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1

Tellurium Inclusions and Carrier Trapping Times in Detector Grade ...  

Science Conference Proceedings (OSTI)

Spatial mapping of carrier trapping times and defect densities in CZT was performed to determine the relationship between defect density and electronic decay.

2

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

E-Print Network (OSTI)

Trapping Mechanisms in Single CdSe/ZnS Quantum Dots fromTrapping Mechanisms in Single CdSe/ZnS Quantum Dots fromintermittency of single CdSe/ZnS core/shell quantum dot

Cordones, Amy Ashbrook

2012-01-01T23:59:59.000Z

3

Possible mechanism for enhancing the trapping and cooling of antihydrogen  

SciTech Connect

We propose a usage of microwave radiation in a magnetic trap for improving the cooling and trapping of cold antihydrogen atoms which are initially produced in high magnetic moment states. Inducing transitions toward lower magnetic moments near the turning points of the atom in the trap, followed by spontaneous emission, should enhance the number of trappable atoms. We present results of simulations based on a typical experimental condition of the antihydrogen experiments at CERN. This technique should also be applicable to other trapped high magnetic moment Rydberg atoms.

Cesar, C. L.; Zagury, N. [Instituto de Fisica, Universidade Federal do Rio de Janeiro, 21941-972 Rio de Janeiro, RJ (Brazil); Robicheaux, F. [Department of Physics, Auburn University, Auburn, Alabama 36849 (United States)

2009-10-15T23:59:59.000Z

4

Investigation of Aging Mechanisms in Lean NOx Traps  

Science Conference Proceedings (OSTI)

Lean NO{sub x} traps (LNTs) represent a promising technology for the abatement of NO{sub x} under lean conditions. Although LNTs are starting to find commercial application, the issue of catalyst durability remains problematic. LNT susceptibility to sulfur poisoning is the single most important factor determining effective catalyst lifetime. The NO{sub x} storage element of the catalyst has a greater affinity for SO{sub 3} than it does for NO{sub 2}, and the resulting sulfate is more stable than the stored nitrate. Although this sulfate can be removed from the catalyst by means of high temperature treatment under rich conditions, the required conditions give rise to deactivation mechanisms such as precious metal sintering, total surface area loss, and solid state reactions between the various oxides present. The principle objective of this project was to improve understanding of the mechanisms of lean NO{sub x} trap aging, and to understand the effect of washcoat composition on catalyst aging characteristics. The approach utilized involved detailed characterization of model catalysts prior to and after aging, in tandem with measurement of catalyst performance in NO{sub x} storage and reduction. In this manner, NO{sub x} storage and reduction characteristics were correlated with the evolution of catalyst physico-chemical properties upon aging. Rather than using poorly characterized proprietary catalysts, or simple model catalysts of the Pt/BaO/Al{sub 2}O{sub 3} type (representing the first generation of LNTs), Pt/Rh/BaO/Al{sub 2}O{sub 3} catalysts were employed which also incorporated CeO{sub 2} or CeO{sub 2}-ZrO{sub 2}, representing a model system which more accurately reflects current LNT formulations. Catalysts were prepared in which the concentration of each of the main components was systematically varied: Pt (50, 75 or 100 g/ft{sup 3}), Rh (10 or 20 g/ft{sup 3}), BaO (15, 30 or 45 g/L), and either CeO{sub 2} (0, 50 or 100 g/L) or CeO{sub 2}-ZrO{sub 2} (0, 50 or 100 g/L). A high surface area La-stabilized alumina was used to support the BaO phase. Catalysts were obtained by washcoating onto standard cordierite substrates, the total washcoat loading being set at 260 g/L. La-stabilized alumina was used as the balance. Subsequent to de-greening, the NO{sub x} storage and reduction characteristics of the catalysts were evaluated on a bench reactor, after which the catalysts were aged on a bench reactor to the equivalent of ca. 75,000 miles of road aging using a published accelerated aging protocol. The aged catalysts were then subjected to the same evaluation proecdure used for the de-greened catalysts. In addition to the use of standard physico-chemical analytical techniques for studying the fresh and aged model catalysts, use was made of advanced analytical tools for characterizing their NO{sub x} storage/reduction and sulfation/desulfation characteristics, such as Spatially resolved capillary-inlet Mass Spectrometry (SpaciMS) and in situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS).

Mark Crocker

2010-03-31T23:59:59.000Z

5

Quantum mechanics of one-dimensional trapped Tonks gases  

E-Print Network (OSTI)

Several experimental groups are currently working towards realizing quasi-one-dimensional (1D) atom waveguides and loading them with ultracold atoms. The dynamics becomes truly 1D in a regime (Tonks gas) of low temperatures and densities and large positive scattering lengths for which the transverse mode becomes frozen, in which case the many-body Schrodinger dynamics becomes exactly soluble via a Fermi-Bose mapping theorem. In this paper we review our recent work on the exact ground state and quantum dynamics of 1D Tonks gases and assess the possibility of approaching the Tonks regime using Bessel beam optical dipole traps.

M. D. Girardeau; E. M. Wright

2001-04-30T23:59:59.000Z

6

Generation of continuous variable squeezing and entanglement of trapped ions in time-varying potentials  

Science Conference Proceedings (OSTI)

We investigate the generation of squeezing and entanglement for the motional degrees of freedom of ions in linear traps, confined by time-varying and oscillating potentials, comprised of a DC and an AC component. We show that high degrees of squeezing ... Keywords: 03.67.Bg, 05.45.Xt, 37.10.Vz, 42.50.Dv, Control, Entanglement, Ion traps

Alessio Serafini; Alex Retzker; Martin B. Plenio

2009-12-01T23:59:59.000Z

7

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

SciTech Connect

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.

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

2011-11-01T23:59:59.000Z

8

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

Science Conference Proceedings (OSTI)

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.

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

2008-06-10T23:59:59.000Z

9

Experimental investigation of the trapping and energy loss mechanisms of intense relativistic electron rings in hydrogen gas and plasma  

DOE Green Energy (OSTI)

The results of an experimental study on the trapping and energy loss mechanisms of intense, relativistic electron rings confined in Astron-like magnetic field geometries are presented. The work is subdivided into four sections: gas trapping; average ring electron energetics; plasma trapping, and hollow-beam cusp-injection into gas and plasma. The mechanisms by which the injected beam coalesces into a current ring in the existing Cornell RECE-Berta facility are considered. To investigate the nature of ring electron energy loss mechanisms following completion of the trapping process, a diagnostic was developed utilizing multi-foil X-ray absorption spectroscopy to analyze the Bremsstrahlung generated by the electrons as they impinge upon a thin tungsten wire target suspended in the circulating current. Finally, a set of preliminary experimental results is presented in which an annular electron beam was passed through a coaxial, non-adiabatic magnetic cusp located at one end of a magnetic mirror well.

Smith, A.C. Jr.

1977-04-25T23:59:59.000Z

10

ESI/Ion Trap/Ion Mobility/Time-of-Flight Mass Spectrometry for Rapid and Sensitive Analysis of  

E-Print Network (OSTI)

discuss a new separation strategy for biomolecules that is based on differences in ion mobilitiesESI/Ion Trap/Ion Mobility/Time-of-Flight Mass Spectrometry for Rapid and Sensitive Analysis* Department of Chemistry, Indiana University, Bloomington, Indiana 47405 An ion trap/ion mobility

Clemmer, David E.

11

Quantum mechanics as "space-time statistical mechanics"?  

E-Print Network (OSTI)

In this paper we discuss and analyse the idea of trying to see (non-relativistic) quantum mechanics as a ``space-time statistical mechanics'', by using the classical statistical mechanical method on objective microscopic space-time configurations. It is argued that this could perhaps be accomplished by giving up the assumption that the objective ``state'' of a system is independent of a future measurement performed on the system. This idea is then applied in an example of quantum state estimation on a qubit system.

Anders Mĺnsson

2005-01-24T23:59:59.000Z

12

Unfaulting mechanism of trapped self-interstitial atom clusters in bcc Fe: A kinetic study based on the potential energy landscape  

E-Print Network (OSTI)

We report on the complete unfaulting mechanism of a trapped self-interstitial atom cluster in the form of a nonparallel configuration (NPC), investigated using the autonomous basin climbing (ABC) method. A detailed set of ...

Yildiz, Bilge

13

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

SciTech Connect

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.

Catherine L. Hanks

2008-12-31T23:59:59.000Z

14

Quantum mechanics of time travel through post-selected teleportation  

E-Print Network (OSTI)

This paper discusses the quantum mechanics of closed-timelike curves (CTCs) and of other potential methods for time travel. We analyze a specific proposal for such quantum time travel, the quantum description of CTCs based ...

Maccone, Lorenzo

15

Experimental investigation of the trapping and energy loss mechanisms of intense relativistic electron rings in hydrogen gas and plasma  

DOE Green Energy (OSTI)

This volume is a direct continuation of Volume 1. Included are chapters 5 and 6 which deal with the trapping and confinement of electron rings in preionized media, neutral gases, and plasma.

Smith, A.C. Jr.

1977-04-25T23:59:59.000Z

16

Overhead elimination mechanisms in real-time systems  

Science Conference Proceedings (OSTI)

The OEM (Overhead Elimination Mechanism), a scheduler for finding minimal overheads with reduced context switches in real-time systems, was developed using procedural methods. Software produced by these methods has often proven to be inflexible and difficult ... Keywords: Real-time scheduling, context switches, object-oriented, procedural, rate monotonic algorithm

Ilhyun Lee; Haesun K. Lee; Narayan Debnath

2006-04-01T23:59:59.000Z

17

Nonlinear integrable ion traps  

Science Conference Proceedings (OSTI)

Quadrupole ion traps can be transformed into nonlinear traps with integrable motion by adding special electrostatic potentials. This can be done with both stationary potentials (electrostatic plus a uniform magnetic field) and with time-dependent electric potentials. These potentials are chosen such that the single particle Hamilton-Jacobi equations of motion are separable in some coordinate systems. The electrostatic potentials have several free adjustable parameters allowing for a quadrupole trap to be transformed into, for example, a double-well or a toroidal-well system. The particle motion remains regular, non-chaotic, integrable in quadratures, and stable for a wide range of parameters. We present two examples of how to realize such a system in case of a time-independent (the Penning trap) as well as a time-dependent (the Paul trap) configuration.

Nagaitsev, S.; /Fermilab; Danilov, V.; /SNS Project, Oak Ridge

2011-10-01T23:59:59.000Z

18

Generic Mechanism of Optimal Energy Transfer Efficiency: A Scaling Theory of the Mean First Passage Time in Exciton Systems  

E-Print Network (OSTI)

An asymptotic scaling theory is presented using the conceptual basis of trapping-free subspace (i.e., orthogonal subspace) to establish the generic mechanism of optimal efficiency of excitation energy transfer (EET) in light-harvesting systems. Analogous to Kramers' turnover in classical rate theory, the enhanced efficiency in the weak damping limit and the suppressed efficiency in the strong damping limit define two asymptotic scaling regimes, which are interpolated to predict the functional form of optimal efficiency of the trapping-free subspace. In the presence of static disorder, the scaling law of transfer time with respect to dephasing rate changes from linear to square root, suggesting a weaker dependence on the environment. Though formulated in the context of EET, the analysis and conclusions apply in general to open quantum processes, including electron transfer, fluorescence emission, and heat conduction.

Wu, Jianlan; Silbey, Robert J

2013-01-01T23:59:59.000Z

19

COLD TRAPS  

DOE Patents (OSTI)

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

Thompson, W.I.

1958-09-30T23:59:59.000Z

20

A dynamical time operator in Dirac's relativistic quantum mechanics  

E-Print Network (OSTI)

A self-adjoint dynamical time operator is introduced in Dirac's relativistic formulation of quantum mechanics and shown to satisfy a commutation relation with the Hamiltonian analogous to that of the position and momentum operators. The ensuing time-energy uncertainty relation involves the uncertainty in the instant of time when the wave packet passes a particular spatial position and the energy uncertainty associated with the wave packet at the same time, as envisaged originally by Bohr. The instantaneous rate of change of the position expectation value with respect to the simultaneous expectation value of the dynamical time operator is shown to be the phase velocity, in agreement with de Broglie's hypothesis of a particle associated wave whose phase velocity is larger than c. Thus, these two elements of the original basis and interpretation of quantum mechanics are integrated into its formal mathematical structure. Pauli's objection is shown to be resolved or circumvented. Possible relevance to current developments in interference in time, in Zitterbewegung like effects in spintronics, grapheme and superconducting systems and in cosmology is noted.

Mariano Bauer

2009-08-19T23:59:59.000Z

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


21

Time and Entropy in the Foundations of Mechanics  

E-Print Network (OSTI)

This contribution analyses the classical laws of motion by means of an approach relating time and entropy. We argue that adopting the notion of change of states as opposed to the usual derivation of Newton's laws in terms of fields a broader picture is obtained, suggesting that diverse branches of physics- classical, quantum, relativistic and statistical mechanics - turn out to be related by a common foundation.

R Assumpcao

2007-06-17T23:59:59.000Z

22

Quantum mechanics in curved space-time II  

E-Print Network (OSTI)

This paper is a sequence of the work presented in [1], where, the principles of the general relativity have been used to formulate quantum wave equations taking into account the effect of the electromagnetic and strong interactions in the space-time metric of quantum systems. Now, the role of the energy-momentum tensor in this theory is studied, and it is consistent with the formulation of the general quantum mechanics shown in [1]. With this procedure, a dynamical cut-off is generated and the constant $A$ of the field equation is calculated.

C. C. Barros Jr

2005-09-01T23:59:59.000Z

23

Hybrid quadrupole mass filter/quadrupole ion trap/time-of-flight-mass spectrometer for infrared multiple photon dissociation spectroscopy of mass-selected ions  

Science Conference Proceedings (OSTI)

We present a laboratory-constructed mass spectrometer optimized for recording infrared multiple photon dissociation (IRMPD) spectra of mass-selected ions using a benchtop tunable infrared optical parametric oscillator/amplifier (OPO/A). The instrument is equipped with two ionization sources, an electrospray ionization source, as well as an electron ionization source for troubleshooting. This hybrid mass spectrometer is composed of a quadrupole mass filter for mass selection, a reduced pressure ({approx}10{sup -5} Torr) quadrupole ion trap (QIT) for OPO irradiation, and a reflectron time-of-flight drift tube for detecting the remaining precursor and photofragment ions. A helium gas pulse is introduced into the QIT to temporarily increase the pressure and hence enhance the trapping efficiency of axially injected ions. After a brief pump-down delay, the compact ion cloud is subjected to the focused output from the continuous wave OPO. In a recent study, we implemented this setup in the study of protonated tryptophan, TrpH{sup +}, as well as collision-induced dissociation products of this protonated amino acid [W. K. Mino, Jr., K. Gulyuz, D. Wang, C. N. Stedwell, and N. C. Polfer, J. Phys. Chem. Lett. 2, 299 (2011)]. Here, we give a more detailed account on the figures of merit of such IRMPD experiments. The appreciable photodissociation yields in these measurements demonstrate that IRMPD spectroscopy of covalently bound ions can be routinely carried out using benchtop OPO setups.

Gulyuz, Kerim; Stedwell, Corey N.; Wang Da; Polfer, Nick C. [Department of Chemistry, University of Florida, P.O. Box 117200, Gainesville, Florida 32611 (United States)

2011-05-15T23:59:59.000Z

24

Mode trap  

DOE Patents (OSTI)

This report discusses a mode trap to trap and absorb transverse modes formed by a beam in a linear accelerator includes a waveguide having a multiplicity of electrically conductive (preferably copper) irises and rings, each iris and ring including an aperture, and the irises and rings being stacked in a side-by-side, alternating fashion such that the apertures of the irises and rings are concentrically aligned. An absorbing material layer such as a dielectric is embedded in each iris and ring, and this absorbing material layer encircles, but is circumferentially spaced from its respective aperture. Each iris and ring includes a plurality of circumferentially spaced slots around it`s aperture and extending radially out toward it`s absorbing material layer.

Chojnacki, E.P.

1992-12-31T23:59:59.000Z

25

Interaction of trapped ions with trapped atoms  

E-Print Network (OSTI)

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 ...

Grier, Andrew T. (Andrew Todd)

2011-01-01T23:59:59.000Z

26

COLD TRAP  

DOE Patents (OSTI)

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

Milleron, N.

1963-03-12T23:59:59.000Z

27

Dipole traps for neutral atoms formed by nonuniformly polarised Laguerre modes  

SciTech Connect

Field configurations of two counterpropagating nonuniformly polarised Laguerre modes forming three-dimensional dipole traps for neutral atoms are proposed. Peculiarities of the stochastic dynamics of atoms in such traps, associated with the anisotropy of dipole forces and manifestations of various radiative friction mechanisms are analysed. The problem of increasing the confinement time for atoms in such field configurations is studied. (laser applications and other topics in quantum electronics)

Bezverbny, Aleksandr V [Maritime State University, Vladivostok (Russian Federation); Niz'ev, Vladimir G [Institute on Laser and Information Technologies, Russian Academy of Sciences, Shatura, Moscow Region (Russian Federation); Tumaikin, Anatolii M [Institute of Laser Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk (Russian Federation)

2004-07-31T23:59:59.000Z

28

Trapped Inflation  

Science Conference Proceedings (OSTI)

We analyze a distinctive mechanism for inflation in which particle production slows down a scalar field on a steep potential, and show how it descends from angular moduli in string compactifications. The analysis of density perturbations - taking into account the integrated effect of the produced particles and their quantum fluctuations - requires somewhat new techniques that we develop. We then determine the conditions for this effect to produce sixty e-foldings of inflation with the correct amplitude of density perturbations at the Gaussian level, and show that these requirements can be straightforwardly satisfied. Finally, we estimate the amplitude of the non-Gaussianity in the power spectrum and find a significant equilateral contribution.

Green, Daniel; Horn, Bart; /SLAC /Stanford U., Phys. Dept.; Senatore, Leonardo; /Princeton, Inst. Advanced Study /Harvard U., Phys. Dept. /Harvard-Smithsonian Ctr. Astrophys.; Silverstein, Eva; /SLAC /Stanford U., Phys. Dept.

2009-06-19T23:59:59.000Z

29

Using semiclassical trajectories for the time-evolution of interacting quantum-mechanical systems  

Science Conference Proceedings (OSTI)

We have developed a method that recasts the time-propagation of dynamic, mutually interacting quantum-mechanical wavefunctions principally as the time-evolution of many classical particles. Our approach utilizes an approximation of Feynman path integrals, ... Keywords: Feynman, WKB, grid method, interacting, lagrangian, parallel computation, particle-based, path integral, plasma PIC, quantum particle-in-cell, semiclassical, stationary phase, time evolving

D. E. Dauger; V. K. Decyk; J. M. Dawson

2005-11-01T23:59:59.000Z

30

Microfabricated Ion Traps  

E-Print Network (OSTI)

Ion traps offer the opportunity to study fundamental quantum systems with high level of accuracy highly decoupled from the environment. Individual atomic ions can be controlled and manipulated with electric fields, cooled to the ground state of motion with laser cooling and coherently manipulated using optical and microwave radiation. Microfabricated ion traps hold the advantage of allowing for smaller trap dimensions and better scalability towards large ion trap arrays also making them a vital ingredient for next generation quantum technologies. Here we provide an introduction into the principles and operation of microfabricated ion traps. We show an overview of material and electrical considerations which are vital for the design of such trap structures. We provide guidance in how to choose the appropriate fabrication design, consider different methods for the fabrication of microfabricated ion traps and discuss previously realized structures. We also discuss the phenomenon of anomalous heating of ions within ion traps, which becomes an important factor in the miniaturization of ion traps.

Marcus D. Hughes; Bjoern Lekitsch; Jiddu A. Broersma; Winfried K. Hensinger

2011-01-17T23:59:59.000Z

31

Trapping Rydberg Atoms in an Optical Lattice  

Science Conference Proceedings (OSTI)

Rubidium Rydberg atoms are laser excited and subsequently trapped in a one-dimensional optical lattice (wavelength 1064 nm). Efficient trapping is achieved by a lattice inversion immediately after laser excitation using an electro-optic technique. The trapping efficiency is probed via analysis of the trap-induced shift of the two-photon microwave transition 50S{yields}51S. The inversion technique allows us to reach a trapping efficiency of 90%. The dependence of the efficiency on the timing of the lattice inversion and on the trap laser power is studied. The dwell time of 50D{sub 5/2} Rydberg atoms in the lattice is analyzed using lattice-induced photoionization.

Anderson, S. E.; Younge, K. C.; Raithel, G. [FOCUS Center, Department of Physics, University of Michigan, Ann Arbor, Michigan 48109 (United States)

2011-12-23T23:59:59.000Z

32

Cosmological perturbations from inhomogeneous preheating and multi-field trapping  

E-Print Network (OSTI)

We consider inhomogeneous preheating in a multi-field trapping model. The curvature perturbation is generated by inhomogeneous preheating which induces multi-field trapping at the enhanced symmetric point (ESP), and results in fluctuation in the number of e-foldings. Instead of considering simple reheating after preheating, we consider a scenario of shoulder inflation induced by the trapping. The fluctuation in the number of e-foldings is generated during this weak inflationary period, when the additional light scalar field is trapped at the local maximum of its potential. The situation may look similar to locked or thermal inflation or even to hybrid inflation, but we will show that the present mechanism of generating the curvature perturbation is very different from these others. Unlike the conventional trapped inflationary scenario, we do not make the assumption that an ESP appears at some unstable point on the inflaton potential. This assumption is crucial in the original scenario, but it is not important in the multi-field model. We also discuss inhomogeneous preheating at late-time oscillation, in which the magnitude of the curvature fluctuation can be enhanced to accommodate low inflationary scale.

Tomohiro Matsuda

2007-07-04T23:59:59.000Z

33

Superconducting microfabricated ion traps  

E-Print Network (OSTI)

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 ...

Wang, Shannon Xuanyue

34

Ion trap simulation tools.  

Science Conference Proceedings (OSTI)

Ion traps present a potential architecture for future quantum computers. These computers are of interest due to their increased power over classical computers stemming from the superposition of states and the resulting capability to simultaneously perform many computations. This paper describes a software application used to prepare and visualize simulations of trapping and maneuvering ions in ion traps.

Hamlet, Benjamin Roger

2009-02-01T23:59:59.000Z

35

Steam Trap Application  

E-Print Network (OSTI)

The effective application of steam traps encompasses three primary areas which are the selection and sizing, the installation, and the monitoring of the steam trapping system. Proper application of steam traps will improve production rates, product quality, and reduce energy and maintenance costs.

Murphy, J. J.

1982-01-01T23:59:59.000Z

36

Superconducting microfabricated ion traps  

E-Print Network (OSTI)

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.

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

2010-10-28T23:59:59.000Z

37

Microfabricated Ion Traps  

E-Print Network (OSTI)

Ion traps offer the opportunity to study fundamental quantum systems with high level of accuracy highly decoupled from the environment. Individual atomic ions can be controlled and manipulated with electric fields, cooled to the ground state of motion with laser cooling and coherently manipulated using optical and microwave radiation. Microfabricated ion traps hold the advantage of allowing for smaller trap dimensions and better scalability towards large ion trap arrays also making them a vital ingredient for next generation quantum technologies. Here we provide an introduction into the principles and operation of microfabricated ion traps. We show an overview of material and electrical considerations which are vital for the design of such trap structures. We provide guidance in how to choose the appropriate fabrication design, consider different methods for the fabrication of microfabricated ion traps and discuss previously realized structures. We also discuss the phenomenon of anomalous heating of ions with...

Hughes, Marcus D; Broersma, Jiddu A; Hensinger, Winfried K

2011-01-01T23:59:59.000Z

38

Scaling self-timed systems powered by mechanical vibration energy harvesting  

Science Conference Proceedings (OSTI)

Passive energy harvesting from mechanical vibration has wide application in wearable devices and wireless sensors to complement or replace batteries. Energy harvesting efficiency can be increased by eliminating AC/DC conversion. A test chip demonstrating ... Keywords: AC power supply, DRAM, energy harvesting, energy-aware systems, integrated circuits, low-power design, power-on reset, scaling, self-timed

Justin Wenck; Jamie Collier; Jeff Siebert; Rajeevan Amirtharajah

2010-06-01T23:59:59.000Z

39

Model simulations of continuous ion injection into electron-beam ion source trap with slanted electrostatic mirror  

Science Conference Proceedings (OSTI)

The efficiency of trapping ions in an electron-beam ion source (EBIS) is of primary importance for many applications requiring operations with externally produced ions: RIA breeders, ion sources, and traps. At the present time, the most popular method of ion injection is pulsed injection, when short bunches of ions get trapped in a longitudinal trap while traversing the trap region. Continuous trapping is a challenge for EBIS devices because mechanisms which reduce the longitudinal ion energy per charge in a trap (cooling with residual gas, energy exchange with other ions, and ionization) are not very effective, and accumulation of ions is slow. A possible approach to increase trapping efficiency is to slant the mirror at the end of the trap which is opposite to the injection end. A slanted mirror will convert longitudinal motion of ions into transverse motion, and, by reducing their longitudinal velocity, prevent these ions from escaping the trap on their way out. The trade-off for the increased trapping efficiency this way is an increase in the initial transverse energy of the accumulated ions. The slanted mirror can be realized if the ends of two adjacent electrodes, drift tubes, which act as an electrostatic mirror, are machined to produce a slanted gap, rather than an upright one. Applying different voltages to these electrodes will produce a slanted mirror. The results of two-dimensional (2D) and three-dimensional (3D) computer simulations of the ion injection into an EBIS are presented using simplified models of an EBIS with conical (2D simulations) and slanted (3D simulations) mirror electrodes.

Pikin, A.; Kponou, A.; Alessi, J. G.; Beebe, E. N.; Prelec, K.; Raparia, D. [Brookhaven National Laboratory, Upton, New York 11973 (United States)

2008-02-15T23:59:59.000Z

40

Mechanism of Radial Redistribution of Energetic Trapped Ions Due to m=2/n=1 Internal Reconnection in Joint European Torus Shear Optimized Plasmas  

DOE Green Energy (OSTI)

Internal radial redistribution of MeV energy ICRF-driven hydrogen minority ions was inferred from neutral particle analyzer measurements during large amplitude MHD activity leading to internal reconnection in Shear Optimized plasmas in the Joint European Torus (JET). A theory is developed for energetic ion redistribution during a reconnection driven by an m=2/n=1 internal kink mode. Plasma motion during reconnection generates an electric field which can change the energy and radial position of the energetic ions. The magnitude of ion energy change depends on the value of the safety factor at the plasma core from which the energetic ions are redistributed. A relation is found for corresponding change in canonical momentum. P(subscript phi), which leads to radial displacement of the ions. The model yields distinctive new features of energetic ion redistribution under such conditions. Predicted characteristics of ion redistribution are compared with the NPA measurements, and good correlation is found. Sometimes fast ions were transported to the plasma edge due to interaction with a long-lived magnetic island which developed after the reconnection and had chirping frequency in the laboratory frame. Convection of resonant ions trapped in a radially moving phase-space island is modeled to understand the physics of such events.

N.N. Gorelenkov; A. Gondhalekar; A.A. Korotkov; S.E. Sharapov; D. Testa; and Contributors to the EFDA-JET Workprogramme

2002-01-18T23:59:59.000Z

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


41

Evaluating Steam Trap Performance  

E-Print Network (OSTI)

Laboratory tests were conducted on several types of steam traps at Holston Defense Corporation in Kingsport, Tennessee. Data from these tests, which determined their relative efficiencies, were used in performing economic analyses to determine their equivalent uniform annual cost (EUAC). The comparison was made using a computer program written for the Apple II computer to evaluate overall steam trap economics. This program calculates the EUAC for any steam trap based on 12 input variables including capital, maintenance and steam costs, interest rate and trap life. After determinIng the EUAC, the program will perform sensitivity analyses on any of the twelve variables. (This computer program is available from the author.) This study shows that inverted bucket traps have lower EUAC's under more conditions than other types of traps. Also, this study shows 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.

Fuller, N. Y.

1986-06-01T23:59:59.000Z

42

Modular cryostat for ion trapping with surface-electrode ion traps  

E-Print Network (OSTI)

We present a simple cryostat purpose built for use with surface-electrode ion traps, designed around an affordable, large cooling power commercial pulse tube refrigerator. A modular vacuum enclosure with a single vacuum space facilitates interior access, and enables rapid turnaround and flexiblity for future modifications. Long rectangular windows provide nearly 360 degrees of optical access in the plane of the ion trap, while a circular bottom window near the trap enables NA 0.4 light collection without the need for in-vacuum optics. We evaluate the system's mechanical and thermal characteristics, and we quantify ion trapping performance by trapping 40Ca+, finding small stray electric fields, long ion lifetimes, and low ion heating rates.

Grahame Vittorini; Kenneth Wright; Kenneth R. Brown; Alexa W. Harter; S. Charles Doret

2013-02-20T23:59:59.000Z

43

Trapping of strangelets in the geomagnetic field  

E-Print Network (OSTI)

Strangelets coming from the interstellar medium (ISM) are an interesting target to experiments searching for evidence of this hypothetic state of hadronic matter. We entertain the possibility of a {\\it trapped} strangelet population, quite analogous to ordinary nuclei and electron belts. For a population of strangelets to be trapped by the geomagnetic field, these incoming particles would have to fulfill certain conditions, namely having magnetic rigidities above the geomagnetic cutoff and below a certain threshold for adiabatic motion to hold. We show in this work that, for fully ionized strangelets, there is a narrow window for stable trapping. An estimate of the stationary population is presented and the dominant loss mechanisms discussed. It is shown that the population would be substantially enhanced with respect to the ISM flux (up to two orders of magnitude) due to quasi-stable trapping.

L. Paulucci; J. E. Horvath; G. A. Medina-Tanco

2007-07-22T23:59:59.000Z

44

Trapping of strangelets in the geomagnetic field  

Science Conference Proceedings (OSTI)

Strangelets arriving from the interstellar medium are an interesting target for experiments searching for evidence of this hypothetical state of hadronic matter. We entertain the possibility of a trapped strangelet population, quite analogous to ordinary nuclei and electron belts. For a population of strangelets to be trapped by the geomagnetic field, these incoming particles would have to fulfill certain conditions, namely, having magnetic rigidities above the geomagnetic cutoff and below a certain threshold for adiabatic motion to hold. We show in this work that, for fully ionized strangelets, there is a narrow window for stable trapping. An estimate of the stationary population is presented and the dominant loss mechanisms discussed. It is shown that the population would be substantially enhanced with respect to the interstellar medium flux (up to 2 orders of magnitude) due to quasistable trapping.

Paulucci, L.; Horvath, J. E.; Medina-Tanco, G. A. [Instituto de Fisica-Universidade de Sao Paulo, Rua do Matao, Travessa R, 187, 05508-090, Cidade Universitaria, Sao Paulo SP (Brazil); Instituto de Astronomia, Geofisica e Ciencias Atmosfericas-Universidade de Sao Paulo, Rua do Matao, 1226, 05508-900, Cidade Universitaria, Sao Paulo SP (Brazil); Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico A.P. 70-543, C.U. Mexico D.F. (Mexico)

2008-02-15T23:59:59.000Z

45

Trapping of strangelets in the geomagnetic field  

E-Print Network (OSTI)

Strangelets coming from the interstellar medium (ISM) are an interesting target to experiments searching for evidence of this hypothetic state of hadronic matter. We entertain the possibility of a {\\it trapped} strangelet population, quite analogous to ordinary nuclei and electron belts. For a population of strangelets to be trapped by the geomagnetic field, these incoming particles would have to fulfill certain conditions, namely having magnetic rigidities above the geomagnetic cutoff and below a certain threshold for adiabatic motion to hold. We show in this work that, for fully ionized strangelets, there is a narrow window for stable trapping. An estimate of the stationary population is presented and the dominant loss mechanisms discussed. It is shown that the population would be substantially enhanced with respect to the ISM flux (up to two orders of magnitude) due to quasi-stable trapping.

Paulucci, L; Medina-Tanco, G A

2007-01-01T23:59:59.000Z

46

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

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

and Stored November 18, 2010 The Department's Lawrence Berkeley National Laboratory (LBNL) announces that atoms of antimatter have been trapped and stored for the first time in...

47

Workshop on Ion Trap Technology  

Science Conference Proceedings (OSTI)

... optical components, conventional and microfabricated ion traps, and classical control ... will bring together experts on trapped-ion physics, laser optics ...

2011-03-01T23:59:59.000Z

48

Trapping of quantum particles and light beams by switchable potential wells  

E-Print Network (OSTI)

We consider basic dynamical effects in settings based on a pair of local potential traps that may be effectively switched on and off, or suddenly displaced, by means of appropriate control mechanisms, such as the scanning tunneling microscopy (STM) or photo-switchable quantum dots. The same models, based on the linear Schrodinger equation with time-dependent trapping potentials, apply to the description of optical planar systems designed for the switching of trapped light beams. The analysis is carried out in the analytical form, using exact solutions of the Schrodinger equation. The first dynamical problem considered in this work is the retention of a particle released from a trap which was suddenly turned off, while another local trap was switched on at a distance - immediately or with a delay. In this case, we demonstrate that the maximum of the retention rate is achieved at a specific finite value of the strength of the new trap, and at a finite value of the temporal delay, depending on the distance between the two traps. Another ptoblem is retrapping of the bound particle when the addition of the second trap transforms the single-well setting into a double-well potential (DWP). In that case, we find probabilities for the retrapping into the ground or first excited state of the DWP. We also analyze effects entailed by the application of a kick to a bound particle, the most interesting one being a kick-induced transition between the DWP's ground and excited states. In the latter case, the largest transition probability is achieved at particular strength of the kick.

Eduard Sonkin; Boris A. Malomed; Er'el Granot; Avi Marchewka

2010-07-14T23:59:59.000Z

49

Parameter exploration of optically trapped liquid aerosols  

E-Print Network (OSTI)

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.

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

2009-07-27T23:59:59.000Z

50

Steam trap monitor  

DOE Patents (OSTI)

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.

Ryan, M.J.

1987-05-04T23:59:59.000Z

51

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

E-Print Network (OSTI)

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.

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

2012-01-01T23:59:59.000Z

52

Magnetars: Time Evolution, Superfluid Properties, and Mechanism of Magnetic Field Decay  

E-Print Network (OSTI)

We calculate the coupled thermal evolution and magnetic field decay in relativistic model neutron stars threaded by superstrong magnetic fields (B > 10^{15} G). Our main goal is to evaluate how such ``magnetars'' evolve with time and how field decay modifies the transitions to core superfluidity and cooling dominated by surface X-ray emission. Observations of a thermal X-ray spectral component and fast timing noise place strong constraints on the presence of a superfluid core. We find that the transition to core superfluidity can be significantly delayed by field decay in the age range ~ 10^3-10^5 yrs. The mechanism of Hall drift is related to the stability of the core magnetic field, and to currents flowing outward through the crust. The heating effect is enhanced if it is continuous rather than spasmodic. Condensation of a heavy element layer at the surface is shown to cause only modest changes in the outward conduction of heat.

P. Arras; A. Cumming; C. Thompson

2004-01-27T23:59:59.000Z

53

Photoluminescence Blinking Dynamics of Colloidal Quantum Dots in the Presence of Controlled External Electron Traps  

Science Conference Proceedings (OSTI)

The effect of the external charge trap on the photoluminescence blinking dynamics of individual colloidal quantum dots is investigated with a series of colloidal quantum dot-bridge-fullerene dimers with varying bridge lengths, where the fullerene moiety acts as a well-defined, well-positioned external charge trap. It is found that charge transfer followed by charge recombination is an important mechanism in determining the blinking behavior of quantum dots when the external trap is properly coupled with the excited state of the quantum dot, leading to a quasi-continuous distribution of 'on' states and an early fall-off from a power-law distribution for both 'on' and 'off' times associated with quantum dot photoluminescence blinking.

Cotlet, M.; Xu, Z.

2012-01-23T23:59:59.000Z

54

What To Do With Cold Traps and Why  

E-Print Network (OSTI)

Increased emphasis on energy management has helped sites reduce system cost through the diagnosis and repair of “Leaking” or “Blowing” steam traps (“Leakage Failures”). Timely maintenance response is a significant action to lower energy use and GHG emissions generated by steam production. But, what action should be taken with Cold Traps? In every steam trap survey to determine the steam trap population’s current state of health, there are usually a significant amount of steam traps determined to be “Cold” or “Low Temp” (“Drainage Failures” or “Cold Traps”). It seems that site personnel commonly assign a lower response priority to these Drainage Failures traps, and sometimes actually implement a practice to intentionally convert Leaking traps into Cold Traps by closing the inlet stop valve to immediately stop energy leakage. Subsequently, they may label those traps as “Valved- Out” or “Out of Service,” but those trap stations were originally designed as needed to drain retained condensate from the system. So, the correct designation for such a trap station is “Cold,” regardless of the current intention. If the trap station does not drain condensate and is not hot, it is “Cold.” It can be astounding that many sites are not convinced of what actions or priority to take to repair Cold Traps, even while intrinsically understanding that there is something wrong with having Cold Traps that cannot drain condensate from a steam system. It often is simply because sites may not be fully aware of the potential dangers of uncorrected Cold Traps or the significant safety, reliability, and energy benefits of addressing them. Although safety is always the main priority, it cannot be overstated that there are huge reliability and energy benefits to prioritized repair of Cold Traps. Unfortunately, proactive response to repair Cold Traps in a steam system is not always achieved, often because the real benefits of such a response are not understood. Therefore, further review of “WHAT TO DO ABOUT COLD TRAPS…AND WHY?” is warranted for safe, reliable, and energy-efficient management of the condensate discharge locations (CDLs). Several tables are provided to help sites valuate the cost impact of Cold Traps in their steam systems by using readily available historical data.

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

2012-01-01T23:59:59.000Z

55

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

DOE Patents (OSTI)

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.

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

2013-07-23T23:59:59.000Z

56

Effects of alterations in sarcomere structure and prestretch timing on cardiac muscle mechanics  

E-Print Network (OSTI)

of cardiac ventricular mechanics to lumped systems models ofWaldman LK, McCulloch AD. Mechanics of active contraction inin passive ventricular mechanics. Am J Physiol Heart Circ

Tangney, Jared Rylan

2012-01-01T23:59:59.000Z

57

Antihydrogen and mirror-trapped antiproton discrimination: Discriminating between antihydrogen and mirror-trapped antiprotons in a minimum-B trap  

E-Print Network (OSTI)

Recently, antihydrogen atoms were trapped at CERN in a magnetic minimum (minimum-B) trap formed by superconducting octupole and mirror magnet coils. The trapped antiatoms were detected by rapidly turning off these magnets, thereby eliminating the magnetic minimum and releasing any antiatoms contained in the trap. Once released, these antiatoms quickly hit the trap wall, whereupon the positrons and antiprotons in the antiatoms annihilated. The antiproton annihilations produce easily detected signals; we used these signals to prove that we trapped antihydrogen. However, our technique could be confounded by mirror-trapped antiprotons, which would produce seemingly-identical annihilation signals upon hitting the trap wall. In this paper, we discuss possible sources of mirror-trapped antiprotons and show that antihydrogen and antiprotons can be readily distinguished, often with the aid of applied electric fields, by analyzing the annihilation locations and times. We further discuss the general properties of antiproton and antihydrogen trajectories in this magnetic geometry, and reconstruct the antihydrogen energy distribution from the measured annihilation time history.

C. Amole; G. B. Andresen; M. D. Ashkezari; M. Baquero-Ruiz; W. Bertsche; E. Butler; C. L. Cesar; S. Chapman; M. Charlton; A. Deller; S. Eriksson; J. Fajans; T. Friesen; M. C. Fujiwara; D. R. Gill; A. Gutierrez; J. S. Hangst; W. N. Hardy; M. E. Hayden; A. J. Humphries; R. Hydomako; L. Kurchaninov; S. Jonsell; N. Madsen; S. Menary; P. Nolan; K. Olchanski; A. Olin; A. Povilus; P. Pusa; F. Robicheaux; E. Sarid; D. M. Silveira; C. So; J. W. Storey; R. I. Thompson; D. P. van der Werf; J. S. Wurtele

2012-01-18T23:59:59.000Z

58

Searching fast for a target on a DNA without falling to traps  

E-Print Network (OSTI)

Genomic expression depends critically both on the ability of regulatory proteins to locate specific target sites on a DNA within seconds and on the formation of long lived (many minutes) complexes between these proteins and the DNA. Equilibrium experiments show that indeed regulatory proteins bind tightly to their target site. However, they also find strong binding to other non-specific sites which act as traps that can dramatically increase the time needed to locate the target. This gives rise to a conflict between the speed and stability requirements. Here we suggest a simple mechanism which can resolve this long-standing paradox by allowing the target sites to be located by proteins within short time scales even in the presence of traps. Our theoretical analysis shows that the mechanism is robust in the presence of generic disorder in the DNA sequence and does not require a specially designed target site.

O. Bénichou; Y. Kafri; M. Sheinman; R. Voituriez

2009-01-27T23:59:59.000Z

59

Asymmetric ion trap  

DOE Patents (OSTI)

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.

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

1997-01-01T23:59:59.000Z

60

Venus Fly Trap Experiment  

NLE Websites -- All DOE Office Websites (Extended Search)

Venus Fly Trap Experiment Venus Fly Trap Experiment Name: Jeremy Bailey Status: N/A Age: N/A Location: N/A Country: N/A Date: N/A Question: My name is Jeremy Bailey, and I am a student of Dorseyville Middle School. I have been working on a science project about Venus' Fly Traps. A recent addition to the project involved designing an experiment about something I found interesting about them. However, I don't know where to get them or how to grow them in the moderate climate of Pittsburgh. Also, I don't know how a successful experiment could be designed. Replies: Jeremy, I believe Venus Fly traps can be found 'in the wild' in the coastal floodplain of the Carolinas. As far as where to buy them, look in the phonebook yellow pages under plants or houseplants and do some calling. I live in eastern Pennsylvania, and over here they even sell them in hardware stores like Hechinger's and Home Depot (in their garden departments). I don't think you will have luck trying to grow them outside, our winters here are a bit too harsh for them. From what I recall they require substantial moisture and more moderate climes. You might try looking for houseplant books at your local library for more detailed information.

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


61

Steam trap monitor  

DOE Patents (OSTI)

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.

Ryan, Michael J. (Plainfield, IL)

1988-01-01T23:59:59.000Z

62

WATER-TRAPPED WORLDS  

Science Conference Proceedings (OSTI)

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

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

2013-09-01T23:59:59.000Z

63

Nuclear Physics with trapped  

E-Print Network (OSTI)

Nuclear Physics with trapped atoms and ions #12;2/2/2013Dan Melconian #12;2/2/2013Dan Melconian Outline · Scope and applications of nuclear physics precision frontier compliments LHC properties and aquifers in the Sahara #12;2/2/2013Dan Melconian What is Nuclear Physics? · Began with the study

Boas, Harold P.

64

Growth mechanism of photoreduced silver nanostructures on periodically proton exchanged lithium niobate: Time and concentration dependence  

SciTech Connect

Photodeposition of metallic nanostructures onto ferroelectric surfaces, which have been chemically patterned using a proton exchange process, has recently been demonstrated. By varying the molar concentration of the AgNO{sub 3} solution and the illumination time, one can determine the initial nucleation sites, control the rate of nucleation and the height of silver nanostructures formed, and study the mechanisms by which these processes occurs. The nanoparticles are found to deposit preferentially in the boundary between ferroelectric and proton exchanged regions, in an area proton exchanged via lateral diffusion under the masking layer used for chemical patterning, consistent with our previous results. Using a short illumination time (3 min), we are able to determine that the initial nucleation of the silver nanostructure, having a width of 0.17 {+-} 0.02 {mu}m and a height of 1.61 {+-} 0.98 nm, occurs near the edge of the reactive ion etched area within this lateral diffusion region. Over longer illumination times (15 min), we find that the silver deposition has spread to a width of 1.29 {+-} 0.06 {mu}m, extending across the entire lateral diffusion region. We report that at a high molar concentration of AgNO{sub 3} (10{sup -2} M), the amount of silver deposition for 5 min UV illumination is greater (2.88 {+-} 0.58 nm) compared to that at low (10{sup -4} M) concentrations (0.78 {+-} 0.35 nm), however, this is not the case for longer time periods. With increasing illumination time (15 min), experiments at 10{sup -4} M had greater overall deposition, 6.90 {+-} 1.52 nm, compared to 4.50 {+-} 0.76 nm at 10{sup -2} M. For longer exposure times (30 min) at 10{sup -2} M, the nanostructure height is 4.72 {+-} 0.59 nm, suggesting a saturation in the nanostructure height. The results are discussed in terms of the electric double layer that forms at the crystal surface. There is an order of magnitude difference between the Debye lengths for 10{sup -2} and 10{sup -4} M solutions, i.e., 3.04 vs. 30.40 nm, which suggests the Debye length plays a role in the availability of Ag{sup +} ions at the surface.

Craig Carville, N.; Denning, Denise; Rodriguez, Brian J. [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland) [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland); Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4 (Ireland); Manzo, Michele; Gallo, Katia [Department of Applied Physics, KTH-Royal Institute of Technology, Roslagstullbacken 21, 106 91 Stockholm (Sweden)] [Department of Applied Physics, KTH-Royal Institute of Technology, Roslagstullbacken 21, 106 91 Stockholm (Sweden)

2013-05-14T23:59:59.000Z

65

Josephson oscillations between exciton condensates in electrostatic traps  

SciTech Connect

Technological advances allow for tunable lateral confinement of cold dipolar excitons in coupled quantum wells. We consider theoretically the Josephson effect between exciton condensates in two traps separated by a weak link. The flow of the exciton supercurrent is driven by the dipole-energy difference between the traps. The Josephson oscillations may be observed after ensemble average of the time correlation of photons separately emitted from the two traps. The fringe visibility is controlled by the trap coupling and is robust against quantum and thermal fluctuations.

Rontani, Massimo [CNR-INFM Research Center on nanoStructures and bioSystems at Surfaces (S3), Via Campi 213/A, 41125 Modena (Italy); Sham, L. J. [Department of Physics, University of California San Diego, La Jolla, California 92093-0319 (United States)

2009-08-15T23:59:59.000Z

66

Self-trapping dynamics in a 2D optical lattice  

E-Print Network (OSTI)

We describe theoretical models for the recent experimental observation of Macroscopic Quantum Self-Trapping (MQST) in the transverse dynamics of an ultracold bosonic gas in a 2D lattice. The pure mean-field model based on the solution of coupled nonlinear equations fails to reproduce the experimental observations. It greatly overestimates the initial expansion rates at short times and predicts a slower expansion rate of the cloud at longer times. It also predicts the formation of a hole surrounded by a steep square fort-like barrier which was not observed in the experiment. An improved theoretical description based on a simplified Truncated Wigner Approximation (TWA), which adds phase and number fluctuations in the initial conditions, pushes the theoretical results closer to the experimental observations but fails to quantitatively reproduce them. An explanation of the delayed expansion as a consequence of a new type of self-trapping mechanism, where quantum correlations suppress tunneling even when there are no density gradients, is discussed and supported by numerical time-dependent Density Matrix Renormalization Group (t-DMRG) calculations performed in a simplified two coupled tubes set-up.

Shuming Li; Salvatore R. Manmana; Ana Maria Rey; Rafael Hipolito; Aaron Reinhard; Jean-Félix Riou; Laura A. Zundel; David S. Weiss

2013-05-20T23:59:59.000Z

67

Relativity in binary systems as root of quantum mechanics and space-time  

E-Print Network (OSTI)

Inspired by Bohr's dictum that "physical phenomena are observed relative to different experimental setups", this article investigates the notion of relativity in Bohr's sense, starting from a set of binary elements. The most general form of information coding within such sets requires a description by four-component states. By using Bohr's dictum as a guideline a quantum mechanical description of the set is obtained in the form of a SO(3,2) based spin network. For large (macroscopic) sub-networks a flat-space approximation of SO(3,2) leads to a Poincare symmetrical Hilbert space. The concept of a position of four-component spinors relative to macroscopic sub-networks then delivers the description of 'free' massive spin-1/2 particles with a Poincare symmetrical Hilbert space. Hence Minkowskian space-time, equipped with spin-1/2 particles, is obtained as an inherent property of a system of binary elements when individual elements are described relative to macroscopic sub-systems.

W. Smilga

2004-08-14T23:59:59.000Z

68

Time dependence of mechanical properties of specimens made from "grey gypsum"  

Science Conference Proceedings (OSTI)

The paper present monitoring of mechanical properties of grey calcined gypsum. The samples of dimension 40 × 40 × 160 mm were made from this material and put in laboratory conditions (relatively humidity 50 % and temperature 20 °C). Material ... Keywords: calcined gypsum, creep of gypsum, destructive methods, mechanical properties, shrinkage

P. Padev?t; P. Tesárek; T. Plachý

2010-11-01T23:59:59.000Z

69

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

SciTech Connect

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

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

70

Dissecting the Operating Mechanism of a Biological Motor One Molecule at a Time  

E-Print Network (OSTI)

replicative hexameric helicase of SV40 large tumor antigen.Activation of the MCM2-7 helicase by association with Cdc45site architecture and helicase mechanism of an archaeal MCM.

Chistol, Gheorghe

2013-01-01T23:59:59.000Z

71

Mechanisms Driving the Time-Dependent Salt Flux in a Partially Stratified Estuary  

Science Conference Proceedings (OSTI)

The subtidal salt balance and the mechanisms driving the downgradient salt flux in the Hudson River estuary are investigated using measurements from a cross-channel mooring array of current meters, temperature and conductivity sensors, and cross-...

James A. Lerczak; W. Rockwell Geyer; Robert J. Chant

2006-12-01T23:59:59.000Z

72

Time-Dependent Failure Mechanisms in Silicon Carbide Composites for Fusion Energy Applications  

SciTech Connect

Silicon carbide has many properties that are attractive for applications in fusion energy systems. The reliability of monolithic silicon carbide is insufficient for its use in large components, due to its brittle failure behavior and flaw sensitivity. Ceramic matrix composites, on the other hand, offer greater flaw tolerance and reliability, but their failure mechanisms are less well understood. This work has focussed on studying potential failure mechanisms in silicon carbide fiber-reinforced, silicon carbide matrix (SiCf/SiCm) composites. In the event of cracks caused by accidental overloads, excessive creep, thermal shock from plasma disruptions, handling during installation, or resulting from processing, subcritical crack growth will occur due to creep of fibers that bridge the crack faces. It is presumed that irradiation will enhance the creep rate of the fibers and, subsequently, the subcritical crack growth rate. At certain temperatures the presence of even small amounts of oxygen leads to oxidation of the interphase material to gaseous products. In this case, subcritical crack growth occurs by a separate mechanism. In addition, fiber shrinkage or weakening due to exposure to radiation can promote additional failure mechanisms, including embrittlement. These mechanisms, the conditions, under which they occur, and the current state of models of the crack growth mechanisms will be discussed.

Lewinsohn, Charles A.; Youngblood, Gerald E.; Henager, Charles H.; Simonen, Edward P.; Jones, Russell H.

2000-11-01T23:59:59.000Z

73

DNA Separation Using Photoelectrophoretic Traps  

SciTech Connect

In our recent publications we presented a design that allows formation of highly localized and optically controlled electrophoretic traps. 1,2 We demonstrated that electrophoretic traps can be utilized for biomolecule photoconcentration, optically directed transport, and separation by size. 1,2 In the current publication we suggest a hybrid design for biomolecule separation which implements electrophoretic traps in tandem with well-established electrophoretic techniques. We perform Monte Carlo simulations that demonstrate that the resolution of well-established electrophoretic techniques can be greatly enhanced by introducing photoelectrophoretic traps.

Braiman, Avital [ORNL; Thundat, Thomas George [ORNL; Rudakov, Fedor M [ORNL

2011-01-01T23:59:59.000Z

74

Electron Trapping by Molecular Vibration  

NLE Websites -- All DOE Office Websites (Extended Search)

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

75

Laser Cooling of Trapped Ions.  

Science Conference Proceedings (OSTI)

... period, so it can be assumed to give an in- stantaneous impulse to the ... In sympathetic laser cooling, two different ion species are loaded into a trap. ...

2002-11-15T23:59:59.000Z

76

A Model for Vortex-Trapped Internal Waves  

Science Conference Proceedings (OSTI)

Regions of negative vorticity are observed to trap and amplify near-inertial internal waves, which are sources of turbulent mixing 10–100 times higher than typically found in the stratified ocean interior. Because these regions are of finite ...

Eric Kunze; Emmanuel Boss

1998-10-01T23:59:59.000Z

77

On the Damping of Free Coastal-Trapped Waves  

Science Conference Proceedings (OSTI)

A perturbative method is presented for estimating the decay time of subinertial coastal-trapped waves under a wide range of conditions where damping is relatively weak. Bottom friction is sometimes much more important than “long-wave” results ...

K. H. Brink

1990-08-01T23:59:59.000Z

78

Classical and Quantum-Mechanical Axioms with the Higher Time Derivative Formalism  

E-Print Network (OSTI)

A Newtonian mechanics model is essentially the model of a point body in an inertial reference frame. How to describe extended bodies in non-inertial (vibrational) reference frames with the random initial conditions? One of the most general description (known as the higher derivatives formalism) consists in taking into account the infinite number of the higher order temporal derivatives of the coordinates in the Lagrange function. Such formalism describes physical objects in the in?finite dimensional space does not contradict quantum mechanics and infinite dimensional Hilbert space.

Timur Kamalov

2013-07-04T23:59:59.000Z

79

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

E-Print Network (OSTI)

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.

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

2012-01-01T23:59:59.000Z

80

Noise-enhanced trapping in chaotic scattering  

E-Print Network (OSTI)

We show that noise enhances the trapping of trajectories in scattering systems. In fully chaotic systems, the decay rate can decrease with increasing noise due to a generic mismatch between the noiseless escape rate and the value predicted by the Liouville measure of the exit set. In Hamiltonian systems with mixed phase space we show that noise leads to a slower algebraic decay due to trajectories performing a random walk inside Kolmogorov-Arnold-Moser islands. We argue that these noise-enhanced trapping mechanisms exist in most scattering systems and are likely to be dominant for small noise intensities, which is confirmed through a detailed investigation in the Henon map. Our results can be tested in fluid experiments, affect the fractal Weyl's law of quantum systems, and modify the estimations of chemical reaction rates based on phase-space transition state theory.

Altmann, Eduardo G; 10.1103/PhysRevLett.105.244102

2010-01-01T23:59:59.000Z

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


81

Inferring mechanism from time-series data: Delay-differential equations  

E-Print Network (OSTI)

D 110 (1997) 182–194 Fig. 3. ACF of the residual errors ofautocorrelation function (ACF) as the diagnostic for non-autocorrelation function (ACF) of the residual time series.

Ellner, Stephen Paul; Kendall, Bruce E.; Wood, Simon N.; McCauley, Ed; Briggs, Cheryl J

1997-01-01T23:59:59.000Z

82

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

E-Print Network (OSTI)

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 ...

Martin, Katherine C.

2007-01-01T23:59:59.000Z

83

Theory and application of planar ion traps  

E-Print Network (OSTI)

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 ...

Pearson, Christopher Elliott

2006-01-01T23:59:59.000Z

84

Double-well magnetic trap for Bose-Einstein condensates  

E-Print Network (OSTI)

We present a magnetic trapping scheme for neutral atoms based on a hybrid of Ioffe-Pritchard and Time-averaged Orbiting Potential traps. The resulting double-well magnetic potential has readily controllable barrier height and well separation. This offers a new tool for studying the behavior of Bose condensates in double-well potentials, including atom interferometry and Josephson tunneling. We formulate a description for the potential of this magnetic trap and discuss practical issues such as loading with atoms, evaporative cooling and manipulating the potential.

N. R. Thomas; C. J. Foot; A. C. Wilson

2001-08-10T23:59:59.000Z

85

First Attempts at Antihydrogen Trapping in ALPHA  

SciTech Connect

The ALPHA apparatus is designed to produce and trap antihydrogen atoms. The device comprises a multifunction Penning trap and a superconducting, neutral atom trap having a minimum-B configuration. The atom trap features an octupole magnet for transverse confinement and solenoidal mirror coils for longitudinal confinement. The magnetic trap employs a fast shutdown system to maximize the probability of detecting the annihilation of released antihydrogen. In this article we describe the first attempts to observe antihydrogen trapping.

Andresen, G. B.; Bowe, P. D.; Hangst, J. S. [Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C (Denmark); Bertsche, W.; Butler, E.; Charlton, M.; Humphries, A. J.; Jenkins, M. J.; Joergensen, L. V.; Madsen, N.; Werf, D. P. van der [Department of Physics, Swansea University, Swansea SA2 8PP (United Kingdom); Bray, C. C.; Chapman, S.; Fajans, J.; Povilus, A.; Wurtele, J. S. [Department of Physics, University of California at Berkeley, Berkeley, CA 94720-7300 (United States); Cesar, C. L.; Lambo, R.; Silveira, D. M. [Instituto de Fisica Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-972 (Brazil); Fujiwara, M. C. [TRIUMF, 4004 Wesbrook Mall, Vancouver BC, V6T 2A3 (Canada)] (and others)

2008-08-08T23:59:59.000Z

86

A time-domain Discontinuous Galerkin method for mechanical resonator quality factor computations  

Science Conference Proceedings (OSTI)

Numerical simulations are becoming increasingly important in the design of micromechanical resonators, in particular for the prediction of complex frequency response in high quality devices where damping is controlled by anchor losses. Frequency based ... Keywords: Anchor loss, Discontinuous Galerkin, Filter diagonalization, Helmholtz, Linear elasticity, MEMS resonator, Quality factor, Time-domain

Sanjay Govindjee; Per-Olof Persson

2012-08-01T23:59:59.000Z

87

Time-dependent simulations of large-scale quantum mechanical processes  

SciTech Connect

Time dependent linear and nonlinear equations govern the evolution of an extensive set of physical systems and processes describing, to enumerate just a few, Bose-Einstein condensates; soliton propagation in optical and photonic band-gap fibers; quantum control of atomic and molecular collisions and reactions; highly-compressed liquids; and dense and ultracold plasmas. While the media vary substantially, the basic computational procedures have many common features. We focus on the nonlinear Schrodinger equation and discuss two powerful approaches to its propagation: the Arnoldi/Lanczos(AL)l and Real Space Product Formula(RSPF)2. Both provide efficient systematic approximations to the short-time exponential propagator that moves the solution between time steps. We implement the former in a discrete variable representation (DVR)3 both in spatial grid and finite element forms and the latter in a spatial mesh with a finite difference representation of the kinetic energy operator. Both approaches require O(N) operations to propagate the wavefunction between time steps and handle multidimensional systems. We shall also draw connections with Liouville formulations used in quantum molecular dynamics simulations of large collections of atoms and molecules. After briefly outlining these formulations, we shall discuss some of the varied applications.

Collins, L. A. (Lee A.)

2002-01-01T23:59:59.000Z

88

Trapped Quintessential Inflation  

E-Print Network (OSTI)

Quintessential inflation is studied using a string modulus as the inflaton - quintessence field. The modulus begins its evolution at the steep part of its scalar potential, which is due to non-perturbative effects (e.g. gaugino condensation). It is assumed that the modulus crosses an enhanced symmetry point (ESP) in field space. Particle production at the ESP temporarily traps the modulus resulting in a brief period of inflation. More inflation follows, due to the flatness of the potential, since the ESP generates either an extremum (maximum or minimum) or a flat inflection point in the scalar potential. Eventually, the potential becomes steep again and inflation is terminated. After reheating the modulus freezes due to cosmological friction at a large value, such that its scalar potential is dominated by contributions due to fluxes in the extra dimensions or other effects. The modulus remains frozen until the present, when it can become quintessence and account for the dark energy necessary to explain the observed accelerated expansion.

J. C. Bueno Sanchez; K. Dimopoulos

2006-05-26T23:59:59.000Z

89

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

SciTech Connect

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

Menegatti, Carlos R.; Marangoni, Bruno S.; Marcassa, Luis G. [Instituto de Fisica de Sao Carlos, Universidade de Sao Paulo, Caixa Postal 369, 13560-970, Sao Carlos, SP (Brazil)

2011-11-15T23:59:59.000Z

90

Inspect and Repair Steam Traps  

SciTech Connect

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.

Not Available

2006-01-01T23:59:59.000Z

91

Electronic Trap States in Methanofullerenes  

E-Print Network (OSTI)

The trap states in three fullerene derivatives, namely PC61BM ([6,6]-phenyl C61 butyric acid methyl ester), bisPC61BM (bis[6,6]-phenyl C61 butyric acid methyl ester) and PC71BM ([6,6]-phenyl C71 butyric acid methyl ester), are investigated by thermally stimulated current measurements (TSC). Thereby, the lower limit of the trap densities for all studied methanofullerenes exhibits values in the order of 10^22 m^-3 with the highest trap density in bisPC61BM and the lowest in PC61BM. Fractional TSC measurements on PC61BM reveal a broad trap distribution instead of discrete trap levels with activation energies ranging from 15 meV to 270 meV and the maximum at about 75 meV. The activation energies of the most prominent traps in the other two fullerene derivatives are significantly higher, being at 96 meV and 223 meV for PC71BM and 184 meV for bisPC61BM, respectively. The influence of these findings on the performance of organic solar cells is discussed.

Julia Schafferhans; Carsten Deibel; Vladimir Dyakonov

2011-07-18T23:59:59.000Z

92

Gravity-induced resonances in a rotating trap  

E-Print Network (OSTI)

It is shown that in an anisotropic harmonic trap that rotates with the properly chosen rotation rate, the force of gravity leads to a resonant behavior. Full analysis of the dynamics in an anisotropic, rotating trap in 3D is presented and several regions of stability are identified. On resonance, the oscillation amplitude of a single particle, or of the center of mass of a many-particle system (for example, BEC), grows linearly with time and all particles are expelled from the trap. The resonances can only occur when the rotation axis is tilted away from the vertical position. The positions of the resonances (there are always two of them) do not depend on the mass but only on the characteristic frequencies of the trap and on the direction of the angular velocity of rotation.

Iwo Bialynicki-Birula; Tomasz Sowinski

2004-12-01T23:59:59.000Z

93

Laser-driven Sisyphus cooling in an optical dipole trap  

Science Conference Proceedings (OSTI)

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

Ivanov, Vladyslav V.; Gupta, Subhadeep [Physics Department, University of Wisconsin, Madison, Wisconsin 53706 (United States); Physics Department, University of Washington, Seattle, Washington 98195 (United States)

2011-12-15T23:59:59.000Z

94

Neutron lifetime measurements using gravitationally trapped ultracold neutrons  

E-Print Network (OSTI)

Our experiment using gravitationally trapped ultracold neutrons (UCN) to measure the neutron lifetime is reviewed. Ultracold neutrons were trapped in a material bottle covered with perfluoropolyether. The neutron lifetime was deduced from comparison of UCN losses in the traps with different surface-to-volume ratios. The precise value of the neutron lifetime is of fundamental importance to particle physics and cosmology. In this experiment, the UCN storage time is brought closer to the neutron lifetime than in any experiments before:the probability of UCN losses from the trap was only 1% of that for neutron beta decay. The neutron lifetime obtained,878.5+/-0.7stat+/-0.3sys s, is the most accurate experimental measurement to date.

A. P. Serebrov; V. E. Varlamov; A. G. Kharitonov; A. K. Fomin; Yu. N. Pokotilovski; P. Geltenbort; I. A. Krasnoschekova; M. S. Lasakov; R. R. Taldaev; A. V. Vassiljev; O. M. Zherebtsov

2007-02-06T23:59:59.000Z

95

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

E-Print Network (OSTI)

The demands for higher clock speeds and larger current magnitude in high-performance flip-chip electronic packaging configurations of small footprint have inevitably raised the concern over rapid thermal transients and large thermal spatial gradients that could severely compromise package performance. Coupled electrical-thermal-mechanical multi-physics were explored to evaluate the concern and to establish the knowledge base necessary for improving flip-chip reliability. It was found that within the first few hundred nanoseconds upon power-on, there were fast attenuating, dispersive shock waves of extremely high frequency propagating in the package. The notions of high cycle fatigue, power density and joint time-frequency analysis were employed to characterize the waves and the various failure modes associated with the moving of these short-lived dynamical disturbances in bulk materials and along interfaces. A qualitative measure for failure was also developed which enables the extent of damages inflicted by short-time wave propagation to be calculated in the probability sense. Failure modes identified in this study are all in agreement with what have been observed in industry. This suggests that micron cracks or interfacial flaws initiated at the short-time scale would be further propagated by the CTE-induced thermal stresses at the long-time scale and result in eventual electrical disruptions. Although epoxy-based underfills with fillers were shown to be effective in alleviating thermal stresses and improving solder joint fatigue performance in thermal cycling tests of long-time scale, underfill material viscoelasticity was found to be insignificant in attenuating short-time scale wave propagation. On the other hand, the inclusion of Cu interconnecting layers in flip-chips was shown to perform significantly better than Al layers in suppressing short-time scale effects. These results imply that, if improved flip-chip reliability is to be achieved, all packaging constituent materials need to be formulated to have well-defined short-time scale and long-time scale properties. In addition, the results also suggest that the composition and layout of all packaging components be optimized to achieve discouraging or suppressing short-time scale dynamic effects. In summary, results reported herein and numerical procedures developed for the research would not just render higher packaging manufacturing yield, but also bring out significant impact on packaging development, packaging material formulation and micro-circuit layout design.

Oh, Yoonchan

2004-08-01T23:59:59.000Z

96

Electron Trapping by Molecular Vibration  

NLE Websites -- All DOE Office Websites (Extended Search)

Electron Trapping by Molecular Vibration Print Electron Trapping by Molecular Vibration Print In photoelectron spectroscopy experiments performed at the ALS, a group of researchers has found that electronic transitions normally thought to be forbidden can in fact be excited in conjunction with certain types of molecular vibrations. Specifically, they found that when the symmetry of a linear triatomic molecule is broken by asymmetric vibrational modes, photoelectrons can become temporarily trapped by the molecule before ultimately escaping, giving rise to a broad feature in the photoelectron spectrum known as a shape resonance. This process represents a novel type of symmetry-breaking phenomenon that has not been observed previously but appears to be widespread. Such coupling between electronic motion and nuclear motion becomes increasingly important as scientists learn more about the geometry and dynamics of novel chemical structures such as those found in nanodevices and transient chemical species, and the results have implications for studies that use photoelectron spectroscopy as a diagnostic tool.

97

Electron Trapping by Molecular Vibration  

NLE Websites -- All DOE Office Websites (Extended Search)

Electron Trapping by Molecular Vibration Print Electron Trapping by Molecular Vibration Print In photoelectron spectroscopy experiments performed at the ALS, a group of researchers has found that electronic transitions normally thought to be forbidden can in fact be excited in conjunction with certain types of molecular vibrations. Specifically, they found that when the symmetry of a linear triatomic molecule is broken by asymmetric vibrational modes, photoelectrons can become temporarily trapped by the molecule before ultimately escaping, giving rise to a broad feature in the photoelectron spectrum known as a shape resonance. This process represents a novel type of symmetry-breaking phenomenon that has not been observed previously but appears to be widespread. Such coupling between electronic motion and nuclear motion becomes increasingly important as scientists learn more about the geometry and dynamics of novel chemical structures such as those found in nanodevices and transient chemical species, and the results have implications for studies that use photoelectron spectroscopy as a diagnostic tool.

98

Universal digital quantum simulation with trapped ions  

E-Print Network (OSTI)

A digital quantum simulator is an envisioned quantum device that can be pro- grammed to efficiently simulate any other local system. We demonstrate and investigate the digital approach to quantum simulation in a system of trapped ions. Using sequences of up to 100 gates and 6 qubits, the full time dynamics of a range of spin systems are digitally simulated. Interactions beyond those naturally present in our simulator are accurately reproduced and quantitative bounds are provided for the overall simulation quality. Our results demon- strate the key principles of digital quantum simulation and provide evidence that the level of control required for a full-scale device is within reach.

B. P. Lanyon; C. Hempel; D. Nigg; M. Müller; R. Gerritsma; F. Zähringer; P. Schindler; J. T. Barreiro; M. Rambach; G. Kirchmair; M. Hennrich; P. Zoller; R. Blatt; C. F. Roos

2011-09-07T23:59:59.000Z

99

Formation of Antihydrogen Rydberg atoms in strong magnetic field traps  

SciTech Connect

It is shown that several features of antihydrogen production in nested Penning traps can be described with accurate and efficient Monte Carlo simulations. It is found that cold deeply-bound Rydberg states of antihydrogen (H-bar) are produced in three-body capture in the ATRAP experiments and an additional formation mechanism -Rydberg charge transfer-, particular to the nested Penning trap geometry, is responsible for the observed fast (hot) H-bar atoms. Detailed description of the numerical propagation technique for following extreme close encounters is given. An analytic derivation of the power law behavior of the field ionization spectrum is provided.

Pohl, T.; Sadeghpour, H. R. [ITAMP, Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge MA 02138 (United States)

2008-08-08T23:59:59.000Z

100

A General Systems Theory for Chaos, Quantum Mechanics and Gravity for Dynamical Systems of all Space-Time Scales  

E-Print Network (OSTI)

Non-local connections, i. e. long-range space-time correlations intrinsic to the observed subatomic dynamics of quantum systems is also exhibited by macro-scale dynamical systems as selfsimilar fractal space-time fluctuations and is identified as self-organized criticality. The author has developed a general systems theory for the observed self-organized criticality applicable to dynamical systems of all space-time scales based on the concept that spatial integration of enclosed small-scale fluctuations results in the formation of large eddy circulation. The eddy energy spectrum therefore represents the statistical normal distribution according to the Central Limit Theorem. The additive amplitudes of eddies, when squared (variance or eddy kinetic energy), represent the statistical normal (probability) distribution, a result observed in the subatomic dynamics of quantum systems. The model predicts Kepler's laws of planetary motion for eddy circulation dynamics. Inverse square law of gravitation therefore applies to the eddy continuum ranging from subatomic to macro-scale dynamical systems, e.g. weather systems. The model is similar to a superstring model for subatomic dynamics which unifies quantum mechanical and classical concepts and manifestation of matter is visualised as vibrational modes in string-like energy flow patterns. The cumulative sum of centripetal forces in a hierarchy of vortex circulations may result in the observed inverse square law form for gravitational attraction between inertial masses of the eddies.

A M Selvam

2005-03-03T23:59:59.000Z

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


101

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

E-Print Network (OSTI)

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 ...

Sheng, Xing

102

Electron Trapping by Molecular Vibration  

NLE Websites -- All DOE Office Websites (Extended Search)

Electron Trapping by Molecular Electron Trapping by Molecular Vibration Electron Trapping by Molecular Vibration Print Wednesday, 27 April 2005 00:00 In photoelectron spectroscopy experiments performed at the ALS, a group of researchers has found that electronic transitions normally thought to be forbidden can in fact be excited in conjunction with certain types of molecular vibrations. Specifically, they found that when the symmetry of a linear triatomic molecule is broken by asymmetric vibrational modes, photoelectrons can become temporarily trapped by the molecule before ultimately escaping, giving rise to a broad feature in the photoelectron spectrum known as a shape resonance. This process represents a novel type of symmetry-breaking phenomenon that has not been observed previously but appears to be widespread. Such coupling between electronic motion and nuclear motion becomes increasingly important as scientists learn more about the geometry and dynamics of novel chemical structures such as those found in nanodevices and transient chemical species, and the results have implications for studies that use photoelectron spectroscopy as a diagnostic tool.

103

Trapped-flux superconducting memory  

Science Conference Proceedings (OSTI)

A memory cell based on trapped flux in superconductors has been built and tested. The cell is constructed entirely by vacuum evaporation of thin films and can be selected by coincident current or by other techniques, with drive-current requirements less ...

J. W. Crowe

1957-10-01T23:59:59.000Z

104

Long-Wave Trapping by Oceanic Ridges  

Science Conference Proceedings (OSTI)

Long waves are affected by bottom topography and under certain conditions may be trapped along topographical contours which then act as wave guides transmitting wave energy for great distances with little loss. This study examines waves trapped ...

Richard Paul Shaw; Wayne Neu

1981-10-01T23:59:59.000Z

105

A Neutrally Buoyant, Upper Ocean Sediment Trap  

Science Conference Proceedings (OSTI)

The authors have designed and deployed a neutrally buoyant sediment trap (NBST) intended for use in the upper ocean. The aim was to minimize hydrodynamic flow interference by making a sediment trap that drifted freely with the ambient current. ...

James R. Valdes; James F. Price

2000-01-01T23:59:59.000Z

106

Inertial measurement via dynamics of trapped particles  

E-Print Network (OSTI)

We describe theoretical and practical aspects of the particle trap as an inertial sensor. The insight motivating this approach is that a trapped particle acts like a mass on a spring, but the restoring forces are provided ...

Post, E. Rehmi, 1966-

2003-01-01T23:59:59.000Z

107

Determination of Hydrogen Peak Temperatures and Trapping ...  

Science Conference Proceedings (OSTI)

Presentation Title, Determination of Hydrogen Peak Temperatures and Trapping Energies of Various Lattice Defects In Iron Using Thermal Desorption ...

108

Void trapping of hydrogen in sintered iron  

DOE Green Energy (OSTI)

The effect of void trapping of hydrogen in iron was studied using the gas-phase permeation technique. Iron membranes of controlled void density, varying from 92% to 98% were prepared by press and sintering of electrolytic iron powder. The presence of internal voids showed no effect on the steady state flux of hydrogen through the membrane. The effective diffusivity, obtained by the time lag method, increased with the increase of input hydrogen partial pressure. This disagreement with the prediction of the theory in literature was explained by the existence of hydrogen in both the diatomic gaseous form and as adsorbed hydrogen. This explanation was further confirmed by examining the dependence of trapped hydrogen concentration with pressure. The linear dependence of trapped hydrogen concentration in voids with external hydrogen partial pressure for samples of 96%, 94% and 92% dense were given respectively by C/sub g/ = (1.5 +- 0.2) x 10/sup 15/ P + (3.2 +- 0.5) x 10/sup 14/ atoms of H/c.c. C/sub g/ = (2.1 +- 0.6) x 10/sup 15/ P + (1.7 +- 0.5) x 10/sup 15/ atoms of H/c.c. C/sub g/ = (4.5 +- 0.3) x 10/sup 15/ P + (6.5 +- 0.2) x 10/sup 15/ atoms of H/c.c. The discrepancy between the reported values and the values predicted by theory was explained by the poisoning of some of the voids by surface oxides.

Wong, K.C.

1976-09-01T23:59:59.000Z

109

Capturing Energy Savings with Steam Traps  

E-Print Network (OSTI)

This paper will discuss the energy savings potential of steam traps and present the energy, economic, and environmental reason why an active steam trap maintenance program is good for the company's bottom line. Several case studies will be discussed to demonstrate the merits of steam trap technology.

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

1997-04-01T23:59:59.000Z

110

Hybrid particle traps and conditioning procedure for gas insulated transmission lines  

DOE Patents (OSTI)

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.

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

1982-01-01T23:59:59.000Z

111

The Elimination of Steam Traps  

E-Print Network (OSTI)

How would you like to have a share of $154,000,000,000 a year? According to the Department of Energy that is roughly what was spent for creating steam in 1978. Steam generation accounts for fully one half of the industrial and commercial energy dollar. That figure could be reduced by 10-20% or more by the simple elimination of steam traps. Recent engineering developments show that steam traps can be eliminated. Documented results demonstrate that the retrofitting of existing facilities to alternative methods of condensate removal is simple and economically feasible, with paybacks of less than 12 months. Advantages obtained in the first year remain consistent for several years after conversion with virtual elimination of maintenance.

Dickman, F.

1985-05-01T23:59:59.000Z

112

Electron Trapping in Shear Alfven Waves that Power the Aurora  

Science Conference Proceedings (OSTI)

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.

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

2009-01-30T23:59:59.000Z

113

New novel cleaning technique for extending mean time between mechanical cleans in a Genus tungsten CVD reactor  

SciTech Connect

During the chemical vapor deposition of blanket tungsten from the reduction of tungsten hexafluoride (WF{sub 6}), metallic parts within the reaction chamber accumulate metallic tungsten, tungsten oxyfluorides, and other related tungsten species. The usual method for removal of the chamber deposits is to open the chamber and perform a labor intensive mechanical clean, which involves the use of hydrogen peroxide (H{sub 2}O{sub 2}) and deionized (DI) water, or an in-situ fluorine-base plasma clean. The authors have investigated the use of repetitive in-situ nitrogen trifluoride (NF{sub 3}) plasma cleans during the course of operating a Genuse 8721 tungsten chemical vapor deposition reactor. The Genuse reactor has been retrofitted with self-ratchetting linear slides, which allow the wafer clamps to be extended into the NF{sub 3} plasma. They have extended the mean time between failures (MTBF) due to the use of 10 minute plasma clean every 75--100 wafers. Deposition for this process is 8,000 angstroms per wafer, using 6 deposition sites. The total tungsten deposition for a 0.5 micron tungsten plug is 4 microns, per a 25 wafer lot. Instead of a total removal of the accumulated tungsten from the chamber hardware, a partial etchback of the deposition from the wafer clamps and wafer chucks was performed. With this, sources for particles and backside deposition were eliminated. They see an increase in wafer-to-wafer uniformity, lot-to-lot repeatability, and particle reduction due to the use of frequent plasma clean. Recovery time after a plasma clean is excellent and no detrimental effects from hydrogen fluoride ``poisoning`` were seen.

Lujan, R.D.; Fleming, J.G.; Baird, J.L.; Gentry, M.S. [Sandia National Labs., Albuquerque, NM (United States). Center for Microelectronics Technologies

1994-12-31T23:59:59.000Z

114

Transparent ion trap with integrated photodetector  

E-Print Network (OSTI)

Fluorescence collection sets the efficiency of state detection and the rate of entanglement generation between remote trapped ion qubits. Despite efforts to improve light collection using various optical elements, solid angle capture is limited to ~10% for implementations that are scalable to many ions. We present an approach based on fluorescence detection through a transparent trap using an integrated photodetector, combining collection efficiency approaching 50% with scalability. We microfabricate transparent surface traps with indium tin oxide and verify stable trapping of single ions. The fluorescence from a cloud of ions is detected using a photodiode sandwiched with a transparent trap.

Amira M. Eltony; Shannon X. Wang; Gleb M. Akselrod; Peter F. Herskind; Isaac L. Chuang

2012-12-06T23:59:59.000Z

115

Transparent ion trap with integrated photodetector  

E-Print Network (OSTI)

Fluorescence collection sets the efficiency of state detection and the rate of entanglement generation between remote trapped ion qubits. Despite efforts to improve light collection using various optical elements, solid angle capture is limited to ~10% for implementations that are scalable to many ions. We present an approach based on fluorescence detection through a transparent trap using an integrated photodetector, combining collection efficiency approaching 50% with scalability. We microfabricate transparent surface traps with indium tin oxide and verify stable trapping of single ions. The fluorescence from a cloud of ions is detected using a photodiode sandwiched with a transparent trap.

Eltony, Amira M; Akselrod, Gleb M; Herskind, Peter F; Chuang, Isaac L

2012-01-01T23:59:59.000Z

116

Trapped electron losses by interactions with coherent VLF waves  

SciTech Connect

VLF whistler waves from lightning enter the magnetosphere and cause the precipitation of energetic trapped electrons by pitch angle scattering. These events, known as Lightning-induced Electron Precipitation (LEP) have been detected by satellite and rocket instruments and by perturbations of VLF waves traveling in the earth-ionosphere waveguide. Detailed comparison of precipitating electron energy spectra and time dependence are in general agreement with calculations of trapped electron interactions with ducted whistler waves. In particular the temporal structure of the precipitation and the dynamic energy spectra of the electrons confirm this interpretation of the phenomena. There are discrepancies between observed and measured electron flux intensities and pitch angle distributions, but these quantities are sensitive to unknown wave intensities and trapped particle fluxes near the loss cone angle. The overall effect of lightning generated VLF waves on the lifetime of trapped electrons is still uncertain. The flux of electrons deflected into the bounce loss cone by a discrete whistler wave has been measured in a few cases. However, the area of the precipitation region is not known, and thus the total number of electrons lost in an LEP event can only be estimated. While the LEP events are dramatic, more important effects on trapped electrons may arise from the small but numerous deflections which increase the pitch angle diffusion rate of the electron population. {copyright} {ital 1996 American Institute of Physics.}

Walt, M.; Inan, U.S. [Space, Telecommunications and Radioscience Laboratory, Stanford University, Stanford, California (United States); Voss, H.D. [Lockheed Missiles and Space Co. (United States)

1996-07-01T23:59:59.000Z

117

Energy trapping from Hagedorn densities of states  

E-Print Network (OSTI)

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.

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

2013-04-26T23:59:59.000Z

118

The Ramsey method in high-precision mass spectrometry with Penning traps: Experimental results  

E-Print Network (OSTI)

The highest precision in direct mass measurements is obtained with Penning trap mass spectrometry. Most experiments use the interconversion of the magnetron and cyclotron motional modes of the stored ion due to excitation by external radiofrequency-quadrupole fields. In this work a new excitation scheme, Ramsey's method of time-separated oscillatory fields, has been successfully tested. It has been shown to reduce significantly the uncertainty in the determination of the cyclotron frequency and thus of the ion mass of interest. The theoretical description of the ion motion excited with Ramsey's method in a Penning trap and subsequently the calculation of the resonance line shapes for different excitation times, pulse structures, and detunings of the quadrupole field has been carried out in a quantum mechanical framework and is discussed in detail in the preceding article in this journal by M. Kretzschmar. Here, the new excitation technique has been applied with the ISOLTRAP mass spectrometer at ISOLDE/CERN for mass measurements on stable as well as short-lived nuclides. The experimental resonances are in agreement with the theoretical predictions and a precision gain close to a factor of four was achieved compared to the use of the conventional excitation technique.

S. George; K. Blaum; F. Herfurth; A. Herlert; M. Kretzschmar; S. Nagy; S. Schwarz; L. Schweikhard; C. Yazidjian

2007-01-22T23:59:59.000Z

119

TRANSIENT QUANTUM MECHANICAL PROCESSES  

SciTech Connect

Our principal objective has centered on the development of sophisticated computational techniques to solve the time-dependent Schroedinger equation that governs the evolution of quantum mechanical systems. We have perfected two complementary methods, discrete variable representation and real space product formula, that show great promise in solving these complicated temporal problems. We have applied these methods to the interaction of laser light with molecules with the intent of not only investigating the basic mechanisms but also devising schemes for actually controlling the outcome of microscopic processes. Lasers now exist that produce pulses of such short duration as to probe a molecular process many times within its characteristic period--allowing the actual observation of an evolving quantum mechanical system. We have studied the potassium dimer as an example and found agreement with experimental changes in the intermediate state populations as a function of laser frequency--a simple control prescription. We have also employed elaborate quantum chemistry programs to improve the accuracy of basic input such as bound-bound and bound-free coupling moments. These techniques have far-ranging applicability; for example, to trapped quantum systems at very low temperatures such as Bose-Einstein condensates.

L. COLLINS; J. KRESS; R. WALKER

1999-07-01T23:59:59.000Z

120

Texas A&M Penning Trap Facility - Design of the Measurement Trap  

E-Print Network (OSTI)

A tandem Penning trap facility has been designed and is under construction at the Texas A&M University Cyclotron Institute (TAMU-TRAP). The initial experimental program will be the study of correlation parameters for T=2 superallowed beta-delayed proton emitters. The measurement trap is a unique large-bore optimized 5-electrode cylindrical Penning trap, which features a 90 mm free radius, larger than in any existing Penning trap. This novel geometry allows for full radial containment of decay products of interest. The trap has also been designed to exhibit a "tunable" and "orthogonalized" geometry, which is useful for alternate experiments.

Mehlman, M; Shidling, P D

2012-01-01T23:59:59.000Z

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


121

Texas A&M Penning Trap Facility - Design of the Measurement Trap  

E-Print Network (OSTI)

A tandem Penning trap facility has been designed and is under construction at the Texas A&M University Cyclotron Institute (TAMU-TRAP). The initial experimental program will be the study of correlation parameters for T=2 superallowed beta-delayed proton emitters. The measurement trap is a unique large-bore optimized 5-electrode cylindrical Penning trap, which features a 90 mm free radius, larger than in any existing Penning trap. This novel geometry allows for full radial containment of decay products of interest. The trap has also been designed to exhibit a "tunable" and "orthogonalized" geometry, which is useful for alternate experiments.

M. Mehlman; D. Melconian; P. D. Shidling

2012-08-20T23:59:59.000Z

122

Temperature-Driven Structural Phase Transition for Trapped Ions and a Proposal for its Experimental Detection  

SciTech Connect

A Wigner crystal formed with trapped ions can undergo a structural phase transition, which is determined only by the mechanical conditions on a classical level. Instead of this classical result, we show that through consideration of quantum and thermal fluctuation, a structural phase transition can be driven solely by a change in the system's temperature. We determine a finite-temperature phase diagram for trapped ions using the renormalization group method and the path integral formalism, and propose an experimental scheme to observe the predicted temperature-driven structural phase transition, which is well within the reach of the current ion trap technology.

Gong Zhexuan; Lin, G.-D.; Duan, L.-M. [Department of Physics and MCTP, University of Michigan, Ann Arbor, Michigan 48109 (United States)

2010-12-31T23:59:59.000Z

123

Trapping and Measuring Charged Particles in Liquids  

Genome sequencing especially benefits from the nanoscale approach. The trap is a three-layer, three-dimensional crossing metal/insulator structure.

124

Trapping and Measuring Charged Particles in Liquids  

Using molecular dynamics simulations, the researchers found that particles are trapped in liquid environments when appropriate AC/DC electric fields ...

125

Impact of nonaqueous phase liquid (NAPL) source zone architecture on mass removal mechanisms in strongly layered heterogeneous porous media during soil vapor extraction  

Science Conference Proceedings (OSTI)

An existing multiphase flow simulator was modified in order to determine the effects of four mechanisms on NAPL mass removal in a strongly layered heterogeneous vadose zone during soil vapor extraction (SVE): a) NAPL flow, b) diffusion and dispersion from low permeability zones, c) slow desorption from sediment grains, and d) rate-limited dissolution of trapped NAPL. The impact of water and NAPL saturation distribution, NAPL type (i.e., free, residual, or trapped) distribution, and spatial heterogeneity of the permeability field on these mechanisms were evaluated. Two different initial source zone architectures (one with and one without trapped NAPL) were considered and these architectures were used to evaluate seven different SVE scenarios. For all runs, slow diffusion from low permeability zones that gas flow bypassed was a dominant factor for diminished SVE effectiveness at later times. This effect was more significant at high water saturation due to the decrease of gas-phase relative permeability. Transverse dispersion contributed to fast NAPL mass removal from the low permeability layer in both source zone architectures, but longitudinal dispersion did not affect overall mass removal time. Both slow desorption from sediment grains and rate-limited mass transfer from trapped NAPL only marginally affected removal times. However, mass transfer from trapped NAPL did affect mass removal at late time, as well as the NAPL distribution. NAPL flow from low to high permeability zones contributed to faster mass removal from the low permeability layer, and this effect increased when water infiltration was eliminated. These simulations indicate that if trapped NAPL exists in heterogeneous porous media, mass transfer can be improved by delivering gas directly to zones with trapped NAPL and by lowering the water content, which increases the gas relative permeability and changes trapped NAPL to free NAPL.

Yoon, Hongkyu; Werth, Charlie; Valocchi, Albert J.; Oostrom, Martinus

2008-09-26T23:59:59.000Z

126

Long-term drifts of stray electric fields in a Paul trap  

E-Print Network (OSTI)

We investigate the evolution of quasi-static stray electric fields in a linear Paul trap over a period of several months. Depending on how these electric fields are initially induced we observe very different time scales for the field drifts. Photo-induced electric fields decay on time scales of days. We interpret this as photo-electrically generated charges on insulating materials which decay via discharge currents. In contrast, stray fields due to the exposure of the ion trap to a beam of Ba atoms mainly exhibit slow dynamics on the order of months. We explain this observation as a consequence of a coating of the trap electrodes by the atomic beam. This may lead to contact potentials which can slowly drift over time due to atomic diffusion and chemical processes on the surface. In order not to perturb the field evolutions, we suppress the generation of additional charges and atomic coatings in the Paul trap during the measurements. For this, we shield the ion trap from ambient light and only allow the use of near-infrared lasers. Furthermore, we minimize the flux of atoms into the ion trap chamber. Long-term operation of our shielded trap led us to a regime of very low residual electric field drifts of less than 0.03 V/m per day.

Arne Härter; Artjom Krükow; Andreas Brunner; Johannes Hecker Denschlag

2013-05-29T23:59:59.000Z

127

Bohmian mechanics contradicts quantum mechanics  

E-Print Network (OSTI)

Bohmian mechanics contradicts quantum mechanics Arnold Neumaier Institut fur Mathematik, Universit://solon.cma.univie.ac.at/#24;neum/ Abstract. It is shown that, for a harmonic oscillator in the ground state, Bohmian mechanics and quantum mechanics predict values of opposite sign for certain time correlations. The discrepancy can

Neumaier, Arnold

128

Ion Trap in a Semiconductor Chip  

E-Print Network (OSTI)

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.

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

2006-01-09T23:59:59.000Z

129

Hydrogen trapping in bearing steels: mechanisms and alloy design  

E-Print Network (OSTI)

removal by white structure flaking on wind turbine bearing inner ring [3]. This type of failure demands complete replacement of the bearing. In addition, mon- itoring the development of damage is difficult when it starts under the surface, so it is hardly... 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...

Szost, Blanka Angelika

2013-02-05T23:59:59.000Z

130

Rossby waves trapped by quantum mechanics Thierry Paul  

E-Print Network (OSTI)

. Grenier: Oscillatory Perturbations of the Navier­Stokes Equations, Journal de Math´ematiques Pures et (1994), pages 476-512. 3 hal-00798790,version1-10Mar2013 #12;

131

Fuel traps: mapping stability via water association.  

DOE Green Energy (OSTI)

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.

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

132

The Development of a Detailed Chemical Kinetic Mechanism for Diisobutylene and Comparison to Shock Tube Ignition Times  

DOE Green Energy (OSTI)

There is much demand for chemical kinetic models to represent practical fuels such as gasoline, diesel and aviation fuel. These blended fuels contain hundreds of components whose identity and amounts are often unknown. A chemical kinetic mechanism that would represent the oxidation of all these species with accompanying chemical reactions is intractable with current computational capabilities, chemical knowledge and manpower resources. The use of surrogate fuels is an approach to make the development of chemical kinetic mechanisms for practical fuels tractable. A surrogate fuel model consists of a small number of fuel components that can be used to represent the practical fuel and still predict desired characteristics of the practical fuel. These desired fuel characteristics may include ignition behavior, burning velocity, fuel viscosity, fuel vaporization, and fuel emissions (carbon monoxide, hydrocarbons, soot and nitric oxides). Gasoline consists of many different classes of hydrocarbons including n-alkanes, alkenes, iso-alkanes, cycloalkanes, cycloalkenes, and aromatics. One approach is to use a fuel surrogate that has a single component from each class of hydrocarbon in gasoline so that the unique molecular structure of each class is represented. This approach may lead to reliable predictions of many of the combustion properties of the practical fuel. In order to obtain a fuel surrogate mechanism, detailed chemical kinetic mechanisms must be developed for each component in the surrogate. In this study, a detailed chemical kinetic mechanism is developed for diisobutylene, a fuel intended to represent alkenes in practical fuels such as gasoline, diesel, and aviation fuel. The fuel component diisobutylene usually consists of a mixture of two conjugate olefins of iso-octane: 1- or 2-pentene, 2,4,4-trimethyl. Diisobutylene has a similar molecular structure to iso-octane, so that its kinetics offers insight into the effect of including a double bond in the carbon skeletal structure of iso-octane. There are few previous studies on diisobutylene. Kaiser et al. [1] examined the exhaust emission from a production spark ignition engine with neat diisobutylene and with it mixed with gasoline. They found the exhaust emissions of diisobutylene to be similar to that of iso-octane. They saw a significant increase in the amount of 2-methyl-1,3-butadiene measured in the exhaust of the engine. They also found appreciable amount of propene in the exhaust, but could not explain the source of this product as they did others in terms of C-C bond beta scission of alkyl radicals. Risberg et al. [2] studied a number of fuel blends to evaluate their autoignition quality for use in a homogeneous charge compression ignition engine, using diisobutylene to represent olefins in one of their test fuels. In this study, experiments on the shock tube ignition of both isomers of diisobutylene will be described. Then, the development of a detailed chemical kinetic mechanism for the two isomers of diisobutylene will be discussed.

Metcalfe, W; Curran, H J; Simmie, J M; Pitz, W J; Westbrook, C K

2005-01-21T23:59:59.000Z

133

Effects of trap anisotropy on impurity scattering regime in a Fermi gas  

E-Print Network (OSTI)

We evaluate the low-lying oscillation modes and the ballistic expansion properties of a harmonically trapped gas of fermionic K40 atoms containing thermal Rb87 impurities as functions of the anisotropy of the trap. Numerical results are obtained by solving the Vlasov-Landau equations for the one-body phase-space distribution functions and are used to test simple scaling Ansatzes. Starting from the gas in a weak impurity-scattering regime inside a spherical trap, the time scales associated to motions in the axial and azimuthal directions enter into competition as the trap is deformed to an elongated cigar-like shape. This competition gives rise to coexistence of collisionless and hydrodynamic behaviors in the low-lying surface modes of the gas as well as to a dependence of the aspect ratio of the expanding cloud on the collision time.

P. Capuzzi; P. Vignolo; M. P. Tosi

2005-06-20T23:59:59.000Z

134

Controlling trapping and ejection of ions from multipole ...  

Controlling trapping and ejection of ions from multipole guides and traps ... The concept can be used to control the kinetic energy of the

135

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

Science Conference Proceedings (OSTI)

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.

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

2008-09-15T23:59:59.000Z

136

Trapping of Implanted He at Cu/Nb Interfaces Measured by Neutron Reflectometry  

Science Conference Proceedings (OSTI)

In single crystalline metals, He is insoluble and precipitates into bubbles. In contrast, Cu-Nb multilayers show no evidence of bubble formation below a critical concentration. The conclusions of this paper are: (1) He is trapped at Cu/Nb , Cu/Mo interfaces; (2) He is trapped interstitially; (3) The interface swells {approx} 10 times; and (4) The layered structure retains despite the swell of interfaces.

Wang, Peng [Los Alamos National Laboratory; Zhernenkov, Mikhail [Applications Scientist at Nanometrics; Kashinath, Abishek [MIT; Demkowicz, Michael [MIT; Baldwin, Jon K. [Los Alamos National Laboratory; Majewski, Jaroslaw [Los Alamos National Laboratory

2012-06-20T23:59:59.000Z

137

Long-term drifts of stray electric fields in a Paul trap  

E-Print Network (OSTI)

We investigate the evolution of stray electric fields in a linear Paul trap over a period of several months. We demonstrate a way to clearly distinguish between the two main sources of these fields, namely insulated charged up patches and patch charges originating from contact potentials. To achieve high sensitivity in these measurements, we operate the trap in a way that strongly suppresses the generation of additional patch charges. For this, we shield the ion trap from ambient light and only allow the use of near-infrared lasers. Furthermore, we minimize additional contaminations of the trap electrodes by minimizing the flux of atoms into the ion trap chamber. We find that photo-induced electric fields decay on time scales of days. In contrast, stray fields due to contamination-induced contact potentials on trap electrodes mainly exhibit slow dynamics on the order of months, probably dominated by diffusion and slow chemical processes. Long-term operation of our shielded trap led us to a regime of very low ...

Härter, Arne; Brunner, Andreas; Denschlag, Johannes Hecker

2013-01-01T23:59:59.000Z

138

Selective interactions in trapped ions: State reconstruction and quantum logic  

SciTech Connect

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

Solano, E. [Max-Planck-Institut fuer Quantenoptik, Hans-Kopfermann-Strasse 1, D-85748 Garching, Germany and Seccion Fisica, Departamento de Ciencias, Pontificia Universidad Catolica del Peru, Apartado 1761, Lima (Peru)

2005-01-01T23:59:59.000Z

139

Ionization Induced Trapping in a Laser Wakefield Accelerator  

Science Conference Proceedings (OSTI)

Experimental studies of electrons produced in a laser wakefield accelerator indicate trapping initiated by ionization of target gas atoms. Targets composed of helium and controlled amounts of various gases were found to increase the beam charge by as much as an order of magnitude compared to pure helium at the same electron density and decrease the beam divergence from 5.1+-1.0 to 2.9+-0.8 mrad. The measurements are supported by particle-in-cell modeling including ionization. This mechanism should allow generation of electron beams with lower emittance and higher charge than in preionized gas.

McGuffey, C.; Thomas, A. G. R.; Schumaker, W.; Matsuoka, T.; Chvykov, V.; Dollar, F. J.; Kalintchenko, G.; Yanovsky, V.; Maksimchuk, A.; Krushelnick, K.; Bychenkov, V. Yu.; Glazyrin, I. V.; Karpeev, A. V. [Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109 (United States); P. N. Lebedev Physics Institute, Russian Academy of Science, Leninskii Prospect 53, Moscow 119991 (Russian Federation); RFNC-VNIITF, Snezhinsk 456770, Chelyabinsk region (Russian Federation)

2010-01-15T23:59:59.000Z

140

FEMP-FTA--Steam Trap Performance Assessment  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Steam Trap Function Steam Trap Function Steam traps are automatic valves used in every steam system to remove conden- sate, air, and other non-condensable gases while preventing or minimizing the passing of steam. If condensate is allowed to collect, it reduces the flow capacity of steam lines and the thermal capacity of heat transfer equipment. In addition, excess condensate can lead to "water hammer," with potentially destructive and dangerous results. Air that remains after system startup reduces steam pressure and temperature and may also reduce the thermal capacity of heat transfer equipment. Non-condensable gases, such as oxygen and carbon dioxide, cause corrosion. Steam that passes through the trap provides no heating ser- vice. This effectively reduces the heating capacity

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


141

Trapped Ions and Laser Cooling 11  

Science Conference Proceedings (OSTI)

... 2 GHz I ... monic well, eg, the absorption spectrum for the secular motion in an rf trap ... a sin- gle atom [mass of 100 u (atomic mass units)] starts from rest ...

2002-08-07T23:59:59.000Z

142

Microfabrication techniques for trapped ion quantum ...  

Science Conference Proceedings (OSTI)

... used for micro-traps, starting with stacking multiple wafers to form a ... dc rf dc rf dc ... This section starts with a description of the tried and true gold-on ...

2010-07-21T23:59:59.000Z

143

Laser cooling and trapping of neutral atoms*  

Science Conference Proceedings (OSTI)

... 1 m/s, any gas in equilibrium (other than spin-polarized atomic hydro- ... lattice-trapped atoms, a physical picture with the simplicity and power of the ...

2010-08-23T23:59:59.000Z

144

Shale gas is natural gas trapped inside  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Shale gas is natural gas trapped inside formations of shale - fine grained sedimentary rocks that can be rich sources of petroleum and natural gas. Just a few years ago, much of...

145

Nuclear spin qubits in a trapped-ion quantum computer  

E-Print Network (OSTI)

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.

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

2009-04-26T23:59:59.000Z

146

Triplet Transport to and Trapping by Acceptor End Groups on Conjugated  

NLE Websites -- All DOE Office Websites (Extended Search)

Triplet Transport to and Trapping by Acceptor End Groups on Conjugated Triplet Transport to and Trapping by Acceptor End Groups on Conjugated Polyfluorene Chains Paiboon Sreearunothai, Alexis Estrada, Sadayuki Asaoka, Marta Kowalczyk, Seogjoo Jang, Andrew R. Cook, Jack M. Preses and John R. Miller J. Phys. Chem. C 115, 19569-19577 (2011). [Find paper at ACS Publications] Abstract: 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 ~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 10-4 cm2 s-1, which is 30 times typical molecular diffusion and close to a value for triplet transport

147

An imaging co-axial tube electrodynamic trap for manipulation of charged particles  

Science Conference Proceedings (OSTI)

A tubular particle trapping device was designed and fabricated using two co-axial electrically conductive tubes with diameters of 5 mm and 7 mm, respectively. The device was integrated with an imaging camera and optical fiber bundle for real time monitoring of trapped particle motion. Charged microparticles of 3 to 50 m diameter can be suspended in air at ambient pressure using the device utilizing a quadrupole potential with an alternating voltage of amplitude 300 V to 750 V and frequency of 30 Hz to 140 Hz. Controlled trapping of a single particle or multiple particles can be achieved by tuning the voltage amplitude. The particle remained trapped when the entire assembly was translated or rotated. The device can be used as a manipulator for charged particle transport and repositioning.

Jiang, Ms. Linan [University of Arizona; Whitten, William B [ORNL; Pau, Dr. Stanley [University of Arizona/Bell Labs

2011-01-01T23:59:59.000Z

148

Trapping and dark current in plasma-based accelerators  

SciTech Connect

The trapping of thermal electrons in a nonlinear plasma wave of arbitrary phase velocity is investigated. The threshold plasma wave amplitude for trapping plasma electrons is calculated, thereby determining the fraction trapped and the expected dark current in a plasma-based accelerator. It is shown that the presence of a laser field (e.g., trapping in the self-modulated regime of the laser wakefield accelerator) increases the trapping threshold. Implications for experimental and numerical laser-plasma studies are discussed.

Schroder, C.B.; Esarey, E.; Shadwick, B.A.; Leemans, W.P.

2004-06-01T23:59:59.000Z

149

Development of Metal Substrate for Denox Catalysts and Particulate Trap  

DOE Green Energy (OSTI)

The objective of this project was to develop advanced metallic catalyst substrate materials and designs for use in off-highway applications. The new materials and designs will be used as catalyst substrates and diesel particulate traps. They will increase durability, reduce flow resistance, decrease time to light-off, and reduce cost relative to cordierite substrates. Metallic catalyst substrates are used extensively for diesel oxidation catalysts and have the potential to be used in other catalytic systems for diesel engines. Metallic substrates have many advantages over ceramic materials including improved durability and resistance to thermal shock and vibration. However, the cost is generally higher than cordierite. The most common foil material used for metallic substrates is FeCr Alloy, which is expensive and has temperature capabilities beyond what is necessary for diesel applications. The first task in the project was Identification and Testing of New Materials. In this task, several materials were analyzed to determine if a low cost substitute for FeCr Alloy was available or could be developed. Two materials were identified as having lower cost while showing no decrease in mechanical properties or oxidation resistance at the application temperatures. Also, the ability to fabricate these materials into a finished substrate was not compromised, and the ability to washcoat these materials was satisfactory. Therefore, both candidate materials were recommended for cost savings depending on which would be less expensive in production quantities. The second task dealt with the use of novel flow designs to improve the converter efficiency while possibly decreasing the size of the converter to reduce cost even more. A non-linear flow path was simulated to determine if there would be an increase in efficiency. From there, small samples were produced for bench testing. Bench tests showed that the use of non-linear channels significantly reduced the light-off temperature for diesel oxidation catalytic converters. Finally, the third task was to implement these materials and designs into a full-size converter. Hot shake testing of 13-inch diameter straight channel substrates showed no significant difference in durability between the current material and the two proposed materials. At the time that this program ended, preparations were being made for full-scale emissions testing of the new design converter for comparison to a traditional straight channel with equal catalyst loading.

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

2005-12-31T23:59:59.000Z

150

Controlling trapping potentials and stray electric fields in a microfabricated ion trap through design and compensation  

E-Print Network (OSTI)

Recent advances in quantum information processing with trapped ions have demonstrated the need for new ion trap architectures capable of holding and manipulating chains of many (>10) ions. Here we present the design and detailed characterization of a new linear trap, microfabricated with scalable complementary metal-oxide-semiconductor (CMOS) techniques, that is well-suited to this challenge. Forty-four individually controlled DC electrodes provide the many degrees of freedom required to construct anharmonic potential wells, shuttle ions, merge and split ion chains, precisely tune secular mode frequencies, and adjust the orientation of trap axes. Microfabricated capacitors on DC electrodes suppress radio-frequency pickup and excess micromotion, while a top-level ground layer simplifies modeling of electric fields and protects trap structures underneath. A localized aperture in the substrate provides access to the trapping region from an oven below, permitting deterministic loading of particular isotopic/elemental sequences via species-selective photoionization. The shapes of the aperture and radio-frequency electrodes are optimized to minimize perturbation of the trapping pseudopotential. Laboratory experiments verify simulated potentials and characterize trapping lifetimes, stray electric fields, and ion heating rates, while measurement and cancellation of spatially-varying stray electric fields permits the formation of nearly-equally spaced ion chains.

S. Charles Doret; Jason M. Amini; Kenneth Wright; Curtis Volin; Tyler Killian; Arkadas Ozakin; Douglas Denison; Harley Hayden; C. -S. Pai; Richart E. Slusher; Alexa W. Harter

2012-04-18T23:59:59.000Z

151

Effects of sulfation level on the desulfation behavior of pre-sulfated Pt BaO/Al2O3 lean NOx trap catalysts: a combined H2 Temperature-Programmed Reaction, in-situ sulfur K-edge X-ray Absorption Near-Edge Spectroscopy, X-ray Photoelectron Spectroscopy, and Time-Resolved X-ray Diffraction Study  

SciTech Connect

Desulfation by hydrogen of pre-sulfated Pt(2wt%) BaO(20wt%)/Al2O3 with various sulfur loading (S/Ba = 0.12, 0.31 and 0.62) were investigated by combining H2 temperature programmed reaction (TPRX), x-ray photoelectron spectroscopy (XPS), in-situ sulfur K-edge x-ray absorption near-edge spectroscopy (XANES), and synchrotron time-resolved x-ray diffraction (TR-XRD) techniques. We find that the amount of H2S desorbed during the desulfation in the H2 TPRX experiments is not proportional to the amount of initial sulfur loading. The results of both in-situ sulfur K-edge XANES and TR-XRD show that at low sulfur loadings, sulfates were transformed to a BaS phase and remained in the catalyst, rather than being removed as H2S. On the other hand, when the deposited sulfur level exceeded a certain threshold (at least S/Ba = 0.31) sulfates were reduced to form H2S, and the relative amount of the residual sulfide species in the catalyst was much less than at low sulfur loading. Unlike samples with high sulfur loading (e.g., S/Ba = 0.62), H2O did not promote the desulfation for the sample with S/Ba of 0.12, implying that the formed BaS species originating from the reduction of sulfates at low sulfur loading are more stable to hydrolysis. The results of this combined spectroscopy investigation provide clear evidence to show that sulfates at low sulfur loadings are less likely to be removed as H2S and have a greater tendency to be transformed to BaS on the material, leading to the conclusion that desulfation behavior of Pt BaO/Al2O3 lean NOx trap catalysts is markedly dependent on the sulfation levels.

Kim, Do Heui; Szanyi, Janos; Kwak, Ja Hun; Wang, Xianqin; Hanson, Jonathan C.; Engelhard, Mark H.; Peden, Charles HF

2009-04-03T23:59:59.000Z

152

Charge trapping in imidazolium ionic liquids  

NLE Websites -- All DOE Office Websites (Extended Search)

trapping in imidazolium ionic liquids trapping in imidazolium ionic liquids I. A. Shkrob and J. F. Wishart J. Phys. Chem. B 113, 5582-5592 (2009). [Find paper at ACS Publications] or use ACS Articles on Request Abstract: Room-temperature ionic liquids (ILs) are a promising class of solvents for applications ranging from photovoltaics to solvent extractions. Some of these applications involve the exposure of the ILs to ionizing radiation, which stimulates interest in their radiation and photo- chemistry. In the case of ILs consisting of 1,3-dialkylimidazolium cations and hydrophobic anions, ionization, charge transfer and redox reactions yield charge-trapped species thought to be radicals resulting from neutralization of the constituent ions. Using computational chemistry methods and the recent results on electron spin resonance (ESR) and transient absorption

153

Energy Savings Through Steam Trap Management  

E-Print Network (OSTI)

Sustainability and energy management are broad topics which have become a common focus in industry. Recognizing the need for greater cost reduction and competitive advantage through sustainability, industry is putting forth resources to improve energy management controls. When the topic of energy management relates to steam trap management however, the focus becomes less clear and action less notable. The seemingly “low hanging” fruit of steam traps are not often tied to significant and sustainable energy management projects. Typically this holds true because of the failure of industry to put a value on the cost of steam and because of the lack of energy tracking from failed steam traps as part of best practice. The use of technology can help industry transform how steam systems are managed and sustainability in steam systems is achieved.

Gibbs, C.

2008-01-01T23:59:59.000Z

154

Trapping Fermionic $^{40}$K and Bosonic $^{87}$Rb on a Chip  

E-Print Network (OSTI)

We demonstrate the loading of a Bose-Fermi mixture into a microfabricated magnetic trap. In a single-chamber vacuum system, laser-cooled atoms are transported to the surface of a substrate on which gold wires have been microfabricated. The magnetic field minimum formed near these current-carrying wires is used to confine up to $6\\times10^4$ neutral $^{40}$K atoms. In addition, we can simultaneously load $2 \\times 10^5$ $^{87}$Rb atoms, demonstrating the confinement of two distinct elements with such a trap. In a sequence optimized for $^{87}$Rb alone, we observe up to $1 \\times 10^7$ trapped atoms. We describe in detail the experimental apparatus, and discuss prospects for evaporative cooling towards quantum degeneracy in both species.

S. Aubin; M. H. T. Extavour; S. Myrskog; L. J. LeBlanc; J. Esteve; S. Singh; P. Scrutton; D. McKay; R. McKenzie; I. D. Leroux; A. Stummer; J. H. Thywissen

2005-02-08T23:59:59.000Z

155

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

E-Print Network (OSTI)

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.

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

2007-11-19T23:59:59.000Z

156

Hawking-like radiation does not require a trapped region  

E-Print Network (OSTI)

We discuss the issue of quasi-particle production by ``analogue black holes'' with particular attention to the possibility of reproducing Hawking radiation in a laboratory. By constructing simple geometric acoustic models, we obtain a somewhat unexpected result: We show that in order to obtain a stationary and Planckian emission of quasi-particles, it is not necessary to create a trapped region in the acoustic spacetime (corresponding to a supersonic regime in the fluid flow). It is sufficient to set up a dynamically changing flow asymptotically approaching a sonic regime with sufficient rapidity in laboratory time.

Carlos Barcelo; Stefano Liberati; Sebastiano Sonego; Matt Visser

2006-07-03T23:59:59.000Z

157

Energy trapping and shock disintegration in a composite granular medium  

E-Print Network (OSTI)

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.

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

2005-09-24T23:59:59.000Z

158

Thermal electric vapor trap arrangement and method  

DOE Patents (OSTI)

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.

Alger, Terry (Tracy, CA)

1988-01-01T23:59:59.000Z

159

Marginally outer trapped surfaces in higher dimensions  

E-Print Network (OSTI)

We review the basic setup of Kaluza-Klein theory, namely a 5-dimensional vacuum with a cyclic isometry, which corresponds to Einstein-Maxwell-dilaton theory in 4-dimensional spacetime. We first recall the behaviour of Killing horizons and its generators under bundle lift and projection. We then show that the property of compact surfaces of being (stably) marginally trapped is preserved under lift and projection provided the appropriate ("Pauli-") conformal scaling is used for the spacetime metric. We also discuss and compare recently proven area inequalities for stable axially symmetric 2-dimensional and 3-dimensional marginally outer trapped surfaces.

Tim-Torben Paetz; Walter Simon

2013-02-13T23:59:59.000Z

160

Parametric Resonance of Optically Trapped Aerosols  

E-Print Network (OSTI)

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.

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

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


161

Trapped-Particle Instability Leading to Bursting in Stimulated Raman Scattering Simulations  

SciTech Connect

Nonlinear, kinetic simulations of Stimulated Raman Scattering (SRS) for laser-fusion-relevant conditions present a bursting behavior. Different explanations for this regime has been given in previous studies: Saturation of SRS by increased nonlinear Landau damping [K. Estabrook et al., Phys. Fluids B 1 (1989) 1282] and detuning due to the nonlinear frequency shift of the plasma wave [H.X. Vu et al., Phys. Rev. Lett. 86 (2001) 4306]. Another mechanism, also assigning a key role to the trapped electrons, is proposed here: The break-up of the plasma wave through the trapped-particle instability.

S. Brunner; E. Valeo

2001-11-08T23:59:59.000Z

162

The Engineered Approach to Energy and Maintenance Effective Steam Trapping  

E-Print Network (OSTI)

The engineered approach to steam trap sizing, selection and application has proven effective in significantly reducing a plant's fuel consumption, maintenance and trap replacement costs while improving thermal efficiency and overall steam system performance. New field test procedures for measuring condensate load and steam loss have proven valuable in sizing traps and to determine which trap is the most energy efficient. The combination of using the engineered approach to steam trapping, field tests to verify trap performance and good maintenance practices has contributed to a major reduction in energy consumption of 10-50% in many industrial plants.

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

1980-01-01T23:59:59.000Z

163

Marginally trapped surfaces in spaces of oriented geodesics  

E-Print Network (OSTI)

We investigate the geometric properties of marginally trapped surfaces (surfaces which have null mean curvature vector) in the spaces of oriented geodesics of Euclidean 3-space and hyperbolic 3-space, endowed with their canonical neutral Kaehler structures. We prove that every rank one surface in these four manifolds is marginally trapped. In the Euclidean case we show that Lagrangian rotationally symmetric sections are marginally trapped and construct an explicit family of marginally trapped Lagrangian tori. In the hyperbolic case we explore the relationship between marginally trapped and Weingarten surfaces, and construct examples of marginally trapped surfaces with various properties.

Brendan Guilfoyle; Nikos Georgiou

2013-05-28T23:59:59.000Z

164

The Spindown of Bottom-Trapped Plumes  

Science Conference Proceedings (OSTI)

This note considers the decay of a bottom-trapped freshwater plume after the causative freshwater inflow has ceased. It is shown that shortly after the low-density inflow stops, the barotropic pressure field that it created radiates away and the ...

Ricardo P. Matano; Elbio D. Palma

2010-07-01T23:59:59.000Z

165

Effects of Sulfation Level on the Desulfation Behavior of Presulfated Pt-BaO/Al2O3 Lean NOx Trap Catalysts: A Combined H2 Temperature-Programmed Reaction, in Situ Sulfur K-Edge X-ray Absorption Near-Edge Spectroscopy, X-ray Photoelectron Spectroscopy, and Time-Resolved X-ray Diffraction Study  

SciTech Connect

Desulfation by hydrogen of presulfated Pt (2 wt %)-BaO(20 wt %)/Al{sub 2}O{sub 3} with various sulfur loading (S/Ba = 0.12, 0.31, and 0.62) were investigated by combining H{sub 2} temperature programmed reaction (TPRX), X-ray photoelectron spectroscopy (XPS), in situ sulfur K-edge X-ray absorption near-edge spectroscopy (XANES), and synchrotron time-resolved X-ray diffraction (TR-XRD) techniques. We find that the amount of H{sub 2}S desorbed during the desulfation in the H{sub 2} TPRX experiments is not proportional to the amount of initial sulfur loading. The results of both in situ sulfur K-edge XANES and TR-XRD show that at low sulfur loadings, sulfates were transformed to a BaS phase and remained in the catalyst rather than being removed as H{sub 2}S. On the other hand, when the deposited sulfur level exceeded a certain threshold (at least S/Ba = 0.31) sulfates were reduced to form H{sub 2}S, and the relative amount of the residual sulfide species in the catalyst was much less than at low sulfur loading. Unlike samples with high sulfur loading (e.g., S/Ba = 0.62), H{sub 2}O did not promote the desulfation for the sample with S/Ba of 0.12, implying that the formed BaS species originating from the reduction of sulfates at low sulfur loading are more stable to hydrolysis. The results of this combined spectroscopy investigation provide clear evidence to show that sulfates at low sulfur loadings are less likely to be removed as H{sub 2}S and have a greater tendency to be transformed to BaS on the material, leading to the conclusion that desulfation behavior of Pt-BaO/Al{sub 2}O{sub 3} lean NO{sub x} trap catalysts is markedly dependent on the sulfation levels.

Kim, D.H.; Hanson, J.; Szanyi, J.; Kwak, J.H.; Wang, X.; Hanson, J.C.; Engelhard, M.; and Peden, C.H.F.

2009-04-30T23:59:59.000Z

166

Towards a cryogenic planar ion trap for Sr-88  

E-Print Network (OSTI)

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 ...

Bakr, Waseem (Waseem S.)

2006-01-01T23:59:59.000Z

167

Two-dimensional ion trap lattice on a microchip  

E-Print Network (OSTI)

Microfabricated ion traps are a major advancement towards scalable quantum computing with trapped ions. The development of more flexible ion trap designs, in which tailored arrays of ions are positioned in two dimensions above a microfabricated surface, would lead to applications in fields as varied as quantum simulation, metrology and atom-ion interactions. Current surface ion traps often have low trap depths and high heating rates, due to the size of the voltages that can be applied to them, limiting the fidelity of quantum gates. In this article we report on a fabrication process that allows for the application of very high voltages to microfabricated devices in general and we apply this advance to fabricate a 2D ion trap lattice on a microchip. Our scalable microfabricated architecture allows for reliable trapping of 2D ion lattices, long ion lifetimes due to the deep trapping potential, rudimentary shuttling between lattice sites and the ability to deterministically introduce defects into the ion lattice.

R. C. Sterling; H. Rattanasonti; S. Weidt; K. Lake; P. Srinivasan; S. C. Webster; M. Kraft; W. K. Hensinger

2013-02-15T23:59:59.000Z

168

Ideal Multipole Ion Traps from Planar Ring Electrodes  

E-Print Network (OSTI)

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.

Robert J. Clark

2012-07-25T23:59:59.000Z

169

Transport of Trapped-Ion Qubits within a Scalable Quantum ...  

Science Conference Proceedings (OSTI)

... 158 6.13 Glass vacuum envelope. . . . . ... 159 6.14 Picture of the trap inside of the glass envelope. . . . . ...

2010-12-03T23:59:59.000Z

170

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

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.

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

2012-05-03T23:59:59.000Z

171

High voltage gas insulated transmission line with continuous particle trapping  

DOE Patents (OSTI)

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

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

1983-01-01T23:59:59.000Z

172

Laser cooling and sympathetic cooling in a linear quadrupole rf trap  

E-Print Network (OSTI)

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. The dependence of rf heating rates on the ion temperature, trapping parameters, and the number of ions is obtained. New rf heating mechanism affecting ultra-cold ion clouds exposed to laser radiation is described.The saturation spectroscopy setup of the hyperfine spectra of the molecular iodine has been built to provide an accurate frequency reference for the laser wavelength. This reference is used to obtain the fluorescence lineshapes of the laser cooled Mg$^+$ ions under different trapping conditions.The ion temperatures are deduced from the measurements, and the influence of the rf heating rates on the fluorescence lineshapes is also discussed. Cooling of the heavy ($m=720$a.u.) fullerene ions to under 10K by the means of the sympathetic cooling by the Mg$^+$ ions($m=24$a.u.) is demonstrated. The single-photon imaging system has been developed and used to obtain the images of the Mg$^+$ ion crystal structures at mK temperatures.

Ryjkov, Vladimir Leonidovich

2003-12-01T23:59:59.000Z

173

Use of Bullet Traps and Steel Targets  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

USE OF BULLET TRAPS AND USE OF BULLET TRAPS AND STEEL TARGETS U.S. DEPARTMENT OF ENERGY Office of Health, Safety and Security AVAILABLE ONLINE AT: INITIATED BY: http://www.hss.energy.gov Office of Health, Safety and Security Notices This document is intended for the exclusive use of elements of the Department of Energy (DOE), to include the National Nuclear Security Administration, their contractors, and other government agencies/individuals authorized to use DOE facilities. DOE disclaims any and all liability for personal injury or property damage due to use of this document in any context by any organization, group, or individual, other than during official government activities. Local DOE management is responsible for the proper execution of firearms-related programs for

174

A quantum information processor with trapped ions  

E-Print Network (OSTI)

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. In this work we present a small-scale quantum information processor based on a string of $^{40}$Ca${^+}$ ions confined in a macroscopic linear Paul trap. We review our set of operations which includes non-coherent operations allowing us to realize arbitrary Markovian processes. In order to build a larger quantum information processor it is mandatory to reduce the error rate of the available operations which is only possible if the physics of the noise processes is well understood. We identify the dominant noise sources in our system and discuss their effects on different algorithms. Finally we demonstrate how our entire set of operations can be used to facilitate the implementation of algorithms by examples of the quantum Fourier transform and the quantum order finding algorithm.

Philipp Schindler; Daniel Nigg; Thomas Monz; Julio T. Barreiro; Esteban Martinez; Shannon X. Wang; Stephan Quint; Matthias F. Brandl; Volckmar Nebendahl; Christian F. Roos; Michael Chwalla; Markus Hennrich; Rainer Blatt

2013-08-14T23:59:59.000Z

175

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

E-Print Network (OSTI)

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.

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

2008-12-09T23:59:59.000Z

176

Analysis of electron dynamics in non-ideal Penning traps  

Science Conference Proceedings (OSTI)

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

Coppa, G.; Mulas, R. [Dipartimento Energia, Politecnico di Torino, 10129 Torino (Italy); D'Angola, A. [Dipartimento di Ingegneria e Fisica dell'Ambiente, Universita della Basilicata, 85100 Potenza (Italy)

2012-06-15T23:59:59.000Z

177

Iterated dynamical maps in an ion trap  

E-Print Network (OSTI)

Iterated dynamical maps offer an ideal setting to investigate quantum dynamical bifurcations and are well adapted to few-qubit quantum computer realisations. We show that a single trapped ion, subject to periodic impulsive forces, exhibits a rich structure of dynamical bifurcations derived from the Jahn-Teller Hamiltonian flow model. We show that the entanglement between the oscillator and electronic degrees of freedom reflects the underlying dynamical bifurcation in a Floquet eigenstate.

M. Duncan; J. Links; G. J. Milburn

2007-11-16T23:59:59.000Z

178

Effect of trapping in degenerate quantum plasmas  

SciTech Connect

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.

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

179

Demonstration of a scalable, multiplexed ion trap for quantum information processing  

Science Conference Proceedings (OSTI)

A scalable, multiplexed ion trap for quantum information processing is fabricated and tested. The trap design and fabrication process are optimized for scalability to small trap size and large numbers of interconnected traps, and for integration of control ...

D. R. Leibrandt; J. Labaziewicz; R. J. Clark; I. L. Chuang; R. J. Epstein; C. Ospelkaus; J. H. Wesenberg; J. J. Bollinger; D. Leibfried; D. J. Wineland; D. Stick; J. Sterk; C. Monroe; C.-S. Pai; Y. Low; R. Frahm; R. E. Slusher

2009-11-01T23:59:59.000Z

180

The laser ion source trap for highest isobaric selectivity in online exotic isotope production  

Science Conference Proceedings (OSTI)

The improvement in the performance of a conventional laser ion source in the laser ion source and trap (LIST) project is presented, which envisages installation of a repeller electrode and a linear Paul trap/ion guide structure. This approach promises highest isobaric purity and optimum temporal and spatial control of the radioactive ion beam produced at an online isotope separator facility. The functionality of the LIST was explored at the offline test separators of University of Mainz (UMz) and ISOLDE/CERN, using the UMz solid state laser system. Ionization efficiency and selectivity as well as time structure and transversal emittance of the produced ion beam was determined. Next step after complete characterization is the construction and installation of the radiation-hard final trap structure and its first online application.

Schwellnus, F.; Gottwald, T.; Mattolat, C.; Wendt, K. [Institut fuer Physik, Johannes Gutenberg-Universitaet, D-55099 Mainz (Germany); Blaum, K. [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany); Catherall, R.; Crepieux, B.; Fedosseev, V.; Marsh, B.; Rothe, S.; Stora, T. [CERN, CH-1211 Geneva 23 (Switzerland); Kluge, H.-J. [GSI, Planckstrasse 1, D-64291 Darmstadt (Germany)

2010-02-15T23:59:59.000Z

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


181

Steam Traps-The Oft Forgotten Energy Conservation Treasure  

E-Print Network (OSTI)

In these days of high technology, the steam trap is often treated as a commodity item, forgotten by many and respected by a relative few. Yet, in many facilities, widespread undetected failure of steam traps has wasted 5-15% of a plant's total steam generation. Stopping this waste represents a major energy conservation treasure characterized by low investment and a fast payback. The proper application of steam trap technology requires the experience and judgment of a dedicated champion at each location. This paper will present an overview of a working steam trap program starting with the initial survey and loss estimates. Trap characteristics and performance by generic type will be discussed with practical examples utilized to illustrate the myths in steam trap sizing and the consequences of over-sizing. Standardization of trap inventory, training and follow-up are the other key program elements addressed.

Pychewicz, F. S.

1985-05-01T23:59:59.000Z

182

Entropic Time  

Science Conference Proceedings (OSTI)

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.

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

2011-03-14T23:59:59.000Z

183

Gas turbine engines with particle traps  

DOE Patents (OSTI)

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).

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

184

Impurity beam-trapping instability in tokamaks  

SciTech Connect

The sensitivity of neutron energy production to the impurity trapping of injected neutral beams is considered. This process is affected by inherent low-Z contamination of the tritium pre-heat plasma, by the species composition of the neutral beam, and by the entrance angle of the beam. The sensitivities of the process to these variables, and to the variation of wall material are compared. One finds that successful use of a low-Z, low-sputtering material can appreciably lengthen the useful pulse length. (auth)

Hogan, J.T.; Howe, H.C.

1976-01-01T23:59:59.000Z

185

Trapped Quintessential Inflation from Flux Compactifications  

E-Print Network (OSTI)

Quintessential inflation is studied using a string modulus as the inflaton - quintessence field. It is assumed that the modulus crosses an enhanced symmetry point (ESP) in field space. Particle production at the ESP temporarily traps the modulus resulting in a period of inflation. After reheating, the modulus freezes due to cosmological friction at a large value, such that its scalar potential is dominated by contributions due to fluxes in the extra dimensions. The modulus remains frozen until the present, when it can become quintessence.

Konstantinos Dimopoulos

2007-02-01T23:59:59.000Z

186

Mitigation of Sulfur Effects on a Lean NOx Trap Catalyst by Sorbate Reapplication  

DOE Green Energy (OSTI)

Lean NOx trap catalysis has demonstrated the ability to reduce NOx emissions from lean natural gas reciprocating engines by >90%. The technology operates in a cyclic fashion where NOx is trapped on the catalyst during lean operation and released and reduced to N2 under rich exhaust conditions; the rich cleansing operation of the cycle is referred to as "regeneration" since the catalyst is reactivated for more NOx trapping. Natural gas combusted over partial oxidation catalysts in the exhaust can be used to obtain the rich exhaust conditions necessary for catalyst regeneration. Thus, the lean NOx trap technology is well suited for lean natural gas engine applications. One potential limitation of the lean NOx trap technology is sulfur poisoning. Sulfur compounds directly bond to the NOx trapping sites of the catalyst and render them ineffective; over time, the sulfur poisoning leads to degradation in overall NOx reduction performance. In order to mitigate the effects of sulfur poisoning, a process has been developed to restore catalyst activity after sulfur poisoning has occurred. The process is an aqueous-based wash process that removes the poisoned sorbate component of the catalyst. A new sorbate component is reapplied after removal of the poisoned sorbate. The process is low cost and does not involve reapplication of precious metal components of the catalyst. Experiments were conducted to investigate the feasibility of the washing process on a lean 8.3-liter natural gas engine on a dynamometer platform. The catalyst was rapidly sulfur poisoned with bottled SO2 gas; then, the catalyst sorbate was washed and reapplied and performance was re-evaluated. Results show that the sorbate reapplication process is effective at restoring lost performance due to sulfur poisoning. Specific details relative to the implementation of the process for large stationary natural gas engines will be discussed.

Parks, II, James E [ORNL

2007-01-01T23:59:59.000Z

187

New nano trap protects environment | Argonne National Laboratory  

NLE Websites -- All DOE Office Websites (Extended Search)

New nano trap protects environment New nano trap protects environment By Tona Kunz * October 31, 2012 Tweet EmailPrint This story was originally published in volume 10, number 5 of Innovation magazine. A new type of nanoscale molecular trap makes it possible for industry to store large amounts of hydrogen in small fuel cells or capture, compact and remove volatile radioactive gas from spent nuclear fuel in an affordable, easily commercialized way. The ability to adjust the size of the trap openings to select for specific molecules or to alter how molecules are released at industrially accessible pressures makes the trap uniquely versatile. The trap is constructed of commercially available material and made possible through collaborative work at Argonne and Sandia national laboratories. "This introduces a new class of materials to nuclear waste remediation,"

188

Volatiles trapped in coals: Second quarterly report  

SciTech Connect

We have been able to collect and characterize volatiles that are evolved in the grinding of coal. We have developed a very sensitive method for collecting volatiles evolved in grinding. A sealed, gas tight, grinding apparatus has been built. With this system we can collect volatiles freed from the coal matrix during grinding. To do this a 125 cm/sup 3/ sample of coal is placed in to a 1 liter sealable ball mill jar. The jar is evacuated and the coal ground for 1 hr. The jar is then removed from the ball mill and evacuated into our sample collection system. Gas from the jar is pumped through two stages of dust filtering into a liquid nitrogen cold trap charged with 5 ml of methylene chloride. After warming the trap is shaken so that any gas from the sample mixes with and dissolves in the methylene chloride. One microliter samples of the methylene chloride are injected into a Finnegan GCMS. Preliminary analysis of mass spectra from peaks in the RIC show the presence of hydrocarbons. It was possible to definitively identify cyclohexene. The total amount of hydrocarbons seen is low. The attached figure is the mass spectra of the cyclohexene that was collected from the ground coal. 1 fig.

Sutter, J.R.; Halpern, J.B.

1988-01-01T23:59:59.000Z

189

Gas insulated transmission line having tapered particle trapping ring  

DOE Patents (OSTI)

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

Cookson, Alan H. (Pittsburgh, PA)

1982-01-01T23:59:59.000Z

190

Trap-depth determination from residual gas collisions  

SciTech Connect

We present a method for determining the depth of an atomic or molecular trap of any type. This method relies on a measurement of the trap loss rate induced by collisions with background gas particles. Given a fixed gas composition, the loss rate uniquely determines the trap depth. Because of the ''soft'' long-range nature of the van der Waals interaction, these collisions transfer kinetic energy to trapped particles across a broad range of energy scales, from room temperature to the microkelvin energy scale. The resulting loss rate therefore exhibits a significant variation over an enormous range of trap depths, making this technique a powerful diagnostic with a large dynamic range. We present trap depth measurements of a Rb magneto-optical trap using this method and a different technique that relies on measurements of loss rates during optical excitation of colliding atoms to a repulsive molecular state. The main advantage of the method presented here is its large dynamic range and applicability to traps of any type requiring only knowledge of the background gas density and the interaction potential between the trapped and background gas particles.

Van Dongen, J.; Zhu, C.; Clement, D.; Dufour, G.; Madison, K. W. [Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, British Columbia, V6T 1Z1 (Canada); Booth, J. L. [Physics Department, British Columbia Institute of Technology, 3700 Willingdon Avenue, Burnaby, British Columbia, V5G 3H2 (Canada)

2011-08-15T23:59:59.000Z

191

Bon MOT: Innovative Atom Trap Catches Highly Magnetic ...  

Science Conference Proceedings (OSTI)

... of a cloud of erbium atoms trapped and cooled and a ... all the while extracting energy and cooling them ... only a single laser and can cool erbium atoms ...

2011-07-18T23:59:59.000Z

192

Controlled Kinetic Energy Ion Source for Miniature Ion Trap ...  

with electronic signal sources coupled to the electrodes. The ion trap can be machined with conventional materials and methods and has demonstrated

193

Onset of Fermi Degeneracy in a Trapped Atomic Gas  

Science Conference Proceedings (OSTI)

... in the total energy of the ultra- cold, trapped ... of charge e onto a cryogenic capacitor C, and ... standards are known as “calculable capacitors” and rely ...

2010-07-12T23:59:59.000Z

194

NIST Racetrack Ion Trap is a Contender in Quantum ...  

Science Conference Proceedings (OSTI)

... ion trap under development as possible hardware for a future quantum computer. ... loading of 10 magnesium ions at once and transport of an ion ...

2011-10-26T23:59:59.000Z

195

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

Genome sequencing especially benefits from the nanoscale approach. Description. The trap is a three-layer, three-dimensional crossing metal/insulator ...

196

How Algae Use a "Sulfate Trap" to Selectively Biomineralize Strontium...  

NLE Websites -- All DOE Office Websites (Extended Search)

| 2003 | 2002 2001 | 2000 | 1998 | Subscribe to APS Science Highlights rss feed How Algae Use a "Sulfate Trap" to Selectively Biomineralize Strontium OCTOBER 20, 2011 Bookmark...

197

Bait formulations and longevity of navel orangeworm egg traps tested  

E-Print Network (OSTI)

there were 1% or 3% crude almond oil received more eggshaving no letters crude almond oil or traps baited with inone standard error. crude almond oil received significantly

Kuenen, L.P.S. Bas; Bentley, Walt; Rowe, Heather; Ribeiro, Brian

2008-01-01T23:59:59.000Z

198

`Trapped' Ions Provide First View of Light Property  

Science Conference Proceedings (OSTI)

... PHYSICS `Trapped' Ions Provide First View of Light Property. ... Quantum theory states that light can act either as a wave or as a particle. ...

199

Bait formulations and longevity of navel orangeworm egg traps tested  

E-Print Network (OSTI)

traps tested by L.P.S. (Bas) Kuenen, Walt Bentley, Heatherfor at least 10 weeks. L.P.S. (Bas) Kuenen is Research

Kuenen, L.P.S. Bas; Bentley, Walt; Rowe, Heather; Ribeiro, Brian

2008-01-01T23:59:59.000Z

200

The angular momentum of a magnetically trapped atomic condensate  

E-Print Network (OSTI)

For an atomic condensate in an axially symmetric magnetic trap, the sum of the axial components of the orbital angular momentum and the hyperfine spin is conserved. Inside an Ioffe-Pritchard trap (IPT) whose magnetic field (B-field) is not axially symmetric, the difference of the two becomes surprisingly conserved. In this paper we investigate the relationship between the values of the sum/difference angular momentums for an atomic condensate inside a magnetic trap and the associated gauge potential induced by the adiabatic approximation. Our result provides significant new insight into the vorticity of magnetically trapped atomic quantum gases.

P. Zhang; H. H. Jen; C. P. Sun; L. You

2006-11-14T23:59:59.000Z

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


201

Electron traps in organic light-emitting diodes  

Science Conference Proceedings (OSTI)

This work presents the effects of electron traps in organic light-emitting diodes using a model which includes charge injection

Min-Jan Tsai; Hsin-Fei Meng

2005-01-01T23:59:59.000Z

202

TIMING APPARATUS  

DOE Patents (OSTI)

The timing device comprises an escapement wheel and pallet, a spring drive to rotate the escapement wheel to a zero position, means to wind the pretensioned spring proportional to the desired signal time, and a cam mechanism to control an electrical signal switch by energizing the switch when the spring has been wound to the desired position, and deenergizing it when it reaches the zero position. This device produces an accurately timed signal variably witain the control of the operator.

Bennett, A.E.; Geisow, J.C.H.

1956-04-17T23:59:59.000Z

203

Characterization of Trapped Lignin-Degrading Microbes in Tropical Forest Soil  

DOE Green Energy (OSTI)

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.

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

2011-07-14T23:59:59.000Z

204

Selection, Sizing, and Testing of Stream Traps in Commercial Buildings  

E-Print Network (OSTI)

For maximum effectiveness in steam systems, steam traps should have operating characteristics which closely match the requirements of the applications for which they are used. A trap which holds back condensate until it is subcooled and some of the sensible heat has been utilized is unsuitable where the need is to get maximum output from an exchanger by discharging condensate as soon as it forms. Equally, a trap discharging condensate at steam temperature can exacerbate flash steam problems in cases where surplus heat exchange area exists and a subcooling trap might be more suitable. In all cases, undersized traps simply cannot drain condensate from the steam equipment at the required rate, while oversized traps which cost more will usually wear faster and begin leaking expensive steam. This emphasizes the need for carefully selecting trap sizes that are properly engineered for maximum system efficiency. And, of course, the ability of a trap to cope with varying loads and to discharge noncondensible gases is often important. The recommended procedure is to first select the trap type which has performance capabilities that satisfy specific application needs, and then to choose a size which handles the condensate load without any unnecessary excess capacity. The Selection Guide, Table 1, is not comprehensive but helps in many applications where no unusual operating conditions or severe corrosion problems exist. Choosing the correct trap size then implies estimating the steam consumption rate, which of course equals the condensate load. Sometimes the load has already been measured, or the rated output of the steam equipment is known or can be obtained from the original manufacturer. In other cases, an estimate must be made and a Table o f Load Formulas will help although it, too, cannot be comprehensive. After making the best possible estimate of the load, a safety factor is applied. This allows for any inaccuracies in the estimating, for increased condensation rates at start-up, and for lower than anticipated pressure differentials across the trap.

Armer, A.; Risko, J. R.

1984-01-01T23:59:59.000Z

205

Debris trap in a turbine cooling system  

SciTech Connect

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.

Wilson, Ian David (Clifton Park, NY)

2002-01-01T23:59:59.000Z

206

Can aerosols be trapped in open flows?  

E-Print Network (OSTI)

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.

Rafael D. Vilela; Adilson E. Motter

2007-06-10T23:59:59.000Z

207

Design of a millimetre-scale magnetic surface trap for cold atoms  

E-Print Network (OSTI)

We study a novel millimetre-scale magnetic trap for ultracold atoms, in which the current carrying conductors can be situated outside the vacuum region, a few mm away from the atoms. This design generates a magnetic field gradient in excess of \\SI{1000}{G/cm} at a distance of \\SI{2}{mm} from the conductors. We perform electromagnetic and thermo-mechanical characterisation using Finite Element Methods (FEM). The predicted behaviour has been verified by electrical and thermal measurements on a prototype, but has not been implemented on an apparatus with cold atoms. Operating this trap at the highest gradient allows for rapid evaporative cooling comparable to that achieved by atom chips.

Trypogeorgos, Dimitris

2013-01-01T23:59:59.000Z

208

Thermodynamics analogue for self-trapped spinning-stationary Madelung fluid  

E-Print Network (OSTI)

We discuss two-dimensional Madelung fluid dynamics whose irrotational case reduces into the Schr\\"odinger equation for a free single particle. We show that the self-trapped spinning-stationary Madelung fluid reported in the previous paper can be analogically identified as an equilibrium thermodynamics system. This is done by making correspondence between Shannon entropy over Madelung density and internal energy to be defined in the main text, respectively with thermal-entropy and thermal-internal energy of equilibrium thermodynamics system. This leads us to identify a Madelung fluid analog of thermal-temperature at the vanishing value of which the stationary Madelung fluid will be no more spinning and is equal to the quantum mechanical ground state of a particle trapped inside a cylindrical tube external potential.

Agung Budiyono

2006-01-31T23:59:59.000Z

209

Storage of ultracold neutrons in the UCN$?$ magneto-gravitational trap  

E-Print Network (OSTI)

The UCN$\\tau$ experiment is designed to measure the lifetime $\\tau_{n}$ of the free neutron by trapping ultracold neutrons (UCN) in a magneto-gravitational trap. An asymmetric bowl-shaped NdFeB magnet Halbach array confines low-field-seeking UCN within the apparatus, and a set of electromagnetic coils in a toroidal geometry provide a background "holding" field to eliminate depolarization-induced UCN loss caused by magnetic field nodes. We present a measurement of the storage time $\\tau_{store}$ of the trap by storing UCN for various times, and counting the survivors. The data are consistent with a single exponential decay, and we find $\\tau_{store}=860\\pm19$ s: within $1 \\sigma$ of current global averages for $\\tau_{n}$. The storage time with the holding field deactiveated is found to be $\\tau_{store}=470 \\pm 160$ s; this decreased storage time is due to the loss of UCN which undergo Majorana spin-flips while being stored. We discuss plans to increase the statistical sensitivity of the measurement and investigate potential systematic effects.

D. J. Salvat; E. R. Adamek; D. Barlow; L. J. Broussard; J. D. Bowman; N. B. Callahan; S. M. Clayton; C. Cude-Woods; S. Currie; E. B. Dees; W. Fox; P. Geltenbort; K. P. Hickerson; A. T. Holley; C. -Y. Liu; M. Makela; J. Medina; D. J. Morley; C. L. Morris; S. I. Penttila; J. Ramsey; A. Saunders; S. J. Seestrom; S. K. L. Sjue; B. A. Slaughter; E. I. Sharapov; J. Vanderwerp; B. VornDick; P. L. Walstrom; Z. Wang; T. L. Womack; A. R. Young

2013-10-21T23:59:59.000Z

210

Storage of ultracold neutrons in the UCN$\\tau$ magneto-gravitational trap  

E-Print Network (OSTI)

The UCN$\\tau$ experiment is designed to measure the lifetime $\\tau_{n}$ of the free neutron by trapping ultracold neutrons (UCN) in a magneto-gravitational trap. An asymmetric bowl-shaped NdFeB magnet Halbach array confines low-field-seeking UCN within the apparatus, and a set of electromagnetic coils in a toroidal geometry provide a background "holding" field to eliminate depolarization-induced UCN loss caused by magnetic field nodes. We present a measurement of the storage time $\\tau_{store}$ of the trap by storing UCN for various times, and counting the survivors. The data are consistent with a single exponential decay, and we find $\\tau_{store}=860\\pm19$ s: within $1 \\sigma$ of current global averages for $\\tau_{n}$. The storage time with the holding field deactiveated is found to be $\\tau_{store}=470 \\pm 160$ s; this decreased storage time is due to the loss of UCN which undergo Majorana spin-flips while being stored. We discuss plans to increase the statistical sensitivity of the measurement and investi...

Salvat, D J; Barlow, D; Broussard, L J; Bowman, J D; Callahan, N B; Clayton, S M; Cude-Woods, C; Currie, S; Dees, E B; Fox, W; Hickerson, K P; Holley, A T; Liu, C -Y; Makela, M; Medina, J; Morley, D J; Morris, C L; Penttila, S I; Ramsey, J; Saunders, A; Seestrom, S J; Sjue, S K L; Slaughter, B A; Sharapov, E I; Vanderwerp, J; VornDick, B; Walstrom, P L; Wang, Z; Womack, T L; Young, A R

2013-01-01T23:59:59.000Z

211

Hydrobiologia vol. 65, I, pag. 65-68, 1979 A SIZE SELECTIVE UNDERWATER LIGHT TRAP  

E-Print Network (OSTI)

Hydrobiologia vol. 65, I, pag. 65-68, 1979 A SIZE SELECTIVE UNDERWATER LIGHT TRAP R. B. AIKEN underwater light trap isdescribed. Trap records indicate that the trap iseffective in taking a wide variety. (1955) described the construction and operation of an underwater light trap. Their records indi- cate

Aiken, Ron

212

Effective Steam Trap Selection/Maintenance - Its Payback  

E-Print Network (OSTI)

In oil refineries and petrochemical plants large number of steam traps are used to discharge condensate from steam mains, tracers and process equipment. Early efforts on steam traps focused almost exclusively on their selection and sizing, and it was not until the 1973 oil embargo that a need for regular maintenance became recognized. Although relatively small pieces of equipment, traps are responsible for large quantities of steam losses, decreased equipment efficiency and high maintenance costs; e.g., a steam trap leaking 100 psig steam through a 1/8 inch orifice costs at least $2k/yr if steam is valued at $5/k lb. Typically, a steam trap survey identifies 20-60% of traps malfunctioning. Therefore, establishing an effective steam trap selection/maintenance program is not simple but can be extremely profitable. This paper will show how a successful checking/maintenance program can result in high returns by using a case study at an Exxon plant. The example also shows how a central engineering organization can interact with plant technicians/ maintenance personnel to help implement an effective steam trap maintenance program at competitive costs and high returns.

Garcia, E.

1984-01-01T23:59:59.000Z

213

Two-dimensional Vlasov simulation of electron plasma wave trapping, wavefront bowing, self-focusing, and sideloss  

Science Conference Proceedings (OSTI)

Two-dimensional Vlasov simulations of nonlinear electron plasma waves are presented, in which the interplay of linear and nonlinear kinetic effects is evident. The plasma wave is created with an external traveling wave potential with a transverse envelope of width {Delta}y such that thermal electrons transit the wave in a ''sideloss'' time, t{sub sl{approx}{Delta}}y/v{sub e}. Here, v{sub e} is the electron thermal velocity. The quasisteady distribution of trapped electrons and its self-consistent plasma wave are studied after the external field is turned off. In cases of particular interest, the bounce frequency, {omega}{sub be}=k{radical}(e{phi}/m{sub e}), satisfies the trapping condition {omega}{sub be}t{sub sl}>2{pi} such that the wave frequency is nonlinearly downshifted by an amount proportional to the number of trapped electrons. Here, k is the wavenumber of the plasma wave and {phi} is its electric potential. For sufficiently short times, the magnitude of the negative frequency shift is a local function of {phi}. Because the trapping frequency shift is negative, the phase of the wave on axis lags the off-axis phase if the trapping nonlinearity dominates linear wave diffraction. In this case, the phasefronts are curved in a focusing sense. In the opposite limit, the phasefronts are curved in a defocusing sense. Analysis and simulations in which the wave amplitude and transverse width are varied establish criteria for the development of each type of wavefront. The damping and trapped-electron-induced focusing of the finite-amplitude electron plasma wave are also simulated. The damping rate of the field energy of the wave is found to be about the sideloss rate, {nu}{sub e{approx}}t{sub sl}{sup -1}. For large wave amplitudes or widths {Delta}y, a trapping-induced self-focusing of the wave is demonstrated.

Banks, J. W.; Berger, R. L.; Cohen, B. I.; Hittinger, J. A. F. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); Brunner, S. [Centre de Recherches en Physique des Plasmas, Ecole Polytechnique Federale de Lausanne, Lausanne (Switzerland)

2011-05-15T23:59:59.000Z

214

Energy Efficient Steam Trapping of Trace Heating Systems  

E-Print Network (OSTI)

Since as many as 40-60% of a plant's steam traps may be used on steam tracer lines, it is essential to select the correct, properly sized 'traps'; to optimize the efficient removal of condensate while providing maximum heat transfer to maintain desired product temperatures and greatly reduce steam losses. Factors related to achieving uniform product temperatures and maximum heat transfer rates and energy efficiency are: 1.Types and Methods used for Steam Tracing; 2. Systematic heat balance required to achieve economic tracer lengths; 3. Maximum allowable trapping distance for specific applications 4.Data important to determine condensate loads; 5. Trap selection, sizing, good installation practices, and proper maintenance. Using an engineered approach to steam trapping of trace heating systems have resulted in stable tracer line temperatures while reducing steam consumption 10-50% with minimum maintenance.

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

1981-01-01T23:59:59.000Z

215

Mechanics of Interfacial Composite Materials  

E-Print Network (OSTI)

Recent experiments and simulations have demonstrated that particle-covered interfaces can exist in stable non-spherical shapes as a result of the steric jamming of the interfacially trapped particles, which confers the interface with solid-like properties. We provide an experimental and theoretical characterization of the mechanical properties of these armored objects, with attention given to the two-dimensional granular state of the interface. Small inhomogeneous stresses produce a plastic response while homogeneous stresses produce a weak elastic response. Shear-driven particle-scale rearrangements explain the basic threshold needed to obtain the near-perfect plastic deformation that is observed. Furthermore, the inhomogeneous stress state of the interface is exhibited experimentally by using surfactants to destabilize the particles on the surface. Since the interfacially trapped particles retain their individual characteristics, armored interfaces can be recognized as a kind of composite material with distinct chemical, structural and mechanical properties.

Anand Bala Subramaniam; Manouk Abkarian; L. Mahadevan; Howard A. Stone

2006-05-25T23:59:59.000Z

216

Measurement of one-particle correlations and momentum distributions for trapped 1D gases  

E-Print Network (OSTI)

van Hove's theory of scattering of probe particles by a macroscopic target is generalized so as to relate the differential cross section for atomic ejection via stimulated Raman transitions to one-particle momentum-time correlations and momentum distributions of 1D trapped gases. This method is well suited to probing the longitudinal momentum distributions of 1D gases in situ, and examples are given for bosonic and fermionic atoms.

M. D. Girardeau; E. M. Wright

2000-12-19T23:59:59.000Z

217

Compliant mechanisms  

E-Print Network (OSTI)

The motivation for this work has been a variety of motions like navigation of pipelines, insertion operations in assembly, and gripping actions, which require the adaptation of the mechanism to the external constraints, rather than avoid them. To this effect, efforts have been made in building mechanisms that obtain the required degrees of freedom through deformations rather than explicit joints in them. Although the use of many joints provides the required number of degrees of freedom, it does so at the cost of making the system very bulky and complex. With the advent of new polymers, the possibility of building joint-free mechanisms that fulfil the requirements of adaptation has increased. Based on this approach, a Magneto Active Polymer (MAP) material has been developed here at the Texas A\\&M University, in which the actuation is performed by the conversion of electromagnetic energy into mechanical energy. The initial experimentation has proved the vast potential of the use of such a material and a few mechanisms like a magneto active peristaltic pump, have been designed and tested for the first time using this material. In this mechanism, the pumping action is obtained when a moving magnetic field produces peristaltic waves in the magneto active material shaped as a tube. Also for the first time, experiments have been conducted to analyze the response of the MAP material to a pulsating magnetic field with the intent of using the experimental results to develop a model of the MAP. In developing the design for the peristaltic pump and other conceptual models described in this thesis, ideas have been drawn from the different modes of locomotion and actuators present in lower organisms. These have been good sources of inspiration for the work done in this thesis and they have been documented in detail.

Venkataraghavan, Janarthanan T

2001-01-01T23:59:59.000Z

218

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

SciTech Connect

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.

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

2012-01-01T23:59:59.000Z

219

Properties of Trapped Electron Bunches in a Plasma Wakefield Accelerator  

Science Conference Proceedings (OSTI)

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.

Kirby, Neil; /SLAC

2009-10-30T23:59:59.000Z

220

Measurements of electric field noise and light-induced charging in cryogenic surface electrode ion traps  

E-Print Network (OSTI)

Ion traps provide an excellent tool for controlling and observing the state of a single trapped ion. For this reason, ion traps have been proposed as a possible system for large-scale quantum computation. However, many ...

Lachenmyer, Nathan S. (Nathan Scott)

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "timing trapping mechanism" from the National Library of EnergyBeta (NLEBeta).
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221

Quantum hologram of macroscopically entangled light via the mechanism of diffuse light storage  

E-Print Network (OSTI)

In the present paper we consider a quantum memory scheme for light diffusely propagating through a spatially disordered atomic gas. The diffuse trapping of the signal light pulse can be naturally integrated with the mechanism of stimulated Raman conversion into a long-lived spin coherence. Then the quantum state of the light can be mapped onto the disordered atomic spin subsystem and can be stored in it for a relatively long time. The proposed memory scheme can be applicable for storage of the macroscopic analog of the $\\Psi^{(-)}$ Bell state and the prepared entangled atomic state performs its quantum hologram, which suggests the possibility of further quantum information processing.

L. V. Gerasimov; I. M. Sokolov; D. V. Kupriyanov; M. D. Havey

2011-11-29T23:59:59.000Z

222

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

SciTech Connect

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

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

2005-01-01T23:59:59.000Z

223

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

E-Print Network (OSTI)

(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.

Steinberger, Julia K., 1974-

2004-01-01T23:59:59.000Z

224

Steam Trap Testing and Evaluation: An Actual Plant Case Study  

E-Print Network (OSTI)

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 equipment and that a minimum life be achieved. This paper deals with the history of the steam system/condensate systems, the setting up of the testing procedure, which traps were and were not tested and the results of the testing program to date.

Feldman, A. L.

1981-01-01T23:59:59.000Z

225

Coherence of a qubit stored in Zeeman levels of a single optically trapped atom  

E-Print Network (OSTI)

We experimentally investigate the coherence properties of a qubit stored in the Zeeman substates of the 5S1/2, F=1 hyperfine ground level of a single optically trapped Rb-87 atom. Larmor precession of a single atomic spin-1 system is observed by preparing the atom in a defined initial spin-state and then measuring the resulting state after a programmable period of free evolution. Additionally, by performing quantum state tomography, maximum knowledge about the spin coherence is gathered. By using an active magnetic field stabilization and without application of a magnetic guiding field we achieve transverse and longitudinal dephasing times of T2*=75..150 \\mus and T1>0.5 ms respectively. We derive the light-shift distribution of a single atom in the approximately harmonic potential of a dipole trap and show that the measured atomic spin coherence is limited mainly by residual position- and state-dependent effects in the optical trapping potential. The improved understanding enables longer coherence times, an i...

Rosenfeld, Wenjamin; Weber, Markus; Weinfurter, Harald

2011-01-01T23:59:59.000Z

226

Coherence of a qubit stored in Zeeman levels of a single optically trapped atom  

E-Print Network (OSTI)

We experimentally investigate the coherence properties of a qubit stored in the Zeeman substates of the 5S1/2, F=1 hyperfine ground level of a single optically trapped Rb-87 atom. Larmor precession of a single atomic spin-1 system is observed by preparing the atom in a defined initial spin-state and then measuring the resulting state after a programmable period of free evolution. Additionally, by performing quantum state tomography, maximum knowledge about the spin coherence is gathered. By using an active magnetic field stabilization and without application of a magnetic guiding field we achieve transverse and longitudinal dephasing times of T2*=75..150 \\mus and T1>0.5 ms respectively. We derive the light-shift distribution of a single atom in the approximately harmonic potential of a dipole trap and show that the measured atomic spin coherence is limited mainly by residual position- and state-dependent effects in the optical trapping potential. The improved understanding enables longer coherence times, an important prerequisite for future applications in long-distance quantum communication and computation with atoms in optical lattices or for a loophole-free test of Bell's inequality.

Wenjamin Rosenfeld; Jürgen Volz; Markus Weber; Harald Weinfurter

2011-07-25T23:59:59.000Z

227

Precise asymptotics for the parabolic Anderson model with a moving catalyst or trap  

E-Print Network (OSTI)

We consider the solution $u\\colon [0,\\infty) \\times\\mathbb{Z}^d\\rightarrow [0,\\infty) $ to the parabolic Anderson model, where the potential is given by $(t,x)\\mapsto\\gamma\\delta_{Y_t}\\left(x\\right)$ with $Y$ a simple symmetric random walk on $\\mathbb{Z}^d$. Depending on the parameter $\\gamma\\in[-\\infty,\\infty)$, the potential is interpreted as a randomly moving catalyst or trap. In the trap case, i.e., $\\gamma0$), we consider the solution $u$ from the perspective of the catalyst, i.e., the expression $u(t,Y_t+x)$. Focusing on the cases where moments grow exponentially fast (that is, $\\gamma$ sufficiently large), we describe the moment asymptotics of the expression above up to equivalence. Here, it is crucial to prove the existence of a principal eigenfunction of the corresponding Hamilton operator. While this is well-established for the first moment, we have found an extension to higher moments.

Schnitzler, Adrian

2010-01-01T23:59:59.000Z

228

Polish permian basin: Lithofacies traps for gas within the Rotliegende deposits as a new exploration potential  

SciTech Connect

Rotliegende deposits are the most prospective reservoir gas rocks in the Polish Permian basin. Thirty years of their exploration have led to location of numerous gas fields in the upper-most part of these series, particularly in the area of the Fore-Sudetic monocline. Up to this time, exploration studies concentrated mainly on structural objects, and most of the structures were positive gas traps. Well and seismic data also indicate an occurrence of lithofacies gas traps; they occur mainly in the sandstone zones within the fanglomerates surrounding the Wolsztyn Ridge. When comparing the facies regularities in the known gas fields in the German Permian basin (interfingering sandstones and claystones) to the facies patterns of the Polish Permian basin, one may suspect similar exploration possibilities. These are the first promising results. Advances in analysis of the Rotliegende depositional systems will enable us to create a new exploration potential.

Karnkowski, P.H. (Warsaw Univ., Warsaw (Poland))

1993-09-01T23:59:59.000Z

229

Spatial correlation functions for the collective degrees of freedom of many trapped ions  

E-Print Network (OSTI)

Spatial correlation functions provide a glimpse into the quantum correlations within a quantum system. Ions in a linear trap collectively form a nonuniform, discretized background on which a scalar field of phonons propagates. Trapped ions have the experimental advantage of each having their own "built-in" motional detector: electronic states that can be coupled, via an external laser, to the ion's vibrational motion. The post-interaction electronic state can be read out with high efficiency, giving a stochastic measurement record whose classical correlations reflect the quantum correlations of the ions' collective vibrational state. Here we calculate this general result, then we discuss the long detection-time limit and specialize to Gaussian states, and finally we compare the results for thermal versus squeezed states.

Nicolas C. Menicucci; G. J. Milburn

2008-07-22T23:59:59.000Z

230

Thick-film technology for ultra high vacuum interfaces of micro-structured traps  

E-Print Network (OSTI)

We adopt thick-film technology to produce ultra high vacuum compatible interfaces for electrical signals. These interfaces permit voltages of hundreds of Volts and currents of several Amperes and allow for very compact vacuum setups, useful in quantum optics in general, and especially for quantum information and quantum simulations using miniaturized traps for ions or neutral atoms. Such printed circuits can also be useful as pure in-vacuum devices. We demonstrate a specific interface, which provides eleven current feedthroughs, more than 70 dc feedthroughs and a feedthrough for radio frequencies. We achieve a pressure in the low 1e-11mbar range and demonstrate the full functionality of the interface by trapping chains of cold ytterbium ions, which requires all of the signals mentioned above being present. In addition, a versatile multi-channel device for supplying precise time-dependent voltages has been developed.

Delia Kaufmann; Thomas Collath; M. Tanveer Baig; Peter Kaufmann; Eman Asenwar; Michael Johanning; Christof Wunderlich

2011-07-20T23:59:59.000Z

231

Effects of trapping and finite temperature in a relativistic degenerate plasma  

SciTech Connect

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.

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

232

Effect of surface treatments on self-trapped exciton luminescence in single-crystal CaF{sub 2}  

SciTech Connect

We show that near-surface defects produced by mechanical treatments and electron irradiation can significantly enhance the intensity of luminescence due to the decay of self-trapped excitons (STEs) in single-crystal calcium fluoride during 157- and 193-nm irradiation. For example, polishing can double the intensity of the STE luminescence. Defects produced by mechanical indentation can either increase or decrease the luminescence intensity, depending on the indentation force. Electron irradiation also enhances subsequent STE luminescence. When electron-irradiated samples are annealed, additional increases in luminescence intensity are observed. Plausible mechanisms for the observed effects on STE luminescence intensity are discussed.

Cramer, L.P.; Cumby, T.D.; Leraas, J.A.; Langford, S.C.; Dickinson, J.T. [Department of Physics and Materials Science Program, Washington State University, Pullman, Washington 99164-2814 (United States)

2005-05-15T23:59:59.000Z

233

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

SciTech Connect

Penning trap mass measurements of short-lived nuclides have been performed for the first time with highly charged ions, 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 unrivaled precision with gains of 1-2 orders of magnitude. The method is particularly suited for short-lived nuclides such as the superallowed {beta} emitter {sup 74}Rb (T{sub 1/2}=65 ms). The determination of its atomic mass and an improved Q{sub EC} value are presented.

Ettenauer, S.; Gallant, A. T.; Dilling, J. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3 (Canada); Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z1 (Canada); Simon, M. C.; Chaudhuri, A.; Mane, E.; Delheij, P.; Pearson, M. R. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3 (Canada); Brunner, T. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3 (Canada); Physik Department E12, Technische Universitaet Muenchen, D-85748 Garching (Germany); Chowdhury, U. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3 (Canada); Department of Physics and Astronomy, University of Manitoba, Winnipeg, MB R3T 2N2 (Canada); Simon, V. V. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3 (Canada); Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany); Ruprecht-Karls-Universitaet, Heidelberg (Germany); Brodeur, M. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3 (Canada); Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z1 (Canada); National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824 (United States); Andreoiu, C. [Department of Chemistry, Simon Fraser University, Burnaby, BC V5A 1S6 (Canada); Audi, G. [CSNSM-IN2P3-CNRS, Universite Paris 11, 91405 Orsay (France); Lopez-Urrutia, J. R. Crespo; Ullrich, J. [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany); Gwinner, G. [Dept. of Physics and Astronomy, Univ. of Manitoba, Winnipeg, MB R3T 2N2 (Canada); Lapierre, A. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3 (Canada); National Superconducting Cyclotron Lab., Michigan State Univ., East Lansing, Michigan 48824 (United States); Lunney, D. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3 (Canada); CSNSM-IN2P3-CNRS, Univ. Paris 11, 91405 Orsay (France); Ringle, R. [National Superconducting Cyclotron Lab., Michigan State Univ., East Lansing, Michigan 48824 (United States)

2011-12-30T23:59:59.000Z

234

Testing quantum physics in space using optically trapped nanospheres  

E-Print Network (OSTI)

Recent developments in space technology like micro-propulsion systems for drag-free control, thermal shielding, ultra-stable laser sources and stable optical cavities set an ideal platform for quantum optomechanical experiments with optically trapped dielectric spheres. Here, we will provide an overview of the results of recent studies aiming at the realization of the space mission MAQRO to test the foundations of quantum physics in a parameter regime orders of magnitude beyond existing experiments. In particular, we will discuss DECIDE, which is an experiment to prepare and then study a Schr\\"odinger-cat-type state, where a dielectric nanosphere of around 100nm radius is prepared in a superposition of being in two clearly distinct positions at the same time. This superposition leads to double-slit-type interference, and the visibility of the interference pattern will be compared to the predictions of quantum theory. This approach allows for testing for possible deviations from quantum theory as our test objects approach macroscopic dimensions. With DECIDE, it will be possible to distinctly test several prominent theoretical models that predict such deviations, for example: the Di\\'osi-Pensrose model, the continuous-spontaneous-localization model of Ghirardi, Rimini, Weber and Pearle, and the model of K\\'arolyh\\'azy.

Rainer Kaltenbaek

2013-07-26T23:59:59.000Z

235

Dynamics of Methane Trapped in C(60) Interstices  

SciTech Connect

In order to understand the hindered rotational and vibrational dynamics of methane trapped in C{sub 60} interstices and to determine the structure around the interstitial site, they have carried out inelastic neutron scattering studies of the methane/C{sub 60} system. At temperatures of 20K and below, they observe inelastic peaks from rotational transitions of the CH{sub 4}. These transitions allow unambiguous assignment of the hindered rotational energy levels and a determination of the interaction potential. The appearance of two peaks for one of the J = 0{r_arrow}3 transitions implies the existence of two distinct kinds of interstitial sites and the measured transition energies suggest a rotational barrier of about 26 and 16 meV for these sites. Time-dependent changes in peak heights indicate slow t{sub 1/2} ({approx} 2.6 hrs) triplet{r_arrow}quintet nuclear spin conversion that necessarily accompanies the J = 1{r_arrow}0 rotational relaxation. They also have observed a sharp inelastic peak at 9.3 meV, which corresponds to a local vibrational mode of CH{sub 4} rattling in its cage at {approximately} 2.2 THz. Other peaks involving higher-energy vibrational excitations in CD{sub 4}/C{sub 60} correspond in energy to assigned peaks in the inelastic neutron scattering spectra of C{sub 60}, albeit sometimes with different intensities.

KING, HARRY F.; KWEI, GEORGE H.; MOROSIN, BRUNO; TROUW, FRANS

1999-09-01T23:59:59.000Z

236

Purple traps yield Reservation's first detection of Emerald Ash Borer  

NLE Websites -- All DOE Office Websites (Extended Search)

traps yield Reservation's first detection of Emerald Ash Borer traps yield Reservation's first detection of Emerald Ash Borer The question of whether or not DOE's forests are infested with Emerald Ash Borer (EAB) has been answered. On May 10, a trap on Highway 95 at the Highway 58 interchange produced the first instance of the destructive non-native insect in Roane County. Five days later, a second trap on Bethel Valley Road near the East Portal turned up the first capture in Anderson County. "Unfortunately, these finds signal the beginning of a decline of ash species throughout the reservation" according to Greg Byrd, forester with the ORNL Natural Resources Program. "Dieback will become more prominent as the insect populations expand. Native ash trees have little defense against this pest, which was

237

Energy Conservation in Coastal-Trapped Wave Calculations  

Science Conference Proceedings (OSTI)

A consideration of energy conservation for coastal-trapped waves shows that, for a slowly varying medium, the normalization of the wave modes is not arbitrary. Errors related to incorrect normalization are demonstrated for a simple analytic ...

K. H. Brink

1989-07-01T23:59:59.000Z

238

Energy Trapping near the Equator in a Numerical Ocean Model  

Science Conference Proceedings (OSTI)

The trapped equatorial standing modes described theoretically by Gent (1979) are reproduced in a single vertical-mode numerical ocean model. integrations are carried out in domains whose longitudinal extents are characteristic of the widths of ...

Peter R. Gent; Albert J. Semtner Jr.

1980-06-01T23:59:59.000Z

239

Trapped Lee Wave Interference in the Presence of Surface Friction  

Science Conference Proceedings (OSTI)

Trapped lee wave interference over double bell-shaped obstacles in the presence of surface friction is examined. Idealized high-resolution numerical experiments with the nonhydrostatic Coupled Ocean–Atmosphere Mesoscale Prediction System (COAMPS) ...

Ivana Stiperski; Vanda Grubiši?

2011-04-01T23:59:59.000Z

240

From transistor to trapped-ion computers for quantum chemistry  

E-Print Network (OSTI)

Over the last few decades, quantum chemistry has progressed through the development of computational methods based on modern digital computers. However, these methods can hardly fulfill the exponentially-growing resource requirements when applied to large quantum systems. As pointed out by Feynman, this restriction is intrinsic to all computational models based on classical physics. Recently, the rapid advancement of trapped-ion technologies has opened new possibilities for quantum control and quantum simulations. Here, we present an efficient toolkit that exploits both the internal and motional degrees of freedom of trapped ions for solving problems in quantum chemistry, including molecular electronic structure, molecular dynamics, and vibronic coupling. We focus on applications that go beyond the capacity of classical computers, but may be realizable on state-of-the-art trapped-ion systems. These results allow us to envision a new paradigm of quantum chemistry that shifts from the current transistor to a near-future trapped-ion-based technology.

M. -H. Yung; J. Casanova; A. Mezzacapo; J. McClean; L. Lamata; A. Aspuru-Guzik; E. Solano

2013-07-16T23:59:59.000Z

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


241

Electron source for a mini ion trap mass spectrometer  

DOE Patents (OSTI)

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.

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

1995-12-19T23:59:59.000Z

242

Trapped Ion Imaging with a High Numerical Aperture Spherical Mirror  

E-Print Network (OSTI)

Efficient collection and analysis of trapped ion qubit fluorescence is essential for robust qubit state detection in trapped ion quantum computing schemes. We discuss simple techniques of improving photon collection efficiency using high numerical aperture (N.A.) reflective optics. To test these techniques we placed a spherical mirror with an effective N.A. of about 0.9 inside a vacuum chamber in the vicinity of a linear Paul trap. We demonstrate stable and reliable trapping of single barium ions, in excellent agreement with our simulations of the electric field in this setup. While a large N.A. spherical mirror introduces significant spherical aberration, the ion image quality can be greatly improved by a specially designed aspheric corrector lens located outside the vacuum system. Our simulations show that the spherical mirror/corrector design is an easy and cost-effective way to achieve high photon collection rates when compared to a more sophisticated parabolic mirror setup.

G Shu; M R Dietrich; N Kurz; B B Blinov

2009-01-29T23:59:59.000Z

243

Trapped Ion Imaging with a High Numerical Aperture Spherical Mirror  

E-Print Network (OSTI)

Efficient collection and analysis of trapped ion qubit fluorescence is essential for robust qubit state detection in trapped ion quantum computing schemes. We discuss simple techniques of improving photon collection efficiency using high numerical aperture (N.A.) reflective optics. To test these techniques we placed a spherical mirror with an effective N.A. of about 0.9 inside a vacuum chamber in the vicinity of a linear Paul trap. We demonstrate stable and reliable trapping of single barium ions, in excellent agreement with our simulations of the electric field in this setup. While a large N.A. spherical mirror introduces significant spherical aberration, the ion image quality can be greatly improved by a specially designed aspheric corrector lens located outside the vacuum system. Our simulations show that the spherical mirror/corrector design is an easy and cost-effective way to achieve high photon collection rates when compared to a more sophisticated parabolic mirror setup.

Shu, G; Kurz, N; Blinov, B B

2009-01-01T23:59:59.000Z

244

Life Cycle of a Linear Coastal-Trapped Disturbance  

Science Conference Proceedings (OSTI)

A recent climatology of observed coastal-trapped disturbances in the marine atmospheric boundary layer along the United States west coast motivates the detailed examination, for a specific form of imposed forcing, of a linear shallow-water ...

R. M. Samelson; A. M. Rogerson

1996-08-01T23:59:59.000Z

245

Light trapping limits in plasmonic solar cells: an analytical investigation  

E-Print Network (OSTI)

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 ...

Sheng, Xing

246

Novel trapping techniques for shaping Bose-Einstein condensates  

E-Print Network (OSTI)

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) ...

Boyd, Micah (Micah Scott)

2007-01-01T23:59:59.000Z

247

Quantum gates, sensors, and systems with trapped ions  

E-Print Network (OSTI)

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 ...

Wang, Shannon Xuanyue

2012-01-01T23:59:59.000Z

248

Heating of trapped ions from the quantum ground state  

E-Print Network (OSTI)

We have investigated motional heating of laser-cooled 9Be+ ions held in radio-frequency (Paul) traps. We have measured heating rates in a variety of traps with different geometries, electrode materials, and characteristic sizes. The results show that heating is due to electric-field noise from the trap electrodes which exerts a stochastic fluctuating force on the ion. The scaling of the heating rate with trap size is much stronger than that expected from a spatially uniform noise source on the electrodes (such as Johnson noise from external circuits), indicating that a microscopic uncorrelated noise source on the electrodes (such as fluctuating patch-potential fields) is a more likely candidate for the source of heating.

Q. A. Turchette; D. Kielpinski; B. E. King; D. Leibfried; D. M. Meekhof; C. J. Myatt; M. A. Rowe; C. A. Sackett; C. S. Wood; W. M. Itano; C. Monroe; D. J. Wineland

2000-02-14T23:59:59.000Z

249

Dissipative trapped electron modes in ell = 2 torsatrons  

SciTech Connect

Trapped electron modes in stellarators can be more unstable than those in tokamaks. They could be easier to detect in a stellarator and may be responsible for anomalous losses in the low collisionality regime. 5 refs., 1 fig.

Carreras, B.A.; Dominguez, N.; Lynch, V.E. (Oak Ridge National Lab., TN (USA)); Diamond, P.H. (California Univ., San Diego, CA (USA))

1989-01-01T23:59:59.000Z

250

Plant View On Reducing Steam Trap Energy Loss  

E-Print Network (OSTI)

Energy will continue to be an ever increasingly important factor in the cost of doing business in the decade of the 80' s. In many petrochemical industries, energy is the second most costly item in producing a product. About 36% of our nation's total energy consumption is used by industry in producing the goods which are consumed around the world. Steam is the most commonly used energy source for the petrochemical industry. Most of this steam is used for heating and evaporating the many petrochemical liquids. This steam is then condensed and is removed from the system at the same rate as it is being formed or the loss of heat transfer will result. From a cost standpoint only condensate should be allowed through the trap. But at many plants half of the steam traps are passing excess steam. This is caused by neglect of aged steam traps which have worn out and misapplication of steam traps by oversizing or using the 'wrong' type trap. Elimination of steam wastes by an effective well engineered steam trap program is what is covered by this article.

Vallery, S. J.

1982-01-01T23:59:59.000Z

251

Prethermalization and dynamical transition in an isolated trapped ion spin chain  

E-Print Network (OSTI)

We propose an experimental scheme to observe prethermalization and dynamical transition in one-dimensional XY spin chain with long range interaction and inhomogeneous lattice spacing, which can be readily implemented with the recently developed trapped-ion quantum simulator. Local physical observables are found to relax to prethermal values at intermediate time scale, followed by complete relaxation to thermal values at much longer time. The physical origin of prethermalization is explained by spotting a non-trivial structure in lower half of the energy spectrum. The dynamical behavior of the system is shown to cross difference phases when the interaction range is continuously tuned, indicating the existence of dynamical phase transition.

Zhe-Xuan Gong; L. -M. Duan

2013-05-05T23:59:59.000Z

252

Formation, stability and mobility of self-trapped excitations in NaI and NaI1-xTIx from first principles  

Science Conference Proceedings (OSTI)

We present ab initio calculations studying the formation, mobility, and stability of self trapped excitons (STE) and self trapped holes (STH) and electrons in NaI and NaI(Tl). While previously proposed models assumed a highly mobile STE and a slower STH, we find that both carriers in pure NaI have similar mobilities, with an activation energy of about 0.2 eV. We propose an alternate interpretation of experimental record including a new migration mechanism for the STE. In the Tl-doped material excitons preferentially trap at dopants, inducing off center distortions that have a structure unlike an STE providing a mechanism for light emission at multiple wavelengths. The calculated results are generally in excellent agreement with available data.

Prange, Micah P.; Van Ginhoven, Renee M.; Govind, Niranjan; Gao, Fei

2013-03-04T23:59:59.000Z

253

Signal Enhancement Magnetic Trap - Microchip Appratus and ...  

Sample volumes required for molecular diagnostic analysis such as PCR are up to one million times smaller than current commercial instruments;

254

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

Science Conference Proceedings (OSTI)

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.

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

2013-01-01T23:59:59.000Z

255

Trapping of antiprotons -- a first step on the way to antihydrogen  

DOE Green Energy (OSTI)

A first step towards producing and effectively utilizing antihydrogen atoms consists of trapping antiprotons. The immediate next step must then be to control, i.e. trap the produced antihydrogen. The current state of the art in trapping antiprotons and positrons is reviewed, and the challenges in trapping the resulting neutral particles are discussed.

Holzscheiter, M.H.

1993-07-01T23:59:59.000Z

256

Towards in-situ cleaning of a trapped ion quantum computer  

E-Print Network (OSTI)

A plasma glow discharge system was created using a conventional microwave oven to ignite and maintain the plasma. The system was used for plasma cleaning and its properties were analysed to assess its viability for removing surface contaminants, which cause anomalous heating, from Paul trap electrodes used in ion trapping. Qualitative results showed that the argon plasma could remove copper oxide layers formed on thin sheets in 1-2 minutes. The addition of air into the plasma system allowed for the cleaning of more complex hydrocarbon contaminants, as highlighted by the removal of permanent marker pen. The surface removal rate of the system was evaluated by measuring the time taken to remove gold plating from washers and aluminium plates. A nominal rate of 5-15 nm per min was found under optimal conditions. Plasma treatment, in addition to wet chemical cleaning, was found to increase the finesse of an optical cavity by a factor of two, compared to acetone cleaning alone. These results are promising for the system's in-situ use on Paul trap electrodes and could be a feasible technique for increasing their lifetime.

Timothy Harrison

2012-07-08T23:59:59.000Z

257

Poly(vinyl alcohol)-based buffering membranes for isoelectric trapping separations  

E-Print Network (OSTI)

Isoelectric trapping (IET) in multicompartment electrolyzers (MCE) has been widely used for the electrophoretic separation of ampholytic compounds such as proteins. In IET, the separation occurs in the buffering membranes that form a step-wise pH gradient in the MCE. Typically, buffering membranes have been made by copolymerizing acrylamide with Immobiline compounds, which are acidic and basic acylamido buffers. One major problem, however, is that these buffering membranes are not stable when exposed to high concentrations of acid and base due to hydrolysis of the amide bonds. Poly(vinyl alcohol)-based, or PVA-based, membranes were made as an alternative to the polyacrylamide-based membranes since they provide more hydrolytic and mechanical stability. Four mid-pH, PVA-based buffering membranes that contain single ampholytes were synthesized. These buffering membranes were used to trap small molecular weight pI markers for up to three hours, and were also used in desalting experiments to remove strong electrolytes from a solution of ampholytes. Additionally, the membranes were used in IET experiments to separate mixtures of pI markers, and to fractionate the major proteins in chicken egg white. The membranes did not show any degradation when stored in 3 M NaOH for up to 6 months and were shown to tolerate current densities as high as 16 mA/cm2. In addition, six series of PVA-based membranes, whose pH values can be tuned over the 3 < pH < 10 range, were synthesized by covalently binding aminodicarboxylic acids, and monoamines or diamines to the PVA matrix. These tunable buffering membranes were used in trapping experiments to trap ampholytes for up to three hours, and in desalting experiments to remove strong electrolytes from a solution of ampholytes. These tunable buffering membranes were also used in IET experiments to separate proteins, some with pI values that differ by only 0.1 pH unit. The tunable buffering membranes did not show any signs of degradation when exposed to 3 M NaOH for up to 3 months, and could be used in IET experiments with current densities as high as 20 mA/cm2. These tunable buffering membranes are expected to broaden the application areas of isoelectric trapping separations.

Craver, Helen C.

2007-05-01T23:59:59.000Z

258

LASER INDUCED FLUORESCENCE OF TRAPPED MOLECULAR IONS  

E-Print Network (OSTI)

System Laser Power Measurement Wavelength Calibration SystemLaser Power Measurement Wavelength Calibration PAGE Fluorescence Detection Systemmeasurement system. The actual time for initiation of the detection gate with respect to the laser

Grieman, Frederick Joseph.

2010-01-01T23:59:59.000Z

259

Self-Similar Nonlinear Dynamical Solutions for One-Component Nonneutral Plasma in a Time-Dependent Linear Focusing Field  

Science Conference Proceedings (OSTI)

In a linear trap confining a one-component nonneutral plasma, the external focusing force is a linear function of the configuration coordinates and/or the velocity coordinates. Linear traps include the classical Paul trap and the Penning trap, as well as the newly proposed rotating-radio- frequency traps and the Mobius accelerator. This paper describes a class of self-similar nonlinear solutions of nonneutral plasma in general time-dependent linear focusing devices, with self-consistent electrostatic field. This class of nonlinear solutions includes many known solutions as special cases.

Hong Qin and Ronald C. Davidson

2011-07-19T23:59:59.000Z

260

Lean NOx Trap Modeling in Vehicle Systems Simulations  

DOE Green Energy (OSTI)

A one-dimensional model for simulating lean NOx trap (LNT) performance is developed and validated using both steady state cycling data and transient data from FTP testing cycles. The model consists of the conservation equations for chemical species and energy in the bulk flow, energy of the solid walls, O2 storage and NOx storage (in the form of nitrites and nitrates). Nitrites and nitrates are formed by diffusion of NO and NO2, respectively, into sorbent particles (assumed to be hemi-spherical in shape) along with O2 and their formation rates are controlled by chemical kinetics as well as solid-phase diffusion rates of NOx species. The model also accounts for thermal aging and sulfation of LNTs. Empirical correlations are developed on the basis of published experimental data to capture these effects. These empirical correlations depend on total mileage for which the LNT has been in use, the mileage accumulated since the last desulfation event in addition to the freshly degreened catalyst characteristics. The model has been used in studies of vehicle systems (integration, performance etc.) including hybrid powertrain configurations. Since the engines in hybrid vehicles turn on and off multiple number of times during single drive cycles, the exhaust systems may encounter multiple cold start transients. Accurate modeling of catalyst warm-up and cooling is, therefore, very important to simulate LNT performance in such vehicles. For this purpose, the convective heat loss from the LNT to the ambient is modeled using a Nusselt number correlation that includes effects of both forced convection and natural convection (with later being important when vehicle is stationary). Using the model, the fuel penalty associated with operating LNTs on small diesel engine powered car during FTP drive cycles is estimated.

Gao, Zhiming [ORNL; Chakravarthy, Veerathu K [ORNL; Daw, C Stuart [ORNL; Conklin, Jim [ORNL

2010-09-01T23:59:59.000Z

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


261

Bohmian Mechanics  

E-Print Network (OSTI)

Bohmian mechanics is a theory about point particles moving along trajectories. It has the property that in a world governed by Bohmian mechanics, observers see the same statistics for experimental results as predicted by quantum mechanics. Bohmian mechanics thus provides an explanation of quantum mechanics. Moreover, the Bohmian trajectories are defined in a non-conspiratorial way by a few simple laws.

Detlef Duerr; Sheldon Goldstein; Roderich Tumulka; Nino Zanghi

2009-03-15T23:59:59.000Z

262

Storing Electrons Instead of Positrons Without Trapping of Positive Ions  

NLE Websites -- All DOE Office Websites (Extended Search)

Electrons Instead of Positrons Without Electrons Instead of Positrons Without Trapping of Positive Ions LS-75 T. K. Khoe October, 1986 In this note, a procedure to inject and store electrons in the ring without trapping ions will be described. The minimum injection current per bunch below which ion trapping occur will be determined. Since the vertical beam size is smaller than the horizontal beam size, we will consider the vertical motion only. The following assumptions are made: 1. The bunch period is much longer than the bunch length. This assumption allow us to use the thin lens approximation for the focusing effect of the electron bunch. 2. The bunch length is much larger than the transverse dimensions of the beam. A two-dimensional calculation can then be used to obtain the

263

Recent progress in tailoring trap-based positron beams  

SciTech Connect

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.

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

264

Mechanical down jar mechanism  

SciTech Connect

This paper describes a mechanical down jar mechanism for freeing stuck objects within a well bore and for conducting other down hole activities. It comprises: an elongate tubular housing having anvil means; mandrel means adapted for connection to an object to be moved downwardly within the well bore and being disposed in telescoping relation with the anvil means and the elongate tubular housing, the mandrel means adapted to be struck by the anvil means to impart a downwardly directed jarring force to the object; the elongate tubular housing having internal firing and recocking detent groove means located in axially spaced relation and forming a firing lug support land therebetween; a radially expandable and retractable firing lug assembly being disposed within the elongate tubular housing and in absence of force being applied axially thereto being radially restrained by the firing lug support land; load spring means being disposed within the elongate tubular housing and being in downward force transmitting relation with the firing lug assembly; recocking spring means being disposed within the elongate tubular housing and having upward axial force transmitting relation with the firing lug assembly.

Taylor, W.T.

1991-12-03T23:59:59.000Z

265

High intensity electron beam ion trap for charge state boosting of radioactive ion beams  

SciTech Connect

A high intensity electron beam ion trap under development at LLNL could be adapted for charge state boosting of radioactive ion beams, enabling a substantial reduction in the size and cost of a post-accelerator. We report estimates of the acceptance, ionization time, charge state distribution, emittance, and beam intensity for charge state boosting of radioactive ions in this device. The estimates imply that, for tin isotopes, over 10{sup 10} ions/s can be ionized to q = 40+ with an absolute emittance of approximately 1 (pi) mm mrad at an energy of 30 x q.k.

Marrs, R.

1998-09-30T23:59:59.000Z

266

Heating of trapped ions from the quantum ground state  

E-Print Network (OSTI)

We have investigated motional heating of laser-cooled 9Be+ ions held inradio-frequency (Paul) traps. We have measured heating rates in a variety oftraps with different geometries, electrode materials, and characteristic sizes.The results show that heating is due to electric-field noise from the trapelectrodes which exerts a stochastic fluctuating force on the ion. The scalingof the heating rate with trap size is much stronger than that expected from aspatially uniform noise source on the electrodes (such as Johnson noise fromexternal circuits), indicating that a microscopic uncorrelated noise source onthe electrodes (such as fluctuating patch-potential fields) is a more likelycandidate for the source of heating.

Turchette, Q A; King, B E; Leibfried, D; Meekhof, D M; Myatt, C J; Rowe, M A; Sackett, C A; Wood, C S; Itano, W M; Monroe, C; Wineland, D J

2000-01-01T23:59:59.000Z

267

Quantum Energy Teleportation with Trapped Ions  

E-Print Network (OSTI)

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.

Masahiro Hotta

2009-08-20T23:59:59.000Z

268

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

SciTech Connect

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.

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

269

Brouwer's problem on a heavy particle in a rotating vessel: wave propagation, ion traps, and rotor dynamics  

E-Print Network (OSTI)

In 1918 Brouwer considered stability of a heavy particle in a rotating vessel. This was the first demonstration of a rotating saddle trap which is a mechanical analogue for quadrupole particle traps of Penning and Paul. We revisit this pioneering work in order to uncover its intriguing connections with classical rotor dynamics and fluid dynamics, stability theory of Hamiltonian and non-conservative systems as well as with the modern works on crystal optics and atomic physics. In particular, we find that the boundary of the stability domain of the undamped Brouwer's problem possesses the Swallowtail singularity corresponding to the quadruple zero eigenvalue. In the presence of dissipative and non-conservative positional forces there is a couple of Whitney umbrellas on the boundary of the asymptotic stability domain. The handles of the umbrellas form a set where all eigenvalues of the system are pure imaginary despite the presence of dissipative and non-conservative positional forces.

Oleg N. Kirillov

2010-12-04T23:59:59.000Z

270

Trapped and escaping orbits in an axially symmetric galactic-type potential  

E-Print Network (OSTI)

In the present article, we investigate the behavior of orbits in a time independent axially symmetric galactic type potential. This dynamical model can be considered to describe the motion in the central parts of a galaxy, for values of energies larger than the energy of escape. We use the classical method of the surface of section, in order to visualize and interpret the structure of the phase space of the dynamical system. Moreover, the Lyapunov Characteristic Exponent (LCE), is used in order to make an estimation of the degree of the chaoticity of the orbits in our galactic model. Our numerical calculations suggest that in this galactic type potential, there are two kinds of orbits: (i) escaping orbits and (ii) trapped orbits which do not escape at all. Furthermore, a large number of orbits of the dynamical system, display chaotic motion. Among the chaotic orbits, there are orbits that escape fast and also orbits that remain trapped for vast time intervals. When the value of the test particle's energy exceeds slightly the energy of escape, the amount of the trapped regular orbits increases, as the the value of the angular momentum increases. Therefore, the extent of the chaotic regions observed in the phase plane decreases as the value of the energy increases. Moreover, we calculate the average value of the escape period of the chaotic orbits and we try to correlate it with the value of the energy and also with the maximum value of the z component of the orbits. In addition, we find that the value of the LCE corresponding to each chaotic region, for different values of the energy, increases exponentially as the value of the energy increases. Some theoretical arguments in order to support the numerically obtained outcomes are presented.

Euaggelos E. Zotos

2012-06-12T23:59:59.000Z

271

Detection of Magnetically Trapped Neutrons: Liquid Helium as a Scintillator  

E-Print Network (OSTI)

by Daniel Nicholas McKinsey to The Department of Physics in partial fulfillment of the requirements February 2002 #12;c 2002 - Daniel Nicholas McKinsey All rights reserved. #12;To my parents #12;Thesis advisor Author John Morrissey Doyle Daniel Nicholas McKinsey Detection of Magnetically Trapped Neutrons

McKinsey, Daniel

272

Synthesis of Cold Antihydrogen in a Cusp Trap  

Science Conference Proceedings (OSTI)

We report here the first successful synthesis of cold antihydrogen atoms employing a cusp trap, which consists of a superconducting anti-Helmholtz coil and a stack of multiple ring electrodes. This success opens a new path to make a stringent test of the CPT symmetry via high precision microwave spectroscopy of ground-state hyperfine transitions of antihydrogen atoms.

Enomoto, Y.; Nagata, Y.; Kanai, Y.; Mohri, A. [RIKEN Advanced Science Institute, Hirosawa, Wako, Saitama 351-0198 (Japan); Kuroda, N.; Kim, C. H.; Torii, H. A.; Fujii, K.; Ohtsuka, M.; Tanaka, K.; Matsuda, Y. [Graduate School of Arts and Sciences, University of Tokyo, Komaba, Meguro, Tokyo 153-8902 (Japan); Michishio, K.; Nagashima, Y. [Department of Physics, Tokyo University of Science, Kagurazaka, Shinjuku, Tokyo 162-8601 (Japan); Higaki, H. [Graduate School of Advanced Sciences of Matter, Hiroshima University, Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8530 (Japan); Corradini, M.; Leali, M.; Lodi-Rizzini, E.; Mascagna, V.; Venturelli, L.; Zurlo, N. [Dipartimento di Chimica e Fisica per l'Ingegneria e per i Materiali, Universita di Brescia and Istituto Nazionale di Fisica Nucleare, Gruppo Collegato di Brescia, 25133 Brescia (Italy)

2010-12-10T23:59:59.000Z

273

Manipulation and assembly of nanowires with holographic optical traps  

E-Print Network (OSTI)

We demonstrate that semiconductor nanowires measuring just a few nanometers in diameter can be translated, rotated, cut, fused and organized into nontrivial structures using holographic optical traps. The holographic approach to nano-assembly allows for simultaneous independent manipulation of multiple nanowires, including relative translation and relative rotation.

Ritesh Agarwal; Kosta Ladavac; Yael Roichman; Guiha Yu; Charles M. Lieber; David G. Grier

2005-09-12T23:59:59.000Z

274

EXPERIMENTAL RESULTS ON TRAPPING A GUN PLASMA IN TORMAC P-l  

SciTech Connect

A start-up scheme for producing a plasma in the biscusp field configuration of TORMAC which involves the radial injection and trapping of a toroidal gun plasma is described. The peloidal field of the external cusp coils acts as a barrier to the outward travel of the plasma ring. Interferometry and magnetic probe measurements observed the stopping of the expanding plasma ring which has a velocity of 17 cm/{micro}sec. Once stopped, the fields are arranged to hold the plasma in a magnetic well. Interferometry measurements observed a well defined outer boundary remaining stationary during the 20 {micro}sec of the measurement. The inner boundary was also in evidence as shown particularly by the particle flux distribution emanating from the cusp region. The indications are that a sheath exists having a width of 1 to 1.5 ion gyro radii in the poloidial field. Measurements of Thomson and interferometry give a T{sub e} of 15eV, a 15 {micro}sec density decay time, and a 5 {micro}sec energy decay time. These results show that this injection and trapping method is successful, and thus a higher gun plasma energy combined with a flux conserving barrier may lead to higher temperatures for testing containment in TORMAC.

Pincosy, P.A.; Myers, B.R.; Levine, M.A.; Feinberg, B.; Niland, R.A.; Soroka, L.

1981-07-01T23:59:59.000Z

275

Trapped and escaping orbits in an axially symmetric galactic-type potential  

E-Print Network (OSTI)

In the present article, we investigate the behavior of orbits in a time independent axially symmetric galactic type potential. This dynamical model can be considered to describe the motion in the central parts of a galaxy, for values of energies larger than the energy of escape. We use the classical method of the surface of section, in order to visualize and interpret the structure of the phase space of the dynamical system. Moreover, the Lyapunov Characteristic Exponent (LCE), is used in order to make an estimation of the degree of the chaoticity of the orbits in our galactic model. Our numerical calculations suggest that in this galactic type potential, there are two kinds of orbits: (i) escaping orbits and (ii) trapped orbits which do not escape at all. Furthermore, a large number of orbits of the dynamical system, display chaotic motion. Among the chaotic orbits, there are orbits that escape fast and also orbits that remain trapped for vast time intervals. When the value of the test particle's energy exce...

Zotos, Euaggelos E

2012-01-01T23:59:59.000Z

276

Onset and saturation of backward stimulated Raman scattering of laser in trapping regime in three spatial dimensions  

SciTech Connect

A suite of three-dimensional (3D) VPIC[K. J. Bowers et al., Phys. Plasmas 15, 055703 (2008)] particle-in-cell simulations of backward stimulated Raman scattering (SRS) in inertial confinement fusion hohlraum plasma has been performed on the heterogeneous multicore supercomputer, Roadrunner, presently the world's most powerful supercomputer. These calculations reveal the complex nonlinear behavior of SRS and point to a new era of 'at scale' 3D modeling of SRS in solitary and multiple laser speckles. The physics governing nonlinear saturation of SRS in a laser speckle in 3D is consistent with that of prior two-dimensional (2D) studies [L. Yin et al., Phys. Rev. Lett. 99, 265004 (2007)], but with important differences arising from enhanced diffraction and side loss in 3D compared with 2D. In addition to wave front bowing of electron plasma waves (EPWs) due to trapped electron nonlinear frequency shift and amplitude-dependent damping, we find for the first time that EPW self-focusing, which evolved from trapped particle modulational instability [H. A. Rose and L. Yin, Phys. Plasmas 15, 042311 (2008)], also exhibits loss of angular coherence by formation of a filament necklace, a process not available in 2D. These processes in 2D and 3D increase the side-loss rate of trapped electrons, increase wave damping, decrease source coherence for backscattered light, and fundamentally limit how much backscatter can occur from a laser speckle. For both SRS onset and saturation, the nonlinear trapping induced physics is not captured in linear gain modeling of SRS. A simple metric is described for using single-speckle reflectivities obtained from VPIC simulations to infer the total reflectivity from the population of laser speckles of amplitude sufficient for significant trapping-induced nonlinearity to arise.

Yin, L.; Albright, B. J.; Rose, H. A.; Bowers, K. J.; Bergen, B.; Montgomery, D. S.; Kline, J. L.; Fernandez, J. C. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

2009-11-15T23:59:59.000Z

277

Z5, Effect of Traps Spatial Localization on GaN HEMT Static ...  

Science Conference Proceedings (OSTI)

Conference Tools for 2010 Electronic Materials Conference ... In this work we discuss how trap state formation during reverse gate-source and ... by means of the commercial DESSIS-ISE (Synopsis Inc.) simulator showed that acceptor traps

278

Observations of Seasonal Variations in Atmospheric Greenhouse Trapping and Its Enhancement at High Sea Surface Temperature  

Science Conference Proceedings (OSTI)

The correlation between observed values of atmospheric greenhouse trapping and sea surface temperature is found to vary seasonally. Atmospheric greenhouse trapping is defined here as the difference between infrared emissions from the earth's ...

Robert Hallberg; Anand K. Inamdar

1993-05-01T23:59:59.000Z

279

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

E-Print Network (OSTI)

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 ...

Shields, Brendan John

2006-01-01T23:59:59.000Z

280

Finite-geometry models of electric field noise from patch potentials in ion traps  

E-Print Network (OSTI)

We model electric field noise from fluctuating patch potentials on conducting surfaces by taking into account the finite geometry of the ion trap electrodes to gain insight into the origin of anomalous heating in ion traps. ...

Low, Guang Hao

Note: This page contains sample records for the topic "timing trapping mechanism" from the National Library of EnergyBeta (NLEBeta).
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281

Use of Bullet Traps and Steel Targets - June 4, 2012 | Department...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Use of Bullet Traps and Steel Targets - June 4, 2012 Use of Bullet Traps and Steel Targets - June 4, 2012 June 4, 2012 This supplement contains the currently approved document, Use...

282

Microfabricated surface ion trap on a high-finesse optical mirror  

E-Print Network (OSTI)

A novel approach to optics integration in ion traps is demonstrated based on a surface electrode ion trap that is microfabricated on top of a dielectric mirror. Additional optical losses due to fabrication are found to be ...

Herskind, Peter F.

283

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

E-Print Network (OSTI)

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 ...

Meyer, David Thomas

2011-01-01T23:59:59.000Z

284

The Extension of Baroclinic Coastal-Trapped Wave Theory to Superinertial Frequencies  

Science Conference Proceedings (OSTI)

The problem of finding baroclinic coastal-trapped wave modes is generalized from subinertial to superinertial frequencies at which complete trapping can only occur in special cases. Modes are found by a numerical resonance searching method in ...

Andrew C. Dale; Toby J. Sherwin

1996-11-01T23:59:59.000Z

285

Evaluation of Sorbent Trap Materials and Methods for Flue Gas Mercury Measurement  

Science Conference Proceedings (OSTI)

Sorbent traps are used as an alternative to continuous mercury monitors (CMM) for measuring vapor phase mercury concentrations in stacks of coal-fired power plants and for relative accuracy test audits (RATAs) of CMMs. EPRI has an ongoing program of research on sorbent trap methods, evaluating the performance of sorbent materials and the methods used to measure mercury on the sorbent traps. This report presents results of two investigations targeted at evaluating the performance of sorbent trap methods f...

2009-02-16T23:59:59.000Z

286

Atom trapping in a bottle beam created by a diffractive optical element  

E-Print Network (OSTI)

A diffractive optical element (DOE) has been fabricated for creating blue detuned atomic bottle beam traps. The DOE integrates several diffractive lenses for trap creation and imaging of atomic fluorescence. We characterize the performance of the DOE and demonstrate trapping of cold Cesium atoms inside a bottle beam.

V. V. Ivanov; J. A. Isaacs; M. Saffman; S. A. Kemme; A. R. Ellis; G. R. Brady; J. R. Wendt; G. W. Biedermann; S. Samora

2013-05-23T23:59:59.000Z

287

Atom trapping in a bottle beam created by a diffractive optical element  

E-Print Network (OSTI)

A diffractive optical element (DOE) has been fabricated for creating blue detuned atomic bottle beam traps. The DOE integrates several diffractive lenses for trap creation and imaging of atomic fluorescence. We characterize the performance of the DOE and demonstrate trapping of cold Cesium atoms inside a bottle beam.

Ivanov, V V; Saffman, M; Kemme, S A; Ellis, A R; Brady, G R; Wendt, J R; Biedermann, G W; Samora, S

2013-01-01T23:59:59.000Z

288

Opto–Mechanical and Electric Design of a Tunnel–Trap Si ...  

Science Conference Proceedings (OSTI)

... 4. Photodiode arrangement and beam propagation in the ... of the feedback resistances should determine ... However, a feedback resistance is usually ...

2012-10-10T23:59:59.000Z

289

Enumeration of Juvenile Salmonids in the Okanogan Basin Using Rotary Screw Traps, Performance Period: March 15, 2006 - July 15, 2006.  

DOE Green Energy (OSTI)

The Colville Tribes identified the need for collecting baseline census data on the timing and abundance of juvenile salmonids in the Okanogan River basin for the purpose of documenting local fish populations, augmenting existing fishery data and assessing natural production trends of salmonids. This report documents and assesses the pilot year of rotary trap capture of salmonid smolts on the Okanogan River. The project is a component of the Colville Tribes Okanogan Basin Monitoring and Evaluation Program (OBMEP) which began in 2004. Trapping for outmigrating fish began on 14 March 2006 and continued through 11 July 2006. Anadromous forms of Oncorhynchus, including summer steelhead (O. mykiss), Chinook (O. tshawytscha), and sockeye (O. nerka), were targeted for this study; all have verified, natural production in the Okanogan basin. Both 8-ft and 5-ft rotary screw traps were deployed on the Okanogan River from the Highway 20 Bridge and typically fished during evening hours or 24 hours per day, depending upon trap position and discharge conditions. Juvenile Chinook salmon were the most abundant species trapped in 2006 (10,682 fry and 2,024 smolts), followed by sockeye (205 parr and 3,291 smolts) and steelhead (1 fry and 333 smolts). Of the trapped Chinook, all fry were wild origin and all but five of the smolts were hatchery-reared. All trapped sockeye were wild origin and 88% of the steelhead smolts were hatchery-reared. Mark-recapture experiments were conducted using Chinook fry and hatchery-reared steelhead smolts (sockeye were not used in 2006 because the peak of the juvenile migration occurred prior to the onset of the mark-recapture experiments). A total of 930 chinook fry were marked and released across eight separate release dates (numbers of marked Chinook fry released per day ranged from 34 to 290 fish). A total of 11 chinook fry were recaptured for an overall trap efficiency of 1.18%. A total of 710 hatchery-reared steelhead were marked and released across three separate release dates (numbers of steelhead released per day ranged from 100 to 500 fish). A total of 12 steelhead were recaptured for an overall trap efficiency of 1.69%. A pooled Peterson estimator with a Chapman modification was used to produce population estimates for wild Chinook fry and hatchery-reared steelhead based on the results of the mark-recapture experiments. The 2006 populations for Chinook and steelhead were estimated to be 381,554 (95% confidence intervals: 175,731-587,377) and 14,164 (6,999-21,330), respectively. The population estimates were based on the periods in which mark-recapture experiments were initialized through the end of the trapping season (10 May for steelhead and 1 June for Chinook).

Johnson, Peter N.; Rayton, Michael D.

2007-05-01T23:59:59.000Z

290

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

DOE Green Energy (OSTI)

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

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

2011-07-01T23:59:59.000Z

291

Trapping of charge carriers into InAs/AlAs quantum dots at liquid-helium temperature  

Science Conference Proceedings (OSTI)

The problem of how the probability of trapping of charge carriers into quantum dots via the wetting layer influences the steady-state and time-dependent luminescence of the wetting layer and quantum dots excited via the matrix is analyzed in the context of some simple models. It is shown that the increase in the integrated steady-state luminescence intensity of quantum dots with increasing area fraction occupied by the quantum dots in the structure is indicative of the suppression of trapping of charge carriers from the wetting layer into the quantum dots. The same conclusion follows from the independent decays of the time-dependent luminescence signals from the wetting layer and quantum dots. The processes of trapping of charge carriers into the InAs quantum dots in the AlAs matrix at 5 K are studied experimentally by exploring the steady-state and time-dependent photoluminescence. A series of structures with different densities of quantum dots has been grown by molecular-beam epitaxy on a semi-insulating GaAs (001) substrate. It is found that the integrated photoluminescence intensity of quantum dots almost linearly increases with increasing area occupied with the quantum dots in the structure. It is also found that, after pulsed excitation, the photoluminescence intensity of the wetting layer decays more slowly than the photoluminescence intensity of the quantum dots. According to the analysis, these experimental observations suggest that trapping of excitons from the wetting layer into the InAs/AlAs quantum dots at 5 K is suppressed.

Abramkin, D. S., E-mail: demid@thermo.isp.nsc.ru; Zhuravlev, K. S.; Shamirzaev, T. S.; Nenashev, A. V.; Kalagin, A. K. [Russian Academy of Sciences, Institute of Semiconductor Physics, Siberian Branch (Russian Federation)

2011-02-15T23:59:59.000Z

292

A Toy Model Study of Decay Trapping | Superconducting Magnet Division  

NLE Websites -- All DOE Office Websites (Extended Search)

A Toy Model Study of Decay Trapping, reported by Brett Parker A Toy Model Study of Decay Trapping, reported by Brett Parker Introduction A group from the BNL Superconducting Magnet Division is looking at various options for dipole magnets which would be suitable for use in a muon storage ring that is used as a neutrino factory. Since the useful neutrino beams from a neutrino factory come from straight sections it is desirable to minimize the rings arc circumference, in relation to straight section length, in order to ensure that the fraction of muons which decay in the straight section is as large as possible. Therefore superconducting magnets, with higher B-fields and smaller bend radii, are reasonable to consider for this application. Unfortunately the decay electrons generated along with the neutrinos carry on average about a third of the original

293

Photoionizing Trapped Highly Charged Ions with Synchrotron Radiation  

SciTech Connect

Photoabsorption by highly charged ions plays an essential role in astrophysical plasmas. Diagnostics of photoionized plasmas surrounding binary systems rely heavily on precise identification of absorption lines and on the knowledge of their cross sections and widths. Novel experiments using an electron beam ion trap, FLASH EBIT, in combination with monochromatic synchrotron radiation allow us to investigate ions in charge states hitherto out of reach. Trapped ions can be prepared in any charge state at target densities sufficient to measure absorption cross sections below 0.1 Mb. The results benchmark state-of-the-art predictions of the transitions wavelengths, widths, and absolute cross sections. Recent high resolution results on Fe{sup 14+}, Fe{sup 15+}, and Ar{sup 12+} at photon energies up to 1 keV are presented.

Crespo, J R; Simon, M; Beilmann, C; Rudolph, J; Steinbruegge, R; Eberle, S; Schwarz, M; Baumann, T; Schmitt, B; Brunner, F; Ginzel, R; Klawitter, R; Kubicek, K; Epp, S; Mokler, P; Maeckel, V; Ullrich, J; Brown, G V; Graf, A; Leutenegger, M; Beiersdorfer, P; Behar, E; Follath, R; Reichardt, G; Schwarzkopf, O

2011-09-12T23:59:59.000Z

294

Trapped Quintessential Inflation in the context of Flux Compactifications  

E-Print Network (OSTI)

We present a model for quintessential inflation using a string modulus for the inflaton - quintessence field. The scalar potential of our model is based on generic non-perturbative potentials arising in flux compactifications. We assume an enhanced symmetry point (ESP), which fixes the initial conditions for slow-roll inflation. When crossing the ESP the modulus becomes temporarily trapped, which leads to a brief stage of trapped inflation. This is followed by enough slow roll inflation to solve the flatness and horizon problems. After inflation, the field rolls down the potential and eventually freezes to a certain value because of cosmological friction. The latter is due to the thermal bath of the hot big bang, which is produced by the decay of a curvaton field. The modulus remains frozen until the present, when it becomes quintessence.

J. C. Bueno Sanchez; K. Dimopoulos

2006-06-22T23:59:59.000Z

295

Umatilla River Basin Trap and Haul Program : Annual Report 1993.  

DOE Green Energy (OSTI)

Threemile Falls Dam is the major counting and collection point for adult salmonids returning to the Umatilla River. Returning salmon and steelhead were collected at Threemile Dam from October 23, 1992 to July 14, 1993. A total of 1,913 summer steelhead; 239 adult and 64 jack fall chinook; 355 adult and 174 jack coho; and 1,205 adult and 16 jack spring chinook were collected. Fish collected were hauled upstream from Threemile Dam using either a 370 or 3,000 gallon liberation unit. The Westland Canal facility, the major collection point for outmigrating juvenile salmonids and steelhead kelts was in operation from February 15 to July 29, 1993. During that period, fish were trapped 46 days. An estimated 3,228 pounds of fish were transported from the Westland Canal trap to the Umatilla River boat ramp at rivermile 0.5.

Zimmerman, Brian C.; Duke, Bill B.

1993-11-01T23:59:59.000Z

296

Wolf Trap, Virginia: Energy Resources | Open Energy Information  

Open Energy Info (EERE)

Trap, Virginia: Energy Resources Trap, Virginia: Energy Resources Jump to: navigation, search Equivalent URI DBpedia Coordinates 38.9398329°, -77.286094° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":38.9398329,"lon":-77.286094,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

297

Experimental Evidence for a Reduction in Electron Thermal Diffusion due to Trapped Particles  

Science Conference Proceedings (OSTI)

New high time resolution measurements of the electron thermal diffusion {chi}{sub e} throughout the sawtooth cycle of the Madison Symmetric Torus reversed-field pinch have been made by utilizing the enhanced capabilities of the upgraded multipoint, multipulse Thomson scattering system. These measurements are compared to the {chi}{sub e} due to magnetic diffusion predicted by using information from a new high spectral resolution zero-{beta} nonlinear resistive magnetohydrodynamic simulation performed, for the first time, at the Lundquist number of high current Madison Symmetric Torus plasmas (S{approx_equal}4x10{sup 6}). Agreement between the measured and predicted values is found only if the reduction in thermal diffusion due to trapped particles is taken into account.

Reusch, J. A.; Anderson, J. K.; Schnack, D. D. [Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, Wisconsin 53706 (United States); Den Hartog, D. J.; Ebrahimi, F.; Stephens, H. D.; Forest, C. B. [Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, Wisconsin 53706 (United States); Center for Magnetic Self-Organization in Laboratory and Astrophysical Plasmas, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)

2011-10-07T23:59:59.000Z

298

All optical sensor for automated magnetometry based on Coherent Population Trapping  

E-Print Network (OSTI)

An automated magnetometer suitable for long lasting measurement under stable and controllable experimental conditions has been implemented. The device is based on Coherent Population Trapping (CPT) produced by a multi-frequency excitation. CPT resonance is observed when a frequency comb, generated by diode laser current modulation, excites Cs atoms confined in a $\\pi/4\\times(2.5)^2\\times1 \\textrm{cm}^3$, 2 Torr $N_2$ buffered cell. A fully optical sensor is connected through an optical fiber to the laser head allowing for truly remote sensing and minimization of the field perturbation. A detailed analysis of the CPT resonance parameters as a function of the optical detuning has been made in order to get high sensitivity measurements. The magnetic field monitoring performances and the best sensitivity obtained in a balanced differential configuration of the sensor are presented.

Belfi, J; Biancalana, V; Dancheva, Y; Moi, L

2007-01-01T23:59:59.000Z

299

Coupled quantized mechanical oscillators  

Science Conference Proceedings (OSTI)

... that the ions are already in separate wells, ready for distribution to separate ... example, a trapped ion could act as a quantum transformer between a ...

2011-03-10T23:59:59.000Z

300

Persistent currents in Bose gases confined in annular traps  

SciTech Connect

We examine the problem of stability of persistent currents in a mixture of two Bose gases trapped in an annular potential. We evaluate the critical coupling for metastability in the transition from quasi-one- to two-dimensional motion. We also evaluate the critical coupling for metastability in a mixture of two species as a function of the population imbalance. The stability of the currents is shown to be sensitive to the deviation from one-dimensional motion.

Bargi, S.; Malet, F.; Reimann, S. M. [Mathematical Physics, Lund Institute of Technology, P.O. Box 118, SE-22100 Lund (Sweden); Kavoulakis, G. M. [Technological Educational Institute of Crete, P.O. Box 1939, GR-71004, Heraklion (Greece)

2010-10-15T23:59:59.000Z

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


301

Mixtures of Bose gases confined in concentrically coupled annular traps  

SciTech Connect

A two-component Bose-Einstein condensate confined in an axially symmetric potential with two local minima, resembling two concentric annular traps, is investigated. The system shows a number of phase transitions that result from the competition between phase coexistence and radial-azimuthal phase separation. The ground-state phase diagram, as well as the rotational properties, including the (meta)stability of currents in this system, is analyzed.

Malet, F.; Reimann, S. M. [Mathematical Physics, LTH, Lund University, Post Office Box 118, SE-22100 Lund (Sweden); Kavoulakis, G. M. [Technological Education Institute of Crete, Post Office Box 1939, GR-71004, Heraklion (Greece)

2010-01-15T23:59:59.000Z

302

Hydrogen trapping, diffusion, and recombination in austenitic stainless steels  

DOE Green Energy (OSTI)

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

Langley, R.A.

1984-01-01T23:59:59.000Z

303

Observation of Spin Flips with a Single Trapped Proton  

Science Conference Proceedings (OSTI)

Radio-frequency induced spin transitions of one individual proton are observed. The spin quantum jumps are detected via the continuous Stern-Gerlach effect, which is used in an experiment with a single proton stored in a cryogenic Penning trap. This is an important milestone towards a direct high-precision measurement of the magnetic moment of the proton and a new test of the matter-antimatter symmetry in the baryon sector.

Ulmer, S. [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany); Institut fuer Physik, Johannes Gutenberg-Universitaet Mainz, D-55099 Mainz (Germany); Ruprecht Karls-Universitaet Heidelberg, D-69047 Heidelberg (Germany); Rodegheri, C. C. [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany); Institut fuer Physik, Johannes Gutenberg-Universitaet Mainz, D-55099 Mainz (Germany); Blaum, K. [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany); Ruprecht Karls-Universitaet Heidelberg, D-69047 Heidelberg (Germany); Kracke, H.; Mooser, A.; Walz, J. [Institut fuer Physik, Johannes Gutenberg-Universitaet Mainz, D-55099 Mainz (Germany); Helmholtz Institut Mainz, D-55099 Mainz (Germany); Quint, W. [Ruprecht Karls-Universitaet Heidelberg, D-69047 Heidelberg (Germany); GSI--Helmholtzzentrum fuer Schwerionenforschung, D-64291 Darmstadt (Germany)

2011-06-24T23:59:59.000Z

304

Adiabatic trapping in coupled kinetic Alfven-acoustic waves  

SciTech Connect

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.

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

305

Post-injection spreading and trapping of CO[subscript 2] in saline aquifers: impact of the plume shape at the end of injection  

E-Print Network (OSTI)

We use an analytical model for the post-injection spreading of a plume of CO[subscript 2] in a saline aquifer under the action of buoyancy and capillary trapping to show that the spreading behavior is at all times strongly ...

Juanes, Ruben

306

Structural Transitions of Electrosprayed Ubiquitin Ions Stored in an Ion Trap over 10 ms Sunnie Myung, Ethan R. Badman, Young Jin Lee, and David E. Clemmer*  

E-Print Network (OSTI)

phase by a new ion trap/ion mobility-mass spectrometry technique. The approach allows transitions ms time scales of previous mobility measurements [J. Am. Soc. Mass Spectrom. 1997, 8, 954] and minute these conformers as they evolve from states that are formed initially by ESI into new gas-phase structures over

Clemmer, David E.

307

Towards in-situ cleaning of a trapped ion quantum computer  

E-Print Network (OSTI)

A plasma glow discharge system was created using a conventional microwave oven to ignite and maintain the plasma. The system was used for plasma cleaning and its properties were analysed to assess its viability for removing surface contaminants, which cause anomalous heating, from Paul trap electrodes used in ion trapping. Qualitative results showed that the argon plasma could remove copper oxide layers formed on thin sheets in 1-2 minutes. The addition of air into the plasma system allowed for the cleaning of more complex hydrocarbon contaminants, as highlighted by the removal of permanent marker pen. The surface removal rate of the system was evaluated by measuring the time taken to remove gold plating from washers and aluminium plates. A nominal rate of 5-15 nm per min was found under optimal conditions. Plasma treatment, in addition to wet chemical cleaning, was found to increase the finesse of an optical cavity by a factor of two, compared to acetone cleaning alone. These results are promising for the sy...

Harrison, Timothy

2012-01-01T23:59:59.000Z

308

Modeling Coastally Trapped Wind Surges over Southeastern Australia. Part I: Timing and Speed of Propagation  

Science Conference Proceedings (OSTI)

During the spring and summer months, the southeast coast of Australia often experiences abrupt southerly wind changes, the leading edge being known locally as a “southerly buster.” The main characteristic of this phenomenon is the sudden shift in ...

Helen J. Reid; Lance M. Leslie

1999-02-01T23:59:59.000Z

309

Revolutionary systems for catalytic combustion and diesel catalytic particulate traps.  

DOE Green Energy (OSTI)

This report is a summary of an LDRD project completed for the development of materials and structures conducive to advancing the state of the art for catalyst supports and diesel particulate traps. An ancillary development for bio-medical bone scaffolding was also realized. Traditionally, a low-pressure drop catalyst support, such as a ceramic honeycomb monolith, is used for catalytic reactions that require high flow rates of gases at high-temperatures. A drawback to the traditional honeycomb monoliths under these operating conditions is poor mass transfer to the catalyst surface in the straight-through channels. ''Robocasting'' is a unique process developed at Sandia National Laboratories that can be used to manufacture ceramic monoliths with alternative 3-dimensional geometries, providing tortuous pathways to increase mass transfer while maintaining low-pressure drops. These alternative 3-dimensional geometries may also provide a foundation for the development of self-regenerating supports capable of trapping and combusting soot particles from a diesel engine exhaust stream. This report describes the structures developed and characterizes the improved catalytic performance that can result. The results show that, relative to honeycomb monolith supports, considerable improvement in mass transfer efficiency is observed for robocast samples synthesized using an FCC-like geometry of alternating rods. Also, there is clearly a trade-off between enhanced mass transfer and increased pressure drop, which can be optimized depending on the particular demands of a given application. Practical applications include the combustion of natural gas for power generation, production of syngas, and hydrogen reforming reactions. The robocast lattice structures also show practicality for diesel particulate trapping. Preliminary results for trapping efficiency are reported as well as the development of electrically resistive lattices that can regenerate the structure by combusting the trapped soot. During this project an ancillary bio-medical application was discovered for lattices of hydroxyapatite. These structures show promise as bone scaffolds for the reparation of damaged bone. A case study depicting the manufacture of a customized device that fits into a damaged mandible is described.

Stuecker, John Nicholas; Witze, Peter O.; Ferrizz, Robert Matthew; Cesarano, Joseph, III; Miller, James Edward

2004-12-01T23:59:59.000Z

310

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

Science Conference Proceedings (OSTI)

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.

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

2004-09-07T23:59:59.000Z

311

Carrier transport mechanism in La-incorporated high-k dielectric/metal gate stack MOSFETs  

Science Conference Proceedings (OSTI)

In this paper, carrier transport mechanism of MOSFETs with HfLaSiON was analyzed. It was shown that gate current is consisted of Schottky emission, Frenkel-Poole (F-P) emission and Fowler-Nordheim (F-N) tunneling components. Schottky barrier height is ... Keywords: Fowler-Nordheim (F-N) tunneling, Frenkel-Poole (F-P) emission, Gate current, HfLaSiON, High-k, Schottky emission, Trap energy level, Trap-assisted tunneling (TAT)

Hyuk-Min Kwon; Won-Ho Choi; In-Shik Han; Min-Ki Na; Sang-Uk Park; Jung-Deuk Bok; Chang-Yong Kang; Byoung-Hun Lee; Raj Jammy; Hi-Deok Lee

2011-12-01T23:59:59.000Z

312

Plasma outflow from a corrugated trap in the kinetic regime  

SciTech Connect

The problem of stationary plasma outflow from an open corrugated trap in the kinetic regime is considered with allowance for pair collisions in the framework of a kinetic equation with the Landau collision integral. The distribution function is studied in the limit of small-scale corrugation and a large mirror ratio. In considering a single corrugation cell, a correction for the distribution function is calculated analytically. An equation describing variations of the distribution function along the system is derived and used to study the problem of plasma outflow into vacuum.

Skovorodin, D. I.; Beklemishev, A. D. [Russian Academy of Sciences, Budker Institute of Nuclear Physics, Siberian Branch (Russian Federation)

2012-03-15T23:59:59.000Z

313

Laser cooling of a trapped particle with increased Rabi frequencies  

Science Conference Proceedings (OSTI)

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}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.

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

314

Anti-hydrogen production with positron beam ion trap  

Science Conference Proceedings (OSTI)

In low-energy antiproton physics, it is advantageous to be able to manipulate anti-particles as freely as normal particles. A robust production and storage system for high-quality positrons and antiprotons would be a substantial advance for the development of anti-matter science. The idea of electron beam ion trap could be applied for storage of anti-particle when the electron beam could be replaced by the positron beam. The bright positron beam would be brought about using synchrotron radiation source with a superconducting wiggler. The new scheme for production of anti-particles is proposed by using new accelerator technologies.

Itahashi, Takahisa [Department of Physics, Graduate School of Science, Osaka University 1-1 Machikaneyama, Toyonaka, Osaka 560-0043 (Japan)

2008-08-08T23:59:59.000Z

315

Selective control of the symmetric Dicke subspace in trapped ions  

SciTech Connect

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

Lopez, C. E.; Retamal, J. C. [Departamento de Fisica, Universidad de Santiago de Chile, Casilla 307 Correo 2, Santiago (Chile); Solano, E. [Physics Department, ASC, and CeNS, Ludwig-Maximilians-Universitaet, Theresienstrasse 37, 80333 Munich (Germany); Seccion Fisica, Departamento de Ciencias, Pontificia Universidad Catolica del Peru, Apartado 1761, Lima (Peru)

2007-09-15T23:59:59.000Z

316

Spectroscopy of Charge Carriers and Traps in Field-Doped Organic Semiconductors  

SciTech Connect

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.

Zhu, Xiaoyang; Frisbie, C Daniel

2012-08-13T23:59:59.000Z

317

Real-time chemical analysis of aerosol particles  

Science Conference Proceedings (OSTI)

An important aspect of environmental atmospheric monitoring requires the characterization of airborne microparticles and aerosols. Unfortunately, traditional sample collection and handling techniques are prone to contamination and interference effects that can render an analysis invalid. These problems can be avoided by using real-time atmospheric sampling techniques followed by immediate mass spectrometric analysis. The former is achieved in these experiments via a two state differential pumping scheme that is attached directly to a commercially available quadruple ion trap mass spectrometer. Particles produced by an external particle generator enter the apparatus and immediately pass through two cw laser/fiberoptic based detectors positioned two centimeters apart. Timing electronics measure the time between detection events, estimate the particles arrival in the center of the ion trap and control the firing of a YAG laser. Ions produced when the UV laser light ablates the particle`s surface are stored by the ion trap for mass analysis. Ion trap mass spectrometers have several advantages over conventional time-of-flight instruments. First, they are capable of MS/MS analysis by the collisional dissociation of a stored species, This permits complete chemical characterization of airborne samples. Second, ion traps are small and lend themselves to portable, field oriented applications.

Yang, M.; Whitten, W.B.; Ramsey, J.M.

1995-04-01T23:59:59.000Z

318

Features of conduction mechanisms in Si/oligo-{beta}-naphthol/metal heterostructures  

Science Conference Proceedings (OSTI)

Conduction mechanisms in Si-polymer-metal heterostructures with oligo-{beta}-naphthol as a wide band-gap polymer have been studied. The results obtained are explained within the models of hopping transport via trap levels, Schottky emission, and field tunneling emission. Different charge transport mechanisms operate in different temperature ranges and under different electric fields.

Hasannli, Sh. M., E-mail: Hasanli_sh@rambler.ru; Mursakulov, N. N.; Samedova, U. F.; Abdulzade, N. N.; Mamedov, B. A. [National Academy of Sciences of Azerbaijan, Institute of Physics (Azerbaijan); Guseynov, R. K. [Ganja State University (Azerbaijan)

2010-07-15T23:59:59.000Z

319

Reliable transport through a microfabricated X-junction surface-electrode ion trap  

E-Print Network (OSTI)

We report the design, fabrication, and characterization of a microfabricated surface-electrode ion trap that supports controlled transport through the two-dimensional intersection of linear trapping zones arranged in a ninety-degree cross. The trap is fabricated with very-large-scalable-integration (VLSI) techniques which are compatible with scaling to a larger quantum information processor. The shape of the radio-frequency (RF) electrodes is optimized with a genetic algorithm to minimize axial pseudopotential barriers and to minimize ion heating during transport. Seventy-eight independent DC control electrodes enable fine control of the trapping potentials. We demonstrate reliable ion transport between junction legs, trapping of ion chains with nearly-equal spacing in one of the trap's linear sections, and merging and splitting ions from these chains. Doppler-cooled ions survive more than 10^5 round-trip transits between junction legs without loss and more than sixty-five consecutive round trips without laser cooling.

Kenneth Wright; Jason M. Amini; Daniel L. Faircloth; Curtis Volin; S. Charles Doret; Harley Hayden; C. -S. Pai; David W. Landgren; Douglas Denison; Tyler Killian; Richart E. Slusher; Alexa W. Harter

2012-10-12T23:59:59.000Z

320

Characterization of a Dominant Electron Trap in GaNAs Using Deep-Level Spectroscopy  

Science Conference Proceedings (OSTI)

Dilute-nitrogen GaNAs epitaxial layers grown by metal-organic chemical vapor deposition were characterized by deep-level transient spectroscopy (DLTS). For all samples, the dominant DLTS signal corresponds to an electron trap having an activation energy of about 0.25 to 0.35 eV. The minority-carrier trap density in the p-type material is quantified based on computer simulation of the devices. The simulations show that only about 2% of the traps in the depleted layer are filled during the transient. The fraction of the traps that are filled depends strongly on the depth of the trap, but only weakly on the doping of the layers and on the conduction-band offset. The simulations provide a pathway to obtain semi-quantitative data for analysis of minority-carrier traps by DLTS.

Johnston, S. W.; Kurtz, S. R.

2006-08-01T23:59:59.000Z

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


321

To:... Subject: Electromagnetic Impact of CEBAF Beam on Hydrogen Trap EXPECTED IMPACT OF CEBAF BEAM ON HYDROGEN TRAP  

E-Print Network (OSTI)

A magnetic ultra-cold trap of fully polarized atomic hydrogen is being considered for using as a target for Mřller polarimetry at CEBAF, at beam currents up to 100 µA. This note addresses possible problems caused by the CEBAF beam impact on such a target. The beam current generates an electromagnetic RF radiation which may cause a target depolarization inducing spin flips. Also, a part of the radiation may be absorbed in the cell pipe, heating it. The beam also heats up the gas by ionization. 1

unknown authors

2003-01-01T23:59:59.000Z

322

THE DISCOVERY OF GEOMAGNETICALLY TRAPPED COSMIC-RAY ANTIPROTONS  

Science Conference Proceedings (OSTI)

The existence of a significant flux of antiprotons confined to Earth's magnetosphere has been considered in several theoretical works. These antiparticles are produced in nuclear interactions of energetic cosmic rays with the terrestrial atmosphere and accumulate in the geomagnetic field at altitudes of several hundred kilometers. A contribution from the decay of albedo antineutrons has been hypothesized in analogy to proton production by neutron decay, which constitutes the main source of trapped protons at energies above some tens of MeV. This Letter reports the discovery of an antiproton radiation belt around the Earth. The trapped antiproton energy spectrum in the South Atlantic Anomaly (SAA) region has been measured by the PAMELA experiment for the kinetic energy range 60-750 MeV. A measurement of the atmospheric sub-cutoff antiproton spectrum outside the radiation belts is also reported. PAMELA data show that the magnetospheric antiproton flux in the SAA exceeds the cosmic-ray antiproton flux by three orders of magnitude at the present solar minimum, and exceeds the sub-cutoff antiproton flux outside radiation belts by four orders of magnitude, constituting the most abundant source of antiprotons near the Earth.

Adriani, O. [Department of Physics, University of Florence, I-50019 Sesto Fiorentino, Florence (Italy); Barbarino, G. C. [Department of Physics, University of Naples 'Federico II', I-80126 Naples (Italy); Bazilevskaya, G. A. [Lebedev Physical Institute, RU-119991, Moscow (Russian Federation); Bellotti, R.; Bruno, A.; Cafagna, F. [Department of Physics, University of Bari, I-70126 Bari (Italy); Boezio, M.; Bonvicini, V. [INFN, Sezione di Trieste, I-34149 Trieste (Italy); Bogomolov, E. A. [Ioffe Physical Technical Institute, RU-194021 St. Petersburg (Russian Federation); Bongi, M.; Bottai, S. [INFN, Sezione di Florence, I-50019 Sesto Fiorentino, Florence (Italy); Borisov, S.; Casolino, M.; De Pascale, M. P.; De Santis, C. [INFN, Sezione di Rome 'Tor Vergata', I-00133 Rome (Italy); Campana, D.; Carbone, R.; Consiglio, L. [INFN, Sezione di Naples, I-80126 Naples (Italy); Carlson, P. [KTH, Department of Physics, and the Oskar Klein Centre for Cosmoparticle Physics, AlbaNova University Centre, SE-10691 Stockholm (Sweden); Castellini, G., E-mail: alessandro.bruno@ba.infn.it [IFAC, I-50019 Sesto Fiorentino, Florence (Italy)

2011-08-20T23:59:59.000Z

323

The discovery of geomagnetically trapped cosmic ray antiprotons  

E-Print Network (OSTI)

The existence of a significant flux of antiprotons confined to Earth's magnetosphere has been considered in several theoretical works. These antiparticles are produced in nuclear interactions of energetic cosmic rays with the terrestrial atmosphere and accumulate in the geomagnetic field at altitudes of several hundred kilometers. A contribution from the decay of albedo antineutrons has been hypothesized in analogy to proton production by neutron decay, which constitutes the main source of trapped protons at energies above some tens of MeV. This Letter reports the discovery of an antiproton radiation belt around the Earth. The trapped antiproton energy spectrum in the South Atlantic Anomaly (SAA) region has been measured by the PAMELA experiment for the kinetic energy range 60--750 MeV. A measurement of the atmospheric sub-cutoff antiproton spectrum outside the radiation belts is also reported. PAMELA data show that the magnetospheric antiproton flux in the SAA exceeds the cosmic-ray antiproton flux by three orders of magnitude at the present solar minimum, and exceeds the sub-cutoff antiproton flux outside radiation belts by four orders of magnitude, constituting the most abundant source of antiprotons near the Earth.

O. Adriani; G. C. Barbarino; G. A. Bazilevskaya; R. Bellotti; M. Boezio; E. A. Bogomolov; M. Bongi; V. Bonvicini; S. Borisov; S. Bottai; A. Bruno; F. Cafagna; D. Campana; R. Carbone; P. Carlson; M. Casolino; G. Castellini; L. Consiglio; M. P. De Pascale; C. De Santis; N. De Simone; V. Di Felice; A. M. Galper; W. Gillard; L. Grishantseva; G. Jerse; A. V. Karelin; M. D. Kheymits; S. V. Koldashov; S. Y. Krutkov; A. N. Kvashnin; A. Leonov; V. Malakhov; L. Marcelli; A. G. Mayorov; W. Menn; V. V. Mikhailov; E. Mocchiutti; A. Monaco; N. Mori; N. Nikonov; G. Osteria; F. Palma; P. Papini; M. Pearce; P. Picozza; C. Pizzolotto; M. Ricci; S. B. Ricciarini; L. Rossetto; R. Sarkar; M. Simon; R. Sparvoli; P. Spillantini; Y. I. Stozhkov; A. Vacchi; E. Vannuccini; G. Vasilyev; S. A. Voronov; Y. T. Yurkin; J. Wu; G. Zampa; N. Zampa; V. G. Zverev

2011-07-25T23:59:59.000Z

324

Trapping ultracold gases near cryogenic materials with rapid reconfigurability  

E-Print Network (OSTI)

We demonstrate a novel atom chip trapping system that allows the placement and high-resolution imaging of ultracold atoms within microns from any exchange with minimal experimental downtime. The sample is not connected to the atom chip, allowing rapid exchange without perturbing the atom chip or laser cooling apparatus. Exchange of the sample and retrapping of atoms has been performed within a week turnaround, limited only by chamber baking. Moreover, the decoupling of sample and atom chip provides the ability to independently tune the sample temperature and its position with respect to the trapped ultracold gas, which itself may remain in the focus of a high-resolution imaging system. As a first demonstration of this new system, we have confined a 700-nK cloud of 8x10^4 87Rb atoms within 100 um of a gold-mirrored 100-um-thick silicon substrate. The substrate was cooled to 35 K without use of a heat shield, while the atom chip, 120 um away, remained at room temperature. Atoms may be imaged and retrapped every 16 s, allowing rapid data collection.

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

2013-11-08T23:59:59.000Z

325

Angular constraint on light-trapping absorption enhancement in solar cells  

E-Print Network (OSTI)

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.

Yu, Zongfu

2010-01-01T23:59:59.000Z

326

Nano-texturization for Light Trapping in Crystalline Silicon Solar Cells  

Science Conference Proceedings (OSTI)

Abstract Scope, To address the question whether random or periodic nanostructures lead to better light trapping in solar cells, we design and fabricate three ...

327

Steven Chu: Laser Cooling and Trapping of Atoms  

NLE Websites -- All DOE Office Websites (Extended Search)

Steven Chu Steven Chu Laser Cooling and Trapping of Atoms Resources with Additional Information · Interviews, Speeches, and Presentations · Patents Steven Chu Photo Credit: Lawrence Berkeley National Laboratory Roy Kaltschmidt, Photographer Steven Chu was appointed by President Barack Obama to be the 12th Secretary of Energy and served in this capacity until April 22, 2013. He was previously Director of Lawrence Berkeley National Laboratory (LBNL), Professor in the Physics Department at the University of California, Berkeley, and 'the Theodore and Frances Geballe Professor of Physics and Applied Physics at Stanford University. Professor Chu's research is in atomic physics, polymer and biophysics. His thesis and postdoctoral work at Berkeley ... was the observation of parity non-conservation in atomic transitions in 1978. This experiment was one of the earliest atomic physics confirmations of the Weinberg-Salam-Glashow theory that unifies the weak and electromagnetic forces.

328

Lean NOx Trap Catalysis for Lean Natural Gas Engine Applications  

Science Conference Proceedings (OSTI)

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 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

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

329

Lean NOx Trap Catalysis for Lean Natural Gas Engine Applications  

DOE Green Energy (OSTI)

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

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

330

Lean Gasoline Engine Reductant Chemistry During Lean NOx Trap Regeneration  

Science Conference Proceedings (OSTI)

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

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

2010-01-01T23:59:59.000Z

331

Steven Chu: Laser Cooling and Trapping of Atoms  

Office of Scientific and Technical Information (OSTI)

Steven Chu Steven Chu Laser Cooling and Trapping of Atoms Resources with Additional Information · Interviews, Speeches, and Presentations · Patents Steven Chu Photo Credit: Lawrence Berkeley National Laboratory Roy Kaltschmidt, Photographer Steven Chu was appointed by President Barack Obama to be the 12th Secretary of Energy and served in this capacity until April 22, 2013. He was previously Director of Lawrence Berkeley National Laboratory (LBNL), Professor in the Physics Department at the University of California, Berkeley, and 'the Theodore and Frances Geballe Professor of Physics and Applied Physics at Stanford University. Professor Chu's research is in atomic physics, polymer and biophysics. His thesis and postdoctoral work at Berkeley ... was the observation of parity non-conservation in atomic transitions in 1978. This experiment was one of the earliest atomic physics confirmations of the Weinberg-Salam-Glashow theory that unifies the weak and electromagnetic forces.

332

Acceleration Mechanisms  

E-Print Network (OSTI)

Glossary I. Background and context of the subject II. Stochastic acceleration III. Resonant scattering IV. Diffusive shock acceleration V. DSA at multiple shocks VI. Applications of DSA VII. Acceleration by parallel electric fields VIII. Other acceleration mechanisms IX. Future directions X. Appendix: Quasilinear equations XI. Bibliography

Melrose, D B

2009-01-01T23:59:59.000Z

333

Direct-energy-regenerated particulate trap technology. Final report  

DOE Green Energy (OSTI)

The objective of this CRADA between Lockheed Martin and Cummins Engine Company was to develop fiber-reinforced silicon carbide (SiC) composite materials for use as diesel engine particulate traps. Chemical vapor deposition techniques were used to partially densify and rigidize a thin fibrous substrate and produce the porous SiC- based filter. Microwave energy was used to directly couple to the deposited SiC to uniformly heat the filter and oxidize the collected carbon particulates. For commercial usage particulate traps must: (1) filter carbon particulates from a high temperature diesel exhaust at an acceptably low backpressure, (2) survive thousands of thermal transients due to regeneration or cleaning of the filter by oxidizing the collected carbon, (3) be durable and reliable over the expected life of the filter (300,000 miles or 10,000 hours), and (4) provide a low overall operating cost which is competitive with other filtering techniques. The development efforts performed as part of this CRADA have resulted in a very promising new technology for Cummins Engine Company. Ceramic fiber based filter papers were developed at Fleetguard, Inc., (a Cummins Subsidiary) and used to produce the spiral wound, corrugated filter cartridges. Optimized SiC coatings were developed at Lockheed Martin which couple with 2.45 GHz microwaves. Prototype particulate filter cartridges fabricated at Fleetguard and rigidized at Lockheed Martin performed well in single cylinder engine tests at Cummins. These prototype filters obtained filtering efficiencies greater than 80% at acceptably low backpressures and could be successfully headed and regenerated using a conventional in-home microwave oven.

Stinton, D.P.; Janney, M.A. [Oak Ridge National Lab., TN (United States); Yonushonis, T.M.; McDonald, A.C.; Wiczynski, P.D. [Cummins Engine Co., Inc., Columbus, IN (United States); Haberkamp, W.C. [Fleetguard, Inc. (United States)

1996-12-01T23:59:59.000Z

334

Synoptic-Scale Structure and the Character of Coastally Trapped Wind Reversals  

Science Conference Proceedings (OSTI)

Coastally trapped wind reversals that occur along the U.S. West Coast have been described in numerous other studies. The synoptic-scale environment and the forcing of a coastally trapped Kelvin wave are highly linked in the development of these ...

Wendell A. Nuss

2007-01-01T23:59:59.000Z

335

Charge trapping in ultrathin Gd2O3 high-k dielectric  

Science Conference Proceedings (OSTI)

Charge trapping in ultrathin high-k Gd"2O"3 dielectric leading to appearance of hysteresis in C-V curves is studied by capacitance-voltage and current-voltage techniques. It was shown that the large leakage current at a negative gate voltage causes the ... Keywords: Charge trapping, Gd2O3, High-k dielectric, Rare earth oxide

A. N. Nazarov; Y. V. Gomeniuk; Y. Y. Gomeniuk; H. D. B. Gottlob; M. Schmidt; M. C. Lemme; M. Czernohorsky; H. J. Osten

2007-09-01T23:59:59.000Z

336

Physica Scripta. Vol. T22, 228-237, 1988. Summary of the Physics in Traps Panel  

E-Print Network (OSTI)

astrophysics, potential condensed matter experiments, and new ideas for optical and magnetic traps for neutral measured [7] their mass difference in a commercial spec- trometer (with cubic trap) to % 1 part in IO4dependence of the correction terms, one can clearly see the advantage of performing the experi- ment

California at San Diego, University of

337

Ion Trapping for Ion Mobility Spectrometry Measurements in a Cyclical Drift Tube  

E-Print Network (OSTI)

us to consider new types of mobility measurements. In traditional IMS instruments, R scales as (ELIon Trapping for Ion Mobility Spectrometry Measurements in a Cyclical Drift Tube Rebecca S. Glaskin 47405, United States ABSTRACT: A new ion trapping technique, involving the accumulation of ions

Clemmer, David E.

338

Loading of a surface-electrode ion trap from a remote, precooled source  

E-Print Network (OSTI)

We demonstrate loading of ions into a surface-electrode trap (SET) from a remote, laser-cooled source of neutral atoms. We first cool and load ?10[superscript 6] neutral [superscript 88]Sr atoms into a magneto-optical trap ...

Sage, Jeremy M.

339

A Novel Method for Fundamental Interaction Studies with Electrostatic Ion Beam Trap  

E-Print Network (OSTI)

Trapped radioactive atoms present exciting opportunities for the study of fundamental interactions and symmetries. For example, detecting beta decay in a trap can probe the minute experimental signal that originates from possible tensor or scalar terms in the weak interaction. Such scalar or tensor terms affect, e.g., the angular correlation between a neutrino and an electron in the beta-decay process, thus probing new physics of "beyond-the-standard-model" nature. In particular, this article focuses on a novel use of an innovative ion trapping device, the Electrostatic Ion Beam Trap (EIBT). Such a trap has not been previously considered for Fundamental Interaction studies and exhibits potentially very significant advantages over other schemes. These advantages include improved injection efficiency of the radionuclide under study, an extended field-free region, ion-beam kinematics for better efficiency and ease-of-operation and the potential for a much larger solid angle for the electron and recoiling atom counters.

S. Vaintraub; M. Hass; O. Aviv; O. Heber; I. Mardor

2010-05-22T23:59:59.000Z

340

Managing time  

Science Conference Proceedings (OSTI)

Professionals overwhelmed with information glut can find hope from new insights about time management.

Peter J. Denning

2011-03-01T23:59:59.000Z

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


341

Construction and Operational Experience with a Superconducting Octupole Used to Trap Antihydrogen  

SciTech Connect

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.

Wanderer P.; Escallier, J.; Marone, A.; Parker, B.

2011-09-06T23:59:59.000Z

342

Classical Mechanics (Prof. P. L. Read)  

E-Print Network (OSTI)

Classical Mechanics (Prof. P. L. Read) Lecture 1 Photograph © Andrew Dunn, 5 November 2004. #12;What is Classical Mechanics? · .. rational mechanics will be the science of motion resulting from any Mechanics? · System of mathematical physics developed since the time of Galileo, Newton & Kepler · Concerned

Read, Peter L.

343

Bose-Einstein condensation in dark power-law laser traps  

Science Conference Proceedings (OSTI)

We investigate theoretically an original route to achieve Bose-Einstein condensation using dark power-law laser traps. We propose to create such traps with two crossing blue-detuned Laguerre-Gaussian optical beams. Controlling their azimuthal order l allows for the exploration of a multitude of power-law trapping situations in one, two, and three dimensions, ranging from the usual harmonic trap to an almost square-well potential, in which a quasihomogeneous Bose gas can be formed. The usual cigar-shaped and disk-shaped Bose-Einstein condensates obtained in a 1D or 2D harmonic trap take the generic form of a 'finger' or of a 'hockey puck' in such Laguerre-Gaussian traps. In addition, for a fixed atom number, higher transition temperatures are obtained in such configurations when compared with a harmonic trap of the same volume. This effect, which results in a substantial acceleration of the condensation dynamics, requires a better but still reasonable focusing of the Laguerre-Gaussian beams.

Jaouadi, A. [Universite Paris-Sud, Institut des Sciences Moleculaires d'Orsay (ISMO), F-91405 Orsay (France); CNRS, Orsay, F-91405 France (France); Laboratoire de Spectroscopie Atomique, Moleculaire et Applications (LSAMA), Department of Physics, Faculty of Science of Tunis, University of Tunis El Manar, T-2092 Tunis (Tunisia); Gaaloul, N. [Institut fuer Quantenoptik, Welfengarten 1, Gottfried Wilhelm Leibniz Universitaet, D-30167 Hannover (Germany); Viaris de Lesegno, B.; Pruvost, L. [CNRS, Laboratoire Aime Cotton (LAC), F-91405 Orsay (France); Universite Paris-Sud, Orsay, F-91405 France (France); Telmini, M. [Laboratoire de Spectroscopie Atomique, Moleculaire et Applications (LSAMA), Department of Physics, Faculty of Science of Tunis, University of Tunis El Manar, T-2092 Tunis (Tunisia); Charron, E. [Universite Paris-Sud, Institut des Sciences Moleculaires d'Orsay (ISMO), F-91405 Orsay (France); CNRS, Orsay, F-91405 (France)

2010-08-15T23:59:59.000Z

344

Operation of the Lower Granite Dam Adult Trap, 2008.  

DOE Green Energy (OSTI)

During 2008 we operated the adult salmonid trap at Lower Granite Dam from 7 March through 25 November, except during a short summer period when water temperatures were too high to safely handle fish. We collected and handled a total of 20,463 steelhead Oncorhynchus mykiss and radio-tagged 34 of the hatchery steelhead. We took scale samples from 3,724 spring/summer Chinook salmon O. tshawytscha for age and genetic analysis. We collected and handled a total of 8,254 fall Chinook salmon. Of those fish, 2,520 adults and 942 jacks were transported to Lyons Ferry Hatchery on the Snake River in Washington. In addition, 961 adults and 107 jacks were transported to the Nez Perce Tribal Hatchery on the Clearwater River in Idaho. The remaining 3,724 fall Chinook salmon were passed upstream. Scales samples were taken from 780 fall Chinook salmon tagged with passive integrated transponder (PIT) tags and collected by the sort-by-code system.

Harmon, Jerrel R.

2009-01-01T23:59:59.000Z

345

Certification Framework Based on Effective Trapping for Geologic Carbon Sequestration  

SciTech Connect

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

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

2009-01-15T23:59:59.000Z

346

Particle trap for compressed gas insulated transmission systems  

DOE Patents (OSTI)

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

Cookson, Alan H. (Pittsburgh, PA)

1985-01-01T23:59:59.000Z

347

Particle trap for compressed gas insulated transmission systems  

DOE Patents (OSTI)

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

Cookson, A.H.

1984-04-26T23:59:59.000Z

348

Higgs Mechanism for Gravitons  

E-Print Network (OSTI)

Just like the vector gauge bosons in the gauge theories, it is now known that gravitons acquire mass in the process of spontaneous symmetry breaking of diffeomorphisms through the condensation of scalar fields. The point is that we should find the gravitational Higgs mechanism such that it results in massive gravity in a flat Minkowski space-time without non-unitary propagating modes. This is usually achieved by including higher-derivative terms in scalars and tuning the cosmological constant to be a negative value in a proper way. Recently, a similar but different gravitational Higgs mechanism has been advocated by Chamseddine and Mukhanov where one can relax the negative cosmological constant to zero or positive one. In this work, we investigate why the non-unitary ghost mode decouples from physical Hilbert space in a general space-time dimension. Moreover, we generalize the model to possess an arbitrary potential and clarify under what conditions the general model exhibits the gravitational Higgs mechanism. By searching for solutions to the conditions, we arrive at two classes of potentials exhibiting gravitational Higgs mechanism. One class includes the model by Chamseddine and Mukhanov in a specific case while the other is completely a new model.

Ichiro Oda

2010-03-07T23:59:59.000Z

349

Star Products for Relativistic Quantum Mechanics  

E-Print Network (OSTI)

The star product formalism has proved to be an alternative formulation for nonrelativistic quantum mechanics. We want introduce here a covariant star product in order to extend the star product formalism to relativistic quantum mechanics in the proper time formulation.

P. Henselder

2007-05-24T23:59:59.000Z

350

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

DOE Patents (OSTI)

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

McKee, Jr., John M. (Hinsdale, IL)

1976-01-01T23:59:59.000Z

351

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

Science Conference Proceedings (OSTI)

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

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

2011-11-15T23:59:59.000Z

352

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

DOE Green Energy (OSTI)

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

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

2012-06-01T23:59:59.000Z

353

TRImP - A new facility to produce and trap radioactive isotopes  

E-Print Network (OSTI)

At the Kernfysisch Vensneller Institiutr (KVI) in Groningen, NL, a new facility (TRImP) is under development. It aims for producing, slowing down, and trapping of radioactive isotopes in order to perform accurate measurements on fundamental symmetries and interactions. A production target station and a dual magnetic separator installed and commissioned. We will slow down the isotopes of interest using an ion catcher and in a further stage a radiofrequency quadropole gas cooler (RFQ). The isotopes will finally be trapped in an atomic trap for precision studies.

Sohani, M

2006-01-01T23:59:59.000Z

354

TRImP - A new facility to produce and trap radioactive isotopes  

E-Print Network (OSTI)

At the Kernfysisch Vensneller Institiutr (KVI) in Groningen, NL, a new facility (TRImP) is under development. It aims for producing, slowing down, and trapping of radioactive isotopes in order to perform accurate measurements on fundamental symmetries and interactions. A production target station and a dual magnetic separator installed and commissioned. We will slow down the isotopes of interest using an ion catcher and in a further stage a radiofrequency quadropole gas cooler (RFQ). The isotopes will finally be trapped in an atomic trap for precision studies.

M. Sohani

2006-01-17T23:59:59.000Z

355

Convergence of clock processes on infinite graphs and aging in Bouchaud's asymmetric trap model on $\\Z^d$  

E-Print Network (OSTI)

Using a method developed by Durrett and Resnick, [23], we establish general criteria for the convergence of properly rescaled clock processes of random dynamics in random environments on infinite graphs. This extends the results of Gayrard, [27], Bovier and Gayrard, [20], and Bovier, Gayrard, and Svejda, [21], and gives a unified framework for proving convergence of clock processes. As a first application we prove that Bouchaud's asymmetric trap model on $Z^d$ exhibits a normal aging behavior for all $d \\geq 2$. Namely, we show that certain two-time correlation functions, among which the classical probability to find the process at the same site at two time points, converge, as the age of the process diverges, to the distribution function of the arcsine law. As a byproduct we prove that the fractional kinetics process ages.

Véronique Gayrard; Adela Svejda

2013-09-12T23:59:59.000Z

356

Self-interfering matter-wave patterns generated by a moving laser obstacle in a two-dimensional Bose-Einstein condensate inside a power trap cut off by box potential boundaries  

SciTech Connect

We report the observation of highly energetic self-interfering matter-wave (SIMW) patterns generated by a moving obstacle in a two-dimensional Bose-Einstein condensate (BEC) inside a power trap cut off by hard-wall box potential boundaries. The obstacle initially excites circular dispersive waves radiating away from the center of the trap which are reflected from hard-wall box boundaries at the edges of the trap. The resulting interference between outgoing waves from the center of the trap and reflected waves from the box boundaries institutes, to the best of our knowledge, unprecedented SIMW patterns. For this purpose we simulated the time-dependent Gross-Pitaevskii equation using the split-step Crank-Nicolson method and the obstacle was modelled by a moving impenetrable Gaussian potential barrier. Various trapping geometries are considered in which the dynamics of the spatial and momentum density, as well as the energy, are considered. The momentum dynamics reveal an oscillatory behavior for the condensate fraction, indicative of excitations out of and de-excitations back into the condensate state. An oscillatory pattern for the energy dynamics reveals the presence of solitons in the system. Some vortex features are also obtained.

Sakhel, Roger R. [Department of Basic Sciences, Faculty of Information Technology, Isra University, Amman 11622 (Jordan); Sakhel, Asaad R. [Department of Applied Sciences, Faculty of Engineering Technology, Al-Balqa Applied University, Amman 11134 (Jordan); Ghassib, Humam B. [Department of Physics, The University of Jordan, Amman 11942 (Jordan)

2011-09-15T23:59:59.000Z

357

Excitation trapping and primary charge stabilization in Rhodopseudomonas viridis cells, measured electrically with picosecond resolution  

SciTech Connect

The transmembrane primary charge separation in the photosynthetic bacterium Rhodopseudomonas viridis was monitored by electric measurements of the light-gradient type. Excitation of whole cells with 30-ps laser pulses at either 532 nm or 1064 nm gave rise to a biphasic increase of the photovoltage. The fast phase, contributing about 50% of the total, rose with an exponential time constant less than or equal to 40 ps and was independent of the redox state of the quinone electron acceptor. It is assigned to the migration of the excitation energy in the antenna and its subsequent trapping by the reaction center, monitored by the ultrafast charge separation between the primary electron donor and the bacteriopheophytin intermediary acceptor. The slower phase (125 +/- 50 ps) only occurred when the quinone was oxidized and disappeared when it was reduced (either chemically or photochemically). It is assigned to the forward electron transfer from the bacteriopheophytin to the quinone. The relative amplitudes of these two electrogenic steps demonstrate that the bacteriopheophytin intermediary acceptor is located halfway between the primary donor and the quinone.

Deprez, J.; Trissl, H.W.; Breton, J.

1986-03-01T23:59:59.000Z

358

Bear Trap Hot Spring Pool & Spa Low Temperature Geothermal Facility | Open  

Open Energy Info (EERE)

Trap Hot Spring Pool & Spa Low Temperature Geothermal Facility Trap Hot Spring Pool & Spa Low Temperature Geothermal Facility Jump to: navigation, search Name Bear Trap Hot Spring Pool & Spa Low Temperature Geothermal Facility Facility Bear Trap Hot Spring Sector Geothermal energy Type Pool and Spa Location Norris, Montana Coordinates 45.5679836°, -111.690808° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[]}

359

Atom Trap Trace Analysis at ANL | U.S. DOE Office of Science (SC)  

Office of Science (SC) Website

Atom Trap Trace Analysis at ANL Atom Trap Trace Analysis at ANL Nuclear Physics (NP) NP Home About Research Facilities Science Highlights Benefits of NP Spinoff Applications Spinoff Archives SBIR/STTR Applications of Nuclear Science and Technology Funding Opportunities Nuclear Science Advisory Committee (NSAC) News & Resources Contact Information Nuclear Physics U.S. Department of Energy SC-26/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-3613 F: (301) 903-3833 E: sc.np@science.doe.gov More Information » Spinoff Archives Atom Trap Trace Analysis at ANL Print Text Size: A A A RSS Feeds FeedbackShare Page Application/instrumentation: Atom Trap Trace Analysis (ATTA) to determine isotopic abundances. Developed at: Argonne National Laboratory Developed in: 1999-current

360

Scattering of Coastal-Trapped Waves by Irregularities in Coastline and Topography  

Science Conference Proceedings (OSTI)

The scattering of freely-propapting coastal-trapped waves (CTWs) by large variations in coastline and topography is studied using a numerical model which accomodates arbitrary density stratification, bathymetry and coastline. Particular attention ...

John L. Wilkin; David C. Chapman

1990-03-01T23:59:59.000Z

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


361

On the application of radio frequency voltages to ion traps via helical resonators  

E-Print Network (OSTI)

Ions confined using a Paul trap require a stable, high voltage and low noise radio frequency (RF) potential. We present a guide for the design and construction of a helical coil resonator for a desired frequency that maximises the quality factor for a set of experimental constraints. We provide an in-depth analysis of the system formed from a shielded helical coil and an ion trap by treating the system as a lumped element model. This allows us to predict the resonant frequency and quality factor in terms of the physical parameters of the resonator and the properties of the ion trap. We also compare theoretical predictions with experimental data for different resonators, and predict the voltage applied to the ion trap as a function of the Q-factor, input power and the properties of the resonant circuit.

Siverns, J D; Weidt, S; Hensinger, W K

2011-01-01T23:59:59.000Z

362

The Scattering of Long Coastal-Trapped Waves in Frictional Seas  

Science Conference Proceedings (OSTI)

The scattering of coastal-trapped waves (CTWs) by a region of irregular shelf bathymetry is determined from a circulation integral of the depth-integrated momentum equations. For relatively weak stratification the conservation of geostrophic mass ...

John F. Middleton; Mark A. Merrifield

1995-04-01T23:59:59.000Z

363

Light trapping in thin film solar cells using textured photonic crystal  

DOE Patents (OSTI)

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

Yi, Yasha (Somerville, MA); Kimerling, Lionel C. (Concord, MA); Duan, Xiaoman (Amesbury, MA); Zeng, Lirong (Cambridge, MA)

2009-01-27T23:59:59.000Z

364

Simple Models of Coastal-Trapped Waves Based on the Shape of the Bottom Topography  

Science Conference Proceedings (OSTI)

Solutions of barotropic coastal-trapped waves in the shallow-water context are discussed for different shapes of the bottom topography. In particular, an infinite family of topographic waves over continental shelves characterized by a shape ...

L. Zavala Sansón

2012-03-01T23:59:59.000Z

365

An optical-fiber interface to a trapped-ion quantum computer  

E-Print Network (OSTI)

The trapped-ion quantum computer is an atom-based implementation of a quantum computer that has successfully demonstrated numerous quantum algorithms and the potential for scalability. Fundamental to its operation is the ...

Kim, Tony Hyun

2011-01-01T23:59:59.000Z

366

Synoptic Forcing Of Coastal-Trapped Disturbances in the Marine Atmospheric Boundary Layer  

Science Conference Proceedings (OSTI)

Motivated by recent observations along the west coast of the United States, the authors investigate the generation and propagation of coastal-trapped disturbances in the marine atmospheric boundary layer. Analytic solutions are obtained in a ...

A. M. Rogerson; R. M. Samelson

1995-06-01T23:59:59.000Z

367

Sensitivity of Coastally Trapped Disturbance Dynamics to Barrier Height and Topographic Variability in a Numerical Model  

Science Conference Proceedings (OSTI)

The sensitivity of a coastally trapped disturbance (CTD) to topographic height is examined using simulations of the 15–18 May 1985 CTD. These simulations include three with uniform topography, in which the North American west coast mountains are ...

K. J. Tory; P. L. Jackson; C. J. C. Reason

2001-12-01T23:59:59.000Z

368

Scattering of Coastally Trapped Waves by Changes in Continental Shelf Width  

Science Conference Proceedings (OSTI)

The scattering of dispersive, barotropic, coastally-trapped waves by narrowing and widening shelves is investigated. The shelves considered maintain a shelf-similar exponential shape. For such shelves, previous investigators have shown that no ...

Ian Webster

1987-07-01T23:59:59.000Z

369

Technological assessment of light-trapping technology for thin-film Si solar cell  

E-Print Network (OSTI)

The proposed light trapping technology of Distributed Bragg Reflector (DBR) with Diffraction Grating (DG) and Anti-Reflection Coating (ARC) for thin film Si solar cell was analyzed from the technology, market, and ...

Susantyoko, Rahmat Agung

2009-01-01T23:59:59.000Z

370

Depletion, quantum jumps, and temperature measurements of ??Sr? ions in a linear Paul Trap  

E-Print Network (OSTI)

This thesis describes the design and construction of two laser systems to probe the 674nm transition of ??Sr? ions in a linear Paul trap. The first laser system made use of a molecular transition in Iodine to stabilize the ...

Richerme, Philip J

2006-01-01T23:59:59.000Z

371

A Comparison of Long Coastal Trapped Wave Theory with Observations off Peru  

Science Conference Proceedings (OSTI)

The agreement between coastal trapped wave theory and observation is studied for the case of observations made off Peru during the 1977 CUEA JOINT-II experiment. Wave properties are calculated using a numerical model with realistic, horizontally ...

K. H. Brink

1982-08-01T23:59:59.000Z

372

Direct Calculation of Low-Frequency Coastally Trapped Waves and Their Scattering  

Science Conference Proceedings (OSTI)

A new, direct numerical method is proposed for finding the phase speeds and pressure fields of low-frequency nondispersive coastally trapped waves in a continuously stratified flow. The usual two-dimensional problem is reduced to a one-...

G. A. Schmidt; E. R. Johnson

1993-06-01T23:59:59.000Z

373

A Modeling Study of Nonstationary Trapped Mountain Lee Waves. Part II: Nonlinearity  

Science Conference Proceedings (OSTI)

The generation of nonstationary trapped mountain lee waves through nonlinear wave dynamics without any concomitant change in the background flow is investigated by conducting two-dimensional mountain wave simulations. These simulations ...

Louisa B. Nance; Dale R. Durran

1998-04-01T23:59:59.000Z

374

On the application of radio frequency voltages to ion traps via helical resonators  

E-Print Network (OSTI)

Ions confined using a Paul trap require a stable, high voltage and low noise radio frequency (RF) potential. We present a guide for the design and construction of a helical coil resonator for a desired frequency that maximises the quality factor for a set of experimental constraints. We provide an in-depth analysis of the system formed from a shielded helical coil and an ion trap by treating the system as a lumped element model. This allows us to predict the resonant frequency and quality factor in terms of the physical parameters of the resonator and the properties of the ion trap. We also compare theoretical predictions with experimental data for different resonators, and predict the voltage applied to the ion trap as a function of the Q-factor, input power and the properties of the resonant circuit.

J. D. Siverns; L. R. Simkins; S. Weidt; W. K. Hensinger

2011-06-24T23:59:59.000Z

375

Ancient Lava Flows Trap CO2 for Long-Term Storage in Big Sky...  

NLE Websites -- All DOE Office Websites (Extended Search)

3, 2013 Ancient Lava Flows Trap CO2 for Long-Term Storage in Big Sky Injection Photo by J.D. Griggs, courtesy of U.S.Geological Survey Photo by J.D. Griggs, courtesy of...

376

An injection-locked 674 nm laser for Strontium-88 ion trapping  

E-Print Network (OSTI)

Energy levels of the valence electron of a single trapped ??Sr+ ion can be harnessed as an effective qubit for quantum information processing. The qubit transition to a metastable energy state can be stimulated by a laser ...

Katz, Rena J. (Rena Jenelle)

2012-01-01T23:59:59.000Z

377

Coastal-Trapped Waves off the Coast of South Africa: Generation, Propagation and Current Structures  

Science Conference Proceedings (OSTI)

Coastal sea level variations from six sites around South Africa are used to establish the characteristics of coastal-trapped wave (CTW) propagation. Substantial amplitudes (>50 cm) are found along the south coast, but further propagation on the ...

E. H. Schumann; K. H. Brink

1990-08-01T23:59:59.000Z

378

Engineering optical traps for new environments and applications in the measurement of biological adhesives and motors  

E-Print Network (OSTI)

Optical traps have played a central role in the exploration of biological systems through the examination of molecular motors, biopolymers, and many other interactions at the nano and micro length scales. This thesis seeks ...

Appleyard, David Collins

2009-01-01T23:59:59.000Z

379

The Energy Source for the Coastal-Trapped Waves in the Australian Coastal Experiment Region  

Science Conference Proceedings (OSTI)

The sea level on the southern Australian coast is examined for the source of the coastal-trapped wave energy observed during the Australian Coastal Experiment. Sea level, adjusted for atmospheric pressure, and atmospheric pressure are observed to ...

John A. Church; Howard J. Freeland

1987-03-01T23:59:59.000Z

380

Cessation of the 22–25 June 2006 Coastally Trapped Wind Reversal  

Science Conference Proceedings (OSTI)

Coastally trapped wind reversals (CTWRs) occur periodically in the marine boundary layer off the western coast of the United States and dramatically change the low-level wind regime and coastal weather. Southerly flow becomes established with the ...

David A. Rahn; Thomas R. Parish

2010-07-01T23:59:59.000Z

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


381

Sea Surface Mixed Layer during the 10–11 June 1994 California Coastally Trapped Event  

Science Conference Proceedings (OSTI)

A midlevel, coastally trapped atmospheric event occurred along the California coast 10–11 June 1994. This feature reversed the surface wind field along the coast in a northerly phase progression. Along the central California coast, the winds at ...

C. E. Dorman; L. Armi; J. M. Bane; D. P. Rogers

1998-03-01T23:59:59.000Z

382

Molecular dynamics simulation of deuterium trapping and bubble formation in tungsten  

E-Print Network (OSTI)

Molecular dynamics simulation of deuterium trapping and bubble formation in tungsten Xue Yang using classical molecular dynamic methods. " Low energy deuterium atoms tend to affix to high environment. The deuterium bombardment of monocrystalline tungsten was modeled by molecular dynamics

Harilal, S. S.

383

Phenomenon of parametric trapping of electromagnetic waves in an inhomogeneous plasma  

SciTech Connect

A theory is developed of absolute parametric aperiodic instability in a spatially inhomogeneous plasma, when the electromagnetic waves generated in the plasma are trapped by the plasma near the peaks of the pumping-wave field.

Silin, V.P.; Starodub, A.N.

1977-10-01T23:59:59.000Z

384

A Systematic Search for Trapped Equatorial Waves in the GATE Velocity Data  

Science Conference Proceedings (OSTI)

Moored current meter data taken over a 60-day period during GATE (GARP Atlantic Tropical Experiment) near the equator at 28°W, have been systematically searched for vertically propagating equatorially trapped waves. Three independent tests ...

A. M. Horigan; R. H. Weisberg

1981-04-01T23:59:59.000Z

385

Numerical Simulation of Flow around a Tall Isolated Seamount. Part II: Resonant Generation of Trapped Waves  

Science Conference Proceedings (OSTI)

A sigma-coordinate, primitive equation ocean circulation model is used to explore the problem of the remnant generation of trapped waves about a tall, circular, isolated seamount by an incident oscillatory barotropic current. The numerical ...

Dale B. Haidvogel; Aike Beckmann; David C. Chapman; Ray-Qing Lin

1993-11-01T23:59:59.000Z

386

Additional Steam Traps Increase Production of a Drum Oven at a Petroleum Jelly Plant  

Science Conference Proceedings (OSTI)

Additional steam traps were installed on the drum oven at a petroleum jelly production facility at an ExxonMobil plant in Nigeria. The installation improved heat transfer and saved energy.

Not Available

2002-03-01T23:59:59.000Z

387

Mesoscale Eddy Formation and Shock Features Associated with a Coastally Trapped Disturbance  

Science Conference Proceedings (OSTI)

On 28 August 2002, a visually striking sequence of events appeared in satellite imagery showing a coastally trapped disturbance (CTD) propagating northward along the coast of California against a northerly background flow. As a narrow tongue of ...

Stephen D. Burk; William T. Thompson

2004-09-01T23:59:59.000Z

388

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

DOE Patents (OSTI)

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

Dale, Steinar J. (Monroeville, PA)

1984-01-01T23:59:59.000Z

389

INDEXING MECHANISM  

DOE Patents (OSTI)

A device is presented for loading and unloading fuel elements containing material fissionable by neutrons of thermal energy. The device comprises a combination of mechanical features Including a base, a lever pivotally attached to the base, an Indexing plate on the base parallel to the plane of lever rotation and having a plurality of apertures, the apertures being disposed In rows, each aperture having a keyway, an Index pin movably disposed to the plane of lever rotation and having a plurality of apertures, the apertures being disposed in rows, each aperture having a keyway, an index pin movably disposed on the lever normal to the plane rotation, a key on the pin, a sleeve on the lever spaced from and parallel to the index pin, a pair of pulleys and a cable disposed between them, an open collar rotatably attached to the sleeve and linked to one of the pulleys, a pin extending from the collar, and a bearing movably mounted in the sleeve and having at least two longitudinal grooves in the outside surface.

Kock, L.J.

1959-09-22T23:59:59.000Z

390

Quantum Mechanics and Closed Timelike Curves  

E-Print Network (OSTI)

General relativity allows solutions exhibiting closed timelike curves. Time travel generates paradoxes and quantum mechanics generalizations were proposed to solve those paradoxes. The implications of self-consistent interactions on acausal region of space-time are investigated. If the correspondence principle is true, then all generalizations of quantum mechanics on acausal manifolds are not renormalizable. Therefore quantum mechanics can only be defined on global hyperbolic manifolds and all general relativity solutions exhibiting time travel are unphysical.

Florin Moldoveanu

2007-04-23T23:59:59.000Z

391

Grooved impactor and inertial trap for sampling inhalable particulate matter. [Patents  

DOE Patents (OSTI)

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

Loo, B.W.

1982-02-23T23:59:59.000Z

392

Mechanical Design  

SciTech Connect

The particle beam of the SXR (soft x-ray) beam line in the LCLS (Linac Coherent Light Source) has a high intensity in order to penetrate through samples at the atomic level. However, the intensity is so high that many experiments fail because of severe damage. To correct this issue, attenuators are put into the beam line to reduce this intensity to a level suitable for experimentation. Attenuation is defined as 'the gradual loss in intensity of any flux through a medium' by [1]. It is found that Beryllium and Boron Carbide can survive the intensity of the beam. At very thin films, both of these materials work very well as filters for reducing the beam intensity. Using a total of 12 filters, the first 9 being made of Beryllium and the rest made of Boron Carbide, the beam's energy range of photons can be attenuated between 800 eV and 9000 eV. The design of the filters allows attenuation for different beam intensities so that experiments can obtain different intensities from the beam if desired. The step of attenuation varies, but is relative to the thickness of the filter as a power function of 2. A relationship for this is f(n) = x{sub 0}2{sup n} where n is the step of attenuation desired and x{sub 0} is the initial thickness of the material. To allow for this desired variation, a mechanism must be designed within the test chamber. This is visualized using a 3D computer aided design modeling tool known as Solid Edge.

2010-08-25T23:59:59.000Z

393

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

SciTech Connect

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

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

2011-03-01T23:59:59.000Z

394

THE EFFECT OF SULFUR ON METHANE PARTIAL OXIDATION AND REFORMING PROCESSES FOR LEAN NOX TRAP CATALYSIS  

Science Conference Proceedings (OSTI)

Lean NOx trap catalysis has demonstrated the ability to reduce NOx emissions from lean natural gas reciprocating engines by >90%. The technology operates in a cyclic fashion where NOx is trapped on the catalyst during lean operation and released and reduced to N2 under rich exhaust conditions; the rich cleansing operation of the cycle is referred to as "regeneration" since the catalyst is reactivated for more NOx trapping after NOx purge. Creating the rich exhaust conditions for regeneration can be accomplished by catalytic partial oxidation of methane in the exhaust system. Furthermore, catalytic reforming of partial oxidation exhaust can enable increased quantities of H2 which is an excellent reductant for lean NOx trap regeneration. It is critical to maintain clean and efficient partial oxidation and reforming processes to keep the lean NOx trap functioning properly and to reduce extra fuel consumption from the regeneration process. Although most exhaust constituents do not impede partial oxidation and reforming, some exhaust constituents may negatively affect the catalysts and result in loss of catalytic efficiency. Of particular concern are common catalyst poisons sulfur, zinc, and phosphorous. These poisons form in the exhaust through combustion of fuel and oil, and although they are present at low concentrations, they can accumulate to significant levels over the life of an engine system. In the work presented here, the effects of sulfur on the partial oxidation and reforming catalytic processes were studied to determine any durability limitations on the production of reductants for lean NOx trap catalyst regeneration.

Parks, II, James E [ORNL; Ponnusamy, Senthil [ORNL

2006-01-01T23:59:59.000Z

395

Variable residence time vortex combustor  

DOE Patents (OSTI)

A variable residence time vortex combustor including a primary combustion chamber for containing a combustion vortex, and a plurality of louvres peripherally disposed about the primary combustion chamber and longitudinally distributed along its primary axis. The louvres are inclined to impel air about the primary combustion chamber to cool its interior surfaces and to impel air inwardly to assist in driving the combustion vortex in a first rotational direction and to feed combustion in the primary combustion chamber. The vortex combustor also includes a second combustion chamber having a secondary zone and a narrowed waist region in the primary combustion chamber interconnecting the output of the primary combustion chamber with the secondary zone for passing only lower density particles and trapping higher density particles in the combustion vortex in the primary combustion chamber for substantial combustion.

Melconian, Jerry O. (76 Beaver Rd., Reading, MA 01867)

1987-01-01T23:59:59.000Z

396

Smolt Condition and Timing of Arrival at Lower Granite Reservoir, 1987 Annual Report.  

DOE Green Energy (OSTI)

This project monitored the daily passage of smolts during the 1988 spring outmigration at two migrant traps; one each on the Snake and Clearwater rivers. Due to the low runoff year, chinook salmon catch at the Snake River trap was very low. Steelhead trout catch was higher than normal, probably due to trap modifications and because the trap was moved to the east side of the river. Chinook salmon and steelhead trout catch at the Clearwater River trap was similar to 1987. Total cumulative recovery of PIT tagged fish at the three dams, with PIT tag detection systems was: 55% for chinook salmon, 73% for hatchery steelhead trout, and 75% for wild steelhead trout. Travel time through Lower Granite Reservoir for PIT tagged chinook salmon and steelhead trout, marked at the head of the reservoir, was affected by discharge. Statistical analysis showed that as discharge increased from 40 kcfs to 80 kcfs, chinook salmon travel time decreased three fold, and steelhead trout travel time decreased two fold. There was a statistical difference between estimates of travel time through Lower Granite Reservoir for PIT tagged and freeze branded steelhead trout, but not for chinook salmon. These differences may be related to the estimation techniques used for PIT tagged and freeze branded groups, rather than real differences in travel time. 10 figs, 15 tabs.

Buettner, Edwin W.; Nelson, V. Lance

1990-01-01T23:59:59.000Z

397

Physicalism versus quantum mechanics  

E-Print Network (OSTI)

Foundations of Quantum Mechanics. (Princeton UniversityMind, Matter, and Quantum Mechanics, (Springer, Berlin & NewMindful Universe: Quantum Mechanics and the Participating

Stapp, Henry P; Theoretical Physics Group; Physics Division

2009-01-01T23:59:59.000Z

398

A trapped single ion inside a Bose-Einstein condensate  

E-Print Network (OSTI)

laser light to the ions. We observe the dynamics of this effect by measuring the mean ion energy after having an initially hot ion immersed into the condensate for various interaction times, while at the same time monitoring the effects of the collisions...

Zipkes, Christoph

2011-10-11T23:59:59.000Z

399

Penning trap mass measurements on (99-109)$Cd with ISOLTRAP and implications on the rp process  

E-Print Network (OSTI)

Penning trap mass measurements on neutron-deficient Cd isotopes (99-109)Cd have been performed with the ISOLTRAP mass spectrometer at ISOLDE/CERN, all with relative mass uncertainties below 3*10^8. A new mass evaluation has been performed. The mass of 99Cd has been determined for the first time which extends the region of accurately known mass values towards the doubly magic nucleus 100Sn. The implication of the results on the reaction path of the rp process in stellar X-ray bursts is discussed. In particular, the uncertainty of the abundance and the overproduction created by the rp-process for the mass A = 99 is demonstrated by reducing the uncertainty of the proton-separation energy of 100In Sp(100In) by a factor of 2.5.

M. Breitenfeldt; G. Audi; D. Beck; K. Blaum; S. George; F. Herfurth; A. Herlert; A. Kellerbauer; H. -J. Kluge; M. Kowalska; D. Lunney; S. Naimi; D. Neidherr; H. Schatz; S. Schwarz; L. Schweikhard

2009-08-18T23:59:59.000Z

400

Digestion time  

NLE Websites -- All DOE Office Websites (Extended Search)

Digestion time Digestion time Name: Don Mancosh Location: N/A Country: N/A Date: N/A Question: I have always given the rule of thumb in class that material we eat is with us for about 24 hours before exiting the body. The question arises about the time value of liquids. Getting a big coke prior to a 3 hour drive generally means that there will be a stop along the way. Is there a generalization made about liquids in the body similar to the one for solid food? Replies: A physician would give a better answer, but I hazard this: the only liquids which people consume (deliberately) in significant quantities are water, ethyl alcohol and various oils. Water and alcohol are absorbed on a time scale of seconds to minutes through the mouth, stomach and digestive tract. The oils are huge molecules, so I'd guess like any other greasy food they get absorbed in the upper digestive tract. Some of them, perhaps the longest and most nonpolar, are not absorbed at all --- cf. the old-time remedy of mineral oil for constipation --- so there should be some average time-before-what's-left-is-excreted such as you're looking for, and my (wild) guess is that it would not differ substantially from that for food. You can define an average lifetime in the body for alcohol, since the natural level is zero. Rough guidelines are widespread in the context of drunk driving laws. But this is not really possible for water. One's body is normally full up to the brim with water, and there's no way for the body to distinguish between water molecules recently absorbed and molecules that've been moping around since the Beatles split up. Thus the water entering the toilet bowl after the pit stop is not in general the same water as was in the big coke. If you were to consider for water just the average time between drinking and peeing, it would seem to depend strongly on how well hydrated the body was before the drink, and how much was drunk. During sustained heavy exertion in the sun and dry air one can easily drink a pint of water an hour without peeing at all. On the other hand, if one is willing to drink enough water fast enough, so as to establish a high excess of body water one can pee 8 ounces 15 minutes or less after drinking 8 ounces.

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


401

Single Cell Mechanics BIOMATERIALS  

E-Print Network (OSTI)

Single Cell Mechanics BIOMATERIALS Our goal is to develop fundamental tools to measure the response of live cells to mechanical stimulation. The mechanisms by which cells convert mechanical forces evaluate the underlying mechanisms of cell mechanics. Objective Impact and Customers · Cancer, heart

402

Linear trap with three orthogonal quadrupole fields for dust charging experiments  

SciTech Connect

Investigations of charging processes on a single dust grain under controlled conditions in laboratory experiments are the unique way to understand the behavior of dust grains in complex plasma (in space, in laboratory, or in technological applications). An electrodynamic trap is often utilized for both holding a single grain and continuously measuring its charge-to-mass ratio. We propose a modified design of the linear quadrupole trap with the electrodes split into two parts; each of them being supplied by a designated source. The paper presents basic calculations and the results of the trap prototype tests. These tests have confirmed our expectations and have shown that the suggested solution is fully applicable for the dust charging experiments. The uncertainty of determination of the dust grain charge does not exceed 10{sup -3}. The main advantages of the suggested design in comparison with other traps used for dust investigations can be summarized as: The trap (i) is more opened, thus it is suitable for a simultaneous application of the ion and electron beams and UV source; (ii) facilitates investigations of dust grains in a broader range of parameters; and (iii) allows the grain to move along the axis in a controlled way.

Beranek, Martin; Nemecek, Zdenek; Safrankova, Jana; Jerab, Martin; Pavlu, Jiri [Charles University, Faculty of Mathematics and Physics, Prague (Czech Republic); Cermak, Ivo [CGC Instruments, Chemnitz (Germany)

2012-11-15T23:59:59.000Z

403

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

SciTech Connect

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

Knapp, D.

1994-11-02T23:59:59.000Z

404

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

DOE Patents (OSTI)

A particle trap to outer elongated conductor or sheath contact for gas-insulated transmission lines. The particle trap to outer sheath contact of the invention is applicable to gas-insulated transmission lines having either corrugated or non-corrugated outer sheaths. The contact of the invention includes an electrical contact disposed on a lever arm which in turn is rotatably disposed on the particle trap and biased in a direction to maintain contact between the electrical contact and the outer sheath.

Fischer, William H. (Pittsburgh, PA); Cookson, Alan H. (Pittsburgh, PA); Yoon, Kue H. (Pittsburgh, PA)

1984-04-10T23:59:59.000Z

405

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

DOE Patents (OSTI)

A non-binding particle trap to outer sheath contact for use in gas insulated transmission lines having a corrugated outer conductor. The non-binding feature of the contact according to the teachings of the invention is accomplished by having a lever arm rotatably attached to a particle trap by a pivot support axis disposed parallel to the direction of travel of the inner conductor/insulator/particle trap assembly.

Fischer, William H. (Pittsburgh, PA)

1984-04-24T23:59:59.000Z

406

The on-line charge breeding program at TRIUMF's Ion Trap For Atomic and Nuclear Science for precision mass measurements  

Science Conference Proceedings (OSTI)

TRIUMF's Ion Trap for Atomic and Nuclear science (TITAN) constitutes the only high precision mass measurement setup coupled to a rare isotope facility capable of increasing the charge state of short-lived nuclides prior to the actual mass determination in a Penning trap. Recent developments around TITAN's charge breeder, the electron beam ion trap, form the basis for several successful experiments on radioactive isotopes with half-lives as low as 65 ms and in charge states as high as 22+.

Simon, M. C.; Eberhardt, B.; Jang, F.; Luichtl, M.; Robertson, D.; Chaudhuri, A.; Delheij, P.; Grossheim, A.; Kwiatkowski, A. A.; Mane, E.; Pearson, M. R.; Schultz, B. E. [TRIUMF, Vancouver, British Columbia V6T 2A3 (Canada); Bale, J. C. [TRIUMF, Vancouver, British Columbia V6T 2A3 (Canada); Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6 (Canada); Chowdhury, U. [TRIUMF, Vancouver, British Columbia V6T 2A3 (Canada); Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba R3T 2N2 (Canada); Ettenauer, S.; Gallant, A. T.; Dilling, J. [TRIUMF, Vancouver, British Columbia V6T 2A3 (Canada); Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1 (Canada); Lennarz, A. [TRIUMF, Vancouver, British Columbia V6T 2A3 (Canada); Institut fuer Kernphysik, Westfaelische Wilhelms-Universitaet, D-48149 Muenster (Germany); Ma, T.; Andreoiu, C. [Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6 (Canada); and others

2012-02-15T23:59:59.000Z

407

Bohmian particle trajectories contradict quantum mechanics  

E-Print Network (OSTI)

The Bohmian interpretation of quantum mechanics adds particle trajectories to the wave function and ensures that the probability distribution of the particle positions agrees with quantum mechanics at any time. This is not sufficient to avoid contradictions with quantum mechanics. There are correlations between particle positions at different times which cannot be reproduced with real particle trajectories. A simple rearrangement of an experimental test of the Bell-CHSH inequality demonstrates this.

Michael Zirpel

2009-03-23T23:59:59.000Z

408

Electron and hole transport to trap groups at the ends of conjugated  

NLE Websites -- All DOE Office Websites (Extended Search)

and hole transport to trap groups at the ends of conjugated and hole transport to trap groups at the ends of conjugated polyfluorenes Sadayuki Asaoka, Norihiko Takeda, Tornokazu Lyoda, Andrew R. Cook and John R. Miller J. Am. Chem. Soc. 130, 11912-11920 (2008). [Find paper at ACS Publications] Abstract: Electrons and holes were injected selectively into poly-2,7-(9,9-dihexylfluorene) (pF) dissolved in a tetrahydrofuran (THF) and a 1,2-dichloroethane (DCE) solution, respectively, using pulse radiolysis. Transient absorption spectra of monoions of both signs revealed two bands attributable to formation of polarons, one in the visible region (pF+* at 580 nm, pF-* at 600 nm) and another in the near-IR region. Polyfluorenes (pF) were synthesized having anthraquinone (AQ) or naphtylimide (NI) end caps that trap electrons or di-p-tolylaminophenyl

409

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

Office of Science (SC) Website

Trapping the Light Fantastic Trapping the Light Fantastic Discovery & Innovation Stories of Discovery & Innovation Brief Science Highlights SBIR/STTR Highlights Contact Information Office of Science U.S. Department of Energy 1000 Independence Ave., SW Washington, DC 20585 P: (202) 586-5430 07.07.11 Trapping the Light Fantastic New solar cell design uses advanced optics and nanotechnology to maximize performance and minimize cost. Discovery moves from lab bench to initial commercial scale-up inside a year. Print Text Size: A A A Subscribe FeedbackShare Page Click to enlarge photo. Enlarge Photo A 3-D graphic showing Si wires, transparent polymer, light-scattering particles, anti-reflective coating and back-reflector Image courtesy of California Institute of Technology Schematic of Atwater team's silicon nanowire solar cell.

410

Ancient Lava Flows Trap CO2 for Long-Term Storage in Big Sky Injection |  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Ancient Lava Flows Trap CO2 for Long-Term Storage in Big Sky Ancient Lava Flows Trap CO2 for Long-Term Storage in Big Sky Injection Ancient Lava Flows Trap CO2 for Long-Term Storage in Big Sky Injection August 13, 2013 - 1:59pm Addthis Photo by J.D. Griggs, courtesy of U.S.Geological Survey Photo by J.D. Griggs, courtesy of U.S.Geological Survey For Additional Information To learn more about the carbon storage projects in which NETL is involved, please visit the NETL Carbon Storage website How can a prehistoric volcanic eruption help us reduce the amount of CO2 released into the atmosphere today? The answer is found in the basalt formations created by the lava - formations that can be used as sites for injecting carbon dioxide (CO2) captured from industrial sources in a process called carbon capture and storage (CCS).

411

Geek-Up[11.19.2010]: Molecular Stencils, GRETINA and Trapped Antimatter |  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Geek-Up[11.19.2010]: Molecular Stencils, GRETINA and Trapped Geek-Up[11.19.2010]: Molecular Stencils, GRETINA and Trapped Antimatter Geek-Up[11.19.2010]: Molecular Stencils, GRETINA and Trapped Antimatter November 19, 2010 - 5:16pm Addthis An optical micrograph of a polymer film that self-assembles into ordered nanoscale structures. | Photo Courtesy of Argonne National Laboratory An optical micrograph of a polymer film that self-assembles into ordered nanoscale structures. | Photo Courtesy of Argonne National Laboratory Niketa Kumar Niketa Kumar Public Affairs Specialist, Office of Public Affairs At Argonne National Laboratory, scientists have developed a technique that may lead to more efficient, lower cost solar energy technologies. Argonne nanoscientist Seth Darling and chemist Jeff Elam have engineered a method

412

Geek-Up[11.19.2010]: Molecular Stencils, GRETINA and Trapped Antimatter |  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Geek-Up[11.19.2010]: Molecular Stencils, GRETINA and Trapped Geek-Up[11.19.2010]: Molecular Stencils, GRETINA and Trapped Antimatter Geek-Up[11.19.2010]: Molecular Stencils, GRETINA and Trapped Antimatter November 19, 2010 - 5:16pm Addthis An optical micrograph of a polymer film that self-assembles into ordered nanoscale structures. | Photo Courtesy of Argonne National Laboratory An optical micrograph of a polymer film that self-assembles into ordered nanoscale structures. | Photo Courtesy of Argonne National Laboratory Niketa Kumar Niketa Kumar Public Affairs Specialist, Office of Public Affairs At Argonne National Laboratory, scientists have developed a technique that may lead to more efficient, lower cost solar energy technologies. Argonne nanoscientist Seth Darling and chemist Jeff Elam have engineered a method

413

Characterization of fluorescence collection optics integrated with a micro-fabricated surface electrode ion trap  

E-Print Network (OSTI)

One of the outstanding challenges for ion trap quantum information processing is to accurately detect the states of many ions in a scalable fashion. In the particular case of surface traps, geometric constraints make imaging perpendicular to the surface appealing for light collection at multiple locations with minimal cross-talk. In this report we describe an experiment integrating Diffractive Optic Elements (DOE's) with surface electrode traps, connected through in-vacuum multi-mode fibers. The square DOE's reported here were all designed with solid angle collection efficiencies of 3.58%; with all losses included a detection efficiency of 0.388% (1.02% excluding the PMT loss) was measured with a single Ca+ ion. The presence of the DOE had minimal effect on the stability of the ion, both in temporal variation of stray electric fields and in motional heating rates.

Clark, Craig R; Ellis, A R; Hunker, Jeff; Kemme, Shanalyn A; Maunz, Peter; Tabakov, Boyan; Tigges, Chris; Stick, Daniel L

2013-01-01T23:59:59.000Z

414

Characterization of fluorescence collection optics integrated with a micro-fabricated surface electrode ion trap  

E-Print Network (OSTI)

One of the outstanding challenges for ion trap quantum information processing is to accurately detect the states of many ions in a scalable fashion. In the particular case of surface traps, geometric constraints make imaging perpendicular to the surface appealing for light collection at multiple locations with minimal cross-talk. In this report we describe an experiment integrating Diffractive Optic Elements (DOE's) with surface electrode traps, connected through in-vacuum multi-mode fibers. The square DOE's reported here were all designed with solid angle collection efficiencies of 3.58%; with all losses included a detection efficiency of 0.388% (1.02% excluding the PMT loss) was measured with a single Ca+ ion. The presence of the DOE had minimal effect on the stability of the ion, both in temporal variation of stray electric fields and in motional heating rates.

Craig R. Clark; Chin-wen Chou; A. R. Ellis; Jeff Hunker; Shanalyn A. Kemme; Peter Maunz; Boyan Tabakov; Chris Tigges; Daniel L. Stick

2013-05-21T23:59:59.000Z

415

Enhanced Efficiency of Light-Trapping Nanoantenna Arrays for Thin Film Solar Cells  

E-Print Network (OSTI)

We suggest a novel concept of efficient light-trapping structures for thin-film solar cells based on arrays of planar nanoantennas operating far from plasmonic resonances. The operation principle of our structures relies on the excitation of chessboard-like collective modes of the nanoantenna arrays with the field localized between the neighboring metal elements. We demonstrated theoretically substantial enhancement of solar-cell short-circuit current by the designed light-trapping structure in the whole spectrum range of the solar-cell operation compared to conventional structures employing anti-reflecting coating. Our approach provides a general background for a design of different types of efficient broadband light-trapping structures for thin-film solar-cell technologically compatible with large-area thin-film fabrication techniques.

Simovski, Constantin R; Voroshilov, Pavel M; Guzhva, Michael E; Belov, Pavel A; Kivshar, Yuri S

2013-01-01T23:59:59.000Z

416

A microscopic model of electronic field noise heating in ion traps  

E-Print Network (OSTI)

Motional heating of ions in micro-fabricated traps is a challenge hindering experimental realization of large-scale quantum processing devices. Recently a series of measurements of the heating rates in surface-electrode ion traps characterized their frequency, distance, and temperature dependencies, but our understanding of the microscopic origin of this noise is still vague. In this work we develop a theoretical model for the electric field noise which is associated with a random distribution of adsorbed atoms on the trap electrode surface. By using first principle calculations of the fluctuating dipole moments of the adsorbed atoms we evaluate the distance, frequency and temperature dependence of the resulting electric field fluctuation spectrum.Our theory calculates the noise spectrum beyond the standard scenario of two-level fluctuators, by incorporating all the relevant vibrational states. The $1/f$ noise is shown to commence at roughly the frequency of the fundamental phonon transition rate and the $d^{...

Safavi-Naini, A; Weck, P; Sadeghpour, H R

2011-01-01T23:59:59.000Z

417

FISSION PRODUCT TRAPS FOR USE IN HIGH-TEMPERATURE GAS-COOLED GRAPHITE REACTORS  

SciTech Connect

A proposal is given of an approach to a fission-product trapping system which appears feasible on the basis of thermodynamic and other data available. Reactor and trapping conditions are outlined. The half-lives, fission yields, and volatility of the fission products of interest are described. To provide the most effective retention at elevated temperatures, two types of reagents are required: a highly electropositive metal that will not melt or appreciably vaporize and which will form stable non-volatile compounds with non-metallic or near non-metallic fission products; and a reagent to provide a highly electronegative element to form stable, non-volatile compounds with metallic fission products. Thermodynamic properties are included for compounds formed by reactions between the fission products and the trapping reagents. (B.O.G.)

Zumwalt, L.R.

1958-03-13T23:59:59.000Z

418

Electron Traps Detected in p-type GaAsN Using Deep Level Transient Spectroscopy  

DOE Green Energy (OSTI)

The GaAsN alloy can have a band gap as small as 1.0 eV when the nitrogen composition is about 2%. Indium can also be added to the alloy to increase lattice matching to GaAs and Ge. These properties are advantageous for developing a highly-efficient, multi-junction solar cell. However, poor GaAsN cell properties, such as low open-circuit voltage, have led to inadequate performance. Deep-level transient spectroscopy of p-type GaAsN has identified an electron trap having an activation energy near 0.2 eV and a trap density of at least 1016 cm-3. This trap level appears with the addition of small amounts of nitrogen to GaAs, which also corresponds to an increased drop in open-circuit voltage.

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

2005-01-01T23:59:59.000Z

419

Light Trapping for High Efficiency Heterojunction Crystalline Si Solar Cells: Preprint  

DOE Green Energy (OSTI)

Light trapping plays an important role to achieve high short circuit current density (Jsc) and high efficiency for amorphous/crystalline Si heterojunction solar cells. Si heterojunction uses hydrogenated amorphous Si for emitter and back contact. This structure of solar cell posses highest open circuit voltage of 0.747 V at one sun for c-Si based solar cells. It also suggests that over 25% record-high efficiency is possible with further improvement of Jsc. Light trapping has two important tasks. The first one is to reduce the surface reflectance of light to zero for the solar spectrum that Si has a response. The second one is to increase the effective absorption length to capture all the photon. For Si heterojunction solar cell, surface texturing, anti-reflectance indium tin oxides (ITO) layer at the front and back are the key area to improve the light trapping.

Wang, Q.; Xu, Y.; Iwaniczko, E.; Page, M.

2011-04-01T23:59:59.000Z

420

Ancient Lava Flows Trap CO2 for Long-Term Storage in Big Sky Injection |  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Ancient Lava Flows Trap CO2 for Long-Term Storage in Big Sky Ancient Lava Flows Trap CO2 for Long-Term Storage in Big Sky Injection Ancient Lava Flows Trap CO2 for Long-Term Storage in Big Sky Injection August 13, 2013 - 1:59pm Addthis Photo by J.D. Griggs, courtesy of U.S.Geological Survey Photo by J.D. Griggs, courtesy of U.S.Geological Survey For Additional Information To learn more about the carbon storage projects in which NETL is involved, please visit the NETL Carbon Storage website How can a prehistoric volcanic eruption help us reduce the amount of CO2 released into the atmosphere today? The answer is found in the basalt formations created by the lava - formations that can be used as sites for injecting carbon dioxide (CO2) captured from industrial sources in a process called carbon capture and storage (CCS).

Note: This page contains sample records for the topic "timing trapping mechanism" from the National Library of EnergyBeta (NLEBeta).
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421

Trapping and Transportation of Adult and Juvenile Salmon in the Lower Umatilla River in Northeast Oregon: Umatilla River Basin Trap and Haul Program, October 1994-September 1995.  

DOE Green Energy (OSTI)

Threemile Falls Dam (Threemile Dam), located near the town of Umatilla, is the major collection and counting point for adult salmonids returning to the Umatilla River. Returning salmon and steelhead were collected at Threemile Dam from August 26, 1994 to June 27, 1995. A total of 1,531 summer steelhead (Oncorhynchus mykiss); 688 adult, 236 jack, and 368 subjack fall chinook (O. tshawvtscha); 984 adult and 62 jack coho (O. kisutch) ; and 388 adult and 108 jack spring chinook (O. tshawvtscha) were collected. All fish were trapped at the east bank facility. Of the fish collected, 971 summer steelhead; 581 adult and 27 jack fall chinook; 500 adult and 22 jack coho; and 363 adult and 61 jack spring chinook were hauled upstream from Threemile Dam. There were also 373 summer steelhead; 12 adult, 186 jack and 317 subjack fall chinook; 379 adult and 32 jack coho; and 15 adult and one jack spring chinook released at Threemile Dam. In addition, 154 summer steelhead were hauled to Bonifer and Minthorn for brood. The Westland Canal facility, located near the town of Echo, is the major collection point for outmigrating juvenile salmonids and steelhead kelts. The facility operated for a total of 179 days between December 2, 1994 and July 19, 1995. During that period, fish were bypassed back to the river 137 days and were trapped 42 days. Three steelhead kelts and an estimated 1,560 pounds of juvenile fish were transported from the Westland Canal trap to the Umatilla River boat ramp at rivermile 0.5. Approximately 98% of the fish transported this year were salmonids. The Threemile Dam west bank juvenile bypass began operating March 25, 1995 and was closed on June 16, 1995. The juvenile trap was operated by Oregon Department of Fish and Wildlife research personnel from April 1, 1995 through the summer to monitor juvenile outmigration.

Zimmerman, Brian C.; Duke, Bill B.

1995-09-01T23:59:59.000Z

422

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

E-Print Network (OSTI)

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 with small faults can compartmentalize reservoirs leading to unreliable estimates of reserves. Measured values of capillary pressure were compared with estimated capillary pressure values from four correlation methods. Based on comparison of estimated pressure with measured pressure, Pittman's method gave the most reliable results for predicting capillary pressure and therefore the height of the oil column. However, all methods for predicting capillary pressure worked well for samples with porosities above 20% and permeabilities above 100 md. Hydrocarbon column heights were then determined from the capillary pressure values. The large sheared zone of the Cities Service Dincans1 (CD1) well, Toro Grande field, Jackson County, has a predicted trapping capacity of up to 1,961 ft of oil at 10,000 ft depth and 35% saturation of oil. Shearing is mostly at the hand specimen scale in the General Crude Kirby Lumber 2 (GCK2) well, East Sour Lake field, Hardin County, which has a maximum trapping capacity of 111 ft. From this study, it is then concluded that a homogenized sheared zone, formed from ductile deformation of sand and shale layers can form a trap to hydrocarbons. Sheared zones may be thick zones, on the order of feet, or smaller zones at microscopic or hand specimen scale. The larger the sheared zone is, the greater the trapping capacity of the fault.

Hintz, Jena Christine

2001-01-01T23:59:59.000Z

423

Further Evidence for Coastal Trapped Waves along the Peru Coast  

Science Conference Proceedings (OSTI)

Time series of coastal sea level during 1976–77, from 2°12?S to 17°S along the west coast of South America, show that low-frequency, ? < 0.25 cycles per day (cpd), fluctuations propagate poleward with the phase speed of baroclinic Kelvin waves (2–...

Richard D. Romea; Robert L. Smith

1983-08-01T23:59:59.000Z

424

Discovery of {sup 229}Rn and the Structure of the Heaviest Rn and Ra Isotopes from Penning-Trap Mass Measurements  

SciTech Connect

The masses of the neutron-rich radon isotopes {sup 223-229}Rn have been determined for the first time, using the ISOLTRAP setup at CERN ISOLDE. In addition, this experiment marks the first discovery of a new nuclide, {sup 229}Rn, by Penning-trap mass measurement. The new, high-accuracy data allow a fine examination of the mass surface, via the valence-nucleon interaction {delta}V{sub pn}. The results reveal intriguing behavior, possibly reflecting either a N=134 subshell closure or an octupolar deformation in this region.

Neidherr, D.; Boehm, Ch. [Institut fuer Physik, Johannes Gutenberg-Universitaet, 55099 Mainz (Germany); Audi, G.; Lunney, D.; Minaya-Ramirez, E.; Naimi, S. [CSNSM-IN2P3-CNRS, Universite de Paris Sud, Orsay (France); Beck, D.; Herfurth, F. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH Darmstadt, 64291 Darmstadt (Germany); Blaum, K.; George, S.; Kellerbauer, A. [Max-Planck-Institut fuer Kernphysik, 69117 Heidelberg (Germany); Breitenfeldt, M.; Rosenbusch, M.; Schweikhard, L. [Institut fuer Physik, Ernst-Moritz-Arndt-Universitaet, 17487 Greifswald (Germany); Cakirli, R. B. [Institut fuer Kernphysik der Universitaet zu Koeln, 50937 Koeln (Germany); Department of Physics, Istanbul University, Istanbul (Turkey); Casten, R. F. [Institut fuer Kernphysik der Universitaet zu Koeln, 50937 Koeln (Germany); Wright Nuclear Structure Laboratory, Yale University, New Haven, Connecticut 06520-8124 (United States); Herlert, A.; Kowalska, M. [Physics Department, CERN, 1211 Geneva 23 (Switzerland); Noah, E.; Penescu, L. [Accelerators and Beams Department, CERN, 1211 Geneva 23 (Switzerland)] (and others)

2009-03-20T23:59:59.000Z

425

Influence of trapping potentials on the phase diagram of bosonic atoms in optical lattices  

SciTech Connect

We study the effect of external trapping potentials on the phase diagram of bosonic atoms in optical lattices. We introduce a generalized Bose-Hubbard Hamiltonian that includes the structure of the energy levels of the trapping potential, and show that these levels are in general populated both at finite and zero temperature. We characterize the properties of the superfluid transition for this situation and compare them with those of the standard Bose-Hubbard description. We briefly discuss similar behaviors for fermionic systems.

Giampaolo, S.M.; Illuminati, F.; Mazzarella, G.; De Siena, S. [Dipartimento di Fisica 'E. R. Caianiello', Universita di Salerno, INFM UdR di Salerno, INFN Sezione di Napoli-Gruppo Collegato di Salerno, I-84081 Baronissi, SA (Italy)

2004-12-01T23:59:59.000Z

426

Influence of trapping potentials on the phase diagram of bosonic atoms in optical lattices  

E-Print Network (OSTI)

We study the effect of external trapping potentials on the phase diagram of bosonic atoms in optical lattices. We introduce a generalized Bose-Hubbard Hamiltonian that includes the structure of the energy levels of the trapping potential, and show that these levels are in general populated both at finite and zero temperature. We characterize the properties of the superfluid transition for this situation and compare them with those of the standard Bose-Hubbard description. We briefly discuss similar behaviors for fermionic systems.

S. M. Giampaolo; F. Illuminati; G. Mazzarella; S. De Siena

2004-03-04T23:59:59.000Z

427

Measurement of localized heating in the focus of an optical trap  

Science Conference Proceedings (OSTI)

Localized heating in the focus of an optical trap operating in water can result in a temperature rise of several kelvins. We present spatially resolved measurements of the refractive-index distribution induced by the localized heating produced in an optical trap and infer the temperature distribution. We have determined a peak temperature rise in water of 4 K in the focus of a 985-nm-wavelength 55-mW laser beam. The localized heating is directly proportional to power and the absorption coefficient. The temperature distribution is in excellent agreement with a model based on the heat equation. (c) 2000 Optical Society of America.

Celliers, Peter M. [Lawerence Livermore National Laboratory, P. O. Box 808, Livermore, California 94550 (United States); Conia, Jerome [Cell Robotics, Inc., 2715 Broadbent Parkway NE, Albuquerque, New Mexico 87107 (United States)

2000-07-01T23:59:59.000Z

428

Soliton propagation, reflection, and transmission in an inhomogeneous plasma with trapped electrons  

Science Conference Proceedings (OSTI)

Transmission and reflection of solitons from a semitransparent grid in an inhomogeneous plasma in the presence of trapped electrons is studied analytically. Conditions are obtained for the obliqueness of the propagation and the drift velocity of ions for the soliton transmission and reflection. Also, a transmission-reflection conservation law is derived. The contribution of trapped electrons to the solitons' propagation and their reflection and transmission is examined through energy, amplitude, and width of the solitons, in addition to the effect of temperature and drift of the ions.

Aziz, Farah; Malik, Hitendra K.; Stroth, Ulrich [Institut fuer Plasmaforschung, Universitaet Stuttgart, 70569 Stuttgart (Germany)

2011-04-15T23:59:59.000Z

429

Electric field noise above surfaces: a model for heating rate scaling law in ion traps  

E-Print Network (OSTI)

We present a model for the scaling laws of the electric field noise spectral density as a function of the distance, $d$, above a conducting surface. Our analytical approach models the patch potentials by introducing a correlation length, $\\zeta$, of the electric potential on the surface. The predicted scaling laws are in excellent agreement with two different classes of experiments (cold trapped ions and cantilevers), that span at least four orders of magnitude of $d$. According to this model, heating rate in miniature ion traps could be greatly reduced by proper material engineering.

Dubessy, Romain; Guidoni, Luca

2008-01-01T23:59:59.000Z

430

Electric field noise above surfaces: a model for heating rate scaling law in ion traps  

E-Print Network (OSTI)

We present a model for the scaling laws of the electric field noise spectral density as a function of the distance, $d$, above a conducting surface. Our analytical approach models the patch potentials by introducing a correlation length, $\\zeta$, of the electric potential on the surface. The predicted scaling laws are in excellent agreement with two different classes of experiments (cold trapped ions and cantilevers), that span at least four orders of magnitude of $d$. According to this model, heating rate in miniature ion traps could be greatly reduced by proper material engineering.

Romain Dubessy; Thomas Coudreau; Luca Guidoni

2008-12-17T23:59:59.000Z

431

Some effects of parallel energy propagation on the structure of dissipative trapped electron modes  

SciTech Connect

The limitation of ballooning by parallel energy propagation is investigated for the dissipative trapped electron mode, wherein the local energy influx is proportional to the poloidally dependent trapped particle fraction. For small energetic asymmetries [mg less than 2.5 ($Omega$/sub i/a/c/sub s/) (a/R/ sup $sup 3$/$sub 4$/] the structure along the field line is predominantly a phase shift, dictated by the condition that the asymmetric energy input be compensated by parallel energy flow. For large asymmetry, mode number, and parallel arc length, the phase and amplitude variations necessitate an integral equation treatment. (auth)

Sauthoff, N. R.

1976-01-01T23:59:59.000Z

432

Static and Dynamic Properties of Trapped Fermionic Tonks-Girardeau Gases  

E-Print Network (OSTI)

We investigate some exact static and dynamic properties of one-dimensional fermionic Tonks-Girardeau gases in tight de Broglie waveguides with attractive p-wave interactions induced by a Feshbach resonance. A closed form solution for the one-body density matrix for harmonic trapping is analyzed in terms of its natural orbitals, with the surprising result that for odd, but not for even, numbers of fermions the maximally occupied natural orbital coincides with the ground harmonic oscillator orbital and has the maximally allowed fermionic occupancy of unity. The exact dynamics of the trapped gas following turnoff of the p-wave interactions are explored.

M. D. Girardeau; E. M. Wright

2005-01-11T23:59:59.000Z

433

Trapping colloids near chemical stripes via critical Casimir forces  

E-Print Network (OSTI)

We study theoretically and experimentally the solvent-mediated critical Casimir force acting on colloidal particles immersed in a binary liquid mixture of water and 2,6-lutidine and close to substrates which are chemically patterned with periodically alternating stripes of antagonistic adsorption preferences. These patterns are experimentally realized via microcontact printing. Upon approaching the critical demixing point of the solvent, normal and lateral critical Casimir forces generate laterally confining effective potentials for the colloids. We analyze in detail the rich behavior of the spherical colloids close to such substrates. For all patterned substrates we investigated, our measurements of these effective potentials agree with the corresponding theoretical predictions. Since both the directions and the strengths of the critical Casimir forces can be tuned by minute temperature changes, this provides a new mechanism for controlling colloids as model systems, opening encouraging perspectives for applications.

Matthias Tröndle; Olga Zvyagolskaya; Andrea Gambassi; Dominik Vogt; Ludger Harnau; Clemens Bechinger; Siegfried Dietrich

2010-12-01T23:59:59.000Z

434

Time Brightness  

NLE Websites -- All DOE Office Websites (Extended Search)

Perlmutter, et al., in Thermonuclear Supernovae, NATO ASI, v. 486 (1997) Perlmutter, et al., in Thermonuclear Supernovae, NATO ASI, v. 486 (1997) Cosmology from . . . Time Brightness ... . . . 50-100 Fields Lunar Calendar Scheduled Follow-Up Imaging at Hubble, Cerro Tololo, WIYN, Isaac Newton Scheduled Follow-Up Spectroscopy at Keck Almost 1000 Galaxies per Field RESULT: ~24 Type Ia supernovae discovered while still brightening, at new moon Berkeley Lab Keck WIYN Cerro Tololo Isaac Newton Hubble Strategy We developed a strategy to guarantee a group of supernova discoveries on a certain date. Just after a new moon, we observe some 50 to 100 high-galactic lattitute fields-each containing almost a thousand high-redshift galaxies-in two nights on the Cerro Tololo 4-meter telescope with Tyson & Bernstein's wide-field camera. We return three weeks later to observe the same

435

Quantum mechanics needs no interpretation  

E-Print Network (OSTI)

Probabilistic description of results of measurements and its consequences for understanding quantum mechanics are discussed. It is shown that the basic mathematical structure of quantum mechanics like the probability amplitude, Born rule, probability density current, commutation relations, momentum operator, uncertainty relations, rules for including the scalar and vector potentials and existence of antiparticles can be derived from the definition of the mean values of the space coordinates and time. Equations of motion of quantum mechanics, the Klein-Gordon equation, Schroedinger equation and Dirac equation are obtained from requirement of the relativistic invariance of the theory. Limit case of localized probability densities leads to the Hamilton-Jacobi equation of classical mechanics. Many particle systems are also discussed.

L. Skala; V. Kapsa

2004-12-22T23:59:59.000Z

436

Student understanding of quantum mechanics  

Science Conference Proceedings (OSTI)

We investigate the difficulties of advanced undergraduate students toward the end of a full year upper-level quantum mechanics course with concepts related to quantum measurements and time development. Our analysis is based upon a test administered to 89 students from six universities and interviews with 9 students. Strikingly

Chandralekha Singh

2001-01-01T23:59:59.000Z

437

Characteristics of Desulfation Behavior for Pre-Sulfated Pt-BaO/CeO2 Lean NOx Trap Catalysts: The Role of the CeO2 Support  

SciTech Connect

The desulfation of pre-sulfated Pt-BaO/CeO2 lean NOx trap catalysts was investigated by H2 TPRX (temperature programmed reaction), in-situ TR-XRD (time-resolved X-ray diffraction) and in-situ S K-edge XANES (X-ray absorption near edge spectroscopy) techniques. Compared with Pt-BaO/Al2O3 materials, the reductive treatment in H2 for a CeO2 supported sample up to 1073 K hardly removes any sulfur species. However, the results of in-situ TR-XRD measurements demonstrate that the quantity of a BaS phase formed on Pt-BaO/CeO2 is much smaller than that on Pt-BaO/Al2O3, implying that the formation of BaS crystallites, which occurs during the reduction from sulfate (SO42-) to sulfide (S2-), is significantly suppressed in the CeO2-supported catalyst. As the desulfation temperature increases under reducing conditions (in H2), the in-situ S XANES spectra show that, compared with alumina-supported samples, the reduction temperature for sulfates (S6+) decreases by about 150 K. Concomitantly, the formation of sulfur species with lower oxidation states (S2- - S4+) is enhanced. The step jump of S XANES spectra before and after desulfation are very similar, implying that the amount of sulfur-containing species removed during the reductive treatment is negligible, in agreement with the results of H2 TPRX. These results suggest that H2S produced by the reduction of BaSO4 is readily re-adsorbed on the ceria support to form ceria-sulfur complexes (e.g. CeS2). The high affinity of ceria for H2S, combined with the ease of reducibility of the ceria support gives rise to various oxidation states of sulfur after high temperature H2 treatments. Thus, the results of this study clearly show that the ceria support strongly affects the overall desulfation mechanism. The intrinsic role of the ceria support during desulfation, and its effect on the overall NOx storage processes are discussed on the basis of the characterization results obtained here.

Kim, Do Heui; Kwak, Ja Hun; Szanyi, Janos; Wang, Xianqin; Li, Guosheng; Hanson, Jonathan C.; Peden, Charles HF

2009-12-17T23:59:59.000Z

438

Characteristics of Desulfation Behavior for Presulfated Pt-BaO/CeO2 Lean NOx Trap Catalyst: The Role of the CeO2 Support  

SciTech Connect

The desulfation of presulfated Pt-BaO/CeO{sub 2} lean NOx trap catalyst was investigated by H{sub 2} TPRX (temperature programmed reaction), in situ TR-XRD (time-resolved X-ray diffraction), and in situ S K-edge XANES (X-ray absorption near edge spectroscopy) techniques. Compared with Pt-BaO/Al{sub 2}O{sub 3} materials, a reductive treatment in H{sub 2} for the CeO{sub 2}-supported sample up to 1073 K removes, at most, only a very small amount of sulfur species. However, the results of in situ TR-XRD measurements demonstrate that the quantity of a BaS phase formed on Pt-BaO/CeO{sub 2} is much smaller than that on Pt-BaO/Al{sub 2}O{sub 3}, implying that the formation of BaS crystallites, which occurs during the reduction from sulfate (SO{sub 4}{sup 2-}) to sulfide (S{sup 2-}), is significantly suppressed in the CeO{sub 2}-supported catalyst. As the desulfation temperature increases under reducing conditions (in H{sub 2}), in situ S XANES spectra show that, compared with alumina-supported samples, the reduction temperature for sulfates (S{sup 6+}) decreases by about 150 K. Concomitantly, the formation of sulfur species with lower oxidation states (S{sup 2}-S{sup 4+}) is enhanced. The absolute intensities of S XANES spectra before and after desulfation are very similar, implying that the amount of sulfur-containing species removed during the reductive treatment is negligible, in agreement with the results of H{sub 2} TPRX. These results suggest that H{sub 2}S produced by the reduction of BaSO{sub 4} is readily readsorbed on the ceria support to form ceria-sulfur complexes (e.g., Ce{sub 2}O{sub 2}S). The high affinity of ceria for H{sub 2}S, combined with the ease of reducibility of the ceria support material gives rise to various oxidation states of sulfur after high-temperature H{sub 2} treatments. Thus, the results of this study clearly show that the ceria support strongly affects the overall desulfation mechanism. The intrinsic role of the ceria support during desulfation and its effect on the overall NOx storage processes are discussed on the basis of the characterization results obtained here.

Kim, D.; Kwak, J; Szanyi, J; Wang, X; Li, G; Hanson, J; Peden, C

2009-01-01T23:59:59.000Z

439

PHYSICAL REVIEW A 84, 022343 (2011) Coherence of a qubit stored in Zeeman levels of a single optically trapped atom  

E-Print Network (OSTI)

experimentally investigate the coherence properties of a qubit stored in the Zeeman substates of the 52 S1/2, F = 1 hyperfine ground level of a single optically trapped 87 Rb atom. Larmor precession of a single and the quantum repeater [1]. There, ground states of trapped atoms or ions are ideal candidates

Weinfurter, Harald

440

MechanicalTesting  

NLE Websites -- All DOE Office Websites (Extended Search)

structures, validation of encapsulant cure stress models, development of frac- ture mechanics tests for use in adhesion studies and understanding the failure mechanism of...

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441

Anomalous electron trapping by magnetic flux tubes and electric current vortices  

E-Print Network (OSTI)

Anomalous electron trapping by magnetic flux tubes and electric current vortices F. Bentosela, a current vortex in the plane. In this case the flux is zero; there is a pair of bound states for a weak with a nonhomogeneous magnetic field B , and investigate the corresponding Pauli Hamiltonian. We prove a lower bound

442

Lattice Trapping Barriers to Brittle Fracture N. Bernstein and D.W. Hess*  

E-Print Network (OSTI)

Lattice Trapping Barriers to Brittle Fracture N. Bernstein and D.W. Hess* Center for Computational HPCMPO CHSSI program, and D.W. H. the National Science Foundation. *Current address: Division, 4029 (1998). [18] N. Bernstein and D.W. Hess, in Multiscale Modeling of Materials--2000, edited by L. P

443

Dynamics of a single trapped ion inside a nonideal QED cavity at zero temperature  

SciTech Connect

We consider a system consisting of a single ion in a Paul trap coupled to a cavity electromagnetic field mode. We analyze the fidelity of a scheme for quantum swapping between vibrational and cavity field states, when the system is in contact with a reservoir at zero temperature.

Rangel, R.; Zagury, N. [Instituto de Fisica, Universidade Federal do Rio de Janeiro, Caixa Postal 68528, 21945-970 Rio de Janeiro (Brazil); Massoni, E. [Seccion Fisica, Departamento de Ciencias, Pontificia Universidad Catolica del Peru, Apartado 1761, Lima (Peru)

2004-02-01T23:59:59.000Z

444

Trapped Lee Waves Observed during PYREX by Constant Volume Balloons: Comparison with Meso-NH Simulations  

Science Conference Proceedings (OSTI)

The main objective of the present paper is the use of a constant volume balloon (CVB) as a tool to (i) study trapped lee waves and (ii) assess the forecasting capability of a nonhydrostatic numerical model. Then, CVB data obtained during the ...

Ernest N’Dri Koffi; Marc Georgelin; Bruno Benech; Evelyne Richard

2000-07-01T23:59:59.000Z

445

Model for hydrogen isotope backscattering, trapping and depth profiles in C and a-Si  

DOE Green Energy (OSTI)

A model of low energy hydrogen trapping and backscattering in carbon and a-silicon is described. Depth profiles are calculated and numerical results presented for various incident angular and energy distributions. The calculations yield a relation between depth profiles and the incident ion energy distribution. The use of this model for tokamak plasma diagnosis is discussed.

Cohen, S.A.; McCracken, G.M.

1979-03-01T23:59:59.000Z

446

Solubility trapping in formation water as dominant CO2 sink in natural gas fields  

E-Print Network (OSTI)

LETTERS Solubility trapping in formation water as dominant CO2 sink in natural gas fields Stuart M removal in nine natural gas fields in North America, China and Europe, using noble gas and carbon isotope tracers. The natural gas fields investigated in our study are dominated by a CO2 phase and provide

Haszeldine, Stuart

447

Trapping of Waves by a Constant Slope internal Interface in a Two-Layer Ocean  

Science Conference Proceedings (OSTI)

It is well known that “edge” and “continental shelf” waves can be trapped by a constant slope nearshore bottom; in a two-layer ocean of great constant depth, a constant slope internal interface, as well as the associated geostrophic current, can ...

Henri Lacombe

1982-04-01T23:59:59.000Z

448

Trapping Conformational Intermediate States in the Reaction Center Protein from Photosynthetic Bacteria  

E-Print Network (OSTI)

+, and reduced QB -, return to the ground state at cryogenic temperature in a conformation that allows a high yield of QB reduction. Thus, RCs frozen under illumination are found to be trapped above the ground 16 ( 3 meV. Thus, there are several conformational substates along the reaction coordinate

Gunner, Marilyn

449

Finite beta and resonant electron effects on trapped-electron instabilities  

SciTech Connect

Finite $beta$ (plasma pressure/magnetic pressure) and resonant electron effects on the dissipative trapped-electron instabilities are analyzed. These modifications are shown to have a strong stabilizing influence on the finite ion gyroradius and electron temperature gradient driven modes, respectively. For relevant tokamak parameters complete stabilization may be possible. Stability criteria for radially local and nonlocal cases are presented. (auth)

Tang, W.M.; Liu, C.S.; Rosenbluth, M.N.; Catto, P.J.; Callen, J.D.

1975-10-01T23:59:59.000Z

450

Steady Wind-driven Upwelling in the Presence of a Baroclinic Coastally Trapped Jet  

Science Conference Proceedings (OSTI)

The usual two-layer model for steady wind-driven upwelling along a uniform coastline is extended to incorporate the effects of an upper-layer jet trapped against the coast. The characteristic width of the jet is the internal deformation radius, ...

A. E. Hay; E. D. Kinsella

1986-08-01T23:59:59.000Z

451

Beauty is more attractive: Particle Production and Moduli trapping with Higher Dimensional Interaction  

E-Print Network (OSTI)

We study quantum effects on moduli dynamics arising from the particle production near the enhanced symmetry point (ESP). We paid special attention to the non-conventional interactions, which are suppressed by the cutoff scale of the effective action but the power of the field is larger. This kind of interaction is sometimes called the "higher dimensional" interaction. Considering the higher dimensional interaction, we find that the particle production is significant in a large area, which is even larger than the area that is expected from the conventional interaction. It is possible to find this possibility from the trivial adiabatic condition; however the quantitative estimation of the particle production and the trapping of the field in motion are far from trivial. In this paper we study the particle production and the trapping in detail, using both the analytical and the numerical calculations, to find a clear and intuitive result that supports trapping in a vast variety of theories. Our study shows that the trapping is possible by the non-conventional interaction that has been disregarded in previous works. Some phenomenological models of the particle physics will be mentioned to complement the discussion.

Seishi Enomoto; Satoshi Iida; Nobuhiro Maekawa; Tomohiro Matsuda

2013-10-17T23:59:59.000Z

452

Final Report - Advanced Ion Trap Mass Spectrometry Program - Oak Ridge National Laboratory - Sandia National Laboratory  

Science Conference Proceedings (OSTI)

This report covers the three main projects that collectively comprised the Advanced Ion Trap Mass Spectrometry Program. Chapter 1 describes the direct interrogation of individual particles by laser desorption within the ion trap mass spectrometer analyzer. The goals were (1) to develop an ''intelligent trigger'' capable of distinguishing particles of biological origin from those of nonbiological origin in the background and interferent particles and (2) to explore the capability for individual particle identification. Direct interrogation of particles by laser ablation and ion trap mass spectrometry was shown to have good promise for discriminating between particles of biological origin and those of nonbiological origin, although detailed protocols and operating conditions were not worked out. A library of more than 20,000 spectra of various types of biological particles has been assembled. Methods based on multivariate analysis and on neural networks were used to discriminate between particles of biological origin and those of nonbiological origin. It was possible to discriminate between at least some species of bacteria if mass spectra of several hundred similar particles were obtained. Chapter 2 addresses the development of a new ion trap mass analyzer geometry that offers the potential for a significant increase in ion storage capacity for a given set of analyzer operating conditions. This geometry may lead to the development of smaller, lower-power field-portable ion trap mass spectrometers while retaining laboratory-scale analytical performance. A novel ion trap mass spectrometer based on toroidal ion storage geometry has been developed. The analyzer geometry is based on the edge rotation of a quadrupolar ion trap cross section into the shape of a torus. Initial performance of this device was poor, however, due to the significant contribution of nonlinear fields introduced by the rotation of the symmetric ion-trapping geometry. These nonlinear resonances contributed to poor mass resolution and sensitivity and to erratic ion ejection behavior. To correct for these nonlinear effects, the geometry of the toroid ion trap analyzer has been modified to create an asymmetric torus, as first suggested by computer simulations that predicted significantly improved performance and unit mass resolution for this geometry. A reduced-sized version (one-fifth scale) has been fabricated but was not tested within the scope of this project. Chapter 3 describes groundbreaking progress toward the use of ion-ion chemistry to control the charge state of ions formed by the electrospray ionization process, which in turn enables precision analysis of whole proteins. In addition, this technique may offer the unique possibility of a priori identification of unknown biological material when employed with existing proteomics and genomic databases. Ion-ion chemistry within the ion trap was used to reduce the ions in highly charged states to states of +1 and +2 charges. Reduction in charge greatly simplifies identification of molecular weights of fragments from large biological molecules. This technique enables the analysis of whole proteins as biomarkers for the detection and identification of all three classes of biological weapons (bacteria, toxins, and viruses). In addition to methods development, tests were carried out with samples of tap water, local creek water, and soil (local red clay) spiked with melittin (bee venom), cholera toxin, and virus MS2. All three analytes were identified in tap water and soil; however, all three were problematic for detection in creek water at concentrations of 1 nM. More development of methods is needed.

Whitten, W.B.

2002-12-18T23:59:59.000Z

453

Observations of seasonal variations in atmospheric greenhouse trapping and its enhancement at high sea surface temperature  

SciTech Connect

The correlation between observed values of atmospheric greenhouse trapping and sea surface temperature is found to vary seasonally. Atmospheric greenhouse trapping is defined here as the difference between infrared emissions from the earth's surface and infrared emissions from the top of the atmosphere through cloudless skies. Infrared surface emissions are calculated from known sea surface temperatures; emissions from the top of the atmosphere are taken from direct satellite measurements. Atmospheric greenhouse trapping at the same sea surface temperature is greater in the winter than in the summer over temperate oceans. In subtropical latitudes, the opposite is true. At surface temperatures above approximately 298 K, atmospheric greenhouse trapping is found to increase even more rapidly from regions of lower sea surface temperature to regions of higher surface temperature than infrared surface emissions. The causes for this [open quotes]super[close quotes] greenhouse effect are explored, and four processes are found to contribute. Water vapor continuum absorption and thermodynamically controlled increases in water vapor concentration at constant relative humidity with increasing atmospheric temperature make significant contributions, but do not explain the entire super greenhouse effect. To explain the observations of atmospheric greenhouse trapping, the upper and middle troposphere, must be increasingly moist over the warmest sea surface temperatures, while the atmospheric temperature profile becomes increasingly unstable. Regions with these high sea surface temperatures are also increasingly subject to deep convection, which suggests that convection moistens the upper and middle troposphere in regions of convective activity relative to nonconvective regions, resulting in the super greenhouse effect. Dynamic processes, along with local thermodynamic processes, are required to explain the observed super greenhouse effect. 30 refs., 3 figs., 2 tabs.

Hallberg, R. (Univ. of Washington, Seattle (United States)); Inamdar, A.K. (Scripps Institution of Oceanography, La Jolla, CA (United States))

1993-05-01T23:59:59.000Z

454

A-21: Effect of Aging Time on Microstructure and Mechanical ...  

Science Conference Proceedings (OSTI)

... as Shielding Materials for Electromagnetic Interference and Radiation Shielding ... for Nuclear Power Plant Steam Generators during Cold-Working Process.

455

Negative capacitance in organic semiconductor devices: bipolar injection and charge recombination mechanism  

E-Print Network (OSTI)

We report negative capacitance at low frequencies in organic semiconductor based diodes and show that it appears only under bipolar injection conditions. We account quantitatively for this phenomenon by the recombination current due to electron-hole annihilation. Simple addition of the recombination current to the well established model of space charge limited current in the presence of traps, yields excellent fits to the experimentally measured admittance data. The dependence of the extracted characteristic recombination time on the bias voltage is indicative of a recombination process which is mediated by localized traps.