Sample records for timing trapping mechanism

  1. Real-time calibration of a feedback trap

    SciTech Connect (OSTI)

    Gavrilov, Mom?ilo; Jun, Yonggun; Bechhoefer, John, E-mail: johnb@sfu.ca [Department of Physics, Simon Fraser University, Burnaby, British Columbia V5A 1S6 (Canada)

    2014-09-15T23:59:59.000Z

    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.

  2. Freely floating structures trapping time-harmonic water waves (revisited)

    E-Print Network [OSTI]

    Nikolay Kuznetsov; Oleg Motygin

    2014-10-22T23:59:59.000Z

    We study the coupled small-amplitude motion of the mechanical system consisting of infinitely deep water and a structure immersed in it. The former is bounded above by a free surface, whereas the latter is formed by an arbitrary finite number of surface-piercing bodies floating freely. The mathematical model of time-harmonic motion is a spectral problem in which the frequency of oscillations serves as the spectral parameter. It is proved that there exist axisymmetric structures consisting of $N \\geq 2$ bodies; every structure has the following properties: (i) a time-harmonic wave mode is trapped by it; (ii) some of its bodies (may be none) are motionless, whereas the rest of the bodies (may be none) are heaving at the same frequency as water. The construction of these structures is based on a generalization of the semi-inverse procedure applied earlier for obtaining trapping bodies that are motionless although float freely.

  3. Time-optimal controls for frictionless cooling in harmonic traps

    E-Print Network [OSTI]

    Salamon, Peter

    OFFPRINT Time-optimal controls for frictionless cooling in harmonic traps K. H. Hoffmann, P payment Details on preparing, submitting and tracking the progress of your manuscript from submission

  4. First Exit Times of Harmonically Trapped Particles: A Didactic Review

    E-Print Network [OSTI]

    D. S. Grebenkov

    2014-11-13T23:59:59.000Z

    We revise the classical problem of characterizing first exit times of a harmonically trapped particle whose motion is described by one- or multi-dimensional Ornstein-Uhlenbeck process. We start by recalling the main derivation steps of a propagator using Langevin and Fokker-Planck equations. The mean exit time, the moment-generating function, and the survival probability are then expressed through confluent hypergeometric functions and thoroughly analyzed. We also present a rapidly converging series representation of confluent hypergeometric functions that is particularly well suited for numerical computation of eigenvalues and eigenfunctions of the governing Fokker-Planck operator. We discuss several applications of first exit times such as detection of time intervals during which motor proteins exert a constant force onto a tracer in optical tweezers single-particle tracking experiments; adhesion bond dissociation under mechanical stress; characterization of active periods of trend following and mean-reverting strategies in algorithmic trading on stock markets; relation to the distribution of first crossing times of a moving boundary by Brownian motion. Some extensions are described, including diffusion under quadratic double-well potential and anomalous diffusion.

  5. Supporting Kibble-Zurek Mechanism in Quantum Ising Model through a Trapped Ion

    E-Print Network [OSTI]

    Jin-Ming Cui; Yun-Feng Huang; Zhao Wang; Dong-Yang Cao; Jian Wang; Wei-Min Lv; Yong Lu; Le Luo; Adolfo del Campo; Yong-Jian Han; Chuan-Feng Li; Guang-Can Guo

    2015-05-21T23:59:59.000Z

    Progress in quantum simulation has fostered the research on far-from-equilibrium dynamics. The Kibble-Zurek mechanism is the paradigmatic framework to account for the non adiabatic critical dynamics of a system driven across a phase transition in a finite time. Its study in the quantum regime is hindered by the requisite of ground state cooling. We report the experimental quantum simulation of critical dynamics in the transverse-field Ising model by a set of non-equilibrium processes in the pseudo-momentum space, that can be probed with high accuracy using a single trapped ion. Our results support the validity of the Kibble-Zurek mechanism in the quantum regime and advance the quantum simulation of critical systems far-away from equilibrium.

  6. Time Gravity and Quantum Mechanics

    E-Print Network [OSTI]

    W. G. Unruh

    1993-12-17T23:59:59.000Z

    Time plays different roles in quantum mechanics and gravity. These roles are examined and the problems that the conflict in the roles presents for quantum gravity are briefly summarised.

  7. High-k shallow traps observed by charge pumping with varying discharging times

    SciTech Connect (OSTI)

    Ho, Szu-Han; Chen, Ching-En; Tseng, Tseung-Yuen [Department of Electronics Engineering, National Chiao Tung University, Hsinchu 300, Taiwan (China); Chang, Ting-Chang, E-mail: tcchang@mail.phys.nsysu.edu.tw [Department of Physics, National Sun Yat-Sen University, Kaohsiung 804, Taiwan (China); Advanced Optoelectronics Technology Center, National Cheng Kung University, Tainan, Taiwan (China); Lu, Ying-Hsin; Lo, Wen-Hung; Tsai, Jyun-Yu; Liu, Kuan-Ju [Department of Physics, National Sun Yat-Sen University, Kaohsiung 804, Taiwan (China); Wang, Bin-Wei; Cao, Xi-Xin [Department of Embedded System Engineering, Peking University, Beijing, P.R.China (China); Chen, Hua-Mao [Department of Photonics and Institute of Electro-Optical Engineering, National Chiao Tung University, Hsinchu, Taiwan (China); Cheng, Osbert; Huang, Cheng-Tung; Chen, Tsai-Fu [Device Department, United Microelectronics Corporation, Tainan Science Park, Taiwan (China)

    2013-11-07T23:59:59.000Z

    In this paper, we investigate the influence of falling time and base level time on high-k bulk shallow traps measured by charge pumping technique in n-channel metal-oxide-semiconductor field-effect transistors with HfO{sub 2}/metal gate stacks. N{sub T}-V{sub high} {sub level} characteristic curves with different duty ratios indicate that the electron detrapping time dominates the value of N{sub T} for extra contribution of I{sub cp} traps. N{sub T} is the number of traps, and I{sub cp} is charge pumping current. By fitting discharge formula at different temperatures, the results show that extra contribution of I{sub cp} traps at high voltage are in fact high-k bulk shallow traps. This is also verified through a comparison of different interlayer thicknesses and different Ti{sub x}N{sub 1?x} metal gate concentrations. Next, N{sub T}-V{sub high} {sub level} characteristic curves with different falling times (t{sub falling} {sub time}) and base level times (t{sub base} {sub level}) show that extra contribution of I{sub cp} traps decrease with an increase in t{sub falling} {sub time}. By fitting discharge formula for different t{sub falling} {sub time}, the results show that electrons trapped in high-k bulk shallow traps first discharge to the channel and then to source and drain during t{sub falling} {sub time}. This current cannot be measured by the charge pumping technique. Subsequent measurements of N{sub T} by charge pumping technique at t{sub base} {sub level} reveal a remainder of electrons trapped in high-k bulk shallow traps.

  8. Pore-scale study of capillary trapping mechanism during CO2 injection in geological formations

    SciTech Connect (OSTI)

    Bandara, Uditha C.; Tartakovsky, Alexandre M.; Palmer, Bruce J.

    2011-11-01T23:59:59.000Z

    Geological sequestration of CO{sub 2} gas emerged as a promising solution for reducing amount of green house gases in atmosphere. A number of continuum scale models are available to describe the transport phenomena of CO{sub 2} sequestration. These models rely heavily on a phenomenological description of subsurface transport phenomena and the predictions can be highly uncertain. Pore-scale models provide a better understanding of fluid displacement processes, nonetheless such models are rare. In this work we use a Smoothed Particle Hydrodynamics (SPH) model to study pore-scale displacement and capillary trapping mechanisms of super-critical CO{sub 2} in the subsurface. Simulations are carried out to investigate the effects of gravitational, viscous, and capillary forces in terms of Gravity, Capillary, and Bond numbers. Contrary to the other published continuum scale investigations, we found that not only Gravity number but also Capillary number plays an important role on the fate of injected CO{sub 2}. For large Gravity numbers (on the order of 10), most of the injected CO{sub 2} reaches the cap-rock due to gravity segregation. A significant portion of CO{sub 2} gets trapped by capillary forces when Gravity number is small (on the order of 0.1). When Gravity number is moderately high (on the order of 1), trapping patterns are heavily dependent on Capillary number. If Capillary number is very small (less than 0.001), then capillary forces dominate the buoyancy forces and a significant fraction of injected CO{sub 2} is trapped by the capillary forces. Conversely, if Capillary number is high (higher than 0.001), capillary trapping is relatively small since buoyancy dominates the capillary forces. In addition, our simulations reveal different types of capillary trapping and flow displacement mechanisms during and after injection. In gravity dominated cases leave behind was the widespread trapping mechanism. Division was the primary trapping mechanism in viscous dominated cases. In capillary dominated cases, snap-off of the CO{sub 2} plume is the most commonly observed displacement mechanism. Large CO{sub 2} blobs are created due to coalescence mechanism.

  9. Treating Time Travel Quantum Mechanically

    E-Print Network [OSTI]

    John-Mark A. Allen

    2014-10-10T23:59:59.000Z

    The fact that closed timelike curves (CTCs) are permitted by general relativity raises the question as to how quantum systems behave when time travel to the past occurs. Research into answering this question by utilising the quantum circuit formalism has given rise to two theories: Deutschian-CTCs (D-CTCs) and "postselected" CTCs (P-CTCs). In this paper the quantum circuit approach is thoroughly reviewed, and the strengths and shortcomings of D-CTCs and P-CTCs are presented in view of their non-linearity and time travel paradoxes. In particular, the "equivalent circuit model"---which aims to make equivalent predictions to D-CTCs, while avoiding some of the difficulties of the original theory---is shown to contain errors. The discussion of D-CTCs and P-CTCs is used to motivate an analysis of the features one might require of a theory of quantum time travel, following which two overlapping classes of new theories are identified. One such theory, the theory of "transition probability" CTCs (T-CTCs), is fully developed. The theory of T-CTCs is shown not to have certain undesirable features---such as time travel paradoxes, the ability to distinguish non-orthogonal states with certainty, and the ability to clone or delete arbitrary pure states---that are present with D-CTCs and P-CTCs. The problems with non-linear extensions to quantum mechanics are discussed in relation to the interpretation of these theories, and the physical motivations of all three theories are discussed and compared.

  10. Long-term Variations of CO2 Trapped in Different Mechanisms in Deep Saline Formations: A Case Study of the Songliao Basin, China

    SciTech Connect (OSTI)

    Zhang, Wei; Li, Yilian; Xu, Tianfu; Cheng, Huilin; Zheng, Yan; Xiong, Peng

    2008-06-10T23:59:59.000Z

    The geological storage of CO{sub 2} in deep saline formations is increasing seen as a viable strategy to reduce the release of greenhouse gases to the atmosphere. There are numerous sedimentary basins in China, in which a number of suitable CO{sub 2} geologic reservoirs are potentially available. To identify the multi-phase processes, geochemical changes and mineral alteration, and CO{sub 2} trapping mechanisms after CO{sub 2} injection, reactive geochemical transport simulations using a simple 2D model were performed. Mineralogical composition and water chemistry from a deep saline formation of Songliao Basin were used. Results indicate that different storage forms of CO{sub 2} vary with time. In the CO{sub 2} injection period, a large amount of CO{sub 2} remains as a free supercritical phase (gas trapping), and the amount dissolved in the formation water (solubility trapping) gradually increases. Later, gas trapping decreases, solubility trapping increases significantly due to migration and diffusion of the CO{sub 2} plume, and the amount trapped by carbonate minerals increases gradually with time. The residual CO{sub 2} gas keeps dissolving into groundwater and precipitating carbonate minerals. For the Songliao Basin sandstone, variations in the reaction rate and abundance of chlorite, and plagioclase composition affect significantly the estimates of mineral alteration and CO{sub 2} storage in different trapping mechanisms. The effect of vertical permeability and residual gas saturation on the overall storage is smaller compared to the geochemical factors. However, they can affect the spatial distribution of the injected CO{sub 2} in the formations. The CO{sub 2} mineral trapping capacity could be in the order of ten kilogram per cubic meter medium for the Songliao Basin sandstone, and may be higher depending on the composition of primary aluminosilicate minerals especially the content of Ca, Mg, and Fe.

  11. Quantum mechanical time contradicts the uncertainty principle

    E-Print Network [OSTI]

    Hitoshi Kitada

    1999-11-17T23:59:59.000Z

    The a priori time in conventional quantum mechanics is shown to contradict the uncertainty principle. A possible solution is given.

  12. Real-Time Virus Trapping and Fluorescent Imaging in Microfluidic

    E-Print Network [OSTI]

    Bashir, Rashid

    particles; however, this method requires the samples to be dried, fixed, coated, and laboriously prepared time, the images were collected with a computer running a video image capture

  13. Time evolution of snow regions and planet traps in an evolving protoplanetary disk

    E-Print Network [OSTI]

    Baillié, Kévin; Pantin, Éric

    2015-01-01T23:59:59.000Z

    Aims. We track the time evolution of planet traps and snowlines in a viscously evolving protoplanetary disk using an opacity table that accounts for the composition of the dust material. Methods. We coupled a dynamical and thermodynamical disk model with a temperature-dependent opacity table (that accounts for the sublimation of the main dust components) to investigate the formation and evolution of snowlines and planet traps during the first million years of disk evolution. Results. Starting from a minimum mass solar nebula (MMSN), we find that the disk mid-plane temperature profile shows several plateaux (0.1-1 AU wide) at the different sublimation temperatures of the species that make up the dust. For water ice, the correspond- ing plateau can be larger than 1 AU, which means that this is a snow "region" rather than a snow "line". As a consequence, the surface density of solids in the snow region may increase gradually, not abruptly. Several planet traps and desert regions appear naturally as a result of a...

  14. Ion Funnel Trap Interface for Orthogonal Time-of-Flight Mass...

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

    developed and characterized. The ion trap was incorporated through the use of added terminal electrodynamic ion funnel electrodes enabling control over the axial dc gradient in...

  15. Long storage time of collective coherence in an optically trapped Bose-Einstein condensate Yutaka Yoshikawa,1,2,* Kazuyuki Nakayama,2

    E-Print Network [OSTI]

    Torii, Yoshio

    Long storage time of collective coherence in an optically trapped Bose-Einstein condensate Yutaka of the storage time realized by loading the atoms into an optical dipole trap, wherein an unfavorable spin-dependent phase shift and spatial diffusion of atoms can be suppressed. The measured storage time was 0.57 2 ms

  16. Quantum mechanics and the direction of time

    SciTech Connect (OSTI)

    Hasegawa, H.; Petrosky, T. (Univ. of Texas, Austin (United States)); Prigogine, I. (Univ. of Texas, Austin (United States) International Solvay Inst. for Physics and Chemistry, Brussels (Belgium)); Tasaki, S. (International Solvay Inst. for Physics and Chemistry, Brussels (Belgium))

    1991-03-01T23:59:59.000Z

    In recent papers the authors have discussed the dynamical properties of large Poincare systems (LPS), that is, nonintegrable systems with a continuous spectrum (both classical and quantum). An interesting example of LPS is given by the Friedrichs model of field theory. As is well known, perturbation methods analytic in the coupling constant diverge because of resonant denominators. They show that this Poincare catastrophe can be eliminated by a natural time ordering of the dynamical states. They obtain then a dynamical theory which incorporates a privileged direction of time (and therefore the second law of thermodynamics). However, it is only in very simple situations that his time ordering can be performed in an extended Hilbert space. In general, they need to go to the Liouville space (superspace) and introduce a time ordering of dynamical states according to the number of particles involved in correlations. This leads then to a generalization of quantum mechanics in which the usual Heisenberg's eigenvalue problem is replaced by a complex eigenvalue problem in the Liouville space.

  17. Structure and dynamics of ion clusters in linear octupole traps: Phase diagrams, chirality, and melting mechanisms

    SciTech Connect (OSTI)

    Yurtsever, E.; Onal, E. D.; Calvo, F. [Koc University, Rumelifeneriyolu, Sariyer, Istanbul TR-34450 (Turkey); LASIM, Universite de Lyon and CNRS UMR 5579, 43 Bd du 11 Novembre 1918, FR-69622 Villeurbanne Cedex (France)

    2011-05-15T23:59:59.000Z

    The stable structures and melting dynamics of clusters of identical ions bound by linear octupole radiofrequency traps are theoretically investigated by global optimization methods and molecular dynamics simulations. By varying the cluster sizes in the range of 10-1000 ions and the extent of trap anisotropy by more than one order of magnitude, we find a broad variety of stable structures based on multiple rings at small sizes evolving into tubular geometries at large sizes. The binding energy of these clusters is well represented by two contributions arising from isotropic linear and octupolar traps. The structures generally exhibit strong size effects, and chiral arrangements spontaneously emerge in many crystals. Sufficiently large clusters form nested, coaxial tubes with different thermal stabilities. As in isotropic octupolar clusters, the inner tubes melt at temperatures that are lower than the overall melting point.

  18. Influence of Time-Varying External Magnetic Fields on Trapped Fields in Bulk Superconductors

    E-Print Network [OSTI]

    Zou, Jin; Ainslie, Mark D.; Hu, Di; Cardwell, David A.

    2014-12-12T23:59:59.000Z

    Large, single-grain bulk high-temperature superconductors (HTS) can trap magnetic fields over 17 T below 30 K and up to 3 T at 77 K, and have significant potential to replace permanent magnets, the fields from which are limited to significantly less...

  19. HP Steam Trap Monitoring

    E-Print Network [OSTI]

    Pascone, S.

    2011-01-01T23:59:59.000Z

    STEAM MONITORING HP Steam Trap Monitoring HP Steam Trap Monitoring ? 12-18 months payback! ? 3-5% permanent reduction in consumption ? LEED Pt.? Innovation in Operations EB O&M ? Saved clients over $1,000,000 Annual consumption... Steam Trap Monitoring ? Real-time monitoring for high-pressure critical traps (>15 PSIG) ? Average total system cost $25K - $50K ? Web-Based or Modbus/BMS Integration Basic Installation Wireless Signal Transmitter Receiver Repeater...

  20. Feedback cooling of a single trapped ion

    E-Print Network [OSTI]

    Pavel Bushev; Daniel Rotter; Alex Wilson; Francois Dubin; Christoph Becher; Juergen Eschner; Rainer Blatt; Viktor Steixner; Peter Rabl; Peter Zoller

    2005-09-19T23:59:59.000Z

    Based on a real-time measurement of the motion of a single ion in a Paul trap, we demonstrate its electro-mechanical cooling below the Doppler limit by homodyne feedback control (cold damping). The feedback cooling results are well described by a model based on a quantum mechanical Master Equation.

  1. Unraveling the Timing of Fluid Migration and Trap Formation in the Brooks Range Foothills: A Key to Discovering Hydrocarbons

    SciTech Connect (OSTI)

    Catherine L. Hanks

    2008-12-31T23:59:59.000Z

    Naturally occurring fractures can play a key role in the evolution and producibility of a hydrocarbon accumulation. Understanding the evolution of fractures in the Brooks Range/Colville basin system of northern Alaska is critical to developing a better working model of the hydrocarbon potential of the region. This study addressed this problem by collecting detailed and regional data on fracture distribution and character, structural geometry, temperature, the timing of deformation along the Brooks Range rangefront and adjacent parts of the Colville basin, and the in situ stress distribution within the Colville basin. This new and existing data then were used to develop a model of how fractures evolved in northern Alaska, both spatially and temporally. The results of the study indicate that fractures formed episodically throughout the evolution of northern Alaska, due to a variety of mechanisms. Four distinct fracture sets were observed. The earliest fractures formed in deep parts of the Colville basin and in the underlying Ellesmerian sequence rocks as these rocks experienced compression associated with the growing Brooks Range fold-and-thrust belt. The orientation of these deep basin fractures was controlled by the maximum in situ horizontal stress in the basin at the time of their formation, which was perpendicular to the active Brooks Range thrust front. This orientation stayed consistently NS-striking for most of the early history of the Brooks Range and Colville basin, but changed to NW-striking with the development of the northeastern Brooks Range during the early Tertiary. Subsequent incorporation of these rocks into the fold-and-thrust belt resulted in overprinting of these deep basin fractures by fractures caused by thrusting and related folding. The youngest fractures developed as rocks were uplifted and exposed. While this general order of fracturing remains consistent across the Brooks Range and adjacent Colville basin, the absolute age at any one location varies. Fracturing started in the southwest deep in the stratigraphic section during the Late Jurassic and Early Cretaceous, moving northeastward and upsection as the Colville basin filled from the west. Active fracturing is occurring today in the northeastern parts of the Colville basin, north of the northeastern Brooks thrust front. Across northern Alaska, the early deep basin fractures were probably synchronous with hydrocarbon generation. Initially, these early fractures would have been good migration pathways, but would have been destroyed where subsequently overridden by the advancing Brooks Range fold-and-thrust belt. However, at these locations younger fracture sets related to folding and thrusting could have enhanced reservoir permeability and/or served as vertical migration pathways to overlying structural traps.

  2. Percolation mechanism through trapping/de-trapping process at defect states for resistive switching devices with structure of Ag/Si{sub x}C{sub 1?x}/p-Si

    SciTech Connect (OSTI)

    Liu, Yanhong; Gao, Ping; Li, La; Peng, Wei [School of Physics and Optoelectronic Engineering, Dalian University of Technology, No. 2 Linggong Road, Ganjingzi District, Dalian 116024 (China); Jiang, Xuening; Zhang, Jialiang [Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Ministry of Education, Dalian University of Technology, No. 2 Linggong Road, Ganjingzi District, Dalian 116024 (China)

    2014-08-14T23:59:59.000Z

    Pure Si{sub x}C{sub 1?x} (x?>?0.5) and B-containing Si{sub x}C{sub 1?x} (x?>?0.5) based resistive switching devices (RSD) with the structure of Ag/Si{sub x}C{sub 1?x}/p-Si were fabricated and their switching characteristics and mechanism were investigated systematically. Percolation mechanism through trapping/ de-trapping at defect states was suggested for the switching process. Through the introduction of B atoms into Si{sub x}C{sub 1?x}, the density of defect states was reduced, then, the SET and RESET voltages were also decreased. Based on the percolation theory, the dependence of SET/RESET voltage on the density of defect states was analyzed. These results supply a deep understanding for the SiC-based RSD, which have a potential application in extreme ambient conditions.

  3. Enhancement of Mechanical Q Factors by Optical Trapping D. J. Wilson,1

    E-Print Network [OSTI]

    Painter, Oskar

    the maximum response of an oscillator to a disturbance at its resonance frequency (signal) and the coupling frequency by storing most of the mechanical energy in a nearly lossless optical potential, thereby strongly wave, we achieve an increase in the pendulum center-of-mass frequency from 6.2 to 145 k

  4. Quantum Mechanics and Discrete Time from "Timeless" Classical Dynamics

    E-Print Network [OSTI]

    H. -T. Elze

    2003-07-03T23:59:59.000Z

    We study classical Hamiltonian systems in which the intrinsic proper time evolution parameter is related through a probability distribution to the physical time, which is assumed to be discrete. - This is motivated by the ``timeless'' reparametrization invariant model of a relativistic particle with two compactified extradimensions. In this example, discrete physical time is constructed based on quasi-local observables. - Generally, employing the path-integral formulation of classical mechanics developed by Gozzi et al., we show that these deterministic classical systems can be naturally described as unitary quantum mechanical models. The emergent quantum Hamiltonian is derived from the underlying classical one. It is closely related to the Liouville operator. We demonstrate in several examples the necessity of regularization, in order to arrive at quantum models with bounded spectrum and stable groundstate.

  5. Collisionless Weibel shocks: Full formation mechanism and timing

    SciTech Connect (OSTI)

    Bret, A. [ETSI Industriales, Universidad de Castilla-La Mancha, 13071 Ciudad Real (Spain); Instituto de Investigaciones Energéticas y Aplicaciones Industriales, Campus Universitario de Ciudad Real, 13071 Ciudad Real (Spain); Stockem, A. [GoLP/Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Lisbon (Portugal); Institut für Theoretische Physik, Lehrstuhl IV: Weltraum- und Astrophysik, Ruhr-Universität Bochum, D-44780 Bochum (Germany); Narayan, R. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS-51 Cambridge, Massachusetts 02138 (United States); Silva, L. O. [GoLP/Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Lisbon (Portugal)

    2014-07-15T23:59:59.000Z

    Collisionless shocks in plasmas play an important role in space physics (Earth's bow shock) and astrophysics (supernova remnants, relativistic jets, gamma-ray bursts, high energy cosmic rays). While the formation of a fluid shock through the steepening of a large amplitude sound wave has been understood for long, there is currently no detailed picture of the mechanism responsible for the formation of a collisionless shock. We unravel the physical mechanism at work and show that an electromagnetic Weibel shock always forms when two relativistic collisionless, initially unmagnetized, plasma shells encounter. The predicted shock formation time is in good agreement with 2D and 3D particle-in-cell simulations of counterstreaming pair plasmas. By predicting the shock formation time, experimental setups aiming at producing such shocks can be optimised to favourable conditions.

  6. Effect of trapped electron on the dust ion acoustic waves in dusty plasma using time fractional modified Korteweg-de Vries equation

    SciTech Connect (OSTI)

    Nazari-Golshan, A. [Department of Physics, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of)] [Department of Physics, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Nourazar, S. S. [Department of Physics, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of) [Department of Physics, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Department of Mechanical Engineering, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of)

    2013-10-15T23:59:59.000Z

    The time fractional modified Korteweg-de Vries (TFMKdV) equation is solved to study the nonlinear propagation of small but finite amplitude dust ion-acoustic (DIA) solitary waves in un-magnetized dusty plasma with trapped electrons. The plasma is composed of a cold ion fluid, stationary dust grains, and hot electrons obeying a trapped electron distribution. The TFMKdV equation is derived by using the semi-inverse and Agrawal's methods and then solved by the Laplace Adomian decomposition method. Our results show that the amplitude of the DIA solitary waves increases with the increase of time fractional order ?, the wave velocity v{sub 0}, and the population of the background free electrons ?. However, it is vice-versa for the deviation from isothermality parameter b, which is in agreement with the result obtained previously.

  7. Attonewton force detection using microspheres in a dual-beam optical trap in high vacuum

    E-Print Network [OSTI]

    Ranjit, Gambhir; Stutz, Jordan H; Cunningham, Mark; Geraci, Andrew A

    2015-01-01T23:59:59.000Z

    We describe the implementation of laser-cooled silica microspheres as force sensors in a dual-beam optical dipole trap in high vacuum. Using this system we have demonstrated trap lifetimes exceeding several days, attonewton force detection capability, and wide tunability in trapping and cooling parameters. Measurements have been performed with charged and neutral beads to calibrate the sensitivity of the detector. This work establishes the suitability of dual beam optical dipole traps for precision force measurement in high vacuum with long averaging times, and enables future applications including the study of gravitational inverse square law violations at short range, Casimir forces, acceleration sensing, and quantum opto-mechanics.

  8. Attonewton force detection using microspheres in a dual-beam optical trap in high vacuum

    E-Print Network [OSTI]

    Gambhir Ranjit; David P. Atherton; Jordan H. Stutz; Mark Cunningham; Andrew A. Geraci

    2015-03-30T23:59:59.000Z

    We describe the implementation of laser-cooled silica microspheres as force sensors in a dual-beam optical dipole trap in high vacuum. Using this system we have demonstrated trap lifetimes exceeding several days, attonewton force detection capability, and wide tunability in trapping and cooling parameters. Measurements have been performed with charged and neutral beads to calibrate the sensitivity of the detector. This work establishes the suitability of dual beam optical dipole traps for precision force measurement in high vacuum with long averaging times, and enables future applications including the study of gravitational inverse square law violations at short range, Casimir forces, acceleration sensing, and quantum opto-mechanics.

  9. Attonewton force detection using microspheres in a dual-beam optical trap in high vacuum

    E-Print Network [OSTI]

    Gambhir Ranjit; David P. Atherton; Jordan H. Stutz; Mark Cunningham; Andrew A. Geraci

    2015-04-03T23:59:59.000Z

    We describe the implementation of laser-cooled silica microspheres as force sensors in a dual-beam optical dipole trap in high vacuum. Using this system we have demonstrated trap lifetimes exceeding several days, attonewton force detection capability, and wide tunability in trapping and cooling parameters. Measurements have been performed with charged and neutral beads to calibrate the sensitivity of the detector. This work establishes the suitability of dual beam optical dipole traps for precision force measurement in high vacuum with long averaging times, and enables future applications including the study of gravitational inverse square law violations at short range, Casimir forces, acceleration sensing, and quantum opto-mechanics.

  10. Modeling genome-wide replication kinetics reveals a mechanism for regulation of replication timing

    E-Print Network [OSTI]

    Bechhoefer, John

    Modeling genome-wide replication kinetics reveals a mechanism for regulation of replication timing, University of Massachusetts Medical School, Worcester, MA, USA * Corresponding author. Department of Physics, testable, biochemically plausible mechanism for the regulation of replication timing in eukaryotes

  11. A non-blocking buffer mechanism for real-time event message communication

    E-Print Network [OSTI]

    Kim, KHK

    2006-01-01T23:59:59.000Z

    of time- constrained messages", IEEE Trans. on Computers,Mechanism for Real-Time Event Message Communicatoin K. H. (in facilitating state message communication from a producer

  12. A Comparative Study of State Saving Mechanisms for Time Warp Synchronized Parallel Discrete Event Simulation

    E-Print Network [OSTI]

    Boyer, Edmond

    A Comparative Study of State Saving Mechanisms for Time Warp Synchronized Parallel Discrete Event of Technology SWEDEN Abstract The state saving mechanism constitutes an essential part of any system in which Synchronization mechanism. In this type of systems the state saving and restoration mechanism is essential

  13. Cryogenic Ion Trapping Systems with Surface-Electrode Traps

    E-Print Network [OSTI]

    P. B. Antohi; D. Schuster; G. M. Akselrod; J. Labaziewicz; Y. Ge; Z. Lin; W. S. Bakr; I. L. Chuang

    2008-07-29T23:59:59.000Z

    We present two simple cryogenic RF ion trap systems in which cryogenic temperatures and ultra high vacuum pressures can be reached in as little as 12 hours. The ion traps are operated either in a liquid helium bath cryostat or in a low vibration closed cycle cryostat. The fast turn around time and availability of buffer gas cooling made the systems ideal for testing surface-electrode ion traps. The vibration amplitude of the closed cycled cryostat was found to be below 106 nm. We evaluated the systems by loading surface-electrode ion traps with $^{88}$Sr$^+$ ions using laser ablation, which is compatible with the cryogenic environment. Using Doppler cooling we observed small ion crystals in which optically resolved ions have a trapped lifetime over 2500 minutes.

  14. Real-time Health Monitoring of Mechanical Structures

    E-Print Network [OSTI]

    Ray, Asok

    , years for bridges and roads, and number of starts for diesel engines. It is also assumed that the state of damage in a mechanical structure bears a direct correlation with the amount of usage. However, one

  15. Interaction of trapped ions with trapped atoms

    E-Print Network [OSTI]

    Grier, Andrew T. (Andrew Todd)

    2011-01-01T23:59:59.000Z

    In this thesis, I present results from two Paul-trap based ion traps carried out in the Vuleti? laboratory: the Atom-Ion trap for collision studies between cold atoms and cold ions, and the Cavity-Array trap for studying ...

  16. Energy Conservation Thru Steam Trap Surveys and Preventive Maintenance Programs

    E-Print Network [OSTI]

    Boynton, T.; Dewhirst, B.

    1980-01-01T23:59:59.000Z

    This paper will deal with steam trap surveys and preventive maintenance programs and the energy savings that may be realized from such efforts. Trap survey organization, flexibility, simplicity, and mechanics will be reviewed, including the economic...

  17. High-field penning-malmberg trap: confinement properties and use in positron accumulation

    SciTech Connect (OSTI)

    Hartley, J.H.

    1997-09-01T23:59:59.000Z

    This dissertation reports on the development of the 60 kG cryogenic positron trap at Lawrence Livermore National Laboratory, and compares the trap`s confinement properties with other nonneutral plasma devices. The device is designed for the accumulation of up to 2{times}10{sup 9} positrons from a linear-accelerator source. This positron plasma could then be used in Bhabha scattering experiments. Initial efforts at time-of-flight accumulation of positrons from the accelerator show rapid ({approximately}100 ms) deconfinement, inconsistent with the long electron lifetimes. Several possible deconfinement mechanisms have been explored, including annihilation on residual gas, injection heating, rf noise from the accelerator, magnet field curvature, and stray fields. Detailed studies of electron confinement demonstrate that the empirical scaling law used to design the trap cannot be extrapolated into the parameter regime of this device. Several possible methods for overcoming these limitations are presented.

  18. A Short-Time Quantum Mechanical Expansion Approach to Vibrational Relaxation Eran Rabani*,

    E-Print Network [OSTI]

    Rabani, Eran

    A Short-Time Quantum Mechanical Expansion Approach to Vibrational Relaxation Eran Rabani*, School" molecule embedded in a "quantum" host is approached from the perspective of a short-time expansion that depend on both position and momentum. A simple ansatz is used to connect the short-time and long

  19. Steam Trap Management

    E-Print Network [OSTI]

    Murphy, J. J.; Hirtner, H. H.

    problemA of water hammer and high back pressure. ? Exorbitantly hi~h percentage of cold trapA. ? External steam leaks within the steam trap stations, bypasA valves and/or strainer blowdown valvefl open, blowin~ steam. ! I ? Dirt nssociated... Trapping 2 Trap Installed Backwards 1 Misapplication of Technology 1 Strainer Blowdown Connections Capped 285 (*b) Test Tee Connections Capped 11 Trap Inlet Connected to Steam Line Strainer Blowdown Connection 3 Water Logged Coils (Vacuum Present) 7...

  20. Evaluating Steam Trap Performance

    E-Print Network [OSTI]

    Fuller, N. Y.

    EVALUATING STEAM TRAP PERFORMANCE Noel Y Fuller, P.E. Holston Defense Corporation Kingsport, Tennessee ABSTRACT Laboratory tests were conducted on several types of steam traps at Holston Defense Corporation in Kingsport, Tennessee. Data... that live steam loss is the heaviest contributor to the annual operating cost of any steam trap and that maintenance frequency and repair cost are also more important than a trap's first cost. INTRODUCTION Steam traps used on distribution line drip...

  1. Trapped-ion Lissajous trajectories

    E-Print Network [OSTI]

    R. F. Rossetti; G. D. de Moraes Neto; J. Carlos Egues; M. H. Y. Moussa

    2015-02-25T23:59:59.000Z

    Here we present a protocol for generating Lissajous curves with a trapped ion by engineering Rashba- and the Dresselhaus-type spin-orbit interactions in a Paul trap. The unique anisotropic Rashba $\\alpha_{x}$, $\\alpha_{y}$ and Dresselhaus $\\beta_{x}$, $\\beta_{y}$ couplings afforded by our setup also enables us to obtain an "unusual" Zitterbewegung, i.e., the semiconductor analog of the relativistic trembling motion of electrons, with cycloidal trajectories in the absence of magnetic fields. We have also introduced bounded SO interactions, confined to an upper-bound vibrational subspace of the Fock states, as an additional mechanism to manipulate the Lissajous motion of the trapped ion. Finally, we accounted for dissipative effects on the vibrational degrees of freedom of the ion and find that the Lissajous trajectories are still robust and well defined for realistic parameters.

  2. Highlighting the mechanism of the quantum speedup by time-symmetric and relational quantum mechanics

    E-Print Network [OSTI]

    Giuseppe Castagnoli

    2014-12-11T23:59:59.000Z

    Bob hides a ball in one of four drawers. Alice is to locate it. Classically she has to open up to three drawers, quantally just one. The fundamental reason for this quantum speedup is not known. We explain it by extending the usual representation of the quantum algorithm, limited to the process of solving the problem, to the process of setting the problem. The number of the drawer with the ball becomes a unitary transformation of the random outcome of the preparation measurement. This brings in relational quantum mechanics: the extension is with respect to Bob and cannot be with respect to Alice. It would tell her the drawer number before she opens any drawer. To Alice, the projection of the quantum state due to the preparation measurement should be retarded at the end of her search; in the input state of the search, the drawer number is determined to Bob and undetermined to Alice. A second consequence is the emergence of an ambiguity. Either the preparation measurement or the final one required to read the solution selects the solution. For reasons of symmetry, we assume that the selection shares evenly between the two measurements. All is as if Alice, by reading the solution, selected half of the information that specifies the drawer number. This selection leaves the input state to Bob unaltered and projects that to Alice on a state of lower entropy where she knows that half in advance. The quantum algorithm is a sum over histories in each of which Alice knows in advance that the ball is in a pair of drawers and locates it by opening one of the two. More in general, given an oracle problem, this explanation of the speedup predicts the number of queries required to solve it in an optimal quantum way.

  3. Damage mechanisms identification of polymer based composite materials: time-frequency investigation of

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Damage mechanisms identification of polymer based composite materials: time-frequency investigation 2012, Nantes, France 2045 #12;Presented in this paper, a time-frequency damage characterization Emission (AE) signals by the Hilbert-Huang transform (HHT). It is to be noted that the study of damage

  4. An Efficient Threshold-Based Power Management Mechanism for Heterogeneous Soft Real-Time Clusters

    E-Print Network [OSTI]

    Lu, Ying

    An Efficient Threshold-Based Power Management Mechanism for Heterogeneous Soft Real-Time Clusters {lwang, ylu}@cse.unl.edu Abstract With growing cost of electricity, the power management of server proposes an efficient algorithm for power management of heterogeneous soft real-time clusters. It is built

  5. On the Design of Traps for Feeding 3D Parts on Vibratory Tracks

    E-Print Network [OSTI]

    Utrecht, Universiteit

    a sequence of mechanical devices such as wiper blades, grooves and traps. Most of these devices are filters

  6. Superconducting microfabricated ion traps

    E-Print Network [OSTI]

    Wang, Shannon Xuanyue

    We fabricate superconducting ion traps with niobium and niobium nitride and trap single [superscript 88]Sr ions at cryogenic temperatures. The superconducting transition is verified and characterized by measuring the ...

  7. Superconducting microfabricated ion traps

    E-Print Network [OSTI]

    Shannon X. Wang; Yufei Ge; Jaroslaw Labaziewicz; Eric Dauler; Karl Berggren; Isaac L. Chuang

    2010-12-14T23:59:59.000Z

    We fabricate superconducting ion traps with niobium and niobium nitride and trap single 88Sr ions at cryogenic temperatures. The superconducting transition is verified and characterized by measuring the resistance and critical current using a 4-wire measurement on the trap structure, and observing change in the rf reflection. The lowest observed heating rate is 2.1(3) quanta/sec at 800 kHz at 6 K and shows no significant change across the superconducting transition, suggesting that anomalous heating is primarily caused by noise sources on the surface. This demonstration of superconducting ion traps opens up possibilities for integrating trapped ions and molecular ions with superconducting devices.

  8. Schwinger Mechanism for Fermion Pair Production in the Presence of Arbitrary Time Dependent Background Electric Field

    E-Print Network [OSTI]

    Fred Cooper; Gouranga C. Nayak

    2006-12-29T23:59:59.000Z

    We study the Schwinger mechanism for the pair production of fermions in the presence of an arbitrary time-dependent background electric field E(t) by directly evaluating the path integral. We obtain an exact non-perturbative result for the probability of fermion-antifermion pair production per unit time per unit volume per unit transverse momentum (of the fermion or antifermion) from the arbitrary time dependent electric field E(t) via Schwinger mechanism. We find that the exact non-perturbative result is independent of all the time derivatives d^nE(t)/dt^n, where n=1,2,....\\infty. This result has the same functional dependence on E as the Schwinger's constant electric field E result with the replacement: E -> E(t).

  9. Pricing mechanism for real-time balancing in regional electricity markets

    E-Print Network [OSTI]

    de Weerdt, Mathijs

    an econometric analysis of the regulating power market on the Nordic power exchange Nord Pool, and M¨oller et al , Wolfgang Ketter , and John Collins Abstract We consider the problem of designing a pricing mechanism for precisely controlling the real-time balance in electricity markets, where retail brokers aggregate

  10. GRANIT project: a trap for gravitational quantum states of UCN

    E-Print Network [OSTI]

    Pignol, G; Rebreyend, D; Vezzu, F; Nesvizhevsky, V V; Petukhov, A K; Börner, H G; Soldner, T; Schmidt-Wellenburg, P; Kreuz, M; Forest, D; Ganau, P; Mackowski, J M; Michel, C; Montorio, J L; Morgado, N; Pinard, L; Remillieux, A; Gagarski, A M; Petrov, G A; Kusmina, A M; Strelkov, A V; Abele, H; Baeßler, S; Voronin, A Yu

    2007-01-01T23:59:59.000Z

    Previous studies of gravitationally bound states of ultracold neutrons showed the quantization of energy levels, and confirmed quantum mechanical predictions for the average size of the two lowest energy states wave functions. Improvements in position-like measurements can increase the accuracy by an order of magnitude only. We therefore develop another approach, consisting in accurate measurements of the energy levels. The GRANIT experiment is devoted to the study of resonant transitions between quantum states induced by an oscillating perturbation. According to Heisenberg's uncertainty relations, the accuracy of measurement of the energy levels is limited by the time available to perform the transitions. Thus, trapping quantum states will be necessary, and each source of losses has to be controlled in order to maximize the lifetime of the states. We discuss the general principles of transitions between quantum states, and consider the main systematical losses of neutrons in a trap.

  11. GRANIT project: a trap for gravitational quantum states of UCN

    E-Print Network [OSTI]

    G. Pignol; K. V. Protasov; D. Rebreyend; F. Vezzu; V. V. Nesvizhevsky; A. K. Petukhov; H. G. Börner; T. Soldner; P. Schmidt-Wellenburg; M. Kreuz; D. Forest; P. Ganau; J. M. Mackowski; C. Michel; J. L. Montorio; N. Morgado; L. Pinard; A. Remillieux; A. M. Gagarski; G. A. Petrov; A. M. Kusmina; A. V. Strelkov; H. Abele; S. Baeßler; A. Yu. Voronin

    2007-08-19T23:59:59.000Z

    Previous studies of gravitationally bound states of ultracold neutrons showed the quantization of energy levels, and confirmed quantum mechanical predictions for the average size of the two lowest energy states wave functions. Improvements in position-like measurements can increase the accuracy by an order of magnitude only. We therefore develop another approach, consisting in accurate measurements of the energy levels. The GRANIT experiment is devoted to the study of resonant transitions between quantum states induced by an oscillating perturbation. According to Heisenberg's uncertainty relations, the accuracy of measurement of the energy levels is limited by the time available to perform the transitions. Thus, trapping quantum states will be necessary, and each source of losses has to be controlled in order to maximize the lifetime of the states. We discuss the general principles of transitions between quantum states, and consider the main systematical losses of neutrons in a trap.

  12. Laser trapping of {sup 21}Na atoms

    SciTech Connect (OSTI)

    Lu, Zheng-Tian

    1994-09-01T23:59:59.000Z

    This thesis describes an experiment in which about four thousand radioactive {sup 21}Na (t{sub l/2} = 22 sec) atoms were trapped in a magneto-optical trap with laser beams. Trapped {sup 21}Na atoms can be used as a beta source in a precision measurement of the beta-asymmetry parameter of the decay of {sup 21}Na {yields} {sup 21}Ne + {Beta}{sup +} + v{sub e}, which is a promising way to search for an anomalous right-handed current coupling in charged weak interactions. Although the number o trapped atoms that we have achieved is still about two orders of magnitude lower than what is needed to conduct a measurement of the beta-asymmetry parameter at 1% of precision level, the result of this experiment proved the feasibility of trapping short-lived radioactive atoms. In this experiment, {sup 21}Na atoms were produced by bombarding {sup 24}Mg with protons of 25 MeV at the 88 in. Cyclotron of Lawrence Berkeley Laboratory. A few recently developed techniques of laser manipulation of neutral atoms were applied in this experiment. The {sup 21}Na atoms emerging from a heated oven were first transversely cooled. As a result, the on-axis atomic beam intensity was increased by a factor of 16. The atoms in the beam were then slowed down from thermal speed by applying Zeeman-tuned slowing technique, and subsequently loaded into a magneto-optical trap at the end of the slowing path. The last two chapters of this thesis present two studies on the magneto-optical trap of sodium atoms. In particular, the mechanisms of magneto-optical traps at various laser frequencies and the collisional loss mechanisms of these traps were examined.

  13. Microfabricated ion trap array

    DOE Patents [OSTI]

    Blain, Matthew G. (Albuquerque, NM); Fleming, James G. (Albuquerque, NM)

    2006-12-26T23:59:59.000Z

    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.

  14. Current leakage relaxation and charge trapping in ultra-porous low-k materials

    SciTech Connect (OSTI)

    Borja, Juan; Plawsky, Joel L., E-mail: plawsky@rpi.edu; Gill, William N. [Howard P. Isermann Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States); Lu, T.-M. [Department of Physics, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States); Bakhru, Hassaram [University at Albany's College of Nanoscale Science and Engineering (CNSE), Albany, New York 12203 (United States)

    2014-02-28T23:59:59.000Z

    Time dependent dielectric failure has become a pivotal aspect of interconnect design as industry pursues integration of sub-22?nm process-technology nodes. Literature has provided key information about the role played by individual species such as electrons, holes, ions, and neutral impurity atoms. However, no mechanism has been shown to describe how such species interact and influence failure. Current leakage relaxation in low-k dielectrics was studied using bipolar field experiments to gain insight into how charge carrier flow becomes impeded by defects within the dielectric matrix. Leakage current decay was correlated to injection and trapping of electrons. We show that current relaxation upon inversion of the applied field can be described by the stretched exponential function. The kinetics of charge trapping events are consistent with a time-dependent reaction rate constant, k=k{sub 0}?(t+1){sup ??1}, where 0?trapping reactions in amorphous solids by W. H. Hamill and K. Funabashi, Phys. Rev. B 16, 5523–5527 (1977). We explain the relaxation process in charge trapping events by introducing a nonlinear charge trapping model. This model provides a description on the manner in which the transport of mobile defects affects the long-tail current relaxation processes in low-k films.

  15. Inertial measurement with trapped particles: A microdynamical system

    SciTech Connect (OSTI)

    Post, E. Rehmi; Popescu, George A.; Gershenfeld, Neil [Center for Bits and Atoms, Massachusetts Institute of Technology, 20 Ames Street, Cambridge, Massachusetts 02139 (United States)

    2010-04-05T23:59:59.000Z

    We describe an inertial measurement device based on an electrodynamically trapped proof mass. Mechanical constraints are replaced by guiding fields, permitting the trap stiffness to be tuned dynamically. Optical readout of the proof mass motion provides a measurement of acceleration and rotation, resulting in an integrated six degree of freedom inertial measurement device. We demonstrate such a device - constructed without microfabrication - with sensitivity comparable to that of commercial microelectromechanical systems technology and show how trapping parameters may be adjusted to increase dynamic range.

  16. Reduce Steam Trap Failures at Chambers Works 

    E-Print Network [OSTI]

    Kouba, C.

    2010-01-01T23:59:59.000Z

    automatically within SAP ? Survey performed and work orders created ? Surveyor/Team Leader coordinates repair work ? Use backlog of work to justify number of mechanics ? Prioritize work for mechanics ? Repair Mechanics work across the site ? SAP Work Order... history updated for individual traps ? Surveyor updates excel spreadsheet with repair history ? Monthly reports sent to area and site management 10/20/2010 11Piloted Solution Key Learnings ? SAP Cumbersome and slows repair process ? Use SAP...

  17. Heating of trapped ultracold atoms by collapse dynamics

    E-Print Network [OSTI]

    Franck Laloë; William J. Mullin; Philip Pearle

    2014-11-12T23:59:59.000Z

    {The Continuous Spontaneous Localization (CSL) theory alters the Schr\\"odinger equation. It describes wave function collapse as a dynamical process instead of an ill-defined postulate, thereby providing macroscopic uniqueness and solving the so-called measurement problem of standard quantum theory. CSL contains a parameter $\\lambda$ giving the collapse rate of an isolated nucleon in a superposition of two spatially separated states and, more generally, characterizing the collapse time for any physical situation. CSL is experimentally testable, since it predicts some behavior different from that predicted by standard quantum theory. One example is the narrowing of wave functions, which results in energy imparted to particles. Here we consider energy given to trapped ultra-cold atoms. Since these are the coldest samples under experimental investigation, it is worth inquiring how they are affected by the CSL heating mechanism. We examine the CSL heating of a BEC in contact with its thermal cloud. Of course, other mechanisms also provide heat and also particle loss. From varied data on optically trapped cesium BEC's, we present an energy audit for known heating and loss mechanisms. The result provides an upper limit on CSL heating and thereby an upper limit on the parameter $\\lambda$. We obtain $\\lambda\\lesssim 1(\\pm1)\\times 10^{-7}$sec$^{-1}$.}

  18. Surface trap for ytterbium ions

    E-Print Network [OSTI]

    Campbell, Jonathan A. (Jonathan Alan)

    2006-01-01T23:59:59.000Z

    We conducted an experiment to load a shallow planar ion trap from a cold atom source of Ytterbium using photoionization. The surface trap consisted of a three-rod radio frequency Paul trap fabricated using standard printed ...

  19. Parameter exploration of optically trapped liquid aerosols

    E-Print Network [OSTI]

    D. R. Burnham; P. J. Reece; D. McGloin

    2010-06-24T23:59:59.000Z

    When studying the motion of optically trapped particles on the $\\mu s$ time scale, in low viscous media such as air, inertia cannot be neglected. Resolution of unusual and interesting behaviour not seen in colloidal trapping experiments is possible. In attempt to explain the phenomena we use power spectral methods to perform a parameter study of the Brownian motion of optically trapped liquid aerosol droplets concentrated around the critically damped regime. We present evidence that the system is suitably described by a simple harmonic oscillator model which must include a description of Fax\\'{e}n's correction, but not necessarily frequency dependent hydrodynamic corrections to Stokes' law. We also provide results describing how the system behaves under several variables and discuss the difficulty in decoupling the parameters responsible for the observed behaviour. We show that due to the relatively low dynamic viscosity and high trap stiffness it is easy to transfer between over- and under-damped motion by experimentally altering either trap stiffness or damping. Our results suggest stable aerosol trapping may be achieved in under-damped conditions, but the onset of deleterious optical forces at high trapping powers prevents the probing of the upper stability limits due to Brownian motion.

  20. From Discrete Space-Time to Minkowski Space: Basic Mechanisms, Methods and Perspectives

    E-Print Network [OSTI]

    Felix Finster

    2008-02-22T23:59:59.000Z

    This survey article reviews recent results on fermion system in discrete space-time and corresponding systems in Minkowski space. After a basic introduction to the discrete setting, we explain a mechanism of spontaneous symmetry breaking which leads to the emergence of a discrete causal structure. As methods to study the transition between discrete space-time and Minkowski space, we describe a lattice model for a static and isotropic space-time, outline the analysis of regularization tails of vacuum Dirac sea configurations, and introduce a Lorentz invariant action for the masses of the Dirac seas. We mention the method of the continuum limit, which allows to analyze interacting systems. Open problems are discussed.

  1. Transport of hydrogen in metals with occupancy dependent trap energies

    SciTech Connect (OSTI)

    Schmid, K., E-mail: klaus.schmid@ipp.mpg.de; Toussaint, U. von; Schwarz-Selinger, T. [Max-Planck-Institut für Plasmaphysik, Boltzmannstraße 2, D-85748 Garching b. München (Germany)

    2014-10-07T23:59:59.000Z

    Common diffusion trapping models for modeling hydrogen transport in metals are limited to traps with single de-trapping energies and a saturation occupancy of one. While they are successful in predicting typical mono isotopic ion implantation and thermal degassing experiments, they fail at describing recent experiments on isotope exchange at low temperatures. This paper presents a new modified diffusion trapping model with fill level dependent de-trapping energies that can also explain these new isotope exchange experiments. Density function theory (DFT) calculations predict that even mono vacancies can store between 6 and 12?H atoms with de-trapping energies that depend on the fill level of the mono vacancy. The new fill level dependent diffusion trapping model allows to test these DFT results by bridging the gap in length and time scale between DFT calculations and experiment.

  2. Time Synchronization Attack in Smart Grid-Part II: Cross Layer Detection Mechanism

    E-Print Network [OSTI]

    Zhang, Zhenghao; Dimitrovski, Aleksandar D; Li, Husheng

    2012-01-01T23:59:59.000Z

    A novel time synchronization attack (TSA) on wide area monitoring systems in smart grid has been identified in the first part of this paper. A cross layer detection mechanism is proposed to combat TSA in part II of this paper. In the physical layer, we propose a GPS carrier signal noise ratio (C/No) based spoofing detection technique. In addition, a patch-monopole hybrid antenna is applied to receive GPS signal. By computing the standard deviation of the C/No difference from two GPS receivers, a priori probability of spoofing detection is fed to the upper layer, where power system state is estimated and controlled. A trustworthiness based evaluation method is applied to identify the PMU being under TSA. Both the physical layer and upper layer algorithms are integrated to detect the TSA, thus forming a cross layer mechanism. Experiment is carried out to verify the effectiveness of the proposed TSA detection algorithm.

  3. Chemical dynamics in the gas phase: Time-dependent quantum mechanics of chemical reactions

    SciTech Connect (OSTI)

    Gray, S.K. [Argonne National Laboratory, IL (United States)

    1993-12-01T23:59:59.000Z

    A major goal of this research is to obtain an understanding of the molecular reaction dynamics of three and four atom chemical reactions using numerically accurate quantum dynamics. This work involves: (i) the development and/or improvement of accurate quantum mechanical methods for the calculation and analysis of the properties of chemical reactions (e.g., rate constants and product distributions), and (ii) the determination of accurate dynamical results for selected chemical systems, which allow one to compare directly with experiment, determine the reliability of the underlying potential energy surfaces, and test the validity of approximate theories. This research emphasizes the use of recently developed time-dependent quantum mechanical methods, i.e. wave packet methods.

  4. 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

    2013-07-23T23:59:59.000Z

    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.

  5. 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

    2012-10-23T23:59:59.000Z

    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.

  6. Single trap dynamics in electrolyte-gated Si-nanowire field effect transistors

    SciTech Connect (OSTI)

    Pud, S.; Li, J.; Offenhäusser, A.; Vitusevich, S. A., E-mail: s.vitusevich@fz-juelich.de [Peter Grünberg Institute (PGI-8), Forschungszentrum Jülich, 52425 Jülich (Germany); Gasparyan, F. [Peter Grünberg Institute (PGI-8), Forschungszentrum Jülich, 52425 Jülich (Germany); Department of Semiconductor Physics and Microelectronics, Yerevan State University, 1 Alex Manoogian St., 0025 Yerevan (Armenia); Petrychuk, M. [Radiophysics Faculty, T. Shevchenko National University of Kyiv, 60 Volodymyrska St., 01601 Kyiv (Ukraine)

    2014-06-21T23:59:59.000Z

    Liquid-gated silicon nanowire (NW) field effect transistors (FETs) are fabricated and their transport and dynamic properties are investigated experimentally and theoretically. Random telegraph signal (RTS) fluctuations were registered in the nanolength channel FETs and used for the experimental and theoretical analysis of transport properties. The drain current and the carrier interaction processes with a single trap are analyzed using a quantum-mechanical evaluation of carrier distribution in the channel and also a classical evaluation. Both approaches are applied to treat the experimental data and to define an appropriate solution for describing the drain current behavior influenced by single trap resulting in RTS fluctuations in the Si NW FETs. It is shown that quantization and tunneling effects explain the behavior of the electron capture time on the single trap. Based on the experimental data, parameters of the single trap were determined. The trap is located at a distance of about 2?nm from the interface Si/SiO{sub 2} and has a repulsive character. The theory of dynamic processes in liquid-gated Si NW FET put forward here is in good agreement with experimental observations of transport in the structures and highlights the importance of quantization in carrier distribution for analyzing dynamic processes in the nanostructures.

  7. Steam trap monitor

    DOE Patents [OSTI]

    Ryan, M.J.

    1987-05-04T23:59:59.000Z

    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.

  8. Steam Trap Application

    E-Print Network [OSTI]

    Murphy, J. J.

    1982-01-01T23:59:59.000Z

    Equipment Collecting leg, same size as equip ment connection but not less than Install a Yarway Process Trap below be drained. Install a Provide vacuum strainer with a blow down valve. Use and Yarway Aldrain valves full ported stop valves, (gate... and Corrosion Problems Like any critical control device the steam trap should be protected from dirt and scale if optimum operation and adequate service life are to be attained. Strainers should be equipped with blowdown valves to provide an effective...

  9. Microfabricated cylindrical ion trap

    DOE Patents [OSTI]

    Blain, Matthew G.

    2005-03-22T23:59:59.000Z

    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.

  10. Broadband laser cooling of trapped atoms with ultrafast pulses

    E-Print Network [OSTI]

    B. B. Blinov; R. N. Kohn Jr.; M. J. Madsen; P. Maunz; D. L. Moehring; C. Monroe

    2005-07-07T23:59:59.000Z

    We demonstrate broadband laser cooling of atomic ions in an rf trap using ultrafast pulses from a modelocked laser. The temperature of a single ion is measured by observing the size of a time-averaged image of the ion in the known harmonic trap potential. While the lowest observed temperature was only about 1 K, this method efficiently cools very hot atoms and can sufficiently localize trapped atoms to produce near diffraction-limited atomic images.

  11. Cold trapped positrons and progress to cold antihydrogen

    E-Print Network [OSTI]

    Estrada, John Karl, 1970-

    2002-01-01T23:59:59.000Z

    A new physical mechanism for positron accumulation is explained and demonstrated. Strongly magnetized Rydberg positronium is formed and then ionized, allowing us to trap equal numbers of either positrons or electrons over ...

  12. Reduce Steam Trap Failures at Chambers Works

    E-Print Network [OSTI]

    Kouba, C.

    Maintenance Mechanic), Rick Ragsdale (Fluor), Joyce Finkle (PC), Denis P Humphreys (Fluoroproducts), Jack Hemmert, Charlie Brown 10/20/2010 2 Steam trap failures are nothing new Steam trap programs are nothing new WHAT makes this program have such a huge... impact and How is it sustainable HOW we went about finding a solution What do you have learn from this 10/20/2010 3 Six Sigma Methodology was KEY to success Savings: $1MM annualized in only 6 months! 10/20/2010 4Define: Project CTQ?s Customer...

  13. Mechanisms for the convergence of time-parallelized, parareal turbulent plasma simulations

    SciTech Connect (OSTI)

    Reynolds-Barredo, J. [University of Alaska; University Carlos III de Madrid; Newman, David E [University of Alaska; Sanchez, R. [Universidad Carlos III, Madrid, Spain; Samaddar, D. [ITER Organization, Saint Paul Lez Durance, France; Berry, Lee A [ORNL; Elwasif, Wael R [ORNL

    2012-01-01T23:59:59.000Z

    Parareal is a recent algorithm able to parallelize the time dimension in spite of its sequential nature. It has been applied to several linear and nonlinear problems and, very recently, to a simulation of fully-developed, two-dimensional drift wave turbulence. The mere fact that parareal works in such a turbulent regime is in itself somewhat unexpected, due to the characteristic sensitivity of turbulence to any change in initial conditions. This fundamental property of any turbulent system should render the iterative correction procedure characteristic of the parareal method inoperative, but this seems not to be the case. In addition, the choices that must be made to implement parareal (division of the temporal domain, election of the coarse solver and so on) are currently made using trial-and-error approaches. Here, we identify the mechanisms responsible for the convergence of parareal of these simulations of drift wave turbulence. We also investigate which conditions these mechanisms impose on any successful parareal implementation. The results reported here should be useful to guide future implementations of parareal within the much wider context of fully-developed fluid and plasma turbulent simulations.

  14. Antihydrogen Trapped in the ALPHA Experiment

    ScienceCinema (OSTI)

    None

    2011-04-25T23:59:59.000Z

    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 Excitation of Antiproton Plasmas' G.B. Andresen et al., Phys. Rev. Lett. 106, 025002 (2011) Organizer: Ferdinand Hahn PH/DT Detector Seminar webpage  

  15. Development of a Kingdon ion trap system for trapping externally injected highly charged ions

    SciTech Connect (OSTI)

    Numadate, Naoki; Okada, Kunihiro, E-mail: okada-k@sophia.ac.jp [Department of Physics, Sophia University, 7-1 Kioicho, Chiyoda, Tokyo 102-8554 (Japan); Nakamura, Nobuyuki [Institute for Laser Science, University of Electro-Communications, 1-5-1 Chofugaoka, Chofu, Tokyo 182-0021 (Japan); Tanuma, Hajime [Department of Physics, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397 (Japan)

    2014-10-15T23:59:59.000Z

    We have developed a Kingdon ion trap system for the purpose of the laboratory observation of the x-ray forbidden transitions of highly charged ions (HCIs). Externally injected Ar{sup q+} (q = 5?7) with kinetic energies of 6q keV were successfully trapped in the ion trap. The energy distribution of trapped ions is discussed in detail on the basis of numerical simulations. The combination of the Kingdon ion trap and the time-of-flight mass spectrometer enabled us to measure precise trapping lifetimes of HCIs. As a performance test of the instrument, we measured trapping lifetimes of Ar{sup q+} (q = 5?7) under a constant number density of H{sub 2} and determined the charge-transfer cross sections of Ar{sup q+}(q = 5, 6)-H{sub 2} collision systems at binary collision energies of a few eV. It was confirmed that the present cross section data are consistent with previous data and the values estimated by some scaling formula.

  16. Fast optimal frictionless atom cooling in harmonic traps

    E-Print Network [OSTI]

    Xi Chen; A. Ruschhaupt; S. Schmidt; A. del Campo; D. Guery-Odelin; J. G. Muga

    2009-10-05T23:59:59.000Z

    A method is proposed to cool down atoms in a harmonic trap without phase-space compression as in a perfectly slow adiabatic expansion, i.e., keeping the populations of the instantaneous initial and final levels invariant, but in a much shorter time. This may require that the harmonic trap becomes an expulsive parabolic potential in some time interval. The cooling times achieved are also shorter than previous minimal times using optimal-control bang-bang methods and real frequencies.

  17. 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)

    2010-02-15T23:59:59.000Z

    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.

  18. 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

    2011-02-15T23:59:59.000Z

    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.

  19. Thermoelectrically cooled water trap

    DOE Patents [OSTI]

    Micheels, Ronald H. (Concord, MA)

    2006-02-21T23:59:59.000Z

    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.

  20. Optothermal Molecule Trap

    E-Print Network [OSTI]

    Duhr, S; Duhr, Stefan; Braun, Dieter

    2006-01-01T23:59:59.000Z

    Thermophoresis moves molecules along temperature gradients, typically from hot to cold. We superpose fluid flow with thermophoretic molecule flow under well defined microfluidic conditions, imaged by fluorescence microscopy. DNA is trapped and accumulated 16-fold in regions where both flows move in opposite directions. Strong 800-fold accumulation is expected, however with slow trapping kinetics. The experiment is equally described by a three-dimensional and one-dimensional analytical model. As an application, we show how a radially converging temperature field confines short DNA into a 10 um small spot.

  1. Asymmetric ion trap

    DOE Patents [OSTI]

    Barlow, Stephan E. (Richland, WA); Alexander, Michael L. (Richland, WA); Follansbee, James C. (Pasco, WA)

    1997-01-01T23:59:59.000Z

    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.

  2. Asymmetric ion trap

    DOE Patents [OSTI]

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

    1997-12-02T23:59:59.000Z

    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.

  3. A system for trapping barium ions in a microfabricated surface trap

    SciTech Connect (OSTI)

    Graham, R. D., E-mail: rdgraham@uw.edu; Sakrejda, T.; Wright, J.; Zhou, Z.; Blinov, B. B., E-mail: blinov@uw.edu [University of Washington, Department of Physics, Box 351560, Seattle, WA 98195-1560 (United States); Chen, S.-P. [University of Washington, Department of Electrical Engineering, 185 Stevens Way, Paul Allen Center - Room AE100R, Campus Box 352500, Seattle, WA 98195-2500 (United States)

    2014-05-15T23:59:59.000Z

    We have developed a vacuum chamber and control system for rapid testing of microfabricated surface ion traps. Our system is modular in design and is based on an in-vacuum printed circuit board with integrated filters. We have used this system to successfully trap and cool barium ions and have achieved ion ‘dark' lifetimes of 31.6 s ± 3.4 s with controlled shuttling of ions. We provide a detailed description of the ion trap system including the in-vacuum materials used, control electronics and neutral atom source. We discuss the challenges presented in achieving a system which can work reliably over two years of operations in which the trap under test was changed at least 10 times.

  4. Bose-Einstein Condensation in an electro-pneumatically transformed quadrupole-Ioffe magnetic trap

    E-Print Network [OSTI]

    Sunil Kumar; Sumit Sarkar; Gunjan Verma; Chetan Vishwakarma; Md. Noaman; Umakant Rapol

    2014-08-20T23:59:59.000Z

    We report a novel approach for preparing a Bose-Einstein condensate (BEC) of $^{87}$Rb atoms using electro-pneumatically driven transfer of atoms into a Quadrupole-Ioffe magnetic trap (QUIC Trap). More than 5$\\times$$10^{8}$ atoms from a Magneto-optical trap are loaded into a spherical quadrupole trap and then these atoms are transferred into an Ioffe trap by moving the Ioffe coil towards the center of the quadrupole coil, thereby, changing the distance between quadrupole trap center and the Ioffe coil. The transfer efficiency is more than 80 \\%. This approach is different from a conventional approach of loading the atoms into a QUIC trap wherein the spherical quadrupole trap is transformed into a QUIC trap by changing the currents in the quadrupole and the Ioffe coils. The phase space density is then increased by forced rf evaporative cooling to achieve the Bose-Einstein condensation having more than $10^{5}$ atoms.

  5. Steam trap monitor

    DOE Patents [OSTI]

    Ryan, Michael J. (Plainfield, IL)

    1988-01-01T23:59:59.000Z

    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.

  6. Master equation approach to protein folding and kinetic traps

    E-Print Network [OSTI]

    Marek Cieplak; Malte Henkel; Jan Karbowski; Jayanth R. Banavar

    1998-04-21T23:59:59.000Z

    The master equation for 12-monomer lattice heteropolymers is solved numerically and the time evolution of the occupancy of the native state is determined. At low temperatures, the median folding time follows the Arrhenius law and is governed by the longest relaxation time. For good folders, significant kinetic traps appear in the folding funnel whereas for bad folders, the traps also occur in non-native energy valleys.

  7. Controlling fast transport of cold trapped ions

    E-Print Network [OSTI]

    Andreas Walther; Frank Ziesel; Thomas Ruster; Sam T. Dawkins; Konstantin Ott; Max Hettrich; Kilian Singer; Ferdinand Schmidt-Kaler; Ulrich Poschinger

    2012-06-02T23:59:59.000Z

    We realize fast transport of ions in a segmented micro-structured Paul trap. The ion is shuttled over a distance of more than 10^4 times its groundstate wavefunction size during only 5 motional cycles of the trap (280 micro meter in 3.6 micro seconds). Starting from a ground-state-cooled ion, we find an optimized transport such that the energy increase is as low as 0.10 $\\pm$ 0.01 motional quanta. In addition, we demonstrate that quantum information stored in a spin-motion entangled state is preserved throughout the transport. Shuttling operations are concatenated, as a proof-of-principle for the shuttling-based architecture to scalable ion trap quantum computing.

  8. Steam Trap Maintenance as a Profit Center

    E-Print Network [OSTI]

    Bouchillon, J. L.

    of the proper piping arrangements to all your basic equipment showing the traps, strainers, air vents, vacuum breakers, etc. These diagrams need to apply only to your plant, not to the hundreds of possibilities found in an all-purpose publication. See Fig... and rust ("dirt") E Size L Mechanical failure usually is... OJ Recommended design factor 2-3 Loud, popping condensate discharge No Renewable wlo piping disassembly No Requires strainer No Tbennal efficiency (low steam loss) Fair Condensate Wscharge...

  9. Nanoantennas for enhanced light trapping in transparent organic solar cells

    E-Print Network [OSTI]

    Voroshilov, Pavel M; Belov, Pavel A

    2014-01-01T23:59:59.000Z

    We propose a light-trapping structure offering a significant enhancement of photovoltaic absorption in transparent organic solar cells operating at infrared while the visible light transmission keeps sufficiently high. The main mechanism of light trapping is related with the excitation of collective oscillations of the metal nanoantenna arrays, characterized by advantageous field distribution in the volume of the solar cell. It allows more than triple increase of infrared photovoltaic absorption.

  10. Wednesday, January 30, 2013 Infrared Trapping the "Greenhouse Effect"

    E-Print Network [OSTI]

    Toohey, Darin W.

    Wednesday, January 30, 2013 Infrared Trapping ­ the "Greenhouse Effect" Goals ­ to look is the same as a 1.8 degree F change. #12;Last time - Greenhouse effect demo Selective absorption. Greenhouse

  11. Acceleration of trapped particles and beams

    E-Print Network [OSTI]

    Er'el Granot; Boris Malomed

    2011-07-30T23:59:59.000Z

    The dynamics of a quantum particle bound by an accelerating delta-functional potential is investigated. Three cases are considered, using the reference frame moving along with the {\\delta}-function, in which the acceleration is converted into the additional linear potential. (i) A stationary regime, which corresponds to a resonance state, with a minimum degree of delocalization, supported by the accelerating potential trap. (ii) A pulling scenario: an initially bound particle follows the accelerating delta-functional trap, within a finite time. (iii) The pushing scenario: the particle, which was initially localized to the right of the repulsive delta-function, is shoved to the right by the accelerating potential. For the two latter scenarios, the life time of the trapped particle, and the largest velocity to which it can be accelerated while staying trapped, are found. Analytical approximations are developed for the cases of small and large accelerations in the pulling regime, and also for a small acceleration in the stationary situation, and in the regime of pushing. The same regimes may be realized by Airy-like planar optical beams guided by a narrow bending potential channel or crest. Physical estimates are given for an atom steered by a stylus of a scanning tunneling microscope (STM), and for the optical beam guided by a bending stripe.

  12. Simplified motional heating rate measurements of trapped ions

    E-Print Network [OSTI]

    Epstein, R J; Leibfried, D; Wesenberg, J H; Bollinger, J J; Amini, J M; Blakestad, R B; Britton, J; Home, J P; Itano, W M; Jost, J D; Knill, E; Langer, C; Ozeri, R; Shiga, N; Wineland, D J

    2007-01-01T23:59:59.000Z

    We have measured motional heating rates of trapped atomic ions, a factor that can influence multi-ion quantum logic gate fidelities. Two simplified techniques were developed for this purpose: one relies on Raman sideband detection implemented with a single laser source, while the second is even simpler and is based on time-resolved fluorescence detection during Doppler recooling. We applied these methods to determine heating rates in a microfrabricated surface-electrode trap made of gold on fused quartz, which traps ions 40 microns above its surface. Heating rates obtained from the two techniques were found to be in reasonable agreement. In addition, the trap gives rise to a heating rate of 300 plus or minus 30 per second for a motional frequency of 5.25 MHz, substantially below the trend observed in other traps.

  13. Theory of phonon dynamics in an ion trap

    E-Print Network [OSTI]

    Dutta, T; Sengupta, K

    2015-01-01T23:59:59.000Z

    We develop a theory to address the non-equilibrium dynamics of phonons in a one-dimensional trapped ion system. We elaborate our earlier results obtained in Phys. Rev. Lett. {\\bf 111}, 170406 (2013) to chart out the mechanism of dynamics-induced cooling and entanglement generation between phonons in these systems when subjected to a linear ramp protocol inducing site-specific tuning of on-site interactions between the phonons. We further extend these studies to non-linear ramps and periodic drive protocols and identify the optimal ramp protocol for minimal cooling and entanglement generation time. We qualitatively address the effect of noise arising out of fluctuation of the intensity of the laser used to generate entanglement and provide a detailed discussion of a realistic experimental setup which may serve as a test bed for our theory.

  14. Final Technical Report of project: "Contactless Real-Time Monitoring of Paper Mechanical Behavior During Papermaking"

    SciTech Connect (OSTI)

    Emmanuel Lafond; Paul Ridgway; Ted Jackson; Rick Russo; Ken Telschow; Vance Deason; Yves Berthelot; David Griggs; Xinya Zhang; Gary Baum

    2005-08-30T23:59:59.000Z

    The early precursors of laser ultrasonics on paper were Prof. Y. Berthelot from the Georgia Institute of Technology/Mechanical Engineering department, and Prof. P. Brodeur from the Institute of Paper Science and Technology, both located in Atlanta, Georgia. The first Ph.D. thesis that shed quite some light on the topic, but also left some questions unanswered, was completed by Mont A. Johnson in 1996. Mont Johnson was Prof. Berthelot's student at Georgia Tech. In 1997 P. Brodeur proposed a project involving himself, Y. Berthelot, Dr. Ken Telschow and Mr. Vance Deason from INL, Honeywell-Measurex and Dr. Rick Russo from LBNL. The first time the proposal was not accepted and P. Brodeur decided to re-propose it without the involvement from LBNL. Rick Russo proposed a separate project on the same topic on his side. Both proposals were finally accepted and work started in the fall of 1997 on the two projects. Early on, the biggest challenge was to find an optical detection method which could detect laser-induced displacements of the web surface that are of the order of .1 micron in the ultrasonic range. This was to be done while the web was having an out-of-plane amplitude of motion in the mm range due to web flutter; while moving at 10 m/s to 30 m/s in the plane of the web, on the paper machine. Both teams grappled with the same problems and tried similar methods in some cases, but came up with two similar but different solutions one year later. The IPST, GT, INL team found that an interferometer made by Lasson Technologies Inc. using the photo-induced electro-motive force in Gallium Arsenide was able to detect ultrasonic waves up to 12-15 m/s. It also developed in house an interferometer using the Two-Wave Mixing effect in photorefractive crystals that showed good promises for on-line applications, and experimented with a scanning mirror to reduce motion-induced texture noise from the web and improve signal to noise ratio. On its side, LBNL had the idea to combine a commercial Mach-Zehnder interferometer to a spinning mirror synchronized to the web speed, in order to make almost stationary measurements. The method was demonstrated at up to 10 m/s. Both teams developed their own version of a web simulator that was driving a web of paper at 10 m/s or higher. The Department of Energy and members of the Agenda 2020 started to make a push for merging the two projects. This made sense because their topics were really identical but this was not well received by Prof. Brodeur. Finally IPST decided to reassign the direction of the IPST-INL-GT project in the spring of 1999 to Prof. Chuck Habeger so that the two teams could work together. Also at this time, Honeywell-Measurex dropped as a member of the team. It was replaced by ABB Industrial Systems whose engineers had extensive previous experience of working with ultrasonic sensors on paperboard. INL also finished its work on the project as its competencies were partly redundant with LBNL. From the summer of 1999, the IPST-GT and LBNL teams were working together and helped each other often by collaborating and visiting either laboratory when was necessary. Around the beginning of 2000, began an effort at IPST to create an off-line laser-ultrasonics instrument that could perform automated measurements of paper and paperboard's bending stiffness. It was widely known that the mechanical bending tests of paper used for years by the paper industry were very inaccurate and exhibited poor reproducibility; therefore the team needed a new instrument of reference to validate its future on-line results. In 1999-2000, the focus of the on-line instrument was on a pre-industrial demonstration on a pilot coater while reducing the damage to the web caused by the generation laser, below the threshold where it could be visible by the naked eye. During the spring of 2000 Paul Ridgway traveled to IPST and brought with him a redesigned system still using the same Mach-Zehnder interferometer as before, but this time employing an electric motor-driven spinning mirror instead of the previously belt-driven m

  15. Gated charged-particle trap

    DOE Patents [OSTI]

    Benner, W. Henry (Danville, CA)

    1999-01-01T23:59:59.000Z

    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.

  16. Time Stamp Attack in Smart Grid: Physical Mechanism and Damage Analysis

    E-Print Network [OSTI]

    Gong, Shuping; Li, Husheng; Dimitrovski, Aleksandar D

    2012-01-01T23:59:59.000Z

    Many operations in power grids, such as fault detection and event location estimation, depend on precise timing information. In this paper, a novel time stamp attack (TSA) is proposed to attack the timing information in smart grid. Since many applications in smart grid utilize synchronous measurements and most of the measurement devices are equipped with global positioning system (GPS) for precise timing, it is highly probable to attack the measurement system by spoofing the GPS. The effectiveness of TSA is demonstrated for three applications of phasor measurement unit (PMU) in smart grid, namely transmission line fault detection, voltage stability monitoring and event locationing.

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

    SciTech Connect (OSTI)

    El-Atab, Nazek; Rizk, Ayman; Nayfeh, Ammar [Institute Center for Microsystems – iMicro, Department of Electrical Engineering and Computer Science (EECS), Masdar Institute of Science and Technology Abu Dhabi (United Arab Emirates)] [Institute Center for Microsystems – iMicro, Department of Electrical Engineering and Computer Science (EECS), Masdar Institute of Science and Technology Abu Dhabi (United Arab Emirates); Okyay, Ali K. [Department of Electrical and Electronics Engineering, Bilkent University, 06800 Ankara (Turkey) [Department of Electrical and Electronics Engineering, Bilkent University, 06800 Ankara (Turkey); UNAM-National Nanotechnology Research Center and Institute of Materials Science and Nanotechnology, Bilkent University, 06800 Ankara (Turkey)

    2013-11-15T23:59:59.000Z

    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.

  18. Commissioning of the Francium Trapping Facility at TRIUMF

    E-Print Network [OSTI]

    M. Tandecki; J. Zhang; R. Collister; S. Aubin; J. A. Behr; E. Gomez; G. Gwinner; L. A. Orozco; M. R. Pearson

    2013-12-12T23:59:59.000Z

    We report on the successful commissioning of the Francium Trapping Facility at TRIUMF. Large laser-cooled samples of francium are produced from a francium ion beam delivered by the ISAC radioactive ion beam facility. The ion beam is neutralized on an yttrium foil, which is subsequently heated to transfer the atoms into the magneto-optical trapping region. We have successfully trapped $^{207}$Fr, $^{209}$Fr and $^{221}$Fr, with a maximum of $2.5 \\times 10^5$ $^{209}$Fr atoms. The neutral cold atoms will be used in studies of the weak interaction through measurements of atomic parity non-conservation.

  19. Mechanisms for mechanical trapping of geologically sequestered carbon dioxide

    E-Print Network [OSTI]

    Cohen, Yossi

    Carbon dioxide (CO[subscript 2]) sequestration in subsurface reservoirs is important for limiting atmospheric CO[subscript 2] concentrations. However, a complete physical picture able to predict the structure developing ...

  20. Schwinger Mechanism for Gluon Pair Production in the Presence of Arbitrary Time Dependent Chromo-Electric Field in Arbitrary Gauge

    E-Print Network [OSTI]

    Gouranga C Nayak

    2009-10-02T23:59:59.000Z

    We study non-perturbative gluon pair production from arbitrary time dependent chromo-electric field E^a(t) with arbitrary color index a =1,2,...8 via Schwinger mechanism in arbitrary covariant background gauge \\alpha. We show that the probability of non-perturbative gluon pair production per unit time per unit volume per unit transverse momentum \\frac{dW}{d^4xd^2p_T} is independent of gauge fixing parameter \\alpha. Hence the result obtained in the Fynman-'t Hooft gauge, \\alpha=1, is the correct gauge invariant and gauge parameter \\alpha independent result.

  1. Cryogenic silicon surface ion trap

    E-Print Network [OSTI]

    Michael Niedermayr; Kirill Lakhmanskiy; Muir Kumph; Stefan Partel; Johannes Edlinger; Michael Brownnutt; Rainer Blatt

    2015-05-01T23:59:59.000Z

    Trapped ions are pre-eminent candidates for building quantum information processors and quantum simulators. They have been used to demonstrate quantum gates and algorithms, quantum error correction, and basic quantum simulations. However, to realise the full potential of such systems and make scalable trapped-ion quantum computing a reality, there exist a number of practical problems which must be solved. These include tackling the observed high ion-heating rates and creating scalable trap structures which can be simply and reliably produced. Here, we report on cryogenically operated silicon ion traps which can be rapidly and easily fabricated using standard semiconductor technologies. Single $^{40}$Ca$^+$ ions have been trapped and used to characterize the trap operation. Long ion lifetimes were observed with the traps exhibiting heating rates as low as $\\dot{\\bar{n}}=$ 0.33 phonons/s at an ion-electrode distance of 230 $\\mu$m. These results open many new avenues to arrays of micro-fabricated ion traps.

  2. Radiation trapping in coherent media

    E-Print Network [OSTI]

    A. B. Matsko; I. Novikova; M. O. Scully; G. R. Welch

    2001-01-31T23:59:59.000Z

    We show that the effective decay rate of Zeeman coherence, generated in a Rb87 vapor by linearly polarized laser light, increases significantly with the atomic density. We explain this phenomenon as the result of radiation trapping. Our study shows that radiation trapping must be taken into account to fully understand many electromagnetically induced transparency experiments with optically thick media.

  3. Time and location differentiated NOX control in competitive electricity markets using cap-and-trade mechanisms

    E-Print Network [OSTI]

    Martin, Katherine C.

    2007-01-01T23:59:59.000Z

    Due to variations in weather and atmospheric chemistry, the timing and location of nitrogen oxide (NOX) reductions determine their effectiveness in reducing ground-level ozone, which adversely impacts human health. Electric ...

  4. Theory and application of planar ion traps

    E-Print Network [OSTI]

    Pearson, Christopher Elliott

    2006-01-01T23:59:59.000Z

    In this thesis, we investigate a new geometry of Paul trap with electrodes in a plane. These planar ion traps are compatible with modern silicon microfabrication, and can be scaled up to large arrays with multiple trapping ...

  5. Optimal traps in graphene

    E-Print Network [OSTI]

    C. A. Downing; A. R. Pearce; R. J. Churchill; M. E. Portnoi

    2015-03-27T23:59:59.000Z

    We transform the two-dimensional Dirac-Weyl equation, which governs the charge carriers in graphene, into a non-linear first-order differential equation for scattering phase shift, using the so-called variable phase method. This allows us to utilize the Levinson Theorem to find zero-energy bound states created electrostatically in realistic structures. These confined states are formed at critical potential strengths, which leads to us posit the use of `optimal traps' to combat the chiral tunneling found in graphene, which could be explored experimentally with an artificial network of point charges held above the graphene layer. We also discuss scattering on these states and find the zero angular momentum states create a dominant peak in scattering cross-section as energy tends towards the Dirac point energy, suggesting a dominant contribution to resistivity.

  6. Short time scale thermal mechanical shock wave propagation in high performance microelectronic packaging configuration

    E-Print Network [OSTI]

    Nagaraj, Mahavir

    2004-11-15T23:59:59.000Z

    joint fatigue during the prototyping stage. Vandevelde et al. [2] conducted a parameter based thermomechanical modeling of Chip Scale Package (CSP) assemblies. Using parameters related to solder joint geometry, CSP dimensions and a fatigue... GPa Poisson Ration (? ) 0.22 Density (? ) 2330 kg/m3 Specific heat (cv) 700 J/kg?C Thermal conductivity (k) 155 W/m?C Expansion coefficient (? ) 2.3 ?? /?C It can be seen that the mechanical wave speed is essentially constant for t2 less...

  7. Physiologically realistic modelling of a mechanism for neural representation of intervals of time

    E-Print Network [OSTI]

    Fukai, Tomoki

    -8610, Japan c CREST, Japan Science and Technology (JST), Saitama 332-0012, Japan Abstract A model, Fuji Xerox Co. Ltd., 430 Sakai, Nakai-machi, Ashigarakami-gun, Kanagawa 259-0157, Japan b Department as well as the difference stated above, will lead us to the idea that an interval of time, T

  8. ME 354, MECHANICS OF MATERIALS LABORATORY TIME-DEPENDENT DEFORMATION: CREEP

    E-Print Network [OSTI]

    Sniadecki, Nathan J.

    forces. Specifically, short-term creep tests will be used to identify constants in the 'min = Bn relation from long-term creep tests of this same alloy. EQUIPMENT · Constant gage section diameter sections-weight," lever arm creep test machine. · Various "dead-weight" masses of 0.5, 1.0, 2.0 and 5.0 kg. · Timing

  9. Cooling trapped atoms in optical resonators

    E-Print Network [OSTI]

    Stefano Zippilli; Giovanna Morigi

    2007-03-20T23:59:59.000Z

    We derive an equation for the cooling dynamics of the quantum motion of an atom trapped by an external potential inside an optical resonator. This equation has broad validity and allows us to identify novel regimes where the motion can be efficiently cooled to the potential ground state. Our result shows that the motion is critically affected by quantum correlations induced by the mechanical coupling with the resonator, which may lead to selective suppression of certain transitions for the appropriate parameters regimes, thereby increasing the cooling efficiency.

  10. Laser cooling and sympathetic cooling in a linear quadrupole rf trap 

    E-Print Network [OSTI]

    Ryjkov, Vladimir Leonidovich

    2005-02-17T23:59:59.000Z

    An investigation of the sympathetic cooling method for the studies of large ultra-cold molecular ions in a quadrupole ion trap has been conducted.Molecular dynamics simulations are performed to study the rf heating mechanisms in the ion trap...

  11. Real-Time Transport in Open Quantum Systems From $\\mathcal{PT}$-Symmetric Quantum Mechanics

    E-Print Network [OSTI]

    Justin E. Elenewski; Hanning Chen

    2014-08-07T23:59:59.000Z

    Nanoscale electronic transport is of intense technological interest, with applications ranging from semiconducting devices and molecular junctions to charge migration in biological systems. Most explicit theoretical approaches treat transport using a combination of density functional theory (DFT) and non-equilibrium Green's functions. This is a static formalism, with dynamic response properties accommodated only through complicated extensions. To circumvent this limitation, the carrier density may be propagated using real-time time-dependent DFT (RT-TDDFT), with boundary conditions corresponding to an open quantum system. Complex absorbing potentials can emulate outgoing particles at the simulation boundary, although these do not account for introduction of charge density. It is demonstrated that the desired positive particle flux is afforded by a class of $\\mathcal{PT}$-symmetric generating potentials that are characterized by anisotropic transmission resonances. These potentials add density every time a particle traverses the cell boundary, and may be used to engineer a continuous pulse train for incident packets. This is a first step toward developing a complete transport formalism unique to RT-TDDFT.

  12. Intercalation mechanisms and time dependencies of work parameters of electrochromic layers

    SciTech Connect (OSTI)

    Heckner, K.H.; Rothe, A. [Humboldt Univ., Berlin (Germany). Inst. of Physical and Theoretical Chemistry

    1994-12-31T23:59:59.000Z

    The phenomenon of electrochromism offers new routes for convenient devices of light modulation which can be exploited for the fabrication of several optical devices of technological importance. Electrochromic devices have a significant potential for the use as ``smart`` windows for the control of light transmission in response to the change in brightness of the environment, anti-glare rear view mirrors and sun roofs for automobiles, large area optical information displays and consumer sun glasses, just to cite the most relevant examples. This paper describes some essential properties of all-solid-state transmissive electrochromic devices based on a combination of polyaniline (PANI) and tungsten trioxide (WO{sub 3}) layers on ITO sandwiching a proton conducting polymeric layer. The single electrochromic layers were prepared by electrochemical deposition onto ITO/glass electrodes. Proton conducting polymeric electrolytes were prepared by mixing protonic acids with (poly)vinylalcohol. The fabricated all solid-state electrochromic devices exhibit electrochromic response times with color contrasts of about 50% in the range between 0.1 and 1 s, depending on the thickness of the single electrochromic layers, on the cell voltage, on the ion conductivity of the polymeric layer and on the electronic conductivity of the ITO layers. The observed color can be changed from transparent clear yellow to deep blue by applied voltages in the range between 0.5--2 V. The response time of the single investigated electrochromic layers is governed by the rate of proton transport within the layers. The response times of single PANI/ITO/glass half cells in acid aqueous electrolytes show asymmetric characteristics and can be less than 0.2 s.

  13. Precursory signatures of protein folding/unfolding: From time series correlation analysis to atomistic mechanisms

    SciTech Connect (OSTI)

    Hsu, P. J.; Lai, S. K., E-mail: sklai@coll.phy.ncu.edu.tw [Complex Liquids Laboratory, Department of Physics, National Central University, Chungli 320 Taiwan (China); Molecular Science and Technology Program, Taiwan International Graduate Program, Academia Sinica, Taipei 115, Taiwan (China); Cheong, S. A. [Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371 (Singapore)

    2014-05-28T23:59:59.000Z

    Folded conformations of proteins in thermodynamically stable states have long lifetimes. Before it folds into a stable conformation, or after unfolding from a stable conformation, the protein will generally stray from one random conformation to another leading thus to rapid fluctuations. Brief structural changes therefore occur before folding and unfolding events. These short-lived movements are easily overlooked in studies of folding/unfolding for they represent momentary excursions of the protein to explore conformations in the neighborhood of the stable conformation. The present study looks for precursory signatures of protein folding/unfolding within these rapid fluctuations through a combination of three techniques: (1) ultrafast shape recognition, (2) time series segmentation, and (3) time series correlation analysis. The first procedure measures the differences between statistical distance distributions of atoms in different conformations by calculating shape similarity indices from molecular dynamics simulation trajectories. The second procedure is used to discover the times at which the protein makes transitions from one conformation to another. Finally, we employ the third technique to exploit spatial fingerprints of the stable conformations; this procedure is to map out the sequences of changes preceding the actual folding and unfolding events, since strongly correlated atoms in different conformations are different due to bond and steric constraints. The aforementioned high-frequency fluctuations are therefore characterized by distinct correlational and structural changes that are associated with rate-limiting precursors that translate into brief segments. Guided by these technical procedures, we choose a model system, a fragment of the protein transthyretin, for identifying in this system not only the precursory signatures of transitions associated with ? helix and ? hairpin, but also the important role played by weaker correlations in such protein folding dynamics.

  14. Mini ion trap mass spectrometer

    DOE Patents [OSTI]

    Dietrich, Daniel D. (Livermore, CA); Keville, Robert F. (Valley Springs, CA)

    1995-01-01T23:59:59.000Z

    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.

  15. Mini ion trap mass spectrometer

    DOE Patents [OSTI]

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

    1995-09-19T23:59:59.000Z

    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.

  16. Inspect and Repair Steam Traps

    SciTech Connect (OSTI)

    Not Available

    2006-01-01T23:59:59.000Z

    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.

  17. Managing the Steam Trap Population

    E-Print Network [OSTI]

    Atlas, R. D.

    1983-01-01T23:59:59.000Z

    item? .However, some converts to the gospel of enlighten ed steam trap management expect to achieve the following benefits: A 95% trap performance level which is a better than 30% improvement over the industry norm. Plus, we have found a well... trained. This may six surveys per year with a guaf'8nteed performance level involve two days of training per man including of better than 9596. This program usually has the best cash classroom and field instruction plus periodic flow, and faster...

  18. In situ study on low-k interconnect time-dependent-dielectric-breakdown mechanisms

    SciTech Connect (OSTI)

    Boon Yeap, Kong, E-mail: KongBoon.Yeap@globalfoundries.com [GLOBALFOUNDRIES, Fab8, 400 Stonebreak Rd. Extension, Malta, New York 12020 (United States); Fraunhofer Institute for Ceramic Technologies and Systems, Maria-Reiche-Str. 2, D-01109 Dresden (Germany); Gall, Martin; Liao, Zhongquan; Sander, Christoph; Muehle, Uwe; Zschech, Ehrenfried [Fraunhofer Institute for Ceramic Technologies and Systems, Maria-Reiche-Str. 2, D-01109 Dresden (Germany); Justison, Patrick [GLOBALFOUNDRIES, Fab8, 400 Stonebreak Rd. Extension, Malta, New York 12020 (United States); Aubel, Oliver; Hauschildt, Meike; Beyer, Armand; Vogel, Norman [GLOBALFOUNDRIES Dresden Module One LLC and Co. KG, Wilschdorfer Landstr. 101, D-01109 Dresden (Germany)

    2014-03-28T23:59:59.000Z

    An in situ transmission-electron-microscopy methodology is developed to observe time-dependent dielectric breakdown (TDDB) in an advanced Cu/ultra-low-k interconnect stack. A test structure, namely a “tip-to-tip” structure, was designed to localize the TDDB degradation in small dielectrics regions. A constant voltage is applied at 25?°C to the “tip-to-tip” structure, while structural changes are observed at nanoscale. Cu nanoparticle formation, agglomeration, and migration processes are observed after dielectric breakdown. The Cu nanoparticles are positively charged, since they move in opposite direction to the electron flow. Measurements of ionic current, using the Triangular-Voltage-Stress method, suggest that Cu migration is not possible before dielectric breakdown, unless the Cu/ultra-low-k interconnect stacks are heated to 200?°C and above.

  19. Schwinger Mechanism for Quark-Antiquark Production in the Presence of Arbitrary Time Dependent Chromo-Electric Field

    E-Print Network [OSTI]

    Gouranga C. Nayak

    2011-05-23T23:59:59.000Z

    We study the Schwinger mechanism in QCD in the presence of an arbitrary time-dependent chromo-electric background field $E^a(t)$ with arbitrary color index $a$=1,2,...8 in SU(3). We obtain an exact result for the non-perturbative quark (antiquark) production from an arbitrary $E^a(t)$ by directly evaluating the path integral. We find that the exact result is independent of all the time derivatives $\\frac{d^nE^a(t)}{dt^n}$ where $n=1,2,...\\infty$. This result has the same functional dependence on two Casimir invariants $[E^a(t)E^a(t)]$ and $[d_{abc}E^a(t)E^b(t)E^c(t)]^2$ as the constant chromo-electric field $E^a$ result with the replacement: $E^a \\rightarrow E^a(t)$. This result relies crucially on the validity of the shift conjecture, which has not yet been established.

  20. Temporally, spatially, and spectrally resolved barrier discharge produced in trapped helium gas at atmospheric pressure

    SciTech Connect (OSTI)

    Chiper, Alina Silvia; Popa, Gheorghe [Faculty of Physics, Alexandru Ioan Cuza University, 700506 Iasi (Romania)] [Faculty of Physics, Alexandru Ioan Cuza University, 700506 Iasi (Romania)

    2013-06-07T23:59:59.000Z

    Experimental study was made on induced effects by trapped helium gas in the pulsed positive dielectric barrier discharge (DBD) operating in symmetrical electrode configuration at atmospheric pressure. Using fast photography technique and electrical measurements, the differences in the discharge regimes between the stationary and the flowing helium are investigated. It was shown experimentally that the trapped gas atmosphere (TGA) has notable impact on the barrier discharge regime compared with the influence of the flowing gas atmosphere. According to our experimental results, the DBD discharge produced in trapped helium gas can be categorized as a multi-glow (pseudo-glow) discharge, each discharge working in the sub-normal glow regime. This conclusion is made by considering the duration of current pulse (few {mu}s), their maximum values (tens of mA), the presence of negative slope on the voltage-current characteristic, and the spatio-temporal evolution of the most representative excited species in the discharge gap. The paper focuses on the space-time distribution of the active species with a view to better understand the pseudo-glow discharge mechanism. The physical basis for these effects was suggested. A transition to filamentary discharge is suppressed in TGA mode due to the formation of supplementary source of seed electrons by surface processes (by desorption of electrons due to vibrationally excited nitrogen molecules, originated from barriers surfaces) rather than volume processes (by enhanced Penning ionisation). Finally, we show that the pseudo-glow discharge can be generated by working gas trapping only; maintaining unchanged all the electrical and constructive parameters.

  1. Integrated photonic structures for light trapping in thin-film Si solar cells

    E-Print Network [OSTI]

    Sheng, Xing

    We explore the mechanisms for an efficient light trapping structure for thin-film silicon solar cells. The design combines a distributed Bragg reflector (DBR) and periodic gratings. Using photonic band theories and numerical ...

  2. Fidelity decay in trapped Bose-Einstein condensates

    E-Print Network [OSTI]

    G. Manfredi; P. -A. Hervieux

    2008-01-29T23:59:59.000Z

    The quantum coherence of a Bose-Einstein condensate is studied using the concept of quantum fidelity (Loschmidt echo). The condensate is confined in an elongated anharmonic trap and subjected to a small random potential such as that created by a laser speckle. Numerical experiments show that the quantum fidelity stays constant until a critical time, after which it drops abruptly over a single trap oscillation period. The critical time depends logarithmically on the number of condensed atoms and on the perturbation amplitude. This behavior may be observable by measuring the interference fringes of two condensates evolving in slightly different potentials.

  3. Effect of Residence Time on Ni-Sorption Mechanisms on Clay and Oxide Minerals: An X-ray Absorption Fine Structure (XAFS) Study

    E-Print Network [OSTI]

    Sparks, Donald L.

    Effect of Residence Time on Ni-Sorption Mechanisms on Clay and Oxide Minerals: An X-ray Absorption minerals is typically fast initially, then the rates gradually diminish. In the literature the decline

  4. High-Sensitivity Two-Photon Spectroscopy in a Dark Optical Trap, based on Electron Shelving

    E-Print Network [OSTI]

    Khaykovich, B; Baluschev, S; Fathi, D; Davidson, N E

    1999-01-01T23:59:59.000Z

    We propose a new spectroscopic method for measuring weak transitions in cold and trapped atoms, which exploits the long interaction times and tight confinement offered by dark optical traps together with an electron shelving technique to achieve extremely high sensitivity. We demonstrate our scheme by measuring a 5S_{1/2}-> 5D_{5/2} two-photon transition in cold Rb atoms trapped in a new single-beam dark optical trap, using an extremely weak probe laser power of 25 micro-Watt. We were able to measure transitions with as small excitation rate as 0.09 sec^(-1).

  5. Microfabricated linear Paul-Straubel ion trap

    DOE Patents [OSTI]

    Mangan, Michael A. (Albuquerque, NM); Blain, Matthew G. (Albuquerque, NM); Tigges, Chris P. (Albuquerque, NM); Linker, Kevin L. (Albuquerque, NM)

    2011-04-19T23:59:59.000Z

    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.

  6. Surface-electrode point Paul trap

    SciTech Connect (OSTI)

    Kim, Tony Hyun; Herskind, Peter F.; Chuang, Isaac L. [Center for Ultracold Atoms, Department of Physics, Massachusetts Institute of Technology 77 Massachusetts Avenue, Cambridge, Massachusetts 02139 (United States); Kim, Taehyun; Kim, Jungsang [Department of Electrical and Computer Engineering, Duke University Durham, North Carolina 27708 (United States)

    2010-10-15T23:59:59.000Z

    We present a model as well as experimental results for a surface electrode radiofrequency Paul trap that has a circular electrode geometry well suited for trapping single ions and two-dimensional planar ion crystals. The trap design is compatible with microfabrication and offers a simple method by which the height of the trapped ions above the surface may be changed in situ. We demonstrate trapping of single {sup 88}Sr{sup +} ions over an ion height range of 200-1000 {mu}m for several hours under Doppler laser cooling and use these to characterize the trap, finding good agreement with our model.

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

    DOE Patents [OSTI]

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

    1982-01-01T23:59:59.000Z

    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.

  8. Equilibrium Theory for a Particle Pulled by a Moving Optical Trap

    E-Print Network [OSTI]

    R. Dean Astumian

    2006-08-16T23:59:59.000Z

    The viscous drag on a colloidal particle pulled through solution by an optical trap is large enough that on experimentally relavant time scales the mechanical force exerted by the trap is equal and op- posite the viscous drag force. The rapid mechanical equilibritation allows the system to be modeled using equilibrium theory, where the effects of the energy dissipation (thermodynamic disequilibrium) show up only in the coordinate transformations that map the system from the laboratory frame of reference, relative to which the particle is moving, to a frame of reference in which the particle is, on average, stationary and on which the stochastic dynamics is governed by a canonical equilib- rium distribution function. The simple equations in the stationary frame can be analyzed using the Onsager-Machlup theory for stochastic systems and provide generalizations of equilibrium and near equilibrium concepts such as detailed balance and fluctuation-dissipation relations applicable to a wide range of systems including molecular motors, pumps, and other nano-scale machines.

  9. Optical Trapping by Radiometric Flow

    E-Print Network [OSTI]

    William L. Clarke

    1998-12-13T23:59:59.000Z

    Micron sized, neutral, non-dielectric particles immersed in a viscous fluid can be trapped in the focal plane of a Gaussian beam. A particle can absorb energy from such a beam with a large radial intensity gradient, resulting in substantial temperature gradients and a radiometric torque which causes it to spin rapidly about an axis perpendicular to the flux of radiant energy. The particles are also observed to orbit around the optical axis. Here we investigate the fundamental physics of this system, the Radiometric Particle Trap, and discuss its force laws using gas-kinetic theory.

  10. Heating of trapped ions from the quantum ground state Q. A. Turchette,*,

    E-Print Network [OSTI]

    Sackett, Cass

    Heating of trapped ions from the quantum ground state Q. A. Turchette,*, D. Kielpinski, B. E. King. Monroe, and D. J. Wineland Time and Frequency Division, National Institute of Standards and Technology heating of laser-cooled 9 Be ions held in radio-frequency Paul traps. We have measured heating rates

  11. Repulsive trap for two electrons in a magnetic field A. D. Chepelianskii1

    E-Print Network [OSTI]

    Shepelyansky, Dima

    of crossed electric and magnetic fields. It is found that near one antidot the electron pair can be trapped for a long time, and the escape rate from such a trap is proportional to the square of a weak electric field field. Experiments with antidot lattices were car- ried out by different experimental groups see, e

  12. Cs-Exchange in Birnessite: Raction Mechanisms Inferred from Time-Resolved X-ray Diffraction and Transmission Electron Microscopy

    SciTech Connect (OSTI)

    Lopano, C.; Heaney, P; Post, J

    2009-01-01T23:59:59.000Z

    We have explored the exchange of Cs for interlayer Na in birnessite using several techniques, including transmission electron microscopy (TEM) and time-resolved synchrotron X-ray diffraction (XRD). Our goal was to test which of two possible exchange mechanisms is operative during the reaction: (1) diffusion of cations in and out of the interlayer or (2) dissolution of Na-birnessite and reprecipitation of Cs-birnessite. The appearance of distinct XRD peaks for Na- and Cs-rich phases in partially exchanged samples offered support for a simple diffusion model, but it was inconsistent with the compositional and crystallographic homogeneity of (Na,Cs)-birnessite platelets from core to rim as ascertained by TEM. Time-resolved XRD revealed systematic changes in the structure of the emergent Cs-rich birnessite phase during exchange, in conflict with a dissolution and reprecipitation model. Instead, we propose that exchange occurred by sequential delamination of Mn oxide octahedral sheets. Exfoliation of a given interlayer region allowed for wholesale replacement of Na by Cs and was rapidly followed by reassembly. This model accounts for the rapidity of metal exchange in birnessite, the co-existence of distinct Na- and Cs-birnessite phases during the process of exchange, and the uniformly mixed Na- and Cs-compositions ascertained from point analyses by selected area electron diffraction and energy dispersive spectroscopy of partially exchanged grains.

  13. A study of the regeneration process in diesel particulate traps using a copper fuel additive

    SciTech Connect (OSTI)

    Tan, J.C.; Opris, C.N.; Baumgard, K.J.; Johnson, J.H. [Michigan Technological Univ., Houghton, MI (United States)

    1996-09-01T23:59:59.000Z

    The goals of this research are to understand the regeneration process in ceramic (Cordierite) monolith traps using a copper fuel additive and to investigate the various conditions that lead to trap regeneration failure. The copper additive lowers the trap regeneration temperature from approximately 500 C to 375 C and decreases the time necessary for regeneration. Because of these characteristics, it is important to understand the effect of the additive on regeneration when excessive particulate matter accumulation occurs in the trap. The effects of particulate mass loading on regeneration temperatures and regeneration time were studied for both the controlled (engine operated at full load rated speed) and uncontrolled conditions. The trap peak temperatures were higher for the uncontrolled than the controlled regeneration. The higher peak trap temperatures were predominantly controlled by the effect of the exhaust flow rates on the energy transfer processes. The total regeneration time was faster for the controlled regeneration compared to the uncontrolled regeneration. All traps passed the controlled regeneration tests having maximum temperatures less than 900 C. During the uncontrolled regeneration tests, trap failure occurred at 135 and 139 g particulate matter loadings. The maximum temperatures were in excess of 1,150 C. The pressure drop across the trap was modeled using the one dimensional Darcy`s law which accounted for the pressure drop due to the ceramic wall and the particulate layer. The experimental results for the substrate correlate well with the empirical substrate pressure drop models available in the literature. The models also enable an estimate to be made regarding trap mass loading. These data along with the laboratory data have indicated that mass loadings greater than 110 g followed by high temperature operation and subsequent engine idling can result in trap failures during regeneration.

  14. Residence Time Effects on Arsenate Adsorption/Desorption Mechanisms on Goethite S. E. O'Reilly,* D. G. Strawn, and D. L. Sparks

    E-Print Network [OSTI]

    Sparks, Donald L.

    Residence Time Effects on Arsenate Adsorption/Desorption Mechanisms on Goethite S. E. O'Reilly,* D and desorption on goethite, and to combine spectro- Xu et al., 1988). For example, arsenate sorption on scopic x and Glaubig, 1988).showed that arsenate sorption on goethite increased with time. Sorp- Goethite ( ­Fe

  15. Fiber optic integration in planar ion traps

    E-Print Network [OSTI]

    George, Elizabeth Marie

    2008-01-01T23:59:59.000Z

    Atomic ion traps are are excellent tools in atomic physics for studying single ions. Accurate measurement of the ion's electronic state in these ion traps is required by both atomic clocks and quantum computation. Quantum ...

  16. Ion-neutral sympathetic cooling in a hybrid linear rf Paul and magneto-optical trap

    E-Print Network [OSTI]

    Goodman, D S; Wells, J E; Narducci, F A; Smith, W W

    2012-01-01T23:59:59.000Z

    Long range polarization forces between ions and neutral atoms result in large elastic scattering cross sections, e.g., 10^6 a.u. for Na+ on Na or Ca+ on Na at cold and ultracold temperatures. This suggests that a hybrid ion-neutral trap should offer a general means for significant sympathetic cooling of atomic or molecular ions. We present SIMION 7.0 simulation results concerning the advantages and limitations of sympathetic cooling within a hybrid trap apparatus, consisting of a linear rf Paul trap concentric with a Na magneto-optical trap (MOT). This paper explores the impact of various heating mechanisms on the hybrid system and how parameters related to the MOT, Paul trap, number of ions, and ion species affect the efficiency of the sympathetic cooling.

  17. Ion-neutral sympathetic cooling in a hybrid linear rf Paul and magneto-optical trap

    E-Print Network [OSTI]

    D. S. Goodman; I. Sivarajah; J. E. Wells; F. A. Narducci; W. W. Smith

    2012-08-31T23:59:59.000Z

    Long range polarization forces between ions and neutral atoms result in large elastic scattering cross sections, e.g., 10^6 a.u. for Na+ on Na or Ca+ on Na at cold and ultracold temperatures. This suggests that a hybrid ion-neutral trap should offer a general means for significant sympathetic cooling of atomic or molecular ions. We present SIMION 7.0 simulation results concerning the advantages and limitations of sympathetic cooling within a hybrid trap apparatus, consisting of a linear rf Paul trap concentric with a Na magneto-optical trap (MOT). This paper explores the impact of various heating mechanisms on the hybrid system and how parameters related to the MOT, Paul trap, number of ions, and ion species affect the efficiency of the sympathetic cooling.

  18. Electron Trapping in Shear Alfven Waves that Power the Aurora

    SciTech Connect (OSTI)

    Watt, Clare E. J.; Rankin, Robert [University of Alberta, Edmonton, Alberta (Canada)

    2009-01-30T23:59:59.000Z

    Results from 1D Vlasov drift-kinetic plasma simulations reveal how and where auroral electrons are accelerated along Earth's geomagnetic field. In the warm plasma sheet, electrons become trapped in shear Alfven waves, preventing immediate wave damping. As waves move to regions with larger v{sub Te}/v{sub A}, their parallel electric field decreases, and the trapped electrons escape their influence. The resulting electron distribution functions compare favorably with in situ observations, demonstrating for the first time a self-consistent link between Alfven waves and electrons that form aurora.

  19. instructions HisTrap FF crude,

    E-Print Network [OSTI]

    Lebendiker, Mario

    · p1 instructions HisTrap FF crude, 1 ml and 5 ml i 11-0012-38 Edition AA HisTrapTM FF crude, such as degradation and oxidation of sensitive target proteins, and is therefore of great importance. HisTrap FF crude properties HisTrap FF crude 1-ml and 5-ml columns are prepacked with the affinity medium Ni Sepharose 6 Fast

  20. Single Ion Trapping for the Enriched Xenon Observatory

    SciTech Connect (OSTI)

    Waldman, Samuel J.; /Stanford U., Phys. Dept. /SLAC; ,

    2006-03-28T23:59:59.000Z

    In the last decade, a variety of neutrino oscillation experiments have established that there is a mass difference between neutrino flavors, without determining the absolute neutrino mass scale. The Enriched Xenon Observatory for neutrinoless double beta decay (EXO) will search for the rare decays of xenon to determine the absolute value of the neutrino mass. The experiment uses a novel technique to minimize backgrounds, identifying the decay daughter product in real time using single ion spectroscopy. Here, we describe single ion trapping and spectroscopy compatible with the EXO detector. We extend the technique of single ion trapping in ultrahigh vacuum to trapping in xenon gas. With this technique, EXO will achieve a neutrino mass sensitivity of {approx_equal} .010 eV.

  1. Energy trapping from Hagedorn densities of states

    E-Print Network [OSTI]

    Connor Behan; Klaus Larjo; Nima Lashkari; Brian Swingle; Mark Van Raamsdonk

    2013-04-26T23:59:59.000Z

    In this note, we construct simple stochastic toy models for holographic gauge theories in which distributions of energy on a collection of sites evolve by a master equation with some specified transition rates. We build in only energy conservation, locality, and the standard thermodynamic requirement that all states with a given energy are equally likely in equilibrium. In these models, we investigate the qualitative behavior of the dynamics of the energy distributions for different choices of the density of states for the individual sites. For typical field theory densities of states (\\log(\\rho(E)) ~ E^{\\alphaenergy spread out relatively quickly. For large N gauge theories with gravitational duals, the density of states for a finite volume of field theory degrees of freedom typically includes a Hagedorn regime (\\log(\\rho(E)) ~ E). We find that this gives rise to a trapping of energy in subsets of degrees of freedom for parametrically long time scales before the energy leaks away. We speculate that this Hagedorn trapping may be part of a holographic explanation for long-lived gravitational bound states (black holes) in gravitational theories.

  2. Qualitative analysis of trapped Dirac fermions in graphene

    E-Print Network [OSTI]

    Vit Jakubsky; David Krejcirik

    2015-01-07T23:59:59.000Z

    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.

  3. Microscale ion trap mass spectrometer

    DOE Patents [OSTI]

    Ramsey, J. Michael (Knoxville, TN); Witten, William B. (Lancing, TN); Kornienko, Oleg (Lansdale, PA)

    2002-01-01T23:59:59.000Z

    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.

  4. Tachyon Physics with Trapped Ions

    E-Print Network [OSTI]

    Lee, Tony E; Cheng, Xiao-Hang; Lamata, Lucas; Solano, Enrique

    2015-01-01T23:59:59.000Z

    It has been predicted that particles with imaginary mass, called tachyons, would be able to travel faster than the speed of light. So far, there has not been any experimental evidence for tachyons in either natural or engineered systems. Here, we propose how to experimentally simulate Dirac tachyons with trapped ions. Quantum measurement on a Dirac particle simulated by a trapped ion causes it to have an imaginary mass so that it may travel faster than the effective speed of light. We show that a Dirac tachyon must have spinor-motion entanglement in order to be superluminal. We also show that it exhibits significantly more Klein tunneling than a normal Dirac particle. We provide numerical simulations with realistic ion systems and show that our scheme is feasible with current technology.

  5. Cooling Techniques for Trapped Ions

    E-Print Network [OSTI]

    Daniel M. Segal; Christof Wunderlich

    2014-09-24T23:59:59.000Z

    This book chapter gives an introduction to, and an overview of, methods for cooling trapped ions. The main addressees are researchers entering the field. It is not intended as a comprehensive survey and historical account of the extensive literature on this topic. We present the physical ideas behind several cooling schemes, outline their mathematical description, and point to relevant literature useful for a more in-depth study of this topic.

  6. EFFECT OF PORE SIZE ON TRAPPING ZINC VAPORS

    SciTech Connect (OSTI)

    Korinko, P.

    2010-12-17T23:59:59.000Z

    A series of experiments were conducted to determine the effect of pore size on pumping efficiency and zinc vapor trapping efficiency. A simple pumping efficiency test was conducted for all five pore diameters where it was observed that evacuation times were adversely affected by reducing the pore size below 5 {micro}m. Common test conditions for the zinc trapping efficiency experiments were used. These conditions resulted in some variability, to ascribe different efficiencies to the filter media. However, the data suggest that there is no significant difference in trapping efficiency for filter media with pores from 0.2 to 20 {micro}m with a thickness of 0.065-inch. Consequently, the 20 {micro}m pore filter media that is currently used at SRS is a suitable filter material for to utilize for future extractions. There is evidence that smaller pore filter will adversely affect the pumping times for the TEF and little evidence to suggest that a smaller pore diameters have significant impact on the trapping efficiency.

  7. Sudden Expansion of a One-Dimensional Bose Gas from Power-Law Traps

    E-Print Network [OSTI]

    A. S. Campbell; D. M. Gangardt; K. V. Kheruntsyan

    2015-03-27T23:59:59.000Z

    We analyze free expansion of a trapped one-dimensional Bose gas after a sudden release from the confining trap potential. By using the stationary phase and local density approximations, we show that the long-time asymptotic density profile and the momentum distribution of the gas are determined by the initial distribution of Bethe rapidities (quasimomenta) and hence can be obtained from the solutions to the Lieb-Liniger equations in the thermodynamic limit. For expansion from a harmonic trap, and in the limits of very weak and very strong interactions, we recover the self-similar scaling solutions known from the hydrodynamic approach. For all other power-law traps and arbitrary interaction strengths, the expansion is not self-similar and shows strong dependence of the density profile evolution on the trap anharmonicity. We also characterize dynamical fermionization of the expanding cloud in terms of correlation functions describing phase and density fluctuations.

  8. Electromagnetic field generation in the downstream of electrostatic shocks due to electron trapping

    E-Print Network [OSTI]

    Stockem, A; Fonseca, R A; Silva, L O

    2014-01-01T23:59:59.000Z

    A new magnetic field generation mechanism in electrostatic shocks is found, which can produce fields with magnetic energy density as high as 0.01 of the kinetic energy density of the flows on time scales $ \\tilde \\, 10^4 \\, {\\omega}_{pe}^{-1}$. Electron trapping during the shock formation process creates a strong temperature anisotropy in the distribution function, giving rise to the pure Weibel instability. The generated magnetic field is well-confined to the downstream region of the electrostatic shock. The shock formation process is not modified and the features of the shock front responsible for ion acceleration, which are currently probed in laser-plasma laboratory experiments, are maintained. However, such a strong magnetic field determines the particle trajectories downstream and has the potential to modify the signatures of the collisionless shock.

  9. Residence Time Effects on P Sorption/Desorption on Ferrihydrite Understanding mechanisms of P retention/release on soil mineral surfaces is

    E-Print Network [OSTI]

    Sparks, Donald L.

    Residence Time Effects on P Sorption/Desorption on Ferrihydrite Y. Arai Understanding mechanisms of P retention/release on soil mineral surfaces is fundamental in assessing the P biogeochemistry that are high ammonium oxalate extractable P, due to long-term manure amendments. Since there is a high

  10. Electron Trapping by Molecular Vibration

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville Power AdministrationField Campaign:INEAWater UseC Supports - Energy3 PierreElectron Trapping by

  11. Electron Trapping by Molecular Vibration

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville Power AdministrationField Campaign:INEAWater UseC Supports - Energy3 PierreElectron Trapping

  12. State-insensitive bichromatic optical trapping

    E-Print Network [OSTI]

    Bindiya Arora; M. S. Safronova; Charles W. Clark

    2010-05-07T23:59:59.000Z

    We propose a scheme for state-insensitive trapping of neutral atoms by using light with two independent wavelengths. In particular, we describe the use of trapping and control lasers to minimize the variance of the potential experienced by a trapped Rb atom in ground and excited states. We present calculated values of wavelength pairs for which the 5s and 5p_{3/2} levels have the same ac Stark shifts in the presence of two laser fields.

  13. 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)

    2011-09-15T23:59:59.000Z

    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.

  14. Quantum-enhanced deliberation of learning agents using trapped ions

    E-Print Network [OSTI]

    Vedran Dunjko; Nicolai Friis; Hans J. Briegel

    2015-01-31T23:59:59.000Z

    A scheme that successfully employs quantum mechanics in the design of autonomous learning agents has recently been reported in the context of the projective simulation (PS) model for artificial intelligence. In that approach, the key feature of a PS agent, a specific type of memory which is explored via random walks, was shown to be amenable to quantization. In particular, classical random walks were substituted by Szegedy-type quantum walks, allowing for a speed-up. In this work we propose how such classical and quantum agents can be implemented in systems of trapped ions. We employ a generic construction by which the classical agents are `upgraded' to their quantum counterparts by nested coherent controlization, and we outline how this construction can be realized in ion traps. Our results provide a flexible modular architecture for the design of PS agents. Furthermore, we present numerical simulations of simple PS agents which analyze the robustness of our proposal under certain noise models.

  15. Physical Mechanisms of Interaction of Cold Plasma with Polymer Surfaces

    E-Print Network [OSTI]

    Bormashenko, Edward; Multanen, Victor; Shulzinger, Evgeny; Chaniel, Gilad

    2015-01-01T23:59:59.000Z

    Physical mechanisms of the interaction of cold plasmas with organic surfaces are discussed. Trapping of plasma ions by the CH2 groups of polymer surfaces resulting in their electrical charging is treated. Polyethylene surfaces were exposed to the cold radiofrequency air plasma for different intervals of time. The change in the wettability of these surfaces was registered. The experimentally established characteristic time scales of the interaction of cold plasma with polymer surfaces are inversely proportional to the concentration of ions. The phenomenological kinetic model of the electrical charging of polymer surfaces by plasmas is introduced and analyzed.

  16. Enhanced trapping of colding lithium by using the multiple-sideband cooling in a two-dimensional magneto-optical trap

    E-Print Network [OSTI]

    Li, Kai; Gao, Tianyou; Peng, Shi-Guo; Jiang, Kaijun

    2015-01-01T23:59:59.000Z

    Trapping lithium with a big number in a simplified experimental setup has difficulties and challenges today. In this paper, we experimentally demonstrate the enhancement of \\textsuperscript{6}Li trapping efficiency in a three-dimensional magneto-optical trap (3D MOT) by using the multiple-sideband cooling in a two-dimensional magneto-optical trap (2D MOT). To improve the number of trapped atoms, we broaden the cooling light spectrum to 102 MHz composed of seven frequency components and then trap atoms with a number of $6.0\\times10^8$ which is about 4 times compared to that in the single-frequency cooling. The capture velocity and dependence of atomic number on the laser detuning have been analyzed, where the experimental result has a good agreement with the theoretical prediction based on a simple two-level model. We also analyze the loss rate of alkali metals due to fine-structure exchanging collisions and find that the multiple-sideband cooling is special valid for lithium.

  17. Dipole Excitation With A Paul Ion Trap Mass Spectrometer

    SciTech Connect (OSTI)

    MacAskill, J. A.; Madzunkov, S. M.; Chutjian, A. [Atomic and Molecular Physics Group, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)

    2011-06-01T23:59:59.000Z

    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.

  18. Escaping the poverty trap: modeling the interplay between economic growth and the ecology of infectious disease

    E-Print Network [OSTI]

    Goerg, Georg M; Hébert-Dufresne, Laurent; Althouse, Benjamin M

    2013-01-01T23:59:59.000Z

    The dynamics of economies and infectious disease are inexorably linked: economic well-being influences health (sanitation, nutrition, treatment capacity, etc.) and health influences economic well-being (labor productivity lost to sickness and disease). Often societies are locked into ``poverty traps'' of poor health and poor economy. Here, using a simplified coupled disease-economic model with endogenous capital growth we demonstrate the formation of poverty traps, as well as ways to escape them. We suggest two possible mechanisms of escape both motivated by empirical data: one, through an influx of capital (development aid), and another through changing the percentage of GDP spent on healthcare. We find that a large influx of capital is successful in escaping the poverty trap, but increasing health spending alone is not. Our results demonstrate that escape from a poverty trap may be possible, and carry important policy implications in the world-wide distribution of aid and within-country healthcare spending.

  19. 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)

    2014-03-10T23:59:59.000Z

    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 0.4–20?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.

  20. 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, Universität Erlangen-Nürnberg, 96049 Bamberg (Germany)

    2014-11-15T23:59:59.000Z

    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.

  1. Detection of Fusion Neutrons on the Multimirror Trap GOL-3

    SciTech Connect (OSTI)

    Burdakov, A.V. [Budker Institute of Nuclear Physics (Russian Federation); England, A.C. [Korea Basic Science Institute (Korea, Republic of); Kim, C.S. [Korea Basic Science Institute (Korea, Republic of); Koidan, V.S. [Budker Institute of Nuclear Physics (Russian Federation); Kwon, M. [Korea Basic Science Institute (Korea, Republic of); Postupaev, V.V. [Budker Institute of Nuclear Physics (Russian Federation); Rovenskikh, A.F. [Budker Institute of Nuclear Physics (Russian Federation); Sulyaev, Yu.S. [Budker Institute of Nuclear Physics (Russian Federation)

    2005-01-15T23:59:59.000Z

    Recently GOL-3 has been reconfigured to a multimirror trap with improved confinement and high ion temperature. A dense plasma is created with a life time in the millisecond range. BTI neutron bubble detectors, a stilbene scintillation crystal, a BC501A liquid scintillator, and a silver-activation counter have been used for measurements of the neutron emission from GOL-3. The results are in agreement with charge-exchange (CX), spectral broadening of the D{alpha} line, and diamagnetic measurements.

  2. Photon trap for neutralization of negative ions beams

    E-Print Network [OSTI]

    Popov, S S; Ivanov, A A; Kotelnikov, I A

    2015-01-01T23:59:59.000Z

    For effectively neutralization of the powerful negative ions beams of hydrogen and deuterium the photon target is considered in long time. The attractiveness of the traditional approach (Fabry-Perot resonators) to their creation is limited to a number of stringent technical requirements and large economic costs. In this paper we propose a new concept of non-resonant photon trap (storage) for creation more technologically simple optical neutralizers.

  3. Multi-physics investigation on the failure mechanism and short-time scale wave motion in flip-chip configuration

    E-Print Network [OSTI]

    Oh, Yoonchan

    2005-11-01T23:59:59.000Z

    scale package of 2 Watts steady state power is subjected to 1000 Watts for about 1 ms, junction temperature was seen to rise 50 o C. Mercado et al. [29] did an integrated transient thermal and mechanical analysis for a molded plastic ball grid array...

  4. Laser cooling of trapped ions Jurgen Eschner

    E-Print Network [OSTI]

    Blatt, Rainer

    of the art is reported, and several new cooling techniques are outlined. The principles of ion trapping by elucidating several milestone experiments. In addition, a number of special cooling techniques pertainingLaser cooling of trapped ions Ju¨rgen Eschner Institut fu¨ r Experimentalphysik, Universita

  5. Holographic optical trapping David G. Grier

    E-Print Network [OSTI]

    Grier, David

    Holographic optical trapping David G. Grier Yael Roichman Department of Physics and Center for Soft Matter Research, New York University, 4 Washington Place, New York, NY 10003 Holographic optical tweezers­beam optical traps use­ ful for capturing, moving and transforming mesoscopic objects. Through a combination

  6. Holographic optical trapping David G. Grier

    E-Print Network [OSTI]

    Grier, David

    Holographic optical trapping David G. Grier Yael Roichman Department of Physics and Center for Soft Matter Research, New York University, 4 Washington Place, New York, NY 10003 Holographic optical tweezers-beam optical traps use- ful for capturing, moving and transforming mesoscopic objects. Through a combination

  7. Compression of Antiproton Clouds for Antihydrogen Trapping

    E-Print Network [OSTI]

    G. B. Andresen; W. Bertsche; P. D. Bowe; C. C. Bray; E. Butler; C. L. Cesar; S. Chapman; M. Charlton; J. Fajans; M. C. Fujiwara; R. Funakoshi; D. R. Gill; J. S. Hangst; W. N. Hardy; R. S. Hayano; M. E. Hayden; R. Hydomako; M. J. Jenkins; L. V. Jorgensen; L. Kurchaninov; R. Lambo; N. Madsen; P. Nolan; K. Olchanski; A. Olin; A. Povilus; P. Pusa; F. Robicheaux; E. Sarid; S. Seif El Nasr; D. M. Silveira; J. W. Storey; R. I. Thompson; D. P. van der Werf; J. S. Wurtele; Y. Yamazaki

    2008-06-30T23:59:59.000Z

    Control of the radial profile of trapped antiproton clouds is critical to trapping antihydrogen. We report the first detailed measurements of the radial manipulation of antiproton clouds, including areal density compressions by factors as large as ten, by manipulating spatially overlapped electron plasmas. We show detailed measurements of the near-axis antiproton radial profile and its relation to that of the electron plasma.

  8. Trapping atoms using nanoscale quantum vacuum forces

    E-Print Network [OSTI]

    D. E. Chang; K. Sinha; J. M. Taylor; H. J. Kimble

    2013-10-22T23:59:59.000Z

    Quantum vacuum forces dictate the interaction between individual atoms and dielectric surfaces at nanoscale distances. For example, their large strengths typically overwhelm externally applied forces, which makes it challenging to controllably interface cold atoms with nearby nanophotonic systems. Here, we show that it is possible to tailor the vacuum forces themselves to provide strong trapping potentials. The trapping scheme takes advantage of the attractive ground state potential and adiabatic dressing with an excited state whose potential is engineered to be resonantly enhanced and repulsive. This procedure yields a strong metastable trap, with the fraction of excited state population scaling inversely with the quality factor of the resonance of the dielectric structure. We analyze realistic limitations to the trap lifetime and discuss possible applications that might emerge from the large trap depths and nanoscale confinement.

  9. Ion Trap in a Semiconductor Chip

    E-Print Network [OSTI]

    D. Stick; W. K. Hensinger; S. Olmschenk; M. J. Madsen; K. Schwab; C. Monroe

    2006-01-09T23:59:59.000Z

    The electromagnetic manipulation of isolated atoms has led to many advances in physics, from laser cooling and Bose-Einstein condensation of cold gases to the precise quantum control of individual atomic ion. Work on miniaturizing electromagnetic traps to the micrometer scale promises even higher levels of control and reliability. Compared with 'chip traps' for confining neutral atoms, ion traps with similar dimensions and power dissipation offer much higher confinement forces and allow unparalleled control at the single-atom level. Moreover, ion microtraps are of great interest in the development of miniature mass spectrometer arrays, compact atomic clocks, and most notably, large scale quantum information processors. Here we report the operation of a micrometer-scale ion trap, fabricated on a monolithic chip using semiconductor micro-electromechanical systems (MEMS) technology. We confine, laser cool, and measure heating of a single 111Cd+ ion in an integrated radiofrequency trap etched from a doped gallium arsenide (GaAs) heterostructure.

  10. When a trap is not a trap: converging entry and exit rates and their effect on trap saturation of black sea bass (Centropristis striata)

    E-Print Network [OSTI]

    When a trap is not a trap: converging entry and exit rates and their effect on trap saturation entries and exits of black sea bass (Centropristis striata) from chevron traps (n ¼ 26) to quantify catch at50 min, when the entry ratedeclined and the exit rate increased to a point where their confidence

  11. Wafer heating mechanisms in a molecular gas, inductively coupled plasma: in situ, real time wafer surface measurements and three-dimensional thermal modeling

    SciTech Connect (OSTI)

    Titus, M. J.; Graves, D. B. [Department of Chemical Engineering, University of California, Berkeley, California 94720 (United States)

    2008-09-15T23:59:59.000Z

    The authors report measurements and modeling of wafer heating mechanisms in an Ar/O{sub 2} inductively coupled plasma (ICP). The authors employed a commercially available on-wafer sensor system (PlasmaTemp developed by KLA-Tencor) consisting of an on-board electronics module housing battery power and data storage with 30 temperature sensors embedded onto the wafer at different radial positions. This system allows for real time, in situ wafer temperature measurements. Wafer heating mechanisms were investigated by combining temperature measurements from the PlasmaTemp sensor wafer with a three-dimensional heat transfer model of the wafer and a model of the ICP. Comparisons between pure Ar and Ar/O{sub 2} discharges demonstrated that two additional wafer heating mechanisms can be important in molecular gas plasmas compared to atomic gas discharges. The two mechanisms are heating from the gas phase and O-atom surface recombination. These mechanisms were shown to contribute as much as 60% to wafer heating under conditions of low bias power. This study demonstrated how the 'on-wafer' temperature sensor not only yields a temperature profile distribution across the wafer, but can be used to help determine plasma characteristics, such as ion flux profiles or plasma processing temperatures.

  12. 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

    2007-03-01T23:59:59.000Z

    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.

  13. Microfabricated Renewable Beads-Trapping/Releasing Flow Cell...

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

    Microfabricated Renewable Beads-TrappingReleasing Flow Cell for Rapid Antigen-Antibody Reaction in Chemiluminescent Immunoassay Microfabricated Renewable Beads-TrappingReleasing...

  14. NOx Adsorber (Lean NOx Trap) Fundamentals (Agreement #10049 ...

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

    (Lean NOx Trap) Fundamentals (Agreement 10049 - PNNL Project 47120) NOx Adsorber (Lean NOx Trap) Fundamentals (Agreement 10049 - PNNL Project 47120) Presentation from the U.S....

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

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

    Sam Crane August 28, 2003 H 2 -Assisted NOx Traps: Test Cell Results Vehicle Installations 2 Project Objectives * Determine Advantages of H 2 Assisted NO x Trap Regeneration *...

  16. Charge Trapping in High Efficiency Alternating Copolymers: Implication...

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

    Charge Trapping in High Efficiency Alternating Copolymers: Implications in Organic Photovoltaic Device Efficiency Home > Research > ANSER Research Highlights > Charge Trapping in...

  17. Vibrational Cooling in A Cold Ion Trap: Vibrationally Resolved...

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

    Vibrational Cooling in A Cold Ion Trap: Vibrationally Resolved Photoelectron Spectroscopy of Cold C60- Anions. Vibrational Cooling in A Cold Ion Trap: Vibrationally Resolved...

  18. atom trap trace: Topics by E-print Network

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

    1 An atom trap trace analysis system for measuring krypton contamination in xenon dark matter detectors Physics Websites Summary: An atom trap trace analysis system for measuring...

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

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

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

  20. Demagnetization dynamics of non-interacting trapped fermions

    E-Print Network [OSTI]

    Koller, Andrew P; Wall, Michael L; Rey, Ana Maria

    2015-01-01T23:59:59.000Z

    Motivated by several experimental efforts to understand spin diffusion and transport in ultracold fermionic gases, we study the spin dynamics of initially spin-polarized ensembles of harmonically trapped non-interacting spin-1/2 fermionic atoms, subjected to a magnetic field gradient. We obtain simple analytic expressions for spin observables in the presence of both constant and linear magnetic field gradients, with and without a spin-echo pulse, and at zero and finite temperatures. The analysis shows the relevance of spin-motional coupling in the non-interacting regime where the demagnetization decay rate at short times can be faster than the experimentally measured rates in the strongly interacting regime under similar trapping conditions. Our calculations also show that particle motion limits the ability of a spin-echo pulse to remove the effect of magnetic field inhomogeneity, and that a spin-echo pulse can instead lead to an increased decay of magnetization at times comparable to the trapping period.

  1. Hydrogen trapping in bearing steels: mechanisms and alloy design

    E-Print Network [OSTI]

    Szost, Blanka Angelika

    2013-02-05T23:59:59.000Z

    diffusion into steel may cause premature cracking in various components such as tempered martensitic and bainitic bearing parts, pearlitic and bainitic rail tracks, gear boxes, wind turbines, aerospace and marine engine parts. The damage caused by hydrogen... in the flux as well as the coating of manual metal arc electrodes determines the amount of hydrogen present. The type and cleanliness of the electrode are highly important, as well as the oil and grease, rust, paint and cleaning fluids on the welded surfaces...

  2. Theoretical investigation of energy-trapping mechanism by atomic systems

    E-Print Network [OSTI]

    Srivastava, Rajendra P.

    1978-06-01T23:59:59.000Z

    The theoretical results are presented here in detail for the atomic device proposed earlier by the author. This device absorbs energy from a continuous radiation source and stores some of it with atoms in metastable states ...

  3. Investigation of Aging Mechanisms in Lean NOx Traps

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

    24 Tim e (s) H 2 concentration (%) In Cat 0.25 Cat 0.50 Cat Out Cat 30-100 30-100 0.0 1.0 2.0 3.0 12 16 20 24 Tim e (s) H 2 concentration (%) In Cat 0.25 Cat 0.50 Cat Out Cat 30-0...

  4. Benchmark Reaction Mechanisms and Kinetics for Lean NOx Traps

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

    accomplishments (continued) * Simulations are consistent with hypotheses about the sequence of events occurring (spatially and temporally) during regeneration - Near the...

  5. Benchmark Reaction Mechanisms and Kinetics for Lean NOx Traps | Department

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't Your Destiny: The FutureCommentsEnergy Christopher Smith,Commerce |Committeeof Energy

  6. Benchmark Reaction Mechanisms and Kinetics for Lean NOx Traps | Department

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't Your Destiny: The FutureCommentsEnergy Christopher Smith,Commerce |Committeeof Energyof

  7. Triplet Transport to and Trapping by Acceptor End Groups on Conjugated Polyfluorene Chains

    SciTech Connect (OSTI)

    Sreearunothai, P.; Miller, J.; Estrada, A.; Asaoka, S.; Kowalczyk, M.; Jang, S.; Cook, A.R.; Preses, J.M.

    2011-08-31T23:59:59.000Z

    Triplet excited states created in polyfluorene (pF) molecules having average lengths up to 170 repeat units were transported to and captured by trap groups at the ends in less {approx}40 ns. Almost all of the triplets attached to the chains reached the trap groups, ruling out the presence of substantial numbers of defects that prevent transport. The transport yields a diffusion coefficient D of at least 3 x 10{sup -4} cm{sup 2} s{sup -1}, which is 30 times typical molecular diffusion and close to a value for triplet transport reported by Keller (J. Am. Chem. Soc.2011, 133, 11289-11298). The triplet states were created in solution by pulse radiolysis; time resolution was limited by the rate of attachment of triplets to the pF chains. Naphthylimide (NI) or anthraquinone (AQ) groups attached to the ends of the chains acted as traps for the triplets, although AQ would not have been expected to serve as a trap on the basis of triplet energies of the separate molecules. The depths of the NI and AQ triplet traps were determined by intermolecular triplet transfer equilibria and temperature dependence. The trap depths are shallow, just a few times thermal energy for both, so a small fraction of the triplets reside in the pF chains in equilibrium with the end-trapped triplets. Trapping by AQ appears to arise from charge transfer interactions between the pF chains and the electron-accepting AQ groups. Absorption bands of the end-trapped triplet states are similar in peak wavelength (760 nm) and shape to the 760 nm bands of triplets in the pF chains but have reduced intensities. When an electron donor, N,N,N',N'-tetramethyl-p-phenylenediamine (TMPD), is added to the solution, it reacts with the end-trapped triplets to remove the 760 nm bands and to make the trapping irreversible. New bands created upon reaction with TMPD may be due to charge transfer states.

  8. Trapping efficiency depending on particulate size

    SciTech Connect (OSTI)

    Mayer, A.; Czerwinski, J.; Scheidegger, P.

    1996-09-01T23:59:59.000Z

    There is growing concern about the risk potential of Diesel particulates. This prompted two Swiss R and D projects focused on the capabilities of different soot trap concepts for filtering finest particulates. Eight different filter media, some in numerous variants, were tested on four different Diesel engines. All traps attained their gravimetric target. However, there are noticeable performance differences for finest particulates at or smaller than 50 nm. Fiber deep filters seem to be noticeably better than other filter types. If the carcinogens are mainly the finest particulates, then this criterion may become important in future trap evaluation.

  9. An Atom Trap Relying on Optical Pumping

    E-Print Network [OSTI]

    P. Bouyer; P. Lemonde; M. Ben Dahan; A. Michaud; C. Salomon; J. Dalibard

    2005-09-21T23:59:59.000Z

    We have investigated a new radiation pressure trap which relies on optical pumping and does not require any magnetic field. It employs six circularly polarized divergent beams and works on the red of a $J_{g} \\longrightarrow J_{e} = J_{g} + 1$ atomic transition with $J_{g} \\geq 1/2$. We have demonstrated this trap with cesium atoms from a vapour cell using the 852 nm $J_{g} = 4 \\longrightarrow J_{e} = 5$ resonance transition. The trap contained up to $3 \\cdot 10^{7}$ atoms in a cloud of $1/\\sqrt{e}$ radius of 330 $\\mu$m.

  10. Nuclear spin qubits in a trapped-ion quantum computer

    E-Print Network [OSTI]

    M. Feng; Y. Y. Xu; F. Zhou; D. Suter

    2009-04-26T23:59:59.000Z

    Physical systems must fulfill a number of conditions to qualify as useful quantum bits (qubits) for quantum information processing, including ease of manipulation, long decoherence times, and high fidelity readout operations. Since these conditions are hard to satisfy with a single system, it may be necessary to combine different degrees of freedom. Here we discuss a possible system, based on electronic and nuclear spin degrees of freedom in trapped ions. The nuclear spin yields long decoherence times, while the electronic spin, in a magnetic field gradient, provides efficient manipulation, and the optical transitions of the ions assure a selective and efficient initialization and readout.

  11. Nonlinear Spectroscopy of Trapped Ions

    E-Print Network [OSTI]

    Frank Schlawin; Manuel Gessner; Shaul Mukamel; Andreas Buchleitner

    2014-10-07T23:59:59.000Z

    Nonlinear spectroscopy employs a series of laser pulses to interrogate dynamics in large interacting many-body systems, and has become a highly successful method for experiments in chemical physics. Current quantum optical experiments approach system sizes and levels of complexity which require the development of efficient techniques to assess spectral and dynamical features with scalable experimental overhead. However, established methods from optical spectroscopy of macroscopic ensembles cannot be applied straightforwardly to few-atom systems. Based on the ideas proposed in [M. Gessner et al. New J. Phys. 16 092001 (2014)], we develop a diagrammatic approach to construct nonlinear measurement protocols for controlled quantum systems and discuss experimental implementations with trapped ion technology in detail. These methods in combination with distinct features of ultra-cold matter systems allow us to monitor and analyze excitation dynamics in both the electronic and vibrational degrees of freedom. They are independent of system size, and can therefore reliably probe systems where, e.g., quantum state tomography becomes prohibitively expensive. We propose signals that can probe steady state currents, detect the influence of anharmonicities on phonon transport, and identify signatures of chaotic dynamics near a quantum phase transition in an Ising-type spin chain.

  12. Exchange of deeply trapped and interstitial hydrogen in silicon Blair Tuttle

    E-Print Network [OSTI]

    Adams, James B

    Exchange of deeply trapped and interstitial hydrogen in silicon Blair Tuttle Department of Physics Engineering, Arizona State University, Tempe, Arizona 85287-6006 Received 22 May 1998; revised manuscript mechanisms between an interstitial hydrogen atom and a deeply bound H at a silicon-hydrogen bond. We

  13. In-situ, Real-Time Monitoring of Mechanical and Chemical Structure Changes in a V2O5 Battery Electrode Using a MEMS Optical Sensor

    SciTech Connect (OSTI)

    Jung, H. [University of Maryland; Gerasopoulos, K. [University of Maryland; Gnerlich, Markus [University of Maryland; Talin, A. Alec [Sandia National Laboratories; Ghodssi, Reza [University of Maryland

    2014-06-01T23:59:59.000Z

    This work presents the first demonstration of a MEMS optical sensor for in-situ, real-time monitoring of both mechanical and chemical structure evolutions in a V2O5 lithium-ion battery (LIB) cathode during battery operation. A reflective membrane forms one side of a Fabry-Perot (FP) interferometer, while the other side is coated with V2O5 and exposed to electrolyte in a half-cell LIB. Using one microscope and two laser sources, both the induced membrane deflection and the corresponding Raman intensity changes are observed during lithium cycling. Results are in good agreement with the expected mechanical behavior and disorder change of the V2O5 layers, highlighting the significant potential of MEMS as enabling tools for advanced scientific investigations.

  14. A quantum information processor with trapped ions

    E-Print Network [OSTI]

    Schindler, Philipp

    Quantum computers hold the promise to solve certain problems exponentially faster than their classical counterparts. Trapped atomic ions are among the physical systems in which building such a computing device seems viable. ...

  15. Molten Hydroxide Trapping Process for Radioiodine

    SciTech Connect (OSTI)

    Trowbridge, L.D.

    2003-01-28T23:59:59.000Z

    A molten hydroxide trapping process has been considered for removing radioiodine species from off-gas streams whereby iodine is reacted directly with molten hydroxides such as NaOH or KOH. The resulting product is the corresponding iodide, which can be separated by simple cooling of the molten mixture to grow the iodide primary phase once the mixture reaches 70-80 mol% in the iodide component. Thermodynamic analysis indicates that such a chemical process is highly favorable. Experimental testing of the trapping process using molecular iodine showed trapping of up to 96% of the volatile iodine. The trapping efficiency was dependent on operational parameters such as temperature and gas-melt contact efficiency, and higher efficiencies are expected as the process is further developed. While an iodide phase could be effectively isolated by slow cooling of a molten iodide-hydroxide mixture, the persistent appearance of hydroxide indicated that an appreciable solubility of hydroxide occurred in the iodide phase.

  16. Use of Bullet Traps and Steel Targets

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

    design criteria and deployment specifications of bullet traps on U.S. Department of Energy (DOE) live-fire ranges. Deviation from these design and deployment criteria must be...

  17. Millikelvin cooling of an optically trapped microsphere in vacuum

    E-Print Network [OSTI]

    Tongcang Li; Simon Kheifets; Mark G. Raizen

    2011-01-07T23:59:59.000Z

    The apparent conflict between general relativity and quantum mechanics remains one of the unresolved mysteries of the physical world. According to recent theories, this conflict results in gravity-induced quantum state reduction of "Schr\\"odinger cats", quantum superpositions of macroscopic observables. In recent years, great progress has been made in cooling micromechanical resonators towards their quantum mechanical ground state. This work is an important step towards the creation of Schr\\"odinger cats in the laboratory, and the study of their destruction by decoherence. A direct test of the gravity-induced state reduction scenario may therefore be within reach. However, a recent analysis shows that for all systems reported to date, quantum superpositions are destroyed by environmental decoherence long before gravitational state reduction takes effect. Here we report optical trapping of glass microspheres in vacuum with high oscillation frequencies, and cooling of the center-of-mass motion from room temperature to a minimum temperature of 1.5 mK. This new system eliminates the physical contact inherent to clamped cantilevers, and can allow ground-state cooling from room temperature. After cooling, the optical trap can be switched off, allowing a microsphere to undergo free-fall in vacuum. During free-fall, light scattering and other sources of environmental decoherence are absent, so this system is ideal for studying gravitational state reduction. A cooled optically trapped object in vacuum can also be used to search for non-Newtonian gravity forces at small scales, measure the impact of a single air molecule, and even produce Schr\\"odinger cats of living organisms.

  18. Capturing Energy Savings with Steam Traps

    E-Print Network [OSTI]

    Bockwinkel, R. G.; French, S. A.

    , it's important to select and install the correct type and size steam trap for each application. This means a corruninnent must be made to training those who select, install, test and maintain steam traps on a. daily Scott A. French Application... generated. This paper will review each of these topics and then explore some of the new services, products, practices and technology available to help you maintain or improve the efficiency of your steam system. COSTLY STEAM LEAKS ENERGY RESOURCES...

  19. RICE UNIVERSITY A New Optical Trap System for

    E-Print Network [OSTI]

    Killian, Thomas C.

    profiles . . . . . . . . . . . . . . . . . . . . 14 2.1.3 Alignment of the loading trap beams . . . . . . . . . . . . . . 14 2.1.4 Power locking system for loading trap . . . . . . . . . . . . . . 15 2.2 Loading trap depth . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 3.1.1 Description of trap optical design and beam profiles . . . . . . 22 3.1.2 Power locking

  20. The time as an emergent property of quantum mechanics, a synthetic description of a first experimental approach

    E-Print Network [OSTI]

    E Moreva; G Brida; M Gramegna; V Giovannetti; L Maccone; M Genovese

    2015-02-11T23:59:59.000Z

    The "problem of time" in present physics substantially consists in the fact that a straightforward quantization of the general relativistic evolution equation and constraints generates for the Universe wave function the Wheeler-De Witt equation, which describes a static Universe. Page and Wootters considered the fact that there exist states of a system composed by entangled subsystems that are stationary, but one can interpret the component subsystems as evolving: this leads them to suppose that the global state of the universe can be envisaged as one of this static entangled state, whereas the state of the subsystems can evolve. Here we synthetically present an experiment, based on PDC polarization entangled photons, that allows showing with a practical example a situation where this idea works, i.e. a subsystem of an entangled state works as a "clock" of another subsystem.

  1. Scaling of capillary trapping in unstable two-phase flow: Application to CO[subscript 2] sequestration in deep saline aquifers

    E-Print Network [OSTI]

    Szulczewski, Michael L.

    The effect of flow instabilities on capillary trapping mechanisms is a major source of uncertainty in CO2 sequestration in deep saline aquifers. Standard macroscopic models of multiphase flow in porous media are unable to ...

  2. Resonant interaction of trapped cold atoms with a magnetic cantilever tip

    E-Print Network [OSTI]

    Montoya, Cris; Geraci, Andrew A; Eardley, Matthew; Moreland, John; Hollberg, Leo; Kitching, John

    2015-01-01T23:59:59.000Z

    Magnetic resonance in an ensemble of laser-cooled trapped Rb atoms is excited using a micro- cantilever with a magnetic tip. The cantilever is mounted on a multi-layer chip designed to capture, cool, and magnetically transport cold atoms. The coupling is observed by measuring the loss from a magnetic trap as the oscillating cantilever induces Zeeman state transitions in the atoms. Interfacing cold atoms with mechanical devices could enable probing and manipulating atomic spins with nanometer spatial resolution and single-spin sensitivity, leading to new capabilities in quantum computation, quantum simulation, or precision sensing.

  3. Resonant interaction of trapped cold atoms with a magnetic cantilever tip

    E-Print Network [OSTI]

    Cris Montoya; Jose Valencia; Andrew A. Geraci; Matthew Eardley; John Moreland; Leo Hollberg; John Kitching

    2015-03-26T23:59:59.000Z

    Magnetic resonance in an ensemble of laser-cooled trapped Rb atoms is excited using a micro- cantilever with a magnetic tip. The cantilever is mounted on a multi-layer chip designed to capture, cool, and magnetically transport cold atoms. The coupling is observed by measuring the loss from a magnetic trap as the oscillating cantilever induces Zeeman state transitions in the atoms. Interfacing cold atoms with mechanical devices could enable probing and manipulating atomic spins with nanometer spatial resolution and single-spin sensitivity, leading to new capabilities in quantum computation, quantum simulation, or precision sensing.

  4. Photonic assisted light trapping integrated in ultrathin crystalline silicon solar cells by nanoimprint lithography

    E-Print Network [OSTI]

    Trompoukis, Christos; Depauw, Valérie; Gordon, Ivan; Poortmans, Jef; 10.1063/1.4749810.

    2012-01-01T23:59:59.000Z

    We report on the fabrication of two-dimensional periodic photonic nanostructures by nanoimprint lithography and dry etching, and their integration into a 1-{\\mu}m-thin mono-crystalline silicon solar cell. Thanks to the periodic nanopatterning, a better in-coupling and trapping of light is achieved, resulting in an absorption enhancement. The proposed light trapping mechanism can be explained as the superposition of a graded index effect and of the diffraction of light inside the photoactive layer. The absorption enhancement is translated into a 23% increase in short-circuit current, as compared to the benchmark cell, resulting in an increase in energy-conversion efficiency.

  5. Experimental demonstration of a compact stellarator magnetic trap using four circular coils

    SciTech Connect (OSTI)

    Pedersen, T. Sunn; Kremer, J.P.; Lefrancois, R.G.; Marksteiner, Q.; Sarasola, X.; Ahmad, N. [Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027 (United States); University of California-Berkeley, Berkeley, California 94720 (United States)

    2006-01-15T23:59:59.000Z

    An experimental demonstration of a compact stellarator magnetic trap created from four circular coils is presented. The coil manufacturing and assembly tolerances were on the order of 0.5-1%, far less stringent than most other stellarators. The simplicity, loose mechanical tolerances, and low cost of the trap design makes it feasible for stellarators to be used for a variety of novel physics experiments, in addition to their present use for magnetic confinement fusion. The experiment, the Columbia Non-neutral Torus, has several other desirable features such as no significant internal island chains and the lowest aspect ratio, A{<=}1.9, of any stellarator built to date.

  6. Transport of ions in a segmented linear Paul trap in printed-circuit-board technology

    E-Print Network [OSTI]

    G. Huber; T. Deuschle; W. Schnitzler; R. Reichle; K. Singer; F. Schmidt-Kaler

    2007-11-19T23:59:59.000Z

    We describe the construction and operation of a segmented linear Paul trap, fabricated in printed-circuit-board technology with an electrode segment width of 500 microns. We prove the applicability of this technology to reliable ion trapping and report the observation of Doppler cooled ion crystals of Ca-40 with this kind of traps. Measured trap frequencies agree with numerical simulations at the level of a few percent from which we infer a high fabrication accuracy of the segmented trap. To demonstrate its usefulness and versatility for trapped ion experiments we study the fast transport of a single ion. Our experimental results show a success rate of 99.0(1)% for a transport distance of 2x2mm in a round-trip time of T=20us, which corresponds to 4 axial oscillations only. We theoretically and experimentally investigate the excitation of oscillations caused by fast ion transports with error-function voltage ramps: For a slightly slower transport (a round-trip shuttle within T=30us) we observe non-adiabatic motional excitation of 0.89(15)meV.

  7. Loading of a surface electrode ion trap from a remote, pre-cooled source

    E-Print Network [OSTI]

    Sage, Jeremy M; Chiaverini, John

    2012-01-01T23:59:59.000Z

    We demonstrate for the first time the loading of ions into a surface electrode trap (SET) from a remote, laser-cooled source of neutral atoms. We first cool and load $\\sim$ $10^6$ neutral $^{88}$Sr atoms into a magneto-optical trap (MOT) from an oven that has no line-of-sight with the SET. The cold atoms are then pushed with a resonant laser into the trap region where they are subsequently photoionized and trapped in an SET operated at a cryogenic temperature of 4.6 K. We present studies of the loading process and show that our technique achieves ion loading into a shallow (15 meV depth) trap at rates as high as 125 ions/s while drastically reducing the amount of deposition of metal on the trap surface as compared with direct loading from a hot vapor. Furthermore, we note that due to multiple stages of isotopic filtering in our loading process, this technique has enhanced isotopic selectivity over other loading methods. Rapid loading from a clean, isotopically pure, and pre-cooled source will potentially enab...

  8. Chapter 44. Cooling and Trapping Neutral Atoms Cooling and Trapping Neutral Atoms

    E-Print Network [OSTI]

    transition. This year, we made progress in developing novel detection and cooling techniques. 1. SpinChapter 44. Cooling and Trapping Neutral Atoms 44-1 Cooling and Trapping Neutral Atoms RLE Groups in optical lattices. Additional cooling methods will be needed to reach this very interesting temperature

  9. Physical process Mechanical mechanisms

    E-Print Network [OSTI]

    Berlin,Technische Universität

    1 Physical process Generation · Mechanical mechanisms F = m·a · Electric/Magnetic mechanisms F = B·i·l · Fluid dynamic/Hydraulic mechanisms q, p, ij · Thermal/Optical #12;2 Source unit

  10. Energy trapping and shock disintegration in a composite granular medium

    E-Print Network [OSTI]

    C. Daraio; V. F. Nesterenko; E. B. Herbold; S. Jin

    2005-09-24T23:59:59.000Z

    Granular materials demonstrate a strongly nonlinear behavior influencing the wave propagation in the medium. We report the first experimental observation of impulse energy confinement and the resultant disintegration of shock and solitary waves. The medium consists of alternating ensambles of high-modulus vs orders of magnitude lower modulus chains of different masses. The trapped energy is contained within the "softer" portions of the composite chain and is slowly released in the form of weak, separated pulses over an extended period of time. This effect is enhanced by using a specific group assembly and superimposed force.

  11. Superconducting qubits can be coupled and addressed as trapped ions

    E-Print Network [OSTI]

    Yu-xi Liu; L. F. Wei; J. R. Johansson; J. S. Tsai; Franco Nori

    2007-11-20T23:59:59.000Z

    Exploiting the intrinsic nonlinearity of superconducting Josephson junctions, we propose a scalable circuit with superconducting qubits (SCQs) which is very similar to the successful one now being used for trapped ions. The SCQs are coupled to the "vibrational" mode provided by a superconducting LC circuit or its equivalent (e.g., a SQUID). Both single-qubit rotations and qubit-LC-circuit couplings/decouplings can be controlled by the frequencies of the time-dependent magnetic fluxes. The circuit is scalable since the qubit-qubit interactions, mediated by the LC circuit, can be selectively performed, and the information transfer can be realized in a controllable way.

  12. The Elimination of Steam Traps

    E-Print Network [OSTI]

    Dickman, F.

    (the calculations are cumbersome) and the basic limita tions of sharp-edged orifice plates with small surface strainers. An engineer of one major oil company summed it up best when he described the gasket corporation's ground-breaking efforts... to the mechanical design of the central devices, and other changes were adopted. These changes later proved to solve the screen plugging and erosion problems. New patents were granted. Working quietly and building upon past success, Engineering Resources placed...

  13. Ball-grid array architecture for microfabricated ion traps

    E-Print Network [OSTI]

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

    2015-05-05T23:59:59.000Z

    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 $^{40}$Ca$^+$ 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 $^{171}$Yb$^+$ ions in a second BGA trap.

  14. Enhanced Raman sideband cooling of caesium atoms in a vapour-loaded magneto-optical trap

    E-Print Network [OSTI]

    Li, Y; Feng, G; Nute, J; Piano, S; Hackermuller, L; Ma, J; Xiao, L; Jia, S

    2015-01-01T23:59:59.000Z

    We report enhanced three-dimensional degenerated Raman sideband cooling (3D DRSC) of caesium (Cs) atoms in a standard single-cell vapour-loading magneto-optical trap. Our improved scheme involves using a separate repumping laser and optimized lattice detuning. We load $1.5 \\times 10^7$ atoms into the Raman lattice with a detuning of -15.5 GHz (to the ground F = 3 state). Enhanced 3D DRSC is used to cool them from 60 $\\mu$K to 1.7 $\\mu$K within 12 ms and the number of obtained atoms is about $1.2 \\times 10^7$. A theoretical model is proposed to simulate the measured number of trapped atoms. The result shows good agreement with the experimental data. The technique paves the way for loading a large number of ultracold Cs atoms into a crossed dipole trap and efficient evaporative cooling in a single-cell system.

  15. INFLUENCE OF FILM STRUCTURE AND LIGHT ON CHARGE TRAPPING AND DISSIPATION DYNAMICS IN SPUN-CAST ORGANIC THIN-FILM TRANSISTORS MEASURED BY SCANNING KELVIN PROBE MICROSCOPY

    SciTech Connect (OSTI)

    Teague, L.; Moth, M.; Anthony, J.

    2012-05-03T23:59:59.000Z

    Herein, time-dependent scanning Kelvin probe microscopy of solution processed organic thin film transistors (OTFTs) reveals a correlation between film microstructure and OTFT device performance with the location of trapped charge within the device channel. The accumulation of the observed trapped charge is concurrent with the decrease in I{sub SD} during operation (V{sub G}=-40 V, V{sub SD}= -10 V). We discuss the charge trapping and dissipation dynamics as they relate to the film structure and show that application of light quickly dissipates the observed trapped charge.

  16. Signal enhancement using a switchable magnetic trap

    DOE Patents [OSTI]

    Beer, Neil Reginald (Pleasanton, CA)

    2012-05-29T23:59:59.000Z

    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.

  17. Screening the Hanford tanks for trapped gas

    SciTech Connect (OSTI)

    Whitney, P.

    1995-10-01T23:59:59.000Z

    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.

  18. Parametric Resonance of Optically Trapped Aerosols

    E-Print Network [OSTI]

    R. Di Leonardo; G. Ruocco; J. Leach; M. J. Padgett; A. J. Wright; J. M. Girkin; D. R. Burnham; D. McGloin

    2007-02-23T23:59:59.000Z

    The Brownian dynamics of an optically trapped water droplet are investigated across the transition from over to under-damped oscillations. The spectrum of position fluctuations evolves from a Lorentzian shape typical of over-damped systems (beads in liquid solvents), to a damped harmonic oscillator spectrum showing a resonance peak. In this later under-damped regime, we excite parametric resonance by periodically modulating the trapping power at twice the resonant frequency. The power spectra of position fluctuations are in excellent agreement with the obtained analytical solutions of a parametrically modulated Langevin equation.

  19. Thermal electric vapor trap arrangement and method

    DOE Patents [OSTI]

    Alger, T.

    1988-03-15T23:59:59.000Z

    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.

  20. Thermal electric vapor trap arrangement and method

    DOE Patents [OSTI]

    Alger, Terry (Tracy, CA)

    1988-01-01T23:59:59.000Z

    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.

  1. Shelving and Probe Efficiency in Trapped Ion Experiments

    E-Print Network [OSTI]

    Schacht, M

    2014-01-01T23:59:59.000Z

    A generalized probe sequence typical of trapped ion experiments using shelving is studied. Detection efficiency is analyzed for finite shelved state lifetimes and using multi-modal count distributions. Multi-modal distributions are more appropriate for measurements that use a small number of ions than the simple Poisson counting statistics usually considered and have a larger variance that may be significant in determining uncertainties and in making weighted fits. Optimal probe times and the resulting state detection efficiency and sensitivity are determined for arbitrary cooling rates, initial states and shelved state lifetimes, in terms of a probe coherence time {\\tau}p. A universal optimal probe time of tp ~ 0.43{\\tau}p is shown to give an almost optimal probe sensitivity for most systems.

  2. Storage of very cold neutrons in a trap with nano-structured walls

    E-Print Network [OSTI]

    E. V. Lychagin; A. Yu. Muzychka; V. V. Nesvizhevsky; G. Pignol; K. V. Protasov; A. V. Strelkov

    2008-12-09T23:59:59.000Z

    We report on storage of Very Cold Neutrons (VCN) in a trap with walls containing powder of diamond nanoparticles. The efficient VCN reflection is provided by multiple diffusive elastic scattering of VCN at single nanoparticles in powder. The VCN storage times are sufficiently long for accumulating large density of neutrons with complete VCN energy range of up to a few times 10(-4) eV. Methods for further improvements of VCN storage times are discussed.

  3. Carbon dioxide dissolution in structural and stratigraphic traps

    E-Print Network [OSTI]

    Hesse, M. A.

    The geologic sequestration of carbon dioxide (CO[subscript 2]) in structural and stratigraphic traps is a viable option to reduce anthropogenic emissions. While dissolution of the CO[subscript 2] stored in these traps ...

  4. Ideal Multipole Ion Traps from Planar Ring Electrodes

    E-Print Network [OSTI]

    Robert J. Clark

    2012-08-21T23:59:59.000Z

    We present designs for multipole ion traps based on a set of planar, annular, concentric electrodes which require only rf potentials to confine ions. We illustrate the desirable properties of the traps by considering a few simple cases of confined ions. We predict that mm-scale surface traps may have trap depths as high as tens of electron volts, or micromotion amplitudes in a 2-D ion crystal as low as tens of nanometers, when parameters of a magnitude common in the field are chosen. Several example traps are studied, and the scaling of those properties with voltage, frequency, and trap scale, for small numbers of ions, is derived. In addition, ions with very high charge-to-mass ratios may be confined in the trap, and species of very different charge-to-mass ratios may be simultaneously confined. Applications of these traps include quantum information science, frequency metrology, and cold ion-atom collisions.

  5. In-Vacuum Active Electronics for Microfabricated Ion Traps

    E-Print Network [OSTI]

    Nicholas D. Guise; Spencer D. Fallek; Harley Hayden; C-S Pai; Curtis Volin; K. R. Brown; J. True Merrill; Alexa W. Harter; Jason M. Amini; Lisa M. Lust; Kelly Muldoon; Doug Carlson; Jerry Budach

    2014-06-02T23:59:59.000Z

    The advent of microfabricated ion traps for the quantum information community has allowed research groups to build traps that incorporate an unprecedented number of trapping zones. However, as device complexity has grown, the number of digital-to-analog converter (DAC) channels needed to control these devices has grown as well, with some of the largest trap assemblies now requiring nearly one hundred DAC channels. Providing electrical connections for these channels into a vacuum chamber can be bulky and difficult to scale beyond the current numbers of trap electrodes. This paper reports on the development and testing of an in-vacuum DAC system that uses only 9 vacuum feedthrough connections to control a 78-electrode microfabricated ion trap. The system is characterized by trapping single and multiple $^{40}$Ca$^+$ ions. The measured axial mode stability, ion heating rates, and transport fidelities for a trapped ion are comparable to systems with external(air-side) commercial DACs.

  6. Towards a cryogenic planar ion trap for Sr-88

    E-Print Network [OSTI]

    Bakr, Waseem (Waseem S.)

    2006-01-01T23:59:59.000Z

    This thesis describes experiments with ion traps constructed with electrodes in a single two-dimensional plane, and ion traps operated in a cryogenic environment at 77K and 4K temperatures. These two technologies address ...

  7. Single microbe trap and release in sub-microfluidics. | EMSL

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

    Single microbe trap and release in sub-microfluidics. Single microbe trap and release in sub-microfluidics. Abstract: Lab-on-a-chip systems have substantially impacted the way...

  8. Simulating a quantum magnet with trapped ions

    E-Print Network [OSTI]

    Loss, Daniel

    systems we need a quantum leap in computer simulations. We cannot translate quantum behaviour arising from dynamics, we need a `quantum leap' in simulation efficiency. As proposed in ref. 1, a universal quantumLETTERS Simulating a quantum magnet with trapped ions A. FRIEDENAUER*, H. SCHMITZ*, J. T. GLUECKERT

  9. Quantum Stochastic Heating of a Trapped Ion

    E-Print Network [OSTI]

    L. Horvath; R. Fisher; M. J. Collett; H. J. Carmichael

    2007-11-09T23:59:59.000Z

    The resonant heating of a harmonically trapped ion by a standing-wave light field is described as a quantum stochastic process combining a coherent Schroedinger evolution with Bohr-Einstein quantum jumps. Quantum and semi-quantum treatments are compared.

  10. Dynamical Localization in the Paul Trap

    E-Print Network [OSTI]

    M. El Ghafar; P. Torma; V. Savichev; E. Mayr; A. Zeiler; W. P. Schleich

    1996-12-18T23:59:59.000Z

    We show that quantum localization occurs in the center-of-mass motion of an ion stored in a Paul trap and interacting with a standing laser field. The present experimental state of the art makes the observation of this phenomenon feasible.

  11. Trapping Light With Mirrors David Milovich Jr.

    E-Print Network [OSTI]

    Milovich, David

    Trapping Light With Mirrors David Milovich Jr. February 20, 2004 Abstract. We show that, given finitely many line-segment mirrors in the plane, that do not touch, and an arbitrary point source of light emitted light beams escape. This result is shown to imply that, for a given point source of light

  12. Dissipative dynamics of a vortex state in a trapped Bose-condensed gas

    E-Print Network [OSTI]

    P. O. Fedichev; G. V. Shlyapnikov

    1999-06-15T23:59:59.000Z

    We discuss dissipative dynamics of a vortex state in a trapped Bose-condensed gas at finite temperature and draw a scenario of decay of this state in a static trap. The interaction of the vortex with the thermal cloud transfers energy from the vortex to the cloud and induces the motion of the vortex core to the border of the condensate. Once the vortex reaches the border, it immediately decays through the creation of excitations. We calculate the characteristic life-time of a vortex state and address the question of how the dissipative dynamics of vortices can be studied experimentally.

  13. Trap Design for Vibratory Bowl Feeders Robert-Paul Berretty

    E-Print Network [OSTI]

    Utrecht, Universiteit

    devices such as wiper blades, grooves and traps. Most of these devices are filters Research is supported

  14. Local Detection of Quantum Correlations with a Single Trapped Ion

    E-Print Network [OSTI]

    M. Gessner; M. Ramm; T. Pruttivarasin; A. Buchleitner; H. -P. Breuer; H. Haeffner

    2014-08-11T23:59:59.000Z

    As one of the most striking features of quantum mechanics, quantum correlations are at the heart of quantum information science. Detection of correlations usually requires access to all the correlated subsystems. However, in many realistic scenarios this is not feasible since only some of the subsystems can be controlled and measured. Such cases can be treated as open quantum systems interacting with an inaccessible environment. Initial system-environment correlations play a fundamental role for the dynamics of open quantum systems. Following a recent proposal, we exploit the impact of the correlations on the open-system dynamics to detect system-environment quantum correlations without accessing the environment. We use two degrees of freedom of a trapped ion to model an open system and its environment. The present method does not require any assumptions about the environment, the interaction or the initial state and therefore provides a versatile tool for the study of quantum systems.

  15. Resonance capture by hydrogenous impurities and losses of ultracold neutrons in solid material traps

    E-Print Network [OSTI]

    G. S. Danilov

    2009-03-03T23:59:59.000Z

    The capture of trapped ultracold neutrons (UCNs) by closed hydrogenous impurities within a solid coating of the trap is discussed as a possible cause of observed anomalously large losses of UCNs in solid material UCN traps. Then significant losses of UCNs arise only if resonances occur in the UCN-impurity scattering amplitude. For a large size impurity, higher partial waves in the UCN-impurity interaction are important, and they are taken into account in the present paper. The method of the calculation is applicable to irregular shape impurities as well. A small distortion of an impurity shape, if it splits the resonance, can increase the UCN losses by a few times. UCN losses in the beryllium trap are calculated assuming they are due to the UCN capture by ice spherical impurities within the coating of the trap walls. Both s- and p-wave resonances contribute significantly to the UCN losses considered. As an example, observed anomalous large UCN losses are achieved if the average radius of the impurity is about 600 Angstroms and the impurity density is about 3*10^{14}/cm^3. A distortion of the spherical shape of the impurity could increase the UCN losses and therefore decrease the impurity density.

  16. First Attempts at Antihydrogen Trapping in G.B. Andresen

    E-Print Network [OSTI]

    Wurtele, Jonathan

    . The ALPHA apparatus is designed to produce and trap antihydrogen atoms. The de- vice comprises OF EACH PAPER CP1037, Cold Antimatter Plasmas and Application to Fundamental Physics, edited by Y. Kanai captured and cooled antiprotons in the catching trap. The catching trap includes a "rotating wall" electric

  17. An optical trap for relativistic plasmaa... Ping Zhang,b)

    E-Print Network [OSTI]

    Umstadter, Donald

    An optical trap for relativistic plasmaa... Ping Zhang,b) Ned Saleh, Shouyuan Chen, Zhengming Sheng November 2002; accepted 14 February 2003 The first optical trap capable of confining relativistic electrons that the optical trap acted to heat electrons, increasing their temperature by two orders of magnitude

  18. Enhancing entanglement trapping by weak measurement and quantum measurement reversal

    E-Print Network [OSTI]

    Ying-Jie Zhang; Wei Han; Heng Fan; Yun-Jie Xia

    2015-01-13T23:59:59.000Z

    In this paper, we propose a scheme to enhance trapping of entanglement of two qubits in the environment of a photonic band gap material. Our entanglement trapping promotion scheme makes use of combined weak measurements and quantum measurement reversals. The optimal promotion of entanglement trapping can be acquired with a reasonable finite success probability by adjusting measurement strengths.

  19. Light trapping in photonic crystals Ken Xingze Wang,ab

    E-Print Network [OSTI]

    Cui, Yi

    Light trapping in photonic crystals Ken Xingze Wang,ab Zongfu Yu,bc Victor Liu,bd Aaswath Raman,b Yi Cuief and Shanhui Fan*b We consider light trapping in photonic crystals in the weak material-integrated absorption enhancement by light trapping is proportional to the photonic density of states. The tight bound

  20. Commons as insurance: safety nets or poverty traps? Philippe Delacote

    E-Print Network [OSTI]

    Langerhans, Brian

    Commons as insurance: safety nets or poverty traps? Philippe Delacote Economics Department, EUI. The aim of this paper is to consider the potential poverty-trap implications of this use. If the capacity, the introduction of an insurance scheme could be an exit to the poverty trap and relax pressure on the resource

  1. Quantum Theory of Cavityless Feedback Cooling of An Optically Trapped Nanoparticle

    E-Print Network [OSTI]

    Rodenburg, B; Vamivakas, A N; Bhattacharya, M

    2015-01-01T23:59:59.000Z

    We present a quantum theory of cavityless feedback cooling of an optically trapped harmonically oscillating subwavelength dielectric particle, a configuration recently realized in several experiments. Specifically, we derive a Markovian master equation that treats the mechanical as well as optical degrees of freedom quantum mechanically. Employing this equation, we solve for the nanoparticle phonon number dynamics exactly, and extract analytic expressions for the cooling timescale and the steady state phonon number. We present experimental data verifying the predictions of our model in the classical regime, and also demonstrate that quantum ground state preparation is within reach of ongoing experiments. Our work provides a quantitative framework for future theoretical modeling of the cavityless quantum optomechanics of optically trapped dielectric particles.

  2. Quantum Theory of Cavityless Feedback Cooling of An Optically Trapped Nanoparticle

    E-Print Network [OSTI]

    B. Rodenburg; L. P. Neukirch; A. N. Vamivakas; M. Bhattacharya

    2015-03-17T23:59:59.000Z

    We present a quantum theory of cavityless feedback cooling of an optically trapped harmonically oscillating subwavelength dielectric particle, a configuration recently realized in several experiments. Specifically, we derive a Markovian master equation that treats the mechanical as well as optical degrees of freedom quantum mechanically. Employing this equation, we solve for the nanoparticle phonon number dynamics exactly, and extract analytic expressions for the cooling timescale and the steady state phonon number. We present experimental data verifying the predictions of our model in the classical regime, and also demonstrate that quantum ground state preparation is within reach of ongoing experiments. Our work provides a quantitative framework for future theoretical modeling of the cavityless quantum optomechanics of optically trapped dielectric particles.

  3. Landau damping and the onset of particle trapping in quantum plasmas

    SciTech Connect (OSTI)

    Daligault, Jérôme [Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2014-04-15T23:59:59.000Z

    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.

  4. Energy Efficient Steam Trapping of Trace Heating Systems

    E-Print Network [OSTI]

    Krueger, R. G.; Wilt, G. W.

    1981-01-01T23:59:59.000Z

    to insure low back pressure. Caution: Make certain the trap you select can handle the system back pressure. Each trap has specific limitations in this regard. 8. A Y-Strainer is considered mandatory for use on any Tracer Trap to reduce the potential... for plugging based on the small orifice sizes being employed. (Refer to Fig. 3). 9. Freeze-proofing each trap should be in accord with each manufacturer's recommendations. 10. When multiple traps are installed to discharge into a common manifold, check...

  5. Trapped surfaces in vacuum arising dynamically from mild incoming radiation

    E-Print Network [OSTI]

    Xinliang An; Jonathan Luk

    2014-09-22T23:59:59.000Z

    In this paper, we study the "minimal requirement" on the incoming radiation that guarantees a trapped surface to form in vacuum. First, we extend the region of existence in Christodoulou's theorem on the formation of trapped surfaces and consequently show that the lower bound required to form a trapped surface can be relaxed. Second, we demonstrate that trapped surfaces form dynamically from a class of initial data which are large merely in a scaling-critical norm. This result is motivated in part by the scaling in Christodoulou's formation of trapped surfaces theorem for the Einstein-scalar field system in spherical symmetry.

  6. An ion trap built with photonic crystal fibre technology

    E-Print Network [OSTI]

    F. Lindenfelser; B. Keitch; D. Kienzler; D. Bykov; P. Uebel; M. A. Schmidt; P. St. J. Russell; J. P. Home

    2015-01-20T23:59:59.000Z

    We demonstrate a surface-electrode ion trap fabricated using techniques transferred from the manufacture of photonic-crystal fibres. This provides a relatively straightforward route for realizing traps with an electrode structure on the 100 micron scale with high optical access. We demonstrate the basic functionality of the trap by cooling a single ion to the quantum ground state, allowing us to measure a heating rate from the ground state of 787(24) quanta/s. Variation of the fabrication procedure used here may provide access to traps in this geometry with trap scales between 100 um and 10 um.

  7. An ion trap built with photonic crystal fibre technology

    E-Print Network [OSTI]

    Lindenfelser, F; Kienzler, D; Bykov, D; Uebel, P; Schmidt, M A; Russell, P St J; Home, J P

    2015-01-01T23:59:59.000Z

    We demonstrate a surface-electrode ion trap fabricated using techniques transferred from the manufacture of photonic-crystal fibres. This provides a relatively straightforward route for realizing traps with an electrode structure on the 100 micron scale with high optical access. We demonstrate the basic functionality of the trap by cooling a single ion to the quantum ground state, allowing us to measure a heating rate from the ground state of 787(24) quanta/s. Variation of the fabrication procedure used here may provide access to traps in this geometry with trap scales between 100 um and 10 um.

  8. 1120 IEEE TRANSACTIONS ON ELECTRON DEVICES, VOL. 53, NO. 5, MAY 2006 Theory of Interface-Trap-Induced NBTI Degradation

    E-Print Network [OSTI]

    Alam, Muhammad A.

    mechanisms that generate traps at the Si-channel/gate-oxide interface of MOSFETs during transistor operation. The semiconductor/oxide interface is a rough surface where the highly ordered crystalline channel and the amor lead to poor device performance; therefore, the transistors are annealed in hydrogen ambient during

  9. Effect of trapping in degenerate quantum plasmas

    SciTech Connect (OSTI)

    Shah, H. A.; Qureshi, M. N. S. [Department of Physics, GC University, Lahore 54000 (Pakistan); Tsintsadze, N. [Department of Physics, GC University, Lahore 54000 (Pakistan); Salam Chair, GC University, Lahore 54000 (Pakistan)

    2010-03-15T23:59:59.000Z

    In the present work we consider the effect of trapping as a microscopic process in a plasma consisting of quantum electrons and nondegenerate ions. The formation of solitary structures is investigated in two cases: first when the electrons are fully degenerate and second when small temperature effects are taken into account. It is seen that not only rarefactive but coupled rarefactive and compressive solitons are obtained under different temperature conditions.

  10. Thermodynamics of Interacting Fermions in Atomic Traps

    SciTech Connect (OSTI)

    Chen Qijin; Stajic, Jelena; Levin, K. [James Franck Institute and Department of Physics, University of Chicago, Chicago, Illinois 60637 (United States)

    2005-12-31T23:59:59.000Z

    We calculate the entropy in a trapped, resonantly interacting Fermi gas as a function of temperature for a wide range of magnetic fields between the BCS and Bose-Einstein condensation end points. This provides a basis for the important technique of adiabatic sweep thermometry and serves to characterize quantitatively the evolution and nature of the excitations of the gas. The results are then used to calibrate the temperature in several ground breaking experiments on {sup 6}Li and {sup 40}K.

  11. Offline trapping of $^{221}$Fr in a magneto-optical trap from implantation of an $^{225}$Ac ion beam

    E-Print Network [OSTI]

    M. Tandecki; J. Zhang; S. Aubin; J. A. Behr; R. Collister; E. Gomez; G. Gwinner; H. Heggen; J. Lassen; L. A. Orozco; M. R. Pearson; S. Raeder; A. Teigelhöfer

    2014-09-30T23:59:59.000Z

    We demonstrate a new technique to prepare an offline source of francium for trapping in a magneto-optical trap. Implanting a radioactive beam of $^{225}$Ac, $t_{1/2} = 9.920(3)$ days, in a foil, allows use of the decay products, i.e.$^{221}$Fr, $t_{1/2} = 288.0(4)$ s. $^{221}$Fr is ejected from the foil by the $\\alpha$ decay of $^{225}$Ac. This technique is compatible with the online accumulation of a laser-cooled atomic francium sample for a series of planned parity non-conservation measurements at TRIUMF. We obtain a 34% release efficiency for $^{221}$Fr from the recoil source based on particle detector measurements. We find that laser cooling operation with the source is $8^{+10}_{-5}$ times less efficient than from a mass-separated ion beam of $^{221}$Fr in the current geometry. While the flux of this source is two to three orders of magnitude lower than typical francium beams from ISOL facilities, the source provides a longer-term supply of francium for offline studies.

  12. The relative efficiency of the Malaise trap and animal-baited traps for collecting biting flies in Southwest Texas

    E-Print Network [OSTI]

    Easton, Emmett Richard

    1967-01-01T23:59:59.000Z

    to laboratory animals. A trap model was desired that would require little or no handling of the trapped animal. Disney (1966) placed a metal sheet around a cubical rat cage and liberally applied castor oil to the metal sheet so that phlebotomine sand flies... could be caught and trapped in the castor oil. Since this sand fly moves in a hopping fashion the trap would seem to be more efficient for this fly than for mosquitoes. Bellamy and Res~ca (1952) employed a 110-lb. lard can as a portable baited trap...

  13. Entropic Time

    SciTech Connect (OSTI)

    Caticha, Ariel [Department of Physics, University at Albany-SUNY, Albany, NY 12222 (United States)

    2011-03-14T23:59:59.000Z

    The formulation of quantum mechanics within the framework of entropic dynamics includes several new elements. In this paper we concentrate on one of them: the implications for the theory of time. Entropic time is introduced as a book-keeping device to keep track of the accumulation of changes. One new feature is that, unlike other concepts of time appearing in the so-called fundamental laws of physics, entropic time incorporates a natural distinction between past and future.

  14. Error Compensation of Single-Qubit Gates in a Surface Electrode Ion Trap Using Composite Pulses

    E-Print Network [OSTI]

    Emily Mount; Chingiz Kabytayev; Stephen Crain; Robin Harper; So-Young Baek; Geert Vrijsen; Steven Flammia; Kenneth R. Brown; Peter Maunz; Jungsang Kim

    2015-04-06T23:59:59.000Z

    The trapped atomic ion qubits feature desirable properties for use in a quantum computer such as long coherence times (Langer et al., 2005), high qubit measurement fidelity (Noek et al., 2013), and universal logic gates (Home et al., 2009). The quality of quantum logic gate operations on trapped ion qubits has been limited by the stability of the control fields at the ion location used to implement the gate operations. For this reason, the logic gates utilizing microwave fields (Brown et al., 2011; Shappert et al., 2013; Harty et al., 2014) have shown gate fidelities several orders of magnitude better than those using laser fields (Knill et al., 2008; Benhelm et al., 2008; Ballance et al., 2014). Here, we demonstrate low-error single-qubit gates performed using stimulated Raman transitions on an ion qubit trapped in a microfabricated chip trap. Gate errors are measured using a randomized benchmarking protocol (Knill et al., 2008; Wallman et al., 2014; Magesan et al., 2012), where amplitude error in the control beam is compensated using various pulse sequence techniques (Wimperis, 1994; Low et al., 2014). Using B2 compensation (Wimperis, 1994), we demonstrate single qubit gates with an average error per randomized Clifford group gate of $3.6(3)\\times10^{-4}$. We also show that compact palindromic pulse compensation sequences (PD$n$) (Low et al., 2014) compensate for amplitude errors as designed.

  15. A study of time-dependent responses of a mechanical displacement ventilation (DV) system and an underfloor air distribution (UFAD) system : building energy performance of the UFAD system

    E-Print Network [OSTI]

    Yu, Jong Keun

    2010-01-01T23:59:59.000Z

    Displacement Ventilation system . . . . . . . . . . 1.1.2responses of mechanical Displacement Ventilation system 2.1of Displacement Ventilation Systems . Experi- mental and

  16. Graphene plasmonics for light trapping and absorption engineering

    E-Print Network [OSTI]

    Zhang, Jianfa; Liu, Wei; Yuan, Xiaodong; Qin, Shiqiao

    2015-01-01T23:59:59.000Z

    Plasmonics can be used to improve absorption in optoelectronic devices and has been intensively studied for solar cells and photodetectors. Graphene has recently emerged as a powerful plasmonic material. It shows significantly less losses compared to traditional plasmonic materials such as gold and silver and its plasmons can be tuned by changing the Fermi energy with chemical or electrical doping. Here we propose the usage of graphene plasmonics for light trapping in optoelectronic devices and show that the excitation of localized plasmons in doped, nanostructured graphene can enhance optical absorption in its surrounding media including both bulky and two-dimensional materials by tens of times, which may lead to a new generation of highly efficient, spectrally selective photodetectors in mid-infrared and THz ranges. The proposed concept could even revolutionize the field of plasmonic solar cells if graphene plasmons in the visible and near-infrared are realized.

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

    SciTech Connect (OSTI)

    Chakrabarty, Rajan K., E-mail: rajan.chakrabarty@gmail.com [Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130 (United States); Laboratory for Aerosol Science, Spectroscopy, and Optics, Desert Research Institute, Nevada System of Higher Education, Reno, Nevada 89512 (United States); Novosselov, Igor V. [Department of Mechanical Engineering, University of Washington, Seattle, Washington 98195 (United States); Enertechnix Inc., Maple Valley, Washington 98068 (United States); Beres, Nicholas D.; Moosmüller, Hans [Laboratory for Aerosol Science, Spectroscopy, and Optics, Desert Research Institute, Nevada System of Higher Education, Reno, Nevada 89512 (United States); Sorensen, Christopher M. [Condensed Matter Laboratory, Department of Physics, Kansas State University, Manhattan, Kansas 66506 (United States); Stipe, Christopher B. [TSI Incorporated, 500 Cardigan Rd, Shoreview, Minnesota 55126 (United States)

    2014-06-16T23:59:59.000Z

    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.

  18. Characterization of trapped lignin-degrading microbes in tropical forest soil

    SciTech Connect (OSTI)

    DeAngelis, K.M.; Allgaier, M.; Chavarria, Y.; Fortney, J.L.; Hugenholz, P.; Simmons, B.; Sublette, K.; Silver, W.L.; Hazen, T.C.

    2011-03-01T23:59:59.000Z

    Lignin is often the most difficult portion of plant biomass to degrade, with fungi generally thought to dominate during late stage decomposition. Lignin in feedstock plant material represents a barrier to more efficient plant biomass conversion and can also hinder enzymatic access to cellulose, which is critical for biofuels production. Tropical rain forest soils in Puerto Rico are characterized by frequent anoxic conditions and fluctuating redox, suggesting the presence of lignin-degrading organisms and mechanisms that are different from known fungal decomposers and oxygen-dependent enzyme activities. We explored microbial lignin-degraders by burying bio-traps containing lignin-amended and unamended biosep beads in the soil for 1, 4, 13 and 30 weeks. At each time point, phenol oxidase and peroxidase enzyme activity was found to be elevated in the lignin-amended versus the unamended beads, while cellulolytic enzyme activities were significantly depressed in lignin-amended beads. Quantitative PCR of bacterial communities showed more bacterial colonization in the lignin-amended compared to the unamended beads after one and four weeks, suggesting that the lignin supported increased bacterial abundance. The microbial community was analyzed by small subunit 16S ribosomal RNA genes using microarray (PhyloChip) and by high-throughput amplicon pyrosequencing based on universal primers targeting bacterial, archaeal, and eukaryotic communities. Community trends were significantly affected by time and the presence of lignin on the beads. Lignin-amended beads have higher relative abundances of representatives from the phyla Actinobacteria, Firmicutes, Acidobacteria and Proteobacteria compared to unamended beads. This study suggests that in low and fluctuating redox soils, bacteria could play a role in anaerobic lignin decomposition.

  19. Characterization of Trapped Lignin-Degrading Microbes in Tropical Forest Soil

    SciTech Connect (OSTI)

    DeAngelis, Kristen M.; Allgaier, Martin; Chavarria, Yaucin; Fortney, Julian L.; Hugenholtz, Philip; Simmons, Blake A.; Sublette, Kerry; Silver, Whendee; Hazen, Terry C.

    2011-04-29T23:59:59.000Z

    Lignin is often the most difficult portion of plant biomass to degrade, with fungi generally thought to dominate during late stage decomposition. Lignin in feedstock plant material represents a barrier to more efficient plant biomass conversion and can also hinder enzymatic access to cellulose, which is critical for biofuels production. Tropical rain forest soils in Puerto Rico are characterized by frequent anoxic conditions and fluctuating redox, suggesting the presence of lignin-degrading organisms and mechanisms that are different from known fungal decomposers and oxygen-dependent enzyme activities. We explored microbial lignin-degraders by burying bio-traps containing lignin-amended and unamended biosep beads in the soil for 1, 4, 13 and 30 weeks. At each time point, phenol oxidase and peroxidase enzyme activity was found to be elevated in the lignin-amended versus the unamended beads, while cellulolytic enzyme activities were significantly depressed in lignin-amended beads. Quantitative PCR of bacterial communities showed more bacterial colonization in the lignin-amended compared to the unamended beads after one and four weeks, suggesting that the lignin supported increased bacterial abundance. The microbial community was analyzed by small subunit 16S ribosomal RNA genes using microarray (PhyloChip) and by high-throughput amplicon pyrosequencing based on universal primers targeting bacterial, archaeal, and eukaryotic communities. Community trends were significantly affected by time and the presence of lignin on the beads. Lignin-amended beads have higher relative abundances of representatives from the phyla Actinobacteria, Firmicutes, Acidobacteria and Proteobacteria compared to unamended beads. This study suggests that in low and fluctuating redox soils, bacteria could play a role in anaerobic lignin decomposition.

  20. Characterization of Trapped Lignin-Degrading Microbes in Tropical Forest Soil

    SciTech Connect (OSTI)

    DeAngelis, Kristen; Allgaier, Martin; Chavarria, Yaucin; Fortney, Julian; Hugenholtz, Phillip; Simmons, Blake; Sublette, Kerry; Silver, Whendee; Hazen, Terry

    2011-07-14T23:59:59.000Z

    Lignin is often the most difficult portion of plant biomass to degrade, with fungi generally thought to dominate during late stage decomposition. Lignin in feedstock plant material represents a barrier to more efficient plant biomass conversion and can also hinder enzymatic access to cellulose, which is critical for biofuels production. Tropical rain forest soils in Puerto Rico are characterized by frequent anoxic conditions and fluctuating redox, suggesting the presence of lignin-degrading organisms and mechanisms that are different from known fungal decomposers and oxygen-dependent enzyme activities. We explored microbial lignin-degraders by burying bio-traps containing lignin-amended and unamended biosep beads in the soil for 1, 4, 13 and 30 weeks. At each time point, phenol oxidase and peroxidase enzyme activity was found to be elevated in the lignin-amended versus the unamended beads, while cellulolytic enzyme activities were significantly depressed in lignin-amended beads. Quantitative PCR of bacterial communities showed more bacterial colonization in the lignin-amended compared to the unamended beads after one and four weeks, suggesting that the lignin supported increased bacterial abundance. The microbial community was analyzed by small subunit 16S ribosomal RNA genes using microarray (PhyloChip) and by high-throughput amplicon pyrosequencing based on universal primers targeting bacterial, archaeal, and eukaryotic communities. Community trends were significantly affected by time and the presence of lignin on the beads. Lignin-amended beads have higher relative abundances of representatives from the phyla Actinobacteria, Firmicutes, Acidobacteria and Proteobacteria compared to unamended beads. This study suggests that in low and fluctuating redox soils, bacteria could play a role in anaerobic lignin decomposition.

  1. Energy Conservation Through Effective Steam Trapping

    E-Print Network [OSTI]

    Diamante, L.; Nagengast, C.

    1979-01-01T23:59:59.000Z

    fixed at one end with the valve plug on the other. The bellows are fillediwith the valve plug on the other. The bellows are filled with a liquid whose boiling temperature/pressure relationship parallels that of water only a few degrees be~ow it... resistance to the flow based on valve plug position. This promotes smooth control and additionally by allowing the pressure drop to occur in steps reduces wear on the critical seating surfaces. This trap provides excellent proportional control without...

  2. Gas turbine engines with particle traps

    DOE Patents [OSTI]

    Boyd, Gary L. (Tempe, AZ); Sumner, D. Warren (Phoenix, AZ); Sheoran, Yogendra (Scottsdale, AZ); Judd, Z. Daniel (Phoenix, AZ)

    1992-01-01T23:59:59.000Z

    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).

  3. Parallel ion strings in linear multipole traps

    E-Print Network [OSTI]

    Mathieu Marciante; Caroline Champenois; J. Pedregosa-Gutierrez; Annette Calisti; Martina Knoop

    2011-03-13T23:59:59.000Z

    Additional radio-frequency (rf) potentials applied to linear multipole traps create extra field nodes in the radial plane which allow one to confine single ions, or strings of ions, in totally rf field-free regions. The number of nodes depends on the order of the applied multipole potentials and their relative distance can be easily tuned by the amplitude variation of the applied voltages. Simulations using molecular dynamics show that strings of ions can be laser cooled down to the Doppler limit in all directions of space. Once cooled, organized systems can be moved with very limited heating, even if the cooling process is turned off.

  4. Isotopic abundance in atom trap trace analysis

    DOE Patents [OSTI]

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

    2014-03-18T23:59:59.000Z

    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.

  5. Measurements of PM Traps | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't YourTransport(FactDepartment3311, 3312), October 20122Technologies |Measurements of PM Traps

  6. Effective Steam Trap Selection/Maintenance - Its Payback

    E-Print Network [OSTI]

    Garcia, E.

    1984-01-01T23:59:59.000Z

    trap location, service, manufacturer, model, steam pressures, pipe size, type of connect ion, associated valves, strainer, and insulation. The condition in which each trap was found in the plant was reported and summarized as in Table 1. Other... leaks and any unsafe situations were also noted. Of the 5,000 surveyed traps, approximately 20% had failed open or were in another failure mode where live steam was leaking, 5% were found plugged, and 10% were found not losing steam but needing...

  7. Ratchet Cellular Automata for Colloids in Dynamic Traps

    E-Print Network [OSTI]

    C. J. Olson Reichhardt; C. Reichhardt

    2006-02-13T23:59:59.000Z

    We numerically investigate the transport of kinks in a ratchet cellular automata geometry for colloids interacting with dynamical traps. We find that thermal effects can enhance the transport efficiency in agreement with recent experiments. At high temperatures we observe the creation and annihilation of thermally induced kinks that degrade the signal transmission. We consider both the deterministic and stochastic cases and show how the trap geometry can be adjusted to switch between these two cases. The operation of the dynamical trap geometry can be achieved with the adjustment of fewer parameters than ratchet cellular automata constructed using static traps.

  8. Location Of Hole And Electron Traps On Nanocrystalline Anatase...

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

    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...

  9. adult trapping program: Topics by E-print Network

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

    Annual Industrial...EVALUATING STEAM TRAP PERFORMANCE Noel Y Fuller, P.E. Holston Defense Corporation Kingsport, Tennessee ABSTRACT Laboratory tests were conducted on several types...

  10. ap-8 trapped proton: Topics by E-print Network

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

    Annual Industrial...EVALUATING STEAM TRAP PERFORMANCE Noel Y Fuller, P.E. Holston Defense Corporation Kingsport, Tennessee ABSTRACT Laboratory tests were conducted on several types...

  11. acid phosphatase trap: Topics by E-print Network

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

    Annual Industrial...EVALUATING STEAM TRAP PERFORMANCE Noel Y Fuller, P.E. Holston Defense Corporation Kingsport, Tennessee ABSTRACT Laboratory tests were conducted on several types...

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

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

    Requirements Driven Diesel Catalyzed Particulate Trap (DCPT) Design and Optimization Tom Harris, Donna McConnell and Danan Dou Delphi Catalyst Tulsa, Oklahoma 2 Euro 45 Light Duty...

  13. Wavebreaking and Particle Trapping in Collisionless Plasmas: Final Report

    SciTech Connect (OSTI)

    Shadwick, Bradley A [University of Nebraska-Lincoln

    2013-08-01T23:59:59.000Z

    The final report describing accomplishments in understanding phase-space processes involved in particle trapping and in developing advance numerical models of laser-plasma interactions.

  14. Parallel heat flux and flow acceleration in open field line plasmas with magnetic trapping

    SciTech Connect (OSTI)

    Guo, Zehua; Tang, Xian-Zhu; McDevitt, Chris [Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2014-10-15T23:59:59.000Z

    The magnetic field strength modulation in a tokamak scrape-off layer (SOL) provides both flux expansion next to the divertor plates and magnetic trapping in a large portion of the SOL. Previously, we have focused on a flux expander with long mean-free-path, motivated by the high temperature and low density edge anticipated for an absorbing boundary enabled by liquid lithium surfaces. Here, the effects of magnetic trapping and a marginal collisionality on parallel heat flux and parallel flow acceleration are examined. The various transport mechanisms are captured by kinetic simulations in a simple but representative mirror-expander geometry. The observed parallel flow acceleration is interpreted and elucidated with a modified Chew-Goldberger-Low model that retains temperature anisotropy and finite collisionality.

  15. Spacetime near isolated and dynamical trapping horizons

    E-Print Network [OSTI]

    Ivan Booth

    2014-06-02T23:59:59.000Z

    We study the near-horizon spacetime for isolated and dynamical trapping horizons (equivalently marginally outer trapped tubes). The metric is expanded relative to an ingoing Gaussian null coordinate and the terms of that expansion are explicitly calculated to second order. For the spacelike case, knowledge of the intrinsic and extrinsic geometry of the (dynamical) horizon is sufficient to determine the near-horizon spacetime, while for the null case (an isolated horizon) more information is needed. In both cases spacetime is allowed to be of arbitrary dimension and the formalism accomodates both general relativity as well as more general field equations. The formalism is demonstrated for two applications. First, spacetime is considered near an isolated horizon and the construction is both checked against the Kerr-Newman solution and compared to the well-known near-horizon limit for stationary extremal black hole spacetimes. Second, spacetime is examined in the vicinity of a slowly evolving horizon and it is demonstrated that there is always an event horizon candidate in this region. The geometry and other properties of this null surface match those of the slowly evolving horizon to leading order and in this approximation the candidate evolves in a locally determined way. This generalizes known results for Vaidya as well as certain spacetimes known from studies of the fluid-gravity correspondence.

  16. ECOLOGY AND BEHAVIOR Treating Panel Traps With a Fluoropolymer Enhances Their Efficiency

    E-Print Network [OSTI]

    Hanks, Lawrence M.

    ECOLOGY AND BEHAVIOR Treating Panel Traps With a Fluoropolymer Enhances Their Efficiency to improve trap capture and retention, researchers have treated intercept traps with Rain-X, a polysiloxane that are deployed to capture cerambycid beetles, using untreated traps as controls. Fluon-treated traps captured

  17. Measurement of low-energy Na^+ -- Na total collision rate in an ion--neutral hybrid trap

    E-Print Network [OSTI]

    Goodman, D S; Kwolek, J M; Blümel, R; Narducci, F A; Smith, W W

    2014-01-01T23:59:59.000Z

    We present measurements of the total elastic and resonant charge-exchange ion-atom collision rate coefficient $k_\\mathrm{ia}$ of cold sodium (\\ce{Na}) with optically-dark low energy \\ce{Na+} ions in a hybrid ion-neutral trap. To determine $k_\\mathrm{ia}$, we measured the trap loading and loss from both a \\ce{Na} magneto-optical trap (MOT) and a linear radio frequency quadrupole Paul trap. We found the total rate coefficient to be $7.4 \\pm 1.9 \\times 10^{-8}$ cm$^3$/s for the type I \\ce{Na} MOT immersed within an $\\approx 140$ K ion cloud and $1.10 \\pm 0.25 \\times 10^{-7}$ cm$^3$/s for the type II \\ce{Na} MOT within an $\\approx 1070$ K ion cloud. Our measurements show excellent agreement with previously reported theoretical fully quantal \\textit{ab initio} calculations. In the process of determining the total rate coefficient, we demonstrate that a MOT can be used to probe an optically dark ion cloud's spatial distribution within a hybrid trap.

  18. An Energy Signature Scheme for Steam Trap Assessment and Flow Rate Estimation Using Pipe-Induced Acoustic Measurements

    SciTech Connect (OSTI)

    Olama, Mohammed M [ORNL; Allgood, Glenn O [ORNL; Kuruganti, Phani Teja [ORNL; Lake, Joe E [ORNL

    2012-01-01T23:59:59.000Z

    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.

  19. Optimal control of entangling operations for trapped-ion quantum computing V. Nebendahl,1

    E-Print Network [OSTI]

    Blatt, Rainer

    . In the quantum circuit model, information is encoded in quantum bits qu- bits and manipulated by applying unitary to a vibrational mode of the ions' motion in the trap. To achieve a gate on either a specific ion or a pair of ions that it interacts only with a single ion at a time 6 . Then, a CNOT gate or an equivalent entangling gate between

  20. Magnetic multipole induced zero-rotation frequency bounce-resonant loss in a PenningMalmberg trap used for antihydrogen trapping

    E-Print Network [OSTI]

    Wurtele, Jonathan

    Magnetic multipole induced zero-rotation frequency bounce-resonant loss in a Penning­Malmberg trap of the antiprotons around the trap axis to pass through zero. In the presence of a transverse magnetic multipole into the trap wall when the trap also employs a magnetic multipole. The multipole's function is to confine H

  1. Fundamental limit of nanophotonic light trapping in solar cells

    E-Print Network [OSTI]

    Fan, Shanhui

    -generation solar cells. The ultimate success of photovoltaic (PV) cell technology requires great advancementsFundamental limit of nanophotonic light trapping in solar cells Zongfu Yu1 , Aaswath Raman and is becoming increasingly urgent for current solar cell research. The standard theory of light trapping

  2. Broadband laser cooling of trapped atoms with ultrafast pulses

    E-Print Network [OSTI]

    Blinov, Boris

    Broadband laser cooling of trapped atoms with ultrafast pulses B. B. Blinov,* R. N. Kohn, Jr., M. J ions in an rf trap using ultrafast pulses from a mode-locked laser. The temperature of a single ion On the other hand, an ultrafast laser whose pulse is a few picoseconds long will naturally have a bandwidth

  3. Blue Crab, Callinectes sapidus, Trap Selectivity Studies: Mesh Size

    E-Print Network [OSTI]

    Blue Crab, Callinectes sapidus, Trap Selectivity Studies: Mesh Size VINCENT GUILLORY and PAUL had replaced drop nets and trot lines as the dominant gear in the commercial blue crab, Callinectes, LA 70343. ABSTRACT-Catch rates and sizes of blue crabs, Callinectes sapidus, were com pared in traps

  4. A Microscale Gas Trapping Investigation Markus Buchgraber, Anthony R. Kovscek

    E-Print Network [OSTI]

    Stanford University

    A Microscale Gas Trapping Investigation Markus Buchgraber, Anthony R. Kovscek Department of Energy unit Residual Trapping Sgi Sg,max krg krg Sgt(Soi) Sgt,max Gas Saturation Gas relative Land Model * * ** 1 )( gi gi gigt CS S SS + = Sgf Sg Sgt,max kd rg Sg Gas Saturation

  5. Surface-electrode ion trap with integrated light source

    E-Print Network [OSTI]

    Kim, Tony Hyun

    An atomic ion is trapped at the tip of a single-mode optical fiber in a cryogenic (8 K) surface-electrode ion trap. The fiber serves as an integrated source of laser light, which drives the quadrupolequbit transition of ...

  6. Steam Trap Testing and Evaluation: An Actual Plant Case Study

    E-Print Network [OSTI]

    Feldman, A. L.

    1981-01-01T23:59:59.000Z

    With rising steam costs and a high failure rate on the Joliet Plants standard steam trap, a testing and evaluation program was begun to find a steam trap that would work at Olin-Joliet. The basis was to conduct the test on the actual process...

  7. Novel Dipole Trapped Spheromak Configuration M. R. Brown,1,

    E-Print Network [OSTI]

    Brown, Michael R.

    Novel Dipole Trapped Spheromak Configuration M. R. Brown,1, * C. D. Cothran,1 J. Fung,1 M. J. Schaffer,2 and E. Belova3 We report the observation and characterization of a spheromak formed in the Swarthmore Spheromak Experiment (SSX) and trapped in a simple dipole magnetic field. The spheromak is studied

  8. Simulations of plasma confinement in an antihydrogen trap

    SciTech Connect (OSTI)

    Gomberoff, K.; Fajans, J.; Friedman, A.; Grote, D.; Vay, J.-L.; Wurtele, J.S.

    2007-10-15T23:59:59.000Z

    The three-dimensional particle-in-cell (3-D PIC) simulation code WARP is used to study positron confinement in antihydrogen traps. The magnetic geometry is close to that of a UC Berkeley experiment conducted, with electrons, as part of the ALPHA collaboration (W. Bertsche et al., AIP Conf. Proc. 796, 301 (2005)). In order to trap antihydrogen atoms, multipole magnetic fields are added to a conventional Malmberg-Penning trap. These multipole fields must be strong enough to confine the antihydrogen, leading to multipole field strengths at the trap wall comparable to those of the axial magnetic field. Numerical simulations reported here confirm recent experimental measurements of reduced particle confinement when a quadrupole field is added to a Malmberg-Penning trap. It is shown that, for parameters relevant to various antihydrogen experiments, the use of an octupole field significantly reducesthe positron losses seen with a quadrupole field. A unique method for obtaining a 3-D equilibrium of the positrons in the trap with a collisionless PIC code was developed especially for the study of the antihydrogen trap; however, it is of practical use for other traps as well.

  9. Fabrication and heating rate study of microscopic surface electrode ion traps

    E-Print Network [OSTI]

    Daniilidis, N.

    We report heating rate measurements in a microfabricated gold-on-sapphire surface electrode ion trap with a trapping height of approximately 240 ?m. Using the Doppler recooling method, we characterize the trap heating rates ...

  10. A Pneumatic Actuated Microfluidic Beads-Trapping Device

    SciTech Connect (OSTI)

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

    2011-08-20T23:59:59.000Z

    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.

  11. Can aerosols be trapped in open flows?

    E-Print Network [OSTI]

    Rafael D. Vilela; Adilson E. Motter

    2008-01-22T23:59:59.000Z

    The fate of aerosols in open flows is relevant in a variety of physical contexts. Previous results are consistent with the assumption that such finite-size particles always escape in open chaotic advection. Here we show that a different behavior is possible. We analyze the dynamics of aerosols both in the absence and presence of gravitational effects, and both when the dynamics of the fluid particles is hyperbolic and nonhyperbolic. Permanent trapping of aerosols much heavier than the advecting fluid is shown to occur in all these cases. This phenomenon is determined by the occurrence of multiple vortices in the flow and is predicted to happen for realistic particle-fluid density ratios.

  12. Contaminant trap for gas-insulated apparatus

    DOE Patents [OSTI]

    Adcock, James L. (Knoxville, TN); Pace, Marshall O. (Knoxville, TN); Christophorou, Loucas G. (Oak Ridge, TN)

    1984-01-01T23:59:59.000Z

    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.

  13. Switchable cell trapping using superparamagnetic beads

    SciTech Connect (OSTI)

    Bryan, M. T.; Smith, K. H.; Real, M. E.; Bashir, M. A.; Fry, P. W.; Fischer, P.; Im, M.-Y.; Schrefl, T.; Allwood, D. A.; Haycock, J. W.

    2010-04-30T23:59:59.000Z

    Ni{sub 81}Fe{sub 19} microwires are investigated as the basis of a switchable template for positioning magnetically-labeled neural Schwann cells. Magnetic transmission X-ray microscopy and micromagnetic modeling show that magnetic domain walls can be created or removed in zigzagged structures by an applied magnetic field. Schwann cells containing superparamagnetic beads are trapped by the field emanating from the domain walls. The design allows Schwann cells to be organized on a surface to form a connected network and then released from the surface if required. As aligned Schwann cells can guide nerve regeneration, this technique is of value for developing glial-neuronal co-culture models in the future treatment of peripheral nerve injuries.

  14. Debris trap in a turbine cooling system

    DOE Patents [OSTI]

    Wilson, Ian David (Clifton Park, NY)

    2002-01-01T23:59:59.000Z

    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.

  15. Modelling the influence of temperature and relative humidity on the time-dependent mechanical behaviour of a short glass fibre reinforced polyamide

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    . Introduction Carmakers are facing the challenge of reducing CO2 emis- sions, and are thus strongly interested. Both temperature and relative humidity are known to have an impact on mechanical properties strength of SGFR polyamides is highly sensitive to both temperature and relative humidity (Bernasconi et al

  16. Laser Cooling of Trapped Ions. W. M. ITANO,J. C. BERGQUIST,J. J. BOLLINGERand D. J. WINELAND

    E-Print Network [OSTI]

    techniques, because the ions can be held for long peri- ods in a well-controlled environment. CoolingLaser Cooling of Trapped Ions. W. M. ITANO,J. C. BERGQUIST,J. J. BOLLINGERand D. J. WINELAND Time ordered structures of ions, can be observed only at low temperatures. We use the term cooling*to mean

  17. Sensitivity test of a blue-detuned dipole trap designed for parity non-conservation measurements in Fr

    E-Print Network [OSTI]

    Dong Sheng; Jiehang Zhang; Luis A. Orozco

    2012-04-23T23:59:59.000Z

    A dynamic blue-detuned optical dipole trap with stable $^{87}Rb$ atoms produces a differential ac Stark shift of 18 Hz in the ground state hyperfine transition, and it preserves the ground state hyperfine superpositions for a long coherence time of 180 ms. The trapped atoms undergoing microwave Rabi oscillations are sensitive to a small signal, artificially generated with a second microwave source, phase locked to the first allow- ing a simple and effective method for determining signal-to-noise ratio limits through interference techniques. This provides an excellent means of calibrating sensitivity in experiments such as our ongoing Fr parity non-conservation measurement.

  18. Phase-Space Volume of Regions of Trapped Motion: Multiple Ring Components and Arcs

    E-Print Network [OSTI]

    L. Benet; O. Merlo

    2008-10-30T23:59:59.000Z

    The phase--space volume of regions of regular or trapped motion, for bounded or scattering systems with two degrees of freedom respectively, displays universal properties. In particular, sudden reductions in the phase-space volume or gaps are observed at specific values of the parameter which tunes the dynamics; these locations are approximated by the stability resonances. The latter are defined by a resonant condition on the stability exponents of a central linearly stable periodic orbit. We show that, for more than two degrees of freedom, these resonances can be excited opening up gaps, which effectively separate and reduce the regions of trapped motion in phase space. Using the scattering approach to narrow rings and a billiard system as example, we demonstrate that this mechanism yields rings with two or more components. Arcs are also obtained, specifically when an additional (mean-motion) resonance condition is met. We obtain a complete representation of the phase-space volume occupied by the regions of trapped motion.

  19. 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...

  20. Nanoscale interfacial structure for Novel Opto-electronic and Ion-trapping Devices

    E-Print Network [OSTI]

    Ulin-Avila, Erick

    2013-01-01T23:59:59.000Z

    SEM pictures of Aluminum alloy trap A,B. ) trap details C. )including Graphene, Aluminum alloys, Copper, Gold andwe use an specific aluminum alloy, which annealed increases

  1. Progress towards high precision measurements on ultracold metastable hydrogen and trapping deuterium

    E-Print Network [OSTI]

    Steinberger, Julia K., 1974-

    2004-01-01T23:59:59.000Z

    (cont.) not achieve deuterium trapping through helium-surface cooling. It is proposed that buffer gas loading can be used to cryogenically cool and trap deuterium.

  2. Properties of Trapped Electron Bunches in a Plasma Wakefield Accelerator

    SciTech Connect (OSTI)

    Kirby, Neil; /SLAC

    2009-10-30T23:59:59.000Z

    Plasma-based accelerators use the propagation of a drive bunch through plasma to create large electric fields. Recent plasma wakefield accelerator (PWFA) experiments, carried out at the Stanford Linear Accelerator Center (SLAC), successfully doubled the energy for some of the 42 GeV drive bunch electrons in less than a meter; this feat would have required 3 km in the SLAC linac. This dissertation covers one phenomenon associated with the PWFA, electron trapping. Recently it was shown that PWFAs, operated in the nonlinear bubble regime, can trap electrons that are released by ionization inside the plasma wake and accelerate them to high energies. These trapped electrons occupy and can degrade the accelerating portion of the plasma wake, so it is important to understand their origins and how to remove them. Here, the onset of electron trapping is connected to the drive bunch properties. Additionally, the trapped electron bunches are observed with normalized transverse emittance divided by peak current, {epsilon}{sub N,x}/I{sub t}, below the level of 0.2 {micro}m/kA. A theoretical model of the trapped electron emittance, developed here, indicates that the emittance scales inversely with the square root of the plasma density in the non-linear 'bubble' regime of the PWFA. This model and simulations indicate that the observed values of {epsilon}{sub N,x}/I{sub t} result from multi-GeV trapped electron bunches with emittances of a few {micro}m and multi-kA peak currents. These properties make the trapped electrons a possible particle source for next generation light sources. This dissertation is organized as follows. The first chapter is an overview of the PWFA, which includes a review of the accelerating and focusing fields and a survey of the remaining issues for a plasma-based particle collider. Then, the second chapter examines the physics of electron trapping in the PWFA. The third chapter uses theory and simulations to analyze the properties of the trapped electron bunches. Chapters four and five present the experimental diagnostics and measurements for the trapped electrons. Next, the sixth chapter introduces suggestions for future trapped electron experiments. Then, Chapter seven contains the conclusions. In addition, there is an appendix chapter that covers a topic which is extraneous to electron trapping, but relevant to the PWFA. This chapter explores the feasibility of one idea for the production of a hollow channel plasma, which if produced could solve some of the remaining issues for a plasma-based collider.

  3. Charge-trapping characteristics of fluorinated thin ZrO{sub 2} film for nonvolatile memory applications

    SciTech Connect (OSTI)

    Huang, X. D., E-mail: eexdhuang@gmail.com, E-mail: laip@eee.hku.hk [Key Laboratory of MEMS of the Ministry of Education, Southeast University, Nanjing 210096 (China); Shi, R. P.; Lai, P. T., E-mail: eexdhuang@gmail.com, E-mail: laip@eee.hku.hk [Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong (China)

    2014-04-21T23:59:59.000Z

    The effects of fluorine treatment on the charge-trapping characteristics of thin ZrO{sub 2} film are investigated by physical and electrical characterization techniques. The formation of silicate interlayer at the ZrO{sub 2}/SiO{sub 2} interface is effectively suppressed by fluorine passivation. However, excessive fluorine diffusion into the Si substrate deteriorates the quality of the SiO{sub 2}/Si interface. Compared with the ZrO{sub 2}-based memory devices with no or excessive fluorine treatment, the one with suitable fluorine-treatment time shows higher operating speed and better retention due to less resistance of built-in electric field (formed by trapped electrons) against electron injection from the substrate and smaller trap-assisted tunneling leakage, resulting from improved ZrO{sub 2}/SiO{sub 2} and SiO{sub 2}/Si interfaces.

  4. First Use of High Charge States for Mass Measurements of Short-lived Nuclides in a Penning Trap

    E-Print Network [OSTI]

    S. Ettenauer; M. C. Simon; A. T. Gallant; T. Brunner; U. Chowdhury; V. V. Simon; M. Brodeur; A. Chaudhuri; E. Mané; C. Andreoiu; G. Audi; J. R. Crespo López-Urrutia; P. Delheij; G. Gwinner; A. Lapierre; D. Lunney; M. R. Pearson; R. Ringle; J. Ullrich; J. Dilling

    2011-09-15T23:59:59.000Z

    Penning trap mass measurements of short-lived nuclides have been performed for the first time with highly-charged ions (HCI), using the TITAN facility at TRIUMF. Compared to singly-charged ions, this provides an improvement in experimental precision that scales with the charge state q. Neutron-deficient Rb-isotopes have been charge bred in an electron beam ion trap to q = 8 - 12+ prior to injection into the Penning trap. In combination with the Ramsey excitation scheme, this unique setup creating low energy, highly-charged ions at a radioactive beam facility opens the door to unrivalled precision with gains of 1-2 orders of magnitude. The method is particularly suited for short-lived nuclides such as the superallowed {\\beta} emitter 74Rb (T1/2 = 65 ms). The determination of its atomic mass and an improved QEC-value are presented.

  5. Two-dimensional water waves in the presence of a freely floating body: conditions for the absence of trapped modes

    E-Print Network [OSTI]

    Nikolay Kuznetsov

    2015-03-07T23:59:59.000Z

    The coupled motion is investigated for a mechanical system consisting of water and a body freely floating in it. Water occupies either a half-space or a layer of constant depth into which an infinitely long surface-piercing cylinder is immersed, thus allowing us to study two-dimensional modes. Under the assumption that the motion is of small amplitude near equilibrium, a linear setting is applicable and for the time-harmonic oscillations it reduces to a spectral problem with the frequency of oscillations as the spectral parameter. It is essential that one of the problem's relations is linear with respect to the parameter, whereas two others are quadratic with respect to it. Within this framework, it is shown that the total energy of the water motion is finite and the equipartition of energy holds for the whole system. On this basis, it is proved that no wave modes can be trapped provided their frequencies exceed a bound depending on cylinder's properties, whereas its geometry is subject to some restrictions and, in some cases, certain restrictions are imposed on the type of mode.

  6. Effects of trapping and finite temperature in a relativistic degenerate plasma

    SciTech Connect (OSTI)

    Shah, H. A.; Qureshi, M. N. S. [Physics Department, GC University, Lahore 54000 (Pakistan); Masood, W. [Theoretical Plasma Physics Division, PINSTECH, P.O. Nilore, Islamabad 44000 (Pakistan); Tsintsadze, N. L. [Physics Department, GC University, Lahore 54000 (Pakistan); Institute of Physics, Georgian Academy of Sciences, Tblisi 380077 (Georgia)

    2011-10-15T23:59:59.000Z

    In the present work, we have undertaken, for the first time, investigation on the effect of trapping on the formation of solitary structures in relativistic degenerate plasmas. Such plasmas have been observed in dense astrophysical objects, and in laboratory these may result due to the interaction of intense lasers with matter. We have used the relativistic Fermi-Dirac distribution to describe the dynamics of the degenerate trapped electrons by solving the kinetic equation. The Sagdeev potential approach has been employed to obtain the arbitrary amplitude solitary structures both when the plasma has been considered cold and when small temperature effects have been taken into account. The theoretical results obtained have been analyzed numerically for different parameter values, and the results have been presented graphically.

  7. Storage of fiber-guided light in a nanofiber-trapped ensemble of cold atoms

    E-Print Network [OSTI]

    C. Sayrin; C. Clausen; B. Albrecht; P. Schneeweiss; A. Rauschenbeutel

    2015-02-04T23:59:59.000Z

    Tapered optical fibers with a nanofiber waist are versatile tools for interfacing light and matter. In this context, laser-cooled atoms trapped in the evanescent field surrounding the optical nanofiber are of particular interest: They exhibit both long ground-state coherence times and efficient coupling to fiber-guided fields. Here, we demonstrate electromagnetically induced transparency, slow light, and the storage of fiber-guided optical pulses in an ensemble of cold atoms trapped in a nanofiber-based optical lattice. We measure a slow-down of light pulses to group velocities of 50 m/s. Moreover, we store optical pulses at the single photon level and retrieve them on demand in the fiber after 2 microseconds with an overall efficiency of (3.0 +/- 0.4) %. Our results show that nanofiber-based interfaces for cold atoms have great potential for the realization of building blocks for future optical quantum information networks.

  8. Stability and dynamics of ion rings in linear multipole traps

    E-Print Network [OSTI]

    Florian Cartarius; Cecilia Cormick; Giovanna Morigi

    2013-01-10T23:59:59.000Z

    Trapped singly-charged ions can crystallize as a result of laser cooling. The emerging structure depends on the number of particles and on the geometry of the trapping potential. In linear multipole radiofrequency traps, the geometry of the radial potential can lead to the formation of single-ring structures. We analyse the conditions and stability of single rings as a function of the number of poles. For larger numbers of ions the rings form tubes in which the arrangement of the ions corresponds to a triangular lattice folded onto a cylinder. The stability of these tubular structures is numerically studied for different lattice constants and their normal mode spectrum is determined.

  9. Trap seal for open circuit liquid cooled turbines

    DOE Patents [OSTI]

    Grondahl, Clayton M. (Clifton Park, NY); Germain, Malcolm R. (Ballston Lake, NY)

    1980-01-01T23:59:59.000Z

    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.

  10. Quantum information processing with trapped electrons and superconducting electronics

    E-Print Network [OSTI]

    Nikos Daniilidis; Dylan J Gorman; Lin Tian; Hartmut Häffner

    2013-04-17T23:59:59.000Z

    We describe a parametric frequency conversion scheme for trapped charged particles which enables a coherent interface between atomic and solid-state quantum systems. The scheme uses geometric non-linearities of the potential of a coupling electrode near a trapped particle. Our scheme does not rely on actively driven solid-state devices, and is hence largely immune to noise in such devices. We present a toolbox which can be used to build electron-based quantum information processing platforms, as well as quantum interfaces between trapped electrons and superconducting electronics.

  11. Trapped Ion Quantum Error Correcting Protocols Using Only Global Operations

    E-Print Network [OSTI]

    Joseph F. Goodwin; Benjamin J. Brown; Graham Stutter; Howard Dale; Richard C. Thompson; Terry Rudolph

    2014-07-07T23:59:59.000Z

    Quantum error-correcting codes are many-body entangled states that are prepared and measured using complex sequences of entangling operations. Each element of such an entangling sequence introduces noise to delicate quantum information during the encoding or reading out of the code. It is important therefore to find efficient entangling protocols to avoid the loss of information. Here we propose an experiment that uses only global entangling operations to encode an arbitrary logical qubit to either the five-qubit repetition code or the five-qubit code, with a six-ion Coulomb crystal architecture in a Penning trap. We show that the use of global operations enables us to prepare and read out these codes using only six and ten global entangling pulses, respectively. The proposed experiment also allows the acquisition of syndrome information during readout. We provide a noise analysis for the presented protocols, estimating that we can achieve a six-fold improvement in coherence time with noise as high as $\\sim 1\\%$ on each entangling operation.

  12. ablation ion trap: Topics by E-print Network

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

    geometry that generates a two dimensional lattice of point Paul traps. C. E. Pearson; D. R. Leibrandt; W. S. Bakr; W. J. Mallard; K. R. Brown; I. L. Chuang 2005-11-02 15...

  13. advanced ion trap: Topics by E-print Network

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

    geometry that generates a two dimensional lattice of point Paul traps. C. E. Pearson; D. R. Leibrandt; W. S. Bakr; W. J. Mallard; K. R. Brown; I. L. Chuang 2005-11-02 17 Cold...

  14. acoustic waves trapped: Topics by E-print Network

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

    in a magnetoplasma with a pair of trapped ions CERN Preprints Summary: The nonlinear propagation of dust-acoustic (DA) waves in a magnetized dusty plasma with a pair of...

  15. Laser ablation loading of a surface-electrode ion trap

    E-Print Network [OSTI]

    David R. Leibrandt; Robert J. Clark; Jaroslaw Labaziewicz; Paul Antohi; Waseem Bakr; Kenneth R. Brown; Isaac L. Chuang

    2007-06-22T23:59:59.000Z

    We demonstrate loading by laser ablation of $^{88}$Sr$^+$ ions into a mm-scale surface-electrode ion trap. The laser used for ablation is a pulsed, frequency-tripled Nd:YAG with pulse energies of 1-10 mJ and durations of 3-5 ns. An additional laser is not required to photoionize the ablated material. The efficiency and lifetime of several candidate materials for the laser ablation target are characterized by measuring the trapped ion fluorescence signal for a number of consecutive loads. Additionally, laser ablation is used to load traps with a trap depth (40 meV) below where electron impact ionization loading is typically successful ($\\gtrsim$ 500 meV).

  16. The Release of Trapped Gases from Amorphous Solid Water Films...

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

    I. Top-Down" Crystallization-Induced Crack Propagation Probed The Release of Trapped Gases from Amorphous Solid Water Films: I. Top-Down" Crystallization-Induced Crack Propagation...

  17. Coherent control of a qubit is trap-free

    E-Print Network [OSTI]

    Alexander Pechen; Nikolay Il'in

    2014-07-19T23:59:59.000Z

    There is a strong interest in optimal manipulating of quantum systems by external controls. Traps are controls which are optimal only locally but not globally. If they exist, they can be serious obstacles to the search of globally optimal controls in numerical and laboratory experiments, and for this reason the analysis of traps attracts considerable attention. In this paper we prove that for a wide range of control problems for two-level quantum systems all locally optimal controls are also globally optimal. Hence we conclude that two-level systems in general are trap-free. In particular, manipulating qubits---two-level quantum systems forming a basic building block for quantum computation---is free of traps for fundamental problems such as the state preparation and gate generation.

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

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

    Regeneration Selectivity Towards N2O -- Similarities and Differences Between H2, CO and C3H6 Reductants Lean NOx Trap Regeneration Selectivity Towards N2O -- Similarities and...

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

    SciTech Connect (OSTI)

    John, Sajeev [University of Toronto

    2014-08-15T23:59:59.000Z

    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.

  20. Novel trapping techniques for shaping Bose-Einstein condensates

    E-Print Network [OSTI]

    Boyd, Micah (Micah Scott)

    2007-01-01T23:59:59.000Z

    A combination of radio frequency radiation and magnetic field gradients was used to trap atoms in dressed states. In a magnetic field with a quadrupole minimum. RF fields resonant with the (I F. m)) 11. -1) -- 1, 0) ...

  1. Electron source for a mini ion trap mass spectrometer

    DOE Patents [OSTI]

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

    1995-12-19T23:59:59.000Z

    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.

  2. Electron source for a mini ion trap mass spectrometer

    DOE Patents [OSTI]

    Dietrich, Daniel D. (Livermore, CA); Keville, Robert F. (Valley Springs, CA)

    1995-01-01T23:59:59.000Z

    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.

  3. Quantum gates, sensors, and systems with trapped ions

    E-Print Network [OSTI]

    Wang, Shannon Xuanyue

    2012-01-01T23:59:59.000Z

    Quantum information science promises a host of new and useful applications in communication, simulation, and computational algorithms. Trapped atomic ions are one of the leading physical systems with potential to implement ...

  4. Solar cell efficiency enhancement via light trapping in printable resonant

    E-Print Network [OSTI]

    Atwater, Harry

    Solar cell efficiency enhancement via light trapping in printable resonant dielectric nanosphere´de´rale de Lausanne (EPFL), Institute of Microengineering (IMT), Photovoltaics and Thin Film Electronics, photovoltaics, resonant dielectric structures, solar cells * Corresponding author: e-mail jgrandid

  5. Light trapping limits in plasmonic solar cells: an analytical investigation

    E-Print Network [OSTI]

    Sheng, Xing

    We analytically investigate the light trapping performance in plasmonic solar cells with Si/metallic structures. We consider absorption enhancements for surface plasmon polaritons (SPPs) at planar Si/metal interfaces and ...

  6. Low temperature cold trapping of uranium hexafluoride containing hydrogen fluoride

    SciTech Connect (OSTI)

    Hobbs, W.E.; Barber, E.J.; Jones, C.G.

    1990-10-01T23:59:59.000Z

    The use of a freezer-sublimer system operating at low desublimation pressures to replace 10-in. nuclearly safe cold traps for low assay (<5% U-235) uranium hexafluoride (UF{sub 6}) would significantly simplify operations and is economically attractive provided the nuclear safety of the system can be assured. A major requirement of such assurance is the availability of conditions guaranteeing that the nuclear safety design criterion, which requires that the H/U atomic ratio in the condensate in the freezer-sublimer always be less than 0.33 for assays up to 5%, will never be violated. A general vapor pressure equation giving the vapor pressure of HF-UF{sub 6} solutions as a function of temperature and mole fraction UF{sub 6} has been developed. The precision of the data at the 95% confidence level is {plus minus}0.1 torr at temperatures between {minus}100{degree}F and {minus}121{degree}F. The calculated vapor pressure of pure HF is 4.6 torr at {minus}100{degree}F and 3.1 torr at {minus}108{degree}F. Theoretical considerations suggest that the true value will be slightly lower. In experimental studies of the cold trapping operation at {minus}108{degree}F and at a trap pressure of 2.2 torr, only 7.3% of the HF entering the trap was retained in the trap. At a trap pressure of 4.6 torr, over 80% of the HF entering the trap was retained. The data obtained in this study confirms that the physical chemistry of the HF-UF{sub 6} system previously developed accurately describes the behavior of the system and that so long as the pressure in the trap is maintained below the vapor pressure of pure HF at the trap temperatures, there is no way that sufficient HF can be trapped to give an H/U ratio of 0.33 regardless of the HF/UF{sub 6} ratio in the feed to the trap. 5 refs., 4 tabs.

  7. Quantum Mechanics in Space--Time: the Feynman Path Amplitude Description of Physical Optics, de Broglie Matter Waves and Quark and Neutrino Flavour Oscillations

    E-Print Network [OSTI]

    J. H. Field

    2005-03-02T23:59:59.000Z

    Feynman's laws of quantum dynamics are concisely stated, discussed in comparison with other formulations of quantum mechanics and applied to selected problems in the physical optics of photons and massive particles as well as flavour oscillations. The classical wave theory of light is derived from these laws for the case in which temporal variation of path amplitudes may be neglected, whereas specific experiments, sensitive to the temporal properties of path amplitudes, are suggested. The reflection coefficient of light from the surface of a transparent medium is found to be markedly different to that predicted by the classical Fresnel formula. Except for neutrino oscillations, good agreement is otherwise found with previous calculations of spatially dependent quantum interference effects.

  8. Laser induced rotation of trapped chiral and achiral nematic droplets

    E-Print Network [OSTI]

    Marjan Mosallaeipour; Yashodhan Hatwalne; N. V. Madhusudana; Sharath Ananthamurthy

    2010-02-05T23:59:59.000Z

    We study the response of optically trapped achiral and chiralised nematic liquid crystal droplets to linear as well as circular polarised light. We find that there is internal dissipation in rotating achiral nematic droplets trapped in glycerine. We also demonstrate that some chiralised droplets rotate under linearly polarised light. The best fit to our data on chiralised droplets indicates that rotational frequency of these droplets with radius R is approximately proportional to1/R^2, rather than to 1/R^3.

  9. What To Do With Cold Traps and Why

    E-Print Network [OSTI]

    Risko, J. R.; Walter, J. P.

    2012-01-01T23:59:59.000Z

    . Individual CDL often consist of up to a full-size tee on a distribution line, inlet strainer, isolation valves, steam trap, check valve, mud leg, blowdown valve, bypass line, tagging, and pipe insulation. The initial cost for designing and installing... or resource to periodically blow down strainers / drip pockets? 14. Is there a ?one size fits all? approach towards steam trap selection; using the same model for all drip and tracer applications? 15. Does the site remove strainer screens from steam...

  10. Optical Trapping and Control of a Nanowire by a Nanoaperture

    E-Print Network [OSTI]

    Aporvari, Mehdi Shafiei; Volpe, Giovanni

    2015-01-01T23:59:59.000Z

    We demonstrate that a single sub-wavelength nanoaperture in a metallic thin film can be used to achieve dynamic optical trapping and control of a single dielectric nanowire. A nanoaperture can trap a nanowire, control its orientation when illuminated by a linearly-polarized incident field, and also rotate the nanowire when illuminated by a circularly-polarized incident field. Compared to other designs, this approach has the advantages of a low-power driving field entailing low heating and photodamage.

  11. Thermal Trap for DNA Replication Christof B. Mast and Dieter Braun*

    E-Print Network [OSTI]

    Kersting, Roland

    and simultaneously accumulates the replicated molecules in an efficient thermophoretic trap. The non- equilibrium

  12. Trapping of Single Nano-objects in Dynamic Temperature Fields Marco Braun and Frank Cichos

    E-Print Network [OSTI]

    Boyer, Edmond

    is considered. The present study complements the dynamic thermophoretic trapping with a theoretical basis

  13. Global sound modes in mirror traps with anisotropic pressure

    SciTech Connect (OSTI)

    Skovorodin, D. I.; Zaytsev, K. V.; Beklemishev, A. D. [Budker Institute of Nuclear Physics, Novosibirsk State University, Novosibirsk 630090 (Russian Federation)] [Budker Institute of Nuclear Physics, Novosibirsk State University, Novosibirsk 630090 (Russian Federation)

    2013-10-15T23:59:59.000Z

    Global oscillations of inhomogeneous plasma with frequencies close to the bounce frequency of ions in mirror traps have been studied. It has been shown that, in some cases, the sound can be reflected from the axial plasma inhomogeneity. The ideal magnetohydrodynamic (MHD) model with Chew-Goldberger-Low approximation has been utilized to determine conditions of existence of the standing waves in the mirror-confined plasma. Linearized wave equation for the longitudinal plasma oscillations in thin anisotropic inhomogeneous plasma with finite ? has been derived. The wave equation has been treated numerically. The oscillations are studied for the case of the trap with partially filled loss-cone and the trap with sloshing ions. It has been shown that in cells of the multiple-mirror trap standing waves can exist. The frequency of the wave is of the order of the mean bounce-frequency of ions. In the trap with sloshing ions, the mode supported by the pressure of fast ions could exist. The results of oscillations observation in the experiment on the Gas Dynamic Trap have been presented.

  14. EBIT (Electron Beam Ion Trap), N-Division Experimental Physics. Annual report, 1994

    SciTech Connect (OSTI)

    Schneider, D. [ed.

    1995-10-01T23:59:59.000Z

    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.

  15. Ion-trap measurements of electric-field noise near surfaces

    E-Print Network [OSTI]

    M. Brownnutt; M. Kumph; P. Rabl; R. Blatt

    2014-09-23T23:59:59.000Z

    Electric-field noise near surfaces is a common problem in diverse areas of physics, and a limiting factor for many precision measurements. There are multiple mechanisms by which such noise is generated, many of which are poorly understood. Laser-cooled, trapped ions provide one of the most sensitive systems to probe electric-field noise at MHz frequencies and over a distance range 30 - 3000 $\\mu$m from the surface. Over recent years numerous experiments have reported spectral densities of electric-field noise inferred from ion heating-rate measurements and several different theoretical explanations for the observed noise characteristics have been proposed. This paper provides an extensive summary and critical review of electric-field noise measurements in ion traps, and compares these experimental findings with known and conjectured mechanisms for the origin of this noise. This reveals that the presence of multiple noise sources, as well as the different scalings added by geometrical considerations, complicate the interpretation of these results. It is thus the purpose of this review to assess which conclusions can be reasonably drawn from the existing data, and which important questions are still open. In so doing it provides a framework for future investigations of surface-noise processes.

  16. Constitutive Model for the Time-Dependent Mechanical Behavior of 430 Stainless Steel and FeCrAlY Foams in Sulfur-Bearing Environments

    SciTech Connect (OSTI)

    Hemrick, James Gordon [ORNL; Lara-Curzio, Edgar [ORNL

    2013-01-01T23:59:59.000Z

    The mechanical behavior of 430 stainless steel and pre-oxidized FeCrAlY open-cell foam materials of various densities was evaluated in compression at temperatures between 450 C and 600 C in an environment containing hydrogen sulfide and water vapor. Both materials showed negligible corrosion due to the gaseous atmosphere for up to 168 hours. The monotonic stress-strain response of these materials was found to be dependent on both the strain rate and their density, and the 430 stainless steel foam materials exhibited less stress relaxation than FeCrAlY for similar experimental conditions. Using the results from multiple hardening-relaxation and monotonic tests, an empirical constitutive equation was derived to predict the stress-strain behavior of FeCrAlY foams as a function of temperature and strain rate. These results are discussed in the context of using these materials in a black liquor gasifier to accommodate the chemical expansion of the refractory liner resulting from its reaction with the soda in the black liquor.

  17. Respiratory Mechanisms of Support

    E-Print Network [OSTI]

    Kay, Mark A.

    Respiratory Mechanisms of Support Nasal Cannula Hi Flow Nasal Cannula CPAP Continuous positive the respiratory system is working to compensate for a metabolic issue so as to normalize the blood pH. HCO3 - 22 uses PIP Mechanical Ventilation: Volume vs. Pressure: Volume Control Pressure Control Cycle Volume Time

  18. Quantum Mechanical Clock and Classical Relativistic Clock

    E-Print Network [OSTI]

    Hitoshi Kitada

    2004-07-08T23:59:59.000Z

    A cyclic nature of quantum mechanical clock is discussed as ``quantization of time." Quantum mechanical clock is seen to be equivalent to the relativistic classical clock.

  19. Quantum feedback cooling of a single trapped ion in front of a mirror

    E-Print Network [OSTI]

    V. Steixner; P. Rabl; P. Zoller

    2005-06-22T23:59:59.000Z

    We develop a theory of quantum feedback cooling of a single ion trapped in front of a mirror. By monitoring the motional sidebands of the light emitted into the mirror mode we infer the position of the ion, and act back with an appropriate force to cool the ion. We derive a feedback master equation along the lines of the quantum feedback theory developed by Wiseman and Milburn, which provides us with cooling times and final temperatures as a function of feedback gain and various system parameters.

  20. Simplified implementation of the quantum Fourier transform with Ising-type Hamiltonians: Example with ion traps

    E-Print Network [OSTI]

    Svetoslav S. Ivanov; Michael Johanning; Christof Wunderlich

    2015-03-30T23:59:59.000Z

    We propose a simplified mathematical construction of the quantum Fourier transform which is suited for systems described by Ising-type Hamiltonians. By contrast to the standard scheme, which prescribes concatenated sequences of control phase gates, our implementation is based on one-qubit gates and a free evolution process. We show a realization of our method with homogeneous microwave driven ion traps in a magnetic field with gradient. In this setup our implementation presents a series of microwave $\\pi$ or $\\pi/2$ pulses applied at certain times.

  1. Revealing the escape mechanism of three-dimensional orbits in a tidally limited star cluster

    E-Print Network [OSTI]

    Euaggelos E. Zotos

    2014-11-18T23:59:59.000Z

    The aim of this work is to explore the escape process of three-dimensional orbits in a star cluster rotating around its parent galaxy in a circular orbit. The gravitational field of the cluster is represented by a smooth, spherically symmetric Plummer potential, while the tidal approximation was used to model the steady tidal field of the galaxy. We conduct a thorough numerical analysis distinguishing between regular and chaotic orbits as well as between trapped and escaping orbits, considering only unbounded motion for several energy levels. It is of particular interest to locate the escape basins towards the two exit channels and relate them with the corresponding escape times of the orbits. For this purpose, we split our investigation into three cases depending on the initial value of the $z$ coordinate which was used for launching the stars. The most noticeable finding is that the majority of stars initiated very close to the primary $(x,y)$ plane move in chaotic orbits and they remain trapped for vast time intervals, while orbits with relatively high values of $z_0$ on the other hand, form well-defined basins of escape. It was also observed, that for energy levels close to the critical escape energy the escape rates of orbits are large, while for much higher values of energy most of the orbits have low escape periods or they escape immediately to infinity. We hope our outcomes to be useful for a further understanding of the dissolution process and the escape mechanism in open star clusters.

  2. Simulation of lean NOx trap performance with microkinetic chemistry and without mass transfer.

    SciTech Connect (OSTI)

    Larson, Rich; Daw, C. Stuart (Oak Ridge National Laboratory, Knoxville, TN); Pihl, Josh A. (Oak Ridge National Laboratory, Knoxville, TN); Chakravarthy, V. Kalyana (Oak Ridge National Laboratory, Knoxville, TN)

    2011-08-01T23:59:59.000Z

    A microkinetic chemical reaction mechanism capable of describing both the storage and regeneration processes in a fully formulated lean NO{sub x} trap (LNT) is presented. The mechanism includes steps occurring on the precious metal, barium oxide (NO{sub x} storage), and cerium oxide (oxygen storage) sites of the catalyst. The complete reaction set is used in conjunction with a transient plug flow reactor code to simulate not only conventional storage/regeneration cycles with a CO/H{sub 2} reductant, but also steady flow temperature sweep experiments that were previously analyzed with just a precious metal mechanism and a steady state code. The results show that NO{sub x} storage is not negligible during some of the temperature ramps, necessitating a re-evaluation of the precious metal kinetic parameters. The parameters for the entire mechanism are inferred by finding the best overall fit to the complete set of experiments. Rigorous thermodynamic consistency is enforced for parallel reaction pathways and with respect to known data for all of the gas phase species involved. It is found that, with a few minor exceptions, all of the basic experimental observations can be reproduced with these purely kinetic simulations, i.e., without including mass-transfer limitations. In addition to accounting for normal cycling behavior, the final mechanism should provide a starting point for the description of further LNT phenomena such as desulfation and the role of alternative reductants.

  3. Extremely scaled high-k/In?.??Ga?.??As gate stacks with low leakage and low interface trap densities

    SciTech Connect (OSTI)

    Chobpattana, Varistha; Mikheev, Evgeny; Zhang, Jack Y.; Mates, Thomas E.; Stemmer, Susanne [Materials Department, University of California, Santa Barbara, California 93106-5050 (United States)

    2014-09-28T23:59:59.000Z

    Highly scaled gate dielectric stacks with low leakage and low interface trap densities are required for complementary metal-oxide-semiconductor technology with III-V semiconductor channels. Here, we show that a novel pre-deposition technique, consisting of alternating cycles of nitrogen plasma and tetrakis(dimethylamino)titanium, allows for HfO? and ZrO? gate stacks with extremely high accumulation capacitance densities of more than 5 ?F/cm? at 1 MHz, low leakage current, low frequency dispersion, and low midgap interface trap densities (10¹²cm?²eV?¹range). Using x-ray photoelectron spectroscopy, we show that the interface contains TiO? and small quantities of In?O?, but no detectable Ga- or As-oxides, or As-As bonding. The results allow for insights into the microscopic mechanisms that control leakage and frequency dispersion in high-k/III-V gate stacks.

  4. Nano Vacancy Clusters and Trap Limited Diffusion of Si Interstitials in Silicon

    SciTech Connect (OSTI)

    Prof. Wei-Kan Chu

    2010-05-05T23:59:59.000Z

    The objective of this project is to develop a method to characterize nano vacancy clusters and the dynamics of their formation in ion-irradiated silicon. It will impact (1) semiconductor device processing involving ion implantation, and (2) device design concerning irradiation hardness in harsh environments. It also aims to enhance minority participation in research and curricula on emerging materials and ion beam science. Vacancy defects are of scientific and technological importance since they are ubiquitous when the host materials are exposed to particle irradiation. Studies on vacancy clustering in the past decades were mainly theoretical and the approach heavily relied on the total-energy calculation methods. The lack of experimental data is mainly due to the formidable task in measuring the cluster size and density using modern metrological techniques, including transmission electron microscopy and positron annihilation spectroscopy. To surmount these challenges, we proposed a novel approach to tackle the metrological problems on the nano vacancy clusters, especially in determining densities and sizes of the nano vacancies based on the premise that the vacancy-clusters act as diffusion-trapping centers. For a silicon substrate containing vacancyclusters, the diffusion of interstitials (from the surface) can be classified into three phases: (1) an ultrafast phase-I in which the trapping centers have little effect on the diffusion of interstitials; (2) a prolonged phase-II in which the loss rate of interstitials by trapping balances the influx of interstitials from the surface; and (3) a phase-III diffusion in which surface influx of interstitials depletes the trapping centers and interstitials consequently propagate deeper into the bulk. By measuring diffusion profiles of Si interstitials as a function of diffusion time, void sizes and void densities can be obtained through fitting. Experimentally, our approach to characterize voids is realized through three consecutive steps. (a) First, high energy self ion irradiation is used to create a wide vacancy-rich region, and to form voids by post implantation annealing. (b) In an additional annealing step in oxygen ambient, Si interstitials are injected in by surface oxidation. (c) Analyzing trap-limited diffusion of Si interstitials, which is experimentally detectable by studying the diffusion of multiple boron superlattices grown in Si, and enables us to characterize the nano voids, e.g. their sizes and densities.

  5. Cascade phonon-assisted trapping of positrons by divacancies in n-FZ-Si(P) single crystals irradiated with 15 MeV protons

    SciTech Connect (OSTI)

    Arutyunov, N. Yu., E-mail: n-arutyunov@yahoo.com [Martin Luther University Halle, Department of Physics, 06120 Halle, Germany and Inst. of Ion-Plasma and Laser Technologies (Inst. of Electronics), 700187 Tashkent (Uzbekistan); Emtsev, V. V.; Oganesyan, G. A. [Ioffe Physico-Technical Institute, 194021 St. Petersburg (Russian Federation); Krause-Rehberg, R.; Kessler, C. [Martin Luther University Halle, Department of Physics, 06120 Halle (Germany); Elsayed, M. [Martin Luther University Halle, Department of Physics, 06120 Halle, Germany and Minia university, Faculty of Science, Physics Department, P.O. box 61519 Minia (Egypt); Kozlovski, V. V. [St. Petersburg State Polytechnic University, 195251 St. Petersburg (Russian Federation)

    2014-02-21T23:59:59.000Z

    The trapping of positrons by the radiation defects in moderately doped oxygen-lean n-FZ-Si(P) single crystal irradiated with 15 MeV protons has been investigated in a comparative way using the positron lifetime spectroscopy and Hall effect measurements. The experiments were carried out within a wide temperature interval ranging from 25 K – 29 K to 300 K. The positron trapping rate for divacancies was reconstructed in the course of many-stage isochronal annealing. The concentration and the charged states of divacancies (V{sub 2}{sup ?} and V{sub 2}{sup ??}) were estimated. The temperature dependency of the trapping cross section of positrons by the negatively charged divacancies is in a good agreement with the data of calculations based on the assumptions of the cascade phonon-assisted mechanism of exchange of the energy between the positron and acoustic long-wave phonons. Obeying ? T{sup ?3} law, the cross-section of the trapping of positrons by divacancies changes considerably ranging from ?1.7×10{sup ?12} cm{sup 2} (66 – 100 K) to ?2×10{sup ?14} cm{sup 2} (? 250 K). The characteristic length of trapping of the positron by V{sub 2}{sup ??} divacancy was estimated to be l{sub 0}(V{sub 2}{sup ??})?(3.4±0.2)×10{sup ?8} cm.

  6. Measurement of vapor phase mercury emissions at coal-fired power plants using regular and speciating sorbent traps with in-stack and out-of-stack sampling methods

    SciTech Connect (OSTI)

    Chin-Min Cheng; Chien-Wei Chen; Jiashun Zhu; Chin-Wei Chen; Yao-Wen Kuo; Tung-Han Lin; Shu-Hsien Wen; Yong-Siang Zeng; Juei-Chun Liu; Wei-Ping Pan [Western Kentucky University, Bowling Green, KY (United States). Institute for Combustion Science and Environmental Technology

    2009-09-15T23:59:59.000Z

    A systematic investigation of sorbent-trap sampling, which is a method that uses paired sorbent traps to measure total vapor phase mercury (Hg), was carried out at two coal-fired power plants. The objective of the study was to evaluate the effects (if any) on data quality when the following aspects of the sorbent trap method are varied: (a) sorbent trap configuration; (b) sampling time; and (c) analytical technique. Also, the performance of a speciating sorbent trap (i.e., a trap capable of separating elemental Hg from oxidized Hg), was evaluated by direct comparison against the Ontario Hydro (OH) reference method. Flue gas samples were taken using both 'regular' and modified sorbent trap measurement systems. Both short-term (1.5 h) and long-term (18 h to 10 days) samples were collected. The in-stack and out-of-stack sampling methods produced satisfactory relative accuracy results for both the short-term and long-term testing. For the short-term tests, the in-stack sampling results compared more favorably to the OH method than did the out-of-stack results. The relative deviation between the paired traps was considerably higher for the short-term out-of-stack tests than for the long-term tests. A one-way analysis of variance (ANOVA), showed a statistically significant difference (p < 0.1) between the direct combustion and wet-chemistry analytical methods used in the study; the results from the direct combustion method were consistently higher than the wet-chemistry results. The evaluation of the speciating mercury sorbent trap demonstrated that the trap is capable of providing reasonably accurate total mercury concentrations and speciation data that are somewhat comparable to data obtained with the OH method. 5 refs., 4 figs., 8 tabs.

  7. Recent progress in tailoring trap-based positron beams

    SciTech Connect (OSTI)

    Natisin, M. R.; Hurst, N. C.; Danielson, J. R.; Surko, C. M. [Physics Department, University of California, San Diego La Jolla CA 92093-0319 (United States)

    2013-03-19T23:59:59.000Z

    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.

  8. Plasma-beam traps and radiofrequency quadrupole beam coolers

    SciTech Connect (OSTI)

    Maggiore, M., E-mail: mario.maggiore@lnl.infn.it; Cavenago, M.; Comunian, M.; Chirulotto, F.; Galatà, A.; De Lazzari, M.; Porcellato, A. M.; Roncolato, C.; Stark, S. [INFN-LNL, viale dell’Università 2, 35020 Legnaro (Italy)] [INFN-LNL, viale dell’Università 2, 35020 Legnaro (Italy); Caruso, A.; Longhitano, A. [INFN-LNS, via S. Sofia 54, 95123 Catania (Italy)] [INFN-LNS, via S. Sofia 54, 95123 Catania (Italy); Cavaliere, F.; Maero, G.; Paroli, B.; Pozzoli, R.; Romé, M. [INFN Sezione di Milano and Dipartimento di Fisica, Università degli Studi di Milano, via Celoria 16, 20133 Milano (Italy)] [INFN Sezione di Milano and Dipartimento di Fisica, Università degli Studi di Milano, via Celoria 16, 20133 Milano (Italy)

    2014-02-15T23:59:59.000Z

    Two linear trap devices for particle beam manipulation (including emittance reduction, cooling, control of instabilities, dust dynamics, and non-neutral plasmas) are here presented, namely, a radiofrequency quadrupole (RFQ) beam cooler and a compact Penning trap with a dust injector. Both beam dynamics studies by means of dedicated codes including the interaction of the ions with a buffer gas (up to 3 Pa pressure), and the electromagnetic design of the RFQ beam cooler are reported. The compact multipurpose Penning trap is aimed to the study of multispecies charged particle samples, primarily electron beams interacting with a background gas and/or a micrometric dust contaminant. Using a 0.9 T solenoid and an electrode stack where both static and RF electric fields can be applied, both beam transport and confinement operations will be available. The design of the apparatus is presented.

  9. Scalable Digital Hardware for a Trapped Ion Quantum Computer

    E-Print Network [OSTI]

    Mount, Emily; Vrijsen, Geert; Adams, Michael; Baek, So-Young; Hudek, Kai; Isabella, Louis; Crain, Stephen; van Rynbach, Andre; Maunz, Peter; Kim, Jungsang

    2015-01-01T23:59:59.000Z

    Many of the challenges of scaling quantum computer hardware lie at the interface between the qubits and the classical control signals used to manipulate them. Modular ion trap quantum computer architectures address scalability by constructing individual quantum processors interconnected via a network of quantum communication channels. Successful operation of such quantum hardware requires a fully programmable classical control system capable of frequency stabilizing the continuous wave lasers necessary for trapping and cooling the ion qubits, stabilizing the optical frequency combs used to drive logic gate operations on the ion qubits, providing a large number of analog voltage sources to drive the trap electrodes, and a scheme for maintaining phase coherence among all the controllers that manipulate the qubits. In this work, we describe scalable solutions to these hardware development challenges.

  10. & Mechanical Engineering

    E-Print Network [OSTI]

    Zhou, Chongwu

    , robotics, and the development of new tools for integrated approaches to concurrent engineeringAME Aerospace & Mechanical Engineering #12;Aerospace and Mechanical Engineers design complex Engineering (AME) students conduct basic and applied research within and across the usual disciplinary

  11. Narrowing of the coherent population trapping resonance under zone pumping in cells with different characteristics of the wall coating

    SciTech Connect (OSTI)

    Kazakov, G A; Litvinov, A N; Matisov, B G [St. Petersburg State Polytechnic University, St. Petersburg (Russian Federation)

    2012-02-28T23:59:59.000Z

    It is shown that when coherent population trapping (CPT) resonance is excited by a narrow laser beam, the presence of elastic collisions with the cell wall significantly affects the line shape of the CPT-resonance. We have constructed a theoretical model, which is based on averaging over the random Ramsey sequences of the atom dwell time in the beam and dark zones and takes into account the probability of elastic bounce of an atom from the wall.

  12. Ion trapping in the emitter sheath in thermionic converters

    SciTech Connect (OSTI)

    Lundgren, L.

    1985-12-01T23:59:59.000Z

    The effect of ion trapping in the emitter sheath in ignited thermionic converters is studied. The ion trapping prevents the emitter-sheath barrier from being higher than approximately 0.1 eV, when the current decreases in the converter. This gives a condition for the constriction of the arc. I-V curves are calculated for an ignited thermionic converter with a hydrodynamic plasma theory that takes into account the effect of Coulomb scattering and volume recombination, but assumes that the electron temperature is constant in the plasma.

  13. Independent trapping and manipulation of microparticles using dexterous acoustic tweezers

    SciTech Connect (OSTI)

    Courtney, Charles R. P., E-mail: c.r.p.courtney@bath.ac.uk [Department of Mechanical Engineering, University of Bath, Bath (United Kingdom); Demore, Christine E. M.; Wu, Hongxiao; Cochran, Sandy [Institute of Medical Science and Technology, University of Dundee, Dundee (United Kingdom); Grinenko, Alon; Wilcox, Paul D.; Drinkwater, Bruce W. [Department of Mechanical Engineering, University of Bristol, Bristol (United Kingdom)

    2014-04-14T23:59:59.000Z

    An electronically controlled acoustic tweezer was used to demonstrate two acoustic manipulation phenomena: superposition of Bessel functions to allow independent manipulation of multiple particles and the use of higher-order Bessel functions to trap particles in larger regions than is possible with first-order traps. The acoustic tweezers consist of a circular 64-element ultrasonic array operating at 2.35?MHz which generates ultrasonic pressure fields in a millimeter-scale fluid-filled chamber. The manipulation capabilities were demonstrated experimentally with 45 and 90-?m-diameter polystyrene spheres. These capabilities bring the dexterity of acoustic tweezers substantially closer to that of optical tweezers.

  14. Interface-trap charge-pump temperature sensor

    E-Print Network [OSTI]

    Sharifi, Reza

    2001-01-01T23:59:59.000Z

    and connections. If the source is kept at a constant voltage to allow the area underneath the gate to move between inversion and accumulation the following relations must hold: VGP & VFB+ VW Voa ? Vs & Vr (2) Where VFs is flat band voltage, Vr is Threshold... occupied energy level in conduction band corresponds to free electron energy. These two bands are separated by bandgap where traps energy levels are located. The density of traps in the bandgap is a process dependent quality. vo vw Source vs N (well...

  15. Magneto-optical trapping of potassium isotopes

    E-Print Network [OSTI]

    Walker, Thad G.

    managed to fool nearly everyone with outrageous but nearly believable stories. On the more serious side and good spirits have made the past few demanding months of this project much more bearable. Of course, he've thoroughly enjoyed the time spent working with both of these guys in the labs, building and learning. Ren

  16. Recurrent Shocks, Poverty Traps and the Degradation of the Social Capital Base of Pastoralism: A Case Study from Southern Ethiopia

    E-Print Network [OSTI]

    Berhanu, Wassie

    2009-01-01T23:59:59.000Z

    2009 Recurrent Shocks, Poverty Traps and the Degradation of2009) Recurrent Shocks, Poverty Traps and the Degradation ofMay J, 2006. Exploring Poverty Traps and Social Exclusion in

  17. Loading a planar RF Paul Trap from a cold Yb? source

    E-Print Network [OSTI]

    Shields, Brendan John

    2006-01-01T23:59:59.000Z

    In this thesis, we demonstrate a functioning planar radio frequency, three-rod Paul Trap, loaded with Yb+ ions that have been photoionized from a source of neutral atoms, which were cooled in a magneto-optical trap. Planar ...

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

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

    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...

  19. Comparison of traps and baits for censusing small mammals in Neotropical lowlands.

    E-Print Network [OSTI]

    Woodman, Neal; Timm, Robert M.; Slade, Norman A.; Doonan, Terry J.

    1996-02-01T23:59:59.000Z

    Snap-traps, live-traps, and baits affect the ability to capture small mammals, but few previous studies have involved sampling communities of small mammals in tropical environments. We tested differences in captures of small marsupials and rodents...

  20. Solar energy trapping with modulated silicon nanowire photonic crystals Guillaume Demsy and Sajeev John

    E-Print Network [OSTI]

    John, Sajeev

    Solar energy trapping with modulated silicon nanowire photonic crystals Guillaume Demésy and Sajeev://jap.aip.org/about/rights_and_permissions #12;Solar energy trapping with modulated silicon nanowire photonic crystals Guillaume Demesya

  1. Design of superconducting transmission line integrated surface-electrode ion-traps

    E-Print Network [OSTI]

    Meyer, David Thomas

    2011-01-01T23:59:59.000Z

    We fabricated superconducting surface electrode ion traps with integrated microwave coplanar waveguides using direct-write optical lithography and a niobium on sapphire process. We then tested these traps in a closed cycle ...

  2. Trapping capacity of fault zones, downdip Yegua Formation, Texas Gulf Coast basin 

    E-Print Network [OSTI]

    Hintz, Jena Christine

    2001-01-01T23:59:59.000Z

    The homogenization of sediment from shearing forms traps in both the hanging wall and footwall due to capillary pressure differences. The sheared zone associated with large faults can form traps. Sheared zones associated ...

  3. Coronal Trapping of Energetic Flare Particles: Yohkoh/HXT Observations

    E-Print Network [OSTI]

    Metcalf, Thomas R.

    the energization of the solar corona. The most common interpretation for the production of the observed HXR fluxes Alexander Lockheed Martin Solar and Astrophysics Laboratory, Department H1­12, Bldg. 252, 3251 Hanover St in a search for spectral evidence of the coronal trapping of energetic particles during solar flares. Two

  4. Classical thermodynamics of particles in harmonic traps Martin Ligarea

    E-Print Network [OSTI]

    Ligare, Martin

    , and the heat capacities. I also consider cyclic thermodynamic processes in a harmonically confined gas. © 2010 of state for a gas of N noninteract- ing particles in a rigid volume V is derived in almost every text and pressure vary with position within such traps, and the volume of the gas is not well defined

  5. Steam Traps-The Oft Forgotten Energy Conservation Treasure

    E-Print Network [OSTI]

    Pychewicz, F. S.

    on the part of several vendors to design trap internals to our specifications; namely, a thermostatic bellows with a restricted orifice (5/64") and an internal strainer screen. Another criteria was a fail closed design. The vendors primarily feared use...

  6. Progress in year 1995 1. Optically plugged magnetic quadrupole trap

    E-Print Network [OSTI]

    Progress in year 1995 1. Optically plugged magnetic quadrupole trap In 1995, we have demonstrated samples of ultracold atoms at unprecedented densities (>1014 cm-3) and to evaporatively cool atoms to Bose Dressed-StateEnergyMagneticField Atoms During evaporative cooling, the cloud shrunk and finally split up

  7. The TITAN in-trap decay spectroscopy facility at TRIUMF

    E-Print Network [OSTI]

    K. G. Leach; A. Grossheim; A. Lennarz; T. Brunner; J. R. Crespo López-Urrutia; A. T. Gallant; M. Good; R. Klawitter; A. A. Kwiatkowski; T. Ma; T. D. Macdonald; S. Seeraji; M. C. Simon; C. Andreoiu; J. Dilling; D. Frekers

    2014-11-22T23:59:59.000Z

    This article presents an upgraded in-trap decay spectroscopy apparatus which has been developed and constructed for use with TRIUMF's Ion Trap for Atomic and Nuclear science (TITAN). This device consists of an open-access electron-beam ion-trap (EBIT), which is surrounded radially by seven low-energy planar Si(Li) detectors. The environment of the EBIT allows for the detection of low-energy photons by providing backing-free storage of the radioactive ions, while guiding charged decay particles away from the trap centre via the strong (up to 6 T) magnetic field. In addition to excellent ion confinement and storage, the EBIT also provides a venue for performing decay spectroscopy on highly-charged radioactive ions. Recent technical advancements have been able to provide a significant increase in sensitivity for low-energy photon detection, towards the goal of measuring weak electron-capture branching ratios of the intermediate nuclei in the two-neutrino double beta ($2\

  8. Light Trapping in Solar Cells Using Resonant Nanostructures P. Spinelli

    E-Print Network [OSTI]

    van Rooij, Robert

    and by improving their photovoltaic conversion efficiency. For Si solar cells, both challenges can be achievedLight Trapping in Solar Cells Using Resonant Nanostructures P. Spinelli #12;Summary Photovoltaics of energy for our society. In order for this to happen, photovoltaics needs to be economically competitive

  9. Radiation trapping in a cold atomic gas Guillaume Labeyrie,1

    E-Print Network [OSTI]

    field of study deals with the transport of near resonant light in such media. Using cold atoms, one can at the end of the 20th century that studies of light transport in optically thick clouds of cold atomsRadiation trapping in a cold atomic gas Guillaume Labeyrie,1 Robin Kaiser,1, and Dominique Delande

  10. Dielectric nanostructures for broadband light trapping in organic solar cells

    E-Print Network [OSTI]

    Fan, Shanhui

    Dielectric nanostructures for broadband light trapping in organic solar cells Aaswath Raman, Zongfu@stanford.edu Abstract: Organic bulk heterojunction solar cells are a promising candidate for low-cost next lying on top of the organic solar cell stack produce a 8-15% increase in photocurrent for a model

  11. Towards electron-electron entanglement in Penning traps

    E-Print Network [OSTI]

    L. Lamata; D. Porras; J. I. Cirac; J. Goldman; G. Gabrielse

    2010-02-05T23:59:59.000Z

    Entanglement of isolated elementary particles other than photons has not yet been achieved. We show how building blocks demonstrated with one trapped electron might be used to make a model system and method for entangling two electrons. Applications are then considered, including two-qubit gates and more precise quantum metrology protocols.

  12. Theory and Simulation of Neoclassical Transport Processes, with Local Trapping

    E-Print Network [OSTI]

    California at San Diego, University of

    Theory and Simulation of Neoclassical Transport Processes, with Local Trapping Daniel H. E. Dubin of a plasma with static electric and/or magnetic fields are of central importance in plasma theory and experiment. For exam- ple, in the theory of neoclassical transport, a magnetically confined plasma interacts

  13. Quantum energy teleportation with trapped ions

    SciTech Connect (OSTI)

    Hotta, Masahiro [Department of Physics, Faculty of Science, Tohoku University, Sendai 980-8578 (Japan)

    2009-10-15T23:59:59.000Z

    We analyze a protocol of quantum energy teleportation that transports energy from the left edge of a linear ion crystal to the right edge by local operations and classical communication at a speed considerably greater than the speed of a phonon in the crystal. A probe qubit is strongly coupled with phonon fluctuation in the ground state for a short time and it is projectively measured in order to obtain information about this phonon fluctuation. During the measurement process, phonons are excited by the time-dependent measurement interaction and the energy of the excited phonons must be infused from outside the system. The obtained information is transferred to the right edge of the crystal through a classical channel. Even though the phonons excited at the left edge do not arrive at the right edge at the same time as when the information arrives at the right edge, we are able to soon extract energy from the ions at the right edge by using the transferred information. Because the intermediate ions of the crystal are not excited during the execution of the protocol, energy is transmitted in the energy-transfer channel without heat generation.

  14. Quantum Energy Teleportation with Trapped Ions

    E-Print Network [OSTI]

    Masahiro Hotta

    2009-09-30T23:59:59.000Z

    We analyse a protocol of quantum energy teleportation that transports energy from the left edge of a linear ion crystal to the right edge by local operations and classical communication at a speed considerably greater than the speed of a phonon in the crystal. A probe qubit is strongly coupled with phonon fluctuation in the ground state for a short time, and it is projectively measured in order to obtain information about this phonon fluctuation. During the measurement process, phonons are excited by the time-dependent measurement interaction, and the energy of the excited phonons must be infused from outside the system. The obtained information is transferred to the right edge of the crystal through a classical channel. Even though the phonons excited at the left edge do not arrive at the right edge at the same time as when the information arrives at the right edge, we are able to soon extract energy from the ions at the right edge by using the transferred information. Because the intermediate ions of the crystal are not excited during the execution of the protocol, energy is transmitted in the energy transfer channel without heat generation.

  15. Minimal Trap Design Pankaj K. Agarwal, Anne D. Collinsy, and John L. Harerz

    E-Print Network [OSTI]

    Agarwal, Pankaj K.

    ].) Along this track is placed a sequence of obstacles (ramps, wiper blades, traps, etc.) designed to allow

  16. Trap Design for Vibratory Bowl Feeders # RobertPaul Berretty +# Ken Goldberg Mark H. Overmars +

    E-Print Network [OSTI]

    Utrecht, Universiteit

    devices such as wiper blades, grooves and traps. Most of these devices are filters # Research is supported

  17. Trapping and hysteresis in two-phase flow in porous media: A pore-network study

    E-Print Network [OSTI]

    Wildenschild, Dorthe

    of hydrocarbon, and carbon sequestration problems where trap- ping of CO2 leads to safe underground storage. [4

  18. Undrilled shallow giant trap in Denver basin, Colorado: mountain-front thrust

    SciTech Connect (OSTI)

    Jacob, A.F.

    1983-03-01T23:59:59.000Z

    Along the southwestern margin of the Denver basin, Precambrian rocks have been upthrusted at least 15,000 ft (4600 m) in the Front Range and 8000 to 10,000 ft (2400 to 3000 m) or more in the Wet Mountains. Below the Precambrian, the precise configuration of the strata and the faults is unknown because there are no available seismic or drilling data, but reasonable interpretations can be made by analogy with other similar areas. Important reservoirs in the basin are the Permian Lyons Sandstone, the Lower Cretaceous J and D sandstones, and the Upper Cretaceous Codell Sandstone, Niobrara Formation, and Pierre Shale. Directly overlying the J are the major hydrocarbon-source rocks in the basin. Black shale is interstratified with the Lyons Sandstone in at least one drill hole in front of the upthrust. All source rocks probably reached maturity in late Cretaceous time and still are generating today. Below the Precambrian, simple upfolding permits an oil column as much as 5000 ft (1500 m) high, or more, the J, and as much as 4000 ft (1200 m) high, or more, in the Lyons, assuming a fault dip of 70/sup 0/ at depth; lower fault dips permit higher oil columns. Clayey fault gouge, breccia, and minute faulting, in a zone that is in many places hundreds of feet wide at the fault, should be a good hydrocarbon seal, like a cork in a tilted 5000-ft (1500 m) high bottle. If the strata roll over to the west to form a large anticline below the Precambrian, a different kind of trap of very large dimensions would be present. Any kind of trap can extend a combined north-south distance of nearly 65 mi (105 km). Even if roll over is absent and the fault dips steeply, drilling depths to most traps are likely to be only several thousand feet.

  19. Light trapping for emission from a photovoltaic cell under normally incident monochromatic illumination

    SciTech Connect (OSTI)

    Takeda, Yasuhiko, E-mail: takeda@mosk.tytlabs.co.jp; Iizuka, Hideo; Mizuno, Shintaro; Hasegawa, Kazuo; Ichikawa, Tadashi; Ito, Hiroshi; Kajino, Tsutomu [Toyota Central Research and Development Laboratories, Inc., 41-1, Yokomichi, Nagakute, Aichi 480-1192 (Japan); Ichiki, Akihisa; Motohiro, Tomoyoshi [Green Mobility Collaborative Research Center, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601 (Japan)

    2014-09-28T23:59:59.000Z

    We have theoretically demonstrated a new light-trapping mechanism to reduce emission from a photovoltaic (PV) cell used for a monochromatic light source, which improves limiting conversion efficiency determined by the detailed balance. A multilayered bandpass filter formed on the surface of a PV cell has been found to prevent the light generated inside by radiative recombination from escaping the cell, resulting in a remarkable decrease of the effective solid angle for the emission. We have clarified a guide to design a suitable configuration of the bandpass filter and achieved significant reduction of the emission. The resultant gain in monochromatic conversion efficiency in the radiative limit due to the optimally designed 18-layerd bandpass filters is as high as 6% under normally incident 1064?nm illumination of 10 mW/cm{sup 2?}??1?kW/cm{sup 2}, compared with the efficiency for the perfect anti-reflection treatment to the surface of a conventional solar cell.

  20. Characteristics of Pt-K/MgAl2O4 lean NOx trap catalysts. | EMSL

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

    Pt-KMgAl2O4 lean NOx trap catalysts. Characteristics of Pt-KMgAl2O4 lean NOx trap catalysts. Abstract: We report the various characteristics of Pt-KMgAl2O4 lean NOx trap (LNT)...

  1. Note and Record A note on polyvinyl chloride (PVC) pipe traps for

    E-Print Network [OSTI]

    Pretoria, University of

    Note and Record A note on polyvinyl chloride (PVC) pipe traps for sampling vegetation of traditional traps, and many are furtive (Myers et al., 2007; Pittman et al., 2008). PVC pipe traps, which and Hyperolius (see Channing, 2001; du Preez & Carruthers, 2009), may be attracted to artificial refugia of PVC

  2. A Double Ion Trap for Large Coulomb Crystals Caroline Champenois, Jofre Pedregosa-Gutierrez, Mathieu Marciante,

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    : 37.10.Ty; 52.25.Kn;52.27.Jt MULTIPOLE TRAPS Thirty years after Wolfgang Paul's introduction of the 3D, the multipole trap is combined in line with a quadrupole trap, using a shuttling protocol between both parts

  3. DISSERTATION THE EFFECT OF TRAPPING DEFECTS ON CIGS SOLAR-CELL

    E-Print Network [OSTI]

    Sites, James R.

    DISSERTATION THE EFFECT OF TRAPPING DEFECTS ON CIGS SOLAR-CELL PERFORMANCE Submitted by Pamela K ENTITLED THE EFFECT OF TRAPPING DEFECTS ON CIGS SOLAR-CELL PERFORMANCE BE ACCEPTED AS FULFILLING IN PART RE OF DISSERTATION THE EFFECT OF TRAPPING DEFECTS ON CIGS SOLAR-CELL PERFORMANCE The relationship between basic solar-cell

  4. Cooling and Heating of the Quantum Motion of Trapped Cd+ Louis Deslauriers

    E-Print Network [OSTI]

    Monroe, Christopher

    ABSTRACT Cooling and Heating of the Quantum Motion of Trapped Cd+ Ions by Louis Deslauriers Chair information processor has seen tremendous progress in many fields of physics. In the last decade, trapped ions for entanglement generation limiting the fidelity of quantum logic gates. Effective ground state cooling of trapped

  5. Future works The Ion trap -Laser cooling technique has the ad-

    E-Print Network [OSTI]

    Hensinger, Winfried

    Future works The Ion trap - Laser cooling technique has the ad- vantages to easily manipulate apparatus for trace isotope analysis. Guidance of the ion beams to the trap Laser cooling of ions with this apparatus Realization of trapping ions from ICP-MS Optimization of the experimental system for detecting

  6. Angular constraint on light-trapping absorption enhancement in solar cells and Shanhui Fan

    E-Print Network [OSTI]

    Fan, Shanhui

    trapping results in a thinner active region in a solar cell, which lowers the pro- duction cost by reducingAngular constraint on light-trapping absorption enhancement in solar cells Zongfu Yua and Shanhui 2010; accepted 5 December 2010; published online 4 January 2011 Light trapping for solar cells can

  7. Light traps are one of a number of different gears used to sample

    E-Print Network [OSTI]

    438 Light traps are one of a number of different gears used to sample pelagic larval and juvenile fishes. In contrast to conventional towed nets, light traps primarily collect larger size classes and Cowen, 1996; Wilson, 2001). The relative ease with which multiple synoptic light trap samples can

  8. Academy of Natural Sciences An Effective Trapping and Marking Method for Aquatic Beetles

    E-Print Network [OSTI]

    Aiken, Ron

    suffer from one or more deficiencies. Glass bottles are heavy, awkwardto store and subject to vandalismin, Hydradephaga,marking, trapping] The first discussion of bottle traps used to studyaquaticbeetlesin North trapand a varietyof othersam- pling devices used in his studies in California ponds. His bottle trap

  9. FLUCTUATION IN TRAP-NET CATCHES IN THE UPPER MISSISSIPPI RIVER

    E-Print Network [OSTI]

    FLUCTUATION IN TRAP-NET CATCHES IN THE UPPER MISSISSIPPI RIVER if; Marine Biological LabofdiuryKay, Secretary Fish and Wildlife Service, Albert M. Day, Director FLUCTUATION IN TRAP NET CATCHES IN THE UPPER Gear used 3 Methods 5 Statistical considerations 5 Season trends in catch of trap nets 6 Black crappie

  10. Efficient Dynamic Contracts: Enabling A Poor borrower To Get Out of Poverty Trap

    E-Print Network [OSTI]

    Bandyopadhyay, Antar

    of poverty trap is synonymous to getting loan from the formal sector. The MFI discipline the borrower to saveEfficient Dynamic Contracts: Enabling A Poor borrower To Get Out of Poverty Trap Dyotona Dasgupta, New Delhi 110016, India Keywords: Dynamic Contracts, Progressive Lending, Collateral, Poverty Trap

  11. With Exhaustible Resources, Can A Developing Country Escape From The Poverty Trap?

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    With Exhaustible Resources, Can A Developing Country Escape From The Poverty Trap? Cuong Le Van is convex-concave, so that the economy may be locked into a poverty trap. We show that the extent to which the country will escape from the poverty trap depends, besides the interactions between its technology and its

  12. The Impact of Simple Institutions in Experimental Economies with Poverty Traps

    E-Print Network [OSTI]

    Greer, Julia R.

    The Impact of Simple Institutions in Experimental Economies with Poverty Traps C. Mónica Capra a threshold. The threshold externality generates two equilibria--a suboptimal "poverty trap" and an optimal typically sink into the poverty trap and the optimal equilibrium is never reached. However, the ability

  13. Simulation of diffusion and trapping in digitized heterogeneous media David A. Coke@ and Salvatore Torquatob)

    E-Print Network [OSTI]

    Torquato, Salvatore

    Simulation of diffusion and trapping in digitized heterogeneous media David A. Coke@ and Salvatore of a Brownian particle diffusing among a, digitized lattice-based domain of traps. Following the first, the inverse of the trapping rate, is obtained for a variety of configurations involving digitized spheres

  14. Laser Stabilization for Quantum Computing with Trapped Barium ions Corey Adams

    E-Print Network [OSTI]

    Blinov, Boris

    system used to trap and cool Ba+ ions used for quantum computation research. The lasers, at 650 and 985 perform ex- periments, including trapping ions themselves. A trap works using both a laser cooling system in the cooling system is important to its success. A proposed method to stabilize lasers is to use an external

  15. Electronic quantum effects mapped onto non-Born-Oppenheimer nuclear paths: Nonclassical surmounting over potential barriers and trapping above the transition states due to nonadiabatic path-branching

    SciTech Connect (OSTI)

    Yamamoto, Kentaro, E-mail: kyamamoto@mns2.c.u-tokyo.ac.jp; Takatsuka, Kazuo, E-mail: kaztak@mns2.c.u-tokyo.ac.jp [Department of Basic Science, The University of Tokyo, Komaba, 153-8902 Tokyo (Japan)] [Department of Basic Science, The University of Tokyo, Komaba, 153-8902 Tokyo (Japan)

    2014-03-28T23:59:59.000Z

    We develop the path-branching representation for nonadiabatic electron wavepacket dynamics [T. Yonehara and K. Takatsuka, J. Chem. Phys. 132, 244102 (2010)] so as to treat dynamics in an energy range comparable to the barrier height of adiabatic potential energy curves. With this representation two characteristic chemical reaction dynamics are studied, in which an incident nuclear wavepacket encounters a potential barrier, on top of which lies another nonadiabatically coupled adiabatic potential curve: (1) Dynamics of initial paths coming into the nonadiabatic interaction region with energy lower than the barrier height. They branch into two pieces (and repeat branching subsequently), the upper counterparts of which can penetrate into a classically inaccessible high energy region and eventually branch back to the product region on the ground state curve. This is so to say surmounting the potential barrier via nonadiabatically coupled excited state, and phenomenologically looks like the so-called deep tunneling. (2) Dynamics of classical paths whose initial energies are a little higher than the barrier but may be lower than the bottom of the excited state. They can undergo branching and some of those components are trapped on top of the potential barrier, being followed by the population decay down to the lower state flowing both to product and reactant sites. Such expectations arising from the path-branching representation are numerically confirmed with full quantum mechanical wavepacket dynamics. This phenomenon may be experimentally observed as time-delayed pulses of wavepacket trains.

  16. Mechanism of Gravity Impulse

    E-Print Network [OSTI]

    Ning Wu

    2005-10-01T23:59:59.000Z

    It is well-known that energy-momentum is the source of gravitational field. For a long time, it is generally believed that only stars with huge masses can generate strong gravitational field. Based on the unified theory of gravitational interactions and electromagnetic interactions, a new mechanism of the generation of gravitational field is studied. According to this mechanism, in some special conditions, electromagnetic energy can be directly converted into gravitational energy, and strong gravitational field can be generated without massive stars. Gravity impulse found in experiments is generated by this mechanism.

  17. Quantum Energy Teleportation with Trapped Ions

    E-Print Network [OSTI]

    Hotta, Masahiro

    2009-01-01T23:59:59.000Z

    We analyze a protocol of quantum energy teleportation that transports energy from the left edge of a linear ion crystal to the right edge by local operations and classical communication at a speed much higher than the speed of the phonon in the crystal. A probe qubit is strongly coupled with the phonon fluctuation in the ground state during short time and is projectively measured in order to get information about this phonon fluctuation. During the measurement process, phonons are excited by the time-dependent measurement interaction and energy of the excited phonons must be infused from outside the system. The obtained information is announced to the right edge of the crystal through a classical channel. Even though the phonons excited at the left edge do not arrive at the right edge yet when the information arrives at the right edge, we are able to soon extract energy from the ion at the right edge by using the announced information. Because the intermediate ions of the crystal are not excited during the ex...

  18. EFFECT OF FILTER TEMPERATURE ON TRAPPING ZINC VAPOR

    SciTech Connect (OSTI)

    Korinko, P.

    2011-03-25T23:59:59.000Z

    To address the {sup 65}Zn contamination issue in the TEF, a multi-task experimental program was initiated. The first experimental task was completed and is reported in Ref. 1. The results of the second experimental task are reported here. This task examined the effect of filter temperature on trapping efficiency and deposit morphology. Based on the first experimental tasks that examined filter pore size and trapping efficiency, stainless steel filter media with a 20 {micro}m pore size was selected. A series of experiments using these filters was conducted during this second task to determine the effect of filter temperature on zinc vapor trapping efficiency, adhesion and morphology. The tests were conducted with the filters heated to 60, 120, and 200 C; the zinc source material was heated to 400 C for all the experiments to provide a consistent zinc source. The samples were evaluated for mass change, deposit adhesion and morphology. As expected from the physical vapor deposition literature, a difference in deposit morphology and appearance was observed between the three filter temperatures. The filter held at 60 C had the largest average mass gain while the 120 and 200 C filters exhibited similar but lower weight gains. The standard deviations were large and suggest that all three temperatures exhibited comparable gains. No zinc was detected on the backside surface of the filters indicating high efficiency for front and internal trapping. A zinc rich deposit was formed on the surface of the 60 C filter. Based on a simple tape adhesion test, the surface zinc was readily removed from the 60 C filter while less zinc deposit was removed from the 120 and 200 C filter samples. It is surmised that the higher temperatures enable the zinc to deposit within the filter media rather than on the surface. Based on the findings that all three statistically trapped the same quantity of zinc vapor and that the higher temperatures resulted in a more adherent/better trapped product, operating the filters at 120 to 200 C is recommended.

  19. Hydrocarbon trapping mechanisms in the Miller Creek area of the Powder River Basin, Wyoming

    E-Print Network [OSTI]

    Armstrong, Jennifer Ann

    1975-01-01T23:59:59.000Z

    production comes from Lower Cretaceous and Lower Permian sandstones. The horison studied, the Lower Cretaceous Dakota Sandstone, is a thin clastic wedge deposited during the initial Cretaceous transgression oi' the Artie Ocean - Gulf of Mexico seaway over... for the channels end orobable Recerwoir Trigood Lucerne 3 32-AN-66W Regional Pet Inc Corda%1 F-1 9-AN-68M SP -10~ 0 oem-m 50 0 oh'-m SP -10+ 6' 5900 Figure 3, Rlectric Log Profiles of Regional and Reservoir Dakota Sandstones. 10 I Q MILLER CREEK...

  20. Mechanisms for Fluorescence Blinking and Charge Carrier Trapping in Single Semiconductor Nanocrystals

    E-Print Network [OSTI]

    Cordones, Amy Ashbrook

    2012-01-01T23:59:59.000Z

    photovoltaics and higher radiative recombination efficienciesfor example, in photovoltaics) or the high efficiency ofefficiencies much lower than is theorized for nanocrystal-based photovoltaics,

  1. Investigation of Aging Mechanisms in Lean NOx Traps | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't YourTransport(FactDepartment ofLetter Report: I11IG002 Investigation Letter

  2. Investigation of Aging Mechanisms in Lean NOx Traps | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't YourTransport(FactDepartment ofLetter Report: I11IG002 Investigation Letter2009 DOE Hydrogen

  3. Thermal Deactivation Mechanisms of Fully-Formed Lean NOx Trap Catalysts

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn'tOriginEducationVideoStrategic|Industrial Sector,Department of Energy (DOE) notice )Code

  4. Measurement of the beta-neutrino correlation in laser trapped {sup 21}Na

    SciTech Connect (OSTI)

    Scielzo, Nicholas David

    2003-06-01T23:59:59.000Z

    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.

  5. A comb-sampling method for enhanced mass analysis in linear electrostatic ion traps

    SciTech Connect (OSTI)

    Greenwood, J. B.; Kelly, O.; Calvert, C. R.; Duffy, M. J.; King, R. B.; Belshaw, L.; Graham, L.; Alexander, J. D.; Williams, I. D. [Centre for Plasma Physics, School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN (United Kingdom); Bryan, W. A. [Department of Physics, Swansea University, Swansea SA2 8PP (United Kingdom); Turcu, I. C. E.; Cacho, C. M.; Springate, E. [Central Laser Facility, STFC Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0QX (United Kingdom)

    2011-04-15T23:59:59.000Z

    In this paper an algorithm for extracting spectral information from signals containing a series of narrow periodic impulses is presented. Such signals can typically be acquired by pickup detectors from the image-charge of ion bunches oscillating in a linear electrostatic ion trap, where frequency analysis provides a scheme for high-resolution mass spectrometry. To provide an improved technique for such frequency analysis, we introduce the CHIMERA algorithm (Comb-sampling for High-resolution IMpulse-train frequency ExtRAaction). This algorithm utilizes a comb function to generate frequency coefficients, rather than using sinusoids via a Fourier transform, since the comb provides a superior match to the data. This new technique is developed theoretically, applied to synthetic data, and then used to perform high resolution mass spectrometry on real data from an ion trap. If the ions are generated at a localized point in time and space, and the data is simultaneously acquired with multiple pickup rings, the method is shown to be a significant improvement on Fourier analysis. The mass spectra generated typically have an order of magnitude higher resolution compared with that obtained from fundamental Fourier frequencies, and are absent of large contributions from harmonic frequency components.

  6. Fabrication and heating rate study of microscopic surface electrode ion traps

    E-Print Network [OSTI]

    N. Daniilidis; S. Narayanan; S. A. Möller; R. Clark; T. E. Lee; P. J. Leek; A. Wallraff; St. Schulz; F. Schmidt-Kaler; H. Häffner

    2010-09-15T23:59:59.000Z

    We report heating rate measurements in a microfabricated gold-on-sapphire surface electrode ion trap with trapping height of approximately 240 micron. Using the Doppler recooling method, we characterize the trap heating rates over an extended region of the trap. The noise spectral density of the trap falls in the range of noise spectra reported in ion traps at room temperature. We find that during the first months of operation the heating rates increase by approximately one order of magnitude. The increase in heating rates is largest in the ion loading region of the trap, providing a strong hint that surface contamination plays a major role for excessive heating rates. We discuss data found in the literature and possible relation of anomalous heating to sources of noise and dissipation in other systems, namely impurity atoms adsorbed on metal surfaces and amorphous dielectrics.

  7. Injection of CO2 with H2S and SO2 and Subsequent Mineral Trapping in Sandstone-Shale Formation

    SciTech Connect (OSTI)

    Xu, Tianfu; Apps, John A.; Pruess, Karsten; Yamamoto, Hajime

    2004-09-07T23:59:59.000Z

    Carbon dioxide (CO{sub 2}) injection into deep geologic formations can potentially reduce atmospheric emissions of greenhouse gases. Sequestering less-pure CO{sub 2} waste streams (containing H{sub 2}S and/or SO{sub 2}) would be less expensive or would require less energy than separating CO{sub 2} from flue gas or a coal gasification process. The long-term interaction of these injected acid gases with shale-confining layers of a sandstone injection zone has not been well investigated. We therefore have developed a conceptual model of injection of CO{sub 2} with H{sub 2}S and/or SO{sub 2} into a sandstone-shale sequence, using hydrogeologic properties and mineral compositions commonly encountered in Gulf Coast sediments of the United States. We have performed numerical simulations of a 1-D radial well region considering sandstone alone and a 2-D model using a sandstone-shale sequence under acid-gas injection conditions. Results indicate that shale plays a limited role in mineral alteration and sequestration of gases within a sandstone horizon for short time periods (10,000 years in present simulations). The co-injection of SO{sub 2} results in different pH distribution, mineral alteration patterns, and CO{sub 2} mineral sequestration than the co-injection of H{sub 2}S or injection of CO{sub 2} alone. Simulations generate a zonal distribution of mineral alteration and formation of carbon and sulfur trapping minerals that depends on the pH distribution. The co-injection of SO{sub 2} results in a larger and stronger acidified zone close to the well. Precipitation of carbon trapping minerals occurs within the higher pH regions beyond the acidified zones. In contrast, sulfur trapping minerals are stable at low pH ranges (below 5) within the front of the acidified zone. Corrosion and well abandonment due to the co-injection of SO{sub 2} could be important issues. Significant CO{sub 2} is sequestered in ankerite and dawsonite, and some in siderite. The CO{sub 2} mineral-trapping capability can reach 80 kg per cubic meter of medium. Most sulfur is trapped through alunite precipitation, although some is trapped by anhydrite precipitation and minor amount of pyrite. The addition of the acid gases and induced mineral alteration result in changes in porosity. The limited information currently available on the mineralogy of natural high-pressure acid-gas reservoirs is generally consistent with our simulations.

  8. Scattering of short laser pulses from trapped fermions

    E-Print Network [OSTI]

    T. Wong; Ozgur Mustecaplioglu; L. You; M. Lewenstein

    2000-03-28T23:59:59.000Z

    We investigate the scattering of intense short laser pulses off trapped cold fermionic atoms. We discuss the sensitivity of the scattered light to the quantum statistics of the atoms. The temperature dependence of the scattered light spectrum is calculated. Comparisons are made with a system of classical atoms who obey Maxwell-Boltzmann statistics. We find the total scattering increases as the fermions become cooler but eventually tails off at very low temperatures (far below the Fermi temperature). At these low temperatures the fermionic degeneracy plays an important role in the scattering as it inhibits spontaneous emission into occupied energy levels below the Fermi surface. We demonstrate temperature dependent qualitative changes in the differential and total spectrum can be utilized to probe quantum degeneracy of trapped Fermi gas when the total number of atoms are sufficiently large $(\\geq 10^6)$. At smaller number of atoms, incoherent scattering dominates and it displays weak temperature dependence.

  9. Jaynes-Cummings Models with trapped electrons on liquid Helium

    E-Print Network [OSTI]

    Miao Zhang; H. Y. Jia; L. F. Wei

    2009-09-01T23:59:59.000Z

    Jaynes-Cummings model is a typical model in quantum optics and has been realized with various physical systems (e.g, cavity QED, trapped ions, and circuit QED etc..) of two-level atoms interacting with quantized bosonic fields. Here, we propose a new implementation of this model by using a single classical laser beam to drive an electron floating on liquid Helium. Two lowest levels of the {\\it vertical} motion of the electron acts as a two-level "atom", and the quantized vibration of the electron along one of the {\\it parallel} directions, e.g., $x$-direction, serves the bosonic mode. These two degrees of freedom of the trapped electron can be coupled together by using a classical laser field. If the frequencies of the applied laser fields are properly set, the desirable Jaynes-Cummings models could be effectively realized.

  10. Precise determination of micromotion for trapped-ion optical clocks

    E-Print Network [OSTI]

    Keller, J; Burgermeister, T; Mehlstäubler, T E

    2015-01-01T23:59:59.000Z

    As relative systematic frequency uncertainties in trapped-ion spectroscopy are approaching the low 10^{-18} range, motional frequency shifts account for a considerable fraction of the uncertainty budget. Micromotion, a driven motion fundamentally connected to the principle of the Paul trap, is a particular concern in these systems. In this article, we experimentally investigate at this level three common methods for minimizing and determining the micromotion amplitude. We develop a generalized model for a quantitative application of the photon-correlation technique, which is applicable in the commonly encountered regime where the transition linewidth is comparable to the rf drive frequency. We show that a fractional frequency uncertainty due to the 2nd-order Doppler shift below 1 x 10^{-20} can be achieved. The quantitative evaluation is verified in an interleaved measurement with the conceptually simpler resolved sideband method. If not performed deep within the Lamb-Dicke regime, a temperature-dependent off...

  11. Passive regeneration of catalyst coated knitted fiber diesel particulate traps

    SciTech Connect (OSTI)

    Mayer, A.; Emig, G.; Gmehling, B.; Popovska, N.; Hoelemann, K.; Buck, A.

    1996-09-01T23:59:59.000Z

    Knitted fiber particulate traps facilitate deep-bed structures. These have excellent filtration properties, particularly for ultra-fine particulates. They are also suitable as substrate for catalytic processes. The two characteristics are: high total surface area of the filaments, and good mass transfer. These are prerequisites for intense catalytic activity. The deposited soot is uniformly distributed. Therefore, temperature peaks are avoided during regeneration. The tested coatings lower the regeneration temperature by about 200 C to burn-off temperatures below 350 C. Further improvements seem attainable. Thus, a purely passive regeneration appears feasible for most applications. The system is autonomous and cost effective. However, in extreme low load situations, e.g. city bus services, the necessary exhaust temperatures are not attained. Hence, burners or electrical heating is necessary for trap regeneration. Nevertheless, catalytic coating is attractive for substantially reducing the regeneration energy requirements.

  12. Adiabatic trapping in coupled kinetic Alfven-acoustic waves

    SciTech Connect (OSTI)

    Shah, H. A.; Ali, Z. [Department of Physics, G.C. University, 54000 Lahore (Pakistan); Masood, W. [COMSATS, Institute of Information Technology, Park Road, Chak Shahzad, Islamabad 44000 (Pakistan); National Centre for Physics (NCP), Shahdara Valley Road, 44000 Islamabad (Pakistan); Theoretical Plasma Physics Division, P. O. Nilore, Islamabad (Pakistan)

    2013-03-15T23:59:59.000Z

    In the present work, we have discussed the effects of adiabatic trapping of electrons on obliquely propagating Alfven waves in a low {beta} plasma. Using the two potential theory and employing the Sagdeev potential approach, we have investigated the existence of arbitrary amplitude coupled kinetic Alfven-acoustic solitary waves in both the sub and super Alfvenic cases. The results obtained have been analyzed and presented graphically and can be applied to regions of space where the low {beta} assumption holds true.

  13. Selection, Sizing, and Testing of Stream Traps in Commercial Buildings

    E-Print Network [OSTI]

    Armer, A.; Risko, J. R.

    1984-01-01T23:59:59.000Z

    Pressure tow and Medium Pressure Unit Heaters Slerilirers Autoclaves Dryers FIRST CHOICE Thermo-Matic Thermostatic Float-and-Thermostatic Float-and-Thermostatic Thermo-Matic Thcrmostalic Thermo-Matic Thermostatic Thermo-Dynamic Float...-and-Thermostatic Float-and-Thermostar ic Thcrmo-Dynamic Thermo-Dynamic Bimetallic Balanced Pressure Thermostatic Balanced-Pressure Thermostatic Platen Presses I L NOTE: Unusual operating conditions, or severe corrosion may influence the choice of a steam trap...

  14. Collective coherent population trapping in a thermal field

    E-Print Network [OSTI]

    M. Macovei; Z. Ficek; C. H. Keitel

    2006-06-01T23:59:59.000Z

    We analyzed the efficiency of coherent population trapping (CPT) in a superposition of the ground states of three-level atoms under the influence of the decoherence process induced by a broadband thermal field. We showed that in a single atom there is no perfect CPT when the atomic transitions are affected by the thermal field. The perfect CPT may occur when only one of the two atomic transitions is affected by the thermal field. In the case when both atomic transitions are affected by the thermal field, we demonstrated that regardless of the intensity of the thermal field the destructive effect on the CPT can be circumvented by the collective behavior of the atoms. An analytic expression was obtained for the populations of the upper atomic levels which can be considered as a measure of the level of thermal decoherence. The results show that the collective interaction between the atoms can significantly enhance the population trapping in that the population of the upper state decreases with increased number of atoms. The physical origin of this feature was explained by the semiclassical dressed atom model of the system. We introduced the concept of multiatom collective coherent population trapping by demonstrating the existence of collective (entangled) states whose storage capacity is larger than that of the equivalent states of independent atoms.

  15. Production trap improvements using high-efficiency internals

    SciTech Connect (OSTI)

    Delavan, D.P.; Wilson, T.T.

    1995-10-01T23:59:59.000Z

    Most of the Gas-Oil Separation Plants (GOSP) in Southern Area Producing of Saudi Aramco will be producing between 40% and 75% water cuts by the turn of the century. Many GOSPs will be producing more than twice the amount of water they were originally designed for. Consequently, modifications must be made to the GOSPs so that they will have the capacity to separate and clean up these large volumes of produced water. The most attractive option is to improve the separation efficiency of the High Pressure Production Traps (HPPT) where formation water is first removed from the wellhead fluid. These traps have historically removed very little water from the wellhead fluid. However, the following modifications have proven to significantly improve the separation efficiency of the traps: double the height of the weir, and raise the oil level from 40% to 65% full; install a new inlet device to minimize the formation of foam; install coalescing and foam-breaking internals to enhance oil/water coalescing and separation and to break the foam on top of the oil layer.

  16. FORMATION OF PLANETARY CORES AT TYPE I MIGRATION TRAPS

    SciTech Connect (OSTI)

    Sandor, Zsolt; Dullemond, Cornelis P. [Max Planck Research Group, Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, 69117 Heidelberg (Germany); Lyra, Wladimir, E-mail: sandor@mpia.de [Department of Astrophysics, American Museum of Natural History, 79th Street at Central Park West, New York, NY 10024 (United States)

    2011-02-10T23:59:59.000Z

    One of the long-standing unsolved problems of planet formation is how solid bodies of a few decimeters in size can 'stick' to form large planetesimals. This is known as the 'meter-size barrier'. In recent years, it has become increasingly clear that some form of 'particle trapping' must have played a role in overcoming the meter-size barrier. Particles can be trapped in long-lived local pressure maxima, such as those in anticyclonic vortices, zonal flows, or those believed to occur near ice lines or at dead zone boundaries. Such pressure traps are the ideal sites for the formation of planetesimals and small planetary embryos. Moreover, they likely produce large quantities of such bodies in a small region, making it likely that subsequent N-body evolution may lead to even larger planetary embryos. The goal of this Letter is to show that this indeed happens, and to study how efficient it is. In particular, we wish to find out if rocky/icy bodies as large as 10 M{sub +} can form within 1 Myr, since such bodies are the precursors of gas giant planets in the core accretion scenario.

  17. Single microbe trap and release in sub-microfluidics

    SciTech Connect (OSTI)

    Vasdekis, Andreas E.

    2013-05-08T23:59:59.000Z

    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.

  18. Mechanical & Aerospace Engineering

    E-Print Network [OSTI]

    implementation of predictive methods in commercial, numerical codes. Finally, opportunities for students University in 2007. During this time, he has been elected to several leadership positions within the ASME, including as the secretary of the ASME Research Committee on the Mechanics of Jointed Structures, he has

  19. Consequences of three-dimensional physical and electromagnetic structures on dust particle trapping in high plasma density

    E-Print Network [OSTI]

    Kushner, Mark

    gradients are present, which introduce fluid drag and thermophoretic forces, dust particle traps may

  20. Kinetic and Performance Studies of the Regeneration Phase of Model Pt/Ba/Rh NOx Traps for Design and Optimization

    SciTech Connect (OSTI)

    Michael Harold; Vemuri Balakotaiah

    2010-05-31T23:59:59.000Z

    In this project a combined experimental and theoretical approach was taken to advance our understanding of lean NOx trap (LNT) technology. Fundamental kinetics studies were carried out of model LNT catalysts containing variable loadings of precious metals (Pt, Rh), and storage components (BaO, CeO{sub 2}). The Temporal Analysis of Products (TAP) reactor provided transient data under well-characterized conditions for both powder and monolith catalysts, enabling the identification of key reaction pathways and estimation of the corresponding kinetic parameters. The performance of model NOx storage and reduction (NSR) monolith catalysts were evaluated in a bench scale NOx trap using synthetic exhaust, with attention placed on the effect of the pulse timing and composition on the instantaneous and cycle-averaged product distributions. From these experiments we formulated a global model that predicts the main spatio-temporal features of the LNT and a mechanistic-based microkinetic models that incorporates a detailed understanding of the chemistry and predicts more detailed selectivity features of the LNT. The NOx trap models were used to determine its ability to simulate bench-scale data and ultimately to evaluate alternative LNT designs and operating strategies. The four-year project led to the training of several doctoral students and the dissemination of the findings as 47 presentations in conferences, catalysis societies, and academic departments as well 23 manuscripts in peer-reviewed journals. A condensed review of NOx storage and reduction was published in an encyclopedia of technology.

  1. Time reversal in thermoacoustic tomography - an error estimate

    E-Print Network [OSTI]

    Hristova, Yulia

    2008-01-01T23:59:59.000Z

    The time reversal method in thermoacoustic tomography is used for approximating the initial pressure inside a biological object using measurements of the pressure wave made outside the object. This article presents error estimates for the time reversal method in the cases of variable, non-trapping sound speeds.

  2. Capillary exit pressure as a basin sealing mechanism

    SciTech Connect (OSTI)

    Shosa, J.; Cathles, L. [Cornell Univ., Ithaca, NY (United States)

    1996-12-31T23:59:59.000Z

    Abnormally pressured compartments in sedimentary basins require an efficient sealing mechanism. Most sealing mechanisms rely on either intrinsically low formation permeabilities or on the entry pressure of a non-aqueous phase into a fine-grained unit. However, the nanodarcy permeabilities required to maintain overpressures over significant geologic time are not plausible over wide areas. Entry pressures, while effective in trapping a non-aqueous phase in a local reservoir, can not prevent leakage where the non-aqueous phase is not ponded against the seal. The capillary exit pressure required to displace water from a fine-grained formation into a coarse-grained formation which contains a non-aqueous phase provides an alternative sealing mechanism. Capillary exit pressure seals require contrasts in grain size and the presence of two phases in the coarse-grained unit, but do not require 100% saturation of the non-aqueous phase. These conditions can exist on all sides of a pressure compartment, and can account for sealing on the top, bottom, and sides of a compartment. We have shown in the laboratory that capillary exit pressure seals under reservoir conditions allow no fluid flow across the seal until a threshold pressure is exceeded (e.g., the seat is not a relative permeability effect) and that exit pressures are additive over a series of fine/coarse interfaces. Capillary exit pressure seals can maintain the abnormal pressures observed in the South Eugene Island Block 330 field. Both a sufficient number of sand/shale layers and a gas phase are present in the pressure transition zone there. We believe capillary exit pressure seals are a general feature of sedimentary basins and are important in controlling large scale fluid flow.

  3. Capillary exit pressure as a basin sealing mechanism

    SciTech Connect (OSTI)

    Shosa, J.; Cathles, L. (Cornell Univ., Ithaca, NY (United States))

    1996-01-01T23:59:59.000Z

    Abnormally pressured compartments in sedimentary basins require an efficient sealing mechanism. Most sealing mechanisms rely on either intrinsically low formation permeabilities or on the entry pressure of a non-aqueous phase into a fine-grained unit. However, the nanodarcy permeabilities required to maintain overpressures over significant geologic time are not plausible over wide areas. Entry pressures, while effective in trapping a non-aqueous phase in a local reservoir, can not prevent leakage where the non-aqueous phase is not ponded against the seal. The capillary exit pressure required to displace water from a fine-grained formation into a coarse-grained formation which contains a non-aqueous phase provides an alternative sealing mechanism. Capillary exit pressure seals require contrasts in grain size and the presence of two phases in the coarse-grained unit, but do not require 100% saturation of the non-aqueous phase. These conditions can exist on all sides of a pressure compartment, and can account for sealing on the top, bottom, and sides of a compartment. We have shown in the laboratory that capillary exit pressure seals under reservoir conditions allow no fluid flow across the seal until a threshold pressure is exceeded (e.g., the seat is not a relative permeability effect) and that exit pressures are additive over a series of fine/coarse interfaces. Capillary exit pressure seals can maintain the abnormal pressures observed in the South Eugene Island Block 330 field. Both a sufficient number of sand/shale layers and a gas phase are present in the pressure transition zone there. We believe capillary exit pressure seals are a general feature of sedimentary basins and are important in controlling large scale fluid flow.

  4. Velocity tuning of friction with two trapped atoms

    E-Print Network [OSTI]

    Gangloff, Dorian; Counts, Ian; Jhe, Wonho; Vuleti?, Vladan

    2015-01-01T23:59:59.000Z

    Friction is the basic, ubiquitous mechanical interaction between two surfaces that results in resistance to motion and energy dissipation. In spite of its technological and economic significance, our ability to control friction remains modest, and our understanding of the microscopic processes incomplete. At the atomic scale, mismatch between the two contacting crystal lattices can lead to a reduction of stick-slip friction (structural lubricity), while thermally activated atomic motion can give rise to a complex velocity dependence, and nearly vanishing friction at sufficiently low velocities (thermal lubricity). Atomic force microscopy has provided a wealth of experimental results, but limitations in the dynamic range, time resolution, and control at the single-atom level have hampered a full quantitative description from first principles. Here, using an ion-crystal friction emulator with single-atom, single substrate-site spatial resolution and single-slip temporal resolution, we measure the friction force...

  5. Long-time evolution of sequestered CO$_2$ in porous media

    E-Print Network [OSTI]

    Cohen, Yossi

    2014-01-01T23:59:59.000Z

    CO$_2$ sequestration in subsurface reservoirs is important for limiting atmospheric CO$_2$ concentrations. However, a complete physical picture able to predict the structure developing within the porous medium is lacking. We investigate theoretically reactive transport in the long-time evolution of carbon in the brine-rock environment. As CO$_2$ is injected into a brine-rock environment, a carbonate-rich region is created amid brine. Within the carbonate-rich region minerals dissolve and migrate from regions of high concentration to low concentration, along with other dissolved carbonate species. This causes mineral precipitation at the interface between the two regions. We argue that precipitation in a small layer reduces diffusivity, and eventually causes mechanical trapping of the CO$_2$. Consequently, only a small fraction of the CO$_2$ is converted to solid mineral; the remainder either dissolves in water or is trapped in its original form. We also study the case of a pure CO$_2$ bubble surrounded by bri...

  6. Precision lifetime measurements of a single trapped ion with ultrafast laser pulses

    E-Print Network [OSTI]

    D. L. Moehring; B. B. Blinov; D. W. Gidley; R. N. Kohn Jr.; M. J. Madsen; T. D. Sanderson; R. S. Vallery; C. Monroe

    2005-05-15T23:59:59.000Z

    We report precision measurements of the excited state lifetime of the $5p$ $^2P_{1/2}$ and $5p$ $^2P_{3/2}$ levels of a single trapped Cd$^+$ ion. The ion is excited with picosecond laser pulses from a mode-locked laser and the distribution of arrival times of spontaneously emitted photons is recorded. The resulting lifetimes are 3.148 $\\pm$ 0.011 ns and 2.647 $\\pm$ 0.010 ns for $^2P_{1/2}$ and $^2P_{3/2}$ respectively. With a total uncertainty of under 0.4%, these are among the most precise measurements of any atomic state lifetimes to date.

  7. Fast nondestructive temperature measurement of two-electron atoms in a magneto-optical trap

    SciTech Connect (OSTI)

    Cristiani, Matteo; Valenzuela, Tristan; Gothe, Hannes; Eschner, Juergen [ICFO-Institut de Ciencies Fotoniques, Mediterranean Technology Park, E-08860 Castelldefels (Barcelona) (Spain)

    2010-06-15T23:59:59.000Z

    We extend the technique originally proposed by [Honda et al., Phys. Rev. A 59, R934 (1999)] to measure the temperature of ytterbium and alkaline-earth-metal atoms confined in a magneto-optical trap (MOT). The method is based on the analysis of excitation spectra obtained by probing the {sup 1}S{sub 0}{yields}{sup 3}P{sub 1} intercombination line. Thanks to a careful analysis and modeling of the effects caused by the MOT light on the probe transition we overcome the resolution and precision limits encountered in previous works. Ground-state light shift and Rabi broadening are measured and successfully compared with calculated values. This knowledge allows us to properly extract the Doppler contribution to the linewidth, thus obtaining a reliable measurement of the cloud temperature. We finally show how spectroscopy on free-falling atoms provides an alternative method to determine the sample temperature which resembles the standard time-of-flight technique.

  8. Spectroscopy of Charge Carriers and Traps in Field-Doped Organic Semiconductors

    SciTech Connect (OSTI)

    Zhu, Xiaoyang; Frisbie, C Daniel

    2012-08-13T23:59:59.000Z

    This research project aims to achieve quantitative and molecular level understanding of charge carriers and traps in field-doped organic semiconductors via in situ optical absorption spectroscopy, in conjunction with time-resolved electrical measurements. During the funding period, we have made major progress in three general areas: (1) probed charge injection at the interface between a polymeric semiconductor and a polymer electrolyte dielectric and developed a thermodynamic model to quantitatively describe the transition from electrostatic to electrochemical doping; (2) developed vibrational Stark effect to probe electric field at buried organic semiconductor interfaces; (3) used displacement current measurement (DCM) to study charge transport at organic/dielectric interfaces and charge injection at metal/organic interfaces.

  9. Observation of a single-beam gradient force acoustical trap for elastic particles: acoustical tweezers

    E-Print Network [OSTI]

    Baresch, Diego; Marchiano, Régis

    2014-01-01T23:59:59.000Z

    The ability to manipulate matter precisely is critical for the study and development of a large variety of systems. Optical tweezers are excellent tools to handle particles ranging in size from a few micrometers to hundreds of nanometers but become inefficient and damaging on larger objects. We demonstrate for the first reported time the trapping of elastic particles by the large gradient force of a single acoustical beam in three dimensions. We show that at equal power, acoustical forces overtake by 8 orders of magnitude that of optical ones on macroscopic objects. Acoustical tweezers can push, pull and accurately control both the position of the particle and the forces exerted under damage-free conditions. The large spectrum of frequencies covered by coherent ultrasonic sources will provide a wide variety of manipulation possibilities from macro- to microscopic length scales. We believe our observations improve the prospects for wider use of non-contact manipulation in biology, biophysics, microfluidics and...

  10. Ground-state cooling of a trapped ion using long-wavelength radiation

    E-Print Network [OSTI]

    S. Weidt; J. Randall; S. C. Webster; E. D. Standing; A. Rodriguez; A. E. Webb; B. Lekitsch; W. K. Hensinger

    2015-01-07T23:59:59.000Z

    We demonstrate ground-state cooling of a trapped ion using long-wavelength radiation. This is a powerful tool for the implementation of quantum operations, where long-wavelength radiation instead of lasers is used for motional quantum state engineering. We measure a mean phonon number of $\\overline{n} = 0.13(4)$ after sideband cooling, corresponding to a ground-state occupation probability of 88(7)\\%. After preparing in the vibrational Fock state $\\left|n=0\\right\\rangle$, we implement sideband Rabi oscillations which last for more than 10 ms, demonstrating the long coherence time of our system. We also use the ability to ground-state cool to accurately measure the motional heating rate and report a reduction by almost two orders of magnitude compared to our previously measured result, which we attribute to carefully eliminating sources of electrical noise in the system.

  11. Ground-state cooling of a trapped ion using long-wavelength radiation

    E-Print Network [OSTI]

    Weidt, S; Webster, S C; Standing, E D; Rodriguez, A; Webb, A E; Lekitsch, B; Hensinger, W K

    2015-01-01T23:59:59.000Z

    We demonstrate ground-state cooling of a trapped ion using long-wavelength radiation. This is a powerful tool for the implementation of quantum operations, where long-wavelength radiation instead of lasers is used for motional quantum state engineering. We measure a mean phonon number of $\\overline{n} = 0.13(4)$ after sideband cooling, corresponding to a ground-state occupation probability of 88(7)\\%. After preparing in the vibrational Fock state $\\left|n=0\\right\\rangle$, we implement sideband Rabi oscillations which last for more than 10 ms, demonstrating the long coherence time of our system. We also use the ability to ground-state cool to accurately measure the motional heating rate and report a reduction by almost two orders of magnitude compared to our previously measured result, which we attribute to carefully eliminating sources of electrical noise in the system.

  12. Computational mechanics

    SciTech Connect (OSTI)

    Goudreau, G.L.

    1993-03-01T23:59:59.000Z

    The Computational Mechanics thrust area sponsors research into the underlying solid, structural and fluid mechanics and heat transfer necessary for the development of state-of-the-art general purpose computational software. The scale of computational capability spans office workstations, departmental computer servers, and Cray-class supercomputers. The DYNA, NIKE, and TOPAZ codes have achieved world fame through our broad collaborators program, in addition to their strong support of on-going Lawrence Livermore National Laboratory (LLNL) programs. Several technology transfer initiatives have been based on these established codes, teaming LLNL analysts and researchers with counterparts in industry, extending code capability to specific industrial interests of casting, metalforming, and automobile crash dynamics. The next-generation solid/structural mechanics code, ParaDyn, is targeted toward massively parallel computers, which will extend performance from gigaflop to teraflop power. Our work for FY-92 is described in the following eight articles: (1) Solution Strategies: New Approaches for Strongly Nonlinear Quasistatic Problems Using DYNA3D; (2) Enhanced Enforcement of Mechanical Contact: The Method of Augmented Lagrangians; (3) ParaDyn: New Generation Solid/Structural Mechanics Codes for Massively Parallel Processors; (4) Composite Damage Modeling; (5) HYDRA: A Parallel/Vector Flow Solver for Three-Dimensional, Transient, Incompressible Viscous How; (6) Development and Testing of the TRIM3D Radiation Heat Transfer Code; (7) A Methodology for Calculating the Seismic Response of Critical Structures; and (8) Reinforced Concrete Damage Modeling.

  13. Computational mechanics

    SciTech Connect (OSTI)

    Raboin, P J

    1998-01-01T23:59:59.000Z

    The Computational Mechanics thrust area is a vital and growing facet of the Mechanical Engineering Department at Lawrence Livermore National Laboratory (LLNL). This work supports the development of computational analysis tools in the areas of structural mechanics and heat transfer. Over 75 analysts depend on thrust area-supported software running on a variety of computing platforms to meet the demands of LLNL programs. Interactions with the Department of Defense (DOD) High Performance Computing and Modernization Program and the Defense Special Weapons Agency are of special importance as they support our ParaDyn project in its development of new parallel capabilities for DYNA3D. Working with DOD customers has been invaluable to driving this technology in directions mutually beneficial to the Department of Energy. Other projects associated with the Computational Mechanics thrust area include work with the Partnership for a New Generation Vehicle (PNGV) for ''Springback Predictability'' and with the Federal Aviation Administration (FAA) for the ''Development of Methodologies for Evaluating Containment and Mitigation of Uncontained Engine Debris.'' In this report for FY-97, there are five articles detailing three code development activities and two projects that synthesized new code capabilities with new analytic research in damage/failure and biomechanics. The article this year are: (1) Energy- and Momentum-Conserving Rigid-Body Contact for NIKE3D and DYNA3D; (2) Computational Modeling of Prosthetics: A New Approach to Implant Design; (3) Characterization of Laser-Induced Mechanical Failure Damage of Optical Components; (4) Parallel Algorithm Research for Solid Mechanics Applications Using Finite Element Analysis; and (5) An Accurate One-Step Elasto-Plasticity Algorithm for Shell Elements in DYNA3D.

  14. Single-ion nonlinear mechanical oscillator

    SciTech Connect (OSTI)

    Akerman, N.; Kotler, S.; Glickman, Y.; Dallal, Y.; Keselman, A.; Ozeri, R. [Physics of Complex Systems, Weizmann Institute of Science, Rehovot 76100 (Israel)

    2010-12-15T23:59:59.000Z

    We study the steady-state motion of a single trapped ion oscillator driven to the nonlinear regime. Damping is achieved via Doppler laser cooling. The ion motion is found to be well described by the Duffing oscillator model with an additional nonlinear damping term. We demonstrate here the unique ability of tuning both the linear as well as the nonlinear damping coefficients by controlling the laser-cooling parameters. Our observations pave the way for the investigation of nonlinear dynamics on the quantum-to-classical interface as well as mechanical noise squeezing in laser-cooling dynamics.

  15. Combining Capillary Electrochromatography with Ion Trap Accumulation and Time-of-Flight Mass Spectrometry 

    E-Print Network [OSTI]

    Simpson, David C

    metre, an average chromatographic efficiency of 95,000 was obtained with a test mixture that consisted of acenaphthene, biphenyl, fluorene, naphthalene and phenanthrene. Furthermore, using the leak inlet, naphthalene was detected as a 100 nM solution...

  16. Drunken robber, tipsy cop: First passage times, mobile traps, and Hopf bifurcations

    E-Print Network [OSTI]

    Kolokolnikov, Theodore

    -bifurcation, reaction-diffusion, matched asymptotics, boundary layer 1 Introduction Numerous problems in nature can bifurcation that induces oscillatory motion in the location of the spike. We use this correspondence to prove

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

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn'tOrigin of ContaminationHubs+18, 2012 Qualified11Department of Energy

  18. Modeling sickle cell vasoocculsion in the rat leg: Quantification of trapped sickle cells and correlation with sup 31 P metabolic and sup 1 H magnetic resonance imaging changes

    SciTech Connect (OSTI)

    Fabry, M.E.; Rajanayagam, V.; Fine, E.; Holland, S.; Gore, J.C.; Nagel, R.L.; Kaul, D.K. (Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY (USA))

    1989-05-01T23:59:59.000Z

    The authors have developed an animal model to elucidate the acute effects of perfusion abnormalities on muscle metabolism induced by different density-defined classes of erythrocytes isolated from sickle cell anemia patients. Technetium-99m ({sup 99m}Tc)-labeled, saline-washed normal (AA), homozygous sickle (SS), or high-density SS (SS4) erythrocytes were injected into the femoral artery of the rat and quantitative {sup 99m}Tc imaging, {sup 31}P magnetic resonance spectroscopy by surface coil at 2 teslas, and {sup 1}H magnetic resonance imaging at 0.15 tesla were performed. Between 5 and 25 {mu}l of SS4 cells was trapped in the microcirculation of the thigh. In contrast, fewer SS discocytes (SS2) or AA cells were trapped. After injection of SS4 cells an initial increase in inorganic phosphate was observed in the region of the thigh served by the femoral artery, intracellular pH decreased, and subsequently the proton relaxation time T{sub 1} reached a broad maximum at 18-28 hr. When T{sub 1} obtained at this time was plotted against the volume of cells trapped, an increase of T{sub 1} over the control value of 411 {plus minus} 48 msec was found that was proportional to the number of cells trapped. They conclude that the densest SS cells are most effective at producing vasoocclusion. The extent of the change detected by {sup 1}H magnetic resonance imaging is dependent on the amount of cells trapped in the microcirculation and the magnitude of the initial increase of inorganic phosphate.

  19. The Engineered Approach to Energy and Maintenance Effective Steam Trapping

    E-Print Network [OSTI]

    Krueger, R. G.; Wilt, G. W.

    1980-01-01T23:59:59.000Z

    # Y Strainer with 0.020" Perlorated Plate Basket 114" NPS - 600# Globe Valve 112" NPS - 600# Gate Valve 112" x 4" Nipple (Schedule 80) 1/2" x 6" Nipple (Schedule 80) 114" x 4" Nipple (Schedule 80) Orifice Plate FIGURE 3 TYPICAL DRIP LEG... down before test rig is installed. 3. "Y" Strainer ahead of steam trap may be blown down and test rig connected at strainer blow down point. FIGURE 3A 398 ESL-IE-80-04-73 Proceedings from the Second Industrial Energy Technology Conference Houston...

  20. Measuring molecular electric dipoles using trapped atomic ions and ultrafast laser pulses

    E-Print Network [OSTI]

    Jordi Mur-Petit; Juan José García-Ripoll

    2015-01-12T23:59:59.000Z

    We study a hybrid quantum system composed of an ion and an electric dipole. We show how a trapped ion can be used to measure the small electric field generated by a classical dipole. We discuss the application of this scheme to measure the electric dipole moment of cold polar molecules, whose internal state can be controlled with ultrafast laser pulses, by trapping them in the vicinity of a trapped ion.

  1. Angular constraint on light-trapping absorption enhancement in solar cells

    E-Print Network [OSTI]

    Yu, Zongfu

    2010-01-01T23:59:59.000Z

    Light trapping for solar cells can reduce production cost and improve energy conversion efficiency. Understanding some of the basic theoretical constraints on light trapping is therefore of fundamental importance. Here, we develop a general angular constraint on the absorption enhancement in light trapping. We show that there is an upper limit for the angular integration of absorption enhancement factors. This limit is determined by the number of accessible resonances supported by an absorber.

  2. Two-stream cyclotron radiative instabilities due to the marginally mirror-trapped fraction for fustion alphas in tokamaks

    SciTech Connect (OSTI)

    Arunasalam, V.

    1995-07-01T23:59:59.000Z

    It is shown here that the marginally mirror-trapped fraction of the newly-born fusion alpha particles in the deuterium-tritium (DT) reaction dominated tokamak plasmas can induce a two-stream cyclotron radiative instability for the fast Alfven waves propagating near the harmonics of the alpha particle cyclotron frequency {omega}{sub c{alpha}}. This can explain both the experimentally observed time behavior and the spatially localized origin of the fusion product ion cyclotron emission (ICE) in TFTR at frequencies {omega} {approx} m{omega}{sub c{alpha}}.

  3. Variation of carrier concentration and interface trap density in 8MeV electron irradiated c-Si solar cells

    SciTech Connect (OSTI)

    Bhat, Sathyanarayana, E-mail: asharao76@gmail.com; Rao, Asha, E-mail: asharao76@gmail.com [Department of Physics, Mangalore Institute of Technology and Engineering, Moodabidri, Mangalore-574225 (India); Krishnan, Sheeja [Department of Physics, Sri Devi Institute of Technology, Kenjar, Mangalore-574142 (India); Sanjeev, Ganesh [Microtron Centre, Department of Physics, Mangalore University, Mangalagangothri-574199 (India); Suresh, E. P. [Solar Panel Division, ISRO Satellite Centre, Bangalore-560017 (India)

    2014-04-24T23:59:59.000Z

    The capacitance and conductance measurements were carried out for c-Si solar cells, irradiated with 8 MeV electrons with doses ranging from 5kGy – 100kGy in order to investigate the anomalous degradation of the cells in the radiation harsh environments. Capacitance – Voltage measurements indicate that there is a slight reduction in the carrier concentration upon electron irradiation due to the creation of radiation induced defects. The conductance measurement results reveal that the interface state densities and the trap time constant increases with electron dose due to displacement damages in c-Si solar cells.

  4. Mass fluctuations and diffusion in time-dependent random environments

    E-Print Network [OSTI]

    Giorgio Krstulovic; Rehab Bitane; Jeremie Bec

    2012-03-27T23:59:59.000Z

    A mass ejection model in a time-dependent random environment with both temporal and spatial correlations is introduced. When the environment has a finite correlation length, individual particle trajectories are found to diffuse at large times with a displacement distribution that approaches a Gaussian. The collective dynamics of diffusing particles reaches a statistically stationary state, which is characterized in terms of a fluctuating mass density field. The probability distribution of density is studied numerically for both smooth and non-smooth scale-invariant random environments. A competition between trapping in the regions where the ejection rate of the environment vanishes and mixing due to its temporal dependence leads to large fluctuations of mass. These mechanisms are found to result in the presence of intermediate power-law tails in the probability distribution of the mass density. For spatially differentiable environments, the exponent of the right tail is shown to be universal and equal to -3/2. However, at small values, it is found to depend on the environment. Finally, spatial scaling properties of the mass distribution are investigated. The distribution of the coarse-grained density is shown to posses some rescaling properties that depend on the scale, the amplitude of the ejection rate, and the H\\"older exponent of the environment.

  5. Matter: Space without Time

    E-Print Network [OSTI]

    Yousef Ghazi-Tabatabai

    2012-11-19T23:59:59.000Z

    While Quantum Gravity remains elusive and Quantum Field Theory retains the interpretational difficulties of Quantum Mechanics, we have introduced an alternate approach to the unification of particles, fields, space and time, suggesting that the concept of matter as space without time provides a framework which unifies matter with spacetime and in which we anticipate the development of complete theories (ideally a single unified theory) describing observed 'particles, charges, fields and forces' solely with the geometry of our matter-space-time universe.

  6. Cryogenic surface electrode ion traps with integrated superconducting microwave resonators for polar molecular ion spectroscopy

    E-Print Network [OSTI]

    Antohi, Paul Bogdan

    2011-01-01T23:59:59.000Z

    Trapped cold molecules open the possibility of studying ultracold chemistry and astrophysical processes in laboratory settings. Their rich internal structure also makes them suitable for quantum information manipulation ...

  7. E-Print Network 3.0 - aerosol trapping effect Sample Search Results

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

    of this infrared radiation is trapped... 'S TEMPERATURE IS RISING This is the greenhouse effect. Without it, the Earths climate would be ... Source: Brookhaven National...

  8. Bose-Einstein condensate in traps: A Diffusion Monte Carlo analysis

    E-Print Network [OSTI]

    Glyde, Henry R.

    Bosons, we note that the energy of a single particle in a typical harmonic trap (e.g. 87 Rb) is (3/2)¯hho

  9. Non-contact, non-destructive, quantitative probing of interfacial trap sites for charge carrier transport at semiconductor-insulator boundary

    SciTech Connect (OSTI)

    Choi, Wookjin; Miyakai, Tomoyo; Sakurai, Tsuneaki; Saeki, Akinori [Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita 565-0871 (Japan); Yokoyama, Masaaki [Kaneka Fundamental Technology Research Alliance Laboratories, Graduate School of Engineering, Osaka University, Suita 565-0871 (Japan); Seki, Shu, E-mail: seki@chem.eng.osaka-u.ac.jp [Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita 565-0871 (Japan); Kaneka Fundamental Technology Research Alliance Laboratories, Graduate School of Engineering, Osaka University, Suita 565-0871 (Japan)

    2014-07-21T23:59:59.000Z

    The density of traps at semiconductor–insulator interfaces was successfully estimated using microwave dielectric loss spectroscopy with model thin-film organic field-effect transistors. The non-contact, non-destructive analysis technique is referred to as field-induced time-resolved microwave conductivity (FI-TRMC) at interfaces. Kinetic traces of FI-TRMC transients clearly distinguished the mobile charge carriers at the interfaces from the immobile charges trapped at defects, allowing both the mobility of charge carriers and the number density of trap sites to be determined at the semiconductor-insulator interfaces. The number density of defects at the interface between evaporated pentacene on a poly(methylmethacrylate) insulating layer was determined to be 10{sup 12?}cm{sup ?2}, and the hole mobility was up to 6.5?cm{sup 2} V{sup ?1} s{sup ?1} after filling the defects with trapped carriers. The FI-TRMC at interfaces technique has the potential to provide rapid screening for the assessment of interfacial electronic states in a variety of semiconductor devices.

  10. Conformal mechanics

    SciTech Connect (OSTI)

    Gonera, Joanna, E-mail: jgonera@uni.lodz.pl

    2013-08-15T23:59:59.000Z

    The SL(2,R) invariant Hamiltonian systems are discussed within the framework of the orbit method. It is shown that both the dynamics and the symmetry transformations are globally well-defined on phase space. The flexibility in the choice of the time variable and the Hamiltonian function described in the paper by de Alfaro et al. [Nuovo Cimento 34A (1976) 569] is related to the nontrivial global structure of 1+0-dimensional space–time. The operational definition of time is discussed.

  11. Probing Entanglement in Adiabatic Quantum Optimization with Trapped Ions

    E-Print Network [OSTI]

    Philipp Hauke; Lars Bonnes; Markus Heyl; Wolfgang Lechner

    2015-03-19T23:59:59.000Z

    Adiabatic quantum optimization has been proposed as a route to solve NP-complete problems, with a possible quantum speedup compared to classical algorithms. However, the precise role of quantum effects, such as entanglement, in these optimization protocols is still unclear. We propose a setup of cold trapped ions that allows one to quantitatively characterize, in a controlled experiment, the interplay of entanglement, decoherence, and non-adiabaticity in adiabatic quantum optimization. We show that, in this way, a broad class of NP-complete problems becomes accessible for quantum simulations, including the knapsack problem, number partitioning, and instances of the max-cut problem. Moreover, a general theoretical study reveals correlations of the success probability with entanglement at the end of the protocol. From exact numerical simulations for small systems and linear ramps, however, we find no substantial correlations with the entanglement during the optimization. For the final state, we derive analytically a universal upper bound for the success probability as a function of entanglement, which can be measured in experiment. The proposed trapped-ion setups and the presented study of entanglement address pertinent questions of adiabatic quantum optimization, which may be of general interest across experimental platforms.

  12. Upgrade of the electron beam ion trap in Shanghai

    SciTech Connect (OSTI)

    Lu, D.; Yang, Y.; Xiao, J.; Shen, Y.; Fu, Y.; Wei, B.; Yao, K.; Hutton, R.; Zou, Y., E-mail: zouym@fudan.edu.cn [The Key Lab of Applied Ion Beam Physics, Ministry of Education, 200433 Shanghai (China); Shanghai EBIT Lab, Institute of Modern Physics, Fudan University, 200433 Shanghai (China)

    2014-09-15T23:59:59.000Z

    Over the last few years the Shanghai electron beam ion trap (EBIT) has been successfully redesigned and rebuilt. The original machine, developed under collaboration with the Shanghai Institute of Applied Physics, first produced an electron beam in 2005. It could be tuned with electron energies between 1 and 130 keV and beam current up to 160 mA. After several years of operation, it was found that several modifications for improvements were necessary to reach the goals of better electron optics, higher photon detection, and ion injection efficiencies, and more economical running costs. The upgraded Shanghai-EBIT is made almost entirely from Ti instead of stainless steel and achieves a vacuum of less than 10{sup ?10} Torr, which helps to minimize the loss of highly changed ions through charge exchange. Meanwhile, a more compact structure and efficient cryogenic system, and excellent optical alignment have been of satisfactory. The magnetic field in the central trap region can reach up till 4.8 T with a uniformity of 2.77 × 10{sup ?4}. So far the upgraded Shanghai-EBIT has been operated up to an electron energy of 151 keV and a beam current of up to 218 mA, although promotion to even higher energy is still in progress. Radiation from ions as highly charged as Xe{sup 53+,} {sup 54+} has been produced and the characterization of current density is estimated from the measured electron beam width.

  13. INFLUENCE OF LOCAL CAPILLARY TRAPPING ON CONTAINMENT SYSTEM EFFECTIVENESS

    SciTech Connect (OSTI)

    Bryant, Steven

    2014-03-31T23:59:59.000Z

    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, approaching a percolation threshold while non-barrier regions remain numerous. The maximum possible extent of LCT thus occurs at Pc,entrycrit near this threshold. Testing predictions of this simple algorithm against full-physics simulations of buoyancy-driven CO2 migration support the concept of critical capillary entry pressure. However, further research is needed to determine whether a single value of critical capillary entry pressure always applies and how that value can be determined a priori. Simulations of injection into high-resolution (cells 0.3 m on a side) 2D and 3D heterogeneous domains show two characteristic behaviors. At small gravity numbers (vertical flow velocity much less than horizontal flow velocity) the CO2 fills local traps as well as regions that would act as local barriers if CO2 weremoving only due to buoyancy. When injection ceases, the CO2 migrates vertically to establish large saturations within local traps and residual saturation elsewhere. At large gravity numbers, the CO2 invades a smaller portion of the perforated interval. Within this smaller swept zone the local barriers are not invaded, but local traps are filled to large saturation during injection and remain during post-injection gravity-driven migration. The small gravity number behavior is expected in the region within 100 m of a vertical injection well at anticipated rates of injection for commercial GCS. Simulations of leakage scenarios (through-going region of large permeability imposed in overlying seal) indicate that LCT persists (i.e. CO2 remains held in a large fraction of the local iv traps) and the persistence is independent of injection rate during storage. Simulations of leakage for the limiting case of CO2 migrating vertically from an areally extensive emplacement in the lower portion of a reservoir showed similar strong persistence of LCT. This research has two broad implications for GCS. The first is that LCT can retain a significant fraction of the CO2 stored in a reservoir – above and beyond the residual saturation -- if the overlying seal were to fail. Thus frameworks for risk assessment should be extended to account for LCT. The second implication is that compared to press

  14. Trap Design for Vibratory Bowl Feeders Robert-Paul Berretty

    E-Print Network [OSTI]

    Goldberg, Ken

    that causes parts to move up the track, where they encounter a sequence of mechanical devices such as wiper

  15. Gravid Mosquito Trap P462 -Trap The ChemTica GMT operates on 4 size D cell batteries. A photo-activated switch turns on the fan

    E-Print Network [OSTI]

    Ishida, Yuko

    batteries. A photo-activated switch turns on the fan at dusk. Manual shutoff is required at dawn to prevent at dawn to prevent loss of trapped mosquitoes. Power is supplied by four D cell batteries. The upper case

  16. Travelling times in scattering by obstacles

    E-Print Network [OSTI]

    Lyle Noakes; Luchezar Stoyanov

    2014-09-29T23:59:59.000Z

    The paper deals with some problems related to recovering information about an obstacle in an Euclidean space from certain measurements of lengths of generalized geodesics in the exterior of the obstacle. The main result is that if two obstacles satisfy some generic regularity conditions and have (almost) the same traveling times, then the generalized geodesic flows in their exteriors are conjugate on the non-trapping part of their phase spaces with a time preserving conjugacy. In the case of a union of two strictly convex domains in the plane, a constructive algorithm is described to recover the obstacle from traveling times.

  17. Statistical mechanics of the vacuum

    E-Print Network [OSTI]

    Christian Beck

    2012-03-01T23:59:59.000Z

    The vacuum is full of virtual particles which exist for short moments of time. In this paper we construct a chaotic model of vacuum fluctuations associated with a fundamental entropic field that generates an arrow of time. The dynamics can be physically interpreted in terms of fluctuating virtual momenta. This model leads to a generalized statistical mechanics that distinguishes fundamental constants of nature.

  18. Title of dissertation: ULTRAFAST CONTROL OF SPIN AND MOTION IN TRAPPED IONS

    E-Print Network [OSTI]

    Monroe, Christopher

    , I report here on the first experiments using ultrafast laser pulses to control the internalABSTRACT Title of dissertation: ULTRAFAST CONTROL OF SPIN AND MOTION IN TRAPPED IONS Jonathan and external states of a single trapped ion. I begin with experiments in ultrafast spin control, showing how

  19. Quantum Reactive Scattering of Ultracold NHX 3 Radicals in a Magnetic Trap

    E-Print Network [OSTI]

    trap using Stark deceleration [23,24] and buffer gas cooling techniques [15,25,26], and earlier cooling more difficult than previously anticipated. DOI: 10.1103/PhysRevLett.110.063201 PACS numbers: 34 cooling. These second-stage cooling methods, which rely on strong elastic collisions between trapped

  20. Ultracold molecules for the masses: evaporative cooling and magneto-optical trapping

    E-Print Network [OSTI]

    Jin, Deborah

    cooling, until now none of these techniques have been applicable to molecules. In this thesis, two majorUltracold molecules for the masses: evaporative cooling and magneto-optical trapping by B. K. Stuhl for the masses: evaporative cooling and magneto-optical trapping written by B. K. Stuhl has been approved

  1. Thermodynamic limits of nanophotonic light trapping in thin film silicon solar cells1

    E-Print Network [OSTI]

    Schiff, Eric A.

    with solar tracking may realize the predicted JSC improvement. PACS Nos.: 88.40.jj, 42.79.Dj, 88.05.De to a significant improvement in light-trapping for cells used with solar trackingARTICLE Thermodynamic limits of nanophotonic light trapping in thin film silicon solar cells1 Brian

  2. Euler buckling-induced folding and rotation of red blood cells in an optical trap

    E-Print Network [OSTI]

    Sharma, Shobhona

    Euler buckling-induced folding and rotation of red blood cells in an optical trap A Ghosha 005, India Abstract. We investigate the physics of an optically-driven micromotor of biological origin. When a single, live red blood cell is placed in an optical trap, the normal biconcave disk shape

  3. Passive torque wrench and angular position detection using a single-beam optical trap

    E-Print Network [OSTI]

    Wang, Michelle

    Passive torque wrench and angular position detection using a single-beam optical trap James Inman,1 August 26, 2010 The recent advent of angular optical trapping techniques has allowed for rotational torsional measurements across a wide range of biological systems. © 2010 Optical Society of America OCIS

  4. Torque-generating malaria-infected red blood cells in an optical trap

    E-Print Network [OSTI]

    Sharma, Shobhona

    Torque-generating malaria-infected red blood cells in an optical trap J.A. Dharmadhikari, S. Roy, A 005, India # atmol1@tifr.res.in Abstract: We have used optical tweezers to trap normal and Plasmodium emerge from our experiments. Firstly, while the optical field modifies both types of RBCs in the same

  5. I. Top 20 TA Traps 83 II. Team Meeting Guidelines 85

    E-Print Network [OSTI]

    Minnesota, University of

    Other Teaching Resources Page I. Top 20 TA Traps 83 II. Team Meeting Guidelines 85 III. TA Office I. Top 20 TA Traps This list has been compiled by mentor TAs to help you avoid some common pitfalls of being a TA. These are the top twenty things TAs do that interfere with the work of teaching. General

  6. I. Top 20 TA Traps 129 II. Team Meeting Guidelines 131

    E-Print Network [OSTI]

    Minnesota, University of

    Chapter 5 Other Teaching Resources Page I. Top 20 TA Traps 129 II. Team Meeting Guidelines 131 III for TAs 152 #12;#12;Page 129 I. Top 20 TA Traps This list has been compiled by mentor TAs to help you avoid some common pitfalls of being a TA. These are the top twenty things TAs do that interfere

  7. I. Top 20 TA Traps 129 II. Team Meeting Guidelines 131

    E-Print Network [OSTI]

    Minnesota, University of

    Chapter 5 Other Teaching Resources Page I. Top 20 TA Traps 129 II. Team Meeting Guidelines 131 III for TAs 152 #12;#12;I. Top 20 TA Traps This list has been compiled by mentor TAs to help you avoid some common pitfalls of being a TA. These are the top twenty things TAs do that interfere with the work

  8. Ion Crystals Produced by Laser and Sympathetic Cooling in a Linear RF Ion Trap

    E-Print Network [OSTI]

    Zhu, Feng

    2012-02-14T23:59:59.000Z

    A detailed investigation of ion crystals produced by laser and sympathetic cooling in a linear RF trap has been conducted. The laser cooling methods were examined and applied to the trapped ^24Mg^(positive) ions. The crystals produced by the laser...

  9. Efficiency of Surveying, Baiting, and Trapping Wild Pigs at Fort Benning, Georgia Brian Lee Williams

    E-Print Network [OSTI]

    Ditchkoff, Steve

    Efficiency of Surveying, Baiting, and Trapping Wild Pigs at Fort Benning, Georgia by Brian Lee surveys, trapping efficiency, Fort Benning Copyright 2010 by Brian Lee Williams Approved by Stephen S This study, conducted at Fort Benning, Georgia, sought to develop more efficient ways of surveying

  10. PHYSICAL REVIEW E 84, 031108 (2011) Noise associated with nonconservative forces in optical traps

    E-Print Network [OSTI]

    La Porta, Arthur

    nonconservative fluctuations to direct thermal fluctuations scales inversely with the square root of trap power) It is known that for a particle held in an optical trap the interaction of thermal fluctuations by a force Fg proportional to the optical intensity gradient. The force exerted on the particle

  11. The responses of freshwater macroinvertebrates to different wavelengths in submerged aquatic light traps

    E-Print Network [OSTI]

    Moeller, Edward F.

    1996-01-01T23:59:59.000Z

    attracted to green light emitting diodes more than infrared, amber, orange, red, white, or unlit diodes. The vertical placement of the trap in the water column is also important. Beehler and Webb (1992) found that traps placed at the bottom of the water...

  12. Poverty Trap with Convex Production Function: The role of Public and Private Capital

    E-Print Network [OSTI]

    Bandyopadhyay, Antar

    Poverty Trap with Convex Production Function: The role of Public and Private Capital Kumar Aniket University of Cambridge 20 September 2014 Abstract. The objective of the paper is to explain why poverty, there is a poverty trap region or a threshold below which the economy is in a low steady state. The paper shows

  13. Joule heating effects on electrokinetic focusing and trapping of particles in constriction microchannels

    E-Print Network [OSTI]

    Xuan, Xiangchun "Schwann"

    Joule heating effects on electrokinetic focusing and trapping of particles in constriction for more Home Search Collections Journals About Contact us My IOPscience #12;IOP PUBLISHING JOURNAL.1088/0960-1317/22/7/075011 Joule heating effects on electrokinetic focusing and trapping of particles in constriction microchannels

  14. Light trapping design for low band-gap polymer solar cells

    E-Print Network [OSTI]

    John, Sajeev

    Light trapping design for low band-gap polymer solar cells Stephen Foster1,* and Sajeev John1,2 1 demonstrate numerically a 2-D nanostructured design for light trapping in a low band-gap polymer solar cell observe an enhancement in solar absorption of almost 40% relative to a planar cell. Improvements

  15. Ion Crystals Produced by Laser and Sympathetic Cooling in a Linear RF Ion Trap 

    E-Print Network [OSTI]

    Zhu, Feng

    2012-02-14T23:59:59.000Z

    A detailed investigation of ion crystals produced by laser and sympathetic cooling in a linear RF trap has been conducted. The laser cooling methods were examined and applied to the trapped ^24Mg^(positive) ions. The crystals produced by the laser...

  16. Dynamical quantum noise in trapped Bose-Einstein condensates M. J. Steel,1,2

    E-Print Network [OSTI]

    Queensland, University of

    Dynamical quantum noise in trapped Bose-Einstein condensates M. J. Steel,1,2 M. K. Olsen,1, * L. I introduce the study of dynamical quantum noise in Bose-Einstein condensates through numerical simu- lation equations for a single trapped condensate in both the positive-P and Wigner representations and perform

  17. Kinetics for evaporative cooling of a trapped gas Kirstine BergSrensen \\Lambda

    E-Print Network [OSTI]

    Berg-Sørensen, Kirstine

    the kinetic theory for evaporative cooling of a dilute collisional gas in a trap. The analysis in 0. J. Luiten and increase the phase­space density of an atomic, bosonic gas towards a Bose­Einstein condensate (BECKinetics for evaporative cooling of a trapped gas Kirstine Berg­Sørensen \\Lambda The Rowland

  18. Role of holes in the isotope effect and mechanisms for the metaloxidesemiconductor device degradation

    E-Print Network [OSTI]

    Chen, Zhi

    degradation Zhi Chen,a) Pradeep Garg,b) and Vijay Singh Department of Electrical Engineering, University degradation phenomena. The isotope effect is exclusively due to hot electrons, not hot holes. Holes might break the Si­O bonds to generate interface traps at VG near VT . The dominant degradation mechanism

  19. On the foundation of Mechanics

    E-Print Network [OSTI]

    Ricardo J. Alonso-Blanco; Jesús Muñoz-Díaz

    2014-12-09T23:59:59.000Z

    This note is an extended version of "A note on the foundations of Mechanics", arXiv: 1404.1321 [math-ph]. A presentation of its contents was given in a talk in memorial homage to the professor Juan B. Sancho Guimer\\'a. For this reason, it was written in spanish language. The matter of the note is a systematic foundation of the most classical part of Mechanics. The content by sections is: 0) Notions and basic results, 1) Conservative systems 2) Time. Time constraints, 3) Proper time. Relativistic forces, 4) Electromagnetic fields, 5) On the Hamilton-Noether Principle, 6) Schr\\"odinger equation.

  20. Intrinsic Time Quantum Geometrodynamics

    E-Print Network [OSTI]

    Eyo Eyo Ita III; Chopin Soo; Hoi-Lai Yu

    2015-02-06T23:59:59.000Z

    Quantum Geometrodynamics with intrinsic time development and momentric variables is presented. An underlying SU(3) group structure at each spatial point regulates the theory. The intrinsic time behavior of the theory is analyzed, together with its ground state and primordial quantum fluctuations. Cotton-York potential dominates at early times when the universe was small; the ground state naturally resolves Penrose's Weyl Curvature Hypothesis, and thermodynamic and gravitational `arrows of time' point in the same direction. Ricci scalar potential corresponding to Einstein's General Relativity emerges as a zero-point energy contribution. A new set of fundamental commutation relations without Planck's constant emerges from the unification of Gravitation and Quantum Mechanics.

  1. Intrinsic Time Quantum Geometrodynamics

    E-Print Network [OSTI]

    Ita, Eyo Eyo; Yu, Hoi-Lai

    2015-01-01T23:59:59.000Z

    Quantum Geometrodynamics with intrinsic time development and momentric variables is presented. An underlying SU(3) group structure at each spatial point regulates the theory. The intrinsic time behavior of the theory is analyzed, together with its ground state and primordial quantum fluctuations. Cotton-York potential dominates at early times when the universe was small; the ground state naturally resolves Penrose's Weyl Curvature Hypothesis, and thermodynamic and gravitational `arrows of time' point in the same direction. Ricci scalar potential corresponding to Einstein's General Relativity emerges as a zero-point energy contribution. A new set of fundamental canonical commutation relations without Planck's constant emerges from the unification of Gravitation and Quantum Mechanics.

  2. Free-fall in a uniform gravitational field in non-commutative quantum mechanics

    E-Print Network [OSTI]

    K. H. C. Castello-Branco; A. G. Martins

    2011-05-23T23:59:59.000Z

    We study the free-fall of a quantum particle in the context of noncommutative quantum mechanics (NCQM). Assuming noncommutativity of the canonical type between the coordinates of a two-dimensional configuration space, we consider a neutral particle trapped in a gravitational well and exactly solve the energy eigenvalue problem. By resorting to experimental data from the GRANIT experiment, in which the first energy levels of freely falling quantum ultracold neutrons were determined, we impose an upper-bound on the noncommutativity parameter. We also investigate the time of flight of a quantum particle moving in a uniform gravitational field in NCQM. This is related to the weak equivalence principle. As we consider stationary, energy eigenstates, i.e., delocalized states, the time of flight must be measured by a quantum clock, suitably coupled to the particle. By considering the clock as a small perturbation, we solve the (stationary) scattering problem associated and show that the time of flight is equal to the classical result, when the measurement is made far from the turning point. This result is interpreted as an extension of the equivalence principle to the realm of NCQM.

  3. Free-fall in a uniform gravitational field in noncommutative quantum mechanics

    SciTech Connect (OSTI)

    Castello-Branco, K. H. C. [Instituto de Fisica de Sao Carlos, Universidade de Sao Paulo, Av. Trabalhador Sao-Carlense, 400, Sao Carlos, Sao Paulo 13560-970 (Brazil); Martins, A. G. [Departamento de Ciencias Naturais, Universidade do Estado do Para, Av. Djalma Dutra, s/n, Belem, Para 66113-200 (Brazil)

    2010-10-15T23:59:59.000Z

    We study the free-fall of a quantum particle in the context of noncommutative quantum mechanics (NCQM). Assuming noncommutativity of the canonical type between the coordinates of a two-dimensional configuration space, we consider a neutral particle trapped in a gravitational well and exactly solve the energy eigenvalue problem. By resorting to experimental data from the GRANIT experiment, in which the first energy levels of freely falling quantum ultracold neutrons were determined, we impose an upper-bound on the noncommutativity parameter. We also investigate the time of flight of a quantum particle moving in a uniform gravitational field in NCQM. This is related to the weak equivalence principle. As we consider stationary, energy eigenstates, i.e., delocalized states, the time of flight must be measured by a quantum clock, suitably coupled to the particle. By considering the clock as a small perturbation, we solve the (stationary) scattering problem associated and show that the time of flight is equal to the classical result, when the measurement is made far from the turning point. This result is interpreted as an extension of the equivalence principle to the realm of NCQM.

  4. Efficient Photoionization-Loading of Trapped Cadmium Ions with Ultrafast Pulses

    E-Print Network [OSTI]

    L. Deslauriers; M. Acton; B. B. Blinov; K. -A. Brickman; P. C. Haljan; W. K. Hensinger; D. Hucul; S. Katnik; R. N. Kohn, Jr.; P. J. Lee; M. J. Madsen; P. Maunz; S. Olmschenk; D. L. Moehring; D. Stick; J. Sterk; M. Yeo; K. C. Younge; C. Monroe

    2006-08-04T23:59:59.000Z

    Atomic cadmium ions are loaded into radiofrequency ion traps by photoionization of atoms in a cadmium vapor with ultrafast laser pulses. The photoionization is driven through an intermediate atomic resonance with a frequency-quadrupled mode-locked Ti:Sapphire laser that produces pulses of either 100 fsec or 1 psec duration at a central wavelength of 229 nm. The large bandwidth of the pulses photoionizes all velocity classes of the Cd vapor, resulting in high loading efficiencies compared to previous ion trap loading techniques. Measured loading rates are compared with a simple theoretical model, and we conclude that this technique can potentially ionize every atom traversing the laser beam within the trapping volume. This may allow the operation of ion traps with lower levels of background pressures and less trap electrode surface contamination. The technique and laser system reported here should be applicable to loading most laser-cooled ion species.

  5. Low-temperature Bessel beam trap for single submicrometer aerosol particle studies

    SciTech Connect (OSTI)

    Lu, Jessica W.; Chasovskikh, Egor; Stapfer, David [Laboratory of Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, CH-8093 Zürich (Switzerland); Isenor, Merrill; Signorell, Ruth [Laboratory of Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, CH-8093 Zürich (Switzerland); Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1 (Canada)

    2014-09-01T23:59:59.000Z

    We report on a new instrument for single aerosol particle studies at low temperatures that combines an optical trap consisting of two counter-propagating Bessel beams (CPBBs) and temperature control down to 223 K (?50?°C). The apparatus is capable of capturing and stably trapping individual submicrometer- to micrometer-sized aerosol particles for up to several hours. First results from studies of hexadecane, dodecane, and water aerosols reveal that we can trap and freeze supercooled droplets ranging in size from ?450 nm to 5500 nm (radius). We have conducted homogeneous and heterogeneous freezing experiments, freezing-melting cycles, and evaporation studies. To our knowledge, this is the first reported observation of the freezing process for levitated single submicrometer-sized droplets in air using optical trapping techniques. These results show that a temperature-controlled CPBB trap is an attractive new method for studying phase transitions of individual submicrometer aerosol particles.

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

    SciTech Connect (OSTI)

    Mandal, Debraj; Sharma, Devendra [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)

    2014-10-15T23:59:59.000Z

    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.

  7. Soot combustion during regeneration of filter ceramic traps for Diesel engines

    SciTech Connect (OSTI)

    Romero-Lopez, A.F.; Gutierrez-Salinas, R.; Garcia-Moreno, R.

    1996-09-01T23:59:59.000Z

    A retro-fit system for buses and heavy duty trucks is presented, along with the mathematical modeling of soot (particulate matter or PM) combustion. In spite of the fact that the use of ceramic traps has lost popularity in the US during the last few years, mainly due to the severe problems encountered during regeneration, a new approach to Diesel emissions control, is presented. The main objective is to attain the emissions levels set forth by the EPA for 1998, both on PM and NOx emissions. The very high levels of temperature required for thermal regeneration and elaborate controls, have almost eliminated the preference for ceramic filters. However, a new approach is presented by using catalyzed filters which considerably reduce the high temperature requirements. Along with the mathematical modeling a new hardware is presented, which is capable of performing filtering, regeneration, and operation with somewhat simpler and more economical controls. Improvements in the design of combustion chambers, higher injection pressures, better fuels and lubricants, etc., have made possible to re-think the concept of mechanical filtration of Diesel Particulate Matter (DPM). The development of the system has been partially sponsored by the Mexico City Government in an attempt to reduce the air pollution within the overloaded atmosphere of the large Mexico City Metropolitan Area (MCMA). Reported results are of the public domain.

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

    SciTech Connect (OSTI)

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

    2007-09-01T23:59:59.000Z

    Distributed energy is an approach for meeting energy needs that has several advantages. Distributed energy improves energy security during natural disasters or terrorist actions, improves transmission grid reliability by reducing grid load, and enhances power quality through voltage support and reactive power. In addition, distributed energy can be efficient since transmission losses are minimized. One prime mover for distributed energy is the natural gas reciprocating engine generator set. Natural gas reciprocating engines are flexible and scalable solutions for many distributed energy needs. The engines can be run continuously or occasionally as peak demand requires, and their operation and maintenance is straightforward. Furthermore, system efficiencies can be maximized when natural gas reciprocating engines are combined with thermal energy recovery for cooling, heating, and power applications. Expansion of natural gas reciprocating engines for distributed energy is dependent on several factors, but two prominent factors are efficiency and emissions. Efficiencies must be high enough to enable low operating costs, and emissions must be low enough to permit significant operation hours, especially in non-attainment areas where emissions are stringently regulated. To address these issues the U.S. Department of Energy and the California Energy Commission launched research and development programs called Advanced Reciprocating Engine Systems (ARES) and Advanced Reciprocating Internal Combustion Engines (ARICE), respectively. Fuel efficiency and low emissions are two primary goals of these programs. The work presented here was funded by the ARES program and, thus, addresses the ARES 2010 goals of 50% thermal efficiency (fuel efficiency) and <0.1 g/bhp-hr emissions of oxides of nitrogen (NOx). A summary of the goals for the ARES program is given in Table 1-1. ARICE 2007 goals are 45% thermal efficiency and <0.015 g/bhp-hr NOx. Several approaches for improving the 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 oxidation and reforming chemistry, and the effects of sulfur poisons on the partial oxidation

  9. Gyrotactic trapping in laminar and turbulent Kolmogorov flow

    E-Print Network [OSTI]

    Francesco Santamaria; Filippo De Lillo; Massimo Cencini; Guido Boffetta

    2014-10-07T23:59:59.000Z

    Phytoplankton patchiness, namely the heterogeneous distribution of microalgae over multiple spatial scales, dramatically impacts marine ecology. A spectacular example of such heterogeneity occurs in thin phytoplankton layers (TPLs), where large numbers of photosynthetic microorganisms are found within a small depth interval. Some species of motile phytoplankton can form TPLs by gyrotactic trapping due to the interplay of their particular swimming style (directed motion biased against gravity) and the transport by a flow with shear along the direction of gravity. Here we consider gyrotactic swimmers in numerical simulations of the Kolmogorov shear flow, both in laminar and turbulent regimes. In the laminar case, we show that the swimmer motion is integrable and the formation of TPLs can be fully characterized by means of dynamical systems tools. We then study the effects of rotational Brownian motion or turbulent fluctuations (appearing when the Reynolds number is large enough) on TPLs. In both cases we show that TPLs become transient, and we characterize their persistence.

  10. Gas turbine engine combustor can with trapped vortex cavity

    DOE Patents [OSTI]

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

    2005-10-04T23:59:59.000Z

    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.

  11. Laser cooling of a trapped particle with increased Rabi frequencies

    SciTech Connect (OSTI)

    Blake, Tony; Kurcz, Andreas; Saleem, Norah S.; Beige, Almut [School of Physics and Astronomy, University of Leeds, Leeds, LS2 9JT (United Kingdom)

    2011-11-15T23:59:59.000Z

    This paper analyzes the cooling of a single particle in a harmonic trap with red-detuned laser light with fewer approximations than previously done in the literature. We avoid the adiabatic elimination of the excited atomic state but are still interested in Lamb-Dicke parameters {eta}<<1. Our results show that the Rabi frequency of the cooling laser can be chosen higher than previously assumed, thereby increasing the effective cooling rate but not affecting the final outcome of the cooling process. Since laser cooling is already a well-established experimental technique, the main aim of this paper is to present a model which can be extended to more complex scenarios, like cavity-mediated laser cooling.

  12. Laser cooling of a trapped particle with increased Rabi frequencies

    E-Print Network [OSTI]

    Tony Blake; Andreas Kurcz; Norah S. Saleem; Almut Beige

    2011-10-14T23:59:59.000Z

    This paper analyses the cooling of a single particle in a harmonic trap with red-detuned laser light with fewer approximations than previously done in the literature. We avoid the adiabatic elimination of the excited atomic state but are still interested in Lamb-Dicke parameters $\\eta \\ll 1$. Our results show that the Rabi frequency of the cooling laser can be chosen higher than previously assumed, thereby increasing the effective cooling rate but {\\em not} affecting the final outcome of the cooling process. Since laser cooling is already a well established experimental technique, the main aim of this paper is to present a model which can be extended to more complex scenarios, like cavity-mediated laser cooling.

  13. Magnetic-field dependent trap loss of ultracold metastable helium

    E-Print Network [OSTI]

    J. S. Borbely; R. van Rooij; S. Knoop; W. Vassen

    2011-11-24T23:59:59.000Z

    We have experimentally studied the magnetic-field dependence of the decay of a Bose-Einstein condensate of metastable 4He atoms confined in an optical dipole trap, for atoms in the m=+1 and m=-1 magnetic substates, and up to 450 G. Our measurements confirm long-standing calculations of the two-body loss rate coefficient that show an increase above 50 G. We demonstrate that for m=-1 atoms, decay is due to three-body recombination only, with a three-body loss rate coefficient of 6.5(0.4)(0.6)10^(-27)cm^6s^(-1), which is interesting in the context of universal few-body theory. We have also searched for a recently-predicted d-wave Feshbach resonance, but did not observe it.

  14. Loopless non-trapping invasion percolation model for fracking

    E-Print Network [OSTI]

    Norris, J Quinn; Rundle, John B

    2014-01-01T23:59:59.000Z

    Recent developments in hydraulic fracturing (fracking) have enabled the recovery of large quantities of natural gas and oil from old, low permeability shales. These developments include a change from low-volume, high-viscosity fluid injection to high-volume, low-viscosity injection. The injected fluid introduces distributed damage that provides fracture permeability for the extraction of the gas and oil. In order to model this process, we utilize a loopless non-trapping invasion percolation previously introduced to model optimal polymers in a strongly disordered medium, and for determining minimum energy spanning trees on a lattice. We performed numerical simulations on a 2D square lattice and find significant differences from other percolation models. Additionally, we find that the growing fracture network satisfies both Horton-Strahler and Tokunaga network statistics. As with other invasion percolation models, our model displays burst dynamics, in which the cluster extends rapidly into a connected region. W...

  15. Weakly bound molecules trapped with discrete scaling symmetries

    E-Print Network [OSTI]

    Yusuke Nishida; Dean Lee

    2012-09-12T23:59:59.000Z

    When the scattering length is proportional to the distance from the center of the system, two particles are shown to be trapped about the center. Furthermore, their spectrum exhibits discrete scale invariance, whose scale factor is controlled by the slope of the scattering length. While this resembles the Efimov effect, our system has a number of advantages when realized with ultracold atoms. We also elucidate how the emergent discrete scaling symmetry is violated for more than two bosons, which may shed new light on Efimov physics. Our system thus serves as a tunable model system to investigate universal physics involving scale invariance, quantum anomaly, and renormalization group limit cycle, which are important in a broad range of quantum physics.

  16. Entropic Trapping of Particles at Polymer Surfaces and Interfaces

    E-Print Network [OSTI]

    Galen T. Pickett

    2015-05-22T23:59:59.000Z

    I consider the possibility that Gaussian random walk statistics are sufficient to trap nanoscopic additives at either a polymer interface or surface. When an additive particle goes to the free surface, two portions of the polymer surface energy behave quite differently. The purely enthalpic contribution increases the overall free energy when the additive protrudes above the level of the polymer matrix. The entropic part of the surface energy arising from constraints that segments near a surface can't cross it, is partly relaxed when the additive moves to the free surface. These two portions of the polymer surface energy determine the equilibrium wetting angle formed between the additive and the polymer matrix, the measurement of which in an experiment would allow an independent determination of each piece of the polymer surface energy.

  17. Spontaneous recoil effects of optical pumping on trapped atoms

    E-Print Network [OSTI]

    S. Wallentowitz; P. E. Toschek

    2008-08-08T23:59:59.000Z

    The recoil effects of spontaneous photon emissions during optical pumping of a trapped three-level atom are exactly calculated. Without resort to the Lamb-Dicke approximation, and considering arbitrary detuning and saturation of the pump laser, the density of recoil shifts in phase space is derived. It is shown that this density is not of Gaussian shape, and that it becomes isotropic in phase space only for a branching ratio corresponding to fluorescence scattering but unfavorable for optical pumping. The dependence of its anisotropy on the laser saturation is discussed in the resonant case, and the mapping of moments of the atom's center-of-mass motion due to the pumping is presented. Moreover, it is shown how optimum parameters for protecting the center-of-mass quantum state from pump-induced disturbance depend on the specific property to be protected.

  18. Dust trapping by spiral arms in gravitationally unstable protostellar discs

    E-Print Network [OSTI]

    Dipierro, Giovanni; Lodato, Giuseppe; Testi, Leonardo

    2015-01-01T23:59:59.000Z

    In this paper we discuss the influence of gravitational instabilities in massive protostellar discs on the dynamics of dust grains. Starting from a Smoothed Particle Hydrodynamics (SPH) simulation, we have computed the evolution of the dust in a quasi-static gas density structure typical of self-gravitating disc. For different grain size distributions we have investigated the capability of spiral arms to trap particles. We have run 3D radiative transfer simulations in order to construct maps of the expected emission at (sub-)millimetre and near-infrared wavelengths. Finally, we have simulated realistic observations of our disc models at (sub-)millimetre and near-infrared wavelengths as they may appear with the Atacama Large Millimetre/sub-millimetre Array (ALMA) and the High-Contrast Coronographic Imager for Adaptive Optics (HiCIAO) in order to investigate whether there are observational signatures of the spiral structure. We find that the pressure inhomogeites induced by gravitational instabilities produce a...

  19. Remark on laser linewidth hazard in opto-mechanical cooling

    E-Print Network [OSTI]

    Lajos Diósi

    2008-07-23T23:59:59.000Z

    I discuss the robustness of the pumped cavity dynamics against phase diffusion of the laser and conclude that opto-mechanical cooling has extreme sensitivity compared to laser cooling of atoms. Certain proposals of ground state opto-mechanical cooling by single cavity would require an unrealistic sharp laser linewidth or equivalently, a very low level of phase noise. A systematic way to cancel classical excess phase noise is the interferometric twin-cavity pumping, initiated for optically trapped macro-mirrors of future gravitational-wave detectors.

  20. Construction and Operational Experience with a Superconducting Octupole Used to Trap Antihydrogen

    SciTech Connect (OSTI)

    Wanderer P.; Escallier, J.; Marone, A.; Parker, B.

    2011-09-06T23:59:59.000Z

    A superconducting octupole magnet has seen extensive service as part of the ALPHA experiment at CERN. ALPHA has trapped antihydrogen, a crucial step towards performing precision measurements of anti-atoms. The octupole was made at the Direct Wind facility by the Superconducting Magnet Division at Brookhaven National Laboratory. The magnet was wound with a six-around-one NbTi cable about 1 mm in diameter. It is about 300 mm long, with a radius of 25 mm and a peak field at the conductor of 4.04 T. Specific features of the magnet, including a minimal amount of material in the coil and coil ends with low multipole content, were advantageous to its use in ALPHA. The magnet was operated for six months a year for five years. During this time it underwent about 900 thermal cycles (between 4K and 100K). A novel operational feature is that during the course of data-taking the magnet was repeatedly shut off from its 950 A operating current. The magnet quenches during the shutoff, with a decay constant of 9 ms. Over the course of the five years, the magnet was deliberately quenched many thousands of times. It still performs well.