n([SnSe]1+?)p(NbSe?)q([SnSe]1+?)r(NbSe?)s where m, n, p, q, r, and s are integers and m + p + r = n + q + s = 4 were prepared using the modulated elemental reactant technique. This series of all six possible isomers provides an opportunity to study the influence of interface density on properties while maintaining the same unit cell size and composition. As expected, all six compounds were observed to have the same atomic compositions and an almost c-axis lattice parameter of ?4.90 (5) nm, with a slight trend in the c-axis lattice parameter correlated with the different number of interfaces in the isomers: two, four and six. The structures of the constituents in the ab-plane were independent of one another, confirming the nonepitaxial relationship between them. The temperature dependent electrical resistivities revealed metallic behavior for all the six compounds. Surprisingly, the electrical resistivity at room temperature decreases with increasing number of interfaces. Hall measurements suggest this results from changes in carrier concentration, which increases with increasing thickness of the thickest SnSe block in the isomer. Carrier mobility scales with the thickness of the thickest NbSe? block due to increased interfacial scattering as the NbSe? blocks become thinner. The observed behavior suggests that the two constituents serve different purposes with respect to electrical transport. SnSe acts as a charge donor and NbSe? acts as the charge transport layer. This separation of function suggests that such heterostructures can be designed to optimize performance through choice of constituent, layer thickness, and layer sequence. A simplistic model, which predicts the properties of the complex isomers from a weighted sum of the properties of

  15. Reduced Cu(InGa)Se2 Thickness in Solar Cells Using a Superstrate Configuration

    SciTech Connect (OSTI)

    Shafarman, William N.

    2015-03-30

    is incident through the substrate into the back of the absorber layer. The primary junction is then formed after Cu(InGa)Se2 deposition. This allows the potential benefits of superstrate cells for optical enhancement while maintaining processing advantages of the substrate configuration and avoiding the harmful effects of high temperature deposition on p-n junction formation. Backwall devices have outperformed substrate cells at absorber thicknesses of 0.1-0.5 µm through enhanced JSC due to easy incorporation of a Ag reflector and, with light incident on the absorber, the elimination of parasitic absorption in the CdS buffer. An efficiency of 9.7% has been achieved for a backwall Cu(InGa)Se2 device with absorber thickness ~0.4 μm. A critical achievement that enabled implementation of the backwall cell was the development of a transparent back contact using MoO3 or WO3. Processes for controlled deposition of each material by reactive rf sputtering from metal targets were developed. These contacts have wide bandgaps making them well-suited for application as contacts for backwall devices as well as potential use in bifacial cells and as the top cell of tandem CuInSe2-based devices. Optical enhancement will be critical for further improvements. Wet chemical texturing of ZnO films has been developed for a simple, low cost light-trapping scheme for backwall superstrate devices to enhance long wavelength quantum efficiency. An aqueous oxalic acid etch was developed and found to strongly texture sputtered ZnO with high haze ≈ 0.9 observed across the whole spectrum. And finally, advanced optical models have been developed to assist the characterization and optimization of Cu(InGa)Se2 cells with thin absorbers

  16. Heterojunctions of model CdTe/CdSe mixtures

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

    van Swol, Frank; Zhou, Xiaowang W.; Challa, Sivakumar R.; Martin, James E.

    2015-03-18

    We report on the strain behavior of compound mixtures of model group II-VI semiconductors. We use the Stillinger-Weber Hamiltonian that we recently introduced, specifically developed to model binary mixtures of group II-VI compounds such as CdTe and CdSe. We also employ molecular dynamics simulations to examine the behavior of thin sheets of material, bilayers of CdTe and CdSe. The lattice mismatch between the two compounds leads to a strong bending of the entire sheet, with about a 0.5 to 1° deflection between neighboring planes. To further analyze bilayer bending, we introduce a simple one-dimensional model and use energy minimization tomore » find the angle of deflection. The analysis is equivalent to a least-squares straight line fit. We consider the effects of bilayers which are asymmetric with respect to the thickness of the CdTe and CdSe parts. We thus learn that the bending can be subdivided into four kinds depending on the compressive/tensile nature of each outer plane of the sheet. We use this approach to directly compare our findings with experimental results on the bending of CdTe/CdSe rods. To reduce the effects of the lattice mismatch we explore diffuse interfaces, where we mix (i.e. alloy) Te and Se, and estimate the strain response.« less

  17. Heterojunctions of model CdTe/CdSe mixtures

    SciTech Connect (OSTI)

    van Swol, Frank; Zhou, Xiaowang W.; Challa, Sivakumar R.; Martin, James E.

    2015-03-18

    We report on the strain behavior of compound mixtures of model group II-VI semiconductors. We use the Stillinger-Weber Hamiltonian that we recently introduced, specifically developed to model binary mixtures of group II-VI compounds such as CdTe and CdSe. We also employ molecular dynamics simulations to examine the behavior of thin sheets of material, bilayers of CdTe and CdSe. The lattice mismatch between the two compounds leads to a strong bending of the entire sheet, with about a 0.5 to 1° deflection between neighboring planes. To further analyze bilayer bending, we introduce a simple one-dimensional model and use energy minimization to find the angle of deflection. The analysis is equivalent to a least-squares straight line fit. We consider the effects of bilayers which are asymmetric with respect to the thickness of the CdTe and CdSe parts. We thus learn that the bending can be subdivided into four kinds depending on the compressive/tensile nature of each outer plane of the sheet. We use this approach to directly compare our findings with experimental results on the bending of CdTe/CdSe rods. To reduce the effects of the lattice mismatch we explore diffuse interfaces, where we mix (i.e. alloy) Te and Se, and estimate the strain response.

  18. EMPaSE: an Extensible Multi-Paradigm Simulation Environment

    Energy Science and Technology Software Center (OSTI)

    2010-08-05

    EMPaSE is a hierarchical, extensible, modular modeling environment for developing and running hybrid simulations of sequential-modular, systems dynamics, discrete-event, and agent-based paradigms. It contains two principle components: a multi-paradigm simulation engine and a graphical user interface. EMPaSE models are defined through a hierarchically-defined set of computational modules that define the simulation logic. Inter-module communication occurs through two complimentary systems: pull-based "ports" for general computation patterns and push-based "plugs" for event processing. Entities (i.e. agents) withinmore » the simulation operate within an abstract multi-network environment. The EMPaSE simulation engine is designed around a flexible plug-in architecture, allowing simulations to import computational modules, engine customizations, and interfaces to external applications from independent plug-in libraries. The EMPaSE GUI environment provides an environment for graphically constructing, executing, and debugging EMPaSE models. As with the simulation engine, the GUI is constructed on top of an extensible architecture that supports rapid customization of the user experience through external plug-in libraries.« less

  19. Heterojunctions of model CdTe/CdSe mixtures

    SciTech Connect (OSTI)

    van Swol, Frank; Zhou, Xiaowang W.; Challa, Sivakumar R.; Martin, James E.

    2015-03-18

    We report on the strain behavior of compound mixtures of model group IIVI semiconductors. We use the StillingerWeber Hamiltonian that we recently introduced, specifically developed to model binary mixtures of group IIVI compounds such as CdTe and CdSe. We also employ molecular dynamics simulations to examine the behavior of thin sheets of material, bilayers of CdTe and CdSe. The lattice mismatch between the two compounds leads to a strong bending of the entire sheet, with about a 0.5 to 1 deflection between neighboring planes. To further analyze bilayer bending, we introduce a simple one-dimensional model and use energy minimization to find the angle of deflection. The analysis is equivalent to a least-squares straight line fit. We consider the effects of bilayers which are asymmetric with respect to the thickness of the CdTe and CdSe parts. We thus learn that the bending can be subdivided into four kinds depending on the compressive/tensile nature of each outer plane of the sheet. We use this approach to directly compare our findings with experimental results on the bending of CdTe/CdSe rods. To reduce the effects of the lattice mismatch we explore diffuse interfaces, where we mix (i.e. alloy) Te and Se, and estimate the strain response.

  20. Features of the electrical conductivity of TlInSe{sub 2} under photoexcitation and X-ray excitation

    SciTech Connect (OSTI)

    Madatov, R. S. Najafov, A. I.; Mustafayev, Yu. M.; Gazanfarov, M. R.; Movsumova, I. M.

    2015-09-15

    The current–voltage characteristics of TlInSe{sub 2} crystals under photoexcitation and X-ray excitation are studied. The parameters of the trap, which are equal to N{sub t} = 5 × 10{sup 16} cm{sup –3}, n{sub t} = 4.5 × 10{sup 12} cm{sup –3}, and ΔE{sub t} = 0.42 eV, are calculated. The calculated values of N{sub t} and n{sub t} before and after X-ray excitation are equal to 3 × 10{sup 16} cm{sup –3} and 3.2 × 10{sup 12} cm{sup –3}, respectively. The dependences of the X-ray conductances on the radiation intensity are studied for TlInSe{sub 2} crystals at various accelerating voltages V{sub a} and it is determined that the X-ray conductance K{sub σ} decreases exponentially as the accelerating voltage V{sub a} and radiation dose increase.

  1. Reverse Monte Carlo simulation of Se{sub 80}Te{sub 20} and Se{sub 80}Te{sub 15}Sb{sub 5} glasses

    SciTech Connect (OSTI)

    Abdel-Baset, A. M.; Rashad, M.; Moharram, A. H.

    2013-12-16

    Two-dimensional Monte Carlo of the total pair distribution functions g(r) is determined for Se{sub 80}Te{sub 20} and Se{sub 80}Te{sub 15}Sb{sub 5} alloys, and then it used to assemble the three-dimensional atomic configurations using the reverse Monte Carlo simulation. The partial pair distribution functions g{sub ij}(r) indicate that the basic structure unit in the Se{sub 80}Te{sub 15}Sb{sub 5} glass is di-antimony tri-selenide units connected together through Se-Se and Se-Te chain. The structure of Se{sub 80}Te{sub 20} alloys is a chain of Se-Te and Se-Se in addition to some rings of Se atoms.

  2. Electrochemical solar cells using CdSe thin film electrodes

    SciTech Connect (OSTI)

    Xiao, Xu-Rui; Tien, H.Ti.

    1983-01-01

    Electrochemical photocells consisting of a CdSe thin film anode and a Pt cathode immersed in 1M Na/sub 2/S-NaOH-S solution have been studied. CdSe thin films were formed on Ti, Cr, Mo, SnO/sub 2/, glassy carbon, and graphite substrates by coating an aqueous mixture of CdSe, ZnCl/sub 2/, and surfactant, subsequently sintering at 400/sup 0/-500/sup 0/C in air. The current-voltage (I-V) relations, output power efficiency, open-circuit voltage, and short-circuit current were measured. Seven percent power conversion efficiency was obtained at 20 mW/cm/sup 2/ light intensity after photoetching. The monochromatic I-V curves were analyzed.

  3. Infrared spectra of small molecular ions trapped in solid neon

    SciTech Connect (OSTI)

    Jacox, Marilyn E.

    2015-01-22

    The infrared spectrum of a molecular ion provides a unique signature for that species, gives information on its structure, and is amenable to remote sensing. It also serves as a comparison standard for refining ab initio calculations. Experiments in this laboratory trap molecular ions in dilute solid solution in neon at 4.2 K in sufficient concentration for observation of their infrared spectra between 450 and 4000 cm{sup !1}. Discharge-excited neon atoms produce cations by photoionization and/or Penning ionization of the parent molecule. The resulting electrons are captured by other molecules, yielding anions which provide for overall charge neutrality of the deposit. Recent observations of ions produced from C{sub 2}H{sub 4} and BF{sub 3} will be discussed. Because of their relatively large possibility of having low-lying excited electronic states, small, symmetric molecular cations are especially vulnerable to breakdown of the Born-Oppenheimer approximation. Some phenomena which can result from this breakdown will be discussed. Ion-molecule reaction rates are sufficiently high that in some systems absorptions of dimer cations and anions are also observed. When H{sub 2} is introduced into the system, the initially-formed ion may react with it. Among the species resulting from such ion-molecule reactions that have recently been studied are O{sub 4}{sup +}, NH{sub 4}{sup +}, HOCO{sup +}, and HCO{sub 2}{sup !}.

  4. A Landau fluid model for dissipative trapped electron modes

    SciTech Connect (OSTI)

    Hedrick, C.L.; Leboeuf, J.N.; Sidikman, K.L.

    1995-09-01

    A Landau fluid model for dissipative trapped electron modes is developed which focuses on an improved description of the ion dynamics. The model is simple enough to allow nonlinear calculations with many harmonics for the times necessary to reach saturation. The model is motivated by a discussion that starts with the gyro-kinetic equation and emphasizes the importance of simultaneously including particular features of magnetic drift resonance, shear, and Landau effects. To ensure that these features are simultaneously incorporated in a Landau fluid model with only two evolution equations, a new approach to determining the closure coefficients is employed. The effect of this technique is to reduce the matching of fluid and kinetic responses to a single variable, rather than two, and to allow focusing on essential features of the fluctuations in question, rather than features that are only important for other types of fluctuations. Radially resolved nonlinear calculations of this model, advanced in time to reach saturation, are presented to partially illustrate its intended use. These calculations have a large number of poloidal and toroidal harmonics to represent the nonlinear dynamics in a converged steady state which includes cascading of energy to both short and long wavelengths.

  5. Particle trap for compressed gas insulated transmission systems

    DOE Patents [OSTI]

    Cookson, Alan H.

    1985-01-01

    A particle trap is provided for gas insulated transmission lines having a central high voltage conductor supported within an outer coaxial conductive sheath by a dielectric support member. A cavity between the inner conductor and outer sheath is filled with a dielectric insulating gas. A cone-like particle deflector, mounted to the inner conductor, deflects moving particles away from the support member, to radially outer portions of the cavity. A conductive shield is disposed adjacent the outer sheath to form a field-free region in radially outer portions of the cavity, between the shield and the sheath. Particles traveling along the cavity are deflected by the cone-like deflector into the field-free region where they are held immobile. In a vertical embodiment, particles enter the field-free region through an upper end of a gap formed between shield and sheath members. In a horizontal embodiment, the deflector cone has a base which is terminated radially internally of the shield. Apertures in the shield located adjacent the deflector allow passage of deflected particles into the field-free region. The dielectric support member is thereby protected from contaminating particles that may otherwise come to rest thereon.

  6. Particle trap for compressed gas insulated transmission systems

    DOE Patents [OSTI]

    Cookson, A.H.

    1984-04-26

    A particle trap is provided for gas insulated transmission lines having a central high voltage conductor supported within an outer coaxial conductive sheath by a dielectric support member. A cavity between the inner conductor and outer sheath is filled with a dielectric insulating gas. A cone-like particle deflector, mounted to the inner conductor, deflects moving particles away from the support member, to radially outer portions of the cavity. A conductive shield is disposed adjacent the outer sheath to form a field-free region in radially outer portions of the cavity, between the shield and the sheath. Particles traveling along the cavity are deflected by the cone-like deflector into the field-free region where they are held immobile. In a vertical embodiment, particles enter the field-free region through an upper end of a gap formed between shield and sheath members. In a horizontal embodiment, the deflector cone has a base which is terminated radially internally of the shield. Apertures in the shield located adjacent the deflector allow passage of deflected particles into the field-free region. The dielectric support member is thereby protected from contaminating particles that may otherwise come to rest thereon.

  7. Certification Framework Based on Effective Trapping for Geologic Carbon Sequestration

    SciTech Connect (OSTI)

    Oldenburg, Curtis M.; Bryant, Steven L.; Nicot, Jean-Philippe

    2009-01-15

    We have developed a certification framework (CF) for certifying the safety and effectiveness of geologic carbon sequestration (GCS) sites. Safety and effectiveness are achieved if CO{sub 2} and displaced brine have no significant impact on humans, other living things, resources, or the environment. In the CF, we relate effective trapping to CO{sub 2} leakage risk which takes into account both the impact and probability of leakage. We achieve simplicity in the CF by using (1) wells and faults as the potential leakage pathways, (2) compartments to represent environmental resources that may be impacted by leakage, (3) CO{sub 2} fluxes and concentrations in the compartments as proxies for impact to vulnerable entities, (4) broad ranges of storage formation properties to generate a catalog of simulated plume movements, and (5) probabilities of intersection of the CO{sub 2} plume with the conduits and compartments. We demonstrate the approach on a hypothetical GCS site in a Texas Gulf Coast saline formation. Through its generality and flexibility, the CF can contribute to the assessment of risk of CO{sub 2} and brine leakage as part of the certification process for licensing and permitting of GCS sites around the world regardless of the specific regulations in place in any given country.

  8. Three-dimensional light trap for reflective particles

    DOE Patents [OSTI]

    Neal, Daniel R.

    1999-01-01

    A system for containing either a reflective particle or a particle having an index of refraction lower than that of the surrounding media in a three-dimensional light cage. A light beam from a single source illuminates an optics system and generates a set of at least three discrete focussed beams that emanate from a single exit aperture and focus on to a focal plane located close to the particle. The set of focal spots defines a ring that surrounds the particle. The set of focussed beams creates a "light cage" and circumscribes a zone of no light within which the particle lies. The surrounding beams apply constraining forces (created by radiation pressure) to the particle, thereby containing it in a three-dimensional force field trap. A diffractive element, such as an aperture multiplexed lens, or either a Dammann grating or phase element in combination with a focusing lens, may be used to generate the beams. A zoom lens may be used to adjust the size of the light cage, permitting particles of various sizes to be captured and contained.

  9. Three-dimensional light trap for reflective particles

    DOE Patents [OSTI]

    Neal, D.R.

    1999-08-17

    A system is disclosed for containing either a reflective particle or a particle having an index of refraction lower than that of the surrounding media in a three-dimensional light cage. A light beam from a single source illuminates an optics system and generates a set of at least three discrete focused beams that emanate from a single exit aperture and focus on to a focal plane located close to the particle. The set of focal spots defines a ring that surrounds the particle. The set of focused beams creates a ``light cage`` and circumscribes a zone of no light within which the particle lies. The surrounding beams apply constraining forces (created by radiation pressure) to the particle, thereby containing it in a three-dimensional force field trap. A diffractive element, such as an aperture multiplexed lens, or either a Dammann grating or phase element in combination with a focusing lens, may be used to generate the beams. A zoom lens may be used to adjust the size of the light cage, permitting particles of various sizes to be captured and contained. 10 figs.

  10. Eolian paleotopographic highs as stratigraphic traps: origin and distinction

    SciTech Connect (OSTI)

    Eschner, T.B.; Kocurek, G.A.

    1985-02-01

    Significant hydrocarbon accumulations occur where eolian paleotopographic highs are preserved beneath transgressive marine deposits. Paleotopographic highs can represent erosional remnants of an unconformity, or partly preserved eolian dunes, or combinations of both. Paleotopography reflects the extent of modification undergone by eolian units prior to or during transgression. Modification varies between extremes of (1) destruction - where eolian deposits are deeply eroded and the former dunal profile is lost, and (2) preservation - where dunes and interdune areas are preserved nearly intact. The extent of modification that occurs during transgression is controlled primarily by (1) the energy of the transgressing sea, (2) the speed of transgression, and (3) the abundance of sand-stabilizing early cements or plants. High-energy seas destroy dunes through persistent erosion by tides and waves and by initiating dune collapse and mass flowage of dune sands. Preservation occurs where quiescent seas flood interdune areas and create shallow to periodically emergent marine environments, such as interdune sabkhas or tidal flats. Gradual filling of interdune areas with shallow marine sediments can fortify and preserve adjacent dunes. These varied processes that interact between marine and eolian environments to create different types of topography are exemplified in ancient eolian-marine sequences of the Western Interior of North America, and preserved Holocene dunes of coastal Australia. Different types of eolian highs can be recognized by analysis of bounding surfaces in outcrop or core. An understanding of eolian-marine processes and environments that create topography allows for prediction of areas of potential stratigraphic traps.

  11. Unconformity related traps and production, Lower Cretaceous through Mississippian Strata, central and northern Rocky Mountains

    SciTech Connect (OSTI)

    Dolson, J. )

    1990-05-01

    Unconformities provide a useful means of equating stratigraphic traps between basins. Systematic mapping can define new concepts through analogy, often from geographically separate areas. Lower Cretaceous through Mississippian surfaces in the central and northern Rockies provide examples. Late Mississippian and Early Pennsylvanian surfaces formed at least four paleodrainage basins separated by the Transcontinental arch. Tyler Formation valley fills (Montana, North Dakota) have produced more than 100 million BOE. Analogous targets in Utah remain untested, but the Mid-Continent Morrow trend continues to yield new reserves. Permian and Triassic paleodrainages filled primarily with seals and form regional traps. A breached Madison trap (Mississippian, Colorado), more than 350 million BOE (Permian Minnelusa, Wyoming), more than 8 billion BOE (from the White Rim Sandstone tar deposits Permian Utah), and eastern Williston basin (Mississippian) are examples. Minor basal valley fill trapping also occurs. Transgressive carbonate facies changes have trapped more than 40 million BOE (Permian Phosphoria Formation, Wyoming). Additional deep gas potential exists. Jurassic unconformities control seal distribution over Nugget Sandstone (Jurassic) reservoirs and partially control Mississippian porosity on the Sweetgrass arch (Montana). Minor paleohill trapping also occurs. Lower Cretaceous surfaces have trapped nearly 2 billion BOE hydrocarbons in 10 paleodrainage networks. Undrilled paleodrainage basins remain deep gas targets. The systematic examination of Rocky Mountain unconformities has been understudied. New exploration concepts and reserve additions await the creative interpreter.

  12. Optoelectronically probing the density of nanowire surface trap states to the single state limit

    SciTech Connect (OSTI)

    Dan, Yaping

    2015-02-02

    Surface trap states play a dominant role in the optoelectronic properties of nanoscale devices. Understanding the surface trap states allows us to properly engineer the device surfaces for better performance. But characterization of surface trap states at nanoscale has been a formidable challenge using the traditional capacitive techniques. Here, we demonstrate a simple but powerful optoelectronic method to probe the density of nanowire surface trap states to the single state limit. In this method, we choose to tune the quasi-Fermi level across the bandgap of a silicon nanowire photoconductor, allowing for capture and emission of photogenerated charge carriers by surface trap states. The experimental data show that the energy density of nanowire surface trap states is in a range from 10{sup 9 }cm{sup −2}/eV at deep levels to 10{sup 12 }cm{sup −2}/eV near the conduction band edge. This optoelectronic method allows us to conveniently probe trap states of ultra-scaled nano/quantum devices at extremely high precision.

  13. Porous materials with pre-designed single-molecule traps for CO2 selective adsorption

    SciTech Connect (OSTI)

    Li, JR; Yu, JM; Lu, WG; Sun, LB; Sculley, J; Balbuena, PB; Zhou, HC

    2013-02-26

    Despite tremendous efforts, precise control in the synthesis of porous materials with pre-designed pore properties for desired applications remains challenging. Newly emerged porous metal-organic materials, such as metal-organic polyhedra and metal-organic frameworks, are amenable to design and property tuning, enabling precise control of functionality by accurate design of structures at the molecular level. Here we propose and validate, both experimentally and computationally, a precisely designed cavity, termed a 'single-molecule trap', with the desired size and properties suitable for trapping target CO2 molecules. Such a single-molecule trap can strengthen CO2-host interactions without evoking chemical bonding, thus showing potential for CO2 capture. Molecular single-molecule traps in the form of metal-organic polyhedra are designed, synthesised and tested for selective adsorption of CO2 over N-2 and CH4, demonstrating the trapping effect. Building these pre-designed single-molecule traps into extended frameworks yields metal-organic frameworks with efficient mass transfer, whereas the CO2 selective adsorption nature of single-molecule traps is preserved.

  14. Friedrich: Order (2014-SE-15010) | Department of Energy

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

    Order (2014-SE-15010) Friedrich: Order (2014-SE-15010) October 27, 2015 DOE ordered Friedrich Air Conditioning Co. to pay a civil penalty of $1,494,626.25 after finding Friedrich had manufactured and distributed in commerce in the U.S. 8,241 units of Friedrich model SQ10N10, a noncompliant room air conditioner. The Order adopted a Compromise Agreement, which reflected settlement terms between DOE and Friedrich. Federal law subjects manufacturers and private labelers to civil penalties if those

  15. Excited-State Relaxation in PbSe Quantum Dots

    SciTech Connect (OSTI)

    An, J. M.; Califano, M.; Franceschetti, A.; Zunger, A.

    2008-01-01

    In solids the phonon-assisted, nonradiative decay from high-energy electronic excited states to low-energy electronic excited states is picosecond fast. It was hoped that electron and hole relaxation could be slowed down in quantum dots, due to the unavailability of phonons energy matched to the large energy-level spacings ('phonon-bottleneck'). However, excited-state relaxation was observed to be rather fast ({le}1 ps) in InP, CdSe, and ZnO dots, and explained by an efficient Auger mechanism, whereby the excess energy of electrons is nonradiatively transferred to holes, which can then rapidly decay by phonon emission, by virtue of the densely spaced valence-band levels. The recent emergence of PbSe as a novel quantum-dot material has rekindled the hope for a slow down of excited-state relaxation because hole relaxation was deemed to be ineffective on account of the widely spaced hole levels. The assumption of sparse hole energy levels in PbSe was based on an effective-mass argument based on the light effective mass of the hole. Surprisingly, fast intraband relaxation times of 1-7 ps were observed in PbSe quantum dots and have been considered contradictory with the Auger cooling mechanism because of the assumed sparsity of the hole energy levels. Our pseudopotential calculations, however, do not support the scenario of sparse hole levels in PbSe: Because of the existence of three valence-band maxima in the bulk PbSe band structure, hole energy levels are densely spaced, in contradiction with simple effective-mass models. The remaining question is whether the Auger decay channel is sufficiently fast to account for the fast intraband relaxation. Using the atomistic pseudopotential wave functions of Pb{sub 2046}Se{sub 2117} and Pb{sub 260}Se{sub 249} quantum dots, we explicitly calculated the electron-hole Coulomb integrals and the P {yields} S electron Auger relaxation rate. We find that the Auger mechanism can explain the experimentally observed P {yields} S

  16. Utility: Order (2016-SE-42003) | Department of Energy

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

    SE-42003) Utility: Order (2016-SE-42003) March 1, 2016 DOE ordered Utility Refrigerator to pay a $200 civil penalty after finding Utility manufactured and distributed in commerce in the U.S. 1 unit of a Utility brand commercial refrigerator, model PT-R-75-SS-3S-3S-N. The Order adopted a Compromise Agreement, which reflected settlement terms between DOE and Utility. Federal law subjects manufacturers and private labelers to civil penalties if those parties distribute in the U.S. products that do

  17. Generation and decay of entanglement in exciton/polariton trapped systems

    SciTech Connect (OSTI)

    Quiroga, L.; Tejedor, C.

    2011-12-23

    The entanglement evolution of interacting trapped solid-state bosons, i.e. excitons or polaritons, is theoretically studied. From an initially separable state the quasi-particle interactions generate boson entanglement which is degraded as dissipation takes place. Based on exact solutions of a Markovian Master equation at T = 0 K, we discuss how dissipation affects the quantum entanglement dynamics of coupled solid-state boson systems. The single trap Wigner function is also calculated and its relationship to the trapped boson entanglement is discussed.

  18. Rare-earth neutral metal injection into an electron beam ion trap plasma

    SciTech Connect (OSTI)

    Magee, E. W., E-mail: magee1@llnl.gov; Beiersdorfer, P.; Brown, G. V. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Hell, N. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Dr. Remeis-Sternwarte and ECAP, Universitt Erlangen-Nrnberg, 96049 Bamberg (Germany)

    2014-11-15

    We have designed and implemented a neutral metal vapor injector on the SuperEBIT high-energy electron beam ion trap at the Lawrence Livermore National Laboratory. A horizontally directed vapor of a europium metal is created using a thermal evaporation technique. The metal vapor is then spatially collimated prior to injection into the trap. The source's form and quantity constraints are significantly reduced making plasmas out of metal with vapor pressures ?10{sup ?7} Torr at ?1000?C more obtainable. A long pulsed or constant feed metal vapor injection method adds new flexibility by varying the timing of injection and rate of material being introduced into the trap.

  19. GreenPowerTM Trap-Muffler System | Department of Energy

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

    GreenPowerTM Trap-Muffler System GreenPowerTM Trap-Muffler System Poster presentation at the 2007 Diesel Engine-Efficiency & Emissions Research Conference (DEER 2007). 13-16 August, 2007, Detroit, Michigan. Sponsored by the U.S. Department of Energy's (DOE) Office of FreedomCAR and Vehicle Technologies (OFCVT). deer07_rim.pdf (186.86 KB) More Documents & Publications GreenPower Trap Water-Muffler System DPF -"Hydrated EGR" Fuel Saver

  20. Method and apparatus for regenerating cold traps within liquid-metal systems

    DOE Patents [OSTI]

    McKee, Jr., John M.

    1976-01-01

    Oxide and hydride impurities of a liquid metal such as sodium are removed from a cold trap by heating to a temperature at which the metal hydroxide is stable in a molten state. The partial pressure of hydrogen within the system is measured to determine if excess hydride or oxide is present. Excess hydride is removed by venting hydrogen gas while excess oxide can be converted to molten hydroxide through the addition of hydrogen. The resulting, molten hydroxide is drained from the trap which is then returned to service at cold trap temperatures within the liquid-metal system.

  1. Light Trapping for Thin Silicon Solar Cells by Femtosecond Laser Texturing: Preprint

    SciTech Connect (OSTI)

    Lee, B. G.; Lin, Y. T.; Sher, M. J.; Mazur, E.; Branz, H. M.

    2012-06-01

    Femtosecond laser texturing is used to create nano- to micron-scale surface roughness that strongly enhances light-trapping in thin crystalline silicon solar cells. Light trapping is crucial for thin solar cells where a single light-pass through the absorber is insufficient to capture the weakly absorbed red and near-infrared photons, especially with an indirect-gap semiconductor absorber layer such as crystalline Si which is less than 20 um thick. We achieve enhancement of the optical absorption from light-trapping that approaches the Yablonovitch limit.

  2. Optical trapping and rotation of airborne absorbing particles with a single focused laser beam

    SciTech Connect (OSTI)

    Lin, Jinda; Li, Yong-qing, E-mail: liy@ecu.edu [Department of Physics, East Carolina University, Greenville, North Carolina 27858-4353 (United States)] [Department of Physics, East Carolina University, Greenville, North Carolina 27858-4353 (United States)

    2014-03-10

    We measure the periodic circular motion of single absorbing aerosol particles that are optically trapped with a single focused Gaussian beam and rotate around the laser propagation direction. The scattered light from the trapped particle is observed to be directional and change periodically at 0.420?kHz. The instantaneous positions of the moving particle within a rotation period are measured by a high-speed imaging technique using a charge coupled device camera and a repetitively pulsed light-emitting diode illumination. The centripetal acceleration of the trapped particle as high as ?20 times the gravitational acceleration is observed and is attributed to the photophoretic forces.

  3. Radial transport of energetic ions in the presence of trapped electron mode turbulence

    SciTech Connect (OSTI)

    Chowdhury, J.; Wang, W.; Ethier, S.; Manickam, J. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Ganesh, R. [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)

    2011-11-15

    The nature of transport of hot ions is studied in the presence of microturbulence generated by the trapped electron mode in a Tokamak using massively parallel, first principle based global nonlinear gyrokinetic simulation, and with the help of a passive tracer method. Passing and trapped hot ions are observed to exhibit inverse and inverse square scaling with energy, while those with isotropic pitch distribution are found to exhibit inverse dependence on energy. For all types of hot ions, namely, isotropic, passing, and trapped, the radial transport appears to be subdiffusive for the parameters considered.

  4. Orbitally-driven giant phonon anharmonicity in SnSe

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

    Li, Chen W.; Hong, Jiawang; May, Andrew F.; Bansal, Dipanshu; Chi, Songxue; Hong, Tao; Ehlers, Georg; Delaire, Olivier A.

    2015-10-19

    We understand that elementary excitations and their couplings in condensed matter systems is critical to develop better energy-conversion devices. In thermoelectric materials, the heat-to-electricity conversion efficiency is directly improved by suppressing the propagation of phonon quasiparticles responsible for macroscopic thermal transport. The material with the current record for thermoelectric conversion efficiency, SnSe, achieves an ultra-low thermal conductivity, but the mechanism enabling this strong phonon scattering remains largely unknown. Using inelastic neutron scattering measurements and first-principles simulations, we mapped the four-dimensional phonon dispersion surfaces of SnSe, and revealed the origin of ionic-potential anharmonicity responsible for the unique properties of SnSe. Wemore » show that the giant phonon scattering arises from an unstable electronic structure, with orbital interactions leading to a ferroelectric-like lattice instability. Our results provide a microscopic picture connecting electronic structure and phonon anharmonicity in SnSe, and offers precious insights on how electron-phonon and phononphonon interactions may lead to the realization of ultra-low thermal conductivity.« less

  5. Orbitally-driven giant phonon anharmonicity in SnSe

    SciTech Connect (OSTI)

    Li, Chen W.; Hong, Jiawang; May, Andrew F.; Bansal, Dipanshu; Chi, Songxue; Hong, Tao; Ehlers, Georg; Delaire, Olivier A.

    2015-10-19

    We understand that elementary excitations and their couplings in condensed matter systems is critical to develop better energy-conversion devices. In thermoelectric materials, the heat-to-electricity conversion efficiency is directly improved by suppressing the propagation of phonon quasiparticles responsible for macroscopic thermal transport. The material with the current record for thermoelectric conversion efficiency, SnSe, achieves an ultra-low thermal conductivity, but the mechanism enabling this strong phonon scattering remains largely unknown. Using inelastic neutron scattering measurements and first-principles simulations, we mapped the four-dimensional phonon dispersion surfaces of SnSe, and revealed the origin of ionic-potential anharmonicity responsible for the unique properties of SnSe. We show that the giant phonon scattering arises from an unstable electronic structure, with orbital interactions leading to a ferroelectric-like lattice instability. Our results provide a microscopic picture connecting electronic structure and phonon anharmonicity in SnSe, and offers precious insights on how electron-phonon and phononphonon interactions may lead to the realization of ultra-low thermal conductivity.

  6. Investigation of Aging Mechanisms in Lean NOx Traps

    SciTech Connect (OSTI)

    Mark Crocker

    2010-03-31

    Lean NO{sub x} traps (LNTs) represent a promising technology for the abatement of NO{sub x} under lean conditions. Although LNTs are starting to find commercial application, the issue of catalyst durability remains problematic. LNT susceptibility to sulfur poisoning is the single most important factor determining effective catalyst lifetime. The NO{sub x} storage element of the catalyst has a greater affinity for SO{sub 3} than it does for NO{sub 2}, and the resulting sulfate is more stable than the stored nitrate. Although this sulfate can be removed from the catalyst by means of high temperature treatment under rich conditions, the required conditions give rise to deactivation mechanisms such as precious metal sintering, total surface area loss, and solid state reactions between the various oxides present. The principle objective of this project was to improve understanding of the mechanisms of lean NO{sub x} trap aging, and to understand the effect of washcoat composition on catalyst aging characteristics. The approach utilized involved detailed characterization of model catalysts prior to and after aging, in tandem with measurement of catalyst performance in NO{sub x} storage and reduction. In this manner, NO{sub x} storage and reduction characteristics were correlated with the evolution of catalyst physico-chemical properties upon aging. Rather than using poorly characterized proprietary catalysts, or simple model catalysts of the Pt/BaO/Al{sub 2}O{sub 3} type (representing the first generation of LNTs), Pt/Rh/BaO/Al{sub 2}O{sub 3} catalysts were employed which also incorporated CeO{sub 2} or CeO{sub 2}-ZrO{sub 2}, representing a model system which more accurately reflects current LNT formulations. Catalysts were prepared in which the concentration of each of the main components was systematically varied: Pt (50, 75 or 100 g/ft{sup 3}), Rh (10 or 20 g/ft{sup 3}), BaO (15, 30 or 45 g/L), and either CeO{sub 2} (0, 50 or 100 g/L) or CeO{sub 2}-ZrO{sub 2} (0, 50

  7. Sulfate Storage and Stability on Common Lean NOx Trap Components

    SciTech Connect (OSTI)

    Ottinger, Nathan A; Toops, Todd J; Pihl, Josh A; Roop, Justin T; Choi, Jae-Soon; Partridge Jr, William P

    2012-01-01

    Components found in a commercial lean NO{sub x} trap have been studied in order to determine their impact on sulfate storage and release. A micro-reactor and a diffuse reflectance infrared Fourier transform spectrometer (DRIFTS) were used to compare components MgAl{sub 2}O{sub 4}, Pt/MgAl{sub 2}O{sub 4}, Pt/Al{sub 2}O{sub 3}, Pt/Ba/Al{sub 2}O{sub 3}, Pt/CeO{sub 2}-ZrO{sub 2}, and Pt/Ba/CeO{sub 2}-ZrO{sub 2}, as well as physical mixtures of Pt/Al{sub 2}O{sub 3} + MgAl{sub 2}O{sub 4} and Pt/Ba/CeO{sub 2}-ZrO{sub 2} + MgAl{sub 2}O{sub 4}. Desulfation temperature profiles as well as DRIFTS NO{sub x} and SO{sub x} storage spectra are presented for all components. This systematic approach highlighted the ability of the underlying support to impact sulfate stability, in particular when Ba was supported on ceria-zirconia rather than alumina the desulfation temperature decreased by 60-120 C. A conceptual model of sulfation progression on the ceria-zirconia support is proposed that explains the high uptake of sulfur and low temperature release when it is employed. It was also determined that the close proximity of platinum is not necessary for much of the sulfation and desulfation chemistry that occurs, as physical mixtures with platinum dispersed on only one phase displayed similar behavior to samples with platinum dispersed on both phases.

  8. Vertically aligned gas-insulated transmission line having particle traps at the inner conductor

    DOE Patents [OSTI]

    Dale, Steinar J.

    1984-01-01

    Gas insulated electrical apparatus having first and second conductors separated by an insulating support within an insulating gas environment, and particle traps disposed along the surface of the high potential conductor for trapping and inactivating foreign particles which may be present within the insulating gas medium. Several embodiments of the invention were developed which are particularly suited for vertically aligned gas insulated transmission lines. The particle traps are grooves or cavities formed into the walls of the tubular inner conductor, without extending into the hollow portion of the conductor. In other embodiments, the traps are appendages or insert flanges extending from the inner conductor, with the insulator supports contacting the appendages instead of the inner conductor.

  9. in situ plasma removal of surface contaminants from ion trap electrodes

    SciTech Connect (OSTI)

    Haltli, Raymond A.

    2015-04-01

    This research resulted in a construction and implementation of an in situ plasma discharge to remove surface contaminants from electrodes in an ion trapping experimental system is presented with results.

  10. Light trapping in thin film solar cells using textured photonic crystal

    DOE Patents [OSTI]

    Yi, Yasha; Kimerling, Lionel C.; Duan, Xiaoman; Zeng, Lirong

    2009-01-27

    A solar cell includes a photoactive region that receives light. A photonic crystal is coupled to the photoactive region, wherein the photonic crystal comprises a distributed Bragg reflector (DBR) for trapping the light.

  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. High Contrast Ramsey Fringes with Coherent-Population-Trapping Pulses in a Double Lambda Atomic System

    SciTech Connect (OSTI)

    Zanon, T.; Guerandel, S.; Clercq, E. de; Holleville, D.; Dimarcq, N.; Clairon, A. [SYRTE, Observatoire de Paris, 61 Avenue de l'Observatoire, 75014 Paris (France)

    2005-05-20

    We report the observation of Raman-Ramsey fringes using a double lambda scheme creating coherent population trapping in an atomic ensemble combined with pulsed optical radiations. The observation was made in a Cs vapor mixed with N{sub 2} buffer gas in a closed cell. The double lambda scheme is created with lin perpendicular lin polarized laser beams leading to higher contrast than the usual simple lambda scheme. The pulsed trapping technique leads to narrow fringe widths scaling as 1/(2T) with high contrasts which are no longer limited by the saturation effect. This technique operates in a different way from the classical Ramsey sequence: the signal is done by applying a long trapping pulse to prepare the atomic state superposition, and fringe detection is accomplished by optical transmission during a short second trapping pulse without any perturbation of the dark state.

  13. Detection of minority carrier traps in p-type 4H-SiC

    SciTech Connect (OSTI)

    Alfieri, G.; Kimoto, T.

    2014-03-03

    Contrarily to the case of n-type 4H-SiC, very little is known about the presence of minority carrier traps in p-type epilayers. In this study, we performed the electrical characterization of as-grown, electron irradiated, and thermally oxidized p-type 4H-SiC, by using minority carrier transient spectroscopy. Four minority carrier traps are reported in 1.6–2.3 eV energy range above the valence band edge (E{sub V}). Particular emphasis is given to the mid-gap minority carrier trap (EH{sub 6∕7}) and to its correlation to an energetically close mid-gap majority carrier trap (HK4)

  14. Ion Trapping, Storage, and Ejection in Structures for Lossless Ion Manipulations

    SciTech Connect (OSTI)

    Zhang, Xinyu; Garimella, Venkata BS; Prost, Spencer A.; Webb, Ian K.; Chen, Tsung-Chi; Tang, Keqi; Tolmachev, Aleksey V.; Norheim, Randolph V.; Baker, Erin Shammel; Anderson, Gordon A.; Ibrahim, Yehia M.; Smith, Richard D.

    2015-06-16

    A structure for lossless ion manipulation (SLIM) module was constructed with electrode arrays patterned on a pair of parallel printed circuit boards (PCB) separated by 5 mm and utilized to investigate capabilities for ion trapping at 4 Torr. Positive ions were confined by application of RF having alternating phases on a series of inner rung electrodes and by positive DC potentials on surrounding guard electrodes on each PCB. An axial DC field was also introduced by stepwise varying the DC potential of the inner rung electrodes so as to control the ion transport and accumulation inside the ion trap. We show that ions could be trapped and accumulated with 100% efficiency, stored for at least 5 hours with no losses, and could be rapidly ejected from the SLIM trap.

  15. Control Of Screening Of A Charged Particle In Electrolytic Aqueous Paul Trap

    SciTech Connect (OSTI)

    Park, Jae Hyun; Krstic, Predrag S.

    2011-06-01

    Individual charged particles could be trapped and confined by the combined radio-frequency and DC quadrupole electric field of an aqueous Paul trap. Viscosity of water improves confinement and extends the range of the trap parameters which characterize the stability of the trap. Electrolyte, if present in aqueous solution, may screen the charged particle and thus partially or fully suppress electrophoretic interaction with the applied filed, possibly reducing it to a generally much weaker dielectrophoretic interaction with an induced dipole. Applying molecular dynamics simulation we show that the quadrupole field has a different effect at the electrolyte ions and at much heavier charged particle, effectively eliminating the screening by electrolyte ions and reinstating the electrophoretic confinement.

  16. Clock transition for a future optical frequency standard with trapped atoms

    SciTech Connect (OSTI)

    Courtillot, Irene; Quessada, Audrey; Kovacich, Richard P.; Brusch, Anders; Kolker, Dmitri; Zondy, Jean-Jacques; Rovera, Giovanni D.; Lemonde, Pierre

    2003-09-01

    We report direct excitation of the strongly forbidden 5s{sup 2} {sup 1}S{sub 0}-5s5p {sup 3}P{sub 0} transition in {sup 87}Sr. Its frequency is 429 228 004 235(20) kHz. A resonant laser creates a small leak in a magneto-optical trap (MOT): atoms build up to the metastable {sup 3}P{sub 0} state and escape the trapping process, leading to a detectable decrease in the MOT fluorescence. This line has a natural width of 10{sup -3} Hz and can be used for a new generation of optical frequency standards using atoms trapped in a light-shift-free dipole trap.

  17. Subtask 4.27 - Evaluation of the Multielement Sorbent Trap (MEST...

    Office of Scientific and Technical Information (OSTI)

    Coal-Fired Plant Citation Details In-Document Search Title: Subtask 4.27 - Evaluation of the Multielement Sorbent Trap (MEST) Method at an Illinois Coal-Fired Plant Owners of ...

  18. Subtask 4.27 - Evaluation of the Multielement Sorbent Trap (MEST...

    Office of Scientific and Technical Information (OSTI)

    Subtask 4.27 - Evaluation of the Multielement Sorbent Trap (MEST) Method at an Illinois Coal-Fired Plant Citation Details In-Document Search Title: Subtask 4.27 - Evaluation of the ...

  19. Giant piezoelectricity of monolayer group IV monochalcogenides: SnSe, SnS, GeSe, and GeS

    SciTech Connect (OSTI)

    Fei, Ruixiang; Yang, Li; Li, Wenbin; Li, Ju

    2015-10-26

    We predict enormous, anisotropic piezoelectric effects in intrinsic monolayer group IV monochalcogenides (MX, M=Sn or Ge, X=Se or S), including SnSe, SnS, GeSe, and GeS. Using first-principle simulations based on the modern theory of polarization, we find that their piezoelectric coefficients are about one to two orders of magnitude larger than those of other 2D materials, such as MoS{sub 2} and GaSe, and bulk quartz and AlN which are widely used in industry. This enhancement is a result of the unique “puckered” C{sub 2v} symmetry and electronic structure of monolayer group IV monochalcogenides. Given the achieved experimental advances in the fabrication of monolayers, their flexible character, and ability to withstand enormous strain, these 2D structures with giant piezoelectric effects may be promising for a broad range of applications such as nano-sized sensors, piezotronics, and energy harvesting in portable electronic devices.

  20. Direct probing of electron and hole trapping into nano-floating-gate in organic field-effect transistor nonvolatile memories

    SciTech Connect (OSTI)

    Cui, Ze-Qun; Wang, Shun; Chen, Jian-Mei; Gao, Xu; Dong, Bin E-mail: chilf@suda.edu.cn Chi, Li-Feng E-mail: chilf@suda.edu.cn Wang, Sui-Dong E-mail: chilf@suda.edu.cn

    2015-03-23

    Electron and hole trapping into the nano-floating-gate of a pentacene-based organic field-effect transistor nonvolatile memory is directly probed by Kelvin probe force microscopy. The probing is straightforward and non-destructive. The measured surface potential change can quantitatively profile the charge trapping, and the surface characterization results are in good accord with the corresponding device behavior. Both electrons and holes can be trapped into the nano-floating-gate, with a preference of electron trapping than hole trapping. The trapped charge quantity has an approximately linear relation with the programming/erasing gate bias, indicating that the charge trapping in the device is a field-controlled process.

  1. Combining Low-Temperature Combustion with Lean-NOx Trap Yields Progress

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

    Toward Targets of Efficient NOx Control for Diesels | Department of Energy Low-Temperature Combustion with Lean-NOx Trap Yields Progress Toward Targets of Efficient NOx Control for Diesels Combining Low-Temperature Combustion with Lean-NOx Trap Yields Progress Toward Targets of Efficient NOx Control for Diesels 2005 Diesel Engine Emissions Reduction (DEER) Conference Presentations and Posters 2005_deer_huff.pdf (547.35 KB) More Documents & Publications Intra-catalyst Reductant Chemistry

  2. Trapping the Light Fantastic | U.S. DOE Office of Science (SC)

    Office of Science (SC) Website

    Trapping the Light Fantastic News News Home Featured Articles 2016 2015 2014 2013 2012 2011 2010 2009 2008 2007 2006 2005 Science Headlines Science Highlights Presentations & Testimony News Archives Communications and Public Affairs Contact Information Office of Science U.S. Department of Energy 1000 Independence Ave., SW Washington, DC 20585 P: (202) 586-5430 07.07.11 Trapping the Light Fantastic New solar cell design uses advanced optics and nanotechnology to maximize performance and

  3. Real-Time Measurement of Diesel Trap Efficiency | Department of Energy

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

    Measurement of Diesel Trap Efficiency Real-Time Measurement of Diesel Trap Efficiency 2005 Diesel Engine Emissions Reduction (DEER) Conference Presentations and Posters 2005_deer_niemela.pdf (555.43 KB) More Documents & Publications Update on 2007 Diesel Particulate Measurement Research 2007 Diesel Particulate Measurement Research (E-66 Project) Evaluation of the European PMP Methodologies Using Chassis Dynamometer and On-road Testing of Heavy-duty Vehicles

  4. Activation of water soluble amines by halogens for trapping methyl radioactive iodine from air streams

    DOE Patents [OSTI]

    Deitz, Victor R.; Blachly, Charles H.

    1977-01-01

    Gas adsorbent charcoals impregnated with an aqueous solution of the reaction product of a tertiary amine and elemental iodine or bromine are better than 99 per cent efficient in trapping methyl iodine.sup.131. The chemical addition of iodine or bromine to the tertiary amine molecule increases the efficiency of the impregnated charcoal as a trapping agent, and in conjunction with the high flash point of the tertiary amine raises the ignition temperature of the impregnated charcoal.

  5. H2-Assisted NOx Traps: Test Cell Results Vehicle Installations | Department

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

    of Energy -Assisted NOx Traps: Test Cell Results Vehicle Installations H2-Assisted NOx Traps: Test Cell Results Vehicle Installations 2003 DEER Conference Presentation: ArvinMeritor 2003_deer_crane.pdf (630.37 KB) More Documents & Publications Hydrogen generation from plasmatron reformers and use for diesel exhaust aftertreatment On-Board Ammonia Generation Using Delphi Diesel Fuel Reformer Use of a Diesel Fuel Processor for Rapid and Efficient Regeneration of Single Leg NOx Adsorber

  6. Extending Penning trap mass measurements with SHIPTRAP to the heaviest elements

    SciTech Connect (OSTI)

    Block, M.; Ackermann, D.; Herfurth, F.; Hofmann, S.; Blaum, K.; Droese, C.; Marx, G.; Schweikhard, L.; Duellmann, Ch. E.; Eibach, M.; Eliseev, S.; Haettner, E.; Plass, W. R.; Scheidenberger, C.; Hessberger, F. P.; Ramirez, E. Minaya; Nesterenko, D.; and others

    2013-03-19

    Penning-trap mass spectrometry of radionuclides provides accurate mass values and absolute binding energies. Such mass measurements are sensitive indicators of the nuclear structure evolution far away from stability. Recently, direct mass measurements have been extended to the heavy elements nobelium (Z=102) and lawrencium (Z=103) with the Penning-trap mass spectrometer SHIPTRAP. The results probe nuclear shell effects at N=152. New developments will pave the way to access even heavier nuclides.

  7. Synergies of High-Efficiency Clean Combustion and Lean NOx Trap Catalysts |

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

    Department of Energy Synergies of High-Efficiency Clean Combustion and Lean NOx Trap Catalysts Synergies of High-Efficiency Clean Combustion and Lean NOx Trap Catalysts investigation of potential synergies of low emission advanced combustion techniques and advanced lean exhaust catalytic aftertreatment. deer08_parks.pdf (718 KB) More Documents & Publications Measurement and Characterization of Lean NOx Adsorber Regeneration and Desulfation and Controlling NOx from Multi-mode High

  8. Stories of Discovery & Innovation: Trapping the Light Fantastic| U.S. DOE

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

    Office of Science (SC) Trapping the Light Fantastic Energy Frontier Research Centers (EFRCs) EFRCs Home Centers Research Science Highlights News & Events EFRC News EFRC Events DOE Announcements Publications History Contact BES Home 07.07.11 Stories of Discovery & Innovation: Trapping the Light Fantastic Print Text Size: A A A Subscribe FeedbackShare Page New solar cell design uses advanced optics and nanotechnology to maximize performance and minimize cost. Discovery moves from lab

  9. Lean NOx Traps - Microstructural Studies of Real World and Model Catalysts

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

    | Department of Energy Traps - Microstructural Studies of Real World and Model Catalysts Lean NOx Traps - Microstructural Studies of Real World and Model Catalysts 2005 Diesel Engine Emissions Reduction (DEER) Conference Presentations and Posters 2005_deer_narula.pdf (143.66 KB) More Documents & Publications Vehicle Technologies Office Merit Review 2016: Next Generation Three-Way Catalysts for Future, Highly Efficient Gasoline Engines Low Temperature Emission Control Pre-Competitive

  10. Engineering Stark Potentials for Precision Measurements: Optical Lattice Clock and Electrodynamic Surface Trap

    SciTech Connect (OSTI)

    Katori, Hidetoshi; Takamoto, Masao; Hachisu, Hidekazu; Fujiki, Jun; Higashi, Ryoichi; Yasuda, Masami; Kishimoto, Tetsuo

    2005-05-05

    Employing the engineered electric fields, we demonstrate novel platforms for precision measurements with neutral atoms. (1) Applying the light shift cancellation technique, atoms trapped in an optical lattice reveal 50-Hz-narrow optical spectrum, yielding nearly an order of magnitude improvement over existing neutral-atom-based clocks. (2) Surface Stark trap has been developed to manipulate scalar atoms that are intrinsically robust to decoherence.

  11. Location Of Hole And Electron Traps On Nanocrystalline Anatase TiO2

    SciTech Connect (OSTI)

    Mercado, Candy C.; Knorr, Fritz J.; McHale, Jeanne L.; Usmani, Shirin M.; Ichimura, Andrew S.; Saraf, Laxmikant V.

    2012-05-17

    The defect photoluminescence from TiO2 nanoparticles in the anatase phase is reported for nanosheets which expose predominantly (001) surfaces, and compared to that from conventional anatase nanoparticles which expose mostly (101) surfaces. Also reported is the weak defect photoluminescence of TiO2 nanotubes, which we find using electron back-scattered diffraction to consist of walls which expose (110) and (100) facets. The nanotubes exhibit photoluminescence that is blue-shifted and much weaker than that from conventional TiO2 nanoparticles. Despite the preponderance of (001) surfaces in the nanosheet samples, they exhibit photoluminescence similar to that of conventional nanoparticles. We assign the broad visible photoluminescence of anatase nanoparticles to two overlapping distributions: hole trap emission associated with oxygen vacancies on (101) exposed surfaces, which peaks in the green, and a broader emission extending into the red which results from electron traps on under-coordinated titanium atoms, which are prevalent on (001) facets. The results of this study suggest how morphology of TiO2 nanoparticles could be optimized to control the distribution and activity of surface traps. Our results also shed light on the mechanism by which the TiCl4 surface treatment heals traps on anatase and mixed-phase TiO2 films, and reveals distinct differences in the trap-state distributions of TiO2 nanoparticles and nanotubes. The molecular basis for electron and hole traps and their spatial separation on different facets is discussed.

  12. Effect of dislocation trapping on deuterium diffusion in deformed, single-crystal Pd

    SciTech Connect (OSTI)

    Heuser, B.J.; King, J.S.

    1998-06-01

    Small-angle neutron scattering (SANS) has been used to characterize deuterium trapping at dislocations in deformed, single-crystal Pd during in situ gas evolution experiments. Two methods of deformation were employed--cold rolling and hydride cycling--which create different dislocation arrangements or substructures in Pd. The reduction of the trapped deuterium concentration at dislocations during evolution was directly monitored with SANS. Exponential decay rates of the trapped concentration were observed for both sample types, as is expected in a bulk diffusion process modified by the dislocation trapping interaction. The deuterium concentration reduction proceeded 1.2 to 1.4 times faster in the cold-rolled sample material than in the cycled material. This is attributed to the presence of a smaller number of dislocation trapping sites in the cold-rolled material. The binding energy of deuterium at dislocations was determined by applying a diffusion-based model. A binding energy of 0.20 eV was found to characterize the trapping interaction in both cold-rolled and hydride-cycled Pd.

  13. Immobilization of Cesium Traps from the BN-350 Fast Reactor (Aktau, Kazakhstan)

    SciTech Connect (OSTI)

    J. A. Michelbacher; C. Knight; O. G. Romanenko; I. L. Tazhibaeva; I. L. Yakovlev; A. V. Rovneyko; V. I. Maev; D. Wells; A. Herrick

    2011-03-01

    During BN-350 reactor operations and also during the initial stages of decommissioning, cesium traps were used to decontaminate the reactor’s primary sodium coolant. Two different types of carbon-based trap were used – the MAVR series, low ash granulated graphite adsorber (LAG) contained in a carrier designed to be inserted into the reactor core during shutdown; and a series of ex-reactor trap accumulators(TAs) which used reticulated vitreous carbon (RVC) to reduce Cs-137 levels in the sodium after final reactor shutdown. In total four MAVRs and seven TAs were used at BN-350 to remove an estimated cumulative 755 TBq of cesium. The traps, which also contain residual sodium, need to be immobilized in an appropriate way to allow them to be consigned as waste packages for long term storage and, ultimately, disposal. The present paper reports on the current status of the implementation phase, with particular reference to the work done to date on the trap accumulators, which have the most similarity with the cesium traps used at other reactors.

  14. Mobility-Selected Ion Trapping and Enrichment Using Structures for Lossless Ion Manipulations

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

    Chen, Tsung-Chi; Ibrahim, Yehia M.; Webb, Ian K.; Garimella, Sandilya V. B.; Zhang, Xing; Hamid, Ahmed M.; Deng, Liulin; Karnesky, William E.; Prost, Spencer A.; Sandoval, Jeremy A.; et al

    2016-01-11

    The integration of ion mobility spectrometry (IMS) with mass spectrometry (MS) and the ability to trap ions in IMS-MS measurements is of great importance for performing reactions, accumulating ions, and increasing analytical measurement sensitivity. The development of Structures for Lossless Ion Manipulations (SLIM) offers the potential for ion manipulations in a more reliable and cost-effective manner, while opening opportunities for much more complex sequences of manipulations. Here, we demonstrate an ion separation and trapping module and a method based upon SLIM that consists of a linear mobility ion drift region, a switch/tee and a trapping region that allows the isolationmore » and accumulation of mobility-separated species. The operation and optimization of the SLIM switch/tee and trap are described and demonstrated for the enrichment of the low abundance ions. Lastly, we observed a linear increase in ion intensity with the number of trapping/accumulation events using the SLIM trap, illustrating its potential for enhancing the sensitivity of low abundance or targeted species.« less

  15. Epitaxial growth of CZT(S,Se) on silicon

    DOE Patents [OSTI]

    Bojarczuk, Nestor A.; Gershon, Talia S.; Guha, Supratik; Shin, Byungha; Zhu, Yu

    2016-03-15

    Techniques for epitaxial growth of CZT(S,Se) materials on Si are provided. In one aspect, a method of forming an epitaxial kesterite material is provided which includes the steps of: selecting a Si substrate based on a crystallographic orientation of the Si substrate; forming an epitaxial oxide interlayer on the Si substrate to enhance wettability of the epitaxial kesterite material on the Si substrate, wherein the epitaxial oxide interlayer is formed from a material that is lattice-matched to Si; and forming the epitaxial kesterite material on a side of the epitaxial oxide interlayer opposite the Si substrate, wherein the epitaxial kesterite material includes Cu, Zn, Sn, and at least one of S and Se, and wherein a crystallographic orientation of the epitaxial kesterite material is based on the crystallographic orientation of the Si substrate. A method of forming an epitaxial kesterite-based photovoltaic device and an epitaxial kesterite-based device are also provided.

  16. Deformation potentials of CdSe quantum dots

    SciTech Connect (OSTI)

    Li, Jingbo; Wang, Lin-Wang

    2004-06-02

    The size dependent deformation potentials of CdSe quantum dots are studied by first principle and semi-empirical pseudopotentials calculations. They find that the amplitude of the quantum dot deformation potential is only slightly larger than the bulk value, and this increase is mostly caused by the off {Lambda} point deformation potentials in the bulk, which are larger in amplitude than the {Lambda} point deformation potential.

  17. Major UMass User Facilities-Resources-PHaSe-EFRC

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

    Major UMass User Facilities TRPL photo Researchers can access the capabilities of the various investigator interested in organic electronic materials, in PHaSE's original participating departments, and other centers and facilities, including the following: Materials Research Science & Engineering Center Center for Hierarchal Manufacturing High Field NMR Facility Mass Spectrometry Facility EPR Facility Keck Nanostructures Laboratory X-ray powder and single crystal diffraction Polymer

  18. Islandaire: Noncompliance Determination (2015-SE-43007) | Department of

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

    Energy 7) Islandaire: Noncompliance Determination (2015-SE-43007) February 25, 2016 DOE issued a Notice of Noncompliance Determination to Islandaire, Inc. finding that the Islandaire package terminal air conditioner basic model CPZ-09ANR1-B, which includes models EZ4209B and EZDR09B, does not comport with the applicable energy conservation standards. DOE determined the product was noncompliant based on DOE testing. Islandaire must immediately notify each person (or company) to whom it

  19. Islandaire: Noncompliance Determination (2015-SE-43008) | Department of

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

    Energy 8) Islandaire: Noncompliance Determination (2015-SE-43008) February 25, 2016 DOE issued a Notice of Noncompliance Determination to Islandaire, Inc. finding that the Islandaire package terminal air conditioner basic model CPZ-129ANR1-B, which includes model EZDR12B, does not comport with the applicable energy conservation standards. DOE determined the product was noncompliant based on DOE testing. Islandaire must immediately notify each person (or company) to whom it distributed the

  20. Islandaire: Noncompliance Determination (2015-SE-43009) | Department of

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

    Energy 9) Islandaire: Noncompliance Determination (2015-SE-43009) February 25, 2016 DOE issued a Notice of Noncompliance Determination to Islandaire, Inc. finding that the Islandaire package terminal air conditioner basic model CPZ-07ANR1-B, which includes model EZDR07B, does not comport with the applicable energy conservation standards. DOE determined the product was noncompliant based on DOE testing. Islandaire must immediately notify each person (or company) to whom it distributed the

  1. Quantum confined acceptors and donors in InSe nanosheets

    SciTech Connect (OSTI)

    Mudd, G. W.; Patan, A. Makarovsky, O.; Eaves, L.; Kudrynskyi, Z. R.; Kovalyuk, Z. D.; Fay, M. W.; Zlyomi, V.; Falko, V.

    2014-12-01

    We report on the radiative recombination of photo-excited carriers bound at native donors and acceptors in exfoliated nanoflakes of nominally undoped rhombohedral ?-polytype InSe. The binding energies of these states are found to increase with the decrease in flake thickness, L. We model their dependence on L using a two-dimensional hydrogenic model for impurities and show that they are strongly sensitive to the position of the impurities within the nanolayer.

  2. American Ref-Fuel of SE CT Biomass Facility | Open Energy Information

    Open Energy Info (EERE)

    Ref-Fuel of SE CT Biomass Facility Jump to: navigation, search Name American Ref-Fuel of SE CT Biomass Facility Facility American Ref-Fuel of SE CT Sector Biomass Facility Type...

  3. SpacePak: Proposed Penalty (2014-SE-16012) | Department of Energy

    Office of Environmental Management (EM)

    SpacePak: Proposed Penalty (2014-SE-16012) (19.1 KB) More Documents & Publications SpacePak: Noncompliance Determination (2014-SE-16012) SpacePak: Order (2014-SE-16012) Crane: ...

  4. Development of Metal Substrate for Denox Catalysts and Particulate Trap

    SciTech Connect (OSTI)

    Pollard, Michael; Habeger, Craig; Frary, Megan; Haines, Scott; Fluharty, Amy; Dakhoul, Youssef; Carr, Michael; Park, Paul; Stefanick, Matthew; DaCosta, Herbert; Balmer-Millar, M Lou; Readey, Michael; McCluskey, Philip

    2005-12-31

    The objective of this project was to develop advanced metallic catalyst substrate materials and designs for use in off-highway applications. The new materials and designs will be used as catalyst substrates and diesel particulate traps. They will increase durability, reduce flow resistance, decrease time to light-off, and reduce cost relative to cordierite substrates. Metallic catalyst substrates are used extensively for diesel oxidation catalysts and have the potential to be used in other catalytic systems for diesel engines. Metallic substrates have many advantages over ceramic materials including improved durability and resistance to thermal shock and vibration. However, the cost is generally higher than cordierite. The most common foil material used for metallic substrates is FeCr Alloy, which is expensive and has temperature capabilities beyond what is necessary for diesel applications. The first task in the project was Identification and Testing of New Materials. In this task, several materials were analyzed to determine if a low cost substitute for FeCr Alloy was available or could be developed. Two materials were identified as having lower cost while showing no decrease in mechanical properties or oxidation resistance at the application temperatures. Also, the ability to fabricate these materials into a finished substrate was not compromised, and the ability to washcoat these materials was satisfactory. Therefore, both candidate materials were recommended for cost savings depending on which would be less expensive in production quantities. The second task dealt with the use of novel flow designs to improve the converter efficiency while possibly decreasing the size of the converter to reduce cost even more. A non-linear flow path was simulated to determine if there would be an increase in efficiency. From there, small samples were produced for bench testing. Bench tests showed that the use of non-linear channels significantly reduced the light

  5. Pressure-dependent Optical Behaviors of Colloidal CdSe Nanoplatelets...

    Office of Scientific and Technical Information (OSTI)

    dependent Optical Behaviors of Colloidal CdSe Nanoplatelets Citation Details In-Document Search Title: Pressure-dependent Optical Behaviors of Colloidal CdSe Nanoplatelets Authors: ...

  6. Electron Traps In p-Type GaAsN Characterized by Deep-Level Transient Spectroscopy

    SciTech Connect (OSTI)

    Johnston, S. W.; Kurtz, S.; Friedman, D. J.; Ptak, A. J.; Ahrenkiel, R. K.; Crandall, R. S.

    2005-02-01

    We have used deep-level transient spectroscopy to detect traps in p-type GaAsN grown by metal-organic chemical vapor deposition. Although minority-carrier electrons are not intentionally injected into the depletion region of the measured samples, electron traps are detected in both Schottky barrier and p-n junction devices. The electron-trap signal can exist using only reverse biases during measurement, and checks of series resistance and minority-carrier injection using an optical source also confirm the electron-trap signal. For dilute-nitrogen p-n junction samples, the electron trap gives the dominant signal peak. The peak's magnitude, which corresponds to trap density, correlates to amounts of nitrogen incorporated during growth and reduced open-circuit voltage during light characterization. The p-type GaAsN layers have net acceptor carrier concentrations in the mid-1016 to low-1017 cm-3, as determined by capacitance-voltage profiling. The electron-trap concentration depends on the N content, but values, when traps are filled to saturation, range from 1015 to 1016 cm-3. The electron signal peak shows a shoulder peak on some samples, giving another close energy level. The electron-trap activation energy is somewhat dependent on the trap filling time, but ranges from about 0.15 to 0.30 eV, and is usually near 0.2 eV for the largest peak when filled to saturation.

  7. Crab trapping causes population decline and demographic changes in diamondback terrapins over two decades

    SciTech Connect (OSTI)

    Dorcas, M.E., J.D. Willson and J.W. Gibbons

    2007-01-01

    Diamondback terrapins (Malaclemys terrapin) are thought to be declining throughout their range. Although many factors have been proposed to contribute to terrapin declines, including increased predation of nests and adults, habitat loss and degradation, road mortality, commercial harvest for food, and mortality as bycatch in crab traps, few studies have provided evidence linking these agents to population declines. Because male and small female terrapins are most susceptible to mortality in crab traps, population declines should coincide with shifts in the age and size distributions of the population and a shift to a more female-biased sex ratio. We used twenty-one years of mark-recapture data (>2800 captures of 1399 individuals) from a declining diamondback terrapin population in South Carolina to test the prediction that the decline is the result of mortality in crab traps. Since the 1980s, the modal size of both male and female terrapins has increased substantially and the proportion that are females is higher than in earlier samples. Additionally, the population now contains more old and fewer young individuals than before. The changes in demography and sex ratio we observed suggest that this terrapin population has declined as a result of selective mortality of smaller individuals in crab traps. The use of bycatch-reduction devices on crab traps may help prevent terrapins from entering the traps, but current models are too large to prevent mortality of males and many females in this population. Future research should focus on design and testing of effective bycatch-reduction devices for specific regions and other methods to prevent terrapin mortality in crab traps.

  8. Bi-Se doped with Cu, p-type semiconductor

    DOE Patents [OSTI]

    Bhattacharya, Raghu Nath; Phok, Sovannary; Parilla, Philip Anthony

    2013-08-20

    A Bi--Se doped with Cu, p-type semiconductor, preferably used as an absorber material in a photovoltaic device. Preferably the semiconductor has at least 20 molar percent Cu. In a preferred embodiment, the semiconductor comprises at least 28 molar percent of Cu. In one embodiment, the semiconductor comprises a molar percentage of Cu and Bi whereby the molar percentage of Cu divided by the molar percentage of Bi is greater than 1.2. In a preferred embodiment, the semiconductor is manufactured as a thin film having a thickness less than 600 nm.

  9. Trapping two types of particles using a double-ring-shaped radially polarized beam

    SciTech Connect (OSTI)

    Zhang Yaoju; Ding Biaofeng; Suyama, Taikei

    2010-02-15

    An optical-trap method based on the illumination of a double-ring-shaped radially polarized beam (R-TEM{sub 11}*) is proposed. The numerical results based on the vector diffraction theory show that a highly focused R-TEM{sub 11}* beam not only can produce a bright spot but also can form an optical cage in the focal region by changing the truncation parameter {beta}, defined as the ratio of the radius of the aperture to the waist of the beam. The radiation forces acting on Rayleigh particles are calculated by using the Rayleigh scattering theory. The bright spot generated by the R-TEM{sub 11}* beam with a {beta} value close to 2 can three-dimensionally trap a particle with a refractive index larger than that of the ambient. An optical cage or three-dimensional dark spot generated by the R-TEM{sub 11}* beam with a {beta} value close to 1.3 can three-dimensionally trap a particle with refractive index smaller than that of the ambient. Because the adjustment of the truncation parameter can be actualized by simply changing the radius of a circular aperture inserted in the front of the lens, only one optical-trap system in the present method can be used to three-dimensionally trap two types of particles with different refractive indices.

  10. Dislocation-related trap levels in nitride-based light emitting diodes

    SciTech Connect (OSTI)

    Venturi, Giulia; Castaldini, Antonio; Cavallini, Anna

    2014-05-26

    Deep level transient spectroscopy was performed on InGaN/GaN multiple quantum well light emitting diodes (LEDs) in order to determine the effect of the dislocation density on the deep intragap electronic levels. The LEDs were grown by metalorganic vapor phase epitaxy on GaN templates with a high dislocation density of 8 10{sup 9} cm{sup ?2} and a low dislocation density of 3 10{sup 8} cm{sup ?2}. Three trapping levels for electrons were revealed, named A, A1, and B, with energies E{sub A}???0.04?eV, E{sub A1}???0.13?eV, and E{sub B}???0.54?eV, respectively. The trapping level A has a much higher concentration in the LEDs grown on the template with a high density of dislocations. The logarithmic dependence of the peak amplitude on the bias pulse width for traps A and A1 identifies the defects responsible for these traps as associated with linearly arranged defects. We conclude that traps A and A1 are dislocation-related intragap energy levels.

  11. The uses of electron beam ion traps in the study of highly charged ions

    SciTech Connect (OSTI)

    Knapp, D.

    1994-11-02

    The Electron Beam Ion Trap (EBIT) is a relatively new tool for the study of highly charged ions. Its development has led to a variety of new experimental opportunities; measurements have been performed with EBITs using techniques impossible with conventional ion sources or storage rings. In this paper, I will highlight the various experimental techniques we have developed and the results we have obtained using the EBIT and higher-energy Super-EBIT built at the Lawrence Livermore National Laboratory. The EBIT employs a high-current-density electron beam to trap, ionize, and excite a population of ions. The ions can be studied in situ or extracted from the trap for external experiments. The trapped ions form an ionization-state equilibrium determined by the relative ionization and recombination rates. Ions of several different elements may simultaneously be present in the trap. The ions are nearly at rest, and, for most systems, all in their ground-state configurations. The electron-ion interaction energy has a narrow distribution and can be varied over a wide range. We have used the EBIT devices for the measurement of electron-ion interactions, ion structure, ion-surface interactions, and the behavior of low-density plasmas.

  12. Region with trapped surfaces in spherical symmetry, its core, and their boundaries

    SciTech Connect (OSTI)

    Bengtsson, Ingemar; Senovilla, Jose M. M.

    2011-02-15

    We consider the region T in spacetime containing future-trapped closed surfaces and its boundary B, and derive some of their general properties. We then concentrate on the case of spherical symmetry, but the methods we use are general and applicable to other situations. We argue that closed trapped surfaces have a nonlocal property, ''clairvoyance'', which is inherited by B. We prove that B is not a marginally trapped tube in general, and that it can have portions in regions whose whole past is flat. For asymptotically flat black holes, we identify a general past barrier, well inside the event horizon, to the location of B under physically reasonable conditions. We also define the core Z of the trapped region as that part of T which is indispensable to sustain closed trapped surfaces. We prove that the unique spherically symmetric dynamical horizon is the boundary of such a core, and we argue that this may serve to single it out. To illustrate the results, some explicit examples are discussed, namely, Robertson-Walker geometries and the imploding Vaidya spacetime.

  13. Phonon anharmonicity and negative thermal expansion in SnSe

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

    Bansal, Dipanshu; Hong, Jiawang; Li, Chen W.; May, Andrew F.; Porter, Wallace; Hu, Michael Y.; Abernathy, Douglas L.; Delaire, Olivier

    2016-08-09

    In this paper, the anharmonic phonon properties of SnSe in the Pnma phase were investigated with a combination of experiments and first-principles simulations. Using inelastic neutron scattering (INS) and nuclear resonant inelastic X-ray scattering (NRIXS), we have measured the phonon dispersions and density of states (DOS) and their temperature dependence, which revealed a strong, inhomogeneous shift and broadening of the spectrum on warming. First-principles simulations were performed to rationalize these measurements, and to explain the previously reported anisotropic thermal expansion, in particular the negative thermal expansion within the Sn-Se bilayers. Including the anisotropic strain dependence of the phonon free energy,more » in addition to the electronic ground state energy, is essential to reproduce the negative thermal expansion. From the phonon DOS obtained with INS and additional calorimetry measurements, we quantify the harmonic, dilational, and anharmonic components of the phonon entropy, heat capacity, and free energy. Finally, the origin of the anharmonic phonon thermodynamics is linked to the electronic structure.« less

  14. Thermodynamic properties of model CdTe/CdSe mixtures

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

    van Swol, Frank; Zhou, Xiaowang W.; Challa, Sivakumar R.; Martin, James E.

    2015-02-20

    We report on the thermodynamic properties of binary compound mixtures of model groups II–VI semiconductors. We use the recently introduced Stillinger–Weber Hamiltonian to model binary mixtures of CdTe and CdSe. We use molecular dynamics simulations to calculate the volume and enthalpy of mixing as a function of mole fraction. The lattice parameter of the mixture closely follows Vegard's law: a linear relation. This implies that the excess volume is a cubic function of mole fraction. A connection is made with hard sphere models of mixed fcc and zincblende structures. We found that the potential energy exhibits a positive deviation frommore » ideal soluton behaviour; the excess enthalpy is nearly independent of temperatures studied (300 and 533 K) and is well described by a simple cubic function of the mole fraction. Using a regular solution approach (combining non-ideal behaviour for the enthalpy with ideal solution behaviour for the entropy of mixing), we arrive at the Gibbs free energy of the mixture. The Gibbs free energy results indicate that the CdTe and CdSe mixtures exhibit phase separation. The upper consolute temperature is found to be 335 K. Finally, we provide the surface energy as a function of composition. Moreover, it roughly follows ideal solution theory, but with a negative deviation (negative excess surface energy). This indicates that alloying increases the stability, even for nano-particles.« less

  15. Particle trap to sheath non-binding contact for a gas-insulated transmission line having a corrugated outer conductor

    DOE Patents [OSTI]

    Fischer, William H.

    1984-04-24

    A non-binding particle trap to outer sheath contact for use in gas insulated transmission lines having a corrugated outer conductor. The non-binding feature of the contact according to the teachings of the invention is accomplished by having a lever arm rotatably attached to a particle trap by a pivot support axis disposed parallel to the direction of travel of the inner conductor/insulator/particle trap assembly.

  16. Particle trap to sheath contact for a gas-insulated transmission line having a corrugated outer conductor

    DOE Patents [OSTI]

    Fischer, William H.; Cookson, Alan H.; Yoon, Kue H.

    1984-04-10

    A particle trap to outer elongated conductor or sheath contact for gas-insulated transmission lines. The particle trap to outer sheath contact of the invention is applicable to gas-insulated transmission lines having either corrugated or non-corrugated outer sheaths. The contact of the invention includes an electrical contact disposed on a lever arm which in turn is rotatably disposed on the particle trap and biased in a direction to maintain contact between the electrical contact and the outer sheath.

  17. ADVANCED GASIFICATION MERCURY/TRACE METAL CONTROL WITH MONOLITH TRAPS

    SciTech Connect (OSTI)

    Mark A. Musich; Michael L. Swanson; Grant E. Dunham; Joshua J. Stanislowski

    2010-07-31

    Two Corning monoliths and a non-carbon-based material have been identified as potential additives for mercury capture in syngas at temperatures above 400F and pressure of 600 psig. A new Corning monolith formulation, GR-F1-2189, described as an active sample appeared to be the best monolith tested to date. The Corning SR Liquid monolith concept continues to be a strong candidate for mercury capture. Both monolith types allowed mercury reduction to below 5-?g/m3 (~5 ppb), a current U.S. Department of Energy (DOE) goal for trace metal control. Preparation methods for formulating the SR Liquid monolith impacted the ability of the monolith to capture mercury. The Energy & Environmental Research Center (EERC)-prepared Noncarbon Sorbents 1 and 2 appeared to offer potential for sustained and significant reduction of mercury concentration in the simulated fuel gas. The Noncarbon Sorbent 1 allowed sustained mercury reduction to below 5-?g/m3 (~5 ppb). The non-carbon-based sorbent appeared to offer the potential for regeneration, that is, desorption of mercury by temperature swing (using nitrogen and steam at temperatures above where adsorption takes place). A Corning cordierite monolith treated with a Group IB metal offered limited potential as a mercury sorbent. However, a Corning carbon-based monolith containing prereduced metallic species similar to those found on the noncarbon sorbents did not exhibit significant or sustained mercury reduction. EERC sorbents prepared with Group IB and IIB selenide appeared to have some promise for mercury capture. Unfortunately, these sorbents also released Se, as was evidenced by the measurement of H2Se in the effluent gas. All sorbents tested with arsine or hydrogen selenide, including Corning monoliths and the Group IB and IIB metal-based materials, showed an ability to capture arsine or hydrogen selenide at 400F and 600 psig. Based on current testing, the noncarbon metal-based sorbents appear to be the most effective arsine and

  18. Anomalous reduction of the switching voltage of Bi-doped Ge{sub 0.5}Se{sub 0.5} ovonic threshold switching devices

    SciTech Connect (OSTI)

    Seo, Juhee; Ahn, Hyung-Woo; Shin, Sang-yeol; Cheong, Byung-ki; Lee, Suyoun

    2014-04-14

    Switching devices based on Ovonic Threshold Switching (OTS) have been considered as a solution to overcoming limitations of Si-based electronic devices, but the reduction of switching voltage is a major challenge. Here, we investigated the effect of Bi-doping in Ge{sub 0.5}Se{sub 0.5} thin films on their thermal, optical, electrical properties, as well as on the characteristics of OTS devices. As Bi increased, it was found that both of the optical energy gap (E{sub g}{sup opt}) and the depth of trap states decreased resulting in a drastic reduction of the threshold voltage (V{sub th}) by over 50%. In addition, E{sub g}{sup opt} was found to be about three times of the conduction activation energy for each composition. These results are explained in terms of the Mott delocalization effect by doping Bi.

  19. Reducing interface recombination for Cu(In,Ga)Se{sub 2} by atomic layer deposited buffer layers

    SciTech Connect (OSTI)

    Hultqvist, Adam; Bent, Stacey F.; Li, Jian V.; Kuciauskas, Darius; Dippo, Patricia; Contreras, Miguel A.; Levi, Dean H.

    2015-07-20

    Partial CuInGaSe{sub 2} (CIGS) solar cell stacks with different atomic layer deposited buffer layers and pretreatments were analyzed by photoluminescence (PL) and capacitance voltage (CV) measurements to investigate the buffer layer/CIGS interface. Atomic layer deposited ZnS, ZnO, and SnO{sub x} buffer layers were compared with chemical bath deposited CdS buffer layers. Band bending, charge density, and interface state density were extracted from the CV measurement using an analysis technique new to CIGS. The surface recombination velocity calculated from the density of interface traps for a ZnS/CIGS stack shows a remarkably low value of 810 cm/s, approaching the range of single crystalline II–VI systems. Both the PL spectra and its lifetime depend on the buffer layer; thus, these measurements are not only sensitive to the absorber but also to the absorber/buffer layer system. Pretreatment of the CIGS prior to the buffer layer deposition plays a significant role on the electrical properties for the same buffer layer/CIGS stack, further illuminating the importance of good interface formation. Finally, ZnS is found to be the best performing buffer layer in this study, especially if the CIGS surface is pretreated with potassium cyanide.

  20. Structural, electrical and anisotropic properties of Tl{sub 4}Se{sub 3}S chain crystals

    SciTech Connect (OSTI)

    Qasrawi, A.F.; Gasanly, N.M.

    2009-10-15

    The structure, the anisotropy effect on the current transport mechanism and the space charge limited current in Tl{sub 4}Se{sub 3}S chain crystals have been studied by means of X-ray diffraction, electrical conductivity measurements along and perpendicular to the crystal's c-axis and the current voltage characteristics. The temperature-dependent electrical conductivity analysis in the region of 150-400 K, revealed the domination of the thermionic emission of charge carriers over the chain boundaries above 210 and 270 K along and perpendicular to the c-axis, respectively. Below these temperatures, the variable range hopping is dominant. At a consistent temperature range, the thermionic emission analysis results in conductivity activation energies of 280 and 182 meV, along and perpendicular to the c-axis, respectively. Likewise, the hopping parameters are altered significantly by the conductivity anisotropy. The current-voltage characteristics revealed the existence of hole trapping state being located at 350 meV above the valence band of the crystal.

  1. Thermal Deactivation Mechanisms of Fully-Formed Lean NOx Trap Catalysts Aged by Lean/Rich Cycling

    Broader source: Energy.gov [DOE]

    Catalysts in fully formulated lean NOx traps are aged and evaluated in a bench-flow reactor using simulated diesel engine exhaust.

  2. Photoluminescence study of the substitution of Cd by Zn during the growth by atomic layer epitaxy of alternate CdSe and ZnSe monolayers

    SciTech Connect (OSTI)

    Hernndez-Caldern, I.; Salcedo-Reyes, J. C.

    2014-05-15

    We present a study of the substitution of Cd atoms by Zn atoms during the growth of alternate ZnSe and CdSe compound monolayers (ML) by atomic layer epitaxy (ALE) as a function of substrate temperature. Samples contained two quantum wells (QWs), each one made of alternate CdSe and ZnSe monolayers with total thickness of 12 ML but different growth parameters. The QWs were studied by low temperature photoluminescence (PL) spectroscopy. We show that the Cd content of underlying CdSe layers is affected by the exposure of the quantum well film to the Zn flux during the growth of ZnSe monolayers. The amount of Cd of the quantum well film decreases with higher exposures to the Zn flux. A brief discussion about the difficulties to grow the Zn{sub 0.5}Cd{sub 0.5}Se ordered alloy (CuAu-I type) by ALE is presented.

  3. Off-resonance energy absorption in a linear Paul trap due to mass selective resonant quenching

    SciTech Connect (OSTI)

    Sivarajah, I.; Goodman, D. S.; Wells, J. E.; Smith, W. W.; Narducci, F. A.

    2013-11-15

    Linear Paul traps (LPT) are used in many experimental studies such as mass spectrometry, atom-ion collisions, and ion-molecule reactions. Mass selective resonant quenching (MSRQ) is implemented in LPT either to identify a charged particle's mass or to remove unwanted ions from a controlled experimental environment. In the latter case, MSRQ can introduce undesired heating to co-trapped ions of different mass, whose secular motion is off resonance with the quenching ac field, which we call off-resonance energy absorption (OREA). We present simulations and experimental evidence that show that the OREA increases exponentially with the number of ions loaded into the trap and with the amplitude of the off-resonance external ac field.

  4. Electron Traps Detected in p-type GaAsN Using Deep Level Transient Spectroscopy

    SciTech Connect (OSTI)

    Johnston, S.; Kurtz, S.; Friedman, D.; Ptak, A.; Ahrenkiel, R.; Crandall, R.

    2005-01-01

    The GaAsN alloy can have a band gap as small as 1.0 eV when the nitrogen composition is about 2%. Indium can also be added to the alloy to increase lattice matching to GaAs and Ge. These properties are advantageous for developing a highly-efficient, multi-junction solar cell. However, poor GaAsN cell properties, such as low open-circuit voltage, have led to inadequate performance. Deep-level transient spectroscopy of p-type GaAsN has identified an electron trap having an activation energy near 0.2 eV and a trap density of at least 1016 cm-3. This trap level appears with the addition of small amounts of nitrogen to GaAs, which also corresponds to an increased drop in open-circuit voltage.

  5. Characterization of trapped gas saturation and heterogeneity in core sampling using miscible-displacement experiments

    SciTech Connect (OSTI)

    Smith, D.H.; Jikich, S.A.

    1994-12-31

    Trapped gas saturation and permeability heterogeneity were evaluated in Berea cores at reservoir conditions, using standard miscible displacement experiments, with and without surfactants. Pressure and production history were influenced by core heterogeneity and foam lamellae formation when aqueous surfactant was present in the core. The objective of the dispersion-capacitance model was to estimate trapped gas saturations; however longitudinal dispersion and mass transfer also were examined. The results show that the dispersion-capacitance model accurately fits trapped gas saturation controlled by rock heterogeneities and foam lamellae for lamella generating mechanisms that allow a continuous gas phase (leave-behind lamellae). The practical applications resulting from this study can aid in core sample selection and scaling short laboratory corefloods to field dimensions for applications to foam stimulation and underground storage of natural gas.

  6. Importance of hydrophobic traps for proton diffusion in lyotropic liquid crystals

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

    McDaniel, Jesse G.; Yethiraj, Arun

    2016-03-04

    The diffusion of protons in self-assembled systems is potentially important for the design of efficient proton exchange membranes. In this work, we study proton dynamics in a low-water content, lamellar phase of an sodium-carboxylate gemini surfactant/water system using computer simulations. The hopping of protons via the Grotthuss mechanism is explicity allowed through the multi-state empirical valence bond (MS-EVB) method. We find that the hydronium ion is trapped on the hydrophobic side of the surfactant-water interface, and proton diffusion then proceeds by hopping between surface sites. The importance of hydrophobic traps is surprising, because one would expect the hydronium ions tomore » be trapped at the charged head-groups. Finally, the physics illustrated in this system should be relevant to the proton dynamics in other amphiphilic membrane systems, whenever there exists exposed hydrophobic surface regions.« less

  7. Luther-Emery Phase and Atomic-Density Waves in a Trapped Fermion Gas

    SciTech Connect (OSTI)

    Gao Xianlong; Rizzi, M.; Polini, Marco; Tosi, M. P.; Fazio, Rosario; Campo, V. L. Jr.; Capelle, K.

    2007-01-19

    The Luther-Emery liquid is a state of matter that is predicted to occur in one-dimensional systems of interacting fermions and is characterized by a gapless charge spectrum and a gapped spin spectrum. In this Letter we discuss a realization of the Luther-Emery phase in a trapped cold-atom gas. We study by means of the density-matrix renormalization-group technique a two-component atomic Fermi gas with attractive interactions subject to parabolic trapping inside an optical lattice. We demonstrate how this system exhibits compound phases characterized by the coexistence of spin pairing and atomic-density waves. A smooth crossover occurs with increasing magnitude of the atom-atom attraction to a state in which tightly bound spin-singlet dimers occupy the center of the trap. The existence of atomic-density waves could be detected in the elastic contribution to the light-scattering diffraction pattern.

  8. Dark soliton decay due to trap anharmonicity in atomic Bose-Einstein condensates

    SciTech Connect (OSTI)

    Parker, N. G.; Proukakis, N. P.; Adams, C. S.

    2010-03-15

    A number of recent experiments with nearly pure atomic Bose-Einstein condensates have confirmed the predicted dark soliton oscillations when under harmonic trapping. However, a dark soliton propagating in an inhomogeneous condensate has also been predicted to be unstable to the emission of sound waves. Although harmonic trapping supports an equilibrium between the coexisting soliton and sound, we show that the ensuing dynamics are sensitive to trap anharmonicities. Such anharmonicities can break the soliton-sound equilibrium and lead to the net decay of the soliton on a considerably shorter time scale than other dissipation mechanisms. Thus, we propose that small realistic modifications to existing experimental setups could enable the experimental observation of this decay channel.

  9. Light Trapping for High Efficiency Heterojunction Crystalline Si Solar Cells: Preprint

    SciTech Connect (OSTI)

    Wang, Q.; Xu, Y.; Iwaniczko, E.; Page, M.

    2011-04-01

    Light trapping plays an important role to achieve high short circuit current density (Jsc) and high efficiency for amorphous/crystalline Si heterojunction solar cells. Si heterojunction uses hydrogenated amorphous Si for emitter and back contact. This structure of solar cell posses highest open circuit voltage of 0.747 V at one sun for c-Si based solar cells. It also suggests that over 25% record-high efficiency is possible with further improvement of Jsc. Light trapping has two important tasks. The first one is to reduce the surface reflectance of light to zero for the solar spectrum that Si has a response. The second one is to increase the effective absorption length to capture all the photon. For Si heterojunction solar cell, surface texturing, anti-reflectance indium tin oxides (ITO) layer at the front and back are the key area to improve the light trapping.

  10. Multi-particle trapping and manipulation by a high-frequency array transducer

    SciTech Connect (OSTI)

    Yoon, Changhan; Kang, Bong Jin; Lee, Changyang; Kim, Hyung Ham Shung, K. Kirk

    2014-11-24

    We report the multiple micro-particle trapping and manipulation by a single-beam acoustic tweezer using a high-frequency array transducer. A single acoustic beam generated by a 30 MHz ultrasonic linear array transducer can entrap and transport multiple micro-particles located at the main lobe and the grating lobes. The distance between trapped particles can be adjusted by changing the transmit arrangement of array-based acoustic tweezers and subsequently the location of grating lobes. The experiment results showed that the proposed method can trap and manipulate multiple particles within a range of hundreds of micrometers. Due to its simplicity and low acoustic power, which is critical to protect cells from any thermal and mechanical damages, the technique may be used for transportation of cells in cell biology, biosensors, and tissue engineering.

  11. Unconventional gas hydrate seals may trap gas off southeast US. [North Carolina, South Carolina

    SciTech Connect (OSTI)

    Dillion, W.P.; Grow, J.A.; Paull, C.K.

    1980-01-07

    Seismic profiles have indicated to the US Geological Survey that an unconventional seal, created by gas hydrates that form in near-bottom sediments, may provide gas traps in continental slopes and rises offshore North and South Carolina. The most frequently cited evidence for the presence of gas hydrate in ocean sediments is the observation of a seismic reflection event that occurs about 1/2 s below and parallel with the seafloor. If gas-hydrate traps do exist, they will occur at very shallow sub-bottom depths of about 1600 ft (500m). Exploration of such traps will probably take place in the federally controlled Blake Ridge area off the coast of South Carolina where seismic data suggest a high incidence of gas hydrates. However, drilling through the gas-hydrate-cemented layer may require new engineering techniques for sealing the casing.

  12. Experimental nonlinear dynamical studies in cesium magneto-optical trap using time-series analysis

    SciTech Connect (OSTI)

    Anwar, M. Islam, R.; Faisal, M.; Sikandar, M.; Ahmed, M.

    2015-03-30

    A magneto-optical trap of neutral atoms is essentially a dissipative quantum system. The fast thermal atoms continuously dissipate their energy to the environment via spontaneous emissions during the cooling. The atoms are, therefore, strongly coupled with the vacuum reservoir and the laser field. The vacuum fluctuations as well as the field fluctuations are imparted to the atoms as random photon recoils. Consequently, the external and internal dynamics of atoms becomes stochastic. In this paper, we have investigated the stochastic dynamics of the atoms in a magneto-optical trap during the loading process. The time series analysis of the fluorescence signal shows that the dynamics of the atoms evolves, like all dissipative systems, from deterministic to the chaotic regime. The subsequent disappearance and revival of chaos was attributed to chaos synchronization between spatially different atoms in the magneto-optical trap.

  13. TRAPPED PROTON FLUXES AT LOW EARTH ORBITS MEASURED BY THE PAMELA EXPERIMENT

    SciTech Connect (OSTI)

    Adriani, O.; Bongi, M.; Barbarino, G. C.; Bazilevskaya, G. A.; Bellotti, R.; Bruno, A.; Boezio, M.; Bonvicini, V.; Carbone, R.; Bogomolov, E. A.; Bottai, S.; Cafagna, F.; Campana, D.; Carlson, P.; Casolino, M.; De Donato, C.; De Santis, C.; De Simone, N.; Felice, V. Di; Castellini, G.; and others

    2015-01-20

    We report an accurate measurement of the geomagnetically trapped proton fluxes for kinetic energy above ∼70 MeV performed by the PAMELA mission at low Earth orbits (350 ÷ 610 km). Data were analyzed in the frame of the adiabatic theory of charged particle motion in the geomagnetic field. Flux properties were investigated in detail, providing a full characterization of the particle radiation in the South Atlantic Anomaly region, including locations, energy spectra, and pitch angle distributions. PAMELA results significantly improve the description of the Earth's radiation environment at low altitudes, placing important constraints on the trapping and interaction processes, and can be used to validate current trapped particle radiation models.

  14. Self-trapped exciton and core-valence luminescence in BaF{sub 2} nanoparticles

    SciTech Connect (OSTI)

    Vistovskyy, V. V. Zhyshkovych, A. V.; Chornodolskyy, Ya. M.; Voloshinovskii, A. S.; Myagkota, O. S.; Gloskovskii, A.; Gektin, A. V.; Vasil'ev, A. N.; Rodnyi, P. A.

    2013-11-21

    The influence of the BaF{sub 2} nanoparticle size on the intensity of the self-trapped exciton luminescence and the radiative core-valence transitions is studied by the luminescence spectroscopy methods using synchrotron radiation. The decrease of the self-trapped exciton emission intensity at energies of exciting photons in the range of optical exciton creation (h? ? E{sub g}) is less sensitive to the reduction of the nanoparticle sizes than in the case of band-to-band excitation, where excitons are formed by the recombination way. The intensity of the core-valence luminescence shows considerably weaker dependence on the nanoparticle sizes in comparison with the intensity of self-trapped exciton luminescence. The revealed regularities are explained by considering the relationship between nanoparticle size and photoelectron or photohole thermalization length as well as the size of electronic excitations.

  15. Spatiotemporal Monte Carlo transport methods in x-ray semiconductor detectors: Application to pulse-height spectroscopy in a-Se

    SciTech Connect (OSTI)

    Fang Yuan; Badal, Andreu; Allec, Nicholas; Karim, Karim S.; Badano, Aldo

    2012-01-15

    Purpose: The authors describe a detailed Monte Carlo (MC) method for the coupled transport of ionizing particles and charge carriers in amorphous selenium (a-Se) semiconductor x-ray detectors, and model the effect of statistical variations on the detected signal. Methods: A detailed transport code was developed for modeling the signal formation process in semiconductor x-ray detectors. The charge transport routines include three-dimensional spatial and temporal models of electron-hole pair transport taking into account recombination and trapping. Many electron-hole pairs are created simultaneously in bursts from energy deposition events. Carrier transport processes include drift due to external field and Coulombic interactions, and diffusion due to Brownian motion. Results: Pulse-height spectra (PHS) have been simulated with different transport conditions for a range of monoenergetic incident x-ray energies and mammography radiation beam qualities. Two methods for calculating Swank factors from simulated PHS are shown, one using the entire PHS distribution, and the other using the photopeak. The latter ignores contributions from Compton scattering and K-fluorescence. Comparisons differ by approximately 2% between experimental measurements and simulations. Conclusions: The a-Se x-ray detector PHS responses simulated in this work include three-dimensional spatial and temporal transport of electron-hole pairs. These PHS were used to calculate the Swank factor and compare it with experimental measurements. The Swank factor was shown to be a function of x-ray energy and applied electric field. Trapping and recombination models are all shown to affect the Swank factor.

  16. Magnetooptical study of CdSe/ZnMnSe semimagnetic quantum-dot ensembles with n-type modulation doping

    SciTech Connect (OSTI)

    Reshina, I. I. Ivanov, S. V.

    2014-12-15

    Magnetic and polarization investigations of the photoluminescence and resonant electron spin-flip Raman scattering in ensembles of self-organized CdSe/ZnMnSe semimagnetic quantum dots with n-type modulation doping are carried out. It is demonstrated that exciton transitions contribute to the photoluminescence band intensity, along with the transitions of trions in the singlet state. In the Hanle-effect measurements, negative circular polarization in zero magnetic field is observed, which is related to the optical orientation of a trion heavy hole. The lifetime and spin-relaxation time of a heavy hole are estimated as ?3 and ?1 ps, respectively. Such short times are assumed to be due to Auger recombination with the excitation of an intrinsic transition in a Mn{sup 2+} ion. Investigations of the photoluminescence-maximum intensity and shift in a longitudinal magnetic field at the ?{sup ?}?{sup +} and ?{sup ?}?{sup ?} polarizations reveal the pronounced spin polarization of electrons. Under resonant excitation conditions, a sharp increase in the photoluminescence-band maximum intensity at ?{sup ?} excitation polarization over the ?{sup +} one is observed. The Raman scattering peak at the electron spin-flip transition is observed upon resonant excitation in a transverse magnetic field in crossed linear polarizations. This peak is shown to be a Brillouin function of a magnetic field.

  17. High-precision Penning trap mass measurements for tests of the Standard Model

    SciTech Connect (OSTI)

    Blaum, Klaus; Eliseev, Sergey; Nagy, Szilard

    2010-08-04

    With the nowadays achievable accuracy in Penning trap mass spectrometry on short-lived exotic nuclides as well as stable atoms, precision fundamental tests can be performed, among them a test of the Standard Model, in particular with regard to the weak interaction, the CPT symmetry conservation, and the unitarity of the Cabibbo-Kobayashi-Maskawa quark mixing matrix. In addition, accurate mass values of specific nuclides are important for neutrino physics. The presently best tests of the Standard Model with high-precision Penning trap mass spectrometry will be reviewed.

  18. NH3 generation over commercial Three-Way Catalysts and Lean-NOx Traps |

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

    Department of Energy generation over commercial Three-Way Catalysts and Lean-NOx Traps NH3 generation over commercial Three-Way Catalysts and Lean-NOx Traps Research to identify most promising catalytic formulations and operation for the in-situ generation of NH3, storage on a downstream SCR catalyst, and utilized to reduce the remaining NOx deer12_toops.pdf (3.08 MB) More Documents & Publications Emissions Control for Lean Gasoline Engines Emissions Control for Lean Gasoline Engines

  19. Ising antiferromagnet with ultracold bosonic mixtures confined in a harmonic trap

    SciTech Connect (OSTI)

    Guglielmino, M.; Penna, V.; Capogrosso-Sansone, B.

    2011-09-15

    We present accurate results based on quantum Monte Carlo simulations of two-component bosonic systems on a square lattice and in the presence of an external harmonic confinement. Starting from hopping parameters and interaction strengths which stabilize the Ising antiferromagnetic phase in the homogeneous case and at half-integer filling factor, we study how the presence of the harmonic confinement challenges the realization of such a phase. We consider realistic trapping frequencies and number of particles, and we establish under which conditions, i.e., total number of particles and population imbalance, the antiferromagnetic phase can be observed in the trap.

  20. Nonlinearity-mediated soliton ejection from trapping potentials in nonlocal media

    SciTech Connect (OSTI)

    Ye Fangwei; Kartashov, Yaroslav V.; Torner, Lluis; Hu Bambi

    2010-08-15

    We address the properties of optical solitons in thermal nonlinear media with a local refractive index defect that is capable of trapping solitons launched close to the sample boundary despite the boundary-mediated forces that tend to deflect all beams toward the center of the sample. We show that while such forces become more pronounced with an increasing of the input beam power the defect can trap only light below a critical power above which solitons are ejected. The dynamics of soliton ejection and the subsequent propagation may be controlled.

  1. Soliton propagation, reflection, and transmission in an inhomogeneous plasma with trapped electrons

    SciTech Connect (OSTI)

    Aziz, Farah; Malik, Hitendra K.; Stroth, Ulrich

    2011-04-15

    Transmission and reflection of solitons from a semitransparent grid in an inhomogeneous plasma in the presence of trapped electrons is studied analytically. Conditions are obtained for the obliqueness of the propagation and the drift velocity of ions for the soliton transmission and reflection. Also, a transmission-reflection conservation law is derived. The contribution of trapped electrons to the solitons' propagation and their reflection and transmission is examined through energy, amplitude, and width of the solitons, in addition to the effect of temperature and drift of the ions.

  2. Effect of trapped electrons on soliton propagation in a plasma having a density gradient

    SciTech Connect (OSTI)

    Aziz, Farah; Stroth, Ulrich

    2009-03-15

    A Korteweg-deVries equation with an additional term due to the density gradient is obtained using reductive perturbation technique in an unmagnetized plasma having a density gradient, finite temperature ions, and two-temperature nonisothermal (trapped) electrons. This equation is solved to get the solitary wave solution using sine-cosine method. The phase velocity, soliton amplitude, and width are examined under the effect of electron and ion temperatures and their concentrations. The effect of ion (electron) temperature is found to be more significant in the presence of larger (smaller) number of trapped electrons in the plasma.

  3. Controlling soliton interactions in Bose-Einstein condensates by synchronizing the Feshbach resonance and harmonic trap

    SciTech Connect (OSTI)

    Zhang Xiaofei |; Yang Qin |; Zhang Jiefang; Chen, X. Z.; Liu, W. M.

    2008-02-15

    We present how to control interactions between solitons, either bright or dark, in Bose-Einstein condensates by synchronizing Feshbach resonance and harmonic trap. Our results show that as long as the scattering length is to be modulated in time via a changing magnetic field near the Feshbach resonance, and the harmonic trapping frequencies are also modulated in time, exact solutions of the one-dimensional nonlinear Schroedinger equation can be found in a general closed form, and interactions between two solitons are modulated in detail in currently experimental conditions. We also propose experimental protocols to observe the phenomena such as fusion, fission, warp, oscillation, elastic collision in future experiments.

  4. Resonant trapping in the transport of a matter-wave soliton through a quantum well

    SciTech Connect (OSTI)

    Ernst, Thomas; Brand, Joachim

    2010-03-15

    We theoretically investigate the scattering of bright solitons in a Bose-Einstein condensate on narrow attractive potential wells. Reflection, transmission, and trapping of an incident soliton are predicted to occur with remarkably abrupt transitions upon varying the potential depth. Numerical simulations of the nonlinear Schroedinger equation are complemented by a variational collective coordinate approach. The mechanism for nonlinear trapping is found to rely both on resonant interaction between the soliton and bound states in the potential well and on the radiation of small-amplitude waves. These results suggest that solitons can be used to probe bound states that are not accessible through scattering with single atoms.

  5. Pt-free, Perovskite-based Lean NOx Trap Catalysts | Department of Energy

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

    Pt-free, Perovskite-based Lean NOx Trap Catalysts Pt-free, Perovskite-based Lean NOx Trap Catalysts Perovskite-based lean NOx catalysts shown to achieve comparable NOx reduction performance as commercial platinum based counterpart deer10_qi.pdf (1.8 MB) More Documents & Publications Catalyst Design for Urea-less Passive Ammonia SCR Lean-Burn SIDI Aftertreatment System Emissions Control for Lean Gasoline Engines Vehicle Technologies Office Merit Review 2015: Metal Oxide Nano-Array Catalysts

  6. Intra-catalyst Reductant Chemistry in Lean NOx Traps: A Study on Sulfur

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

    Effects | Department of Energy Intra-catalyst Reductant Chemistry in Lean NOx Traps: A Study on Sulfur Effects Intra-catalyst Reductant Chemistry in Lean NOx Traps: A Study on Sulfur Effects Presentation given at DEER 2006, August 20-24, 2006, Detroit, Michigan. Sponsored by the U.S. DOE's EERE FreedomCar and Fuel Partnership and 21st Century Truck Programs. 2006_deer_parks.pdf (655.5 KB) More Documents & Publications The Next Regulatory Chapter for Commercial Vehicles Review of Diesel

  7. Synthesis, structural, optical and Raman studies of pure and lanthanum doped ZnSe nanoparticles

    SciTech Connect (OSTI)

    Kumar, Pushpendra; Singh, Jai; Pandey, Mukesh Kumar; Jeyanthi, C.E.; Siddheswaran, R.; Paulraj, M.; Hui, K.N.; Hui, K.S.

    2014-01-01

    Graphical abstract: - Highlights: • Template-free synthesis of ZnSe and ZnSe:La nanoparticles was developed at low temperature 100 °C. • Cubic ZnSe and ZnSe:La nanoparticles were obtained by chemical route. • As-synthesized ZnSe:La nanoparticles showed higher emission intensity than ZnSe nanoparticles. • Band gap (E{sub g}) of ZnSe nanoparticles was bigger than ZnSe nanoparticles due to nanosized effect. - Abstract: In this work, a simple, effective and reproducible chemical synthetic route for the production of high-quality, pure ZnSe nanoparticles (NPs), and lanthanum-doped ZnSe (ZnSe:La) NPs is presented. The wide bandgap, luminescent pure ZnSe and ZnSe:La NPs has been synthesized at a low temperature (100 °C) in a single template-free step. The size and optical bandgap of the NPs was analyzed from powder X-ray diffraction (XRD), UV–visible (UV–vis) spectroscopy, transmission electron microscopy (TEM), and high resolution transmission electron microscopy (HRTEM). A broad photoluminescence (PL) emission across the visible spectrum has been demonstrated by a systematic blue-shift in emission due to the formation of small nanoparticles. Here, contribution to emission intensity from surface states of NPs increases with La doping. TEM data revealed that the average size of ZnSe and ZnSe:La NPs is 14 and 8 nm, respectively. On the other hand, band gap energy E{sub g} of ZnSe and ZnSe:La NPs were found to be 3.59 eV and 3.65 eV, respectively. Results showed that hydrazine hydrate played multiple roles in the formation of ZnSe and ZnSe:La NPs. A possible reaction mechanism for the growth of NPs is also discussed.

  8. Detection of a MoSe{sub 2} secondary phase layer in CZTSe by spectroscopic ellipsometry

    SciTech Connect (OSTI)

    Demircioğlu, Özden; Riedel, Ingo; Gütay, Levent; Mousel, Marina; Redinger, Alex; Rey, Germain; Weiss, Thomas; Siebentritt, Susanne

    2015-11-14

    We demonstrate the application of Spectroscopic Ellipsometry (SE) for identification of secondary phase MoSe{sub 2} in polycrystalline Cu{sub 2}ZnSnSe{sub 4} (CZTSe) samples. A MoSe{sub 2} reference sample was analyzed, and its optical constants (ε{sub 1} and ε{sub 2}) were extracted by SE analysis. This dataset was implemented into an optical model for analyzing SE data from a glass/Mo/CZTSe sample containing MoSe{sub 2} at the back side of the absorber. We present results on the n and k values of CZTSe and show the extraction of the thickness of the secondary phase MoSe{sub 2} layer. Raman spectroscopy and scanning electron microscopy were applied to confirm the SE results.

  9. The new misfit compound (BiSe){sub 1.15}(TiSe{sub 2}){sub 2} and the role of dimensionality in the Cu{sub x}(BiSe){sub 1+δ}(TiSe{sub 2}){sub n} series

    SciTech Connect (OSTI)

    Trump, Benjamin A.; Livi, Kenneth J.T.; McQueen, Tyrel M.

    2014-01-15

    The synthesis and physical properties of the new misfit compound (BiSe){sub 1.15}(TiSe{sub 2}){sub 2} are reported. Transmission electron microscopy and powder X-ray diffraction show that the structure consists of alternating rock-salt type BiSe layers and hexagonal (TiSe{sub 2}){sub 2} double layers. Resistivity, specific heat, and magnetization measurements show that it has metallic and diamagnetic behaviors. These results are interpreted and discussed in the context of the transition between single-layer (BiSe){sub 1.13}(TiSe{sub 2}), which shows no charge density wave, and infinite-layered (bulk) 1T-TiSe{sub 2}, which undergoes a charge density wave transition at T=202 K. Intercalation with copper, Cu{sub x}(BiSe){sub 1.15}(TiSe{sub 2}){sub 2}, (0≤x≤0.10) is also reported, but unlike Cu{sub x}TiSe{sub 2}, no superconductivity is observed down to T=0.05 K. Thus, the series Cu{sub x}(BiSe){sub 1+δ}(TiSe{sub 2}){sub n} provides an effective approach to elucidate the impact of dimensionality on charge density wave formation and superconductivity. - Graphical abstract: The newly discovered misfit compound (BiSe){sub 1.15}(TiSe{sub 2}){sub 2} shown in the series (BiSe){sub 1+δ}(TiSe{sub 2}){sub n}. Display Omitted - Highlights: • Reports the structure and properties of the new misfit compound (BiSe){sub 1.15}(TiSe{sub 2}){sub 2}. • The structure consists of a rock salt type BiSe layer and a double (TiSe{sub 2}){sub 2} layer. • The n=1, 2 misfits (BiSe){sub 1+δ}(TiSe{sub 2}){sub n} are found not to exhibit CDW transitions. • Evidence is presented that there is likely a low-lying CDW excited state. • The series Cu{sub x}(BiSe){sub 1+δ}(TiSe{sub 2}){sub 2} does not superconduct, unlike Cu{sub x}TiSe{sub 2}.

  10. Landau damping and the onset of particle trapping in quantum plasmas

    SciTech Connect (OSTI)

    Daligault, Jrme

    2014-04-15

    Using analytical theory and simulations, we assess the impact of quantum effects on non-linear wave-particle interactions in quantum plasmas. We more specifically focus on the resonant interaction between Langmuir waves and electrons, which, in classical plasmas, lead to particle trapping. Two regimes are identified depending on the difference between the time scale of oscillation t{sub B}(k)=?(m/eEk) of a trapped electron and the quantum time scale t{sub q}(k)=2m/?k{sup 2} related to recoil effect, where E and k are the wave amplitude and wave vector. In the classical-like regime, t{sub B}(k)?trapped in the wave troughs and greatly affect the evolution of the system long before the wave has had time to Landau damp by a large amount according to linear theory. In the quantum regime, t{sub B}(k)?>?t{sub q}(k), particle trapping is hampered by the finite recoil imparted to resonant electrons in their interactions with plasmons.

  11. A highly miniaturized vacuum package for a trapped ion atomic clock

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

    Schwindt, Peter D. D.; Jau, Yuan-Yu; Partner, Heather; Casias, Adrian; Wagner, Adrian R.; Moorman, Matthew; Manginell, Ronald P.; Kellogg, James R.; Prestage, John D.

    2016-05-12

    We report on the development of a highly miniaturized vacuum package for use in an atomic clock utilizing trapped ytterbium-171 ions. The vacuum package is approximately 1 cm3 in size and contains a linear quadrupole RF Paul ion trap, miniature neutral Yb sources, and a non-evaporable getter pump. We describe the fabrication process for making the Yb sources and assembling the vacuum package. To prepare the vacuum package for ion trapping, it was evacuated, baked at a high temperature, and then back filled with a helium buffer gas. Once appropriate vacuum conditions were achieved in the package, the package wasmore » sealed with a copper pinch-off and was then pumped only by the non-evaporable getter. We demonstrated ion trapping in this vacuum package and the operation of an atomic clock, stabilizing a local oscillator to the 12.6 GHz hyperfine transition of 171Yb+. The fractional frequency stability of the clock was measured to be 2 × 10-11 / τ1/2.« less

  12. Centrality measures highlight proton traps and access points to proton highways in kinetic Monte Carlo trajectories

    SciTech Connect (OSTI)

    Krueger, Rachel A.; Haibach, Frederick G.; Fry, Dana L.; Gomez, Maria A.

    2015-04-21

    A centrality measure based on the time of first returns rather than the number of steps is developed and applied to finding proton traps and access points to proton highways in the doped perovskite oxides: AZr{sub 0.875}D{sub 0.125}O{sub 3}, where A is Ba or Sr and the dopant D is Y or Al. The high centrality region near the dopant is wider in the SrZrO{sub 3} systems than the BaZrO{sub 3} systems. In the aluminum-doped systems, a region of intermediate centrality (secondary region) is found in a plane away from the dopant. Kinetic Monte Carlo (kMC) trajectories show that this secondary region is an entry to fast conduction planes in the aluminum-doped systems in contrast to the highest centrality area near the dopant trap. The yttrium-doped systems do not show this secondary region because the fast conduction routes are in the same plane as the dopant and hence already in the high centrality trapped area. This centrality measure complements kMC by highlighting key areas in trajectories. The limiting activation barriers found via kMC are in very good agreement with experiments and related to the barriers to escape dopant traps.

  13. Dynamics of a single trapped ion inside a nonideal QED cavity at zero temperature

    SciTech Connect (OSTI)

    Rangel, R.; Zagury, N.; Massoni, E.

    2004-02-01

    We consider a system consisting of a single ion in a Paul trap coupled to a cavity electromagnetic field mode. We analyze the fidelity of a scheme for quantum swapping between vibrational and cavity field states, when the system is in contact with a reservoir at zero temperature.

  14. Production of Ar{sup q+} ions with a tandem linear Paul trap

    SciTech Connect (OSTI)

    Higaki, H. Nagayasu, K.; Iwai, T.; Ito, K.; Okamoto, H.

    2015-06-29

    A tandem linear Paul trap was used to create highly charged Argon ions by electron impact ionizations. By improving the operation scheme, the production of Ar{sup 4+} ions was confirmed. Possible improvements for the future experiments with laser cooled Ca{sup +} ions are suggested.

  15. A thermal desorption spectroscopy study of hydrogen trapping in polycrystalline α-uranium

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

    Lillard, R. S.; Forsyth, R. T.

    2015-03-14

    The kinetics of hydrogen desorption from polycrystalline α-uranium (α-U) was examined using thermal desorption spectroscopy (TDS). The goal was to identify the major trap sites for hydrogen and their associated trap energies. In polycrystalline α-U six TDS adsorption peaks were observed at temperatures of 521 K, 556 K, 607 K, 681 K, 793 K and 905 K. In addition, the desorption was determined to be second order based on peak shape. The position of the first three peaks was consistent with desorption from UH3. To identify the trap site corresponding to the high temperature peaks the data were compared tomore » a plastically deformed sample and a high purity single crystal sample. The plastically deformed sample allowed the identification of trapping at dislocations while the single crystal sample allow for the identification of high angle boundaries and impurities. Thus, with respect to the desorption energy associated with each peak, values between 12.9 and 26.5 kJ/mole were measured.« less

  16. Electron trap level of hydrogen incorporated nitrogen vacancies in silicon nitride

    SciTech Connect (OSTI)

    Sonoda, Ken'ichiro Tsukuda, Eiji; Tanizawa, Motoaki; Yamaguchi, Yasuo

    2015-03-14

    Hydrogen incorporation into nitrogen vacancies in silicon nitride and its effects on electron trap level are analyzed using simulation based on density functional theory with temperature- and pressure-dependent hydrogen chemical potential. If the silicon dangling bonds around a nitrogen vacancy are well separated each other, hydrogen incorporation is energetically stable up to 900 °C, which is in agreement with the experimentally observed desorption temperature. On the other hand, if the dangling bonds strongly interact, the incorporation is energetically unfavorable even at room temperature because of steric hindrance. An electron trap level caused by a nitrogen vacancy becomes shallow by the hydrogen incorporation. An electron is trapped in a deep level created by a silicon dangling bond before hydrogen incorporation, whereas it is trapped in a shallow level created by an anti-bonding state of a silicon-silicon bond after hydrogen incorporation. The simulation results qualitatively explain the experiment, in which reduced hydrogen content in silicon nitride shows superior charge retention characteristics.

  17. Tapered laser rods as a means of minimizing the path length of trapped barrel mode rays

    DOE Patents [OSTI]

    Beach, Raymond J.; Honea, Eric C.; Payne, Stephen A.; Mercer, Ian; Perry, Michael D.

    2005-08-30

    By tapering the diameter of a flanged barrel laser rod over its length, the maximum trapped path length of a barrel mode can be dramatically reduced, thereby reducing the ability of the trapped spontaneous emission to negatively impact laser performance through amplified spontaneous emission (ASE). Laser rods with polished barrels and flanged end caps have found increasing application in diode array end-pumped laser systems. The polished barrel of the rod serves to confine diode array pump light within the rod. In systems utilizing an end-pumping geometry and such polished barrel laser rods, the pump light that is introduced into one or both ends of the laser rod, is ducted down the length of the rod via the total internal reflections (TIRs) that occur when the light strikes the rod's barrel. A disadvantage of using polished barrel laser rods is that such rods are very susceptible to barrel mode paths that can trap spontaneous emission over long path lengths. This trapped spontaneous emission can then be amplified through stimulated emission resulting in a situation where the stored energy available to the desired lasing mode is effectively depleted, which then negatively impacts the laser's performance, a result that is effectively reduced by introducing a taper onto the laser rod.

  18. A thermal desorption spectroscopy study of hydrogen trapping in polycrystalline ?-uranium

    SciTech Connect (OSTI)

    Lillard, R. S.; Forsyth, R. T.

    2015-03-14

    The kinetics of hydrogen desorption from polycrystalline ?-uranium (?-U) was examined using thermal desorption spectroscopy (TDS). The goal was to identify the major trap sites for hydrogen and their associated trap energies. In polycrystalline ?-U six TDS adsorption peaks were observed at temperatures of 521 K, 556 K, 607 K, 681 K, 793 K and 905 K. In addition, the desorption was determined to be second order based on peak shape. The position of the first three peaks was consistent with desorption from UH3. To identify the trap site corresponding to the high temperature peaks the data were compared to a plastically deformed sample and a high purity single crystal sample. The plastically deformed sample allowed the identification of trapping at dislocations while the single crystal sample allow for the identification of high angle boundaries and impurities. Thus, with respect to the desorption energy associated with each peak, values between 12.9 and 26.5 kJ/mole were measured.

  19. Dynamical stability and quantum chaos of ions in a linear trap

    SciTech Connect (OSTI)

    Berman, G. P. [Group T-13 and CNLS, University of California, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Group T-13 and CNLS, University of California, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); James, D. F. V. [Group T-4, University of California, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Group T-4, University of California, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Hughes, R. J. [Group P-23, University of California, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Group P-23, University of California, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Gulley, M. S. [Group P-25, University of California, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Group P-25, University of California, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Holzscheiter, M. H. [Group P-23, University of California, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Group P-23, University of California, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Lopez, G. V. [Departamento de Fisica, Universidad de Guadalajara, Corregidora 500, S.R. 44420, Guadalajara, Jalisco, (Mexico)] [Departamento de Fisica, Universidad de Guadalajara, Corregidora 500, S.R. 44420, Guadalajara, Jalisco, (Mexico)

    2000-02-01

    The realization of a paradigm chaotic system, namely, the harmonically driven oscillator, in the quantum domain using cold trapped ions driven by lasers is theoretically investigated. The simplest characteristics of regular and chaotic dynamics are calculated. The possibilities of experimental realization are discussed. (c) 2000 The American Physical Society.

  20. Intersubband absorption in CdSe/Zn{sub x}Cd{sub y}Mg{sub 1-x-y}Se self-assembled quantum dot multilayers

    SciTech Connect (OSTI)

    Shen, A.; Lu, H.; Charles, W.; Yokomizo, I.; Tamargo, M. C.; Franz, K. J.; Gmachl, C.; Zhang, S. K.; Zhou, X.; Alfano, R. R.; Liu, H. C.

    2007-02-12

    The authors report the observation of intersubband absorption in multilayers of CdSe/Zn{sub x}Cd{sub y}Mg{sub 1-x-y}Se self-assembled quantum dots. The samples were grown by molecular beam epitaxy on InP substrates. For samples with the CdSe dot layers doped with Cl and with the deposited CdSe equivalent layer thickness between 5.2 and 6.9 ML, peak absorption between 2.5 and 3.5 {mu}m was observed. These materials are promising for intersubband devices operating in the mid- and near-infrared ranges.

  1. The effects of deep level traps on the electrical properties of semi-insulating CdZnTe

    SciTech Connect (OSTI)

    Zha, Gangqiang; Yang, Jian; Xu, Lingyan; Feng, Tao; Wang, Ning; Jie, Wanqi

    2014-01-28

    Deep level traps have considerable effects on the electrical properties and radiation detection performance of high resistivity CdZnTe. A deep-trap model for high resistivity CdZnTe was proposed in this paper. The high resistivity mechanism and the electrical properties were analyzed based on this model. High resistivity CdZnTe with high trap ionization energy E{sub t} can withstand high bias voltages. The leakage current is dependent on both the deep traps and the shallow impurities. The performance of a CdZnTe radiation detector will deteriorate at low temperatures, and the way in which sub-bandgap light excitation could improve the low temperature performance can be explained using the deep trap model.

  2. Small-angle neutron scattering measurement of deuterium trapping at dislocations and grain boundaries in palladium

    SciTech Connect (OSTI)

    Heuser, B.J.

    1991-01-01

    Small angle neutron scattering measurements have been performed on deformed single and polycrystalline palladium with and without deuterium dissolved in the solution phase at room temperature. The purpose of these experiments was to directly measure the spatial distribution of trapped deuterium at dislocations in the deformed metal. The net scattering cross section for the same smaple with and without deuterium shows a behavior expected from deuterium correlation with dislocations froming rod-like scattering structures. The measured cross sections indicate the trapped deuterium is within 2 to 3 Burgers vectors of the dislocation core. On average 1 to 3 deuterons per {angstrom} are trapped at the dislocations in the deformed samples. The measurements also indicate the straight, rod-like correlation geometry extends on average 50 to 100 {angstrom} along the dislocations. Dislocation densities on the order of 5 {times} 10{sup 11} cm/cm{sup 3} were found for all samples investigated. Net scattering from a well annealed polycrystalline palladium sample exhibiting a behavior expected from spherical shells has been observed. This net scattering is attributed to deuterium trapping at grain boundaries in the polycrystalline sample. net scattering in excess of that expected from deuterium correlated at dislocations was also observed in a deformed polycrystalline measurement. This too is attributed to deuterium trapping at grain boundaries. The dislocation substructure of the deformed palladium samples was characterized by transmission electron microscopy (TEM). This analysis illustrated the cellular arrangement that evolved in palladium during cold working. The presence of MnO particles also was confirmed by TEM analysis.

  3. SE Gobe: Papua New Guinea`s second oil development

    SciTech Connect (OSTI)

    Langston, M.V.; McCaul, T.R.; Fitzmorris, R.E.

    1994-12-31

    A reservoir development plan was developed from a detailed geological model of the SE Gobe Iagifu reservoir. This model incorporated sequence stratigraphy and extensive core and log analysis to provide the detailed layering framework for reservoir simulation. Cross-sectional balancing techniques were applied to field derived dip and strike, dipmeter log, and RFT data to obtain a structural model for the reservoir. Cross-sectional, sector and, finally, full field reservoir simulation models were constructed and used by the team to generate a reservoir development and management plan. The simulation models were used to examine the relative merits of vertical, deviated and horizontal wells, well placement, offtake rates, gas compression requirements and pressure maintenance strategies. Due to the uncertainty in the size and shape of the field, development options were considered at each of three reserve levels: proven, probable and possible. The simulation results showed that well rates should be held to less than 8,000 stb/d and that horizontal wells, with a length of at least 700 m, generally out-performed vertical wells. Oil recovery ranged between 34 and 45% of OOIP. The cases offering the best recoveries included both water injection and horizontal wells.

  4. Pulsed laser deposition of Mn doped CdSe quantum dots for improved...

    Office of Scientific and Technical Information (OSTI)

    Pulsed laser deposition of Mn doped CdSe quantum dots for improved solar cell performance Citation Details In-Document Search Title: Pulsed laser deposition of Mn doped CdSe ...

  5. The US/SE Program Offices' FY 2016 Congressional Budget Request |

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

    Department of Energy The US/SE Program Offices' FY 2016 Congressional Budget Request The US/SE Program Offices' FY 2016 Congressional Budget Request Figure 2.1: The US/SE Program Offices' FY 2016 Congressional Budget Request (SEP, page 19) Figure 2.1: The US/SE Program Offices' FY 2016 Congressional Budget Request (SEP, page 19) The Under Secretary for Science and Energy (US/SE) program offices lead the Department's engagement in transformative science, technology innovation, and market

  6. Nanoimprinted Diffraction Gratings for Light Trapping in Crystal-Silicon Film Photovoltaics

    SciTech Connect (OSTI)

    Dirk Weiss

    2010-11-29

    Crystal-silicon (c-Si) film photovoltaics hold the promise of combining the advantages of state-of-the-art wafer-silicon technology with the scalability and the inherently much lower cost of thin-film solar technologies. In the thickness range of 2-20 ?¼m very effective light trapping is essential to absorb sufficient red and near-infrared (NIR) light and reach targeted efficiencies of 16%â??18%, as defined by the U.S. National Solar Technology Roadmap. One proposed method is diffractive light trapping, which, at least in certain wavelength ranges, can theoretically outperform light trapping through random scattering at a rough surface or interface. The goals of this project were (1) to develop a nanoimprinting process for a high-refractive-index dielectric material, (2) to fabricate diffraction gratings as back-reflectors using this material, and (3) to demonstrate for a 2 ?¼m c-Si film an improvement in AM1.5 photon absorption of at least 80% relative to single-pass absorption. We achieved goals (1) and (2). We developed a soft-imprint method for sol-based titanium dioxide precursor films (index range 2.3-2.4) and integrated imprinted films in thin-film silicon devices. We did not fully reach goal (3): depending on the model used for interpretation of the optical experimental data, AM1.5 photon absorption was improved by only 53% (coherent electromagnetic model) to 66% (non-coherent ray-tracing model). When compared to a metallized flat reference film (double-pass absorption), the improvement due to the grating is only 6%, if the (more conservative) electromagnetic model is used. Other important achievements from this project were: -We perfected an imprinting method for another ceramic material, aluminum oxide phosphate, which is index-matched with glass. -We tested diffractive light trapping at different incidence angles and found positive evidence for light trapping for angles up to 50?°, although the light-trapping efficiency decreased with increasing

  7. Current transient spectroscopy for trapping analysis on Au-free AlGaN/GaN Schottky barrier diode

    SciTech Connect (OSTI)

    Hu, J. Groeseneken, G.; Stoffels, S.; Lenci, S.; Venegas, R.; Decoutere, S.; Bakeroot, B.

    2015-02-23

    This paper presents a combined technique of high voltage off-state stress and current transient measurements to investigate the trapping/de-trapping characteristics of Au-free AlGaN/GaN Schottky barrier diodes. The device features a symmetric three-terminal structure with a central anode contact surrounded by two separate cathodes. Under the diode off-state stress conditions, the two separate cathodes were electrically shorted. The de-trapping dynamics was studied by monitoring the recovery of the two-dimensional electron gas (2DEG) current at different temperatures by applying 0.5?V at cathode 2 while grounding cathode 1. During the recovery, the anode contact acts as a sensor of changes in diode leakage current. This leakage variation was found to be mainly due to the barrier height variation. With this method, the energy level and capture cross section of different traps in the AlGaN/GaN Schottky barrier diode can be extracted. Furthermore, the physical location of different trapping phenomena is indicated by studying the variation of the diode leakage current during the recovery. We have identified two distinct trapping mechanisms: (i) electron trapping at the AlGaN surface in the vicinity of the Schottky contact which results in the leakage reduction (barrier height ?{sub B} increase) together with R{sub ON} degradation; (ii) the electron trapping in the GaN channel layer which partially depletes the 2DEG. The physical origin of the two different traps is discussed in the text.

  8. Elastic and surface energies: Two key parameters for CdSe quantum dot formation

    SciTech Connect (OSTI)

    Robin, Ivan-Christophe; Andre, Regis; Bougerol, Catherine; Aichele, Thomas; Tatarenko, Serge

    2006-06-05

    The two-dimensional-three-dimensional transition of a strained CdSe layer on (001) ZnSe induced by the use of amorphous selenium is studied. To precisely control the thickness of the CdSe layer, atomic layer epitaxy growth mode is used. Atomic force microscopy and reflection high-energy electron diffraction measurements reveal the formation of CdSe islands when 3 ML (monolayers) of CdSe, corresponding to the critical thickness, are deposited. When only 2.5 ML of CdSe are deposited another relaxation mechanism is observed, leading to the appearance of strong undulations on the surface. For a 3 ML thick CdSe layer, transmission electron microscopy images indicate that the formation of the islands occurs only after the amorphous selenium desorption.

  9. Method of synthesizing and growing copper-indium-diselenide (CuInSe.sub.2) crystals

    DOE Patents [OSTI]

    Ciszek, Theodore F.

    1987-01-01

    A process for preparing CuInSe.sub.2 crystals includes melting a sufficient quantity of B.sub.2 O.sub.3 along with stoichiometric quantities of Cu, In, and Se in a crucible in a high pressure atmosphere of inert gas to encapsulate the CuInSe.sub.2 melt and confine the Se to the crucible. Additional Se in the range of 1.8 to 2.2 percent over the stoichiometric quantity is preferred to make up for small amounts of Se lost in the process. The crystal is grown by inserting a seed crystal through the B.sub.2 O.sub.3 encapsulate into contact with the CuInSe.sub.2 melt and withdrawing the seed upwardly to grow the crystal thereon from the melt.

  10. Method of synthesizing and growing copper-indium-diselenide (CuInSe/sub 2/) crystals

    DOE Patents [OSTI]

    Ciszek, T.F.

    1984-11-29

    A process for preparing CuInSe/sub 2/ crystals includes melting a sufficient quantity of B/sub 2/O/sub 2/ along with stochiometric quantities of Cu, In, and Se in a crucible in a high-pressure atmosphere of inert gas to encapsulate the CuInSe/sub 2/ melt and confine the Se to the crucible. Additional Se in the range of 1.8 to 2.2% over the stochiometric quantity is preferred to make up for small amounts of Se lost in the process. The melt can then be cooled slowly to form the crystal as direct solidification, or the crystal can be grown by inserting a seed crystal through the B/sub 2/O/sub 3/ encapsulate into contact with the CuInSe/sub 2/ melt and withdrawing the seed upwardly to grow the crystal thereon from the melt.

  11. Mode trap for absorbing transverse modes of an accelerated electron beam

    DOE Patents [OSTI]

    Chojnacki, Eric P.

    1994-01-01

    A mode trap to trap and absorb transverse modes formed by a beam in a linear accelerator includes a waveguide having a multiplicity of electrically conductive (preferably copper) irises and rings, each iris and ring including an aperture, and the irises and rings being stacked in a side-by-side, alternating fashion such that the apertures of the irises and rings are concentrically aligned. An absorbing material layer such as a dielectric is embedded in each iris and ring, and this absorbing material layer encircles, but is circumferentially spaced from its respective aperture. Each iris and ring includes a plurality of circumferentially spaced slots around its aperture and extending radially out toward its absorbing material layer.

  12. The regenerable trap oxidizer-An emission control technique for diesel engines

    SciTech Connect (OSTI)

    Abthoff, J.; Schuster, H.D.; Langer, H.J.; Loose, G.

    1985-01-01

    Daimler-Benz made an early start with the development of systems for the aftertreatment of the exhaust gas emitted by diesel engines. The more important limiting conditions could best be met by the provision of a ceramic, selfcleaning trap oxidizer (TO). In such filters, self-regeneration is effected continuously while driving without any external control. Either partial or complete regeneration is effected, depending on the temperature, oxygen content and rate of flow of the exhaust gas, the amount of soot in the filter and the period for which a given operating condition is maintained. Such a trap oxidizer was developed for a 3.0 liter turbocharged diesel engine to the extent necessary for series production and has been fitted to type 300 SD and 300 D turbocharged diesel of model year 1985 in California.

  13. Mode trap for absorbing transverse modes of an accelerated electron beam

    DOE Patents [OSTI]

    Chojnacki, E.P.

    1994-05-31

    A mode trap to trap and absorb transverse modes formed by a beam in a linear accelerator includes a waveguide having a multiplicity of electrically conductive (preferably copper) irises and rings, each iris and ring including an aperture, and the irises and rings being stacked in a side-by-side, alternating fashion such that the apertures of the irises and rings are concentrically aligned. An absorbing material layer such as a dielectric is embedded in each iris and ring, and this absorbing material layer encircles, but is circumferentially spaced from its respective aperture. Each iris and ring includes a plurality of circumferentially spaced slots around its aperture and extending radially out toward its absorbing material layer. 9 figs.

  14. Role of fourth-order phase-space moments in collective modes of trapped Fermi gases

    SciTech Connect (OSTI)

    Chiacchiera, Silvia; Lepers, Thomas; Davesne, Dany; Urban, Michael

    2011-10-15

    We study the transition from hydrodynamic to collisionless behavior in collective modes of ultracold trapped Fermi gases. To that end, we solve the Boltzmann equation for the trapped Fermi gas via the moments method. We showed previously that it is necessary to go beyond second-order moments if one wants to reproduce the results of a numerical solution of the Boltzmann equation. Here, we will give the detailed description of the method including fourth-order moments. We apply this method to the case of realistic parameters, and compare the results for the radial quadrupole and scissors modes at unitarity to experimental data obtained by the Innsbruck group. It turns out that the inclusion of fourth-order moments clearly improves the agreement with the experimental data. In particular, the fourth-order moments reduce the effect of collisions and therefore partially compensate the effect of the enhanced in-medium cross section at low temperatures.

  15. Polish permian basin: Lithofacies traps for gas within the Rotliegende deposits as a new exploration potential

    SciTech Connect (OSTI)

    Karnkowski, P.H. )

    1993-09-01

    Rotliegende deposits are the most prospective reservoir gas rocks in the Polish Permian basin. Thirty years of their exploration have led to location of numerous gas fields in the upper-most part of these series, particularly in the area of the Fore-Sudetic monocline. Up to this time, exploration studies concentrated mainly on structural objects, and most of the structures were positive gas traps. Well and seismic data also indicate an occurrence of lithofacies gas traps; they occur mainly in the sandstone zones within the fanglomerates surrounding the Wolsztyn Ridge. When comparing the facies regularities in the known gas fields in the German Permian basin (interfingering sandstones and claystones) to the facies patterns of the Polish Permian basin, one may suspect similar exploration possibilities. These are the first promising results. Advances in analysis of the Rotliegende depositional systems will enable us to create a new exploration potential.

  16. Particle trap with dielectric barrier for use in gas insulated transmission lines

    DOE Patents [OSTI]

    Dale, S.J.

    1982-06-15

    A gas-insulated transmission line includes an outer sheath, an inner conductor within the outer sheath, insulating supports supporting the inner conductor within the outer sheath, and an insulating gas electrically insulating the inner conductor from the outer sheath. An apertured particle trapping electrode is disposed within the outer sheath, and the electrode has a pair of dielectric members secured at each longitudinal end thereof, with the dielectric members extending outwardly from the apertured electrode. 7 figs.

  17. Particle trap with dielectric barrier for use in gas insulated transmission lines

    DOE Patents [OSTI]

    Dale, Steinar J.

    1982-01-01

    A gas-insulated transmission line includes an outer sheath, an inner conductor within the outer sheath, insulating supports supporting the inner conductor within the outer sheath, and an insulating gas electrically insulating the inner conductor from the outer sheath. An apertured particle trapping electrode is disposed within the outer sheath, and the electrode has a pair of dielectric members secured at each longitudinal end thereof, with the dielectric members extending outwardly from the apertured electrode.

  18. Atom Trap Trace Analysis at ANL | U.S. DOE Office of Science (SC)

    Office of Science (SC) Website

    Atom Trap Trace Analysis at ANL Nuclear Physics (NP) NP Home About Research Facilities Science Highlights Benefits of NP Applications of Nuclear Science Applications of Nuclear Science Archives Small Business Innovation Research / Small Business Technology Transfer Funding Opportunities Nuclear Science Advisory Committee (NSAC) Community Resources Contact Information Nuclear Physics U.S. Department of Energy SC-26/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301)

  19. Assembling a ring-shaped crystal in a microfabricated surface ion trap

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

    Stick, Daniel Lynn; Univ. of New Mexico, Albuquerque, NM; Tabakov, Boyan; Univ. of New Mexico, Albuquerque, NM; Benito, Francisco; Blain, Matthew; Clark, Craig R.; Clark, Susan; Haltli, Raymond A.; Maunz, Peter; et al

    2015-09-01

    We report on experiments with a microfabricated surface trap designed for confining a chain of ions in a ring. Uniform ion separation over most of the ring is achieved with a rotationally symmetric design and by measuring and suppressing undesired electric fields. After reducing stray fields, the ions are confined primarily by a radio-frequency pseudopotential and their mutual Coulomb repulsion. As a result, approximately 400 40Ca+ ions with an average separation of 9 μm comprise the ion crystal.

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

    SciTech Connect (OSTI)

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

    2014-03-31

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

  1. EBIT (Electron Beam Ion Trap), N-Division Experimental Physics. Annual report, 1994

    SciTech Connect (OSTI)

    Schneider, D.

    1995-10-01

    The experimental groups in the Electron Beam Ion Trap (EBIT) program continue to perform front-line research with trapped and extracted highly charged ions (HCI) in the areas of ion/surface interactions, atomic spectroscopy, electron-ion interaction and structure measurements, highly charged ion confinement, and EBIT development studies. The ion surface/interaction studies which were initiated five years ago have reached a stage where they an carry out routine investigations, as well as produce breakthrough results towards the development of novel nanotechnology. At EBIT and SuperEBIT studies of the x-ray emission from trapped ions continue to produce significant atomic structure data with high precision for few electron systems of high-Z ions. Furthermore, diagnostics development for magnetic and laser fusion, supporting research for the x-ray laser and weapons programs, and laboratory astrophysics experiments in support of NASA`s astrophysics program are a continuing effort. The two-electron contributions to the binding energy of helium like ions were measured for the first time. The results are significant because their precision is an order of magnitude better than those of competing measurements at accelerators, and the novel technique isolates the energy corrections that are the most interesting. The RETRAP project which was initiated three years ago has reached a stage where trapping, confining and electronic cooling of HCI ions up to Th{sup 80+} can be performed routinely. Measurements of the rates and cross sections for electron transfer from H{sub 2} performed to determine the lifetime of HCI up to Xe{sup q+} and Th{sup q+} (35 {le} q {le} 80) have been studied at mean energies estimated to be {approximately} 5 q eV. This combination of heavy ions with very high charges and very low energies is rare in nature, but may be encountered in planned fusion energy demonstration devices, in highly charged ion sources, or in certain astrophysical events.

  2. Trapping of oil drops in a noncircular pore throat and mobilization upon contact with a surfactant

    SciTech Connect (OSTI)

    Arriola, A.; Green, D.W.; Willhite, G.P.

    1983-02-01

    An experimental apparatus was developed to study trapping and mobilization of oil drops in a capillary of square cross section (100 microns X 100 microns (100 ..mu..m X 100 ..mu..m)) having a constriction also approximately square in shape. Experiments to investigate trapping consisted of injecting a drop of nonwetting phase liquid (''oil'') into a flowing water stream (wetting phase). Pre-equilibrated alcohol/water systems were used to study effects of interfacial tension (IFT). A drop was displaced toward the constriction by the flowing water. The behavior of the drop as it approached and was trapped by the constriction or as it moved through the constriction was observed as a function of flow rate, drop length, and IFT between the water and nonwetting liquid. Mobilization by surfactants was investigated by conducting a series of displacement experiments in the capillary cell. Data from the mobilization experiments allowed two mechanisms to be identified. In Mechanism 1, minute quantities of the surfactant and/or cosurfactant were carried ahead of the main surfactant slug by brine that bypassed the slug. This reduced the IFT between the oil and brine. The oil drop moved further into the constriction and a snap-off process ensued. Mechanism 2 occurred when a sharp interface of the surfactant slug contacted the trailing edge of a nonane drop that was either trapped or in a snap-off process. A series of events that mobilized the drop occurred over a very short time period (< 4.0 seconds). The events included rupture of the drop interface, rolling motions inside the drop with resulting emulsification, and passage of the emulsified drop through the pore constriction without snap-off.

  3. Radiation detection system using semiconductor detector with differential carrier trapping and mobility

    DOE Patents [OSTI]

    Whited, Richard C. (Santa Barbara, CA)

    1981-01-01

    A system for obtaining improved resolution in relatively thick semiconductor radiation detectors, such as HgI.sub.2, which exhibit significant hole trapping. Two amplifiers are used: the first measures the charge collected and the second the contribution of the electrons to the charge collected. The outputs of the two amplifiers are utilized to unfold the total charge generated within the detector in response to a radiation event.

  4. Nanowire photonic crystal waveguides for single-atom trapping and strong light-matter interactions

    SciTech Connect (OSTI)

    Yu, S.-P.; Hood, J. D.; Muniz, J. A.; Martin, M. J.; Hung, C.-L.; Kimble, H. J.; Norte, Richard; Meenehan, Sen M.; Cohen, Justin D.; Painter, Oskar

    2014-03-17

    We present a comprehensive study of dispersion-engineered nanowire photonic crystal waveguides suitable for experiments in quantum optics and atomic physics with optically trapped atoms. Detailed design methodology and specifications are provided, as are the processing steps used to create silicon nitride waveguides of low optical loss in the near-IR. Measurements of the waveguide optical properties and power-handling capability are also presented.

  5. Species characterization and responses of subcortical insects to trap-logs and ethanol in a hardwood biomass plantation: Subcortical insects in hardwood plantations

    SciTech Connect (OSTI)

    Coyle, David R.; Brissey, Courtney L.; Gandhi, Kamal J. K.

    2015-01-02

    1. We characterized subcortical insect assemblages in economically important eastern cottonwood (Populus deltoides Bartr.), sycamore (Platanus occidentalis L.) and sweetgum (Liquidambar styraciflua L.) plantations in the southeastern U.S.A. Furthermore, we compared insect responses between freshly-cut plant material by placing traps directly over cut hardwood logs (trap-logs), traps baited with ethanol lures and unbaited (control) traps. 2. We captured a total of 15 506 insects representing 127 species in four families in 2011 and 2013. Approximately 9% and 62% of total species and individuals, respectively, and 23% and 79% of total Scolytinae species and individuals, respectively, were non-native to North America. 3. We captured more Scolytinae using cottonwood trap-logs compared with control traps in both years, although this was the case with sycamore and sweetgum only in 2013. More woodborers were captured using cottonwood and sweetgum trap-logs compared with control traps in both years, although only with sycamore in 2013. 4. Ethanol was an effective lure for capturing non-native Scolytinae; however, not all non-native species were captured using ethanol lures. Ambrosiophilus atratus (Eichhoff) and Hypothenemus crudiae (Panzer) were captured with both trap-logs and control traps, whereas Coccotrypes distinctus (Motschulsky) and Xyleborus glabratus Eichhoff were only captured on trap-logs. 5. Indicator species analysis revealed that certain scolytines [e.g. Cnestus mutilates (Blandford) and Xylosandrus crassiusculus (Motschulsky)] showed significant associations with trap-logs or ethanol baits in poplar or sweetgum trap-logs. In general, the species composition of subcortical insects, especially woodboring insects, was distinct among the three tree species and between those associated with trap-logs and control traps.

  6. Precision polarization measurements of atoms in a far-off-resonance optical dipole trap

    SciTech Connect (OSTI)

    Fang, F.; Vieira, D. J.; Zhao, X.

    2011-01-15

    Precision measurement of atomic and nuclear polarization is an essential step for beta-asymmetry measurement of radioactive atoms. In this paper, we report the polarization measurement of Rb atoms in an yttrium-aluminum-garnet (YAG) far-off-resonance optical dipole trap. We have prepared a cold cloud of polarized Rb atoms in the YAG dipole trap by optical pumping and achieved an initial nuclear polarization of up to 97.2(5)%. The initial atom distribution in different Zeeman levels is measured by using a combination of microwave excitation, laser pushing, and atomic retrap techniques. The nuclear-spin polarization is further purified to 99.2(2)% in 10 s and maintained above 99% because the two-body collision loss rate between atoms in mixed spin states is greater than the one-body trap loss rate. Systematic effects on the nuclear polarization, including the off-resonance Raman scattering, magnetic field gradient, and background gas collisions, are discussed.

  7. Microscopic model of electric-field-noise heating in ion traps

    SciTech Connect (OSTI)

    Safavi-Naini, A.; Rabl, P.; Weck, P. F.; Sadeghpour, H. R.

    2011-08-15

    Motional heating of ions in microfabricated traps is one of the open challenges hindering experimental realizations of large-scale quantum processing devices. Recently, a series of measurements of the heating rates in surface-electrode ion traps characterized their frequency, distance, and temperature dependencies, but our understanding of the microscopic origin of this noise remains incomplete. In this work we develop a theoretical model for the electric field noise which is associated with a random distribution of adsorbed atoms on the trap electrode surface. By using first-principles calculations of the fluctuating dipole moments of the adsorbed atoms we evaluate the distance, frequency, and temperature dependence of the resulting electric field fluctuation spectrum. Our theory reproduces correctly the d{sup -4} dependence with distance of the ion from the electrode surface and calculates the noise spectrum beyond the standard scenario of two-level fluctuators by incorporating all the relevant vibrational states. Our model predicts a regime of 1/f noise which commences at roughly the frequency of the fundamental phonon transition rate and a thermally activated noise spectrum which for higher temperatures exhibits a crossover as a function of frequency.

  8. Effects of magnetization on fusion product trapping and secondary neutron spectra

    SciTech Connect (OSTI)

    Knapp, Patrick F.; Schmit, Paul F.; Hansen, Stephanie B.; Gomez, Matthew R.; Hahn, Kelly D.; Sinars, Daniel Brian; Peterson, Kyle J.; Slutz, Stephen A.; Sefkow, Adam B.; Awe, Thomas James; Harding, Eric; Jennings, Christopher A.; Desjarlais, M. P.; Chandler, Gordon A.; Cooper, Gary Wayne; Cuneo, Michael Edward; Geissel, Matthias; Harvey-Thompson, Adam James; Porter, John L.; Rochau, Gregory A.; Rovang, Dean C.; Ruiz, Carlos L.; Savage, Mark E.; Smith, Ian C.; Stygar, William A.; Herrmann, Mark

    2015-05-14

    In magnetizing the fusion fuel in inertial confinement fusion (ICF) systems, we found that the required stagnation pressure and density can be relaxed dramatically. This happens because the magnetic field insulates the hot fuel from the cold pusher and traps the charged fusion burn products. This trapping allows the burn products to deposit their energy in the fuel, facilitating plasma self-heating. Here, we report on a comprehensive theory of this trapping in a cylindrical DD plasma magnetized with a purely axial magnetic field. Using this theory, we are able to show that the secondary fusion reactions can be used to infer the magnetic field-radius product, BR, during fusion burn. This parameter, not ?R, is the primary confinement parameter in magnetized ICF. Using this method, we analyze data from recent Magnetized Liner InertialFusion experiments conducted on the Z machine at Sandia National Laboratories. Furthermore, we show that in these experiments BR ? 0.34(+0.14/-0.06) MG cm, a ~ 14 increase in BR from the initial value, and confirming that the DD-fusion tritons are magnetized at stagnation. Lastly, this is the first experimental verification of charged burn product magnetization facilitated by compression of an initial seed magnetic flux.

  9. Storage of Ultracold Neutrons in the Magneto-Gravitational Trap of the UCN Experiment

    SciTech Connect (OSTI)

    Salvat, D. J.; Adamek, E. R.; Barlow, D.; Bowman, James D; Broussard, L. J.; Callahan, N. B.; Clayton, S. M.; Cude-Woods, C.; Currie, S.; Dees, E. B.; Fox, W.; Geltenbort, P.; Hickerson, K. P.; Holley, A. T.; Liu, C.-Y.; Makela, M.; Medina, J.; Morley, D. J.; Morris, C. L.; Penttila, Seppo I; Ramsey, J.; Saunders, A.; Seestrom, S. J.; Sharapov, E. I.; Sjue, S. K. L.; Slaughter, B. A.; Vanderwerp, J.; VornDick, B.; Walstrom, P. L.; Wang, Z.; Womack, T. L.; Young, A. R.

    2014-01-01

    The UCN experiment is designed to measure the lifetime n of the free neutron by trapping ultracold neutrons (UCN) in a magneto-gravitational trap. An asymmetric bowl-shaped NdFeB magnet Halbach array confines low-field-seeking UCN within the apparatus, and a set of electromagnetic coils in a toroidal geometry provides a background holding field to eliminate depolarization-induced UCN loss caused by magnetic field nodes. We present a measurement of the storage time store of the trap by storing UCN for various times and counting the survivors. The data are consistent with a single exponential decay, and we find store = 860 19 s, within 1 of current global averages for n. The storage time with the holding field deactivated is found to be store = 470 160 s; this decreased storage time is due to the loss of UCN, which undergo Majorana spin flips while being stored. We discuss plans to increase the statistical sensitivity of the measurement and investigate potential systematic effects.

  10. Light trapping in thin-film solar cells measured by Raman spectroscopy

    SciTech Connect (OSTI)

    Ledinský, M.; Moulin, E.; Bugnon, G.; Meillaud, F.; Ballif, C.; Ganzerová, K.; Vetushka, A.; Fejfar, A.

    2014-09-15

    In this study, Raman spectroscopy is used as a tool to determine the light-trapping capability of textured ZnO front electrodes implemented in microcrystalline silicon (μc-Si:H) solar cells. Microcrystalline silicon films deposited on superstrates of various roughnesses are characterized by Raman micro-spectroscopy at excitation wavelengths of 442 nm, 514 nm, 633 nm, and 785 nm, respectively. The way to measure quantitatively and with a high level of reproducibility the Raman intensity is described in details. By varying the superstrate texture and with it the light trapping in the μc-Si:H absorber layer, we find significant differences in the absolute Raman intensity measured in the near infrared wavelength region (where light trapping is relevant). A good agreement between the absolute Raman intensity and the external quantum efficiency of the μc-Si:H solar cells is obtained, demonstrating the validity of the introduced method. Applications to thin-film solar cells, in general, and other optoelectronic devices are discussed.

  11. Fluctuation characteristics and transport properties of collisionless trapped electron mode turbulence

    SciTech Connect (OSTI)

    Xiao Yong; Holod, Ihor; Zhang Wenlu; Lin Zhihong [Department of Physics and Astronomy, University of California, Irvine, California 92697 (United States); Klasky, Scott [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

    2010-02-15

    The collisionless trapped electron mode turbulence is investigated by global gyrokinetic particle simulation. The zonal flow dominated by low frequency and short wavelength acts as a very important saturation mechanism. The turbulent eddies are mostly microscopic, but with a significant portion in the mesoscale. The ion heat transport is found to be diffusive and follows the local radial profile of the turbulence intensity. However, the electron heat transport demonstrates some nondiffusive features and only follows the global profile of the turbulence intensity. The nondiffusive features of the electron heat transport is further confirmed by nonlognormal statistics of the flux-surface-averaged electron heat flux. The radial and time correlation functions are calculated to obtain the radial correlation length and autocorrelation time. Characteristic time scale analysis shows that the zonal flow shearing time and eddy turnover time are very close to the effective decorrelation time, which suggests that the trapped electrons move with the fluid eddies. The fluidlike behaviors of the trapped electrons and the persistence of the mesoscale eddies contribute to the transition of the electron turbulent transport from gyro-Bohm scaling to Bohm scaling when the device size decreases.

  12. Experimental investigation of plasma flows in open trap with toroidal diverter under ECR discharge

    SciTech Connect (OSTI)

    Berezkin, A. V. Bragin, E. Yu. Zhil’tsov, V. A. Kulygin, V. M. Yanchenkov, S. V.

    2015-12-15

    The results of experimental investigations of plasma flows from an open trap with a toroidal diverter are presented. Cold plasma is generated when introducing microwave power under conditions of electron cyclotron resonance (ECR). The radiation is introduced by a waveguide through a vacuum-tight ceramic window across the axis of the device. By means of the Langmuir probes, the spatial distributions of plasma parameters are measured. The highest density is limited to a critical value n{sub c} (∼10{sup 12} cm{sup –3}) for the generator frequency under use. It is found that the temperature and density of the plasma in the trap and in escaping flows are almost independent of the radius when the ECR zone is located near the open-trap confinement region and the density is close to n{sub c}. At the density n < n{sub c}, ring plasma structures, which collapse under the action of a low-frequency instability, are observed near the separatrix. The possible mechanisms of the occurrence of plasma structures and the nature of the plasma streams are discussed.

  13. Characterization of trapped gas saturation and heterogeneity in core samples using miscible-displacement experiments

    SciTech Connect (OSTI)

    Smith, D.H.; Jikich, S.A.

    1994-12-31

    Trapped gas saturation and permeability heterogeneity were evaluated in Berea cores at reservoir conditions, using standard miscible displacement experiments, with and without surfactants. Pressure and production history were influenced by core heterogeneity and foam lamellae formation when aqueous surfactant was present in the core. A simple dispersion model and a three-coefficient dispersion-capacitance model (Coates-Smith) were fit to the experimental data. The dispersion-capacitance model successfully matched the experiments in which foam lamella formed, while the simple dispersion model was used only for determining initial core flow heterogeneity. The objective of the dispersion-capacitance model was to estimate trapped gas saturations; however longitudinal dispersion and mass transfer also were examined. The results show that the dispersion-capacitance model accurately fits trapped gas saturation controlled by rock heterogeneities and foam lamellae for lamella generating mechanisms that allow a continuous gas phase (leave-behind lamellae). The practical applications resulting from this study can aid in core sample selection and scaling short laboratory corefloods to field dimensions for applications to foam stimulation and underground storage of natural gas.

  14. Effects of magnetization on fusion product trapping and secondary neutron spectra

    SciTech Connect (OSTI)

    Knapp, P. F.; Schmit, P. F.; Hansen, S. B.; Gomez, M. R.; Hahn, K. D.; Sinars, D. B.; Peterson, K. J.; Slutz, S. A.; Sefkow, A. B.; Awe, T. J.; Harding, E.; Jennings, C. A.; Desjarlais, M. P.; Chandler, G. A.; Cooper, G. W.; Cuneo, M. E.; Geissel, M.; Harvey-Thompson, A. J.; Porter, J. L.; Rochau, G. A.; and others

    2015-05-15

    By magnetizing the fusion fuel in inertial confinement fusion (ICF) systems, the required stagnation pressure and density can be relaxed dramatically. This happens because the magnetic field insulates the hot fuel from the cold pusher and traps the charged fusion burn products. This trapping allows the burn products to deposit their energy in the fuel, facilitating plasma self-heating. Here, we report on a comprehensive theory of this trapping in a cylindrical DD plasma magnetized with a purely axial magnetic field. Using this theory, we are able to show that the secondary fusion reactions can be used to infer the magnetic field-radius product, BR, during fusion burn. This parameter, not ρR, is the primary confinement parameter in magnetized ICF. Using this method, we analyze data from recent Magnetized Liner Inertial Fusion experiments conducted on the Z machine at Sandia National Laboratories. We show that in these experiments BR ≈ 0.34(+0.14/−0.06) MG · cm, a ∼ 14× increase in BR from the initial value, and confirming that the DD-fusion tritons are magnetized at stagnation. This is the first experimental verification of charged burn product magnetization facilitated by compression of an initial seed magnetic flux.

  15. Plasma regenerated particulate trap and NO.sub.x reduction system

    DOE Patents [OSTI]

    Penetrante, Bernardino M.; Vogtlin, George E.; Merritt, Bernard T.; Brusasco, Raymond M.

    2000-01-01

    A non-catalytic two-stage process for removal of NO.sub.x and particulates from engine exhaust comprises a first stage that plasma converts NO to NO.sub.2 in the presence of O.sub.2 and hydrocarbons, and a second stage, which preferably occurs simultaneously with the first stage, that converts NO.sub.2 and carbon soot particles to respective environmentally benign gases that include N.sub.2 and CO.sub.2. By preconverting NO to NO.sub.2 in the first stage, the efficiency of the second stage for NO.sub.x reduction is enhanced while carbon soot from trapped particulates is simultaneously converted to CO.sub.2 when reacting with the NO.sub.2 (that converts to N.sub.2). For example, an internal combustion engine exhaust is connected by a pipe to a chamber where carbon-containing particulates are electrostatically trapped or filtered and a non-thermal plasma converts NO to NO.sub.2 in the presence of O.sub.2 and hydrocarbons. Volatile hydrocarbons (C.sub.x H.sub.y) from the trapped particulates are oxidized in the plasma and the remaining soot from the particulates reacts with the NO.sub.2 to convert NO.sub.2 to N.sub.2, and the soot to CO.sub.2. The nitrogen exhaust components remain in the gas phase throughout the process, with no accompanying adsorption.

  16. Cooling the motion of diamond nanocrystals in a magneto-gravitational trap in high vacuum

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

    Hsu, Jen -Feng; Ji, Peng; Lewandowski, Charles W.; D’Urso, Brian

    2016-07-22

    Levitated diamond nanocrystals with nitrogen-vacancy (NV) centres in high vacuum have been proposed as a unique system for experiments in fundamental quantum mechanics, including the generation of large quantum superposition states and tests of quantum gravity. This system promises extreme isolation from its environment while providing quantum control and sensing through the NV centre spin. While optical trapping has been the most explored method of levitation, recent results indicate that excessive optical heating of the nanodiamonds under vacuum may make the method impractical with currently available materials. Here, we study an alternative magneto-gravitational trap for diamagnetic particles, such as diamondmore » nanocrystals, with stable levitation from atmospheric pressure to high vacuum. Magnetic field gradients from permanent magnets confine the particle in two dimensions, while confinement in the third dimension is gravitational. Furthermore, we demonstrate that feedback cooling of the centre-of-mass motion of a trapped nanodiamond cluster results in cooling of one degree of freedom to less than 1 K.« less

  17. Effects of magnetization on fusion product trapping and secondary neutron spectra

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

    Knapp, Patrick F.; Schmit, Paul F.; Hansen, Stephanie B.; Gomez, Matthew R.; Hahn, Kelly D.; Sinars, Daniel Brian; Peterson, Kyle J.; Slutz, Stephen A.; Sefkow, Adam B.; Awe, Thomas James; et al

    2015-05-14

    In magnetizing the fusion fuel in inertial confinement fusion (ICF) systems, we found that the required stagnation pressure and density can be relaxed dramatically. This happens because the magnetic field insulates the hot fuel from the cold pusher and traps the charged fusion burn products. This trapping allows the burn products to deposit their energy in the fuel, facilitating plasma self-heating. Here, we report on a comprehensive theory of this trapping in a cylindrical DD plasma magnetized with a purely axial magnetic field. Using this theory, we are able to show that the secondary fusion reactions can be used tomore » infer the magnetic field-radius product, BR, during fusion burn. This parameter, not ρR, is the primary confinement parameter in magnetized ICF. Using this method, we analyze data from recent Magnetized Liner InertialFusion experiments conducted on the Z machine at Sandia National Laboratories. Furthermore, we show that in these experiments BR ≈ 0.34(+0.14/-0.06) MG · cm, a ~ 14× increase in BR from the initial value, and confirming that the DD-fusion tritons are magnetized at stagnation. Lastly, this is the first experimental verification of charged burn product magnetization facilitated by compression of an initial seed magnetic flux.« less

  18. Near-field acoustic microbead trapping as remote anchor for single particle manipulation

    SciTech Connect (OSTI)

    Hwang, Jae Youn; Cheon, Dong Young; Shin, Hyunjune; Kim, Hyun Bin; Lee, Jungwoo

    2015-05-04

    We recently proposed an analytical model of a two-dimensional acoustic trapping of polystyrene beads in the ray acoustics regime, where a bead diameter is larger than the wavelength used. As its experimental validation, this paper demonstrates the transverse (or lateral) trapping of individual polystyrene beads in the near field of focused ultrasound. A 100 μm bead is immobilized on the central beam axis by a focused sound beam from a 30 MHz single element lithium niobate transducer, after being laterally displaced through hundreds of micrometers. Maximum displacement, a longest lateral distance at which a trapped bead can be directed towards the central axis, is thus measured over a discrete frequency range from 24 MHz to 36 MHz. The displacement data are found to be between 323.7 μm and 470.2 μm, depending on the transducer's driving frequency and input voltage amplitude. The experimental results are compared with their corresponding model values, and their relative errors lie between 0.9% and 3.9%. The results suggest that this remote maneuvering technique may be employed to manipulate individual cells through solid microbeads, provoking certain cellular reactions to localized mechanical disturbance without direct contact.

  19. Effects of magnetization on fusion product trapping and secondary neutron spectra

    SciTech Connect (OSTI)

    Knapp, Patrick F.; Schmit, Paul F.; Hansen, Stephanie B.; Gomez, Matthew R.; Hahn, Kelly D.; Sinars, Daniel Brian; Peterson, Kyle J.; Slutz, Stephen A.; Sefkow, Adam B.; Awe, Thomas James; Harding, Eric; Jennings, Christopher A.; Desjarlais, M. P.; Chandler, Gordon A.; Cooper, Gary Wayne; Cuneo, Michael Edward; Geissel, Matthias; Harvey-Thompson, Adam James; Porter, John L.; Rochau, Gregory A.; Rovang, Dean C.; Ruiz, Carlos L.; Savage, Mark E.; Smith, Ian C.; Stygar, William A.; Herrmann, Mark

    2015-05-14

    In magnetizing the fusion fuel in inertial confinement fusion (ICF) systems, we found that the required stagnation pressure and density can be relaxed dramatically. This happens because the magnetic field insulates the hot fuel from the cold pusher and traps the charged fusion burn products. This trapping allows the burn products to deposit their energy in the fuel, facilitating plasma self-heating. Here, we report on a comprehensive theory of this trapping in a cylindrical DD plasma magnetized with a purely axial magnetic field. Using this theory, we are able to show that the secondary fusion reactions can be used to infer the magnetic field-radius product, BR, during fusion burn. This parameter, not ρR, is the primary confinement parameter in magnetized ICF. Using this method, we analyze data from recent Magnetized Liner InertialFusion experiments conducted on the Z machine at Sandia National Laboratories. Furthermore, we show that in these experiments BR ≈ 0.34(+0.14/-0.06) MG · cm, a ~ 14× increase in BR from the initial value, and confirming that the DD-fusion tritons are magnetized at stagnation. Lastly, this is the first experimental verification of charged burn product magnetization facilitated by compression of an initial seed magnetic flux.

  20. Structural evolution of the Permian-Triassic Cooper basin, Australia: Relation to hydrocarbon trap styles

    SciTech Connect (OSTI)

    Apak, S.N.; Stuart, W.J.; Lemon, N.M.; Wood, G.

    1997-04-01

    The structural and depositional history of the Cooper basin in eastern central Australia has revealed that the basin is a mildly compressional structural depression controlled by northwestrending and northeast-trending pre-Permian basement features. Pronounced pre-Permian compressions are indicated by northeast-trending major structures, the Gidgealpa-Merrimelia-Innamincka and Murteree-Nappacoongee trends. Detailed chronostratigraphic facies analysis, with closely spaced palynological control, of the Patchawarra Formation revealed that two pronounced phases of uplift occurred during the Sakmarian. The major intrabasin highs were rejuvenated during these tectonic events, as documented by crestal unconformities (middle and upper Patchawarra unconformities). Evidence of each event is dominantly tectonic in character, with similar depositional patterns over these highs related to each event. These events are also recognizable in midflank areas and basin margins with contemporaneous deposition in deeper parts of the basin. Results from this research show potential for future hydrocarbon discoveries within structural, stratigraphic, and structural/stratigraphic traps in the Cooper basin. Various trap styles are closely associated with faults, unconformities, and lateral facies changes. Lowside fault closures, onlap plays, and unconformity traps are expected to be well developed along intrabasinal highs, basin margins, and preexisting structures. The primary reservoir targets would be deltaic sequences comprising shoreline sandstones, distributary and delta-mouth bar deposits that may be well developed in synclinal areas, and flanks of intrabasin highs in the Copper basin.

  1. Effect of dust charging and trapped electrons on nonlinear solitary structures in an inhomogeneous magnetized plasma

    SciTech Connect (OSTI)

    Kumar, Ravinder; Malik, Hitendra K.; Singh, Khushvant

    2012-01-15

    Main concerns of the present article are to investigate the effects of dust charging and trapped electrons on the solitary structures evolved in an inhomogeneous magnetized plasma. Such a plasma is found to support two types of waves, namely, fast wave and slow wave. Slow wave propagates in the plasma only when the wave propagation angle {theta} satisfies the condition {theta}{>=}tan{sup -1}{l_brace}({radical}((1+2{sigma})-[(n{sub dlh}({gamma}{sub 1}-1))/(1+n{sub dlh}{gamma}{sub 1})])-v{sub 0}/u{sub 0}){r_brace}, where v{sub 0}(u{sub 0}) is the z- (x-) component of ion drift velocity, {sigma} = T{sub i}/T{sub eff}, n{sub dlh} = n{sub d0}/(n{sub el0} + n{sub eh0}), and {gamma}{sub 1}=-(1/{Phi}{sub i0})[(1-{Phi}{sub i0}/1+{sigma}(1-{Phi}{sub i0}))] together with T{sub i} as ion temperature, n{sub el0}(n{sub eh0}) as the density of trapped (isothermal) electrons, {Phi}{sub i0} as the dust grain (density n{sub d0}) surface potential relative to zero plasma potential, and T{sub eff}=(n{sub elo}+n{sub eho})T{sub el}T{sub eh}/(n{sub elo}T{sub eh}+n{sub eho}T{sub el}), where T{sub el}(T{sub eh}) is the temperature of trapped (isothermal) electrons. Both the waves evolve in the form of density hill type structures in the plasma, confirming that these solitary structures are compressive in nature. These structures are found to attain higher amplitude when the charge on the dust grains is fluctuated (in comparison with the case of fixed charge) and also when the dust grains and trapped electrons are more in number; the same is the case with higher temperature of ions and electrons. Slow solitary structures show weak dependence on the dust concentration. Both types of structures are found to become narrower under the application of stronger magnetic field. With regard to the charging of dust grains, it is observed that the charge gets reduced for the higher trapped electron density and temperature of ions and electrons, and dust charging shows weak dependence on the ion

  2. Electron tunneling spectroscopy study of electrically active traps in AlGaN/GaN high electron mobility transistors

    SciTech Connect (OSTI)

    Yang, Jie Cui, Sharon; Ma, T. P.; Hung, Ting-Hsiang; Nath, Digbijoy; Krishnamoorthy, Sriram; Rajan, Siddharth

    2013-11-25

    We investigate the energy levels of electron traps in AlGaN/GaN high electron mobility transistors by the use of electron tunneling spectroscopy. Detailed analysis of a typical spectrum, obtained in a wide gate bias range and with both bias polarities, suggests the existence of electron traps both in the bulk of AlGaN and at the AlGaN/GaN interface. The energy levels of the electron traps have been determined to lie within a 0.5?eV band below the conduction band minimum of AlGaN, and there is strong evidence suggesting that these traps contribute to Frenkel-Poole conduction through the AlGaN barrier.

  3. Role of self-trapped holes in the photoconductive gain of β-gallium oxide Schottky diodes

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

    Armstrong, Andrew M.; Crawford, Mary H.; Jayawardena, Asanka; Ahyi, Ayayi; Dhar, Sarit

    2016-03-10

    Solar-blind photodetection and photoconductive gain > 50 corresponding to a responsivity > 8 A/W was observed for β-Ga2O3 Schottky photodiodes. We investigated the origin of photoconductive gain. Current-voltage characteristics of the diodes did not indicate avalanche breakdown, which excludes carrier multiplication by impact ionization as the source for gain. However, photocapacitance measurements indicated a mechanism for hole localization for above-band gap illumination, suggesting self-trapped hole formation. Comparison of photoconductivity and photocapacitance spectra indicated that self-trapped hole formation coincides with the strong photoconductive gain. We conclude that self-trapped hole formation near the Schottky diode lowers the effective Schottky barrier in reversemore » bias, producing photoconductive gain. Ascribing photoconductive gain to an inherent property like self-trapping of holes can explain the operation of a variety of β-Ga2O3 photodetectors.« less

  4. Electrical properties of In{sub 2}Se{sub 3} single crystals and photosensitivity of Al/In{sub 2}Se{sub 3} Schottky barriers

    SciTech Connect (OSTI)

    Bodnar, I. V.; Ilchuk, G. A.; Petrus', R. Yu.; Rud', V. Yu.; Rud', Yu. V.; Serginov, M.

    2009-09-15

    In{sub 2}Se{sub 3} single crystals {approx}40 mm long and 14 mm in diameter were grown by the Bridgman method. The composition of grown single crystals and their crystal structure were determined. The conductivity ({sigma}) and Hall constant (R) of grown single crystals were measured and the first Schottky barriers Al/n-In{sub 2}Se{sub 3} were fabricated. Rectification and photovoltaic effect were detected in the new structures. Based on the study of the photosensitivity spectra of Al/n-In{sub 2}Se{sub 3} structures, the nature of the interband transitions and band gap of In{sub 2}Se{sub 3} crystals were determined. It was concluded that the new structures can be applied to develop broadband photoconverters of optical radiation.

  5. Radionuclide trap

    DOE Patents [OSTI]

    McGuire, Joseph C.

    1978-01-01

    The deposition of radionuclides manganese-54, cobalt-58 and cobalt-60 from liquid sodium coolant is controlled by providing surfaces of nickel or high nickel alloys to extract the radionuclides from the liquid sodium, and by providing surfaces of tungsten, molybdenum or tantalum to prevent or retard radionuclide deposition.

  6. Trapping and laser cooling of Ca{sup +} ions toward future optical frequency standards: Observation of clock transitions

    SciTech Connect (OSTI)

    Urabe, S.; Hayasaka, K.; Watanabe, M.

    1994-12-31

    Experimental results of trapping and laser cooling of Ca{sup +} ions for future optical frequency standards are reported. Ca{sup +} ions were trapped and laser-cooled to below 1K. To observe the electric-quadrupole-allowed transitions (clock transitions), the laser diode operated at low temperature was developed. With this laser, the clock transitions were observed using the shelved electron double resonance method.

  7. Pulsed laser deposition of Mn doped CdSe quantum dots for improved solar cell performance

    SciTech Connect (OSTI)

    Dai, Qilin; Wang, Wenyong E-mail: jtang2@uwyo.edu; Tang, Jinke E-mail: jtang2@uwyo.edu; Sabio, Erwin M.

    2014-05-05

    In this work, we demonstrate (1) a facile method to prepare Mn doped CdSe quantum dots (QDs) on Zn{sub 2}SnO{sub 4} photoanodes by pulsed laser deposition and (2) improved device performance of quantum dot sensitized solar cells of the Mn doped QDs (CdSe:Mn) compared to the undoped QDs (CdSe). The band diagram of photoanode Zn{sub 2}SnO{sub 4} and sensitizer CdSe:Mn QD is proposed based on the incident-photon-to-electron conversion efficiency (IPCE) data. Mn-modified band structure leads to absorption at longer wavelengths than the undoped CdSe QDs, which is due to the exchange splitting of the CdSe:Mn conduction band by the Mn dopant. Three-fold increase in the IPCE efficiency has also been observed for the Mn doped samples.

  8. Towards high efficiency thin-film crystalline silicon solar cells: The roles of light trapping and non-radiative recombinations

    SciTech Connect (OSTI)

    Bozzola, A. Kowalczewski, P.; Andreani, L. C.

    2014-03-07

    Thin-film solar cells based on silicon have emerged as an alternative to standard thick wafers technology, but they are less efficient, because of incomplete absorption of sunlight, and non-radiative recombinations. In this paper, we focus on the case of crystalline silicon (c-Si) devices, and we present a full analytic electro-optical model for p-n junction solar cells with Lambertian light trapping. This model is validated against numerical solutions of the drift-diffusion equations. We use this model to investigate the interplay between light trapping, and bulk and surface recombination. Special attention is paid to surface recombination processes, which become more important in thinner devices. These effects are further amplified due to the textures required for light trapping, which lead to increased surface area. We show that c-Si solar cells with thickness of a few microns can overcome 20% efficiency and outperform bulk ones when light trapping is implemented. The optimal device thickness in presence of light trapping, bulk and surface recombination, is quantified to be in the range of 1080??m, depending on the bulk quality. These results hold, provided the effective surface recombination is kept below a critical level of the order of 100?cm/s. We discuss the possibility of meeting this requirement, in the context of state-of-the-art techniques for light trapping and surface passivation. We show that our predictions are within the capability of present day silicon technologies.

  9. PHaSE | U.S. DOE Office of Science (SC)

    Office of Science (SC) Website

    PHaSE Energy Frontier Research Centers (EFRCs) EFRCs Home Centers EFRC External Websites Research Science Highlights News & Events Publications History Contact BES Home Centers PHaSE Print Text Size: A A A FeedbackShare Page Polymer-Based Materials for Harvesting Solar Energy (PHaSE) Director(s): Thomas P. Russell and Paul M. Lahti Lead Institution: University of Massachusetts, Amherst Years: 2009-2014 Mission: To carry out fundamental photovoltaic-oriented research on the use of

  10. The PHaSE Photovoltaic & Optical Spectroscopy Facility Facility Director: Dr. Volodimyr Duzhko

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

    ! 32 The PHaSE Photovoltaic & Optical Spectroscopy Facility Facility Director: Dr. Volodimyr Duzhko The central facilities of the DOE-supported Energy Frontier Research Center "Polymer-Based Materials for Harvesting Solar Energy" (PHaSE) are housed in 1305 sq ft of newly renovated space, Rooms B523 and B524 of the Silvio O. Conte National Center for Polymer Research. The renovation was carried out with EFRC PHaSE ARRA funding. These facilities provide the PHaSE members and external

  11. Flow of US/SE Program Funding to National Laboratories (FY 2014 Enacted) |

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

    Department of Energy Flow of US/SE Program Funding to National Laboratories (FY 2014 Enacted) Flow of US/SE Program Funding to National Laboratories (FY 2014 Enacted) Figure 4.2: Flow of US/SE Program Funding to National Laboratories—FY 2014 Enacted (SEP, page 157) Figure 4.2: Flow of US/SE Program Funding to National Laboratories-FY 2014 Enacted (SEP, page 157) This figure illustrates the flow of funding to each of 17 DOE National Laboratories from five of the six Under Secretary for

  12. V-181: Oracle Java SE Critical Patch Update Advisory - June 2013 |

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

    Department of Energy 1: Oracle Java SE Critical Patch Update Advisory - June 2013 V-181: Oracle Java SE Critical Patch Update Advisory - June 2013 June 19, 2013 - 1:06am Addthis PROBLEM: Oracle Java SE Critical Patch Update Advisory - June 2013 PLATFORM: Version(s): 5.0 Update 45, 6 Update 45, 7 Update 21; and prior versions ABSTRACT: Multiple vulnerabilities were reported in Oracle Java. REFERENCE LINKS: Oracle Java SE Critical Patch Update June 2013 SecurityTracker Alert ID: 1028679

  13. A Novel and Functional Single Layer Sheet of ZnSe (Journal Article...

    Office of Scientific and Technical Information (OSTI)

    A Novel and Functional Single Layer Sheet of ZnSe Citation ... In this Communication, we report a novel singlelayer sheet ... Type: Accepted Manuscript Journal Name: ACS Applied ...

  14. SE HAN FINALIZADO LOS PREPARATIVOS PARA LA CONFERENCIA NACIONAL DE JUSTICIA MEDIOAMBIENTAL Y PROGRAMA DE FORMACIÓN 2013

    Broader source: Energy.gov [DOE]

    La National Environmental Justice Conference, Inc. (Conferencia de Justicia Medioambiental) se prepara para otro exitoso acontecimiento, ya que se aproxima la Conferencia Nacional de Justicia...

  15. BASIN VER DE GREAT ER ANETH BU G BAR KER DOME HOR SESH OE UTE...

    U.S. Energy Information Administration (EIA) Indexed Site

    Lands' Oil and Gas Resources and Reserves and the Extent and Nature of Restrictions to Their Development", prepared by the US Departments of Interior, Agriculture and Energy. ...

  16. BASIN VER DE GREAT ER ANETH BU G BAR KER DOME HOR SESH OE UTE...

    U.S. Energy Information Administration (EIA) Indexed Site

    Map created June 2005; projection is UTM-13, NAD-27. Authors: Sam Limerick (1), Lucy Luo (1), Gary Long (2), David Morehouse (2), Jack Perrin (1), Steve Jackson (1) and Robert King ...

  17. BASIN VER DE GREAT ER ANETH BU G BAR KER DOME HOR SESH OE UTE...

    U.S. Energy Information Administration (EIA) Indexed Site

    Unnamed fields and fields generically named "wildcat" were renamed to a concatenate of their basin and state of occurrence, e.g. UPUT (Uinta-Piceance Basin and Utah). Map created ...

  18. BASIN VER DE GREAT ER ANETH BU G BAR KER DOME HOR SESH OE UTE DOME

    U.S. Energy Information Administration (EIA) Indexed Site

    BOE Reserve Class 0 20 40 10 30 Miles ± The mapped oil and gas field boundary outlines were created by the Reserves and Production Division, Office of Oil and Gas, Energy Information Administration pursuant to studies required by Section 604 of the Energy Policy and Conservation Act Amendments of 2000 (P.L. 106-469). The boundaries are not informed by subsurface structural information. The data and methods used in their creation are detailed in a report, "Scientific Inventory of Onshore

  19. BASIN VER DE GREAT ER ANETH BU G BAR KER DOME HOR SESH OE UTE DOME

    U.S. Energy Information Administration (EIA) Indexed Site

    Gas Reserve Class 0 20 40 10 30 Miles ± The mapped oil and gas field boundary outlines were created by the Reserves and Production Division, Office of Oil and Gas, Energy Information Administration pursuant to studies required by Section 604 of the Energy Policy and Conservation Act Amendments of 2000 (P.L. 106-469). The boundaries are not informed by subsurface structural information. The data and methods used in their creation are detailed in a report, "Scientific Inventory of Onshore

  20. BASIN VER DE GREAT ER ANETH BU G BAR KER DOME HOR SESH OE UTE DOME

    U.S. Energy Information Administration (EIA) Indexed Site

    Liquids Reserve Class 0 20 40 10 30 Miles ± The mapped oil and gas field boundary outlines were created by the Reserves and Production Division, Office of Oil and Gas, Energy Information Administration pursuant to studies required by Section 604 of the Energy Policy and Conservation Act Amendments of 2000 (P.L. 106-469). The boundaries are not informed by subsurface structural information. The data and methods used in their creation are detailed in a report, "Scientific Inventory of

  1. Electron Flood Charge Compensation Device for Ion Trap Secondary Ion Mass Spectrometry

    SciTech Connect (OSTI)

    Appelhans, Anthony David; Ward, Michael Blair; Olson, John Eric

    2002-11-01

    During secondary ion mass spectrometry (SIMS) analyses of organophosphorous compounds adsorbed onto soils, the measured anion signals were lower than expected and it was hypothesized that the low signals could be due to sample charging. An electron flood gun was designed, constructed and used to investigate sample charging of these and other sample types. The flood gun was integrated into one end cap of an ion trap secondary ion mass spectrometer and the design maintained the geometry of the self-stabilizing extraction optics used in this instrument. The SIMION ion optics program was used to design the flood gun, and experimental results agreed with the predicted performance. Results showed the low anion signals from the soils were not due to sample charging. Other insulating and conducting samples were tested using both a ReO4- and a Cs+ primary ion beam. The proximity of the sample and electron source to the ion trap aperture resulted in generation of background ions in the ion trap via electron impact (EI) ionization during the period the electron gun was flooding the sample region. When using the electron gun with the ReO4- primary beam, the required electron current was low enough that the EI background was negligible; however, the high electron flood current required with the Cs+ beam produced background EI ions that degraded the quality of the mass spectra. The consequences of the EI produced cations will have to be evaluated on a sample-by-sample basis when using electron flood. It was shown that the electron flood gun could be intentionally operated to produce EI spectra in this instrument. This offers the opportunity to measure, nearly simultaneously, species evaporating from a sample, via EI, and species bound to the surface, via SIMS.

  2. Differences in chemical doping matter: Superconductivity in Ti1-xTaxSe2 but not in Ti1-xNbxSe2

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

    Luo, Huixia; Zhu, Yimei; Xie, Weiwei; Tao, Jing; Pletikosic, Ivo; Valla, Tonica; Sahasrabudhe, Girija S.; Osterhoudt, Gavin; Sutton, Eric; Burch, Kenneth S.; et al

    2016-02-21

    We report that 1T-TiSe2, an archetypical layered transition metal dichalcogenide, becomes superconducting when Ta is substituted for Ti but not when Nb is substituted for Ti. This is unexpected because Nb and Ta should be chemically equivalent electron donors. Superconductivity emerges near x = 0.02 for Ti1–xTaxSe2, while, for Ti1–xNbxSe2, no superconducting transitions are observed above 0.4 K. The equivalent chemical nature of the dopants is confirmed by X-ray photoelectron spectroscopy. ARPES and Raman scattering studies show similarities and differences between the two systems, but the fundamental reasons why the Nb and Ta dopants yield such different behavior are unknown.more » We present a comparison of the electronic phase diagrams of many electron-doped 1T-TiSe2 systems, showing that they behave quite differently, which may have broad implications in the search for new superconductors. Here, we propose that superconducting Ti0.8Ta0.2Se2 will be suitable for devices and other studies based on exfoliated crystal flakes.« less

  3. Assembling a ring-shaped crystal in a microfabricated surface ion trap

    SciTech Connect (OSTI)

    Stick, Daniel Lynn; Tabakov, Boyan; Benito, Francisco; Blain, Matthew; Clark, Craig R.; Clark, Susan; Haltli, Raymond A.; Maunz, Peter; Sterk, Jonathan D.; Tigges, Chris

    2015-09-01

    We report on experiments with a microfabricated surface trap designed for confining a chain of ions in a ring. Uniform ion separation over most of the ring is achieved with a rotationally symmetric design and by measuring and suppressing undesired electric fields. After reducing stray fields, the ions are confined primarily by a radio-frequency pseudopotential and their mutual Coulomb repulsion. As a result, approximately 400 40Ca+ ions with an average separation of 9 μm comprise the ion crystal.

  4. Testing the density matrix expansion against ab initio calculations of trapped neutron drops

    SciTech Connect (OSTI)

    Bogner, S. K.; Hergert, H.; Furnstahl, R. J.; Kortelainen, Erno M; Stoitsov, M. V.; Maris, Pieter; Vary, J. P.

    2011-01-01

    Microscopic input to a universal nuclear energy density functional can be provided through the density matrix expansion (DME), which has recently been revived and improved. Several DME implementation strategies are tested for neutron drop systems in harmonic traps by comparing to Hartree-Fock (HF) and ab initio no-core full configuration (NCFC) calculations with a model interaction (Minnesota potential). The new DME with exact treatment of Hartree contributions is found to best reproduce HF results and supplementing the functional with fit Skyrme-like contact terms shows systematic improvement toward the full NCFC results.

  5. Quantum signatures of the self-trapping transition in attractive lattice bosons

    SciTech Connect (OSTI)

    Buonsante, P.; Penna, V.; Vezzani, A.

    2010-10-15

    We consider the Bose-Hubbard model describing attractive bosonic particles hopping across the sites of a translation-invariant lattice and compare the relevant ground-state properties with those of the corresponding symmetry-breaking semiclassical nonlinear theory. The introduction of a suitable measure allows us to highlight many correspondences between the nonlinear theory and the inherently linear quantum theory, characterized by the well-known self-trapping phenomenon. In particular we demonstrate that the localization properties and bifurcation pattern of the semiclassical ground state can be clearly recognized at the quantum level. Our analysis highlights a finite-number effect.

  6. Stochastic processes of particle trapping and detrapping by a wave in a magnetized plasma

    SciTech Connect (OSTI)

    Zaslavsky, A.; Krafft, C.; Volokitin, A.

    2006-01-15

    This paper presents some relevant numerical simulations of the three-dimensional evolution of a monochromatic lower hybrid wave interacting at the Landau resonance with a Maxwellian electron beam in a magnetized plasma. A statistical study of the stochastic trapping-detrapping transitions performed by a large set of quasiresonant test particles moving self-consistently in the wave's potential has been carried out using dynamical criteria based on simple physical arguments. The paper allows us to explain the role of the stochastic processes at work in the wave-particle interactions and to shed light on their influence on the dynamical evolution of the system over a long range of time.

  7. Dirac Equation and Quantum Relativistic Effects in a Single Trapped Ion

    SciTech Connect (OSTI)

    Lamata, L.; Leon, J.; Schaetz, T.; Solano, E.

    2007-06-22

    We present a method of simulating the Dirac equation in 3+1 dimensions for a free spin-1/2 particle in a single trapped ion. The Dirac bispinor is represented by four ionic internal states, and position and momentum of the Dirac particle are associated with the respective ionic variables. We show also how to simulate the simplified 1+1 case, requiring the manipulation of only two internal levels and one motional degree of freedom. Moreover, we study relevant quantum-relativistic effects, like the Zitterbewegung and Klein's paradox, the transition from massless to massive fermions, and the relativistic and nonrelativistic limits, via the tuning of controllable experimental parameters.

  8. Spin Self-Rephasing and Very Long Coherence Times in a Trapped Atomic Ensemble

    SciTech Connect (OSTI)

    Deutsch, C.; Reinhard, F.; Schneider, T.; Laloee, F.; Reichel, J. [Laboratoire Kastler Brossel, ENS, UPMC, CNRS, 24 rue Lhomond, 75005 Paris (France); Ramirez-Martinez, F.; Lacroute, C.; Rosenbusch, P. [LNE-SYRTE, Observatoire de Paris, UPMC, CNRS, 61 av de l'Observatoire, 75014 Paris (France); Fuchs, J. N.; Piechon, F. [Laboratoire de Physique des Solides, CNRS UMR 8502, Univ. Paris-Sud, 91405 Orsay (France)

    2010-07-09

    We perform Ramsey spectroscopy on the ground state of ultracold {sup 87}Rb atoms magnetically trapped on a chip in the Knudsen regime. Field inhomogeneities over the sample should limit the 1/e contrast decay time to about 3 s, while decay times of 58{+-}12 s are actually observed. We explain this surprising result by a spin self-rephasing mechanism induced by the identical spin rotation effect originating from particle indistinguishability. We propose a theory of this synchronization mechanism and obtain good agreement with the experimental observations. The effect is general and may appear in other physical systems.

  9. On the Equivalence of Trapped Colloids, Pinned Vortices, and Spin Ice

    SciTech Connect (OSTI)

    Nisoli, Cristiano

    2014-04-23

    We investigate the recently reported analogies between pinned vortices in nano-structured superconductors or colloids in optical traps, and spin ice materials. The frustration of the two models, one describing colloids and vortices, the other describing spin ice, differs essentially. However, their effective energetics is made identical by the contribution of an emergent field associated to a topological charge. This equivalence extends to the local low-energy dynamics of the ice manifold, yet breaks down in lattices of mixed coordination, because of topological charge transfer between sub-latices.

  10. Electron collisions in the trapped gyro-Landau fluid transport model

    SciTech Connect (OSTI)

    Staebler, G. M.; Kinsey, J. E.

    2010-12-15

    Accurately modeling electron collisions in the trapped gyro-Landau fluid (TGLF) equations has been a major challenge. Insights gained from numerically solving the gyrokinetic equation have lead to a significant improvement of the low order TGLF model. The theoretical motivation and verification of this model with the velocity-space gyrokinetic code GYRO[J. Candy and R. E. Waltz, J. Comput. Phys. 186, 545 (2003)] will be presented. The improvement in the fidelity of TGLF to GYRO is shown to also lead to better prediction of experimental temperature profiles by TGLF for a dedicated collision frequency scan.

  11. Lean NOx Trap Regeneration Selectivity Towards N2O -- Similarities and

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

    Differences Between H2, CO and C3H6 Reductants | Department of Energy Regeneration Selectivity Towards N2O -- Similarities and Differences Between H2, CO and C3H6 Reductants Lean NOx Trap Regeneration Selectivity Towards N2O -- Similarities and Differences Between H2, CO and C3H6 Reductants At lower-intermediate exhaust temperatures, N2O is emitted in two peaks. This presentation uses a global model for the primary and secondary peaks to explain the chemical reactions. deer12_bartova.pdf

  12. High-fidelity ion-trap quantum computing with hyperfine clock states

    SciTech Connect (OSTI)

    Aolita, L.; Kim, K.; Benhelm, J.; Roos, C. F.; Haeffner, H.

    2007-10-15

    We propose the implementation of a geometric-phase gate on magnetic-field-insensitive qubits with {sigma}{sup z}-dependent forces for trapped ion quantum computing. The force is exerted by two laser beams in a Raman configuration. Qubit-state dependency is achieved by a small frequency detuning from the virtually excited state. Ion species with excited states of long radiative lifetimes are used to reduce the chance of a spontaneous photon emission to less than 10{sup -8} per gate run. This eliminates the main source of gate infidelity in previous implementations. With this scheme it seems possible to reach the fault-tolerant threshold.

  13. Development of a Low Cost Insulated Foil Substrate for Cu(InGaSe)2 Photovoltaics

    SciTech Connect (OSTI)

    ERTEN ESER

    2012-01-22

    The project validated the use of stainless steel flexible substrate coated with silicone-based resin dielectric, developed by Dow Corning Corporation, for Cu(InGa)Se2 based photovoltaics. The projects driving force was the high performance of Cu(InGa)Se2 based photovoltaics coupled with potential cost reduction that could be achieved with dielectric coated SS web substrate.

  14. Ligand-Mediated Modification of the Electronic Structure of CdSe Quantum Dots

    SciTech Connect (OSTI)

    Lee, Jonathan R.; Whitley, Heather D.; Meulenberg, Robert W.; Wolcott, Abraham; Zhang, Jin Z.; Prendergast, Peter; Lovingood, Derek D.; Strouse, Geoffrey F.; Ogitsu, Tadashi; Schwegler, Eric; Terminello, Louis J.; Van Buuren, Tony W.

    2012-05-18

    X-ray absorption spectroscopy and ab initio modeling of the experimental spectra have been used to investigate the effects of surface passivation on the unoccupied electronic states of CdSe quantum dots (QDs). Significant differences are observed in the unoccupied electronic structure of the CdSe QDs, which are shown to arise from variations in specific ligand-surface bonding interactions.

  15. Two-dimensional Vlasov simulation of electron plasma wave trapping, wavefront bowing, self-focusing, and sideloss

    SciTech Connect (OSTI)

    Banks, J. W.; Berger, R. L.; Cohen, B. I.; Hittinger, J. A. F.; Brunner, S.

    2011-05-15

    Two-dimensional Vlasov simulations of nonlinear electron plasma waves are presented, in which the interplay of linear and nonlinear kinetic effects is evident. The plasma wave is created with an external traveling wave potential with a transverse envelope of width {Delta}y such that thermal electrons transit the wave in a ''sideloss'' time, t{sub sl{approx}{Delta}}y/v{sub e}. Here, v{sub e} is the electron thermal velocity. The quasisteady distribution of trapped electrons and its self-consistent plasma wave are studied after the external field is turned off. In cases of particular interest, the bounce frequency, {omega}{sub be}=k{radical}(e{phi}/m{sub e}), satisfies the trapping condition {omega}{sub be}t{sub sl}>2{pi} such that the wave frequency is nonlinearly downshifted by an amount proportional to the number of trapped electrons. Here, k is the wavenumber of the plasma wave and {phi} is its electric potential. For sufficiently short times, the magnitude of the negative frequency shift is a local function of {phi}. Because the trapping frequency shift is negative, the phase of the wave on axis lags the off-axis phase if the trapping nonlinearity dominates linear wave diffraction. In this case, the phasefronts are curved in a focusing sense. In the opposite limit, the phasefronts are curved in a defocusing sense. Analysis and simulations in which the wave amplitude and transverse width are varied establish criteria for the development of each type of wavefront. The damping and trapped-electron-induced focusing of the finite-amplitude electron plasma wave are also simulated. The damping rate of the field energy of the wave is found to be about the sideloss rate, {nu}{sub e{approx}}t{sub sl}{sup -1}. For large wave amplitudes or widths {Delta}y, a trapping-induced self-focusing of the wave is demonstrated.

  16. NOx Reduction with Natural Gas for Lean Large-Bore Engine Applications Using Lean NOx Trap Aftertreatment

    SciTech Connect (OSTI)

    Parks, JE

    2005-02-11

    Large-bore natural gas engines are used for distributed energy and gas compression since natural gas fuel offers a convenient and reliable fuel source via the natural gas pipeline and distribution infrastructure. Lean engines enable better fuel efficiency and lower operating costs; however, NOx emissions from lean engines are difficult to control. Technologies that reduce NOx in lean exhaust are desired to enable broader use of efficient lean engines. Lean NOx trap catalysts have demonstrated greater than 90% NOx reduction in lean exhaust from engines operating with gasoline, diesel, and natural gas fuels. In addition to the clean nature of the technology, lean NOx traps reduce NOx with the fuel source of the engine thereby eliminating the requirement for storage and handling of secondary fuels or reducing agents. A study of lean NOx trap catalysts for lean natural gas engines is presented here. Testing was performed on a Cummins C8.3G (CG-280) engine on a motor dynamometer. Lean NOx trap catalysts were tested for NOx reduction performance under various engine operating conditions, and the utilization of natural gas as the reductant fuel source was characterized. Engine test results show that temperature greatly affects the catalytic processes involved, specifically methane oxidation and NOx storage on the lean NOx trap. Additional studies on a bench flow reactor demonstrate the effect of precious metal loading (a primary cost factor) on lean NOx trap performance at different temperatures. Results and issues related to the potential of the lean NOx trap technology for large-bore engine applications will be discussed.

  17. Surface Plasmon Excitation via Au Nanoparticles in CdSe Semiconductor

    SciTech Connect (OSTI)

    Pradhan, A. K.; Konda, R. B.; Mundle, R.; Mustafa, H.; Bamiduro, O.; Roy, U. N.; Cui, Y.; Burger, A.

    2008-10-23

    We present experimental evidence for the large Raman and photoluminescence enhancement in CdSe semiconductor films grown on Si and glass substrates due to excitation of surface plasmon resonances in proximate gold metal nanoparticles deposited on the surface of CdSe film. Heterojunction diodes containing n-CdSe on p-Si semiconductor were fabricated and the surface of the diodes was in situ coated with Au nanoparticles using the ultra-high vacuum pulsed-laser deposition technique. A significant enhancement of the photocurrent was obtained in CdSe/p-Si containing Au nanoparticles on the surface compared to CdSe/p-Si due to the enhanced photo-absorption within the semiconductor by the phenomenon of surface plasmon resonance. These observations suggest a variety of approaches for improving the performance of devices such as photodetectors, photovoltaic, and related devices, including biosensors.

  18. Glass formation and the third harmonic generation of Cu{sub 2}Se–GeSe{sub 2}–As{sub 2}Se{sub 3} glasses

    SciTech Connect (OSTI)

    Reshak, A. H.; Klymovych, O. S.; Zmiy, O. F.; Myronchuk, G. L.; Zamuruyeva, O. V.; Alahmed, Z. A.; Chyský, J.; Bila, Jiri; Kamarudin, H.

    2014-10-14

    We have performed the investigation of the nonlinear optical properties namely the third harmonic generation (THG) of the glass-formation region in the Cu{sub 2}Se–GeSe{sub 2}–As{sub 2}Se{sub 3} system. The samples were synthesized by direct single-temperature method from high-purity elementary substances. We have found that the value of disorder parameter Δ depends on the composition of the glassy alloys. The measurements show that increasing the Cu{sub 2}Se concentration leads to increased slope of the absorption edge, which may be explained by the decrease of the height of random potential relief for the electrons in the tails of the state density which border the band edges. A very sharp increase in the THG at low temperature was observed. Significant enhancement in THG was obtained with decreasing the energy gap, which agreed well with the nonlinear optical susceptibilities obtained from other glasses.

  19. Spatial shaping for generating arbitrary optical dipole traps for ultracold degenerate gases

    SciTech Connect (OSTI)

    Lee, Jeffrey G.; Hill, W. T.

    2014-10-15

    We present two spatial-shaping approaches phase and amplitude for creating two-dimensional optical dipole potentials for ultracold neutral atoms. When combined with an attractive or repulsive Gaussian sheet formed by an astigmatically focused beam, atoms are trapped in three dimensions resulting in planar confinement with an arbitrary network of potentials a free-space atom chip. The first approach utilizes an adaptation of the generalized phase-contrast technique to convert a phase structure embedded in a beam after traversing a phase mask, to an identical intensity profile in the image plane. Phase masks, and a requisite phase-contrast filter, can be chemically etched into optical material (e.g., fused silica) or implemented with spatial light modulators; etching provides the highest quality while spatial light modulators enable prototyping and realtime structure modification. This approach was demonstrated on an ensemble of thermal atoms. Amplitude shaping is possible when the potential structure is made as an opaque mask in the path of a dipole trap beam, followed by imaging the shadow onto the plane of the atoms. While much more lossy, this very simple and inexpensive approach can produce dipole potentials suitable for containing degenerate gases. High-quality amplitude masks can be produced with standard photolithography techniques. Amplitude shaping was demonstrated on a Bose-Einstein condensate.

  20. Perturbation analysis of trapped-particle dynamics in axisymmetric dipole geometry

    SciTech Connect (OSTI)

    Duthoit, F.-X.; Brizard, A. J.; Peysson, Y.; Decker, J.

    2010-10-15

    The bounce-action-angle coordinates (J,{zeta}) for charged particles trapped in an axisymmetric dipole magnetic field are constructed by perturbation analysis. First, the lowest-order bounce-action-angle coordinates (J{sub 0},{zeta}{sub 0}) are derived for deeply trapped particles in the harmonic-oscillator approximation. Next, the Lie-transform perturbation method is used to derive higher-order anharmonic action-angle corrections (J=J{sub 0}+{epsilon}{sub t}J{sub 1}, {zeta}={zeta}{sub 0}+{epsilon}{sub t{zeta}1}), where the dimensionless parameter {epsilon}{sub t{identical_to}}(s{sub b}/r{sub e}){sup 2}<<1 is defined as the ratio of the turning-point distance |s{sub b}| (measured from the equator) along a magnetic field line labeled by the equatorial distance r{sub e}. Explicit expressions (with anharmonic corrections) for the canonical parallel coordinates s(J,{zeta}) and p{sub ||}(J,{zeta}) are presented, which satisfy the canonical identity {l_brace}s,p{sub ||{r_brace}{identical_to}}1. Lastly, analytical expressions for the bounce and drift frequencies (which include anharmonic corrections) yield excellent agreement with exact numerical results.

  1. Trapping the M sub 1 and M sub 2 substrates of bacteriorhodopsin for electron diffraction studies

    SciTech Connect (OSTI)

    Perkins, G.A.

    1992-05-01

    Visible and Fourier transform infrared (FTIR) absorption spectroscopies are used to observe protein conformational changes occuring during the bacteriorhodopsin photocycle. Spectroscopic measurements which define the conditions under which bacteriorhodopsin can be isolated and trapped in two distinct substates of the m intermediate of the photocycle, M{sub 1}, and M{sub 2}, are described. A protocol that can be used for high-resolution electron diffraction studies is presented that will trap glucose-embedded purple membrane in the M{sub 1}and M{sub 2} substates at greater than 90% concentration. It was discovered that glucose alone does not provide a fully hydrated environment for bacteriorhodopsin. Equilibration of glucose-embedded samples at high humidity can result in a physical state that is demonstrably closer to the native, fully hydrated state. An extension of the C-T Model of bacteriorhodopsin functionality (Fodor et al., 1988; Mathies et al., 1991) is proposed based on FTIR results and guided by published spectra from resonance Raman and FTIR work. 105 refs.

  2. Tritium trapping in silicon carbide in contact with solid breeder under high flux isotope reactor irradiation

    SciTech Connect (OSTI)

    H. Katsui; Y. Katoh; A. Hasegawa; M. Shimada; Y. Hatano; T. Hinoki; S. Nogami; T. Tanaka; S. Nagata; T. Shikama

    2013-11-01

    The trapping of tritium in silicon carbide (SiC) injected from ceramic breeding materials was examined via tritium measurements using imaging plate (IP) techniques. Monolithic SiC in contact with ternary lithium oxide (lithium titanate and lithium aluminate) as a ceramic breeder was irradiated in the High Flux Isotope Reactor (HFIR) in Oak Ridge, Tennessee, USA. The distribution of photo-stimulated luminescence (PSL) of tritium in SiC was successfully obtained, which separated the contribution of 14C -rays to the PSL. The tritium incident from ceramic breeders was retained in the vicinity of the SiC surface even after irradiation at 1073 K over the duration of ~3000 h, while trapping of tritium was not observed in the bulk region. The PSL intensity near the SiC surface in contact with lithium titanate was higher than that obtained with lithium aluminate. The amount of the incident tritium and/or the formation of a Li2SiO3 phase on SiC due to the reaction with lithium aluminate under irradiation likely were responsible for this observation.

  3. Evidence for old crust in the provenance of the Trap Falls Formation, southwestern Connecticut

    SciTech Connect (OSTI)

    McDaniel, D.K.; Sevigny, J.H.; Bock, B.; Hanson, G.N.; McLennan, S.M. . Dept. of Earth and Space Sciences)

    1993-03-01

    The Trap Fall Formation is a multiply deformed, amphibolite facies metasedimentary sequence in southwestern Connecticut. It contains interlayered pelitic schists and lesser quartzites, and may represent turbidites. The major element compositions of 3 schists are compatible with a shale protolith. Their aluminous nature (CIA = 68--70) suggests a weathering history in the source, but may in part be a result of metamorphic processes. High SiO[sub 2] (85--91%) and Zr (305--370 ppm) concentrations in the quartzites are consistent with a significant component of recycled sediment in the source. A single abraded detrital zircon from a quartzite gives a concordant U-Pb age of 1,009 [plus minus] 6 Ma and suggests a source in Grenville-aged crust. E[sub Nd] at 450 Ma of [minus] 9.2 for one schist sample is also consistent with older crust. REE patterns for 2 pelitic schists and a quartzite (Fig.) are parallel to PAAS (post-Archean average shale). Thus the authors suggest that recycled sediment derived from older cratonic sources dominates the source for the Trap Falls Formation. Models for the tectonic setting of deposition should be consistent with these observations.

  4. Global strings in extra dimensions: The full map of solutions, matter trapping, and the hierarchy problem

    SciTech Connect (OSTI)

    Bronnikov, K. A.; Meierovich, B. E.

    2008-02-15

    We consider (d{sub 0} + 2)-dimensional configurations with global strings in two extra dimensions and a flat metric in d{sub 0} dimensions, endowed with a warp factor e{sup 2{gamma}} depending on the distance l from the string center. All possible regular solutions of the field equations are classified by the behavior of the warp factor and the extradimensional circular radius r(l). Solutions with r {yields} {infinity} and r {yields} const > 0 as l {yields} {infinity} are interpreted in terms of thick brane-world models. Solutions with r {yields} 0 as l {yields} l{sub c} > 0, i.e., those with a second center, are interpreted as either multibrane systems (which are appropriate for large enough distances l{sub c} between the centers) or as Kaluza-Klein-type configurations with extra dimensions invisible due to their smallness. In the case of the Mexican-hat symmetry-breaking potential, we build the full map of regular solutions on the ({epsilon}, {Gamma}) parameter plane, where {epsilon} acts as an effective cosmological constant and {Gamma} characterizes the gravitational field strength. The trapping properties of candidate brane worlds for test scalar fields are discussed. Good trapping properties for massive fields are found for models with increasing warp factors. Kaluza-Klein-type models are shown to have nontrivial warp factor behaviors, leading to matter particle mass spectra that seem promising from the standpoint of hierarchy problems.

  5. Global strings in extra dimensions: The full map of solutions, matter trapping, and the hierarchy problem

    SciTech Connect (OSTI)

    Bronnikov, K. A.; Meierovich, B. E.

    2008-02-15

    We consider (d{sub 0} + 2)-dimensional configurations with global strings in two extra dimensions and a flat metric in d{sub 0} dimensions, endowed with a warp factor e{sup 2{gamma}} depending on the distance l from the string center. All possible regular solutions of the field equations are classified by the behavior of the warp factor and the extradimensional circular radius r(l). Solutions with r {sup {yields}} {infinity} and r {sup {yields}} const > 0 as l {sup {yields}} {infinity} are interpreted in terms of thick brane-world models. Solutions with r {sup {yields}} 0 as l {sup {yields}} l{sub c} > 0, i.e., those with a second center, are interpreted as either multibrane systems (which are appropriate for large enough distances l{sub c} between the centers) or as Kaluza-Klein-type configurations with extra dimensions invisible due to their smallness. In the case of the Mexican-hat symmetry-breaking potential, we build the full map of regular solutions on the ({epsilon}, {gamma}) parameter plane, where {epsilon} acts as an effective cosmological constant and {gamma} characterizes the gravitational field strength. The trapping properties of candidate brane worlds for test scalar fields are discussed. Good trapping properties for massive fields are found for models with increasing warp factors. Kaluza-Klein-type models are shown to have nontrivial warp factor behaviors, leading to matter particle mass spectra that seem promising from the standpoint of hierarchy problems.

  6. Effect of reductive treatments on Pt behavior and NOx storage in lean NOx trap catalysts

    SciTech Connect (OSTI)

    Wang, Xianqin; Kim, Do Heui; Kwak, Ja Hun; Wang, Chong M.; Szanyi, Janos; Peden, Charles HF

    2011-10-01

    Lean NOx trap (LNT) catalysts represent a promising approach to meet increasingly stringent NOx emission regulations on diesel and other lean-burn engines. Pt material properties, including dispersion and particle size, are known to be important factors in determining NOx uptake performance, since Pt provides active sites for NO oxidation to NO2 necessary for storing NOx as nitrates, and for the reduction of nitrates to N2. In this work, the physicochemical properties of Pt in Pt-BaO/Al2O3 LNT catalysts, such as the Pt accessible surface area and particle size, were investigated by using various tools, such as irreversible volumetric H2 chemisorption, high resolution transmission electron microscopy (HRTEM), and X-ray diffraction (XRD), following successive reductive treatments at elevated temperatures. NOx uptake activities were also measured to establish a relationship between the properties of Pt and NOx storage following identical high-temperature reductive treatments. We find that the reductive treatments of Pt-BaO/Al2O3 lean NOx trap catalysts at temperatures up to 500 ºC promote a significant increase in NOx uptake explained, in part, by an induced close interaction between Pt and BaO phases in the catalyst, thus enabling facilitation of the NOx storage process.

  7. Electron scattering and nonlinear trapping by oblique whistler waves: The critical wave intensity for nonlinear effects

    SciTech Connect (OSTI)

    Artemyev, A. V. Vasiliev, A. A.; Mourenas, D.; Krasnoselskikh, V. V.

    2014-10-15

    In this paper, we consider high-energy electron scattering and nonlinear trapping by oblique whistler waves via the Landau resonance. We use recent spacecraft observations in the radiation belts to construct the whistler wave model. The main purpose of the paper is to provide an estimate of the critical wave amplitude for which the nonlinear wave-particle resonant interaction becomes more important than particle scattering. To this aim, we derive an analytical expression describing the particle scattering by large amplitude whistler waves and compare the corresponding effect with the nonlinear particle acceleration due to trapping. The latter is much more rare but the corresponding change of energy is substantially larger than energy jumps due to scattering. We show that for reasonable wave amplitudes ?10100?mV/m of strong whistlers, the nonlinear effects are more important than the linear and nonlinear scattering for electrons with energies ?1050?keV. We test the dependencies of the critical wave amplitude on system parameters (background plasma density, wave frequency, etc.). We discuss the role of obtained results for the theoretical description of the nonlinear wave amplification in radiation belts.

  8. Collision Processes of Highly Charged Ions with Electrons Studied with an Electron Beam Ion Trap

    SciTech Connect (OSTI)

    Nakamura, Nobuyuki; Watanabe, Tsutomu; Ohtani, Shunsuke; Kavanagh, Anthony P.; Currell, Fred J.; Watanabe, Hirofumi; Sakaue, Hiroyuki A.; Kato, Daiji; Li Yueming; Tong Xiaoming

    2009-09-10

    The electron beam ion trap in Tokyo (Tokyo-EBIT)is suitable for studying relativistic effects in the collisions of highly charged heavy ions with electrons because it can produce and trap very highly charged heavy ions which interact with a mono-energetic and unidirectional relativistic electron beam with an energy of up to 200 keV. Recently, we have been studying resonant processes in ionization and recombination by measuring the charge abundance inside the EBIT at the equilibrium. The abundance ratio between adjacent charge states varies slowly with the electron energy when there is no resonant process. However, when the electron energy coincides with the resonant energy at which ionization or recombination is enhanced, the abundance ratio can drastically change. Thus, the resonant processes can be studied by measuring the abundance ratio between adjacent ions as a function of electron beam energy. In this talk, recent progress for heavy ions with very high charge states up to He-like Bi{sup 81+}, is presented. For such ions, relativistic effects significantly affect the resonant processes. For example, the generalized Breit interaction (GBI) effect, which treats the retardation in the exchange of single virtual photon between the free and orbital electrons, has been clearly observed in the DR resonant strength in Li-like Bi{sup 80+}. Recently we have also found that the GBI effect plays an important role in the interference between non-resonant and resonant recombinations. Experimental results are presented in comparison with theoretical calculations.

  9. Electron and recoil ion momentum imaging with a magneto-optically trapped target

    SciTech Connect (OSTI)

    Hubele, R.; Schuricke, M.; Goullon, J.; Lindenblatt, H.; Ferreira, N.; Laforge, A.; Brhl, E.; Globig, D.; Misra, D.; Sell, M.; Song, Z.; Wang, X.; Zhang, S.; Jesus, V. L. B. de; Kelkar, A.; Schneider, K.; Schulz, M.; Fischer, D.

    2015-03-15

    A reaction microscope (ReMi) has been combined with a magneto-optical trap (MOT) for the kinematically complete investigation of atomic break-up processes. With the novel MOTReMi apparatus, the momentum vectors of the fragments of laser-cooled and state-prepared lithium atoms are measured in coincidence and over the full solid angle. The first successful implementation of a MOTReMi could be realized due to an optimized design of the present setup, a nonstandard operation of the MOT, and by employing a switching cycle with alternating measuring and trapping periods. The very low target temperature in the MOT (?2 mK) allows for an excellent momentum resolution. Optical preparation of the target atoms in the excited Li 2{sup 2}P{sub 3/2} state was demonstrated providing an atomic polarization of close to 100%. While first experimental results were reported earlier, in this work, we focus on the technical description of the setup and its performance in commissioning experiments involving target ionization in 266 nm laser pulses and in collisions with projectile ions.

  10. Trapping radiodine, in the form of methyl iodide, on nuclear carbon

    SciTech Connect (OSTI)

    Nacapricha, D.; Taylor, C.

    1996-12-31

    Studies have been performed on potassium-iodide-impregnated charcoals of the type used in the nuclear industry for trapping radioiodine released during nuclear fission. The effects of various parameters on the trapping efficiency of methyl iodide have been investigated. A variation in particle size within a bulk charcoal caused poor precision in K value measurements because of differences in surface area, pore volume, and bed density, leading to differences in the deposition of the impregnant. Precision is improved by sieving the charcoal to a narrower size because smaller particles have a higher porosity. This finding is supported by surface area and pore measurements. Two methods of impregnation are compared by measuring K values and the deposition of potassium iodide. Charcoal impregnated by rotary evaporation exhibits both higher K values and higher potassium iodide contents than sprayed charcoal. Two designs of spraying drum are compared: a drum with helical vanes allows more efficient deposition and more uniform distribution of impregnant than a drum with axial vanes. A decrease in the K value with increasing humidity correlates with the available surface area. A similar correlation exists between water content and available pore volume. Aging of potassium-iodide-impregnated charcoal, caused by the formation of oxygen complexes on the surface, is associated with significant falls in K value. K values of charcoals also can be restored to at least their original values by heat treatment in the absence of air. 12 refs., 6 figs., 1 tab.

  11. Measurement of the beta-neutrino correlation in laser trapped {sup 21}Na

    SciTech Connect (OSTI)

    Scielzo, Nicholas David

    2003-06-01

    Trapped radioactive atoms are an appealing source for precise measurements of the beta-neutrino correlation coefficient, a, since the momentum of the neutrino can be inferred from the detection of the unperturbed low-energy recoil daughter nucleus. Sodium-21 is produced on-line at the 88'' cyclotron at Lawrence Berkeley National Laboratory, and 8e5 atoms have been maintained in a magneto-optical trap. A static electric field draws daughter Neon-21 ions to a microchannel plate detector and betas are detected in coincidence with a plastic scintillator beta detector. The Neon-21 time-of-flight distribution determines the beta neutrino correlation coefficient, a. The resulting charge-state distribution is compared to a simple model based on the sudden approximation which suggests a small but important contribution from nuclear recoil-induced ionization. A larger than expected fraction of the daughters are detected in positive charge-states, but no dependence on either the beta or recoil nucleus energy was observed. We find a = 0.5243 plus or minus 0.0092, which is in 3.6 sigma disagreement with the Standard Model prediction of a = 0.559 plus or minus 0.003. Aside from a deviation from the Standard Model, a possible explanation for the discrepancy is that the branching ratio to the first excited state is in error.

  12. Enhanced memory effect with embedded graphene nanoplatelets in ZnO charge trapping layer

    SciTech Connect (OSTI)

    El-Atab, Nazek; Nayfeh, Ammar; Cimen, Furkan; Alkis, Sabri; Okyay, Ali K.

    2014-07-21

    A charge trapping memory with graphene nanoplatelets embedded in atomic layer deposited ZnO (GNIZ) is demonstrated. The memory shows a large threshold voltage V{sub t} shift (4?V) at low operating voltage (6/?6?V), good retention (>10 yr), and good endurance characteristic (>10{sup 4} cycles). This memory performance is compared to control devices with graphene nanoplatelets (or ZnO) and a thicker tunnel oxide. These structures showed a reduced V{sub t} shift and retention characteristic. The GNIZ structure allows for scaling down the tunnel oxide thickness along with improving the memory window and retention of data. The larger V{sub t} shift indicates that the ZnO adds available trap states and enhances the emission and retention of charges. The charge emission mechanism in the memory structures with graphene nanoplatelets at an electric field E???5.57 MV/cm is found to be based on Fowler-Nordheim tunneling. The fabrication of this memory device is compatible with current semiconductor processing, therefore, has great potential in low-cost nano-memory applications.

  13. Trapping in GaN-based metal-insulator-semiconductor transistors: Role of high drain bias and hot electrons

    SciTech Connect (OSTI)

    Meneghini, M. Bisi, D.; Meneghesso, G.; Zanoni, E.

    2014-04-07

    This paper describes an extensive analysis of the role of off-state and semi-on state bias in inducing the trapping in GaN-based power High Electron Mobility Transistors. The study is based on combined pulsed characterization and on-resistance transient measurements. We demonstrate thatby changing the quiescent bias point from the off-state to the semi-on stateit is possible to separately analyze two relevant trapping mechanisms: (i) the trapping of electrons in the gate-drain access region, activated by the exposure to high drain bias in the off-state; (ii) the trapping of hot-electrons within the AlGaN barrier or the gate insulator, which occurs when the devices are operated in the semi-on state. The dependence of these two mechanisms on the bias conditions and on temperature, and the properties (activation energy and cross section) of the related traps are described in the text.

  14. Advanced quadrupole ion trap instrumentation for low level vehicle emissions measurements. CRADA final report for number ORNL93-0238

    SciTech Connect (OSTI)

    McLuckey, S.A.; Buchanan, M.V.; Asano, K.G.; Hart, K.J.; Goeringer, D.E.; Dearth, M.A.

    1997-09-01

    Quadrupole ion trap mass spectrometry has been evaluated for its potential use in vehicle emissions measurements in vehicle test facilities as an analyzer for the top 15 compounds contributing to smog generation. A variety of ionization methods were explored including ion trap in situ chemical ionization, atmospheric sampling glow discharge ionization, and nitric oxide chemical ionization in a glow discharge ionization source coupled with anion trap mass spectrometer. Emphasis was placed on the determination of hydrocarbons and oxygenated hydrocarbons at parts per million to parts per billion levels. Ion trap in situ water chemical ionization and atmospheric sampling glow discharge ionization were both shown to be amenable to the analysis of arenes, alcohols, aldehydes and, to some degree, alkenes. Atmospheric sampling glow discharge also generated molecular ions of methyl-t-butyl ether (MTBE). Neither of these ionization methods, however, were found to generate diagnostic ions for the alkanes. Nitric oxide chemical ionization, on the other hand, was found to yield diagnostic ions for alkanes, alkenes, arenes, alcohols, aldehydes, and MTBE. The ability to measure a variety of hydrocarbons present at roughly 15 parts per billion at measurement rates of 3 Hz was demonstrated. These results have demonstrated that the ion trap has an excellent combination of sensitivity, specificity, speed, and flexibility with respect to the technical requirements of the top 15 analyzer.

  15. An Energy Signature Scheme for Steam Trap Assessment and Flow Rate Estimation Using Pipe-Induced Acoustic Measurements

    SciTech Connect (OSTI)

    Olama, Mohammed M; Allgood, Glenn O; Kuruganti, Phani Teja; Lake, Joe E

    2012-01-01

    The US Congress has passed legislation dictating that all government agencies establish a plan and process for improving energy efficiencies at their sites. In response to this legislation, Oak Ridge National Laboratory (ORNL) has recently conducted a pilot study to explore the deployment of a wireless sensor system for a real-time measurement-based energy efficiency optimization framework within the steam distribution system within the ORNL campus. We make assessments on the real-time status of the distribution system by observing the state measurements of acoustic sensors mounted on the steam pipes/traps/valves. In this paper, we describe a spectral-based energy signature scheme that interprets acoustic vibration sensor data to estimate steam flow rates and assess steam traps health status. Experimental results show that the energy signature scheme has the potential to identify different steam trap health status and it has sufficient sensitivity to estimate steam flow rate. Moreover, results indicate a nearly quadratic relationship over the test region between the overall energy signature factor and flow rate in the pipe. The analysis based on estimated steam flow and steam trap status helps generate alerts that enable operators and maintenance personnel to take remedial action. The goal is to achieve significant energy-saving in steam lines by monitoring and acting on leaking steam pipes/traps/valves.

  16. Generation of high charge state metal ion beams by electron cyclotron resonance heating of vacuum arc plasma in cusp trap

    SciTech Connect (OSTI)

    Nikolaev, A. G.; Savkin, K. P.; Oks, E. M.; Vizir, A. V.; Yushkov, G. Yu.; Vodopyanov, A. V.; Izotov, I. V.; Mansfeld, D. A.

    2012-02-15

    A method for generating high charge state heavy metal ion beams based on high power microwave heating of vacuum arc plasma confined in a magnetic trap under electron cyclotron resonance conditions has been developed. A feature of the work described here is the use of a cusp magnetic field with inherent ''minimum-B'' structure as the confinement geometry, as opposed to a simple mirror device as we have reported on previously. The cusp configuration has been successfully used for microwave heating of gas discharge plasma and extraction from the plasma of highly charged, high current, gaseous ion beams. Now we use the trap for heavy metal ion beam generation. Two different approaches were used for injecting the vacuum arc metal plasma into the trap - axial injection from a miniature arc source located on-axis near the microwave window, and radial injection from sources mounted radially at the midplane of the trap. Here, we describe preliminary results of heating vacuum arc plasma in a cusp magnetic trap by pulsed (400 {mu}s) high power (up to 100 kW) microwave radiation at 37.5 GHz for the generation of highly charged heavy metal ion beams.

  17. Extending the applicability of an open-ring trap to perform experiments with a single laser-cooled ion

    SciTech Connect (OSTI)

    Cornejo, J. M.; Colombano, M.; Doménech, J.; Rodríguez, D.; Block, M.; Delahaye, P.

    2015-10-15

    A special ion trap was initially built up to perform β-ν correlation experiments with radioactive ions. The trap geometry is also well suited to perform experiments with laser-cooled ions, serving for the development of a new type of Penning trap, in the framework of the project TRAPSENSOR at the University of Granada. The goal of this project is to use a single {sup 40}Ca{sup +} ion as detector for single-ion mass spectrometry. Within this project and without any modification to the initial electrode configuration, it was possible to perform Doppler cooling on {sup 40}Ca{sup +} ions, starting from large clouds and reaching single ion sensitivity. This new feature of the trap might be important also for other experiments with ions produced at radioactive ion beam facilities. In this publication, the trap and the laser system will be described, together with their performance with respect to laser cooling applied to large ion clouds down to a single ion.

  18. Inherent room temperature ferromagnetism and dopant dependent Raman studies of PbSe, Pb{sub 1−x}Cu{sub x}Se, and Pb{sub 1−x}Ni{sub x}Se

    SciTech Connect (OSTI)

    Gayner, Chhatrasal; Kar, Kamal K.

    2015-03-14

    Polycrystalline lead selenide (PbSe) doped with copper (Cu) and nickel (Ni) was prepared to understand its magnetic behaviour and Raman activity. The processing conditions, influence of dopants (magnetically active and non-active) and their respective compositions on the magnetic properties and Raman active mode were studied. A surprising/anomalous room temperature ferromagnetism (hysteresis loop) is noticed in bulk diamagnetic PbSe, which is found to be natural or inherent characteristic of material, and depends on the crystallite size, dopant, and developed strain due to dopant/defects. The magnetic susceptibility (−1.71 × 10{sup −4} emu/mol Oe) and saturated magnetic susceptibility (−2.74 × 10{sup −4} emu/mol Oe) are found to be higher than the earlier reported value (diamagnetic: −1.0 × 10{sup −4} emu/mol Oe) in bulk PbSe. With increase of Cu concentration (2% to 10%) in PbSe, the saturated magnetic susceptibility decreases from −1.22 × 10{sup −4} to −0.85 × 10{sup −4} emu/mol Oe. Whereas for Ni dopant, the saturated magnetic susceptibility increases to −2.96 × 10{sup −4} emu/mol Oe at 2% Ni doped PbSe. But it further decreases with dopant concentration. In these doped PbSe, the shifting of longitudinal (LO) phonon mode was also studied by the Raman spectroscopy. The shifting of LO mode is found to be dopant dependent, and the frequency shift of LO mode is associated with the induced strain that created by the dopants and vacancies. This asymmetry in LO phonon mode (peak shift and shape) may be due to the intraband electronic transition of dopants. The variation in magnetic susceptibility and Raman shifts are sensitive to crystallite size, nature of dopant, concentration of dopants, and induced strain due to dopants.

  19. Study of the recombination process at crystallite boundaries in CuIn{sub 1-x}Ga{sub x}Se{sub 2} (CIGS) films by microwave photoconductivity

    SciTech Connect (OSTI)

    Bocharov, K. V.; Novikov, G. F.; Hsieh, T. Y.; Gapanovich, M. V.; Jeng, M. J.

    2013-03-15

    The loss kinetics of photogenerated charge carriers in thin polycrystalline chalcopyrite CuIn{sub 1-x}Ga{sub x}Se{sub 2} (CIGS) films has been studied by microwave photoconductivity (at 36 GHz). The films were synthesized using the ampoule method and three variants of physical vapor deposition with subsequent selenization: magnetron sputtering, thermal deposition, and modified thermal deposition with intermetallic precursors. The photoconductivity was excited by 8-ns nitrogen laser pulses with maximum intensity of 4 Multiplication-Sign 10{sup 14} photons/cm per pulse. Measurements were performed in the temperature range 148-293 K. The photoresponse amplitude is found to depend linearly on the sizes of coherent-scattering regions in the film grains, which were calculated from X-ray diffraction data. The photoresponse decay obeys hyperbolic law. The photoresponse half-decay time increases with a decrease in both temperature and light intensity. It is shown that the recombination of free holes with trapped electrons is very efficient near the crystallite boundaries.

  20. Probing the size and environment induced phase transformation in CdSe quantum dots

    SciTech Connect (OSTI)

    Karakoti, Ajay S.; Sanghavi, Shail P.; Nachimuthu, Ponnusamy; Yang, Ping; Thevuthasan, Suntharampillai

    2011-11-17

    The structural and electronic properties of CdSe quantum dots in toluene and drop-casted on Si wafer were investigated by in-situ micro X-ray diffraction, X-ray photoelectron spectroscopy and UV-Vis absorption and emission spectroscopy. The in-situ micro diffraction data show that the CdSe quantum dots capped with TOPO or hexadecylamine (HDA) in toluene exhibit predominantly wurtzite crystal structure, which undergoes a phase transformation to zinc blende crystal structure following drop casting on Si and this phase transition increases with decreasing the size of the CdSe quantum dots. Decreasing the size of quantum dots also increases the Se vacancies that facilitate the phase transformation. The X-ray photoelectron spectra show a systematic increase in the core level binding energies of Cd 3d and Se 3d, the band gap and the Cd/Se ratio as the size of the quantum dots decreases from 6.6nm to 2.1nm. This is attributed to the quantum confinement of CdSe crystallites by the capping ligands in toluene which increases with decreasing the size of the quantum dots. However, drop-casting quantum dots on Si alter the density and arrangement of capping ligands and solvent molecules on the quantum dots which causes significant phase transformation.