National Library of Energy BETA

Sample records for modes mode fraction

  1. Synchronization of Fractional-order Chaotic Systems with Gaussian fluctuation by Sliding Mode Control

    E-Print Network [OSTI]

    Yong Xu; Hua Wang

    2013-09-04

    This paper is devoted to the problem of synchronization between fractional-order chaotic systems with Gaussian fluctuation by the method of fractional-order sliding mode control. A fractional integral (FI) sliding surface is proposed for synchronizing the uncertain fractional-order system, and then the sliding mode control technique is carried out to realize the synchronization of the given systems. One theorem about sliding mode controller is presented to prove the proposed controller can make the system synchronize. As a case study, the presented method is applied to the fractional-order Chen-L\\"u system as the drive-response dynamical system. Simulation results show a good performance of the proposed control approach in synchronizing the chaotic systems in presence of Gaussian noise.

  2. Energy-dependence of skin-mode fraction in $E1$ excitations of neutron-rich nuclei

    E-Print Network [OSTI]

    H. Nakada; T. Inakura; H. Sawai

    2015-02-17

    We have extensively investigated characters of the low-energy $E1$ strengths in $N>Z$ nuclei, by analyzing the transition densities obtained by the HF+RPA calculations with several effective interactions. Crossover behavior has been confirmed, from the skin mode at low energy to the $pn$ mode at higher energy. Decomposing the $E1$ strengths into the skin-mode, $pn$-mode and interference fractions, we show that the ratio of the skin-mode strength to the full strength may be regarded as a generic function of the excitation energy, insensitive to nuclides and effective interactions, particularly beyond Ni.

  3. Received 21 Jan 2014 | Accepted 7 May 2014 | Published 6 Jun 2014 Proliferation of neutral modes in fractional

    E-Print Network [OSTI]

    Heiblum, Mordehai "Moty"

    of fractional statistics. DOI: 10.1038/ncomms5067 1 Braun Center for Submicron Research, Department of Condensed a sensitive heat sensor in a thinly polished substrate14, our group detected the presence of neutral modes

  4. Mode Analyses

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass map shines light on77 PAGEMission Mission Missionof EnergyJennings= a nMode Analyses

  5. Observable primordial vector modes

    E-Print Network [OSTI]

    Antony Lewis

    2004-06-04

    Primordial vector modes describe vortical fluid perturbations in the early universe. A regular solution exists with constant non-zero radiation vorticities on super-horizon scales. Baryons are tightly coupled to the photons, and the baryon velocity only decays by an order unity factor by recombination, leading to an observable CMB anisotropy signature via the Doppler effect. There is also a large B-mode CMB polarization signal, with significant power on scales larger than l~2000. This B-mode signature is distinct from that expected from tensor modes or gravitational lensing, and makes a primordial vector to scalar mode power ratio ~10^(-6) detectable. Future observations aimed at detecting large scale B-modes from gravitational waves will also be sensitive to regular vector modes at around this level.

  6. Mixed-mode cooling.

    E-Print Network [OSTI]

    Brager, Gail

    2006-01-01

    ASHRAE’s permission. Mixed-Mode Cooling Photo Credit: Paulnatural ventilation for cooling. Buildings typically had1950s of large-scale mechanical cooling, along with other

  7. Cluster Compatibility Mode

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

    the needed runtime environment. Users can also compile codes for CCM on Hopper. All compilers available to Hopper's native programming environment (Extreme Scalability Mode, ESM...

  8. Parafermionic zero modes in ultracold bosonic systems

    E-Print Network [OSTI]

    Mohammad F. Maghrebi; Sriram Ganeshan; David J. Clarke; Alexey V. Gorshkov; Jay D. Sau

    2015-04-20

    Exotic topologically protected zero modes with parafermionic statistics (also called fractionalized Majorana modes) have been proposed to emerge in devices fabricated from a fractional quantum Hall system and a superconductor. The fractionalized statistics of these modes takes them an important step beyond the simplest non-Abelian anyons, Majorana fermions. Building on recent advances towards the realization of fractional quantum Hall states of bosonic ultracold atoms, we propose a realization of parafermions in a system consisting of Bose-Einstein-condensate trenches within a bosonic fractional quantum Hall state. We show that parafermionic zero modes emerge at the endpoints of the trenches and give rise to a topologically protected degeneracy. We also discuss methods for preparing and detecting these modes.

  9. The electron geodesic acoustic mode

    SciTech Connect (OSTI)

    Chakrabarti, N. [Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Calcutta 700 064 (India); Guzdar, P. N. [Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742 (United States); Kaw, P. K. [Institute for Plasma Research Bhat, Gandhinagar 382428 (India)

    2012-09-15

    In this report, a novel new mode, named the electron geodesic acoustic mode, is presented. This mode can occur in toroidal plasmas like the conventional geodesic acoustic mode (GAM). The frequency of this new mode is much larger than that of the conventional GAM by a factor equal to the square root of the ion to electron mass ratio.

  10. Modes of perceiving and imagining 

    E-Print Network [OSTI]

    Nudds, Matthew

    2000-01-01

    We enjoy modes of sensory imagining corresponding to our five modes of perception - seeing, touching, hearing, smelling and tasting. An account of what constitutes these different modes of perseption needs also to explain ...

  11. Cluster Compatibility Mode

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room News PublicationsAuditsCluster Compatibility Mode Cluster Compatibility Mode Edison compute

  12. Cluster Compatibility Mode

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room News PublicationsAuditsCluster Compatibility Mode Cluster Compatibility Mode Edison

  13. Elemental Modes of Occurrence in an Illinois #6 Coal and Fractions Prepared by Physical Separation Techniques at a Coal Preparation Plant

    SciTech Connect (OSTI)

    Huggins, F.; Seidu, L; Shah, N; Huffman, G; Honaker, R; Kyger, J; Higgins, B; Robertson, J; Pal, S; Seehra, M

    2009-01-01

    In order to gain better insight into elemental partitioning between clean coal and tailings, modes of occurrence have been determined for a number of major and trace elements (S, K, Ca, V, Cr, Mn, Fe, Zn, As, Se, Pb) in an Illinois No.6 coal and fractions prepared by physical separation methods at a commercial coal preparation plant. Elemental modes of occurrence were largely determined directly by XAFS or Moessbauer spectroscopic methods because the concentrations of major minerals and wt.% ash were found to be highly correlated for this coal and derived fractions, rendering correlations between individual elements and minerals ambiguous for inferring elemental modes of occurrence. Of the major elements investigated, iron and potassium are shown to be entirely inorganic in occurrence. Most (90%) of the iron is present as pyrite, with minor fractions in the form of clays and sulfates. All potassium is present in illitic clays. Calcium in the original coal is 80-90% inorganic and is divided between calcite, gypsum, and illite, with the remainder of the calcium present as carboxyl-bound calcium. In the clean coal fraction, organically associated Ca exceeds 50% of the total calcium. This organically-associated form of Ca explains the poorer separation of Ca relative to both K and ash. Among the trace elements, V and Cr are predominantly inorganically associated with illite, but minor amounts (5-15% Cr, 20-30% V) of these elements are also organically associated. Estimates of the V and Cr contents of illite are 420 ppm and 630 ppm, respectively, whereas these elements average 20 and 8 ppm in the macerals. Arsenic in the coal is almost entirely associated with pyrite, with an average As content of about 150 ppm, but some As ({approx} 10%) is present as arsenate due to minor oxidation of the pyrite. The mode of occurrence of Zn, although entirely inorganic, is more complex than normally noted for Illinois basin coals; about 2/3 is present in sphalerite, with lesser amounts associated with illite and a third form yet to be conclusively identified. The non-sulfide zinc forms are removed predominantly by the first stage of separation (rotary breaker), whereas the sphalerite is removed by the second stage (heavy media). Germanium is the only trace element determined to have a predominantly organic association.

  14. Constraining primordial vector mode from B-mode polarization

    SciTech Connect (OSTI)

    Saga, Shohei; Ichiki, Kiyotomo; Shiraishi, Maresuke E-mail: maresuke.shiraishi@pd.infn.it

    2014-10-01

    The B-mode polarization spectrum of the Cosmic Microwave Background (CMB) may be the smoking gun of not only the primordial tensor mode but also of the primordial vector mode. If there exist nonzero vector-mode metric perturbations in the early Universe, they are known to be supported by anisotropic stress fluctuations of free-streaming particles such as neutrinos, and to create characteristic signatures on both the CMB temperature, E-mode, and B-mode polarization anisotropies. We place constraints on the properties of the primordial vector mode characterized by the vector-to-scalar ratio r{sub v} and the spectral index n{sub v} of the vector-shear power spectrum, from the Planck and BICEP2 B-mode data. We find that, for scale-invariant initial spectra, the ?CDM model including the vector mode fits the data better than the model including the tensor mode. The difference in ?{sup 2} between the vector and tensor models is ??{sup 2} = 3.294, because, on large scales the vector mode generates smaller temperature fluctuations than the tensor mode, which is preferred for the data. In contrast, the tensor mode can fit the data set equally well if we allow a significantly blue-tilted spectrum. We find that the best-fitting tensor mode has a large blue tilt and leads to an indistinct reionization bump on larger angular scales. The slightly red-tilted vector mode supported by the current data set can also create O(10{sup -22})-Gauss magnetic fields at cosmological recombination. Our constraints should motivate research that considers models of the early Universe that involve the vector mode.

  15. R-mode astronomy

    E-Print Network [OSTI]

    Kokkotas, Kostas D

    2015-01-01

    Next generation gravitational wave detectors will start taking data in the near future. Here we discuss the chances to detect the continuous emission from r-mode oscillations in compact stars and study which properties of compact stars we can infer from such novel data. In particular we show that the combination of the gravitational wave data with electromagnetic multi-messenger observations could give us detailed insight into compact star properties, ranging from precise mass-radius measurements to the determination of the equation of state and the phase structure of dense matter.

  16. Electron geodesic acoustic modes in electron temperature gradient mode turbulence

    SciTech Connect (OSTI)

    Anderson, Johan; Nordman, Hans [Department of Earth and Space Sciences, Chalmers University of Technology, SE-412 96 Goeteborg (Sweden); Singh, Raghvendra; Kaw, Predhiman [Institute for Plasma Research, Bhat, Gandhinagar, Gujarat 382428 (India)

    2012-08-15

    In this work, the first demonstration of an electron branch of the geodesic acoustic mode (el-GAM) driven by electron temperature gradient (ETG) modes is presented. The work is based on a fluid description of the ETG mode retaining non-adiabatic ions and the dispersion relation for el-GAMs driven nonlinearly by ETG modes is derived. A new saturation mechanism for ETG turbulence through the interaction with el-GAMs is found, resulting in a significantly enhanced ETG turbulence saturation level compared to the mixing length estimate.

  17. Multi-dimensional laser mode combs (mode hyper-combs)

    E-Print Network [OSTI]

    Schwartz, Alon

    2012-01-01

    Laser frequency combs, as most lasers, are one-dimensional. Here we present a realization of d-dimensional laser mode lattices (mode hyper-combs) with unique properties. They are constructed from regular 1-dimensional combs by multi-frequency modulation in active mode-locking (AML). The hyper-comb, with near neighbor mode interaction and noise functioning as temperature, is mapped to interacting magnetic spin-lattices in the spherical-model, which is one of the few statistical-mechanics systems soluble in all dimensions. The important result is that such systems have, in d>2 dimensions, a phase-transition to a global mode-phase-ordered hyper-comb. It changes the nature of AML lasers, giving ultimately short and robust pulses which can capture very broad frequency bandwidths. Additionally, the hyper-combs can serve as a rare physical realization of the spherical-model in any dimension.

  18. Thermal entanglement of bosonic modes

    E-Print Network [OSTI]

    M. Asoudeh

    2006-07-21

    We study the change of entanglement under general linear transformation of modes in a bosonic system and determine the conditions under which entanglement can be generated under such transformation. As an example we consider the thermal entanglement between the vibrational modes of two coupled oscillators and determine the temperature above which quantum correlations are destroyed by thermal fluctuations.

  19. Mode Competition in Dual-Mode Quantum Dots Semiconductor Microlaser

    E-Print Network [OSTI]

    Chusseau, Laurent; Viktorovitch, P; Letartre, Xavier

    2013-01-01

    This paper describes the modeling of quantum dots lasers with the aim of assessing the conditions for stable cw dual-mode operation when the mode separation lies in the THz range. Several possible models suited for InAs quantum dots in InP barriers are analytically evaluated, in particular quantum dots electrically coupled through a direct exchange of excitation by the wetting layer or quantum dots optically coupled through the homogeneous broadening of their optical gain. A stable dual-mode regime is shown possible in all cases when quantum dots are used as active layer whereas a gain medium of quantum well or bulk type inevitably leads to bistable behavior. The choice of a quantum dots gain medium perfectly matched the production of dual-mode lasers devoted to THz generation by photomixing.

  20. Mode Competition in Dual-Mode Quantum Dots Semiconductor Microlaser

    E-Print Network [OSTI]

    Laurent Chusseau; Fabrice Philippe; P. Viktorovitch; Xavier Letartre

    2013-03-07

    This paper describes the modeling of quantum dots lasers with the aim of assessing the conditions for stable cw dual-mode operation when the mode separation lies in the THz range. Several possible models suited for InAs quantum dots in InP barriers are analytically evaluated, in particular quantum dots electrically coupled through a direct exchange of excitation by the wetting layer or quantum dots optically coupled through the homogeneous broadening of their optical gain. A stable dual-mode regime is shown possible in all cases when quantum dots are used as active layer whereas a gain medium of quantum well or bulk type inevitably leads to bistable behavior. The choice of a quantum dots gain medium perfectly matched the production of dual-mode lasers devoted to THz generation by photomixing.

  1. Multi-mode radio frequency device

    DOE Patents [OSTI]

    Gilbert, Ronald W. (Morgan Hill, CA); Carrender, Curtis Lee (Morgan Hill, CA); Anderson, Gordon A. (Benton City, WA); Steele, Kerry D. (Kennewick, WA)

    2007-02-13

    A transponder device having multiple modes of operation, such as an active mode and a passive mode, wherein the modes of operation are selected in response to the strength of a received radio frequency signal. A communication system is also provided having a transceiver configured to transmit a radio frequency signal and to receive a responsive signal, and a transponder configured to operate in a plurality of modes and to activate modes of operation in response to the radio frequency signal. Ideally, each mode of operation is activated and deactivated independent of the other modes, although two or more modes may be concurrently operational.

  2. Decoherence of interacting Majorana modes

    E-Print Network [OSTI]

    H. T. Ng

    2015-07-31

    We study the decoherence of Majorana modes of a fermion chain, where the fermions interact with their nearest neighbours. We investigate the effect of dissipation and dephasing on the Majorana modes of a fermionic chain. The dissipative and dephasing noises induce the non-parity- and parity-preserving transitions between the eigenstates of the system, respectively. Therefore, these two types of noises lead to the different decoherence mechanisms. In each type of noise, we discuss the low- and high-frequency regimes to describe the different environments. We numerically calculate the dissipation and dephasing rates in the presence of long-range interactions. We find that the decoherence rate of interacting Majorana modes is different to that of non-interacting modes. We show the examples that the long-range interactions can reduce the decoherence rate. It is advantageous to the potential applications of quantum information processing.

  3. Evaluation of Some Blockcipher Modes of Operation

    E-Print Network [OSTI]

    Rogaway, Phillip

    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 4. CBC, CFB, and OFB Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 5. CTR; many are widely used. The modes under consideration are the encryption schemes ECB, CBC, CFB, OFB, CTR

  4. Scissors modes: The first overtone

    SciTech Connect (OSTI)

    Hatada, Keisuke [Instituto de Ciencia de Materiales de Aragon, CSIC-Universidad de Zaragoza, E-50009 Zaragoza (Spain); INFN Laboratori Nazionali di Frascati, c.p. 13, I-00044 Frascati (Italy); Hayakawa, Kuniko [INFN Laboratori Nazionali di Frascati, c.p. 13, I-00044 Frascati (Italy); Centro Fermi, Compendio Viminale, Roma I-00184 (Italy); Palumbo, Fabrizio [INFN Laboratori Nazionali di Frascati, c.p. 13, I-00044 Frascati (Italy)

    2011-07-15

    Scissors modes were predicted in the framework of the two-rotor model. This model has an intrinsic harmonic spectrum, so that the level above the scissors mode, the first overtone, has excitation energy twice that of the scissors mode. Because the latter is of the order of 3 MeV in the rare-earth region, the energy of the overtone is below threshold for nucleon emission, and its width should remain small enough for the overtone to be observable. We find that B(E2){up_arrow}{sub overtone}=(1/64 {theta}{sub 0}{sup 2})B(E2){up_arrow}{sub scissors}, where {theta}{sub 0} is the zero-point oscillation amplitude, which in the rare-earth region is of order 10{sup -1}.

  5. Continuous scanning mode for ptychography

    SciTech Connect (OSTI)

    Clark, Jesse N.; Huang, Xiaojing; Harder, Ross J.; Robinson, Ian K.

    2014-10-15

    We outline how ptychographic imaging can be performed without the need for discrete scan positions. Through an idealized experiment, we demonstrate how a discrete-position scan regime can be replaced with a continuously scanned one with suitable modification of the reconstruction scheme based on coherent modes. The impact of this is that acquisition times can be reduced, significantly aiding ptychographic imaging with x rays, electrons, or visible light.

  6. Continuous scanning mode for ptychography

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

    Clark, Jesse N.; Huang, Xiaojing; Harder, Ross J.; Robinson, Ian K.

    2014-01-01

    We outline how ptychographic imaging can be performed without the need for discrete scan positions. Through an idealized experiment, we demonstrate how a discrete-position scan regime can be replaced with a continuously scanned one with suitable modification of the reconstruction scheme based on coherent modes. The impact of this is that acquisition times can be reduced, significantly aiding ptychographic imaging with x rays, electrons, or visible light.

  7. Path planning during combustion mode switch

    DOE Patents [OSTI]

    Jiang, Li; Ravi, Nikhil

    2015-12-29

    Systems and methods are provided for transitioning between a first combustion mode and a second combustion mode in an internal combustion engine. A current operating point of the engine is identified and a target operating point for the internal combustion engine in the second combustion mode is also determined. A predefined optimized transition operating point is selected from memory. While operating in the first combustion mode, one or more engine actuator settings are adjusted to cause the operating point of the internal combustion engine to approach the selected optimized transition operating point. When the engine is operating at the selected optimized transition operating point, the combustion mode is switched from the first combustion mode to the second combustion mode. While operating in the second combustion mode, one or more engine actuator settings are adjusted to cause the operating point of the internal combustion to approach the target operating point.

  8. Interferometric detection of mode splitting for whispering gallery mode biosensors

    E-Print Network [OSTI]

    Knittel, Joachim; Lee, Kwan H; Bowen, Warwick P

    2010-01-01

    Sensors based on whispering gallery mode resonators can detect single nanoparticles and even single molecules. Particles attaching to the resonator induce a doublet in the transmission spectrum which provides a self-referenced detection signal. However, in practice this spectral feature is often obscured by the width of the resonance line which hides the doublet structure. This happens particularly in liquid environments that reduce the effective Q factor of the resonator. In this paper we demonstrate an interferometric set-up that allows the direct detection of the hidden doublet and thus provides a pathway for developing practical sensor applications.

  9. Optical waveguides having flattened high order modes

    DOE Patents [OSTI]

    Messerly, Michael Joseph; Beach, Raymond John; Heebner, John Edward; Dawson, Jay Walter; Pax, Paul Henry

    2014-08-05

    A deterministic methodology is provided for designing optical fibers that support field-flattened, ring-like higher order modes. The effective and group indices of its modes can be tuned by adjusting the widths of the guide's field-flattened layers or the average index of certain groups of layers. The approach outlined here provides a path to designing fibers that simultaneously have large mode areas and large separations between the propagation constants of its modes.

  10. Batch-mode Supervised Learning Linear regression

    E-Print Network [OSTI]

    Wehenkel, Louis

    Batch-mode Supervised Learning Linear regression Applied inductive learning - Lecture 3 Louis (& Pierre Geurts)AIA... (1/19) #12;Batch-mode Supervised Learning Linear regression Batch-mode Supervised Learning Linear regression Least mean square error solution Regularization and algorithmics Residual

  11. Hydrodynamic Lyapunov Modes in Translation Invariant Systems

    E-Print Network [OSTI]

    Hydrodynamic Lyapunov Modes in Translation Invariant Systems Jean­Pierre Eckmann and Omri Gat De modes in the slowly growing part of the Lyapunov spectrum, which are analogous to the hydrodynamic modes)]. The hydrodynamic Lyapunov vectors loose the typical random structure and exhibit instead the structure of weakly

  12. Hydrodynamic Lyapunov Modes in Translation Invariant Systems

    E-Print Network [OSTI]

    Eckmann, Jean-Pierre

    Hydrodynamic Lyapunov Modes in Translation Invariant Systems Jean­Pierre Eckmann and Omri Gat De modes in the slowly growing part of the Lyapunov spectrum, which are analogous to the hydrodynamic modes)]. The hydrodynamic Lyapunov vectors loose the typical random structure and exhibit instead the structure of weakly

  13. New Modes of Nuclear Excitations

    E-Print Network [OSTI]

    Nadia Tsoneva; Horst Lenske

    2013-10-01

    We present a theoretical approach based on density functional theory supplemented by a microscopic multi-phonon model which is applied for investigations of pygmy resonances and other excitations of different multipolarities in stable and exotic nuclei. The possible relation of low-energy modes to the properties of neutron or proton skins is systematically studied in isotonic and isotopic chains. The fine structure of nuclear electric and magnetic response functions is analyzed and compared to experimental data. Their relevance to nuclear astrophysics is discussed.

  14. Mode Meter - Energy Innovation Portal

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass map shines light on77 PAGEMission Mission Missionof EnergyJennings= a nMode

  15. Quantum Accelerator Modes from the Farey Tree

    E-Print Network [OSTI]

    A. Buchleitner; M. B. d'Arcy; S. Fishman; S. A. Gardiner; I. Guarneri; Z. -Y. Ma; L. Rebuzzini; G. S. Summy

    2006-06-09

    We show that mode-locking finds a purely quantum non-dissipative counterpart in atom-optical quantum accelerator modes. These modes are formed by exposing cold atoms to periodic kicks in the direction of the gravitational field. They are anchored to generalized Arnol'd tongues, parameter regions where driven nonlinear classical systems exhibit mode-locking. A hierarchy for the rational numbers known as the Farey Tree provides an ordering of the Arnol'd tongues and hence of experimentally observed accelerator modes.

  16. Batch-mode vs Online-mode Supervised Learning Motivations for Artificial Neural Networks

    E-Print Network [OSTI]

    Wehenkel, Louis

    Batch-mode vs Online-mode Supervised Learning Motivations for Artificial Neural Networks Linear ANN-mode vs Online-mode Supervised Learning Motivations for Artificial Neural Networks Linear ANN Models for Artificial Neural Networks Linear ANN Models Single neuron models Single layer models Nonlinear ANN Models

  17. Mirror Modes in the Heliosheath

    SciTech Connect (OSTI)

    Tsurutani, B. T. [Jet Propulsion Lab., Calif. Inst. Tech., Pasadena, CA (United States); Guarnieri, F. L. [UNIVAP, Sao Jose dos Campos, SP (Brazil); Echer, E. E. [INPE, Sao Jose dos Campos, SP (Brazil); Lakhina, G. S. [Indian Institute of Geomagnetism, Navi Mumbai (India); Verkhoglyadova, O. P. [CSPAR, Univ. Alabama, Huntsville, AL (United States)

    2011-01-04

    Mirror mode (MM) structures are identified in the Voyager 1 heliosheath magnetic field data. Their characteristics are: (1) quasiperiodic structures with a typical scale size of {approx}57 {rho}{sub p}(proton gyroradii), (2) little or no angular changes across the structures ({approx}3 deg. longitude and {approx}3 deg. latitude), and (3) a lack of sharp boundaries at the magnetic dip edges. It is proposed that the pickup of interstellar neutrals in the upstream region of the termination shock (TS) is the likely cause of MM instability during intervals when the IMF is nearly orthogonal to the solar wind flow direction. Concomitant (quasiperpendicular) shock compression of the MM structures at the TS and additional injection of pickup ions (PUIs) throughout the heliosheath will enhance MM growth.

  18. Program steering : improving adaptability and mode selection via dynamic analysis

    E-Print Network [OSTI]

    Lin, Lee Chuan

    2004-01-01

    A multi-mode software system contains several distinct modes of operation and a controller for deciding when to switch between modes. Even when developers rigorously test a multi-mode system before deployment, they cannot ...

  19. Mode propagation and attenuation in lined ducts

    E-Print Network [OSTI]

    BI, Wenping

    2014-01-01

    Optimal impedance for each mode is an important concept in an infinitely long duct lined with uniform absorption material. However it is not valid for finite length linings. This is because that the modes in lined ducts are not power-orthogonal; the total sound power is not equal to the sum of the sound power of each mode; cross-power terms may play important roles. In this paper, we study sound propagation and attenuation in an infinite rigid duct lined with a finite length of lining impedance. The lining impedance may be axial segments and circumferentially non-uniform. We propose two new physical quantities Kp and S to describe the self-overlap of the left eigenfunction and right eigenfunction of one mode and the normalized overlap between modes, respectively. The two new physical quantities describe totally the mode behaviors in lined ducts.

  20. Mode coupling in solar spicule oscillations

    E-Print Network [OSTI]

    Fazel, Zahra

    2015-01-01

    In a real medium which has oscillations, the perturbations can cause the energy transfer between different modes. The perturbation interpreted as an interaction between the modes is inferred as mode coupling. Mode coupling process in an inhomogeneous medium such as solar spicules may lead to the coupling of kink waves to local Alfven waves. This coupling occurs practically in any conditions when there is smooth variation in density in the radial direction. This process is seen as the decay of transverse kink waves in the medium. To study the damping of kink waves due to mode coupling, a 2.5-dimensional numerical simulation of the initial wave is considered in spicules. The initial perturbation is assumed to be in a plane perpendicular to the spicule axis. The considered kink wave is a standing wave which shows an exponential damping in the inhomogeneous layer after occurrence of the mode coupling.

  1. Mode-Wise Entanglement of Gaussian States

    E-Print Network [OSTI]

    Alonso Botero; Benni Reznik

    2003-01-16

    We address the decomposition of a multi-mode pure Gaussian state with respect to a bi-partite division of the modes. For any such division the state can always be expressed as a product state involving entangled two-mode squeezed states and single mode local states at each side. The character of entanglement of the state can therefore be understood modewise; that is, a given mode on one side is entangled with only one corresponding mode of the other, and therefore the total bi-partite entanglement is the sum of the modewise entanglement. This decomposition is generally not applicable to all mixed Gaussian states. However, the result can be extended to a special family of "isotropic" states, characterized by a phase space covariance matrix with a completely degenerate symplectic spectrum.

  2. Using X-mode L, R and O-mode reflectometry cutoffs to measure...

    Office of Scientific and Technical Information (OSTI)

    Using X-mode L, R and O-mode reflectometry cutoffs to measure scrape-off-layer density profiles for upgraded ORNL reflectometer on NSTX-U Citation Details In-Document Search Title:...

  3. New proofs for old modes Mark Wooding

    E-Print Network [OSTI]

    International Association for Cryptologic Research (IACR)

    the standard block cipher modes of operation: CBC, CFB, and OFB and analyse their security. We don't look in (full­width) CFB and OFB modes and that generalized counters encrypted using the block cipher (with Ciphertext feedback (CFB) en­ cryption 19 4.1 Description . . . . . . . . . 19 4.2 Sliding strings

  4. New proofs for old modes Mark Wooding

    E-Print Network [OSTI]

    International Association for Cryptologic Research (IACR)

    the standard block cipher modes of operation: CBC, CFB, and OFB and analyse their security. We don't look in (full-width) CFB and OFB modes and that generalized counters encrypted using the block cipher (with Ciphertext feedback (CFB) en- cryption 19 4.1 Description . . . . . . . . . 19 4.2 Sliding strings

  5. Normalizable fermion modes in a holographic superconductor

    E-Print Network [OSTI]

    Steven S. Gubser; Fabio D. Rocha; Pedro Talavera

    2009-11-18

    We consider fermions in a zero-temperature superconducting anti-de Sitter domain wall solution and find continuous bands of normal modes. These bands can be either partially filled or totally empty and gapped. We present a semi-classical argument which approximately captures the main features of the normal mode spectrum.

  6. Spatial mode properties of plasmon assisted transmission

    E-Print Network [OSTI]

    Xi-Feng Ren; Guo-Ping Guo; Yun-Feng Huang; Zhi-Wei Wang; Guang-Can Guo

    2006-09-11

    Orbital angular momentum of photons is explored to study the spatial mode properties of plasmon assisted transmission process. We found that photons carrying different orbital angular momentums have different transmission efficiencies, while the coherence between these spatial modes can be preserved.

  7. CRITERION DELINEATING THE MODE OF HEADCUT MIGRATION

    E-Print Network [OSTI]

    Julien, Pierre Y.

    CRITERION DELINEATING THE MODE OF HEADCUT MIGRATION By O. R. Stein,l Associate Member, ASCE, and P- tating headcutsthat tend to flatten as they migrate; and (2) stepped headcutsthat tend to retain nearly detachmentpotentialimmediatelyupstreamanddownstreamofthe headcutisused to delineate these modes of migration. The delineatingparameter is the ratio

  8. Mode suppression means for gyrotron cavities

    DOE Patents [OSTI]

    Chodorow, Marvin (Stanford, CA); Symons, Robert S. (Los Altos, CA)

    1983-08-09

    In a gyrotron electron tube of the gyro-klystron or gyro-monotron type, having a cavity supporting an electromagnetic mode with circular electric field, spurious resonances can occur in modes having noncircular electric field. These spurious resonances are damped and their frequencies shifted by a circular groove in the cavity parallel to the electric field.

  9. Multiple Oscillatory Modes of the Argentine Basin. Part II: The Spectral Origin of Basin Modes

    E-Print Network [OSTI]

    Weijer, Wilbert

    Multiple Oscillatory Modes of the Argentine Basin. Part II: The Spectral Origin of Basin Modes et Approches Numériques, Paris, France SARAH T. GILLE Scripps Institution of Oceanography, La Jolla In this paper the spectrum of barotropic basin modes of the Argentine Basin is shown to be connected

  10. Sliding mode control of quantum systems

    E-Print Network [OSTI]

    Daoyi Dong; Ian R. Petersen

    2009-10-31

    This paper proposes a new robust control method for quantum systems with uncertainties involving sliding mode control (SMC). Sliding mode control is a widely used approach in classical control theory and industrial applications. We show that SMC is also a useful method for robust control of quantum systems. In this paper, we define two specific classes of sliding modes (i.e., eigenstates and state subspaces) and propose two novel methods combining unitary control and periodic projective measurements for the design of quantum sliding mode control systems. Two examples including a two-level system and a three-level system are presented to demonstrate the proposed SMC method. One of main features of the proposed method is that the designed control laws can guarantee desired control performance in the presence of uncertainties in the system Hamiltonian. This sliding mode control approach provides a useful control theoretic tool for robust quantum information processing with uncertainties.

  11. Topological modes driven by Lyapunov control

    E-Print Network [OSTI]

    Z. C. Shi; X. L. Zhao; X. X. Yi

    2014-11-20

    By Lyapunov control, we present a proposal to drive quasiparticles into a topological mode in quantum systems described by quadratic Hamiltonian. The merit of this control strategy is that only manipulation of the boundary sites are required, and the proposal works for both Fermi and Bose systems. We take the Kitaev's chain as an illustration for Fermi system and show that by manipulating the chemical potential of the boundary sites, we can steer an arbitrary excitation mode into the Majorana zero mode. For Bose system, taking the noninteracting Su-Schrieffer-Heeger (SSH) model as an example, we illustrate how to drive the system into the edge mode, i.e., the mode localized at the boundary sites. Finally, we explore the possibility to replace the continuous control field by square wave pulses.

  12. Guiding Center Equations for Ideal Magnetohydrodynamic Modes

    SciTech Connect (OSTI)

    Roscoe B. White

    2013-02-21

    Guiding center simulations are routinely used for the discovery of mode-particle resonances in tokamaks, for both resistive and ideal instabilities and to find modifications of particle distributions caused by a given spectrum of modes, including large scale avalanches during events with a number of large amplitude modes. One of the most fundamental properties of ideal magnetohydrodynamics is the condition that plasma motion cannot change magnetic topology. The conventional representation of ideal magnetohydrodynamic modes by perturbing a toroidal equilibrium field through ?~B = ? X (? X B) however perturbs the magnetic topology, introducing extraneous magnetic islands in the field. A proper treatment of an ideal perturbation involves a full Lagrangian displacement of the field due to the perturbation and conserves magnetic topology as it should. In order to examine the effect of ideal magnetohydrodynamic modes on particle trajectories the guiding center equations should include a correct Lagrangian treatment. Guiding center equations for an ideal displacement ? are derived which perserve the magnetic topology and are used to examine mode particle resonances in toroidal confinement devices. These simulations are compared to others which are identical in all respects except that they use the linear representation for the field. Unlike the case for the magnetic field, the use of the linear field perturbation in the guiding center equations does not result in extraneous mode particle resonances.

  13. Guiding center equations for ideal magnetohydrodynamic modes

    SciTech Connect (OSTI)

    White, R. B. [Plasma Physics Laboratory, Princeton University, P.O. Box 451, Princeton, New Jersey 08543 (United States)

    2013-04-15

    Guiding center simulations are routinely used for the discovery of mode-particle resonances in tokamaks, for both resistive and ideal instabilities and to find modifications of particle distributions caused by a given spectrum of modes, including large scale avalanches during events with a number of large amplitude modes. One of the most fundamental properties of ideal magnetohydrodynamics is the condition that plasma motion cannot change magnetic topology. The conventional representation of ideal magnetohydrodynamic modes by perturbing a toroidal equilibrium field through {delta}B-vector={nabla} Multiplication-Sign ({xi}-vector Multiplication-Sign B-vector), however, perturbs the magnetic topology, introducing extraneous magnetic islands in the field. A proper treatment of an ideal perturbation involves a full Lagrangian displacement of the field due to the perturbation and conserves magnetic topology as it should. In order to examine the effect of ideal magnetohydrodynamic modes on particle trajectories, the guiding center equations should include a correct Lagrangian treatment. Guiding center equations for an ideal displacement {xi}-vector are derived which preserve the magnetic topology and are used to examine mode particle resonances in toroidal confinement devices. These simulations are compared to others which are identical in all respects except that they use the linear representation for the field. Unlike the case for the magnetic field, the use of the linear field perturbation in the guiding center equations does not result in extraneous mode particle resonances.

  14. ToF-SIMS Depth Profiling Of Insulating Samples, Interlaced Mode Or Non-interlaced Mode?

    SciTech Connect (OSTI)

    Wang, Zhaoying; Jin, Ke; Zhang, Yanwen; Wang, Fuyi; Zhu, Zihua

    2014-11-01

    Dual beam depth profiling strategy has been widely adopted in ToF-SIMS depth profiling, in which two basic operation modes, interlaced mode and non-interlaced mode, are commonly used. Generally, interlaced mode is recommended for conductive or semi-conductive samples, whereas non-interlaced mode is recommended for insulating samples, where charge compensation can be an issue. Recent publications, however, show that the interlaced mode can be used effectively for glass depth profiling, despite the fact that glass is an insulator. In this study, we provide a simple guide for choosing between interlaced mode and non-interlaced mode for insulator depth profiling. Two representative cases are presented: (1) depth profiling of a leached glass sample, and (2) depth profiling of a single crystal MgO sample. In brief, the interlaced mode should be attempted first, because (1) it may provide reasonable-quality data, and (2) it is time-saving for most cases, and (3) it introduces low H/C/O background. If data quality is the top priority and measurement time is flexible, non-interlaced mode is recommended because interlaced mode may suffer from low signal intensity and poor mass resolution. A big challenge is tracking trace H/C/O in a highly insulating sample (e.g., MgO), because non-interlaced mode may introduce strong H/C/O background but interlaced mode may suffer from low signal intensity. Meanwhile, a C or Au coating is found to be very effective to improve the signal intensity. Surprisingly, the best analyzing location is not on the C or Au coating, but at the edge (outside) of the coating.

  15. RANDOM COEFFICIENT H MODE CONFINEMENT SCALINGS

    E-Print Network [OSTI]

    ;nement time for most other machines, we are e#11;ectively penalising ASDEX. This small penalty may device scalings are more uniform and closer to standard L mode con#12;nement scaling. To model

  16. Creation mechanism of quantum accelerator modes

    E-Print Network [OSTI]

    Summy, G. S.

    We investigate the creation mechanism of quantum accelerator modes which are attributed to the existence of the stability islands in an underlying pseudoclassical phase space of the quantum delta-kicked accelerator. Quantum ...

  17. Temperature compensated two-mode fiber interferometer 

    E-Print Network [OSTI]

    Doma, Jagdish Ramchandra

    1993-01-01

    In this thesis we propose an innovative approach of designing and implementing a temperature compensated two-mode optical fiber interferometer in a control system of stabilizing the wavelength of a laser. We give the procedure for designing...

  18. Switched-Mode Power Converter Programmable

    E-Print Network [OSTI]

    Switched-Mode Power Converter Programmable compensator Identification & design Vref DPWM vout digital controller design for switching power converters. Starting from an experimentally identified Digital Controller Design for Switching Converters Abstract--This paper presents an approach to automated

  19. Single mode pulsed dye laser oscillator

    DOE Patents [OSTI]

    Hackel, Richard P. (Livermore, CA)

    1992-01-01

    A single mode pulsed dye laser oscillator is disclosed. The dye laser oscillator provides for improved power efficiency by reducing the physical dimensions of the overall laser cavity, which improves frequency selection capability.

  20. Failure modes in surface micromachined microelectromechanical actuators

    SciTech Connect (OSTI)

    Miller, S.L.; Rodgers, M.S.; LaVigne, G.; Sniegowski, J.J.; Clews, P.; Tanner, D.M.; Peterson, K.A.

    1998-03-01

    In order for the rapidly emerging field of MicroElectroMechanical Systems (MEMS) to meet its extraordinary expectations regarding commercial impact, issues pertaining to how they fail must be understood. The authors identify failure modes common to a broad range of MEMS actuators, including adhesion (stiction) and friction induced failures caused by improper operational methods, mechanical instabilities, and electrical instabilities. Demonstrated methods to mitigate these failure modes include implementing optimized designs, model based operational methods, and chemical surface treatments.

  1. Particle Distribution Modification by Low Amplitude Modes

    SciTech Connect (OSTI)

    White, R. B.; Gorelenkov, N.; Heidbrink, W. W.; Van Zeeland, M. A.

    2009-08-28

    Modification of a high energy particle distribution by a spectrum of low amplitude modes is investigated using a guiding center code. Only through resonance are modes effective in modifying the distribution. Diagnostics are used to illustrate the mode-particle interaction and to find which effects are relevant in producing significant resonance, including kinetic Poincare plots and plots showing those orbits with time averaged mode-particle energy transfer. Effects of pitch angle scattering and drag are studied, as well as plasma rotation and time dependence of the equilibrium and mode frequencies. A specific example of changes observed in a DIII-D deuterium beam distribution in the presence of low amplitude experimentally validated Toroidal Alfven (TAE) eigenmodes and Reversed Shear Alfven (RSAE) eigenmodes is examined in detail. Comparison with experimental data shows that multiple low amplitude modes can account for significant modification of high energy beam particle distributions. It is found that there is a stochastic threshold for beam profile modification, and that the experimental amplitudes are only slightly above this threshold.

  2. Forecasting Turbulent Modes with Nonparametric Diffusion Models

    E-Print Network [OSTI]

    Tyrus Berry; John Harlim

    2015-01-27

    This paper presents a nonparametric diffusion modeling approach for forecasting partially observed noisy turbulent modes. The proposed forecast model uses a basis of smooth functions (constructed with the diffusion maps algorithm) to represent probability densities, so that the forecast model becomes a linear map in this basis. We estimate this linear map by exploiting a previously established rigorous connection between the discrete time shift map and the semi-group solution associated to the backward Kolmogorov equation. In order to smooth the noisy data, we apply diffusion maps to a delay embedding of the noisy data, which also helps to account for the interactions between the observed and unobserved modes. We show that this delay embedding biases the geometry of the data in a way which extracts the most predictable component of the dynamics. The resulting model approximates the semigroup solutions of the generator of the underlying dynamics in the limit of large data and in the observation noise limit. We will show numerical examples on a wide-range of well-studied turbulent modes, including the Fourier modes of the energy conserving Truncated Burgers-Hopf (TBH) model, the Lorenz-96 model in weakly chaotic to fully turbulent regimes, and the barotropic modes of a quasi-geostrophic model with baroclinic instabilities. In these examples, forecasting skills of the nonparametric diffusion model are compared to a wide-range of stochastic parametric modeling approaches, which account for the nonlinear interactions between the observed and unobserved modes with white and colored noises.

  3. Edge-localized-modes in tokamaks

    SciTech Connect (OSTI)

    Leonard, A. W.

    2014-09-15

    Edge-localized-modes (ELMs) are a ubiquitous feature of H-mode in tokamaks. When gradients in the H-mode transport barrier grow to exceed the MHD stability limit the ELM instability grows explosively, rapidly transporting energy and particles onto open field lines and material surfaces. Though ELMs provide additional particle and impurity transport through the H-mode transport barrier, enabling steady operation, the resulting heat flux transients to plasma facing surfaces project to large amplitude in future low collisionality burning plasma tokamaks. Measurements of the ELM heat flux deposition onto material surfaces in the divertor and main chamber indicate significant broadening compared to inter-ELM heat flux, with a timescale for energy deposition that is consistent with sonic ion flow and numerical simulation. Comprehensive ELM simulation is highlighting the important physics processes of ELM transport including parallel transport due to magnetic reconnection and turbulence resulting from collapse of the H-mode transport barrier. Encouraging prospects for ELM control and/or suppression in future tokamaks include intrinsic modes of ELM free operation, ELM triggering with frequent small pellet injection and the application of 3D magnetic fields.

  4. Lyapunov Modes for a Nonequilibrium System with a Heat Flux

    E-Print Network [OSTI]

    Tooru Taniguchi; Gary P. Morriss

    2006-11-23

    We present the first numerical observation of Lyapunov modes (mode structure of Lyapunov vectors) in a system maintained in a nonequilibrium steady state. The modes show some similarities and some differences when compared with the results for equilibrium systems. The breaking of energy conservation removes a zero exponent and introduces a new mode. The transverse modes are only weakly altered but there are systematic changes to the longitudinal and momentum dependent modes.

  5. Mode Initialization for On-line Estimation of Power System Electromechanical Modes

    SciTech Connect (OSTI)

    Zhou, Ning; Trudnowski, Daniel; Pierre, John W.

    2009-03-18

    Measurement-based mode estimation methods are utilized to estimate electromechanical modes of a power system using phasor measurement units (PMU) data. These methods need to extract a certain amount of information before they can give useable mode estimation. Traditionally, the information is gathered solely from measurement data. Priori mode information from other resources (e.g. model eigenvalue analysis, engineering knowledge) are not fully utilized. For real time application, this means that mode estimation takes time to converge. By adding a mode regularization term in the objective function, this paper proposes a mode initialization method to include priori mode information in a regularized robust recursive least squares (R3LS) algorithm for on-line mode estimation. The proposed method is tested using a simple model, a 17 machine model and is shown to be able to shorten the convergence period of the R3LS algorithm. The proposed method is also applied on the measurement data recorded right before a major power outage in the western North American Grid on August 10th 1996 to show its potential applica-tion in detecting an approaching small signal stability problem.

  6. Sequestering Uranium from Seawater: Binding Strength and Modes...

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

    Sequestering Uranium from Seawater: Binding Strength and Modes of Uranyl Complexes with Glutarimidedioxime Sequestering Uranium from Seawater: Binding Strength and Modes of Uranyl...

  7. Fact #602: December 21, 2009 Freight Statistics by Mode, 2007...

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

    2: December 21, 2009 Freight Statistics by Mode, 2007 Commodity Flow Survey Fact 602: December 21, 2009 Freight Statistics by Mode, 2007 Commodity Flow Survey Results from the...

  8. Mixed-mode diesel HCCI with External Mixture Formation: Preliminary...

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

    Mixed-mode diesel HCCI with External Mixture Formation: Preliminary Results Mixed-mode diesel HCCI with External Mixture Formation: Preliminary Results 2003 DEER Conference...

  9. Variable Valve Actuation for Advanced Mode Diesel Combustion...

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

    Valve Actuation for Advanced Mode Diesel Combustion Variable Valve Actuation for Advanced Mode Diesel Combustion Presentation from the U.S. DOE Office of Vehicle Technologies...

  10. Unregulated Emissions from High-Efficiency Clean Combustion Modes...

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

    Unregulated Emissions from High-Efficiency Clean Combustion Modes - ORNL-FEERC Unregulated Emissions from High-Efficiency Clean Combustion Modes - ORNL-FEERC Poster presentation at...

  11. Unbalanced edge modes and topological phase transition in gated...

    Office of Scientific and Technical Information (OSTI)

    Unbalanced edge modes and topological phase transition in gated trilayer graphene Prev Next Title: Unbalanced edge modes and topological phase transition in gated trilayer...

  12. Perturbations of Weakly Resonant Power System Electromechanical Modes

    E-Print Network [OSTI]

    1 Perturbations of Weakly Resonant Power System Electromechanical Modes Ian Dobson, Senior Member. The possible perturbations are illustrated with interactions between electromechanical modes in a 4 bus power

  13. Modeling Combustion Control for High Power Diesel Mode Switching...

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

    Combustion Control for High Power Diesel Mode Switching Modeling Combustion Control for High Power Diesel Mode Switching Poster presentation given at the 16th Directions in...

  14. Growth Mode and Substrate Symmetry Dependent Strain in Epitaxial...

    Office of Scientific and Technical Information (OSTI)

    Growth Mode and Substrate Symmetry Dependent Strain in Epitaxial Graphene. Citation Details In-Document Search Title: Growth Mode and Substrate Symmetry Dependent Strain in...

  15. DISCOVERY OF A NEUTRON STAR OSCILLATION MODE DURING A SUPERBURST

    SciTech Connect (OSTI)

    Strohmayer, Tod [Astrophysics Science Division and Joint Space-Science Institute, NASA's Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Mahmoodifar, Simin [Department of Physics and Joint Space-Science Institute, University of Maryland College Park, MD 20742 (United States)

    2014-10-01

    Neutron stars are among the most compact objects in the universe and provide a unique laboratory for the study of cold ultra-dense matter. While asteroseismology can provide a powerful probe of the interiors of stars, for example, helioseismology has provided unprecedented insights about the interior of the Sun, comparable capabilities for neutron star seismology have not yet been achieved. Here, we report the discovery of a coherent X-ray modulation from the neutron star 4U 1636–536 during the 2001 February 22 thermonuclear superburst seen with NASA's Rossi X-Ray Timing Explorer (RXTE) that is very likely produced by a global oscillation mode. The observed frequency is 835.6440 ± 0.0002 Hz (1.43546 times the stellar spin frequency of 582.14323 Hz) and the modulation is well described by a sinusoid (A + Bsin (? – ?{sub 0})) with a fractional half-amplitude of B/A = 0.19 ± 0.04% (4-15 keV). The observed frequency is consistent with the expected inertial frame frequency of a rotationally modified surface g-mode, an interfacial mode in the ocean-crust interface, or perhaps an r-mode. Observing an inertial frame frequency—as opposed to a co-rotating frame frequency—appears consistent with the superburst's thermal emission arising from the entire surface of the neutron star, and the mode may become visible by perturbing the local surface temperature. We briefly discuss the implications of the mode detection for the neutron star's projected velocity and mass. Our results provide further strong evidence that global oscillation modes can produce observable modulations in the X-ray flux from neutron stars.

  16. Vibration Suppression: Reducced-Order ModeVResidual Mode Filter Control

    E-Print Network [OSTI]

    Vibration Suppression: Reducced-Order ModeVResidual Mode Filter Control Using Smart Structures with large flexible antennas, andor flexible support structures, suppressing vibrations caused by on on the development of improved vibration suppression techniques for flexible spacecraft structures using smart

  17. On Dirac Zero Modes in Hyperdiamond Model

    E-Print Network [OSTI]

    Lalla Btissam Drissi; El Hassan Saidi

    2011-06-26

    Using the SU(5) symmetry of the 4D hyperdiamond and results on the study of 4D graphene given in "Four Dimensional Graphene" (L.B Drissi, E.H Saidi, M. Bousmina, CPM-11-01, Phys. Rev. D (2011)), we engineer a class of 4D lattice QCD fermions whose Dirac operators have two zero modes. We show that generally the zero modes of the Dirac operator in hyperdiamond fermions are captured by a tensor {\\Omega}_{{\\mu}}^{l} with 4\\times5 complex components linking the Euclidean SO(4) vector {\\mu}; and the 5-dimensional representation of SU(5). The Bori\\c{c}i-Creutz (BC) and the Karsten-Wilzeck (KW) models as well as their Dirac zero modes are rederived as particular realizations of {\\Omega}_{{\\mu}}^{l}. Other features are also given. Keywords: Lattice QCD, Bori\\c{c}i-Creutz and Karsten-Wilzeck models, 4D hyperdiamond, 4D graphene, SU(5) Symmetry.

  18. Vibrational mode multiplexing of ultracold atoms

    E-Print Network [OSTI]

    S. Martínez-Garaot; E. Torrontegui; Xi Chen; M. Modugno; D. Guéry-Odelin; Shuo-Yen Tseng; J. G. Muga

    2015-09-08

    Sending multiple messages on qubits encoded in different vibrational modes of cold atoms or ions along a transmission waveguide requires to merge first and then separate the modes at input and output ends. Similarly, different qubits can be stored in the modes of a trap and be separated later. We design the fast splitting of a harmonic trap into an asymmetric double well so that the initial ground vibrational state becomes the ground state of one of two final wells, and the initial first excited state becomes the ground state of the other well. This might be done adiabatically by slowly deforming the trap. We speed up the process by inverse engineering a double-function trap using dynamical invariants. The separation (demultiplexing) followed by an inversion of the asymmetric bias and then by the reverse process (multiplexing) provides a population inversion protocol based solely on trap reshaping.

  19. Observation of Spontaneous Neoclassical Tearing Modes

    SciTech Connect (OSTI)

    E.D. Fredrickson

    2001-10-03

    We present data in this paper from the Tokamak Fusion Test Reactor (TFTR) which challenges the commonly held belief that extrinsic MHD events such as sawteeth or ELMs [edge localized modes] are required to provide the seed islands that trigger Neoclassical Tearing Modes (NTMs). While sawteeth are reported to provide the trigger for most of the NTMs on DIII-D [at General Atomics in San Diego, California] and ASDEX-U [at Max-Planck-Institut fuer Plasmaphysik in Garching, Germany], the majority of NTMs seen in TFTR occur in plasmas without sawteeth, that is which are above the beta threshold for sawtooth stabilization. Examples of NTMs appearing in the absence of any detectable extrinsic MHD activity will be shown. Conversely, large n=1 modes in plasmas above the NTM beta threshold generally do not trigger NTMs. An alternative mechanism for generating seed islands will be discussed.

  20. Hydrogen local vibrational modes in semiconductors

    SciTech Connect (OSTI)

    McCluskey, M D

    1997-06-01

    Following, a review of experimental techniques, theory, and previous work, the results of local vibrational mode (LVM) spectroscopy on hydrogen-related complexes in several different semiconductors are discussed. Hydrogen is introduced either by annealing in a hydrogen ambient. exposure to a hydrogen plasma, or during growth. The hydrogen passivates donors and acceptors in semiconductors, forming neutral complexes. When deuterium is substituted for hydrogen. the frequency of the LVM decreases by approximately the square root of two. By varying the temperature and pressure of the samples, the microscopic structures of hydrogen-related complexes are determined. For group II acceptor-hydrogen complexes in GaAs, InP, and GaP, hydrogen binds to the host anion in a bond-centered orientation, along the [111] direction, adjacent to the acceptor. The temperature dependent shift of the LVMs are proportional to the lattice thermal energy U(T), a consequence of anharmonic coupling between the LVM and acoustical phonons. In the wide band gap semiconductor ZnSe, epilayers grown by metalorganic chemical vapor phase epitaxy (MOCVD) and doped with As form As-H complexes. The hydrogen assumes a bond-centered orientation, adjacent to a host Zn. In AlSb, the DX centers Se and Te are passivated by hydrogen. The second, third, and fourth harmonics of the wag modes are observed. Although the Se-D complex has only one stretch mode, the Se-H stretch mode splits into three peaks. The anomalous splitting is explained by a new interaction between the stretch LVM and multi-phonon modes of the lattice. As the temperature or pressure is varied, and anti-crossing is observed between LVM and phonon modes.

  1. Quantum vacuum photon-modes and superhydrophobicity

    E-Print Network [OSTI]

    Louis Dellieu; Olivier Deparis; Jerome Muller; Michael Sarrazin

    2015-01-14

    Nanostructures are commonly used for developing superhydrophobic surfaces. However, available wetting theoretical models ignore the effect of vacuum photon-modes alteration on van der Waals forces and thus on hydrophobicity. Using first-principle calculations, we show that superhydrophibicity of nanostructured surfaces is dramatically enhanced by vacuum photon-modes tuning. As a case study, wetting contact angles of a water droplet above a polyethylene nanostructured surface are obtained from the interaction potential energy calculated as function of the droplet-surface separation distance. This new approach could pave the way for the design of novel superhydrophobic coatings.

  2. Sandia National Laboratories: Mode Stirred Chamber

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust, High-ThroughputUpcoming Release of thePrograms:Mode Stirred Chamber The Mode Stirred

  3. Global Mode Analysis of Centrifugal and Curvature Driven

    E-Print Network [OSTI]

    Columbia University

    Global Mode Analysis of Centrifugal and Curvature Driven Interchange Instabilities Benjamin Joseph Reserved #12;ABSTRACT Global Mode Analysis of Centrifugal and Curvature Driven Interchange Modes Benjamin- sure and centrifugal forces created in a laboratory magnetic dipole is presented. The mode structures

  4. Head-Tail Modes for Strong Space Charge

    SciTech Connect (OSTI)

    Burov, Alexey

    2008-12-01

    Head-tail modes are described here for the space charge tune shift significantly exceeding the synchrotron tune. General equation for the modes is derived. Spatial shapes of the modes, their frequencies, and coherent growth rates are explored. The Landau damping rates are also found. Suppression of the transverse mode coupling instability by the space charge is explained.

  5. From Lyapunov modes to the exponents for hard disk systems

    E-Print Network [OSTI]

    Tony Chung; Daniel Truant; Gary P. Morriss

    2009-04-08

    We demonstrate the preservation of the Lyapunov modes by the underlying tangent space dynamics of hard disks. This result is exact for the zero modes and correct to order $\\epsilon$ for the transverse and LP modes where $\\epsilon$ is linear in the mode number. For sufficiently large mode numbers the dynamics no longer preserves the mode structure. We propose a Gram-Schmidt procedure based on orthogonality with respect to the centre space that determines the values of the Lyapunov exponents for the modes. This assumes a detailed knowledge of the modes, but from that predicts the values of the exponents from the modes. Thus the modes and the exponents contain the same information.

  6. Thermalization of Green functions and quasinormal modes

    E-Print Network [OSTI]

    Justin R. David; Surbhi Khetrapal

    2015-05-12

    We develop a new method to study the thermalization of time dependent retarded Green function in conformal field theories holographically dual to thin shell AdS Vaidya space times. The method relies on using the information of all time derivatives of the Green function at the shell and then evolving it for later times. The time derivatives of the Green function at the shell is given in terms of a recursion formula. Using this method we obtain analytic results for short time thermalization of the Green function. We show that the late time behaviour of the Green function is determined by the first quasinormal mode. We then implement the method numerically. As applications of this method we study the thermalization of the retarded time dependent Green function corresponding to a minimally coupled scalar in the AdS3 and AdS5 thin Vaidya shells. We see that as expected the late time behaviour is determined by the first quasinormal mode. We apply the method to study the late time behaviour of the shear vector mode in AdS5 Vaidya shell. At small momentum the corresponding time dependent Green function is expected to relax to equilibrium by the shear hydrodynamic mode. Using this we obtain the universal ratio of the shear viscosity to entropy density from a time dependent process.

  7. HYDROGEN LOCAL VIBRATIONAL MODES IN COMPOUND SEMICONDUCTORS

    E-Print Network [OSTI]

    McCluskey, Matthew

    HYDROGEN LOCAL VIBRATIONAL MODES IN COMPOUND SEMICONDUCTORS M.D. MCCLUSKEY* University) spectroscopy of hydrogen and deuterium in GaP, AlSb, ZnSe, and GaN has provided important information about the structures of dopant- hydrogen complexes and their interaction with the host lattice. In GaN:Mg, for example

  8. Sliding Mode Control with Industrial Applications

    E-Print Network [OSTI]

    Gajic, Zoran

    /Central Jersey Section of IEEE - Circuits and Systems Chapter Meeting #12;The Old Oil-Peddler Ouyang Show(1007 Chapter Meeting #12;Sliding Mode: an illustration to fill oil into a bottle through a funnel 2008/11/17 4 Extrusion P.) Rod-less Pneumatic Cylinder Servo Wireless Network Power Control Singular Perturbations

  9. TERMINATION OF SIMPLY MODED WELLTYPED LOGIC PROGRAMS

    E-Print Network [OSTI]

    Giesl, Juergen

    is borrowed from [9], defining a similar notion in the context of termination of off­line partial evaluation only partially corresponds to our intuitive notion of a ``terminating computation''. This is becauseTERMINATION OF SIMPLY MODED WELL­TYPED LOGIC PROGRAMS UNDER TABLED EXECUTION MECHANISM Sofie

  10. Thermodynamics, Optical Properties and Coordination Modes of Np(V) with Dipicolinic Acid

    E-Print Network [OSTI]

    Tian, Guoxin

    2010-01-01

    Thermodynamics, Optical Properties and Coordination Modes ofacid, complexation, thermodynamics, coordination mode 1.

  11. Resistive wall mode and neoclassical tearing mode coupling in rotating tokamak plasmas

    E-Print Network [OSTI]

    McAdams, Rachel; Chapman, I T

    2013-01-01

    A model system of equations has been derived to describe a toroidally rotating tokamak plasma, unstable to Resistive Wall Modes (RWMs) and metastable to Neoclassical Tearing Modes (NTMs), using a linear RWM model and a nonlinear NTM model. If no wall is present, the NTM growth shows the typical threshold/saturation island widths, whereas a linearly unstable kink mode grows exponentially in this model plasma system. When a resistive wall is present, the growth of the linearly unstable RWM is accelerated by an unstable island: a form of coupled RWM-NTM mode. Crucially, this coupled system has no threshold island width, giving the impression of a triggerless NTM, observed in high beta tokamak discharges. In addition, increasing plasma rotation at the island location can mitigate its growth, but does not restore the threshold width.

  12. Edge-localized mode avoidance and pedestal structure in I-mode plasmas

    E-Print Network [OSTI]

    White, A. E.

    I-mode is a high-performance tokamak regime characterized by the formation of a temperature pedestal and enhanced energy confinement, without an accompanying density pedestal or drop in particle and impurity transport. ...

  13. Mode-synthesizing atomic force microscopy and mode-synthesizing sensing

    DOE Patents [OSTI]

    Passain, Ali; Thundat, Thomas George; Tetard, Laurene

    2014-07-22

    A method of analyzing a sample that includes applying a first set of energies at a first set of frequencies to a sample and applying, simultaneously with the applying the first set of energies, a second set of energies at a second set of frequencies, wherein the first set of energies and the second set of energies form a multi-mode coupling. The method further includes detecting an effect of the multi-mode coupling.

  14. Measurements of Time-Dependent CP-Asymmetry Parameters in B Meson Decays to \\eta^{\\prime} K^0 and of Branching Fractions of SU(3) Related Modes with BaBar Experiment at SLAC

    SciTech Connect (OSTI)

    Biassoni, Pietro; /Milan U.

    2009-01-22

    In this thesis work we have measured the following upper limits at 90% of confidence level, for B meson decays (in units of 10{sup -6}), using a statistics of 465.0 x 10{sup 6} B{bar B} pairs: {Beta}(B{sup 0} {yields} {eta}K{sup 0}) < 1.6 {Beta}(B{sup 0} {yields} {eta}{eta}) < 1.4 {Beta}(B{sup 0} {yields} {eta}{prime}{eta}{prime}) < 2.1 {Beta}(B{sup 0} {yields} {eta}{phi}) < 0.52 {Beta}(B{sup 0} {yields} {eta}{omega}) < 1.6 {Beta}(B{sup 0} {yields} {eta}{prime}{phi}) < 1.2 {Beta}(B{sup 0} {yields} {eta}{prime}{omega}) < 1.7 We have no observation of any decay mode, statistical significance for our measurements is in the range 1.3-3.5 standard deviation. We have a 3.5{sigma} evidence for B {yields} {eta}{omega} and a 3.1 {sigma} evidence for B {yields} {eta}{prime}{omega}. The absence of observation of the B{sup 0} {yields} {eta}K{sup 0} open an issue related to the large difference compared to the charged mode B{sup +} {yields} {eta}K{sup +} branching fraction, which is measured to be 3.7 {+-} 0.4 {+-} 0.1 [118]. Our results represent substantial improvements of the previous ones [109, 110, 111] and are consistent with theoretical predictions. All these results were presented at Flavor Physics and CP Violation (FPCP) 2008 Conference, that took place in Taipei, Taiwan. They will be soon included into a paper to be submitted to Physical Review D. For time-dependent analysis, we have reconstructed 1820 {+-} 48 flavor-tagged B{sup 0} {yields} {eta}{prime}K{sup 0} events, using the final BABAR statistic of 467.4 x 10{sup 6} B{bar B} pairs. We use these events to measure the time-dependent asymmetry parameters S and C. We find S = 0.59 {+-} 0.08 {+-} 0.02, and C = -0.06 {+-} 0.06 {+-} 0.02. A non-zero value of C would represent a directly CP non-conserving component in B{sup 0} {yields} {eta}{prime}K{sup 0}, while S would be equal to sin2{beta} measured in B{sup 0} {yields} J/{psi}K{sub s}{sup 0} [108], a mixing-decay interference effect, provided the decay is dominated by amplitudes of a single weak phase. The new measured value of S can be considered in agreement with the expectations of the 'Standard Model', inside the experimental and theoretical uncertainties. Inconsistency of our result for S with CP conservation (S = 0) has a significance of 7.1 standard deviations (statistical and systematics included). Our result for the direct-CP violation parameter C is 0.9 standard deviations from zero (statistical and systematics included). Our results are in agreement with the previous ones [18]. Despite the statistics is only 20% larger than the one used in previous measurement, we improved of 20% the error on S and of 14% the error on C. This error is the smaller ever achieved, by both BABAR and Belle, in Time-Dependent CP Violation Parameters measurement is a b {yields} s transition.

  15. Mode Selective Excitation Using Coherent Control Spectroscopy

    SciTech Connect (OSTI)

    Singh, Ajay K.; Konradi, Jakow; Materny, Arnulf; Sarkar, Sisir K.

    2008-11-14

    Femtosecond time-resolved coherent anti-Stokes Raman scattering (fs-CARS) gives access to ultrafast molecular dynamics. However, femtosecond laser pulses are spectrally broad and therefore coherently excite several molecular modes. While the temporal resolution is high, usually no mode-selective excitation is possible. This paper demonstrates the feasibility of selectively exciting specific molecular vibrations in solution phase with shaped fs laser excitation using a feedback-controlled optimization technique guided by an evolutionary algorithm. This approach is also used to obtain molecule-specific CARS spectra from a mixture of different substances. The optimized phase structures of the fs pulses are characterized to get insight into the control process. Possible applications of the spectrum control are discussed.

  16. BFORE: The B-mode Foreground Experiment

    E-Print Network [OSTI]

    Niemack, Michael D; de Bernardis, Francesco; Boulanger, Francois; Bryan, Sean; Devlin, Mark; Dunkley, Joanna; Eales, Steve; Gomez, Haley; Groppi, Chris; Henderson, Shawn; Hillbrand, Seth; Hubmayr, Johannes; Mauskopf, Philip; McMahon, Jeff; Miville-Deschênes, Marc-Antoine; Pascale, Enzo; Pisano, Giampaolo; Novak, Giles; Scott, Douglas; Soler, Juan; Tucker, Carole

    2015-01-01

    The B-mode Foreground Experiment (BFORE) is a proposed NASA balloon project designed to make optimal use of the sub-orbital platform by concentrating on three dust foreground bands (270, 350, and 600 GHz) that complement ground-based cosmic microwave background (CMB) programs. BFORE will survey ~1/4 of the sky with 1.7 - 3.7 arcminute resolution, enabling precise characterization of the Galactic dust that now limits constraints on inflation from CMB B-mode polarization measurements. In addition, BFORE's combination of frequency coverage, large survey area, and angular resolution enables science far beyond the critical goal of measuring foregrounds. BFORE will constrain the velocities of thousands of galaxy clusters, provide a new window on the cosmic infrared background, and probe magnetic fields in the interstellar medium. We review the BFORE science case, timeline, and instrument design, which is based on a compact off-axis telescope coupled to >10,000 superconducting detectors.

  17. Electromagnetic Transport From Microtearing Mode Turbulence

    SciTech Connect (OSTI)

    Guttenfelder, W; Kaye, S M; Nevins, W M; Wang, E; Bell, R E; Hammett, G W; LeBlanc, B P; Mikkelsen, D R

    2011-03-23

    This Letter presents non-linear gyrokinetic simulations of microtearing mode turbulence. The simulations include collisional and electromagnetic effects and use experimental parameters from a high beta discharge in the National Spherical Torus Experiment (NSTX). The predicted electron thermal transport is comparable to that given by experimental analysis, and it is dominated by the electromagnetic contribution of electrons free streaming along the resulting stochastic magnetic field line trajectories. Experimental values of flow shear can significantly reduce the predicted transport.

  18. Active mode-locking in semiconductor lasers 

    E-Print Network [OSTI]

    Lee, Yong-Hun

    1990-01-01

    at 2 GHz frequency without external feedback. . . . . . . . . . 10 Computer simulated photon density variation (12. 8 ps pulsewidth) in the laser diode by sinusoidal modulation at 2 GHz frequency with 5. 4 % external feedback. . . . . Light... of the fiber external cavity. 20 13 Illustration for the calculation of the effective ref lectivity in the case of feedback. 25 14 Light-current curve of the InGaAsP laser diode with and without feedback. . . , . . . . . . . . . . . . . . . 26 15 Mode...

  19. Zero Net Energy Myths and Modes of Thought

    E-Print Network [OSTI]

    Rajkovich, Nicholas B.

    2010-01-01

    mypp.html. ———. (2009). "Net-Zero Energy CommercialZero Net Energy Myths and Modes of Thought  Nicholas B.  AC02? 05CH11231. Page | i Zero Net Energy Myths and Modes of

  20. Mode conversion current drive experiments on Alcator C-Mod

    E-Print Network [OSTI]

    Parisot, Alexandre, 1979-

    2007-01-01

    In tokamak plasmas with multiple ion species, fast magnetosonic waves (FW) in the Ion Cyclotron Range of Frequency can mode convert to shorter wavelength modes at the Ion-Ion hybrid layer, leading to localized electron ...

  1. Low-energy collective modes of deformed superfluid nuclei within...

    Office of Scientific and Technical Information (OSTI)

    Low-energy collective modes of deformed superfluid nuclei within the finite-amplitude method Citation Details In-Document Search Title: Low-energy collective modes of deformed...

  2. Attitudes towards mode choice in Switzerland Bilge Atasoy

    E-Print Network [OSTI]

    Bierlaire, Michel

    Attitudes towards mode choice in Switzerland Bilge Atasoy Aur´elie Glerum Michel Bierlaire 31st, Switzerland, {bilge.kucuk, aurelie.glerum, michel.bierlaire}@epfl.ch 1 #12;1 Introduction Transport mode

  3. Diagnostic for two-mode variable valve activation device

    DOE Patents [OSTI]

    Fedewa, Andrew M

    2014-01-07

    A method is provided for diagnosing a multi-mode valve train device which selectively provides high lift and low lift to a combustion valve of an internal combustion engine having a camshaft phaser actuated by an electric motor. The method includes applying a variable electric current to the electric motor to achieve a desired camshaft phaser operational mode and commanding the multi-mode valve train device to a desired valve train device operational mode selected from a high lift mode and a low lift mode. The method also includes monitoring the variable electric current and calculating a first characteristic of the parameter. The method also includes comparing the calculated first characteristic against a predetermined value of the first characteristic measured when the multi-mode valve train device is known to be in the desired valve train device operational mode.

  4. Higher Order Modes in Acoustic Logging While Drilling

    E-Print Network [OSTI]

    Chi, Shihong

    2005-01-01

    In multipole acoustic logging while drilling (LWD), the fundamental modes dominate recorded waveforms. Higher order modes may also appear and complicate the processing of LWD data. In dipole LWD measurements, the dipole ...

  5. Skyrmion Vibration Modes within the Rational Map Ansatz

    E-Print Network [OSTI]

    W. T. Lin; B. Piette

    2008-04-30

    We study the vibration modes of the Skyrme model within the rational map ansatz. We show that the vibrations of the radial profiles and the rational maps are decoupled and we consider explicitly the case B=1, B=2 and B=4. We then compare our results with the vibration modes obtained numerically by Barnes et al. and show that qualitatively the rational map reproduces the vibration modes obtained numerically but that the vibration frequencies of these modes do not match very well.

  6. Viscoelastic modes in a strongly coupled, cold, magnetized dusty plasma

    SciTech Connect (OSTI)

    Banerjee, Debabrata; Mylavarapu, Janaki Sita; Chakrabarti, Nikhil

    2010-11-15

    A generalized hydrodynamical model has been used to study the low frequency modes in a strongly coupled, cold, magnetized dusty plasma. Such plasmas exhibit elastic properties due to the strong correlations among dust particles and the tensile stresses imparted by the magnetic field. It has been shown that longitudinal compressional Alfven modes and elasticity modified transverse shear mode exist in such a medium. The features of these collective modes are established and discussed.

  7. Extracting Operating Modes from Building Electrical Load Data: Preprint

    SciTech Connect (OSTI)

    Frank, S.; Polese, L. G.; Rader, E.; Sheppy, M.; Smith, J.

    2012-01-01

    Empirical techniques for characterizing electrical energy use now play a key role in reducing electricity consumption, particularly miscellaneous electrical loads, in buildings. Identifying device operating modes (mode extraction) creates a better understanding of both device and system behaviors. Using clustering to extract operating modes from electrical load data can provide valuable insights into device behavior and identify opportunities for energy savings. We present a fast and effective heuristic clustering method to identify and extract operating modes in electrical load data.

  8. Summary Report: Control Strategies for Mixed-Mode Buildings

    E-Print Network [OSTI]

    Brager, Gail; Borgeson, Sam; Lee, Yoonsu

    2007-01-01

    efficiency. The adage “passive buildings require activesuch that the building is primarily in passive mode most of

  9. Viscoelastic modes in a strongly coupled cold magnetized dusty plasma

    E-Print Network [OSTI]

    Banerjee, Debabrata; Chakrabarti, Nikhil

    2013-01-01

    A generalized hydrodynamical model has been used to study low frequency modes in a strongly coupled, cold, magnetized dusty plasma. Such plasmas exhibit elastic properties due to strong correlations among dust particles and the tensile stresses imparted by the magnetic field. It has been shown that longitudinal compressional Alfven modes and elasticity modified transverse shear mode exist in such a medium. The features of these collective modes are established and discussed.

  10. Achieving Real-time Mode Estimation through Offline Compilation

    E-Print Network [OSTI]

    Achieving Real-time Mode Estimation through Offline Compilation by John M. Van Eepoel B, Committee on Graduate Students #12;Achieving Real-time Mode Estimation through Offline Compilation2 This page intentionally left blank. #12;Achieving Real-time Mode Estimation through Offline Compilation 3

  11. Laser mode hyper-combs Alon Schwartz and Baruch Fischer*

    E-Print Network [OSTI]

    Fischer, Baruch

    -mode lattices (mode hyper-combs) with unique properties. They are obtained from regular 1-dimensional combsLaser mode hyper-combs Alon Schwartz and Baruch Fischer* Department of Electrical Engineering, as lasers, are commonly one- dimensional systems. Here we present a construction of multi-dimensional laser

  12. Lyapunov Modes in HardDisk Systems April 2, 2004

    E-Print Network [OSTI]

    Lyapunov Modes in Hard­Disk Systems April 2, 2004 Jean­Pierre Eckmann 1,2 , Christina Forster 3 the Lyapunov spectrum near the vanishing Lyapunov exponents. To this spectrum are associated ``eigen­directions'', called Lyapunov modes. We carefully analyze these modes and show how they are naturally associated

  13. PROPERTIES OF BALLOONING MODES IN THE PLANAR AXIS HELIOTRON CONFIGURATIONS

    E-Print Network [OSTI]

    Hudson, Stuart

    -Madison, Department of Engineering Physics, Madison, Wisconsin 53706 Received November 18, 2005 Accepted of local mode analyses of the bal- looning modes in the covering space (quasi modes) cannot be directly by the local structure of the magnetic config- uration, i.e., by the local magnetic shear and the local

  14. Inflation, Symmetry, and B-Modes

    E-Print Network [OSTI]

    Mark P. Hertzberg

    2015-07-27

    We examine the role of using symmetry and effective field theory in inflationary model building. We describe the standard formulation of starting with an approximate shift symmetry for a scalar field, and then introducing corrections systematically in order to maintain control over the inflationary potential. We find that this leads to models in good agreement with recent data. On the other hand, there are attempts in the literature to deviate from this paradigm by invoking other symmetries and corrections. In particular: in a suite of recent papers, several authors have made the claim that standard Einstein gravity with a cosmological constant and a massless scalar carries conformal symmetry. They further claim that such a theory carries another hidden symmetry; a global SO(1,1) symmetry. By deforming around the global SO(1,1) symmetry, they are able to produce a range of inflationary models with asymptotically flat potentials, whose flatness is claimed to be protected by these symmetries. These models tend to give rise to B-modes with small amplitude. Here we explain that these authors are merely introducing a redundancy into the description, not an actual conformal symmetry. Furthermore, we explain that the only real (global) symmetry in these models is not at all hidden, but is completely manifest when expressed in the Einstein frame; it is in fact the shift symmetry of a scalar field. When analyzed systematically as an effective field theory, deformations do not generally produce asymptotically flat potentials and small B-modes, but other types of potentials with B-modes of appreciable amplitude. Such simple models typically also produce the observed red spectral index, Gaussian fluctuations, etc. In short: simple models of inflation, organized by expanding around a shift symmetry, are in excellent agreement with recent data.

  15. Low-rise shear wall failure modes

    SciTech Connect (OSTI)

    Farrar, C.R. (Los Alamos National Lab., NM (USA)); Hashimoto, P.S. (EQE Engineering, Inc., Costa Mesa, CA (USA)); Reed, J.W. (Benjamin (J.R.) and Associates, Inc., Mountain View, CA (USA))

    1991-01-01

    A summary of the data that are available concerning the structural response of low-rise shear walls is presented. This data will be used to address two failure modes associated with the shear wall structures. First, data concerning the seismic capacity of the shear walls with emphasis on excessive deformations that can cause equipment failure are examined. Second, data concerning the dynamic properties of shear walls (stiffness and damping) that are necessary to compute the seismic inputs to attached equipment are summarized. This case addresses the failure of equipment when the structure remains functional. 23 refs.

  16. Quasinormal Modes of Dirty Black Holes

    E-Print Network [OSTI]

    P. T. Leung; Y. T. Liu; W. -M. Suen; C. Y. Tam; K. Young

    1999-03-08

    Quasinormal mode (QNM) gravitational radiation from black holes is expected to be observed in a few years. A perturbative formula is derived for the shifts in both the real and the imaginary part of the QNM frequencies away from those of an idealized isolated black hole. The formulation provides a tool for understanding how the astrophysical environment surrounding a black hole, e.g., a massive accretion disk, affects the QNM spectrum of gravitational waves. We show, in a simple model, that the perturbed QNM spectrum can have interesting features.

  17. NSTX Failure Modes & Effects Analysis / NSTX-FMEA-71-10 / p. 1 of 115 FAILURE MODES AND EFFECTS ANALYSIS

    E-Print Network [OSTI]

    Princeton Plasma Physics Laboratory

    NSTX Failure Modes & Effects Analysis / NSTX-FMEA-71-10 / p. 1 of 115 NSTX FAILURE MODES AND EFFECTS ANALYSIS (FMEA) Revision 10 Dated: November 2014 Prepared By: Name/WBS Signature Name: ________________________________________________ Ron Strykowsky, NSTX Upgrade Project Manager #12;NSTX Failure Modes & Effects Analysis / NSTX-FMEA-71

  18. Asymmetric plastic modes in disordered solids

    E-Print Network [OSTI]

    Luka Gartner; Edan Lerner

    2015-07-24

    We propose a framework within which a robust mechanical definition of precursors to plastic instabilities, often termed `soft-spots', naturally emerges. They are shown to be collective displacements (modes) $\\hat{z}_0$ that correspond to local minima of the `barrier function' $b(\\hat{z})$. The latter is derived from the cubic approximation of the variation $\\delta U_{\\hat{z}}(s)$ of the potential energy upon displacing particles a distance $s$ along $\\hat{z}$. We show that modes $\\hat{z}_0$ corresponding to low-lying minima of $b(\\hat{z})$ lead to transitions over energy barriers in the glass, and are therefore associated with highly asymmetric variations $\\delta U_{\\hat{z}}(s)$ with $s$. We further demonstrate how a heuristic search for local minima of $b(\\hat{z})$ can a-priori detect the locus and geometry of imminent plastic instabilities with remarkable accuracy, at strains as large as $\\gamma_c-\\gamma \\sim 10^{-2}$ away from the instability strain $\\gamma_c$, where the non-affine displacements under shear are still largely delocalized. Our findings suggest that the a-priori detection of plastic instabilities can be effectively carried out by the investigation of the landscape of $b(\\hat{z})$.

  19. Nonlinear plastic modes in disordered solids

    E-Print Network [OSTI]

    Luka Gartner; Edan Lerner

    2015-10-27

    We propose a framework within which a robust mechanical definition of precursors to plastic instabilities, often termed `soft-spots', naturally emerges. They are shown to be collective displacements (modes) $\\hat{z}_0$ that correspond to local minima of the `barrier function' $b(\\hat{z})$. The latter is derived from the cubic approximation of the variation $\\delta U_{\\hat{z}}(s)$ of the potential energy upon displacing particles a distance $s$ along $\\hat{z}$. We show that modes $\\hat{z}_0$ corresponding to low-lying minima of $b(\\hat{z})$ lead to transitions over energy barriers in the glass, and are therefore associated with highly asymmetric variations $\\delta U_{\\hat{z}}(s)$ with $s$. We further demonstrate how a heuristic search for local minima of $b(\\hat{z})$ can a-priori detect the locus and geometry of imminent plastic instabilities with remarkable accuracy, at strains as large as $\\gamma_c-\\gamma \\sim 10^{-2}$ away from the instability strain $\\gamma_c$, where the non-affine displacements under shear are still largely delocalized. Our findings suggest that the a-priori detection of plastic instabilities can be effectively carried out by the investigation of the landscape of $b(\\hat{z})$.

  20. Mode coupling of Schwarzschild perturbations: Ringdown frequencies

    SciTech Connect (OSTI)

    Pazos, Enrique [Center for Relativistic Astrophysics, School of Physics, Georgia Institute of Technology, 837 State Street, Atlanta, Georgia 30332-0430 (United States); Departamento de Matematica, Universidad de San Carlos de Guatemala, Edificio T4, Facultad de Ingenieria, Ciudad Universitaria z. 12 (Guatemala); Brizuela, David [Theoretisch-Physikalisches Institut, Friedrich-Schiller-Universitaet, Max-Wien-Platz 1, 07743 Jena (Germany); Martin-Garcia, Jose M. [Institut d'Astrophysique de Paris, CNRS, Universite Pierre et Marie Curie, 98bis Boulevard Arago, 75014 Paris (France); Laboratoire Univers et Theories, CNRS, Universite Paris Diderot, 5 Place Jules Janssen, 92190 Meudon (France); Tiglio, Manuel [Department of Physics, Center for Fundamental Physics, Center for Scientific Computation and Mathematical Modeling, Joint Space Sciences Institute, University of Maryland, College Park, Maryland 20742 (United States)

    2010-11-15

    Within linearized perturbation theory, black holes decay to their final stationary state through the well-known spectrum of quasinormal modes. Here we numerically study whether nonlinearities change this picture. For that purpose we study the ringdown frequencies of gauge-invariant second-order gravitational perturbations induced by self-coupling of linearized perturbations of Schwarzschild black holes. We do so through high-accuracy simulations in the time domain of first and second-order Regge-Wheeler-Zerilli type equations, for a variety of initial data sets. We consider first-order even-parity (l=2, m={+-}2) perturbations and odd-parity (l=2, m=0) ones, and all the multipoles that they generate through self-coupling. For all of them and all the initial data sets considered we find that--in contrast to previous predictions in the literature--the numerical decay frequencies of second-order perturbations are the same ones of linearized theory, and we explain the observed behavior. This would indicate, in particular, that when modeling or searching for ringdown gravitational waves, appropriately including the standard quasinormal modes already takes into account nonlinear effects.

  1. Multi-mode ultrasonic welding control and optimization

    DOE Patents [OSTI]

    Tang, Jason C.H.; Cai, Wayne W

    2013-05-28

    A system and method for providing multi-mode control of an ultrasonic welding system. In one embodiment, the control modes include the energy of the weld, the time of the welding process and the compression displacement of the parts being welded during the welding process. The method includes providing thresholds for each of the modes, and terminating the welding process after the threshold for each mode has been reached, the threshold for more than one mode has been reached or the threshold for one of the modes has been reached. The welding control can be either open-loop or closed-loop, where the open-loop process provides the mode thresholds and once one or more of those thresholds is reached the welding process is terminated. The closed-loop control provides feedback of the weld energy and/or the compression displacement so that the weld power and/or weld pressure can be increased or decreased accordingly.

  2. The concept of a stare-mode astrometric space mission

    E-Print Network [OSTI]

    N. Zacharias; B. Dorland

    2006-08-14

    The concept of a stare-mode astrometric space mission is introduced. The traditionally accepted mode of operation for a mapping astrometric space mission is that of a continuously scanning satellite, like the successful Hipparcos and planned Gaia missions. With the advent of astrometry missions mapping out stars to 20th magnitude, the stare-mode becomes competitive. A stare-mode of operation has several advantages over a scanning missions if absolute parallax and throughput issues can be successfully addressed. Requirements for a stare-mode operation are outlined. The mission precision for a stare-mode astrometric mission is derived as a function of instrumental parameters with examples given. The stare-mode concept has been accepted as baseline for the NASA roadmap study of the Origins Billions Star Survey (OBSS) mission and the Milli-arcsecond Pathfinder Survey (MAPS) micro-satellite proposed project.

  3. Lyapunov Mode Dynamics in Hard-Disk Systems

    E-Print Network [OSTI]

    D. J. Robinson; G. P. Morriss

    2007-09-20

    The tangent dynamics of the Lyapunov modes and their dynamics as generated numerically - {\\it the numerical dynamics} - is considered. We present a new phenomenological description of the numerical dynamical structure that accurately reproduces the experimental data for the quasi-one-dimensional hard-disk system, and shows that the Lyapunov mode numerical dynamics is linear and separate from the rest of the tangent space. Moreover, we propose a new, detailed structure for the Lyapunov mode tangent dynamics, which implies that the Lyapunov modes have well-defined (in)stability in either direction of time. We test this tangent dynamics and its derivative properties numerically with partial success. The phenomenological description involves a time-modal linear combination of all other Lyapunov modes on the same polarization branch and our proposed Lyapunov mode tangent dynamics is based upon the form of the tangent dynamics for the zero modes.

  4. Self-adaptive methods for acoustic focusing and mode extraction in a shallow ocean waveguide

    E-Print Network [OSTI]

    Walker, Shane C.

    2005-01-01

    of MRMF and MI method mode extractions using simulated83 MI method mode extraction results using ultrasonictransducers. The mode extraction method is applied to both

  5. Advancing the Physics Basis of Quiescent H-mode through Exploration of ITER Relevant Parameters

    SciTech Connect (OSTI)

    Solomon, W. M.; Burrell, K. H.; Fenstermacher, M. E.; Garofalo, A. M.; Grierson, B. A.; Loarte, A.; McKee, G. R.; Nazikian, R.; Snyder, B. P.

    2014-09-01

    Recent experiments on DIII-D have overcome a long-standing limitation in accessing quiescent H-mode (QH-mode), a high confinement state of the plasma that does not exhibit the explosive instabilities associated with edge localized modes (ELMs). In the past, QH-mode was associated with low density operation, but has now been extended to high normalized densities compatible with operation envisioned for ITER. Through the use of strong shaping, QH-mode plasmas have been maintained at high densities, both absolute (?e ? 7 × 1019 m—3) and normalized Greenwald fraction (?e/?G > 0:7) . In these plasmas, the pedestal can evolve to very high pressures and current as the density is increased. Calculations of the pedestal height and width from the EPED model are quantitatively consistent with the experimental observed evolution with density. The comparison of the dependence of the maximum density threshold for QH-mode with plasma shape help validate the underlying theoretical peeling-ballooning models describing ELM stability. High density QH-mode operation with strong shaping has allowed stable access to a previously predicted regime of very high pedestal dubbed \\Super H-mode". In general, QH-mode is found to achieve ELM-stable operation while maintaining adequate impurity exhaust, due to the enhanced impurity transport from an edge harmonic oscillation, thought to be a saturated kink- peeling mode driven by rotation shear. In addition, the impurity confinement time is not affected by rotation, even though the energy confinement time and measured E ? B shear is observed to increase at low toroidal rotation. Together with demonstrations of high beta, high confinement and low q95 for many energy confinement times, these results suggest QH-mode as a potentially attractive operating scenario for ITER's Q=10 mission.

  6. Switched Mode Four-Quadrant Converters

    E-Print Network [OSTI]

    Thurel, Y

    2015-01-01

    This paper was originally presented at CAS-2004, and was slightly modified for CAS-2014. It presents a review of the key parameters that impact the design choices for a true four-quadrant power converter, in the range 1-10 kW, mainly based on switching mode converter topology. This paper will first describe the state-of-the-art for this power converter family, giving the drawbacks and advantages of different possible solutions. It will also present practical results obtained from the CERN-designed converter. It will finally give some important tips regarding critical phases like test one, when conducting a project dealing with this type of power converter.

  7. Optical modes in slab waveguides with magnetoelectric effect

    E-Print Network [OSTI]

    Talebi, Nahid

    2015-01-01

    Optical modes in anisotropic slab waveguides with topological and chiral magnetoelectric effects are investigated analytically, by deriving the closed-form characteristic equations of the modes and hence computing the dispersion-diagrams. In order to compute the characteristic equations, a vector-potential approach is introduced by incorporating a generalized Lorentz gauge, and the corresponding Helmholtz equations are derived correspondingly. It will be shown that the formation of the complex modes and hybridization of the optical modes in such slab waveguides is inevitable. Moreover, when the tensorial form of the permittivity in the waveguide allows for a hyperbolic dispersion, complex transition from the photonic kinds of modes to the plasmonic modes is expected.

  8. Optimization to reduce fuel consumption in charge depleting mode

    DOE Patents [OSTI]

    Roos, Bryan Nathaniel; Martini, Ryan D.

    2014-08-26

    A powertrain includes an internal combustion engine, a motor utilizing electrical energy from an energy storage device, and a plug-in connection. A Method for controlling the powertrain includes monitoring a fuel cut mode, ceasing a fuel flow to the engine based upon the fuel cut mode, and through a period of operation including acceleration of the powertrain, providing an entirety of propelling torque to the powertrain with the electrical energy from the energy storage device based upon the fuel cut mode.

  9. Microwave mode shifting antenna system for regenerating particulate filters

    DOE Patents [OSTI]

    Gonze, Eugene V [Pinckney, MI; Kirby, Kevin W [Calabasas Hills, CA; Phelps, Amanda [Malibu, CA; Gregoire, Daniel J [Thousand Oaks, CA

    2011-04-26

    A regeneration system comprises a particulate matter (PM) filter including a microwave energy absorbing surface, and an antenna system comprising N antennas and an antenna driver module that sequentially drives the antenna system in a plurality of transverse modes of the antenna system to heat selected portions of the microwave absorbing surface to regenerate the PM filter, where N is an integer greater than one. The transverse modes may include transverse electric (TE) and/or transverse magnetic (TM) modes.

  10. Hardware Implementation of a High Speed Self-Synchronizing Cipher Mode

    E-Print Network [OSTI]

    Heys, Howard

    in a communication channel. The mechanism of SCFB mode resembles output feedback (OFB) mode and cipher feedback (CFB) mode. However it has self synchronization that OFB mode does not and has higher efficiency than CFB@mun.ca cipher work as a stream cipher. Output Feedback (OFB) mode, Cipher Feedback (CFB) mode and Counter (CTR

  11. Special purpose modes in photonic band gap fibers

    DOE Patents [OSTI]

    Spencer, James; Noble, Robert; Campbell, Sara

    2013-04-02

    Photonic band gap fibers are described having one or more defects suitable for the acceleration of electrons or other charged particles. Methods and devices are described for exciting special purpose modes in the defects including laser coupling schemes as well as various fiber designs and components for facilitating excitation of desired modes. Results are also presented showing effects on modes due to modes in other defects within the fiber and due to the proximity of defects to the fiber edge. Techniques and devices are described for controlling electrons within the defect(s). Various applications for electrons or other energetic charged particles produced by such photonic band gap fibers are also described.

  12. Strong ''Quantum'' Chaos in the Global Ballooning Mode Spectrum...

    Office of Scientific and Technical Information (OSTI)

    formalism a chaotic Hamiltonian billiard problem. The minimum width of the toroidal Fourier spectrum needed for resolving toroidally localized ballooning modes with a global...

  13. Stabilization of the Vertical Mode in Tokamaks by Localized Nonaxisymm...

    Office of Scientific and Technical Information (OSTI)

    Mode in Tokamaks by Localized Nonaxisymmetric Fields Vertical instability of a tokamak plasma can be controlled by nonaxisymmetric magnetic fields localized near the plasma...

  14. Sandia Energy - Failure Mode and Effect Analysis (FMEA) Tutorial

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

    and Effect Analysis (FMEA) Tutorial Home Stationary Power Energy Conversion Efficiency Solar Energy Photovoltaics PV Systems Reliability Tutorial on FMEA Process Failure Mode...

  15. Crushing modes of aluminium tubes under axial compression

    E-Print Network [OSTI]

    Florent Henri Marc Rémy Pled; Wenyi Yan; Cui'E Wen

    2014-08-21

    A numerical study of the crushing of circular aluminium tubes with and without aluminium foam fillers has been carried out to investigate their buckling behaviours under axial compression. A crushing mode classification chart has been established for empty tubes. The influence of boundary conditions on crushing mode has also been investigated. The effect of foam filler on the crushing mode of tubes filled with foam was then examined. The predicted results would assist the design of crashworthy tube components with the preferred crushing mode with the maximum energy absorption.

  16. Stability of coupled tearing and twisting modes in tokamaks

    SciTech Connect (OSTI)

    Fitzpatrick, R.

    1994-03-01

    A dispersion relation is derived for resistive modes of arbitrary parity in a tokamak plasma. At low mode amplitude, tearing and twisting modes which have nonideal MHD behavior at only one rational surface at a time in the plasma are decoupled via sheared rotation and diamagnetic flows. At higher amplitude, more unstable {open_quote}compound{close_quote} modes develop which have nonideal behavior simultaneously at many surfaces. Such modes possess tearing parity layers at some of the nonideal surfaces, and twisting parity layers at others, but mixed parity layers are generally disallowed. At low mode number, {open_quote}compound{close_quote} modes are likely to have tearing parity layers at all of the nonideal surfaces in a very low-{beta} plasma, but twisting parity layers become more probable as the plasma {beta} is increased. At high mode number, unstable twisting modes which exceed a critical amplitude drive conventional magnetic island chains on alternate rational surfaces, to form an interlocking structure in which the O-points and X-points of neighboring chains line up.

  17. Enforcement Policy Statement: Off Mode Standards for Central...

    Energy Savers [EERE]

    central air conditioning heat pumps (CACHP), including a new standard for off mode electrical power consumption. 76 Fed. Reg. 37,408. CACHP units manufactured on or after...

  18. Implementing the DC Mode in Cosmological Simulations with Supercomoving Variables

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

    Gnedin, Nickolay Y; Kravtsov, Andrey V; Rudd, Douglas H

    2011-06-02

    As emphasized by previous studies, proper treatment of the density fluctuation on the fundamental scale of a cosmological simulation volume - the 'DC mode' - is critical for accurate modeling of spatial correlations on scales ~> 10% of simulation box size. We provide further illustration of the effects of the DC mode on the abundance of halos in small boxes and show that it is straightforward to incorporate this mode in cosmological codes that use the 'supercomoving' variables. The equations governing evolution of dark matter and baryons recast with these variables are particularly simple and include the expansion factor, andmore »hence the effect of the DC mode, explicitly only in the Poisson equation.« less

  19. Sandia Energy - Turbulent Mixed-Mode Combustion Studied in a...

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

    Turbulent Mixed-Mode Combustion Studied in a New Piloted Burner Home Transportation Energy CRF Office of Science Capabilities News News & Events Research & Capabilities Fuel...

  20. The ArvinMeritor Dual Mode Hybrid Powertrain (DMHP): Opportunities...

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

    ArvinMeritor Dual Mode Hybrid Powertrain (DMHP): Opportunities and Potential for Systems Optimization 2011 DOE Hydrogen and Fuel Cells Program, and Vehicle Technologies Program...

  1. Combined Field Integral Equation Based Theory of Characteristic Mode

    E-Print Network [OSTI]

    Qi I. Dai; Qin S. Liu; Hui Gan; Weng Cho Chew

    2015-03-04

    Conventional electric field integral equation based theory is susceptible to the spurious internal resonance problem when the characteristic modes of closed perfectly conducting objects are computed iteratively. In this paper, we present a combined field integral equation based theory to remove the difficulty of internal resonances in characteristic mode analysis. The electric and magnetic field integral operators are shown to share a common set of non-trivial characteristic pairs (values and modes), leading to a generalized eigenvalue problem which is immune to the internal resonance corruption. Numerical results are presented to validate the proposed formulation. This work may offer efficient solutions to characteristic mode analysis which involves electrically large closed surfaces.

  2. Quasi-Nambu-Goldstone Modes in Bose-Einstein Condensates

    SciTech Connect (OSTI)

    Uchino, Shun [Department of Physics, University of Tokyo, 7-3-1 Hongo, Tokyo 113-0033 (Japan); Kobayashi, Michikazu [Department of Basic Science, University of Tokyo, 3-8-1 Komaba, Tokyo 153-8902 (Japan); Nitta, Muneto [Department of Physics, and Research and Education Center for Natural Sciences, Keio University, 4-1-1 Hiyoshi, Kanagawa 223-8521 (Japan); Ueda, Masahito [Department of Physics, University of Tokyo, 7-3-1 Hongo, Tokyo 113-0033 (Japan); ERATO Macroscopic Quantum Project, JST, Tokyo 113-8656 (Japan)

    2010-12-03

    We show that quasi-Nambu-Goldstone (NG) modes, which play prominent roles in high energy physics but have been elusive experimentally, can be realized with atomic Bose-Einstein condensates. The quasi-NG modes emerge when the symmetry of a ground state is larger than that of the Hamiltonian. When they appear, the conventional vacuum manifold should be enlarged. Consequently, topological defects that are stable within the conventional vacuum manifold become unstable and decay by emitting the quasi-NG modes. Contrary to conventional wisdom, however, we show that the topological defects are stabilized by quantum fluctuations that make the quasi-NG modes massive, thereby suppressing their emission.

  3. Asymmetric modes decomposition in an overmoded relativistic backward wave oscillator

    SciTech Connect (OSTI)

    Zhang, Dian; Zhang, Jun Zhong, Huihuang; Jin, Zhenxing; Ju, Jinchuan

    2014-09-15

    Most of the investigated overmoded relativistic backward wave oscillators (RBWOs) are azimuthally symmetric; thus, they are designed through two dimensional (2-D) particle-in-cell (PIC) simulations. However, 2-D PIC simulations cannot reveal the effect of asymmetric modes on beam-wave interaction. In order to investigate whether asymmetric mode competition needs to be considered in the design of overmoded RBWOs, a numerical method of determining the composition of both symmetric and asymmetric modes in three dimensional (3-D) PIC simulations is introduced in this paper. The 2-D and 3-D PIC simulation results of an X-band overmoded RBWO are analyzed. Our analysis indicates that the 2-D and 3-D PIC simulation results of our device are quite different due to asymmetric mode competition. In fact, asymmetric surface waves, especially EH{sub 11} mode, can lead to serious mode competition when electron beam propagates near the surface of slow wave structures (SWSs). Therefore, additional method of suppressing asymmetric mode competition, such as adjusting the reflections at both ends of SWSs to decrease the Q-factor of asymmetric modes, needs to be utilized in the design of overmoded RBWOs. Besides, 3-D PIC simulation and modes decomposition are essential for designing overmoded RBWOs.

  4. Plasmon modes of metallic nanowires including quantum nonlocal effects

    SciTech Connect (OSTI)

    Moradi, Afshin

    2015-03-15

    The properties of electrostatic surface and bulk plasmon modes of cylindrical metallic nanowires are investigated, using the quantum hydrodynamic theory of plasmon excitation which allows an analytical study of quantum tunneling effects through the Bohm potential term. New dispersion relations are obtained for each type of mode and their differences with previous treatments based on the standard hydrodynamic model are analyzed in detail. Numerical results show by considering the quantum effects, as the value of wave number increases, the surface modes are slightly red-shifted first and then blue-shifted while the bulk modes are blue-shifted.

  5. Annular modes in multiple migrating zonal jet regime

    E-Print Network [OSTI]

    Chan, Cegeon J

    2006-01-01

    Recent studies have linked hemispheric climate variability to annular modes, zonally symmetric structures that describe the horizontal redistribution of atmospheric mass. The resulting changes in the pressure patterns ...

  6. Mode Splitting for Efficient Plasmoinc Thin-film Solar Cell

    E-Print Network [OSTI]

    Li, Tong; Jiang, Chun

    2010-01-01

    We propose an efficient plasmonic structure consisting of metal strips and thin-film silicon for solar energy absorption. We numerically demonstrate the absorption enhancement in symmetrical structure based on the mode coupling between the localized plasmonic mode in Ag strip pair and the excited waveguide mode in silicon slab. Then we explore the method of symmetry-breaking to excite the dark modes that can further enhance the absorption ability. We compare our structure with bare thin-film Si solar cell, and results show that the integrated quantum efficiency is improved by nearly 90% in such thin geometry. It is a promising way for the solar cell.

  7. Quantum dynamics of two-optical modes and a single mechanical mode optomechanical system: selective energy exchange

    E-Print Network [OSTI]

    Neha Aggarwal; Aranya B Bhattacherjee

    2013-02-06

    We study the quantum dynamics of an optomechanical setup comprising two optical modes and one mechanical mode. We show that the same system can undergo a Dicke-Hepp-Lieb superradiant type phase transition. We found that the coupling between the momentum quadratures of the two optical fields give rise to a new critical point. We show that selective energy exchange between any two modes is possible by coherent control of the coupling parameters. In addition we also demonstrate the occurrence of Normal Mode Splitting (NMS) in the mechanical displacement spectrum.

  8. Two-dimensional defect modes in optically induced photonic lattices

    SciTech Connect (OSTI)

    Wang Jiandong; Yang Jianke; Chen Zhigang [Department of Mathematics and Statistics, University of Vermont, Burlington, Vermont 05401 (United States); Department of Physics and Astronomy, San Francisco State University, San Francisco, California 94132 (United States)

    2007-07-15

    In this article, localized linear defect modes due to band gap guidance in two-dimensional photonic lattices with localized or nonlocalized defects are investigated theoretically. First, when the defect is localized and weak, eigenvalues of defect modes bifurcated from edges of Bloch bands are derived analytically. It is shown that in an attractive (repulsive) defect, defect modes bifurcate out from Bloch-band edges with normal (anomalous) diffraction coefficients. Furthermore, distances between defect-mode eigenvalues and Bloch-band edges decrease exponentially with the defect strength, which is very different from the one-dimensional case where such distances decrease quadratically with the defect strength. It is also found that some defect-mode branches bifurcate not from Bloch-band edges, but from quasiedge points within Bloch bands, which is very unusual. Second, when the defect is localized but strong, defect modes are determined numerically. It is shown that both the repulsive and attractive defects can support various types of defect modes such as fundamental, dipole, quadrupole, and vortex modes. These modes reside in various band gaps of the photonic lattice. As the defect strength increases, defect modes move from lower band gaps to higher ones when the defect is repulsive, but remain within each band gap when the defect is attractive, similar to the one-dimensional case. The same phenomena are observed when the defect is held fixed while the applied dc field (which controls the lattice potential) increases. Lastly, if the defect is nonlocalized (i.e., it persists at large distances in the lattice), it is shown that defect modes can be embedded inside the continuous spectrum, and they can bifurcate out from edges of the continuous spectrum algebraically rather than exponentially.

  9. Dual mode stereotactic localization method and application

    DOE Patents [OSTI]

    Keppel, Cynthia E. (Norfolk, VA); Barbosa, Fernando Jorge (Newport News, VA); Majewski, Stanislaw (Grafton, VA)

    2002-01-01

    The invention described herein combines the structural digital X-ray image provided by conventional stereotactic core biopsy instruments with the additional functional metabolic gamma imaging obtained with a dedicated compact gamma imaging mini-camera. Before the procedure, the patient is injected with an appropriate radiopharmaceutical. The radiopharmaceutical uptake distribution within the breast under compression in a conventional examination table expressed by the intensity of gamma emissions is obtained for comparison (co-registration) with the digital mammography (X-ray) image. This dual modality mode of operation greatly increases the functionality of existing stereotactic biopsy devices by yielding a much smaller number of false positives than would be produced using X-ray images alone. The ability to obtain both the X-ray mammographic image and the nuclear-based medicine gamma image using a single device is made possible largely through the use of a novel, small and movable gamma imaging camera that permits its incorporation into the same table or system as that currently utilized to obtain X-ray based mammographic images for localization of lesions.

  10. Search for the decay modes B±?h±?l

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

    Lees, J. P.; Poireau, V.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Milanes, D. A.; Palano, A.; Pappagallo, M.; Eigen, G.; Stugu, B.; et al

    2012-07-16

    We present a search for the lepton flavor violating decay modes B±?h±?l (h=K, ?; l=e, ?) using the BABAR data sample, which corresponds to 472×10? BB¯¯¯ pairs. The search uses events where one B meson is fully reconstructed in one of several hadronic final states. Using the momenta of the reconstructed B, h, and l candidates, we are able to fully determine the ? four-momentum. The resulting ? candidate mass is our main discriminant against combinatorial background. We see no evidence for B±?h±?l decays and set a 90% confidence level upper limit on each branching fraction at the level ofmore »a few times 10??.« less

  11. Search for the decay modes B±?h±?l

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

    Lees, J. P.; Poireau, V.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Milanes, D. A.; Palano, A.; Pappagallo, M.; Eigen, G.; Stugu, B.; Brown, D. N.; Kerth, L. T.; Kolomensky, Yu. G.; Lynch, G.; Koch, H.; Schroeder, T.; Asgeirsson, D. J.; Hearty, C.; Mattison, T. S.; McKenna, J. A.; Khan, A.; Blinov, V. E.; Buzykaev, A. R.; Druzhinin, V. P.; Golubev, V. B.; Kravchenko, E. A.; Onuchin, A. P.; Serednyakov, S. I.; Skovpen, Yu. I.; Solodov, E. P.; Todyshev, K. Yu.; Yushkov, A. N.; Bondioli, M.; Kirkby, D.; Lankford, A. J.; Mandelkern, M.; Stoker, D. P.; Atmacan, H.; Gary, J. W.; Liu, F.; Long, O.; Vitug, G. M.; Campagnari, C.; Hong, T. M.; Kovalskyi, D.; Richman, J. D.; West, C. A.; Eisner, A. M.; Kroseberg, J.; Lockman, W. S.; Martinez, A. J.; Schalk, T.; Schumm, B. A.; Seiden, A.; Cheng, C. H.; Doll, D. A.; Echenard, B.; Flood, K. T.; Hitlin, D. G.; Ongmongkolkul, P.; Porter, F. C.; Rakitin, A. Y.; Andreassen, R.; Huard, Z.; Meadows, B. T.; Sokoloff, M. D.; Sun, L.; Bloom, P. C.; Ford, W. T.; Gaz, A.; Nagel, M.; Nauenberg, U.; Smith, J. G.; Wagner, S. R.; Ayad, R.; Toki, W. H.; Spaan, B.; Kobel, M. J.; Schubert, K. R.; Schwierz, R.; Bernard, D.; Verderi, M.; Clark, P. J.; Playfer, S.; Bettoni, D.; Bozzi, C.; Calabrese, R.; Cibinetto, G.; Fioravanti, E.; Garzia, I.; Luppi, E.; Munerato, M.; Negrini, M.; Piemontese, L.; Santoro, V.; Baldini-Ferroli, R.; Calcaterra, A.; de Sangro, R.; Finocchiaro, G.; Patteri, P.; Peruzzi, I. M.; Piccolo, M.; Rama, M.; Zallo, A.; Contri, R.; Guido, E.; Lo Vetere, M.; Monge, M. R.; Passaggio, S.; Patrignani, C.; Robutti, E.; Bhuyan, B.; Prasad, V.; Lee, C. L.; Morii, M.; Edwards, A. J.; Adametz, A.; Marks, J.; Uwer, U.; Lacker, H. M.; Lueck, T.; Dauncey, P. D.; Behera, P. K.; Mallik, U.; Chen, C.; Cochran, J.; Meyer, W. T.; Prell, S.; Rubin, A. E.; Gritsan, A. V.; Guo, Z. J.; Arnaud, N.; Davier, M.; Derkach, D.; Grosdidier, G.; Le Diberder, F.; Lutz, A. M.; Malaescu, B.; Roudeau, P.; Schune, M. H.; Stocchi, A.; Wormser, G.; Lange, D. J.; Wright, D. M.; Bingham, I.; Chavez, C. A.; Coleman, J. P.; Fry, J. R.; Gabathuler, E.; Hutchcroft, D. E.; Payne, D. J.; Touramanis, C.; Bevan, A. J.; Di Lodovico, F.; Sacco, R.; Sigamani, M.; Cowan, G.; Brown, D. N.; Davis, C. L.; Denig, A. G.; Fritsch, M.; Gradl, W.; Hafner, A.; Prencipe, E.; Alwyn, K. E.; Bailey, D.; Barlow, R. J.; Jackson, G.; Lafferty, G. D.; Behn, E.; Cenci, R.; Hamilton, B.; Jawahery, A.; Roberts, D. A.; Simi, G.; Dallapiccola, C.; Cowan, R.; Dujmic, D.; Sciolla, G.; Lindemann, D.; Patel, P. M.; Robertson, S. H.; Schram, M.; Biassoni, P.; Neri, N.; Palombo, F.; Stracka, S.; Cremaldi, L.; Godang, R.; Kroeger, R.; Sonnek, P.; Summers, D. J.; Nguyen, X.; Simard, M.; Taras, P.; De Nardo, G.; Monorchio, D.; Onorato, G.; Sciacca, C.; Martinelli, M.; Raven, G.; Jessop, C. P.; Knoepfel, K. J.; LoSecco, J. M.; Wang, W. F.; Honscheid, K.; Kass, R.; Brau, J.; Frey, R.; Sinev, N. B.; Strom, D.; Torrence, E.; Feltresi, E.; Gagliardi, N.; Margoni, M.; Morandin, M.; Posocco, M.; Rotondo, M.; Simonetto, F.; Stroili, R.; Akar, S.; Ben-Haim, E.; Bomben, M.; Bonneaud, G. R.; Briand, H.; Calderini, G.; Chauveau, J.; Hamon, O.; Leruste, Ph.; Marchiori, G.; Ocariz, J.; Sitt, S.; Biasini, M.; Manoni, E.; Pacetti, S.; Rossi, A.; Angelini, C.; Batignani, G.; Bettarini, S.; Carpinelli, M.; Casarosa, G.; Cervelli, A.; Forti, F.; Giorgi, M. A.; Lusiani, A.; Oberhof, B.; Paoloni, E.; Perez, A.; Rizzo, G.; Walsh, J. J.; Lopes Pegna, D.; Lu, C.; Olsen, J.; Smith, A. J. S.; Telnov, A. V.; Anulli, F.; Cavoto, G.; Faccini, R.; Ferrarotto, F.; Ferroni, F.; Gaspero, M.; Li Gioi, L.; Mazzoni, M. A.; Piredda, G.; Bünger, C.; Grünberg, O.; Hartmann, T.; Leddig, T.; Schröder, H.; Voss, C.; Waldi, R.; Adye, T.; Olaiya, E. O.; Wilson, F. F.; Emery, S.; Hamel de Monchenault, G.; Vasseur, G.; Yèche, Ch.; Aston, D.; Bard, D. J.; Bartoldus, R.; Cartaro, C.; Convery, M. R.; Dorfan, J.; Dubois-Felsmann, G. P.; Dunwoodie, W.; Ebert, M.; Field, R. C.; Franco Sevilla, M.; Fulsom, B. G.; Gabareen, A. M.; Graham, M. T.; Grenier, P.; Hast, C.; Innes, W. R.; Kelsey, M. H.; Kim, P.; Kocian, M. L.; Leith, D. W. G. S.; Lewis, P.; Lindquist, B.; Luitz, S.; Luth, V.; Lynch, H. L.; MacFarlane, D. B.; Muller, D. R.; Neal, H.; Nelson, S.; Perl, M.; Pulliam, T.; Ratcliff, B. N.; Roodman, A.; Salnikov, A. A.; Schindler, R. H.; Snyder, A.; Su, D.; Sullivan, M. K.; Va’vra, J.; Wagner, A. P.; Weaver, M.; Wisniewski, W. J.; Wittgen, M.; Wright, D. H.; Wulsin, H. W.; Young, C. C.; Ziegler, V.; Park, W.; Purohit, M. V.; White, R. M.; Wilson, J. R.; Randle-Conde, A.; Sekula, S. J.; Bellis, M.; Benitez, J. F.; Burchat, P. R.; Miyashita, T. S.; Alam, M. S.; Ernst, J. A.; Gorodeisky, R.; Guttman, N.; Peimer, D. R.; Soffer, A.; Lund, P.; Spanier, S. M.; Eckmann, R.; Ritchie, J. L.

    2012-07-01

    We present a search for the lepton flavor violating decay modes B±?h±?l (h=K, ?; l=e, ?) using the BABAR data sample, which corresponds to 472×10? BB¯¯¯ pairs. The search uses events where one B meson is fully reconstructed in one of several hadronic final states. Using the momenta of the reconstructed B, h, and l candidates, we are able to fully determine the ? four-momentum. The resulting ? candidate mass is our main discriminant against combinatorial background. We see no evidence for B±?h±?l decays and set a 90% confidence level upper limit on each branching fraction at the level of a few times 10??.

  12. Tests of mode-coupling theory in two dimensions

    E-Print Network [OSTI]

    Fabian Weysser; David Hajnal

    2011-04-26

    We analyze the glassy dynamics of a binary mixtures of hard disks in two dimensions. Predictions of the Mode-Coupling theory(MCT) are tested with extensive Brownian dynamics simulations. Measuring the collective particle density correlation functions in the vicinity of the glass transition we verify four predicted mixing effects. For instance, for large size disparities, adding a small amount of small particles at fixed packing fraction leads to a speed up in the long time dynamics, while at small size disparity it leads to a slowing down. Qualitative features of the non-ergodicity parameters and the $\\beta$-relaxation which both depend in a non-trivial way on the mixing ratio are found in the simulated correlators. Studying one system in detail we are able to determine its ideal MCT glass transition point as $\\phi^c = 0.7948$ and test MCT predictions quantitatively.

  13. Exact quasinormal modes for a special class of black holes

    E-Print Network [OSTI]

    Julio Oliva; Ricardo Troncoso

    2010-03-11

    Analytic exact expressions for the quasinormal modes of scalar and electromagnetic perturbations around a special class of black holes are found in d\\ge3 dimensions. It is shown that, the size of the black hole provides a bound for the angular momentum of the perturbation. Quasinormal modes appear when this bound is fulfilled, otherwise the excitations become purely damped.

  14. Numerical Study of Acoustic Modes in Ducted Shear Flow

    E-Print Network [OSTI]

    Rienstra, Sjoerd W.

    Numerical Study of Acoustic Modes in Ducted Shear Flow Gregory G. Vilenski & Sjoerd W. Rienstra mean flow inside a duct is studied numerically. For isentropic flow in a circular duct with zero swirl 26, 2007 #12;1 Introduction Normal mode analysis of small-amplitude disturbances in an annular duct

  15. Improved Wireless Performance from Mode Scattering in Ventilation Ducts

    E-Print Network [OSTI]

    Stancil, Daniel D.

    Improved Wireless Performance from Mode Scattering in Ventilation Ducts Benjamin E. Henty, PA 15230. henty@eirp.org and stancil@cmu.edu Abstract Ventilation ducts are a convenient undesirable in a ven- tilation duct setting. With this in mind we investigate the mode scattering effects

  16. Learning in a Studio Mode, Spotlighting Teamwork and

    E-Print Network [OSTI]

    Lin, Xi

    students supported by one instructor, 2 TF's, and 2 LA's" Focus on teamwork & active engagement" Learning student-centered active learning. 3/7/14Learning in a Studio Mode Why do Studio? Better learning overall Students like it better #12;3 Class design: Lecture 3/7/14Learning in a Studio Mode Lecture

  17. Pulse-mode temperature sensing with langasite SAW devices

    E-Print Network [OSTI]

    Greve, David.W.

    combustion process. Their temperature responses were measured in pulse mode both wired to a highPulse-mode temperature sensing with langasite SAW devices Peng Zheng*1,2 , T.-L. Chin1,3 , David W is increasingly important for many industrial processes, such as control of oxy-fuel combustion

  18. Transmission mode and disease thresholds in host communities Janis Antonovics,

    E-Print Network [OSTI]

    Antonovics, Janis

    1 Transmission mode and disease thresholds in host communities Janis Antonovics, Department of Biology, University of Virginia, VA 22904, USA E-mail: ja8n@virginia.edu Running title Transmission mode transmission have close analogies with thresholds for species persistence when there is competition

  19. Localized radio frequency communication using asynchronous transfer mode protocol

    DOE Patents [OSTI]

    Witzke, Edward L. (Edgewood, NM); Robertson, Perry J. (Albuquerque, NM); Pierson, Lyndon G. (Albuquerque, NM)

    2007-08-14

    A localized wireless communication system for communication between a plurality of circuit boards, and between electronic components on the circuit boards. Transceivers are located on each circuit board and electronic component. The transceivers communicate with one another over spread spectrum radio frequencies. An asynchronous transfer mode protocol controls communication flow with asynchronous transfer mode switches located on the circuit boards.

  20. Mirror Mode Structures in the Solar Wind: STEREO Observations

    E-Print Network [OSTI]

    California at Berkeley, University of

    Mirror Mode Structures in the Solar Wind: STEREO Observations O. Enríquez-Rivera1 , X. Blanco-Cano1 Autónoma de México, Coyoacán, D.F., 04510, MEXICO 2. Institute of Geophysics and Planetary Physics of California, Berkeley, CA 94720, USA Abstract. Mirror mode structures occur in the solar wind either

  1. October 6, 1997 ITER L-Mode Con nement Database

    E-Print Network [OSTI]

    October 6, 1997 ITER L-Mode Con nement Database S.M. Kaye and the ITER Con nement Database Working Group Abstract This paper describes the content of an L-mode database that has been compiled with data, and Tore-Supra. The database consists of a total of 2938 entries, 1881 of which are in the L-phase while

  2. FAILURE MODES AND EFFECTS ANALYSIS Dated: May 27, 2010

    E-Print Network [OSTI]

    Princeton Plasma Physics Laboratory

    1 NSTX FAILURE MODES AND EFFECTS ANALYSIS (FMEA) Revision 7 Dated: May 27, 2010 Prepared By: Name.07.13 09:11:02 -04'00' #12;NSTX Failure Modes & Effects Analysis / NSTX-FMEA-71-7 / p. 2 of 120 2 Table

  3. Kinetic theory of geodesic acoustic and related modes

    E-Print Network [OSTI]

    be driven by high energy partricles? Transport regulation/modulation? Coupling to high energy particles-mode?" oscillations with · 1992: Chu, Green et al., Coupling of Alfven and sound continuum via geodesic curvature dispersion relation with 7/4, electromagnetic (Alfven modes) effects but no references to Winsor, Green

  4. Three-dimensional Bernstein-Greene-Kruskal modes in a

    E-Print Network [OSTI]

    Ng, Chung-Sang

    Three-dimensional Bernstein- Greene-Kruskal modes in a multi-species plasma: Void solutions-dimensional (3D) Bernstein- Greene-Kruskal (BGK) mode [Ng and Bhattacharjee, Phys. Rev. Lett., 95, 245004 (2005 and the distribution function of the other species depending on energy and angular momentum. Some of these solutions

  5. Temporal coupled-mode theory for resonant Lieven Verslegers,1,

    E-Print Network [OSTI]

    Fan, Shanhui

    are concepts that are fundamentally important for character- izing electromagnetic properties of individualTemporal coupled-mode theory for resonant apertures Lieven Verslegers,1, * Zongfu Yu,1 Peter B 9, 2010 We develop the coupled-mode theory for nanoscale resonant apertures. We show

  6. Generation of hyper climate modes D. Dommenget1

    E-Print Network [OSTI]

    Dommenget, Dietmar

    -tropics, leading to the formulation of a theory for ``Global Hyper Climate Modes'' as forced by local air climate variability is obtained from a statistical analysis of global SSTs for the period 1870­2004 using `hyper mode' was first coined by T. Barnett, 1994 personal communications). It is characterised

  7. New Equipartition Results for Normal Mode Energies of Anharmonic Chains

    E-Print Network [OSTI]

    Henry, Bruce Ian

    New Equipartition Results for Normal Mode Energies of Anharmonic Chains B.I. Henry 1 and T. Szeredi 2;3 Date: 26 September 1995 The canonical and micro­canonical distribution of energy among. If the inter­particle potential is an even function then energy is distributed uniformly among the normal modes

  8. High-frequency modes in solar-like stars

    E-Print Network [OSTI]

    C. Karoff

    2007-08-14

    p-mode oscillations in solar-like stars are excited by the outer convection zone in these stars and reflected close to the surface. The p-modes are trapped inside an acoustic cavity, but the modes only stay trapped up to a given frequency (known as the acoustic cut-off frequency) as modes with larger frequencies are generally not reflected at the surface. This means that modes with frequency larger than the acoustic cut-off frequency must be traveling waves. The high-frequency modes may provide information about the physics in the outer layers of the stars and the excitation source and are therefore highly interesting as it is the estimation of these two phenomena that causes some of the largest uncertainties when calculating stellar oscillations. High-frequency modes have been detected in the Sun, beta Hydri and in alpha Cen A & B by smoothing the so-called echelle diagram and the large frequency separation as a function of frequency have been estimated. The large frequency separation has been compared with a simple model of the acoustic cavity which suggests that the reflectivity of the photosphere is larger at high frequency than predicted by standard models of the solar atmosphere and that the depth of the excitation source is larger than what has been estimated by other models and might depend on the order n and degree l of the modes.

  9. Low-loss guided modes in photonic crystal waveguides

    E-Print Network [OSTI]

    @fisicavolta.unipv.it Abstract: We study disorder-induced propagation losses of guided modes in photonic crystal slabs with line-defects. Meade, and J. N. Winn, Photonic Crystals: Molding the Flow of Light (Princeton University Press. Takahashi, and I. Yokohama, "Structural tuning of guiding modes of line-defect waveguides of Silicon

  10. CHARACTERIZATION OF ORBITAL ANGULAR MOMENTUM MODES IN FEL RADIATION

    E-Print Network [OSTI]

    Brookhaven National Laboratory

    CHARACTERIZATION OF ORBITAL ANGULAR MOMENTUM MODES IN FEL RADIATION E. Hemsing , G. Andonian, J singularity on axis. Here we discuss current efforts to characterize the mode content of the VISA FEL through are discussed. INTRODUCTION Free-electron lasers (FELs) have long been used as tun- able sources of coherent

  11. Backward and forward modes guided by metal-dielectric-metal

    E-Print Network [OSTI]

    Backward and forward modes guided by metal-dielectric-metal plasmonic waveguides Arthur R. Davoyan by metal-dielectric-metal plasmonic waveguides Arthur R. Davoyan,a Ilya V. Shadrivov,a Sergey I.davoyan@gmail.com Abstract. We revisited the problem of the existence of plasmonic modes guided by metal- dielectric-metal

  12. Mode coherence at megameter ranges in the North Pacific Ocean

    E-Print Network [OSTI]

    Wage, Kathleen

    Mode coherence at megameter ranges in the North Pacific Ocean Kathleen E. Wage, Matthew A and the Acoustical Society of America. #12;Mode coherence at megameter ranges in the North Pacific Ocean Kathleen E Thermometry of Ocean Climate ATOC and Alternate Source Test AST experiments. Vertical line arrays at Hawaii

  13. Keyboard design variables in dual task mode selection 

    E-Print Network [OSTI]

    Hansen, Mark Douglas

    1982-01-01

    -handedness. In addition, each subject signed VHF ALT FLT RPM NAV OPR NpR UHF Mode Selection Di s pl ay ALT VHF FLT RPM OPR UHF NAV FPR~ Spatial Analog on the 3x3 Keyboard Figure 1 Mode Selection Display and Spatial Analog for the Keyboards 12 and dated a...

  14. Relation Between Type-II ELMs, Edge Localized Turbulence, Washboard Modes and Energy Losses Between ELMs in High Density ELMy H-modes on JET

    E-Print Network [OSTI]

    Relation Between Type-II ELMs, Edge Localized Turbulence, Washboard Modes and Energy Losses Between ELMs in High Density ELMy H-modes on JET

  15. On the saturation amplitude of the f-mode instability

    E-Print Network [OSTI]

    Kastaun, Wolfgang; Kokkotas, Kostas D

    2010-01-01

    We investigate strong nonlinear damping effects which occur during high amplitude oscillations of neutron stars, and the gravitational waves they produce. For this, we use a general relativistic nonlinear hydrodynamics code in conjunction with a fixed spacetime (Cowling approximation) and a polytropic equation of state (EOS). Gravitational waves are estimated using the quadrupole formula. Our main interest are $l=m=2$ $f$-modes subject to the CFS (Chandrasekhar, Friedman, Schutz) instability, but we also investigate axisymmetric and quasi-radial modes. We study various models to determine the influence of rotation rate and EOS. We find that axisymmetric oscillations at high amplitudes are predominantly damped by shock formation, while the non-axisymmetric $f$-modes are mainly damped by wave breaking and, for rapidly rotating models, coupling to non-axisymmetric inertial modes. From the observed nonlinear damping, we derive upper limits for the saturation amplitude of CFS-unstable $f$-modes. Finally, we estima...

  16. Nonlinear dynamics of multiple neoclassical tearing modes in tokamaks

    SciTech Connect (OSTI)

    Chandra, D.; Sen, A. [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India); Agullo, O.; Benkadda, S. [France-Japan Magnetic Fusion Lab, LIA 336, CNRS/Lab PIIM, UMR 6633, CNRS-Universite de Provence, 13397 Marseille (France); Garbet, X. [Association Euratom-CEA, DRFC, CEA Cadarache, 13108 St-Paul-Lez-Durance (France)

    2013-04-15

    Numerical simulations investigating the interaction of co-existent 2/1 and 3/1 neoclassical tearing modes are presented. The results obtained from an initial value 3D toroidal code that solves a set of generalized reduced MHD equations exhibit a host of complex phenomena arising from the coupling of the two modes. These include a modification of the island saturation widths of the two modes, a significant modification in the perpendicular flow patterns in the vicinity of the islands, and the excitation of geodesic acoustic mode like oscillations that lead to concomitant oscillations in the kinetic and magnetic energies of the islands. These oscillations only occur in the presence of the neoclassical stress tensor contribution and are absent for two coupled classical tearing modes.

  17. Spin diffusive modes and thermal transport in neutron star crusts

    E-Print Network [OSTI]

    Sedrakian, Armen

    2015-01-01

    In this contribution we first review a method for obtaining the collective modes of pair-correlated neutron matter as found in a neutron star inner crust. We discuss two classes of modes corresponding to density and spin perturbations with energy spectra $\\omega = \\omega_0 + \\alpha q^2$, where $\\omega_0 = 2\\Delta$ is the threshold frequency and $\\Delta$ is the gap in the neutron fluid spectrum. For characteristic values of Landau parameters in neutron star crusts the exitonic density modes have $\\alpha 0$ and they exist above $\\omega_0$ which implies that these modes are damped. As an application of these findings we compute the thermal conductivity due to spin diffusive modes and show that it scales as $T^{1/2} \\exp(-2\\omega_0/T)$ in the case where their two-by-two scattering cross-section is weakly dependent on temperature.

  18. Fast ion transport induced by saturated infernal mode

    SciTech Connect (OSTI)

    Marchenko, V. S., E-mail: march@kinr.kiev.ua [Institute for Nuclear Research, Kyiv (Ukraine)

    2014-05-15

    Tokamak discharges with extended weak-shear central core are known to suffer from infernal modes when the core safety factor approaches the mode ratio. These modes can cause an outward convection of the well-passing energetic ions deposited in the core by fusion reactions and/or neutral beam injection. Convection mechanism consists in collisional slowing down of energetic ions trapped in the Doppler-precession resonance with a finite-amplitude infernal mode. Convection velocity can reach a few m/s in modern spherical tori. Possible relation of this transport with the enhanced fast ion losses in the presence of “long lived modes” in the MAST tokamak [I. T. Chapman et al., Nucl. Fusion 50, 045007 (2010)] is discussed.

  19. Modification of emission from the X-mode at the third electron cyclotron harmonic from mode conversion and reflection

    E-Print Network [OSTI]

    Ng, Chung-Sang

    Modification of emission from the X-mode at the third electron cyclotron harmonic from mode (Received 1 August 1994; accepted 31 October 1994) Both absorption and emission of the X and emission. The transmission is shown to be independent of absorption, and the emission is related

  20. Observation of high-frequency secondary modes during strong tearing mode activity in FTU plasmas without fast ions

    E-Print Network [OSTI]

    Vlad, Gregorio

    1 EX/P5-1 Observation of high-frequency secondary modes during strong tearing mode activity in FTU has revealed high frequency (HF) oscillations between 30 and 70 kHz that accompany the development. Introduction High frequency oscillations in magnetically confined plasmas have been identified as discrete

  1. MemScale: Active Low-Power Modes for Main Memory Qingyuan Deng

    E-Print Network [OSTI]

    Wenisch, Thomas F.

    is responsible for a large and increasing fraction of the energy consumed by servers. Prior work has focused on exploiting DRAM low-power states to conserve energy. However, these states require entire DRAM ranks to conserve memory energy while improving its energy- proportionality by creating active low-power modes

  2. Spontaneous Lorentz and diffeomorphism violation, massive modes, and gravity

    SciTech Connect (OSTI)

    Bluhm, Robert; Fung Shuhong; Kostelecky, V. Alan

    2008-03-15

    Theories with spontaneous local Lorentz and diffeomorphism violation contain massless Nambu-Goldstone modes, which arise as field excitations in the minimum of the symmetry-breaking potential. If the shape of the potential also allows excitations above the minimum, then an alternative gravitational Higgs mechanism can occur in which massive modes involving the metric appear. The origin and basic properties of the massive modes are addressed in the general context involving an arbitrary tensor vacuum value. Special attention is given to the case of bumblebee models, which are gravitationally coupled vector theories with spontaneous local Lorentz and diffeomorphism violation. Mode expansions are presented in both local and spacetime frames, revealing the Nambu-Goldstone and massive modes via decomposition of the metric and bumblebee fields, and the associated symmetry properties and gauge fixing are discussed. The class of bumblebee models with kinetic terms of the Maxwell form is used as a focus for more detailed study. The nature of the associated conservation laws and the interpretation as a candidate alternative to Einstein-Maxwell theory are investigated. Explicit examples involving smooth and Lagrange-multiplier potentials are studied to illustrate features of the massive modes, including their origin, nature, dispersion laws, and effects on gravitational interactions. In the weak static limit, the massive mode and Lagrange-multiplier fields are found to modify the Newton and Coulomb potentials. The nature and implications of these modifications are examined.

  3. Competition between modes with different axial structures in gyrotrons

    SciTech Connect (OSTI)

    Khutoryan, Eduard M.; Nusinovich, Gregory S.; Sinitsyn, Oleksandr V.

    2014-09-15

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

  4. Bunch mode specific rate corrections for PILATUS3 detectors

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

    Trueb, P.; Dejoie, C.; Kobas, M.; Pattison, P.; Peake, D. J.; Radicci, V.; Sobott, B. A.; Walko, D. A.; Broennimann, C.

    2015-04-09

    PILATUS X-ray detectors are in operation at many synchrotron beamlines around the world. This article reports on the characterization of the new PILATUS3 detector generation at high count rates. As for all counting detectors, the measured intensities have to be corrected for the dead-time of the counting mechanism at high photon fluxes. The large number of different bunch modes at these synchrotrons as well as the wide range of detector settings presents a challenge for providing accurate corrections. To avoid the intricate measurement of the count rate behaviour for every bunch mode, a Monte Carlo simulation of the counting mechanismmore »has been implemented, which is able to predict the corrections for arbitrary bunch modes and a wide range of detector settings. This article compares the simulated results with experimental data acquired at different synchrotrons. It is found that the usage of bunch mode specific corrections based on this simulation improves the accuracy of the measured intensities by up to 40% for high photon rates and highly structured bunch modes. For less structured bunch modes, the instant retrigger technology of PILATUS3 detectors substantially reduces the dependency of the rate correction on the bunch mode. The acquired data also demonstrate that the instant retrigger technology allows for data acquisition up to 15 million photons per second per pixel.« less

  5. Separating and combining single-mode and multimode optical beams

    DOE Patents [OSTI]

    Ruggiero, Anthony J; Masquelier, Donald A; Cooke, Jeffery B; Kallman, Jeffery S

    2013-11-12

    Techniques for combining initially separate single mode and multimode optical beams into a single "Dual Mode" fiber optic have been developed. Bi-directional propagation of two beams that are differentiated only by their mode profiles (i.e., wavefront conditions) is provided. The beams can be different wavelengths and or contain different modulation information but still share a common aperture. This method allows the use of conventional micro optics and hybrid photonic packaging techniques to produce small rugged packages suitable for use in industrial or military environments.

  6. Photon temporal modes: a complete framework for quantum information science

    E-Print Network [OSTI]

    B. Brecht; Dileep V. Reddy; C. Silberhorn; M. G. Raymer

    2015-07-30

    Field-orthogonal temporal modes of photonic quantum states provide a new framework for quantum information science (QIS). They intrinsically span a high-dimensional Hilbert space and lend themselves to integration into existing single-mode fiber communication networks. We show that the three main requirements to construct a valid framework for QIS -- the controlled generation of resource states, the targeted and highly efficient manipulation of temporal modes and their efficient detection -- can be fulfilled with current technology. We suggest implementations of diverse QIS applications based on this complete set of building blocks.

  7. Multiprocessor system with multiple concurrent modes of execution

    DOE Patents [OSTI]

    Ahn, Daniel; Ceze, Luis H; Chen, Dong; Gara, Alan; Heidelberger, Philip; Ohmacht, Martin

    2013-12-31

    A multiprocessor system supports multiple concurrent modes of speculative execution. Speculation identification numbers (IDs) are allocated to speculative threads from a pool of available numbers. The pool is divided into domains, with each domain being assigned to a mode of speculation. Modes of speculation include TM, TLS, and rollback. Allocation of the IDs is carried out with respect to a central state table and using hardware pointers. The IDs are used for writing different versions of speculative results in different ways of a set in a cache memory.

  8. CMB hemispherical asymmetry: long mode modulation and non-Gaussianity

    SciTech Connect (OSTI)

    Namjoo, Mohammad Hossein; Baghram, Shant; Firouzjahi, Hassan; Abolhasani, Ali Akbar E-mail: abolhasani@ipm.ir E-mail: firouz@ipm.ir

    2014-08-01

    The observed hemispherical asymmetry in CMB map can be explained by modulation from a long wavelength super horizon mode which non-linearly couples to the CMB modes. We address the criticism in [1] about the role of non-Gaussianities in squeezed and equilateral configurations in generating hemispherical asymmetry from the long mode modulation. We stress that the modulation is sensitive to the non-Gaussianity in the squeezed limit. In addition, we demonstrate the validity of our approach in providing a consistency condition relating the amplitude of dipole asymmetry to f{sub NL} in the squeezed limit.

  9. Comparison of Two Self-Synchronizing Cipher Modes Fang Yang and Howard M. Heys

    E-Print Network [OSTI]

    Heys, Howard

    the basic cipher feedback (CFB) mode, but, although both modes are suitable for high speed digital hardware] and optimized cipher feedback (OCFB) mode [2]. II. BACKGROUND Cipher feedback (CFB) mode and output feedback length and m to represent the feedback size. CFB mode, as shown in Figure 1, encrypts m bits of plaintext

  10. Hardware Design and Analysis of Statistical Cipher Feedback Mode Using Serial Transfer

    E-Print Network [OSTI]

    Heys, Howard

    to the Ciphertext Queue. SCFB mode is the hybrid of output feedback (OFB) mode and cipher feedback (CFB) mode feeds back ciphertext to the input of the block cipher similar to the conventional CFB mode, except- plementation than conventional CFB mode. An iterative based implementation of the Advanced Encryption Strandard

  11. Growth rate of the tidal p-mode g-mode instability in coalescing binary neutron stars

    E-Print Network [OSTI]

    Weinberg, Nevin N

    2015-01-01

    We recently described an instability due to the nonlinear coupling of p-modes to g-modes and, as an application, we studied the stability of the tide in coalescing binary neutron stars. Although we found that the tide is p-g unstable early in the inspiral and rapidly drives modes to large energies, our analysis only accounted for three-mode interactions. Venumadhav, Zimmerman, and Hirata showed that four-mode interactions must also be accounted for as they enter into the analysis at the same order. They found a near-exact cancellation between three- and four-mode interactions and concluded that while the tide in binary neutron stars can be p-g unstable, the growth rates are not fast enough to impact the gravitational wave signal. Their analysis assumes that the linear tide is incompressible, which is true of the static linear tide (the m=0 harmonic) but not the non-static linear tide (m=+/- 2). Here we account for the compressibility of the non-static linear tide and find that the three- and four-mode interac...

  12. Coherence area profiling in multi-spatial-mode squeezed states

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

    Lawrie, Benjamin J.; Pooser, Raphael C.; Otterstrom, Nils T.

    2015-09-12

    The presence of multiple bipartite entangled modes in squeezed states generated by four-wave mixing enables ultra-trace sensing, imaging, and metrology applications that are impossible to achieve with single-spatial-mode squeezed states. For Gaussian seed beams, the spatial distribution of these bipartite entangled modes, or coherence areas, across each beam is largely dependent on the spatial modes present in the pump beam, but it has proven difficult to map the distribution of these coherence areas in frequency and space. We demonstrate an accessible method to map the distribution of the coherence areas within these twin beams. We also show that the pumpmore »shape can impart different noise properties to each coherence area, and that it is possible to select and detect coherence areas with optimal squeezing with this approach.« less

  13. Unusual Layer-Dependent Charge Distribution, Collective Mode...

    Office of Scientific and Technical Information (OSTI)

    Layer-Dependent Charge Distribution, Collective Mode Coupling, and Superconductivity in Multilayer Cuprate Ba2Ca3Cu4O8F2 Citation Details In-Document Search Title: Unusual...

  14. Entanglement conditions for two-mode states: Applications 

    E-Print Network [OSTI]

    Hillery, Mark; Zubairy, M. Suhail

    2006-01-01

    We examine the implications of several recently derived conditions [Hillery and Zubairy, Phys. Rev. Lett. 96, 050503 (2006)] for determining when a two-mode state is entangled. We first find examples of non-Gaussian states ...

  15. High efficiency switching-mode amplifiers for wireless communication systems

    E-Print Network [OSTI]

    Hung, Tsai-Pi

    2008-01-01

    M. Asbeck, “Design of high-efficiency current-mode class-Dand G. Rabjohn, “A high efficiency Chireix Out- phasingE-A new class of high efficiency tuned single-ended power

  16. Synthesis of electromagnetic modes in photonic band gap fibers

    E-Print Network [OSTI]

    Hu, Qichao

    2007-01-01

    In this paper, we report on the successful synthesis of three individual modes, HE11, TEo0, and TE02 for transmission in photonic band gap fibers at near infrared wavelengths. We measure the propagation losses of the HE11 ...

  17. Vertical Transport of Subwavelength Localized Surface Electromagnetic Modes

    E-Print Network [OSTI]

    Gao, Fei; Zhang, Youming; Shi, Xihang; Yang, Zhaoju; Zhang, Baile

    2015-01-01

    Transport of subwavelength electromagnetic (EM) energy has been achieved through near-field coupling of highly confined surface EM modes supported by plasmonic nanoparticles, in a configuration usually staying on a two-dimensional (2D) substrate. Vertical transport of similar modes along the third dimension, on the other hand, can bring more flexibility in designs of functional photonic devices, but this phenomenon has not been observed in reality. In this paper, designer (or spoof) surface plasmon resonators (plasmonic meta-atoms) are stacked in the direction vertical to their individual planes in demonstrating vertical transport of subwavelength localized surface EM modes. Dispersion relation of this vertical transport is determined from coupled mode theory and is verified with near-field transmission spectrum and field mapping with a microwave near-field scanning stage. This work extends the near-field coupled resonator optical waveguide (CROW) theory into the vertical direction, and may find applications ...

  18. A Sliding Mode Multimodel Control for a Sensorless Photovoltaic System

    E-Print Network [OSTI]

    Ahmed Rhif; Zohra Kardous; Naceur BenHadj Braiek

    2013-01-12

    In this work we will talk about a new control test using the sliding mode control with a nonlinear sliding mode observer, which are very solicited in tracking problems, for a sensorless photovoltaic panel. In this case, the panel system will has as a set point the sun position at every second during the day for a period of five years; then the tracker, using sliding mode multimodel controller and a sliding mode observer, will track these positions to make the sunrays orthogonal to the photovoltaic cell that produces more energy. After sunset, the tracker goes back to the initial position (which of sunrise). Experimental measurements show that this autonomic dual axis Sun Tracker increases the power production by over 40%.

  19. MODE II FRACTURE BEHAVIOR OF BONDED VISCOELASTIC THERMAL COMPRESSED WOOD

    E-Print Network [OSTI]

    Nairn, John A.

    MODE II FRACTURE BEHAVIOR OF BONDED VISCOELASTIC THERMAL COMPRESSED WOOD Andreja Kutnar* Graduate Student Department of Wood Science and Technology Biotechnical Faculty University of Ljubljana 1000 Ljubljana, Slovenia Frederick A. Kamke Professor John A. Nairn Professor Department of Wood Science

  20. Gearbox Typical Failure Modes, Detection, and Mitigation Methods (Presentation)

    SciTech Connect (OSTI)

    Sheng, S.

    2014-01-01

    This presentation was given at the AWEA Operations & Maintenance and Safety Seminar and focused on what the typical gearbox failure modes are, how to detect them using detection techniques, and strategies that help mitigate these failures.

  1. Instantons and quark zero modes in AdS/QCD

    E-Print Network [OSTI]

    Jacopo Bechi

    2009-09-16

    In this paper the quark zero modes creation effect is studied in the context of the AdS/QCD approach. This effect is generated, in presence of instantons, by a new that can be added in the bulk.

  2. FlexMarket : a transient mode of local exchange

    E-Print Network [OSTI]

    Dunnam, Jennifer (Jennifer L.)

    2012-01-01

    This thesis presents the idea of a networked, transient mode of local food exchange and proposes a responsive infrastructure for integrating dynamic markets within the urban fabric. Focusing on market typologies as an area ...

  3. Stabilization of the resistive shell mode in tokamaks

    SciTech Connect (OSTI)

    Fitzpatrick, R.; Aydemir, A.

    1995-02-01

    The stability of current-driven external-kink modes is investigated in a tokamak plasma surrounded by an external shell of finite electrical conductivity. According to conventional theory, the ideal mode can be stabilized by placing the shell sufficiently close to the plasma, but the non-rotating ``resistive shell mode,`` which grows on the characteristic L/R time of the shell, always persists. It is demonstrated, using both analytic and numerical techniques, that a combination of strong edge plasma rotation and dissipation somewhere inside the plasma is capable of stabilizing the resistive shell mode. This stabilization mechanism does not necessarily depend on toroidicity or presence of resonant surfaces inside the plasma.

  4. Large mode-volume, large beta, photonic crystal laser resonator

    SciTech Connect (OSTI)

    Dezfouli, Mohsen Kamandar; Dignam, Marc M. [Department of Physics, Engineering Physics and Astronomy, Queen’s University, Kingston, ON K7L 3N6 (Canada)

    2014-12-15

    We propose an optical resonator formed from the coupling of 13, L2 defects in a triangular-lattice photonic crystal slab. Using a tight-binding formalism, we optimized the coupled-defect cavity design to obtain a resonator with predicted single-mode operation, a mode volume five times that of an L2-cavity mode and a beta factor of 0.39. The results are confirmed using finite-difference time domain simulations. This resonator is very promising for use as a single mode photonic crystal vertical-cavity surface-emitting laser with high saturation output power compared to a laser consisting of one of the single-defect cavities.

  5. On the ordinary mode instability for low beta plasmas

    SciTech Connect (OSTI)

    Hadi, F.; Qamar, A. [Institute of Physics and Electronics, University of Peshawar, Peshawar (Pakistan); Bashir, M. F. [Department of Physics, G. C. University, Lahore (Pakistan); Salam Chair in Physics, G. C. University, Lahore (Pakistan); Yoon, P. H. [Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 20742-2431 (United States); School of Space Research, Kyung Hee University, Yongin (Korea, Republic of); Schlickeiser, R. [Institut für Theoretische Physik, Lehrstuhl IV: Weltraum- and Astrophysik, Ruhr-Universität, Bochum (Germany)

    2014-05-15

    The purely growing ordinary (O) mode instability, first discussed by Davidson and Wu [Phys. Fluids 13, 1407 (1970)], has recently received renewed attention owing to its potential applicability to the solar wind plasma. In a series of papers, Ibscher, Schlickeiser, and their colleagues [Phys. Plasmas 19, 072116 (2012); ibid. 20, 012103 (2013); ibid. 20, 042121 (2013); ibid. 21, 022110 (2014)] revisited the O mode instability and extended it to the low-beta plasma regime by considering a counter-streaming bi-Maxwellian model. However, the O-mode instability is, thus, far discussed only on the basis of the marginal stability condition rather than actual numerical solutions of the dispersion relation. The present paper revisits the O-mode instability by considering the actual complex roots. The marginal stability condition as a function of the (electron) temperature anisotropy and beta naturally emerges in such a scheme.

  6. Dual sensitivity mode system for monitoring processes and sensors

    DOE Patents [OSTI]

    Wilks, Alan D. (Mount Prospect, IL); Wegerich, Stephan W. (Glendale Heights, IL); Gross, Kenneth C. (Bolingbrook, IL)

    2000-01-01

    A method and system for analyzing a source of data. The system and method involves initially training a system using a selected data signal, calculating at least two levels of sensitivity using a pattern recognition methodology, activating a first mode of alarm sensitivity to monitor the data source, activating a second mode of alarm sensitivity to monitor the data source and generating a first alarm signal upon the first mode of sensitivity detecting an alarm condition and a second alarm signal upon the second mode of sensitivity detecting an associated alarm condition. The first alarm condition and second alarm condition can be acted upon by an operator and/or analyzed by a specialist or computer program.

  7. A Sliding Mode Multimodel Control for a Sensorless Photovoltaic System

    E-Print Network [OSTI]

    Rhif, Ahmed; Braiek, Naceur BenHadj

    2013-01-01

    In this work we will talk about a new control test using the sliding mode control with a nonlinear sliding mode observer, which are very solicited in tracking problems, for a sensorless photovoltaic panel. In this case, the panel system will has as a set point the sun position at every second during the day for a period of five years; then the tracker, using sliding mode multimodel controller and a sliding mode observer, will track these positions to make the sunrays orthogonal to the photovoltaic cell that produces more energy. After sunset, the tracker goes back to the initial position (which of sunrise). Experimental measurements show that this autonomic dual axis Sun Tracker increases the power production by over 40%.

  8. Charging system with galvanic isolation and multiple operating modes

    DOE Patents [OSTI]

    Kajouke, Lateef A.; Perisic, Milun; Ransom, Ray M.

    2013-01-08

    Systems and methods are provided for operating a charging system with galvanic isolation adapted for multiple operating modes. A vehicle charging system comprises a DC interface, an AC interface, a first conversion module coupled to the DC interface, and a second conversion module coupled to the AC interface. An isolation module is coupled between the first conversion module and the second conversion module. The isolation module comprises a transformer and a switching element coupled between the transformer and the second conversion module. The transformer and the switching element are cooperatively configured for a plurality of operating modes, wherein each operating mode of the plurality of operating modes corresponds to a respective turns ratio of the transformer.

  9. Investigation of dominant spin wave modes by domain walls collision

    SciTech Connect (OSTI)

    Ramu, M.; Purnama, I.; Goolaup, S.; Chandra Sekhar, M.; Lew, W. S.

    2014-06-28

    Spin wave emission due to field-driven domain wall (DW) collision has been investigated numerically and analytically in permalloy nanowires. The spin wave modes generated are diagonally symmetric with respect to the collision point. The non-propagating mode has the highest amplitude along the middle of the width. The frequency of this mode is strongly correlated to the nanowire geometrical dimensions and is independent of the strength of applied field within the range of 0.1?mT to 1?mT. For nanowire with film thickness below 5?nm, a second spin wave harmonic mode is observed. The decay coefficient of the spin wave power suggests that the DWs in a memory device should be at least 300?nm apart for them to be free of interference from the spin waves.

  10. Dose Rate Calculations for Rotary Mode Core Sampling Exhauster

    SciTech Connect (OSTI)

    FOUST, D.J.

    2000-10-26

    This document provides the calculated estimated dose rates for three external locations on the Rotary Mode Core Sampling (RMCS) exhauster HEPA filter housing, per the request of Characterization Field Engineering.

  11. Stability of short wavelength tearing and twisting modes

    SciTech Connect (OSTI)

    Waelbroeck, F.L.

    1998-09-22

    The stability and mutual interaction of tearing and twisting modes in a torus is governed by matrices that generalize the well-known {Delta}{prime} stability index. The diagonal elements of these matrices determine the intrinsic stability of modes that reconnect the magnetic field at a single resonant surface. The off-diagonal elements indicate the strength of the coupling between the different modes. The author shows how the elements of these matrices can be evaluated, in the limit of short wavelength, from the free energy driving radially extended ballooning modes. The author applies the results by calculating the tearing and twisting {Delta}{prime} for a model high-beta equilibrium with circular flux surfaces.

  12. High n ballooning modes in highly elongated tokamaks

    SciTech Connect (OSTI)

    An, C.H.; Bateman, G.

    1980-02-01

    An analytic study of stability against high n ballooning modes in highly elongated axisymmetric plasmas is presented and compared with computational results. From the equation for the marginal pressure gradient, it is found that the local shear plays an important role on the stability of elongated and shifted plasma, and that high elongation deteriorates the stability by decreasing the stabilizing effects of field line bending and local shear. The net contribution of the local shear to stability decreases with elongation and shift for strongly ballooning modes (eigenfunctions strongly localized near the outer edge of the toroidal flux surfaces) but increases for interchange modes (eigenfunctions more uniform along the flux surfaces). The computational study of high n ballooning modes in a highly elongated plasma reveals that lowering the aspect ratio and broadening the pressure profile enhance the marginal beta for ..beta../sub p/ less than unity but severely reduce the marginal beta for ..beta../sub p/ larger than unity.

  13. Pseudo-Goldstone modes in isospin-asymmetric nuclear matter

    SciTech Connect (OSTI)

    Cohen, T.D. [Univ. of Washington, Seattle, WA (United States); Broniowski, W. [H. Niewodniczanski Institute of Nuclear Physics, Cracow (Poland)

    1995-01-01

    The authors analyze the chiral limit in dense isospin-asymmetric nuclear matter. It is shown that the pseudo-Goldstone modes in this system are qualitatively different from the case of isospin-symmetric matter.

  14. Mode conversation losses in overmolded millimeter wave transmission lines

    E-Print Network [OSTI]

    Tax, David S. (David Samuel)

    2008-01-01

    Millimeter wave transmission lines are integral components for many important applications like nuclear fusion and NMR spectroscopy. In low loss corrugated transmission lines propagating the HE,1 mode with a high waveguide ...

  15. QRPA treatment of the transverse wobbling mode reconsidered

    E-Print Network [OSTI]

    Frauendorf, S

    2015-01-01

    The quasiparticle random phase approximation is used to study the properties of the wobbling bands in $^{163}$Lu. Assuming that the wobbling mode represents pure isoscalar orientation oscillations results in too low wobbling frequencies and too strong M1 transitions between the one- and zero-phonon wobbling bands. The inclusion of an LL interaction, which couples the wobbling mode to the scissors mode, generates the right upshift of the wobbling frequencies and the right suppression of the B(M1)$_{out}$ values toward the experimental values. In analogy to the quenching of low-energy E1 transition by coupling to the Isovector Giant Dipole Resonance, a general reduction of the M1 transitions between quasiparticle configurations caused by coupling to the scissors mode is suggested.

  16. QRPA treatment of the transverse wobbling mode reconsidered

    E-Print Network [OSTI]

    S. Frauendorf; F. Doenau

    2015-09-27

    The quasiparticle random phase approximation is used to study the properties of the wobbling bands in $^{163}$Lu. Assuming that the wobbling mode represents pure isoscalar orientation oscillations results in too low wobbling frequencies and too strong M1 transitions between the one- and zero-phonon wobbling bands. The inclusion of an LL interaction, which couples the wobbling mode to the scissors mode, generates the right upshift of the wobbling frequencies and the right suppression of the B(M1)$_{out}$ values toward the experimental values. In analogy to the quenching of low-energy E1 transition by coupling to the Isovector Giant Dipole Resonance, a general reduction of the M1 transitions between quasiparticle configurations caused by coupling to the scissors mode is suggested.

  17. Adaptive sliding mode control for a class of chaotic systems

    SciTech Connect (OSTI)

    Farid, R.; Ibrahim, A.; Zalam, B.

    2015-03-30

    Chaos control here means to design a controller that is able to mitigating or eliminating the chaos behavior of nonlinear systems that experiencing such phenomenon. In this paper, an Adaptive Sliding Mode Controller (ASMC) is presented based on Lyapunov stability theory. The well known Chua's circuit is chosen to be our case study in this paper. The study shows the effectiveness of the proposed adaptive sliding mode controller.

  18. Analysis of azimuthal mode dynamics of mesoscale eddies 

    E-Print Network [OSTI]

    McCalpin, John David

    1984-01-01

    ANALYSIS OF AZIMUTHAL MODE DYNAMICS OF MESOSCALE EDDIES A Thesis by UOHN DAVID MCCALPIN Submitted to the Graduate College of Texas ASM University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE August 1984... Major Subject: Oceanography ANALYSIS OF AZIMUTHAL MODE DYNAMICS OF MESOSCALE EDDIES A Thesis by JOHN DAVID MCCALPIN Approved as to style and content by: rew . as ano (Chairman of Committee) o ert . ei (Member) uy . rancesc &ni (Member) Robert...

  19. The multi-mode quantum Entropy Power Inequality

    E-Print Network [OSTI]

    Giacomo De Palma; Andrea Mari; Seth Lloyd; Vittorio Giovannetti

    2015-03-27

    The quantum version of a fundamental entropic data-processing inequality is presented. It establishes a lower bound for the entropy that can be generated in the output channels of a scattering process, which involves a collection of independent input bosonic modes (e.g., the modes of the electromagnetic field). The impact of this inequality in quantum information theory is potentially large and some relevant implications are considered in this work.

  20. QUADRATURE CLOCK CONVERTER X1 and X4 mode selection

    E-Print Network [OSTI]

    Wedeward, Kevin

    -level selects the X1 mode. In X4 mode, an output pulse is generated for every transition at either A or B input indication output. When A input leads the B input, the UP/DN output goes high indicating that the count 0.7VDD - V - A,B Logic High VIH 3.1 - V VDD = 4.75V 5.0 - V VDD = 9V 5.6 - V VDD = 10.5V ALL OUTPUTS

  1. Steering of a Bosonic Mode with a Double Quantum Dot

    E-Print Network [OSTI]

    T. Brandes; N. Lambert

    2003-02-13

    We investigate the transport and coherence properties of a double quantum dot coupled to a single damped boson mode. Our numerically results reveal how the properties of the boson distribution can be steered by altering parameters of the electronic system such as the energy difference between the dots. Quadrature amplitude variances and the Wigner function are employed to illustrate how the state of the boson mode can be controlled by a stationary electron current through the dots.

  2. Rotary mode core sampling approved checklist: 241-TX-113

    SciTech Connect (OSTI)

    Fowler, K.D.

    1998-08-03

    The safety assessment for rotary mode core sampling was developed using certain bounding assumptions, however, those assumptions were not verified for each of the existing or potential flammable gas tanks. Therefore, a Flammable Gas/Rotary Mode Core Sampling Approved Checklist has been completed for tank 241-TX-113 prior to sampling operations. This transmittal documents the dispositions of the checklist items from the safety assessment.

  3. Rotary mode core sampling approved checklist: 241-TX-116

    SciTech Connect (OSTI)

    FOWLER, K.D.

    1999-02-24

    The safety assessment for rotary mode core sampling was developed using certain bounding assumptions, however, those assumptions were not verified for each of the existing or potential flammable gas tanks. Therefore, a Flammable Gas/Rotary Mode Core Sampling Approved Checklist has been completed for tank 241-TX-116 prior to sampling operations. This transmittal documents the dispositions of the checklist items from the safety assessment.

  4. On the saturation amplitude of the f-mode instability

    E-Print Network [OSTI]

    Wolfgang Kastaun; Beatrix Willburger; Kostas D. Kokkotas

    2011-10-05

    We investigate strong nonlinear damping effects which occur during high amplitude oscillations of neutron stars, and the gravitational waves they produce. For this, we use a general relativistic nonlinear hydrodynamics code in conjunction with a fixed spacetime (Cowling approximation) and a polytropic equation of state (EOS). Gravitational waves are estimated using the quadrupole formula. Our main interest are l=m=2 f modes subject to the CFS (Chandrasekhar, Friedman, Schutz) instability, but we also investigate axisymmetric and quasiradial modes. We study various models to determine the influence of rotation rate and EOS. We find that axisymmetric oscillations at high amplitudes are predominantly damped by shock formation, while the nonaxisymmetric f modes are mainly damped by wave breaking and, for rapidly rotating models, coupling to nonaxisymmetric inertial modes. From the observed nonlinear damping, we derive upper limits for the saturation amplitude of CFS-unstable f modes. Finally, we estimate that the corresponding gravitational waves for an oscillation amplitude at the upper limit should be detectable with the advanced LIGO and VIRGO interferometers at distances above 10 MPc. This strongly depends on the stellar model, in particular on the mode frequency.

  5. Two-mode squeezing in an electromechanical resonator

    E-Print Network [OSTI]

    I. Mahboob; H. Okamoto; K. Onomitsu; H. Yamaguchi

    2014-05-21

    The widespread availability of quantum entanglement with photons, in the guise of two-mode squeezed states, can be attributed to the phenomenon of parametric down-conversion. A reinterpretation of this effect with macroscopic mechanical objects can offer a route towards a purely mechanical entanglement and the unique possibility of probing the quantum mechanical nature of our everyday classical world. In spite of this prospect, mechanical two-mode squeezed states have remained elusive due to the inability to recreate the nonlinear interaction at the heart of this phenomenon in the mechanical domain. To address this we have developed a parametric down-converter, in a mechanical resonator integrated with electrical functionality, which enables mechanical nonlinearities to be dynamically engineered to emulate the parametric down-conversion interaction. In this configuration, phonons are simultaneously generated in pairs in two macroscopic vibration modes which results in the amplification of their motion. In parallel, mechanical two-mode squeezed states are also created which exhibit fluctuations far below the thermal level of their constituent modes as well as harbouring correlations between the modes that become almost perfect as their amplification is increased. This remarkable observation of correlations between two massive phonon ensembles paves the way towards an entangled macroscopic mechanical system at the single phonon level.

  6. Mode dependent lattice thermal conductivity of single layer graphene

    SciTech Connect (OSTI)

    Wei, Zhiyong; Yang, Juekuan; Bi, Kedong; Chen, Yunfei, E-mail: yunfeichen@seu.edu.cn [Jiangsu Key Laboratory for Design and Manufacture of Micro/Nano Biomedical Instruments and School of Mechanical Engineering, Southeast University, Nanjing 210096 (China)

    2014-10-21

    Molecular dynamics simulation is performed to extract the phonon dispersion and phonon lifetime of single layer graphene. The mode dependent thermal conductivity is calculated from the phonon kinetic theory. The predicted thermal conductivity at room temperature exhibits important quantum effects due to the high Debye temperature of graphene. But the quantum effects are reduced significantly when the simulated temperature is as high as 1000 K. Our calculations show that out-of-plane modes contribute about 41.1% to the total thermal conductivity at room temperature. The relative contribution of out-of-plane modes has a little decrease with the increase of temperature. Contact with substrate can reduce both the total thermal conductivity of graphene and the relative contribution of out-of-plane modes, in agreement with previous experiments and theories. Increasing the coupling strength between graphene and substrate can further reduce the relative contribution of out-of-plane modes. The present investigations also show that the relative contribution of different mode phonons is not sensitive to the grain size of graphene. The obtained phonon relaxation time provides useful insight for understanding the phonon mean free path and the size effects in graphene.

  7. Helical mode interactions and spectral transfer processes in magnetohydrodynamic turbulence

    E-Print Network [OSTI]

    Moritz F. Linkmann; Arjun Berera; Mairi E. McKay; Julia Jäger

    2015-08-22

    Spectral transfer processes in magnetohydrodynamic (MHD) turbulence are investigated analytically by decomposition of the velocity and magnetic fields in Fourier space into helical modes. Steady solutions of the dynamical system which governs the evolution of the helical modes are determined, and a stability analysis of these solutions is carried out. The interpretation of the analysis is that unstable solutions lead to energy transfer between the interacting modes while stable solutions do not. From this, a dependence of possible interscale energy and helicity transfers on the helicities of the interacting modes is derived. As expected from the inverse cascade of magnetic helicity in 3D MHD turbulence, mode interactions with like helicities lead to transfer of energy and magnetic helicity to smaller wavenumbers. However, some interactions of modes with unlike helicities also contribute to an inverse energy transfer. As such, an inverse energy cascade for nonhelical magnetic fields is shown to be possible. Furthermore, it is found that high values of the cross-helicity may have an asymmetric effect on forward and reverse transfer of energy, where forward transfer is more quenched in regions of high cross-helicity than reverse transfer. This conforms with recent observations of solar wind turbulence. For specific helical interactions the relation to dynamo action is established.

  8. Helical mode interactions and spectral transfer processes in magnetohydrodynamic turbulence

    E-Print Network [OSTI]

    Moritz F. Linkmann; Arjun Berera; Mairi E. McKay; Julia Jäger

    2015-09-01

    Spectral transfer processes in magnetohydrodynamic (MHD) turbulence are investigated analytically by decomposition of the velocity and magnetic fields in Fourier space into helical modes. Steady solutions of the dynamical system which governs the evolution of the helical modes are determined, and a stability analysis of these solutions is carried out. The interpretation of the analysis is that unstable solutions lead to energy transfer between the interacting modes while stable solutions do not. From this, a dependence of possible interscale energy and helicity transfers on the helicities of the interacting modes is derived. As expected from the inverse cascade of magnetic helicity in 3D MHD turbulence, mode interactions with like helicities lead to transfer of energy and magnetic helicity to smaller wavenumbers. However, some interactions of modes with unlike helicities also contribute to an inverse energy transfer. As such, an inverse energy cascade for nonhelical magnetic fields is shown to be possible. Furthermore, it is found that high values of the cross-helicity may have an asymmetric effect on forward and reverse transfer of energy, where forward transfer is more quenched in regions of high cross-helicity than reverse transfer. This conforms with recent observations of solar wind turbulence. For specific helical interactions the relation to dynamo action is established.

  9. Rouse mode analysis of chain relaxation in homopolymer melts

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

    Kalathi, Jagannathan T.; Kumar, Sanat K.; Rubinstein, Michael; Grest, Gary S.

    2014-09-15

    We use molecular dynamics simulations of the Kremer–Grest (KG) bead–spring model of polymer chains of length between 10 and 500, and a closely related analogue that allows for chain crossing, to clearly delineate the effects of entanglements on the length-scale-dependent chain relaxation in polymer melts. We analyze the resulting trajectories using the Rouse modes of the chains and find that entanglements strongly affect these modes. The relaxation rates of the chains show two limiting effective monomeric frictions, with the local modes experiencing much lower effective friction than the longer modes. The monomeric relaxation rates of longer modes vary approximately inverselymore »with chain length due to kinetic confinement effects. The time-dependent relaxation of Rouse modes has a stretched exponential character with a minimum of stretching exponent in the vicinity of the entanglement chain length. None of these trends are found in models that allow for chain crossing. As a result, these facts, in combination, argue for the confined motion of chains for time scales between the entanglement time and their ultimate free diffusion.« less

  10. Broad-band robustly single-mode hollow-core PCF by resonant filtering of higher order modes

    E-Print Network [OSTI]

    Günendi, Mehmet C; Frosz, Michael H; Russell, Philip St J

    2015-01-01

    We propose and theoretically analyse a novel hollow-core photonic crystal fibre (PCF) that is engineered so as to strongly suppress higher order modes, i.e., to provide robust LP$_{01}$ single-mode guidance in all the wavelength ranges where the fibre guides with low loss. Encircling the core is a single ring of non-touching glass elements whose modes are tailored to ensure resonant phase-matched coupling to higher-order core modes, causing them to leak at a very high rate into the supporting solid glass sheath. Using a model based on coupled capillary waveguides, as well as full vectorial finite element modelling, we show that this modal filtering effect depends on only one dimensionless geometrical parameter, akin to the well-known $d/{\\Lambda}$ parameter for endlessly single-mode solid-core PCF. The design is scalable up to large core sizes and is predicted to deliver LP$_{01}$ mode losses of some $10$s of dB/km in multiple transmission windows, the broadest of which spans more than an octave. At the same ...

  11. RECIPROCAL PASSIVE MODE-LOCKING OF A RHODAMINE 6G DYE LASER AND THE Ar+ PUMP LASER

    E-Print Network [OSTI]

    Yasa, Zafer A.

    2013-01-01

    Letters RECIPROCAL PASSIVE MODE+LOCKING OF A RHODAMINE 6GCalifornia. RECIPROCAL PASSIVE MODE-LOCKING OF A RHODAMINEOctober 1980 RECIPROCAL PASSIVE MODE-LOCKING OF A RHODAMINE

  12. Sequestering Uranium from Seawater: Binding Strength and Modes of Uranyl Complexes with Glutarimidedioxime

    E-Print Network [OSTI]

    Tian, Guoxin

    2013-01-01

    binding strength and modes of uranyl complexes withand the coordination modes in the uranyl glutarimidedioximeof the bonding orbitals of uranyl (? u , ? g , ? u and ? g )

  13. A determining form for the damped driven nonlinear Schrödinger equation-Fourier modes case

    E-Print Network [OSTI]

    Jolly, MS; Sadigov, T; Titi, ES

    2015-01-01

    1984) [5] J. Bourgain, Fourier transformation restrictionStokes equations - the Fourier modes case, Journal ofSCHR ODINGER EQUATION- FOURIER MODES CASE MICHAEL S. JOLLY,

  14. Mode transition of a Hall thruster discharge plasma

    SciTech Connect (OSTI)

    Hara, Kentaro, E-mail: kenhara@umich.edu; Sekerak, Michael J., E-mail: msekerak@umich.edu; Boyd, Iain D.; Gallimore, Alec D. [University of Michigan, Ann Arbor, Michigan 48109 (United States)

    2014-05-28

    A Hall thruster is a cross-field plasma device used for spacecraft propulsion. An important unresolved issue in the development of Hall thrusters concerns the effect of discharge oscillations in the range of 10–30?kHz on their performance. The use of a high speed Langmuir probe system and ultra-fast imaging of the discharge plasma of a Hall thruster suggests that the discharge oscillation mode, often called the breathing mode, is strongly correlated to an axial global ionization mode. Stabilization of the global oscillation mode is achieved as the magnetic field is increased and azimuthally rotating spokes are observed. A hybrid-direct kinetic simulation that takes into account the transport of electronically excited atoms is used to model the discharge plasma of a Hall thruster. The predicted mode transition agrees with experiments in terms of the mean discharge current, the amplitude of discharge current oscillation, and the breathing mode frequency. It is observed that the stabilization of the global oscillation mode is associated with reduced electron transport that suppresses the ionization process inside the channel. As the Joule heating balances the other loss terms including the effects of wall loss and inelastic collisions, the ionization oscillation is damped, and the discharge oscillation stabilizes. A wide range of the stable operation is supported by the formation of a space charge saturated sheath that stabilizes the electron axial drift and balances the Joule heating as the magnetic field increases. Finally, it is indicated from the numerical results that there is a strong correlation between the emitted light intensity and the discharge current.

  15. Topological modes bound to dislocations in mechanical metamaterials

    E-Print Network [OSTI]

    Jayson Paulose; Bryan Gin-ge Chen; Vincenzo Vitelli

    2015-04-23

    Mechanical metamaterials are artificial structures with unusual properties, such as negative Poisson ratio, bistability or tunable vibrational properties, that originate in the geometry of their unit cell. At the heart of such unusual behaviour is often a soft mode: a motion that does not significantly stretch or compress the links between constituent elements. When activated by motors or external fields, soft modes become the building blocks of robots and smart materials. Here, we demonstrate the existence of topological soft modes that can be positioned at desired locations in a metamaterial while being robust against a wide range of structural deformations or changes in material parameters. These protected modes, localized at dislocations, are the mechanical analogue of topological states bound to defects in electronic systems. We create physical realizations of the topological modes in prototypes of kagome lattices built out of rigid triangular plates. We show mathematically that they originate from the interplay between two Berry phases: the Burgers vector of the dislocation and the topological polarization of the lattice. Our work paves the way towards engineering topologically protected nano-mechanical structures for molecular robotics or information storage and read-out.

  16. Lyapunov modes in three-dimensional Lennard-Jones fluids

    E-Print Network [OSTI]

    M. Romero-Bastida; E. Braun

    2008-07-15

    Recent studies on the phase-space dynamics of a one-dimensional Lennard-Jones fluid reveal the existence of regular collective perturbations associated with the smallest positive Lyapunov exponents of the system, called hydrodynamic Lyapunov modes, which previously could only be identified in hard-core fluids. In this work we present a systematic study of the Lyapunov exponents and Lyapunov vectors, i.e. perturbations along each direction of phase space, of a three-dimensional Lennard-Jones fluid. By performing the Fourier transform of the spatial density of the coordinate part of the Lyapunov vector components and then time-averaging this result we find convincing signatures of longitudinal modes, with inconclusive evidence of transverse modes for all studied densities. Furthermore, the longitudinal modes can be more clearly identified for the higher density values. Thus, according to our results, the mixing of modes induced both by the dynamics and the dimensionality induce a hitherto unknown type of order in the tangent space of the model herein studied at high density values.

  17. Effects of a random spatial variation of the plasma density on the mode conversion in cold, unmagnetized, and stratified plasmas

    SciTech Connect (OSTI)

    Jung Yu, Dae; Kim, Kihong

    2013-12-15

    We study the effects of a random spatial variation of the plasma density on the mode conversion of electromagnetic waves into electrostatic oscillations in cold, unmagnetized, and stratified plasmas. Using the invariant imbedding method, we calculate precisely the electromagnetic field distribution and the mode conversion coefficient, which is defined to be the fraction of the incident wave power converted into electrostatic oscillations, for the configuration where a numerically generated random density variation is added to the background linear density profile. We repeat similar calculations for a large number of random configurations and take an average of the results. We obtain a peculiar nonmonotonic dependence of the mode conversion coefficient on the strength of randomness. As the disorder increases from zero, the maximum value of the mode conversion coefficient decreases initially, then increases to a maximum, and finally decreases towards zero. The range of the incident angle in which mode conversion occurs increases monotonically as the disorder increases. We present numerical results suggesting that the decrease of mode conversion mainly results from the increased reflection due to the Anderson localization effect originating from disorder, whereas the increase of mode conversion of the intermediate disorder regime comes from the appearance of many resonance points and the enhanced tunneling between the resonance points and the cutoff point. We also find a very large local enhancement of the magnetic field intensity for particular random configurations. In order to obtain high mode conversion efficiency, it is desirable to restrict the randomness close to the resonance region.

  18. Overview of Common Mode Outages in Power Systems

    SciTech Connect (OSTI)

    Papic, Milorad; Awodele , Kehinde; Billinton, Roy; Dent, Chris; Eager, Dan; Hamoud, Gomaa; Jirutitijaroen, Panida; Kumbale, Murali; Mitra, Joydeep; Samaan, Nader A.; Schneider, Alex; Singh, Chanan

    2012-11-10

    This paper is a result of ongoing activity carried out by Probability Applications for Common Mode Events (PACME) Task Force under the Reliability Risk and Probability Applications (RRPA) Subcommittee. The paper is intended to constitute a valid source of information and references about dealing with common-mode outages in power systems reliability analysis. This effort involves reviewing published literature and presenting state-of-the-art research and practical applications in the area of common-mode outages. Evaluation of available outage statistics show that there is a definite need for collective effort from academia and industry to not only recommended procedures for data collection and monitoring but also to provide appropriate mathematical models to assess such events.

  19. Optical Mode Control by Geometric Phase in Quasicrystal Metasurface

    E-Print Network [OSTI]

    Yulevich, Igor; Shitrit, Nir; Veksler, Dekel; Kleiner, Vladimir; Hasman, Erez

    2015-01-01

    We report on the observation of optical spin-controlled modes from a quasicrystalline metasurface as a result of an aperiodic geometric phase induced by anisotropic subwavelength structure. When geometric phase defects are introduced in the aperiodic structured surface, the modes exhibit polarization helicity dependence resulting in the optical spin-Hall effect. The radiative thermal dispersion bands from a quasicrystal structure were studied where the observed bands arise from the optical spin-orbit interaction induced by the aperiodic space-variant orientations of anisotropic antennas. The optical spin-flip behavior of the revealed modes that arise from the geometric phase pickup was experimentally observed within the visible spectrum by measuring the spin-projected diffraction patterns. The introduced ability to manipulate the light-matter interaction of quasicrystals in a spin-dependent manner provides the route for molding light via spin-optical aperiodic artificial planar surfaces.

  20. Lasing modes in polycrystalline and amorphous photonic structures

    SciTech Connect (OSTI)

    Yang, Jin-Kyu; Noh, Heeso; Liew, Seng Fatt; Rooks, Michael J.; Solomon, Glenn S.; Cao Hui

    2011-09-15

    We systematically studied the lasing characteristics in photonic polycrystalline and amorphous structures. 2D arrays of air holes were fabricated in a GaAs membrane. InAs quantum dots embedded in the membrane provide gain for lasing under optical pumping. The lasing modes are spatially localized, and blue shift as the structural order becomes short ranged. Our three-dimensional numerical simulations reveal that the out-of-plane leakage of the lasing mode dominates over the in-plane leakage. The lasing modes in a photonic polycrystalline move away from the center frequency of the photonic band gap to reduce the out-of-plane leakage. In a photonic amorphous structure, the short-range order improves optical confinement and enhances the quality factor of resonances. Understanding the behavior of photonic polycrystalline laser and amorphous laser opens the possibility of controlling lasing characteristic by varying the degree of structural order.

  1. Study of constant mode in charmonium correlators at finite temperature

    E-Print Network [OSTI]

    Takashi Umeda

    2007-10-01

    Recent studies on the spectral function of charmonium in lattice QCD suggest survival of $J/\\psi$ state in the deconfinement phase till relatively high temperature. Based on the studies, different scenarios of $J/\\psi$ suppression are discussed to understand experimental results in the Heavy Ion Collision experiments. The scenarios require the information on the dissociation temperatures of $\\chi_c$ and $\\psi'$ as well as that of $J/\\psi$. In order to investigate these states in finite temperature lattice QCD, we have to consider an effect of a characteristic constant mode in the correlators. As a result of the study on the constant mode, we find that most drastic change in charmonium correlators for $\\chi_c$ states just above the deconfinement transition are caused by the constant mode. It may indicate the survival of $\\chi_c$ states after the deconfinement transition until, at least, $1.4T_c$.

  2. Direct Optical Probing of Transverse Electric Mode in Graphene

    E-Print Network [OSTI]

    Menabde, Sergey; Kornev, Evgeny; Lee, Changhee; Park, Namkyoo

    2015-01-01

    Unique electrodynamic response of graphene implies a manifestation of an unusual propagating and localised transverse-electric (TE) mode near the spectral onset of interband transitions. However, excitation and further detection of the TE mode supported by graphene is considered to be a challenge for it is extremely sensitive to excitation environment and phase matching condition adherence. Here for the first time, we experimentally prove an existence of the TE mode by its direct optical probing, demonstrating significant coupling to an incident wave in electrically doped multilayer graphene sheet at room temperature. We believe that proposed technique of careful phase matching and obtained access to graphene TE excitation would stimulate further studies of this unique phenomenon, and enable its potential employing in various fields of photonics as well as for characterization of graphene.

  3. Scissors mode of Gd nuclei studied from resonance neutron capture

    SciTech Connect (OSTI)

    Kroll, J.; Baramsai, B.; Becker, J. A.; and others

    2012-10-20

    Spectra of {gamma} rays following the neutron capture at isolated resonances of stable Gd nuclei were measured. The objectives were to get new information on photon strength of {sup 153,155-159}Gd with emphasis on the role of the M1 scissors-mode vibration. An analysis of the data obtained clearly indicates that the scissors mode is coupled not only to the ground state, but also to all excited levels of the nuclei studied. The specificity of our approach ensures unbiasedness in estimating the sumed scissors-mode strength {Sigma}B(M1){up_arrow}, even for odd product nuclei, for which conventional nuclear resonance fluorescence measurements yield only limited information. Our analysis indicates that for these nuclei the sum {Sigma}B(M1){up_arrow} increases with A and for {sup 157,159}Gd it is significantly higher compared to {sup 156,158}Gd.

  4. Resistive wall mode active control physics design for KSTAR

    SciTech Connect (OSTI)

    Park, Y. S., E-mail: ypark@pppl.gov; Sabbagh, S. A.; Bialek, J. M.; Berkery, J. W. [Department of Applied Physics and Applied Mathematics, Columbia University, New York 10027 (United States)] [Department of Applied Physics and Applied Mathematics, Columbia University, New York 10027 (United States); Bak, J. G.; Lee, S. G.; Oh, Y. K. [National Fusion Research Institute, Daejeon 305-806 (Korea, Republic of)] [National Fusion Research Institute, Daejeon 305-806 (Korea, Republic of)

    2014-01-15

    As KSTAR H-mode operation approaches the region where the resistive wall mode (RWM) can be unstable, an important issue for future long pulse, high beta plasma operation is to evaluate RWM active feedback control performance using a planned active/passive RWM stabilization system on the device. In particular, an optimal design of feedback sensors allows mode stabilization up to the highest achievable ?{sub N} close to the ideal with-wall limit, ?{sub N}{sup wall}, with reduced control power requirements. The computed ideal n?=?1 mode structure from the DCON code has been input to the VALEN-3D code to calculate the projected performance of an active RWM control system in the KSTAR three-dimensional conducting structure device geometry. Control performance with the midplane locked mode detection sensors, off-midplane saddle loops, and magnetic pickup coils is examined. The midplane sensors measuring the radial component of the mode perturbation is found to be strongly affected by the wall eddy current. The off-axis saddle loops with proper compensation of the prompt applied field are computed to provide stabilization at ?{sub N} up to 86% of ?{sub N}{sup wall} but the low RWM amplitude computed in the off-axis regions near the sensors can produce a low signal-to-noise ratio. The required control power and bandwidth are also estimated with varied noise levels in the feedback sensors. Further improvements have been explored by examining a new RWM sensor design motivated by the off-midplane poloidal magnetic field sensors in NSTX. The new sensors mounted off of the copper passive stabilizer plates near the device midplane show a clear advantage in control performance corresponding to achieving 99% of ?{sub N}{sup wall} without the need of compensation of the prompt field. The result shows a significant improvement of RWM feedback stabilization using the new sensor set which motivates a future feedback sensor upgrade.

  5. Edge Plasma Boundary Layer Generated By Kink Modes in Tokamaks

    SciTech Connect (OSTI)

    L.E. Zakharov

    2010-11-22

    This paper describes the structure of the electric current generated by external kink modes at the plasma edge using the ideally conducting plasma model. It is found that the edge current layer is created by both wall touching and free boundary kink modes. Near marginal stability, the total edge current has a universal expression as a result of partial compensation of the ?-functional surface current by the bulk current at the edge. The resolution of an apparent paradox with the pressure balance across the plasma boundary in the presence of the surface currents is provided.

  6. Detection limits in plasmonic whispering gallery mode biosensors

    E-Print Network [OSTI]

    Swaim, Jon D; Bowen, Warwick P

    2011-01-01

    We analyze a whispering gallery mode biosensor with a metallic nanorod bound to its surface. It is found that a localized surface plasmon resonance in the nanorod can reduce the optical mode volume of the resonator by as much as four orders of magnitude via a local enhancement of the electric field, thus improving the detection sensitivity. Optical frequency shifts as large as 15 MHz are predicted for typical proteins and, for typical experimental parameters, the biosensor is predicted to be limited by laser frequency noise, leading to a minimum detectable polarizability on the order of 10 cubic angstroms.

  7. Wavelength meter having single mode fiber optics multiplexed inputs

    DOE Patents [OSTI]

    Hackel, Richard P. (Livermore, CA); Paris, Robert D. (San Ramon, CA); Feldman, Mark (Pleasanton, CA)

    1993-01-01

    A wavelength meter having a single mode fiber optics input is disclosed. The single mode fiber enables a plurality of laser beams to be multiplexed to form a multiplexed input to the wavelength meter. The wavelength meter can provide a determination of the wavelength of any one or all of the plurality of laser beams by suitable processing. Another aspect of the present invention is that one of the laser beams could be a known reference laser having a predetermined wavelength. Hence, the improved wavelength meter can provide an on-line calibration capability with the reference laser input as one of the plurality of laser beams.

  8. Accelerator-mode-based technique for studying quantum chaos

    SciTech Connect (OSTI)

    D'Arcy, M.B.; Godun, R.M.; Cassettari, D. [Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford OX1 3PU (United Kingdom); Summy, G.S. [Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford OX1 3PU (United Kingdom); Department of Physics, Oklahoma State University, Stillwater, Oklahoma 74078-3072 (United States)

    2003-02-01

    We experimentally demonstrate a method for selecting small regions of phase space for kicked rotor quantum chaos experiments with cold atoms. Our technique uses quantum accelerator modes to selectively accelerate atomic wave packets with localized spatial and momentum distributions. The potential used to create the accelerator mode and subsequently realize the kicked rotor system is formed by a set of off-resonant standing-wave light pulses. We also propose a method for testing whether a selected region of phase space exhibits chaotic or regular behavior using a Ramsey type separated field experiment.

  9. Mode imaging and loss evaluation of semiconductor waveguides

    SciTech Connect (OSTI)

    Mochizuki, Toshimitsu [Institute for Solid State Physics, The University of Tokyo, Kashiwanoha 5-1-5, Kashiwa, Chiba (Japan); Fukushima Renewable Energy Institute, National Institute of Advanced Industrial Science and Technology, 2-2-9 Machiike-dai, Koriyama, Fukushima (Japan); Kim, Changsu; Yoshita, Masahiro; Nakamura, Takahiro; Akiyama, Hidefumi [Institute for Solid State Physics, The University of Tokyo, Kashiwanoha 5-1-5, Kashiwa, Chiba (Japan); Pfeiffer, Loren N.; West, Ken W. [Department of Electrical Engineering, Princeton University, New Jersey 08544 (United States)

    2014-05-15

    An imaging and loss evaluation method for semiconductor waveguides coupled with non-doped quantum wells is presented. Using the internal emission of the wells as a probe light source, the numbers and widths of the modes of waveguides with various ridge sizes were evaluated by CCD imaging, and the obtained values were consistent with effective index method calculation. Waveguide internal losses were obtained from analyses of the Fabry-Pérot fringes of waveguide emission spectra. We quantified the quality of 29 single-mode waveguide samples as an internal loss and variation of 10.2 ± 0.6??cm{sup ?1}.

  10. Spin-one color superconductors: collective modes and effective Lagrangian

    E-Print Network [OSTI]

    Jin-yi Pang; Tomas Brauner; Qun Wang

    2010-10-11

    We investigate the collective excitations in spin-one color superconductors. We classify the Nambu--Goldstone modes by the pattern of spontaneous symmetry breaking, and then use the Ginzburg--Landau theory to derive their dispersion relations. These soft modes play an important role for the low-energy dynamics of the system such as the transport phenomena and hence are relevant for late-stage evolution of neutron stars. In the case of the color-spin-locking phase, we use a functional technique to obtain the low-energy effective action for the physical Nambu--Goldstone bosons that survive after gauging the color symmetry.

  11. Wavelength meter having single mode fiber optics multiplexed inputs

    DOE Patents [OSTI]

    Hackel, R.P.; Paris, R.D.; Feldman, M.

    1993-02-23

    A wavelength meter having a single mode fiber optics input is disclosed. The single mode fiber enables a plurality of laser beams to be multiplexed to form a multiplexed input to the wavelength meter. The wavelength meter can provide a determination of the wavelength of any one or all of the plurality of laser beams by suitable processing. Another aspect of the present invention is that one of the laser beams could be a known reference laser having a predetermined wavelength. Hence, the improved wavelength meter can provide an on-line calibration capability with the reference laser input as one of the plurality of laser beams.

  12. Wind Turbine Gearbox Failure Modes - A Brief (Presentation)

    SciTech Connect (OSTI)

    Sheng, S.; McDade, M.; Errichello, R.

    2011-10-01

    Wind turbine gearboxes are not always meeting 20-year design life. Premature failure of gearboxes increases cost of energy, turbine downtime, unplanned maintenance, gearbox replacement and rebuild, and increased warranty reserves. The problem is widespread, affects most Original Equipment Manufacturers, and is not caused by manufacturing practices. There is a need to improve gearbox reliability and reduce turbine downtime. The topics of this presentation are: GRC (Gearbox Reliability Collaborative) technical approach; Gearbox failure database; Recorded incidents summary; Top failure modes for bearings; Top failure modes for gears; GRC test gearbox; Bearing nomenclature; Test history; Real damage; Gear sets; Bearings; Observations; and Summary. 5 refs.

  13. An optical cavity with a strongly focused mode

    SciTech Connect (OSTI)

    Durak, Kadir; Victor, Leong Xu Heng; Huan, Nguyen Chi; Maslennikov, Gleb; Kurtsiefer, Christian [NUS, Center for Quantum Technologies/Physics Dept, 3 Science Drive 2, 117543 (Singapore); Straupe, Stanislav [NUS, Center for Quantum Technologies/Physics Dept, 3 Science Drive 2, 117543, Singapore and Faculty of Physics, Moscow State University (Russian Federation)

    2013-12-16

    Atom-photon interfaces are one of the building blocks of the future quantum information protocols. Accomplishing a strong interaction between the atom and the photons can be successfully done by high finesse and small mode volume cavities. However, this method requires sophisticated dielectric coatings and stabilization of the cavity against even small vibrations and small line width of those cavities impose higher input photon numbers if spontaneously emitted photons are to be used, which make it seem hard to scale up such atom-light interfaces to form quantum networks. An alternative method is to use a nearly concentric cavity, which has a strongly focused optical mode.

  14. Geometric signature of reversal modes in ferromagnetic nanowires

    E-Print Network [OSTI]

    Tannous, C; Gieraltowski, J

    2010-01-01

    Magnetic nanowires are a good platform to study fundamental processes in Magnetism and have many attractive applications in recording such as perpendicular storage and in spintronics such as non-volatile magnetic memory devices (MRAM) and magnetic logic devices. In this work, nanowires are used to study magnetization reversal processes through a novel geometric approach. Reversal modes imprint a definite signature on a parametric curve representing the locus of the critical switching field. We show how the different modes affect the geometry of this curve depending on the nature of the anisotropy (uniaxial or cubic anisotropy), demagnetization and exchange effects. The samples we use are electrochemically grown Nickel and Cobalt nanowires.

  15. Entanglement and the Phase Transition in Single Mode Superradiance

    E-Print Network [OSTI]

    Neill Lambert; Clive Emary; Tobias Brandes

    2003-09-02

    We consider the entanglement properties of the quantum phase transition in the single-mode superradiance model, involving the interaction of a boson mode and an ensemble of atoms. For infinite system size, the atom-field entanglement of formation diverges logarithmically with the correlation length exponent. Using a continuous variable representation, we compare this to the divergence of the entropy in conformal field theories, and derive an exact expression for the scaled concurrence and the cusp-like non-analyticity of the momentum squeezing.

  16. Comment on Scattering-Matrix Method for Determining Defect Modes 

    E-Print Network [OSTI]

    Allen, Roland E.

    1971-01-01

    VOLU ME 3, NUMBER 10 15 MAY 1971 Comment on the Scattering-Matrix Method for Determining Defect Modes* R. E. Allen Department of Physics, University of Texas, Austin, Texas 78712 (Received 25 June 1970) It is pointed out that the formulation... of the scattering-matrix method given by Achar and Barsch, which was proposed and used for calculating localized modes at surfaces and other planar defects, is based on an incorrect assumption. A formulation of the scattering-matrix method for calculating...

  17. Suppression of Neoclassical Tearing Modes by the Magnetic Well in Shear-Optimised Tokamak Discharges

    E-Print Network [OSTI]

    Suppression of Neoclassical Tearing Modes by the Magnetic Well in Shear-Optimised Tokamak Discharges

  18. Northwest Energy Innovations (TRL 5 6 System)- WETNZ MtiMode Wave Energy Converter Advancement Project

    Broader source: Energy.gov [DOE]

    Northwest Energy Innovations (TRL 5 6 System) - WETNZ MtiMode Wave Energy Converter Advancement Project

  19. Hybrid mode-locking in a 40 GHz monolithic quantum dot laser G. Fiol,1,a

    E-Print Network [OSTI]

    Vladimirov, Andrei G.

    Hybrid mode-locking in a 40 GHz monolithic quantum dot laser G. Fiol,1,a D. Arsenijevi,1 D. Bimberg; accepted 30 November 2009; published online 5 January 2010 Hybrid mode-locking in monolithic quantum dot QD of hybrid mode-locking ML , a commonly used technique for improving quality of mode- locked pulses

  20. FAST SPATIAL LAYER MODE DECISION BASED ON TEMPORAL LEVELS IN H.264/AVC SCALABLE EXTENSION

    E-Print Network [OSTI]

    Chang, Pao-Chi

    FAST SPATIAL LAYER MODE DECISION BASED ON TEMPORAL LEVELS IN H.264/AVC SCALABLE EXTENSION Yen layer coding. A fast mode decision algorithm that reduces the candidate modes in motion estimation can a little R-D loss is desirable. Recently, many kinds of fast mode decision schemes have been developed

  1. Mitigating Interference between IEEE 802.16 Systems Operating in License-exempt Mode

    E-Print Network [OSTI]

    Murphy, Liam

    Mitigating Interference between IEEE 802.16 Systems Operating in License-exempt Mode Omar Ashagi approach to mitigate interference issues in license-exempt 802.16 systems is presented. This approach can be divided into two mode of operation: licensed mode of operation, and license-exempt mode

  2. Mode-shift characteristics and hysteresis property of injection locking in a semiconductor laser

    E-Print Network [OSTI]

    Wai, Ping-kong Alexander

    -mode injection locking case in Fig. 4 (c) of Ref. [4]. It is straightforward that the mode-shift is directly will have direct implications on the mode-shift. For the injection current above threshold and for not tooMode-shift characteristics and hysteresis property of injection locking in a semiconductor laser K

  3. Failure Modes of Vacuum Plasma Spray Tungsten Coating Created on Carbon Fibre Composites under Thermal Loads

    E-Print Network [OSTI]

    Failure Modes of Vacuum Plasma Spray Tungsten Coating Created on Carbon Fibre Composites under Thermal Loads

  4. Phosphate single mode large mode area all-solid photonic crystal fiber with multi-watt output power

    SciTech Connect (OSTI)

    Wang, Longfei; He, Dongbing; Yu, Chunlei; Hu, Lili; Chen, Danping, E-mail: dpchen2008@aliyun.com [Key Laboratory of High Power Laser Materials, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Liu, Hui [Navigation Staff Room, Anhui Bengbu Petty Officer Academy of Navy, Bengbu 233000 (China); Qiu, Jianrong [Institute of Optical Communication Materials, South China University of Technology, Guangzhou 510641 (China)

    2014-03-31

    An index-depressed active core, single-mode phosphate all-solid large-mode-area photonic crystal fiber (PCF) is theoretically investigated using full-vectorial finite difference approach and experimentally realized. The PCF has a maximum output power of 5.4?W and 31% slope efficiency. Single-mode operation is realized through PCFs with core diameters of 30, 35, and 40??m, respectively. The beam quality is not degraded even at maximum output power. Our simulations and experiments reveal that the laser performance is significantly affected by the center-to-center distance between the two nearest rods ?, the rod diameter d, and their ratio d/?, implying that much attention should be given in employing optimal parameters to achieve excellent laser performance.

  5. Computation of Growth Rates and Threshold of the Electromagnetic Electron Temperature Gradient Modes in Tokamaks

    E-Print Network [OSTI]

    Varun Tangri

    2013-01-29

    In this manuscript, eigenvalues of the Electron Temperature Gradient (ETG) modes and Ion Temperature Gradient (ITG) modes are determined numerically using Hermite and Sinc differentiation matrices based methods. It is shown that these methods are very useful for the computation of growth rates and threshold of the ETG and ITG modes. The total number of accurately computed eigenvalues for the modes have also been computed. The ideas developed here are also of relevance to other modes that use Ballooning formalism.

  6. Computation of Growth Rates and Threshold of the Electromagnetic Electron Temperature Gradient Modes in Tokamaks

    E-Print Network [OSTI]

    Tangri, Varun

    2013-01-01

    In this manuscript, eigenvalues of the Electron Temperature Gradient (ETG) modes and Ion Temperature Gradient (ITG) modes are determined numerically using Hermite and Sinc differentiation matrices based methods. It is shown that these methods are very useful for the computation of growth rates and threshold of the ETG and ITG modes. The total number of accurately computed eigenvalues for the modes have also been computed. The ideas developed here are also of relevance to other modes that use Ballooning formalism.

  7. Lunar Gruithuisen and Mairan domes: Rheology and mode of emplacement

    E-Print Network [OSTI]

    Head III, James William

    Science Department, Lancaster University, Lancaster, United Kingdom James W. Head Department of Geological is very low, $7 Â 10À5 m/s, and the Reynolds number of the motion is $2 Â 10À8 , implying a completely. Head, Lunar Gruithuisen and Mairan domes: Rheology and mode of emplacement, J. Geophys. Res., 108(E2

  8. MAC Sleep Mode Control Considering Downlink Traffic Pattern and Mobility

    E-Print Network [OSTI]

    Bahk, Saewoong

    .11 and IEEE 802.16 include energy saving techniques. These protocols, however, have a problem in minimizing-efficiency. Through simulations, we show that our proposed algorithm improves energy saving and delay performance-- energy saving, sleep mode, doze state. I. INTRODUCTION In wireless communications, the battery power

  9. Energy transport by acoustic modes of harmonic Lisa Harris

    E-Print Network [OSTI]

    Theil, Florian

    Energy transport by acoustic modes of harmonic lattices Lisa Harris , Jani Lukkarinen , Stefan vector, k = 0. To derive equations that describe the macroscopic energy transport we introduce the Wigner concentrating to k = 0. A simple consequence of our result is the complete characterization of energy transport

  10. Acoustic Modes in a Ducted Shear Flow Gregory Vilenski

    E-Print Network [OSTI]

    Eindhoven, Technische Universiteit

    Acoustic Modes in a Ducted Shear Flow Gregory Vilenski Sjoerd W. Rienstra Eindhoven University but sheared mean flow inside a duct is considered. For isentropic flow in a circular duct with zero swirl = dimensional inner duct radius d = dimensional outer duct radius = dimensional frequency m = circumferential

  11. Cosmic variance of the spectral index from mode coupling

    SciTech Connect (OSTI)

    Bramante, Joseph; Kumar, Jason [Department of Physics and Astronomy, University of Hawaii, 2505 Correa Rd., Honolulu HI (United States); Nelson, Elliot; Shandera, Sarah, E-mail: bramante@hawaii.edu, E-mail: jkumar@hawaii.edu, E-mail: eln121@psu.edu, E-mail: shandera@gravity.psu.edu [Institute for Gravitation and the Cosmos, The Pennsylvania State University, University Park, PA 16802 (United States)

    2013-11-01

    We demonstrate that local, scale-dependent non-Gaussianity can generate cosmic variance uncertainty in the observed spectral index of primordial curvature perturbations. In a universe much larger than our current Hubble volume, locally unobservable long wavelength modes can induce a scale-dependence in the power spectrum of typical subvolumes, so that the observed spectral index varies at a cosmologically significant level (|?n{sub s}| ? O(0.04)). Similarly, we show that the observed bispectrum can have an induced scale dependence that varies about the global shape. If tensor modes are coupled to long wavelength modes of a second field, the locally observed tensor power and spectral index can also vary. All of these effects, which can be introduced in models where the observed non-Gaussianity is consistent with bounds from the Planck satellite, loosen the constraints that observations place on the parameters of theories of inflation with mode coupling. We suggest observational constraints that future measurements could aim for to close this window of cosmic variance uncertainty.

  12. Laser-Plasma Wakefield Acceleration with Higher Order Laser Modes

    E-Print Network [OSTI]

    Geddes, Cameron Guy Robinson

    Laser-Plasma Wakefield Acceleration with Higher Order Laser Modes C.G.R. Geddes , E. Cormier. Nevada, Reno and U.C. Berkeley Abstract. Laser-plasma collider designs point to staging of multiple accelerator stages at the 10 GeV level, which are to be developed on the upcoming BELLA laser, while Thomson

  13. Stress Induced Degradation Modes in CIGSS Minimodules (Presentation)

    SciTech Connect (OSTI)

    Kempe, M. D.; Terwilliger, K.; Tarrant, D.

    2008-05-01

    The experimental objectives of this report are: (1) compare the performance of modules exposed to high temperature and humidity; (2) determine the effects of different encapsulants on long term stability of CIGSS modules; and (3) analyze failure modes to determine areas in need of improvement.

  14. Effect of multiperforated plates on the acoustic modes in combustors

    E-Print Network [OSTI]

    Mendez, Simon

    related to the wave equation in the frequency domain, and is able to provide the acoustic modes effect on acoustics [5], [1], which is enhanced by the presence of a mean bias flow [6]. Acoustic waves in the presence of an acoustic wave and is well adapted to be inserted in the Helmholtz solver. It was validated

  15. ASSESSMENT OF TOKAMAK PLASMA OPERATION MODES AS FUSION POWER PLANTS

    E-Print Network [OSTI]

    ASSESSMENT OF TOKAMAK PLASMA OPERATION MODES AS FUSION POWER PLANTS: THE STARLITE STUDY Farrokh of operation for a tokamak power plant and the critical plasma physics and technology issues. During for fusion power plants was made. Five different regimes of operation were considered: (1) steady

  16. Stability of naked singularities and algebraically special modes

    E-Print Network [OSTI]

    Vitor Cardoso; Marco Cavaglia

    2006-07-20

    We show that algebraically special modes lead to the instability of naked singularity spacetimes with negative mass. Four-dimensional negative-mass Schwarzschild and Schwarzschild-de Sitter spacetimes are unstable. Stability of the Schwarzschild-anti-de Sitter spacetime depends on boundary conditions. We briefly discuss the generalization of these results to charged and rotating singularities.

  17. Discrete dissipative localized modes in nonlinear magnetic metamaterials

    E-Print Network [OSTI]

    Discrete dissipative localized modes in nonlinear magnetic metamaterials Nikolay N. Rosanov,1 effects in. References and links 1. N. Engheta and R. W. Ziolkowski, eds. Electromagnetic Metamaterials. Gorkunov, I. V. Shadrivov, and Yu. S. Kivshar, "Metamaterial tuning by manip- ulation of near

  18. Robust Neural Sliding Mode Control of Robot Manipulators

    SciTech Connect (OSTI)

    Nguyen Tran Hiep [Le Quy Don University Hanoi-Vietnam (Viet Nam); Pham Thuong Cat [Institute of Information Technology, Academy of Science and Technology Vietnam (Viet Nam)

    2009-03-05

    This paper proposes a robust neural sliding mode control method for robot tracking problem to overcome the noises and large uncertainties in robot dynamics. The Lyapunov direct method has been used to prove the stability of the overall system. Simulation results are given to illustrate the applicability of the proposed method.

  19. (Approximate) Low-Mode Averaging with a new Multigrid Eigensolver

    E-Print Network [OSTI]

    Gunnar Bali; Sara Collins; Andreas Frommer; Karsten Kahl; Issaku Kanamori; Benjamin Müller; Matthias Rottmann; Jakob Simeth

    2015-09-23

    We present a multigrid based eigensolver for computing low-modes of the Hermitian Wilson Dirac operator. For the non-Hermitian case multigrid methods have already replaced conventional Krylov subspace solvers in many lattice QCD computations. Since the $\\gamma_5$-preserving aggregation based interpolation used in our multigrid method is valid for both, the Hermitian and the non-Hermitian case, inversions of very ill-conditioned shifted systems with the Hermitian operator become feasible. This enables the use of multigrid within shift-and-invert type eigensolvers. We show numerical results from our MPI-C implementation of a Rayleigh quotient iteration with multigrid. For state-of-the-art lattice sizes and moderate numbers of desired low-modes we achieve speed-ups of an order of magnitude and more over PARPACK. We show results and develop strategies how to make use of our eigensolver for calculating disconnected contributions to hadronic quantities that are noisy and still computationally challenging. Here, we explore the possible benefits, using our eigensolver for low-mode averaging and related methods with high and low accuracy eigenvectors. We develop a low-mode averaging type method using only a few of the smallest eigenvectors with low accuracy. This allows us to avoid expensive exact eigensolves, still benefitting from reduced statistical errors.

  20. Perturbative Approach to the Quasinormal Modes of Dirty Black Holes

    E-Print Network [OSTI]

    P. T. Leung; Y. T. Liu; W. -M. Suen; C. Y. Tam; K. Young

    1999-03-08

    Using a recently developed perturbation theory for uasinormal modes (QNM's), we evaluate the shifts in the real and imaginary parts of the QNM frequencies due to a quasi-static perturbation of the black hole spacetime. We show the perturbed QNM spectrum of a black hole can have interesting features using a simple model based on the scalar wave equation.

  1. A Resonant-Mode Model of Pulsar Radio Emission

    E-Print Network [OSTI]

    Matthew D. T. Young

    2003-10-15

    It is argued that the polar gap and flux tube in the pulsar magnetosphere act as a resonant cavity/waveguide system which is excited by oscillations in the primary beam current and accelerating potential. The modes will be converted, probably scattered, to produce radio beams in the frequency range of those observed.

  2. Negative modes in the four-dimensional stringy wormholes

    E-Print Network [OSTI]

    Jin Young Kim; H. W. Lee; Y. S. Myung

    1997-08-27

    We study the Giddings-Strominger wormholes in string theories. We found negative modes among O(4)-symmetric fluctuations about the non-singular wormhole background. Hence the stringy wormhole contribution to the euclidean functional integral is purely imaginary. This means that the stringy wormhole is a bounce (not an instanton) and describes the nucleation and growth of wormholes in the Minkowski spacetime.

  3. Localized Ballooning Modes in Compact Quasiaxially Symmetric Stellarators

    SciTech Connect (OSTI)

    M.H. Redi; J. Canik; R.L. Dewar; E.D. Fredrickson; W.A. Cooper; J.L. Johnson; S. Klasky

    2001-06-14

    Understanding of ballooning mode stability boundaries may lead to performance improvement of toroidal devices through control of plasma disruptions. Toroidally localized ballooning modes have been found as precursors to high-beta plasma disruptions on the Tokamak Fusion Test Reactor (TFTR) arising in conditions of n=1 kink mode asymmetry. Recent optimization has shown that magnetohydrodynamic (MHD) stability as well as good particle confinement are likely to be achievable in the National Compact Stellarator Experiment (NCSX), a compact, quasiaxially symmetric stellarator (QAS) for values of the plasma near beta = 4%. The configuration, with a major radius of 1.42 m, an aspect ratio of 4.4, a toroidal magnetic field 1.2-1.7 T and 6 MW of neutral-beam heating, is stable to MHD instabilities, and is expected to be limited by high-n kink and ballooning modes. This paper describes the ballooning eigenvalue isosurfaces for NCSX, the first step in an examination of the kinetic stabilization of the ballooning beta limit using a hybrid WKB approach.

  4. Sliding-mode amplitude control techniques for harmonic oscillators 

    E-Print Network [OSTI]

    Marquart, Chad A.

    2007-09-17

    for this research. Finally, thanks to all of my friends and family for their support and encourage- ment over the course of this journey. v TABLE OF CONTENTS CHAPTER Page I INTRODUCTION: MODERN WIRELESS COMMUNICATIONS 1 A. VCO Design Challenges... . . . . . . . . . . . . . . . . . . . . . . 51 1. Oscillator Design . . . . . . . . . . . . . . . . . . . . . 53 2. Sliding-Mode Controller . . . . . . . . . . . . . . . . . 55 3. Charge Pump . . . . . . . . . . . . . . . . . . . . . . 57 B. Measurement Results...

  5. Nonlinear dynamics of large amplitude modes in a magnetized plasma

    SciTech Connect (OSTI)

    Brodin, G.; Stenflo, L.

    2014-12-15

    We derive two equations describing the coupling between electromagnetic and electrostatic oscillations in one-dimensional geometry in a magnetized cold and non-relativistic plasma. The nonlinear interaction between the wave modes is studied numerically. The effects of the external magnetic field strength and the initial electromagnetic polarization are of particular interest here. New results can, thus, be identified.

  6. CALCULATION OF THE NEUTRON NOISE INDUCED BY SHELL-MODE

    E-Print Network [OSTI]

    Demazière, Christophe

    CALCULATION OF THE NEUTRON NOISE INDUCED BY SHELL-MODE FISSION REACTORS CORE-BARREL VIBRATIONS-REGION SLAB REACTOR MODEL CARL SUNDE,* CHRISTOPHE DEMAZIÈRE, and IMRE PÁZSIT Chalmers University of Technology. 5 gives a self-contained description of the principles of fluctuation analysis for the diagnostics

  7. An Over-moded Fundamental Power Coupler for the ILC

    SciTech Connect (OSTI)

    Jeff Neilson, Sami Tantawi, Rand Pendleton

    2009-05-20

    The current design of fundamental power couplers for the ILC are expensive and require excessively long conditioning times. The goal of this develoment is design of a coupler that requires little rf processing and is significantly less expensive to build than the present ILC coupler.????? The goal of this program is development of a new technology for power couplers.This new technology is based on the cylindrical TE01 mode and other over-moded technologies developed for the X-band rf distribution system of the NCLTA. During the Phase I program, a TE10 to TE01 mode transducer suitable for use as a part of a power coupler in the ILC will be designed, built and tested. Following a succesful test, prototype designs of the TE01 to cavity coupler and thermal will be produced. A detailed study of the suitability of this overmoded waveguide technology for the ILC power coupler will be provided in the final report. Development of over-moded power couplers for superconducting cavities could find application im many world-wide accelerator projects, such as SNS, Jefferson Lab upgrade, RIA, TESLA in addition to the ILC.

  8. Quantum Accelerator Modes from the Farey Tree A. Buchleitner,1

    E-Print Network [OSTI]

    Summy, Gil

    driven quantum systems [5], quantum reso- nances [6,7], and stochastic web states [8,9]. These ``strong. Eigenmodes of a periodically driven dissipative system are locked in their time evolution onto the phaseQuantum Accelerator Modes from the Farey Tree A. Buchleitner,1 M. B. d'Arcy,2,* S. Fishman,3 S. A

  9. Batch Mode Stochastic-Based Robust Dynamic Resource Allocation

    E-Print Network [OSTI]

    Maciejewski, Anthony A.

    Batch Mode Stochastic-Based Robust Dynamic Resource Allocation in a Heterogeneous Computing System in system parameters is common. Robustness can be defined as the degree to which a system can function in data size and content. Determining a resource allocation that accounts for this uncertainty

  10. NO. ~EV. NO. Failure Modes and Effects Analysis -LRRR

    E-Print Network [OSTI]

    Rathbun, Julie A.

    of the Failure Modes and Effects Analysis (FMEA) is to discover critical failure areas in the LRRR experiment for the critical failure areas. A TM 868 contains the results of a final FMEA for the LRRR experiment. 2. 0 SUMMARY Since an LRRR was successfully deployed on the moon as a part of the Apollo 11 mission, this FMEA

  11. Failure Modes and Effects Analysis 300 Array -LRRR

    E-Print Network [OSTI]

    Rathbun, Julie A.

    of the Failure Modes and Effects Analysis (FMEA) is to discover critical failure areas in a system and to remove failure areas. 1. 2 This memo contains the results of the final FMEA for the 300 Array LRRR experiment was successfully deployed on the moon as a part of the Apollo 11 mission, this FMEA will not dwell in the aspects

  12. INTERNAL ELECTROSTATIC TRANSDUCTION FOR BULK-MODE MEMS RESONATORS

    E-Print Network [OSTI]

    Afshari, Ehsan

    This paper demonstrates a new approach to electrostatic drive and detection of bulk acoustic resonators coupled into the fundamental bending mode. The approach was deemed inefficient because air-gap capacitive by filling the air-gaps with a low Young's modulus, high- dielectric material. A more practical approach

  13. Spurious Modes in Dirac Calculations and How to Avoid Them

    E-Print Network [OSTI]

    Mathieu Lewin; Eric Séré

    2013-09-13

    In this paper we consider the problem of the occurrence of spurious modes when computing the eigenvalues of Dirac operators, with the motivation to describe relativistic electrons in an atom or a molecule. We present recent mathematical results which we illustrate by simple numerical experiments. We also discuss open problems.

  14. Quantum theory of dispersive electromagnetic modes P. D. Drummond

    E-Print Network [OSTI]

    Queensland, University of

    Quantum theory of dispersive electromagnetic modes P. D. Drummond Department of Physics proposals--have the character of fundamental tests of the quantum theory of interacting fields 7 Received 15 June 1998 A quantum theory of dispersion for an inhomogeneous solid is obtained, from

  15. Statistical RKR Modeling of Mixed-Mode Fracture

    E-Print Network [OSTI]

    Ritchie, Robert

    Statistical RKR Modeling of Mixed-Mode Fracture in a Brittle Functionally Graded Material by T. L-calibration for fracture mechanics sample with modulus gradient ·Calculate effect of gradient slope on ·predicted fracture fK x II ijII I ijI ij 2 )( 2 )( )exp( #12;·The RKR fracture model correlates the onset

  16. Recent MARS15 Developments, New Features and Event Generator Modes

    E-Print Network [OSTI]

    McDonald, Kirk

    Recent MARS15 Developments, New Features and Event Generator Modes Fermilab Accelerator Physics-28, 2013 Nikolai Mokhov 8 MARS15 EXCLUSIVE EVENT GENERATORS Improved Cascade-Exciton Model code, CEM03. Mokhov, "CEM03.03 and LAQGSM03.03 Event Generators for the MCNP6, MCNPX and MARS15 Transport Codes", LANL

  17. Adhesive contact delaminating at mixed mode, its thermodynamics and analysis

    E-Print Network [OSTI]

    Rossi, Riccarda

    Adhesive contact delaminating at mixed mode, its thermodynamics and analysis Riccarda Rossi.roubicek@mff.cuni.cz Abstract An adhesive unilateral contact problem between visco-elastic heat-conductive bodies in lin- ear Kelvin-Voigt rheology is scrutinised. The flow-rule for debonding the adhesive is considered rate

  18. Early-stage Power Grid Analysis for Uncertain Working Modes

    E-Print Network [OSTI]

    Sapatnekar, Sachin

    Early-stage Power Grid Analysis for Uncertain Working Modes Haifeng Qian Department of ECE circuits are now reaching the 100-plus watt regime, and power delivery and power grid signal integrity have and Design Aids General Terms Algorithms, Performance, Design, Reliability Keywords Power grid, Supply

  19. Collective modes in the color flavor-locked phase.

    SciTech Connect (OSTI)

    Anglani, R.; Mannarelli, M.; Ruggieri, M. (Physics); (Univ. of Barcelona); (Kyoto Univ.); (Italian National Research Council)

    2011-05-17

    We study the low-energy effective action for some collective modes of the color flavor-locked (CFL) phase of QCD. This phase of matter has long been known to be a superfluid because by picking a phase its order parameter breaks the quark-number U(1){sub B} symmetry spontaneously. We consider the modes describing fluctuations in the magnitude of the condensate, namely the Higgs mode, and in the phase of the condensate, namely the Nambu-Goldstone (NG) (or Anderson-Bogoliubov) mode associated with the breaking of U(1){sub B}. By employing as microscopic theory the Nambu-Jona-Lasinio model, we reproduce known results for the Lagrangian of the NG field to the leading order in the chemical potential and extend such results evaluating corrections due to the gap parameter. Moreover, we determine the interaction terms between the Higgs and the NG field. This study paves the way for a more reliable study of various dissipative processes in rotating compact stars with a quark matter core in the CFL phase.

  20. Review of ModeConversion Calculations in Toroidal Plasmas y

    E-Print Network [OSTI]

    Jaun, André

    , however, allow for an energy transfer from one wave branch to another in a process called mode Institute of Technology SE­100 44 Stockholm, Sweden y work performed during a visit at CRPP, september 1999 ABSTRACT. Recent developments in the gyrokinetic modeling of drift­, Alfvâ??en and Bernstein waves allow

  1. Review of Mode-Conversion Calculations in Toroidal Plasmasy

    E-Print Network [OSTI]

    Jaun, André

    , however, allow for an energy transfer from one wave branch to another in a process called mode Institute of Technology SE-100 44 Stockholm, Sweden y work performed during a visit at CRPP, september 1999 ABSTRACT. Recent developments in the gyrokinetic modeling of drift-, Alfv´en and Bernstein waves allow

  2. Dual-Mode Switching of Diffraction Gratings Based on Azobenzene-

    E-Print Network [OSTI]

    Zhao, Yue

    -irradiated area and can be polymerized further on flood irradiation. If the concentration of the azobenzene-polymerDual-Mode Switching of Diffraction Gratings Based on Azobenzene- Polymer-Stabilized Liquid Crystals include polymer-dispersed liquid crystals (PDLC),[3,4] cholesteric liquid crystals (CLC) with or without

  3. Geological and mathematical framework for failure modes in granular rock

    E-Print Network [OSTI]

    Borja, Ronaldo I.

    Geological and mathematical framework for failure modes in granular rock Atilla Aydina, *, Ronaldo I. Borjab , Peter Eichhubla,1 a Department of Geological and Environmental Sciences, Stanford processes in granular rock and provide a geological framework for the corresponding structures. We describe

  4. Burst Mode Message Loss Effects On WAAS Availability

    E-Print Network [OSTI]

    Stanford University

    Burst Mode Message Loss Effects On WAAS Availability Richard Fuller, Todd Walter, Per Enge, the satellite ranging-source increases the percentage of time that the precise signal is available. In this way, availability, and continuity. The WAAS Signal-In-Space (SIS) has a limited data message bandwidth of 250 bits

  5. Lamb shift due to surface plasmon polariton modes 

    E-Print Network [OSTI]

    Sun, Qingqing; Al-Amri, M.; Kamli, Ali; Zubairy, M. Suhail

    2008-01-01

    The Lamb shift of a hydrogen atom due to the surface plasmon polariton (SPP) modes is calculated and we observe both band edge and surface enhancement. The atom sits inside a thin metal slab which is sandwiched by two semi-infinite dielectrics...

  6. Photonic modes of organic light emitting Submitted by

    E-Print Network [OSTI]

    Exeter, University of

    is a metallic cathode. To achieve high efficiency OLEDs a primary issue to address is how the light resultingPhotonic modes of organic light emitting structures Submitted by Peter Allen Hobson for the award of a degree by this or any other University. #12;Abstract 2 Abstract Organic light emitting diodes

  7. FAST MODES AND DUSTY HORSESHOES IN TRANSITIONAL DISKS

    SciTech Connect (OSTI)

    Mittal, Tushar; Chiang, Eugene

    2015-01-01

    The brightest transitional protoplanetary disks are often azimuthally asymmetric: their millimeter-wave thermal emission peaks strongly on one side. Dust overdensities can exceed ?100:1, while gas densities vary by factors less than a few. We propose that these remarkable ALMA observations—which may bear on how planetesimals form—reflect a gravitational global mode in the gas disk. The mode is (1) fast—its pattern speed equals the disk's mean Keplerian frequency; (2) of azimuthal wavenumber m = 1, displacing the host star from the barycenter; and (3) Toomre-stable. We solve for gas streamlines including the indirect stellar potential in the frame rotating with the pattern speed, under the drastic simplification that gas does not feel its own gravity. Near corotation, the gas disk takes the form of a horseshoe-shaped annulus. Dust particles with aerodynamic stopping times much shorter or much longer than the orbital period are dragged by gas toward the horseshoe center. For intermediate stopping times, dust converges toward a ?45° wide arc on the corotation circle. Particles that do not reach their final accumulation points within disk lifetimes, either because of gas turbulence or long particle drift times, conform to horseshoe-shaped gas streamlines. Our mode is not self-consistent because we neglect gas self-gravity; still, we expect that trends between accumulation location and particle size, similar to those we have found, are generically predicted by fast modes and are potentially observable. Unlike vortices, global modes are not restricted in radial width to the pressure scale height; their large radial and azimuthal extents may better match observations.

  8. Axisymmetric oscillation modes of a double droplet system

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

    Ramalingam, Santhosh K.; Basaran, Osman A.

    2010-01-01

    A double droplet system (DDS) consists of a sessile and a pendant drop that are coupled through a liquid filled cylindrical hole in a plate of thickness d. For a small hole radius R, equilibrium shapes of both drops are sections of spheres. While DDSs have a number of applications in microfluidics, a DDS oscillating about its equilibrium state can be used as a fast focusing liquid lens. Here, a DDS consisting of an isothermal, incompressible Newtonian fluid of constant density p and constant viscosity u that is surrounded by a gas is excited by oscillating in time (a) the pressure in the gas surrounding either drop (pressure excitation), (b) the plate perpendicular to its plane (axial excitation), and (c) the hole radius (radial excitation). In contrast to previous works that assumed transient drop shapes are spherical, they are determined here by simulation and used to identify the natural modes of axisymmetric oscillations from resonances observed during frequency sweeps with DDSs for which the combined volume V of the two drops is less than (4/3)?R3. Pressure and axial excitations are found to have identical responses but axial and radial excitations are shown to excite different modes. These modes are compared to those exhibited by single pendant (sessile) drop systems. In particular, while a single pendant (sessile) drop has one additional oscillation mode compared to a free drop, a DDS is found to exhibit roughly twice as many oscillation modes as a pendant (sessile) drop. The effects of dimensionless volume V/R3, dimensionless plate thickness d/R, and Ohnesorge number Oh =?/??R? , where ? is the surface tension of the DDS-gas interface, on the resonance frequencies are also investigated.

  9. Axisymmetric oscillation modes of a double droplet system

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

    Ramalingam, Santhosh K.; Basaran, Osman A.

    2010-11-15

    A double droplet system (DDS) consists of a sessile and a pendant drop that are coupled through a liquid filled cylindrical hole in a plate of thickness d. For a small hole radius R, equilibrium shapes of both drops are sections of spheres. While DDSs have a number of applications in microfluidics, a DDS oscillating about its equilibrium state can be used as a fast focusing liquid lens. Here, a DDS consisting of an isothermal, incompressible Newtonian fluid of constant density p and constant viscosity u that is surrounded by a gas is excited by oscillating in time (a) themore »pressure in the gas surrounding either drop (pressure excitation), (b) the plate perpendicular to its plane (axial excitation), and (c) the hole radius (radial excitation). In contrast to previous works that assumed transient drop shapes are spherical, they are determined here by simulation and used to identify the natural modes of axisymmetric oscillations from resonances observed during frequency sweeps with DDSs for which the combined volume V of the two drops is less than (4/3)?R3. Pressure and axial excitations are found to have identical responses but axial and radial excitations are shown to excite different modes. These modes are compared to those exhibited by single pendant (sessile) drop systems. Specifically, while a single pendant (sessile) drop has one additional oscillation mode compared to a free drop, a DDS is found to exhibit roughly twice as many oscillation modes as a pendant (sessile) drop. The effects of dimensionless volume V/R3, dimensionless plate thickness d/R, and Ohnesorge number Oh =?/??R? , where ? is the surface tension of the DDS-gas interface, on the resonance frequencies are also investigated.« less

  10. Axisymmetric oscillation modes of a double droplet system

    SciTech Connect (OSTI)

    Ramalingam, Santhosh K.; Basaran, Osman A.

    2010-11-15

    A double droplet system (DDS) consists of a sessile and a pendant drop that are coupled through a liquid filled cylindrical hole in a plate of thickness d. For a small hole radius R, equilibrium shapes of both drops are sections of spheres. While DDSs have a number of applications in microfluidics, a DDS oscillating about its equilibrium state can be used as a fast focusing liquid lens. Here, a DDS consisting of an isothermal, incompressible Newtonian fluid of constant density p and constant viscosity u that is surrounded by a gas is excited by oscillating in time (a) the pressure in the gas surrounding either drop (pressure excitation), (b) the plate perpendicular to its plane (axial excitation), and (c) the hole radius (radial excitation). In contrast to previous works that assumed transient drop shapes are spherical, they are determined here by simulation and used to identify the natural modes of axisymmetric oscillations from resonances observed during frequency sweeps with DDSs for which the combined volume V of the two drops is less than (4/3)?R3. Pressure and axial excitations are found to have identical responses but axial and radial excitations are shown to excite different modes. These modes are compared to those exhibited by single pendant (sessile) drop systems. In particular, while a single pendant (sessile) drop has one additional oscillation mode compared to a free drop, a DDS is found to exhibit roughly twice as many oscillation modes as a pendant (sessile) drop. The effects of dimensionless volume V/R3, dimensionless plate thickness d/R, and Ohnesorge number Oh =?/??R? , where ? is the surface tension of the DDS-gas interface, on the resonance frequencies are also investigated.

  11. THE LIGHT CURVE AND INTERNAL MAGNETIC FIELD OF THE MODE-SWITCHING PULSAR PSR B0943+10

    SciTech Connect (OSTI)

    Storch, Natalia I.; Lai, Dong [Center for Space Research, Department of Astronomy, Cornell University, Ithaca, NY 14853 (United States); Ho, Wynn C. G. [Mathematical Sciences and STAG Research Centre, University of Southampton, Southampton, SO17 1BJ (United Kingdom); Bogdanov, Slavko [Columbia Astrophysics Laboratory, Columbia University, 550 West 120th Street, New York, NY 10027 (United States); Heinke, Craig O. [Department of Physics, University of Alberta, CCIS 4-181, Edmonton, AB, T6G 2E1 (Canada)

    2014-07-10

    A number of radio pulsars exhibit intriguing mode-switching behavior. Recent observations of PSR B0943+10 revealed correlated radio and X-ray mode switches, providing a new avenue for understanding this class of objects. The large X-ray pulse fraction observed during the radio-quiet phase (Q-mode) was previously interpreted as a result of changing obscuration of X-rays by dense magnetosphere plasma. We show that the large X-ray pulse fraction can be explained by including the beaming effect of a magnetic atmosphere, while remaining consistent with the dipole field geometry constrained by radio observations. We also explore a more extreme magnetic field configuration, where a magnetic dipole displaced from the center of the star produces two magnetic polar caps of different sizes and magnetic field strengths. These models are currently consistent with data in radio and X-rays and can be tested or constrained by future X-ray observations.

  12. Quantum theory of a two-mode open-cavity laser

    E-Print Network [OSTI]

    V. Eremeev; S. E. Skipetrov; M. Orszag

    2011-08-25

    We develop the quantum theory of an open-cavity laser assuming that only two modes compete for gain. We show that the modes interact to build up a collective mode that becomes the lasing mode when pumping exceeds a threshold. This collective mode exhibits all the features of a typical laser mode, whereas its precise behavior depends explicitly on the openness of the cavity. We approach the problem by using the density-matrix formalism and derive the master equation for the light field. Our results are of particular interest in the context random laser systems.

  13. Tools for detecting entanglement between different degrees of freedom in quadrature squeezed cylindrically polarized modes

    E-Print Network [OSTI]

    Christian Gabriel; Andrea Aiello; Stefan Berg-Johansen; Christoph Marquardt; Gerd Leuchs

    2011-12-15

    Quadrature squeezed cylindrically polarized modes contain entanglement not only in the polarization and spatial electric field variables but also between these two degrees of freedom [1]. In this paper we present tools to generate and detect this entanglement. Experimentally we demonstrate the generation of quadrature squeezing in cylindrically polarized modes by mode transforming a squeezed Gaussian mode. Specifically, -1.2 dB of amplitude squeezing are achieved in the radially and azimuthally polarized mode. Furthermore, theoretically it is shown how the entanglement contained within these modes can be measured and how strong the quantum correlations, depending on the measurement scheme, are.

  14. Energy of eigen-modes in magnetohydrodynamic flows of ideal fluids

    E-Print Network [OSTI]

    I. V. Khalzov; A. I. Smolyakov; V. I. Ilgisonis

    2007-12-11

    Analytical expression for energy of eigen-modes in magnetohydrodynamic flows of ideal fluids is obtained. It is shown that the energy of unstable modes is zero, while the energy of stable oscillatory modes (waves) can assume both positive and negative values. Negative energy waves always correspond to non-symmetric eigen-modes -- modes that have a component of wave-vector along the equilibrium velocity. These results suggest that all non-symmetric instabilities in ideal MHD systems with flows are associated with coupling of positive and negative energy waves. As an example the energy of eigen-modes is calculated for incompressible conducting fluid rotating in axial magnetic field.

  15. Development of magnetohydrodynamic modes during sawteeth in tokamak plasmas

    SciTech Connect (OSTI)

    Firpo, M.-C.; Ettoumi, W.; Farengo, R.; Ferrari, H. E.; Consejo Nacional de Investigaciones Científicas y Técnicas , Bariloche ; García-Martínez, P. L.; Lifschitz, A. F.

    2013-07-15

    A dynamical analysis applied to a reduced resistive magnetohydrodynamics model is shown to explain the chronology of the nonlinear destabilization of modes observed in tokamak sawteeth. A special emphasis is put on the nonlinear self-consistent perturbation of the axisymmetric m = n = 0 mode that manifests through the q-profile evolution. For the very low fusion-relevant resistivity values, the q-profile is shown to remain almost unchanged on the early nonlinear timescale within the central tokamak region, which supports a partial reconnection scenario. Within the resistive region, indications for a local flattening or even a local reversed-shear of the q-profile are given. The impact of this ingredient in the occurrence of the sawtooth crash is discussed.

  16. Trapped Modes and Steered Dirac Cones in Platonic Crystals

    E-Print Network [OSTI]

    R. C. McPhedran; A. B. Movchan; N. V. Movchan; M. Brun; M. J. A. Smith

    2014-10-01

    This paper discusses the properties of flexural waves obeying the biharmonic equation, propagating in a thin plate pinned at doubly-periodic sets of points. The emphases are on the properties of dispersion surfaces having the Dirac cone topology, and on the related topic of trapped modes in plates with a finite set (cluster) of pinned points. The Dirac cone topologies we exhibit have at least two cones touching at a point in the reciprocal lattice, augmented by another band passing through the point. We show that the Dirac cones can be steered along symmetry lines in the Brillouin zone by varying the aspect ratio of rectangular lattices of pins, and that, as the cones are moved, the involved band surfaces tilt. We link Dirac points with a parabolic profile in their neighbourhood, and the characteristic of this parabolic profile decides the direction of propagation of the trapped mode in finite clusters.

  17. Micro-tearing modes in spherical and conventional tokamaks

    E-Print Network [OSTI]

    Moradi, S; Guttenfelder, W; Fülöp, T; Mollén, A

    2013-01-01

    The onset and characteristics of Micro-Tearing Modes (MTM) in the core of spherical (NSTX) and conventional tokamaks (ASDEX-UG and JET) are studied through local linear gyrokinetic simulations with gyro [J. Candy and E. Belli, General Atomics Report GA-A26818 (2011)]. For experimentally relevant core plasma parameters in the NSTX and ASDEX-UG tokamaks, in agreement with previous works, we find MTMs as the dominant linear instability. Also, for JET-like core parameters considered in our study an MTM is found as the most unstable mode. In all these plasmas, finite collisionality is needed for MTMs to become unstable and the electron temperature gradient is found to be the fundamental drive. However, a significant difference is observed in the dependence of linear growth rate of MTMs on electron temperature gradient. While it varies weakly and non-monotonically in JET and ASDEX-UG plasmas, in NSTX it increases with the electron temperature gradient.

  18. Present and Future Modes of Low Frequency Climate Variability

    SciTech Connect (OSTI)

    Cane, Mark A.

    2014-02-20

    This project addressed area (1) of the FOA, “Interaction of Climate Change and Low Frequency Modes of Natural Climate Variability”. Our overarching objective is to detect, describe and understand the changes in low frequency variability between model simulations of the preindustrial climate and simulations of a doubled CO2 climate. The deliverables are a set of papers providing a dynamical characterization of interannual, decadal, and multidecadal variability in coupled models with attention to the changes in this low frequency variability between pre-industrial concentrations of greenhouse gases and a doubling of atmospheric concentrations of CO2. The principle mode of analysis, singular vector decomposition, is designed to advance our physical, mechanistic understanding. This study will include external natural variability due to solar and volcanic aerosol variations as well as variability internal to the climate system. An important byproduct is a set of analysis tools for estimating global singular vector structures from the archived output of model simulations.

  19. Mode-locked solid state lasers using diode laser excitation

    DOE Patents [OSTI]

    Holtom, Gary R. (Boston, MA)

    2012-03-06

    A mode-locked laser employs a coupled-polarization scheme for efficient longitudinal pumping by reshaped laser diode bars. One or more dielectric polarizers are configured to reflect a pumping wavelength having a first polarization and to reflect a lasing wavelength having a second polarization. An asymmetric cavity provides relatively large beam spot sizes in gain medium to permit efficient coupling to a volume pumped by a laser diode bar. The cavity can include a collimation region with a controlled beam spot size for insertion of a saturable absorber and dispersion components. Beam spot size is selected to provide stable mode locking based on Kerr lensing. Pulse durations of less than 100 fs can be achieved in Yb:KGW.

  20. Estimating the solar meridional circulation by normal mode decomposition

    E-Print Network [OSTI]

    Lars Krieger; Markus Roth; Oskar von der Luehe

    2008-11-05

    The objective of this article is to use Fourier-Hankel decomposition as suggested earlier by Braun & Fan (1998) to estimate the integrated horizontal meridional flow velocity as a function of mode penetration depth, and to find ways of potentially improve this technique. We use a time series of 43200 (30 days) consecutive full-disk Dopplergrams obtained by the MDI (Michelson Doppler Imager) instrument aboard the SOHO (Solar Heliospheric Observatory) spacecraft in April 1999. We find averaged meridional flow estimates of 15 m/s for modes with a penetration depth in the upper 20 Mm of the solar convection zone. This reproduces the results of the earlier investigations. Moreover we conclude that this method has the potential to become a new technique to measure the meridional circulation in the deep convection zone, if some improvements will be applied.

  1. The whistler mode refractive index as a function of gyrofrequency

    SciTech Connect (OSTI)

    Albert, J. M.

    2011-08-15

    The refractive index for a constant-frequency whistler mode wave in an electron-proton plasma is considered as a function of position, through the local gyrofrequencies {Omega}{sub e,i}. The full cold plasma dispersion relation is used. The wave frequency can take any value up to the smaller of {Omega}{sub e} and the plasma frequency {omega}{sub pe}, but {omega}{sub pe} is allowed to take any fixed value, as is the wavenormal angle. It is rigorously established that the refractive index is a decreasing function of {Omega}{sub e}. One application of this is to finding locations of Landau and cyclotron resonances, to evaluate the effects of whistler mode waves on radiation belt electrons.

  2. Staggered fermions, zero modes, and flavor-singlet mesons

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

    Donald, Gordon C; Davies, Christine T.H.; Follana, Eduardo; Kronfeld, Andreas S.

    2011-09-12

    We examine the taste structure of eigenvectors of the staggered-fermion Dirac operator. We derive a set of conditions on the eigenvectors of modes with small eigenvalues (near-zero modes), such that staggered fermions reproduce the 't Hooft vertex in the continuum limit. We also show that, assuming these conditions, the correlators of flavor-singlet mesons are free of contributions singular in 1/m, where m is the quark mass. This conclusion holds also when a single flavor of sea quark is represented by the fourth root of the staggered-fermion determinant. We then test numerically, using the HISQ action, whether these conditions hold onmore »realistic lattice gauge fields. We find that the needed structure does indeed emerge.« less

  3. GONG p-mode frequency changes with solar activity

    E-Print Network [OSTI]

    A. Bhatnagar; Kiran Jain; S. C. Tripathy

    1999-04-01

    We present a correlation analysis of GONG p-mode frequencies with nine solar activity indices for the period 1995 August to 1997 August. This study includes spherical harmonic degree in the range 2 to 150 and the frequency range of 1500-3500 \\mu Hz. Using three statistical tests, the measured mean frequency shifts show strong to good correlation with activity indices. A decrease of 0.06 \\mu Hz in frequency, during the descending phase of solar cycle 22 and an increase of 0.04 \\mu Hz in the ascending phase of solar cycle 23 is observed. These results provide the first evidence for change in p-mode frequencies around the declining phase of solar cycle 22 and beginning of new cycle 23. This analysis further confirms that the temporal behaviour of the solar frequency shifts closely follow the phase of the solar activity cycle.

  4. Scissors Mode of 162 Dy Studied from Resonance Neutron Capture

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

    Baramsai, B.; Be?vá?, F.; Bredeweg, T. A.; Haight, R. C.; Jandel, M.; Kroll, J.; Krti?ka, M.; Mitchell, G. E.; O’Donnell, J. M.; Rundberg, R. S.; et al

    2015-05-28

    Multi-step cascade ?-ray spectra from the neutron capture at isolated resonances of 161Dy nucleus were measured at the LANSCE/DANCE time-of-flight facility in Los Alamos National Laboratory. The objectives of this experiment were to confirm and possibly extend the spin assignment of s-wave neutron resonances and get new information on photon strength functions with emphasis on the role of the M1 scissors mode vibration. The preliminary results show that the scissors mode plays a significant role in all transitions between accessible states of the studied nucleus. The photon strength functions describing well our data are compared to results from 3He-induced reactions,more »(n,?) experiments on Gd isotopes, and (?,?’) reactions.« less

  5. Development and Use of the Dual-Mode Plasma Torch

    SciTech Connect (OSTI)

    Womack, R.; Shuey, M.

    2002-02-26

    After several years of development, a commercially available high-temperature treatment system has been developed and installed that treats heterogeneous low-level radioactive waste. High temperature plasma processing, unique torch design and operating features make it feasible to achieve a volume reduced, permanent, high integrity waste form while eliminating the personnel exposure and costs associated with conventional sorting, characterizing and handling. Plasma technology can also be used to treat previous conditioned waste packages that no longer meet the current acceptance criteria for final disposal. Plasma treatment can result, in many cases, in a substantial volume reduction, which lowers the final disposal costs. This paper covers the recently patented dual mode plasma torch design(1), the lessons learned that fostered its development and the advantages it brings to radioactive waste processing. This paper also provides current full scale Plasma Arc Centrifugal Treatment (PACT) project status and how the dual mode torch is being used in the PACT system.

  6. The Prediction of the Maximum Modes of Decay of Mesons

    E-Print Network [OSTI]

    Ramanna, R

    1999-01-01

    In an earlier work, several properties of fundamental particles were brought together by a simple equation based on continuity and discreteness. It is shown here, that the maximum modes of decay of all fundamental particles can also be predicted without any arbitrary parameters. The method used is to break up the mean lifetimes of particles to obtain the maximum modes of decay. This is done by using a binary expansion of $\\hbar/MT$ where M is the mass of the particle and T is the mean lifetime. The agreements between that obtained from theory and experiment are remarkable. The ordering of the flavours plays an important part in understanding the reasons for this agreement. It is shown that the Zeno effect in Quantum mechanics is connected with use of the binary series.

  7. The Prediction of the Maximum Modes of Decay of Mesons

    E-Print Network [OSTI]

    Raja Ramanna

    1999-04-27

    In an earlier work, several properties of fundamental particles were brought together by a simple equation based on continuity and discreteness. It is shown here, that the maximum modes of decay of all fundamental particles can also be predicted without any arbitrary parameters. The method used is to break up the mean lifetimes of particles to obtain the maximum modes of decay. This is done by using a binary expansion of $\\hbar/MT$ where M is the mass of the particle and T is the mean lifetime. The agreements between that obtained from theory and experiment are remarkable. The ordering of the flavours plays an important part in understanding the reasons for this agreement. It is shown that the Zeno effect in Quantum mechanics is connected with use of the binary series.

  8. Gravitational-wave modes from precessing black-hole binaries

    E-Print Network [OSTI]

    Michael Boyle; Lawrence E. Kidder; Serguei Ossokine; Harald P. Pfeiffer

    2014-09-22

    Gravitational waves from precessing black-hole binaries exhibit features that are absent in nonprecessing systems. The most prominent of these is a parity-violating asymmetry that beams energy and linear momentum preferentially along or opposite to the orbital angular momentum, leading to recoil of the binary. The asymmetry will appear as amplitude and phase modulations at the orbital frequency. For strongly precessing systems, it accounts for at least 3% amplitude modulation for binaries in the sensitivity band of ground-based gravitational-wave detectors, and can exceed 50% for massive systems. Such asymmetric features are also clearly visible when the waves are decomposed into modes of spin-weighted spherical harmonics, and are inherent in the waves themselves---rather than resulting from residual eccentricity in numerical simulations, or from mode-mixing due to precession. In particular, there is generically no instantaneous frame for which the mode decomposition will have any symmetry. We introduce a method to simplify the expressions for waveforms given in analytical relativity, which can be used to combine existing high-order waveforms for nonprecessing systems with expressions for the precessing contributions, leading to improved accuracy and a unified treatment of precessing and nonprecessing binaries. Using this method, it is possible to clarify the nature and the origins of the asymmetries and show the effects of asymmetry on recoils more clearly. We present post-Newtonian (PN) expressions for the waveform modes that include these terms, complete to the relative 2PN level in spin (proportional to $v^4/c^4$ times a certain combination of the spins). Comparing the results of those expressions to numerical results, we find good qualitative agreement. We also demonstrate how these expressions can be used to efficiently calculate waveforms for gravitational-wave astronomy.

  9. Composite slip table of dissimilar materials for damping longitudinal modes

    DOE Patents [OSTI]

    Gregory, Danny L. (Albuquerque, NM); Priddy, Tommy G. (Albuquerque, NM); Smallwood, David O. (Albuquerque, NM); Woodall, Tommy D. (Albuquerque, NM)

    1991-01-01

    A vibration slip table for use in a vibration testing apparatus. The table s comprised of at least three composite layers of material; a first metal layer, a second damping layer, and a third layer having a high acoustic velocity relative to the first layer. The different acoustic velocities between the first and third layers cause relative shear displacements between the layers with the second layer damping the displacements between the first and third layers to reduce the table longitudinal vibration modes.

  10. Electromagnetic quasinormal modes of D-dimensional black holes

    E-Print Network [OSTI]

    A. López-Ortega

    2006-11-02

    Using the monodromy method we calculate the asymptotic quasinormal (QN) frequencies of an electromagnetic field moving in D-dimensional Schwarzschild and Schwarzschild de Sitter (SdS) black holes ($D\\geq 4$). For the D-dimensional Schwarzschild anti-de Sitter (SadS) black hole we also compute these frequencies with a similar method. Moreover, we calculate the electromagnetic normal modes of the D-dimensional anti-de Sitter (AdS) spacetime.

  11. Notes 09. Numerical evaluation of natural modes and frequencies 

    E-Print Network [OSTI]

    San Andres, Luis

    2008-01-01

    MEEN 617 ? HD#9. Numerical methods for finding eigenvalues & eigenvectors L. San Andr?s ? 2008 1 ME617 - Handout 9 Solving the eigenvalue problem - Numerical Evaluation of Natural Modes and Frequencies in MDOF systems The standard... will give you an appreciation of what goes on inside such canned routines. The knowledge below will help you to make an intelligent choice when using or selecting one of the methods detailed. The references listed at the end of this document...

  12. Collective Modes in Strongly Coupled Electronic Bilayer Liquids

    SciTech Connect (OSTI)

    Kalman, G.; Valtchinov, V. [Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467 (United States)] [Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467 (United States); Valtchinov, V. [Department of Radiology, Brigham and Women`s Hospital, Harvard Medical School, Boston, Massachusetts 02115 (United States)] [Department of Radiology, Brigham and Women`s Hospital, Harvard Medical School, Boston, Massachusetts 02115 (United States); Golden, K.I. [Department of Mathematics and Statistics, University of Vermont, Burlington, Vermont 05401 (United States)] [Department of Mathematics and Statistics, University of Vermont, Burlington, Vermont 05401 (United States)

    1999-04-01

    We present the first reliable calculation of the collective mode structure of a strongly coupled electronic bilayer. The calculation is based on a classical model through the 3rd frequency-moment-sum rule preserving quasi-localized-charge approximation, using the recently calculated hypernetted-chain pair correlation functions. The out-of-phase spectrum shows an energy gap at k=0 and the absence of a previously conjectured dynamical instability. {copyright} {ital 1999} {ital The American Physical Society}

  13. Collective modes and thermodynamics of the liquid state

    E-Print Network [OSTI]

    K. Trachenko; V. V. Brazhkin

    2015-12-21

    Strongly interacting, dynamically disordered and with no small parameter, liquids took a theoretical status between gases and solids. We review different approaches to liquids and propose that liquids do not need classifying in terms of their proximity to gases and solids. Instead, they are a unique system in their own class with a notably mixed dynamical state in contrast to pure dynamical states of solids and gases. We start with explaining how the first-principles approach to liquids is an intractable, exponentially complex problem of coupled non-linear oscillators with bifurcations. This is followed by a reduction of the problem based on liquid relaxation time $\\tau$ representing non-perturbative treatment of strong interactions. On the basis of $\\tau$, solid-like high-frequency modes are predicted and we review related recent experiments. We demonstrate how these modes can be derived by generalizing either hydrodynamic or elasticity equations. We comment on the historical trend to approach liquids using hydrodynamics and compare it to an alternative solid-like approach. We subsequently discuss how collective modes evolve with temperature and how this affects liquid energy and other properties such as fast sound. Here, our emphasis is on real, rather than model, liquids. Highlighting the dominant role of high-frequency modes for liquid energy, we review a wide range of liquids: subcritical low-viscous liquids, supercritical state with two different dynamical and thermodynamic regimes separated by the Frenkel line, highly-viscous liquids and liquid-glass transition. We also discuss liquid-liquid phase transitions where the solid-like properties of liquids have become further apparent. We then discuss gas-like and solid-like approaches to quantum liquids and persisting theoretical problems. We list areas where interesting insights may appear and continue the extraordinary liquid story.

  14. Decoherence Patterns of Topological Qubits from Majorana Modes

    E-Print Network [OSTI]

    Shih-Hao Ho; Sung-Po Chao; Chung-Hsien Chou; Feng-Li Lin

    2014-10-21

    We investigate the decoherence patterns of topological qubits in contact with the environment by a novel way of deriving the open system dynamics other than the Feynman-Vernon. Each topological qubit is made of two Majorana modes of a 1D Kitaev's chain. These two Majorana modes interact with the environment in an incoherent way which yields peculiar decoherence patterns of the topological qubit. More specifically, we consider the open system dynamics of the topological qubits which are weakly coupled to the fermionic/bosonic Ohmic-like environments. We find atypical patterns of quantum decoherence. In contrast to the cases of non-topological qubits for which they always decohere completely in all Ohmic-like environments, the topological qubits decohere completely in the Ohmic and sub-Ohmic environments but not in the super-Ohmic ones. Moreover, we find that the fermion parities of the topological qubits though cannot prevent the qubit states from decoherence in the sub-Ohmic environments, can prevent from thermalization turning into Gibbs state. We also study the cases in which each Majorana mode can couple to different Ohmic-like environments and the time dependence of concurrence for two topological qubits.

  15. Differential rotation of the unstable nonlinear r-modes

    E-Print Network [OSTI]

    Friedman, John L; Lockitch, Keith H

    2015-01-01

    At second order in perturbation theory, the $r$-modes of uniformly rotating stars include an axisymmetric part that can be identified with differential rotation of the background star. If one does not include radiation-reaction, the differential rotation is constant in time and has been computed by S\\'a. It has a gauge dependence associated with the family of time-independent perturbations that add differential rotation to the unperturbed equilibrium star: For stars with a barotropic equation of state, one can add to the time-independent second-order solution arbitrary differential rotation that is stratified on cylinders (that is a function of distance $\\varpi$ to the axis of rotation). We show here that the gravitational radiation-reaction force that drives the $r$-mode instability removes this gauge freedom: The expontially growing differential rotation of the unstable second-order $r$-mode is unique. We derive a general expression for this rotation law for Newtonian models and evaluate it explicitly for s...

  16. Buoyancy and g-modes in young superfluid neutron stars

    E-Print Network [OSTI]

    A. Passamonti; N. Andersson; W. C. G. Ho

    2015-04-28

    We consider the local dynamics of a realistic neutron star core, including composition gradients, superfluidity and thermal effects. The main focus is on the gravity g-modes, which are supported by composition stratification and thermal gradients. We derive the equations that govern this problem in full detail, paying particular attention to the input that needs to be provided through the equation of state and distinguishing between normal and superfluid regions. The analysis highlights a number of key issues that should be kept in mind whenever equation of state data is compiled from nuclear physics for use in neutron star calculations. We provide explicit results for a particular stellar model and a specific nucleonic equation of state, making use of cooling simulations to show how the local wave spectrum evolves as the star ages. Our results show that the composition gradient is effectively dominated by the muons whenever they are present. When the star cools below the superfluid transition, the support for g-modes at lower densities (where there are no muons) is entirely thermal. We confirm the recent suggestion that the g-modes in this region may be unstable, but our results indicate that this instability will be weak and would only be present for a brief period of the star's life. Our analysis accounts for the presence of thermal excitations encoded in entrainment between the entropy and the superfluid component. Finally, we discuss the complete spectrum, including the normal sound waves and, in superfluid regions, the second sound.

  17. B-modes and the Nature of Inflation

    E-Print Network [OSTI]

    Daniel Baumann; Daniel Green; Rafael A. Porto

    2015-12-09

    Observations of the cosmic microwave background do not yet determine whether inflation was driven by a slowly-rolling scalar field or involved another physical mechanism. In this paper we discuss the prospects of using the power spectra of scalar and tensor modes to probe the nature of inflation. We focus on the leading modification to the slow-roll dynamics, which entails a sound speed $c_s$ for the scalar fluctuations. We derive analytically a lower bound on $c_s$ in terms of a given tensor-to-scalar ratio $r$, taking into account the difference in the freeze-out times between the scalar and tensor modes. We find that any detection of primordial B-modes with $r > 0.01$ implies a lower bound on $c_s$ that is stronger than the bound derived from the absence of non-Gaussianity in the Planck data. For $r \\gtrsim 0.1$, the bound would be tantalizingly close to a critical value for the sound speed, $(c_s)_\\star = 0.47$ (corresponding to $(f_{\\rm NL}^{\\rm equil})_\\star = -0.93$), which we show serves as a threshold for non-trivial dynamics beyond slow-roll. We also discuss how an order-one level of equilateral non-Gaussianity is a natural observational target for other extensions of the canonical paradigm.

  18. CMR Shuffler System: Passive Mode Calibration and Certification Report

    SciTech Connect (OSTI)

    Frame, Katherine C. [Los Alamos National Laboratory; Gomez, Cipriano D. [Retired CMR-OPS: OPERATIONS; Salazar, William R. [Los Alamos National Laboratory; Mayo, Douglas R. [Los Alamos National Laboratory; Vigil, Georgiana M. [Los Alamos National Laboratory; Crooks, William J. [Los Alamos National Laboratory; Stange, Sy [Los Alamos National Laboratory

    2012-07-20

    Los Alamos National Laboratory has a number of spherical confinement vessels (CVs) remaining from tests involving nuclear materials. These vessels have an inner diameter of 6 feet with 1 to 2 inch thick steel walls. The goal of the Confinement Vessel Disposition (CVD) project is to remove debris and reduce contamination inside the vessels. As debris is removed from the vessels, material will be placed in waste drums. Far-field gamma ray assay will be used to determine when a drum is nearing a {sup 239}Pu equivalent mass of less than 200 g. The drum will then be assayed using a waste drum shuffler operated in passive mode using a neutron coincidence counting method for accountability. This report focuses on the testing and calibration of the CMR waste drum shuffler in passive mode operation. Initial testing was performed to confirm previously accepted measurement parameters. The system was then calibrated using a set of weapons grade Pu (WGPu, {sup 239}Pu > 93%) oxide standards placed inside a 55 gallon drum. The calibration data ranges from Pu mass of 0.5 g to 188.9 g. The CMR waste drum shuffler has been tested and calibrated in passive mode in preparation for safeguards accountability measurements of waste drums containing material removed from CVs for the CVD project.

  19. Proposal for efficient mode converter based on cavity quantum electrodynamics dark mode in a semiconductor quantum dot coupled to a bimodal microcavity

    SciTech Connect (OSTI)

    Li, Jiahua [School of Physics, Huazhong University of Science and Technology, Wuhan 430074 (China); Key Laboratory of Fundamental Physical Quantities Measurement of Ministry of Education, Wuhan 430074 (China); Yu, Rong, E-mail: yurong321@126.com [School of Science, Hubei Province Key Laboratory of Intelligent Robot, Wuhan Institute of Technology, Wuhan 430073 (China); Ma, Jinyong; Wu, Ying, E-mail: yingwu2@163.com [School of Physics, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2014-10-28

    The ability to engineer and convert photons between different modes in a solid-state approach has extensive technological implications not only for classical communication systems but also for future quantum networks. In this paper, we put forward a scheme for coherent mode conversion of optical photons by utilizing the intermediate coupling between a single quantum dot and a bimodal photonic crystal microcavity via a waveguide. Here, one mode of the photonic crystal microcavity is coherently driven by an external single-frequency continuous-wave laser field and the two cavity modes are not coupled to each other due to their orthogonal polarizations. The undriven cavity mode is thus not directly coupled to the input driving laser and the only way it can get light is via the quantum dot. The influences of the system parameters on the photon-conversion efficiency are analyzed in detail in the limit of weak probe field and it is found that high photon-conversion efficiency can be achieved under appropriate conditions. It is shown that the cavity dark mode, which is a superposition of the two optical modes and is decoupled from the quantum dot, can appear in such a hybrid optical system. We discuss the properties of the dark mode and indicate that the formation of the dark mode enables the efficient transfer of optical fields between the two cavity modes.

  20. Failure to deactivate the default mode network indicates a possible endophenotype of autism

    E-Print Network [OSTI]

    Spencer, Michael D.; Chura, Lindsay R.; Holt, Rosemary J.; Suckling, John; Calder, Andrew J.; Bullmore, Edward T.; Baron-Cohen, Simon

    2012-12-03

    Abstract Background Reduced activity during cognitively demanding tasks has been reported in the default mode network in typically developing controls and individuals with autism. However, no study has investigated the default mode network (DMN...

  1. Current mode integrators and their applications in low-voltage high frequency CMOS signal processing 

    E-Print Network [OSTI]

    Smith, Sterling Lane

    1993-01-01

    Low voltage CMOS fully differential integrators for high frequency continuous-time filters using current-mode techniques are presented.. Current mode techniques are employed to avoid the use of the floating differential ...

  2. Radical Matter: Materiality in Postwar and Contemporary American Mixed Mode Poetry

    E-Print Network [OSTI]

    Wang, Sophia

    2012-01-01

    subject  formation  as  well  as   Jonathan  Culler’s  work  on  apostrophe  as  the  fundamental  discursive  mode  subject  formations  intrinsic  to  language,  as  well  as  the  sensory  and  referential   operations  that  function  across  literary  and  non-­?literary  modes  

  3. Modeling streamers in transformer oil: The transitional fast 3rd mode streamer

    E-Print Network [OSTI]

    Zahn, Markus

    This paper presents an electro-thermal hydrodynamic model that explains the development of different streamer modes in transformer oil. The focus is on the difference between the slow 2nd and fast 3rd mode streamers ...

  4. Study of H-mode access conditions on the Alcator C-Mod Tokamak

    E-Print Network [OSTI]

    Ma, Yunxing

    2013-01-01

    Usually when sufficient heating power is injected, tokamak plasma will make an abrupt transition into a state with improved confinement, known as the high-confinement mode, or H-mode. Given the greatly enhanced fusion ...

  5. Performance of Hole-Coupling Resonator in the Presence of Asymmetric Modes and FEL Gain

    E-Print Network [OSTI]

    Xie, M.

    2011-01-01

    is derived in, K. -1. Kim, "FEL Gain Taking into Accountof Asymmetric Modes :1nd FEL Gain M. Xie and K. -J. KimOF ASYMMETRIC MODES AND FEL GAIN· Ming Xie and Kwang-Je Kim

  6. Suppression of Mode-Beating in a Saturated Hole-Coupling FEL Oscillator

    E-Print Network [OSTI]

    Krishnagopal, S.

    2011-01-01

    cavity case L and with an FEL interaction. of mode-beatingMode profiles (with an FEL interaction) at three differentin a Saturated Hole-coupled FEL Oscillator S. Krishnagopal,

  7. Failure and Degradation Modes of PV Modules in a Hot Dry Climate...

    Office of Environmental Management (EM)

    Failure and Degradation Modes of PV Modules in a Hot Dry Climate: Results After 12 to 26 Years of Field Exposure Failure and Degradation Modes of PV Modules in a Hot Dry Climate:...

  8. Multi-Mode RCCI Has Great Potential to Improve Fuel Economy in...

    Office of Environmental Management (EM)

    Mode RCCI Has Great Potential to Improve Fuel Economy in Light-Duty Diesel Engines Multi-Mode RCCI Has Great Potential to Improve Fuel Economy in Light-Duty Diesel Engines February...

  9. Coupled-mode theory for Bose-Einstein condensates Elena A. Ostrovskaya,1

    E-Print Network [OSTI]

    to the nonlinear phase shifting between the modes, power exchange, and self-trapping. In this paper, we apply

  10. Optical injection induced polarization mode switching and correlation analysis on a VCSEL

    E-Print Network [OSTI]

    Damodarakurup, Sajeev; Vudayagiri, Ashok

    2015-01-01

    Vertical cavity Surface Emitting Laser (VCSEL) diodes emit light in two polarization modes. The amount of optical feedback is found to influence the intensities of the emitted modes. We investigate the effect of the amount of total output polarization feedback and polarization selective feedback on the intensities of the two emitted polarization modes. A 40 micro seconds resolution time series correlation analysis is done for different feedback conditions and investigate the power spectral continuity and onset of chaos on two polarization modes

  11. A CLASSIFICATION OF DUCT MODES BASED ON SURFACE WAVES Sjoerd W. Rienstra

    E-Print Network [OSTI]

    Eindhoven, Technische Universiteit

    A CLASSIFICATION OF DUCT MODES BASED ON SURFACE WAVES Sjoerd W. Rienstra Department of Mathematics For the relatively high frequencies relevant in a turbofan engine duct the modes of a lined sec- tion may be classified in two categories: genuine acoustic 3D duct modes resulting from the finiteness of the duct

  12. A CLASSIFICATION OF DUCT MODES BASED ON SURFACE WAVES Sjoerd W. Rienstra

    E-Print Network [OSTI]

    Eindhoven, Technische Universiteit

    A CLASSIFICATION OF DUCT MODES BASED ON SURFACE WAVES Sjoerd W. Rienstra Department of Mathematics For the relatively high frequencies relevant in a turbofan engine duct the modes of a lined sec­ tion may be classified in two categories: genuine acoustic 3D duct modes resulting from the finiteness of the duct

  13. Study and optimisation of the common mode exploitation for xDSL application

    E-Print Network [OSTI]

    the capacity of xDSL systems in a binder MIMO channel. Indeed, N copper pairs can use either differential or Differential mode, common mode, phantom mode, egress, VDSL, MIMO I. INTRODUCTION The growing demand for high speed services like video on demand, peer-to-peer sharing and High Definition TeleVision (HDTV) call

  14. Helical temperature perturbations associated with tearing modes in tokamak Richard Fitzpatrick

    E-Print Network [OSTI]

    Fitzpatrick, Richard

    Helical temperature perturbations associated with tearing modes in tokamak plasmas Richard in a tokamak plasma Phys. Plasmas 12, 082504 (2005); 10.1063/1.1989727 Stability of tearing modes in tokamak in tokamak plasmas Phys. Fluids 29, 200 (1986); 10.1063/1.865977 Turbulence driven tearing modes in a tokamak

  15. Influence of wall thickness on the stability of the resistive wall mode in tokamak Richard Fitzpatrick

    E-Print Network [OSTI]

    Fitzpatrick, Richard

    Influence of wall thickness on the stability of the resistive wall mode in tokamak plasmas Richard.1063/1.2446041 Nonlinear evolution of resistive wall mode in a cylindrical tokamak with poloidal rotation Phys. Plasmas 13); 10.1063/1.1943347 Control of resistive wall modes in a cylindrical tokamak with radial and poloidal

  16. Phase locking of multi-helicity neoclassical tearing modes in tokamak plasmas Richard Fitzpatrick

    E-Print Network [OSTI]

    Fitzpatrick, Richard

    Phase locking of multi-helicity neoclassical tearing modes in tokamak plasmas Richard Fitzpatrick neoclassical tearing modes in tokamaks Phys. Plasmas 20, 042505 (2013); 10.1063/1.4799823 Consequences. Plasmas 19, 092506 (2012); 10.1063/1.4751873 Nonlinear dynamics of rotating drift-tearing modes in tokamak

  17. Stability of coupled tearing and twisting modes in tokamaks Richard Fitzpatrick

    E-Print Network [OSTI]

    Fitzpatrick, Richard

    Stability of coupled tearing and twisting modes in tokamaks Richard Fitzpatrick Citation: Physics tearing and twisting modes in tokamaks''' [Phys. Plasmas 1, 3308 (1994)] Phys. Plasmas 2, 3925 (1995); 10.1063/1.871024 Comment on ``Stability of coupled tearing and twisting modes in tokamaks'' [Phys. Plasmas 1, 3308 (1994

  18. Electromagnetic vacuum energy for two parallel slabs in terms of surface, wave guide and photonic modes

    E-Print Network [OSTI]

    M. Bordag

    2012-01-05

    The formulation of the Lifshitz formula in terms of real frequencies is reconsidered for half spaces described by the plasma model. It is shown that besides the surface modes (for the TM polarization), and the photonic modes, also waveguide modes must be considered.

  19. Full quantum state reconstruction of symmetric two-mode squeezed thermal states via spectral homodyne detection

    E-Print Network [OSTI]

    Simone Cialdi; Carmen Porto; Daniele Cipriani; Stefano Olivares; Matteo G. A. Paris

    2015-11-02

    We suggest and demonstrate a scheme to reconstruct the symmetric two-mode squeezed thermal states of spectral sideband modes from an optical parametric oscillator. The method is based on a single homodyne detector and active stabilization of the cavity. The measurement scheme have been successfully tested on different two-mode squeezed thermal states, ranging from uncorrelated coherent states to entangled states.

  20. The contributions of atmosphere and ocean to North Atlantic Subtropical Mode Water volume anomalies

    E-Print Network [OSTI]

    The formation of Subtropical Mode Water (STMW) in the western North Atlantic has been attributed to both are the subject of a study, the CLIvar MOde Water Dynamics Experiment (CLIMODE), which includes a large fieldThe contributions of atmosphere and ocean to North Atlantic Subtropical Mode Water volume anomalies

  1. An Attack on CFB Mode Encryption As Used By OpenPGP Serge Mister & Robert Zuccherato

    E-Print Network [OSTI]

    International Association for Cryptologic Research (IACR)

    An Attack on CFB Mode Encryption As Used By OpenPGP Serge Mister & Robert Zuccherato Entrust, Inc.mister,robert.zuccherato}@entrust.com Abstract. This paper describes an adaptive-chosen-ciphertext attack on the Cipher Feedback (CFB) mode for each block. Standard CFB mode encryption does not appear to be affected by this attack. It applies

  2. Observation of tearing mode deceleration and locking due to eddy currents induced in a conducting shell

    E-Print Network [OSTI]

    Fitzpatrick, Richard

    Observation of tearing mode deceleration and locking due to eddy currents induced in a conducting eddy currents induced by the rotating mode in the conducting shell surrounding the plasma. According to the amplitude of the mode.4­7 According to this theory, eddy currents induced in the conducting shell

  3. FULLY INTEGRATED CURRENT-MODE SUBAPERTURE CENTROID CIRCUITS AND PHASE RECONTRUCTOR

    E-Print Network [OSTI]

    Furth, Paul

    , New Mexico July 2001 #12;ii "Fully Integrated Current-Mode Subaperture Centroid Circuits and Phase: Electrical Engineering (Analog VLSI Circuit Design) #12;vi ABSTRACT FULLY INTEGRATED CURRENT-MODE SUBAPERTUREFULLY INTEGRATED CURRENT-MODE SUBAPERTURE CENTROID CIRCUITS AND PHASE RECONTRUCTOR BY ALUSHULLA

  4. Horseshoes, Homoclinic Connections and Global Chaos in Current-Mode Controlled DC/DC

    E-Print Network [OSTI]

    Tse, Chi K. "Michael"

    , Japan Abstract-- In this paper, chaos in a current-mode controlled boost converter is studied. Firstly a rigorous proof of chaos in a current-mode controlled boost converter. This is done by proving the existence. Furthermore, we report homoclinic tangency and global chaos in the current-mode controlled boost converter. II

  5. Model for passive mode locking in semiconductor lasers Andrei G. Vladimirov*

    E-Print Network [OSTI]

    Vladimirov, Andrei G.

    Model for passive mode locking in semiconductor lasers Andrei G. Vladimirov* Weierstrass Institute 11 May 2005; published 12 September 2005 We derive and study a model describing passive mode locking.65.Pc INTRODUCTION Passive mode locking ML is a powerful method to gen- erate high-quality short pulses

  6. Mode 2 waves on the continental shelf: Ephemeral components of the nonlinear internal wavefield

    E-Print Network [OSTI]

    waves appear sporadically in mooring records obtained off the coast of New Jersey in the summer of 2006. Turbulent dissipation in the mixed layer and radiation of the short mode 1 waves contributed to rapid energy a few hours. The energy in the leading mode 2 wave was 10­100 times smaller than the energy of mode 1

  7. Investigation of ELM [edge localized mode] Dynamics with the Resonant Magnetic Perturbation Effects

    SciTech Connect (OSTI)

    Pankin, Alexei Y.; Kritz, Arnold H.

    2011-07-19

    Topics covered are: anomalous transport and E x B flow shear effects in the H-mode pedestal; RMP (resonant magnetic perturbation) effects in NSTX discharges; development of a scaling of H-mode pedestal in tokamak plasmas with type I ELMs (edge localized modes); and divertor heat load studies.

  8. FAST MODE DECISION FOR H.264 VIDEO CODING IN PACKET LOSS ENVIRONMENT Yuan Zhang1

    E-Print Network [OSTI]

    Cosman, Pamela C.

    FAST MODE DECISION FOR H.264 VIDEO CODING IN PACKET LOSS ENVIRONMENT Yuan Zhang1 and Pamela C, CA, 92093-0407, USA ABSTRACT In this paper, we propose a fast mode decision scheme for H.264 video communications. Traditional fast mode decision schemes are usually designed based on feature analysis

  9. Mirror-mode storms: STEREO observations of protracted generation of small amplitude waves

    E-Print Network [OSTI]

    California at Berkeley, University of

    Mirror-mode storms: STEREO observations of protracted generation of small amplitude waves C. T. Luhmann (2009), Mirror-mode storms: STEREO observations of protracted generation of small amplitude waves observes mirror-mode storms, periods in which small amplitude waves suddenly appear and persist for hours

  10. Optimal Scheduling for Constant-Rate Multi-Mode Systems Rajeev Alur

    E-Print Network [OSTI]

    Alur, Rajeev

    -mode systems are hybrid systems that can switch freely among a finite set of modes, and whose dynamics Keywords Multi-Mode Systems, Cyber-Physical Systems, Peak Mini- mization, Green Scheduling, Hybrid Automata "heating, ventilation, and air conditioning" (HVAC) systems. The correlation between extreme weather

  11. Standby and off-mode power demand of new appliances in the Anbal de Almeida

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Standby and off-mode power demand of new appliances in the market Aníbal de Almeida ISR regulation to limit the standby and off-mode power consumption of non-networked household electronic involved in the project. Standby and off-mode values by product categories are analyzed and compared

  12. Zonal Jet Structure and the Leading Mode of Variability SCOTT J. EICHELBERGER AND DENNIS L. HARTMANN

    E-Print Network [OSTI]

    Hartmann, Dennis

    Zonal Jet Structure and the Leading Mode of Variability SCOTT J. EICHELBERGER AND DENNIS L the effects of the zonal jet structure on the leading mode of variability in the Northern Hemisphere. Model-driven and subtropical jets. When the jets are well separated, the leading mode of variability describes latitudinal

  13. Mode competition and output power in regular and chaotic dielectric cavity lasers

    E-Print Network [OSTI]

    Stone, A. Douglas

    Mode competition and output power in regular and chaotic dielectric cavity lasers Hakan E. T many modes and their competition can address the mode selection and output power of these lasers lasing patterns of two- dimensional dielectric microcavity lasers of different shape, including

  14. Mixed-mode fracture of human cortical bone Elizabeth A. Zimmermann a,b

    E-Print Network [OSTI]

    Ritchie, Robert

    Mixed-mode fracture of human cortical bone Elizabeth A. Zimmermann a,b , Maximilien E. Launey Available online 1 July 2009 Keywords: Human cortical bone Mixed-mode fracture Fracture toughness Fracture mechanisms a b s t r a c t Although the mode I (tensile opening) fracture toughness has been the focus

  15. Search for invisible decays of Higgs bosons in the vector boson fusion and associated ZH production modes

    SciTech Connect (OSTI)

    Chatrchyan, Serguei; et. al,

    2014-08-01

    A search for invisible decays of Higgs bosons is performed using the vector boson fusion and associated ZH production modes. In the ZH mode, the Z boson is required to decay to a pair of charged leptons or a b b-bar quark pair. The searches use the 8 TeV pp collision dataset collected by the CMS detector at the LHC, corresponding to an integrated luminosity of up to 19.7 inverse femtobarns. Certain channels include data from 7 TeV collisions corresponding to an integrated luminosity of 4.9 inverse femtobarns. The searches are sensitive to non-standard-model invisible decays of the recently observed Higgs boson, as well as additional Higgs bosons with similar production modes and large invisible branching fractions. In all channels, the observed data are consistent with the expected standard model backgrounds. Limits are set on the production cross section times invisible branching fraction, as a function of the Higgs boson mass, for the vector boson fusion and ZH production modes. By combining all channels, and assuming standard model Higgs boson cross sections and acceptances, the observed (expected) upper limit on the invisible branching fraction at m[H] = 125 GeV is found to be 0.58 (0.44) at 95% confidence level. We interpret this limit in terms of a Higgs-portal model of dark matter interactions.

  16. Strong electron dissipation by a mode converted ion hybrid (Bernstein) wave

    SciTech Connect (OSTI)

    Lashmore-Davies, C.N.; Ram, A.K.

    1996-02-01

    The fast wave approximation, extended to include the effects of electron dissipation, is used to calculate the power mode converted to the ion hybrid (Bernstein) wave in the vicinity of the ion hybrid resonance. The power absorbed from the fast wave by ion cyclotron damping and by electron Landau and transit time damping (including cross terms) is also calculated. The fast wave equation is solved for either the Budden configuration of a cut-off-resonance pair or the triplet configuration of cut-off-resonance-cut-off. The fraction mode converted is compared for the triplet case and the Budden multi-pass situation. The electron damping rate of the ion hybrid wave is obtained from the local dispersion relation and a ray tracing code is used to calculate the damping of the mode converted ion hybrid wave by the electrons as it propagates away from the resonance. Quantitative results for a range of conditions relevant to JET, TFTR and ITER are given. {copyright} {ital 1996 American Institute of Physics.}

  17. A comparison of the cost of urban transportation modes 

    E-Print Network [OSTI]

    Hatchell, William Jack

    1968-01-01

    OF SCIEMCE August 1968 Major Subject: Ci~ i] Engincc ri. ng A C~3ldFARJ. OE OF THE COST cJF VRHAN TRJ&SFORTATION HODES A Thesis HTJ. lian Sacs Hatchall ptoa d a. to st le and content by: ( o"aal t ta ~) (I'en bat ) Au. ;us t 196o A Comparison... of the Cost of Urban Transportatron &!odes. (August 1968) !? lliam Jack Uatchell, B. S. , Texas A6!d University Supervised by: Dr. Vergil G. Sto;&er ABSTRACT Th latest co~&. information for six urban trau. , port ate on modes; Autcmobiles . &n Freeways...

  18. Beam dynamics studies for transverse electromagnetic mode type rf deflectors

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

    Ahmed, Shahid; Krafft, Geoffrey A.; Deitrick, Kirsten; De Silva, Subashini U.; Delayen, Jean R.; Spata, Mike; Tiefenback, Michael; Hofler, Alicia; Beard, Kevin

    2012-02-01

    We have performed three-dimensional simulations of beam dynamics for transverse electromagnetic mode (TEM) type rf deflectors: normal and superconducting. The compact size of these cavities as compared to the conventional TM110 type structures is more attractive particularly at low frequency. Highly concentrated electromagnetic fields between the parallel bars provide strong electrical stability to the beam for any mechanical disturbance. An array of six 2-cell normal conducting cavities or a single cell superconducting structure is enough to produce the required vertical displacement at the target point. Both the normal and superconducting structures show very small emittance dilution due to the verticalmore »kick of the beam.« less

  19. Landau Damping of Geodesic Acoustic Mode in Toroidally Rotating Tokamaks

    E-Print Network [OSTI]

    Ren, Haijun

    2015-01-01

    Geodesic acoustic mode (GAM) is analyzed by using gyro-kinetic equations applicable to low-frequency microinstabilities in a rotating axisymmetric plasma. Dispersion relation of GAM in the presence of arbitrary Mach number is analytically dervied. Toroidal rotation plays the same effects on the GAM regardless of the orientation of equilibrium flow. It is shown that the toroidal Mach number increases the GAM frequency and dramatically decreases the Landau damping rate. Classical gyro-kinetic equation is examined to be not suitable for describing the GAM in a torodially rotating tokamak plasma even for very small Mach number.

  20. Electromagnetic quasinormal modes of D-dimensional black holes II

    E-Print Network [OSTI]

    A. López-Ortega

    2007-06-20

    By using the sixth order WKB approximation we calculate for an electromagnetic field propagating in D-dimensional Schwarzschild and Schwarzschild de Sitter black holes its quasinormal frequencies for the fundamental mode and first overtones. We study the dependence of these QN frequencies on the value of the cosmological constant and the spacetime dimension. We also compare with the known results for the gravitational perturbations propagating in the same background. Moreover we exactly compute the QN frequencies of the electromagnetic field propagating in D-dimensional massless topological black hole and for charged D-dimensional Nariai spacetime we exactly calculate the QN frequencies of the coupled electromagnetic and gravitational perturbations.

  1. Entropy mode loops and cosmological correlations during perturbative reheating

    SciTech Connect (OSTI)

    Kaya, Ali; Kutluk, Emine Seyma E-mail: seymakutluk@gmail.com

    2015-01-01

    Recently, it has been shown that during preheating the entropy modes circulating in the loops, which correspond to the inflaton decay products, meaningfully modify the cosmological correlation functions at superhorizon scales. In this paper, we determine the significance of the same effect when reheating occurs in the perturbative regime. In a typical two scalar field model, the magnitude of the loop corrections are shown to depend on several parameters like the background inflaton amplitude in the beginning of reheating, the inflaton decay rate and the inflaton mass. Although the loop contributions turn out to be small as compared to the preheating case, they still come out larger than the loop effects during inflation.

  2. Diffractive optical elements for transformation of modes in lasers

    DOE Patents [OSTI]

    Sridharan, Arun K.; Pax, Paul H.; Heebner, John E.; Drachenberg, Derrek R.; Armstrong, James P.; Dawson, Jay W.

    2015-09-01

    Spatial mode conversion modules are described, with the capability of efficiently transforming a given optical beam profile, at one plane in space into another well-defined optical beam profile at a different plane in space, whose detailed spatial features and symmetry properties can, in general, differ significantly. The modules are comprised of passive, high-efficiency, low-loss diffractive optical elements, combined with Fourier transform optics. Design rules are described that employ phase retrieval techniques and associated algorithms to determine the necessary profiles of the diffractive optical components. System augmentations are described that utilize real-time adaptive optical techniques for enhanced performance as well as power scaling.

  3. Bounded modes to the rescue of optical transmission

    E-Print Network [OSTI]

    Michael Sarrazin; Jean Pol Vigneron

    2007-10-17

    This paper presents a brief survey of the evolution of knowledge about diffraction gratings. After recalling some basic facts, historically and physically, we introduce the concept of Wood anomalies. Next, we present some recent works in order to introduce the role of bounded modes in transmission gratings. The consequences of these recent results are then introduced. This paper is a secondary publication, published in Europhysics News (EPN 38, 3 (2007) 27-31). In the present version, some additional notes have been added with related references.

  4. Tunable dark modes in one-dimensional “diatomic” dielectric gratings

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

    Zeng, Bo; Majumdar, Arka; Wang, Feng

    2015-05-04

    Recently researchers have demonstrated ultra high quality factor (Q) resonances in one-dimensional (1D) dielectric gratings. Here we theoretically investigate a new class of subwavelength 1D gratings, namely “diatomic” gratings with two nonequivalent subcells in one period, and utilize their intrinsic dark modes to achieve robust ultra high Q resonances. Such “diatomic” gratings provide extra design flexibility, and enable high Q resonators using thinner geometry with smaller filling factors compared to conventional designs like the high contrast gratings (HCGs). More importantly, we show that these high Q resonances can be efficiently tuned in situ, making the design appealing in various applicationsmore »including optical sensing, filtering and displays.« less

  5. Composite slip table of dissimilar materials for damping longitudinal modes

    DOE Patents [OSTI]

    Gregory, D.L.; Priddy, T.G.; Smallwood, D.O.; Woodall, T.D.

    1991-06-18

    A vibration slip table for use in a vibration testing apparatus is disclosed. The tables comprised of at least three composite layers of material; a first metal layer, a second damping layer, and a third layer having a high acoustic velocity relative to the first layer. The different acoustic velocities between the first and third layers cause relative shear displacements between the layers with the second layer damping the displacements between the first and third layers to reduce the table longitudinal vibration modes. 6 figures.

  6. Graphene-based perfect optical absorbers harnessing guided mode resonances

    E-Print Network [OSTI]

    Grande, M; Stomeo, T; Bianco, G V; de Ceglia, D; Akozbek, N; Petruzzelli, V; Bruno, G; De Vittorio, M; Scalora, M; Orazio, A D

    2015-01-01

    We numerically and experimentally investigate graphene-based optical absorbers that exploit guided mode resonances (GMRs) achieving perfect absorption over a bandwidth of few nanometers (over the visible and near-infrared ranges) with a 40-fold increase of the monolayer graphene absorption. We analyze the influence of the geometrical parameters on the absorption rate and the angular response for oblique incidence. Finally, we experimentally verify the theoretical predictions in a one-dimensional, dielectric grating and placing it near either a metallic or a dielectric mirror.

  7. Multi-parameter Laser Modes in Paraxial Optics

    E-Print Network [OSTI]

    Christoph Koutschan; Erwin Suazo; Sergei K. Suslov

    2015-04-19

    We study multi-parameter solutions of the inhomogeneous paraxial wave equation in a linear and quadratic approximation which include oscillating laser beams in a parabolic waveguide, spiral light beams, and other important families of propagation-invariant laser modes in weakly varying media. A "smart" lens design and a similar effect of superfocusing of particle beams in a thin monocrystal film are also discussed. In the supplementary electronic material, we provide a computer algebra verification of the results presented here, and of some related mathematical tools that were stated without proofs in the literature.

  8. Active control of the resistive wall mode with power saturation

    SciTech Connect (OSTI)

    Li Li; Liu Yue [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian, 116024 (China); Liu Yueqiang [Euratom/CCFE Fusion Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom)

    2012-01-15

    An analytic model of non-linear feedback stabilization of the resistive wall mode is presented. The non-linearity comes from either the current or the voltage saturation of the control coil power supply. For the so-called flux-to-current control, the current saturation of active coils always results in the loss of control. On the contrary, the flux-to-voltage control scheme tolerates certain degree of the voltage saturation. The minimal voltage limit is calculated, below which the control will be lost.

  9. Mixed mode control method and engine using same

    DOE Patents [OSTI]

    Kesse, Mary L. (Peoria, IL); Duffy, Kevin P. (Metamora, IL)

    2007-04-10

    A method of mixed mode operation of an internal combustion engine includes the steps of controlling a homogeneous charge combustion event timing in a given engine cycle, and controlling a conventional charge injection event to be at least a predetermined time after the homogeneous charge combustion event. An internal combustion engine is provided, including an electronic controller having a computer readable medium with a combustion timing control algorithm recorded thereon, the control algorithm including means for controlling a homogeneous charge combustion event timing and means for controlling a conventional injection event timing to be at least a predetermined time from the homogeneous charge combustion event.

  10. Emergent Soft Monopole Modes in Weakly-Bound Deformed Nuclei

    E-Print Network [OSTI]

    J. C. Pei; M. Kortelainen; Y. N. Zhang; F. R. Xu

    2014-11-13

    Based on the Hartree-Fock-Bogoliubov solutions in large deformed coordinate spaces, the finite amplitude method for quasiparticle random phase approximation (FAM-QRPA) has been implemented, providing a suitable approach to probe collective excitations of weakly-bound nuclei embedded in the continuum. The monopole excitation modes in Magnesium isotopes up to the neutron drip line have been studied with the FAM-QRPA framework on both the coordinate-space and harmonic oscillator basis methods. Enhanced soft monopole strengths and collectivity as a result of weak-binding effects have been unambiguously demonstrated.

  11. Plasmonic modes and extinction properties of a random nanocomposite cylinder

    SciTech Connect (OSTI)

    Moradi, Afshin

    2014-04-15

    We study the properties of surface plasmon-polariton waves of a random metal-dielectric nanocomposite cylinder, consisting of bulk metal embedded with dielectric nanoparticles. We use the Maxwell-Garnett formulation to model the effective dielectric function of the composite medium and show that there exist two surface mode bands. We investigate the extinction properties of the system, and obtain the dependence of the extinction spectrum on the nanoparticles’ shape and concentration as well as the cylinder radius and the incidence angle for both TE and TM polarization.

  12. Beam dynamics studies for transverse electromagnetic mode type rf deflectors

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

    Ahmed, Shahid; Krafft, Geoffrey A.; Deitrick, Kirsten; De Silva, Subashini U.; Delayen, Jean R.; Spata, Mike; Tiefenback, Michael; Hofler, Alicia; Beard, Kevin

    2012-02-01

    We have performed three-dimensional simulations of beam dynamics for transverse electromagnetic mode (TEM) type rf deflectors: normal and superconducting. The compact size of these cavities as compared to the conventional TM110 type structures is more attractive particularly at low frequency. Highly concentrated electromagnetic fields between the parallel bars provide strong electrical stability to the beam for any mechanical disturbance. An array of six 2-cell normal conducting cavities or a single cell superconducting structure is enough to produce the required vertical displacement at the target point. Both the normal and superconducting structures show very small emittance dilution due to the vertical kick of the beam.

  13. Curvature effect on tearing modes in presence of neoclassical friction

    SciTech Connect (OSTI)

    Maget, Patrick; Mellet, Nicolas; Meshcheriakov, Dmytro; Garbet, Xavier [CEA, IRFM, F-13108 Saint Paul-lez-Durance (France)] [CEA, IRFM, F-13108 Saint Paul-lez-Durance (France); Lütjens, Hinrich [Centre de Physique Théorique, Ecole Polytechnique, CNRS (France)] [Centre de Physique Théorique, Ecole Polytechnique, CNRS (France)

    2013-11-15

    Neoclassical physics (here associated to the poloidal variation of the magnetic field strength along field lines in a tokamak) is well known for driving self-generated plasma current and nonlinear magnetic islands associated to it in high performance, ITER relevant plasma discharges. It is demonstrated that the neoclassical friction between a magnetic perturbation and plasma flow already impacts magnetic islands in the linear regime, by inducing a weakening of curvature stabilization for tearing modes. This conclusion holds in particular for regimes where convection is influencing the pressure dynamics, as shown using a simple analytical model and confirmed in full Magneto-Hydro-Dynamics simulations.

  14. Exotic modes of excitation in proton rich nuclei

    SciTech Connect (OSTI)

    Paar, N.

    2011-11-30

    The framework of relativistic energy density functional has been applied in description of excitation phenomena in nuclei close to the proton drip line. In particular, low-lying dipole excitations have been studied using relativistic quasiparticle random phase approximation, based on effective Lagrangians with density dependent meson nucleon couplings. In the isovector dipole channel, the occurrence of pronounced low-lying dipole peaks is predicted, corresponding to the proton pygmy dipole resonance. Since this exotic mode still awaits its experimental confirmation, systematic calculations have been conducted within a pool of neutron deficient nuclei, in order to identify the best possible candidates for measurements.

  15. Limits of ultrashort pulse generation in cw mode-locked dye lasers

    SciTech Connect (OSTI)

    Petrov, V.; Rudolph, W.; Stamm, U.; Wilhelmi, B.

    1989-08-01

    Essential mechanisms limiting the achievable pulse duration in synchronously pumped, hybrid-mode-locked, and passively mode-locked cw subpicosecond dye lasers are analyzed. The action of spontaneously emitted light is shown to be the detrimental factor in synchronous mode locking. The influence of this factor can be suppressed by a saturable absorber in the hybrid-mode-locked lasers. In this case as well as in the case of passive mode locking the combined action of group-velocity dispersion and Kerr-effect-type nonlinearity, though serving as an additional shortening mechanism, causes fluctuations of the pulse parameters and determines the limit of the steady-state regime.

  16. Investigations of the Wideband Spectrum of Higher Order Modes Measured on TESLA-style Cavities at the FLASH Linac

    SciTech Connect (OSTI)

    Molloy, S.; Adolphsen, C.; Bane, K.; Frisch, J.; Li, Z.; May, J.; McCormick, D.; Smith, T.; /SLAC; Baboi, N.; /DESY; Eddy, N.; Piccoli, L.; Rechenmacher, R.; /Fermilab; Jones, R.; /Manchester U.

    2007-06-27

    Higher Order Modes (HOMs) excited by the passage of the beam through an accelerating cavity depend on the properties of both the cavity and the beam. It is possible, therefore, to draw conclusions on the inner geometry of the cavities based on observations of the properties of the HOM spectrum. A data acquisition system based on two 20 GS/s, 6 GHz scopes has been set up at the FLASH facility, DESY, in order to measure a significant fraction of the HOM spectrum predicted to be generated by the TESLA cavities used for the acceleration of its beam. The HOMs from a particular cavity at FLASH were measured under a range of known beam conditions. The dipole modes have been identified in the data. 3D simulations of different manufacturing errors have been made, and it has been shown that these simulations can predict the measured modes.

  17. Concentric core optical fiber with multiple-mode signal transmission

    DOE Patents [OSTI]

    Muhs, J.D.

    1997-05-06

    A concentric core optical fiber provides for the simultaneous but independent transmission of signals over a single optical fiber. The concentric optical fiber is constructed of a single-mode or multimode inner optical fiber defined by a core and a cladding of a lower index of refraction than the core and an outer optical fiber defined by additional cladding concentrically disposed around the cladding and of an index of refraction lower than the first mentioned cladding whereby the latter functions as the core of the outer optical fiber. By employing such an optical fiber construction with a single-mode inner core or optical fiber, highly sensitive interferometric and stable less sensitive amplitude based sensors can be placed along the same length of a concentric core optical fiber. Also, by employing the concentric core optical fiber secure telecommunications can be achieved via the inner optical fiber since an intrusion of the concentric optical fiber will first cause a variation in the light being transmitted through the outer optical fiber and this variation of light being used to trigger a suitable alarm indicative of the intrusion. 3 figs.

  18. A novel electromagnetic mode in neutral Weyl Semimetals

    E-Print Network [OSTI]

    Yago Ferreiros; Alberto Cortijo

    2015-09-01

    We study light propagation in a neutral Weyl semimetal with the Fermi level lying at the Weyl nodes. The nontrivial topology induces a screening effect in one of the two transverse gauge fields, for which we find two branches of attenuated collective excitations. In addition to the known topologically gaped photon mode, a novel massless and slightly damped excitation appears. Strikingly, at low energies this new excitation has a linear dispersion and it propagates with the same velocity than the electrons, while at energies well above the electron-hole continuum threshold it behaves as a massive attenuated photon with velocity similar to the speed of light in the material. There is a crossover at certain momentum in the direction perpendicular to the separation of the Weyl nodes above which the novel gapless mode enters into an overdamped regime. Regarding the unscreened gauge field we show that it is also attenuated, which is a non-topological property shared by Dirac semimetals as well.

  19. A novel electromagnetic mode in neutral Weyl Semimetals

    E-Print Network [OSTI]

    Ferreiros, Yago

    2015-01-01

    We study light propagation in a neutral Weyl semimetal with the Fermi level lying at the Weyl nodes. The nontrivial topology induces a screening effect in one of the two transverse gauge fields, for which we find two branches of attenuated collective excitations. In addition to the known topologically gaped photon mode, a novel massless and slightly damped excitation appears. Strikingly, at low energies this new excitation has a linear dispersion and it propagates with the same velocity than the electrons, while at energies well above the electron-hole continuum threshold it behaves as a massive attenuated photon with velocity similar to the speed of light in the material. There is a crossover at certain momentum in the direction perpendicular to the separation of the Weyl nodes above which the novel gapless mode enters into an overdamped regime. Regarding the unscreened gauge field we show that it is also attenuated, which is a non-topological property shared by Dirac semimetals as well.

  20. R-mode constraints from neutron star equation of state

    E-Print Network [OSTI]

    M. C. Papazoglou; C. C. Moustakidis

    2015-06-15

    The gravitational radiation has been proposed a long time before, as an explanation for the observed relatively low spin frequencies of young neutron stars and of accreting neutron stars in low-mass X-ray binaries as well. In the present work we studied the effects of the neutron star equation of state on the r-mode instability window of rotating neutron stars. Firstly, we employed a set of analytical solution of the Tolman-Oppemheimer-Volkoff equations. In particular, we tried to clarify the effects of the bulk neutron star properties (mass, radius, density distribution, crust size and elasticity) on the r-mode instability window. We found that the critical angular velocity $\\Omega_c$ depends mainly on the neutron star radius. The effects of the gravitational mass and the mass distribution are almost negligible. Secondly, we studied the effect of the elasticity of the crust, via to the slippage factor $S$ and also the effect of the nuclear equation of state, via the slope parameter $L$, on the instability window. We found that the crust effects are more pronounced, compared to those originated from the equation of state. Moreover, we proposed simple analytical expressions which relate the macroscopic quantity $\\Omega_c$ to the radius, the parameter $L$ and the factor ${\\cal S}$. Finally, we investigated the possibility to measure the radius of a neutron star and the factor ${\\cal S}$ with the help of accurate measures of $\\Omega_c$ and the neutron star temperature.

  1. Enhanced gauge symmetry and winding modes in Double Field Theory

    E-Print Network [OSTI]

    G. Aldazabal; M. Graña; S. Iguri; M. Mayo; C. Nuñez; J. A. Rosabal

    2015-10-26

    We provide an explicit example of how the string winding modes can be incorporated in double field theory. Our guiding case is the closed bosonic string compactified on a circle of radius close to the self-dual point, where some modes with non-zero winding or discrete momentum number become massless and enhance the $U(1) \\times U(1)$ symmetry to $SU(2) \\times SU(2)$. We compute three-point string scattering amplitudes of massless and slightly massive states, and extract the corresponding effective low energy gauge field theory. The enhanced gauge symmetry at the self-dual point and the Higgs-like mechanism arising when changing the compactification radius are examined in detail. The extra massless fields associated to the enhancement are incorporated into a generalized frame with $\\frac{O(d+3,d+3)}{O(d+3)\\times O(d+3)}$ structure, where $d$ is the number of non-compact dimensions. We devise a consistent double field theory action that reproduces the low energy string effective action with enhanced gauge symmetry. The construction requires a truly non-geometric frame which explicitly depends on both the compact coordinate along the circle and its dual.

  2. Variational principles with Padé approximants for tearing mode analysis

    SciTech Connect (OSTI)

    Cole, Andrew J.; Finn, John M.

    2014-03-15

    Tearing modes occur in several distinct physical regimes, and it is often important to compute the inner layer response for these modes with various effects. There is a need for an approximate and efficient method of solving the inner layer equations in all these regimes. In this paper, we introduce a method of solving the inner layer equations based on using a variational principle with Padé approximants. For all the regimes considered, the main layer equations to be solved are inhomogeneous, and Padé approximants give a convenient and efficient method of satisfying the correct asymptotic behavior at the edge of the layer. Results using this variational principle—Padé approximant method in three of these regimes is presented. These regimes are the constant-? resistive-inertial (RI) regime, the constant-? viscoresistive regime, and the non-constant-? inviscid tearing regime. The last regime includes the constant-? RI regime and the inertial regime. The results show that reasonable accuracy can be obtained very efficiently with Padé approximants having a small number of parameters.

  3. Saturation of the f-mode instability in neutron stars: I. Theoretical framework

    E-Print Network [OSTI]

    Pnigouras, Pantelis

    2015-01-01

    The basic formulation describing quadratic mode coupling in rotating Newtonian stars is presented, focusing on polar modes. Due to the Chandrasekhar-Friedman-Schutz mechanism, the f-mode (fundamental oscillation) is driven unstable by the emission of gravitational waves. If the star falls inside the so-called instability window, the mode's amplitude grows exponentially, until it is halted by non-linear effects. Quadratic perturbations form three-mode networks inside the star, which evolve as coupled oscillators, exchanging energy. Coupling of the unstable f-mode to other (stable) modes can lead to a parametric resonance and the subsequent saturation of its amplitude, thus suppressing the instability. The saturation point determines the amplitude of the gravitational-wave signal obtained from an individual source, as well as the evolutionary path of the latter inside the instability window.

  4. An overmoded relativistic backward wave oscillator with efficient dual-mode operation

    SciTech Connect (OSTI)

    Xiao, Renzhen; Li, Jiawei; Bai, Xianchen; Song, Zhimin; Teng, Yan; Ye, Hu; Li, Xiaoze; Sun, Jun; Chen, Changhua [Science and Technology on High Power Microwave Laboratory, Northwest Institute of Nuclear Technology, Xi'an 710024 (China); Zhang, Xiaowei [Science and Technology on High Power Microwave Laboratory, Northwest Institute of Nuclear Technology, Xi'an 710024 (China); Key Laboratory of Physical Electronics and Devices of the Ministry of Education, Xi'an Jiaotong University, Xi'an 710049 (China)

    2014-03-03

    A dual-mode operation mechanism in an overmoded relativistic backward wave oscillator is presented. The electron beam interacts with the ?1st space harmonic of TM{sub 01} mode synchronously in the slow wave structure. Then the backward propagating TM{sub 01} mode is converted to the forward propagating TM{sub 02} mode. As the phase velocity of the volume harmonic of TM{sub 02} mode is about twice that of the surface harmonic of TM{sub 01} mode, the TM{sub 02} mode also plays an important role in the high-power microwave generation. Particle-in-cell simulation shows that an efficiency of 48% and a significant improvement of the power capacity have been obtained.

  5. Collective inertia of Nambu-Goldstone mode from linear response theory

    E-Print Network [OSTI]

    Hinohara, Nobuo

    2015-01-01

    Background: Spurious zero-energy Nambu-Goldstone (NG) modes appear when the symmetry of a system is spontaneously broken. The Thouless-Valatin inertia, the collective inertia of the NG mode, contains important information concerning collective motion. Purpose: To establish an efficient and precise method for deriving the collective inertia and the conjugate operator of a NG mode, we derive an expression for the response function in terms of the coordinate-momentum representation of the quasiparticle random-phase approximation which is valid even if a symmetry-restoring zero-energy mode is present. Methods: We use the finite amplitude method for computing the response function of superfluid nuclei with the nuclear density functional theory. Results: We derived analytically the collective inertia and the conjugate coordinate operator of the NG mode from the zero-energy linear response with the momentum operator of the NG mode. The formulation is tested in the cases of translational and pairing rotational modes....

  6. System and methods for determining masking signals for applying empirical mode decomposition (EMD) and for demodulating intrinsic mode functions obtained from application of EMD

    DOE Patents [OSTI]

    Senroy, Nilanjan (New Delhi, IN); Suryanarayanan, Siddharth (Littleton, CO)

    2011-03-15

    A computer-implemented method of signal processing is provided. The method includes generating one or more masking signals based upon a computed Fourier transform of a received signal. The method further includes determining one or more intrinsic mode functions (IMFs) of the received signal by performing a masking-signal-based empirical mode decomposition (EMD) using the at least one masking signal.

  7. Eddy current inspection tool which is selectively operable in a discontinuity detection mode and a discontinuity magnitude mode

    DOE Patents [OSTI]

    Petrini, Richard R. (Livermore, CA); Van Lue, Dorin F. (Livermore, CA)

    1983-01-01

    A miniaturized inspection tool, for testing and inspection of metal objects in locations with difficult accessibility, which comprises eddy current sensing equipment (12) with a probe coil (11), and associated coaxial coil cable (13), coil energizing means (21), and circuit means (21, 12) responsive to impedance changes in the coil as effected by induced eddy currents in a test object to produce a data output signal proportional to such changes. The coil and cable are slideably received in the utility channel of the flexible insertion tube 17 of fiberoptic scope 10. The scope 10 is provided with light transmitting and receiving fiberoptics for viewing through the flexible tube, and articulation means (19, 20) for articulating the distal end of the tube and permitting close control of coil placement relative to a test object. The eddy current sensing equipment includes a tone generator 30 for generating audibly signals responsive to the data output signal. In one selected mode of operation, the tone generator responsive to the output signal above a selected level generates a constant single frequency tone for signalling detection of a discontinuity and, in a second selected mode, generates a tone whose frequency is proportional to the difference between the output signal and a predetermined selected threshold level.

  8. Eddy current inspection tool which is selectively operable in a discontinuity detection mode and a discontinuity magnitude mode

    DOE Patents [OSTI]

    Petrini, R.R.; Van Lue, D.F.

    1983-10-25

    A miniaturized inspection tool, for testing and inspection of metal objects in locations with difficult accessibility, which comprises eddy current sensing equipment with a probe coil, and associated coaxial coil cable, coil energizing means, and circuit means responsive to impedance changes in the coil as effected by induced eddy currents in a test object to produce a data output signal proportional to such changes. The coil and cable are slideably received in the utility channel of the flexible insertion tube of fiberoptic scope. The scope is provided with light transmitting and receiving fiberoptics for viewing through the flexible tube, and articulation means for articulating the distal end of the tube and permitting close control of coil placement relative to a test object. The eddy current sensing equipment includes a tone generator 30 for generating audibly signals responsive to the data output signal. In one selected mode of operation, the tone generator responsive to the output signal above a selected level generates a constant single frequency tone for signaling detection of a discontinuity and, in a second selected mode, generates a tone whose frequency is proportional to the difference between the output signal and a predetermined selected threshold level. 5 figs.

  9. Global gyrokinetic stability of collisionless microtearing modes in large aspect ratio tokamaks

    SciTech Connect (OSTI)

    Swamy, Aditya K.; Ganesh, R., E-mail: ganesh@ipr.res.in [Institute for Plasma Research, Bhat, Gandhinagar (India); Chowdhury, J. [Department of Physics, University of Colorado, Boulder, Colorado 80309 (United States); Brunner, S.; Vaclavik, J.; Villard, L. [CRPP, EPFL, 1015 Lausanne (Switzerland)

    2014-08-15

    Linear full radius gyrokinetic calculations show the existence of unstable microtearing modes (MTMs) in purely collisionless, high temperature, large aspect ratio tokamak plasmas. The present study takes into account fully gyrokinetic highly passing ions and electrons. The global 2-D structures of the collisionless mode with full radius coupling of the poloidal modes is obtained and compared with another electromagnetic mode, namely, the Alfvén Ion Temperature Gradient (AITG) mode (or Kinetic Ballooning Mode, KBM) for the same equilibrium profile. Several important characteristics of the modes are brought out and compared, such as a clear signature in the symmetry properties of the two modes, the plasma–? dependence, and radial and poloidal length scales of the electrostatic and magnetic vector potential fluctuations. Extensive parameter scans for this collisionless microtearing mode reveal the scaling of the growth rate with ? and the electron temperature gradient ?{sub e}. Scans at different ? values show an inverse relationship between the ?{sub e} threshold and ?, leading to a stability diagram, and implying that the mode might exist at moderate to strong temperature gradients for finite ? plasmas in large aspect ratio tokamaks. In contrast to small aspect ratio tokamaks where the trapped electron magnetic drift resonance is found to be important, in large aspect ratio tokamaks, a strong destabilization due to the magnetic drift resonance of passing electrons is observed and is identified as a possible collisionless drive mechanism for the collisionless MTM.

  10. Phonon-roton modes of liquid 4He beyond the roton in MCM-41

    SciTech Connect (OSTI)

    Azuah, Richard T NIST Center for Neutron Research , Gaithersburg, MD; Omar Diallo, Souleymane ORNL; Adams, Mark A. ISIS Facility, Rutherford Appleton Laboratory; Kirichek, Oleg ISIS Facility, Rutherford Appleton Laboratory; Glyde, Henry R University of Delaware

    2013-01-01

    We present neutron scattering measurements of the phonon-roton (P-R) mode of superfluid 4He confined in 47 A MCM-41 at T = 0.5 K at wave vectors, Q, beyond the roton wave vector (QR = 1.92 A-1). Measurements beyond the roton require access to high wave vectors (up to Q = 4 A-1) with excellent energy resolution and high statistical precision. The present results show for the first time that at T = 0.5 K the P-R mode in MCM-41 extends out to wave-vector Q 3.6 A-1 with the same energy and zero width (within precision) as observed in bulk superfluid 4He. Layer modes in the roton region are also observed. Specifically, the P-R mode energy, !Q, increases with Q for Q > QR and reaches a plateau at a maximum energy !Q = 2 where is the roton energy, = 0.74 0.01 meV in MCM-41. This upper limit means the P-R mode decays to two rotons when its energy exceeds 2 . It also means that the P-R mode does not decay to two layers modes. If the P-R could decay to two layer modes, !Q would plateau at a lower energy, !Q = 2 L where L = 0.60 meV is the energy of the roton like minimum of the layer mode. The observation of the P-R mode with energy up to 2 shows that the P-R mode and the layer modes are independent modes with apparently little interaction between them.

  11. Geodesic Acoustic Mode in Toroidally Rotating Anisotropic Tokamaks

    E-Print Network [OSTI]

    Ren, Haijun

    2015-01-01

    Effects of anisotropy on the geodesic acoustic mode (GAM) is analyzed by using gyro-kinetic equations applicable to low-frequency microinstabilities in a toroidally rotating tokamak plasma. Dispersion relation in the presence of arbitrary Mach number $M$, anisotropy strength $\\sigma$, and the temperature ration $\\tau$ is analytically derived. It is shown that when $\\sigma$ is less than $ 3 + 2 \\tau$, the increased electron temperature with fixed ion parallel temperature increases the normalized GAM frequency. When $\\sigma$ is larger than $ 3 + 2 \\tau$, the increasing of electron temperature decreases the GAM frequency. The anisotropy $\\sigma$ always tends to enlarge the GAM frequency. The Landau damping rate is dramatically decreased by the increasing $\\tau$ or $\\sigma$.

  12. Mixed mode fuel injector with individually moveable needle valve members

    DOE Patents [OSTI]

    Stewart, Chris; Chockley, Scott A.; Ibrahim, Daniel R.; Lawrence, Keith; Tomaseki, Jay; Azam, Junru H.; Tian, Steven Ye; Shafer, Scott F.

    2004-08-03

    A fuel injector includes a homogenous charge nozzle outlet set and a conventional nozzle outlet set controlled respectively, by first and second needle valve members. One of the needle valve members moves to an open position while the other needle valve member remains stationary for a homogeneous charge injection event. The former needle valve member stays stationary while the other needle valve member moves to an open position for a conventional injection event. One of the needle valve members is at least partially positioned in the other needle valve member. Thus, the injector can perform homogeneous charge injection events, conventional injection events, or even a mixed mode having both types of injection events in a single engine cycle.

  13. Quasinormal modes of test fields around regular black holes

    E-Print Network [OSTI]

    Bobir Toshmatov; Ahmadjon Abdujabbarov; Zden?k Stuchlík; Bobomurat Ahmedov

    2015-04-25

    We study scalar, electromagnetic and gravitational test fields in the Hayward, Bardeen and Ay\\'on-Beato-Garc\\'ia regular black hole spacetimes and demonstrate that the test fields are stable in all these spacetimes. Using the sixth order WKB approximation of the linear "axial" perturbative scheme, we determine dependence of the quasinormal mode (QNM) frequencies on the characteristic parameters of the test fields and the spacetime charge parameters of the regular black holes. We give also the greybody factors, namely the transmission and reflection coefficients of scattered scalar, electromagnetic and gravitational waves. We show that damping of the QNMs in regular black hole spacetimes is suppressed in comparison to the case of Schwarzschild black holes, and increasing charge parameter of the regular black holes increases reflection and decreases transmission factor of incident waves for each of the test fields.

  14. Wave Propagation in Gravitational Systems: Completeness of Quasinormal Modes

    E-Print Network [OSTI]

    E. S. C. Ching; P. T. Leung; W. M. Suen; K. Young

    1995-07-14

    The dynamics of relativistic stars and black holes are often studied in terms of the quasinormal modes (QNM's) of the Klein-Gordon (KG) equation with different effective potentials $V(x)$. In this paper we present a systematic study of the relation between the structure of the QNM's of the KG equation and the form of $V(x)$. In particular, we determine the requirements on $V(x)$ in order for the QNM's to form complete sets, and discuss in what sense they form complete sets. Among other implications, this study opens up the possibility of using QNM expansions to analyse the behavior of waves in relativistic systems, even for systems whose QNM's do {\\it not} form a complete set. For such systems, we show that a complete set of QNM's can often be obtained by introducing an infinitesimal change in the effective potential.

  15. Buoyancy and g-modes in young superfluid neutron stars

    E-Print Network [OSTI]

    Passamonti, A; Ho, W C G

    2015-01-01

    We consider the local dynamics of a realistic neutron star core, including composition gradients, superfluidity and thermal effects. The main focus is on the gravity g-modes, which are supported by composition stratification and thermal gradients. We derive the equations that govern this problem in full detail, paying particular attention to the input that needs to be provided through the equation of state and distinguishing between normal and superfluid regions. The analysis highlights a number of key issues that should be kept in mind whenever equation of state data is compiled from nuclear physics for use in neutron star calculations. We provide explicit results for a particular stellar model and a specific nucleonic equation of state, making use of cooling simulations to show how the local wave spectrum evolves as the star ages. Our results show that the composition gradient is effectively dominated by the muons whenever they are present. When the star cools below the superfluid transition, the support fo...

  16. Nuclear pygmy modes and the dynamics of the nuclear skin

    E-Print Network [OSTI]

    Nadia Tsoneva; Horst Lenske

    2012-11-05

    The information on pygmy resonances reveals new aspects on the isospin dynamics of the nucleus with important astrophysical consequences. In this connection, the precise knowledge of nuclear response functions plays a key role in the determination of photonuclear reactions cross sections which are of importance for the synthesis of heavy neutron-rich elements. For that purpose, a theoretical method based on density functional theory and multi-phonon approach is applied for investigations of nuclear excitations with different multipolarities and energies in stable and exotic nuclei. The possible relation of low-energy modes to the properties of neutron or proton skins is systematically investigated for isotonic and isotopic chains. Our studies of dipole and quadrupole response functions and the corresponding transition densities indicate new pygmy dipole and pygmy quadrupole resonances, describing oscillations of the nuclear skin. Also, the presence of skins is found to affect the magnetic response of nuclei.

  17. Coupling Mode of Dual-Core Micro Structured Fibers

    E-Print Network [OSTI]

    Debbal, Mohammed

    2015-01-01

    The photonic crystal fibers (PCF) or air-silica microstructured fibers consist of a periodic array of dielectric transverse. By introducing a defect in this structure, it is possible to guide the light by a photonic bandgap effect, whose properties are different fundamentally from the guide by total internal reflection that takes place in conventional fibers. PCF with two cores have significant potential, and this is one of the main motivations witches led us to approach this theme in this article. Analysis of the inter-core coupling was also necessary to study the problem of crosstalk. Their knowledge is important because it is a preliminary work to the study and understanding of multi-core PCF or an array of guides in the microstructured cladding. It then presents the main results on the effects of beating between the various modes under linear conditions.

  18. Plasmon mode excitation and photoluminescence enhancement on silver nanoring

    E-Print Network [OSTI]

    Kuchmizhak, A A; Kulchin, Yu N; Vitrik, O B

    2015-01-01

    We demonstrate a simple and high-performance laser-assisted technique for silver nanoring fabrication, which includes the ablation of the Ag film by focused nanosecond pulses and subsequent reactive ion polishing. The nanoring diameter and thickness can be controlled by optimizing both the pulse energy and the metal film thickness at laser ablation step, while the subsequent reactive ion polishing provides the ability to fabricate the nanoring with desirable height. Scattering patterns of s-polarized collimated laser beam obliquely illuminating the nanoring demonstrate the focal spot inside the nanoring shifted from its center at a distance of ~ 0.57Rring. Five-fold enhancement of the photoluminescence signal from the Rhodamine 6G organic dye near the Ag nanoring was demonstrated. This enhancement was attributed to the increase of the electromagnetic field amplitude near the nanoring surface arising from excitation of the multipole plasmon modes traveling along the nanoring. This assumption was confirmed by d...

  19. Quasinormal mode theory and modelling of electron energy loss spectroscopy

    E-Print Network [OSTI]

    Ge, Rong-Chun

    2015-01-01

    Modelling electron energy loss spectroscopy (EELS) presents a major challenge in computational electrodynamics, requiring the full photon Green function as a function of two space points and frequency. In this work, we present an intuitive and computationally simple method for computing EELS maps using a quasinormal mode (QNM) expansion technique. By separating the contribution of the QNM and the bulk material, we give closed-form analytical formulas for the plasmonic QNM contribution to EELS images. We exemplify our technique for a split ring resonator, a gold nanorod, and a nanorod dimer structure. The method is accurate, intuitive, and gives orders of magnitude improvements over direct dipole simulations that numerically solve the full 3D Maxwell equations.

  20. Geometric entropy and edge modes of the electromagnetic field

    E-Print Network [OSTI]

    William Donnelly; Aron C. Wall

    2015-06-18

    We calculate the vacuum entanglement entropy of Maxwell theory in a class of curved spacetimes by Kaluza-Klein reduction of the theory onto a two-dimensional base manifold. Using two-dimensional duality, we express the geometric entropy of the electromagnetic field as the entropy of a tower of scalar fields, constant electric and magnetic fluxes, and a contact term, whose leading order divergence was discovered by Kabat. The complete contact term takes the form of one negative scalar degree of freedom confined to the entangling surface. We show that the geometric entropy agrees with a statistical definition of entanglement entropy that includes edge modes: classical solutions determined by their boundary values on the entangling surface. This resolves a longstanding puzzle about the statistical interpretation of the contact term in the entanglement entropy. We discuss the implications of this negative term for black hole thermodynamics and the renormalization of Newton's constant.

  1. DIPOLE MODE DETUNING IN THE INJECTOR LINACS OF THE NLC.

    SciTech Connect (OSTI)

    Bane, K

    2004-09-29

    The injector linacs of the JLC/NLC project include the prelinac, the e{sup +} drive linac, the e{sup -} booster, and the e{sup +} booster. The first three will be S-band machines, the last one, an L-band machine. We have demonstrated that by using detuning alone in the accelerator structure design of these linacs we will have acceptable tolerances for emittance growth due to both injection jitter and structure misalignments, for both the nominal (2.8 ns) and alternate (1.4 ns) bunch spacings. For the L-band structure (a structure with 2{pi}/3 phase advance) we take a uniform distribution in synchronous dipole mode frequencies, with central frequency {bar f} = 2.05 GHz and width {Delta}{sub {delta}f} = 3%. For the S-band case our optimized structure (a 3{pi}/4 structure) has a trapezoidal dipole frequency distribution with f = 3.92 GHz, {Delta}{sub {delta}f} = 5.8%, and tilt parameter {alpha} = -.2. The central frequency and phase advance were chosen to put bunches early in the train on the zero crossing of the wake and, at the same time, keep the gradient optimized. We have shown that for random manufacturing errors with rms 5 {micro}m, (equivalent to 10{sup -4} error in synchronous frequency), the injection jitter tolerances are still acceptable. We have also shown that the structure alignment tolerances are loose, and that the cell-to-cell misalignment tolerance is {approx}> 40 {micro}m. Note that in this report we have considered only the effects of modes in the first dipole passband.

  2. Atomic nuclei decay modes by spontaneous emission of heavy ions

    SciTech Connect (OSTI)

    Poenaru, D.N.; Ivascu, M.; Sndulescu, A.; Greiner, W.

    1985-08-01

    The great majority of the known nuclides with Z>40, including the so-called stable nuclides, are metastable with respect to several modes of spontaneous superasymmetric splitting. A model extended from the fission theory of alpha decay allows one to estimate the lifetimes and the branching ratios relative to the alpha decay for these natural radioactivities. From a huge amount of systematic calculations it is concluded that the process should proceed with maximum intensity in the trans-lead nuclei, where the minimum lifetime is obtained from parent-emitted heavy ion combinations leading to a magic (/sup 208/Pb) or almost magic daughter nucleus. More than 140 nuclides with atomic number smaller than 25 are possible candidates to be emitted from heavy nuclei, with half-lives in the range of 10/sup 10/--10/sup 30/ s: /sup 5/He, /sup 8en-dash10/Be, /sup 11,12/B, /sup 12en-dash16/C, /sup 13en-dash17/N, /sup 15en-dash22/O, /sup 18en-dash23/F, /sup 20en-dash26/Ne, /sup 23en-dash28/Na, /sup 23en-dash30/Mg, /sup 27en-dash32/Al, /sup 28en-dash36/Si, /sup 31en-dash39/P, /sup 32en-dash42/S, /sup 35en-dash45/Cl, /sup 37en-dash47/Ar, /sup 40en-dash49/ K, . .Ca, /sup 44en-dash53/ Sc, /sup 46en-dash53/Ti, /sup 48en-dash54/V, and /sup 49en-dash55/ Cr. The shell structure and the pairing effects are clearly manifested in these new decay modes.

  3. Failure modes and effects analysis of fusion magnet systems

    SciTech Connect (OSTI)

    Zimmermann, M; Kazimi, M S; Siu, N O; Thome, R J

    1988-12-01

    A failure modes and consequence analysis of fusion magnet system is an important contributor towards enhancing the design by improving the reliability and reducing the risk associated with the operation of magnet systems. In the first part of this study, a failure mode analysis of a superconducting magnet system is performed. Building on the functional breakdown and the fault tree analysis of the Toroidal Field (TF) coils of the Next European Torus (NET), several subsystem levels are added and an overview of potential sources of failures in a magnet system is provided. The failure analysis is extended to the Poloidal Field (PF) magnet system. Furthermore, an extensive analysis of interactions within the fusion device caused by the operation of the PF magnets is presented in the form of an Interaction Matrix. A number of these interactions may have significant consequences for the TF magnet system particularly interactions triggered by electrical failures in the PF magnet system. In the second part of this study, two basic categories of electrical failures in the PF magnet system are examined: short circuits between the terminals of external PF coils, and faults with a constant voltage applied at external PF coil terminals. An electromagnetic model of the Compact Ignition Tokamak (CIT) is used to examine the mechanical load conditions for the PF and the TF coils resulting from these fault scenarios. It is found that shorts do not pose large threats to the PF coils. Also, the type of plasma disruption has little impact on the net forces on the PF and the TF coils. 39 refs., 30 figs., 12 tabs.

  4. Benchmarking kinetic calculations of resistive wall mode stability

    SciTech Connect (OSTI)

    Berkery, J. W.; Sabbagh, S. A.; Liu, Y. Q.; Betti, R.

    2014-05-15

    Validating the calculations of kinetic resistive wall mode (RWM) stability is important for confidently predicting RWM stable operating regions in ITER and other high performance tokamaks for disruption avoidance. Benchmarking the calculations of the Magnetohydrodynamic Resistive Spectrum—Kinetic (MARS-K) [Y. Liu et al., Phys. Plasmas 15, 112503 (2008)], Modification to Ideal Stability by Kinetic effects (MISK) [B. Hu et al., Phys. Plasmas 12, 057301 (2005)], and Perturbed Equilibrium Nonambipolar Transport (PENT) [N. Logan et al., Phys. Plasmas 20, 122507 (2013)] codes for two Solov'ev analytical equilibria and a projected ITER equilibrium has demonstrated good agreement between the codes. The important particle frequencies, the frequency resonance energy integral in which they are used, the marginally stable eigenfunctions, perturbed Lagrangians, and fluid growth rates are all generally consistent between the codes. The most important kinetic effect at low rotation is the resonance between the mode rotation and the trapped thermal particle's precession drift, and MARS-K, MISK, and PENT show good agreement in this term. The different ways the rational surface contribution was treated historically in the codes is identified as a source of disagreement in the bounce and transit resonance terms at higher plasma rotation. Calculations from all of the codes support the present understanding that RWM stability can be increased by kinetic effects at low rotation through precession drift resonance and at high rotation by bounce and transit resonances, while intermediate rotation can remain susceptible to instability. The applicability of benchmarked kinetic stability calculations to experimental results is demonstrated by the prediction of MISK calculations of near marginal growth rates for experimental marginal stability points from the National Spherical Torus Experiment (NSTX) [M. Ono et al., Nucl. Fusion 40, 557 (2000)].

  5. An experimental study of CTOD for Mode I/Mode II stable crack growth in thin 2024-T3 aluminum specimens

    SciTech Connect (OSTI)

    Amstutz, B.E.; Sutton, M.A.; Dawicke, D.S.; Newman, J.C.

    1995-12-31

    An experimental study of crack tip opening displacement (CTOD) for Mode I/Mode II stable crack growth in thin sheet 2024-T3 aluminum has been conducted. To perform the experiments, an Arcan specimen and fixture was modified so that (1) slippage in the grips was eliminated, (2) large rotations of the fixture components were achievable and (3) bending stresses were minimized. Defining {Theta} to be the angle between the Mode I loading direction (perpendicular to the crack line) and the direction of applied loading, experimental results indicate that (a) for large amounts of crack extension, a {ge} 10mm, the value of CTOD at 1 mm behind the crack tip appears to approach a constant value of 0.1 mm for all modes of loading, (b) the direction of crack extension varied with applied mixed mode loading, (c) Mode I crack extension is predominant for 0{degree} {le} {Theta} {le} 60{degree}, (d) Mode II crack extension is predominant for 75{degree} {le} {Theta} {le} 90{degree} and (e) a transition zone exists for angles {Theta} near 75{degree}.

  6. Peeling-off of the external kink modes at tokamak plasma edge

    E-Print Network [OSTI]

    Zheng, L J

    2014-01-01

    It is pointed that there is a current jump between the edge plasma inside the last closed magnetic surface and the scrape-off layer and the current jump can lead the external kink modes to convert to the tearing modes, due to the current interchange effects [L. J. Zheng and M. Furukawa, Phys. Plasmas 17, 052508 (2010)]. The magnetic reconnection in the presence of tearing modes subsequently causes the tokamak edge plasma to be peeled off to link to the diverters. In particular, the peeling or peeling-ballooning modes can become the "peeling-off" modes in this sense. This phenomenon indicates that the tokamak edge confinement can be worse than the expectation based on the conventional kink mode picture.

  7. One-dimensional full wave simulation on XB mode conversion in electron cyclotron heating

    SciTech Connect (OSTI)

    Kim, S. H., E-mail: shkim95@kaeri.re.kr [Korea Atomic Energy Research Institute, Daejeon 305-353 (Korea, Republic of); Lee, H. Y.; Jo, J. G.; Hwang, Y. S. [Seoul National University, Seoul 151-742 (Korea, Republic of)

    2014-06-15

    The XB mode conversion in electron cyclotron resonance frequency heating has been studied in detail through 1D full wave simulation. The field pattern depends on the density scale length, and the wave absorption near upper hybrid resonance is maximized beyond the R(X) mode cutoff density for optimized density scale length. The simulated mode conversion efficiency has been compared with that of an analytic formula, showing good agreements except for the phase dependent term of the X wave. The mode conversion efficiency is calculated for oblique injections as well, and it is found that the efficiency decreases as the injection angles increases. Short magnetic field scale length is confirmed to relax the short density scale length condition maximizing the XB mode conversion efficiency. Finally, the simulation code is used to analyze the mode conversion and power absorption of a pre-ionization plasma in versatile experiment spherical torus.

  8. Magneto-hydrodynamics simulation study of deflagration mode in co-axial plasma accelerators

    SciTech Connect (OSTI)

    Sitaraman, Hariswaran; Raja, Laxminarayan L.

    2014-01-15

    Experimental studies by Poehlmann et al. [Phys. Plasmas 17(12), 123508 (2010)] on a coaxial electrode magnetohydrodynamic (MHD) plasma accelerator have revealed two modes of operation. A deflagration or stationary mode is observed for lower power settings, while higher input power leads to a detonation or snowplow mode. A numerical modeling study of a coaxial plasma accelerator using the non-ideal MHD equations is presented. The effect of plasma conductivity on the axial distribution of radial current is studied and found to agree well with experiments. Lower conductivities lead to the formation of a high current density, stationary region close to the inlet/breech, which is a characteristic of the deflagration mode, while a propagating current sheet like feature is observed at higher conductivities, similar to the detonation mode. Results confirm that plasma resistivity, which determines magnetic field diffusion effects, is fundamentally responsible for the two modes.

  9. Peeling-off of the external kink modes at tokamak plasma edge

    SciTech Connect (OSTI)

    Zheng, L. J. [Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712 (United States); Furukawa, M. [Graduate School of Engineering, Tottori University, Tottori 680-8552 (Japan)

    2014-08-15

    It is pointed out that there is a current jump between the edge plasma inside the last closed flux surface and the scrape-off layer and that the current jump can lead the external kink modes to convert to the tearing modes, due to the current interchange effects [L. J. Zheng and M. Furukawa, Phys. Plasmas 17, 052508 (2010)]. The magnetic reconnection in the presence of tearing modes subsequently causes the tokamak edge plasma to be peeled off to link to the divertors. In particular, the peeling or peeling-ballooning modes can become the “peeling-off” modes in this sense. This phenomenon indicates that the tokamak edge confinement can be worse than the expectation based on the conventional kink mode picture.

  10. Dispersion relations of Nambu-Goldstone modes at finite temperature and density

    E-Print Network [OSTI]

    Tomoya Hayata; Yoshimasa Hidaka

    2015-03-31

    We discuss the dispersion relations of Nambu-Goldstone (NG) modes associated with spontaneous breaking of internal symmetries at finite temperature and/or density. We show that the dispersion relations of type-A (I) and type-B (II) NG modes are linear and quadratic in momentum, whose imaginary parts are quadratic and quartic, respectively. In both cases, the real parts of the dispersion relations are larger than the imaginary parts when the momentum is small, so that the NG modes can propagate far away. We derive the gap formula for NG modes in the presence of a small explicit breaking term. We also discuss the gapped partners of type-B NG modes, when type-A and type-B NG modes coexist.

  11. Low-frequency Interlayer Breathing Modes in Few-layer Black Phosphorus

    SciTech Connect (OSTI)

    Huang, Shengxi; Puretzky, Alexander A; Geohegan, David B; Sumpter, Bobby G; Kong, Jing; Dresselhaus, M; Meunier, V.; Liang, Liangbo; Ling, Xi

    2015-01-01

    As a new two-dimensional layered material, black phosphorus (BP) is a very promising material for nanoelectronics and nano-optoelectronics. We use Raman spectroscopy and first-principles theory to characterize and understand low-frequency (LF) interlayer breathing modes (<100 cm-1) in few-layer BP for the first time. Using laser polarization dependence study and group theory analysis the breathing modes are assigned to Ag symmetry. Compared to the high-frequency (HF) Raman modes, the LF breathing modes are considerably more sensitive to interlayer coupling and thus their frequencies show stronger dependence on the number of layers. Hence, they constitute an effective means to probe both the crystalline orientation and thickness of few-layer BP. Furthermore, the temperature dependence shows that the breathing modes have a harmonic behavior, in contrast to HF Raman modes which exhibit anharmonicity.

  12. Mixed-mode, high-cycle fatigue-crack growth thresholds in II. Quantication of crack-tip shielding

    E-Print Network [OSTI]

    Ritchie, Robert

    -tip shielding J.P. Campbell, R.O. Ritchie * Department of Materials Science and Mineral Engineering, University 2000; accepted 11 May 2000 Abstract The role of crack-tip shielding in in¯uencing mixed-mode (mode I crack-tip shielding with respect to both the mode I and mode II applied loading, enabling an estimation

  13. Engineering two-mode squeezed states of cold atomic clouds with a superconducting stripline resonator

    E-Print Network [OSTI]

    Pengbo Li; Fuli Li

    2010-09-16

    A scheme is proposed for engineering two-mode squeezed states of two separated cold atomic clouds positioned near the surface of a superconducting stripline resonator. Based on the coherent magnetic coupling between the atomic spins and a stripline resonator mode, the desired two-mode squeezed state can be produced via precisely control on the dynamics of the system. This scheme may be used to realize scalable on-chip quantum networks with cold atoms coupling to stripline resonators.

  14. Abatement of Computational Issues Associated with Dark Modes in Optical Metamaterials

    E-Print Network [OSTI]

    LePain, Matthew

    2015-01-01

    Optical fields in metamaterial nanostructures can be separated into bright modes, whose dispersion is typically described by effective medium parameters, and dark fluctuating fields. Such combination of propagating and evanescent modes poses a serious numerical complication due to poorly conditioned systems of equations for the amplitudes of the modes. We propose a numerical scheme based on a transfer matrix approach, which resolves this issue for a parallel plate metal-dielectric metamaterial, and demonstrate its effectiveness.

  15. A possibility for using an APPLE undulator to generate a photon beam with transverse optical modes.

    SciTech Connect (OSTI)

    Sasaki, S.; McNulty, I.; Shimada, T.; JAEA

    2008-01-01

    We investigate use of an APPLE-type undulator for generating Laguerre-Gaussian (LG) and Hermite-Gaussian (HG) mode beams. We find that the second harmonic radiation in the circular mode corresponds to an LG beam with l=1, and the second harmonic in the linear mode corresponds to an HG beam with l=1. The combination of an APPLE undulator and conventional monochromator optics may provide an opportunity for a new type of experimental research in the synchrotron radiation community.

  16. MULTI-MODE ERROR FIELD CORRECTION ON THE DIII-D TOKAMAK

    SciTech Connect (OSTI)

    SCOVILLE, JT; LAHAYE, RJ

    2002-10-01

    OAK A271 MULTI-MODE ERROR FIELD CORRECTION ON THE DIII-D TOKAMAK. Error field optimization on DIII-D tokamak plasma discharges has routinely been done for the last ten years with the use of the external ''n = 1 coil'' or the ''C-coil''. The optimum level of correction coil current is determined by the ability to avoid the locked mode instability and access previously unstable parameter space at low densities. The locked mode typically has toroidal and poloidal mode numbers n = 1 and m = 2, respectively, and it is this component that initially determined the correction coil current and phase. Realization of the importance of nearby n = 1 mode components m = 1 and m = 3 has led to a revision of the error field correction algorithm. Viscous and toroidal mode coupling effects suggested the need for additional terms in the expression for the radial ''penetration'' field B{sub pen} that can induce a locked mode. To incorporate these effects, the low density locked mode threshold database was expanded. A database of discharges at various toroidal fields, plasma currents, and safety factors was supplement4ed with data from an experiment in which the fields of the n = 1 coil and C-coil were combined, allowing the poloidal mode spectrum of the error field to be varied. A multivariate regression analysis of this new low density locked mode database was done to determine the low density locked mode threshold scaling relationship n{sub e} {proportional_to} B{sub T}{sup -0.01} q{sub 95}{sup -0.79} B{sub pen} and the coefficients of the poloidal mode components in the expression for B{sub pen}. Improved plasma performance is achieved by optimizing B{sub pen} by varying the applied correction coil currents.

  17. DISCHARGE IMPROVEMENT THROUGH CONTROL OF NEOCLASSICAL TEARING MODES BY LOCALIZED ECCD IN DIII-D

    SciTech Connect (OSTI)

    PRATER,R; LAHAYE,RJ; LOHR,J; LUCE,TC; PETTY,CC; FERRON,JR; HUMPHREYS,DA; STRAIT,EJ; PERKINS,FW; HARVEY,RW

    2002-10-01

    A271 DISCHARGE IMPROVEMENT THROUGH CONTROL OF NEOCLASSICAL TEARING MODES BY LOCALIZED ECCD IN DIII-D. Neoclassical tearing modes (NTMs) are MHD modes which can limit the performance of high beta discharges in tokamaks, in some cases leading to a major disruption. The destabilizing effect which results in NTM growth is a helical decrease in the bootstrap current caused by a local reduction of the plasma pressure gradient by seed magnetic islands. The NTM is particularly well suited to control since the mode is linearly stable although nonlinearly unstable, so if the island amplitude can be decreased below a threshold size the mode will decay and vanish. One means of shrinking the island is the replacement of the missing bootstrap current by a localized current generated by electron cyclotron current drive (ECCD). This method has been applied to the m=3/n=2 neoclassical tearing mode in DIII-D, in H-mode plasmas with ongoing ELMs and sawteeth, both of which generate seed islands periodically. In the case of the 3/2 mode, full suppression was obtained robustly by applying about 1.5 MW of ECCD very near the rational surface of the mode. When the mode first appears in the plasma the stored energy decreases by 20%, but after the mode is stabilized by the ECCD the beta may be raised above the initial threshold pressure by 20% by additional neutral beam heating, thereby generating an improvement in the limiting beta of nearly a factor 2. An innovative automated search algorithm was implemented to find and retain the optimum location for the ECCD in the presence of the mode.

  18. Nuclear reaction rates and energy in stellar plasmas : The effect of highly damped modes

    E-Print Network [OSTI]

    Merav Opher; Luis O. Silva; Dean E. Dauger; Viktor K. Decyk; John M. Dawson

    2001-05-09

    The effects of the highly damped modes in the energy and reaction rates in a plasma are discussed. These modes, with wavenumbers $k \\gg k_{D}$, even being only weakly excited, with less than $k_{B}T$ per mode, make a significant contribution to the energy and screening in a plasma. When the de Broglie wavelength is much less than the distance of closest approach of thermal electrons, a classical analysis of the plasma can

  19. Mode-locked terahertz quantum cascade laser by direct phase synchronization

    SciTech Connect (OSTI)

    Maussang, K.; Maysonnave, J.; Jukam, N.; Freeman, J. R.; Cavalié, P.; Dhillon, S. S.; Tignon, J.; Khanna, S. P.; Linfield, E. H.; Davies, A. G.; Beere, H. E.; Ritchie, D. A.

    2013-12-04

    Mode-locking of a terahertz quantum cascade laser is achieved using multimode injection seeding. Contrary to standard methods that rely on gain modulation, here a fixed phase relationship is directly imprinted to the laser modes. In this work, we demonstrate the generation of 9 ps phase mode-locked pulses around 2.75 THz. A direct measurement of the emitted field phase shows that it results from the phase of the initial injection.

  20. Torsional Oscillations of Relativistic Stars with Dipole Magnetic Fields II. Global Alfvén Modes

    E-Print Network [OSTI]

    H. Sotani; K. D. Kokkotas; N. Stergioulas; M. Vavoulidis

    2006-11-21

    We investigate torsional Alfv\\'{e}n modes of relativistic stars with a global dipole magnetic field. It has been noted recently (Glampedakis et al. 2006) that such oscillation modes could serve as as an alternative explanation (in contrast to torsional crustal modes) for the SGR phenomenon, if the magnetic field is not confined to the crust. We compute global Alfv\\'{e}n modes for a representative sample of equations of state and magnetar masses, in the ideal MHD approximation and ignoring $\\ell \\pm 2$ terms in the eigenfunction. We find that the presence of a realistic crust has a negligible effect on Alfv\\'{e}n modes for $B > 4\\times 10^{15}$ G. Furthermore, we find strong avoided crossings between torsional Alfv\\'{e}n modes and torsional crust modes. For magnetar-like magnetic field strengths, the spacing between consecutive Alfv\\'{e}n modes is of the same order as the gap of avoided crossings. As a result, it is not possible to identify modes of predominantly crustal character and all oscillations are predominantly Alfv\\'{e}n-like. Interestingly, we find excellent agreement between our computed frequencies and observed frequencies in two SGRs, for a maximum magnetic field strenght in the range of (0.8--1.2)$\\times 10^{16}$ G.

  1. Higher Order Modes HOM___s in Coupled Cavities of the Flash Module ACC39

    SciTech Connect (OSTI)

    Shinton, I.R.R.; /Manchester U. /Cockcroft Inst. Accel. Sci. Tech.; Jones, R.M.; /Manchester U. /DESY; Li, Z.; /SLAC; Zhang, P.; /Manchester U. /Cockcroft Inst. Accel. Sci. Tech. /DESY

    2012-09-14

    We analyse the higher order modes (HOM's) in the 3.9GHz bunch shaping cavities installed in the FLASH facility at DESY. A suite of finite element computer codes (including HFSS and ACE3P) and globalised scattering matrix calculations (GSM) are used to investigate the modes in these cavities. This study is primarily focused on the dipole component of the multiband expansion of the wakefield, with the emphasis being on the development of a HOM-based BPM system for ACC39. Coupled inter-cavity modes are simulated together with a limited band of trapped modes.

  2. Transportation Sector Energy Use by Mode from EIA AEO 2011 Early...

    Open Energy Info (EERE)

    dataset is an excerpt from the spreadsheet Supplemental Tables to the Annual Energy Outlook 2011, isolating Transportation Sector energy use by Mode. Data and Resources...

  3. The Effect of Evanescent Modes and Chaos on Deterministic Scattering in Electron Waveguides

    E-Print Network [OSTI]

    G. B. Akguc; L. E. Reichl

    2000-12-12

    Statistical properties of Wigner delay times and the effect of evanescent modes on the deterministic scattering of an electron matter wave from a classically chaotic 2-d electron waveguide are studied for the case of 2, 6, and 16 propagating modes. Deterministic reaction matrix theory for this system is generalized to include the effect of evanescent modes on the scattering process. Inclusion of evanescent modes can change the positions of resonance poles in the complex energy plane and can delay electron scattering, particularly at energies where new channels open. The statistical properties of the Wigner delay times for the deterministic scattering process are compared to the predictions of random reaction matrix theory.

  4. Ultrafast spectroscopy of super high frequency mechanical modes of doubly clamped beams

    SciTech Connect (OSTI)

    Ristow, Oliver; Merklein, Moritz; Grossmann, Martin; Hettich, Mike; Schubert, Martin; Bruchhausen, Axel; Scheer, Elke; Dekorsy, Thomas; Barretto, Elaine C. S.; Grebing, Jochen; Erbe, Artur; Mounier, Denis; Gusev, Vitalyi

    2013-12-02

    We use ultrafast pump-probe spectroscopy to study the mechanical vibrations in the time domain of doubly clamped silicon nitride beams. Beams with two different clamping conditions are investigated. Finite element method calculations are performed to analyse the mode spectra of both structures. By calculating the strain integral on the surface of the resonators, we are able to reproduce the effect of the detection mechanism and identify all the measured modes. We show that our spectroscopy technique combined with our modelling tools allow the investigation of several different modes in the super high frequency range (3-30?GHz) and above, bringing more information about the vibration modes of nanomechanical resonators.

  5. Anderson localization of ballooning modes, quantum chaos and the stability of compact quasiaxially symmetric stellarators

    E-Print Network [OSTI]

    Dewar, Robert L.

    - 1 - Anderson localization of ballooning modes, quantum chaos and the stability of compact, isosurfaces are topologically spherical, indicative of strong "quantum chaos". The complexity of QAS marginal

  6. Progress in understanding the enhanced pedestal H-mode in NSTX

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

    Gerhardt, S. P.; Canik, J. M.; Maingi, R.; Battaglia, D.; Bell, R. E.; Guttenfelder, W.; LeBlanc, B. P.; Smith, D. R.; Yuh, H.; Sabbagh, S.

    2014-08-01

    The paper describes the enhanced pedestal (EP) H-mode observed in the National Spherical Torus Experiment (NSTX). The defining characteristics of EP H-mode are given, namely i)transition after the L- to H-mode transition, ii) region of very steep ion temperature gradient, and iii) associated region of strong rotational shear. A newly observed long-pulse EP H-mode example shows quiescent behavior for as long as the heating and current drive sources are maintained. Cases are shown where the region of steep ion temperature gradient is located at the very edge, and cases where it is shifted up to 10 cm inward from themore »plasma edge; these cases are united by a common dependence of the ion temperature gradient on the toroidal rotation frequency shear. EP H-mode examples have been observed across a wide range of q95 and pedestal collisionality. No strong changes in the fluctuation amplitudes have been observed following the eP H-mode transition, and transport analysis indicates that the ion t hermal transport is comparable to or less than anticipated from a simple neoclassical transport model. Cases are shown where EP H-modes were reliably generated, through these low-q95 examples were difficult to sustain. A case where an externally triggered ELM precipitates the transition to EP H-mode is also shown, though an initial experiment designed to trigger EP-H-modes in this fashion was successful.« less

  7. STOCHASTIC MODE REDUCTION FOR PARTICLE-BASED SIMULATION METHODS FOR COMPLEX MICROFLUID SYSTEMS

    E-Print Network [OSTI]

    Kramer, Peter

    STOCHASTIC MODE REDUCTION FOR PARTICLE-BASED SIMULATION METHODS FOR COMPLEX MICROFLUID SYSTEMS (DPD) simulation approaches for complex microfluid systems. The resulting coarse-grained dynamics

  8. Systems acceptance and operability testing for rotary mode core sampling in flammable gas tanks

    SciTech Connect (OSTI)

    Corbett, J.E., Westinghouse Hanford

    1996-07-29

    This document provides instructions for the system acceptance and operability testing of the rotary mode core sampling system, modified for use in flammable gas tanks.

  9. Progress In Understanding The Enhanced Petestal H-mode In NSTX

    SciTech Connect (OSTI)

    Gerhardt, S. P.; Canik, J. M.; Maingi, R.; Battaglia, D.; Bell, R. E.; Guttenfelder, W.; LeBlanc, B. P.; Smith, D. R.; Yuh, H.; Sabbagh, S.

    2014-06-26

    ThIS paper describes the enhanced pedestal (EP) H-mode observed in the National Spherical Torus Experiment (NSTX). The defining characteristics of EP H-mode are given, namely i)transition after the L- to H-mode transition, ii) region of very steep ion temperature gradient, and iii) associated region of strong rotational shear. A newly observed long-pulse EP H-mode example shows quiescent behavior for as long as the heating and current drive sources are maintained. Cases are shown where the region of steep ion temperature gradient is located at the very edge, and cases where it is shifted up to 10 cm inward from the plasma edge; these cases are united by a common dependence of the ion temperature gradient on the toroidal rotation frequency shear. EP H-mode examples have been observed across a wide range of q95 and pedestal collisionality. No strong changes in the fluctuation amplitudes have been observed following the eP H-mode transition, and transport analysis indicates that the ion t hermal transport is comparable to or less than anticipated from a simple neoclassical transport model. Cases are shown where EP H-modes were reliably generated, through these low-q95 examples were difficult to sustain. A case where an externally triggered ELM precipitates the transition to EP H-mode is also shown, though an initial experiment designed to trigger EP-H-modes in this fashion was successful.

  10. Progress in understanding the enhanced pedestal H-mode in NSTX

    SciTech Connect (OSTI)

    Gerhardt, S. P.; Canik, J. M.; Maingi, R.; Battaglia, D.; Bell, R. E.; Guttenfelder, W.; LeBlanc, B. P.; Smith, D. R.; Yuh, H.; Sabbagh, S.

    2014-08-01

    The paper describes the enhanced pedestal (EP) H-mode observed in the National Spherical Torus Experiment (NSTX). The defining characteristics of EP H-mode are given, namely i)transition after the L- to H-mode transition, ii) region of very steep ion temperature gradient, and iii) associated region of strong rotational shear. A newly observed long-pulse EP H-mode example shows quiescent behavior for as long as the heating and current drive sources are maintained. Cases are shown where the region of steep ion temperature gradient is located at the very edge, and cases where it is shifted up to 10 cm inward from the plasma edge; these cases are united by a common dependence of the ion temperature gradient on the toroidal rotation frequency shear. EP H-mode examples have been observed across a wide range of q95 and pedestal collisionality. No strong changes in the fluctuation amplitudes have been observed following the eP H-mode transition, and transport analysis indicates that the ion t hermal transport is comparable to or less than anticipated from a simple neoclassical transport model. Cases are shown where EP H-modes were reliably generated, through these low-q95 examples were difficult to sustain. A case where an externally triggered ELM precipitates the transition to EP H-mode is also shown, though an initial experiment designed to trigger EP-H-modes in this fashion was successful.

  11. New method for computing ideal MHD normal modes in axisymmetric toroidal geometry

    SciTech Connect (OSTI)

    Wysocki, F.; Grimm, R.C.

    1984-11-01

    Analytic elimination of the two magnetic surface components of the displacement vector permits the normal mode ideal MHD equations to be reduced to a scalar form. A Galerkin procedure, similar to that used in the PEST codes, is implemented to determine the normal modes computationally. The method retains the efficient stability capabilities of the PEST 2 energy principle code, while allowing computation of the normal mode frequencies and eigenfunctions, if desired. The procedure is illustrated by comparison with earlier various of PEST and by application to tilting modes in spheromaks, and to stable discrete Alfven waves in tokamak geometry.

  12. Advanced Materials for Reversible Solid Oxide Fuel Cell (RSOFC), Dual Mode Operation with Low

    E-Print Network [OSTI]

    Advanced Materials for Reversible Solid Oxide Fuel Cell (RSOFC), Dual Mode Operation with Low, Director Product Development & Federal Programs #12;Project Background f Reversible Solid Oxide Fuel Cells

  13. Mode transition in CF{sub 4} + Ar inductively coupled plasma

    SciTech Connect (OSTI)

    Liu, Wei; Gao, Fei; Zhao, Shu-Xia; Li, Xue-Chun; Wang, You-Nian [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)] [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)

    2013-12-15

    The E to H mode transitions are studied by a hairpin probe and optical emission spectroscopy in inductively coupled CF{sub 4} + Ar plasmas. Electron density, optical emission intensity of Ar, and the voltage and current are measured during the E to H mode transitions. It is found that the electron density and plasma emission intensity increase continuously at low pressure during the E to H mode transition, while they jump up discontinuously at high pressure. Meanwhile, the transition threshold power and ?P (the power interval between E and H mode) increase by increasing the pressure. When the ratio of CF{sub 4} increases, the E to H mode transition happens at higher applied power, and meanwhile, the ?P also significantly increases. Besides, the effects of CF{sub 4} gas ratio on the plasma properties and the circuit electrical properties in both pure E and H modes were also investigated. The electron density and plasma emission intensity both decrease upon increasing the ratio of CF{sub 4} at the two modes, due to the stronger electrons loss scheme. The applied voltages at E and H modes both increase as increasing the CF{sub 4} gas ratio, however the applied current at two modes behave just oppositely with the gas ratio.

  14. Interpolating relativistic and non-relativistic Nambu-Goldstone and Higgs modes

    E-Print Network [OSTI]

    Michikazu Kobayashi; Muneto Nitta

    2015-05-19

    When a continuous symmetry is spontaneously broken in non-relativistic theories, there appear Nambu-Goldstone (NG) modes, whose dispersion relations are either linear (type-I) or quadratic (type-II). We give a general framework to interpolate between relativistic and non-relativistic NG modes, revealing a nature of type-I and II NG modes in non-relativistic theories. The interpolating Lagrangians have the nonlinear Lorentz invariance which reduces to the Galilei or Schrodinger invariance in the non-relativistic limit. We find that type-I and type-II NG modes in the interpolating region are accompanied with a Higgs mode and a chiral NG partner, respectively, both of which are gapful. In the ultra-relativistic limit, a set of a type-I NG mode and its Higgs partner remains, while a set of type-II NG mode and gapful NG partner turns to a set of two type-I NG modes. In the non-relativistic limit, the both types of accompanied gapful modes become infinitely massive, disappearing from the spectrum. The examples contain a phonon in Bose-Einstein condensates, a magnon in ferromagnets, and a Kelvon and dilaton-magnon localized around a skyrmion line in ferromagnets.

  15. A simple cohesive zone model that generates a mode-mixity dependent toughness

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

    Reedy, Jr., E. D.; Emery, J. M.

    2014-07-24

    A simple, mode-mixity dependent toughness cohesive zone model (MDGc CZM) is described. This phenomenological cohesive zone model has two elements. Mode I energy dissipation is defined by a traction–separation relationship that depends only on normal separation. Mode II (III) dissipation is generated by shear yielding and slip in the cohesive surface elements that lie in front of the region where mode I separation (softening) occurs. The nature of predictions made by analyses that use the MDGc CZM is illustrated by considering the classic problem of an elastic layer loaded by rigid grips. This geometry, which models a thin adhesive bondmore »with a long interfacial edge crack, is similar to that which has been used to measure the dependence of interfacial toughness on crack-tip mode-mixity. The calculated effective toughness vs. applied mode-mixity relationships all display a strong dependence on applied mode-mixity with the effective toughness increasing rapidly with the magnitude of the mode-mixity. The calculated relationships also show a pronounced asymmetry with respect to the applied mode-mixity. As a result, this dependence is similar to that observed experimentally, and calculated results for a glass/epoxy interface are in good agreement with published data that was generated using a test specimen of the same type as analyzed here.« less

  16. Aspect ratio effects on neoclassical tearing modes from comparison between DIII-D and National Spherical Torus Experiment

    SciTech Connect (OSTI)

    La Haye, R. J.; Buttery, R. J. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States); Gerhardt, S. P. [Princeton Plasma Physics Laboratory, P.O. Box 451 Princeton, New Jersey 08543 (United States); Sabbagh, S. A. [Columbia University, 2960 Broadway, New York, New York 10027-6900 (United States); Brennan, D. P. [University of Tulsa, 800 South Tucker Drive, Tulsa, Oklahoma 74104 (United States)

    2012-06-15

    Neoclassical tearing mode islands are sustained by helically perturbed bootstrap currents arising at finite beta from toroidal effects that trap a fraction of the particles in non-circulating orbits. DIII-D and NSTX are here operated with similar shape and cross-sectional area but almost a factor of two difference in inverse aspect ratio a/R. In these experiments, destabilized n=1 tearing modes were self-stabilized (reached the 'marginal point') by reducing neutral-beam power and thus beta. The measure of the marginal island gives information on the small-island stabilizing physics that in part (with seeding) governs onset. The marginal island width on NSTX is found to be about three times the ion banana width and agrees with that measured in DIII-D, except for DIII-D modes closer to the magnetic axis, which are about two times the ion banana width. There is a balance of the helically perturbed bootstrap term with small island effects with the sum of the classical and curvature terms in the modified Rutherford equation for tearing-mode stability at the experimental marginal point. Empirical evaluation of this sum indicates that while the stabilizing effect of the curvature term is negligible in DIII-D, it is important in NSTX. The mode temporal behavior from the start of neutral-beam injection reduction also suggests that NSTX operates closer to marginal classical tearing stability; this explains why there is little hysteresis in beta between mode onset, saturation, and self-stabilization (while DIII-D has large hysteresis in beta). NIMROD code module component calculations based on DIII-D and NSTX reconstructed experimental equilibria are used to diagnose and confirm the relative importance of the stabilizing curvature effect, an advantage for low aspect ratio; the relatively greater curvature effect makes for less susceptibility to NTM onset even if the classical tearing stability index is near marginal.

  17. Quasi-TEM electromagnetic modes of a plasma waveguide with a nonsimply connected cross section in an external magnetic field

    SciTech Connect (OSTI)

    Kartashov, I. N., E-mail: igorkartashov@mail.ru; Kuzelev, M. V., E-mail: kuzelev@mail.ru [Moscow State University, Physics Department (Russian Federation)

    2014-12-15

    Electromagnetic modes of a plasma waveguide with a nonsimply connected cross section in an external magnetic field are investigated. The existence of quasi-TEM modes in a finite-strength magnetic field is demonstrated. It is shown that, in the limits of infinitely strong and zero magnetic fields, this mode transforms into a true TEM mode. The possibility of excitation of such modes by an electron beam in the regime of the anomalous Doppler effect is analyzed.

  18. Frequencies of the geodesic acoustic mode and Alfvén gap modes in high-q{sup 2}? plasmas with non-circular cross section

    SciTech Connect (OSTI)

    Fesenyuk, O. P.; Kolesnichenko, Ya. I.; Yakovenko, Yu. V.; National University of Kyiv Mohyla Academy, Vul. Skovorody 2, Kyiv 04070

    2013-12-15

    This work generalizes recent results [O. P. Fesenyuk et al., Plasma Phys. Controlled Fusion 54, 085014 (2012)] to plasmas with elongated cross section. It suggests new expressions for the frequencies of the geodesic acoustic mode and Alfvén gap modes in tokamaks, with a large ratio of the plasma pressure to the magnetic field pressure and a large safety factor (q?1, which takes place in discharges with reversed-shear configuration and, especially, in hollow-current discharges)

  19. Extraordinary stiffness tunability through thermal expansion of nonlinear defect modes

    E-Print Network [OSTI]

    Marc Serra-Garcia; Joseph Lydon; Chiara Daraio

    2014-11-19

    Incremental stiffness characterizes the variation of a material's force response to a small deformation change. Typically materials have an incremental stiffness that is fixed and positive, but recent technologies, such as super-lenses, low frequency band gap materials and acoustic cloaks, are based on materials with zero, negative or extremely high incremental stiffness. So far, demonstrations of this behavior have been limited either to a narrow range of frequencies, temperatures, stiffness or to specific deformations. Here we demonstrate a mechanism to tune the static incremental stiffness that overcomes those limitations. This tunability is achieved by driving a nonlinear defect mode in a lattice. As in thermal expansion, the defect's vibration amplitude affects the force at the boundary, hence the lattice's stiffness. By using the high sensitivities of nonlinear systems near bifurcation points, we tune the magnitude of the incremental stiffness over a wide range: from positive, to zero, to arbitrarily negative values. The particular deformation where the incremental stiffness is modified can be arbitrarily selected varying the defect's driving frequency. We demonstrate this experimentally in a compressed array of spheres and propose a general theoretical model.

  20. Description of Stellar Acoustic Modes Using the Local Wave Concept

    E-Print Network [OSTI]

    P. A. P. Nghiem

    2006-06-26

    An understanding of stellar acoustic oscillations is attempted, using the local wave concept in semi-analytical calculations. The local homogeneity approximation allows to obtain simplified equations that can nevertheless describe the wave behavior down to the central region, as the gravitational potential perturbation is not neglected. Acoustic modes are calculated as classical standing waves in a cavity, by determining the cavity limits and the wave phases at these limits. The internal boundary condition is determined by a fitting with an Airy function. The external boundary condition is defined as the limit where the spatial variation of the background is important compared to the wavelength. This overall procedure is in accordance with the JWKB approximation. When comparing the results with numerical calculations, some drawbacks of the isothermal atmosphere approximation are revealed. When comparing with seismic observations of the Sun, possible improvements at the surface of solar models are suggested. The present semi-analytical method can potentially predict eigenfrequencies at the precision of +-3microHz in the range 800-5600 microHz, for the degrees l=0-10. A numerical calculation using the same type of external boundary conditions could reach a global agreement with observations better than 1 microHz. This approach could contribute to better determine the absolute values of eigenfrequencies for asteroseismology.

  1. Non-gaussian mode coupling and the statistical cosmological principle

    SciTech Connect (OSTI)

    LoVerde, Marilena [Enrico Fermi Institute, Kavli Institute for Cosmological Physics, Department of Astronomy and Astrophysics, University of Chicago, Chicago, Illinois 60637 (United States); Nelson, Elliot; Shandera, Sarah, E-mail: marilena@uchicago.edu, E-mail: eln121@psu.edu, E-mail: shandera@gravity.psu.edu [Institute for Gravitation and the Cosmos, The Pennsylvania State University, University Park, PA 16802 (United States)

    2013-06-01

    Local-type primordial non-Gaussianity couples statistics of the curvature perturbation ? on vastly different physical scales. Because of this coupling, statistics (i.e. the polyspectra) of ? in our Hubble volume may not be representative of those in the larger universe — that is, they may be biased. The bias depends on the local background value of ?, which includes contributions from all modes with wavelength k?

  2. MEMS Reliability: Infrastructure, Test Structures, Experiments, and Failure Modes

    SciTech Connect (OSTI)

    TANNER,DANELLE M.; SMITH,NORMAN F.; IRWIN,LLOYD W.; EATON,WILLIAM P.; HELGESEN,KAREN SUE; CLEMENT,J. JOSEPH; MILLER,WILLIAM M.; MILLER,SAMUEL L.; DUGGER,MICHAEL T.; WALRAVEN,JEREMY A.; PETERSON,KENNETH A.

    2000-01-01

    The burgeoning new technology of Micro-Electro-Mechanical Systems (MEMS) shows great promise in the weapons arena. We can now conceive of micro-gyros, micro-surety systems, and micro-navigators that are extremely small and inexpensive. Do we want to use this new technology in critical applications such as nuclear weapons? This question drove us to understand the reliability and failure mechanisms of silicon surface-micromachined MEMS. Development of a testing infrastructure was a crucial step to perform reliability experiments on MEMS devices and will be reported here. In addition, reliability test structures have been designed and characterized. Many experiments were performed to investigate failure modes and specifically those in different environments (humidity, temperature, shock, vibration, and storage). A predictive reliability model for wear of rubbing surfaces in microengines was developed. The root causes of failure for operating and non-operating MEMS are discussed. The major failure mechanism for operating MEMS was wear of the polysilicon rubbing surfaces. Reliability design rules for future MEMS devices are established.

  3. Power Supply Changes for NSTX Resistive Wall Mode Coils

    SciTech Connect (OSTI)

    Ramakrishnan, S S.

    2013-06-28

    The National Spherical Torus Experiment (NSTX) has been designed and installed in the existing facilities at Princeton Plasma Physics Laboratory (PPPL). Most of the hardware, plant facilities, auxiliary sub-systems, and power systems originally used for the Tokamak Fusion Test Reactor (TFTR) have been used with suitable modifications to reflect NSTX needs. Prior to 2004, the NSTX power system was feeding twelve (12) circuits in the machine. In 2004 the Resistive Wall Mode (RWM) Coils were installed on the machine to correct error fields. There are six of these coils installed around the machine in the mid-plane. Since these coils need fast and accurate controls, a Switching Power Amplifier (SPA) with three sub-units was procured, installed and commissioned along with other power loop components. Two RWM Coils were connected in series and fed from one SPA sub-unit. After the initial RWM campaign, operational requirements evolved such that each of the RWM coils now requires separate power and control. Hence a second SPA with three sub-units has been procured and installed. The second unit is of improved design and has the controls and power components completely isolated. The existing thyristor rectifier is used as DC Link to both of the Switching Power Amplifiers. The controls for the RWM are integrated into the overall computer control of the DC Power systems for NSTX. This paper describes the design changes in the RWM Power system for NSTX.

  4. Intermittent bursts induced by double tearing mode reconnection

    SciTech Connect (OSTI)

    Wei, Lai; Wang, Zheng-Xiong, E-mail: zxwang@dlut.edu.cn [Key Laboratory of Materials Modification by Beams of the Ministry of Education, School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)

    2014-06-15

    Reversed magnetic shear (RMS) configuration is assumed to be the steady-state operation scenario for the future advanced tokamaks like International Thermonuclear Experimental Reactor. In this work, we numerically discover a phenomenon of violent intermittent bursts induced by self-organized double tearing mode (DTM) reconnection in the RMS configuration during the very long evolution, which may continuously lead to annular sawtooth crashes and thus badly impact the desired steady-state operation of the future advanced RMS tokamaks. The key process of the intermittent bursts in the off-axis region is similar to that of the typical sawtooth relaxation oscillation in the positive magnetic shear configuration. It is interestingly found that in the decay phase of the DTM reconnection, the zonal field significantly counteracts equilibrium field to make the magnetic shear between the two rational surfaces so weak that the residual self-generated vortices of the previous DTM burst are able to trigger a reverse DTM reconnection by curling the field lines.

  5. Real-time multi-mode neutron multiplicity counter

    DOE Patents [OSTI]

    Rowland, Mark S; Alvarez, Raymond A

    2013-02-26

    Embodiments are directed to a digital data acquisition method that collects data regarding nuclear fission at high rates and performs real-time preprocessing of large volumes of data into directly useable forms for use in a system that performs non-destructive assaying of nuclear material and assemblies for mass and multiplication of special nuclear material (SNM). Pulses from a multi-detector array are fed in parallel to individual inputs that are tied to individual bits in a digital word. Data is collected by loading a word at the individual bit level in parallel, to reduce the latency associated with current shift-register systems. The word is read at regular intervals, all bits simultaneously, with no manipulation. The word is passed to a number of storage locations for subsequent processing, thereby removing the front-end problem of pulse pileup. The word is used simultaneously in several internal processing schemes that assemble the data in a number of more directly useable forms. The detector includes a multi-mode counter that executes a number of different count algorithms in parallel to determine different attributes of the count data.

  6. Optothermal transport behavior in whispering gallery mode optical cavities

    SciTech Connect (OSTI)

    Soltani, Soheil; Armani, Andrea M.

    2014-08-04

    Over the past century, whispering gallery mode optical cavities have enabled numerous advances in science and engineering, such as discoveries in quantum mechanics and non-linear optics, as well as the development of optical gyroscopes and add drop filters. One reason for their widespread appeal is their ability to confine light for long periods of time, resulting in high circulating intensities. However, when sufficiently large amounts of optical power are coupled into these cavities, they begin to experience optothermal or photothermal behavior, in which the optical energy is converted into heat. Above the optothermal threshold, the resonance behavior is no longer solely defined by electromagnetics. Previous work has primarily focused on the role of the optothermal coefficient of the material in this instability. However, the physics of this optothermal behavior is significantly more complex. In the present work, we develop a predictive theory based on a generalizable analytical expression in combination with a geometry-specific COMSOL Multiphysics finite element method model. The simulation couples the optical and thermal physics components, accounting for geometry variations as well as the temporal and spatial profile of the optical field. To experimentally verify our theoretical model, the optothermal thresholds of a series of silica toroidal resonant cavities are characterized at different wavelengths (visible through near-infrared) and using different device geometries. The silica toroid offers a particularly rigorous case study for the developed optothermal model because of its complex geometrical structure which provides multiple thermal transport paths.

  7. Kinetic neoclassical transport in the H-mode pedestal

    SciTech Connect (OSTI)

    Battaglia, D. J.; Chang, C. S.; Ku, S.; Grierson, B. A.; Burrell, K. H.; Grassie, J. S. de

    2014-07-15

    Multi-species kinetic neoclassical transport through the QH-mode pedestal and scrape-off layer on DIII-D is calculated using XGC0, a 5D full-f particle-in-cell drift-kinetic solver with self-consistent neutral recycling and sheath potentials. Quantitative agreement between the flux-driven simulation and the experimental electron density, impurity density, and orthogonal measurements of impurity temperature and flow profiles is achieved by adding random-walk particle diffusion to the guiding-center drift motion. The radial electric field (E{sub r}) that maintains ambipolar transport across flux surfaces and to the wall is computed self-consistently on closed and open magnetic field lines and is in excellent agreement with experiment. The E{sub r} inside the separatrix is the unique solution that balances the outward flux of thermal tail deuterium ions against the outward neoclassical electron flux and inward pinch of impurity and colder deuterium ions. Particle transport in the pedestal is primarily due to anomalous transport, while the ion heat and momentum transport are primarily due to the neoclassical transport. The full-f treatment quantifies the non-Maxwellian energy distributions that describe a number of experimental observations in low-collisionallity pedestals on DIII-D, including intrinsic co-I{sub p} parallel flows in the pedestal, ion temperature anisotropy, and large impurity temperatures in the scrape-off layer.

  8. Dynamics and instantaneous normal modes in a liquid with density anomalies

    E-Print Network [OSTI]

    Massimo Pica Ciamarra; Peter Sollich

    2015-08-19

    We investigate the relation between the dynamical features of a supercooled liquid and those of its potential energy landscape, focusing on a model liquid with density anomalies. We consider, at fixed temperature, pairs of state points with different density but the same diffusion constant, and find that surprisingly they have identical dynamical features at all length and time scales. This is shown by the collapse of their mean square displacements and of their self--intermediate scattering functions at different wavevectors. We then investigate how the features of the energy landscape change with density, and establish that state points with equal diffusion constant have different landscapes. In particular, we find a correlation between the fraction of instantaneous normal modes connecting different energy minima and the diffusion constant, but unlike in other systems these two quantities are not in one--to--one correspondence with each other, showing that additional landscape features must be relevant in determining the diffusion constant.

  9. Evaluation of the electrical contact area in contact-mode scanning probe microscopy

    SciTech Connect (OSTI)

    Celano, Umberto E-mail: u.celano@gmail.com; Chintala, Ravi Chandra; Vandervorst, Wilfried; Hantschel, Thomas; Giammaria, Guido; Conard, Thierry; Bender, Hugo

    2015-06-07

    The tunneling current through an atomic force microscopy (AFM) tip is used to evaluate the effective electrical contact area, which exists between tip and sample in contact-AFM electrical measurements. A simple procedure for the evaluation of the effective electrical contact area is described using conductive atomic force microscopy (C-AFM) in combination with a thin dielectric. We characterize the electrical contact area for coated metal and doped-diamond tips operated at low force (<200 nN) in contact mode. In both cases, we observe that only a small fraction (<10?nm{sup 2}) of the physical contact (?100?nm{sup 2}) is effectively contributing to the transport phenomena. Assuming this reduced area is confined to the central area of the physical contact, these results explain the sub-10?nm electrical resolution observed in C-AFM measurements.

  10. Search for the decay modes D??e?e?, D??????, and D??e±??

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

    Lees, J. P.; Poireau, V.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Palano, A.; Eigen, G.; Stugu, B.; Brown, D. N.; Kerth, L. T.; et al

    2012-08-01

    We present searches for the rare decay modes D??e?e?, D0?????, and D??e±?? in continuum e?e??cc¯ events recorded by the BABAR detector in a data sample that corresponds to an integrated luminosity of 468 fb?¹. These decays are highly Glashow–Iliopoulos–Maiani suppressed but may be enhanced in several extensions of the standard model. Our observed event yields are consistent with the expected backgrounds. An excess is seen in the D?????? channel, although the observed yield is consistent with an upward background fluctuation at the 5% level. Using the Feldman–Cousins method, we set the following 90% confidence level intervals on the branching fractions:more »B(D??e?e?)±??)« less

  11. Topological Massive Dirac Edge Modes and Long-Range Superconducting Hamiltonians

    E-Print Network [OSTI]

    O. Viyuela; D. Vodola; G. Pupillo; M. A. Martin-Delgado

    2015-11-16

    We discover novel topological effects in the one-dimensional Kitaev chain modified by long-range Hamiltonian deformations in the hopping and pairing terms. This class of models display symmetry-protected topological order measured by the Berry phase of the ground state and the winding number of the Hamiltonians. For exponentially-decaying hopping amplitudes, the topological sector can be significantly augmented as the penetration length increases, something experimentally achievable. For power-law decaying superconducting pairings, the massless Majorana modes at the edges get paired together into a massive non-local Dirac fermion localised at both edges of the chain: a new topological quasiparticle that we call topological massive Dirac fermion. This topological phase has fractional topological numbers as a consequence of the long-range couplings. Possible applications to current experimental setups and topological quantum computation are also discussed.

  12. Search for the decay modes D??e?e?, D??????, and D??e±??

    SciTech Connect (OSTI)

    Lees, J. P.; Poireau, V.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Palano, A.; Eigen, G.; Stugu, B.; Brown, D. N.; Kerth, L. T.; Kolomensky, Yu. G.; Lynch, G.; Koch, H.; Schroeder, T.; Asgeirsson, D. J.; Hearty, C.; Mattison, T. S.; McKenna, J. A.; So, R. Y.; Khan, A.; Blinov, V. E.; Buzykaev, A. R.; Druzhinin, V. P.; Golubev, V. B.; Kravchenko, E. A.; Onuchin, A. P.; Serednyakov, S. I.; Skovpen, Yu. I.; Solodov, E. P.; Todyshev, K. Yu.; Yushkov, A. N.; Bondioli, M.; Kirkby, D.; Lankford, A. J.; Mandelkern, M.; Atmacan, H.; Gary, J. W.; Liu, F.; Long, O.; Mullin, E.; Vitug, G. M.; Campagnari, C.; Hong, T. M.; Kovalskyi, D.; Richman, J. D.; West, C. A.; Eisner, A. M.; Kroseberg, J.; Lockman, W. S.; Martinez, A. J.; Schumm, B. A.; Seiden, A.; Chao, D. S.; Cheng, C. H.; Echenard, B.; Flood, K. T.; Hitlin, D. G.; Ongmongkolkul, P.; Porter, F. C.; Rakitin, A. Y.; Andreassen, R.; Huard, Z.; Meadows, B. T.; Sokoloff, M. D.; Sun, L.; Bloom, P. C.; Ford, W. T.; Gaz, A.; Nauenberg, U.; Smith, J. G.; Wagner, S. R.; Ayad, R.; Toki, W. H.; Spaan, B.; Schubert, K. R.; Schwierz, R.; Bernard, D.; Verderi, M.; Clark, P. J.; Playfer, S.; Bettoni, D.; Bozzi, C.; Calabrese, R.; Cibinetto, G.; Fioravanti, E.; Garzia, I.; Luppi, E.; Munerato, M.; Piemontese, L.; Santoro, V.; Baldini-Ferroli, R.; Calcaterra, A.; de Sangro, R.; Finocchiaro, G.; Patteri, P.; Peruzzi, I. M.; Piccolo, M.; Rama, M.; Zallo, A.; Contri, R.; Guido, E.; Lo Vetere, M.; Monge, M. R.; Passaggio, S.; Patrignani, C.; Robutti, E.; Bhuyan, B.; Prasad, V.; Lee, C. L.; Morii, M.; Edwards, A. J.; Adametz, A.; Uwer, U.; Lacker, H. M.; Lueck, T.; Dauncey, P. D.; Mallik, U.; Chen, C.; Cochran, J.; Meyer, W. T.; Prell, S.; Rubin, A. E.; Gritsan, A. V.; Guo, Z. J.; Arnaud, N.; Davier, M.; Derkach, D.; Grosdidier, G.; Le Diberder, F.; Lutz, A. M.; Malaescu, B.; Roudeau, P.; Schune, M. H.; Stocchi, A.; Wormser, G.; Lange, D. J.; Wright, D. M.; Chavez, C. A.; Coleman, J. P.; Fry, J. R.; Gabathuler, E.; Hutchcroft, D. E.; Payne, D. J.; Touramanis, C.; Bevan, A. J.; Di Lodovico, F.; Sacco, R.; Sigamani, M.; Cowan, G.; Brown, D. N.; Davis, C. L.; Denig, A. G.; Fritsch, M.; Gradl, W.; Griessinger, K.; Hafner, A.; Prencipe, E.; Barlow, R. J.; Jackson, G.; Lafferty, G. D.; Behn, E.; Cenci, R.; Hamilton, B.; Jawahery, A.; Roberts, D. A.; Dallapiccola, C.; Cowan, R.; Dujmic, D.; Sciolla, G.; Cheaib, R.; Lindemann, D.; Patel, P. M.; Robertson, S. H.; Biassoni, P.; Neri, N.; Palombo, F.; Stracka, S.; Cremaldi, L.; Godang, R.; Kroeger, R.; Sonnek, P.; Summers, D. J.; Nguyen, X.; Simard, M.; Taras, P.; De Nardo, G.; Monorchio, D.; Onorato, G.; Sciacca, C.; Martinelli, M.; Raven, G.; Jessop, C. P.; LoSecco, J. M.; Wang, W. F.; Honscheid, K.; Kass, R.; Brau, J.; Frey, R.; Sinev, N. B.; Strom, D.; Torrence, E.; Feltresi, E.; Gagliardi, N.; Margoni, M.; Morandin, M.; Posocco, M.; Rotondo, M.; Simi, G.; Simonetto, F.; Stroili, R.; Akar, S.; Ben-Haim, E.; Bomben, M.; Bonneaud, G. R.; Briand, H.; Calderini, G.; Chauveau, J.; Hamon, O.; Leruste, Ph.; Marchiori, G.; Ocariz, J.; Sitt, S.; Biasini, M.; Manoni, E.; Pacetti, S.; Rossi, A.; Angelini, C.; Batignani, G.; Bettarini, S.; Carpinelli, M.; Casarosa, G.; Cervelli, A.; Forti, F.; Giorgi, M. A.; Lusiani, A.; Oberhof, B.; Paoloni, E.; Perez, A.; Rizzo, G.; Walsh, J. J.; Lopes Pegna, D.; Olsen, J.; Smith, A. J. S.; Telnov, A. V.; Anulli, F.; Faccini, R.; Ferrarotto, F.; Ferroni, F.; Gaspero, M.; Li Gioi, L.; Mazzoni, M. A.; Piredda, G.; Bünger, C.; Grünberg, O.; Hartmann, T.; Leddig, T.; Schröder, H.; Voss, C.; Waldi, R.; Adye, T.; Olaiya, E. O.; Wilson, F. F.; Emery, S.; Hamel de Monchenault, G.; Vasseur, G.; Yèche, Ch.; Aston, D.; Bard, D. J.; Bartoldus, R.; Benitez, J. F.; Cartaro, C.; Convery, M. R.; Dorfan, J.; Dubois-Felsmann, G. P.; Dunwoodie, W.; Ebert, M.; Field, R. C.; Franco Sevilla, M.; Fulsom, B. G.; Gabareen, A. M.; Graham, M. T.; Grenier, P.; Hast, C.; Innes, W. R.; Kelsey, M. H.; Kim, P.; Kocian, M. L.; Leith, D. W. G. S.; Lewis, P.; Lindquist, B.; Luitz, S.; Luth, V.; Lynch, H. L.; MacFarlane, D. B.; Muller, D. R.; Neal, H.; Nelson, S.; Perl, M.; Pulliam, T.; Ratcliff, B. N.; Roodman, A.; Salnikov, A. A.; Schindler, R. H.; Snyder, A.; Su, D.; Sullivan, M. K.; Va’vra, J.; Wagner, A. P.; Wisniewski, W. J.; Wittgen, M.; Wright, D. H.; Wulsin, H. W.; Young, C. C.; Ziegler, V.; Park, W.; Purohit, M. V.; White, R. M.; Wilson, J. R.; Randle-Conde, A.; Sekula, S. J.; Bellis, M.; Burchat, P. R.; Miyashita, T. S.; Puccio, E. M. T.; Alam, M. S.; Ernst, J. A.; Gorodeisky, R.; Guttman, N.; Peimer, D. R.; Soffer, A.; Lund, P.; Spanier, S. M.; Ritchie, J. L.; Ruland, A. M.; Schwitters, R. F.; Wray, B. C.; Izen, J. M.; Lou, X. C.; Bianchi, F.; Gamba, D.; Zambito, S.; Lanceri, L.; Vitale, L.; Martinez-Vidal, F.

    2012-08-01

    We present searches for the rare decay modes D??e?e?, D0?????, and D??e±?? in continuum e?e??cc¯ events recorded by the BABAR detector in a data sample that corresponds to an integrated luminosity of 468 fb?¹. These decays are highly Glashow–Iliopoulos–Maiani suppressed but may be enhanced in several extensions of the standard model. Our observed event yields are consistent with the expected backgrounds. An excess is seen in the D?????? channel, although the observed yield is consistent with an upward background fluctuation at the 5% level. Using the Feldman–Cousins method, we set the following 90% confidence level intervals on the branching fractions: B(D??e?e?)<1.7×10??, B(D??????) within [0.6,8.1]×10??, and B(D??e±??)<3.3×10??.

  13. Search for the decay modes B±?h±?l

    SciTech Connect (OSTI)

    Lees, J. P.; Poireau, V.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Milanes, D. A.; Palano, A.; Pappagallo, M.; Eigen, G.; Stugu, B.; Brown, D. N.; Kerth, L. T.; Kolomensky, Yu. G.; Lynch, G.; Koch, H.; Schroeder, T.; Asgeirsson, D. J.; Hearty, C.; Mattison, T. S.; McKenna, J. A.; Khan, A.; Blinov, V. E.; Buzykaev, A. R.; Druzhinin, V. P.; Golubev, V. B.; Kravchenko, E. A.; Onuchin, A. P.; Serednyakov, S. I.; Skovpen, Yu. I.; Solodov, E. P.; Todyshev, K. Yu.; Yushkov, A. N.; Bondioli, M.; Kirkby, D.; Lankford, A. J.; Mandelkern, M.; Stoker, D. P.; Atmacan, H.; Gary, J. W.; Liu, F.; Long, O.; Vitug, G. M.; Campagnari, C.; Hong, T. M.; Kovalskyi, D.; Richman, J. D.; West, C. A.; Eisner, A. M.; Kroseberg, J.; Lockman, W. S.; Martinez, A. J.; Schalk, T.; Schumm, B. A.; Seiden, A.; Cheng, C. H.; Doll, D. A.; Echenard, B.; Flood, K. T.; Hitlin, D. G.; Ongmongkolkul, P.; Porter, F. C.; Rakitin, A. Y.; Andreassen, R.; Huard, Z.; Meadows, B. T.; Sokoloff, M. D.; Sun, L.; Bloom, P. C.; Ford, W. T.; Gaz, A.; Nagel, M.; Nauenberg, U.; Smith, J. G.; Wagner, S. R.; Ayad, R.; Toki, W. H.; Spaan, B.; Kobel, M. J.; Schubert, K. R.; Schwierz, R.; Bernard, D.; Verderi, M.; Clark, P. J.; Playfer, S.; Bettoni, D.; Bozzi, C.; Calabrese, R.; Cibinetto, G.; Fioravanti, E.; Garzia, I.; Luppi, E.; Munerato, M.; Negrini, M.; Piemontese, L.; Santoro, V.; Baldini-Ferroli, R.; Calcaterra, A.; de Sangro, R.; Finocchiaro, G.; Patteri, P.; Peruzzi, I. M.; Piccolo, M.; Rama, M.; Zallo, A.; Contri, R.; Guido, E.; Lo Vetere, M.; Monge, M. R.; Passaggio, S.; Patrignani, C.; Robutti, E.; Bhuyan, B.; Prasad, V.; Lee, C. L.; Morii, M.; Edwards, A. J.; Adametz, A.; Marks, J.; Uwer, U.; Lacker, H. M.; Lueck, T.; Dauncey, P. D.; Behera, P. K.; Mallik, U.; Chen, C.; Cochran, J.; Meyer, W. T.; Prell, S.; Rubin, A. E.; Gritsan, A. V.; Guo, Z. J.; Arnaud, N.; Davier, M.; Derkach, D.; Grosdidier, G.; Le Diberder, F.; Lutz, A. M.; Malaescu, B.; Roudeau, P.; Schune, M. H.; Stocchi, A.; Wormser, G.; Lange, D. J.; Wright, D. M.; Bingham, I.; Chavez, C. A.; Coleman, J. P.; Fry, J. R.; Gabathuler, E.; Hutchcroft, D. E.; Payne, D. J.; Touramanis, C.; Bevan, A. J.; Di Lodovico, F.; Sacco, R.; Sigamani, M.; Cowan, G.; Brown, D. N.; Davis, C. L.; Denig, A. G.; Fritsch, M.; Gradl, W.; Hafner, A.; Prencipe, E.; Alwyn, K. E.; Bailey, D.; Barlow, R. J.; Jackson, G.; Lafferty, G. D.; Behn, E.; Cenci, R.; Hamilton, B.; Jawahery, A.; Roberts, D. A.; Simi, G.; Dallapiccola, C.; Cowan, R.; Dujmic, D.; Sciolla, G.; Lindemann, D.; Patel, P. M.; Robertson, S. H.; Schram, M.; Biassoni, P.; Neri, N.; Palombo, F.; Stracka, S.; Cremaldi, L.; Godang, R.; Kroeger, R.; Sonnek, P.; Summers, D. J.; Nguyen, X.; Simard, M.; Taras, P.; De Nardo, G.; Monorchio, D.; Onorato, G.; Sciacca, C.; Martinelli, M.; Raven, G.; Jessop, C. P.; Knoepfel, K. J.; LoSecco, J. M.; Wang, W. F.; Honscheid, K.; Kass, R.; Brau, J.; Frey, R.; Sinev, N. B.; Strom, D.; Torrence, E.; Feltresi, E.; Gagliardi, N.; Margoni, M.; Morandin, M.; Posocco, M.; Rotondo, M.; Simonetto, F.; Stroili, R.; Akar, S.; Ben-Haim, E.; Bomben, M.; Bonneaud, G. R.; Briand, H.; Calderini, G.; Chauveau, J.; Hamon, O.; Leruste, Ph.; Marchiori, G.; Ocariz, J.; Sitt, S.; Biasini, M.; Manoni, E.; Pacetti, S.; Rossi, A.; Angelini, C.; Batignani, G.; Bettarini, S.; Carpinelli, M.; Casarosa, G.; Cervelli, A.; Forti, F.; Giorgi, M. A.; Lusiani, A.; Oberhof, B.; Paoloni, E.; Perez, A.; Rizzo, G.; Walsh, J. J.; Lopes Pegna, D.; Lu, C.; Olsen, J.; Smith, A. J. S.; Telnov, A. V.; Anulli, F.; Cavoto, G.; Faccini, R.; Ferrarotto, F.; Ferroni, F.; Gaspero, M.; Li Gioi, L.; Mazzoni, M. A.; Piredda, G.; Bünger, C.; Grünberg, O.; Hartmann, T.; Leddig, T.; Schröder, H.; Voss, C.; Waldi, R.; Adye, T.; Olaiya, E. O.; Wilson, F. F.; Emery, S.; Hamel de Monchenault, G.; Vasseur, G.; Yèche, Ch.; Aston, D.; Bard, D. J.; Bartoldus, R.; Cartaro, C.; Convery, M. R.; Dorfan, J.; Dubois-Felsmann, G. P.; Dunwoodie, W.; Ebert, M.; Field, R. C.; Franco Sevilla, M.; Fulsom, B. G.; Gabareen, A. M.; Graham, M. T.; Grenier, P.; Hast, C.; Innes, W. R.; Kelsey, M. H.; Kim, P.; Kocian, M. L.; Leith, D. W. G. S.; Lewis, P.; Lindquist, B.; Luitz, S.; Luth, V.; Lynch, H. L.; MacFarlane, D. B.; Muller, D. R.; Neal, H.; Nelson, S.; Perl, M.; Pulliam, T.; Ratcliff, B. N.; Roodman, A.; Salnikov, A. A.; Schindler, R. H.; Snyder, A.; Su, D.; Sullivan, M. K.; Va’vra, J.; Wagner, A. P.; Weaver, M.; Wisniewski, W. J.; Wittgen, M.; Wright, D. H.; Wulsin, H. W.; Young, C. C.; Ziegler, V.; Park, W.; Purohit, M. V.; White, R. M.; Wilson, J. R.; Randle-Conde, A.; Sekula, S. J.; Bellis, M.; Benitez, J. F.; Burchat, P. R.; Miyashita, T. S.; Alam, M. S.; Ernst, J. A.; Gorodeisky, R.; Guttman, N.; Peimer, D. R.; Soffer, A.; Lund, P.; Spanier, S. M.; Eckmann, R.; Ritchie, J. L.

    2012-07-16

    We present a search for the lepton flavor violating decay modes B±?h±?l (h=K, ?; l=e, ?) using the BABAR data sample, which corresponds to 472×10? BB¯¯¯ pairs. The search uses events where one B meson is fully reconstructed in one of several hadronic final states. Using the momenta of the reconstructed B, h, and l candidates, we are able to fully determine the ? four-momentum. The resulting ? candidate mass is our main discriminant against combinatorial background. We see no evidence for B±?h±?l decays and set a 90% confidence level upper limit on each branching fraction at the level of a few times 10??.

  14. Duct spinning mode's particle velocity imaging with in-duct circular microphone array

    E-Print Network [OSTI]

    Huang, Xun

    Duct spinning mode's particle velocity imaging with in-duct circular microphone array Qingkai Wei's Republic of China Nowadays, the measurements within a duct have to be conducted using in-duct microphone. In this work, an imaging method of acoustic spinning modes propagating within a circular duct simply

  15. DETECTING GRAVITY MODES IN THE SOLAR {sup 8} B NEUTRINO FLUX

    SciTech Connect (OSTI)

    Lopes, Ilídio; Turck-Chièze, Sylvaine E-mail: ilopes@uevora.pt

    2014-09-10

    The detection of gravity modes produced in the solar radiative zone has been a challenge in modern astrophysics for more than 30 yr and their amplitude in the core is not yet determined. In this Letter, we develop a new strategy to look for standing gravity modes through solar neutrino fluxes. We note that due to a resonance effect, the gravity modes of low degree and low order have the largest impact on the {sup 8} B neutrino flux. The strongest effect is expected to occur for the dipole mode with radial order 2, corresponding to periods of about 1.5 hr. These standing gravity waves produce temperature fluctuations that are amplified by a factor of 170 in the boron neutrino flux for the corresponding period, in consonance with the gravity modes. From current neutrino observations, we determine that the maximum temperature variation due to the gravity modes in the Sun's core is smaller than 5.8 × 10{sup –4}. This study clearly shows that due to their high sensitivity to the temperature, the {sup 8} B neutrino flux time series is an excellent tool to determine the properties of gravity modes in the solar core. Moreover, if gravity mode footprints are discovered in the {sup 8} B neutrino flux, this opens a new line of research to probe the physics of the solar core as non-standing gravity waves of higher periods cannot be directly detected by helioseismology but could leave their signature on boron neutrino or on other neutrino fluxes.

  16. The electromagneto-acoustic surface wave in a piezoelectric medium: The BleusteinGulyaev mode

    E-Print Network [OSTI]

    Li, Shaofan

    The electromagneto-acoustic surface wave in a piezoelectric medium: The Bleustein­Gulyaev mode electromagneto-acoustic surface wave mode in a class of piezoelectric media. As the wave speed is much less than­Gulyaev wave. The Bleustein­Gulyaev BG sur- face wave is an unique result in the repertoire of surface acoustic

  17. High Speed Architecture for Galois/Counter Mode of Operation (GCM)

    E-Print Network [OSTI]

    International Association for Cryptologic Research (IACR)

    High Speed Architecture for Galois/Counter Mode of Operation (GCM) Bo Yang, Sambit Mishra, Ramesh of the contribution to the high throughput is from the advanced fabrication technology. A fully pipelined AES pipelined high speed hardware architec- ture for Galois/Counter Mode of Operation (GCM) by analyzing

  18. A simple model of the resistive wall mode in tokamaks Richard Fitzpatrick

    E-Print Network [OSTI]

    Fitzpatrick, Richard

    A simple model of the resistive wall mode in tokamaks Richard Fitzpatrick Citation: Physics of feedback stabilization of resistive wall modes in a tokamak plasma Phys. Plasmas 15, 022501 (2008); 10 rotation in a cylindrical tokamak Phys. Plasmas 10, 187 (2003); 10.1063/1.1527042 Physics and control

  19. ORIGINAL PAPER Calculation of infrared and Raman vibration modes of magnesite

    E-Print Network [OSTI]

    Cattin, Rodolphe

    ORIGINAL PAPER Calculation of infrared and Raman vibration modes of magnesite at high pressure) are used to obtain infrared (IR) and Raman magnesite vibration modes as they vary with pressure up to 50 approaches of vibrations in crystals based on empirical models suffer several drawbacks lead- ing

  20. A Digitally Implemented Photovoltaic Simulator with a Double Current Mode Controller

    E-Print Network [OSTI]

    Kimball, Jonathan W.

    A Digitally Implemented Photovoltaic Simulator with a Double Current Mode Controller Jie Zhao-DC converter-based photovoltaic (PV) simulator which emulates the output characteristics of a real solar panel. Keyword ­ digital control, photovoltaic simulator, predictive current mode control, solar panel IV curve

  1. KINK AND LONGITUDINAL OSCILLATIONS IN THE MAGNETIC NETWORK ON THE SUN: NONLINEAR EFFECTS AND MODE TRANSFORMATION

    E-Print Network [OSTI]

    Ulmschneider, Peter

    divided between the two modes. Subject headings: MHD -- Sun: magnetic fields -- Sun: oscillations 1KINK AND LONGITUDINAL OSCILLATIONS IN THE MAGNETIC NETWORK ON THE SUN: NONLINEAR EFFECTS AND MODE, the thin tube approximation is valid up to the layers of formation of the emission features in the H and K

  2. Ultra-low repetition rate mode-locked fiber laser with high-energy pulses

    E-Print Network [OSTI]

    Kobtsev, Sergei M.

    of research into passively mode- locked fiber laser with a record-setting optical length of the resonant-repetition rate high- energy picosecond pulses from a single-wall carbon nanotube mode-locked fiber laser," presented at the Optical Amplifiers and their Applications Conference (OAA 2006), Whistler, British Columbia

  3. On the dynamic nature of azimuthal thermoacoustic modes in annular gas turbine combustion chambers

    E-Print Network [OSTI]

    Daraio, Chiara

    On the dynamic nature of azimuthal thermoacoustic modes in annular gas turbine combustion chambers with the dynamics of standing and rotating azimuthal thermoacoustic modes in annular combustion chambers source intensity, the asymmetry in the system and the strength of the thermo-acoustic interaction

  4. Analysis of an LMS Linear Equalizer for Fading Channels in Decision Directed mode

    E-Print Network [OSTI]

    Sharma, Vinod

    Analysis of an LMS Linear Equalizer for Fading Channels in Decision Directed mode Veeraruna Kavitha varying wireless fading chan- nel, equalized by an LMS linear equalizer in decision directed mode (DD-LMS using an ODE (Ordinary Differential Equation) approximating the DD-LMS-LE. We also show, via examples

  5. Al.SEP Array E -Comm~nd Decoder Failure Modes, Effects 8;

    E-Print Network [OSTI]

    Rathbun, Julie A.

    in the Control Logic Section by locking to the 1 KHz uplink clock generated at the ground station. The phase lock\\ Al.SEP Array E - Comm~nd Decoder Failure Modes, Effects 8; ATM 949 ! Criticality Analysis PAGI OF 27 DATE 6-1-71 This ATM dotuments the Failure Modes, Effects and Criticality Analysis 'on the Bendix

  6. Time resolution capability of the XMM EPIC pnCCD in different readout modes.

    E-Print Network [OSTI]

    Barnstedt, Jürgen

    Time resolution capability of the XMM EPIC pn­CCD in different readout modes. M. Kuster 1 , S to perform high resolution timing analysis as well as high throughput imaging and spectroscopy in six every 73.3 ms. In addition, different readout modes allow high resolution timing analysis by reducing

  7. Discovery of very large amplitude whistler-mode waves in Earth's radiation belts

    E-Print Network [OSTI]

    California at Berkeley, University of

    Discovery of very large amplitude whistler-mode waves in Earth's radiation belts C. Cattell,1 J. R January 2008. [1] During a passage through the Earth's dawn-side outer radiation belt, whistler-mode waves of magnitude larger than previously observed for whistlers in the radiation belt. Although the peak frequency

  8. Investigation of mode coupling in normal-dispersion silicon nitride microresonators

    E-Print Network [OSTI]

    Purdue University

    -dispersion devices highlight mode interactions as a beneficial tool for comb initiation and pulse formation. © 2014Investigation of mode coupling in normal- dispersion silicon nitride microresonators for Kerr microresonators are the subject of intense study for potential applications ranging from short pulse generation

  9. American Institute of Aeronautics and Astronautics Switch-Mode Continuously Variable Transmission

    E-Print Network [OSTI]

    Van de Ven, James D.

    -mode continuously variable transmission (CVT), which is the mechanical analog of a DC-DC power electronics converterAmerican Institute of Aeronautics and Astronautics 1 Switch-Mode Continuously Variable Transmission speed flywheel to the drive train of the vehicle. The transmission for this application must

  10. Centralizing the Power Saving Mode for 802.11 Infrastructure Networks

    E-Print Network [OSTI]

    Chang, Rocky Kow-Chuen

    , power saving mode (PSM) that puts an idle client into a low-power mode (Gast, 2005), transmission power PSM (C-PSM), an AP-centric deployment of the IEEE 802.11 PSM, to optimize power saving and multiple results show that significant improvements can be obtained from the new deployment of C-PSM. The IEEE 802

  11. Centralized PSM: An AP-centric Power Saving Mode for 802.11 Infrastructure Networks

    E-Print Network [OSTI]

    Chang, Rocky Kow-Chuen

    Centralized PSM: An AP-centric Power Saving Mode for 802.11 Infrastructure Networks Yi Xie on their battery life. In this paper, we propose a centralized power saving mode (C-PSM), an AP-centric PSM for 802.11 infrastructure networks. Having the AP select optimal PSM parameters, such as the beacon and listen intervals, C

  12. Improving the Adaptability of Multi-mode Systems via Program Steering

    E-Print Network [OSTI]

    Ernst, Michael

    arise. This research aims to mitigate such problems by creating a new mode selector that examines the current one. The technique, called pro- gram steering, creates a new mode selector via machine learning-long programming competition. Augmenting these programs via our program steering technique had a substantial

  13. An H minority heating regime in Tore Supra showing improved L mode confinement

    E-Print Network [OSTI]

    Budny, Robert

    devoted to the study of high density regimes with radiofrequency heating. Recently, an improved L mode tokamaks have been observed. 1. Introduction High density and high radiation regimes have been investigated. Nowadays, the attractive high radiation improved confinement regime (RI mode), discovered on TEXTOR [1

  14. Label-free bacteria detection using evanescent mode of a suspended core terahertz fiber

    E-Print Network [OSTI]

    Skorobogatiy, Maksim

    Label-free bacteria detection using evanescent mode of a suspended core terahertz fiber Anna time an E. coli bacteria sensor based on the evanescent field of the fundamental mode of a suspended\\ SKDJHV DQG WKHQ GHVWUR\\HG ZLWK a P-size fragments remaining bound to the fiber surface. The bacteria

  15. A CHAOS MODEL OF SUBHARMONIC OSCILLATIONS IN CURRENT MODE PWM BOOST CONVERTERS

    E-Print Network [OSTI]

    A CHAOS MODEL OF SUBHARMONIC OSCILLATIONS IN CURRENT MODE PWM BOOST CONVERTERS Isaac Zafrany in a current mode PWM Boost converter under open and closed outer- loop conditions. A simple expression and explain by a Chaos model the behavior of a CM Boost converter under open and closed outer loop situations

  16. Digital Sliding Mode Pulsed Current Averaging IC Drivers for High Brightness Light Emitting Diodes

    E-Print Network [OSTI]

    Lehman, Brad

    to the load. A variable frequency boost converter in Discontinuous Conduction Mode (DCM) has been used algorithm of the inductor current variations for a digitally controlled DC-DC boost converter operating in Continuous Conduction Mode. [10] describes a microcontroller based digital boost converter for a RGB

  17. General Control for Boost PFC Converter from a Sliding Mode Viewpoint

    E-Print Network [OSTI]

    Tse, Chi K. "Michael"

    4452 General Control for Boost PFC Converter from a Sliding Mode Viewpoint Grace Chu, Siew control methodology for the boost PFC converter based on sliding mode control theory. The resulting rule is derived for the boost PFC converter. The aim is to provide input current tracking under all

  18. Bifurcation in Parallel-Connected Buck Converters under Current-Mode Control

    E-Print Network [OSTI]

    Tse, Chi K. "Michael"

    converter, boost converter and buck-boost converter) have been thoroughly studied in the past decade [1], [2Bifurcation in Parallel-Connected Buck Converters under Current-Mode Control H. H. C. Iu School a system of parallel-connected dc/dc buck converters under current-mode control. The effects of variations

  19. Preparing photon pairs entangled in any desired spatial modes via interference

    E-Print Network [OSTI]

    Galvez, Enrique J. "Kiko"

    Department of Physics and Astronomy, Colgate University, 13 Oak Drive, Hamilton, New York 13346, U in energy-momentum,1 polarization,2,3 and spatial mode.4 Spatial-mode entanglement involves the use high, but not the only alternative. After the spatial filter the pairs are in a product state: |u = |u0 1|u0 2. (2

  20. A laboratory study of low-mode internal tide scattering by finite-amplitude topography

    E-Print Network [OSTI]

    Dauxois, Thierry

    A laboratory study of low-mode internal tide scattering by finite-amplitude topography Thomas concerning the scattering of a low-mode internal tide by finite-amplitude Gaussian topography. Experiments using particle image velocimetry. The results support the belief that finite-amplitude topography