National Library of Energy BETA

Sample records for axial electric field

  1. Evaporative capillary instability for flow in porous media under the influence of axial electric field

    SciTech Connect (OSTI)

    Kumar Awasthi, Mukesh

    2014-04-15

    We study the linear analysis of electrohydrodynamic capillary instability of the interface between two viscous, incompressible and electrically conducting fluids in a fully saturated porous medium, when the phases are enclosed between two horizontal cylindrical surfaces coaxial with the interface and, when there is mass and heat transfer across the interface. The fluids are subjected to a constant electric field in the axial direction. Here, we use an irrotational theory in which the motion and pressure are irrotational and the viscosity enters through the jump in the viscous normal stress in the normal stress balance at the interface. A quadratic dispersion relation that accounts for the growth of axisymmetric waves is obtained and stability criterion is given in terms of a critical value of wave number as well as electric field. It is observed that heat transfer has stabilizing effect on the stability of the considered system while medium porosity destabilizes the interface. The axial electric field has dual effect on the stability analysis.

  2. Axial gap rotating electrical machine

    DOE Patents [OSTI]

    None

    2016-02-23

    Direct drive rotating electrical machines with axial air gaps are disclosed. In these machines, a rotor ring and stator ring define an axial air gap between them. Sets of gap-maintaining rolling supports bear between the rotor ring and the stator ring at their peripheries to maintain the axial air gap. Also disclosed are wind turbines using these generators, and structures and methods for mounting direct drive rotating electrical generators to the hubs of wind turbines. In particular, the rotor ring of the generator may be carried directly by the hub of a wind turbine to rotate relative to a shaft without being mounted directly to the shaft.

  3. Three-dimensional model and simulation of vacuum arcs under axial magnetic fields

    SciTech Connect (OSTI)

    Wang Lijun; Jia Shenli; Zhou Xin; Wang Haijing; Shi Zongqian

    2012-01-15

    In this paper, a three-dimensional (3d) magneto-hydro-dynamic (MHD) model of axial magnetic field vacuum arcs (AMFVAs) is established. Based on this model, AMFVAs are simulated and analyzed. Three-dimensional spatial distributions of many important plasma parameters and electric characteristics in AMFVAs can be obtained, such as ion number density, ion temperature, electron temperature, plasma pressure, current densities along different directions (x, y, and z), ion velocities along different directions, electric fields strength along different directions, and so on. Simulation results show that there exist significant spiral-shaped rotational phenomena in the AMFVAs, this kind of rotational phenomenon also can be verified by the many related experiments (AMFVAs photographs, especially for stronger AMF strength). For current simulation results of AMFVAs, the maximal rotational velocity at anode side is about 1100 m/s. Radial electric field is increased from arc center to arc edge; axial electric field is decreased from cathode side to anode side. Radial electric field at arc edge can be larger than axial electric field. Azimuthal electric field in most regions is much smaller than radial and axial electric field, but it can reach about 1.19 kV/m. Radial magnetic field is the smallest one compared with other components, it reaches to maximum value at the position near to anode, it can influence arc characteristics.

  4. Nuclear axial currents in chiral effective field theory

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

    Baroni, Alessandro; Girlanda, Luca; Pastore, Saori; Schiavilla, Rocco; Viviani, Michele

    2016-01-11

    Two-nucleon axial charge and current operators are derived in chiral effective field theory up to one loop. The derivation is based on time-ordered perturbation theory and accounts for cancellations between the contributions of irreducible diagrams and the contributions owing to nonstatic corrections from energy denominators of reducible diagrams. Ultraviolet divergencies associated with the loop corrections are isolated in dimensional regularization. The resulting axial current is finite and conserved in the chiral limit, while the axial charge requires renormalization. As a result, a complete set of contact terms for the axial charge up to the relevant order in the power countingmore » is constructed.« less

  5. Electrostatic waves in carbon nanotubes with an axial magnetic field

    SciTech Connect (OSTI)

    Abdikian, Alireza; Bagheri, Mehran

    2013-10-15

    Based on a linearized hydrodynamic model and within the quasi-static approximation, the dispersion relation of electrostatic waves propagating through single-walled carbon nanotubes subject to an axial magnetic field is theoretically explored. In the classical limit, we obtain two main possible waves which in turn are divided into two branches, a low-frequency acoustical and a high-frequency optical plasmon branch. In the quantum case, we have found that the dispersion relation is substantially modified when the electron wavelength becomes large enough compared to the propagation wavelength of the electrostatic waves in the quantum plasma. We also show that the axial magnetic field manifest itself on the perturbed electron density through the quantum term and gives rise to the propagation of the electrostatic waves within the quantum plasma. As a result, the effect of the magnetic field is pronounced in the plasma dispersion relations in such a way that their curves approach to zero when the magnetic field is weak; and for the strong magnetic field, they asymptotically meet the constant lines.

  6. Collimation of laser-produced plasmas using axial magnetic field

    SciTech Connect (OSTI)

    Roy, Amitava; Harilal, Sivanandan S.; Hassan, Syed M.; Endo, Akira; Mocek, Tomas; Hassanein, A.

    2015-06-01

    We investigated the expansion dynamics of laser-produced plasmas expanding into an axial magnetic field. Plasmas were generated by focusing 1.064 µm Nd:YAG laser pulses onto a planar tin target in vacuum and allowed to expand into a 0.5 T magnetic-filed where field lines were aligned along the plume expansion direction. Gated images employing intensified CCD showed focusing of the plasma plume, which were also compared with results obtained using particle-in-cell modelling methods. The estimated density and temperature of the plasma plumes employing emission spectroscopy revealed significant changes in the presence and absence of the 0.5T magnetic field. In the presence of the field, the electron temperature is increased with distance from the target, while the density showed opposite effects.

  7. Dispersion relation and growth rate in a Cherenkov free electron laser: Finite axial magnetic field

    SciTech Connect (OSTI)

    Kheiri, Golshad; Esmaeilzadeh, Mahdi

    2013-12-15

    A theoretical analysis is presented for dispersion relation and growth rate in a Cherenkov free electron laser with finite axial magnetic field. It is shown that the growth rate and the resonance frequency of Cherenkov free electron laser increase with increasing axial magnetic field for low axial magnetic fields, while for high axial magnetic fields, they go to a saturation value. The growth rate and resonance frequency saturation values are exactly the same as those for infinite axial magnetic field approximation. The effects of electron beam self-fields on growth rate are investigated, and it is shown that the growth rate decreases in the presence of self-fields. It is found that there is an optimum value for electron beam density and Lorentz relativistic factor at which the maximum growth rate can take place. Also, the effects of velocity spread of electron beam are studied and it is found that the growth rate decreases due to the electron velocity spread.

  8. Electric field divertor plasma pump

    DOE Patents [OSTI]

    Schaffer, M.J.

    1994-10-04

    An electric field plasma pump includes a toroidal ring bias electrode positioned near the divertor strike point of a poloidal divertor of a tokamak, or similar plasma-confining apparatus. For optimum plasma pumping, the separatrix of the poloidal divertor contacts the ring electrode, which then also acts as a divertor plate. A plenum or other duct near the electrode includes an entrance aperture open to receive electrically-driven plasma. The electrode is insulated laterally with insulators, one of which is positioned opposite the electrode at the entrance aperture. An electric field E is established between the ring electrode and a vacuum vessel wall, with the polarity of the bias applied to the electrode being relative to the vessel wall selected such that the resultant electric field E interacts with the magnetic field B already existing in the tokamak to create an E [times] B/B[sup 2] drift velocity that drives plasma into the entrance aperture. The pumped plasma flow into the entrance aperture is insensitive to variations, intentional or otherwise, of the pump and divertor geometry. Pressure buildups in the plenum or duct connected to the entrance aperture in excess of 10 mtorr are achievable. 11 figs.

  9. Electric field divertor plasma pump

    DOE Patents [OSTI]

    Schaffer, Michael J.

    1994-01-01

    An electric field plasma pump includes a toroidal ring bias electrode (56) positioned near the divertor strike point of a poloidal divertor of a tokamak (20), or similar plasma-confining apparatus. For optimum plasma pumping, the separatrix (40) of the poloidal divertor contacts the ring electrode (56), which then also acts as a divertor plate. A plenum (54) or other duct near the electrode (56) includes an entrance aperture open to receive electrically-driven plasma. The electrode (56) is insulated laterally with insulators (63,64), one of which (64) is positioned opposite the electrode at the entrance aperture. An electric field E is established between the ring electrode (56) and a vacuum vessel wall (22), with the polarity of the bias applied to the electrode being relative to the vessel wall selected such that the resultant electric field E interacts with the magnetic field B already existing in the tokamak to create an E.times.B/B.sup.2 drift velocity that drives plasma into the entrance aperture. The pumped plasma flow into the entrance aperture is insensitive to variations, intentional or otherwise, of the pump and divertor geometry. Pressure buildups in the plenum or duct connected to the entrance aperture in excess of 10 mtorr are achievable.

  10. Linear electric field mass spectrometry

    DOE Patents [OSTI]

    McComas, D.J.; Nordholt, J.E.

    1992-12-01

    A mass spectrometer and methods for mass spectrometry are described. The apparatus is compact and of low weight and has a low power requirement, making it suitable for use on a space satellite and as a portable detector for the presence of substances. High mass resolution measurements are made by timing ions moving through a gridless cylindrically symmetric linear electric field. 8 figs.

  11. Linear electric field mass spectrometry

    DOE Patents [OSTI]

    McComas, David J.; Nordholt, Jane E.

    1992-01-01

    A mass spectrometer and methods for mass spectrometry. The apparatus is compact and of low weight and has a low power requirement, making it suitable for use on a space satellite and as a portable detector for the presence of substances. High mass resolution measurements are made by timing ions moving through a gridless cylindrically symmetric linear electric field.

  12. Apparatuses and methods for generating electric fields

    DOE Patents [OSTI]

    Scott, Jill R; McJunkin, Timothy R; Tremblay, Paul L

    2013-08-06

    Apparatuses and methods relating to generating an electric field are disclosed. An electric field generator may include a semiconductive material configured in a physical shape substantially different from a shape of an electric field to be generated thereby. The electric field is generated when a voltage drop exists across the semiconductive material. A method for generating an electric field may include applying a voltage to a shaped semiconductive material to generate a complex, substantially nonlinear electric field. The shape of the complex, substantially nonlinear electric field may be configured for directing charged particles to a desired location. Other apparatuses and methods are disclosed.

  13. PIC simulation of electrodeless plasma thruster with rotating electric field

    SciTech Connect (OSTI)

    Nomura, Ryosuke; Ohnishi, Naofumi; Nishida, Hiroyuki

    2012-11-27

    For longer lifetime of electric propulsion system, an electrodeless plasma thruster with rotating electric field have been proposed utilizing a helicon plasma source. The rotating electric field may produce so-called Lissajous acceleration of helicon plasma in the presence of diverging magnetic field through a complicated mechanism originating from many parameters. Two-dimensional simulations of the Lissajous acceleration were conducted by a code based on Particle-In-Cell (PIC) method and Monte Carlo Collision (MCC) method for understanding plasma motion in acceleration area and for finding the optimal condition. Obtained results show that azimuthal current depends on ratio of electron drift radius to plasma region length, AC frequency, and axial magnetic field. When ratio of cyclotron frequency to the AC frequency is higher than unity, reduction of the azimuthal current by collision effect is little or nothing.

  14. Self-field effects on instability of wave modes in a two-stream free-electron laser with an axial magnetic field

    SciTech Connect (OSTI)

    Mohsenpour, Taghi Rezaee Rami, Omme Kolsoum

    2014-07-15

    Free electron lasers (FEL) play major roles in the Raman Regime, due to the charge and current densities of the beam self-field. The method of perturbation has been applied to study the influence of self-electric and self-magnetic fields. A dispersion relation for two-stream free electron lasers with a helical wiggler and an axial magnetic field has been found. This dispersion relation is solved numerically to investigate the influence of self-fields on the FEL coupling and the two-stream instability. It was found that self-fields can produce very large effects on the FEL coupling, but they have almost negligible effects on two-stream instability.

  15. Radiofrequency hydrogen ion source with permanent magnets providing axial magnetic field

    SciTech Connect (OSTI)

    Oikawa, Kohei Saito, Yuta; Komizunai, Shota; Takahashi, Kazunori; Ando, Akira

    2014-02-15

    Uniform axial magnetic field of about 70 G is applied to a radiofrequency (rf) hydrogen ion source by arrays of permanent magnets. The plasma density and electron temperature downstream of the source and near the magnetic filter are compared with those in the previously described ion source, where the axial field has been applied by two solenoids. The source is operated at ∼350 kHz and above 10 kW rf power with a field-effect-transistor-based invertor power supply in 1.5 Pa hydrogen. The results show that the plasma density of ∼10{sup 19} m{sup −3} near the source exit and ∼10{sup 18} m{sup −3} near the magnetic filter can be obtained, which are higher than those with the solenoids.

  16. Fe XII STALKS AND THE ORIGIN OF THE AXIAL FIELD IN FILAMENT CHANNELS

    SciTech Connect (OSTI)

    Wang, Y.-M.; Sheeley, N. R. Jr.; Stenborg, G. E-mail: neil.sheeley@nrl.navy.mil

    2013-06-10

    Employing Fe XII images and line-of-sight magnetograms, we deduce the direction of the axial field in high-latitude filament channels from the orientation of the adjacent stalklike structures. Throughout the rising phase of the current solar cycle 24, filament channels poleward of latitude 30 Degree-Sign overwhelmingly obeyed the hemispheric chirality rule, being dextral (sinistral) in the northern (southern) hemisphere, corresponding to negative (positive) helicity. During the deep minimum of 2007-2009, the orientation of the Fe XII stalks was often difficult to determine, but no obvious violations of the rule were found. Although the hemispheric trend was still present during the maximum and early declining phase of cycle 23 (2000-2003), several high-latitude exceptions were identified at that time. From the observation that dextral (sinistral) filament channels form through the decay of active regions whose Fe XII features show a counterclockwise (clockwise) whorl, we conclude that the axial field direction is determined by the intrinsic helicity of the active regions. In contrast, generation of the axial field component by the photospheric differential rotation is difficult to reconcile with the observed chirality of polar crown and circular filament channels, and with the presence of filament channels along the equator. The main role of differential rotation in filament channel formation is to expedite the cancellation of flux and thus the removal of the transverse field component. We propose further that, rather than being ejected into the heliosphere, the axial field is eventually resubmerged by flux cancellation as the adjacent unipolar regions become increasingly mixed.

  17. Structures of water molecules in carbon nanotubes under electric fields

    SciTech Connect (OSTI)

    Winarto,; Takaiwa, Daisuke; Yamamoto, Eiji; Yasuoka, Kenji

    2015-03-28

    Carbon nanotubes (CNTs) are promising for water transport through membranes and for use as nano-pumps. The development of CNT-based nanofluidic devices, however, requires a better understanding of the properties of water molecules in CNTs because they can be very different from those in the bulk. Using all-atom molecular dynamics simulations, we investigate the effect of axial electric fields on the structure of water molecules in CNTs having diameters ranging from (7,7) to (10,10). The water dipole moments were aligned parallel to the electric field, which increases the density of water inside the CNTs and forms ordered ice-like structures. The electric field induces the transition from liquid to ice nanotubes in a wide range of CNT diameters. Moreover, we found an increase in the lifetime of hydrogen bonds for water structures in the CNTs. Fast librational motion breaks some hydrogen bonds, but the molecular pairs do not separate and the hydrogen bonds reform. Thus, hydrogen bonds maintain the water structure in the CNTs, and the water molecules move collectively, decreasing the axial diffusion coefficient and permeation rate.

  18. Measurement of the three-dimensional tip region flow field in an axial compressor

    SciTech Connect (OSTI)

    Stauter, R.C. )

    1993-07-01

    A two-color, five-beam LDV system has been configured to make simultaneous three-component velocity measurements of the flow field in a two-stage axial compressor model. The system has been used to make time-resolved measurements both between compressor blade rows and within the rotating blade passages in an axial compressor. The data show the nature and behavior of the complex, three-dimensional flow phenomena present in the tip region of a compressor as the convect downstream. In particular, the nature of the tip leakage vortex is apparent, being manifested by high blockage as well as the expected vortical motion. The data indicate that the radial flows associated with the tip leakage vortex begin to decrease while within the rotor passage, and that they temporarily increase aft of the passage.

  19. Electric and magnetic fields program overview

    SciTech Connect (OSTI)

    1995-09-01

    DOE`s EMF Program is presented. The possibility of biological effects from electromagnetic fields created by electricity is examined. Current research at many National Laboratories is reviewed.

  20. Measurements of the Ion Species of Cathodic Arc Plasma in an Axial Magnetic Field

    SciTech Connect (OSTI)

    Oks, Efim; Anders, Andre

    2010-10-19

    Metal and gas ion species and their charge state distributions were measured for pulsed copper cathodic arcs in argon background gas in the presence of an axial magnetic field. It was found that changing the cathode position relative to anode and ion extraction system as well as increasing the gas pressure did not much affect the arc burning voltage and the related power dissipation. However, the burning voltage and power dissipation greatly increased as the magnetic field strength was increased. The fraction of metal ions and the mean ion charge state were reduced as the discharge length was increased. The observations can be explained by the combination of charge exchange collisions and electron impact ionization. They confirm that previously published data on characteristic material-dependent charge state distributions (e.g., Anders and Yushkov, J. Appl. Phys., Vol. 91, pp. 4824-4832, 2002) are not universal but valid for high vacuum conditions and the specifics of the applied magnetic fields.

  1. Space charge field in a FEL with axially symmetric electron beam

    SciTech Connect (OSTI)

    Goncharov, I.A.; Belyavskiy, E.D.

    1995-12-31

    Nonlinear two-dimensional theory of the space charge of an axially symmetric electron beam propagating in combined right-hand polarized wiggler and uniform axial guide fields in a presence of high-frequency electromagnetic wave is presented. The well-known TE{sub 01} mode in a cylindrical waveguide for the model of radiation fields and paraxial approximation for the wiggler field are used. Space charge field components are written in the Lagrange coordinates by the twice averaged Green`s functions of two equally charged infinitely thin discs. For that {open_quotes}compensating charges{close_quotes} method is applied in which an electron ring model is substituted by one with two different radii and signs discs. On this approach the initial Green`s functions peculiarities are eliminated and all calculations are considerably simplified. Coefficients of a twice averaged Green`s function expansion into a Fourier series are obtained by use of corresponding expansion coefficients of longitudinal Green`s functions of equal radii discs and identical rings known from the one-dimensional theory of super HF devices taking into account electron bunches periodicity. This approach permit the space charge field components for an arbitrary stratified stream to be expressed in a simple and strict enough form. The expressions obtained can be employed in a nonlinear two-dimensional FEL theory in order to investigate beam dynamical defocusing and electrons failing on the waveguide walls in the high gain regime. This is especially important for FEL operation in mm and submm.

  2. Nanomechanical electric and electromagnetic field sensor

    SciTech Connect (OSTI)

    Datskos, Panagiotis George; Lavrik, Nickolay

    2015-03-24

    The present invention provides a system for detecting and analyzing at least one of an electric field and an electromagnetic field. The system includes a micro/nanomechanical oscillator which oscillates in the presence of at least one of the electric field and the electromagnetic field. The micro/nanomechanical oscillator includes a dense array of cantilevers mounted to a substrate. A charge localized on a tip of each cantilever interacts with and oscillates in the presence of the electric and/or electromagnetic field. The system further includes a subsystem for recording the movement of the cantilever to extract information from the electric and/or electromagnetic field. The system further includes a means of adjusting a stiffness of the cantilever to heterodyne tune an operating frequency of the system over a frequency range.

  3. Electric/magnetic field sensor

    DOE Patents [OSTI]

    Schill, Jr., Robert A.; Popek, Marc [Las Vegas, NV

    2009-01-27

    A UNLV novel electric/magnetic dot sensor includes a loop of conductor having two ends to the loop, a first end and a second end; the first end of the conductor seamlessly secured to a first conductor within a first sheath; the second end of the conductor seamlessly secured to a second conductor within a second sheath; and the first sheath and the second sheath positioned adjacent each other. The UNLV novel sensor can be made by removing outer layers in a segment of coaxial cable, leaving a continuous link of essentially uncovered conductor between two coaxial cable legs.

  4. Exact analysis of particle dynamics in combined field of finite duration laser pulse and static axial magnetic field

    SciTech Connect (OSTI)

    Sagar, Vikram; Sengupta, Sudip; Kaw, Predhiman [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)

    2012-11-15

    Dynamics of a charged particle is studied in the field of a relativistically intense linearly polarized finite duration laser pulse in the presence of a static axial magnetic field. For a finite duration laser pulse whose temporal shape is defined by Gaussian profile, exact analytical expressions are derived for the particle trajectory, momentum, and energy as function of laser phase. From the solutions, it is shown that, unlike for the monochromatic plane wave case, resonant phase locking time between the particle and laser pulse is finite. The net energy transferred to the particle does not increase monotonically but tends to saturate. It is further shown that appropriate tuning of cyclotron frequency of the particle with the characteristic frequency in the pulse spectrum can lead to the generation of accelerated particles with variable energies in MeV-TeV range.

  5. Crystal growth under external electric fields

    SciTech Connect (OSTI)

    Uda, Satoshi; Koizumi, Haruhiko; Nozawa, Jun; Fujiwara, Kozo

    2014-10-06

    This is a review article concerning the crystal growth under external electric fields that has been studied in our lab for the past 10 years. An external field is applied electrostatically either through an electrically insulating phase or a direct injection of an electric current to the solid-interface-liquid. The former changes the chemical potential of both solid and liquid and controls the phase relationship while the latter modifies the transport and partitioning of ionic solutes in the oxide melt during crystallization and changes the solute distribution in the crystal.

  6. Biological effects of electric fields: EPRI's role

    SciTech Connect (OSTI)

    Kavet, R.

    1982-07-01

    Since 1973 the Electric Power Research Institute (EPRI) has supported research to evaluate the biological effects which may result from exposure to electric fields produced by AC overhead transmission lines; more recently, EPRI has also begun DC research. Through 1981 EPRI will have expended $8.7M on these efforts. Ongoing AC projects are studying a variety of lifeforms exposed to electric fields; these include humans, miniature swine, rats, honeybees, chick embryos, and crops. The status of these projects is discussed. The DC program has not as yet produced data. These studies will add to the current data base so as to enable a more complete assessment of health risks which may be associated with exposure to electric fields at power frequencies.

  7. Electric field induced spin-polarized current

    DOE Patents [OSTI]

    Murakami, Shuichi; Nagaosa, Naoto; Zhang, Shoucheng

    2006-05-02

    A device and a method for generating an electric-field-induced spin current are disclosed. A highly spin-polarized electric current is generated using a semiconductor structure and an applied electric field across the semiconductor structure. The semiconductor structure can be a hole-doped semiconductor having finite or zero bandgap or an undoped semiconductor of zero bandgap. In one embodiment, a device for injecting spin-polarized current into a current output terminal includes a semiconductor structure including first and second electrodes, along a first axis, receiving an applied electric field and a third electrode, along a direction perpendicular to the first axis, providing the spin-polarized current. The semiconductor structure includes a semiconductor material whose spin orbit coupling energy is greater than room temperature (300 Kelvin) times the Boltzmann constant. In one embodiment, the semiconductor structure is a hole-doped semiconductor structure, such as a p-type GaAs semiconductor layer.

  8. Dynamics of multiple viscoelastic carbon nanotube based nanocomposites with axial magnetic field

    SciTech Connect (OSTI)

    Karli?i?, Danilo; Caji?, Milan; Murmu, Tony; Kozi?, Predrag; Adhikari, Sondipon

    2014-06-21

    Nanocomposites and magnetic field effects on nanostructures have received great attention in recent years. A large amount of research work was focused on developing the proper theoretical framework for describing many physical effects appearing in structures on nanoscale level. Great step in this direction was successful application of nonlocal continuum field theory of Eringen. In the present paper, the free transverse vibration analysis is carried out for the system composed of multiple single walled carbon nanotubes (MSWCNT) embedded in a polymer matrix and under the influence of an axial magnetic field. Equivalent nonlocal model of MSWCNT is adopted as viscoelastically coupled multi-nanobeam system (MNBS) under the influence of longitudinal magnetic field. Governing equations of motion are derived using the Newton second low and nonlocal Rayleigh beam theory, which take into account small-scale effects, the effect of nanobeam angular acceleration, internal damping and Maxwell relation. Explicit expressions for complex natural frequency are derived based on the method of separation of variables and trigonometric method for the Clamped-Chain system. In addition, an analytical method is proposed in order to obtain asymptotic damped natural frequency and the critical damping ratio, which are independent of boundary conditions and a number of nanobeams in MNBS. The validity of obtained results is confirmed by comparing the results obtained for complex frequencies via trigonometric method with the results obtained by using numerical methods. The influence of the longitudinal magnetic field on the free vibration response of viscoelastically coupled MNBS is discussed in detail. In addition, numerical results are presented to point out the effects of the nonlocal parameter, internal damping, and parameters of viscoelastic medium on complex natural frequencies of the system. The results demonstrate the efficiency of the suggested methodology to find the closed form

  9. Gas storage and separation by electric field swing adsorption...

    Office of Scientific and Technical Information (OSTI)

    Data Explorer Search Results Gas storage and separation by electric field swing adsorption Title: Gas storage and separation by electric field swing adsorption Gases are stored, ...

  10. Electric field controlled emulsion phase contactor

    DOE Patents [OSTI]

    Scott, T.C.

    1995-01-31

    A system is described for contacting liquid phases comprising a column for transporting a liquid phase contacting system, the column having upper and lower regions. The upper region has a nozzle for introducing a dispersed phase and means for applying thereto a vertically oriented high intensity pulsed electric field. This electric field allows improved flow rates while shattering the dispersed phase into many micro-droplets upon exiting the nozzle to form a dispersion within a continuous phase. The lower region employs means for applying to the dispersed phase a horizontally oriented high intensity pulsed electric field so that the dispersed phase undergoes continuous coalescence and redispersion while being urged from side to side as it progresses through the system, increasing greatly the mass transfer opportunity. 5 figs.

  11. Electric field controlled emulsion phase contactor

    DOE Patents [OSTI]

    Scott, Timothy C.

    1995-01-01

    A system for contacting liquid phases comprising a column for transporting a liquid phase contacting system, the column having upper and lower regions. The upper region has a nozzle for introducing a dispersed phase and means for applying thereto a vertically oriented high intensity pulsed electric field. This electric field allows improved flow rates while shattering the dispersed phase into many micro-droplets upon exiting the nozzle to form a dispersion within a continuous phase. The lower region employs means for applying to the dispersed phase a horizontally oriented high intensity pulsed electric field so that the dispersed phase undergoes continuous coalescence and redispersion while being urged from side to side as it progresses through the system, increasing greatly the mass transfer opportunity.

  12. Axial interaction free-electron laser

    DOE Patents [OSTI]

    Carlsten, B.E.

    1997-09-02

    Electron orbits from a helical axial wiggler in an axial guide field are absolutely unstable as power is extracted from the particles. For off-axis beams an axial FEL mechanism exists when the axial electric field in a TM mode is wiggled to interact with the axial velocity of the electrons that form the beam. The interaction strength is comparable to that for helical FELs and is insensitive to beam orbit errors. The orbits for this mechanism are extremely stable in the absence of space charge and lead to high extraction efficiencies without particle phasing incoherence or interception. This interaction mechanism is suitable for use with intense annular electron beams for high power generation at microwave frequencies. 5 figs.

  13. Axial interaction free-electron laser

    DOE Patents [OSTI]

    Carlsten, Bruce E.

    1997-01-01

    Electron orbits from a helical axial wiggler in an axial guide field are absolutely unstable as power is extracted from the particles. For off-axis beams an axial FEL mechanism exists when the axial electric field in a TM mode is wiggled to interact with the axial velocity of the electrons that form the beam. The interaction strength is comparable to that for helical FELs and is insensitive to beam orbit errors. The orbits for this mechanism are extremely stable in the absence of space charge and lead to high extraction efficiencies without particle phasing incoherence or interception. This interaction mechanism is suitable for use with intense annular electron beams for high power generation at microwave frequencies.

  14. Electric cartridge-type heater for producing a given non-uniform axial power distribution

    DOE Patents [OSTI]

    Clark, D.L.; Kress, T.S.

    1975-10-14

    An electric cartridge heater is provided to simulate a reactor fuel element for use in safety and thermal-hydraulic tests of model nuclear reactor systems. The electric heat-generating element of the cartridge heater consists of a specifically shaped strip of metal cut with variable width from a flat sheet of the element material. When spirally wrapped around a mandrel, the strip produces a coiled element of the desired length and diameter. The coiled element is particularly characterized by an electrical resistance that varies along its length due to variations in strip width. Thus, the cartridge heater is constructed such that it will produce a more realistic simulation of the actual nonuniform (approximately ''chopped'' cosine) power distribution of a reactor fuel element.

  15. Method of electric field flow fractionation wherein the polarity of the electric field is periodically reversed

    DOE Patents [OSTI]

    Stevens, Fred J. (Naperville, IL)

    1992-01-01

    A novel method of electric field flow fractionation for separating solute molecules from a carrier solution is disclosed. The method of the invention utilizes an electric field that is periodically reversed in polarity, in a time-dependent, wave-like manner. The parameters of the waveform, including amplitude, frequency and wave shape may be varied to optimize separation of solute species. The waveform may further include discontinuities to enhance separation.

  16. Signatures of confinement in axial gauge QCD

    SciTech Connect (OSTI)

    Lenz, F.; Moniz, Ernest J.; Thies, M.

    1995-09-01

    A comparative dynamical study of axial gauge QED and QCD is presented. Elementary excitations associated with particular field configurations are investigated. Gluonic excitations analogous to linearly polarized photons are shown to acquire infinite energy. Suppression of this class of excitations in QCD results from quantization of the chromo-electric flux and is interpreted as a dual Meissner effect, i.e., as expulsion from the QCD vacuum of chromo-electric fields which are constant over significant distances. This interpretation is supported by a comparative evaluation of the interaction energy of static charges in the axial gauge representation of QED and QCD. {copyright} 1995 Academic Press, Inc.

  17. Arrangement for measuring the field angle of a magnetic field as a function of axial position within a magnet bore tube

    DOE Patents [OSTI]

    Pidcoe, Stephen V.; Zink, Roger A.; Boroski, William N.; McCaw, William R.

    1993-01-01

    An arrangement for measuring the field angle of a magnetic field as a function of axial position within a magnet bore tube of a magnet such as is used with the Superconducting Super Collider (SSC). The arrangement includes a magnetic field alignment gauge that is carried through the magnet bore tube by a positioning shuttle in predetermined increments. The positioning shuttle includes an extensible body assembly which is actuated by an internal piston arrangement. A pair of spaced inflatable cuffs are carried by the body assembly and are selectively actuated in cooperation with pressurizing of the piston to selectively drive the positioning shuttle in an axial direction. Control of the shuttle is provided by programmed electronic computer means located exteriorly of the bore tube and which controls valves provided pressurized fluid to the inflatable cuss and the piston arrangement.

  18. Spin relaxation and linear-in-electric-field frequency shift...

    Office of Scientific and Technical Information (OSTI)

    Country of Publication: United States Language: English Subject: 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; APPROXIMATIONS; DIFFUSION; ELECTRIC FIELDS; GEOMETRY; MAGNETIC FIELDS; ...

  19. Two-dimensional simulations of thermonuclear burn in ignition-scale inertial confinement fusion targets under compressed axial magnetic fields

    SciTech Connect (OSTI)

    Perkins, L. J.; Logan, B. G.; Zimmerman, G. B.; Werner, C. J.

    2013-07-15

    We report for the first time on full 2-D radiation-hydrodynamic implosion simulations that explore the impact of highly compressed imposed magnetic fields on the ignition and burn of perturbed spherical implosions of ignition-scale cryogenic capsules. Using perturbations that highly convolute the cold fuel boundary of the hotspot and prevent ignition without applied fields, we impose initial axial seed fields of 20100 T (potentially attainable using present experimental methods) that compress to greater than 4 10{sup 4} T (400 MG) under implosion, thereby relaxing hotspot areal densities and pressures required for ignition and propagating burn by ?50%. The compressed field is high enough to suppress transverse electron heat conduction, and to allow alphas to couple energy into the hotspot even when highly deformed by large low-mode amplitudes. This might permit the recovery of ignition, or at least significant alpha particle heating, in submarginal capsules that would otherwise fail because of adverse hydrodynamic instabilities.

  20. Inhibition of brain tumor cell proliferation by alternating electric fields

    SciTech Connect (OSTI)

    Jeong, Hyesun; Oh, Seung-ick; Hong, Sunghoi E-mail: radioyoon@korea.ac.kr; Sung, Jiwon; Jeong, Seonghoon; Yoon, Myonggeun E-mail: radioyoon@korea.ac.kr; Koh, Eui Kwan

    2014-11-17

    This study was designed to investigate the mechanism by which electric fields affect cell function, and to determine the optimal conditions for electric field inhibition of cancer cell proliferation. Low-intensity (<2 V/cm) and intermediate-frequency (100–300 kHz) alternating electric fields were applied to glioblastoma cell lines. These electric fields inhibited cell proliferation by inducing cell cycle arrest and abnormal mitosis due to the malformation of microtubules. These effects were significantly dependent on the intensity and frequency of applied electric fields.

  1. Computer Calculations of Eddy-Current Power Loss in Rotating Titanium Wheels and Rims in Localized Axial Magnetic Fields

    SciTech Connect (OSTI)

    Mayhall, D J; Stein, W; Gronberg, J B

    2006-05-15

    We have performed preliminary computer-based, transient, magnetostatic calculations of the eddy-current power loss in rotating titanium-alloy and aluminum wheels and wheel rims in the predominantly axially-directed, steady magnetic fields of two small, solenoidal coils. These calculations have been undertaken to assess the eddy-current power loss in various possible International Linear Collider (ILC) positron target wheels. They have also been done to validate the simulation code module against known results published in the literature. The commercially available software package used in these calculations is the Maxwell 3D, Version 10, Transient Module from the Ansoft Corporation.

  2. Limiting current of axisymmetric relativistic charged-particle beam propagating in strong axial magnetic field in coaxial drift tube

    SciTech Connect (OSTI)

    Yatsenko, T.; Ilyenko, K.; Sotnikov, G. V.

    2012-06-15

    In the strong axial magnetic field approximation, we calculate the space-charge limited (SCL) current of axisymmetric relativistic charged-particle beam in a coaxial drift tube of finite length. Results are compared to analytical estimates and numerical modeling of SCL current in the infinitely long drift tube. For the infinitely long drift tube, which inner conductor is biased and the outer conductor is lined with a finite-width dielectric insert, analytic approximations for the SCL current in the bias voltage are developed.

  3. Liquid methanol under a static electric field

    SciTech Connect (OSTI)

    Cassone, Giuseppe; Giaquinta, Paolo V.; Saija, Franz; Saitta, A. Marco

    2015-02-07

    We report on an ab initio molecular dynamics study of liquid methanol under the effect of a static electric field. We found that the hydrogen-bond structure of methanol is more robust and persistent for field intensities below the molecular dissociation threshold whose value (?0.31 V/) turns out to be moderately larger than the corresponding estimate obtained for liquid water. A sustained ionic current, with ohmic current-voltage behavior, flows in this material for field intensities above 0.36 V/, as is also the case of water, but the resulting ionic conductivity (?0.40 S cm{sup ?1}) is at least one order of magnitude lower than that of water, a circumstance that evidences a lower efficiency of proton transfer processes. We surmise that this study may be relevant for the understanding of the properties and functioning of technological materials which exploit ionic conduction, such as direct-methanol fuel cells and Nafion membranes.

  4. Linear electric field time-of-flight ion mass spectrometer

    DOE Patents [OSTI]

    Funsten, Herbert O.; Feldman, William C.

    2008-06-10

    A linear electric field ion mass spectrometer having an evacuated enclosure with means for generating a linear electric field located in the evacuated enclosure and means for injecting a sample material into the linear electric field. A source of pulsed ionizing radiation injects ionizing radiation into the linear electric field to ionize atoms or molecules of the sample material, and timing means determine the time elapsed between ionization of atoms or molecules and arrival of an ion out of the ionized atoms or molecules at a predetermined position.

  5. Electric field effects in liquid crystals with dielectric dispersion

    SciTech Connect (OSTI)

    Lavrentovich, Oleg D.

    2014-11-29

    The project is focused on the experimental and theoretical exploration of the coupling of an externally applied electric field and a nematic liquid crystal.

  6. Built-in Electric Field Induced Mechanical Property Change at...

    Office of Scientific and Technical Information (OSTI)

    and nanoelectromechanical systems, but relatively unexplored for nanoscale materials. ... electric field and the mechanical properties on the nanoscale for perovskite materials. ...

  7. Quantum Confinement Induced Oscillatory Electric Field on a Stepped...

    Office of Scientific and Technical Information (OSTI)

    surface of the wedge-shaped Pb(111) films. The alternating electric field has significant influence on surface reactivity, leading to selective even- or odd-layer adsorption...

  8. Phase Equilibria Modification by Electric Fields (Technical Report...

    Office of Scientific and Technical Information (OSTI)

    and solid-liquid systems under electric fields. ... be used to process liquid waste or contaminated groundwater ... Sponsoring Org: USDOE Office of Environmental Management ...

  9. Spin relaxation and linear-in-electric-field frequency shift...

    Office of Scientific and Technical Information (OSTI)

    arbitrary, time-independent magnetic field Citation Details In-Document Search Title: Spin relaxation and linear-in-electric-field frequency shift in an arbitrary, time-independen...

  10. High-frequency electric field measurement using a toroidal antenna

    DOE Patents [OSTI]

    Lee, Ki Ha

    2002-01-01

    A simple and compact method and apparatus for detecting high frequency electric fields, particularly in the frequency range of 1 MHz to 100 MHz, uses a compact toroidal antenna. For typical geophysical applications the sensor will be used to detect electric fields for a wide range of spectrum starting from about 1 MHz, in particular in the frequency range between 1 to 100 MHz, to detect small objects in the upper few meters of the ground. Time-varying magnetic fields associated with time-varying electric fields induce an emf (voltage) in a toroidal coil. The electric field at the center of (and perpendicular to the plane of) the toroid is shown to be linearly related to this induced voltage. By measuring the voltage across a toroidal coil one can easily and accurately determine the electric field.

  11. Fracture and buckling of piezoelectric nanowires subject to an electric field

    SciTech Connect (OSTI)

    Zhang, Jin; Wang, Chengyuan Adhikari, Sondipon

    2013-11-07

    Fracture and buckling are major failure modes of thin and long nanowires (NWs), which could be affected significantly by an electric field when piezoelectricity is involved in the NWs. This paper aims to examine the issue based on the molecular dynamics simulations, where the gallium nitride (GaN) NWs are taken as an example. The results show that the influence of the electric field is strong for the fracture and the critical buckling strains, detectable for the fracture strength but almost negligible for the critical buckling stress. In addition, the reversed effects are achieved for the fracture and the critical buckling strains. Subsequently, the Timoshenko beam model is utilized to account for the effect of the electric field on the axial buckling of the GaN NWs, where nonlocal effect is observed and characterized by the nonlocal coefficient e{sub 0}a=1.1 nm. The results show that the fracture and buckling of piezoelectric NWs can be controlled by applying an electric field.

  12. Electric Field Control of Local Ferromagnetism with a Magnetoelectric

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

    Multiferroic Electric Field Control of Local Ferromagnetism with a Magnetoelectric Multiferroic Electric Field Control of Local Ferromagnetism with a Magnetoelectric Multiferroic Print Wednesday, 30 July 2008 00:00 Magnetoelectric multiferroics-materials that simultaneously show some form of magnetic and ferroelectric order-have excited condensed-matter researchers worldwide with the promise of coupling between magnetic and electric order parameters. A Berkeley-Stanford-Swiss group has now

  13. Radial electric field 3D modeling for wire arrays driving dynamic hohlraums on Z.

    SciTech Connect (OSTI)

    Mock, Raymond Cecil

    2007-06-01

    The anode-cathode structure of the Z-machine wire array results in a higher negative radial electric field (Er) on the wires near the cathode relative to the anode. The magnitude of this field has been shown to anti-correlate with the axial radiation top/bottom symmetry in the DH (Dynamic Hohlraum). Using 3D modeling, the structure of this field is revealed for different wire-array configurations and for progressive mechanical alterations, providing insight for minimizing the negative Er on the wire array in the anode-to-cathode region of the DH. Also, the 3D model is compared to Sasorov's approximation, which describes Er at the surface of the wire in terms of wire-array parameters.

  14. Analytic treatment of vortex states in cylindrical superconductors in applied axial magnetic field

    SciTech Connect (OSTI)

    Ludu, A.; Van Deun, J.; Cuyt, A.; Milosevic, M. V.; Peeters, F. M.

    2010-08-15

    We solve the linear Ginzburg-Landau (GL) equation in the presence of a uniform magnetic field with cylindrical symmetry and we find analytic expressions for the eigenfunctions in terms of the confluent hypergeometric functions. The discrete spectrum results from an implicit equation associated to the boundary conditions and it is resolved in analytic form using the continued fractions formalism. We study the dependence of the spectrum and the eigenfunctions on the sample size and the surface conditions for solid and hollow cylindrical superconductors. Finally, the solutions of the nonlinear GL formalism are constructed as expansions in the linear GL eigenfunction basis and selected by minimization of the free energy. We present examples of vortex states and their energies for different samples in enhancing/suppressing superconductivity surroundings.

  15. The hydrogen atom in plasmas with an external electric field

    SciTech Connect (OSTI)

    Bahar, M. K.; Soylu, A.

    2014-09-15

    We numerically solve the Schrdinger equation, using a more general exponential cosine screened Coulomb (MGECSC) potential with an electric field, in order to investigate the screening and weak external electric field effects on the hydrogen atom in plasmas. The MGECSC potential is examined for four different cases, corresponding to different screening parameters of the potential and the external electric field. The influences of the different screening parameters and the weak external electric field on the energy eigenvalues are determined by solving the corresponding equations using the asymptotic iteration method (AIM). It is found that the corresponding energy values shift when a weak external electric field is applied to the hydrogen atom in a plasma. This study shows that a more general exponential cosine screened Coulomb potential allows the influence of an applied, weak, external electric field on the hydrogen atom to be investigated in detail, for both Debye and quantum plasmas simultaneously. This suggests that such a potential would be useful in modeling similar effects in other applications of plasma physics, and that AIM is an appropriate method for solving the Schrdinger equation, the solution of which becomes more complex due to the use of the MGECSC potential with an applied external electric field.

  16. Electric Field Control of Local Ferromagnetism with a Magnetoelectric

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

    Multiferroic Electric Field Control of Local Ferromagnetism with a Magnetoelectric Multiferroic Print Magnetoelectric multiferroics-materials that simultaneously show some form of magnetic and ferroelectric order-have excited condensed-matter researchers worldwide with the promise of coupling between magnetic and electric order parameters. A Berkeley-Stanford-Swiss group has now used the multiferroic bismuth-iron-oxygen compound BiFeO3 (BFO) to explore electrical control of magnetism through

  17. Electric Field Control of Local Ferromagnetism with a Magnetoelectric

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

    Multiferroic Electric Field Control of Local Ferromagnetism with a Magnetoelectric Multiferroic Print Magnetoelectric multiferroics-materials that simultaneously show some form of magnetic and ferroelectric order-have excited condensed-matter researchers worldwide with the promise of coupling between magnetic and electric order parameters. A Berkeley-Stanford-Swiss group has now used the multiferroic bismuth-iron-oxygen compound BiFeO3 (BFO) to explore electrical control of magnetism through

  18. Electric Field Control of Local Ferromagnetism with a Magnetoelectric

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

    Multiferroic Electric Field Control of Local Ferromagnetism with a Magnetoelectric Multiferroic Print Magnetoelectric multiferroics-materials that simultaneously show some form of magnetic and ferroelectric order-have excited condensed-matter researchers worldwide with the promise of coupling between magnetic and electric order parameters. A Berkeley-Stanford-Swiss group has now used the multiferroic bismuth-iron-oxygen compound BiFeO3 (BFO) to explore electrical control of magnetism through

  19. Electric Field Control of Local Ferromagnetism with a Magnetoelectric

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

    Multiferroic Electric Field Control of Local Ferromagnetism with a Magnetoelectric Multiferroic Print Magnetoelectric multiferroics-materials that simultaneously show some form of magnetic and ferroelectric order-have excited condensed-matter researchers worldwide with the promise of coupling between magnetic and electric order parameters. A Berkeley-Stanford-Swiss group has now used the multiferroic bismuth-iron-oxygen compound BiFeO3 (BFO) to explore electrical control of magnetism through

  20. Electric Field Control of Local Ferromagnetism with a Magnetoelectric

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

    Multiferroic Electric Field Control of Local Ferromagnetism with a Magnetoelectric Multiferroic Print Magnetoelectric multiferroics-materials that simultaneously show some form of magnetic and ferroelectric order-have excited condensed-matter researchers worldwide with the promise of coupling between magnetic and electric order parameters. A Berkeley-Stanford-Swiss group has now used the multiferroic bismuth-iron-oxygen compound BiFeO3 (BFO) to explore electrical control of magnetism through

  1. Electric Field Control of Local Ferromagnetism with a Magnetoelectric

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

    Multiferroic Electric Field Control of Local Ferromagnetism with a Magnetoelectric Multiferroic Print Magnetoelectric multiferroics-materials that simultaneously show some form of magnetic and ferroelectric order-have excited condensed-matter researchers worldwide with the promise of coupling between magnetic and electric order parameters. A Berkeley-Stanford-Swiss group has now used the multiferroic bismuth-iron-oxygen compound BiFeO3 (BFO) to explore electrical control of magnetism through

  2. Insurance for electric and magnetic field litigation: Are you covered

    SciTech Connect (OSTI)

    Anderson, E.R.; Stewart, C.A. III

    1993-04-01

    Electrical power generating companies, power transmission companies and large generators and users of electrical power recently felt the sting of a second shock. The first shock came when lawsuits were first filed against companies in the electrical power industry claiming real or imagined damages from electrical and magnetic fields ([open quotes]EMFs[close quotes]). The new and second shock is potentially more devastating because it comes from the [open quotes]safe hands[close quotes] of the insurance industry. Standard-form comprehensive general liability ([open quotes]CGL[close quotes]) insurance policies purchased by nearly every company in the electrical power industry for generations are supposed to cover EMF bodily injury and property damage claims. Not so, say the lawyers for the most prominent insurance company selling insurance coverage to electric utilities, Associated Electric Gas Insurance Services, Ltd. ([open quotes]AEGIS[close quotes]).

  3. Demonstrating Strong Electric Fields in Liquid Helium for Tests...

    Office of Science (SC) Website

    Image courtesy of Los Alamos National Laboratory The Medium Scale High Voltage Test apparatus in TA-53 Building 10 allowed scientists to test electric fields in liquid helium, a ...

  4. Vacuum gaps with small tunnel currents at large electric field...

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

    small tunnel currents at large electric field and its potential applications for energy storage, charge storage and power supplies. Friday, May 27, 2011 - 4:00pm SSRL Conference...

  5. Axial magnetic field and toroidally streaming fast ions in the dense plasma focus are natural consequences of conservation laws in the curved axisymmetric geometry of the current sheath

    SciTech Connect (OSTI)

    Auluck, S. K. H.

    2014-10-15

    Direct measurement of axial magnetic field in the PF-1000 dense plasma focus (DPF), and its reported correlation with neutron emission, call for a fresh look at previous reports of existence of axial magnetic field component in the DPF from other laboratories, and associated data suggesting toroidal directionality of fast ions participating in fusion reactions, with a view to understand the underlying physics. In this context, recent work dealing with application of the hyperbolic conservation law formalism to the DPF is extended in this paper to a curvilinear coordinate system, which reflects the shape of the DPF current sheath. Locally unidirectional shock propagation in this coordinate system enables construction of a system of 7 one-dimensional hyperbolic conservation law equations with geometric source terms, taking into account all the components of magnetic field and flow velocity. Rankine-Hugoniot jump conditions for this system lead to expressions for the axial magnetic field and three components of fluid velocity having high ion kinetic energy.

  6. Electric field effect in ultrathin black phosphorus

    SciTech Connect (OSTI)

    Koenig, Steven P.; Schmidt, Hennrik; Doganov, Rostislav A.; Castro Neto, A. H.; Özyilmaz, Barbaros

    2014-03-10

    Black phosphorus exhibits a layered structure similar to graphene, allowing mechanical exfoliation of ultrathin single crystals. Here, we demonstrate few-layer black phosphorus field effect devices on Si/SiO{sub 2} and measure charge carrier mobility in a four-probe configuration as well as drain current modulation in a two-point configuration. We find room-temperature mobilities of up to 300 cm{sup 2}/Vs and drain current modulation of over 10{sup 3}. At low temperatures, the on-off ratio exceeds 10{sup 5}, and the device exhibits both electron and hole conduction. Using atomic force microscopy, we observe significant surface roughening of thin black phosphorus crystals over the course of 1 h after exfoliation.

  7. Electric and magnetic field reduction by alternative transmission line options

    SciTech Connect (OSTI)

    Stewart, J.R. ); Dale, S.J. ); Klein, K.W. )

    1991-01-01

    Ground level electric, and more recently magnetic, fields from overhead power transmission lines are increasingly important considerations in right of way specification, with states setting or planning to set edge of right of way limits. Research has been conducted in high phase order power transmission wherein six of twelve phases are used to transmit power in less physical space and with reduced electrical environmental effects than conventional designs. The first magnetic field testing, as reported in this paper, has verified predictive methods for determination of magnetic fields from high phase order lines. Based on these analytical methods, field profiles have been determined for lines of different phase order of comparable power capacity. Potential advantages of high phase order as a means of field mitigation are discussed. 10 refs., 12 figs., 3 tabs.

  8. Method of using an electric field controlled emulsion phase contactor

    DOE Patents [OSTI]

    Scott, Timothy C.

    1993-01-01

    A system for contacting liquid phases comprising a column for transporting a liquid phase contacting system, the column having upper and lower regions. The upper region has a nozzle for introducing a dispersed phase and means for applying thereto a vertically oriented high intensity pulsed electric field. This electric field allows improved flow rates while shattering the dispersed phase into many micro-droplets upon exiting the nozzle to form a dispersion within a continuous phase. The lower region employs means for applying to the dispersed phase a horizontally oriented high intensity pulsed electric field so that the dispersed phase undergoes continuous coalescence and redispersion while being urged from side to side as it progresses through the system, increasing greatly the mass transfer opportunity.

  9. Method of using an electric field controlled emulsion phase contactor

    DOE Patents [OSTI]

    Scott, T.C.

    1993-11-16

    A system is described for contacting liquid phases comprising a column for transporting a liquid phase contacting system, the column having upper and lower regions. The upper region has a nozzle for introducing a dispersed phase and means for applying thereto a vertically oriented high intensity pulsed electric field. This electric field allows improved flow rates while shattering the dispersed phase into many micro-droplets upon exiting the nozzle to form a dispersion within a continuous phase. The lower region employs means for applying to the dispersed phase a horizontally oriented high intensity pulsed electric field so that the dispersed phase undergoes continuous coalescence and redispersion while being urged from side to side as it progresses through the system, increasing greatly the mass transfer opportunity. 5 figures.

  10. Small animal electric and magnetic field exposure systems. Final report

    SciTech Connect (OSTI)

    Patterson, R.C.; Dietrich, F.M.

    1993-10-01

    Laboratory evaluation of electric and magnetic fields (EMF) and cancer in animals requires exposure of relatively large numbers of animals, usually rats or mice, to 60-Hz fields under very well controlled conditions for periods of up to two years. This report describes two exposure systems, the first of which is based on modifications of an existing electric field exposure system to include magnetic field exposure capability. In this system, each module houses 576--768 mice, which can be exposed to electric field levels of up to 100 kV/m and magnetic field levels of up to 10 Gauss. When a module was operated at 10 Gauss, measured levels of noise and vibration fell substantially below the detection threshold for humans. Moreover, temperature rise in the coils did not exceed 12{degrees}C at the 10 Gauss level. Specifications and test results for the second system, which provides magnetic field exposure capability only, are similar, except that each module houses 624--780 mice. After installation of the second system at the West Los Angeles Veterans Medical Center in Los Angeles, California, additional results were obtained. This report provides a complete description of the engineering design, specifications, and test results for the completed systems.

  11. Radiation from electrons in graphene in strong electric field

    SciTech Connect (OSTI)

    Yokomizo, N.

    2014-12-15

    We study the interaction of electrons in graphene with the quantized electromagnetic field in the presence of an applied uniform electric field using the Dirac model of graphene. Electronic states are represented by exact solutions of the Dirac equation in the electric background, and amplitudes of first-order Feynman diagrams describing the interaction with the photon field are calculated for massive Dirac particles in both valleys. Photon emission probabilities from a single electron and from a many-electron system at the charge neutrality point are derived, including the angular and frequency dependence, and several limiting cases are analyzed. The pattern of photon emission at the Dirac point in a strong field is determined by an interplay between the nonperturbative creation of electronhole pairs and spontaneous emission, allowing for the possibility of observing the Schwinger effect in measurements of the radiation emitted by pristine graphene under DC voltage.

  12. Electric Field Assisted Assembly of Perpendicular Oriented NanorodSuperlattices

    SciTech Connect (OSTI)

    Ryan, Kevin M.; Mastroianni, Alex; Stancil, Kimani A.; Liu,Haitao; Alivisatos, Paul A.

    2006-04-10

    We observe the assembly of CdS nanorod superlattices by thecombination of a DC electric field and solvent evaporation. In eachelectric field (1 V/um) assisted assembly, CdS nanorods (5 x 30 nm)suspended initially in toluene were observed to align perpendicularly tothe substrate. Azimuthal alignment along the nanorod crystal faces andthe presence of stacking faults indicate that both 2D and 3D assemblieswere formed by a process of controlled super crystal growth.

  13. Ponderomotive force in the presence of electric fields

    SciTech Connect (OSTI)

    Khazanov, G. V.; Krivorutsky, E. N.

    2013-02-15

    This paper presents averaged equations of particle motion in an electromagnetic wave of arbitrary frequency with its wave vector directed along the ambient magnetic field. The particle is also subjected to an E(vector sign) Multiplication-Sign B(vector sign) drift and a background electric field slowly changing in space and acting along the magnetic field line. The fields, wave amplitude, and the wave vector depend on the coordinate along the magnetic field line. The derivations of the ponderomotive forces are done by assuming that the drift velocity in the ambient magnetic field is comparable to the particle velocity. Such a scenario leads to new ponderomotive forces, dependent on the wave magnetic field intensity, and, as a result, to the additional energy exchange between the wave and the plasma particles. It is found that the parallel electric field can lead to the change of the particle-wave energy exchange rate comparable to that produced by the previously discussed ponderomotive forces.

  14. High-frequency electric field measurement using a toroidal antenna

    SciTech Connect (OSTI)

    Lee, K.H.

    1997-01-01

    In this paper the author describes an innovative method of measuring high-frequency electric fields using a toroid. For typical geophysical applications the new sensor will detect electric fields for a wide range of spectrum starting from 1.0 MHz. This window, in particular the lower frequency range between 1.0 to 100 MHz, has not been used for existing electromagnetic or radar systems to detect small objects in the upper few meters of the ground. Ground penetrating radar (GPR) can be used successfully in this depth range if the ground is resistive but most soils are, in fact, conductive (0.01 to 1.0 S/m) rendering GPR inefficient. Other factors controlling the resolution of GPR system for small objects is the spatial averaging inherent in the electric dipole antenna and the scattering caused by soil inhomogeneities of dimensions comparable to the wavelength (and antenna size). For maximum resolution it is desirable to use the highest frequencies but the scattering is large and target identification is poor. Time-varying magnetic fields induce an emf (voltage) in a toroid. The electric field at the center of the toroid is shown to be linearly related to this induced voltage. By measuring the voltage across a toroid one can easily and accurately determine the electric field. The new sensor will greatly simplify the cumbersome procedure involved with GPR measurements with its center frequency less than 100 MHz. The overall size of the toroidal sensor can be as small as a few inches. It is this size advantage that will not only allow easy fabrication and deployment of multi-component devices either on the surface or in a borehole, but it will render greatly improved resolution over conventional systems.

  15. Estimating of pulsed electric fields using optical measurements.

    SciTech Connect (OSTI)

    Flanagan, Timothy McGuire; Chantler, Gary R.

    2013-09-01

    We performed optical electric field measurements ion nanosecond time scales using the electrooptic crystal beta barium borate (BBO). Tests were based on a preliminary bench top design intended to be a proofofprinciple stepping stone towards a modulardesign optical Efield diagnostic that has no metal in the interrogated environment. The long term goal is to field a modular version of the diagnostic in experiments on large scale xray source facilities, or similarly harsh environments.

  16. Study of the electric field formation in a multi-cusped magnetic field

    SciTech Connect (OSTI)

    Liu, Hui Yu, Daren; Wu, Huan; Zhao, Yinjian; Ma, Chengyu; Wang, Di; Wei, Haoyu

    2014-09-15

    The multi-cusped field thruster is a kind of electric thruster adopting a cusped magnetic field to achieve a potentially longer lifetime. It is observed in some experiments that the main electric potential drop forms near the exhaust plane, but the formation mechanism of the electric field in this kind of thrusters is not fully clear yet. Based on the analysis of the electron movement, a 2D Particle-in-Cell plus Monte Carlo model is built to reveal the difference of the constraint to electrons between the central leak path and the lateral region of the thruster. Electron trajectories from cathode are analyzed furthermore. It is found that the central leak path inside the discharge channel may play a significant role in the formation of the main electric potential drop near the exhaust plane.

  17. Nonlinear electric field structures in the inner magnetosphere

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

    Malaspina, D. M.; Andersson, L.; Ergun, R. E.; Wygant, J. R.; Bonnell, J. W.; Kletzing, C.; Reeves, G. D.; Skoug, R. M.; Larsen, B. A.

    2014-08-28

    Recent observations by the Van Allen Probes spacecraft have demonstrated that a variety of electric field structures and nonlinear waves frequently occur in the inner terrestrial magnetosphere, including phase space holes, kinetic field-line resonances, nonlinear whistler-mode waves, and several types of double layer. However, it is nuclear whether such structures and waves have a significant impact on the dynamics of the inner magnetosphere, including the radiation belts and ring current. To make progress toward quantifying their importance, this study statistically evaluates the correlation of such structures and waves with plasma boundaries. A strong correlation is found. These statistical results, combinedmore » with observations of electric field activity at propagating plasma boundaries, are consistent with the identification of these boundaries as the source of free energy responsible for generating the electric field structures and nonlinear waves of interest. Therefore, the ability of these structures and waves to influence plasma in the inner magnetosphere is governed by the spatial extent and dynamics of macroscopic plasma boundaries in that region.« less

  18. Nonlinear electric field structures in the inner magnetosphere

    SciTech Connect (OSTI)

    Malaspina, D. M.; Andersson, L.; Ergun, R. E.; Wygant, J. R.; Bonnell, J. W.; Kletzing, C.; Reeves, G. D.; Skoug, R. M.; Larsen, B. A.

    2014-08-28

    Recent observations by the Van Allen Probes spacecraft have demonstrated that a variety of electric field structures and nonlinear waves frequently occur in the inner terrestrial magnetosphere, including phase space holes, kinetic field-line resonances, nonlinear whistler-mode waves, and several types of double layer. However, it is nuclear whether such structures and waves have a significant impact on the dynamics of the inner magnetosphere, including the radiation belts and ring current. To make progress toward quantifying their importance, this study statistically evaluates the correlation of such structures and waves with plasma boundaries. A strong correlation is found. These statistical results, combined with observations of electric field activity at propagating plasma boundaries, are consistent with the identification of these boundaries as the source of free energy responsible for generating the electric field structures and nonlinear waves of interest. Therefore, the ability of these structures and waves to influence plasma in the inner magnetosphere is governed by the spatial extent and dynamics of macroscopic plasma boundaries in that region.

  19. Gas storage and separation by electric field swing adsorption

    DOE Patents [OSTI]

    Currier, Robert P; Obrey, Stephen J; Devlin, David J; Sansinena, Jose Maria

    2013-05-28

    Gases are stored, separated, and/or concentrated. An electric field is applied across a porous dielectric adsorbent material. A gas component from a gas mixture may be selectively separated inside the energized dielectric. Gas is stored in the energized dielectric for as long as the dielectric is energized. The energized dielectric selectively separates, or concentrates, a gas component of the gas mixture. When the potential is removed, gas from inside the dielectric is released.

  20. Dynamics of lysozyme and its hydration water under electric field

    SciTech Connect (OSTI)

    Favi, Pelagie M; Zhang, Qiu; O'Neill, Hugh Michael; Mamontov, Eugene; Omar Diallo, Souleymane; Palmer, Jeremy

    2014-01-01

    The effects of static electric field on the dynamics of lysozyme and its hydration water have been investigated by means of incoherent quasi-elastic neutron scattering (QENS). Measurements were performed on lysozyme samples, hydrated respectively with heavy water (D2O) to capture the protein dynamics, and with light water (H2O), to probe the dynamics of the hydration shell, in the temperature range from 210 < T < 260 K. The hydration fraction in both cases was about 0.38 gram of water per gram of dry protein. The field strengths investigated were respectively 0 kV/mm and 2 kV/mm ( 2 106 V/m) for the protein hydrated with D2O and 0 kV and 1 kV/mm for the H2O-hydrated counterpart. While the overall internal protons dynamics of the protein appears to be unaffected by the application of electric field up to 2 kV/mm, likely due to the stronger intra-molecular interactions, there is also no appreciable quantitative enhancement of the diffusive dynamics of the hydration water, as would be anticipated based on our recent observations in water confined in silica pores under field values of 2.5 kV/mm. This may be due to the difference in surface interactions between water and the two adsorption hosts (silica and protein), or to the existence of a critical threshold field value Ec 2 3 kV/mm for increased molecular diffusion, for which electrical breakdown is a limitation for our sample.

  1. Electric Power Generation from Co-Produced and Other Oil Field...

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

    Electric Power Generation from Co-Produced and Other Oil Field Fluids Electric Power Generation from Co-Produced and Other Oil Field Fluids Co-produced and low-temperature ...

  2. A Reactive Force Field study of Li/C Systems for Electrical Energy...

    Office of Scientific and Technical Information (OSTI)

    A Reactive Force Field study of LiC Systems for Electrical Energy Storage Citation Details In-Document Search Title: A Reactive Force Field study of LiC Systems for Electrical ...

  3. Tokamak with liquid metal for inducing toroidal electrical field

    DOE Patents [OSTI]

    Ohkawa, Tihiro

    1981-01-01

    A tokamak apparatus includes a vessel for defining a reservoir and confining liquid therein. A toroidal liner disposed within said vessel defines a toroidal space within the liner confines gas therein. Liquid metal fills the reservoir outside the liner. A magnetic field is established in the liquid metal to develop magnetic flux linking the toroidal space. The gas is ionized. The liquid metal and the toroidal space are moved relative to one another transversely of the space to generate electric current in the ionized gas in the toroidal space about its major axis and thereby heat plasma developed in the toroidal space.

  4. Nondestructive acoustic electric field probe apparatus and method

    DOE Patents [OSTI]

    Migliori, Albert

    1982-01-01

    The disclosure relates to a nondestructive acoustic electric field probe and its method of use. A source of acoustic pulses of arbitrary but selected shape is placed in an oil bath along with material to be tested across which a voltage is disposed and means for receiving acoustic pulses after they have passed through the material. The received pulses are compared with voltage changes across the material occurring while acoustic pulses pass through it and analysis is made thereof to determine preselected characteristics of the material.

  5. 10 Ways to "See" the Electric Field | Department of Energy

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

    10 Ways to "See" the Electric Field 10 Ways to "See" the Electric Field Addthis Description How can you demonstrate the electric field if it's invisible? This video shows you 10 activities and experiments that help to teach about the electric field using various apparatuses, such as a plasma ball or a Van de Graaff generator. Duration 8:07 Credit James Lincoln, AAPT Films

  6. Electric Power Generation from Co-Produced and Other Oil Field...

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

    Electric Power Generation from Co- Produced and Other Oil Field Fluids William Gosnold ... entrepreneurship in development of oil field geothermal resources and to train ...

  7. Electric-field enhanced performance in catalysis and solid-state devices involving gases

    DOE Patents [OSTI]

    Blackburn, Bryan M.; Wachsman, Eric D.; Van Assche, IV, Frederick Martin

    2015-05-19

    Electrode configurations for electric-field enhanced performance in catalysis and solid-state devices involving gases are provided. According to an embodiment, electric-field electrodes can be incorporated in devices such as gas sensors and fuel cells to shape an electric field provided with respect to sensing electrodes for the gas sensors and surfaces of the fuel cells. The shaped electric fields can alter surface dynamics, system thermodynamics, reaction kinetics, and adsorption/desorption processes. In one embodiment, ring-shaped electric-field electrodes can be provided around sensing electrodes of a planar gas sensor.

  8. Strong radial electric field shear and reduced fluctuations in a reversed-field pinch

    SciTech Connect (OSTI)

    Chapman, B.E.; Chiang, C.S.; Prager, S.C.; Sarff, J.S.

    1997-05-01

    A strongly sheared radial electric field is observed in enhanced confinement discharges in the MST reversed-field pinch. The strong shear develops in a narrow region in the plasma edge. Electrostatic fluctuations are reduced over the entire plasma edge with an extra reduction in the shear region. Magnetic fluctuations, resonant in the plasma core but global in extent, are also reduced. The reduction of fluctuations in the shear region is presumably due to the strong shear, but the causes of the reductions outside this region have not been established.

  9. Internal magnetic field structure and parallel electric field profile evolution during the sawtooth cycle in MST

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

    magnetic field structure and parallel electric field profile evolution during the sawtooth cycle in MST This article has been downloaded from IOPscience. Please scroll down to see the full text article. 2008 Plasma Phys. Control. Fusion 50 115013 (http://iopscience.iop.org/0741-3335/50/11/115013) Download details: IP Address: 128.104.166.214 The article was downloaded on 13/10/2010 at 22:35 Please note that terms and conditions apply. View the table of contents for this issue, or go to the

  10. SU-D-9A-04: Brain PET/CT Imaging On a Scanner with a Large Axial Field-Of-View

    SciTech Connect (OSTI)

    Park, M; Gerbaudo, V; Hamberg, L; Seaver, K; Kijewski, M

    2014-06-01

    Purpose: Large axial field-of-view (FOV) PET/CT scanners are valued for high sensitivity. Brain PET image quality may depend on the head position within the FOV. We investigated the precision of activity estimation for brain PET imaging when the brain was positioned at the end (END) and in the middle (CEN) of the FOV. The additional CT dose for the CEN position was recorded. Methods: An image quality (Jaszczak) phantom and a striatal phantom were filled with F-18 and positioned in END and CEN locations. For each phantom and each location, we acquired a ∼1-hr listmode PET, rebinned the data into 10 frames with equal number of coincidence events, and reconstructed each frame using an iterative algorithm. For the striatal phantom, END and CEN were compared by drawing on each image three regions of interest (ROI) in axially separated uniform areas. The standard deviation of the activity estimation within each ROI was averaged over the 10 images. The coefficient of variation (CV) for activity estimation was calculated at each position. Image quality was assessed by inspecting the resolution bar pattern in the Jaszczak phantom at two different head positions. Results: The CV was the lowest for ROIs near the center of the FOV. For slices near the end, not only was the CV highest, but also the resolution pattern was degraded. CTDIvol summarized in the dose report indicated that the CT dose was ∼ 10% higher for CEN as compared to END position. Conclusion: Positioning the brain in the middle of the FOV in a large FOV PET/CT scanner allows more precise measurement of tracer uptake and better image quality at the cost of increased CT dose. For the end location longer scan times may minimize image quality degradation without any additional CT dose.

  11. Vertical electric field induced suppression of fine structure...

    Office of Scientific and Technical Information (OSTI)

    Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577 (Japan) (Egypt) ...

  12. Electric field controlled reversible magnetic anisotropy switching studied by spin rectification

    SciTech Connect (OSTI)

    Zhou, Hengan; Fan, Xiaolong Wang, Fenglong; Jiang, Changjun; Rao, Jinwei; Zhao, Xiaobing; Xue, Desheng; Gui, Y. S.; Hu, C.-M.

    2014-03-10

    In this letter, spin rectification was used to study the electric field controlled dynamic magnetic properties of the multiferroic composite which is a Co stripe with induced in-plane anisotropy deposited onto a Pb(Mg{sub 1∕3}Nb{sub 2∕3})O{sub 3}-PbTiO{sub 3} substrate. Due to the coupling between piezoelectric and magnetoelastic effects, a reversible in-plane anisotropy switching has been realized by varying the history of the applied electric field. This merit results from the electric hysteresis of the polarization in the nonlinear piezoelectric regime, which has been proved by a butterfly type electric field dependence of the in-plane anisotropy field. Moreover, the electric field dependent effective demagnetization field and linewidth have been observed at the same time.

  13. Flexible gas insulated transmission line having regions of reduced electric field

    DOE Patents [OSTI]

    Cookson, Alan H.; Fischer, William H.; Yoon, Kue H.; Meyer, Jeffry R.

    1983-01-01

    A gas insulated transmission line having radially flexible field control means for reducing the electric field along the periphery of the inner conductor at predetermined locations wherein the support insulators are located. The radially flexible field control means of the invention includes several structural variations of the inner conductor, wherein careful controlling of the length to depth of surface depressions produces regions of reduced electric field. Several embodiments of the invention dispose a flexible connector at the predetermined location along the inner conductor where the surface depressions that control the reduced electric field are located.

  14. Electric Power Generation from Co-Produced and Other Oil Field Fluids |

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

    Department of Energy Electric Power Generation from Co-Produced and Other Oil Field Fluids Electric Power Generation from Co-Produced and Other Oil Field Fluids Co-produced and low-temperature demonstration projects presentation at the 2013 peer review meeting held in Denver, Colorado. coproduced_demoprojects_peerreview2013.pdf (2.47 MB) More Documents & Publications Chena Hot Springs Resort - Electric Power Generation Using Geothermal Fluid Coproduced from Oil and/or Gas Wells

  15. Surface area generation and droplet size control in solvent extraction systems utilizing high intensity electric fields

    DOE Patents [OSTI]

    Scott, Timothy C.; Wham, Robert M.

    1988-01-01

    A method and system for solvent extraction where droplets are shattered by a high intensity electric field. These shattered droplets form a plurality of smaller droplets which have a greater combined surface area than the original droplet. Dispersion, coalescence and phase separation are accomplished in one vessel through the use of the single pulsing high intensity electric field. Electric field conditions are chosen so that simultaneous dispersion and coalescence are taking place in the emulsion formed in the electric field. The electric field creates a large amount of interfacial surface area for solvent extraction when the droplet is disintegrated and is capable of controlling droplet size and thus droplet stability. These operations take place in the presence of a counter current flow of the continuous phase.

  16. Electric field control of spin-resolved edge states in graphene quantum nanorings

    SciTech Connect (OSTI)

    Farghadan, R.; Saffarzadeh, A.

    2014-05-07

    The electric-field effect on the electronic and magnetic properties of triangular and hexagonal graphene quantum rings with zigzag edge termination is investigated by means of the single-band tight-binding Hamiltonian and the mean-field Hubbard model. It is shown how the electron and spin states in the nanoring structures can be manipulated by applying an electric field. We find different spin-depolarization behaviors with variation of electric field strength due to the dependence of spin densities on the shapes and edges of this kind of nanorings. In the case of triangular quantum rings, the magnetization on the inner and outer edges can be selectively tuned and the spin states depolarize gradually as the field strength is increased, while in the case of hexagonal nanorings, the transverse electric field reduces the magnetic moments on both inner and outer edges symmetrically and rapidly.

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

    DOE Patents [OSTI]

    Miles, Robin R.

    2004-07-20

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

  18. Simulation of radio emission from air showers in atmospheric electric fields

    SciTech Connect (OSTI)

    Buitink, S.; Huege, T.; Falcke, H; Kuijpers, J.

    2010-02-25

    We study the effect of atmospheric electric fields on the radio pulse emitted by cos- mic ray air showers. Under fair weather conditions the dominant part of the radio emission is driven by the geomagnetic field. When the shower charges are accelerated and deflected in an electric field additional radiation is emitted. We simulate this effect with the Monte Carlo code REAS2, using CORSIKA-simulated showers as input. In both codes a routine has been implemented that treats the effect of the electric field on the shower particles. We find that the radio pulse is significantly altered in background fields of the order of ~100 V/cm and higher. Practically, this means that air showers passing through thunderstorms emit radio pulses that are not a reliable measure for the shower energy. Under other weather circumstances significant electric field effects are expected to occur rarely, but nimbostratus clouds can harbor fields that are large enough. In general, the contribution of the electric field to the radio pulse has polarization properties that are different from the geomagnetic pulse. In order to filter out radio pulses that have been affected by electric field effects, radio air shower experiments should keep weatherinformation and perform full polarization measurements of the radio signal.

  19. On electric field in anti-de Sitter spacetime

    SciTech Connect (OSTI)

    Cheong, Lee Yen E-mail: chewxy01813@gmail.com Yan, Chew Xiao E-mail: chewxy01813@gmail.com Ching, Dennis Ling Chuan E-mail: chewxy01813@gmail.com

    2014-10-24

    In this paper we calculate the electromagnetic field produced using retarded Green's function in Anti-de Sitter spacetime (AdS). Since this spacetime is non-globally hyperbolic and has no Cauchy surface, we only consider the field originated from a charge moving along its geodesic in the region consists of points covered by future null geodesic of the charge.

  20. Passing particle toroidal precession induced by electric field in a tokamak

    SciTech Connect (OSTI)

    Andreev, V. V.; Ilgisonis, V. I.; Sorokina, E. A.; NRC “Kurchatov Institute”, Kurchatov Sq. 1, Moscow 123182

    2013-12-15

    Characteristics of a rotation of passing particles in a tokamak with radial electric field are calculated. The expression for time-averaged toroidal velocity of the passing particle induced by the electric field is derived. The electric-field-induced additive to the toroidal velocity of the passing particle appears to be much smaller than the velocity of the electric drift calculated for the poloidal magnetic field typical for the trapped particle. This quantity can even have the different sign depending on the azimuthal position of the particle starting point. The unified approach for the calculation of the bounce period and of the time-averaged toroidal velocity of both trapped and passing particles in the whole volume of plasma column is presented. The results are obtained analytically and are confirmed by 3D numerical calculations of the trajectories of charged particles.

  1. Inducing chaos by breaking axial symmetry in a black hole magnetosphere

    SciTech Connect (OSTI)

    Kopáček, O.; Karas, V.

    2014-06-01

    While the motion of particles near a rotating, electrically neutral (Kerr), and charged (Kerr-Newman) black hole is always strictly regular, a perturbation in the gravitational or the electromagnetic field generally leads to chaos. The transition from regular to chaotic dynamics is relatively gradual if the system preserves axial symmetry, whereas non-axisymmetry induces chaos more efficiently. Here we study the development of chaos in an oblique (electro-vacuum) magnetosphere of a magnetized black hole. Besides the strong gravity of the massive source represented by the Kerr metric, we consider the presence of a weak, ordered, large-scale magnetic field. An axially symmetric model consisting of a rotating black hole embedded in an aligned magnetic field is generalized by allowing an oblique direction of the field having a general inclination with respect to the rotation axis of the system. The inclination of the field acts as an additional perturbation to the motion of charged particles as it breaks the axial symmetry of the system and cancels the related integral of motion. The axial component of angular momentum is no longer conserved and the resulting system thus has three degrees of freedom. Our primary concern within this contribution is to find out how sensitive the system of bound particles is to the inclination of the field. We employ the method of the maximal Lyapunov exponent to distinguish between regular and chaotic orbits and to quantify their chaoticity. We find that even a small misalignment induces chaotic motion.

  2. Solvable Examples of Drift and Diffusion of Ions in Non-uniform Electric Fields

    SciTech Connect (OSTI)

    Cahn, Robert; Cahn, Robert N.; Jackson, John David

    2008-05-30

    The drift and diffusion of a cloud of ions in a fluid are distorted by an inhomogeneous electric field. If the electric field carries the center of the distribution in a straight line and the field configuration is suitably symmetric, the distortion can be calculated analytically. We examine the specific examples of fields with cylindrical and spherical symmetry in detail assuming the ion distributions to be of a generally Gaussian form. The effects of differing diffusion coefficients in the transverse and longitudinal directions are included.

  3. Electric field measurement in microwave discharge ion thruster with electro-optic probe

    SciTech Connect (OSTI)

    Ise, Toshiyuki; Tsukizaki, Ryudo; Koizumi, Hiroyuki; Togo, Hiroyoshi; Kuninaka, Hitoshi

    2012-12-15

    In order to understand the internal phenomena in a microwave discharge ion thruster, it is important to measure the distribution of the microwave electric field inside the discharge chamber, which is directly related to the plasma production. In this study, we proposed a novel method of measuring a microwave electric field with an electro-optic (EO) probe based on the Pockels effect. The probe, including a cooling system, contains no metal and can be accessed in the discharge chamber with less disruption to the microwave distribution. This method enables measurement of the electric field profile under ion beam acceleration. We first verified the measurement with the EO probe by a comparison with a finite-difference time domain numerical simulation of the microwave electric field in atmosphere. Second, we showed that the deviations of the reflected microwave power and the beam current were less than 8% due to inserting the EO probe into the ion thruster under ion beam acceleration. Finally, we successfully demonstrated the measurement of the electric-field profile in the ion thruster under ion beam acceleration. These measurements show that the electric field distribution in the thruster dramatically changes in the ion thruster under ion beam acceleration as the propellant mass flow rate increases. These results indicate that this new method using an EO probe can provide a useful guide for improving the propulsion of microwave discharge ion thrusters.

  4. Electric Field Effects on the Intermolecular Interactions in Water Whiskers: Insight from Structures, Energetics, and Properties

    SciTech Connect (OSTI)

    Bai, Yang; He, Hui-Min; Li, Ying; Zhou, Zhong-Jun; Wang, Jia-Jun; Wu, Di; Chen, Wei; Gu, Feng-Long; Sumpter, Bobby G.; Huang, Jingsong

    2015-02-19

    Modulation of intermolecular interactions in response to external electric fields could be fundamental to the formation of unusual forms of water, such as water whiskers. However, a detailed understanding of the nature of intermolecular interactions in such systems is lacking. In this study, we present novel theoretical results based on electron correlation calculations regarding the nature of H-bonds in water whiskers, which is revealed by studying their evolution under external electric fields with various field strengths. We find that the water whiskers consisting of 2-7 water molecules all have a chain-length dependent critical electric field. Under the critical electric field, the most compact chain structures are obtained, featuring very strong H-bonds, herein referred to as covalent H-bonds. In the case of a water dimer whisker, the bond length of the novel covalent H-bond shortens by 25%, the covalent bond order increases by 9 times, and accordingly the H-bond energy is strengthened by 5 times compared to the normal H-bond in a (H2O)2 cluster. Below the critical electric field, it is observed that with increasing field strength, H-bonding orbitals display gradual evolutions in the orbital energy, orbital ordering, and orbital nature (i.e., from typical -style orbital to unusual -style double H-bonding orbital). We also show that beyond the critical electric field, a single water whisker may disintegrate to form a loosely bound zwitterionic chain due to a relay-style proton transfer, whereas two water whiskers may undergo intermolecular cross-linking to form a quasi-two-dimensional water network. In conclusion, these results help shed new insight on the effects of electric fields on water whisker formation.

  5. Electric Field Effects on the Intermolecular Interactions in Water Whiskers: Insight from Structures, Energetics, and Properties

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

    Bai, Yang; He, Hui-Min; Li, Ying; Zhou, Zhong-Jun; Wang, Jia-Jun; Wu, Di; Chen, Wei; Gu, Feng-Long; Sumpter, Bobby G.; Huang, Jingsong

    2015-02-19

    Modulation of intermolecular interactions in response to external electric fields could be fundamental to the formation of unusual forms of water, such as water whiskers. However, a detailed understanding of the nature of intermolecular interactions in such systems is lacking. In this study, we present novel theoretical results based on electron correlation calculations regarding the nature of H-bonds in water whiskers, which is revealed by studying their evolution under external electric fields with various field strengths. We find that the water whiskers consisting of 2-7 water molecules all have a chain-length dependent critical electric field. Under the critical electric field,more » the most compact chain structures are obtained, featuring very strong H-bonds, herein referred to as covalent H-bonds. In the case of a water dimer whisker, the bond length of the novel covalent H-bond shortens by 25%, the covalent bond order increases by 9 times, and accordingly the H-bond energy is strengthened by 5 times compared to the normal H-bond in a (H2O)2 cluster. Below the critical electric field, it is observed that with increasing field strength, H-bonding orbitals display gradual evolutions in the orbital energy, orbital ordering, and orbital nature (i.e., from typical -style orbital to unusual -style double H-bonding orbital). We also show that beyond the critical electric field, a single water whisker may disintegrate to form a loosely bound zwitterionic chain due to a relay-style proton transfer, whereas two water whiskers may undergo intermolecular cross-linking to form a quasi-two-dimensional water network. In conclusion, these results help shed new insight on the effects of electric fields on water whisker formation.« less

  6. Measuring axial pump thrust

    DOE Patents [OSTI]

    Suchoza, Bernard P.; Becse, Imre

    1988-01-01

    An apparatus for measuring the hydraulic axial thrust of a pump under operation conditions is disclosed. The axial thrust is determined by forcing the rotating impeller off of an associated thrust bearing by use of an elongate rod extending coaxially with the pump shaft. The elongate rod contacts an impeller retainer bolt where a bearing is provided. Suitable measuring devices measure when the rod moves to force the impeller off of the associated thrust bearing and the axial force exerted on the rod at that time. The elongate rod is preferably provided in a housing with a heat dissipation mechanism whereby the hot fluid does not affect the measuring devices.

  7. Measuring axial pump thrust

    DOE Patents [OSTI]

    Suchoza, B.P.; Becse, I.

    1988-11-08

    An apparatus for measuring the hydraulic axial thrust of a pump under operation conditions is disclosed. The axial thrust is determined by forcing the rotating impeller off of an associated thrust bearing by use of an elongate rod extending coaxially with the pump shaft. The elongate rod contacts an impeller retainer bolt where a bearing is provided. Suitable measuring devices measure when the rod moves to force the impeller off of the associated thrust bearing and the axial force exerted on the rod at that time. The elongate rod is preferably provided in a housing with a heat dissipation mechanism whereby the hot fluid does not affect the measuring devices. 1 fig.

  8. Deep-subwavelength imaging of both electric and magnetic localized optical fields by plasmonic campanile nanoantenna

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

    Caselli, Niccolò; La China, Federico; Bao, Wei; Riboli, Francesco; Gerardino, Annamaria; Li, Lianhe; Linfield, Edmund H.; Pagliano, Francesco; Fiore, Andrea; Schuck, P. James; et al

    2015-06-05

    Tailoring the electromagnetic field at the nanoscale has led to artificial materials exhibiting fascinating optical properties unavailable in naturally occurring substances. Besides having fundamental implications for classical and quantum optics, nanoscale metamaterials provide a platform for developing disruptive novel technologies, in which a combination of both the electric and magnetic radiation field components at optical frequencies is relevant to engineer the light-matter interaction. Thus, an experimental investigation of the spatial distribution of the photonic states at the nanoscale for both field components is of crucial importance. Here we experimentally demonstrate a concomitant deep-subwavelength near-field imaging of the electric and magneticmore » intensities of the optical modes localized in a photonic crystal nanocavity. We take advantage of the “campanile tip”, a plasmonic near-field probe that efficiently combines broadband field enhancement with strong far-field to near-field coupling. In conclusion, by exploiting the electric and magnetic polarizability components of the campanile tip along with the perturbation imaging method, we are able to map in a single measurement both the electric and magnetic localized near-field distributions.« less

  9. Deep-subwavelength imaging of both electric and magnetic localized optical fields by plasmonic campanile nanoantenna

    SciTech Connect (OSTI)

    Caselli, Niccolò; La China, Federico; Bao, Wei; Riboli, Francesco; Gerardino, Annamaria; Li, Lianhe; Linfield, Edmund H.; Pagliano, Francesco; Fiore, Andrea; Schuck, P. James; Cabrini, Stefano; Weber-Bargioni, Alexander; Gurioli, Massimo; Intonti, Francesca

    2015-06-05

    Tailoring the electromagnetic field at the nanoscale has led to artificial materials exhibiting fascinating optical properties unavailable in naturally occurring substances. Besides having fundamental implications for classical and quantum optics, nanoscale metamaterials provide a platform for developing disruptive novel technologies, in which a combination of both the electric and magnetic radiation field components at optical frequencies is relevant to engineer the light-matter interaction. Thus, an experimental investigation of the spatial distribution of the photonic states at the nanoscale for both field components is of crucial importance. Here we experimentally demonstrate a concomitant deep-subwavelength near-field imaging of the electric and magnetic intensities of the optical modes localized in a photonic crystal nanocavity. We take advantage of the “campanile tip”, a plasmonic near-field probe that efficiently combines broadband field enhancement with strong far-field to near-field coupling. In conclusion, by exploiting the electric and magnetic polarizability components of the campanile tip along with the perturbation imaging method, we are able to map in a single measurement both the electric and magnetic localized near-field distributions.

  10. Axial static mixer

    DOE Patents [OSTI]

    Sandrock, H.E.

    1982-05-06

    Static axial mixing apparatus includes a plurality of channels, forming flow paths of different dimensions. The axial mixer includes a flow adjusting device for adjustable selective control of flow resistance of various flow paths in order to provide substantially identical flows through the various channels, thereby reducing nonuniform coating of interior surfaces of the channels. The flow adjusting device may include diaphragm valves, and may further include a pressure regulating system therefor.

  11. Spatial feature tracking impedence sensor using multiple electric fields

    DOE Patents [OSTI]

    Novak, J.L.

    1998-08-11

    Linear and other features on a workpiece are tracked by measuring the fields generated between electrodes arrayed in pairs. One electrode in each pair operates as a transmitter and the other as a receiver, and both electrodes in a pair are arrayed on a carrier. By combining and subtracting fields between electrodes in one pair and between a transmitting electrode in one pair and a receiving electrode in another pair, information describing the location and orientation of the sensor relative to the workpiece in up to six degrees of freedom may be obtained. Typical applications will measure capacitance, but other impedance components may be measured as well. The sensor is designed to track a linear feature axis or a protrusion or pocket in a workpiece. Seams and ridges can be tracked by this non-contact sensor. The sensor output is useful for robotic applications. 10 figs.

  12. Spatial feature tracking impedence sensor using multiple electric fields

    DOE Patents [OSTI]

    Novak, James L.

    1998-01-01

    Linear and other features on a workpiece are tracked by measuring the fields generated between electrodes arrayed in pairs. One electrode in each pair operates as a transmitter and the other as a receiver, and both electrodes in a pair are arrayed on a carrier. By combining and subtracting fields between electrodes in one pair and between a transmitting electrode in one pair and a receiving electrode in another pair, information describing the location and orientation of the sensor relative to the workpiece in up to six degrees of freedom may be obtained. Typical applications will measure capacitance, but other impedance components may be measured as well. The sensor is designed to track a linear feature axis or a protrusion or pocket in a workpiece. Seams and ridges can be tracked by this non-contact sensor. The sensor output is useful for robotic applications.

  13. Property:AxialMeasurement | Open Energy Information

    Open Energy Info (EERE)

    String Description MHK Axial Load Measurement Categories Used in FormTemplate MHKSensor & MHKInstrument Allows Values Strain (Axial);3-axis (Axial);2-axis (Axial);1-axis...

  14. Solvation structure and transport properties of alkali cations in dimethyl sulfoxide under exogenous static electric fields

    SciTech Connect (OSTI)

    Kerisit, Sebastien; Vijayakumar, M. E-mail: karl.mueller@pnnl.gov; Han, Kee Sung; Mueller, Karl T. E-mail: karl.mueller@pnnl.gov

    2015-06-14

    A combination of molecular dynamics simulations and pulsed field gradient nuclear magnetic resonance spectroscopy is used to investigate the role of exogenous electric fields on the solvation structure and dynamics of alkali ions in dimethyl sulfoxide (DMSO) and as a function of temperature. Good agreement was obtained, for select alkali ions in the absence of an electric field, between calculated and experimentally determined diffusion coefficients normalized to that of pure DMSO. Our results indicate that temperatures of up to 400 K and external electric fields of up to 1 V nm{sup −1} have minimal effects on the solvation structure of the smaller alkali cations (Li{sup +} and Na{sup +}) due to their relatively strong ion-solvent interactions, whereas the solvation structures of the larger alkali cations (K{sup +}, Rb{sup +}, and Cs{sup +}) are significantly affected. In addition, although the DMSO exchange dynamics in the first solvation shell differ markedly for the two groups, the drift velocities and mobilities are not significantly affected by the nature of the alkali ion. Overall, although exogenous electric fields induce a drift displacement, their presence does not significantly affect the random diffusive displacement of the alkali ions in DMSO. System temperature is found to have generally a stronger influence on dynamical properties, such as the DMSO exchange dynamics and the ion mobilities, than the presence of electric fields.

  15. Ultrafast thermionic emission from metal irradiated using a femtosecond laser and an electric field in combination

    SciTech Connect (OSTI)

    Wang, Tingfeng; Guo, Jin; Shao, Junfeng; Wang, Dinan; Chen, Anmin E-mail: mxjin@jlu.edu.cn; Jin, Mingxing E-mail: mxjin@jlu.edu.cn

    2015-03-15

    Ultrafast thermionic emission from gold film irradiated with a femtosecond laser pulse in the presence of an additional electric field is analyzed using a two-temperature equation combined with a modified Richardson equation. The calculated results show that the duration of the emission is below 1 ps. Supplying an additional electric field is found to change the emission from the metal surface. Given the same laser fluence, this additional field reduces the work function of the metal, and thus improves the efficiency of thermionic emission. These results help to understand the mechanism and suggest ways to improve emissions in the context of ultrafast thermalized electron systems.

  16. Light bending by nonlinear electrodynamics under strong electric and magnetic field

    SciTech Connect (OSTI)

    Kim, Jin Young; Lee, Taekoon E-mail: tlee@kunsan.ac.kr

    2011-11-01

    We calculate the bending angles of light under the strong electric and magnetic fields by a charged black hole and a magnetized neutron star according to the nonlinear electrodynamics of Euler-Heisenberg interaction. The bending angle of light by the electric field of charged black hole is computed from geometric optics and a general formula is derived for light bending valid for any orientation of the magnetic dipole. The astronomical significance of the light bending by magnetic field of a neutron star is discussed.

  17. Charged Particle in a Time-dependent Electric Field: A White Noise Functional Approach

    SciTech Connect (OSTI)

    Gravador, E. B.; Bornales, J. B.; Liwanag, M. J.

    2008-06-18

    The propagator for a charged particle in a time-dependent electric field is calculated following Hida and Streit's framework where the propagator is the T-transform of Feynman functional. However, we have to regard the potential V = -qE({tau})x{identical_to}{radical}((m/({Dirac_h}/2{pi}))){xi}x following C. C. Bernido and M. V. Carpio-Bernido's prescription of time-dependent potentials. The result agrees with the limiting form of Eqn. (16) of N. Morgenstern Horing, H. L. Cui, and G. Fiorenza, when the magnetic field is switched off, and Eqn. (17) of [3] when the electric field is constant in time.

  18. Observation of transient electric fields in particle-in-cell simulation of capacitively coupled discharges

    SciTech Connect (OSTI)

    Sharma, S., E-mail: sarvsarvesh@gmail.com; Mishra, S. K.; Kaw, Predhiman K. [Institute for Plasma Research (IPR), Bhat, Gandhinagar 382428 (India)

    2014-07-15

    The analytical prediction of the presence of transient electric field regions between the bulk plasma and sheath edge in radio frequency capacitively coupled plasma (RF-CCP) discharges has been reported by Kaganovich [Phys. Rev. Lett. 89, 265006 (2002)]. In this paper, we have used the semi-infinite particle-in-cell (PIC) simulation technique to verify the theoretical prediction for the existence of transient electric field in the linear regime; it is shown that the PIC simulation results are in good agreement with the results predicted by analytical model in this regime. It is also demonstrated that the linear theory overestimates the transient electric field as one moves from linear to weakly nonlinear regime. The effect of applied RF current density and electron temperature on evolution of transition field and phase mixing regime has been explored.

  19. Calcite precipitation dominates the electrical signatures of zero valent iron columns under simulated field conditions

    SciTech Connect (OSTI)

    Wu, Yuxin; Versteeg, R.; Slater, L.; LaBrecque, D.

    2009-06-01

    Calcium carbonate is a secondary mineral precipitate influencing zero valent iron (ZVI) barrier reactivity and hydraulic performance. We conducted column experiments to investigate electrical signatures resulting from concurrent CaCO{sub 3} and iron oxides precipitation under simulated field geochemical conditions. We identified CaCO{sub 3} as a major mineral phase throughout the columns, with magnetite present primarily close to the influent based on XRD analysis. Electrical measurements revealed decreases in conductivity and polarization of both columns, suggesting that electrically insulating CaCO{sub 3} dominates the electrical response despite the presence of electrically conductive iron oxides. SEM/EDX imaging suggests that the electrical signal reflects the geometrical arrangement of the mineral phases. CaCO{sub 3} forms insulating films on ZVI/magnetite surfaces, restricting charge transfer between the pore electrolyte and ZVI particles, as well as across interconnected ZVI particles. As surface reactivity also depends on the ability of the surface to engage in redox reactions via charge transfer, electrical measurements may provide a minimally invasive technology for monitoring reactivity loss due to CaCO{sub 3} precipitation. Comparison between laboratory and field data shows consistent changes in electrical signatures due to iron corrosion and secondary mineral precipitation.

  20. Electric field geometries dominate quantum transport coupling in silicon nanoring

    SciTech Connect (OSTI)

    Lee, Tsung-Han E-mail: sfhu.hu@gmail.com; Hu, Shu-Fen E-mail: sfhu.hu@gmail.com

    2014-03-28

    Investigations on the relation between the geometries of silicon nanodevices and the quantum phenomenon they exhibit, such as the Aharonov–Bohm (AB) effect and the Coulomb blockade, were conducted. An arsenic doped silicon nanoring coupled with a nanowire by electron beam lithography was fabricated. At 1.47 K, Coulomb blockade oscillations were observed under modulation from the top gate voltage, and a periodic AB oscillation of ΔB = 0.178 T was estimated for a ring radius of 86 nm under a high sweeping magnetic field. Modulating the flat top gate and the pointed side gate was performed to cluster and separate the many electron quantum dots, which demonstrated that quantum confinement and interference effects coexisted in the doped silicon nanoring.

  1. Exposure to residential electric and magnetic fields and risk of childhood leukemia

    SciTech Connect (OSTI)

    Peters, J.M.; Thomas, D.C.; Bowman, J.D.; Sobel, E.; London, S.J.; Cheng, T.C. )

    1991-11-01

    This study was conducted on 232 cases of childhood leukemia occurring in children age 10 and under between 1980 and 1987 in Los Angeles County. Two hundred thirty-two controls were selected from the same geographic area and were matched on sex, age and race. The parents of the 464 subjects were interviewed by telephone to elicit information on medical histories of the parents and child, residential histories of the subjects, occupational histories of both parents, environmental chemical histories, personal histories including drug use and smoking habits, and time and space occupancy of subjects, including exposures to electrical appliances. An extensive assessment of exposure to electric and magnetic fields was made by determining wiring configurations of most subjects (90%), by measuring electric and magnetic fields in various areas of the inside and outside of the home, and by measuring magnetic fields for 24 to 72 hours in the child's sleeping area (66%). We conclude that our data offer no support for a relationship between measured electric field exposure and leukemia risk, little support for the relationship between measured magnetic field exposure and leukemia risk, considerable support for a relationship between wiring configuration and leukemia risk, and considerable support for a relationship between children's electrical appliance use and leukemia risk. The reason(s) why wiring configuration correlates with leukemia risk better than measured exposure are not clear. It is also not clear whether short-term, very high exposure of children to magnetic (or electric) fields from electric appliances are responsible for the observed risk or whether associated exposures or recall biases are responsible. These latter two issues deserve continued research. 41 refs., 31 tabs.

  2. Exposure to residential electric and magnetic fields and risk of childhood leukemia

    SciTech Connect (OSTI)

    Peters, J.M.; Thomas, D.C.; Bowman, J.D.; Sobel, E.; London, S.J.; Cheng, T.C.

    1991-11-01

    This study was conducted on 232 cases of childhood leukemia occurring in children age 10 and under between 1980 and 1987 in Los Angeles County. Two hundred thirty-two controls were selected from the same geographic area and were matched on sex, age and race. The parents of the 464 subjects were interviewed by telephone to elicit information on medical histories of the parents and child, residential histories of the subjects, occupational histories of both parents, environmental chemical histories, personal histories including drug use and smoking habits, and time and space occupancy of subjects, including exposures to electrical appliances. An extensive assessment of exposure to electric and magnetic fields was made by determining wiring configurations of most subjects (90%), by measuring electric and magnetic fields in various areas of the inside and outside of the home, and by measuring magnetic fields for 24 to 72 hours in the child`s sleeping area (66%). We conclude that our data offer no support for a relationship between measured electric field exposure and leukemia risk, little support for the relationship between measured magnetic field exposure and leukemia risk, considerable support for a relationship between wiring configuration and leukemia risk, and considerable support for a relationship between children`s electrical appliance use and leukemia risk. The reason(s) why wiring configuration correlates with leukemia risk better than measured exposure are not clear. It is also not clear whether short-term, very high exposure of children to magnetic (or electric) fields from electric appliances are responsible for the observed risk or whether associated exposures or recall biases are responsible. These latter two issues deserve continued research. 41 refs., 31 tabs.

  3. Structural characterization of electric-field assisted dip-coating of gold nanoparticles on silicon

    SciTech Connect (OSTI)

    Dushaq, Ghada H.; Alkhatib, Amro; Rasras, Mahmoud S.; Nayfeh, Ammar M.

    2015-09-15

    We report the effect of applying an electric field on the surface coverage of 40nm gold colloidal nanoparticles on silicon wafer using dip-coating and electrochemical cell set up. By applying electric field during the dip-coating of silicon wafer in a solution of gold nano particles (GNP) the surface coverage increased by 10% when the electric field varied from 5V/cm to 25V/cm at fixed deposition time of 90s. Ultra High Resolution Scanning Electron Microscopy (HRSEM) images shows that the particle agglomeration becomes more noticeable at higher electric field and as the deposition time increases from 90 s to 20 min a thin film of gold is achieved. Moreover, the results are discussed in terms of chemical bonding, electrostatic force and electrophoretic mobility of Au nano particles during the electric field enhanced deposition on the Si surface. Applied voltage, time of dipping, concentration of the aqueous solution, and particles zeta potential are all can be controlled to enhance the uniformity and particles profile on the silicon surface.

  4. Vacuum gaps with small tunnel currents at large electric field and its

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

    potential applications for energy storage, charge storage and power supplies. | Stanford Synchrotron Radiation Lightsource Vacuum gaps with small tunnel currents at large electric field and its potential applications for energy storage, charge storage and power supplies. Friday, May 27, 2011 - 4:00pm SSRL Conference Room 137-226 Alfred Hubler, Department of Physics, University of Illinois, Urbana-Champaign We study tunnel currents and electric break down in vacuum gaps experimentally and

  5. Internal Electric Field Behavior of Cadmium Zinc Telluride Radiation Detectors Under High Carrier Injection

    SciTech Connect (OSTI)

    Yang, G.; Bolotnikov, A.E.; Camarda, G.S.; Cui, Y.; Hossain, A.; Kim, K.H.; Gul, R.; and James, R.B.

    2010-10-26

    The behavior of the internal electric-field of nuclear-radiation detectors substantially affects the detector's performance. We investigated the distribution of the internal field in cadmium zinc telluride (CZT) detectors under high carrier injection. We noted the build-up of a space charge region near the cathode that produces a built-in field opposing the applied field. Its presence entails the collapse of the electric field in the rest of detector, other than the portion near the cathode. Such a space-charge region originates from serious hole-trapping in CZT. The device's operating temperature greatly affects the width of the space-charge region. With increasing temperature from 5 C to 35 C, its width expanded from about 1/6 to 1/2 of the total depth of the detector.

  6. Time evolution of the total electric-field strength in multimode lasers

    SciTech Connect (OSTI)

    Brunner, W.; Fischer, R.; Paul, H.

    1988-05-01

    Our previous numerical studies of the output characteristics of multimode lasers are extended to include the evolution of the total electric-field strength. The regular or irregular behavior of the system, which becomes manifest in the evolution of the amplitudes and the phases in the different modes, is reflected also in the evolution of the total electric-field strength in a stroboscopic view. (The total electric-field strength, with its high-frequency time dependence suppressed, is considered at times t, t+..delta..t, t+2..delta..t,..., where ..delta..t is a multiple of the round-trip time in the resonator.) Moreover, it is demonstrated that the evolution of the system is very sensitive to slight changes in the initial conditions. This finding supports the view that the irregularity falls in the class of the so-called deterministic chaos.

  7. Interaction of biological systems with static and ELF electric and magnetic fields

    SciTech Connect (OSTI)

    Anderson, L.E.; Kelman, B.J.; Weigel, R.J.

    1987-01-01

    Although background levels of atmospheric electric and geomagnetic field levels are extremely low, over the past several decades, human beings and other life forms on this planet have been subjected to a dramatically changing electromagnetic milieu. An exponential increase in exposure to electromagnetic fields has occurred, largely because of such technological advances as the growth of electrical power generation and transmission systems, the increased use of wireless communications, and the use of radar. In addition, electromagnetic field generating devices have proliferated in industrial plants, office buildings, homes, public transportation systems, and elsewhere. Although significant increases have occurred in electromagnetic field strenghths spanning all frequency ranges, this symposium addresses only the impact of these fields at static and extremely low frequencies (ELF), primarily 50 and 60 Hz. This volume contains the proceedings of the symposium entitled /open quotes/Interaction of biological systems with static and ELF electric and magnetic fields/close quotes/. The purpose of the symposium was to provide a forum for discussions of all aspects of research on the interaction of static and ELF electromagnetic fields with biological systems. These systems include simple biophysical models, cell and organ preparations, whole animals, and man. Dosimetry, exposure system design, and artifacts in ELF bioeffects research were also addressed, along with current investigations that examine fundamental mechanisms of interactions between the fields and biological processes. Papers are indexed separately.

  8. Electric field driven magnetic domain wall motion in ferromagnetic-ferroelectric heterostructures

    SciTech Connect (OSTI)

    Van de Wiele, Ben; Laurson, Lasse; Franke, Kvin J. A.; Dijken, Sebastiaan van

    2014-01-06

    We investigate magnetic domain wall (MDW) dynamics induced by applied electric fields in ferromagnetic-ferroelectric thin-film heterostructures. In contrast to conventional driving mechanisms where MDW motion is induced directly by magnetic fields or electric currents, MDW motion arises here as a result of strong pinning of MDWs onto ferroelectric domain walls (FDWs) via local strain coupling. By performing extensive micromagnetic simulations, we find several dynamical regimes, including instabilities such as spin wave emission and complex transformations of the MDW structure. In all cases, the time-averaged MDW velocity equals that of the FDW, indicating the absence of Walker breakdown.

  9. Measurement of rapidly varying electric fields through parity oscillations in the Rydberg states of hydrogenic atoms

    SciTech Connect (OSTI)

    Shafer-Ray, N.E.; Zare, R.N.

    1996-12-01

    Oscillations are shown to exist in the inversion symmetry of the electronic wave function of a hydrogenic atom coherently excited to a Rydberg state by a short pulse of laser radiation in a uniform electric field. The dependence of these oscillations on field strength is shown to scale as {ital n}{sup 2} where {ital n} is the principal quantum number. The possibility of using these oscillations to measure electric signals on picosecond timescales (terahertz frequencies) is suggested. {copyright} {ital 1996 American Institute of Physics.}

  10. Simultaneous investigation of ultrafast structural dynamics and transient electric field by sub-picosecond electron pulses

    SciTech Connect (OSTI)

    Li, Run-Ze; Zhu, Pengfei; Chen, Long; Chen, Jie E-mail: jzhang1@sjtu.edu.cn; Sheng, Zheng-Ming; Zhang, Jie E-mail: jzhang1@sjtu.edu.cn; Cao, Jianming

    2014-05-14

    The ultrafast structure dynamics and surface transient electric field, which are concurrently induced by laser excited electrons of an aluminum nanofilm, have been investigated simultaneously by the same transmission electron diffraction patterns. These two processes are found to be significantly different and distinguishable by tracing the time dependent changes of electron diffraction and deflection angles, respectively. This study also provides a practical means to evaluate simultaneously the effect of transient electric field during the study of structural dynamics under low pump fluence by transmission ultrafast electron diffraction.

  11. A tunable metamaterial dependent on electric field at terahertz with barium strontium titanate thin film

    SciTech Connect (OSTI)

    Bian, Yanlong; Zhai, Jiwei; Wu, Chao; Li, Hongqiang

    2014-01-27

    A tunable metamaterial with resonance frequency at terahertz (THz) was developed. Electromagnetic response of the metamaterial was characterized with THz time domain spectrometer at various direct current electric fields. The resonance frequency increased monotonously with increasing electric field. The finite difference time domain method was used to simulate the transmission spectra of the metamaterial at THz frequencies. By comparing the simulated resonance frequency with the experimental curve, dielectric property of the Ba{sub 0.6}Sr{sub 0.4}TiO{sub 3} (BST60) thin film at THz, over 033?kV/cm, was evaluated.

  12. Enhancement of crystal homogeneity of protein crystals under application of an external alternating current electric field

    SciTech Connect (OSTI)

    Koizumi, H.; Uda, S.; Fujiwara, K.; Nozawa, J.; Tachibana, M.; Kojima, K.

    2014-10-06

    X-ray diffraction rocking-curve measurements were performed on tetragonal hen egg white (HEW) lysozyme crystals grown with and without the application of an external alternating current (AC) electric field. The crystal quality was assessed by the full width at half maximum (FWHM) value for each rocking curve. For two-dimensional maps of the FWHMs measured on the 440 and the 12 12 0 reflection, the crystal homogeneity was improved under application of an external electric field at 1 MHz, compared with that without. In particular, the significant improvement of the crystal homogeneity was observed for the 12 12 0 reflection.

  13. Quantum aspects of a moving magnetic quadrupole moment interacting with an electric field

    SciTech Connect (OSTI)

    Fonseca, I. C.; Bakke, K.

    2015-06-15

    The quantum dynamics of a moving particle with a magnetic quadrupole moment that interacts with electric and magnetic fields is introduced. By dealing with the interaction between an electric field and the magnetic quadrupole moment, it is shown that an analogue of the Coulomb potential can be generated and bound state solutions can be obtained. Besides, the influence of the Coulomb-type potential on the harmonic oscillator is investigated, where bound state solutions to both repulsive and attractive Coulomb-type potentials are achieved and the arising of a quantum effect characterized by the dependence of the harmonic oscillator frequency on the quantum numbers of the system is discussed.

  14. Kinetic model for electric-field induced point defect redistribution near semiconductor surfaces

    SciTech Connect (OSTI)

    Gorai, Prashun; Seebauer, Edmund G.

    2014-07-14

    The spatial distribution of point defects near semiconductor surfaces affects the efficiency of devices. Near-surface band bending generates electric fields that influence the spatial redistribution of charged mobile defects that exchange infrequently with the lattice, as recently demonstrated for pile-up of isotopic oxygen near rutile TiO{sub 2} (110). The present work derives a mathematical model to describe such redistribution and establishes its temporal dependence on defect injection rate and band bending. The model shows that band bending of only a few meV induces significant redistribution, and that the direction of the electric field governs formation of either a valley or a pile-up.

  15. Geodesic acoustic modes in tokamak plasmas with a radial equilibrium electric field

    SciTech Connect (OSTI)

    Zhou, Deng

    2015-09-15

    The dispersion relation of geodesic acoustic modes in the tokamak plasma with an equilibrium radial electric field is derived and analyzed. Multiple branches of eigenmodes have been found, similar to the result given by the fluid model with a poloidal mass flow. Frequencies and damping rates of both the geodesic acoustic mode and the sound wave increase with respect to the strength of radial electric field, while the frequency and the damping rate of the lower frequency branch slightly decrease. Possible connection to the experimental observation is discussed.

  16. An exposure chamber for studies on human perception of DC electric fields and ions

    SciTech Connect (OSTI)

    Nguyen, D.H.; Maruvada, P.S. )

    1994-10-01

    Direct current (DC) transmission lines are often used, for technical and economic reasons, as interconnections in modern high voltage power systems, which are essentially of the alternating current (AC) type. Significant differences exist, however, between the field effects produced in the vicinity of AC and DC transmission lines. DC electric fields induce charges, on the surface of a conducting body such as a human being and may therefore be ''perceived'' by humans due to hair stimulation and other sensations experienced by the skin. A human being exposed to the ionized field of a DC transmission line experiences not only surface charges but also the conducted ion currents. A systematic laboratory study has been undertaken by Hydro Quebec to investigate human perception, using well established psycho physical techniques, of DC electric fields and ions. The design, construction and operation of an exposure chamber for this purpose, in the high voltage laboratory of IREQ, are described in this paper.

  17. Perturbation theory for electric-field amplitude and phase ripple transfer in frequency doubling and tripling

    SciTech Connect (OSTI)

    Auerbach, J.M.; Eimerl, D.; Milam, D.; Milonni, P.W.

    1997-01-01

    A theory is presented for the transfer of a perturbation of the electric field from the input to the output of a frequency converter. The transfer relationship for the field ripple is shown to depend on the plane-wave operating parameters of the converter. Predictions of the theory are shown to be in excellent agreement with full numerical simulations of doubling and tripling and experiments measuring ripple transfer in frequency doubling. {copyright} 1997 Optical Society of America

  18. Method of measuring the dc electric field and other tokamak parameters

    DOE Patents [OSTI]

    Fisch, Nathaniel J.; Kirtz, Arnold H.

    1992-01-01

    A method including externally imposing an impulsive momentum-space flux to perturb hot tokamak electrons thereby producing a transient synchrotron radiation signal, in frequency-time space, and the inference, using very fast algorithms, of plasma parameters including the effective ion charge state Z.sub.eff, the direction of the magnetic field, and the position and width in velocity space of the impulsive momentum-space flux, and, in particular, the dc toroidal electric field.

  19. Axial diagnostic package for Z

    SciTech Connect (OSTI)

    Nash, T.J.; Derzon, M.S.; Chandler, G.

    1998-06-01

    The authors have developed and fielded an axial diagnostic package for the 20 MA, 100 ns, z-pinch driver Z. The package is used to diagnose dynamic hohlraum experiments which require an axial line of sight. The heart of the package is a reentrant cone originally used to diagnose ion-beam-driven hohlraums on PBFA-H. It has one diagnostic line of sight at 0 degrees, 4 at 6 degrees, and 4 at 9 degrees. In addition it has a number of viewing, alignment, and vacuum feedthrough ports. The front of the package sits approximately 5 feet from the pinch. This allows much closer proximity to the pinch, with inherently better resolution and signal, than is presently possible in viewing the pinch from the side. Debris that is preferentially directed along the axis is mitigated by two apertures for each line of sight, and by fast valves and imaging pinholes or cross slits for each diagnostic. In the initial run with this package they fielded a time resolved pinhole camera, a five-channel pinhole-apertured x-ray diode array, a bolometer, a spatially resolved time-integrated crystal spectrometer, and a spatially and temporally resolved crystal spectrometer. They present data obtained from these diagnostics in the dynamic hohlraum research conducted on Z.

  20. Electric field-induced magnetic switching in Mn:ZnO film

    SciTech Connect (OSTI)

    Ren, S. X.; Sun, G. W.; Zhao, J.; Dong, J. Y.; Zhao, X.; Chen, W.; Wei, Y.; Ma, Z. C.

    2014-06-09

    A large magnetic modulation, accompanied by stable bipolar resistive switching (RS) behavior, was observed in a Mn:ZnO film by applying a reversible electric field. A significant enhancement of the ferromagnetism of the film, to about five times larger than that in the initial (as-grown) state (IS), was obtained by switching the film into the low resistance state. X-ray photoelectron spectroscopy demonstrated the existence of abundant oxygen vacancies in the IS of the film. We suggest that this electric field-induced magnetic switching effect originates with the migration and redistribution of oxygen vacancies during RS. Our work indicates that electric switching is an effective and simple method to increase the ferromagnetism of diluted magnetic oxide films. This provides a promising direction for research in spintronic devices.

  1. Field Operations Program, Toyota PRIUS Hybrid Electric Vehicle Performance Characterization Report

    SciTech Connect (OSTI)

    Francfort, James Edward; Nguyen, N.; Phung, J.; Smith, J.; Wehrey, M.

    2001-12-01

    The U.S. Department of Energy’s Field Operations Program evaluates advanced technology vehicles in real-world applications and environments. Advanced technology vehicles include pure electric, hybrid electric, hydrogen, and other vehicles that use emerging technologies such as fuel cells. Information generated by the Program is targeted to fleet managers and others considering the deployment of advanced technology vehicles. As part of the above activities, the Field Operations Program has initiated the testing of the Toyota Prius hybrid electric vehicle (HEV), a technology increasingly being considered for use in fleet applications. This report describes the Pomona Loop testing of the Prius, providing not only initial operational and performance information, but also a better understanding of HEV testing issues. The Pomona Loop testing includes both Urban and Freeway drive cycles, each conducted at four operating scenarios that mix minimum and maximum payloads with different auxiliary (e.g., lights, air conditioning) load levels.

  2. Control of high-order harmonics for attoscience using a static-electric-field pattern

    SciTech Connect (OSTI)

    Serrat, Carles

    2011-12-15

    Quantum control in high-order-harmonic generation is considered theoretically by using a spatial distribution of static electric fields along the propagation direction of the driving field. It is shown that the trajectories of the electrons during its acceleration by the laser field in the high-harmonics-generation process can be controlled by periodically distributed static electric fields, which conveniently shape the driving laser field during propagation. Applying this mechanism, a quasi-phase-matching scheme that leads to filtered enhanced high harmonics is achieved. The harmonics in the plateau region are enhanced due to periodical phase variations in the long quantum trajectories as a consequence of the faster change experienced by the intensity-dependent phase along the longer electron trajectories. This effect should be observed in all quasi-phase-matching schemes based on perturbation of the microscopic quantum phase. The richness of adding a static-electric-field spatial pattern in the interaction region suggests a general scheme for feedback loop control in high-order-harmonic generation.

  3. Effective tight-binding model for MX2 under electric and magnetic fields

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

    Shanavas, Kavungal Veedu; Satpathy, S.

    2015-06-15

    We present a systematic method for developing a five band Hamiltonian for the metal d orbitals that can be used to study the effect of electric and magnetic fields on multilayer MX2 (M=Mo,W and X=S,Se) systems. On a hexagonal lattice of d orbitals, the broken inversion symmetry of the monolayers is incorporated via fictitious s orbitals at the chalcogenide sites. A tight-binding Hamiltonian is constructed and then downfolded to get effective d orbital overlap parameters using quasidegenerate perturbation theory. The steps to incorporate the effects of multiple layers, external electric and magnetic fields are also detailed. We find that anmore » electric field produces a linear-k Rashba splitting around the Γ point, while a magnetic field removes the valley pseudospin degeneracy at the ±K points. Lastly, our model provides a simple tool to understand the recent experiments on electric and magnetic control of valley pseudospin in monolayer dichalcogendies.« less

  4. Electric and Magnetic Fields (EMF) RAPID Engineering Program, Project 7: Development of Field Exposure Models

    SciTech Connect (OSTI)

    Bracken, T.D.; Rankin, R.F.; Wiley, J.A.

    1999-05-01

    The purpose of this project was to develop a conceptual model for estimating magnetic field (EMF) personal exposure (PE) of individuals or groups and construct a working model using existing data.

  5. Electric field effects in graphene/LaAlO{sub 3}/SrTiO{sub 3}...

    Office of Scientific and Technical Information (OSTI)

    exfoliation and transfer from chemical-vapor deposition on ultraflat copper substrates. ... MICROSCOPY; CHEMICAL VAPOR DEPOSITION; COPPER; ELECTRIC FIELDS; ENERGY BEAM DEPOSITION; ...

  6. The influence of intense electric fields on three-dimensional asymmetric magnetic reconnection

    SciTech Connect (OSTI)

    Pritchett, P. L.

    2013-06-15

    A three-dimensional particle-in-cell simulation of magnetic reconnection in an asymmetric configuration without a guide field and with temperature ratio T{sub i}/T{sub e}>1 demonstrates that intense perpendicular electric fields are produced on the low-density side of the current layer where there is a strong gradient in the plasma density. The simulation shows that the 3-D reconnection rate is unaffected by these intense electric fields, that the electron current layer near the X line remains coherent and does not break up, but that localized regions of strong energy dissipation exist along the low-density separatrices. Near the X line the dominant term in the generalized Ohm's law for the reconnection electric field remains the off-diagonal electron pressure gradient ∂P{sub exy}/∂x. On the low-beta separatrix, however, the anomalous drag −<δnδE{sub y}>/ makes an equally important contribution to that of the pressure gradient to the average E{sub y} field.

  7. Recent studies in the behavioral toxicology of ELF electric and magnetic fields

    SciTech Connect (OSTI)

    Lovely, R.H.

    1988-01-01

    Behavioral responses to ELF electric and magnetic fields are reviewed starting with the simple sensory awareness or detection by an animal and moving on through more-complicated behavioral responses such as behavior that averts exposure. The literature selected in this review is taken primarily from the area of behavioral toxicology. As such, it does not review work on specialized response systems to ELF fields. The most notable of these omitted specialized response systems are electroreception, which occurs in a number of fish species, and homing/navigation and communication of the location of food that occurs in several species of birds and in honeybees, respectively. The toxicologic orientation of most researches that evaluate the effects of exposure to ELF electric and magnetic fields has been influenced primarily by the missions of DOE and the power industry programs to determine the health effects of power frequency (50- and 60-Hz) electric and magnetic fields. Because of these large programmatic efforts, most of the recent research has in fact been done at 50 or 60 Hz. In the context of the above limitations, remarkably few robust behavioral effects have been reported. Those that have been reported probably relate to an animal's perception of the electric field, although there are some exceptions to this generalization. The apparent lack of deleterious effects in animals is consistent with recent studies on humans that have been conducted in the UK. With this in mind, it is tempting to conclude that exposure to an ELF field is a rather innocuous event and, other than possible mini-shocks, is without hazard. 43 references.

  8. Sensitivity Reach of the Neutron EDM Experiment: The Electric Field Strength

    SciTech Connect (OSTI)

    Hennings-Yeomans, R.; Cooper, M.; Currie, S. A.; Makela, M. F.; Ramsey, J. C.; Tajima, S.; Womack, T. L.; Long, J. C.; Stanislaus, S.

    2010-08-04

    The search for an electric dipole moment of the neutron tests physics beyond the Standard Model such as new sources of CP-violation and Supersymmetry. The nEDM experiment aims to improve the sensitivity on the current limit of the electric dipole moment of the neutron to <10{sup -27} e{center_dot}cm. The experiment will use a flux of Ultra Cold Neutrons (UCNs) produced and stored in a bath of superfluid He-II. A change in precession frequency is expected for a non-zero EDM when an electric field is applied parallel and antiparallel to a magnetic field across the neutron storage cell. A dominant parameter in terms of reducing the statistical uncertainty of this measurement is the strength of the applied electric field. An experiment to measure if superfluid He-II can sustain up to 50 kV/cm for a volume and electrode spacings comparable to the nEDM experiment has been constructed at Los Alamos National Laboratory. It consists in a large-area parallel plate capacitor immersed in a 200 liter central volume inside a suitable cryostat that in turn is connected to a dilution refrigerator unit. A description of test runs and the status of the experiment is presented.

  9. Biological interactions of extremely-low-frequency electric and magnetic fields

    SciTech Connect (OSTI)

    Tenforde, T.S.

    1990-03-01

    A description is given of the fundamental physical properties of extremely-low frequency (ELF) electromagnetic fields, and the mechanisms through which these fields interact with the human body at a macroscopic level. the mechanisms through which ELF electric and magnetic fields induce currents in humans and other living objects are described. Evidence is presented that cell membranes play an important role in transducing ELF signals. Both experimental evidence and theoretical models are described that relate pericellular currents and electrochemical events at the outer membrane surface to transmembrane signaling pathways and cytoplasmic responses. Biological responses to ELF fields at the tissue, cellular and molecular levels are summarized, including new evidence that ELF field exposure produces alterations in messenger RNA synthesis, gene expression and the cytoplasmic concentrations of specific proteins. 50 refs., 9 figs., 2 tabs.

  10. Effect of a uniform electric field on soot in laminar premixed ethylene/air flames

    SciTech Connect (OSTI)

    Wang, Y.; Yao, Q. [Key Laboratory of Thermal Science and Power Engineering of Ministry of Education, Department of Thermal Engineering, Tsinghua University, 100084 Beijing (China); Nathan, G.J. [School of Mechanical Engineering, Centre for Energy Technology, The University of Adelaide, S.A. 5005 (Australia); Alwahabi, Z.T.; King, K.D.; Ho, K. [School of Chemical Engineering, Centre for Energy Technology, The University of Adelaide, S.A. 5005 (Australia)

    2010-07-15

    The effect of a nominally uniform electric field on the initially uniform distribution of soot has been assessed for laminar premixed ethylene/air flames from a McKenna burner. An electrophoretic influence on charged soot particles was measured through changes to the deposition rate of soot on the McKenna plug, using laser extinction (LE). Soot volume fraction was measured in situ using laser-induced incandescence (LII). Particle size and morphologies were assessed through ex situ transmission electron microscopy (TEM) using thermophoretic sampling particle diagnostics (TSPD). The results show that the majority of these soot particles are positively charged. The presence of a negatively charged plug was found to decrease the particle residence times in the flame and to influence the formation and oxidation progress. A positively charged plug has the opposite effect. The effect on soot volume fraction, particles size and morphology with electric field strength is also reported. Flame stability was also found to be affected by the presence of the electric field, with the balance of the electrophoretic force and drag force controlling the transition to unstable flame flicker. The presence of charged species generated by the flame was found to reduce the dielectric field strength to one seventh that of air. (author)

  11. Endogenous field feedback promotes the detectability for exogenous electric signal in the hybrid coupled population

    SciTech Connect (OSTI)

    Wei, Xile; Zhang, Danhong; Wang, Jiang; Yu, Haitao; Lu, Meili; Che, Yanqiu

    2015-01-15

    This paper presents the endogenous electric field in chemical or electrical synaptic coupled networks, aiming to study the role of endogenous field feedback in the signal propagation in neural systems. It shows that the feedback of endogenous fields to network activities can reduce the required energy of the noise and enhance the transmission of input signals in hybrid coupled populations. As a common and important nonsynaptic interactive method among neurons, particularly, the endogenous filed feedback can not only promote the detectability of exogenous weak signal in hybrid coupled neural population but also enhance the robustness of the detectability against noise. Furthermore, with the increasing of field coupling strengths, the endogenous field feedback is conductive to the stochastic resonance by facilitating the transition of cluster activities from the no spiking to spiking regions. Distinct from synaptic coupling, the endogenous field feedback can play a role as internal driving force to boost the population activities, which is similar to the noise. Thus, it can help to transmit exogenous weak signals within the network in the absence of noise drive via the stochastic-like resonance.

  12. Semi-flexible gas-insulated transmission line using electric field stress shields

    DOE Patents [OSTI]

    Cookson, A.H.; Dale, S.J.; Bolin, P.C.

    1982-12-28

    A gas-insulated transmission line includes an outer sheath, an inner conductor, an insulating gas electrically insulating the inner conductor from the outer sheath, and insulating supports insulatably supporting the inner conductor within the outer sheath. The inner conductor is provided with flexibility by use of main conductor sections which are joined together through a conductor hub section and flexible flexing elements. Stress shields are provided to control the electric field at the locations of the conductor hub sections where the insulating supports are contacting the inner conductor. The flexing elements and the stress shields may also be utilized in connection with a plug and socket arrangement for providing electrical connection between main conductor sections. 10 figs.

  13. Semi-flexible gas-insulated transmission line using electric field stress shields

    DOE Patents [OSTI]

    Cookson, Alan H.; Dale, Steinar J.; Bolin, Philip C.

    1982-12-28

    A gas-insulated transmission line includes an outer sheath, an inner conductor, an insulating gas electrically insulating the inner conductor from the outer sheath, and insulating supports insulatably supporting the inner conductor within the outer sheath. The inner conductor is provided with flexibility by use of main conductor sections which are joined together through a conductor hub section and flexible flexing elements. Stress shields are provided to control the electric field at the locations of the conductor hub sections where the insulating supports are contacting the inner conductor. The flexing elements and the stress shields may also be utilized in connection with a plug and socket arrangement for providing electrical connection between main conductor sections.

  14. Simulation of Electric Field in Semi Insulating Au/CdTe/Au Detector under Flux

    SciTech Connect (OSTI)

    Franc, J.; James, R.; Grill, R.; Kubat, J.; Belas, E.; Hoschl, P.; Moravec, P.; Praus, P.

    2009-08-02

    We report our simulations on the profile of the electric field in semi insulating CdTe and CdZnTe with Au contacts under radiation flux. The type of the space charge and electric field distribution in the Au/CdTe/Au structure is at high fluxes result of a combined influence of charge formed due to band bending at the electrodes and from photo generated carriers, which are trapped at deep levels. Simultaneous solution of drift-diffusion and Poisson equations is used for the calculation. We show, that the space charge originating from trapped photo-carriers starts to dominate at fluxes 10{sup 15}-10{sup 16}cm{sup -2}s{sup -1}, when the influence of contacts starts to be negligible.

  15. K-shell spectroscopy of silicon ions as diagnostic for high electric fields

    SciTech Connect (OSTI)

    Loetzsch, R.; Jaeckel, O.; Hoefer, S.; Kaempfer, T.; Uschmann, I.; Kaluza, M. C.; Polz, J.; Foerster, E.; Stambulchik, E.; Kroupp, E.; Maron, Y.

    2012-11-15

    We developed a detection scheme, capable of measuring X-ray line shape of tracer ions in {mu}m thick layers at the rear side of a target foil irradiated by ultra intense laser pulses. We performed simulations of the effect of strong electric fields on the K-shell emission of silicon and developed a spectrometer dedicated to record this emission. The combination of a cylindrically bent crystal in von Hamos geometry and a CCD camera with its single photon counting capability allows for a high dynamic range of the instrument and background free spectra. This approach will be used in future experiments to study electric fields of the order of TV/m at high density plasmas close to solid density.

  16. SEM technique for imaging and measuring electronic transport in nanocomposites based on electric field induced contrast

    DOE Patents [OSTI]

    Jesse, Stephen [Knoxville, TN; Geohegan, David B. [Knoxville, TN; Guillorn, Michael [Brooktondale, NY

    2009-02-17

    Methods and apparatus are described for SEM imaging and measuring electronic transport in nanocomposites based on electric field induced contrast. A method includes mounting a sample onto a sample holder, the sample including a sample material; wire bonding leads from the sample holder onto the sample; placing the sample holder in a vacuum chamber of a scanning electron microscope; connecting leads from the sample holder to a power source located outside the vacuum chamber; controlling secondary electron emission from the sample by applying a predetermined voltage to the sample through the leads; and generating an image of the secondary electron emission from the sample. An apparatus includes a sample holder for a scanning electron microscope having an electrical interconnect and leads on top of the sample holder electrically connected to the electrical interconnect; a power source and a controller connected to the electrical interconnect for applying voltage to the sample holder to control the secondary electron emission from a sample mounted on the sample holder; and a computer coupled to a secondary electron detector to generate images of the secondary electron emission from the sample.

  17. Dynamics of particle production by strong electric fields in non-Abelian plasmas

    SciTech Connect (OSTI)

    Dawson, John F.; Mihaila, Bogdan; Cooper, Fred

    2010-03-01

    We develop methods for computing the dynamics of fermion pair production by strong color electric fields including backreaction using the semiclassical Boltzmann-Vlasov (B-V) equation. We implement the Schwinger pair production by inserting a source term in the B-V equation which includes Pauli-Blocking effects. We present numerical results for a model with SU(2) symmetries in (1+1) Cartesian dimensions.

  18. Organic Photovoltaic Cells with an Electric Field Integrally-Formed at the

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

    Heterojunction Interface - Energy Innovation Portal Solar Photovoltaic Solar Photovoltaic Find More Like This Return to Search Organic Photovoltaic Cells with an Electric Field Integrally-Formed at the Heterojunction Interface National Renewable Energy Laboratory Brookhaven National Laboratory Contact NREL About This Technology Figure 4 Figure 4 Figure 6 Figure 6 Technology Marketing SummaryStandard solar cells made from inorganic semiconductors, such as silicon cells, have dominated the

  19. Detection of pico-Tesla magnetic fields using magneto-electric sensors at room temperature

    SciTech Connect (OSTI)

    Zhai Junyi; Xing Zengping; Dong Shuxiang; Li Jiefang; Viehland, D. [Department of Materials Science and Engineering, Virginia Tech, Blacksburg, Virginia 24061 (United States)

    2006-02-06

    The measurement of low-frequency (10{sup -2}-10{sup 3} Hz) minute magnetic field variations (10{sup -12} Tesla) at room temperature in a passive mode of operation would be critically enabling for deployable neurological signal interfacing and magnetic anomaly detection applications. However, there is presently no magnetic field sensor capable of meeting all of these requirements. Here, we present new bimorph and push-pull magneto-electric laminate composites, which incorporate a charge compensation mechanism (or bridge) that dramatically enhances noise rejection, enabling achievement of such requirements.

  20. Dynamical characteristics of Rydberg electrons released by a weak electric field

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

    Diesen, Elias; Saalmann, Ulf; Richter, Martin; Kunitski, Maksim; Dorner, Reinhard; Rost, Jan M.

    2016-04-08

    This paper discuss the dynamics of ultraslow electrons in the combined potential of an ionic core and a static electric field. With state-of-the-art detection it is possible to create such electrons through strong intense-field photoabsorption and to detect them via high-resolution time-of-flight spectroscopy despite their very low kinetic energy. The characteristic feature of their momentum spectrum, which emerges at the same position for different laser orientations, is derived and could be revealed experimentally with an energy resolution of the order of 1 meV.

  1. Modeling electron transport in the presence of electric and magnetic fields.

    SciTech Connect (OSTI)

    Fan, Wesley C.; Drumm, Clifton Russell; Pautz, Shawn D.; Turner, C. David

    2013-09-01

    This report describes the theoretical background on modeling electron transport in the presence of electric and magnetic fields by incorporating the effects of the Lorentz force on electron motion into the Boltzmann transport equation. Electromagnetic fields alter the electron energy and trajectory continuously, and these effects can be characterized mathematically by differential operators in terms of electron energy and direction. Numerical solution techniques, based on the discrete-ordinates and finite-element methods, are developed and implemented in an existing radiation transport code, SCEPTRE.

  2. Note: Versatile sample stick for neutron scattering experiments in high electric fields

    SciTech Connect (OSTI)

    Bartkowiak, M., E-mail: marek.bartkowiak@psi.ch [Laboratory for Developments and Methods, Paul Scherrer Institut, CH-5232 Villigen (Switzerland); White, J. S. [Laboratory for Neutron Scattering, Paul Scherrer Institut, CH-5232 Villigen (Switzerland) [Laboratory for Neutron Scattering, Paul Scherrer Institut, CH-5232 Villigen (Switzerland); Laboratory for Quantum Magnetism, Ecole Polytechnique Fdrale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland); Rnnow, H. M.; Pra, K. [Laboratory for Quantum Magnetism, Ecole Polytechnique Fdrale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland)] [Laboratory for Quantum Magnetism, Ecole Polytechnique Fdrale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland)

    2014-02-15

    We present a versatile high voltage sample stick that fits into all cryomagnets and standard cryostats at the Swiss Spallation Neutron Source, Paul Scherrer Institut, and which provides a low effort route to neutron scattering experiments that combine electric field with low temperature and magnetic field. The stick allows for voltages up to 5 kV and can be easily adapted for different scattering geometries. We discuss the design consideration and thermal behavior of the stick, and give one example to showcase the abilities of the device.

  3. Electric fields effect on liftoff and blowoff of nonpremixed laminar jet flames in a coflow

    SciTech Connect (OSTI)

    Kim, M.K.; Ryu, S.K.; Won, S.H. [School of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-742 (Korea); Chung, S.H. [Clean Combustion Research Center, King Abdullah University of Science and Technology, Thuwal (Saudi Arabia)

    2010-01-15

    The stabilization characteristics of liftoff and blowoff in nonpremixed laminar jet flames in a coflow have been investigated experimentally for propane fuel by applying AC and DC electric fields to the fuel nozzle with a single-electrode configuration. The liftoff and blowoff velocities have been measured by varying the applied voltage and frequency of AC and the voltage and the polarity of DC. The result showed that the AC electric fields extended the stabilization regime of nozzle-attached flame in terms of jet velocity. As the applied AC voltage increased, the nozzle-attached flame was maintained even over the blowout velocity without having electric fields. In such a case, a blowoff occurred directly without experiencing a lifted flame. While for the DC cases, the influence on liftoff was minimal. There existed three different regimes depending on the applied AC voltage. In the low voltage regime, the nozzle-detachment velocity of either liftoff or blowoff increased linearly with the applied voltage, while nonlinearly with the AC frequency. In the intermediate voltage regime, the detachment velocity decreased with the applied voltage and reasonably independent of the AC frequency. At the high voltage regime, the detachment was significantly influenced by the generation of discharges. (author)

  4. Inhomogeneities of plasma density and electric field as sources of electrostatic turbulence in the auroral region

    SciTech Connect (OSTI)

    Ilyasov, Askar A.; Chernyshov, Alexander A. Mogilevsky, Mikhail M.; Golovchanskaya, Irina V. Kozelov, Boris V.

    2015-03-15

    Inhomogeneities of plasma density and non-uniform electric fields are compared as possible sources of a sort of electrostatic ion cyclotron waves that can be identified with broadband extremely low frequency electrostatic turbulence in the topside auroral ionosphere. Such waves are excited by inhomogeneous energy-density-driven instability. To gain a deeper insight in generation of these waves, computational modeling is performed with various plasma parameters. It is demonstrated that inhomogeneities of plasma density can give rise to this instability even in the absence of electric fields. By using both satellite-observed and model spatial distributions of plasma density and electric field in our modeling, we show that specific details of the spatial distributions are of minor importance for the wave generation. The solutions of the nonlocal inhomogeneous energy-density-driven dispersion relation are investigated for various ion-to-electron temperature ratios and directions of wave propagation. The relevance of the solutions to the observed spectra of broadband extremely low frequency emissions is shown.

  5. Electric field induced needle-pulsed arc discharge carbon nanotube production apparatus: Circuitry and mechanical design

    SciTech Connect (OSTI)

    Kia, Kaveh Kazemi; Bonabi, Fahimeh

    2012-12-15

    A simple and low cost apparatus is reported to produce multiwall carbon nanotubes and carbon nano-onions by a low power short pulsed arc discharge reactor. The electric circuitry and the mechanical design details and a micro-filtering assembly are described. The pulsed-plasma is generated and applied between two graphite electrodes. The pulse width is 0.3 {mu}s. A strong dc electric field is established along side the electrodes. The repetitive discharges occur in less than 1 mm distance between a sharp tip graphite rod as anode, and a tubular graphite as cathode. A hydrocarbon vapor, as carbon source, is introduced through the graphite nozzle in the cathode assembly. The pressure of the chamber is controlled by a vacuum pump. A magnetic field, perpendicular to the plasma path, is provided. The results show that the synergetic use of a pulsed-current and a dc power supply enables us to synthesize carbon nanoparticles with short pulsed plasma. The simplicity and inexpensiveness of this plan is noticeable. Pulsed nature of plasma provides some extra degrees of freedom that make the production more controllable. Effects of some design parameters such as electric field, pulse frequency, and cathode shape are discussed. The products are examined using scanning probe microscopy techniques.

  6. Diagnosis of magnetic and electric fields of chromospheric jets through spectropolarimetric observations of H I Paschen lines

    SciTech Connect (OSTI)

    Anan, T.; Ichimoto, K.; Casini, R. E-mail: ichimoto@kwasan.kyoto-u.ac.jp

    2014-05-10

    Magnetic fields govern the plasma dynamics in the outer layers of the solar atmosphere, and electric fields acting on neutral atoms that move across the magnetic field enable us to study the dynamical coupling between neutrals and ions in the plasma. In order to measure the magnetic and electric fields of chromospheric jets, the full Stokes spectra of the Paschen series of neutral hydrogen in a surge and in some active region jets that took place at the solar limb were observed on 2012 May 5, using the spectropolarimeter of the Domeless Solar Telescope at Hida observatory, Japan. First, we inverted the Stokes spectra taking into account only the effect of magnetic fields on the energy structure and polarization of the hydrogen levels. Having found no definitive evidence of the effects of electric fields in the observed Stokes profiles, we then estimated an upper bound for these fields by calculating the polarization degree under the magnetic field configuration derived in the first step, with the additional presence of a perpendicular (Lorentz type) electric field of varying strength. The inferred direction of the magnetic field on the plane of the sky approximately aligns to the active region jets and the surge, with magnetic field strengths in the range 10 G < B < 640 G for the surge. Using magnetic field strengths of 70, 200, and 600 G, we obtained upper limits for possible electric fields of 0.04, 0.3, and 0.8 V cm{sup –1}, respectively. This upper bound is conservative, since in our modeling we neglected the possible contribution of collisional depolarization. Because the velocity of neutral atoms of hydrogen moving across the magnetic field derived from these upper limits of the Lorentz electric field is far below the bulk velocity of the plasma perpendicular to the magnetic field as measured by the Doppler shift, we conclude that the neutral atoms must be highly frozen to the magnetic field in the surge.

  7. Dependence of nuclear quadrupole resonance transitions on the electric field gradient asymmetry parameter for nuclides with half-integer spins

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

    Cho, Herman

    2016-02-28

    Allowed transition energies and eigenstate expansions have been calculated and tabulated in numerical form as functions of the electric field gradient asymmetry parameter for the zero field Hamiltonian of quadrupolar nuclides with I = 3/2,5/2,7/2, and 9/2. These results are essential to interpret nuclear quadrupole resonance (NQR) spectra and extract accurate values of the electric field gradient tensors. Furthermore, applications of NQR methods to studies of electronic structure in heavy element systems are proposed.

  8. Method of sustaining a radial electric field and poloidal plasma rotation over most of the cross-section of a tokamak

    DOE Patents [OSTI]

    Darrow, Douglass S.; Ono, Masayuki

    1990-01-01

    A radial electric field of a desired magnitude and configuration is created hroughout a substantial portion of the cross-section of the plasma of a tokamak. The radial electric field is created by injection of a unidirectional electron beam. The magnitude and configuration of the radial electric field may be controlled by the strength of the toroidal magnetic field of the tokamak.

  9. Method of sustaining a radial electric field and poloidal plasma rotation over most of the cross-section of a tokamak

    DOE Patents [OSTI]

    Darrow, Douglass S.; Ono, Masayuki

    1990-03-06

    A radial electric field of a desired magnitude and configuration is created throughout a substantial portion of the cross-section of the plasma of a tokamak. The radial electric field is created by injection of a unidirectional electron beam. The magnitude and configuration of the radial electric field may be controlled by the strength of the toroidal magnetic field of the tokamak.

  10. CO2 Capture Using Electric Fields: Low-Cost Electrochromic Film on Plastic for Net-Zero Energy Building

    SciTech Connect (OSTI)

    2010-01-01

    Broad Funding Opportunity Announcement Project: Two faculty members at Lehigh University created a new technique called supercapacitive swing adsorption (SSA) that uses electrical charges to encourage materials to capture and release CO2. Current CO2 capture methods include expensive processes that involve changes in temperature or pressure. Lehigh University’s approach uses electric fields to improve the ability of inexpensive carbon sorbents to trap CO2. Because this process uses electric fields and not electric current, the overall energy consumption is projected to be much lower than conventional methods. Lehigh University is now optimizing the materials to maximize CO2 capture and minimize the energy needed for the process.

  11. Investigation of exposure to Extremely Low Frequency (ELF) magnetic and electric fields: Ongoing animal studies

    SciTech Connect (OSTI)

    Anderson, L.E.

    1994-03-01

    There is now convincing evidence from a large number of laboratories, that exposure to extremely low frequency (ELF) magnetic and electric fields produces biological responses in animals. Many of the observed effects appear to be directly or indirectly associated with the neural or neuroendocrine systems. Such effects include increased neuronal excitability, chemical and hormonal changes in the nervous system, altered behavioral responses, some of which are related to sensing the presence of the field, and changes in endogenous biological rhythms. Additional indices of general physiological status appear relatively unaffected by exposure, although effects have occasionally been described in bone growth and fracture repair, reproduction and development, and immune system function. A major current emphasis in laboratory research is to determine whether or not the reported epidemiological studies that suggest an association between EMF exposure and risk of cancer are supported in studies using animal models. Three major challenges exist for ongoing research: (1) knowledge about the mechanisms underlying observed bioeffects is incomplete, (2) researchers do not as yet understand what physical aspects of exposure produce biological responses, and (3) health consequences resulting from ELF exposure are unknown. Although no animal studies clearly demonstrate deleterious effects of ELF fields, several are suggestive of potential health impacts. From the perspective of laboratory animal studies, this paper will discuss biological responses to ELF magnetic and/or electric field exposures.

  12. Controlled nanopatterning of a polymerized ionic liquid in a strong electric field

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

    Bocharova, Vera; Agapov, Alexander L.; Tselev, Alexander; Kumar, Rajeev; Berdzinski, Stefan; Strehmel, Veronika; Kisliuk, Alexander; Kravchenko, Ivan I.; Sumpter, Bobby G.; Sokolov, Alexei P.; et al

    2014-12-17

    Nanolithography has become a driving force in advancements of the modern day's electronics, allowing for miniaturization of devices and a steady increase of the calculation, power, and storage densities. Among various nanofabrication approaches, scanning probe techniques, including atomic force microscopy (AFM), are versatile tools for creating nanoscale patterns utilizing a range of physical stimuli such as force, heat, or electric field confined to the nanoscale. In this study, the potential of using the electric field localized at the apex of an AFM tip to induce and control changes in the mechanical properties of an ion containing polymer—a polymerized ionic liquidmore » (PolyIL)—on a very localized scale is explored. In particular, it is demonstrated that by means of AFM, one can form topographical features on the surface of PolyIL-based thin films with a significantly lower electric potential and power consumption as compared to nonconductive polymer materials. Lastly,, by tuning the applied voltage and ambient air humidity, control over dimensions of the formed structures is reproducibly achieved.« less

  13. On the smoothness of electric fields near plane gratings of cylindrical conductors

    SciTech Connect (OSTI)

    Judd, D.L.

    1995-02-01

    The electric field near an infinite plane grating of equally spaced round rods at the same potential, forming the boundary of a uniform field, is determined analytically to good accuracy by conformal transformations and evaluated numerically. This contribution, which has a frankly pedagogical flavor, to the Klaus Halbach Festschrift is offered to honor his displayed mastery of conformal techniques. Although the numerical work and the form of its presentation are new, the transformation used is not original. However, to locate its antecedents in an archival journal it was necessary to seek out a paper published in 1923 (close to the year of his birth, and of mine), in a place obscure to modern physicists, so the authors efforts cannot be said to replicate recent published work. A new insight is obtained in the form of a simple estimate of departures from field uniformity at all distances from rods of any size.

  14. Enhanced excitonic photoconductivity due to built-in internal electric field in TlGaSe{sub 2} layered semiconductor

    SciTech Connect (OSTI)

    Seyidov, MirHasan Yu. Suleymanov, Rauf A.; ?ale, Yasin; Balaban, Ertan

    2014-12-07

    The strong enhancement, by several orders of magnitude, of the excitonic peak within the photoconductivity spectrum of TlGaSe{sub 2} semiconductor was observed. The samples were polarized in external dc electric field, which was applied prior to the measurements. Due to the accumulation of charges near the surface, an internal electric field was formed. Electron-hole pairs that were created after the absorption of light are fallen in and then separated by the built-in electric field, which prevents radiative recombination process.

  15. Method for extracting relevant electrical parameters from graphene field-effect transistors using a physical model

    SciTech Connect (OSTI)

    Boscá, A.; Pedrós, J.; Martínez, J.; Calle, F.

    2015-01-28

    Due to its intrinsic high mobility, graphene has proved to be a suitable material for high-speed electronics, where graphene field-effect transistor (GFET) has shown excellent properties. In this work, we present a method for extracting relevant electrical parameters from GFET devices using a simple electrical characterization and a model fitting. With experimental data from the device output characteristics, the method allows to calculate parameters such as the mobility, the contact resistance, and the fixed charge. Differentiated electron and hole mobilities and direct connection with intrinsic material properties are some of the key aspects of this method. Moreover, the method output values can be correlated with several issues during key fabrication steps such as the graphene growth and transfer, the lithographic steps, or the metalization processes, providing a flexible tool for quality control in GFET fabrication, as well as a valuable feedback for improving the material-growth process.

  16. Electric and magnetic fields research and public information dissemination program. Progress report

    SciTech Connect (OSTI)

    1995-12-01

    The Electric and Magnetic Fields (EMF) Research and Public Information Dissemination (RAPID) Program was authorized by the Energy Policy Act of 1992 (enacted October 24, 1992) to determine whether or not exposure to EMF produced by the generation, transmission, and use of electric energy affects human health. Two Federal agencies, the Department of Energy (DOE) and the National Institute of Environmental Health Sciences (NIEHS), have primary responsibility for the program, but other Federal agencies are key participants as well. This program requires that Federal appropriations be matched by contributions from non-Federal sources. The authorized level of funding for the program was $65 million over a 5-year period (fiscal years 1993-1997 inclusive). For EMF RAPID to be a fully funded program, $32.5 million over 5 years will have to be appropriated by Congress and matched by non-Federal contributions.

  17. Apparatus for sensing patterns of electrical field variations across a surface

    DOE Patents [OSTI]

    Warren, William L.; Devine, Roderick A. B.

    2001-01-01

    An array of nonvolatile field effect transistors used to sense electric potential variations. The transistors owe their nonvolatility to the movement of protons within the oxide layer that occurs only in response to an externally applied electric potential between the gate on one side of the oxide and the source/drain on the other side. The position of the protons within the oxide layer either creates or destroys a conducting channel in the adjacent source/channel/drain layer below it, the current in the channel being measured as the state of the nonvolatile memory. The protons can also be moved by potentials created by other instrumentalities, such as charges on fingerprints or styluses above the gates, pressure on a piezoelectric layer above the gates, light shining upon a photoconductive layer above the gates. The invention allows sensing of fingerprints, handwriting, and optical images, which are converted into digitized images thereof in a nonvolatile format.

  18. Electric and magnetic field exposures for people living near a 735-Kilovolt power line

    SciTech Connect (OSTI)

    Levallois, P.; Gauvin, D.; St. Laurent, J.

    1995-09-01

    The purpose of this study was to assess the effect of a 735-kV transmission line on the electric and magnetic field exposures of people living at the edge of the line`s right of way. Exposure of 18 adults, mostly white-collar workers, living in different bungalows located 190-240 feet from the line (exposed subjects) was compared to that of 17 adults living in similar residences far away from any transmission line. Each subject carried a Positron meter for 24 hr during 1 workday, which measured 60-Hz electric and magnetic fields every minute. All measurements were carried out in parallel for exposed and unexposed subjects during the same weeks between September and December. During measurements the average loading on the line varied between 600 and 1100 A. The average magnetic field intensity while at home was 4.4 times higher among exposed subjects than unexposed (7.1 versus 1.6 Mg, p=0.0001) and 6.2 times higher when considering only the sleeping period (6.8 versus 1.1 mG, p=0.0001). Based on the 24-hr measurement, average magnetic field exposure was three times higher among the exposed was positively correlated with the loading on the line (r=0.8, p+0.001). Percentage of time above a magnetic field threshold F(2 mG or 7.8 mG) was a good indicator to distinguish the two types of exposure. Percentage of time above 20 V/m was significantly different, but percentage of time above 78 V/m was rare and comparable for the two groups. Variability of exposure was very low. This study demonstrates that a 735-kV line contributes significantly to residential 60-Hz magnetic field exposure and, to a lesser extent, electric fields for people living at the edge of the right way. Because of the limited size of our sample, caution is recommended before generalizing these results. Nevertheless, due to the uncertainty on the risks associated with such an unusual high residential exposure, research is needed on its possible effects. 30 refs., 1 fig., 7 tabs.

  19. Electrical breakdown at low pressure in the presence of a weak magnetic field

    SciTech Connect (OSTI)

    Alport, M.J.; Antoniades, J.A.; Boyd, D.A.; Greaves, R.G.; Ellis, R.F. )

    1990-05-01

    Electron trapping in crossed electric and magnetic fields is an important mechanism by which electrical discharges can develop in low pressure gases. The authors report observations of discharges produced by this mechanism around a spherical anode in two space simulation chambers, namely the Space Plasma Interaction Experiment (SPIE) at the University of Maryland, and the NASA-Lewis B-2 chamber. They have identified two types of discharges in these experiments. In the B-2 chamber, the breakdown takes the form of a runaway dischage with spherical topology, limited only by the ability of the power supply to provide the current. In the SPIE chamber this type of discharge also occurs, in addition to a low current toroidal discharge which is observed at higher magnetic fields. They present measurements of both types of discharge and show how the trapping effect of the magnetic field together with secondary electron emission by high energy ion bombardment of the chamber walls may initiate and sustains these discharges.

  20. Probing the plasma near high power wave launchers in fusion devices for static and dynamic electric fields (invited)

    SciTech Connect (OSTI)

    Klepper, C. C. Isler, R. C.; Biewer, T. M.; Caughman, J. B.; Green, D. L.; Harris, J. H.; Hillis, D. L.; Martin, E. H.; Colas, L.; Goniche, M.; Hillairet, J.; Panayotis, S.; Pegourié, B.; Jacquot, J.; Lotte, Ph.; Colledani, G.; Ekedahl, A.; Litaudon, X.; Shannon, S. C.

    2014-11-15

    An exploratory study was carried out in the long-pulse tokamak Tore Supra, to determine if electric fields in the plasma around high-power, RF wave launchers could be measured with non-intrusive, passive, optical emission spectroscopy. The focus was in particular on the use of the external electric field Stark effect. The feasibility was found to be strongly dependent on the spatial extent of the electric fields and overlap between regions of strong (>∼1 kV/cm) electric fields and regions of plasma particle recycling and plasma-induced, spectral line emission. Most amenable to the measurement was the RF electric field in edge plasma, in front of a lower hybrid heating and current drive launcher. Electric field strengths and direction, derived from fitting the acquired spectra to a model including time-dependent Stark effect and the tokamak-range magnetic field Zeeman-effect, were found to be in good agreement with full-wave modeling of the observed launcher.

  1. Probing the plasma near high power wave launchers in fusion devices for static and dynamic electric fields

    SciTech Connect (OSTI)

    Klepper, C Christopher; Martin, Elijah H; Isler, Ralph C; Colas, L.; Goniche, M.; Hillairet, J.; Panayotis, Stephanie; Jacquot, Jonathan; Lotte, Ph.; Colledani, G.; Biewer, Theodore M; Caughman, J. B. O.; Ekedahl, A.; Green, David L; Harris, Jeffrey H; Hillis, Donald Lee; Shannon, Prof. Steven; Litaudon, X

    2014-01-01

    An exploratory study was carried out in the long-pulse tokamak Tore Supra, to determine if electric fields in the plasma around high-power, RF wave launchers could be measured with non-intrusive, passive, optical emission spectroscopy. The focus was in particular on the use of the external electric field Stark effect. The feasibility was found to be strongly dependent on the spatial extent of the electric fields and overlap between regions of strong (> 1 kV/cm) electric fields and regions of plasma particle recycling and plasma-induced, spectral line emission. Most amenable to the measurement was the RF electric field in edge plasma, in front of a lower hybrid heating and current drive launcher. Electric field strengths and direction, derived from fitting the acquired spectra to a model including time-dependent Stark effect and the tokamak-range magnetic field Zeeman-effect, were found to be in good agreement with full-wave modeling of the observed launcher.

  2. Thin film deposition by electric and magnetic crossed-field diode sputtering. [Patent application

    DOE Patents [OSTI]

    Welch, K.M.

    1975-04-04

    Applying a coating of titanium nitride to a klystron window by means of a cross-field diode sputtering array is described. The array is comprised of a cohesive group of numerous small hollow electrically conducting cylinders and is mounted so that the open ends of the cylinders on one side of the group are adjacent to a titanium cathode plate. The workpiece is mounted so as to face the open ends of the other side of the group. A magnetic field is applied to the array so as to be coaxial with the cylinders and a potential is applied across the cylinders and the cathode plate, the cylinders as an anode being positive with respect to the cathode plate. The cylinders, the cathode plate, and the workpiece are situated in an atmosphere of nitrogen which becomes ionized such as by field emission because of the electric field between the cylinders and cathode plate, thereby establishing an anode-cathode discharge that results in sputtering of the titanium plate. The sputtered titanium coats the workpiece and chemically combines with the nitrogen to form a titanium nitride coating on the workpiece. Gas pressure, gas mixtures, cathode material composition, voltages applied to the cathode and anode, the magnetic field, cathode, anode and workpiece spacing, and the aspect ratio (ratio of length to inner diameter) of the anode cylinders, all may be controlled to provide consistent optimum thin film coatings of various compositions and thickness. Another facet of the disclosure is the coating of microwave components per se with titanium nitride to reduce multifactoring under operating conditions of the components.

  3. Thin film deposition by electric and magnetic crossed-field diode sputtering

    DOE Patents [OSTI]

    Welch, Kimo M.

    1977-01-01

    Applying a thin film coating to the surface of a workpiece, in particular, applying a coating of titanium nitride to a klystron window by means of a crossed-field diode sputtering array. The array is comprised of a cohesive group of numerous small hollow electrically conducting cylinders and is mounted so that the open ends of the cylinders on one side of the group are adjacent a titanium cathode plate. The workpiece is mounted so as to face the open ends of the other side of the group. A magnetic field is applied to the array so as to be coaxial with the cylinders and a potential is applied across the cylinders and the cathode plate, the cylinders as an anode being positive with respect to the cathode plate. The cylinders, the cathode plate and the workpiece are situated in an atmosphere of nitrogen which becomes ionized such as by field emission because of the electric field between the cylinders and cathode plate, thereby establishing an anode-cathode discharge that results in sputtering of the titanium plate. The sputtered titanium coats the workpiece and chemically combines with the nitrogen to form a titanium nitride coating on the workpiece. Gas pressure, gas mixtures, cathode material composition, voltages applied to the cathode and anode, the magnetic field, cathode, anode and workpiece spacing, and the aspect ratio (ratio of length to inner diameter) of the anode cylinders, all may be controlled to provide consistent optimum thin film coatings of various compositions and thicknesses. Another facet of the disclosure is the coating of microwave components per se with titanium nitride to reduce multipactoring under operating conditions of the components.

  4. Thin film deposition by electric and magnetic crossed-field diode sputtering

    DOE Patents [OSTI]

    Welch, Kimo M.

    1980-01-01

    Applying a thin film coating to the surface of a workpiece, in particular, applying a coating of titanium nitride to a klystron window by means of a crossed-field diode sputtering array. The array is comprised of a cohesive group of numerous small hollow electrically conducting cylinders and is mounted so that the open ends of the cylinders on one side of the group are adjacent a titanium cathode plate. The workpiece is mounted so as to face the open ends of the other side of the group. A magnetic field is applied to the array so as to be coaxial with the cylinders and a potential is applied across the cylinders and the cathode plate, the cylinders as an anode being positive with respect to the cathode plate. The cylinders, the cathode plate and the workpiece are situated in an atmosphere of nitrogen which becomes ionized such as by field emission because of the electric field between the cylinders and cathode plate, thereby establishing an anode-cathode discharge that results in sputtering of the titanium plate. The sputtered titanium coats the workpiece and chemically combines with the nitrogen to form a titanium nitride coating on the workpiece. Gas pressure, gas mixtures, cathode material composition, voltages applied to the cathode and anode, the magnetic field, cathode, anode and workpiece spacing, and the aspect ratio (ratio of length to inner diameter) of the anode cylinders, all may be controlled to provide consistent optimum thin film coatings of various compositions and thicknesses. Another facet of the disclosure is the coating of microwave components per se with titanium nitride to reduce multipactoring under operating conditions of the components.

  5. Electric field-controlled magnetization in bilayered magnetic films for magnetoelectric memory

    SciTech Connect (OSTI)

    Yang, Wei-Gang; Morley, Nicola A.; Rainforth, W. Mark

    2015-07-21

    Bilayered magnetic films (Co{sub 50}Fe{sub 50} (CoFe)/Metglas) were RF sputtered on both (001)-oriented and (011)-oriented PMN-PT (lead magnesium niobate-lead titanate) substrates. Electric field-controlled magnetization changes were observed in all these samples: 65 nm CoFe/24 nm Metglas/(001) PMN-PT, 65 nm CoFe/24 nm Metglas/(011) PMN-PT, and 30 nm CoFe/12 nm Metglas/(011) PMN-PT. The maximum magnetic remanence ratio change (ΔM{sub r}/M{sub s}) was 46% for CoFe/Metglas/(001) PMN-PT. In this heterostructure, the electric-field created two new non-volatile switchable remanence states and the as-grown remanence state was altered permanently. High-resolution transmission electron microscopy images show a sharp and smooth interface between Metglas and substrate and conversely a rougher interface was observed between Metglas and CoFe films. In the 30 nm CoFe/12 nm Metglas/(011) PMN-PT sample, a large ΔM{sub r}/M{sub s} of 80% along the [100] direction was measured, while the ΔM{sub r}/M{sub s} along the [01-1] direction was 60% at the applied electric field of 5 kV/cm, corresponding to a giant magnetoelectric coupling constant α = μ{sub o}ΔM{sub r}/E = 2.9 × 10{sup −6} s/m.

  6. {ital Ab Initio} Calculation of Crystalline Electric Fields and Kondo Temperatures in Ce Compounds

    SciTech Connect (OSTI)

    Han, J.; Alouani, M.; Cox, D.; Han, J.; Cox, D.; Alouani, M.

    1997-02-01

    We have calculated the band-f hybridizations for Ce{sub x}La{sub 1-x}M{sub 3} compounds (x=1 and x{r_arrow}0; M=Pb,In,Sn,Pd) within the local density approximation and fed this into a noncrossing approximation for the Anderson impurity model applied to both dilute and concentrated limits. Our calculations produce crystalline electric field splittings and Kondo temperatures with trends in good agreement with experiment and demonstrate the need for detailed electronic structure information on hybridization to describe the diverse behaviors of these Ce compounds. {copyright} {ital 1997} {ital The American Physical Society}

  7. Effect of nonlinear absorption on electric field applied lead chloride by Z-scan technique

    SciTech Connect (OSTI)

    Rejeena, I.; Lillibai,; Nampoori, V. P. N.; Radhakrishnan, P.; Rahimkutty, M. H.

    2014-10-15

    The preparation, spectral response and optical nonlinearity of gel grown lead chloride single crystals subjected to electric field of 20V using parallel plate arrangements have been investigated. Optical band gap of the samples were determined using linear absorption spectra. Open aperture z-scan was employed for the determination of nonlinear absorption coefficient of PbCl{sub 2} solution. The normalized transmittance curve exhibits a valley shows reverse saturable absorption. The non linear absorption at different input fluences were recorded using a single Gaussian laser beam in tight focus geometry. The RSA nature of the sample makes it suitable for optical limiting applications.

  8. NMR chemical shifts in amino acids: Effects of environments, electric field, and amine group rotation

    SciTech Connect (OSTI)

    Yoon, Young-Gui; Pfrommer, Bernd G.; Louie, Steven G.; Canning, Andrew

    2002-03-03

    The authors present calculations of NMR chemical shifts in crystalline phases of some representative amino acids such as glycine, alanine, and alanyl-alanine. To get an insight on how different environments affect the chemical shifts, they study the transition from the crystalline phase to completely isolated molecules of glycine. In the crystalline limit, the shifts are dominated by intermolecular hydrogen-bonds. In the molecular limit, however, dipole electric field effects dominate the behavior of the chemical shifts. They show that it is necessary to average the chemical shifts in glycine over geometries. Tensor components are analyzed to get the angle dependent proton chemical shifts, which is a more refined characterization method.

  9. Electric field induced spin and valley polarization within a magnetically confined silicene channel

    SciTech Connect (OSTI)

    Liu, Yiman; Zhou, Xiaoying; Zhou, Ma; Zhou, Guanghui; Long, Meng-Qiu

    2014-12-28

    We study the electronic structure and transport properties of Dirac electrons along a channel created by an exchange field through the proximity of ferromagnets on a silicene sheet. The multiple total internal reflection induces localized states in the channel, which behaves like an electron waveguide. An effect of spin- and valley-filtering originating from the coupling between valley and spin degrees is predicted for such a structure. Interestingly, this feature can be tuned significantly by locally applying electric and exchange fields simultaneously. The parameter condition for observing fully spin- and valley-polarized current is obtained. These findings may be observable in todays' experimental technique and useful for spintronic and valleytronic applications based on silicene.

  10. Electric field-driven, magnetically-stabilized ferro-emulsion phase contactor

    DOE Patents [OSTI]

    Scott, Timothy C.

    1990-01-01

    Methods and systems for interfacial surface area contact between a dispersed phase liquid and a continuous phase liquid in counter-current flow for purposes such as solvent extraction. Initial droplets of a dispersed phase liquid material containing ferromagnetic particles functioning as a "packing" are introduced to a counter-current flow of the continuous phase. A high intensity pulsed electric field is applied so as to shatter the initial droplets into a ferromagnetic emulsion comprising many smaller daughter droplets having a greater combined total surface area than that of the initial droplets in contact with the continuous phase material. A magnetic field is applied to control the position of the ferromagnetic emulsion for enhanced coalescence of the daughter droplets into larger reformed droplets.

  11. Electric field-driven, magnetically-stabilized ferro-emulsion phase contactor

    DOE Patents [OSTI]

    Scott, T.C.

    1990-07-17

    Methods and systems are disclosed for interfacial surface area contact between a dispersed phase liquid and a continuous phase liquid in counter-current flow for purposes such as solvent extraction. Initial droplets of a dispersed phase liquid material containing ferromagnetic particles functioning as a packing'' are introduced to a counter-current flow of the continuous phase. A high intensity pulsed electric field is applied so as to shatter the initial droplets into a ferromagnetic emulsion comprising many smaller daughter droplets having a greater combined total surface area than that of the initial droplets in contact with the continuous phase material. A magnetic field is applied to control the position of the ferromagnetic emulsion for enhanced coalescence of the daughter droplets into larger reformed droplets. 2 figs.

  12. Wave function for harmonically confined electrons in time-dependent electric and magnetostatic fields

    SciTech Connect (OSTI)

    Zhu, Hong-Ming; Chen, Jin-Wang; Pan, Xiao-Yin; Sahni, Viraht

    2014-01-14

    We derive via the interaction “representation” the many-body wave function for harmonically confined electrons in the presence of a magnetostatic field and perturbed by a spatially homogeneous time-dependent electric field—the Generalized Kohn Theorem (GKT) wave function. In the absence of the harmonic confinement – the uniform electron gas – the GKT wave function reduces to the Kohn Theorem wave function. Without the magnetostatic field, the GKT wave function is the Harmonic Potential Theorem wave function. We further prove the validity of the connection between the GKT wave function derived and the system in an accelerated frame of reference. Finally, we provide examples of the application of the GKT wave function.

  13. Nanoscale lubrication of ionic surfaces controlled via a strong electric field

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

    Strelcov, Evgheni; Bocharova, Vera; Sumpter, Bobby G.; Tselev, Alexander; Kalinin, Sergei V.; Kumar, Rajeev

    2015-01-27

    Frictional forces arise whenever objects around us are set in motion. Controlling them in a rational manner means gaining leverage over mechanical energy losses and wear. This paper presents a way of manipulating nanoscale friction by means of in situ lubrication and interfacial electrochemistry. Water lubricant is directionally condensed from the vapor phase at a moving metal-ionic crystal interface by a strong confined electric field, thereby allowing friction to be tuned up or down via an applied bias. The electric potential polarity and ionic solid solubility are shown to strongly influence friction between the atomic force microscope (AFM) tip andmore » salt surface. An increase in friction is associated with the AFM tip digging into the surface, whereas reducing friction does not influence its topography. No current flows during friction variation, which excludes Joule heating and associated electrical energy losses. Lastly, the demonstrated novel effect can be of significant technological importance for controlling friction in nano- and micro-electromechanical systems.« less

  14. Fatigue of extracted lead zirconate titanate multilayer actuators under unipolar high field electric cycling

    SciTech Connect (OSTI)

    Wang, Hong; Lee, Sung Min; Wang, James L.; Lin, Hua-Tay

    2014-12-19

    Testing of large prototype lead zirconate titanate (PZT) stacks presents substantial technical challenges to electronic testing systems, so an alternative approach that uses subunits extracted from prototypes has been pursued. Extracted 10-layer and 20-layer plate specimens were subjected to an electric cycle test under an electric field of 3.0/0.0 kV/mm, 100 Hz to 10^8 cycles. The effects of measurement field level and stack size (number of PZT layers) on the fatigue responses of piezoelectric and dielectric coefficients were observed. On-line monitoring permitted examination of the fatigue response of the PZT stacks. The fatigue rate (based on on-line monitoring) and the fatigue index (based on the conductance spectrum from impedance measurement or small signal measurement) were developed to quantify the fatigue status of the PZT stacks. The controlling fatigue mechanism was analyzed against the fatigue observations. The data presented can serve as input to design optimization of PZT stacks and to operation optimization in critical applications such as piezoelectric fuel injectors in heavy-duty diesel engines.

  15. Fatigue of extracted lead zirconate titanate multilayer actuators under unipolar high field electric cycling

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

    Wang, Hong; Lee, Sung Min; Wang, James L.; Lin, Hua-Tay

    2014-12-19

    Testing of large prototype lead zirconate titanate (PZT) stacks presents substantial technical challenges to electronic testing systems, so an alternative approach that uses subunits extracted from prototypes has been pursued. Extracted 10-layer and 20-layer plate specimens were subjected to an electric cycle test under an electric field of 3.0/0.0 kV/mm, 100 Hz to 10^8 cycles. The effects of measurement field level and stack size (number of PZT layers) on the fatigue responses of piezoelectric and dielectric coefficients were observed. On-line monitoring permitted examination of the fatigue response of the PZT stacks. The fatigue rate (based on on-line monitoring) and themore » fatigue index (based on the conductance spectrum from impedance measurement or small signal measurement) were developed to quantify the fatigue status of the PZT stacks. The controlling fatigue mechanism was analyzed against the fatigue observations. The data presented can serve as input to design optimization of PZT stacks and to operation optimization in critical applications such as piezoelectric fuel injectors in heavy-duty diesel engines.« less

  16. Microscopic model of electric-field-noise heating in ion traps

    SciTech Connect (OSTI)

    Safavi-Naini, A.; Rabl, P.; Weck, P. F.; Sadeghpour, H. R.

    2011-08-15

    Motional heating of ions in microfabricated traps is one of the open challenges hindering experimental realizations of large-scale quantum processing devices. Recently, a series of measurements of the heating rates in surface-electrode ion traps characterized their frequency, distance, and temperature dependencies, but our understanding of the microscopic origin of this noise remains incomplete. In this work we develop a theoretical model for the electric field noise which is associated with a random distribution of adsorbed atoms on the trap electrode surface. By using first-principles calculations of the fluctuating dipole moments of the adsorbed atoms we evaluate the distance, frequency, and temperature dependence of the resulting electric field fluctuation spectrum. Our theory reproduces correctly the d{sup -4} dependence with distance of the ion from the electrode surface and calculates the noise spectrum beyond the standard scenario of two-level fluctuators by incorporating all the relevant vibrational states. Our model predicts a regime of 1/f noise which commences at roughly the frequency of the fundamental phonon transition rate and a thermally activated noise spectrum which for higher temperatures exhibits a crossover as a function of frequency.

  17. Ultrathin Palladium Membranes Prepared by a Novel Electric Field Assisted Activation

    SciTech Connect (OSTI)

    Yun, Samhun; Ko, Joon Ho; Oyama, S. Ted

    2011-03-01

    Ultra-thin Pd composite membranes with a thickness of 1 ?m were prepared by a novel electric-field assisted activation technique followed by electroless deposition of Pd on a hollow-fiber ?-alumina support. The novel activation method places Pd precursors and a reducing agent on opposite sides of a porous substrate and uses an electric field to cause migration of Pd ions to the outer surface where they are reduced to form seeds in high density in a narrow spatial region. The resulting membranes showed a high hydrogen permeance in the range of 4.05.0 10{sup ?6} mol m{sup ?2} s{sup ?1} Pa{sup ?1} and stable H{sub 2}/N{sub 2} selectivity of 30009000 during stability tests for 150 h at 733 K with H{sub 2} flow. The formation of the thin, defect-less and robust Pd layer can be ascribed to the evenly distributed Pd seeds on the support layer and the enhanced bonding between the Pd layer and the support layer resulting from the strong anchoring of the Pd seeds onto the support in the new activation step.

  18. Electric-field-induced local and mesoscale structural changes in polycrystalline dielectrics and ferroelectrics

    SciTech Connect (OSTI)

    Usher, Tedi -Marie; Levin, Igor; Daniels, John E.; Jones, Jacob L.

    2015-10-01

    In this study, the atomic-scale response of dielectrics/ferroelectrics to electric fields is central to their functionality. Here we introduce an in situ characterization method that reveals changes in the local atomic structure in polycrystalline materials under fields. The method employs atomic pair distribution functions (PDFs), determined from X-ray total scattering that depends on orientation relative to the applied field, to probe structural changes over length scales from sub-Ångstrom to several nanometres. The PDF is sensitive to local ionic displacements and their short-range order, a key uniqueness relative to other techniques. The method is applied to representative ferroelectrics, BaTiO3 and Na½Bi½TiO3, and dielectric SrTiO3. For Na½Bi½TiO3, the results reveal an abrupt field-induced monoclinic to rhombohedral phase transition, accompanied by ordering of the local Bi displacements and reorientation of the nanoscale ferroelectric domains. For BaTiO3 and SrTiO3, the local/nanoscale structural changes observed in the PDFs are dominated by piezoelectric lattice strain and ionic polarizability, respectively.

  19. Electric-field-induced local and mesoscale structural changes in polycrystalline dielectrics and ferroelectrics

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

    Usher, Tedi -Marie; Levin, Igor; Daniels, John E.; Jones, Jacob L.

    2015-10-01

    In this study, the atomic-scale response of dielectrics/ferroelectrics to electric fields is central to their functionality. Here we introduce an in situ characterization method that reveals changes in the local atomic structure in polycrystalline materials under fields. The method employs atomic pair distribution functions (PDFs), determined from X-ray total scattering that depends on orientation relative to the applied field, to probe structural changes over length scales from sub-Ångstrom to several nanometres. The PDF is sensitive to local ionic displacements and their short-range order, a key uniqueness relative to other techniques. The method is applied to representative ferroelectrics, BaTiO3 and Na½Bi½TiO3,more » and dielectric SrTiO3. For Na½Bi½TiO3, the results reveal an abrupt field-induced monoclinic to rhombohedral phase transition, accompanied by ordering of the local Bi displacements and reorientation of the nanoscale ferroelectric domains. For BaTiO3 and SrTiO3, the local/nanoscale structural changes observed in the PDFs are dominated by piezoelectric lattice strain and ionic polarizability, respectively.« less

  20. Electric Field Penetration in Au/Nb:SrTiO3 Schottky Junctions Probed by Bias-Dependent Internal Photoemission

    SciTech Connect (OSTI)

    Hikita, Y.

    2011-08-15

    Electric field penetration into the metallic side of a Schottky junction is in principle a universal phenomenon, the magnitude of which increases with the semiconductor permittivity. Here, we quantitatively probe this effect using bias-dependent internal photoemission spectroscopy at the Schottky junction between a large dielectric permittivity semiconductor SrTiO{sub 3} and gold. A clear linear reduction of the barrier height with increasing interface electric field was observed, highlighting the importance of field penetration into the gold. The interfacial permittivity of SrTiO{sub 3} at the interface is reduced from the bulk value, reflecting intrinsic suppression at the interface.

  1. Stator for a rotating electrical machine having multiple control windings

    DOE Patents [OSTI]

    Shah, Manoj R.; Lewandowski, Chad R.

    2001-07-17

    A rotating electric machine is provided which includes multiple independent control windings for compensating for rotor imbalances and for levitating/centering the rotor. The multiple independent control windings are placed at different axial locations along the rotor to oppose forces created by imbalances at different axial locations along the rotor. The multiple control windings can also be used to levitate/center the rotor with a relatively small magnetic field per unit area since the rotor and/or the main power winding provides the bias field.

  2. Electrical properties of single CuO nanowires for device fabrication: Diodes and field effect transistors

    SciTech Connect (OSTI)

    Florica, Camelia; Costas, Andreea; Boni, Andra Georgia; Negrea, Raluca; Preda, Nicoleta E-mail: encu@infim.ro; Pintilie, Lucian; Enculescu, Ionut E-mail: encu@infim.ro; Ion, Lucian

    2015-06-01

    High aspect ratio CuO nanowires are synthesized by a simple and scalable method, thermal oxidation in air. The structural, morphological, optical, and electrical properties of the semiconducting nanowires were studied. Au-Ti/CuO nanowire and Pt/CuO nanowire electrical contacts were investigated. A dominant Schottky mechanism was evidenced in the Au-Ti/CuO nanowire junction and an ohmic behavior was observed for the Pt/CuO nanowire junction. The Pt/CuO nanowire/Pt structure allows the measurements of the intrinsic transport properties of the single CuO nanowires. It was found that an activation mechanism describes the behavior at higher temperatures, while a nearest neighbor hopping transport mechanism is characteristic at low temperatures. This was also confirmed by four-probe resistivity measurements on the single CuO nanowires. By changing the metal/semiconductor interface, devices such as Schottky diodes and field effect transistors based on single CuO p-type nanowire semiconductor channel are obtained. These devices are suitable for being used in various electronic circuits where their size related properties can be exploited.

  3. Electric-field-induced spin wave generation using multiferroic magnetoelectric cells

    SciTech Connect (OSTI)

    Cherepov, Sergiy; Khalili Amiri, Pedram; Alzate, Juan G.; Wong, Kin; Lewis, Mark; Upadhyaya, Pramey; Nath, Jayshankar; Bao, Mingqiang; Wang, Kang L.; Bur, Alexandre; Wu, Tao; Carman, Gregory P.; Khitun, Alexander

    2014-02-24

    In this work, we report on the demonstration of voltage-driven spin wave excitation, where spin waves are generated by multiferroic magnetoelectric (ME) cell transducers driven by an alternating voltage, rather than an electric current. A multiferroic element consisting of a magnetostrictive Ni film and a piezoelectric [Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}]{sub (1?x)}[PbTiO{sub 3}]{sub x} substrate was used for this purpose. By applying an AC voltage to the piezoelectric, an oscillating electric field is created within the piezoelectric material, which results in an alternating strain-induced magnetic anisotropy in the magnetostrictive Ni layer. The resulting anisotropy-driven magnetization oscillations propagate in the form of spin waves along a 5??m wide Ni/NiFe waveguide. Control experiments confirm the strain-mediated origin of the spin wave excitation. The voltage-driven spin wave excitation, demonstrated in this work, can potentially be used for low-dissipation spin wave-based logic and memory elements.

  4. In-plane electric fields in magnetic islands during collisionless magnetic reconnection

    SciTech Connect (OSTI)

    Chen Lijen; Bhattacharjee, Amitava; Torbert, Roy B.; Bessho, Naoki; Daughton, William; Roytershteyn, Vadim

    2012-11-15

    Magnetic islands are a common feature in both the onset and nonlinear evolution of magnetic reconnection. In collisionless regimes, the onset typically occurs within ion-scale current layers leading to the formation of magnetic islands when multiple X lines are involved. The nonlinear evolution of reconnection often gives rise to extended electron current layers (ECL) which are also unstable to formation of magnetic islands. Here, we show that the excess negative charge and strong out-of-plane electron velocity in the ECL are passed on to the islands generated therein, and that the corresponding observable distinguishing the islands generated in the ECL is the strongly enhanced in-plane electric fields near the island core. The islands formed in ion-scale current layers do not have these properties of the ECL-generated islands. The above result provides a way to assess the occurrence and importance of extended ECLs that are unstable to island formation in space and laboratory plasmas.

  5. Dielectric response of multiwalled carbon nanotubes as a function of applied ac-electric fields

    SciTech Connect (OSTI)

    Basu, Rajratan; Iannacchione, Germano S.

    2008-12-01

    The complex dielectric constant ({epsilon}{sup *}) is reported for multiwalled carbon nanotubes (MWCNTs) up to 10{sup 5} Hz as a function of ac-electric field amplitudes E{sub rot} (in phase and same frequency as the measurement) and E{sub ac} (different phase and fixed frequency with respect to the measurement). A slow relaxation process (mode 1) is observed, which shifts to higher frequency with increasing E{sub rot} but is independent of E{sub ac}. A fast relaxation process (mode 2) is also observed, which is independent of E{sub rot} but shifts to higher frequency with increasing E{sub ac} (opposite to that of mode 1). An ac-conductivity analysis of MWCNT reveals insights on how E{sub rot} and E{sub ac} influence the dissipation.

  6. Band gaps and internal electric fields in semipolar short period InN/GaN superlattices

    SciTech Connect (OSTI)

    Gorczyca, I.; Skrobas, K.; Suski, T.; Christensen, N. E.; Svane, A.

    2014-06-09

    The electronic structures and internal electric fields of semipolar short-period mInN/nGaN superlattices (SLs) have been calculated for several compositions (m, n). Two types of SL are considered, (112{sup ¯}2) and (202{sup ¯}1), corresponding to growth along the wurtzite s2 and s6 directions, respectively. The results are compared to similar calculations for polar SLs (grown in the c-direction) and nonpolar SLs (grown in the a- and m-directions). The calculated band gaps for the semipolar SLs lie between those calculated for the nonpolar and polar SLs: For s2-SLs they fall slightly below the band gaps of a-plane SLs, whereas for s6-SLs they are considerably smaller.

  7. Angular Averaged Profiling of the Radial Electric Field in Compensated FTICR Cells

    SciTech Connect (OSTI)

    Tolmachev, Aleksey V.; Robinson, Errol W.; Wu, Si; Smith, Richard D.; Futrell, Jean H.; Pasa-Tolic, Ljiljana

    2012-05-08

    A recent publication from this laboratory (1) reported a theoretical analysis comparing approaches for creating harmonic ICR cells. We considered two examples of static segmented cells - namely, a seven segment cell developed in this laboratory (2) and one described by Rempel et al (3), along with a recently described dynamically harmonized cell (4). This conceptual design for a dynamically harmonized cell has now been reduced to practice and first experimental results obtained with this cell were recently reported in this journal (5). This publication reports details of cell construction and describes its performance in a 7 Tesla Fourier Transform mass spectrometer. Herein, we describe the extension of theoretical analysis presented in (1) to include angular-averaged radial electric field calculations and a discussion of the influence of trapping plates.

  8. Motion of Doped-Polymer-Cholesteric Liquid Crystal Flakes in a Direct-Current Electric Field

    SciTech Connect (OSTI)

    Trajkovska Petkoska, A.; Kosc, T.Z.; Marshall, K.L.; Hasman, K.; Jacobs, S.D.

    2008-05-02

    The behavior of polymer cholesteric liquid crystal (PCLC) flakes suspended in silicone oil host fluids has been explored in the presence of a direct-current electric field. In addition to neat (undoped) flakes, the PCLC material was doped with either conductive, carbon-based particles or highly dielectric inorganic particles to modify the dielectric properties of the resulting PCLC flakes. Doping with conductive particles produced flakes with a net charge, and they exhibited either translational or rotational motion depending on both the distribution of dopant within the flake and the dielectric characteristics of the host fluid. Flakes doped with titania (TiO2) particles reoriented 90 when suspended in a host fluid with a differing dielectric permittivity

  9. Fission gas retention and axial expansion of irradiated metallic fuel

    SciTech Connect (OSTI)

    Fenske, G.R.; Emerson, J.E.; Savoie, F.E.; Johanson, E.W.

    1986-05-01

    Out-of-reactor experiments utilizing direct electrical heating and infrared heating techniques were performed on irradiated metallic fuel. The results indicate accelerated expansion can occur during thermal transients and that the accelerated expansion is driven by retained fission gases. The results also demonstrate gas retention and, hence, expansion behavior is a function of axial position within the pin.

  10. ELECTRIC

    Office of Legacy Management (LM)

    ELECTRIC cdrtrokArJclaeT 3 I+ &i, y$ \I &OF I*- j< t j,fci..- ir )(yiT !E-li, ( \-,v? Cl -p/4.4 RESEARCH LABORATORIES EAST PITTSBURGH, PA. 8ay 22, 1947 Mr. J. Carrel Vrilson General ?!!mager Atomic Qxzgy Commission 1901 Constitution Avenue Kashington, D. C. Dear Sir: In the course of OUT nuclenr research we are planning to study the enc:ri;y threshold anti cross section for fission. For thib program we require a s<>piAroted sample of metallic Uranium 258 of high purity. A

  11. Distributed and Electric Power System Aggregation Model and Field Configuration Equivalency Validation Testing: Supplemental Report on Penetration Software Algorithms

    SciTech Connect (OSTI)

    Davis, M.; Costyk, D.; Narang, A.

    2005-03-01

    This report supplements the July 2003 report ''Distributed and Electric Power System Aggregation Model and Field Configuration Equivalency Validation Testing'' (NREL/SR-560-33909). The original report presented methods for calculating penetration limits for distributed energy resources interconnected with distribution circuits of utility-owned electric power systems. This report describes the algorithms required to develop application software to calculate penetration limits. The original report can be found at http://www.nrel.gov/docs/fy03osti/33909.pdf.

  12. The inversion layer of electric fields and electron phase-space-hole structure during two-dimensional collisionless magnetic reconnection

    SciTech Connect (OSTI)

    Chen Lijen; Lefebvre, Bertrand; Torbert, Roy B.; Daughton, William S.

    2011-01-15

    Based on two-dimensional fully kinetic simulations that resolve the electron diffusion layer in undriven collisionless magnetic reconnection with zero guide field, this paper reports the existence and evolution of an inversion layer of bipolar electric fields, its corresponding phase-space structure (an electron-hole layer), and the implication to collisionless dissipation. The inversion electric field layer is embedded in the layer of bipolar Hall electric field and extends throughout the entire length of the electron diffusion layer. The electron phase-space hole structure spontaneously arises during the explosive growth phase when there exist significant inflows into the reconnection layer, and electrons perform meandering orbits across the layer while being cyclotron-turned toward the outflow directions. The cyclotron turning of meandering electrons by the magnetic field normal to the reconnection layer is shown to be a primary factor limiting the current density in the region where the reconnection electric field is balanced by the gradient (along the current sheet normal) of the off-diagonal electron pressure-tensor.

  13. Application of electrical submersible pumps in heavy crude oil in Boscan Field

    SciTech Connect (OSTI)

    Bortolin, L.L.

    1995-12-31

    During recent years optimization of artificial lift methods has been applied in the oil industry, in order to evaluate the effect on oil well production and to establish a company`s optimal investment policies. Higher costs on new artificial lifting equipment and facilities for new fields have created the necessity to review the latest available technology of different lifting methods and specially that related to electrical submersible pumps (ESP). Few studies in the area of heavy crude oil production optimization using ESP as a lifting method have been published. This paper discusses the results of an ESP pilot project performed in 24 wells in Boscan field, and analyzes the performance of the equipment and its application range. The ESP equipment was installed in completions at depths ranging from 7000 to 9000 feet, with a 10{degrees}API gravity crude and bottomhole temperature of 180{degrees}F. It was concluded that despite a reduction of the pump`s efficiency, the ESP equipment does qualify as a good alternative lifting method for heavy oil production. It is also possible to obtain higher production rates. The results obtained in this pilot project, confirm that submersible pumps are an alternative method for lifting heavy crude oil from relatively deep reservoirs.

  14. Axial flow plasma shutter

    DOE Patents [OSTI]

    Krausse, George J. (Fort Collins, CO)

    1988-01-01

    A shutter (36) is provided for controlling a beam, or current, of charged particles in a device such as a thyratron (10). The substrate (38) defines an aperture (60) with a gap (32) which is placeable within the current. Coils (48) are formed on the substrate (38) adjacent the aperture (60) to produce a magnetic field for trapping the charged particles in or about aperture (60). The proximity of the coils (48) to the aperture (60) enables an effective magnetic field to be generated by coils (48) having a low inductance suitable for high frequency control. The substantially monolithic structure including the substrate (38) and coils (48) enables the entire shutter assembly (36) to be effectively located with respect to the particle beam.

  15. Piezoelectric axial flow microvalve

    DOE Patents [OSTI]

    Gemmen, Randall; Thornton, Jimmy; Vipperman, Jeffrey S.; Clark, William W.

    2007-01-09

    This invention is directed to a fuel cell operable with a quantity of fuel and a quantity of an oxidizer to produce electrical power, the fuel cell including a fuel cell body including a labyrinth system structured to permit the fuel and the oxidizer to flow therethrough; at least a first catalyst in fluid communication with the labyrinth; and at least a first microvalve operably disposed within at least a portion of the labyrinth. The microvalve utilizes a deflectable member operable upon the application of a voltage from a voltage source. The microvalve includes an elongated flow channel formed therein and extending substantially longitudinally between the first and second ends to permit substantially longitudinal flow of the fluid therethrough and between the first and second ends; and the deflectable member disposed on the valve body, the deflectable member including at least a first piezoelectric portion that is piezoelectrically operable to deflect the deflectable member between an open position and a closed position upon the application of a voltage, the deflectable member in the closed position being operable to resist the flow of the fluid through the flow channel.

  16. Effects of light illumination on electron velocity of AlGaN/GaN heterostructures under high electric field

    SciTech Connect (OSTI)

    Guo, Lei; Yang, Xuelin Cheng, Jianpeng; Sang, Ling; Xu, Fujun; Tang, Ning; Feng, Zhihong; Lv, Yuanjie; Wang, Xinqiang; Shen, B.; Ge, Weikun

    2014-12-15

    We have investigated the variation of electron velocity in AlGaN/GaN heterostructures depending on illuminating light intensity and wavelength. It is shown that the electron velocity at high electric field increases under above-band light illumination. This electron velocity enhancement is found to be related to the photo-generated cold holes which interact with hot electrons and thus accelerate the energy relaxation at high electric field. The results suggest an alternative way to improve the electron energy relaxation rate and hence the electron velocity in GaN based heterostructures.

  17. Local changes of work function near rough features on Cu surfaces operated under high external electric field

    SciTech Connect (OSTI)

    Djurabekova, Flyura Ruzibaev, Avaz; Parviainen, Stefan; Holmstrm, Eero; Hakala, Mikko

    2013-12-28

    Metal surfaces operated under high electric fields produce sparks even if they are held in ultra high vacuum. In spite of extensive research on the topic of vacuum arcs, the mystery of vacuum arc origin still remains unresolved. The indications that the sparking rates depend on the material motivate the research on surface response to extremely high external electric fields. In this work by means of density-functional theory calculations we analyze the redistribution of electron density on (100) Cu surfaces due to self-adatoms and in presence of high electric fields from ?1?V/nm up to ?2?V/nm (?1 to ?2 GV/m, respectively). We also calculate the partial charge induced by the external field on a single adatom and a cluster of two adatoms in order to obtain reliable information on charge redistribution on surface atoms, which can serve as a benchmarking quantity for the assessment of the electric field effects on metal surfaces by means of molecular dynamics simulations. Furthermore, we investigate the modifications of work function around rough surface features, such as step edges and self-adatoms.

  18. Co-axial discharges

    DOE Patents [OSTI]

    Luce, J. S.; Smith, L. P.

    1960-11-22

    An apparatus is described for producing coaxial arc discharges in an evacuated enclosure and within a strong, confining magnetic field. The arcs are maintained at a high potential difference. Electrons diffuse to the more positive arc from the negative arc, and positive ions diffuse from the more positive arc to the negative arc. Coaxial arc discharges have the advantuge that ions that return to strike the positive arc discharge will lose no energy since they do not strike a solid wall or electrode. These discharges are useful in confining an ionized plasma between the discharges and have the advantage of preventing impurities from the walls of the enclosure from entering the plasma area because of the arc barrier set up by the cylindrical outer arc. (auth)

  19. CO-AXIAL DISCHARGES

    DOE Patents [OSTI]

    Luce, J.S.; Smith, L.P.

    1960-11-22

    A method and apparatus are given for producing coaxial arc discharges in an evacuated enclosure and within a strong, confining magnetic field. The arcs are maintained at a high potential difference. Electrons will diffuse to the more positive arc from the negative arc, and positive ions will diffuse from the more positive arc to the negative arc. Coaxial arc discharges have the advantage that ions which return to strike the positive arc discharge will lose no energy since they do not strike a solid wall or electrode. Those discharges are useful in confining an ionized plasma between the discharges, and have the advantage of preventing impurities from the walls of the enclosure from entering ihe plasma area because of the arc barrier set up bv the cylindrical outer arc.

  20. THREE-DIMENSIONAL NON-VACUUM PULSAR OUTER-GAP MODEL: LOCALIZED ACCELERATION ELECTRIC FIELD IN THE HIGHER ALTITUDES

    SciTech Connect (OSTI)

    Hirotani, Kouichi

    2015-01-10

    We investigate the particle accelerator that arises in a rotating neutron-star magnetosphere. Simultaneously solving the Poisson equation for the electro-static potential, the Boltzmann equations for relativistic electrons and positrons, and the radiative transfer equation, we demonstrate that the electric field is substantially screened along the magnetic field lines by pairs that are created and separated within the accelerator. As a result, the magnetic-field-aligned electric field is localized in higher altitudes near the light cylinder and efficiently accelerates the positrons created in the lower altitudes outward but does not accelerate the electrons inward. The resulting photon flux becomes predominantly outward, leading to typical double-peak light curves, which are commonly observed from many high-energy pulsars.

  1. Neutron spectroscopic study of crystalline electric field excitations in stoichiometric and lightly stuffed Yb2Ti2O7

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

    Gaudet, J.; Maharaj, D. D.; Sala, G.; Kermarrec, E.; Ross, K. A.; Dabkowska, H. A.; Kolesnikov, A. I.; Granroth, G. E.; Gaulin, B. D.

    2015-10-27

    Time-of-flight neutron spectroscopy has been used to determine the crystalline electric field Hamiltonian, eigenvalues and eigenvectors appropriate to the J=7/2 Yb3+ ion in the candidate quantum spin ice pyrochlore magnet Yb2Ti2O7. The precise ground state of this exotic, geometrically frustrated magnet is known to be sensitive to weak disorder associated with the growth of single crystals from the melt. Such materials display weak “stuffing,” wherein a small proportion, approximately 2%, of the nonmagnetic Ti4+ sites are occupied by excess Yb3+. We have carried out neutron spectroscopic measurements on a stoichiometric powder sample of Yb2Ti2O7, as well as a crushed singlemore » crystal with weak stuffing and an approximate composition of Yb2+xTi2–xO7+y with x = 0.046. All samples display three crystalline electric field transitions out of the ground state, and the ground state doublet itself is identified as primarily composed of mJ = ±1/2, as expected. However, stuffing at low temperatures in Yb2+xTi2–xO7+y induces a similar finite crystalline electric field lifetime as is induced in stoichiometric Yb2Ti2O7 by elevated temperature. In conclusion, an extended strain field exists about each local “stuffed” site, which produces a distribution of random crystalline electric field environments in the lightly stuffed Yb2+xTi2–xO7+y, in addition to producing a small fraction of Yb ions in defective environments with grossly different crystalline electric field eigenvalues and eigenvectors.« less

  2. Electrical machine

    DOE Patents [OSTI]

    De Bock, Hendrik Pieter Jacobus; Alexander, James Pellegrino; El-Refaie, Ayman Mohamed Fawzi; Gerstler, William Dwight; Shah, Manoj Ramprasad; Shen, Xiaochun

    2016-06-21

    An apparatus, such as an electrical machine, is provided. The apparatus can include a rotor defining a rotor bore and a conduit disposed in and extending axially along the rotor bore. The conduit can have an annular conduit body defining a plurality of orifices disposed axially along the conduit and extending through the conduit body. The rotor can have an inner wall that at least partially defines the rotor bore. The orifices can extend through the conduit body along respective orifice directions, and the rotor and conduit can be configured to provide a line of sight along the orifice direction from the respective orifices to the inner wall.

  3. Quantum mechanical calculation of electric fields and vibrational Stark shifts at active site of human aldose reductase

    SciTech Connect (OSTI)

    Wang, Xianwei; Zhang, John Z. H.; He, Xiao

    2015-11-14

    Recent advance in biophysics has made it possible to directly measure site-specific electric field at internal sites of proteins using molecular probes with C = O or C≡N groups in the context of vibrational Stark effect. These measurements directly probe changes of electric field at specific protein sites due to, e.g., mutation and are very useful in protein design. Computational simulation of the Stark effect based on force fields such as AMBER and OPLS, while providing good insight, shows large errors in comparison to experimental measurement due to inherent difficulties associated with point charge based representation of force fields. In this study, quantum mechanical calculation of protein’s internal electrostatic properties and vibrational Stark shifts was carried out by using electrostatically embedded generalized molecular fractionation with conjugate caps method. Quantum calculated change of mutation-induced electric field and vibrational Stark shift is reported at the internal probing site of enzyme human aldose reductase. The quantum result is in much better agreement with experimental data than those predicted by force fields, underscoring the deficiency of traditional point charge models describing intra-protein electrostatic properties.

  4. Post-deposition control of ferroelastic stripe domains and internal electric field by thermal treatment

    SciTech Connect (OSTI)

    Feigl, L.; Iwanowska, M.; Sandu, C. S.; Setter, N.; Janolin, P.-E.; Yamada, T.

    2015-01-19

    The dependence of the formation of ferroelastic stripe domain patterns on the thermal history is investigated by detailed piezoresponse force microscopy and X-ray diffraction experiments after and during annealing of tensile strained tetragonal Pb(Ti,Zr)O{sub 3} epitaxial thin films on DyScO{sub 3} substrates. In particular, the ferroelastic pattern is reversibly interchanged between a cross-hatched and a stripe domain pattern if the films are cooled at different rates after annealing above the formation temperature of a-domains. Different types of 180 and non-180 patterns can be created, depending on the thermal treatment. The changes in the 180 domain structure and lattice parameters are attributed to a change of oxygen vacancy concentration, which results in a modification of the internal electric field and unit cell size, causing also a shift of T{sub C}. Thermal treatment is done on rhombohedral La:BiFeO{sub 3} thin films as well. It is observed that also in these films, appropriate heat treatment modifies the domain pattern and films with a stripe domain pattern can be created, confirming the general validity of the developed model.

  5. Conjugated ionomers for photovoltaic applications: electric field driven charge separation in organic photovoltaics. Final Technical report

    SciTech Connect (OSTI)

    Lonergan, Mark

    2015-05-29

    Final technical report for Conjugated ionomers for photovoltaic applications, electric field driven charge separation in organic photovoltaics. The central goal of the work we completed was been to understand the photochemical and photovoltaic properties of ionically functionalized conjugated polymers (conjugated ionomers or polyelectrolytes) and energy conversion systems based on them. We primarily studied two classes of conjugated polymer interfaces that we developed based either upon undoped conjugated polymers with an asymmetry in ionic composition (the ionic junction) or doped conjugated polymers with an asymmetry in doping type (the p-n junction). The materials used for these studies have primarily been the polyacetylene ionomers. We completed a detailed study of p-n junctions with systematically varying dopant density, photochemical creation of doped junctions, and experimental and theoretical work on charge transport and injection in polyacetylene ionomers. We have also completed related work on the use of conjugated ionomers as interlayers that improve the efficiency or organic photovoltaic systems and studied several important aspects of the chemistry of ionically functionalized semiconductors, including mechanisms of so-called "anion-doping", the formation of charge transfer complexes with oxygen, and the synthesis of new polyfluorene polyelectrolytes. We also worked worked with the Haley group at the University of Oregon on new indenofluorene-based organic acceptors.

  6. Electric and Magnetic Fields Research and Public Information Dissemination Program annual report for fiscal year 1996

    SciTech Connect (OSTI)

    NONE

    1997-06-01

    The Electric and Magnetic Fields (EMF) Research and Public Information Dissemination (RAPID) Program was authorized by the Energy Policy Act of 1992 as a near-term effort to expand and accelerate the research needed to address the EMF issue. As required by this legislation, the EMF Interagency Committee, the National EMF Advisory Committee (NEMFAC), and the National Academy of Sciences (NAS) are providing valued input and advice for the direction of this program. With this input and advice, the Department of Energy (DOE) and the National Institute of Environmental Health Sciences (NIEHS) have developed and are implementing five-year program plans. Multi-year health effects research projects and related EMF measurement and exposure assessment projects are underway using funds appropriated in fiscal years 1994, 1995, and 1996 together with voluntary non-Federal contributions. The results of these research projects, along with the results of other EMF research, will be used as input to the hazard evaluation effort, which is the focus of the EMF RAPID Program. A coordinated interagency program is underway to communicate needed information on the EMF issue in a clear manner to the public and other decision makers.

  7. Direct measurement of the characteristic three-body electron attachment time in the atmospheric air in direct current electric field

    SciTech Connect (OSTI)

    Shutov, A. V.; Smetanin, I. V.; Ionin, A. A.; Levchenko, A. O.; Seleznev, L. V.; Sinitsyn, D. V.; Ustinovskii, N. N.; Zvorykin, V. D.

    2013-07-15

    We report the results of theoretical and experimental study of the characteristic time for three-body attachment of electrons produced by 100 fs UV laser pulse in the atmosphere air in the external DC electric field ranged from 0.2 to 10 kV/cm.

  8. ASA conference on radiation and health: Health effects of electric and magnetic fields: Statistical support for research strategies. Final report

    SciTech Connect (OSTI)

    Not Available

    1990-05-01

    This report is a collection of papers documenting presentations made at the VIII ASA (American Statistical Association) Conference on Radiation and Health entitled Health Effects of Electric and Magnetic Fields: Statistical Support for Research Strategies. Individual papers are abstracted and indexed for the database.

  9. Built-in Electric Field Induced Mechanical Property Change at the Lanthanum Nickelate/Nb-doped Strontium Titanate Interfaces

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

    Chien, TeYu; Liu, Jian; Yost, Andrew J.; Chakhalian, Jak; Freeland, John W.; Guisinger, Nathan P.

    2016-01-08

    The interactions between electric field and the mechanical properties of materials are important for the applications of microelectromechanical and nanoelectromechanical systems, but relatively unexplored for nanoscale materials. Here, we observe an apparent correlation between the change of the fractured topography of Nb-doped SrTiO3 (Nb:STO) within the presence of a built-in electric field resulting from the Schottky contact at the interface of a metallic LaNiO3 thin film utilizing cross-sectional scanning tunneling microscopy and spectroscopy. The change of the inter-atomic bond length mechanism is argued to be the most plausible origin. This picture is supported by the strong-electric-field-dependent permittivity in STO andmore » the existence of the dielectric dead layer at the interfaces of STO with metallic films. Finally, these results provided direct evidence and a possible mechanism for the interplay between the electric field and the mechanical properties on the nanoscale for perovskite materials.« less

  10. Electrical Engineer

    Broader source: Energy.gov [DOE]

    Transmission Field Services is responsible for field switching operation and maintenance of Bonneville Power Administration's high-voltage electrical transmission system to provide safe, reliable,...

  11. Direct, spectroscopic measurement of electric fields in a plasma-RF antenna interaction region in Tore Supra

    SciTech Connect (OSTI)

    Klepper, C Christopher; Hillis, Donald Lee; Isler, Ralph C; Hillairet, J.; Martin, E. H.; Colas, L.; Ekedahl, A.; Goniche, M.; Lotte, Ph.; Colledani, G.; Martin, V.; Panayotis, Stephanie; Pegourie, B.; Harris, Jeffrey H

    2013-01-01

    Balmer-series spectral line profiles of deuterium emission near a lower-hybrid (3.7 GHz) wave, high power (1-4 MW) launcher were measured with high-spectral resolution in the Tore Supra tokamak and fitted to an atomic physics model which includes both Zeeman and dynamic Stark effects. The magnetic field is static and the electric field is assumed to be monochromatic at 3.7 GHz. The determined strength and direction of the high-frequency electric field is found to be in good agreement with the results of a simulation that computes the propagation of these lower hybrid waves into the plasma in the region around the launch antenna and specifically in the region of estimated peak emission contributing to the measurement. This agreement indicates feasibility for the use of dynamic Stark effect spectroscopy to study interaction at the plasma antenna interactions in a fusion plasma environment. (C) 2013 Elsevier B. V. All rights reserved.

  12. PILOT-SCALE FIELD VALIDATION OF THE LONG ELECTRODE ELECTRICAL RESISTIVITY TOMOGRAPHY METHOD

    SciTech Connect (OSTI)

    GLASER DR; RUCKER DF; CROOK N; LOKE MH

    2011-07-14

    Field validation for the long electrode electrical resistivity tomography (LE-ERT) method was attempted in order to demonstrate the performance of the technique in imaging a simple buried target. The experiment was an approximately 1/17 scale mock-up of a region encompassing a buried nuclear waste tank on the Hanford site. The target of focus was constructed by manually forming a simulated plume within the vadose zone using a tank waste simulant. The LE-ERT results were compared to ERT using conventional point electrodes on the surface and buried within the survey domain. Using a pole-pole array, both point and long electrode imaging techniques identified the lateral extents of the pre-formed plume with reasonable fidelity, but the LE-ERT was handicapped in reconstructing the vertical boundaries. The pole-dipole and dipole-dipole arrays were also tested with the LE-ERT method and were shown to have the least favorable target properties, including the position of the reconstructed plume relative to the known plume and the intensity of false positive targets. The poor performance of the pole-dipole and dipole-dipole arrays was attributed to an inexhaustive and non-optimal coverage of data at key electrodes, as well as an increased noise for electrode combinations with high geometric factors. However, when comparing the model resolution matrix among the different acquisition strategies, the pole-dipole and dipole-dipole arrays using long electrodes were shown to have significantly higher average and maximum values than any pole-pole array. The model resolution describes how well the inversion model resolves the subsurface. Given the model resolution performance of the pole-dipole and dipole-dipole arrays, it may be worth investing in tools to understand the optimum subset of randomly distributed electrode pairs to produce maximum performance from the inversion model.

  13. Terahertz plasmon-polariton modes in graphene driven by electric field inside a Fabry-Prot cavity

    SciTech Connect (OSTI)

    Zhao, C. X.; Li, L. L.; Zhang, C.; Xu, W.; Peeters, F. M.

    2015-06-14

    We present a theoretical study on plasmon-polariton modes in graphene placed inside an optical cavity and driven by a source-to-drain electric field. The electron velocity and electron temperature are determined by solving self-consistently the momentum- and energy-balance equations in which electron interactions with impurities, acoustic-, and optic-phonons are included. Based on many-body self-consistent field theory, we develop a tractable approach to study plasmon-polariton in an electron gas system. We find that when graphene is placed inside a Fabry-Prot cavity, two branches of the plasmon-polariton modes can be observed and these modes are very much optic- or plasmon-like. The frequencies of these modes depend markedly on driving electric field especially at higher resonant frequency regime. Moreover, the plasmon-polariton frequency in graphene is in terahertz (THz) bandwidth and can be tuned by changing the cavity length, gate voltage, and driving electric field. This work is pertinent to the application of graphene-based structures as tunable THz plasmonic devices.

  14. Degradation of the electrical characteristics of MOS structures with erbium, gadolinium, and dysprosium oxides under the effect of an electric field

    SciTech Connect (OSTI)

    Shalimova, M. B. Sachuk, N. V.

    2015-08-15

    The degradation of the characteristics of silicon metal-oxide-semiconductor (MOS) structures with oxides of rare-earth elements under the effect of electric fields with intensities of 0.1–4 MV/cm during the course of electroforming is studied. A specific feature of electroforming consists in the possibility of multiple switching of the structures from the insulating state to the low-resistivity one and back. The temporal characteristics of the degradation of MOS structures during the course of electroforming are exponential. The current-voltage characteristics follow the power law in the range of 0.2–3 V; the effect of an electric field brings about a variation in the distribution of the energy density of traps responsible for currents limited by space charge. It is established that multiple cycles of electroforming lead to an increase in the density of surface states at the Si-oxide interface and to a variation in the energy position of the trap levels, which affects the charge state of the traps.

  15. Real-time observation of dynamic process of oxygen vacancy migration in cerium oxides under electric field

    SciTech Connect (OSTI)

    Li, Xiaomin; Qi, Kuo; Sun, Muhua; Huang, Qianming; Xu, Zhi E-mail: xdbai@iphy.ac.cn; Wang, Wenlong; Bai, Xuedong E-mail: xdbai@iphy.ac.cn

    2015-11-23

    The dynamic process of oxygen vacancy migration driven by the external electric field is directly observed at atomic scale in the cerium oxides (CeO{sub 2}) thin film by in-situ transmission electron microscopy method. When a bias voltage of a proper value is applied across the CeO{sub 2} film, the oxygen vacancies are formed near the interface of CeO{sub 2}/anode, followed by their migration along the direction of the external electric field. The structural modulation occurs in the [110] zone axis due to the ordering of oxygen vacancies. The migration of oxygen vacancies results in the reversible structural transformation, i.e., releasing and storing oxygen processes in CeO{sub 2}, which is of great significance for the ionic and electronic applications of the cerium oxides materials, such as oxygen pump, gas sensor, resistive random access memory, etc.

  16. Selective observation of photo-induced electric fields inside different material components in bulk-heterojunction organic solar cell

    SciTech Connect (OSTI)

    Chen, Xiangyu; Taguchi, Dai; Manaka, Takaaki; Iwamoto, Mitsumasa

    2014-01-06

    By using electric-field-induced optical second-harmonic generation (EFISHG) measurement at two laser wavelengths of 1000 nm and 860 nm, we investigated carrier behavior inside the pentacene and C{sub 60} component of co-deposited pentacene:C{sub 60} bulk-heterojunctions (BHJs) organic solar cells (OSCs). The EFISHG experiments verified the presence of two carrier paths for electrons and holes in BHJs OSCs. That is, two kinds of electric fields pointing in opposite directions are identified as a result of the selectively probing of SHG activation from C{sub 60} and pentacene. Also, under open-circuit conditions, the transient process of the establishment of open-circuit voltage inside the co-deposited layer has been directly probed, in terms of photovoltaic effect. The EFISHG provides an additional promising method to study carrier path of electrons and holes as well as dissociation of excitons in BHJ OSCs.

  17. Holographic recording in films of azo-containing LC polymers in the presence of orienting electric field

    SciTech Connect (OSTI)

    Simonov, A N; Larichev, A V; Shibaev, Valerii P

    2000-07-31

    The dynamics of holographic recording in a film of azo-containing liquid-crystal polymer is studied both experimentally and theoretically in the presence of the orienting electric field. The possibility is demonstrated to efficiently control the optical recording regime by varying the applied field. The specificity of hologram formation in the case of different polarisation of the interacting light beams is considered. A theoretical model describing the holographic recording dynamics in a film of azo-containing nematic polymer is presented; numerical simulation of the processes of recording and read-out in anisotropic holograms is carried out as well. (laser applications and other topics in quantum electronics)

  18. Electromagnetically induced transparency with large delay-bandwidth product induced by magnetic resonance near field coupling to electric resonance

    SciTech Connect (OSTI)

    Li, Hai-ming; Liu, Shao-bin Liu, Si-yuan; Zhang, Hai-feng; Bian, Bo-rui; Kong, Xiang-kun; Wang, Shen-yun

    2015-03-16

    In this paper, we numerically and experimentally demonstrate electromagnetically induced transparency (EIT)-like spectral response with magnetic resonance near field coupling to electric resonance. Six split-ring resonators and a cut wire are chosen as the bright and dark resonator, respectively. An EIT-like transmission peak located between two dips can be observed with incident magnetic field excitation. A large delay bandwidth product (0.39) is obtained, which has potential application in quantum optics and communications. The experimental results are in good agreement with simulated results.

  19. Effect of bulk electric field reversal on the bounce resonance heating in dual-frequency capacitively coupled electronegative plasmas

    SciTech Connect (OSTI)

    Liu Yongxin; Zhang Quanzhi; Liu Jia; Song Yuanhong; Wang Younian [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Bogaerts, Annemie [Department of Chemistry, University of Antwerp, Campus Drie Eiken, Universiteitsplein 1, BE-2610 Wilrijk-Antwerp (Belgium)

    2012-09-10

    The electron bounce resonance heating (BRH) in dual-frequency capacitively coupled plasmas operated in oxygen and argon has been studied by different experimental methods. In comparison with the electropositive argon discharge, the BRH in an electronegative discharge occurs at larger electrode gaps. Kinetic particle simulations reveal that in the oxygen discharge, the bulk electric field becomes quite strong and is out of phase with the sheath field. Therefore, it retards the resonant electrons when traversing the bulk, resulting in a suppressed BRH. This effect becomes more pronounced at lower high-frequency power, when the discharge mode changes from electropositive to electronegative.

  20. Spin- and valley-dependent commensurability oscillations and electric-field-induced quantum Hall plateaux in periodically modulated silicene

    SciTech Connect (OSTI)

    Shakouri, Kh.; Peeters, F. M. [Departement Fysica, Universiteit Antwerpen, Groenenborgerlaan 171, B-2020 Antwerpen (Belgium); Vasilopoulos, P.; Vargiamidis, V. [Department of Physics, Concordia University, 7141 Sherbrooke Ouest Montral, Qubec H4B 1R6 (Canada); Hai, G.-Q. [Instituto de Fisica de So Carlos, Universidade de So Paulo, So Carlos, SP 13560-970 (Brazil)

    2014-05-26

    We study the commensurability oscillations in silicene subject to a perpendicular electric field E{sub z}, a weak magnetic field B, and a weak periodic potential V=V{sub 0}cos(Cy),C=2?/a{sub 0} with a{sub 0} its period. The field E{sub z} and/or the modulation lift the spin degeneracy of the Landau levels and lead to spin and valley resolved Weiss oscillations. The spin resolution is maximal when the field E{sub z} is replaced by a periodic one E{sub z}=E{sub 0}cos(Dy),D=2?/b{sub 0}, while the valley one is maximal for b{sub 0}?=?a{sub 0}. In certain ranges of B values, the current is fully spin or valley polarized. Additional quantum Hall conductivity plateaux arise due to spin and valley intra-Landau-level transitions.

  1. Three-dimensional electrical resistivity tomography and its application to Larderello-Valle Secolo geothermal field in Tuscany, Italy

    SciTech Connect (OSTI)

    Shi, Weiqun; Rodi, W.; Toksoez, M.N.; Morgan, F.D.

    1997-10-01

    The Valle Secolo region in the Larderello geothermal field in western Italy is a vapor-dominated reservoir producing steam primarily from shallow, highly fractured Miscan anhydrites. In this area, water re-injection into various wells has been carried out for many years. During this period, electrical resistivity surveys have been conducted for the purpose of monitoring distribution of re-injected water and steam displacement through changes in subsurface electrical properties. This paper describes a 3-D d.c. electrical resistivity inversion algorithm and its application to data obtained from two surveys conducted in 1991 and 1993, respectively. The objective of this effort is to relate the variations in resistivity with position and time to the injection history. Our inversion models indicate that the primary resistivity variations in the Larderello geothermal field are of structural origin, e.g., the variation of conductivity of the geologic section. However, the models from both surveys contain a low resistivity anomaly at a depth of a few hundred meters that does not correlate with structure. From its location relative to the injection wells, and from changes in its properties between the two surveys, we infer that the anomaly is related to the injection and is probably a zone of high permeability or high water saturation. These preliminary results show that it is possible to detect and monitor the re-injection of fluid through the systematic observation of electrical resistivity at the site. The method is also suitable for the detection of environmental contaminant movement. However, field measurements must be repeated using the same geometry and uniform calibration over time.

  2. Design of electric-field assisted surface plasmon resonance system for the detection of heavy metal ions in water

    SciTech Connect (OSTI)

    Kyaw, Htet Htet; Boonruang, Sakoolkan E-mail: waleed.m@bu.ac.th; Mohammed, Waleed S. E-mail: waleed.m@bu.ac.th; Dutta, Joydeep

    2015-10-15

    Surface Plasmon Resonance (SPR) sensors are widely used in diverse applications. For detecting heavy metal ions in water, surface functionalization of the metal surface is typically used to adsorb target molecules, where the ionic concentration is detected via a resonance shift (resonance angle, resonance wavelength or intensity). This paper studies the potential of a possible alternative approach that could eliminate the need of using surface functionalization by the application of an external electric field in the flow channel. The exerted electrical force on the ions pushes them against the surface for enhanced adsorption; hence it is referred to as “Electric-Field assisted SPR system”. High system sensitivity is achieved by monitoring the time dynamics of the signal shift. The ion deposition dynamics are discussed using a derived theoretical model based on ion mobility in water. On the application of an appropriate force, the target ions stack onto the sensor surface depending on the ionic concentration of target solution, ion mass, and flow rate. In the experimental part, a broad detection range of target cadmium ions (Cd{sup 2+}) in water from several parts per million (ppm) down to a few parts per billion (ppb) can be detected.

  3. Study of nonneutral plasma storage in a magnetic trap with a rotating electric field at the lepta facility

    SciTech Connect (OSTI)

    Eseev, M. K.; Kobets, A. G.; Meshkov, I. N.; Rudakov, A. Yu.; Yakovenko, S. L.

    2013-10-15

    Results from experimental studies of plasma storage in a Penning-Malmberg trap at the LEPTA facility are presented. The number of stored particles is found to increase substantially when using the so-called “rotating wall” method, in which a transverse rotating electric field generated by a cylindrical segmented electrode cut into four pairs is applied to the plasma storage region. The conditions of transverse compression of the plasma bunch under the action of the rotating field and buffer gas are studied. The optimal storage parameters are determined for these experimental conditions. Mechanisms of the action of the rotating field and buffer gas on the process of plasma storage are discussed.

  4. Nanoscale three-dimensional reconstruction of electric and magnetic stray fields around nanowires

    SciTech Connect (OSTI)

    Lubk, A.; Wolf, D.; Sturm, S.; Simon, P.; Wang, C.; Felser, C.

    2014-10-27

    Static electromagnetic stray fields around nanowires (NWs) are characteristic for a number of important physical effects such as field emission or magnetic force microscopy. Consequently, an accurate characterization of these fields is of high interest and electron holographic tomography (EHT) is unique in providing tomographic 3D reconstructions at nm spatial resolution. However, several limitations of the experimental setup and the specimen itself are influencing EHT. Here, we show how a deliberate restriction of the tomographic reconstruction to the exterior of the NWs can be used to mitigate these limitations facilitating a quantitative 3D tomographic reconstruction of static electromagnetic stray fields at the nanoscale. As an example, we reconstruct the electrostatic stray field around a GaAs-AlGaAs core shell NW and the magnetic stray field around a Co{sub 2}FeGa Heusler compound NW.

  5. PWR AXIAL BURNUP PROFILE ANALYSIS

    SciTech Connect (OSTI)

    J.M. Acaglione

    2003-09-17

    The purpose of this activity is to develop a representative ''limiting'' axial burnup profile for pressurized water reactors (PWRs), which would encompass the isotopic axial variations caused by different assembly irradiation histories, and produce conservative isotopics with respect to criticality. The effect that the low burnup regions near the ends of spent fuel have on system reactivity is termed the ''end-effect''. This calculation will quantify the end-effects associated with Pressurized Water Reactor (PWR) fuel assemblies emplaced in a hypothetical 21 PWR waste package. The scope of this calculation covers an initial enrichment range of 3.0 through 5.0 wt% U-235 and a burnup range of 10 through 50 GWd/MTU. This activity supports the validation of the process for ensuring conservative generation of spent fuel isotopics with respect to criticality safety applications, and the use of burnup credit for commercial spent nuclear fuel. The intended use of these results will be in the development of PWR waste package loading curves, and applications involving burnup credit. Limitations of this evaluation are that the limiting profiles are only confirmed for use with the B&W 15 x 15 fuel assembly design. However, this assembly design is considered bounding of all other typical commercial PWR fuel assembly designs. This calculation is subject to the Quality Assurance Requirements and Description (QARD) because this activity supports investigations of items or barriers on the Q-list (YMP 2001).

  6. Acoustic wave propagation in uniform glow discharge plasma at an arbitrary angle between the electric field and wave vectors

    SciTech Connect (OSTI)

    Soukhomlinov, Vladimir; Gerasimov, Nikolay; Sheverev, Valery A.

    2008-08-15

    This paper extends the recently reported one-dimensional model for sound propagation in glow discharge plasma to arbitrary mutual orientation of the plasma electric field and acoustic wave vectors. The results demonstrate that an acoustic wave in plasma may amplify, attenuate, or remain unchanged depending on the angle between these vectors and on the power input into the discharge. Quantitative evaluations indicate that for glow discharge plasma of a self-sustained discharge in air at the electric current densities of the order of 100 mA cm{sup -2}, a gain of as much as 1 m{sup -1} at 0 deg. angle between the vectors changes to similar strength attenuation for the 90 deg. angle.

  7. Effect of increased crystallinity of single-walled carbon nanotubes used as field emitters on their electrical properties

    SciTech Connect (OSTI)

    Shimoi, Norihiro

    2015-12-07

    Single-walled carbon nanotubes (SWCNTs) synthesized by arc discharge are expected to exhibit good field emission (FE) properties at a low driving voltage. We used a coating containing homogeneously dispersed highly crystalline SWCNTs produced by a high-temperature annealing process to fabricate an FE device by a wet-coating process at a low cost. Using the coating, we succeeded in reducing the power consumption of field emitters for planar lighting devices. SWCNTs synthesized by arc discharge have crystal defects in the carbon network, which are considered to induce inelastic electron tunneling that deteriorates the electrical conductivity of the SWCNTs. In this study, the blocking of the transport of electrons in SWCNTs with crystal defects is simulated using an inelastic electron tunneling model. We succeeded in clarifying the mechanism underlying the electrical conductivity of SWCNTs by controlling their crystallinity. In addition, it was confirmed that field emitters using highly crystalline SWCNTs can lead to new applications operating with low power consumption and new devices that may change our daily lives in the future.

  8. Fully alternating, triaxial electric or magnetic fields offer new routes to fluid vorticity

    SciTech Connect (OSTI)

    Martin, James E.; Solis, Kyle J.

    2014-10-31

    Noncontact methods of generating strong fluid vorticity are important to problems involving heat and mass transfer, fluid mixing, active wetting, and droplet transport. Furthermore, because zero or even negative shear viscosities can be induced, vorticity can greatly extend the control range of the smart fluids used in magnetorheological devices. In recent work we have shown that a particular class of ac/ac/dc triaxial fields (so-called symmetry-breaking rational fields) can create strong vorticity in magnetic particle suspensions and have presented a theory of the vorticity that is based on the symmetry of the 2-d Lissajous trajectories of the field and its converse. In this paper we demonstrate that there are three countably infinite sets of fully alternating ac/ac/ac triaxial fields whose frequencies form rational triads that have the symmetry required to drive fluid vorticity. The symmetry of the 3-d Lissajous trajectories of the field and its converse can be derived and from this the direction of the vorticity axis can be predicted, as can the dependence of the sign of the vorticity on the phase relations between the three field components. Experimental results are presented that validate the symmetry theory. These discoveries significantly broaden the class of triaxial fields that can be exploited to produce strong noncontact flow.

  9. Fully alternating, triaxial electric or magnetic fields offer new routes to fluid vorticity

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

    Martin, James E.; Solis, Kyle J.

    2014-10-31

    Noncontact methods of generating strong fluid vorticity are important to problems involving heat and mass transfer, fluid mixing, active wetting, and droplet transport. Furthermore, because zero or even negative shear viscosities can be induced, vorticity can greatly extend the control range of the smart fluids used in magnetorheological devices. In recent work we have shown that a particular class of ac/ac/dc triaxial fields (so-called symmetry-breaking rational fields) can create strong vorticity in magnetic particle suspensions and have presented a theory of the vorticity that is based on the symmetry of the 2-d Lissajous trajectories of the field and its converse.more » In this paper we demonstrate that there are three countably infinite sets of fully alternating ac/ac/ac triaxial fields whose frequencies form rational triads that have the symmetry required to drive fluid vorticity. The symmetry of the 3-d Lissajous trajectories of the field and its converse can be derived and from this the direction of the vorticity axis can be predicted, as can the dependence of the sign of the vorticity on the phase relations between the three field components. Experimental results are presented that validate the symmetry theory. These discoveries significantly broaden the class of triaxial fields that can be exploited to produce strong noncontact flow.« less

  10. Investigation of different magnetic field configurations using an electrical, modular Zeeman slower

    SciTech Connect (OSTI)

    Ohayon, Ben; Ron, Guy

    2015-10-15

    We present a method of constructing an automatically reconfigurable, modular, electronic Zeeman slower, which is remotely controlled. This setup is used to investigate the ability of different magnetic field profiles to slow thermal atoms to the capture velocity of a magneto-optical-trap. We show that a simple numerical optimization process yields better results than the commonly used approach for deciding on the appropriate field and comes close to the optimum field, found by utilizing a fast feedback loop which uses a genetic algorithm. Our new numerical method is easily adaptable to a variety of existing slower designs and may be beneficial where feedback is unavailable.