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Sample records for dynamic electron solutions

  1. Integrated Dynamic Electron Solutions, Inc. | Department of Energy

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

    Integrated Dynamic Electron Solutions, Inc. America's Next Top Energy Innovator Challenge 333 likes Integrated Dynamic Electron Solutions, Inc. Lawrence Livermore National Laboratory Dynamic Transmission Electron Microscopes DTEM reveal unprecedented details of the mechanisms underlying a host of nanoscale systems that are at the core of our current and future energy economy. A vast and growing number of materials utilized in the energy sector rely on nanostructured materials and their unique

  2. Ultrafast studies of solution dynamics

    SciTech Connect (OSTI)

    Woodruff, W.H.; Dyer, R.B.; Callender, R.H.

    1997-10-01

    This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). Fast chemical dynamics generally must be initiated photochemically. This limits the applicability of modern laser methods for following the structural changes that occur during chemical and biological reactions to those systems that have an electronic chromophore that has a significant yield of photoproduct when excited. This project has developed a new and entirely general approach to ultrafast initiation of reactions in solution: laser-induced temperature jump (T-jump). The results open entire new fields of study of ultrafast molecular dynamics in solution. The authors have demonstrated the T-jump technique on time scales of 50 ps and longer, and have applied it to study of the fast events in protein folding. They find that a general lifetime of alpha-helix formation is ca 100 ns, and that tertiary folds (in apomyoglobin) form in ca 100 {mu}s.

  3. Dynamic Transmission Electron Microscopy

    SciTech Connect (OSTI)

    Evans, James E.; Jungjohann, K. L.; Browning, Nigel D.

    2012-10-12

    Dynamic transmission electron microscopy (DTEM) combines the benefits of high spatial resolution electron microscopy with the high temporal resolution of ultrafast lasers. The incorporation of these two components into a single instrument provides a perfect platform for in situ observations of material processes. However, previous DTEM applications have focused on observing structural changes occurring in samples exposed to high vacuum. Therefore, in order to expand the pump-probe experimental regime to more natural environmental conditions, in situ gas and liquid chambers must be coupled with Dynamic TEM. This chapter describes the current and future applications of in situ liquid DTEM to permit time-resolved atomic scale observations in an aqueous environment, Although this chapter focuses mostly on in situ liquid imaging, the same research potential exists for in situ gas experiments and the successful integration of these techniques promises new insights for understanding nanoparticle, catalyst and biological protein dynamics with unprecedented spatiotemporal resolution.

  4. Fissile solution dynamics: Student research

    SciTech Connect (OSTI)

    Hetrick, D.L.

    1994-09-01

    There are two research projects in criticality safety at the University of Arizona: one in dynamic simulation of hypothetical criticality accidents in fissile solutions, and one in criticality benchmarks using transport theory. We have used the data from nuclear excursions in KEWB, CRAC, and SILENE to help in building models for solution excursions. An equation of state for liquids containing gas bubbles has been developed and coupled to point-reactor dynamics in an attempt to predict fission rate, yield, pressure, and kinetic energy. It appears that radiolytic gas is unimportant until after the first peak, but that it does strongly affect the shape of the subsequent power decrease and also the dynamic pressure.

  5. Dynamic imaging with electron microscopy

    ScienceCinema (OSTI)

    Campbell, Geoffrey; McKeown, Joe; Santala, Melissa

    2014-05-30

    Livermore researchers have perfected an electron microscope to study fast-evolving material processes and chemical reactions. By applying engineering, microscopy, and laser expertise to the decades-old technology of electron microscopy, the dynamic transmission electron microscope (DTEM) team has developed a technique that can capture images of phenomena that are both very small and very fast. DTEM uses a precisely timed laser pulse to achieve a short but intense electron beam for imaging. When synchronized with a dynamic event in the microscope's field of view, DTEM allows scientists to record and measure material changes in action. A new movie-mode capability, which earned a 2013 R&D 100 Award from R&D Magazine, uses up to nine laser pulses to sequentially capture fast, irreversible, even one-of-a-kind material changes at the nanometer scale. DTEM projects are advancing basic and applied materials research, including such areas as nanostructure growth, phase transformations, and chemical reactions.

  6. Dynamical effects in electron spectroscopy

    SciTech Connect (OSTI)

    Zhou, Jianqiang Sky Reshetnyak, Igor; Giorgetti, Christine; Sottile, Francesco; Reining, Lucia; Kas, J. J.; Rehr, J. J.; Sponza, Lorenzo; Guzzo, Matteo; Gatti, Matteo

    2015-11-14

    One of the big challenges of theoretical condensed-matter physics is the description, understanding, and prediction of the effects of the Coulomb interaction on materials properties. In electronic spectra, the Coulomb interaction causes a renormalization of energies and change of spectral weight. Most importantly, it can lead to new structures, often called satellites. These can be linked to the coupling of excitations, also termed dynamical effects. State-of-the-art methods in the framework of many-body perturbation theory, in particular, the widely used GW approximation, often fail to describe satellite spectra. Instead, approaches based on a picture of electron-boson coupling such as the cumulant expansion are promising for the description of plasmon satellites. In this work, we give a unified derivation of the GW approximation and the cumulant expansion for the one-body Green’s function. Using the example of bulk sodium, we compare the resulting spectral functions both in the valence and in the core region, and we discuss the dispersion of quasi-particles and satellites. We show that self-consistency is crucial to obtain meaningful results, in particular, at large binding energies. Very good agreement with experiment is obtained when the intrinsic spectral function is corrected for extrinsic and interference effects. Finally, we sketch how one can approach the problem in the case of the two-body Green’s function, and we discuss the cancellation of various dynamical effects that occur in that case.

  7. PIA - Savannah River Nuclear Solution SRNS Electronic Document...

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

    SRNS Electronic Document Workflow RECORDS System (EDWS) PIA - Savannah River Nuclear Solution SRNS Electronic Document Workflow RECORDS System (EDWS) PIA - Savannah River Nuclear ...

  8. PIA - Savannah River Nuclear Solution SRNS Electronic Document Workflow

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

    RECORDS System (EDWS) | Department of Energy SRNS Electronic Document Workflow RECORDS System (EDWS) PIA - Savannah River Nuclear Solution SRNS Electronic Document Workflow RECORDS System (EDWS) PIA - Savannah River Nuclear Solution SRNS Electronic Document Workflow RECORDS System (EDWS) PIA - Savannah River Nuclear Solution SRNS Electronic Document Workflow RECORDS System (EDWS) (3.87 MB) More Documents & Publications PIA - Savannah River Nuclear Solution (SRNS) Procurement Cycle System

  9. PIA - Savannah River Nuclear Solutions Electronic Safeguards Security

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

    System (E3S) | Department of Energy Electronic Safeguards Security System (E3S) PIA - Savannah River Nuclear Solutions Electronic Safeguards Security System (E3S) PIA - Savannah River Nuclear Solutions Electronic Safeguards Security System (E3S) PIA - Savannah River Nuclear Solutions Electronic Safeguards Security System (E3S) (3.6 MB) More Documents & Publications PIA - 10th International Nuclear Graphite Specialists Meeting registration web site PIA - HSPD-12 Physical and Logical

  10. Brownian Dynamics Simulation of Protein Solutions: Structural and Dynamical Properties

    SciTech Connect (OSTI)

    Mereghetti, Paolo; Gabdoulline, Razif; Wade, Rebecca C.

    2010-12-01

    The study of solutions of biomacromolecules provides an important basis for understanding the behavior of many fundamental cellular processes, such as protein folding, self-assembly, biochemical reactions, and signal transduction. Here, we describe a Brownian dynamics simulation procedure and its validation for the study of the dynamic and structural properties of protein solutions. In the model used, the proteins are treated as atomically detailed rigid bodies moving in a continuum solvent. The protein-protein interaction forces are described by the sum of electrostatic interaction, electrostatic desolvation, nonpolar desolvation, and soft-core repulsion terms. The linearized Poisson-Boltzmann equation is solved to compute electrostatic terms. Simulations of homogeneous solutions of three different proteins with varying concentrations, pH, and ionic strength were performed. The results were compared to experimental data and theoretical values in terms of long-time self-diffusion coefficients, second virial coefficients, and structure factors. The results agree with the experimental trends and, in many cases, experimental values are reproduced quantitatively. There are no parameters specific to certain protein types in the interaction model, and hence the model should be applicable to the simulation of the behavior of mixtures of macromolecules in cell-like crowded environments.

  11. Organic electronic devices with multiple solution-processed layers

    DOE Patents [OSTI]

    Forrest, Stephen R.; Lassiter, Brian E.; Zimmerman, Jeramy D.

    2015-08-04

    A method of fabricating a tandem organic photosensitive device involves depositing a first layer of an organic electron donor type material film by solution-processing of the organic electron donor type material dissolved in a first solvent; depositing a first layer of an organic electron acceptor type material over the first layer of the organic electron donor type material film by a dry deposition process; depositing a conductive layer over the interim stack by a dry deposition process; depositing a second layer of the organic electron donor type material over the conductive layer by solution-processing of the organic electron donor type material dissolved in a second solvent, wherein the organic electron acceptor type material and the conductive layer are insoluble in the second solvent; depositing a second layer of an organic electron acceptor type material over the second layer of the organic electron donor type material film by a dry deposition process, resulting in a stack.

  12. Dynamic nuclear-polarization studies of paramagnetic species in solution

    SciTech Connect (OSTI)

    Glad, W.E.

    1982-07-01

    Dynamic Nuclear Polarization (DNP) was used to measure the electron spin lattice relaxation times, T/sub 1/, of transition metal ions in aqueous solution. Saturation which is induced in the electron spin system is transferred to the solvent proton spins by dipole-dipole interactions. The change in the polarization of the proton spins is much larger than it is in the electron spins. The change in proton polarization is easily measured by proton Nuclear Magnetic Resonance (NMR). In one experimental arrangement the sample solution was continuously flowed through a microwave cavity to the NMR coil. The NMR was observed with a continuous wave NMR spectrometer. In a second arrangement the whole sample tube was moved from within the microwave cavity to the NMR coil in less than 40 ms by a blast of compressed air. The NMR was then observed with a pulse-Fourier-transform spectrometer. With the second arrangement a mean-square microwave magnetic field at the sample of more than 10 G/sup 2/ is obtainable with 14 W of microwave power. Measurements of DNP at 9 GHz were made on aqueous solutions of VO/sup 2 +/, Mn/sup 2 +/, Cr(CN)/sub 6//sup 3 -/, Cu/sup 2 +/ and Cu(ethylenediamine)/sub 2/(H/sub 2/0)/sub 2//sup 2 +/ ions from 3 to 60/sup 0/C. It was also possible to observe DNP on resolved proton resonances from mixed water-acetonitrile solutions of VO/sup 2 +/ and Cr(CN)/sub 6//sup 3 -/ ions.

  13. Short-Time Glassy Dynamics in Viscous Protein Solutions with...

    Office of Scientific and Technical Information (OSTI)

    Short-Time Glassy Dynamics in Viscous Protein Solutions with Competing Interactions This content will become publicly available on November 23, 2016 Prev Next Title: ...

  14. Adjoint Fokker-Planck equation and runaway electron dynamics...

    Office of Scientific and Technical Information (OSTI)

    This content will become publicly available on January 13, 2017 Title: Adjoint Fokker-Planck equation and runaway electron dynamics Authors: Liu, Chang 1 ; Brennan, Dylan P. 1 ...

  15. Dynamic behavior of ion acoustic waves in electron-positron-ion magnetoplasmas with superthermal electrons and positrons

    SciTech Connect (OSTI)

    Saha, Asit E-mail: prasantachatterjee1@rediffmail.com; Pal, Nikhil; Chatterjee, Prasanta E-mail: prasantachatterjee1@rediffmail.com

    2014-10-15

    The dynamic behavior of ion acoustic waves in electron-positron-ion magnetoplasmas with superthermal electrons and positrons has been investigated in the framework of perturbed and non-perturbed Kadomtsev-Petviashili (KP) equations. Applying the reductive perturbation technique, we have derived the KP equation in electron-positron-ion magnetoplasma with kappa distributed electrons and positrons. Bifurcations of ion acoustic traveling waves of the KP equation are presented. Using the bifurcation theory of planar dynamical systems, the existence of the solitary wave solutions and the periodic traveling wave solutions has been established. Two exact solutions of these waves have been derived depending on the system parameters. Then, using the Hirota's direct method, we have obtained two-soliton and three-soliton solutions of the KP equation. The effect of the spectral index κ on propagations of the two-soliton and the three-soliton has been shown. Considering an external periodic perturbation, we have presented the quasi periodic behavior of ion acoustic waves in electron-positron-ion magnetoplasmas.

  16. Structure and dynamics of aqueous solution of uranyl ions

    SciTech Connect (OSTI)

    Chopra, Manish; Choudhury, Niharendu

    2014-04-24

    The present work describes a molecular dynamics simulation study of structure and dynamics of aqueous solution of uranyl ions in water. Structural properties of the system in terms of radial distribution functions and dynamical characteristics as obtained through velocity autocorrelation function and mean square displacements have been analyzed. The results for radial distribution functions show the oxygen of water to form the first solvation shell at 2.4 around the uranium atom, whereas the hydrogen atoms of water are distributed around the uranium atom with the major peak at around 3.0 . Analyses of transport behaviors of ions and water through MSD indicates that the diffusion of the uranyl ion is much less as compared to that of the water molecules. It is also observed that the dynamical behavior of water molecules gets modified due to the presence of uranyl ion. The effect of increase in concentration of uranyl ions on the structure and dynamics of water molecules is also studied.

  17. Design and Construction of Experiment for Direct Electron Irradiation of Uranyl Sulfate Solution: Bubble Formation and Thermal Hydraulics Studies

    SciTech Connect (OSTI)

    Chemerisov, Sergey; Gromov, Roman; Makarashvili, Vakho; Heltemes, Thad; Sun, Zaijing; Wardle, Kent E.; Bailey, James; Quigley, Kevin; Stepinski, Dominique; Vandegrift, George

    2014-10-01

    Argonne is assisting SHINE Medical Technologies in developing SHINE, a system for producing fission-product 99Mo using a D/T-accelerator to produce fission in a non-critical target solution of aqueous uranyl sulfate. We have developed an experimental setup for studying thermal-hydraulics and bubble formation in the uranyl sulfate solution to simulate conditions expected in the SHINE target solution during irradiation. A direct electron beam from the linac accelerator will be used to irradiate a 20 L solution (sector of the solution vessel). Because the solution will undergo radiolytic decomposition, we will be able to study bubble formation and dynamics and effects of convection and temperature on bubble behavior. These experiments will serve as a verification/ validation tool for the thermal-hydraulic model. Utilization of the direct electron beam for irradiation allows homogeneous heating of a large solution volume and simplifies observation of the bubble dynamics simultaneously with thermal-hydraulic data collection, which will complement data collected during operation of the miniSHINE experiment. Irradiation will be conducted using a 30-40 MeV electron beam from the high-power linac accelerator. The total electron-beam power will be 20 kW, which will yield a power density on the order of 1 kW/L. The solution volume will be cooled on the front and back surfaces and central tube to mimic the geometry of the proposed SHINE solution vessel. Also, multiple thermocouples will be inserted into the solution vessel to map thermal profiles. The experimental design is now complete, and installation and testing are in progress.

  18. Molecular dynamics of a dilute solution of hydrogen in palladium

    SciTech Connect (OSTI)

    Pratt, L. R.; Eckert, J.

    1989-06-15

    Molecular-dynamics results on a dilute solution of H in Pd are presentedand compared with available incoherent inelastic neutron-scattering results.The embedded-atom model adopted here does a good job of describing the H-Pdatomic forces probed by incoherent inelastic neutron scattering. The timecorrelation functions associated with the computed spectra are strongly dampedand indicative of the anharmonicity that has been suggested as the principalcontribution to the anomalous isotope dependence of the superconductingtransition temperature in PdH. These results highlight the fact that the H-atomvibrations in Pd-H solutions are low-frequency, large-amplitude vibrationsrelative to vibrations of H atoms in usual covalent interactions. The rmsdisplacement of the H atom from its mean position in the center of the Pdoctahedron compares favorably with the available neutron-diffraction results.

  19. Electronic Structure, Phonon Dynamical Properties, and CO2 Capture...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Electronic Structure, Phonon Dynamical Properties, and CO2 Capture Capability of Na2-xMxZrO3 ( MLi ,K): Density-Functional Calculations and Experimental...

  20. Electron Spin Dynamics in Semiconductor Quantum Dots

    SciTech Connect (OSTI)

    Marie, X.; Belhadj, T.; Urbaszek, B.; Amand, T.; Krebs, O.; Lemaitre, A.; Voisin, P.

    2011-07-15

    An electron spin confined to a semiconductor quantum dot is not subject to the classical spin relaxation mechanisms known for free carriers but it strongly interacts with the nuclear spin system via the hyperfine interaction. We show in time resolved photoluminescence spectroscopy experiments on ensembles of self assembled InAs quantum dots in GaAs that this interaction leads to strong electron spin dephasing.

  1. Extensions to Dynamic System Simulation of Fissile Solution Systems

    SciTech Connect (OSTI)

    Klein, Steven Karl; Bernardin, John David; Kimpland, Robert Herbert; Spernjak, Dusan

    2015-08-24

    Previous reports have documented the results of applying dynamic system simulation (DSS) techniques to model a variety of fissile solution systems. The SUPO (Super Power) aqueous homogeneous reactor (AHR) was chosen as the benchmark for comparison of model results to experimental data for steadystate operation.1 Subsequently, DSS was applied to additional AHR to verify results obtained for SUPO and extend modeling to prompt critical excursions, ramp reactivity insertions of various magnitudes and rate, and boiling operations in SILENE and KEWB (Kinetic Experiment Water Boiler).2 Additional models for pressurized cores (HRE: Homogeneous Reactor Experiment), annular core geometries, and accelerator-driven subcritical systems (ADAHR) were developed and results reported.3 The focus of each of these models is core dynamics; neutron kinetics, thermal hydraulics, radiolytic gas generation and transport are coupled to examine the time-based evolution of these systems from start-up through transition to steady-state. A common characteristic of these models is the assumption that (a) core cooling system inlet temperature and flow and (b) plenum gas inlet pressure and flow are held constant; no external (to core) component operations that may result in dynamic change to these parameters are considered. This report discusses extension of models to include explicit reference to cooling structures and radiolytic gas handling. The accelerator-driven subcritical generic system model described in References 3 and 4 is used as a basis for this extension.

  2. Electron Dynamics in Nanostructures in Strong Laser Fields

    SciTech Connect (OSTI)

    Kling, Matthias

    2014-09-11

    The goal of our research was to gain deeper insight into the collective electron dynamics in nanosystems in strong, ultrashort laser fields. The laser field strengths will be strong enough to extract and accelerate electrons from the nanoparticles and to transiently modify the materials electronic properties. We aimed to observe, with sub-cycle resolution reaching the attosecond time domain, how collective electronic excitations in nanoparticles are formed, how the strong field influences the optical and electrical properties of the nanomaterial, and how the excitations in the presence of strong fields decay.

  3. Electronic Structure and Excited State Dynamics in Biological and Nanoscale

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

    Systems | MIT-Harvard Center for Excitonics Electronic Structure and Excited State Dynamics in Biological and Nanoscale Systems February 25, 2009 at 3pm/36-428 Gregory D. Scholes Department of Chemistry, University of Toronto scholes2 abstract: After photoexcitation, energy absorbed by a molecule can be transferred efficiently over a distance of up to several tens of Ångstrom to another molecule by the process of resonance energy transfer, RET (also commonly known as electronic energy

  4. Electronically Nonadiabatic Dynamics via Semiclassical Initial Value Methods

    SciTech Connect (OSTI)

    Miller, William H.

    2008-12-11

    In the late 1970's Meyer and Miller (MM) [J. Chem. Phys. 70, 3214 (1979)] presented a classical Hamiltonian corresponding to a finite set of electronic states of a molecular system (i.e., the various potential energy surfaces and their couplings), so that classical trajectory simulations could be carried out treating the nuclear and electronic degrees of freedom (DOF) in an equivalent dynamical framework (i.e., by classical mechanics), thereby describing non-adiabatic dynamics in a more unified manner. Much later Stock and Thoss (ST) [Phys. Rev. Lett. 78, 578 (1997)] showed that the MM model is actually not a 'model', but rather a 'representation' of the nuclear-electronic system; i.e., were the MMST nuclear-electronic Hamiltonian taken as a Hamiltonian operator and used in the Schroedinger equation, the exact (quantum) nuclear-electronic dynamics would be obtained. In recent years various initial value representations (IVRs) of semiclassical (SC) theory have been used with the MMST Hamiltonian to describe electronically non-adiabatic processes. Of special interest is the fact that though the classical trajectories generated by the MMST Hamiltonian (and which are the 'input' for an SC-IVR treatment) are 'Ehrenfest trajectories', when they are used within the SC-IVR framework the nuclear motion emerges from regions of non-adiabaticity on one potential energy surface (PES) or another, and not on an average PES as in the traditional Ehrenfest model. Examples are presented to illustrate and (hopefully) illuminate this behavior.

  5. Integrated Dynamic Electron Solutions, Inc. | Department of Energy

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

    existing buildings with costs comparable to conventional HVAC. Learn More California Lithium Battery, Inc. Argonne National Laboratory 626 likes California Lithium Battery...

  6. Integrated Dynamic Electron Solutions, Inc. | Department of Energy

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

    transport and stationery power plants, marine, cars and trucks. Learn More California Lithium Battery, Inc. Argonne National Laboratory 626 likes California Lithium Battery...

  7. Integrated Dynamic Electron Solutions, Inc. | Department of Energy

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

    method for building tiny chemical structures to greatly improve the performance of lithium-ion batteries. Lithium-ion batteries are rechargeable batteries that are widely used...

  8. Integrated Dynamic Electron Solutions, Inc. | Department of Energy

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

    - like those used by wounded veterans returning from Iraq and Afghanistan - to military vehicle components, biomedical implants, aerospace fasteners and chemical plant valves....

  9. Determination of the Limits of Quasi-Static and Dynamic Solutions...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Determination of the Limits of Quasi-Static and Dynamic Solutions for Problems with Frictional Interfaces. Citation Details In-Document Search Title: Determination ...

  10. Photocathode Optimization for a Dynamic Transmission Electron Microscope: Final Report

    SciTech Connect (OSTI)

    Ellis, P; Flom, Z; Heinselman, K; Nguyen, T; Tung, S; Haskell, R; Reed, B W; LaGrange, T

    2011-08-04

    The Dynamic Transmission Electron Microscope (DTEM) team at Harvey Mudd College has been sponsored by LLNL to design and build a test setup for optimizing the performance of the DTEM's electron source. Unlike a traditional TEM, the DTEM achieves much faster exposure times by using photoemission from a photocathode to produce electrons for imaging. The DTEM team's work is motivated by the need to improve the coherence and current density of the electron cloud produced by the electron gun in order to increase the image resolution and contrast achievable by DTEM. The photoemission test setup is nearly complete and the team will soon complete baseline tests of electron gun performance. The photoemission laser and high voltage power supply have been repaired; the optics path for relaying the laser to the photocathode has been finalized, assembled, and aligned; the internal setup of the vacuum chamber has been finalized and mostly implemented; and system control, synchronization, and data acquisition has been implemented in LabVIEW. Immediate future work includes determining a consistent alignment procedure to place the laser waist on the photocathode, and taking baseline performance measurements of the tantalum photocathode. Future research will examine the performance of the electron gun as a function of the photoemission laser profile, the photocathode material, and the geometry and voltages of the accelerating and focusing components in the electron gun. This report presents the team's progress and outlines the work that remains.

  11. On the solution of the continuity equation for precipitating electrons in solar flares

    SciTech Connect (OSTI)

    Emslie, A. Gordon; Holman, Gordon D.; Litvinenko, Yuri E. E-mail: gordon.d.holman@nasa.gov

    2014-09-01

    Electrons accelerated in solar flares are injected into the surrounding plasma, where they are subjected to the influence of collisional (Coulomb) energy losses. Their evolution is modeled by a partial differential equation describing continuity of electron number. In a recent paper, Dobranskis and Zharkova claim to have found an 'updated exact analytical solution' to this continuity equation. Their solution contains an additional term that drives an exponential decrease in electron density with depth, leading them to assert that the well-known solution derived by Brown, Syrovatskii and Shmeleva, and many others is invalid. We show that the solution of Dobranskis and Zharkova results from a fundamental error in the application of the method of characteristics and is hence incorrect. Further, their comparison of the 'new' analytical solution with numerical solutions of the Fokker-Planck equation fails to lend support to their result. We conclude that Dobranskis and Zharkova's solution of the universally accepted and well-established continuity equation is incorrect, and that their criticism of the correct solution is unfounded. We also demonstrate the formal equivalence of the approaches of Syrovatskii and Shmeleva and Brown, with particular reference to the evolution of the electron flux and number density (both differential in energy) in a collisional thick target. We strongly urge use of these long-established, correct solutions in future works.

  12. Study of the nanobubble phase of aqueous NaCl solutions by dynamic light scattering

    SciTech Connect (OSTI)

    Bunkin, N F; Shkirin, A V [A M Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation); Burkhanov, I S; Chaikov, L L [P N Lebedev Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation); Lomkova, A K [N.E. Bauman Moscow State Technical University, Moscow (Russian Federation)

    2014-11-30

    Aqueous NaCl solutions with different concentrations have been investigated by dynamic scattering of laser radiation. It is experimentally shown that these solutions contain scattering particles with a wide size distribution in a range of ?10 100 nm. The experimental results indirectly confirm the existence of quasi-stable gas nanobubbles in the bulk of aqueous ionic solutions. (light scattering)

  13. Modeling Crabbing Dynamics in an Electron-Ion Collider

    SciTech Connect (OSTI)

    Castilla, Alejandro; Morozov, Vasiliy S.; Satogata, Todd J.; Delayen, Jean R.

    2015-09-01

    A local crabbing scheme requires ?/2 (mod ?) horizontal betatron phase advances from an interaction point (IP) to the crab cavities on each side of it. However, realistic phase advances generated by sets of quadrupoles, or Final Focusing Blocks (FFB), between the crab cavities located in the expanded beam regions and the IP differ slightly from ?/2. To understand the effect of crabbing on the beam dynamics in this case, a simple model of the optics of the Medium Energy Electron-Ion Collider (MEIC) including local crabbing was developed using linear matrices and then studied numerically over multiple turns (1000 passes) of both electron and proton bunches. The same model was applied to both local and global crabbing schemes to determine the linear-order dynamical effects of the synchro-betatron coupling induced by crabbing.

  14. Complete solution of electronic excitation and ionization in electron-hydrogen molecule scattering

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

    Zammit, Mark C.; Savage, Jeremy S.; Fursa, Dmitry V.; Bray, Igor

    2016-06-01

    The convergent close-coupling method has been used to solve the electron-hydrogen molecule scattering problem in the fixed-nuclei approximation. Excellent agreement with experiment is found for the grand total, elastic, electronic-excitation, and total ionization cross sections from the very low to the very high energies. This shows that for the electronic degrees of freedom the method provides a complete treatment of electron scattering on molecules as it does for atoms.

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

    SciTech Connect (OSTI)

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

    2012-06-15

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

  16. Experimental Results for Direct Electron Irradiation of a Uranyl Sulfate Solution: Bubble Formation and Thermal Hydraulics Studies

    SciTech Connect (OSTI)

    Chemerisov, Sergey; Gromov, R.; Makarashvili, Vakhtang; Heltemes, Thad; Sun, Zaijing; Wardle, Kent E.; Bailey, James; Stepinski, Dominique; Jerden, James; Vandegrift, George F.

    2015-01-30

    In support of the development of accelerator-driven production of fission product Mo-99 as proposed by SHINE Medical Technologies, a 35 MeV electron linac was used to irradiate depleted-uranium (DU) uranyl sulfate dissolved in pH 1 sulfuric acid at average power densities of 6 kW, 12 kW, and 15 kW. During these irradiations, gas bubbles were generated in the solution due to the radiolytic decomposition of water molecules in the solution. Multiple video cameras were used to record the behavior of bubble generation and transport in the solution. Seven six-channel thermocouples were used to record temperature gradients in the solution from self-heating. Measurements of hydrogen and oxygen concentrations in a helium sweep gas were recorded by a gas chromatograph to estimate production rates during irradiation. These data are being used to validate a computational fluid dynamics (CFD) model of the experiment that includes multiphase flow and a custom bubble injection model for the solution region.

  17. Solution of dynamic contact problems by implicit/explicit methods. Final report

    SciTech Connect (OSTI)

    Salveson, M.W.; Taylor, R.L.

    1996-10-14

    The solution of dynamic contact problems within an explicit finite element program such as the LLNL DYNA programs is addressed in the report. The approach is to represent the solution for the deformation of bodies using the explicit algorithm but to solve the contact part of the problem using an implicit approach. Thus, the contact conditions at the next solution state are considered when computing the acceleration state for each explicit time step.

  18. U31: Vehicle Stability and Dynamics: Electronic Stability Control

    SciTech Connect (OSTI)

    Petrolino, Joseph; Spezia, Tony; Arant, Michael; Delorenzis, Damon; LaClair, Tim J; Lim, Alvin; Pape, Doug

    2011-01-01

    A team led by NTRCI is working to improve the roll and yaw stability of heavy duty combination trucks through developing stability algorithms, assembling demonstration hardware, and investigating robust wireless communication. Modern electronic stability control (ESC) products automatically slow a vehicle rounding a corner too quickly or apply individual brakes when necessary to improve the steering characteristics of a vehicle. Air brake systems in North America provide no electronic communication between a tractor and semitrailer, limiting the degree to which control systems can be optimized. Prior research has demonstrated stability improvements where dynamic measurements and control commands are communicated between units of a vehicle. Three related activities were undertaken: (1) Develop an algorithm for the optimum yaw and roll control of a combination vehicle. Vehicle state parameters needed to control the vehicle and the proper brake response were determined. An integrated stability control for the tractor and semitrailer requires communication between the two units. Dynamic models were used to assess the algorithm. (2) Implement the ESC algorithm in the laboratory. Hardware components suitable for the harsh environment for measurement, sensor-to-controller communication, and semitrailer-to-tractor communication and brake actuation were specified and assembled as a working system. The goal was to collect the needed vehicle state information, transmit the information to the ESC system, and then actuate the brakes in response to controller commands. (3) Develop a wireless network with the data rate and reliability necessary to communicate dynamic signals for a vehicle stability control system. Adaptive connectivity-aware, multi-hop routing was selected because it can perform in the harsh environment where packet collisions and fading often will exist. The protocol is to give high priority to urgent messages.

  19. Nonadiabatic electron dynamics of single-electron transport in a perpendicular magnetic field

    SciTech Connect (OSTI)

    He, JianHong; Guo, HuaZhong; Gao, Jie

    2014-04-28

    We present results of our investigation into the nonadiabatic electron dynamics of a moving quantum dot assisted by surface acoustic waves (SAWs) in a perpendicular magnetic field. The measurements show the evolution of a quantized acoustoelectric current in a modulated external field, which provides direct information of the energy spectrum and the occupation of the SAW-induced elliptical dynamical quantum dot. By comparing the magnetic field dependence of the spectrum with that of a somewhat symmetric circular dot, we find the appearance of nonadiabatic excitations at low magnetic fields resulting from the anisotropy of the dot. We also detect the transitions between different quantum states of the elliptical dot, achieved by exploiting the interference of two phase-tuned SAWs. Our results demonstrate that the quantum states in an asymmetric dot are fragile and extremely sensitive to their environment.

  20. Electronic structure and relaxation dynamics in a superconducting topological material

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

    Neupane, Madhab; Ishida, Yukiaki; Sankar, Raman; Zhu, Jian-Xin; Sanchez, Daniel S.; Belopolski, Ilya; Xu, Su-Yang; Alidoust, Nasser; Hosen, M. Mofazzel; Shin, Shik; et al

    2016-03-03

    Topological superconductors host new states of quantum matter which show a pairing gap in the bulk and gapless surface states providing a platform to realize Majorana fermions. Recently, alkaline-earth metal Sr intercalated Bi2Se3 has been reported to show superconductivity with a Tc~3K and a large shielding fraction. Here we report systematic normal state electronic structure studies of Sr0.06Bi2Se3 (Tc~2.5K) by performing photoemission spectroscopy. Using angle-resolved photoemission spectroscopy (ARPES), we observe a quantum well confined two-dimensional (2D) state coexisting with a topological surface state in Sr0.06Bi2Se3. Furthermore, our time-resolved ARPES reveals the relaxation dynamics showing different decay mechanism between the excitedmore » topological surface states and the two-dimensional states. Our experimental observation is understood by considering the intra-band scattering for topological surface states and an additional electron phonon scattering for the 2D states, which is responsible for the superconductivity. Our first-principles calculations agree with the more effective scattering and a shorter lifetime of the 2D states. In conclusion, our results will be helpful in understanding low temperature superconducting states of these topological materials.« less

  1. Electronic spectra and excited state dynamics of pentafluorophenol: Effects of low-lying ??{sup ?} states

    SciTech Connect (OSTI)

    Karmakar, Shreetama; Mukhopadhyay, Deb Pratim; Chakraborty, Tapas

    2015-05-14

    Multiple fluorine atom substitution effect on photophysics of an aromatic chromophore has been investigated using phenol as the reference system. It has been noticed that the discrete vibronic structure of the S{sub 1}?S{sub 0} absorption system of phenol vapor is completely washed out for pentafluorophenol (PFP), and the latter also shows very large Stokes shift in the fluorescence spectrum. For excitations beyond S{sub 1} origin, the emission yield of PFP is reduced sharply with increase in excess vibronic energy. However, in a collisional environment like liquid hydrocarbon, the underlying dynamical process that drives the non-radiative decay is hindered drastically. Electronic structure theory predicts a number of low-lying dark electronic states of ??{sup ?} character in the vicinity of the lowest valence ??{sup ?} state of this molecule. Tentatively, we have attributed the excitation energy dependent non-radiative decay of the molecule observed only in the gas phase to an interplay between the lowest ??{sup ?} and a nearby dissociative ??{sup ?} state. Measurements in different liquids reveal that some of the dark excited states light up with appreciable intensity only in protic liquids like methanol and water due to hydrogen bonding between solute and solvents. Electronic structure theory methods indeed predict that for PFP-(H{sub 2}O){sub n} clusters (n = 1-11), intensities of a number of ??{sup ?} states are enhanced with increase in cluster size. In contrast with emitting behavior of the molecule in the gas phase and solutions of nonpolar and polar aprotic liquids, the fluorescence is completely switched off in polar protic liquids. This behavior is a chemically significant manifestation of perfluoro effect, because a very opposite effect occurs in the case of unsubstituted phenol for which fluorescence yield undergoes a very large enhancement in protic liquids. Several dynamical mechanisms have been suggested to interpret the observed photophysical

  2. Electron momentum spectroscopy of dimethyl ether taking account of nuclear dynamics in the electronic ground state

    SciTech Connect (OSTI)

    Morini, Filippo; Deleuze, Michael Simon; Watanabe, Noboru; Kojima, Masataka; Takahashi, Masahiko

    2015-10-07

    The influence of nuclear dynamics in the electronic ground state on the (e,2e) momentum profiles of dimethyl ether has been analyzed using the harmonic analytical quantum mechanical and Born-Oppenheimer molecular dynamics approaches. In spite of fundamental methodological differences, results obtained with both approaches consistently demonstrate that molecular vibrations in the electronic ground state have a most appreciable influence on the momentum profiles associated to the 2b{sub 1}, 6a{sub 1}, 4b{sub 2}, and 1a{sub 2} orbitals. Taking this influence into account considerably improves the agreement between theoretical and newly obtained experimental momentum profiles, with improved statistical accuracy. Both approaches point out in particular the most appreciable role which is played by a few specific molecular vibrations of A{sub 1}, B{sub 1}, and B{sub 2} symmetries, which correspond to C–H stretching and H–C–H bending modes. In line with the Herzberg-Teller principle, the influence of these molecular vibrations on the computed momentum profiles can be unraveled from considerations on the symmetry characteristics of orbitals and their energy spacing.

  3. Dynamic microscale temperature gradient in a gold nanorod solution measured by diffraction-limited nanothermometry

    SciTech Connect (OSTI)

    Li, Chengmingyue; Gan, Xiaosong; Li, Xiangping; Gu, Min

    2015-09-21

    We quantify the dynamic microscale temperature gradient in a gold nanorod solution using quantum-dot-based microscopic fluorescence nanothermometry. By incorporating CdSe quantum dots into the solution as a nanothermometer, precise temperature mapping with diffraction-limited spatial resolution and sub-degree temperature resolution is achieved. The acquired data on heat generation and dissipation show an excellent agreement with theoretical simulations. This work reveals an effective approach for noninvasive temperature regulation with localized nanoheaters in microfluidic environment.

  4. Method and means for dynamic measurement of rates of adsorption from solutions

    DOE Patents [OSTI]

    Slomka, B.J.; Buttermore, W.H.

    1992-05-05

    A method and apparatus are described for the dynamic measurement of rates of absorption from solutions. The method has the advantage of avoiding the use of solvent normally used to establish a baseline. The method involves pre-evacuating the adsorbent contained in an adsorbent cell and thereafter rapidly contacting the adsorbent with analytical solution, all without prior exposure of adsorbent to pure solvent. The result is a sharp characteristic adsorption line. 5 figs.

  5. Method and means for dynamic measurement of rates of adsorption from solutions

    DOE Patents [OSTI]

    Slomka, Bogdan J.; Buttermore, William H.

    1992-05-05

    A method and apparatus for dynamic measurement of rates of absorption from solutions. The method has the advantage of avoiding the use of solvent normally used to establish a baseline. The method involves pre-evacuating the adsorbent contained in an adsorbent cell and thereafter rapidly contacting the adsorbent with analytical solution, all without prior exposure of adsorbent to pure solvent. The result is a sharp characteristic adsorption line.

  6. Formation and nonlinear dynamics of the squeezed state of a helical electron beam with additional deceleration

    SciTech Connect (OSTI)

    Egorov, E. N. Koronovskii, A. A.; Kurkin, S. A.; Hramov, A. E.

    2013-11-15

    Results of numerical simulations and analysis of the formation and nonlinear dynamics of the squeezed state of a helical electron beam in a vircator with a magnetron injection gun as an electron source and with additional electron deceleration are presented. The ranges of control parameters where the squeezed state can form in such a system are revealed, and specific features of the system dynamics are analyzed. It is shown that the formation of a squeezed state of a nonrelativistic helical electron beam in a system with electron deceleration is accompanied by low-frequency longitudinal dynamics of the space charge.

  7. Electron beam simulation from gun to collector: Towards a complete solution

    SciTech Connect (OSTI)

    Mertzig, R. Shornikov, A. Wenander, F.; Beebe, E.; Pikin, A.

    2015-01-09

    An electron-beam simulation technique for high-resolution complete EBIS/T modelling is presented. The technique was benchmarked on the high compression HEC{sup 2} test-stand with an electron beam current, current density and energy of 10 A, 10 kA/cm{sup 2} and 49.2 keV, and on the immersed electron beam at REXEBIS for electron beam characteristics of 0.4 A, 200 A/cm{sup 2} and 4.5 keV. In both Brillouin-like and immersed beams the electron-beam radius varies from several millimeters at the gun, through some hundreds of micrometers in the ionization region to a few centimeters at the collector over a total length of several meters. We report on our approach for finding optimal meshing parameters, based on the local beam properties such as magnetic field-strength, electron energy and beam radius. This approach combined with dividing the problem domain into sub-domains, and subsequent splicing of the local solutions allowed us to simulate the beam propagation in EBISes from the gun to the collector using a conventional PC in about 24–36 h. Brillouin-like electron beams propagated through the complete EBIS were used to analyze the beam behavior within the collector region. We checked whether elastically reflected paraxial electrons from a Brillouin-like beam will escape from the collector region and add to the loss current. We have also studied the power deposition profiles as function of applied potentials using two electrode geometries for a Brillouin-like beam including the effects of backscattered electrons.

  8. Efficient preconditioning of the electronic structure problem in large scale ab initio molecular dynamics simulations

    SciTech Connect (OSTI)

    Schiffmann, Florian; VandeVondele, Joost

    2015-06-28

    We present an improved preconditioning scheme for electronic structure calculations based on the orbital transformation method. First, a preconditioner is developed which includes information from the full Kohn-Sham matrix but avoids computationally demanding diagonalisation steps in its construction. This reduces the computational cost of its construction, eliminating a bottleneck in large scale simulations, while maintaining rapid convergence. In addition, a modified form of Hotelling’s iterative inversion is introduced to replace the exact inversion of the preconditioner matrix. This method is highly effective during molecular dynamics (MD), as the solution obtained in earlier MD steps is a suitable initial guess. Filtering small elements during sparse matrix multiplication leads to linear scaling inversion, while retaining robustness, already for relatively small systems. For system sizes ranging from a few hundred to a few thousand atoms, which are typical for many practical applications, the improvements to the algorithm lead to a 2-5 fold speedup per MD step.

  9. Energy-dependent dynamics of keV to MeV electrons in the inner...

    Office of Scientific and Technical Information (OSTI)

    Energy-dependent dynamics of keV to MeV electrons in the inner zone, outer zone, and slot regions Title: Energy-dependent dynamics of keV to MeV electrons in the inner zone, outer ...

  10. Molecular dynamics study of saltsolution interface: Solubility and surface charge of salt in water

    SciTech Connect (OSTI)

    Kobayashi, Kazuya; Liang, Yunfeng E-mail: matsuoka@earth.kumst.kyoto-u.ac.jp; Matsuoka, Toshifumi E-mail: matsuoka@earth.kumst.kyoto-u.ac.jp; Sakka, Tetsuo

    2014-04-14

    The NaCl saltsolution interface often serves as an example of an uncharged surface. However, recent laser-Doppler electrophoresis has shown some evidence that the NaCl crystal is positively charged in its saturated solution. Using molecular dynamics (MD) simulations, we have investigated the NaCl saltsolution interface system, and calculated the solubility of the salt using the direct method and free energy calculations, which are kinetic and thermodynamic approaches, respectively. The direct method calculation uses a saltsolution combined system. When the system is equilibrated, the concentration in the solution area is the solubility. In the free energy calculation, we separately calculate the chemical potential of NaCl in two systems, the solid and the solution, using thermodynamic integration with MD simulations. When the chemical potential of NaCl in the solution phase is equal to the chemical potential of the solid phase, the concentration of the solution system is the solubility. The advantage of using two different methods is that the computational methods can be mutually verified. We found that a relatively good estimate of the solubility of the system can be obtained through comparison of the two methods. Furthermore, we found using microsecond time-scale MD simulations that the positively charged NaCl surface was induced by a combination of a sodium-rich surface and the orientation of the interfacial water molecules.

  11. Probing Electron Dynamics with the Laplacian of the Momentum Density

    SciTech Connect (OSTI)

    Sukumar, N.; MacDougall, Preston J.; Levit, M. Creon

    2012-09-24

    This chapter in the above-titled monograph presents topological analysis of the Laplacian of the electron momentum density in organic molecules. It relates topological features in this distribution to chemical and physical properties, particularly aromaticity and electron transport.

  12. Correlated electron dynamics with time-dependent quantum Monte...

    Office of Scientific and Technical Information (OSTI)

    atoms subjected to an external electromagnetic field with amplitude sufficient to ... QUANTUM MECHANICS, GENERAL PHYSICS; ELECTROMAGNETIC FIELDS; ELECTRON CORRELATION; ...

  13. High Resolution Simulation of Beam Dynamics in Electron Linacs for Free Electron Lasers

    SciTech Connect (OSTI)

    Ryne, R.D.; Venturini, M.; Zholents, A.A.; Qiang, J.

    2009-01-05

    In this paper we report on large scale multi-physics simulation of beam dynamics in electron linacs for next generation free electron lasers (FELs). We describe key features of a parallel macroparticle simulation code including three-dimensional (3D) space-charge effects, short-range structure wake fields, longitudinal coherent synchrotron radiation (CSR) wake fields, and treatment of radiofrequency (RF) accelerating cavities using maps obtained from axial field profiles. A macroparticle up-sampling scheme is described that reduces the shot noise from an initial distribution with a smaller number of macroparticles while maintaining the global properties of the original distribution. We present a study of the microbunching instability which is a critical issue for future FELs due to its impact on beam quality at the end of the linac. Using parameters of a planned FEL linac at Lawrence Berkeley National Laboratory (LBNL), we show that a large number of macroparticles (beyond 100 million) is needed to control numerical shot noise that drives the microbunching instability. We also explore the effect of the longitudinal grid on simulation results. We show that acceptable results are obtained with around 2048 longitudinal grid points, and we discuss this in view of the spectral growth rate predicted from linear theory. As an application, we present results from simulations using one billion macroparticles of the FEL linac under design at LBNL. We show that the final uncorrelated energy spread of the beam depends not only on the initial uncorrelated energy spread but also depends strongly on the shape of the initial current profile. By using a parabolic initial current profile, 5 keV initial uncorrelated energy spread at 40 MeV injection energy, and improved linac design, those simulations demonstrate that a reasonable beam quality can be achieved at the end of the linac, with the final distribution having about 100 keV energy spread, 2.4 GeV energy, and 1.2 kA peak

  14. The model with many moments for relativistic electron beams: A simplified solution

    SciTech Connect (OSTI)

    Carrisi, Maria Cristina; Pennisi, Sebastiano

    2011-02-15

    In the 1980s, Amendt and Weitzner proposed an interesting model capable to describe relativistic electron beams. It concerned 14 independent variables and the closure was obtained by using the entropy and the Einstein relativity principles. As we know from literature, an extension to many moments allows to achieve an improvement in the results. Three years ago, we exhibited a macroscopic model with an arbitrary but fixed number of moments for relativistic extended thermodynamics. Such model was more general than those previously appeared in literature, so it was applicable even to materials different from an electron beam. Subsequently, we found the closure of such model consistent with the entropy and the Einstein relativity principles, up to whatever order with respect to equilibrium. The solution was determined in terms of a family of arbitrary single variable functions arising from integration. Those results have a very complex shape and are very difficult to handle so a simplification is necessary. In this paper we will reach this goal. Furthermore, we will prove that by fixing a certain order n{sub p} with respect to equilibrium and a scalar valued single variable function, appearing at that order, then all the terms appearing at orders n{<=}n{sub p} are determined without introducing any other function. This result has already been found for the nonrelativistic case but its extension to the relativistic framework is not straightforward and it requires a supplementary mathematical tool: the above mentioned simplification in the shape of the solutions.

  15. 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.

  16. Electron Transfer Dynamics in Photocatalytic CO2 Conversion | netl.doe.gov

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

    Electron Transfer Dynamics in Photocatalytic CO2 Conversion Electron Transfer Dynamics in Photocatalytic CO2 Conversion Coal is the workhorse of our power industry, responsible for approximately half of the electricity consumed by Americans. Managing carbon dioxide (CO2) emissions from coal utilization is one of the most challenging issues facing the fossil energy industry today. To cost-effectively capture and manage CO2, new and flexible photocatalytic technologies are being developed that can

  17. Hot electron dynamics in graphene (Thesis/Dissertation) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    Thesis/Dissertation: Hot electron dynamics in graphene Citation Details In-Document Search Title: Hot electron dynamics in graphene Graphene, a two-dimensional (2D) honeycomb structure allotrope of carbon atoms, has a long history since the invention of the pencil [Petroski (1989)] and the linear dispersion band structure proposed by Wallace [Wal]; however, only after Novoselov et al. successively isolated graphene from graphite [Novoselov et al. (2004)], it has been studied intensively during

  18. Rapid imaging of mycoplasma in solution using Atmospheric Scanning Electron Microscopy (ASEM)

    SciTech Connect (OSTI)

    Sato, Chikara; Manaka, Sachie; Nakane, Daisuke; Nishiyama, Hidetoshi; Suga, Mitsuo; Nishizaka, Takayuki; Miyata, Makoto; Maruyama, Yuusuke

    2012-01-27

    Highlights: Black-Right-Pointing-Pointer Mycoplasma mobile was observed in buffer with the Atmospheric Scanning Electron Microscope. Black-Right-Pointing-Pointer Characteristic protein localizations were visualized using immuno-labeling. Black-Right-Pointing-Pointer M. mobile attached to sialic acid on the SiN film surface within minutes. Black-Right-Pointing-Pointer Cells were observed at low concentrations. Black-Right-Pointing-Pointer ASEM should promote study and early-stage diagnosis of mycoplasma. -- Abstract: Mycoplasma is a genus of bacterial pathogen that causes disease in vertebrates. In humans, the species Mycoplasma pneumoniae causes 15% or more of community-acquired pneumonia. Because this bacterium is tiny, corresponding in size to a large virus, diagnosis using optical microscopy is not easy. In current methods, chest X-rays are usually the first action, followed by serology, PCR amplification, and/or culture, but all of these are particularly difficult at an early stage of the disease. Using Mycoplasma mobile as a model species, we directly observed mycoplasma in buffer with the newly developed Atmospheric Scanning Electron Microscope (ASEM). This microscope features an open sample dish with a pressure-resistant thin film window in its base, through which the SEM beam scans samples in solution, from below. Because of its 2-3 {mu}m-deep scanning capability, it can observe the whole internal structure of mycoplasma cells stained with metal solutions. Characteristic protein localizations were visualized using immuno-labeling. Cells were observed at low concentrations, because suspended cells concentrate in the observable zone by attaching to sialic acid on the silicon nitride (SiN) film surface within minutes. These results suggest the applicability of the ASEM for the study of mycoplasmas as well as for early-stage mycoplasma infection diagnosis.

  19. Electron Solvation Dynamics and Reactivity in Ionic Liquids Observed by Picosecond RadiolysisTechniques

    SciTech Connect (OSTI)

    Wishart J. F.; Funston, A.M.; Szreder, T.; Cook, A.R.; Gohdo, M.

    2012-01-01

    On time scales of a nanosecond or less, radiolytically-generated excess electrons in ionic liquids undergo solvation processes and reactions that determine all subsequent chemistry and the accumulation of radiolytic damage. Using picosecond pulse radiolysis detection methods, we observed and quantified the solvation response of the electron in 1-methyl-1-butyl-pyrrolidinium bis(trifluoromethylsulfonyl)amide and used it to understand electron scavenging by a typical solute, duroquinone.

  20. Density matrix renormalization group with efficient dynamical electron correlation through range separation

    SciTech Connect (OSTI)

    Hedegård, Erik Donovan Knecht, Stefan; Reiher, Markus; Kielberg, Jesper Skau; Jensen, Hans Jørgen Aagaard

    2015-06-14

    We present a new hybrid multiconfigurational method based on the concept of range-separation that combines the density matrix renormalization group approach with density functional theory. This new method is designed for the simultaneous description of dynamical and static electron-correlation effects in multiconfigurational electronic structure problems.

  1. Electron plasma dynamics during autoresonant excitation of the diocotron mode

    SciTech Connect (OSTI)

    Baker, C. J. Danielson, J. R. Hurst, N. C. Surko, C. M.

    2015-02-15

    Chirped-frequency autoresonant excitation of the diocotron mode is used to move electron plasmas confined in a Penning-Malmberg trap across the magnetic field for advanced plasma and antimatter applications. Plasmas of 10{sup 8} electrons, with radii small compared to that of the confining electrodes, can be moved from the magnetic axis to ?90% of the electrode radius with near unit efficiency and reliable angular positioning. Translations of ?70% of the wall radius are possible for a wider range of plasma parameters. Details of this process, including phase and displacement oscillations in the plasma response and plasma expansion, are discussed, as well as possible extensions of the technique.

  2. Mean ionic activity coefficients in aqueous NaCl solutions from molecular dynamics simulations

    SciTech Connect (OSTI)

    Mester, Zoltan; Panagiotopoulos, Athanassios Z.

    2015-01-28

    The mean ionic activity coefficients of aqueous NaCl solutions of varying concentrations at 298.15 K and 1 bar have been obtained from molecular dynamics simulations by gradually turning on the interactions of an ion pair inserted into the solution. Several common non-polarizable water and ion models have been used in the simulations. Gibbs-Duhem equation calculations of the thermodynamic activity of water are used to confirm the thermodynamic consistency of the mean ionic activity coefficients. While the majority of model combinations predict the correct trends in mean ionic activity coefficients, they overestimate their values at high salt concentrations. The solubility predictions also suffer from inaccuracies, with all models underpredicting the experimental values, some by large factors. These results point to the need for further ion and water model development.

  3. A unified electrostatic and cavitation model for first-principles molecular dynamics in solution

    SciTech Connect (OSTI)

    Scherlis, D A; Fattebert, J; Gygi, F; Cococcioni, M; Marzari, N

    2005-11-14

    The electrostatic continuum solvent model developed by Fattebert and Gygi is combined with a first-principles formulation of the cavitation energy based on a natural quantum-mechanical definition for the surface of a solute. Despite its simplicity, the cavitation contribution calculated by this approach is found to be in remarkable agreement with that obtained by more complex algorithms relying on a large set of parameters. The model allows for very efficient Car-Parrinello simulations of finite or extended systems in solution, and demonstrates a level of accuracy as good as that of established quantum-chemistry continuum solvent methods. They apply this approach to the study of tetracyanoethylene dimers in dichloromethane, providing valuable structural and dynamical insights on the dimerization phenomenon.

  4. Monopole and topological electron dynamics in adiabatic spintronic and graphene systems

    SciTech Connect (OSTI)

    Tan, S.G.; Jalil, M.B.A.; Fujita, T.

    2010-08-15

    A unified theoretical treatment is presented to describe the physics of electron dynamics in semiconductor and graphene systems. Electron spin's fast alignment with the Zeeman magnetic field (physical or effective) is treated as a form of adiabatic spin evolution which necessarily generates a monopole in magnetic space. One could transform this monopole into the physical and intuitive topological magnetic fields in the useful momentum (K) or real spaces (R). The physics of electron dynamics related to spin Hall, torque, oscillations and other technologically useful spinor effects can be inferred from the topological magnetic fields in spintronic, graphene and other SU(2) systems.

  5. Determination of redox reaction rates and orders by in situ liquid cell electron microscopy of Pd and Au solution growth

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

    Sutter, Eli A.; Sutter, Peter W.

    2014-11-19

    In-situ liquid cell transmission and scanning transmission electron microscopy (TEM/STEM) experiments are important as they provide direct insight into processes in liquids, such as solution growth of nanoparticles among others. In liquid cell TEM/STEM redox reaction experiments the hydrated electrons e⁻aq created by the electron beam are responsible for the reduction of metal-ion complexes. Here we investigate the rate equation of redox reactions involving reduction by e⁻aq generated by the electron beam during in-situ liquid TEM/STEM. Specifically we consider the growth of Pd on Au seeds in aqueous solutions containing Pd-chloro complexes. From the quantification of the rate of Pdmore » deposition at different electron beam currents and as a function of distance from a stationary, nanometer-sized exciting beam, we determine that the reaction is first order with respect to the concentration of hydrated electrons, [e⁻aq]. In addition, by comparing Pd- and Au-deposition, we further demonstrate that measurements of the local deposition rate on nanoparticles in the solution via real-time imaging can be used to measure not only [e⁻aq] but also the rate of reduction of a metal-ion complex to zero-valent metal atoms in solution.« less

  6. Determination of redox reaction rates and orders by in situ liquid cell electron microscopy of Pd and Au solution growth

    SciTech Connect (OSTI)

    Sutter, Eli A.; Sutter, Peter W.

    2014-11-19

    In-situ liquid cell transmission and scanning transmission electron microscopy (TEM/STEM) experiments are important as they provide direct insight into processes in liquids, such as solution growth of nanoparticles among others. In liquid cell TEM/STEM redox reaction experiments the hydrated electrons e?aq created by the electron beam are responsible for the reduction of metal-ion complexes. Here we investigate the rate equation of redox reactions involving reduction by e?aq generated by the electron beam during in-situ liquid TEM/STEM. Specifically we consider the growth of Pd on Au seeds in aqueous solutions containing Pd-chloro complexes. From the quantification of the rate of Pd deposition at different electron beam currents and as a function of distance from a stationary, nanometer-sized exciting beam, we determine that the reaction is first order with respect to the concentration of hydrated electrons, [e?aq]. In addition, by comparing Pd- and Au-deposition, we further demonstrate that measurements of the local deposition rate on nanoparticles in the solution via real-time imaging can be used to measure not only [e?aq] but also the rate of reduction of a metal-ion complex to zero-valent metal atoms in solution.

  7. Multichannel Pseudogap Kondo Model: Large-N Solution and Quantum-Critical Dynamics

    SciTech Connect (OSTI)

    Vojta, Matthias

    2001-08-27

    We discuss a multichannel SU(N) Kondo model which displays nontrivial zero-temperature phase transitions due to a conduction electron density of states vanishing with a power law at the Fermi level. In a particular large-N limit, the system is described by coupled integral equations corresponding to a dynamic saddle point. We exactly determine the universal low-energy behavior of spectral densities at the scale-invariant fixed points, obtain anomalous exponents, and compute scaling functions describing the crossover near the quantum-critical points. We argue that our findings are relevant to recent experiments on impurity-doped d -wave superconductors.

  8. Photodissociation and photoisomerization dynamics of CH{sub 2}=CHCHO in solution

    SciTech Connect (OSTI)

    Wu Weiqiang; Yang Chunfan; Zhao Hongmei; Liu Kunhui; Su Hongmei

    2010-03-28

    By means of time-resolved Fourier transform infrared absorption spectroscopy, we have investigated the 193 nm photodissociation and photoisomerization dynamics of the prototype molecule of {alpha},{beta}-enones, acrolein (CH{sub 2}=CHCHO) in CH{sub 3}CN solution. The primary photolysis channels and absolute branching ratios are determined. The most probable reaction mechanisms are clarified by control experiments monitoring the product yields varied with the triplet quencher addition. The predominant channel is the 1,3-H migration yielding the rearrangement product CH{sub 3}CH=C=O with a branching ratio of 0.78 and the less important channel is the {alpha} cleavage of C-H bond yielding radical fragments CH{sub 2}=CHCO+H with a branching ratio of only 0.12. The 1,3-H migration is strongly suggested to correlate with the triplet {sup 3}({pi}{pi}{sup *}) state rather than the ground S{sub 0} state and the {alpha} cleavage of C-H bond is more likely to proceed in the singlet S{sub 1} {sup 1}(n{pi}{sup *}) state. From the solution experiments we have not only acquired clues clarifying the previous controversial mechanisms, but also explored different photochemistry in solution. Compared to the gas phase photolysis which is dominated by photodissociation channels, the most important channel in solution is the photoisomerization of 1,3-H migration. The reason leading to the different photochemistry in solution is further ascribed to the solvent cage effect.

  9. Short-Time Glassy Dynamics in Viscous Protein Solutions with Competing Interactions

    SciTech Connect (OSTI)

    Godfrin, P. Douglas; Hudson, Steven; Hong, Kunlun; Porcar, Lionel; Falus, Peter; Wagner, Norman; Liu, Yun

    2015-11-24

    Although there have been numerous investigations of the glass transition for colloidal dispersions with only a short-ranged attraction, less is understood for systems interacting with a long-ranged repulsion in addition to this attraction, which is ubiquitous in aqueous protein solutions at low ionic strength. Highly puri ed concentrated lysozyme solutions are used as a model system and investigated over a large range of protein concentrations at very low ionic strength. Newtonian liquid behavior is observed at all concentrations, even up to 480 mg/mL, where the zero shear viscosity increases by more than three orders of magnitude with increasing concentration. Remarkably, despite this macroscopic liquid-like behavior, the measurements of the dynamics in the short-time limit shows features typical of glassy colloidal systems. Investigation of the inter-protein structure indicates that the reduced short-time mobility of the protein is caused by localized regions of high density within a heterogeneous density distribution. This structural heterogeneity occurs on intermediate range length scale, driven by the competing potential features, and is distinct from commonly studied colloidal gel systems in which a heterogeneous density distribution tends to extend to the whole system. The presence of long-ranged repulsion also allows for more mobility over large length and long time scales resulting in the macroscopic relaxation of the structure. The experimental results provide evidence for the need to explicitly include intermediate range order in theories for the macroscopic properties of protein solutions interacting via competing potential features.

  10. 2012 ELECTRONIC SPECTROSCOPY & DYNAMICS GORDON RESEARCH CONFERENCE, JULY 22-27, 2012

    SciTech Connect (OSTI)

    Kohler, Bern

    2012-07-27

    Topics covered in this GRC include high-resolution spectroscopy, coherent electronic energy transport in biology, excited state theory and dynamics, excitonics, electronic spectroscopy of cold and ultracold molecules, and the spectroscopy of nanostructures. Several sessions will highlight innovative techniques such as time-resolved x-ray spectroscopy, frequency combs, and liquid microjet photoelectron spectroscopy that have forged stimulating new connections between gas-phase and condensed-phase work.

  11. Effects of humidity during formation of zinc oxide electron contact layers from a diethylzinc precursor solution

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

    Mauger, Scott A.; Steirer, K. Xerxes; Boe, Jonas; Ostrowski, David P.; Olson, Dana C.; Hammond, Scott R.

    2016-01-19

    Here, this work focuses on the role of humidity in the formation of ZnO thin films from a reactive diethylzinc precursor solution for use as the electron contact layer (ECL) in organic photovoltaic (OPV) devices. This method is well suited for flexible devices because the films are annealed at 120 °C, making the process compatible with polymer substrates. ZnO films were prepared by spin coating and annealing at different relative humidity (RH) levels. It is found that RH during coating and annealing affects the chemical and physical properties of the ZnO films. Using x-ray photoelectron spectroscopy it is found thatmore » increasing RH during the formation steps produces a more stoichiometric oxide and a higher Zn/O ratio. Spectroscopic ellipsometry data shows a small decrease in the optical band gap with increased humidity, consistent with a more stoichiometric oxide. Kelvin probe measurements show that increased RH during formation results in a larger work function (i.e. further from vacuum). Consistent with these data, but counter to what might be expected, when these ZnO films are used as ECLs in OPV devices those with ZnO ECLs processed in low RH (less stoichiometric) had higher power conversion efficiency than those with high-RH processed ZnO due to improved open-circuit voltage. The increase in open-circuit voltage with decreasing humidity was observed with two different donor polymers and fullerene acceptors, which shows the trend is due to changes in ZnO. The observed changes in open-circuit voltage follow the same trend as the ZnO work function indicating that the increase in open-circuit voltage with decreasing humidity is the result of improved energetics at the interface between the bulk-heterojunction and the ZnO layer due to a vacuum level shift.« less

  12. Short-Time Glassy Dynamics in Viscous Protein Solutions with Competing Interactions

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

    Godfrin, P. Douglas; Hudson, Steven; Hong, Kunlun; Porcar, Lionel; Falus, Peter; Wagner, Norman; Liu, Yun

    2015-11-24

    Although there have been numerous investigations of the glass transition for colloidal dispersions with only a short-ranged attraction, less is understood for systems interacting with a long-ranged repulsion in addition to this attraction, which is ubiquitous in aqueous protein solutions at low ionic strength. Highly puri ed concentrated lysozyme solutions are used as a model system and investigated over a large range of protein concentrations at very low ionic strength. Newtonian liquid behavior is observed at all concentrations, even up to 480 mg/mL, where the zero shear viscosity increases by more than three orders of magnitude with increasing concentration. Remarkably,more » despite this macroscopic liquid-like behavior, the measurements of the dynamics in the short-time limit shows features typical of glassy colloidal systems. Investigation of the inter-protein structure indicates that the reduced short-time mobility of the protein is caused by localized regions of high density within a heterogeneous density distribution. This structural heterogeneity occurs on intermediate range length scale, driven by the competing potential features, and is distinct from commonly studied colloidal gel systems in which a heterogeneous density distribution tends to extend to the whole system. The presence of long-ranged repulsion also allows for more mobility over large length and long time scales resulting in the macroscopic relaxation of the structure. The experimental results provide evidence for the need to explicitly include intermediate range order in theories for the macroscopic properties of protein solutions interacting via competing potential features.« less

  13. How electronic dynamics with Pauli exclusion produces Fermi-Dirac statistics

    SciTech Connect (OSTI)

    Nguyen, Triet S.; Nanguneri, Ravindra; Parkhill, John

    2015-04-07

    It is important that any dynamics method approaches the correct population distribution at long times. In this paper, we derive a one-body reduced density matrix dynamics for electrons in energetic contact with a bath. We obtain a remarkable equation of motion which shows that in order to reach equilibrium properly, rates of electron transitions depend on the density matrix. Even though the bath drives the electrons towards a Boltzmann distribution, hole blocking factors in our equation of motion cause the electronic populations to relax to a Fermi-Dirac distribution. These factors are an old concept, but we show how they can be derived with a combination of time-dependent perturbation theory and the extended normal ordering of Mukherjee and Kutzelnigg for a general electronic state. The resulting non-equilibrium kinetic equations generalize the usual Redfield theory to many-electron systems, while ensuring that the orbital occupations remain between zero and one. In numerical applications of our equations, we show that relaxation rates of molecules are not constant because of the blocking effect. Other applications to model atomic chains are also presented which highlight the importance of treating both dephasing and relaxation. Finally, we show how the bath localizes the electron density matrix.

  14. Crucial role of nuclear dynamics for electron injection in a dye–semiconductor complex

    SciTech Connect (OSTI)

    Monti, Adriano; Negre, Christian F. A.; Batista, Victor S.; Rego, Luis G. C.; de Groot, Huub J. M.; Buda, Francesco

    2015-06-05

    In this study, we investigate the electron injection from a terrylene-based chromophore to the TiO2 semiconductor bridged by a recently proposed phenyl-amide-phenyl molecular rectifier. The mechanism of electron transfer is studied by means of quantum dynamics simulations using an extended Hückel Hamiltonian. It is found that the inclusion of the nuclear motion is necessary to observe the photoinduced electron transfer. In particular, the fluctuations of the dihedral angle between the terrylene and the phenyl ring modulate the localization and thus the electronic coupling between the donor and acceptor states involved in the injection process. The electron propagation shows characteristic oscillatory features that correlate with interatomic distance fluctuations in the bridge, which are associated with the vibrational modes driving the process. The understanding of such effects is important for the design of functional dyes with optimal injection and rectification properties.

  15. Crucial role of nuclear dynamics for electron injection in a dye–semiconductor complex

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

    Monti, Adriano; Negre, Christian F. A.; Batista, Victor S.; Rego, Luis G. C.; de Groot, Huub J. M.; Buda, Francesco

    2015-06-05

    In this study, we investigate the electron injection from a terrylene-based chromophore to the TiO2 semiconductor bridged by a recently proposed phenyl-amide-phenyl molecular rectifier. The mechanism of electron transfer is studied by means of quantum dynamics simulations using an extended Hückel Hamiltonian. It is found that the inclusion of the nuclear motion is necessary to observe the photoinduced electron transfer. In particular, the fluctuations of the dihedral angle between the terrylene and the phenyl ring modulate the localization and thus the electronic coupling between the donor and acceptor states involved in the injection process. The electron propagation shows characteristic oscillatorymore » features that correlate with interatomic distance fluctuations in the bridge, which are associated with the vibrational modes driving the process. The understanding of such effects is important for the design of functional dyes with optimal injection and rectification properties.« less

  16. Boost the electron mobility of solution-grown organic single crystals via reducing the amount of polar solvent residues

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

    Xue, Guobiao; Xin, Huolin L.; Wu, Jiake; Fan, Congcheng; Liu, Shuang; Huang, Zhuoting; Liu, Yujing; Shan, Bowen; Miao, Qian; Chen, Hongzheng; et al

    2015-10-29

    Enhancing electron transport to match with the development in hole transport is critical for organic electronics in the future. As electron motion is susceptible to extrinsic factors, seeking these factors and avoiding their negative effects have become the central challenge. Here, the existence of polar solvent residues in solution-grown single-crystals of 6,13-bis(triisopropylsilylethynyl)-5,7,12,14-tetraazapentacene is identified as a factor detrimental to electron motion. Field-effect transistors of the crystals exhibit electron mobility boosted by about 60% after the residues are removed. The average electron mobility reaches up to 8.0 ± 2.2 cm2 V–1 s–1 with a highest value of 13.3 cm2 V–1 s–1;more » these results are significantly higher than those obtained previously for the same molecule (1.0–5.0 cm2 V–1 s–1). Furthermore, the achieved mobility is also higher than the maximum reported electron mobility for organic materials (11 cm2 V–1 s–1). As a result, this work should greatly accelerate the advancement of organic electron-transporting materials.« less

  17. Electronic Structure and Lattice Dynamics of the Magnetic Shape Memory Alloy Co2NiGa

    SciTech Connect (OSTI)

    Siewert, M.; Shapiro, S.; Gruner, M.E.; Dannenberg, A.; Hucht, A.; Xu, G.; Schlagel, D.L.; Lograsso, T.A.; Entel1, P.

    2010-08-20

    In addition to the prototypical Ni-Mn-based Heusler alloys, the Co-Ni-Ga systems have recently been suggested as another prospective materials class for magnetic shape-memory applications. We provide a characterization of the dynamical properties of this material and their relation to the electronic structure within a combined experimental and theoretical approach. This relies on inelastic neutron scattering to obtain the phonon dispersion while first-principles calculations provide the link between dynamical properties and electronic structure. In contrast to Ni{sub 2}MnGa, where the softening of the TA{sub 2} phonon branch is related to Fermi-surface nesting, our results reveal that the respective anomalies are absent in Co-Ni-Ga, in the phonon dispersions as well as in the electronic structure.

  18. Backscattering and absorption coefficients for electrons: Solutions of invariant embedding transport equations using a method of convergence

    SciTech Connect (OSTI)

    Figueroa, C.; Brizuela, H.; Heluani, S. P.

    2014-05-21

    The backscattering coefficient is a magnitude whose measurement is fundamental for the characterization of materials with techniques that make use of particle beams and particularly when performing microanalysis. In this work, we report the results of an analytic method to calculate the backscattering and absorption coefficients of electrons in similar conditions to those of electron probe microanalysis. Starting on a five level states ladder model in 3D, we deduced a set of integro-differential coupled equations of the coefficients with a method know as invariant embedding. By means of a procedure proposed by authors, called method of convergence, two types of approximate solutions for the set of equations, namely complete and simple solutions, can be obtained. Although the simple solutions were initially proposed as auxiliary forms to solve higher rank equations, they turned out to be also useful for the estimation of the aforementioned coefficients. In previous reports, we have presented results obtained with the complete solutions. In this paper, we present results obtained with the simple solutions of the coefficients, which exhibit a good degree of fit with the experimental data. Both the model and the calculation method presented here can be generalized to other techniques that make use of different sorts of particle beams.

  19. Dynamic Processes in Biology, Chemistry, and Materials Science: Opportunities for UltraFast Transmission Electron Microscopy - Workshop Summary Report

    SciTech Connect (OSTI)

    Kabius, Bernd C.; Browning, Nigel D.; Thevuthasan, Suntharampillai; Diehl, Barbara L.; Stach, Eric A.

    2012-07-25

    This report summarizes a 2011 workshop that addressed the potential role of rapid, time-resolved electron microscopy measurements in accelerating the solution of important scientific and technical problems. A series of U.S. Department of Energy (DOE) and National Academy of Science workshops have highlighted the critical role advanced research tools play in addressing scientific challenges relevant to biology, sustainable energy, and technologies that will fuel economic development without degrading our environment. Among the specific capability needs for advancing science and technology are tools that extract more detailed information in realistic environments (in situ or operando) at extreme conditions (pressure and temperature) and as a function of time (dynamic and time-dependent). One of the DOE workshops, Future Science Needs and Opportunities for Electron Scattering: Next Generation Instrumentation and Beyond, specifically addressed the importance of electron-based characterization methods for a wide range of energy-relevant Grand Scientific Challenges. Boosted by the electron optical advancement in the last decade, a diversity of in situ capabilities already is available in many laboratories. The obvious remaining major capability gap in electron microscopy is in the ability to make these direct in situ observations over a broad spectrum of fast (µs) to ultrafast (picosecond [ps] and faster) temporal regimes. In an effort to address current capability gaps, EMSL, the Environmental Molecular Sciences Laboratory, organized an Ultrafast Electron Microscopy Workshop, held June 14-15, 2011, with the primary goal to identify the scientific needs that could be met by creating a facility capable of a strongly improved time resolution with integrated in situ capabilities. The workshop brought together more than 40 leading scientists involved in applying and/or advancing electron microscopy to address important scientific problems of relevance to DOE’s research

  20. Electronic excitation induced amorphization in titanate pyrochlores: an ab initio molecular dynamics study

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

    Xiao, Haiyan Y.; Weber, William J.; Zhang, Yanwen; Zu, X. T.; Li, Sean

    2015-02-09

    In this study, the response of titanate pyrochlores (A2Ti2O7, A = Y, Gd and Sm) to electronic excitation is investigated utilizing an ab initio molecular dynamics method. All the titanate pyrochlores are found to undergo a crystalline-to-amorphous structural transition under a low concentration of electronic excitations. The transition temperature at which structural amorphization starts to occur depends on the concentration of electronic excitations. During the structural transition, O2-like molecules are formed, and this anion disorder further drives cation disorder that leads to an amorphous state. This study provides new insights into the mechanisms of amorphization in titanate pyrochlores under laser,more » electron and ion irradiations.« less

  1. Correlated proton-electron hole dynamics in protonated water clusters upon extreme ultraviolet photoionization

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

    Li, Zheng; Vendrell, Oriol

    2016-01-13

    The ultrafast nuclear and electronic dynamics of protonated water clusters H+(H2O)n after extreme ultraviolet photoionization is investigated. In particular, we focus on cluster cations with n = 3, 6, and 21. Upon ionization, two positive charges are present in the cluster related to the excess proton and the missing electron, respectively. A correlation is found between the cluster's geometrical conformation and initial electronic energy with the size of the final fragments produced. As a result, for situations in which the electron hole and proton are initially spatially close, the two entities become correlated and separate in a time-scale of 20more » to 40 fs driven by strong non-adiabatic effects.« less

  2. Analysis of structure and orientation of adsorbed polymers in solution subject to a dynamic shear stress

    SciTech Connect (OSTI)

    Smith, G.; Baker, S.; Toprakcioglu, C.

    1996-09-01

    This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Polymer-based separation techniques rely on the ability of a binding portion of the polymer to interact with a specific molecule in a solution flowing past the polymer. The location of the binding site within or out of the entangled polymer chains is thus crucial to the effectiveness of these methods. For this reason, the details of flow induced deformation of the polymer chains is important in such applications as exclusion chromatography, waste water treatment, ultrafiltration, enhanced oil recovery and microbial adhesion. Few techniques exist to examine the structure and orientation of polymeric materials, and even fewer to examine systems in a dynamic fluid flow. The goal of this project was to understand the molecular structure and orientation of adsorbed polymers with and without active binding ligands as a function of solvent shear rate, solvent power, polymer molecular weight, surface polymer coverage and heterogeneity of the surface polymer chains by neutron reflectometry in a newly designed shear cell. Geometrical effects on binding of molecules in the flow was also studied subject to the same parameters.

  3. Electron dynamics in complex environments with real-time time dependent density functional theory in a QM-MM framework

    SciTech Connect (OSTI)

    Morzan, Uriel N.; Ramrez, Francisco F.; Scherlis, Damin A. E-mail: mcgl@qb.ffyb.uba.ar; Lebrero, Mariano C. Gonzlez E-mail: mcgl@qb.ffyb.uba.ar

    2014-04-28

    This article presents a time dependent density functional theory (TDDFT) implementation to propagate the Kohn-Sham equations in real time, including the effects of a molecular environment through a Quantum-Mechanics Molecular-Mechanics (QM-MM) hamiltonian. The code delivers an all-electron description employing Gaussian basis functions, and incorporates the Amber force-field in the QM-MM treatment. The most expensive parts of the computation, comprising the commutators between the hamiltonian and the density matrixrequired to propagate the electron dynamics, and the evaluation of the exchange-correlation energy, were migrated to the CUDA platform to run on graphics processing units, which remarkably accelerates the performance of the code. The method was validated by reproducing linear-response TDDFT results for the absorption spectra of several molecular species. Two different schemes were tested to propagate the quantum dynamics: (i) a leap-frog Verlet algorithm, and (ii) the Magnus expansion to first-order. These two approaches were confronted, to find that the Magnus scheme is more efficient by a factor of six in small molecules. Interestingly, the presence of iron was found to seriously limitate the length of the integration time step, due to the high frequencies associated with the core-electrons. This highlights the importance of pseudopotentials to alleviate the cost of the propagation of the inner states when heavy nuclei are present. Finally, the methodology was applied to investigate the shifts induced by the chemical environment on the most intense UV absorption bands of two model systems of general relevance: the formamide molecule in water solution, and the carboxy-heme group in Flavohemoglobin. In both cases, shifts of several nanometers are observed, consistently with the available experimental data.

  4. 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.

  5. Building America Technology Solutions Case Study: Photovoltaic Systems with Module-Level Power Electronics

    Broader source: Energy.gov [DOE]

    This guide will show how DC power optimizers and microinverters (both known as module-level power electronics) are being used in new and/or retrofit, single and multifamily homes.

  6. Technology Solutions Case Study: Photovoltaic Systems with Module-Level Power Electronics

    SciTech Connect (OSTI)

    Tim Merrigan

    2015-09-01

    This guide will show how DC power optimizers and microinverters (both known as module-level power electronics) are being used in new and/or retrofit, single and multifamily homes.

  7. Hall-effect-controlled gas dynamics in protoplanetary disks. I. Wind solutions at the inner disk

    SciTech Connect (OSTI)

    Bai, Xue-Ning

    2014-08-20

    The gas dynamics of protoplanetary disks (PPDs) is largely controlled by non-ideal magnetohydrodynamic (MHD) effects including Ohmic resistivity, the Hall effect, and ambipolar diffusion. Among these the role of the Hall effect is the least explored and most poorly understood. In this series, we have included, for the first time, all three non-ideal MHD effects in a self-consistent manner to investigate the role of the Hall effect on PPD gas dynamics using local shearing-box simulations. In this first paper, we focus on the inner region of PPDs, where previous studies (Bai and Stone 2013; Bai 2013) excluding the Hall effect have revealed that the inner disk up to ∼10 AU is largely laminar, with accretion driven by a magnetocentrifugal wind. We confirm this basic picture and show that the Hall effect modifies the wind solutions depending on the polarity of the large-scale poloidal magnetic field B{sub 0} threading the disk. When B{sub 0}⋅Ω>0, the horizontal magnetic field is strongly amplified toward the disk interior, leading to a stronger disk wind (by ∼50% or less in terms of the wind-driven accretion rate). The enhanced horizontal field also leads to much stronger large-scale Maxwell stress (magnetic braking) that contributes to a considerable fraction of the wind-driven accretion rate. When B{sub 0}⋅Ω<0, the horizontal magnetic field is reduced, leading to a weaker disk wind (by ≲ 20%) and negligible magnetic braking. Under fiducial parameters, we find that when B{sub 0}⋅Ω>0, the laminar region extends farther to ∼10-15 AU before the magnetorotational instability sets in, while for B{sub 0}⋅Ω<0, the laminar region extends only to ∼3-5 AU for a typical accretion rate of ∼10{sup –8} to10{sup –7} M {sub ☉} yr{sup –1}. Scaling relations for the wind properties, especially the wind-driven accretion rate, are provided for aligned and anti-aligned field geometries.

  8. Nonlinear electron dynamics of gold ultrathin films induced by intense terahertz waves

    SciTech Connect (OSTI)

    Minami, Yasuo Takeda, Jun; Katayama, Ikufumi; Dao, Thang Duy; Nagao, Tadaaki; Kitajima, Masahiro

    2014-12-15

    Linear and nonlinear electron dynamics of polycrystalline gold (Au) ultrathin films with thicknesses ranging from 1.4 to 5.8?nm were investigated via transmittance terahertz (THz) spectroscopy with intense electric field transients. We prepared ultrathin films with low surface roughness formed on a Si(7??7) reconstructed surface, leading to the observation of monotonic decrease in THz transmittance with respect to film thickness. Furthermore, at all tested thicknesses, the transmittance decreased nonlinearly by 10%30% with the application if high-intensity THz electric fields. Based on a Drude-model analysis, we found a significant decrease in the damping constant induced by the THz electric field, indicating that electrons are driven beyond the polycrystalline grain boundaries in Au thin films, and consequently leading to the suppression of the electronboundary scattering rate.

  9. Optics solutions for pp operation with electron lenses at 100 GeV

    SciTech Connect (OSTI)

    White, S.; Fischer, W.; Luo, Y.

    2014-07-12

    Electron lenses for head-on compensation are currently under commissioning and foreseen to be operational for the 2015 polarized proton run. These devices will provide a partial compensation of head-on beam-beam effects and allow to double the RHIC proton luminosity. This note reviews the optics constraints related to beam-beam compensation and summarizes the current lattice options for proton operation at 100 GeV.

  10. Multicomponent analysis of mixed rare-earth metal ion solutions by the electronic tongue sensor system

    SciTech Connect (OSTI)

    Legin, A.; Kirsanov, D.; Rudnitskaya, A.; Rovny, S.; Logunov, M.

    2007-07-01

    Novel electrochemical sensors based on well-known extracting agents are developed. Sensors have shown high sensitivity towards a variety of rear earth metal ions in acidic media at pH=2. Multi-sensor system (electronic tongue) comprising newly developed sensors was successfully applied for the analysis of binary and ternary mixtures of Ce{sup 3+}, Nd{sup 3+}, Sm{sup 3+} and Gd{sup 3+} cations in different combinations. (authors)

  11. Simulative research on the anode plasma dynamics in the high-power electron beam diode

    SciTech Connect (OSTI)

    Cai, Dan; Liu, Lie; Ju, Jin-Chuan; Zhang, Tian-Yang; Zhao, Xue-Long; Zhou, Hong-Yu

    2015-07-15

    Anode plasma generated by electron beams could limit the electrical pulse-length, modify the impedance and stability of diode, and affect the generator to diode power coupling. In this paper, a particle-in-cell code is used to study the dynamics of anode plasma in the high-power electron beam diode. The effect of gas type, dynamic characteristic of ions on the diode operation with bipolar flow model are presented. With anode plasma appearing, the amplitude of diode current is increased due to charge neutralizations of electron flow. The lever of neutralization can be expressed using saturation factor. At same pressure of the anode gas layer, the saturation factor of CO{sub 2} is bigger than the H{sub 2}O vapor, namely, the generation rate of C{sup +} ions is larger than the H{sup +} ions at the same pressure. The transition time of ions in the anode-cathode gap could be used to estimate the time of diode current maximum.

  12. Observation of the dynamics leading to a conical intersection in dissociative electron attachment to water

    SciTech Connect (OSTI)

    Haxton, Dan; Adaniya, Hidihito; Slaughter, Dan; Rudek, B.; Osipov, Timur; Weber, Thorsten; Rescigno, Tom; McCurdy, Bill; Belkacem, Ali

    2011-06-08

    Following prior work on the lower-energy resonances, we apply techniques of momentum imaging and ab initio scattering calculations to the process of dissociative electron attachment to water via the highest-energy {sup 2}B{sub 2} resonance. We focus on the H{sup -} anion fragment, which is produced via dynamics passing through and avoiding the conical intersection with the lower A{sub 1} state, leading to OH ((sup 2}{Pi}#5;) and OH ({sup 2}{Sigma}#6;), respectively. The momentum imaging technique, when combined with theoretical calculations on the attachment amplitude and dissociation dynamics, demonstrates that the angular distributions provide a signature of the location of the conical intersection in the space of nuclear con#12;gurations.

  13. ON QUIET-TIME SOLAR WIND ELECTRON DISTRIBUTIONS IN DYNAMICAL EQUILIBRIUM WITH LANGMUIR TURBULENCE

    SciTech Connect (OSTI)

    Zaheer, S.; Yoon, P. H.

    2013-10-01

    A recent series of papers put forth a self-consistent theory of an asymptotically steady-state electron distribution function and Langmuir turbulence intensity. The theory was developed in terms of the ? distribution which features Maxwellian low-energy electrons and a non-Maxwellian energetic power-law tail component. The present paper discusses a generalized ? distribution that features a Davydov-Druyvesteyn type of core component and an energetic power-law tail component. The physical motivation for such a generalization is so that the model may reflect the influence of low-energy electrons interacting with low-frequency kinetic Alfvnic turbulence as well as with high-frequency Langmuir turbulence. It is shown that such a solution and the accompanying Langmuir wave spectrum rigorously satisfy the balance requirement between the spontaneous and induced emission processes in both the particle and wave kinetic equations, and approximately satisfy the similar balance requirement between the spontaneous and induced scattering processes, which are nonlinear. In spite of the low velocity modification of the electron distribution function, it is shown that the resulting asymptotic velocity power-law index ?, where f{sub e} ? v {sup ?} is close to the average index observed during the quiet-time solar wind condition, i.e., ? ? O(6.5) whereas ?{sub average} ? 6.69, according to observation.

  14. Acceleration and dynamics of an electron in the degenerate and magnetized plasma elliptical waveguide

    SciTech Connect (OSTI)

    Abdoli-Arani, A.; Jazi, B. [Department of Photonics, Faculty of Physics, University of Kashan, Kashan (Iran, Islamic Republic of); Shokri, B. [Physics Department and Laser-Plasma Research Institute, G. C. Shahid Beheshti University, Tehran (Iran, Islamic Republic of)

    2013-02-15

    The dynamics and energy gain of an electron in the field of a transverse magnetic wave propagating inside an elliptical degenerate plasma waveguide is analytically investigated by finding the field components of the TM{sub mr} mode in this waveguide. Besides, by solving the relativistic momentum and energy equations the deflection angle and the acceleration gradient of the electron in the waveguide are obtained. Furthermore, the field components of the hybrid mode and the transferred power in the presence of the magnetic field in this waveguide are found. Also by applying the boundary conditions at the plasma-conductor interface, we calculate the dispersion relation. It is shown that the cutoff frequency of this mode is dependent on the plasma density but independent of the magnetic field. Then, a single-electron model for numerical calculations of the electron deflection angle and acceleration gradient inside the magnetized plasma-filled elliptical waveguide is generally presented to be used as a cascading process for the acceleration purposes.

  15. Electronic-excitation energy transfer in heterogeneous dye solutions under laser excitation

    SciTech Connect (OSTI)

    Levshin, L.V.; Mukushev, B.T.; Saletskii, A.M.

    1995-10-01

    An experimental study has been made of electronic-excitation energy transfer (EEET) among dye molecules of different types for different exciting-fight wavelengths and temperatures. Upon selective laser excitation of the donor, the inhomogeneous broadening of molecular levels increases the probability of EEET from the donor to acceptor molecules. The efficiency of this process is directly proportional to the acceptor molecule concentration and is temperature dependent. The EEET is accompanied by the spectral migration of energy among donor molecules, which reduces the fluorescence quantum efficiency of the donor. Increasing the frequency of the exciting light decreases in the donor fluorescence quantum efficiency. An increase in the acceptor molecule concentration results in a decrease of the spectral migration of excitation in the donor molecule system. 5 refs., 5 figs.

  16. The EGS4 Code System: Solution of Gamma-ray and Electron Transport Problems

    DOE R&D Accomplishments [OSTI]

    Nelson, W. R.; Namito, Yoshihito

    1990-03-01

    In this paper we present an overview of the EGS4 Code System -- a general purpose package for the Monte Carlo simulation of the transport of electrons and photons. During the last 10-15 years EGS has been widely used to design accelerators and detectors for high-energy physics. More recently the code has been found to be of tremendous use in medical radiation physics and dosimetry. The problem-solving capabilities of EGS4 will be demonstrated by means of a variety of practical examples. To facilitate this review, we will take advantage of a new add-on package, called SHOWGRAF, to display particle trajectories in complicated geometries. These are shown as 2-D laser pictures in the written paper and as photographic slides of a 3-D high-resolution color monitor during the oral presentation. 11 refs., 15 figs.

  17. Exploring the vibrational fingerprint of the electronic excitation energy via molecular dynamics

    SciTech Connect (OSTI)

    Deyne, Andy Van Yperen-De; Pauwels, Ewald; Ghysels, An; Waroquier, Michel; Van Speybroeck, Veronique; Hemelsoet, Karen; De Meyer, Thierry; Department of Textiles, Ghent University, Technologiepark 907, 9052 Zwijnaarde ; De Clerck, Karen

    2014-04-07

    A Fourier-based method is presented to relate changes of the molecular structure during a molecular dynamics simulation with fluctuations in the electronic excitation energy. The method implies sampling of the ground state potential energy surface. Subsequently, the power spectrum of the velocities is compared with the power spectrum of the excitation energy computed using time-dependent density functional theory. Peaks in both spectra are compared, and motions exhibiting a linear or quadratic behavior can be distinguished. The quadratically active motions are mainly responsible for the changes in the excitation energy and hence cause shifts between the dynamic and static values of the spectral property. Moreover, information about the potential energy surface of various excited states can be obtained. The procedure is illustrated with three case studies. The first electronic excitation is explored in detail and dominant vibrational motions responsible for changes in the excitation energy are identified for ethylene, biphenyl, and hexamethylbenzene. The proposed method is also extended to other low-energy excitations. Finally, the vibrational fingerprint of the excitation energy of a more complex molecule, in particular the azo dye ethyl orange in a water environment, is analyzed.

  18. Dynamics of ionization-induced electron injection in the high density regime of laser wakefield acceleration

    SciTech Connect (OSTI)

    Desforges, F. G.; Paradkar, B. S. Ju, J.; Audet, T. L.; Maynard, G.; Cros, B.; Hansson, M.; Senje, L.; Persson, A.; Lundh, O.; Wahlström, C.-G.; Dobosz-Dufrénoy, S.; Monot, P.; Vay, J.-L.

    2014-12-15

    The dynamics of ionization-induced electron injection in high density (∼1.2 × 10{sup 19} cm{sup −3}) regime of laser wakefield acceleration is investigated by analyzing the betatron X-ray emission. In such high density operation, the laser normalized vector potential exceeds the injection-thresholds of both ionization-injection and self-injection due to self-focusing. In this regime, direct experimental evidence of early on-set of ionization-induced injection into the plasma wave is given by mapping the X-ray emission zone inside the plasma. Particle-In-Cell simulations show that this early on-set of ionization-induced injection, due to its lower trapping threshold, suppresses the trapping of self-injected electrons. A comparative study of the electron and X-ray properties is performed for both self-injection and ionization-induced injection. An increase of X-ray fluence by at least a factor of two is observed in the case of ionization-induced injection due to increased trapped charge compared to self-injection mechanism.

  19. TRACING ELECTRON BEAMS IN THE SUN'S CORONA WITH RADIO DYNAMIC IMAGING SPECTROSCOPY

    SciTech Connect (OSTI)

    Chen Bin; Bastian, T. S.; White, S. M.; Gary, D. E.; Perley, R.; Rupen, M.; Carlson, B.

    2013-01-20

    We report observations of type III radio bursts at decimeter wavelengths (type IIIdm bursts)-signatures of suprathermal electron beams propagating in the low corona-using the new technique of radio dynamic imaging spectroscopy provided by the recently upgraded Karl G. Jansky Very Large Array. For the first time, type IIIdm bursts were imaged with high time and frequency resolution over a broad frequency band, allowing electron beam trajectories in the corona to be deduced. Together with simultaneous hard X-ray and extreme ultraviolet observations, we show that these beams emanate from an energy release site located in the low corona at a height below {approx}15 Mm, and propagate along a bundle of discrete magnetic loops upward into the corona. Our observations enable direct measurements of the plasma density along the magnetic loops, and allow us to constrain the diameter of these loops to be less than 100 km. These overdense and ultra-thin loops reveal the fundamentally fibrous structure of the Sun's corona. The impulsive nature of the electron beams, their accessibility to different magnetic field lines, and the detailed structure of the magnetic release site revealed by the radio observations indicate that the localized energy release is highly fragmentary in time and space, supporting a bursty reconnection model that involves secondary magnetic structures for magnetic energy release and particle acceleration.

  20. Dynamics of electron solvation in methanol: Excited state relaxation and generation by charge-transfer-to-solvent

    SciTech Connect (OSTI)

    Elkins, Madeline H.; Williams, Holly L.; Neumark, Daniel M.

    2015-06-21

    The charge-transfer-to-solvent dynamics (CTTS) and excited state relaxation mechanism of the solvated electron in methanol are studied by time-resolved photoelectron spectroscopy on a liquid methanol microjet by means of two-pulse and three-pulse experiments. In the two-pulse experiment, CTTS excitation is followed by a probe photoejection pulse. The resulting time-evolving photoelectron spectrum reveals multiple time scales characteristic of relaxation and geminate recombination of the initially generated electron which are consistent with prior results from transient absorption. In the three-pulse experiment, the relaxation dynamics of the solvated electron following electronic excitation are measured. The internal conversion lifetime of the excited electron is found to be 130 40 fs, in agreement with extrapolated results from clusters and the non-adiabatic relaxation mechanism.

  1. Computation of the free energy due to electron density fluctuation of a solute in solution: A QM/MM method with perturbation approach combined with a theory of solutions

    SciTech Connect (OSTI)

    Suzuoka, Daiki; Takahashi, Hideaki Morita, Akihiro

    2014-04-07

    We developed a perturbation approach to compute solvation free energy ?? within the framework of QM (quantum mechanical)/MM (molecular mechanical) method combined with a theory of energy representation (QM/MM-ER). The energy shift ? of the whole system due to the electronic polarization of the solute is evaluated using the second-order perturbation theory (PT2), where the electric field formed by surrounding solvent molecules is treated as the perturbation to the electronic Hamiltonian of the isolated solute. The point of our approach is that the energy shift ?, thus obtained, is to be adopted for a novel energy coordinate of the distribution functions which serve as fundamental variables in the free energy functional developed in our previous work. The most time-consuming part in the QM/MM-ER simulation can be, thus, avoided without serious loss of accuracy. For our benchmark set of molecules, it is demonstrated that the PT2 approach coupled with QM/MM-ER gives hydration free energies in excellent agreements with those given by the conventional method utilizing the Kohn-Sham SCF procedure except for a few molecules in the benchmark set. A variant of the approach is also proposed to deal with such difficulties associated with the problematic systems. The present approach is also advantageous to parallel implementations. We examined the parallel efficiency of our PT2 code on multi-core processors and found that the speedup increases almost linearly with respect to the number of cores. Thus, it was demonstrated that QM/MM-ER coupled with PT2 deserves practical applications to systems of interest.

  2. Probing Reaction Dynamics of Transition-Metal Complexes in Solution via Time-Resolved X-ray Spectroscopy

    SciTech Connect (OSTI)

    Huse, Nils; Khalil, Munira; Kim, Tae Kyu; Smeigh, Amanda L.; Jamula, Lindsey; McCusker, James K.; Schoenlein, Robert W.

    2009-05-24

    We report measurements of the photo-induced Fe(II) spin crossover reaction dynamics in solution via time-resolved x-ray absorption spectroscopy. EXAFS measurements reveal that the iron?nitrogen bond lengthens by 0.21+-0.03 Angstrom in the high-spin transient excited state relative to the ground state. XANES measurements at the Fe L-edge show directly the influence of the structural change on the ligand-field splitting of the Fe(II) 3d orbitals associated with the spin transition.

  3. Anomalous dynamics of aqueous solutions of di-propylene glycol methylether confined in MCM-41 by quasielastic neutron scattering

    SciTech Connect (OSTI)

    Swenson, Jan Elamin, Khalid; Chen, Guo; Lohstroh, Wiebke; Sakai, Victoria Garcia

    2014-12-07

    The molecular dynamics of solutions of di-propylene glycol methylether (2PGME) and H{sub 2}O (or D{sub 2}O) confined in 28 Å pores of MCM-41 have been studied by quasielastic neutron scattering and differential scanning calorimetry over the concentration range 0–90 wt.% water. This system is of particular interest due to its pronounced non-monotonic concentration dependent dynamics of 2PGME in the corresponding bulk system, showing the important role of hydrogen bonding for the dynamics. In this study we have elucidated how this non-monotonic concentration dependence is affected by the confined geometry. The results show that this behaviour is maintained in the confinement, but the slowest diffusive dynamics of 2PGME is now observed at a considerably higher water concentration; at 75 wt.% water in MCM-41 compared to 30 wt.% water in the corresponding bulk system. This difference can be explained by an improper mixing of the two confined liquids. The results suggest that water up to a concentration of about 20 wt.% is used to hydrate the hydrophilic hydroxyl surface groups of the silica pores, and that it is only at higher water contents the water becomes partly mixed with 2PGME. Hence, due to this partial micro-phase separation of the two liquids larger, and thereby slower relaxing, structural entities of hydrogen bonded water and 2PGME molecules can only be formed at higher water contents than in the bulk system. However, the Q-dependence is unchanged with confinement, showing that the nature of the molecular motions is preserved. Thus, there is no indication of localization of the dynamics at length scales of less than 20 Å. The dynamics of both water and 2PGME is strongly dominated by translational diffusion at a temperature of 280 K.

  4. A water-processable organic electron-selective layer for solution-processed inverted organic solar cells

    SciTech Connect (OSTI)

    Chen, Dongcheng; Zhou, Hu; Cai, Ping; Sun, Shi; Ye, Hua; Su, Shi-Jian Cao, Yong

    2014-02-03

    A triazine- and pyridinium-containing water-soluble material of 1,1?,1?-(4,4?,4?-(1,3,5-triazine-2,4,6-triyl)tris(benzene-4,1-diyl)) tris(methylene)tripyridinium bromide (TzPyBr) was developed as an organic electron-selective layer in solution-processed inverted organic solar cells due to its strong anti-erosion capacity against non-polar organic solvents commonly used for the active layer. Ohmic-like contact with the adjacent active materials like fullerene derivatives is speculated to be formed, as confirmed by the work-function measurements with scanning Kelvin probe and ultraviolet photoelectron spectroscopy techniques. Besides, considering the deep highest occupied molecular orbital energy level of TzPyBr, excellent hole-blocking property of the electron-selective layer is also anticipated. The inverted organic photovoltaic devices based on the TzPyBr/ITO (indium tin oxide) bilayer cathode exhibit dramatically enhanced performance compared to the control devices with bare ITO as the cathode and even higher efficiency than the conventional type devices with ITO and Al as the electrodes.

  5. Ultrafast myoglobin structural dynamics observed with an X-ray free-electron laser

    SciTech Connect (OSTI)

    Levantino, Matteo; Schirò, Giorgio; Lemke, Henrik Till; Cottone, Grazia; Glownia, James Michael; Zhu, Diling; Chollet, Mathieu; Ihee, Hyotcherl; KAIST, Daejeon; Cupane, Antonio; Cammarata, Marco

    2015-04-02

    Light absorption can trigger biologically relevant protein conformational changes. The light induced structural rearrangement at the level of a photoexcited chromophore is known to occur in the femtosecond timescale and is expected to propagate through the protein as a quake-like intramolecular motion. Here we report direct experimental evidence of such ‘proteinquake’ observed in myoglobin through femtosecond X-ray solution scattering measurements performed at the Linac Coherent Light Source X-ray free-electron laser. An ultrafast increase of myoglobin radius of gyration occurs within 1 picosecond and is followed by a delayed protein expansion. As the system approaches equilibrium it undergoes damped oscillations with a ~3.6-picosecond time period. Our results unambiguously show how initially localized chemical changes can propagate at the level of the global protein conformation in the picosecond timescale.

  6. Ultrafast myoglobin structural dynamics observed with an X-ray free-electron laser

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

    Levantino, Matteo; Schirò, Giorgio; Lemke, Henrik Till; Cottone, Grazia; Glownia, James Michael; Zhu, Diling; Chollet, Mathieu; Ihee, Hyotcherl; KAIST, Daejeon; Cupane, Antonio; et al

    2015-04-02

    Light absorption can trigger biologically relevant protein conformational changes. The light induced structural rearrangement at the level of a photoexcited chromophore is known to occur in the femtosecond timescale and is expected to propagate through the protein as a quake-like intramolecular motion. Here we report direct experimental evidence of such ‘proteinquake’ observed in myoglobin through femtosecond X-ray solution scattering measurements performed at the Linac Coherent Light Source X-ray free-electron laser. An ultrafast increase of myoglobin radius of gyration occurs within 1 picosecond and is followed by a delayed protein expansion. As the system approaches equilibrium it undergoes damped oscillations withmore » a ~3.6-picosecond time period. Our results unambiguously show how initially localized chemical changes can propagate at the level of the global protein conformation in the picosecond timescale.« less

  7. Structural, electronic, mechanical, and dynamical properties of graphene oxides: A first principles study

    SciTech Connect (OSTI)

    Dabhi, Shweta D.; Gupta, Sanjay D.; Jha, Prafulla K.

    2014-05-28

    We report the results of a theoretical study on the structural, electronic, mechanical, and vibrational properties of some graphene oxide models (GDO, a-GMO, z-GMO, ep-GMO and mix-GMO) at ambient pressure. The calculations are based on the ab-initio plane-wave pseudo potential density functional theory, within the generalized gradient approximations for the exchange and correlation functional. The calculated values of lattice parameters, bulk modulus, and its first order pressure derivative are in good agreement with other reports. A linear response approach to the density functional theory is used to derive the phonon frequencies. We discuss the contribution of the phonons in the dynamical stability of graphene oxides and detailed analysis of zone centre phonon modes in all the above mentioned models. Our study demonstrates a wide range of energy gap available in the considered models of graphene oxide and hence the possibility of their use in nanodevices.

  8. Dynamics of soft Nanomaterials captured by transmission electron microscopy in liquid water

    SciTech Connect (OSTI)

    Proetto, Maria T.; Rush, Anthony M.; Chien, Miao-Ping; Abellan Baeza, Patricia; Patterson, Joseph P.; Thompson, Matthew P.; Olson, Norman H.; Moore, Curtis E.; Rheingold, Arnold L.; Andolina, Christopher; Millstone, Jill; Howell, Stephen B.; Browning, Nigel D.; Evans, James E.; Gianneschi, Nathan C.

    2014-01-14

    In this paper we present in situ transmission electron microscopy (TEM) of soft, synthetic nanoparticles with a comparative analysis using conventional TEM methods. This comparison is made with the simple aim of describing what is an unprecedented example of in situ imaging by TEM. However, we contend the technique will quickly become essential in the characterization of analogous systems, especially where dynamics are of interest in the solvated state. In this case, particles were studied which were obtained from the direct polymerization of an oxaliplatin analog, designed for an ongoing program in novel chemotherapeutic delivery systems. The resulting nanoparticles provided sufficient contrast for facile imaging in situ, and point toward key design parameters that enable this new characterization approach for organic nanomaterials. We describe the preparation of the synthetic micellar nanoparticles to- gether with their characterization in liquid water.

  9. Electron-beam dynamics for an advanced flash-radiography accelerator

    SciTech Connect (OSTI)

    Ekdahl, Carl August Jr.

    2015-06-22

    Beam dynamics issues were assessed for a new linear induction electron accelerator. Special attention was paid to equilibrium beam transport, possible emittance growth, and beam stability. Especially problematic would be high-frequency beam instabilities that could blur individual radiographic source spots, low-frequency beam motion that could cause pulse-to-pulse spot displacement, and emittance growth that could enlarge the source spots. Beam physics issues were examined through theoretical analysis and computer simulations, including particle-in cell (PIC) codes. Beam instabilities investigated included beam breakup (BBU), image displacement, diocotron, parametric envelope, ion hose, and the resistive wall instability. Beam corkscrew motion and emittance growth from beam mismatch were also studied. It was concluded that a beam with radiographic quality equivalent to the present accelerators at Los Alamos will result if the same engineering standards and construction details are upheld.

  10. HDL surface lipids mediate CETP binding as revealed by electron microscopy and molecular dynamics simulation

    SciTech Connect (OSTI)

    Zhang, Meng; Charles, River; Tong, Huimin; Zhang, Lei; Patel, Mili; Wang, Francis; Rames, Matthew J.; Ren, Amy; Rye, Kerry-Anne; Qiu, Xiayang; Johns, Douglas G.; Charles, M. Arthur; Ren, Gang

    2015-03-04

    Cholesteryl ester transfer protein (CETP) mediates the transfer of cholesterol esters (CE) from atheroprotective high-density lipoproteins (HDL) to atherogenic low-density lipoproteins (LDL). CETP inhibition has been regarded as a promising strategy for increasing HDL levels and subsequently reducing the risk of cardiovascular diseases (CVD). Although the crystal structure of CETP is known, little is known regarding how CETP binds to HDL. Here, we investigated how various HDL-like particles interact with CETP by electron microscopy and molecular dynamics simulations. Results showed that CETP binds to HDL via hydrophobic interactions rather than protein-protein interactions. The HDL surface lipid curvature generates a hydrophobic environment, leading to CETP hydrophobic distal end interaction. This interaction is independent of other HDL components, such as apolipoproteins, cholesteryl esters and triglycerides. Thus, disrupting these hydrophobic interactions could be a new therapeutic strategy for attenuating the interaction of CETP with HDL.

  11. HDL surface lipids mediate CETP binding as revealed by electron microscopy and molecular dynamics simulation

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

    Zhang, Meng; Charles, River; Tong, Huimin; Zhang, Lei; Patel, Mili; Wang, Francis; Rames, Matthew J.; Ren, Amy; Rye, Kerry-Anne; Qiu, Xiayang; et al

    2015-03-04

    Cholesteryl ester transfer protein (CETP) mediates the transfer of cholesterol esters (CE) from atheroprotective high-density lipoproteins (HDL) to atherogenic low-density lipoproteins (LDL). CETP inhibition has been regarded as a promising strategy for increasing HDL levels and subsequently reducing the risk of cardiovascular diseases (CVD). Although the crystal structure of CETP is known, little is known regarding how CETP binds to HDL. Here, we investigated how various HDL-like particles interact with CETP by electron microscopy and molecular dynamics simulations. Results showed that CETP binds to HDL via hydrophobic interactions rather than protein-protein interactions. The HDL surface lipid curvature generates a hydrophobicmore » environment, leading to CETP hydrophobic distal end interaction. This interaction is independent of other HDL components, such as apolipoproteins, cholesteryl esters and triglycerides. Thus, disrupting these hydrophobic interactions could be a new therapeutic strategy for attenuating the interaction of CETP with HDL.« less

  12. Determination of redox reaction rates and orders by in-situ liquid cell electron microscopy of Pd and Au solution growth

    SciTech Connect (OSTI)

    Sutter, Eli A.; Sutter, Peter W.

    2014-11-19

    In-situ liquid cell transmission and scanning transmission electron microscopy (TEM/STEM) experiments are important as they provide direct insight into processes in liquids, such as solution growth of nanoparticles among others. In liquid cell TEM/STEM redox reaction experiments the hydrated electrons e?aq created by the electron beam are responsible for the reduction of metal-ion complexes. Here we investigate the rate equation of redox reactions involving reduction by e?aq generated by the electron beam during in-situ liquid TEM/STEM. Specifically we consider the growth of Pd on Au seeds in aqueous solutions containing Pd-chloro complexes. From the quantification of the rate of Pd deposition at different electron beam currents and as a function of distance from a stationary, nanometer-sized exciting beam, we determine that the reaction is first order with respect to the concentration of hydrated electrons, [e?aq]. By comparing Pd- and Au-deposition, we further demonstrate that measurements of the local deposition rate on nanoparticles in the solution via real-time imaging can be used to measure not only [e?aq] but also the rate of reduction of a metal-ion complex to zero-valent metal atoms in solution.

  13. Dynamics of Magnesite Formation at Low-Temperature and High pCO2 in Aqueous Solution

    SciTech Connect (OSTI)

    Qafoku, Odeta; Dixon, David A.; Rosso, Kevin M.; Schaef, Herbert T.; Bowden, Mark E.; Arey, Bruce W.; Felmy, Andrew R.

    2015-09-17

    Like many metal carbonate minerals, despite conditions of supersaturation, precipitation of magnesite from aqueous solution is kinetically hindered at low temperatures, for reasons that remain poorly understood. The present study examines precipitation products from reaction of Mg(OH)2 in aqueous solutions saturated with supercritical CO2 at high pressures (90 atm and 110 atm) and low temperatures (35 C and 50 C). Traditional bulk characterization (X-ray diffraction) of the initial solid formed indicated the presence of hydrated magnesium carbonates (hydromagnesite and nesquehonite), thermodynamically metastable phases that were found to slowly react during ageing to the more stable anhydrous form, magnesite, at temperatures as low as 35 C (135-140 days) and at a faster rate at 50 C (56 days). Undetected by bulk measurements, detailed examination of the precipitates by scanning electron microscopy (SEM) showed that magnesite is present as a minor component at relatively early reaction times (7 days) at 50 C. In addition to magnesite dominating the solid phases over time, we find that mangesite nucleation and growth occurs more quickly with increasing partial pressure of CO2, and in electrolyte solutions with high bicarbonate content. Furthermore, formation of magnesite was found to be enhanced in sulfate-rich solutions, compared to chloride-rich solutions. We speculate that much of this behavior is possibly due to sulfate serving as sink of protons generated during carbonation reactions. These results support the importance of integrating magnesite as an equilibrium phase in reactive transport calculations of the effects of carbon dioxide sequestration on subsurface formations at long time scales.

  14. Batch crystallization of rhodopsin for structural dynamics using an X-ray free-electron laser

    SciTech Connect (OSTI)

    Wu, Wenting; Nogly, Przemyslaw; Rheinberger, Jan; Kick, Leonhard M.; Gati, Cornelius; Nelson, Garrett; Deupi, Xavier; Standfuss, Jrg; Schertler, Gebhard; Panneels, Valrie

    2015-06-27

    A new batch preparation method is presented for high-density micrometre-sized crystals of the G protein-coupled receptor rhodopsin for use in time-resolved serial femtosecond crystallography at an X-ray free-electron laser using a liquid jet. Rhodopsin is a membrane protein from the G protein-coupled receptor family. Together with its ligand retinal, it forms the visual pigment responsible for night vision. In order to perform ultrafast dynamics studies, a time-resolved serial femtosecond crystallography method is required owing to the nonreversible activation of rhodopsin. In such an approach, microcrystals in suspension are delivered into the X-ray pulses of an X-ray free-electron laser (XFEL) after a precise photoactivation delay. Here, a millilitre batch production of high-density microcrystals was developed by four methodical conversion steps starting from known vapour-diffusion crystallization protocols: (i) screening the low-salt crystallization conditions preferred for serial crystallography by vapour diffusion, (ii) optimization of batch crystallization, (iii) testing the crystal size and quality using second-harmonic generation (SHG) imaging and X-ray powder diffraction and (iv) production of millilitres of rhodopsin crystal suspension in batches for serial crystallography tests; these crystals diffracted at an XFEL at the Linac Coherent Light Source using a liquid-jet setup.

  15. Coupled electron-nuclear dynamics: Charge migration and charge transfer initiated near a conical intersection

    SciTech Connect (OSTI)

    Mendive-Tapia, David; Vacher, Morgane; Bearpark, Michael J.; Robb, Michael A.

    2013-07-28

    Coupled electron-nuclear dynamics, implemented using the Ehrenfest method, has been used to study charge migration with fixed nuclei, together with charge transfer when nuclei are allowed to move. Simulations were initiated at reference geometries of neutral benzene and 2-phenylethylamine (PEA), and at geometries close to potential energy surface crossings in the cations. Cationic eigenstates, and the so-called sudden approximation, involving removal of an electron from a correlated ground-state wavefunction for the neutral species, were used as initial conditions. Charge migration without coupled nuclear motion could be observed if the Ehrenfest simulation, using the sudden approximation, was started near a conical intersection where the states were both strongly coupled and quasi-degenerate. Further, the main features associated with charge migration were still recognizable when the nuclear motion was allowed to couple. In the benzene radical cation, starting from the reference neutral geometry with the sudden approximation, one could observe sub-femtosecond charge migration with a small amplitude, which results from weak interaction with higher electronic states. However, we were able to engineer large amplitude charge migration, with a period between 10 and 100 fs, corresponding to oscillation of the electronic structure between the quinoid and anti-quinoid cationic electronic configurations, by distorting the geometry along the derivative coupling vector from the D{sub 6h} Jahn-Teller crossing to lower symmetry where the states are not degenerate. When the nuclear motion becomes coupled, the period changes only slightly. In PEA, in an Ehrenfest trajectory starting from the D{sub 2} eigenstate and reference geometry, a partial charge transfer occurs after about 12 fs near the first crossing between D{sub 1}, D{sub 2} (N{sup +}-Phenyl, N-Phenyl{sup +}). If the Ehrenfest propagation is started near this point, using the sudden approximation without coupled

  16. Communication: Microsecond dynamics of the protein and water affect electron transfer in a bacterial bc{sub 1} complex

    SciTech Connect (OSTI)

    Martin, Daniel R.; Matyushov, Dmitry V.

    2015-04-28

    Cross-membrane electron transport between cofactors localized in proteins of mitochondrial respiration and bacterial photosynthesis is the source of all biological energy. The statistics and dynamics of nuclear fluctuations in these protein/membrane/water heterogeneous systems are critical for their energetic efficiency. The results of 13 ?s of atomistic molecular dynamics simulations of the membrane-bound bc{sub 1} bacterial complex are analyzed here. The reaction is affected by a broad spectrum of nuclear modes, with the slowest dynamics in the range of time-scales ?0.1-1.6 ?s contributing half of the reaction reorganization energy. Two reorganization energies are required to describe protein electron transfer due to dynamical arrest of protein conformations on the observation window. This mechanistic distinction allows significant lowering of activation barriers for reactions in proteins.

  17. Theoretical study of molecular vibrations in electron momentum spectroscopy experiments on furan: An analytical versus a molecular dynamical approach

    SciTech Connect (OSTI)

    Morini, Filippo; Deleuze, Michael S.; Watanabe, Noboru; Takahashi, Masahiko

    2015-03-07

    The influence of thermally induced nuclear dynamics (molecular vibrations) in the initial electronic ground state on the valence orbital momentum profiles of furan has been theoretically investigated using two different approaches. The first of these approaches employs the principles of Born-Oppenheimer molecular dynamics, whereas the so-called harmonic analytical quantum mechanical approach resorts to an analytical decomposition of contributions arising from quantized harmonic vibrational eigenstates. In spite of their intrinsic differences, the two approaches enable consistent insights into the electron momentum distributions inferred from new measurements employing electron momentum spectroscopy and an electron impact energy of 1.2 keV. Both approaches point out in particular an appreciable influence of a few specific molecular vibrations of A{sub 1} symmetry on the 9a{sub 1} momentum profile, which can be unravelled from considerations on the symmetry characteristics of orbitals and their energy spacing.

  18. Predicting solute partitioning in lipid bilayers: Free energies and partition coefficients from molecular dynamics simulations and COSMOmic

    SciTech Connect (OSTI)

    Jakobtorweihen, S. Ingram, T.; Gerlach, T.; Smirnova, I.; Zuniga, A. Chaides; Keil, F. J.

    2014-07-28

    Quantitative predictions of biomembrane/water partition coefficients are important, as they are a key property in pharmaceutical applications and toxicological studies. Molecular dynamics (MD) simulations are used to calculate free energy profiles for different solutes in lipid bilayers. How to calculate partition coefficients from these profiles is discussed in detail and different definitions of partition coefficients are compared. Importantly, it is shown that the calculated coefficients are in quantitative agreement with experimental results. Furthermore, we compare free energy profiles from MD simulations to profiles obtained by the recent method COSMOmic, which is an extension of the conductor-like screening model for realistic solvation to micelles and biomembranes. The free energy profiles from these molecular methods are in good agreement. Additionally, solute orientations calculated with MD and COSMOmic are compared and again a good agreement is found. Four different solutes are investigated in detail: 4-ethylphenol, propanol, 5-phenylvaleric acid, and dibenz[a,h]anthracene, whereby the latter belongs to the class of polycyclic aromatic hydrocarbons. The convergence of the free energy profiles from biased MD simulations is discussed and the results are shown to be comparable to equilibrium MD simulations. For 5-phenylvaleric acid the influence of the carboxyl group dihedral angle on free energy profiles is analyzed with MD simulations.

  19. Statistical analysis of the dynamics of secondary electrons in the flare of a high-voltage beam-type discharge

    SciTech Connect (OSTI)

    Demkin, V. P.; Mel'nichuk, S. V.

    2014-09-15

    In the present work, results of investigations into the dynamics of secondary electrons with helium atoms in the presence of the reverse electric field arising in the flare of a high-voltage pulsed beam-type discharge and leading to degradation of the primary electron beam are presented. The electric field in the discharge of this type at moderate pressures can reach several hundred V/cm and leads to considerable changes in the kinetics of secondary electrons created in the process of propagation of the electron beam generated in the accelerating gap with a grid anode. Moving in the accelerating electric field toward the anode, secondary electrons create the so-called compensating current to the anode. The character of electron motion and the compensating current itself are determined by the ratio of the field strength to the concentration of atoms (E/n). The energy and angular spectra of secondary electrons are calculated by the Monte Carlo method for different ratios E/n of the electric field strength to the helium atom concentration. The motion of secondary electrons with threshold energy is studied for inelastic collisions of helium atoms and differential analysis is carried out of the collisional processes causing energy losses of electrons in helium for different E/n values. The mechanism of creation and accumulation of slow electrons as a result of inelastic collisions of secondary electrons with helium atoms and selective population of metastable states of helium atoms is considered. It is demonstrated that in a wide range of E/n values the motion of secondary electrons in the beam-type discharge flare has the character of drift. At E/n values characteristic for the discharge of the given type, the drift velocity of these electrons is calculated and compared with the available experimental data.

  20. Electron-Beam Dynamics for an Advanced Flash-Radiography Accelerator

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

    Ekdahl, Carl

    2015-11-17

    Beam dynamics issues were assessed for a new linear induction electron accelerator being designed for multipulse flash radiography of large explosively driven hydrodynamic experiments. Special attention was paid to equilibrium beam transport, possible emittance growth, and beam stability. Especially problematic would be high-frequency beam instabilities that could blur individual radiographic source spots, low-frequency beam motion that could cause pulse-to-pulse spot displacement, and emittance growth that could enlarge the source spots. Furthermore, beam physics issues were examined through theoretical analysis and computer simulations, including particle-in-cell codes. Beam instabilities investigated included beam breakup, image displacement, diocotron, parametric envelope, ion hose, and themore » resistive wall instability. The beam corkscrew motion and emittance growth from beam mismatch were also studied. It was concluded that a beam with radiographic quality equivalent to the present accelerators at Los Alamos National Laboratory will result if the same engineering standards and construction details are upheld.« less

  1. Systematic analysis of proteindetergent complexes applying dynamic light scattering to optimize solutions for crystallization trials

    SciTech Connect (OSTI)

    Meyer, Arne [University of Hamburg, c/o DESY, Building 22a, Notkestrasse 85, 22603 Hamburg (Germany); Dierks, Karsten [University of Hamburg, c/o DESY, Building 22a, Notkestrasse 85, 22603 Hamburg (Germany); XtalConcepts, Marlowring 19, 22525 Hamburg (Germany); Hussein, Rana [University of Hamburg, c/o DESY, Building 22a, Notkestrasse 85, 22603 Hamburg (Germany); Brillet, Karl [ESBS, Ple API, 300 Boulevard Sbastien Brant, CS10413, 67412 Illkirch CEDEX (France); Brognaro, Hevila [So Paulo State University, UNESP/IBILCE, Caixa Postal 136, So Jos do Rio Preto-SP, 15054 (Brazil); Betzel, Christian, E-mail: christian.betzel@uni-hamburg.de [University of Hamburg, c/o DESY, Building 22a, Notkestrasse 85, 22603 Hamburg (Germany)

    2015-01-01

    Application of in situ dynamic light scattering to solutions of proteindetergent complexes permits characterization of these complexes in samples as small as 2 l in volume. Detergents are widely used for the isolation and solubilization of membrane proteins to support crystallization and structure determination. Detergents are amphiphilic molecules that form micelles once the characteristic critical micelle concentration (CMC) is achieved and can solubilize membrane proteins by the formation of micelles around them. The results are presented of a study of micelle formation observed by in situ dynamic light-scattering (DLS) analyses performed on selected detergent solutions using a newly designed advanced hardware device. DLS was initially applied in situ to detergent samples with a total volume of approximately 2 l. When measured with DLS, pure detergents show a monodisperse radial distribution in water at concentrations exceeding the CMC. A series of all-transn-alkyl-?-d-maltopyranosides, from n-hexyl to n-tetradecyl, were used in the investigations. The results obtained verify that the application of DLS in situ is capable of distinguishing differences in the hydrodynamic radii of micelles formed by detergents differing in length by only a single CH{sub 2} group in their aliphatic tails. Subsequently, DLS was applied to investigate the distribution of hydrodynamic radii of membrane proteins and selected water-insoluble proteins in presence of detergent micelles. The results confirm that stable proteindetergent complexes were prepared for (i) bacteriorhodopsin and (ii) FetA in complex with a ligand as examples of transmembrane proteins. A fusion of maltose-binding protein and the Duck hepatitis B virus X protein was added to this investigation as an example of a non-membrane-associated protein with low water solubility. The increased solubility of this protein in the presence of detergent could be monitored, as well as the progress of proteolytic cleavage to

  2. Structural, dynamic, electronic, and vibrational properties of flexible, intermediate, and stressed rigid As-Se glasses and liquids from first principles molecular dynamics

    SciTech Connect (OSTI)

    Bauchy, M.; Kachmar, A.; Micoulaut, M.

    2014-11-21

    The structural, vibrational, electronic, and dynamic properties of amorphous and liquid As{sub x}Se{sub 1-x} (0.10 Dynamics. Within the above range of compositions, thresholds, and anomalies are found in the behavior of reciprocal and real space properties that can be correlated to the experimental location of the Boolchand intermediate phase in these glassy networks, observed at 0.27 dynamical atomic-scale fingerprints for the onset of rigidity within the network, while also providing a much more complex picture than the one derived from mean-field approaches of stiffness transitions.

  3. Electronic excitation induced amorphization in titanate pyrochlores: an ab initio molecular dynamics study

    SciTech Connect (OSTI)

    Xiao, Haiyan Y.; Weber, William J.; Zhang, Yanwen; Zu, X. T.; Li, Sean

    2015-02-09

    In this study, the response of titanate pyrochlores (A2Ti2O7, A = Y, Gd and Sm) to electronic excitation is investigated utilizing an ab initio molecular dynamics method. All the titanate pyrochlores are found to undergo a crystalline-to-amorphous structural transition under a low concentration of electronic excitations. The transition temperature at which structural amorphization starts to occur depends on the concentration of electronic excitations. During the structural transition, O2-like molecules are formed, and this anion disorder further drives cation disorder that leads to an amorphous state. This study provides new insights into the mechanisms of amorphization in titanate pyrochlores under laser, electron and ion irradiations.

  4. Boost the electron mobility of solution-grown organic single crystals via reducing the amount of polar solvent residues

    SciTech Connect (OSTI)

    Xue, Guobiao; Xin, Huolin L.; Wu, Jiake; Fan, Congcheng; Liu, Shuang; Huang, Zhuoting; Liu, Yujing; Shan, Bowen; Miao, Qian; Chen, Hongzheng; Li, Hanying

    2015-10-29

    Enhancing electron transport to match with the development in hole transport is critical for organic electronics in the future. As electron motion is susceptible to extrinsic factors, seeking these factors and avoiding their negative effects have become the central challenge. Here, the existence of polar solvent residues in solution-grown single-crystals of 6,13-bis(triisopropylsilylethynyl)-5,7,12,14-tetraazapentacene is identified as a factor detrimental to electron motion. Field-effect transistors of the crystals exhibit electron mobility boosted by about 60% after the residues are removed. The average electron mobility reaches up to 8.0 ± 2.2 cm2 V–1 s–1 with a highest value of 13.3 cm2 V–1 s–1; these results are significantly higher than those obtained previously for the same molecule (1.0–5.0 cm2 V–1 s–1). Furthermore, the achieved mobility is also higher than the maximum reported electron mobility for organic materials (11 cm2 V–1 s–1). As a result, this work should greatly accelerate the advancement of organic electron-transporting materials.

  5. Role of direct electron-phonon coupling across metal-semiconductor interfaces in thermal transport via molecular dynamics

    SciTech Connect (OSTI)

    Lin, Keng-Hua; Strachan, Alejandro

    2015-07-21

    Motivated by significant interest in metal-semiconductor and metal-insulator interfaces and superlattices for energy conversion applications, we developed a molecular dynamics-based model that captures the thermal transport role of conduction electrons in metals and heat transport across these types of interface. Key features of our model, denoted eleDID (electronic version of dynamics with implicit degrees of freedom), are the natural description of interfaces and free surfaces and the ability to control the spatial extent of electron-phonon (e-ph) coupling. Non-local e-ph coupling enables the energy of conduction electrons to be transferred directly to the semiconductor/insulator phonons (as opposed to having to first couple to the phonons in the metal). We characterize the effect of the spatial e-ph coupling range on interface resistance by simulating heat transport through a metal-semiconductor interface to mimic the conditions of ultrafast laser heating experiments. Direct energy transfer from the conduction electrons to the semiconductor phonons not only decreases interfacial resistance but also increases the ballistic transport behavior in the semiconductor layer. These results provide new insight for experiments designed to characterize e-ph coupling and thermal transport at the metal-semiconductor/insulator interfaces.

  6. Field calculations, single-particle tracking, and beam dynamics with space charge in the electron lens for the Fermilab Integrable Optics Test Accelerator

    SciTech Connect (OSTI)

    Noll, Daniel; Stancari, Giulio

    2015-11-17

    An electron lens is planned for the Fermilab Integrable Optics Test Accelerator as a nonlinear element for integrable dynamics, as an electron cooler, and as an electron trap to study space-charge compensation in rings. We present the main design principles and constraints for nonlinear integrable optics. A magnetic configuration of the solenoids and of the toroidal section is laid out. Singleparticle tracking is used to optimize the electron path. Electron beam dynamics at high intensity is calculated with a particle-in-cell code to estimate current limits, profile distortions, and the effects on the circulating beam. In the conclusions, we summarize the main findings and list directions for further work.

  7. Dynamics of the microstructure of current channels and the generation of high-energy electrons in nanosecond discharges in air

    SciTech Connect (OSTI)

    Karelin, V. I.; Trenkin, A. A. Fedoseev, I. G.

    2015-12-15

    The results of the three-dimensional numerical simulation of the dynamics of the microstructure of high-voltage nanosecond discharges in air at atmospheric pressure are presented. It is established that the fast (at a time of ≈10 ns) broadening and significant decrease in the gas concentration in the microchannels occur as a result of the ohmic heating of microchannels with the diameter of 1–30 μm. It was shown that the broadening of microchannels in a nanosecond diffusive discharge provides an increase in the ratio of the electric field strength to the gas concentration in microchannels to values sufficient for the generation highenergy electron beams and X-ray bremsstrahlung in them. Features of the dynamics of the system of microchannels and its effect on the efficiency of the generation of high-energy electrons in discharges developing in the microstructuring regime of the current channels are considered.

  8. Electron

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

    density measurement by differential interferometry W. X. Ding, D. L. Brower, B. H. Deng, and T. Yates Electrical Engineering Department, University of California-Los Angeles, Los Angeles, California 90095 ͑Received 5 May 2006; presented on 10 May 2006; accepted 16 June 2006; published online 26 September 2006͒ A novel differential interferometer is being developed to measure the electron density gradient and its fluctuations. Two separate laser beams with slight spatial offset and frequency

  9. Charged nanoparticle attraction in multivalent salt solution: A classical-fluids density functional theory and molecular dynamics study

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

    Salerno, K. Michael; Frischknecht, Amalie L.; Stevens, Mark J.

    2016-04-08

    Here, negatively charged nanoparticles (NPs) in 1:1, 1:2, and 1:3 electrolyte solutions are studied in a primitive ion model using molecular dynamics (MD) simulations and classical density functional theory (DFT). We determine the conditions for attractive interactions between the like-charged NPs. Ion density profiles and NP–NP interaction free energies are compared between the two methods and are found to be in qualitative agreement. The NP interaction free energy is purely repulsive for monovalent counterions, but can be attractive for divalent and trivalent counterions. Using DFT, the NP interaction free energy for different NP diameters and charges is calculated. The depthmore » and location of the minimum in the interaction depend strongly on the NPs’ charge. For certain parameters, the depth of the attractive well can reach 8–10 kBT, indicating that kinetic arrest and aggregation of the NPs due to electrostatic interactions is possible. Rich behavior arises from the geometric constraints of counterion packing at the NP surface. Layering of counterions around the NPs is observed and, as secondary counterion layers form the minimum of the NP–NP interaction free energy shifts to larger separation, and the depth of the free energy minimum varies dramatically. We find that attractive interactions occur with and without NP overcharging.« less

  10. Solution-state structure and affinities of cyclodextrin: Fentanyl complexes by nuclear magnetic resonance spectroscopy and molecular dynamics simulation

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

    Mayer, Brian P.; Kennedy, Daniel J.; Lau, Edmond Y.; Valdez, Carlos A.

    2016-02-04

    Cyclodextrins (CDs) are investigated for their ability to form inclusion complexes with the analgesic fentanyl and three similar molecules: acetylfentanyl, thiofentanyl, and acetylthiofentanyl. Stoichiometry, binding strength, and complex structure are revealed through nuclear magnetic resonance (NMR) techniques and discussed in terms of molecular dynamics (MD) simulations. It was found that β-cyclodextrin is generally capable of forming the strongest complexes with the fentanyl panel. Two-dimensional NMR data and computational chemical calculations are used to derive solution-state structures of the complexes. Binding of the fentanyls to the CDs occurs at the amide phenyl ring, leaving the majority of the molecule solvated bymore » water, an observation common to all four fentanyls. This finding suggests a universal binding behavior, as the vast majority of previously synthesized fentanyl analogues contain this structural moiety. Furthermore, this baseline study serves as the most complete work on CD:fentanyl complexes to date and provides the insights into strategies for producing future generations of designer cyclodextrins capable of stronger and more selective complexation of fentanyl and its analogues.« less

  11. Electron

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

    Electron thermal transport within magnetic islands in the reversed-field pinch a... H. D. Stephens, 1,b͒ D. J. Den Hartog, 1,3 C. C. Hegna, 1,2 and J. A. Reusch 1 1 Department of Physics, University of Wisconsin-Madison, 1150 University Ave., Madison, Wisconsin 53706, USA 2 Department of Engineering Physics, University of Wisconsin-Madison, 1500 Engineering Drive, Madison, Wisconsin 53706, USA 3 Center for Magnetic Self-Organization in Laboratory and Astrophysical Plasmas, University of

  12. Visualizing the non-equilibrium dynamics of photoinduced intramolecular electron transfer with femtosecond X-ray pulses

    SciTech Connect (OSTI)

    Canton, Sophie E.; Kjr, Kasper S.; Vank, Gyrgy; van Driel, Tim B.; Adachi, Shin -ichi; Bordage, Amlie; Bressler, Christian; Chabera, Pavel; Christensen, Morten; Dohn, Asmus O.; Galler, Andreas; Gawelda, Wojciech; Gosztola, David; Haldrup, Kristoffer; Harlang, Tobias; Liu, Yizhu; Mller, Klaus B.; Nmeth, Zoltn; Nozawa, Shunsuke; Ppai, Mtys; Sato, Tokushi; Sato, Takahiro; Suarez-Alcantara, Karina; Togashi, Tadashi; Tono, Kensuke; Uhlig, Jens; Vithanage, Dimali A.; Wrnmark, Kenneth; Yabashi, Makina; Zhang, Jianxin; Sundstrm, Villy; Nielsen, Martin M.

    2015-03-02

    Ultrafast photoinduced electron transfer preceding energy equilibration still poses many experimental and conceptual challenges to the optimization of photoconversion since an atomic-scale description has so far been beyond reach. Here we combine femtosecond transient optical absorption spectroscopy with ultrafast X-ray emission spectroscopy and diffuse X-ray scattering at the SACLA facility to track the non-equilibrated electronic and structural dynamics within a bimetallic donoracceptor complex that contains an optically dark centre. Exploiting the 100-fold increase in temporal resolution as compared with storage ring facilities, these measurements constitute the first X-ray-based visualization of a non-equilibrated intramolecular electron transfer process over large interatomic distances. Thus experimental and theoretical results establish that mediation through electronically excited molecular states is a key mechanistic feature. The present study demonstrates the extensive potential of femtosecond X-ray techniques as diagnostics of non-adiabatic electron transfer processes in synthetic and biological systems, and some directions for future studies, are outlined.

  13. Visualizing the non-equilibrium dynamics of photoinduced intramolecular electron transfer with femtosecond X-ray pulses

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

    Canton, Sophie E.; Kjær, Kasper S.; Vankó, György; van Driel, Tim B.; Adachi, Shin -ichi; Bordage, Amélie; Bressler, Christian; Chabera, Pavel; Christensen, Morten; Dohn, Asmus O.; et al

    2015-03-02

    Ultrafast photoinduced electron transfer preceding energy equilibration still poses many experimental and conceptual challenges to the optimization of photoconversion since an atomic-scale description has so far been beyond reach. Here we combine femtosecond transient optical absorption spectroscopy with ultrafast X-ray emission spectroscopy and diffuse X-ray scattering at the SACLA facility to track the non-equilibrated electronic and structural dynamics within a bimetallic donor–acceptor complex that contains an optically dark centre. Exploiting the 100-fold increase in temporal resolution as compared with storage ring facilities, these measurements constitute the first X-ray-based visualization of a non-equilibrated intramolecular electron transfer process over large interatomic distances.more » Thus experimental and theoretical results establish that mediation through electronically excited molecular states is a key mechanistic feature. The present study demonstrates the extensive potential of femtosecond X-ray techniques as diagnostics of non-adiabatic electron transfer processes in synthetic and biological systems, and some directions for future studies, are outlined.« less

  14. Nonlinear space charge dynamics in mixed ionic-electronic conductors: Resistive switching and ferroelectric-like hysteresis of electromechanical response

    SciTech Connect (OSTI)

    Morozovska, Anna N.; Morozovsky, Nicholas V.; Eliseev, Eugene A.; Varenyk, Olexandr V.; Kim, Yunseok; Strelcov, Evgheni; Tselev, Alexander; Kalinin, Sergei V.

    2014-08-14

    We performed self-consistent modelling of nonlinear electrotransport and electromechanical response of thin films of mixed ionic-electronic conductors (MIEC) allowing for steric effects of mobile charged defects (ions, protons, or vacancies), electron degeneration, and Vegard stresses. We establish correlations between the features of the nonlinear space-charge dynamics, current-voltage, and bending-voltage curves for different types of the film electrodes. A pronounced ferroelectric-like hysteresis of the bending-voltage loops and current maxima on the double hysteresis current-voltage loops appear for the electron-transport electrodes. The double hysteresis loop with pronounced humps indicates a memristor-type resistive switching. The switching occurs due to the strong nonlinear coupling between the electronic and ionic subsystems. A sharp meta-stable maximum of the electron density appears near one open electrode and moves to another one during the periodic change of applied voltage. Our results can explain the nonlinear nature and correlation of electrical and mechanical memory effects in thin MIEC films. The analytical expression proving that the electrically induced bending of MIEC films can be detected by interferometric methods is derived.

  15. Hybrid DFT Functional-Based Static and Molecular Dynamics Studies of Excess Electron in Liquid Ethylene Carbonate

    SciTech Connect (OSTI)

    Yu, J. M.; Balbuena, P. B.; Budzien, J. L.; Leung, Kevin

    2011-02-22

    We applied static and dynamic hybrid functional density functional theory (DFT) calculations to study the interactions of one and two excess electrons with ethylene carbonate (EC) liquid and clusters. Optimal structures of (EC)n and (EC)n- clusters devoid of Li+ ions, n = 16, were obtained. The excess electron was found to be localized on a single EC in all cases, and the EC dimeric radical anion exhibits a reduced barrier associated with the breaking of the ethylene carbonoxygen covalent bond compared to EC-. In ab initio molecular dynamics (AIMD) simulations of EC- solvated in liquid EC, large fluctuations in the carbonyl carbonoxygen bond lengths were observed. AIMD simulations of a two-electron attack on EC in EC liquid and on Li metal surfaces yielded products similar to those predicted using nonhybrid DFT functionals, except that CO release did not occur for all attempted initial configurations in the liquid state.

  16. Electron dynamics of the buffer layer and bilayer graphene on SiC

    SciTech Connect (OSTI)

    Shearer, Alex J.; Caplins, Benjamin W.; Suich, David E.; Harris, Charles B., E-mail: cbharris@berkeley.edu [Department of Chemistry, University of California at Berkeley, Berkeley, California 94720 (United States); Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Johns, James E. [Department of Chemistry, University of Minnesota Twin Cities, Minneapolis, Minnesota 55455 (United States); Hersam, Mark C. [Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208 (United States); Department of Chemistry, Northwestern University, Evanston, Illinois 60208 (United States)

    2014-06-09

    Angle- and time-resolved two-photon photoemission (TPPE) was used to investigate electronic states in the buffer layer of 4H-SiC(0001). An image potential state (IPS) series was observed on this strongly surface-bound buffer layer, and dispersion measurements indicated free-electron-like behavior for all states in this series. These results were compared with TPPE taken on bilayer graphene, which also show the existence of a free-electron-like IPS series. Lifetimes for the n?=?2, and n?=?3 states were obtained from time-resolved TPPE; slightly increased lifetimes were observed in the bilayer graphene sample for the n?=?2 the n?=?3 states. Despite the large band gap of graphene at the center of the Brillouin zone, the lifetime results demonstrate that the graphene layers do not behave as a simple tunneling barrier, suggesting that the buffer layer and graphene overlayers play a direct role in the decay of IPS electrons.

  17. Communication: Quantum molecular dynamics simulation of liquid para-hydrogen by nuclear and electron wave packet approach

    SciTech Connect (OSTI)

    Hyeon-Deuk, Kim; Ando, Koji

    2014-05-07

    Liquid para-hydrogen (p-H{sub 2}) is a typical quantum liquid which exhibits strong nuclear quantum effects (NQEs) and thus anomalous static and dynamic properties. We propose a real-time simulation method of wave packet (WP) molecular dynamics (MD) based on non-empirical intra- and inter-molecular interactions of non-spherical hydrogen molecules, and apply it to condensed-phase p-H{sub 2}. The NQEs, such as WP delocalization and zero-point energy, are taken into account without perturbative expansion of prepared model potential functions but with explicit interactions between nuclear and electron WPs. The developed MD simulation for 100 ps with 1200 hydrogen molecules is realized at feasible computational cost, by which basic experimental properties of p-H{sub 2} liquid such as radial distribution functions, self-diffusion coefficients, and shear viscosities are all well reproduced.

  18. Electron beam dynamics in the long-pulse, high-current DARHT-II linear induction accelerator

    SciTech Connect (OSTI)

    Ekdahl, Carl A; Abeyta, Epifanio O; Aragon, Paul; Archuleta, Rita; Cook, Gerald; Dalmas, Dale; Esquibel, Kevin; Gallegos, Robert A; Garnett, Robert; Harrison, James F; Johnson, Jeffrey B; Jacquez, Edward B; Mccuistian, Brian T; Montoya, Nicholas A; Nath, Subrato; Nielsen, Kurt; Oro, David; Prichard, Benjamin; Rowton, Lawrence; Sanchez, Manolito; Scarpetti, Raymond; Schauer, Martin M; Seitz, Gerald; Schulze, Martin; Bender, Howard A; Broste, William B; Carlson, Carl A; Frayer, Daniel K; Johnson, Douglas E; Tom, C Y; Williams, John; Hughes, Thomas; Anaya, Richard; Caporaso, George; Chambers, Frank; Chen, Yu - Jiuan; Falabella, Steve; Guethlein, Gary; Raymond, Brett; Richardson, Roger; Trainham, C; Weir, John; Genoni, Thomas; Toma, Carsten

    2009-01-01

    The DARHT-II linear induction accelerator (LIA) now accelerates 2-kA electron beams to more than 17 MeV. This LIA is unique in that the accelerated current pulse width is greater than 2 microseconds. This pulse has a flat-top region where the final electron kinetic energy varies by less than 1% for more than 1.5 microseconds. The long risetime of the 6-cell injector current pulse is 0.5 {micro}s, which can be scraped off in a beam-head cleanup zone before entering the 68-cell main accelerator. We discuss our experience with tuning this novel accelerator; and present data for the resulting beam transport and dynamics. We also present beam stability data, and relate these to previous stability experiments at lower current and energy.

  19. Electron dynamics and plasma jet formation in a helium atmospheric pressure dielectric barrier discharge jet

    SciTech Connect (OSTI)

    Algwari, Q. Th.; O'Connell, D.

    2011-09-19

    The excitation dynamics within the main plasma production region and the plasma jets of a kHz atmospheric pressure dielectric barrier discharge (DBD) jet operated in helium was investigated. Within the dielectric tube, the plasma ignites as a streamer-type discharge. Plasma jets are emitted from both the powered and grounded electrode end; their dynamics are compared and contrasted. Ignition of these jets are quite different; the jet emitted from the powered electrode is ignited with a slight time delay to plasma ignition inside the dielectric tube, while breakdown of the jet at the grounded electrode end is from charging of the dielectric and is therefore dependent on plasma production and transport within the dielectric tube. Present streamer theories can explain these dynamics.

  20. Beam dynamics study of a 30 MeV electron linear accelerator to drive a neutron source

    SciTech Connect (OSTI)

    Kumar, Sandeep; Yang, Haeryong; Kang, Heung-Sik

    2014-02-14

    An experimental neutron facility based on 32 MeV/18.47 kW electron linac has been studied by means of PARMELA simulation code. Beam dynamics study for a traveling wave constant gradient electron accelerator is carried out to reach the preferential operation parameters (E = 30 MeV, P = 18 kW, dE/E < 12.47% for 99% particles). The whole linac comprises mainly E-gun, pre-buncher, buncher, and 2 accelerating columns. A disk-loaded, on-axis-coupled, 2π/3-mode type accelerating rf cavity is considered for this linac. After numerous optimizations of linac parameters, 32 MeV beam energy is obtained at the end of the linac. As high electron energy is required to produce acceptable neutron flux. The final neutron flux is estimated to be 5 × 10{sup 11} n/cm{sup 2}/s/mA. Future development will be the real design of a 30 MeV electron linac based on S band traveling wave.

  1. The density matrix functional approach to electron correlation: Dynamic and nondynamic correlation along the full dissociation coordinate

    SciTech Connect (OSTI)

    Mentel, ?. M.; Meer, R. van; Gritsenko, O. V.; Baerends, E. J.

    2014-06-07

    For chemistry an accurate description of bond weakening and breaking is vital. The great advantage of density matrix functionals, as opposed to density functionals, is their ability to describe such processes since they naturally cover both nondynamical and dynamical correlation. This is obvious in the Lwdin-Shull functional, the exact natural orbital functional for two-electron systems. We present in this paper extensions of this functional for the breaking of a single electron pair bond in N-electron molecules, using LiH, BeH{sup +}, and Li{sub 2} molecules as prototypes. Attention is given to the proper formulation of the functional in terms of not just J and K integrals but also the two-electron L integrals (K integrals with a different distribution of the complex conjugation of the orbitals), which is crucial for the calculation of response functions. Accurate energy curves are obtained with extended Lwdin-Shull functionals along the complete dissociation coordinate using full CI calculations as benchmark.

  2. High-speed multi-frame dynamic transmission electron microscope image acquisition system with arbitrary timing

    DOE Patents [OSTI]

    Reed, Bryan W.; DeHope, William J.; Huete, Glenn; LaGrange, Thomas B.; Shuttlesworth, Richard M.

    2016-02-23

    An electron microscope is disclosed which has a laser-driven photocathode and an arbitrary waveform generator (AWG) laser system ("laser"). The laser produces a train of temporally-shaped laser pulses each being of a programmable pulse duration, and directs the laser pulses to the laser-driven photocathode to produce a train of electron pulses. An image sensor is used along with a deflector subsystem. The deflector subsystem is arranged downstream of the target but upstream of the image sensor, and has a plurality of plates. A control system having a digital sequencer controls the laser and a plurality of switching components, synchronized with the laser, to independently control excitation of each one of the deflector plates. This allows each electron pulse to be directed to a different portion of the image sensor, as well as to enable programmable pulse durations and programmable inter-pulse spacings.

  3. High-speed multiframe dynamic transmission electron microscope image acquisition system with arbitrary timing

    DOE Patents [OSTI]

    Reed, Bryan W.; DeHope, William J.; Huete, Glenn; LaGrange, Thomas B.; Shuttlesworth, Richard M.

    2015-10-20

    An electron microscope is disclosed which has a laser-driven photocathode and an arbitrary waveform generator (AWG) laser system ("laser"). The laser produces a train of temporally-shaped laser pulses of a predefined pulse duration and waveform, and directs the laser pulses to the laser-driven photocathode to produce a train of electron pulses. An image sensor is used along with a deflector subsystem. The deflector subsystem is arranged downstream of the target but upstream of the image sensor, and has two pairs of plates arranged perpendicular to one another. A control system controls the laser and a plurality of switching components synchronized with the laser, to independently control excitation of each one of the deflector plates. This allows each electron pulse to be directed to a different portion of the image sensor, as well as to be provided with an independently set duration and independently set inter-pulse spacings.

  4. Electron-ion plasma dynamics in the presence of highly charged dust-clusters

    SciTech Connect (OSTI)

    Djebli, Mourad Benkhelifa, El-Amine

    2015-05-15

    Electron-ion plasma expansion is studied in the presence of positively (negatively) highly charged uniformly distributed dust particles, considered as impurities. For that purpose, a multi-fluid model is used, where the charged impurities characteristics are included in Poisson's equation. We found that ion acceleration is enhanced by the presence of positively charged dust. The latter leads to spiky structures in the ion front which have a higher amplitude as the charge increases. The charged impurities have a significant effect when the combination of their charge and density is greater than a critical value which depends on ion to electron temperature ratio.

  5. Tunable mega-ampere electron current propagation in solids by dynamic control of lattice melt

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

    MacLellan, D.  A.; Carroll, D.  C.; Gray, R.  J.; Booth, N.; Burza, M.; Desjarlais, M.  P.; Du, F.; Neely, D.; Powell, H.  W.; Robinson, A.  P. L.; et al

    2014-10-31

    The influence of lattice-melt-induced resistivity gradients on the transport of mega-ampere currents of fast electrons in solids is investigated numerically and experimentally using laser-accelerated protons to induce isochoric heating. Tailoring the heating profile enables the resistive magnetic fields which strongly influence the current propagation to be manipulated. This tunable laser-driven process enables important fast electron beam properties, including the beam divergence, profile, and symmetry to be actively tailored, and without recourse to complex target manufacture.

  6. The structural, electronic and dynamic properties of the L1{sub 2}- type Co{sub 3}Ti alloy

    SciTech Connect (OSTI)

    Arikan, Nihat; zduran, Mustafa

    2014-10-06

    The structural, electronic and dynamic properties of the cubic Co{sub 3}Ti alloy in L1{sub 2} structure have been investigated using a pseudopotential plane wave (PP-PW) method within the generalized gradient approximation proposed by PerdewBurkeErnzerhof (GGA-PBE). The structural properties, including the lattice constant, the bulk modulus and its pressure derivative agree reasonably with the previous results. The density of state (DOS), projected density of state (PDOS) and electronic band structure are also reported. The DOS shows that Co{sub 3}Ti alloy has a metallic character since the energy bands cross the Fermi level. The density of states at Fermi level mainly comes from the Co-3d states. Phonon dispersion curves and their corresponding total densities of states were obtained using a linear response in the framework of the density functional perturbation theory. All computed phonon frequencies are no imaginer and thus, Co{sub 3}Ti alloy is dynamically stable. The zone center phonon modes have been founded to be 9.307, 9.626 and 13.891 THz for Co{sub 3}Ti.

  7. ITP Aluminum: Aluminum Industry Vision: Sustainable Solutions...

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

    Aluminum Industry Vision: Sustainable Solutions for a Dynamic World ITP Aluminum: Aluminum Industry Vision: Sustainable Solutions for a Dynamic World alumvision.pdf (938.86 KB) ...

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

    SciTech Connect (OSTI)

    Hong Qin and Ronald C. Davidson

    2011-07-19

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

  9. Solving the Accelerator-Condenser Coupling Problem in a Nanosecond Dynamic Transmission Electron Microscope

    SciTech Connect (OSTI)

    Reed, B W; LaGrange, T; Shuttlesworth, R M; Gibson, D J; Campbell, G H; Browning, N D

    2009-12-29

    We describe a modification to a transmission electron microscope (TEM) that allows it to briefly (using a pulsed-laser-driven photocathode) operate at currents in excess of 10 mA while keeping the effects of condenser lens aberrations to a minimum. This modification allows real-space imaging of material microstructure with a resolution of order 10 nm over regions several {micro}m across with an exposure time of 15 ns. This is more than 6 orders of magnitude faster than typical video-rate TEM imaging. The key is the addition of a weak magnetic lens to couple the large-diameter high-current beam exiting the accelerator into the acceptance aperture of a conventional TEM condenser lens system. We show that the performance of the system is essentially consistent with models derived from ray tracing and finite element simulations. The instrument can also be operated as a conventional TEM by using the electron gun in a thermionic mode. The modification enables very high electron current densities in {micro}m-sized areas and could also be used in a non-pulsed system for high-throughput imaging and analytical TEM.

  10. Laser-to-hot-electron conversion limitations in relativistic laser matter interactions due to multi-picosecond dynamics

    SciTech Connect (OSTI)

    Schollmeier, Marius; Sefkow, Adam B.; Geissel, Matthias; Arefiev, Alexey V.; Flippo, Kirk A.; Gaillard, Sandrine A.; Johnson, Randy P.; Kimmel, Mark W.; Offermann, Dustin T.; Rambo, Patrick K.; Schwarz, Jens; Shimada, Tom

    2015-04-20

    High-energy short-pulse lasers are pushing the limits of plasma-based particle acceleration, x-ray generation, and high-harmonic generation by creating strong electromagnetic fields at the laser focus where electrons are being accelerated to relativistic velocities. Understanding the relativistic electron dynamics is key for an accurate interpretation of measurements. We present a unified and self-consistent modeling approach in quantitative agreement with measurements and differing trends across multiple target types acquired from two separate laser systems, which differ only in their nanosecond to picosecond-scale rising edge. Insights from high-fidelity modeling of laser-plasma interaction demonstrate that the ps-scale, orders of magnitude weaker rising edge of the main pulse measurably alters target evolution and relativistic electron generation compared to idealized pulse shapes. This can lead for instance to the experimentally observed difference between 45 MeV and 75 MeV maximum energy protons for two nominally identical laser shots, due to ps-scale prepulse variations. Our results indicate that the realistic inclusion of temporal laser pulse profiles in modeling efforts is required if predictive capability and extrapolation are sought for future target and laser designs or for other relativistic laser ion acceleration schemes.

  11. Laser-to-hot-electron conversion limitations in relativistic laser matter interactions due to multi-picosecond dynamics

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

    Schollmeier, Marius; Sefkow, Adam B.; Geissel, Matthias; Arefiev, Alexey V.; Flippo, Kirk A.; Gaillard, Sandrine A.; Johnson, Randy P.; Kimmel, Mark W.; Offermann, Dustin T.; Rambo, Patrick K.; et al

    2015-04-20

    High-energy short-pulse lasers are pushing the limits of plasma-based particle acceleration, x-ray generation, and high-harmonic generation by creating strong electromagnetic fields at the laser focus where electrons are being accelerated to relativistic velocities. Understanding the relativistic electron dynamics is key for an accurate interpretation of measurements. We present a unified and self-consistent modeling approach in quantitative agreement with measurements and differing trends across multiple target types acquired from two separate laser systems, which differ only in their nanosecond to picosecond-scale rising edge. Insights from high-fidelity modeling of laser-plasma interaction demonstrate that the ps-scale, orders of magnitude weaker rising edge ofmore » the main pulse measurably alters target evolution and relativistic electron generation compared to idealized pulse shapes. This can lead for instance to the experimentally observed difference between 45 MeV and 75 MeV maximum energy protons for two nominally identical laser shots, due to ps-scale prepulse variations. Our results indicate that the realistic inclusion of temporal laser pulse profiles in modeling efforts is required if predictive capability and extrapolation are sought for future target and laser designs or for other relativistic laser ion acceleration schemes.« less

  12. Laser-to-hot-electron conversion limitations in relativistic laser matter interactions due to multi-picosecond dynamics

    SciTech Connect (OSTI)

    Schollmeier, M.; Sefkow, A. B.; Geissel, M.; Kimmel, M. W.; Rambo, P. K.; Schwarz, J.; Arefiev, A. V.; Flippo, K. A.; Johnson, R. P.; Shimada, T.; Gaillard, S. A.; Offermann, D. T.

    2015-04-15

    High-energy short-pulse lasers are pushing the limits of plasma-based particle acceleration, x-ray generation, and high-harmonic generation by creating strong electromagnetic fields at the laser focus where electrons are being accelerated to relativistic velocities. Understanding the relativistic electron dynamics is key for an accurate interpretation of measurements. We present a unified and self-consistent modeling approach in quantitative agreement with measurements and differing trends across multiple target types acquired from two separate laser systems, which differ only in their nanosecond to picosecond-scale rising edge. Insights from high-fidelity modeling of laser-plasma interaction demonstrate that the ps-scale, orders of magnitude weaker rising edge of the main pulse measurably alters target evolution and relativistic electron generation compared to idealized pulse shapes. This can lead for instance to the experimentally observed difference between 45 MeV and 75 MeV maximum energy protons for two nominally identical laser shots, due to ps-scale prepulse variations. Our results show that the realistic inclusion of temporal laser pulse profiles in modeling efforts is required if predictive capability and extrapolation are sought for future target and laser designs or for other relativistic laser ion acceleration schemes.

  13. Combining nanocalorimetry and dynamic transmission electron microscopy for in situ characterization of materials processes under rapid heating and cooling

    SciTech Connect (OSTI)

    Grapes, Michael D.; LaGrange, Thomas; Reed, Bryan W.; Campbell, Geoffrey H.; Friedman, Lawrence H.; LaVan, David A.; Weihs, Timothy P.

    2014-08-15

    Nanocalorimetry is a chip-based thermal analysis technique capable of analyzing endothermic and exothermic reactions at very high heating and cooling rates. Here, we couple a nanocalorimeter with an extremely fast in situ microstructural characterization tool to identify the physical origin of rapid enthalpic signals. More specifically, we describe the development of a system to enable in situ nanocalorimetry experiments in the dynamic transmission electron microscope (DTEM), a time-resolved TEM capable of generating images and electron diffraction patterns with exposure times of 30 ns500 ns. The full experimental system consists of a modified nanocalorimeter sensor, a custom-built in situ nanocalorimetry holder, a data acquisition system, and the DTEM itself, and is capable of thermodynamic and microstructural characterization of reactions over a range of heating rates (10{sup 2} K/s10{sup 5} K/s) accessible by conventional (DC) nanocalorimetry. To establish its ability to capture synchronized calorimetric and microstructural data during rapid transformations, this work describes measurements on the melting of an aluminum thin film. We were able to identify the phase transformation in both the nanocalorimetry traces and in electron diffraction patterns taken by the DTEM. Potential applications for the newly developed system are described and future system improvements are discussed.

  14. Probing the Degradation Mechanisms in Electrolyte Solutions for Li-ion Batteries by In-Situ Transmission Electron Microscopy

    SciTech Connect (OSTI)

    Abellan Baeza, Patricia; Mehdi, Beata L.; Parent, Lucas R.; Gu, Meng; Park, Chiwoo; Xu, Wu; Zhang, Yaohui; Arslan, Ilke; Zhang, Jiguang; Wang, Chong M.; Evans, James E.; Browning, Nigel D.

    2014-02-21

    One of the goals in the development of new battery technologies is to find new electrolytes with increased electrochemical stability. In-situ (scanning) transmission electron microscopy ((S)TEM) using an electrochemical fluid cell provides the ability to rapidly and directly characterize electrode/electrolyte interfacial reactions under battery relevant electrochemical conditions. Furthermore, as the electron beam itself causes a localized electrochemical reaction when it interacts with the electrolyte, the breakdown products that occur during the first stages of battery operation can potentially be simulated and characterized using a straightforward in-situ liquid stage (without electrochemical biasing capabilities). In this paper, we have studied the breakdown of a range of inorganic/salt complexes that are used in state-of-the-art Li-ion battery systems. The results of the in-situ (S)TEM experiments matches with previous stability tests performed during battery operation and the breakdown products and mechanisms are also consistent with known mechanisms. This analysis indicates that in-situ liquid stage (S)TEM observations can be used to directly test new electrolyte designs and provide structural insights into the origin of the solid electrolyte interphase (SEI) formation mechanism.

  15. Electronic structure and optical properties of ?-(Fe1-xVx)2O3 solid-solution thin films

    SciTech Connect (OSTI)

    Chamberlin, Sara E.; Nayyar, Iffat H.; Kaspar, Tiffany C.; Sushko, Petr; Chambers, Scott A.

    2015-01-26

    We have examined the effect of V doping on the electronic and optical properties of hematite (?-Fe2O3) by means of ?-(Fe1-xVx)2O3 (0 ? x ? ~0.5) epitaxial films and theoretical modeling. The conductivity is enhanced by several orders of magnitude as x is increased, and this enhancement is manifested in x-ray photoelectron spectra by a growing Doniach-Sunjic tail on the O 1s peak, as well as by increasing intensity at the Fermi level in valence band spectra. Optical absorption shows a reduction in direct band gap by as much as 0.64 eV for x = 0.53 (Eg = 1.46 eV) relative to that of ?-Fe2O3 (Eg = 2.10 eV). Detailed understanding of the character of the optical transitions in the alloys is achieved using first-principles calculations of the ground and excited states. These calculations reveal that V doping results in localized, occupied V 3d states which are hybridized with Fe states and located at approximately mid-gap in ? Fe2O3. The lowest energy transitions involve electronic excitations from occupied V 3d orbitals to unoccupied Fe 3d* orbitals.

  16. High-resolution transmission electron microscopy study of carbon deposited on the NiO/MgO solid solution catalysts

    SciTech Connect (OSTI)

    Hu, Y.H.; Ruckenstein, E.

    1999-05-15

    The carbon deposition due to the CH{sub 4} decomposition at 790 C over NiO/MgO catalysts was investigated by high-resolution transmission electron microscopy. While no deposits could be detected over the catalysts with a NiO content smaller than 9.1 wt%, they were detected over the catalysts with NiO contents of 23 and 50 wt%. The carbon deposits are composed of platelets located at distances of about 0.34 nm, corresponding to the graphitic carbon. Various structures of the deposited carbon were observed: (a) carbon consisting of platelets parallel to the surface of the particle, which covers a catalyst particle, (b) nanotubes composed of platelets parallel to their axis, and (c) carbon vortexes consisting of platelets parallel to their axis.

  17. Gas mixing system for imaging of nanomaterials under dynamic environments by environmental transmission electron microscopy

    SciTech Connect (OSTI)

    Akatay, M. Cem; Zvinevich, Yury; Ribeiro, Fabio H. E-mail: estach@bnl.gov; Baumann, Philipp; Stach, Eric A. E-mail: estach@bnl.gov

    2014-03-15

    A gas mixing manifold system that is capable of delivering a stable pressure stream of a desired composition of gases into an environmental transmission electron microscope has been developed. The system is designed to provide a stable imaging environment upon changes of either the composition of the gas mixture or upon switching from one gas to another. The design of the system is described and the response of the pressure inside the microscope, the sample temperature, and sample drift in response to flow and composition changes of the system are reported.

  18. Lithium electrodeposition dynamics in aprotic electrolyte observed in situ via transmission electron microscopy

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

    Leenheer, Andrew Jay; Jungjohann, Katherine Leigh; Zavadil, Kevin Robert; Sullivan, John P.; Harris, Charles Thomas

    2015-03-18

    Electrodeposited metallic lithium is an ideal negative battery electrode, but nonuniform microstructure evolution during cycling leads to degradation and safety issues. A better understanding of the Li plating and stripping processes is needed to enable practical Li-metal batteries. Here we use a custom microfabricated, sealed liquid cell for in situ scanning transmission electron microscopy (STEM) to image the first few cycles of lithium electrodeposition/dissolution in liquid aprotic electrolyte at submicron resolution. Cycling at current densities from 1 to 25 mA/cm2 leads to variations in grain structure, with higher current densities giving a more needle-like, higher surface area deposit. The effectmore » of the electron beam was explored, and it was found that, even with minimal beam exposure, beam-induced surface film formation could alter the Li microstructure. The electrochemical dissolution was seen to initiate from isolated points on grains rather than uniformly across the Li surface, due to the stabilizing solid electrolyte interphase surface film. As a result, we discuss the implications for operando STEM liquid-cell imaging and Li-battery applications.« less

  19. Measurement of dynamic patterns of an elastic membrane at bi-modal vibration using high speed electronic speckle pattern interferometry

    SciTech Connect (OSTI)

    Preciado, Jorge Sanchez; Lopez, Carlos Perez; Santoyo, Fernando Mendoza

    2014-05-27

    Implementing a hybrid arrangement of Laser Doppler Vibrometry (LDV) and high speed Electronic Speckle Pattern Interferometry (ESPI) we were able to measure the dynamic patterns of a flat rectangular elastic membrane clamped at its edges stimulated with the sum of two resonance frequencies. ESPI is a versatile technique to analyze in real-time the deformation of a membrane since its low computational cost and easy implementation of the optical setup. Elastic membranes present nonlinear behaviors when stimulated with low amplitude signals. The elastic membrane under test, with several non rational related vibrating modals below the 200 Hz, was stimulated with two consecutives resonant frequencies. The ESPI patterns, acquired at high speed rates, shown a similar behavior for the dual frequency stimulation as in the case of patterns formed with the entrainment frequency. We think this may be related to the effects observed in the application of dual frequency stimulation in ultrasound.

  20. Dynamic

    Office of Legacy Management (LM)

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  1. Kinetics of liquid-mediated crystallization of amorphous Ge from multi-frame dynamic transmission electron microscopy

    SciTech Connect (OSTI)

    Santala, M. K. Campbell, G. H.; Raoux, S.

    2015-12-21

    The kinetics of laser-induced, liquid-mediated crystallization of amorphous Ge thin films were studied using multi-frame dynamic transmission electron microscopy (DTEM), a nanosecond-scale photo-emission transmission electron microscopy technique. In these experiments, high temperature gradients are established in thin amorphous Ge films with a 12-ns laser pulse with a Gaussian spatial profile. The hottest region at the center of the laser spot crystallizes in ∼100 ns and becomes nano-crystalline. Over the next several hundred nanoseconds crystallization continues radially outward from the nano-crystalline region forming elongated grains, some many microns long. The growth rate during the formation of these radial grains is measured with time-resolved imaging experiments. Crystal growth rates exceed 10 m/s, which are consistent with crystallization mediated by a very thin, undercooled transient liquid layer, rather than a purely solid-state transformation mechanism. The kinetics of this growth mode have been studied in detail under steady-state conditions, but here we provide a detailed study of liquid-mediated growth in high temperature gradients. Unexpectedly, the propagation rate of the crystallization front was observed to remain constant during this growth mode even when passing through large local temperature gradients, in stark contrast to other similar studies that suggested the growth rate changed dramatically. The high throughput of multi-frame DTEM provides gives a more complete picture of the role of temperature and temperature gradient on laser crystallization than previous DTEM experiments.

  2. Kinetics of liquid-mediated crystallization of amorphous Ge from multi-frame dynamic transmission electron microscopy

    SciTech Connect (OSTI)

    Santala, M. K.; Raoux, S.; Campbell, G. H.

    2015-12-24

    The kinetics of laser-induced, liquid-mediated crystallization of amorphous Ge thin films were studied using multi-frame dynamic transmission electron microscopy (DTEM), a nanosecond-scale photo-emission transmission electron microscopy technique. In these experiments, high temperature gradients are established in thin amorphous Ge films with a 12-ns laser pulse with a Gaussian spatial profile. The hottest region at the center of the laser spot crystallizes in ~100 ns and becomes nano-crystalline. Over the next several hundred nanoseconds crystallization continues radially outward from the nano-crystalline region forming elongated grains, some many microns long. The growth rate during the formation of these radial grains is measured with time-resolved imaging experiments. Crystal growth rates exceed 10 m/s, which are consistent with crystallization mediated by a very thin, undercooled transient liquid layer, rather than a purely solid-state transformation mechanism. The kinetics of this growth mode have been studied in detail under steady-state conditions, but here we provide a detailed study of liquid-mediated growth in high temperature gradients. Unexpectedly, the propagation rate of the crystallization front was observed to remain constant during this growth mode even when passing through large local temperature gradients, in stark contrast to other similar studies that suggested the growth rate changed dramatically. As a result, the high throughput of multi-frame DTEM provides gives a more complete picture of the role of temperature and temperature gradient on laser crystallization than previous DTEM experiments.

  3. Optimizing a dynamical decoupling protocol for solid-state electronic spin ensembles in diamond

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

    Farfurnik, D.; Jarmola, A.; Pham, L. M.; Wang, Z. H.; Dobrovitski, V. V.; Walsworth, R. L.; Budker, D.; Bar-Gill, N.

    2015-08-24

    In this study, we demonstrate significant improvements of the spin coherence time of a dense ensemble of nitrogen-vacancy (NV) centers in diamond through optimized dynamical decoupling (DD). Cooling the sample down to 77 K suppresses longitudinal spin relaxation T1 effects and DD microwave pulses are used to increase the transverse coherence time T2 from ~0.7ms up to ~30ms. Furthermore, we extend previous work of single-axis (Carr-Purcell-Meiboom-Gill) DD towards the preservation of arbitrary spin states. Following a theoretical and experimental characterization of pulse and detuning errors, we compare the performance of various DD protocols. We also identify that the optimal controlmore » scheme for preserving an arbitrary spin state is a recursive protocol, the concatenated version of the XY8 pulse sequence. The improved spin coherence might have an immediate impact on improvements of the sensitivities of ac magnetometry. Moreover, the protocol can be used on denser diamond samples to increase coherence times up to NV-NV interaction time scales, a major step towards the creation of quantum collective NV spin states.« less

  4. Optimizing a dynamical decoupling protocol for solid-state electronic spin ensembles in diamond

    SciTech Connect (OSTI)

    Farfurnik, D.; Jarmola, A.; Pham, L. M.; Wang, Z. H.; Dobrovitski, V. V.; Walsworth, R. L.; Budker, D.; Bar-Gill, N.

    2015-08-24

    In this study, we demonstrate significant improvements of the spin coherence time of a dense ensemble of nitrogen-vacancy (NV) centers in diamond through optimized dynamical decoupling (DD). Cooling the sample down to 77 K suppresses longitudinal spin relaxation T1 effects and DD microwave pulses are used to increase the transverse coherence time T2 from ~0.7ms up to ~30ms. Furthermore, we extend previous work of single-axis (Carr-Purcell-Meiboom-Gill) DD towards the preservation of arbitrary spin states. Following a theoretical and experimental characterization of pulse and detuning errors, we compare the performance of various DD protocols. We also identify that the optimal control scheme for preserving an arbitrary spin state is a recursive protocol, the concatenated version of the XY8 pulse sequence. The improved spin coherence might have an immediate impact on improvements of the sensitivities of ac magnetometry. Moreover, the protocol can be used on denser diamond samples to increase coherence times up to NV-NV interaction time scales, a major step towards the creation of quantum collective NV spin states.

  5. Ultrafast harmonic rf kicker design and beam dynamics analysis for an energy recovery linac based electron circulator cooler ring

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

    Huang, Yulu; Wang, Haipeng; Rimmer, Robert A.; Wang, Shaoheng; Guo, Jiquan

    2016-08-01

    An ultrafast kicker system is being developed for the energy recovery linac (ERL) based electron circulator cooler ring (CCR) in the proposed Jefferson Lab Electron Ion Collider (JLEIC, previously named MEIC). In the CCR, the injected electron bunches can be recirculated while performing ion cooling for 10–30 turns before the extraction, thus reducing the recirculation beam current in the ERL to 1/10–1/30 (150mA–50 mA) of the cooling beam current (up to 1.5 A). Assuming a bunch repetition rate of 476.3 MHz and a recirculating factor of 10 in the CCR, the kicker is required to operate at a pulse repetitionmore » rate of 47.63 MHz with pulse width of around 2 ns, so that only every 10th bunch in the CCR will experience a transverse kick while the rest of the bunches will not be disturbed. Such a kicker pulse can be synthesized by ten harmonic modes of the 47.63 MHz kicker pulse repetition frequency, using up to four quarter wavelength resonator (QWR) based deflecting cavities. In this paper, several methods to synthesize such a kicker waveform will be discussed and a comparison of their beam dynamics performance is made using ELEGANT. Four QWR cavities are envisaged with high transverse shunt impedance requiring less than 100 W of total rf power for a Flat-Top kick pulse. Multipole fields due to the asymmetry of this type of cavity are analyzed. The transverse emittance growth due to the sextupole component is simulated in ELEGANT. In conclusion, off-axis injection and extraction issues and beam optics using a multicavity kick-drift scheme will also be discussed.« less

  6. Time-resolved THz studies of carrier dynamics in semiconductors, superconductors, and strongly-correlated electron materials

    SciTech Connect (OSTI)

    Kaindl, Robert A.; Averitt, Richard D.

    2006-11-14

    materials occur at lower energies. The terahertz (THz) regime is particularly rich in such fundamental resonances. This includes ubiquitous lattice vibrations and low-energy collective oscillations of conduction charges. In nanoscale materials, band structure quantization also yields novel infrared and THz transitions, including intersubband absorption in quantum wells. The formation of excitons in turn leads to low-energy excitations analogous to inter-level transitions in atoms. In transition-metal oxides, fundamental excitation gaps arise from charge pairing into superconducting condensates and other correlated states. This motivates the use of ultrafast THz spectroscopy as a powerful tool to study light-matter interactions and microscopic processes in nanoscale and correlated-electron materials.A distinct advantage of coherent THz pulses is that the amplitude and phase of the electric field can be measured directly, as the THz fields are coherent with the fs pulses from which they are generated. Using THz time-domain spectroscopy (THz-TDS), both the real and imaginary parts of the response functions (such as the dielectric function) are obtained directly without the need for Kramers?Kronig transforms. The THz response can also be expressed in terms of absorption and refractive index, or as the optical conductivity. The optical conductivity describes the current response of a many-body system to an electric field, an ideal tool to study conducting systems. A second important advantage is the ultrafast time resolution that results from the short temporal duration of the THz time-domain sources. In particular, optical-pump THz-probe spectroscopy enables a delicate probe of the transient THz conductivity after optical photoexcitation. These experiments can provide insight into quasiparticle interactions, phase transitions, or nonequilibrium dynamics. In this chapter we will provide many such examples. Since THz spectroscopy of solids is a quickly expanding field

  7. Instrumentation and Beam Dynamics Study of Advanced Electron-Photon Facility in Indiana University

    SciTech Connect (OSTI)

    Luo, Tianhuan; /Indiana U.

    2011-08-01

    The Advanced eLectron-PHoton fAcility (ALPHA) is a compact electron accelerator under construction and being commissioned at the Indiana University Center for Exploration of Energy and Matter (CEEM). In this thesis, we have studied the refurbished Cooler Injector Synchrotron (CIS) RF cavity using both the transmission line model and SUPERFISH simulation. Both low power and high power RF measurements have been carried out to characterize the cavity. Considering the performance limit of ferrite, we have designed a new ferrite loaded, co-axial quarter wave like cavity with similar structure but a more suitable ferrite material. We have also designed a traveling wave stripline kicker for fast extraction by POISSON and Microwave Studio. The strips geometry is trimmed to maximize the uniformity of the kicking field and match the impedance of the power cables. The time response simulation shows the kicker is fast enough for machine operation. The pulsed power supply requirement has also been specified. For the beam diagnosis in the longitudinal direction, we use a wideband Wall Gap Monitor (WGM) served in CIS. With proper shielding and amplification to get good WGM signal, we have characterized the injected and extracted beam signal in single pass commissioning, and also verified the debunching effect of the ALPHA storage ring. A modulation-demodulation signal processing method is developed to measure the current and longitudinal profile of injected beam. By scanning the dipole strength in the injection line, we have reconstructed the tomography of the longitudinal phase space of the LINAC beam. In the accumulation mode, ALPHA will be operated under a low energy and high current condition, where intra beam scattering (IBS) becomes a dominant effect on the beam emittance. A self consistent simulation, including IBS effect, gas scattering and linear coupling, has been carried out to calculate the emittance of the stored beam.

  8. Aggregation behavior of hexaoxyethyleneglycol myristate and hexaoxyethyleneglycol mono (1-methyltridecane) ether and dynamics of their micelles in aqueous solution

    SciTech Connect (OSTI)

    Alami, E.; Zana, R. ); Van Os, N.M.; Jong, B. de; Kerkhof, F.J.M. ); Rupert, L.A.M. )

    1993-10-01

    The title surfactants have similar critical micelle concentrations and cloud temperatures. Their micellar solutions have been investigated by time resolved fluorescence quenching in the range 2--25 c. The micelle aggregation numbers of both surfactants do not differ much, and increase with temperature. Aggregation numbers are large, suggesting anisotropic micelles, and the results show that the micelles are polydisperse. Fast intermicellar exchange of material becomes detectable on the fluorescence timescale ([approximately]1 [mu]s) above T [approx] 10 C, i.e., some 35--40 C below the cloud temperature of the solution. This exchange probably occurs via micelle collisions with temporary merging. Overall the behavior of these two surfactants is very similar to that of the other ethoxylated nonionic surfactants previously examined.

  9. Electron-hole diffusion lengths >175 μm in solution-grown CH3NH3PbI3 single crystals

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

    Dong, Qingfeng; Fang, Yanjun; Shao, Yuchuan; Mulligan, Padhraic; Qiu, Jie; Cao, Lei; Huang, Jinsong

    2015-02-27

    Long, balanced electron and hole diffusion lengths greater than 100 nanometers in the polycrystalline organolead trihalide compound CH3NH3PbI3 are critical for highly efficient perovskite solar cells. We found that the diffusion lengths in CH3NH3PbI3 single crystals grown by a solution-growth method can exceed 175 micrometers under 1 sun (100 mW cm–2) illumination and exceed 3 millimeters under weak light for both electrons and holes. The internal quantum efficiencies approach 100% in 3-millimeter-thick single-crystal perovskite solar cells under weak light. These long diffusion lengths result from greater carrier mobility, longer lifetime, and much smaller trap densities in the single crystals thanmore » in polycrystalline thin films. As a result, the long carrier diffusion lengths enabled the use of CH3NH3PbI3 in radiation sensing and energy harvesting through the gammavoltaic effect, with an efficiency of 3.9% measured with an intense cesium-137 source.« less

  10. Electron-hole diffusion lengths >175 μm in solution-grown CH3NH3PbI3 single crystals

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

    Dong, Qingfeng; Fang, Yanjun; Shao, Yuchuan; Mulligan, Padhraic; Qiu, Jie; Cao, Lei; Huang, Jinsong

    2015-02-27

    Long, balanced electron and hole diffusion lengths greater than 100 nanometers in the polycrystalline organolead trihalide compound CH3NH3PbI3 are critical for highly efficient perovskite solar cells. We found that the diffusion lengths in CH3NH3PbI3 single crystals grown by a solution-growth method can exceed 175 micrometers under 1 sun (100 mW cm–2) illumination and exceed 3 millimeters under weak light for both electrons and holes. The internal quantum efficiencies approach 100% in 3-millimeter-thick single-crystal perovskite solar cells under weak light. These long diffusion lengths result from greater carrier mobility, longer lifetime, and much smaller trap densities in the single crystals thanmore »in polycrystalline thin films. As a result, the long carrier diffusion lengths enabled the use of CH3NH3PbI3 in radiation sensing and energy harvesting through the gammavoltaic effect, with an efficiency of 3.9% measured with an intense cesium-137 source.« less

  11. Multi-satellite simultaneous observations of magnetopause and atmospheric losses of radiation belt electrons during an intense solar wind dynamic pressure pulse

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

    Xiang, Zheng; Ni, Binbin; Zhou, Chen; Zou, Zhengyang; Gu, Xudong; Zhao, Zhengyu; Zhang, Xianguo; Zhang, Xiaoxin; Zhang, Shenyi; Li, Xinlin; et al

    2016-05-03

    Radiation belt electron flux dropouts are a kind of drastic variation in the Earth's magnetosphere, understanding of which is of both scientific and societal importance. We report multi-satellite simultaneous observations of magnetopause and atmospheric losses of radiation belt electrons during an event of intense solar wind dynamic pressure pulse, using electron flux data from a group of 14 satellites. Moreover, when the pulse occurred, magnetopause and atmospheric loss could take effect concurrently contributing to the electron flux dropout. Losses through the magnetopause were observed to be efficient and significant at L ≳ 5, owing to the magnetopause intrusion into Lmore » ~6 and outward radial diffusion associated with sharp negative gradient in electron phase space density. Losses to the atmosphere were directly identified from the precipitating electron flux observations, for which pitch angle scattering by plasma waves could be mainly responsible. While the convection and substorm injections strongly enhanced the energetic electron fluxes up to hundreds of keV, they could delay other than avoid the occurrence of electron flux dropout at these energies. Finally, we demonstrate that the pulse-time radiation belt electron flux dropout depends strongly on the specific interplanetary and magnetospheric conditions and that losses through the magnetopause and to the atmosphere and enhancements of substorm injection play an essential role in combination, which should be incorporated as a whole into future simulations for comprehending the nature of radiation belt electron flux dropouts.« less

  12. A molecular dynamics study of intramolecular proton transfer reaction of malonaldehyde in solutions based upon mixed quantum-classical approximation. I. Proton transfer reaction in water

    SciTech Connect (OSTI)

    Yamada, Atsushi; Kojima, Hidekazu; Okazaki, Susumu

    2014-08-28

    In order to investigate proton transfer reaction in solution, mixed quantum-classical molecular dynamics calculations have been carried out based on our previously proposed quantum equation of motion for the reacting system [A. Yamada and S. Okazaki, J. Chem. Phys. 128, 044507 (2008)]. Surface hopping method was applied to describe forces acting on the solvent classical degrees of freedom. In a series of our studies, quantum and solvent effects on the reaction dynamics in solutions have been analysed in detail. Here, we report our mixed quantum-classical molecular dynamics calculations for intramolecular proton transfer of malonaldehyde in water. Thermally activated proton transfer process, i.e., vibrational excitation in the reactant state followed by transition to the product state and vibrational relaxation in the product state, as well as tunneling reaction can be described by solving the equation of motion. Zero point energy is, of course, included, too. The quantum simulation in water has been compared with the fully classical one and the wave packet calculation in vacuum. The calculated quantum reaction rate in water was 0.70 ps{sup ?1}, which is about 2.5 times faster than that in vacuum, 0.27 ps{sup ?1}. This indicates that the solvent water accelerates the reaction. Further, the quantum calculation resulted in the reaction rate about 2 times faster than the fully classical calculation, which indicates that quantum effect enhances the reaction rate, too. Contribution from three reaction mechanisms, i.e., tunneling, thermal activation, and barrier vanishing reactions, is 33:46:21 in the mixed quantum-classical calculations. This clearly shows that the tunneling effect is important in the reaction.

  13. Kinetics of liquid-mediated crystallization of amorphous Ge from multi-frame dynamic transmission electron microscopy

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

    Santala, M. K.; Raoux, S.; Campbell, G. H.

    2015-12-24

    The kinetics of laser-induced, liquid-mediated crystallization of amorphous Ge thin films were studied using multi-frame dynamic transmission electron microscopy (DTEM), a nanosecond-scale photo-emission transmission electron microscopy technique. In these experiments, high temperature gradients are established in thin amorphous Ge films with a 12-ns laser pulse with a Gaussian spatial profile. The hottest region at the center of the laser spot crystallizes in ~100 ns and becomes nano-crystalline. Over the next several hundred nanoseconds crystallization continues radially outward from the nano-crystalline region forming elongated grains, some many microns long. The growth rate during the formation of these radial grains is measuredmore » with time-resolved imaging experiments. Crystal growth rates exceed 10 m/s, which are consistent with crystallization mediated by a very thin, undercooled transient liquid layer, rather than a purely solid-state transformation mechanism. The kinetics of this growth mode have been studied in detail under steady-state conditions, but here we provide a detailed study of liquid-mediated growth in high temperature gradients. Unexpectedly, the propagation rate of the crystallization front was observed to remain constant during this growth mode even when passing through large local temperature gradients, in stark contrast to other similar studies that suggested the growth rate changed dramatically. As a result, the high throughput of multi-frame DTEM provides gives a more complete picture of the role of temperature and temperature gradient on laser crystallization than previous DTEM experiments.« less

  14. In-situ Study of Dynamic Phenomena at Metal Nanosolder Interfaces Using Aberration Corrected Scanning Transmission Electron Microcopy.

    SciTech Connect (OSTI)

    Lu, Ping

    2014-10-01

    Controlling metallic nanoparticle (NP) interactions plays a vital role in the development of new joining techniques (nanosolder) that bond at lower processing temperatures but remain viable at higher temperatures. The pr imary objective of this project is t o develop a fundamental understanding of the actual reaction processes, associated atomic mechanisms, and the resulting microstructure that occur during thermally - driven bond formation concerning metal - metal nano - scale (<50nm) interfaces. In this LDRD pr oject, we have studied metallic NPs interaction at the elevated temperatures by combining in - situ transmission electron microscopy (TEM ) using an aberration - corrected scanning transmission electron microscope (AC - STEM) and atomic - scale modeling such as m olecular dynamic (MD) simulations. Various metallic NPs such as Ag, Cu and Au are synthesized by chemical routines. Numerous in - situ e xperiments were carried out with focus of the research on study of Ag - Cu system. For the first time, using in - situ STEM he ating experiments , we directly observed t he formation of a 3 - dimensional (3 - D) epitaxial Cu - Ag core - shell nanoparticle during the thermal interaction of Cu and Ag NPs at elevated temperatures (150 - 300 o C). The reaction takes place at temperatures as low as 150 o C and was only observed when care was taken to circumvent the effects of electron beam irradiation during STEM imaging. Atomic - scale modeling verified that the Cu - Ag core - shell structure is energetically favored, and indicated that this phenomenon is a nano - scale effect related to the large surface - to - volume ratio of the NPs. The observation potentially can be used for developing new nanosolder technology that uses Ag shell as the %22glue%22 that stic ks the particles of Cu together. The LDRD has led to several journal publications and numerous conference presentations, and a TA. In addition, we have developed new TEM characterization techniques and phase

  15. Two-photon photodissociation dynamics of H{sub 2}O via the D-tilde electronic state

    SciTech Connect (OSTI)

    Yuan Kaijun; Cheng Lina; Cheng Yuan; Guo Qing; Dai Dongxu; Yang Xueming

    2009-08-21

    Photodissociation dynamics of H{sub 2}O via the D-tilde state by two-photon absorption have been investigated using the H-atom Rydberg tagging time-of-flight technique. The action spectrum of the D-tilde<-X-tilde transition band has been measured. The predissociation lifetime of the D-tilde state is determined to be about 13.5 fs. The quantum state-resolved OH product translational energy distributions and angular distributions have also been measured. By carefully simulating these distributions, quantum state distributions of the OH product as well as the state-resolved angular anisotropy parameters were determined. The most important pathway of the H{sub 2}O dissociation via the D-tilde state leads to the highly rotationally excited OH(X,v=0) products. Vibrationally excited OH(X) products (up to v=10) and electronically excited OH(A,v=0,1,2) have also been observed. The OH(A)/OH(X) branching ratios are determined to be 17.9% at 244.540 nm (2{omega}{sub 1}=81 761.4 cm{sup -1}) and 19.9% at 244.392 nm (2{omega}{sub 2}=81 811 cm{sup -1}), which are considerably smaller than the value predicted by the theory. These discrepancies are attributed to the nonadiabatic coupling effect between the B-tilde and D-tilde surfaces at the bent geometry.

  16. High speed direct imaging of thin metal film ablation by movie-mode dynamic transmission electron microscopy

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

    Hihath, Sahar; Santala, Melissa K.; Cen, Xi; Campbell, Geoffrey; van Benthem, Klaus

    2016-03-11

    Obliteration of matter by pulsed laser beams is not only prevalent in science fiction movies, but finds numerous technological applications ranging from additive manufacturing over machining of micro- and nanostructured features to health care. Pulse lengths ranging from femtoseconds to nanoseconds are utilized at varying laser beam energies and pulse lengths, and enable the removal of nanometric volumes of material. While the mechanisms for removal of material by laser irradiation, i.e., laser ablation, are well understood on the micrometer length scale, it was previously impossible to directly observe obliteration processes on smaller scales due to experimental limitations for the combinationmore » of nanometer spatial and nanosecond temporal resolution. Here, we report the direct observation of metal thin film ablation from a solid substrate through dynamic transmission electron microscopy. Quantitative analysis reveals liquid-phase dewetting of the thin-film, followed by hydrodynamic sputtering of nano- to submicron sized metal droplets. We discovered unexpected fracturing of the substrate due to evolving thermal stresses. This study confirms that hydrodynamic sputtering remains a valid mechanism for droplet expulsion on the nanoscale, while irradiation induced stress fields represent limit laser processing of nanostructured materials. Ultimately, our results allow for improved safety during laser ablation in manufacturing and medical applications.« less

  17. Hydration Shell Structure and Dynamics of Curium(III) in Aqueous Solution: First Principles and Empirical Studies

    SciTech Connect (OSTI)

    Atta-Fynn, Raymond; Bylaska, Eric J.; Schenter, Gregory K.; De Jong, Wibe A.

    2011-05-12

    Results of ab initio molecular dynamics (AIMD), quantum mechanics/molecular mechanics (QM/MM) and classical molecular dynamics (CMD) simulations of Cm3+ in liquid water at a temperature of 300 K are reported. The AIMD simulation was based on the Car-Parrinello MD scheme and GGA-PBE formulation of density functional theory. Two QM/MM simulations were performed by treating Cm3+ and the water molecules in the first shell quantum mechanically using the PBE (QM/MM-PBE) and the hybrid PBE0 density functionals (QM/MM-PBE0). Two CMD simulations were carried out using ab initio derived pair plus three-body potentials (CMD-3B) and empirical Lennard-Jones pair potential (CMD-LJ). The AIMD and QM/MM-PBE simulations predict average first shell hydration numbers of 8, both of which disagree with recent experimental EXAFS and TRLFS value of 9. On the other hand, the average first shell hydration numbers obtained in the QM/MM-PBE0 and CMD simulations was 9, which agrees with experiment. All the simulations predicted a average first shell and second shell Cm-O bond distances of 2.49-2.53 Å and 4.67-4.75 Å respectively, both of which are in fair agreement with corresponding experimental values of 2.45-2.48 Å and 4.65 Å. The average geometric arrangement of the eight-fold and nine-fold coordinated first shell structures corresponded to the square anti-prism and tricapped trigonal prisms respectively. The second shell hydration number for AIMD QM/MM-PBE, QM/MM-PBE0, CMD-3B, and CMD-LJ, were 15.8, 17.2, 17.7, 17.4, and 16.4 respectively, which indicates second hydration shell over-coordination compared to recent EXAFS experimental value of 13. Save the EXAFS spectra CMD-LJ simulation, all the computed EXAFS spectra agree fairly well with experiment and a clear distinction could not be made between configurations with 8-fold and 9-fold coordinated first shells. The mechanisms responsible for the first shell associative and dissociative ligand exchange in the classical simulations

  18. Molecular dynamics simulations of the electrical double layer on smectite surfaces contacting concentrated mixed electrolyte (NaCl-CaCl?) solutions

    SciTech Connect (OSTI)

    Bourg, Ian C.; Sposito, Garrison

    2011-01-01

    We report new molecular dynamics results elucidating the structure of the electrical double layer (EDL) on smectite surfaces contacting mixed NaClCaCl2 electrolyte solutions in the range of concentrations relevant to pore waters in geologic repositories for CO2 or high-level radioactive waste (0.341.83 molc dm-3). Our results confirm the existence of three distinct ion adsorption planes (0-, ?-, and d-planes), often assumed in EDL models, but with two important qualifications: (1) the location of the ?- and d-planes are independent of ionic strength or ion type and (2) indifferent electrolyte ions can occupy all three planes. Charge inversion occurred in the diffuse ion swarm because of the affinity of the clay surface for CaCl+ ion pairs. Therefore, at concentrations {>=0.34 molc dm-3}, properties arising from long-range electrostatics at interfaces (electrophoresis, electro-osmosis, co-ion exclusion, colloidal aggregation) will not be correctly predicted by most EDL models. Co-ion exclusion, typically neglected by surface speciation models, balanced a large part of the clay mineral structural charge in the more concentrated solutions. Water molecules and ions diffused relatively rapidly even in the first statistical water monolayer, contradicting reports of rigid ice-like structures for water on clay mineral surfaces.

  19. Inference on accretion flow dynamics using TCAF solution from the analysis of spectral evolution of H 1743-322 during the 2010 outburst

    SciTech Connect (OSTI)

    Mondal, Santanu; Debnath, Dipak; Chakrabarti, Sandip K. E-mail: dipak@csp.res.in

    2014-05-01

    We study accretion flow dynamics of the Galactic transient black hole candidate (BHC) H 1743-322 during its 2010 outburst by analyzing spectral data using the two-component advective flow (TCAF; Keplerian and sub-Keplerian) solution after its inclusion in XSPEC as a local model. We compare our TCAF solution fitted results with combined disk blackbody (DBB) and power-law (PL) model fitted results and find a similar smooth variation of thermal (Keplerian or DBB) and non-thermal (PL or sub-Keplerian) fluxes/rates in two types of model fits. For a spectral analysis, 2.5-25 keV spectral data from the Rossi X-Ray Timing Explorer Proportional Counter Array instrument are used. From the TCAF solution fit, accretion flow parameters, such as Keplerian rate, sub-Keplerian rate, location of centrifugal pressure-supported shock, and strength of the shock, are extracted, providing a deeper understanding of the accretion process and properties of accretion disks around BHC H 1743-322 during its X-ray outburst. Based on the halo to disk accretion rate ratio, shock properties, accretion rates, and the nature of the quasi-periodic oscillations' (if observed) entire outburst is classified into four different spectral states: hard, hard-intermediate, soft-intermediate, and soft. From the time variation of intrinsic flow parameters, it appears that their evolutions in the declining phase do not retrace the path of the rising phase. Since our current model does not include magnetic fields, spectral turnover at energies beyond 500-600 keV cannot be explained.

  20. Rapid Laser Induced Crystallization of Amorphous NiTi Films Observed by Nanosecond Dynamic Transmission Electron Microscopy (DTEM)

    SciTech Connect (OSTI)

    LaGrange, T; Campbell, G H; Browning, N D; Reed, B W; Grummon, D S

    2010-03-01

    The crystallization processes of the as-deposited, amorphous NiTi thin films have been studied in detail using techniques such as differential scanning calorimetry and, in-situ TEM. The kinetic data have been analyzed in terms of Johnson-Mehl-Avrami-Kolomogrov (JMAK) semi-empirical formula. The kinetic parameters determined from this analysis have been useful in defining process control parameters for tailoring microstructural features and shape memory properties. Due to the commercial push to shrink thin film-based devices, unique processing techniques have been developed using laser-based annealing to spatially control the microstructure evolution down to sub-micron levels. Nanosecond, pulse laser annealing is particularly attractive since it limits the amount of peripheral heating and unwanted microstructural changes to underlying or surrounding material. However, crystallization under pulsed laser irradiation can differ significantly from conventional thermal annealing, e.g., slow heating in a furnace. This is especially true for amorphous NiTi materials and relevant for shape memory thin film based microelectromechanical systems (MEMS) applications. There is little to no data on the crystallization kinetics of NiTi under pulsed laser irradiation, primarily due to the high crystallization rates intrinsic to high temperature annealing and the spatial and temporal resolution limits of standard techniques. However, with the high time and spatial resolution capabilities of the dynamic transmission electron microscope (DTEM) constructed at Lawrence Livermore National Laboratory, the rapid nucleation events occurring from pulsed laser irradiation can be directly observed and nucleation rates can be quantified. This paper briefly explains the DTEM approach and how it used to investigate the pulsed laser induced crystallization processes in NiTi and to determine kinetic parameters.

  1. Torque for electron spin induced by electron permanent electric dipole moment

    SciTech Connect (OSTI)

    Senami, Masato E-mail: akitomo@scl.kyoto-u.ac.jp; Fukuda, Masahiro E-mail: akitomo@scl.kyoto-u.ac.jp; Ogiso, Yoji E-mail: akitomo@scl.kyoto-u.ac.jp; Tachibana, Akitomo E-mail: akitomo@scl.kyoto-u.ac.jp

    2014-10-06

    The spin torque of the electron is studied in relation to the electric dipole moment (EDM) of the electron. The spin dynamics is known to be given by the spin torque and the zeta force in quantum field theory. The effect of the EDM on the torque of the spin brings a new term in the equation of motion of the spin. We study this effect for a solution of the Dirac equation with electromagnetic field.

  2. First Principles Simulation of the Bonding, Vibrational, and Electronic Properties of the Hydration Shells of the High-Spin Fe 3+ Ion in Aqueous Solutions

    SciTech Connect (OSTI)

    Bogatko, Stuart A.; Bylaska, Eric J.; Weare, John H.

    2010-02-11

    Results of parameter-free first principles simulations of a spin up 3d5 Fe3+ ion hydrated in an aqueous solution (64 waters, 30 ps, 300 K) are reported. The first hydration shell associated with the first maximum of the radial distribution function, gFeO(r), at d(Fe-OI) = 2.11-2.15 Å, contains 6 waters with average d(OH) = 0.99 Å, in good agreement with observations. A second shell with average coordination number 13.3 can be identified with average shell radius of d(Fe-OII) = 4.21-4.32 Å. The waters in this hydration shell are coordinated to the first shell via a trigonal H-bond network with d(OI-OII) = 2.7-2.9 Å, also in agreement with experimental measurements. The first shell tilt angle average is 33.4° as compared to the reported value of 41°. Wannier-Boys orbitals (WBO) show an interaction between the unoccupied 3d orbitals of the Fe3+ valence (spin up, 3d5) and the occupied spin down lone pair orbitals of first shell waters. The effect of the spin ordering of the Fe3+ ion on the WBO is not observed beyond the first shell. From this local bond analysis and consistent with other observations, the electronic structure of waters in the second shell is similar to that of a bulk water even in this strongly interacting system. H-bond decomposition shows significant bulk-like structure within the second shell for Fe3+. The vibrational density of states shows a first shell red shift of 230 cm-1 for the v1,2v2,v3 overtone, in reasonable agreement with experimental estimates for trivalent cations (300 cm-1). No exchanges between first and second shell were observed. Waters in the second shell exchanged with bulk waters via dissociative and associative mechanisms. Results are compared with an AIMD study of Al3+ and 64 waters. For Fe3+ the average first shell tilt angle is larger and the tilt angle distribution wider. H-bond decomposition shows that second shell to second shell H-bonding is enhanced in Fe3+ suggesting an earlier onset of bulk

  3. Experimental and numerical study of gas dynamic window for electron beam transport into the space with increased pressure

    SciTech Connect (OSTI)

    Skovorodko, P. A.; Sharafutdinov, R. G.

    2014-12-09

    The paper is devoted to experimental and numerical study of the gas jet technical device for obtaining axisymmetric flow with low pressure in its near axis region. The studied geometry of the device is typical of that used in the plasma generator consisting of an electron gun with a hollow (plasma) cathode and a double supersonic ring nozzle. The geometry of the nozzles as well as the relation between the gas flow rates through the nozzles providing the electron beam extraction into the region with increased pressure are tested both experimentally and numerically. The maximum external pressure of about 0.25 bar that does not disturb the electron beam is achieved.

  4. Electron acoustic wave driven vortices with non-Maxwellian hot electrons in magnetoplasmas

    SciTech Connect (OSTI)

    Haque, Q.; Mirza, Arshad M.; Zakir, U.

    2014-07-15

    Linear dispersion characteristics of the Electron Acoustic Wave (EAW) and the corresponding vortex structures are investigated in a magnetoplasma in the presence of non-Maxwellian hot electrons. In this regard, kappa and Cairns distributed hot electrons are considered. It is noticed that the nonthermal distributions affect the phase velocity of the EAW. Further, it is found that the phase velocity of EAW increases for Cairns and decreases for kappa distributed hot electrons. Nonlinear solutions in the form of dipolar vortices are also obtained for both stationary and non-stationary ions in the presence of kappa distributed hot electrons and dynamic cold electrons. It is found that the amplitude of the nonlinear vortex structures also reduces with kappa factor like the electron acoustic solitons.

  5. Dynamical heavy-quark recombination and the nonphotonic single-electron puzzle at energies available at the BNL Relativistic Heavy Ion Collider (RHIC)

    SciTech Connect (OSTI)

    Ayala, Alejandro; Magnin, J.; Montano, Luis Manuel; Sanchez, G. Toledo

    2009-12-15

    We show that the single, nonphotonic electron nuclear modification factor R{sub AA}{sup e} is affected by the thermal enhancement of the heavy-baryon-to-heavy-meson ratio in relativistic heavy-ion collisions with respect to proton-proton collisions. We make use of the dynamical quark recombination model to compute such a ratio and show that this produces a sizable suppression factor for R{sub AA}{sup e} at intermediate transverse momenta. We argue that this suppression factor needs to be considered, in addition to the energy loss contribution, in calculations of R{sub AA}{sup e}.

  6. First-principles investigation of the dissociation and coupling of methane on small copper clusters: Interplay of collision dynamics and geometric and electronic effects

    SciTech Connect (OSTI)

    Varghese, Jithin J.; Mushrif, Samir H.

    2015-05-14

    Small metal clusters exhibit unique size and morphology dependent catalytic activity. The search for alternate minimum energy pathways and catalysts to transform methane to more useful chemicals and carbon nanomaterials led us to investigate collision induced dissociation of methane on small Cu clusters. We report here for the first time, the free energy barriers for the collision induced activation, dissociation, and coupling of methane on small Cu clusters (Cu{sub n} where n = 2–12) using ab initio molecular dynamics and metadynamics simulations. The collision induced activation of the stretching and bending vibrations of methane significantly reduces the free energy barrier for its dissociation. Increase in the cluster size reduces the barrier for dissociation of methane due to the corresponding increase in delocalisation of electron density within the cluster, as demonstrated using the electron localisation function topology analysis. This enables higher probability of favourable alignment of the C–H stretching vibration of methane towards regions of high electron density within the cluster and makes higher number of sites available for the chemisorption of CH{sub 3} and H upon dissociation. These characteristics contribute in lowering the barrier for dissociation of methane. Distortion and reorganisation of cluster geometry due to high temperature collision dynamics disturb electron delocalisation within them and increase the barrier for dissociation. Coupling reactions of CH{sub x} (x = 1–3) species and recombination of H with CH{sub x} have free energy barriers significantly lower than complete dehydrogenation of methane to carbon. Thus, competition favours the former reactions at high hydrogen saturation on the clusters.

  7. Molecular Dynamics Study of Fe(II) Adsorption, Electron Exchange, and Mobility at Goethite (alpha-FeOOH) Surfaces

    SciTech Connect (OSTI)

    Zarzycki, Piotr P.; Kerisit, Sebastien N.; Rosso, Kevin M.

    2015-02-12

    We present classical molecular simulations of the adsorption free energy profiles for the aqueous Fe(II) ion approaching key low index crystal faces of goethite at neutral surface charge conditions. Calculated profiles show minima corresponding to stable outer- and inner-sphere adsorbed structures. We analyzed the energetics and kinetics of most possible interfacial electron transfer reactions, as well as analyzing the same for subsurface migration pathways of injected electrons through calculating the Marcus free energy surfaces. We conclude that inner-sphere Fe(II)-complex formation is required for the interfacial electron transfer to occur, but the energetic cost of moving from the outer-sphere to inner-sphere geometry may prevent electron injection at some faces. We also show that some surfaces, especially (101), (100) and (001), are more energetically prone toward reduction than others. We demonstrate that subsurface charge migration in directions parallel to the surface, which run along the iron chains, is more energetically plausible than conduction through the resistive crystal bulk phase. Collectively this leads to the conclusion that Fe(II)-catalyzed recrystallization of goethite most likely proceeds by short path length electron migration through specific goethite surfaces along specific directions, until capture at Fe sites structurally susceptible to reduction and release.

  8. Lithium electrodeposition dynamics in aprotic electrolyte observed in situ via transmission electron microscopy

    SciTech Connect (OSTI)

    Leenheer, Andrew Jay; Jungjohann, Katherine Leigh; Zavadil, Kevin Robert; Sullivan, John P.; Harris, Charles Thomas

    2015-03-18

    Electrodeposited metallic lithium is an ideal negative battery electrode, but nonuniform microstructure evolution during cycling leads to degradation and safety issues. A better understanding of the Li plating and stripping processes is needed to enable practical Li-metal batteries. Here we use a custom microfabricated, sealed liquid cell for in situ scanning transmission electron microscopy (STEM) to image the first few cycles of lithium electrodeposition/dissolution in liquid aprotic electrolyte at submicron resolution. Cycling at current densities from 1 to 25 mA/cm2 leads to variations in grain structure, with higher current densities giving a more needle-like, higher surface area deposit. The effect of the electron beam was explored, and it was found that, even with minimal beam exposure, beam-induced surface film formation could alter the Li microstructure. The electrochemical dissolution was seen to initiate from isolated points on grains rather than uniformly across the Li surface, due to the stabilizing solid electrolyte interphase surface film. As a result, we discuss the implications for operando STEM liquid-cell imaging and Li-battery applications.

  9. An efficient computational scheme for electronic excitation spectra of molecules in solution using the symmetry-adapted cluster–configuration interaction method: The accuracy of excitation energies and intuitive charge-transfer indices

    SciTech Connect (OSTI)

    Fukuda, Ryoichi Ehara, Masahiro

    2014-10-21

    Solvent effects on electronic excitation spectra are considerable in many situations; therefore, we propose an efficient and reliable computational scheme that is based on the symmetry-adapted cluster-configuration interaction (SAC-CI) method and the polarizable continuum model (PCM) for describing electronic excitations in solution. The new scheme combines the recently proposed first-order PCM SAC-CI method with the PTE (perturbation theory at the energy level) PCM SAC scheme. This is essentially equivalent to the usual SAC and SAC-CI computations with using the PCM Hartree-Fock orbital and integrals, except for the additional correction terms that represent solute-solvent interactions. The test calculations demonstrate that the present method is a very good approximation of the more costly iterative PCM SAC-CI method for excitation energies of closed-shell molecules in their equilibrium geometry. This method provides very accurate values of electric dipole moments but is insufficient for describing the charge-transfer (CT) indices in polar solvent. The present method accurately reproduces the absorption spectra and their solvatochromism of push-pull type 2,2{sup ′}-bithiophene molecules. Significant solvent and substituent effects on these molecules are intuitively visualized using the CT indices. The present method is the simplest and theoretically consistent extension of SAC-CI method for including PCM environment, and therefore, it is useful for theoretical and computational spectroscopy.

  10. Photo-induced isomerization of ethylene-bridged azobenzene explored by ab initio based non-adiabatic dynamics simulation: A comparative investigation of the isomerization in the gas and solution phases

    SciTech Connect (OSTI)

    Cao Jun; Liu Lihong; Fang Weihai; Xie Zhizhong; Zhang Yong

    2013-04-07

    Azobenzene is one of the most widely used photoactive units and recently an ethylene-bridged azobenzene (BAB) was reported to have greatly enhanced conversion efficiency, quantum yield, and other favorable properties. As the first step towards exploring its photo-switchable character in real systems, we report here a systematic study on the photoisomerization dynamics between trans (E) and cis (Z) isomers in the gas phase and the CH{sub 3}OH solution, using ab initio based surface hopping and molecular dynamics, which is the first report of dynamics simulation to reveal the environmental effects on BAB photoreactions. Results show that while the relatively faster S{sub 1} relaxation of the photo-induced E{yields}Z process is only mildly affected by the solvent effect, the relatively slower S{sub 1} relaxation of the reverse reaction becomes even slower in the solution compared to the gas phase. The subsequent S{sub 0} dynamics from the conical intersection between S{sub 1} and S{sub 0} (CI{sub E}) to Z is accelerated in solution compared to the gas phase because of avoided re-crossing to the S{sub 1} state, while the S{sub 0} dynamics from the conical intersection between S{sub 1} and S{sub 0} (CI{sub Z}) to E are basically the same in both phases. Overall, the solvent effect was found to enhance the back-and-forth photo-switch efficiency between the Z and E isomers compared to the gas phase, while the quantum yields are reduced. But the solution yields of both the forward and backward photoreactions are still around 0.4. Therefore, BAB may have good photo-responsive properties if used as a photoactive unit in real systems. These results will facilitate future experimental and theoretical studies in this area to help design new azobenzene derivatives as photoactive units in biological processes, nanoscale devices, and photo-responsive materials.

  11. Electronic structure and optical properties of ?-(Fe{sub 1-x}V{sub x}){sub 2}O{sub 3} solid-solution thin films

    SciTech Connect (OSTI)

    Chamberlin, S. E.; Nayyar, I. H.; Kaspar, T. C.; Sushko, P. V.; Chambers, S. A.

    2015-01-26

    We have examined the effect of V doping on the electronic and optical properties of epitaxial hematite (?-Fe{sub 2}O{sub 3}) thin films, by employing several characterization techniques and computational modeling. The conductivity of ?-(Fe{sub 1-x}V{sub x}){sub 2}O{sub 3} (0???x????0.5) is enhanced by several orders of magnitude as x is increased, as evidenced by electrical resistivity measurements and x-ray photoelectron spectroscopy core-level and valence-band spectra. Optical absorption shows a reduction in the direct band gap by as much as 0.64?eV for x?=?0.53 (E{sub g}?=?1.46?eV) relative to that of ?-Fe{sub 2}O{sub 3} (E{sub g}?=?2.10?eV). Detailed understanding of the character of the optical transitions in the alloys is achieved using first-principles calculations of the ground and excited states. These calculations reveal that V doping results in occupied V 3d orbitals hybridized with Fe orbitals and located at approximately mid-gap in ?-Fe{sub 2}O{sub 3}. The lowest energy transitions involve charge transfer from occupied V 3d to unoccupied Fe 3d* orbitals. With a low band gap and high conductivity, ?-(Fe{sub 1-x}V{sub x}){sub 2}O{sub 3} is a promising material for photovoltaic and photoelectrochemical applications.

  12. Dynamical impurity problems

    SciTech Connect (OSTI)

    Emery, V.J.; Kivelson, S.A.

    1993-12-31

    In the past few years there has been a resurgence of interest in dynamical impurity problems, as a result of developments in the theory of correlated electron systems. The general dynamical impurity problem is a set of conduction electrons interacting with an impurity which has internal degrees of freedom. The simplest and earliest example, the Kondo problem, has attracted interest since the mid-sixties not only because of its physical importance but also as an example of a model displaying logarithmic divergences order by order in perturbation theory. It provided one of the earliest applications of the renormalization group method, which is designed to deal with just such a situation. As we shall see, the antiferromagnetic Kondo model is controlled by a strong-coupling fixed point, and the essence of the renormalization group solution is to carry out the global renormalization numerically starting from the original (weak-coupling) Hamiltonian. In these lectures, we shall describe an alternative route in which we identify an exactly solvable model which renormalizes to the same fixed point as the original dynamical impurity problem. This approach is akin to determining the critical behavior at a second order phase transition point by solving any model in a given universality class.

  13. Global Solutions

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

    Global Solutions Our Vision National User Facilities Research Areas In Focus Global Solutions ⇒ Navigate Section Our Vision National User Facilities Research Areas In Focus Global Solutions A-Z Index Berkeley Lab masthead U.S. Department of Energy logo Phone Book Jobs Search BANGLADESH INDIA CHINA DAYA BAY CHINA RUSSIA SIBERIA JAPAN SAMOA HAWAII SOUTH POLE ANTARCTICA NEW MEXICO SOUTH DAKOTA TEXAS GULF OF MEXICO NEW YORK PUERTO RICO AMAZON RAIN FOREST CANARY ISLANDS SWITZERLAND ETHIOPIA

  14. Delta Electronics Inc | Open Energy Information

    Open Energy Info (EERE)

    Zip: 114 Product: Provider of power management solutions, electronics components, visual displays, and networkwireless solutions. Coordinates: 25.080441, 121.564194 Show...

  15. Electromarking solution

    DOE Patents [OSTI]

    Bullock, Jonathan S.; Harper, William L.; Peck, Charles G.

    1976-06-22

    This invention is directed to an aqueous halogen-free electromarking solution which possesses the capacity for marking a broad spectrum of metals and alloys selected from different classes. The aqueous solution comprises basically the nitrate salt of an amphoteric metal, a chelating agent, and a corrosion-inhibiting agent.

  16. Electron-hole diffusion lengths >175 μm in solution-grown CH3NH3PbI3 single crystals

    SciTech Connect (OSTI)

    Dong, Qingfeng; Fang, Yanjun; Shao, Yuchuan; Mulligan, Padhraic; Qiu, Jie; Cao, Lei; Huang, Jinsong

    2015-02-27

    Long, balanced electron and hole diffusion lengths greater than 100 nanometers in the polycrystalline organolead trihalide compound CH3NH3PbI3 are critical for highly efficient perovskite solar cells. We found that the diffusion lengths in CH3NH3PbI3 single crystals grown by a solution-growth method can exceed 175 micrometers under 1 sun (100 mW cm–2) illumination and exceed 3 millimeters under weak light for both electrons and holes. The internal quantum efficiencies approach 100% in 3-millimeter-thick single-crystal perovskite solar cells under weak light. These long diffusion lengths result from greater carrier mobility, longer lifetime, and much smaller trap densities in the single crystals than in polycrystalline thin films. As a result, the long carrier diffusion lengths enabled the use of CH3NH3PbI3 in radiation sensing and energy harvesting through the gammavoltaic effect, with an efficiency of 3.9% measured with an intense cesium-137 source.

  17. Quantitative in-situ scanning electron microscope pull-out experiments and molecular dynamics simulations of carbon nanotubes embedded in palladium

    SciTech Connect (OSTI)

    Hartmann, S., E-mail: steffen.hartmann@etit.tu-chemnitz.de; Blaudeck, T.; Hermann, S.; Wunderle, B. [Technische Universitt Chemnitz, Reichenhainer Str. 70, 09126 Chemnitz (Germany); Hlck, O. [Technische Universitt Chemnitz, Reichenhainer Str. 70, 09126 Chemnitz (Germany); Fraunhofer IZM Berlin, Gustav-Meyer-Allee 25, 13355 Berlin (Germany); Schulz, S. E.; Gessner, T. [Technische Universitt Chemnitz, Reichenhainer Str. 70, 09126 Chemnitz (Germany); Fraunhofer ENAS Chemnitz, Technologie-Campus 3, 09126 Chemnitz (Germany)

    2014-04-14

    In this paper, we present our results of experimental and numerical pull-out tests on carbon nanotubes (CNTs) embedded in palladium. We prepared simple specimens by employing standard silicon wafers, physical vapor deposition of palladium and deposition of CNTs with a simple drop coating technique. An AFM cantilever with known stiffness connected to a nanomanipulation system was utilized inside a scanning electron microscope (SEM) as a force sensor to determine forces acting on a CNT during the pull-out process. SEM-images of the cantilever attached to a CNT have been evaluated for subsequent displacement steps with greyscale correlation to determine the cantilever deflection. We compare the experimentally obtained pull-out forces with values of numerical investigations by means of molecular dynamics and give interpretations for deviations according to material impurities or defects and their influence on the pull-out data. We find a very good agreement of force data from simulation and experiment, which is 17 nN and in the range of 1061 nN, respectively. Our findings contribute to the ongoing research of the mechanical characterization of CNT-metal interfaces. This is of significant interest for the design of future mechanical sensors utilizing the intrinsic piezoresistive effect of CNTs or other future devices incorporating CNT-metal interfaces.

  18. Massively-parallel electron dynamics calculations in real-time and real-space: Toward applications to nanostructures of more than ten-nanometers in size

    SciTech Connect (OSTI)

    Noda, Masashi; Ishimura, Kazuya; Nobusada, Katsuyuki; Yabana, Kazuhiro; Boku, Taisuke

    2014-05-15

    A highly efficient program of massively parallel calculations for electron dynamics has been developed in an effort to apply the method to optical response of nanostructures of more than ten-nanometers in size. The approach is based on time-dependent density functional theory calculations in real-time and real-space. The computational code is implemented by using simple algorithms with a finite-difference method in space derivative and Taylor expansion in time-propagation. Since the computational program is free from the algorithms of eigenvalue problems and fast-Fourier-transformation, which are usually implemented in conventional quantum chemistry or band structure calculations, it is highly suitable for massively parallel calculations. Benchmark calculations using the K computer at RIKEN demonstrate that the parallel efficiency of the program is very high on more than 60 000 CPU cores. The method is applied to optical response of arrays of C{sub 60} orderly nanostructures of more than 10 nm in size. The computed absorption spectrum is in good agreement with the experimental observation.

  19. The structures and dynamics of atomic and molecular adsorbates on metal surfaces by scanning tunneling microscopy and low energy electron diffraction

    SciTech Connect (OSTI)

    Yoon, Hyungsuk Alexander

    1996-12-01

    Studies of surface structure and dynamics of atoms and molecules on metal surfaces are presented. My research has focused on understanding the nature of adsorbate-adsorbate and adsorbate-substrate interactions through surface studies of coverage dependency and coadsorption using both scanning tunneling microscopy (STM) and low energy electron diffraction (LEED). The effect of adsorbate coverage on the surface structures of sulfur on Pt(111) and Rh(111) was examined. On Pt(111), sulfur forms p(2x2) at 0.25 ML of sulfur, which transforms into a more compressed ({radical}3x{radical}3)R30{degrees} at 0.33 ML. On both structures, it was found that sulfur adsorbs only in fcc sites. When the coverage of sulfur exceeds 0.33 ML, it formed more complex c({radical}3x7)rect structure with 3 sulfur atoms per unit cell. In this structure, two different adsorption sites for sulfur atoms were observed - two on fcc sites and one on hcp site within the unit cell.

  20. Structure And Dynamics of the Hydrated Palladium(II) Ion in Aqueous Solution a QMCF MD Simulation And EXAFS Spectroscopic Study

    SciTech Connect (OSTI)

    Hofer, T.S.; Randolf, B.R.; Shah, S.Adnan Ali; Rode, B.M.; Persson, I.

    2009-06-01

    The pharmacologically and industrially important palladium(II) ion is usually characterised as square-planar structure in aqueous solution, similar to the platinum(II) ion. Our investigations by means of the most modern experimental and theoretical methods give clear indications, however, that the hydrated palladium(II) ion is hexa-coordinated, with four ligands arranged in a plane at 2.0 {angstrom} plus two additional ligands in axial positions showing an elongated bond distance of 2.7-2.8 A. The second shell consists in average of 8.0 ligands at a mean distance of 4.4 {angstrom}. This structure provides a new basis for the interpretation of the kinetic properties of palladium(II) complexes.

  1. Dynamics of ionization processes in high-pressure nitrogen, air, and SF{sub 6} during a subnanosecond breakdown initiated by runaway electrons

    SciTech Connect (OSTI)

    Tarasenko, V. F. Beloplotov, D. V.; Lomaev, M. I.

    2015-10-15

    The dynamics of ionization processes in high-pressure nitrogen, air, and SF{sub 6} during breakdown of a gap with a nonuniform distribution of the electric field by nanosecond high-voltage pulses was studied experimentally. Measurements of the amplitude and temporal characteristics of a diffuse discharge and its radiation with a subnanosecond time resolution have shown that, at any polarity of the electrode with a small curvature radius, breakdown of the gap occurs via two ionization waves, the first of which is initiated by runaway electrons. For a voltage pulse with an ∼500-ps front, UV radiation from different zones of a diffuse discharge is measured with a subnanosecond time resolution. It is shown that the propagation velocity of the first ionization wave increases after its front has passed one-half of the gap, as well as when the pressure in the discharge chamber is reduced and/or when SF{sub 6} is replaced with air or nitrogen. It is found that, at nitrogen pressures of 0.4 and 0.7 MPa and the positive polarity of the high-voltage electrode with a small curvature radius, the ionization wave forms with a larger (∼30 ps) time delay with respect to applying the voltage pulse to the gap than at the negative polarity. The velocity of the second ionization wave propagating from the plane electrode is measured. In a discharge in nitrogen at a pressure of 0.7 MPa, this velocity is found to be ∼10 cm/ns. It is shown that, as the nitrogen pressure increases to 0.7 MPa, the propagation velocity of the front of the first ionization wave at the positive polarity of the electrode with a small curvature radius becomes lower than that at the negative polarity.

  2. PIA - Savannah River Nuclear Solutions Electronic Safeguards...

    Energy Savers [EERE]

    More Documents & Publications PIA - 10th International Nuclear Graphite Specialists Meeting registration web site PIA - HSPD-12 Physical and Logical Access System PIA - Savannah ...

  3. Solute–solute correlations responsible for the prepeak in structure factors of undercooled Al-rich liquids: A molecular dynamics study

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

    Zhang, Feng; Sun, Yang; Ye, Zhuo; Zhang, Yue; Wang, Cai -Zhuang; Mendelev, Mikhail I.; Ott, Ryan T.; Kramer, Matthew J.; Ding, Ze -Jun; Ho, Kai -Ming

    2015-05-06

    In this study, we have performed molecular dynamics simulations on a typical Al-based alloy Al90Sm10. The short-range and medium-range correlations of the system are reliably produced by ab initio calculations, whereas the long-range correlations are obtained with the assistance of a semi-empirical potential well-fitted to ab initio data. Our calculations show that a prepeak in the structure factor of this system emerges well above the melting temperature, and the intensity of the prepeak increases with increasing undercooling of the liquid. These results are in agreement with x-ray diffraction experiments. The interplay between the short-range order of the system originating frommore » the large affinity between Al and Sm atoms, and the intrinsic repulsion between Sm atoms gives rise to a stronger correlation in the second peak than the first peak in the Sm–Sm partial pair correlation function (PPCF), which in turn produces the prepeak in the structure factor.« less

  4. A molecular dynamics study of intramolecular proton transfer reaction of malonaldehyde in solution based upon a mixed quantumclassical approximation. II. Proton transfer reaction in non-polar solvent

    SciTech Connect (OSTI)

    Kojima, H.; Yamada, A.; Okazaki, S.

    2015-05-07

    The intramolecular proton transfer reaction of malonaldehyde in neon solvent has been investigated by mixed quantumclassical molecular dynamics (QCMD) calculations and fully classical molecular dynamics (FCMD) calculations. Comparing these calculated results with those for malonaldehyde in water reported in Part I [A. Yamada, H. Kojima, and S. Okazaki, J. Chem. Phys. 141, 084509 (2014)], the solvent dependence of the reaction rate, the reaction mechanism involved, and the quantum effect therein have been investigated. With FCMD, the reaction rate in weakly interacting neon is lower than that in strongly interacting water. However, with QCMD, the order of the reaction rates is reversed. To investigate the mechanisms in detail, the reactions were categorized into three mechanisms: tunneling, thermal activation, and barrier vanishing. Then, the quantum and solvent effects were analyzed from the viewpoint of the reaction mechanism focusing on the shape of potential energy curve and its fluctuations. The higher reaction rate that was found for neon in QCMD compared with that found for water solvent arises from the tunneling reactions because of the nearly symmetric double-well shape of the potential curve in neon. The thermal activation and barrier vanishing reactions were also accelerated by the zero-point energy. The number of reactions based on these two mechanisms in water was greater than that in neon in both QCMD and FCMD because these reactions are dominated by the strength of solutesolvent interactions.

  5. Efficient indium-tin-oxide free inverted organic solar cells based on aluminum-doped zinc oxide cathode and low-temperature aqueous solution processed zinc oxide electron extraction layer

    SciTech Connect (OSTI)

    Chen, Dazheng; Zhang, Chunfu Wang, Zhizhe; Zhang, Jincheng; Tang, Shi; Wei, Wei; Sun, Li; Hao, Yue

    2014-06-16

    Indium-tin-oxide (ITO) free inverted organic solar cells (IOSCs) based on aluminum-doped zinc oxide (AZO) cathode, low-temperature aqueous solution processed zinc oxide (ZnO) electron extraction layer, and poly(3-hexylthiophene-2, 5-diyl):[6, 6]-phenyl C{sub 61} butyric acid methyl ester blend were realized in this work. The resulted IOSC with ZnO annealed at 150 °C shows the superior power conversion efficiency (PCE) of 3.01%, if decreasing the ZnO annealing temperature to 100 °C, the obtained IOSC also shows a PCE of 2.76%, and no light soaking issue is observed. It is found that this ZnO film not only acts as an effective buffer layer but also slightly improves the optical transmittance of AZO substrates. Further, despite the relatively inferior air-stability, these un-encapsulated AZO/ZnO IOSCs show comparable PCEs to the referenced ITO/ZnO IOSCs, which demonstrates that the AZO cathode is a potential alternative to ITO in IOSCs. Meanwhile, this simple ZnO process is compatible with large area deposition and plastic substrates, and is promising to be widely used in IOSCs and other relative fields.

  6. Polymer solutions

    DOE Patents [OSTI]

    Krawczyk, Gerhard Erich; Miller, Kevin Michael

    2011-07-26

    There is provided a method of making a polymer solution comprising polymerizing one or more monomer in a solvent, wherein said monomer comprises one or more ethylenically unsaturated monomer that is a multi-functional Michael donor, and wherein said solvent comprises 40% or more by weight, based on the weight of said solvent, one or more multi-functional Michael donor.

  7. Electronic Medical Business Operations System

    SciTech Connect (OSTI)

    Cannon, D. T.; Metcalf, J. R.; North, M. P.; Richardson, T. L.; Underwood, S. A.; Shelton, P. M.; Ray, W. B.; Morrell, M. L.; Caldwell, III, D. C.

    2012-04-16

    Electronic Management of medical records has taken a back seat both in private industry and in the government. Record volumes continue to rise every day and management of these paper records is inefficient and very expensive. In 2005, the White House announced support for the development of electronic medical records across the federal government. In 2006, the DOE issued 10 CFR 851 requiring all medical records be electronically available by 2015. The Y-12 National Security Complex is currently investing funds to develop a comprehensive EMR to incorporate the requirements of an occupational health facility which are common across the Nuclear Weapons Complex (NWC). Scheduling, workflow, and data capture from medical surveillance, certification, and qualification examinations are core pieces of the system. The Electronic Medical Business Operations System (EMBOS) will provide a comprehensive health tool solution to 10 CFR 851 for Y-12 and can be leveraged to the Nuclear Weapon Complex (NWC); all site in the NWC must meet the requirements of 10 CFR 851 which states that all medical records must be electronically available by 2015. There is also potential to leverage EMBOS to the private4 sector. EMBOS is being developed and deployed in phases. When fully deployed the EMBOS will be a state-of-the-art web-enabled integrated electronic solution providing a complete electronic medical record (EMR). EMBOS has been deployed and provides a dynamic electronic medical history and surveillance program (e.g., Asbestos, Hearing Conservation, and Respirator Wearer) questionnaire. Table 1 below lists EMBOS capabilities and data to be tracked. Data to be tracked: Patient Demographics – Current/Historical; Physical Examination Data; Employee Medical Health History; Medical Surveillance Programs; Patient and Provider Schedules; Medical Qualification/Certifications; Laboratory Data; Standardized Abnormal Lab Notifications; Prescription Medication Tracking and Dispensing; Allergies

  8. Electronic Medical Business Operations System

    Energy Science and Technology Software Center (OSTI)

    2012-04-16

    Electronic Management of medical records has taken a back seat both in private industry and in the government. Record volumes continue to rise every day and management of these paper records is inefficient and very expensive. In 2005, the White House announced support for the development of electronic medical records across the federal government. In 2006, the DOE issued 10 CFR 851 requiring all medical records be electronically available by 2015. The Y-12 National Securitymore » Complex is currently investing funds to develop a comprehensive EMR to incorporate the requirements of an occupational health facility which are common across the Nuclear Weapons Complex (NWC). Scheduling, workflow, and data capture from medical surveillance, certification, and qualification examinations are core pieces of the system. The Electronic Medical Business Operations System (EMBOS) will provide a comprehensive health tool solution to 10 CFR 851 for Y-12 and can be leveraged to the Nuclear Weapon Complex (NWC); all site in the NWC must meet the requirements of 10 CFR 851 which states that all medical records must be electronically available by 2015. There is also potential to leverage EMBOS to the private4 sector. EMBOS is being developed and deployed in phases. When fully deployed the EMBOS will be a state-of-the-art web-enabled integrated electronic solution providing a complete electronic medical record (EMR). EMBOS has been deployed and provides a dynamic electronic medical history and surveillance program (e.g., Asbestos, Hearing Conservation, and Respirator Wearer) questionnaire. Table 1 below lists EMBOS capabilities and data to be tracked. Data to be tracked: Patient Demographics – Current/Historical; Physical Examination Data; Employee Medical Health History; Medical Surveillance Programs; Patient and Provider Schedules; Medical Qualification/Certifications; Laboratory Data; Standardized Abnormal Lab Notifications; Prescription Medication Tracking and Dispensing

  9. Influence of chemical disorder on energy dissipation and defect evolution in concentrated solid solution alloys

    SciTech Connect (OSTI)

    Zhang, Yanwen; Stocks, George Malcolm; Jin, Ke; Lu, Chenyang; Bei, Hongbin; Sales, Brian C.; Wang, Lumin; Béland, Laurent K.; Stoller, Roger E.; Samolyuk, German D.; Caro, Magdalena; Caro, Alfredo; Weber, William J.

    2015-10-28

    A long-standing objective in materials research is to understand how energy is dissipated in both the electronic and atomic subsystems in irradiated materials, and how related non-equilibrium processes may affect defect dynamics and microstructure evolution. Here we show that alloy complexity in concentrated solid solution alloys having both an increasing number of principal elements and altered concentrations of specific elements can lead to substantial reduction in the electron mean free path and thermal conductivity, which has a significant impact on energy dissipation and consequentially on defect evolution during ion irradiation. Enhanced radiation resistance with increasing complexity from pure nickel to binary and to more complex quaternary solid solutions is observed under ion irradiation up to an average damage level of 1 displacement per atom. Understanding how materials properties can be tailored by alloy complexity and their influence on defect dynamics may pave the way for new principles for the design of radiation tolerant structural alloys.

  10. Determining the static electronic and vibrational energy correlations via two-dimensional electronic-vibrational spectroscopy

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

    Dong, Hui; Lewis, Nicholas H. C.; Oliver, Thomas A. A.; Fleming, Graham R.

    2015-05-07

    Changes in the electronic structure of pigments in protein environments and of polar molecules in solution inevitably induce a re-adaption of molecular nuclear structure. Both changes of electronic and vibrational energies can be probed with visible or infrared lasers, such as two-dimensional electronic spectroscopy or vibrational spectroscopy. The extent to which the two changes are correlated remains elusive. The recent demonstration of two-dimensional electronic-vibrational (2DEV) spectroscopy potentially enables a direct measurement of this correlation experimentally. However, it has hitherto been unclear how to characterize the correlation from the spectra. In this report, we present a theoretical formalism to demonstrate themore » slope of the nodal line between the excited state absorption and ground state bleach peaks in the spectra as a characterization of the correlation between electronic and vibrational transition energies. In conclusion, we also show the dynamics of the nodal line slope is correlated to the vibrational spectral dynamics. Additionally, we demonstrate the fundamental 2DEV spectral line-shape of a monomer with newly developed response functions« less

  11. Sandia National Laboratories: Power Electronics

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

    Power Electronics Sensors Power electronics is the application of solid-state electronics for routing, control, and conversion of electrical power. Custom Solutions Wide-Bandgap Wide-bandgap semiconductor materials such as silicon carbide (SiC) and gallium nitride (GaN) have the potential to revolutionize the field of power electronics. Sandia National Laboratories is well-suited to understand both performance and reliability in wide-bandgap power electronics. Understanding Material Properties

  12. Electronic Coupling Dependence of Ultrafast Interfacial Electron Transfer

    Office of Scientific and Technical Information (OSTI)

    on Nanocrystalline Thin Films and Single Crystal (Technical Report) | SciTech Connect Electronic Coupling Dependence of Ultrafast Interfacial Electron Transfer on Nanocrystalline Thin Films and Single Crystal Citation Details In-Document Search Title: Electronic Coupling Dependence of Ultrafast Interfacial Electron Transfer on Nanocrystalline Thin Films and Single Crystal The long-term goal of the proposed research is to understand electron transfer dynamics in nanoparticle/liquid interface.

  13. Individual identification of free hole and electron dynamics in CuIn{sub 1?x}Ga{sub x}Se{sub 2} thin films by simultaneous monitoring of two optical transitions

    SciTech Connect (OSTI)

    Okano, Makoto; Hagiya, Hideki; Sakurai, Takeaki; Akimoto, Katsuhiro; Shibata, Hajime; Niki, Shigeru; Kanemitsu, Yoshihiko

    2015-05-04

    The photocarrier dynamics of CuIn{sub 1?x}Ga{sub x}Se{sub 2} (CIGS) thin films were studied using white-light transient absorption (TA) measurements, as an understanding of this behavior is essential for improving the performance of solar cells composed of CIGS thin films. A characteristic double-peak structure due to the splitting of the valence bands in the CIGS was observed in the TA spectra under near-band-gap resonant excitation. From a comparison of the TA decay dynamics monitored at these two peaks, it was found that the slow-decay components of the electron and hole relaxation are on the nanosecond timescale. This finding is clear evidence of the long lifetimes of free photocarriers in polycrystalline CIGS thin films.

  14. Time-resolved Kα spectroscopy measurements of hot-electron equilibration dynamics in thin-foil solid targets: Collisional and collective effects

    SciTech Connect (OSTI)

    Nilson, P. M.; Solodov, A. A.; Davies, J. R.; Theobald, W.; Mileham, C.; Stoeckl, C.; Begishev, I. A.; Zuegel, J. D.; Froula, D. H.; Betti, R.; Meyerhofer, D. D.

    2015-09-25

    Time-resolved Kα spectroscopy measurements from high-intensity laser interactions with thin-foil solid targets are reviewed. Thin Cu foils were irradiated with 1- to 10-J, 1-ps pulses at focused intensities from 1018 to 1019 W/cm2. The experimental data show Kα-emission pulse widths from 3 to 6 ps, increasing with laser intensity. The time-resolved Kα-emission data are compared to a hot-electron transport and Kα-production model that includes collisional electron-energy coupling, resistive heating, and electromagnetic field effects. The experimental data show good agreement with the model when a reduced ponderomotive scaling is used to describe the initial mean hot-electron energy over the relevant intensity range.

  15. Time-resolved Kα spectroscopy measurements of hot-electron equilibration dynamics in thin-foil solid targets: Collisional and collective effects

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

    Nilson, P. M.; Solodov, A. A.; Davies, J. R.; Theobald, W.; Mileham, C.; Stoeckl, C.; Begishev, I. A.; Zuegel, J. D.; Froula, D. H.; Betti, R.; et al

    2015-09-25

    Time-resolved Kα spectroscopy measurements from high-intensity laser interactions with thin-foil solid targets are reviewed. Thin Cu foils were irradiated with 1- to 10-J, 1-ps pulses at focused intensities from 1018 to 1019 W/cm2. The experimental data show Kα-emission pulse widths from 3 to 6 ps, increasing with laser intensity. The time-resolved Kα-emission data are compared to a hot-electron transport and Kα-production model that includes collisional electron-energy coupling, resistive heating, and electromagnetic field effects. The experimental data show good agreement with the model when a reduced ponderomotive scaling is used to describe the initial mean hot-electron energy over the relevant intensitymore » range.« less

  16. Alloy solution hardening with solute pairs

    DOE Patents [OSTI]

    Mitchell, John W.

    1976-08-24

    Solution hardened alloys are formed by using at least two solutes which form associated solute pairs in the solvent metal lattice. Copper containing equal atomic percentages of aluminum and palladium is an example.

  17. Energy-dependent dynamics of keV to MeV electrons in the inner zone, outer zone, and slot regions

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

    Reeves, Geoffrey D.; Friedel, Reiner H. W.; Larsen, Brian A.; Skoug, Ruth M.; Funsten, Herbert O.; Claudepierre, Seth G.; Fennell, Joseph F.; Turner, Drew L.; Denton, Mick H.; Spence, Harlan E.; et al

    2016-01-28

    Here, we present observations of the radiation belts from the Helium Oxygen Proton Electron and Magnetic Electron Ion Spectrometer particle detectors on the Van Allen Probes satellites that illustrate the energy dependence and L shell dependence of radiation belt enhancements and decays. We survey events in 2013 and analyze an event on 1 March in more detail. The observations show the following: (a) at all L shells, lower energy electrons are enhanced more often than higher energies; (b) events that fill the slot region are more common at lower energies; (c) enhancements of electrons in the inner zone are moremore » common at lower energies; and (d) even when events do not fully fill the slot region, enhancements at lower energies tend to extend to lower L shells than higher energies. During enhancement events the outer zone extends to lower L shells at lower energies while being confined to higher L shells at higher energies. The inner zone shows the opposite with an outer boundary at higher L shells for lower energies. Both boundaries are nearly straight in log(energy) versus L shell space. At energies below a few 100 keV, radiation belt electron penetration through the slot region into the inner zone is commonplace, but the number and frequency of “slot filling” events decreases with increasing energy. The inner zone is enhanced only at energies that penetrate through the slot. Energy- and L shell-dependent losses (that are consistent with whistler hiss interactions) return the belts to more quiescent conditions.« less

  18. Code Verification by the Method of Manufactured Solutions (Technical...

    Office of Scientific and Technical Information (OSTI)

    applied to a variety of engineering codes which numerically ... by detailed examples from computational fluid dynamics. ... SOLUTION; FLUID MECHANICS Word Cloud More Like This ...

  19. Electron radiography

    DOE Patents [OSTI]

    Merrill, Frank E.; Morris, Christopher

    2005-05-17

    A system capable of performing radiography using a beam of electrons. Diffuser means receive a beam of electrons and diffuse the electrons before they enter first matching quadrupoles where the diffused electrons are focused prior to the diffused electrons entering an object. First imaging quadrupoles receive the focused diffused electrons after the focused diffused electrons have been scattered by the object for focusing the scattered electrons. Collimator means receive the scattered electrons and remove scattered electrons that have scattered to large angles. Second imaging quadrupoles receive the collimated scattered electrons and refocus the collimated scattered electrons and map the focused collimated scattered electrons to transverse locations on an image plane representative of the electrons' positions in the object.

  20. PROBING DYNAMICS OF ELECTRON ACCELERATION WITH RADIO AND X-RAY SPECTROSCOPY, IMAGING, AND TIMING IN THE 2002 APRIL 11 SOLAR FLARE

    SciTech Connect (OSTI)

    Fleishman, Gregory D.; Nita, Gelu M.; Gary, Dale E.; Kontar, Eduard P.

    2013-05-10

    Based on detailed analysis of radio and X-ray observations of a flare on 2002 April 11 augmented by realistic three-dimensional modeling, we have identified a radio emission component produced directly at the flare acceleration region. This acceleration region radio component has distinctly different (1) spectrum, (2) light curves, (3) spatial location, and, thus, (4) physical parameters from those of the separately identified trapped or precipitating electron components. To derive evolution of physical parameters of the radio sources we apply forward fitting of the radio spectrum time sequence with the gyrosynchrotron source function with five to six free parameters. At the stage when the contribution from the acceleration region dominates the radio spectrum, the X-ray- and radio-derived electron energy spectral indices agree well with each other. During this time the maximum energy of the accelerated electron spectrum displays a monotonic increase with time from {approx}300 keV to {approx}2 MeV over roughly one minute duration indicative of an acceleration process in the form of growth of the power-law tail; the fast electron residence time in the acceleration region is about 2-4 s, which is much longer than the time of flight and so requires a strong diffusion mode there to inhibit free-streaming propagation. The acceleration region has a relatively strong magnetic field, B {approx} 120 G, and a low thermal density, n{sub e} {approx}< 2 Multiplication-Sign 10{sup 9} cm{sup -3}. These acceleration region properties are consistent with a stochastic acceleration mechanism.

  1. Electron-scale dissipative electrostatic solitons in multi-species plasmas

    SciTech Connect (OSTI)

    Sultana, S.; Kourakis, I.

    2015-10-15

    The linear and nonlinear properties of small-amplitude electron-acoustic solitary waves are investigated via the fluid dynamical approach. A three-component plasma is considered, composed of hot electrons, cold electrons, and ions (considered stationary at the scale of interest). A dissipative (wave damping) effect is assumed due to electron-neutral collisions. The background (hot) electrons are characterized by an energetic (excessively superthermal) population and are thus modeled via a κ-type nonthermal distribution. The linear characteristics of electron-acoustic excitations are discussed, for different values of the plasma parameters (superthermality index κ and cold versus hot electron population concentration β). Large wavelengths (beyond a threshold value) are shown to be overdamped. The reductive perturbation technique is used to derive a dissipative Korteweg de-Vries (KdV) equation for small-amplitude electrostatic potential disturbances. These are expressed by exact solutions in the form of dissipative solitary waves, whose dynamics is investigated analytically and numerically. Our results should be useful in elucidating the behavior of space and experimental plasmas characterized by a coexistence of electron populations at different temperatures, where electron-neutral collisions are of relevance.

  2. LPKF Laser Electronics AG | Open Energy Information

    Open Energy Info (EERE)

    German developer of systems and process solutions targeted to the electronics and automotive industries. Coordinates: 52.420475, 9.598595 Show Map Loading map......

  3. Observation of Materials Processes in Liquids in the Electron Microscope

    SciTech Connect (OSTI)

    Wang, Chong M.; Liao, Honggang; Ross, Frances M.

    2015-01-01

    Materials synthesis and the functioning of devices often indispensably involve liquid media. But direct visualization of dynamic process in liquids, especially with high spatial and temporal resolution, has been challenging. For solid materials, advances in aberration corrected electron microscopy have made observation of atomic level features a routine practice. Here we discuss the extent to which one can take advantage of the resolution of modern electron microscopes to image phenomenon occuring in liquids. We will describe the fundamentals of two different experimental approaches, closed and open liquid cells. We will illustrate the capabilities of each approach by considering processes in batteries and nucleation and growth of nanoparticles from solution. We conclude that liquid cell electron microscopy appears to be duly fulfilling its role for in situ studies of nanoscale processes in liquids, revealing physical and chemical processes otherwise difficult to observe.

  4. Ultrafast infrared studies of complex ligand rearrangements in solution

    SciTech Connect (OSTI)

    Payne, Christine K.

    2003-05-31

    The complete description of a chemical reaction in solution depends upon an understanding of the reactive molecule as well as its interactions with the surrounding solvent molecules. Using ultrafast infrared spectroscopy it is possible to observe both the solute-solvent interactions and the rearrangement steps which determine the overall course of a chemical reaction. The topics addressed in these studies focus on reaction mechanisms which require the rearrangement of complex ligands and the spectroscopic techniques necessary for the determination of these mechanisms. Ligand rearrangement is studied by considering two different reaction mechanisms for which the rearrangement of a complex ligand constitutes the most important step of the reaction. The first system concerns the rearrangement of a cyclopentadienyl ring as the response of an organometallic complex to a loss of electron density. This mechanism, commonly referred to as ''ring slip'', is frequently cited to explain reaction mechanisms. However, the ring slipped intermediate is too short-lived to be observed using conventional methods. Using a combination of ultrafast infrared spectroscopy and electronic structure calculations it has been shown that the intermediate exists, but does not form an eighteen-electron intermediate as suggested by traditional molecular orbital models. The second example examines the initial steps of alkyne polymerization. Group 6 (Cr, Mo, W) pentacarbonyl species are generated photolytically and used to catalyze the polymerization of unsaturated hydrocarbons through a series of coordination and rearrangement steps. Observing this reaction on the femto- to millisecond timescale indicates that the initial coordination of an alkyne solvent molecule to the metal center results in a stable intermediate that does not rearrange to form the polymer precursor. This suggests that polymerization requires the dissociation of additional carbonyl ligands before rearrangement can occur. Overall

  5. Xyce(™) Parallel Electronic Simulator

    Energy Science and Technology Software Center (OSTI)

    2013-10-03

    The Xyce Parallel Electronic Simulator simulates electronic circuit behavior in DC, AC, HB, MPDE and transient mode using standard analog (DAE) and/or device (PDE) device models including several age and radiation aware devices. It supports a variety of computing platforms (both serial and parallel) computers. Lastly, it uses a variety of modern solution algorithms dynamic parallel load-balancing and iterative solvers.! ! Xyce is primarily used to simulate the voltage and current behavior of a circuitmore » network (a network of electronic devices connected via a conductive network). As a tool, it is mainly used for the design and analysis of electronic circuits.! ! Kirchoff's conservation laws are enforced over a network using modified nodal analysis. This results in a set of differential algebraic equations (DAEs). The resulting nonlinear problem is solved iteratively using a fully coupled Newton method, which in turn results in a linear system that is solved by either a standard sparse-direct solver or iteratively using Trilinos linear solver packages, also developed at Sandia National Laboratories.« less

  6. Electron Transfer

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

    3 Pierre Kennepohl1,2 and Edward Solomon1* 1Department of Chemistry, Stanford University, Stanford, CA 94305 Electron transfer, or the act of moving an electron from one place to another, is amongst the simplest of chemical processes, yet certainly one of the most critical. The process of efficiently and controllably moving electrons around is one of the primary regulation mechanisms in biology. Without stringent control of electrons in living organisms, life could simply not exist. For example,

  7. A compact electron gun for time-resolved electron diffraction

    SciTech Connect (OSTI)

    Robinson, Matthew S.; Lane, Paul D.; Wann, Derek A.

    2015-01-15

    A novel compact time-resolved electron diffractometer has been built with the primary goal of studying the ultrafast molecular dynamics of photoexcited gas-phase molecules. Here, we discuss the design of the electron gun, which is triggered by a Ti:Sapphire laser, before detailing a series of calibration experiments relating to the electron-beam properties. As a further test of the apparatus, initial diffraction patterns have been collected for thin, polycrystalline platinum samples, which have been shown to match theoretical patterns. The data collected demonstrate the focusing effects of the magnetic lens on the electron beam, and how this relates to the spatial resolution of the diffraction pattern.

  8. Communication: Quantum molecular dynamics simulation of liquid...

    Office of Scientific and Technical Information (OSTI)

    Communication: Quantum molecular dynamics simulation of liquid para-hydrogen by nuclear and electron wave packet approach Citation Details In-Document Search Title: Communication:...

  9. Achieving atomistic understanding of solvation dynamics from...

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

    Mechanics and Quantum Mechanical Molecular Mechanics calculations, we have been ... Achieving atomistic understanding of solvation dynamics from X-ray free-electron laser ...

  10. Consumer Electronics

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

    & Events Expand News & Events Skip navigation links Residential Residential Lighting Energy Star Appliances Consumer Electronics Heat Pump Water Heaters Electric Storage Water...

  11. Electronic Structure, Phonon Dynamical Properties, and Capture...

    Office of Scientific and Technical Information (OSTI)

    Resource Relation: Journal Name: Physical Review Applied; Journal Volume: 3; Journal Issue: 4 Research Org: National Energy Technology Laboratory - In-house Research Sponsoring ...

  12. Dynamic Electronic Control of Catalytic Converters

    Broader source: Energy.gov [DOE]

    Poster presentation at the 2007 Diesel Engine-Efficiency & Emissions Research Conference (DEER 2007). 13-16 August, 2007, Detroit, Michigan. Sponsored by the U.S. Department of Energy's (DOE) Office of FreedomCAR and Vehicle Technologies (OFCVT).

  13. Look-ahead Dynamic Simulation

    Energy Science and Technology Software Center (OSTI)

    2015-10-20

    Look-ahead dynamic simulation software system incorporates the high performance parallel computing technologies, significantly reduces the solution time for each transient simulation case, and brings the dynamic simulation analysis into on-line applications to enable more transparency for better reliability and asset utilization. It takes the snapshot of the current power grid status, functions in parallel computing the system dynamic simulation, and outputs the transient response of the power system in real time.

  14. Influence of chemical disorder on energy dissipation and defect evolution in concentrated solid solution alloys

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

    Zhang, Yanwen; Stocks, George Malcolm; Jin, Ke; Lu, Chenyang; Bei, Hongbin; Sales, Brian C.; Wang, Lumin; Béland, Laurent K.; Stoller, Roger E.; Samolyuk, German D.; et al

    2015-10-28

    A long-standing objective in materials research is to understand how energy is dissipated in both the electronic and atomic subsystems in irradiated materials, and how related non-equilibrium processes may affect defect dynamics and microstructure evolution. Here we show that alloy complexity in concentrated solid solution alloys having both an increasing number of principal elements and altered concentrations of specific elements can lead to substantial reduction in the electron mean free path and thermal conductivity, which has a significant impact on energy dissipation and consequentially on defect evolution during ion irradiation. Enhanced radiation resistance with increasing complexity from pure nickel tomore » binary and to more complex quaternary solid solutions is observed under ion irradiation up to an average damage level of 1 displacement per atom. Understanding how materials properties can be tailored by alloy complexity and their influence on defect dynamics may pave the way for new principles for the design of radiation tolerant structural alloys.« less

  15. Randa Energy Solutions LLC R A Energy Solutions | Open Energy...

    Open Energy Info (EERE)

    LLC R A Energy Solutions Jump to: navigation, search Name: Randa Energy Solutions, LLC (R&A Energy Solutions) Place: North Ridgeville, Ohio Zip: 44039 Product: String...

  16. Solution deposition assembly

    DOE Patents [OSTI]

    Roussillon, Yann; Scholz, Jeremy H; Shelton, Addison; Green, Geoff T; Utthachoo, Piyaphant

    2014-01-21

    Methods and devices are provided for improved deposition systems. In one embodiment of the present invention, a deposition system is provided for use with a solution and a substrate. The system comprises of a solution deposition apparatus; at least one heating chamber, at least one assembly for holding a solution over the substrate; and a substrate curling apparatus for curling at least one edge of the substrate to define a zone capable of containing a volume of the solution over the substrate. In another embodiment of the present invention, a deposition system for use with a substrate, the system comprising a solution deposition apparatus; at heating chamber; and at least assembly for holding solution over the substrate to allow for a depth of at least about 0.5 microns to 10 mm.

  17. TVA- Solar Solutions Initiative

    Broader source: Energy.gov [DOE]

    Solar Solutions Initiative (SSI) is a pilot program that offers additional financial incentives for Solar PV systems participating in the Renewable Standard Offer program. Applications for new...

  18. Mixed oxide solid solutions

    DOE Patents [OSTI]

    Magno, Scott; Wang, Ruiping; Derouane, Eric

    2003-01-01

    The present invention is a mixed oxide solid solution containing a tetravalent and a pentavalent cation that can be used as a support for a metal combustion catalyst. The invention is furthermore a combustion catalyst containing the mixed oxide solid solution and a method of making the mixed oxide solid solution. The tetravalent cation is zirconium(+4), hafnium(+4) or thorium(+4). In one embodiment, the pentavalent cation is tantalum(+5), niobium(+5) or bismuth(+5). Mixed oxide solid solutions of the present invention exhibit enhanced thermal stability, maintaining relatively high surface areas at high temperatures in the presence of water vapor.

  19. Superthermal electron distribution measurements from polarized electron cyclotron emission

    SciTech Connect (OSTI)

    Luce, T.C.; Efthimion, P.C.; Fisch, N.J.

    1988-06-01

    Measurements of the superthermal electron distribution can be made by observing the polarized electron cyclotron emission. The emission is viewed along a constant magnetic field surface. This simplifies the resonance condition and gives a direct correlation between emission frequency and kinetic energy of the emitting electron. A transformation technique is formulated which determines the anisotropy of the distribution and number density of superthermals at each energy measured. The steady-state distribution during lower hybrid current drive and examples of the superthermal dynamics as the runaway conditions is varied are presented for discharges in the PLT tokamak. 15 refs., 8 figs.

  20. 2012 WATER & AQUEOUS SOLUTIONS GORDON RESEARCH CONFERENCE (GRC) AND GORDON RESEARCH SEMINAR (GRS), AUG 10-17, 2012

    SciTech Connect (OSTI)

    Dor Ben-Amotz, PI

    2012-08-17

    Understanding the fundamental principles governing the structure and dynamics of water - and particularly how water mediates chemical interactions and processes - continues to pose formidable challenges and yield abundant surprises. The focus of this Gordon Research Conference is on identifying key questions, describing emerging understandings, and unveiling surprising discoveries related to water and aqueous solutions. The talks and posters at this meeting will describe studies of water and its interactions with objects such as interfaces, channels, electrons, oils, ions, and proteins; probed using optical, electrical, and particle experiments, and described using classical, quantum, and multi-scale theories.

  1. Solvent wash solution

    DOE Patents [OSTI]

    Neace, James C. (Blackville, SC)

    1986-01-01

    Process for removing diluent degradation products from a solvent extraction solution, which has been used to recover uranium and plutonium from spent nuclear fuel. A wash solution and the solvent extraction solution are combined. The wash solution contains (a) water and (b) up to about, and including, 50 volume percent of at least one-polar water-miscible organic solvent based on the total volume of the water and the highly-polar organic solvent. The wash solution also preferably contains at least one inorganic salt. The diluent degradation products dissolve in the highly-polar organic solvent and the organic solvent extraction solvent do not dissolve in the highly-polar organic solvent. The highly-polar organic solvent and the extraction solvent are separated.

  2. Solvent wash solution

    DOE Patents [OSTI]

    Neace, J.C.

    1984-03-13

    A process is claimed for removing diluent degradation products from a solvent extraction solution, which has been used to recover uranium and plutonium from spent nuclear fuel. A wash solution and the solvent extraction solution are combined. The wash solution contains (a) water and (b) up to about, and including, 50 vol % of at least one-polar water-miscible organic solvent based on the total volume of the water and the highly-polar organic solvent. The wash solution also preferably contains at least one inorganic salt. The diluent degradation products dissolve in the highly-polar organic solvent and the organic solvent extraction solvent do not dissolve in the highly-polar organic solvent. The highly-polar organic solvent and the extraction solvent are separated.

  3. Analytical Solutions of Landau (1+1)-Dimensional Hydrodynamics

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

    Sen, Abhisek; Gerhard, Jochen; Torrieri, Giorgio; Read, Jr, Kenneth F

    2014-01-01

    To help guide our intuition, summarize important features, and point out essential elements, we review the analytical solutions of Landau (1+1)-dimensional hydrodynamics and exhibit the full evolution of the dynamics from the very beginning to subsequent times. Special emphasis is placed on the matching and the interplay between the Khalatnikov solution and the Riemann simple wave solution at the earliest times and in the edge regions at later times.

  4. 43 PARTICLE ACCELERATORS; ELECTRON GUNS; BEAM EMITTANCE; CHARGE

    Office of Scientific and Technical Information (OSTI)

    SPACE 430200* -- Particle Accelerators-- Beam Dynamics, Field Calculations, & Ion Optics The evolution of the electron-beam phase space distribution in laser-driven rf guns is...

  5. Electron tube

    DOE Patents [OSTI]

    Suyama, Motohiro; Fukasawa, Atsuhito; Arisaka, Katsushi; Wang, Hanguo

    2011-12-20

    An electron tube of the present invention includes: a vacuum vessel including a face plate portion made of synthetic silica and having a surface on which a photoelectric surface is provided, a stem portion arranged facing the photoelectric surface and made of synthetic silica, and a side tube portion having one end connected to the face plate portion and the other end connected to the stem portion and made of synthetic silica; a projection portion arranged in the vacuum vessel, extending from the stem portion toward the photoelectric surface, and made of synthetic silica; and an electron detector arranged on the projection portion, for detecting electrons from the photoelectric surface, and made of silicon.

  6. Dispersant solutions for dispersing hydrocarbons

    DOE Patents [OSTI]

    Tyndall, R.L.

    1997-03-11

    A dispersant solution includes a hydrocarbon dispersing solution derived from a bacterium from ATCC 75527, ATCC 75529, or ATCC 55638.

  7. Dispersant solutions for dispersing hydrocarbons

    DOE Patents [OSTI]

    Tyndall, Richard L. (Clinton, TN)

    1997-01-01

    A dispersant solution includes a hydrocarbon dispersing solution derived from a bacterium from ATCC 75527, ATCC 75529, or ATCC 55638.

  8. Electronic Coupling Dependence of Ultrafast Interfacial Electron...

    Office of Scientific and Technical Information (OSTI)

    Electronic Coupling Dependence of Ultrafast Interfacial Electron Transfer on Nanocrystalline Thin Films and Single Crystal Citation Details In-Document Search Title: Electronic ...

  9. Electronic system

    DOE Patents [OSTI]

    Robison, G H; Dickson, J F

    1960-11-15

    An electronic system is designed for indicating the occurrence of a plurality of electrically detectable events within predetermined time intervals. The system comprises separate input means electrically associated with the events under observation an electronic channel associated with each input means, including control means and indicating means; timing means adapted to apply a signal from the input means after a predetermined time to the control means to deactivate each of the channels; and means for resetting the system to its initial condition after the observation of each group of events. (D.L.C.)

  10. ELECTRONIC SYSTEM

    DOE Patents [OSTI]

    Robison, G.H. et al.

    1960-11-15

    An electronic system is described for indicating the occurrence of a plurality of electrically detectable events within predetermined time intervals. It is comprised of separate input means electrically associated with the events under observation: an electronic channel associated with each input means including control means and indicating means; timing means associated with each of the input means and the control means and adapted to derive a signal from the input means and apply it after a predetermined time to the control means to effect deactivation of each of the channels; and means for resetting the system to its initial condition after observation of each group of events.

  11. Including the Effects of Electronic Excitations and Electron-Phonon Coupling in Cascade Simulations

    SciTech Connect (OSTI)

    Duffy, Dorothy |

    2008-07-01

    Radiation damage has traditionally been modeled using cascade simulations however such simulations generally neglect the effects of electron-ion interactions, which may be significant in high energy cascades. A model has been developed which includes the effects of electronic stopping and electron-phonon coupling in Molecular Dynamics simulations by means of an inhomogeneous Langevin thermostat. The energy lost by the atoms to electronic excitations is gained by the electronic system and the energy evolution of the electronic system is modeled by the heat diffusion equation. Energy is exchanged between the electronic system and the atoms in the Molecular Dynamics simulation by means of a Langevin thermostat, the temperature of which is the local electronic temperature. The model is applied to a 10 keV cascade simulation for Fe. (authors)

  12. Residential Energy Efficiency Solutions

    Broader source: Energy.gov [DOE]

    Our mission is to increase the availability of high-quality, safe, affordable and workforce housing options. Through innovative reuse and rehabilitation we incorporate economic benefits, environmental stewardship/energy efficiency, and social solutions.

  13. Drama in Dynamics: Boom, Splash, and Speed

    SciTech Connect (OSTI)

    Heather Marie Netzloff

    2004-12-19

    The full nature of chemistry and physics cannot be captured by static calculations alone. Dynamics calculations allow the simulation of time-dependent phenomena. This facilitates both comparisons with experimental data and the prediction and interpretation of details not easily obtainable from experiments. Simulations thus provide a direct link between theory and experiment, between microscopic details of a system and macroscopic observed properties. Many types of dynamics calculations exist. The most important distinction between the methods and the decision of which method to use can be described in terms of the size and type of molecule/reaction under consideration and the type and level of accuracy required in the final properties of interest. These considerations must be balanced with available computational codes and resources as simulations to mimic ''real-life'' may require many time steps. As indicated in the title, the theme of this thesis is dynamics. The goal is to utilize the best type of dynamics for the system under study while trying to perform dynamics in the most accurate way possible. As a quantum chemist, this involves some level of first principles calculations by default. Very accurate calculations of small molecules and molecular systems are now possible with relatively high-level ab initio quantum chemistry. For example, a quantum chemical potential energy surface (PES) can be developed ''on-the-fly'' with dynamic reaction path (DRP) methods. In this way a classical trajectory is developed without prior knowledge of the PES. In order to treat solvation processes and the condensed phase, large numbers of molecules are required, especially in predicting bulk behavior. The Effective Fragment Potential (EFP) method for solvation decreases the cost of a fully quantum mechanical calculation by dividing a chemical system into an ab initio region that contains the solute and an ''effective fragment'' region that contains the remaining solvent

  14. ELECTRONIC MULTIPLIER

    DOE Patents [OSTI]

    Collier, D.M.; Meeks, L.A.; Palmer, J.P.

    1961-01-31

    S>An electronic multiplier is described for use in analog computers. Two electrical input signals are received; one controls the slope of a saw-tooth voltage wave while the other controls the time duration of the wave. A condenser and diode clamps are provided to sustain the crest voltage reached by the wave, and for storing that voltage to provide an output signal which is a steady d-c voltage.

  15. Electron Bernstein

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

    Bernstein wave emission from an overdense reversed field pinch plasma P. K. Chattopadhyay, J. K. Anderson, T. M. Biewer, D. Craig, and C. B. Forest a) Department of Physics, University of Wisconsin, Madison, Wisconsin 53706 R. W. Harvey CompX, Del Mar, California 92014 A. P. Smirnov Moscow State University, Moscow, Russia ͑Received 11 October 2001; accepted 20 November 2001͒ Blackbody levels of emission in the electron cyclotron range of frequencies have been observed from an overdense (␻ pe

  16. Bifurcations of traveling wave solutions for an integrable equation

    SciTech Connect (OSTI)

    Li Jibin; Qiao Zhijun

    2010-04-15

    This paper deals with the following equation m{sub t}=(1/2)(1/m{sup k}){sub xxx}-(1/2)(1/m{sup k}){sub x}, which is proposed by Z. J. Qiao [J. Math. Phys. 48, 082701 (2007)] and Qiao and Liu [Chaos, Solitons Fractals 41, 587 (2009)]. By adopting the phase analysis method of planar dynamical systems and the theory of the singular traveling wave systems to the traveling wave solutions of the equation, it is shown that for different k, the equation may have infinitely many solitary wave solutions, periodic wave solutions, kink/antikink wave solutions, cusped solitary wave solutions, and breaking loop solutions. We discuss in a detail the cases of k=-2,-(1/2),(1/2),2, and parametric representations of all possible bounded traveling wave solutions are given in the different (c,g)-parameter regions.

  17. ELECTRON GUN

    DOE Patents [OSTI]

    Christofilos, N.C.; Ehlers, K.W.

    1960-04-01

    A pulsed electron gun capable of delivering pulses at voltages of the order of 1 mv and currents of the order of 100 amperes is described. The principal novelty resides in a transformer construction which is disposed in the same vacuum housing as the electron source and accelerating electrode structure of the gun to supply the accelerating potential thereto. The transformer is provided by a plurality of magnetic cores disposed in circumferentially spaced relation and having a plurality of primary windings each inductively coupled to a different one of the cores, and a helical secondary winding which is disposed coaxially of the cores and passes therethrough in circumferential succession. Additional novelty resides in the disposition of the electron source cathode filament input leads interiorly of the transformer secondary winding which is hollow, as well as in the employment of a half-wave filament supply which is synchronously operated with the transformer supply such that the transformer is pulsed during the zero current portions of the half-wave cycle.

  18. Cylindrical and spherical electron acoustic solitary waves with nonextensive hot electrons

    SciTech Connect (OSTI)

    Pakzad, Hamid Reza

    2011-08-15

    Nonlinear propagation of cylindrical and spherical electron-acoustic solitons in an unmagnetized plasma consisting cold electron fluid, hot electrons obeying a nonextensive distribution and stationary ions, are investigated. For this purpose, the standard reductive perturbation method is employed to derive the cylindrical/spherical Korteweg-de-Vries equation, which governs the dynamics of electron-acoustic solitons. The effects of nonplanar geometry and nonextensive hot electrons on the behavior of cylindrical and spherical electron acoustic solitons are also studied by numerical simulations.

  19. New technique images nanoparticles in solution

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

    technique images nanoparticles in solution Click to share on Facebook (Opens in new window) Click to share on Twitter (Opens in new window) Click to share on Reddit (Opens in new window) Click to share on Pinterest (Opens in new window) A technique called SINGLE uses in situ transmission electron microscopy imaging of platinum nanocrystals freely rotating in a graphene liquid cell to determine the 3-D structures of individual colloidal nanoparticles. (Image: Berkeley Lab) More » Nanotubes that

  20. Beam Dynamics for ARIA

    SciTech Connect (OSTI)

    Ekdahl, Carl August Jr.

    2014-10-14

    Beam dynamics issues are assessed for a new linear induction electron accelerator being designed for flash radiography of large explosively driven hydrodynamic experiments. Special attention is paid to equilibrium beam transport, possible emittance growth, and beam stability. It is concluded that a radiographic quality beam will be produced possible if engineering standards and construction details are equivalent to those on the present radiography accelerators at Los Alamos.

  1. Solution mass measurement

    SciTech Connect (OSTI)

    Ford, W.; Marshall, R.S.; Osborn, L.C.; Picard, R.; Thomas, C.C. Jr.

    1982-07-01

    This report describes the efforts to develop and demonstrate a solution mass measurement system for use at the Los Alamos Plutonium Facility. Because of inaccuracy of load cell measurements, our major effort was directed towards the pneumatic bubbler tube. The differential pressure between the air inlet to the bubbler tube and the glovebox interior is measured and is proportional to the solution mass in the tank. An inexpensive, reliable pressure transducer system for measuring solution mass in vertical, cylindrical tanks was developed, tested, and evaluated in a laboratory test bed. The system can withstand the over- and underpressures resulting from solution transfer operations and can prevent solution backup into the measurement pressure transducer during transfers. Drifts, noise, quantization error, and other effects limit the accuracy to 30 g. A transportable calibration system using a precision machined tank, pneumatic bubbler tubes, and a Ruska DDR 6000 electromanometer was designed, fabricated, tested, and evaluated. Resolution of the system is +-3.5 g out of 50 kg. The calibration error is 5 g, using room-temperature water as the calibrating fluid. Future efforts will be directed towards in-plant test and evaluation of the tank measurement systems. 16 figures, 3 tables.

  2. Microbial Activity and Precipitation at Solution-Solution Mixing...

    Office of Scientific and Technical Information (OSTI)

    Media -- Subsurface Biogeochemical Research Citation Details In-Document Search Title: Microbial Activity and Precipitation at Solution-Solution Mixing Zones in Porous Media -- ...

  3. Nonaqueous solution synthesis process for preparing oxide powders of lead zirconate titanate and related materials

    DOE Patents [OSTI]

    Voigt, James A.; Sipola, Diana L.; Tuttle, Bruce A.; Anderson, Mark T.

    1999-01-01

    A process for producing powders of perovskite-type compounds which comprises mixing a metal alkoxide solution with a lead acetate solution to form a homogeneous, clear metal solution, adding an oxalic acid/n-propanol solution to this metal solution to form an easily filterable, free-flowing precursor powder and then calcining this powder. This process provides fine perovskite-phase powders with ferroelectric properties which are particularly useful in a variety of electronic applications.

  4. Nonaqueous solution synthesis process for preparing oxide powders of lead zirconate titanate and related materials

    DOE Patents [OSTI]

    Voigt, J.A.; Sipola, D.L.; Tuttle, B.A.; Anderson, M.T.

    1999-06-01

    A process is disclosed for producing powders of perovskite-type compounds which comprises mixing a metal alkoxide solution with a lead acetate solution to form a homogeneous, clear metal solution, adding an oxalic acid/n-propanol solution to this metal solution to form an easily filterable, free-flowing precursor powder and then calcining this powder. This process provides fine perovskite-phase powders with ferroelectric properties which are particularly useful in a variety of electronic applications. 4 figs.

  5. Fissile solution measurement apparatus

    DOE Patents [OSTI]

    Crane, T.W.; Collinsworth, P.R.

    1984-06-11

    An apparatus for determining the content of a fissile material within a solution by detecting delayed fission neutrons emitted by the fissile material after it is temporarily irradiated by a neutron source. The apparatus comprises a container holding the solution and having a portion defining a neutron source cavity centrally disposed within the container. The neutron source cavity temporarily receives the neutron source. The container has portions defining a plurality of neutron detector ports that form an annular pattern and surround the neutron source cavity. A plurality of neutron detectors count delayed fission neutrons emitted by the fissile material. Each neutron detector is located in a separate one of the neutron detector ports.

  6. Sol Solution | Open Energy Information

    Open Energy Info (EERE)

    Solution Jump to: navigation, search Name: Sol Solution Place: Los Gatos, California Zip: 95030 Region: Bay Area Sector: Solar Product: Rainbow Concentrator, Current matching...

  7. Building Solutions | Open Energy Information

    Open Energy Info (EERE)

    Building Solutions Jump to: navigation, search Name: Building Solutions Place: California Sector: Efficiency Product: California-based energy efficiency contractor and consultancy....

  8. Soy Solutions | Open Energy Information

    Open Energy Info (EERE)

    Solutions Jump to: navigation, search Name: Soy Solutions Place: Milford, Iowa Zip: 51351 Product: Manufacturer and distributor of 100 percent Soy-Based Biodiesel References: Soy...

  9. Enspiria Solutions | Open Energy Information

    Open Energy Info (EERE)

    Page Edit with form History Enspiria Solutions Jump to: navigation, search Name: Enspiria Solutions Place: Greenwood Village, Colorado Sector: Services Product: Greenwood...

  10. Powerit Solutions | Open Energy Information

    Open Energy Info (EERE)

    Powerit Solutions Jump to: navigation, search Name: Powerit Solutions Address: 568 First Ave South Place: Seattle, Washington Zip: 98104 Region: Pacific Northwest Area Sector:...

  11. Computational Electronics and Electromagnetics

    SciTech Connect (OSTI)

    DeFord, J.F.

    1993-03-01

    The Computational Electronics and Electromagnetics thrust area is a focal point for computer modeling activities in electronics and electromagnetics in the Electronics Engineering Department of Lawrence Livermore National Laboratory (LLNL). Traditionally, they have focused their efforts in technical areas of importance to existing and developing LLNL programs, and this continues to form the basis for much of their research. A relatively new and increasingly important emphasis for the thrust area is the formation of partnerships with industry and the application of their simulation technology and expertise to the solution of problems faced by industry. The activities of the thrust area fall into three broad categories: (1) the development of theoretical and computational models of electronic and electromagnetic phenomena, (2) the development of useful and robust software tools based on these models, and (3) the application of these tools to programmatic and industrial problems. In FY-92, they worked on projects in all of the areas outlined above. The object of their work on numerical electromagnetic algorithms continues to be the improvement of time-domain algorithms for electromagnetic simulation on unstructured conforming grids. The thrust area is also investigating various technologies for conforming-grid mesh generation to simplify the application of their advanced field solvers to design problems involving complicated geometries. They are developing a major code suite based on the three-dimensional (3-D), conforming-grid, time-domain code DSI3D. They continue to maintain and distribute the 3-D, finite-difference time-domain (FDTD) code TSAR, which is installed at several dozen university, government, and industry sites.

  12. Energy Solutions Conference

    Broader source: Energy.gov [DOE]

    The virtual Energy Solutions Conference will be held March 23–24, 2016. Bioenergy Technologies Office Director Jonathan Male will be giving a virtual presentation on the Office’s activities supporting the federal bioeconomy as part of the renewable energy portion of the program.

  13. SCADA Engineering Solutions

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

    Engineering Solutions - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us Employee Locator Energy & Climate Secure & Sustainable Energy Future Stationary Power Energy Conversion Efficiency Solar Energy Wind Energy Water Power Supercritical CO2 Geothermal Natural Gas Safety, Security & Resilience of the Energy Infrastructure Energy Storage Nuclear Power & Engineering Grid Modernization Battery Testing Nuclear Energy Defense Waste Management Programs Advanced

  14. The chemistry of plutonium(VI) in aqueous carbonate solutions

    SciTech Connect (OSTI)

    Stout, B.E.; Choppin, G.R. . Dept. of Chemistry); Sullivan, J.C. )

    1990-01-01

    The dynamic behavior of carbonate ion as a ligand that interacts with the hexavalent actinyl ions of U, Np, and Pu has been examined by {sup 13}C NMR. The first order rate parameter that describes the exchange between bulk solution and bound carbonate decreases with increasing pH. At a pH of 10.0, 25{degree}C, the respective values of k for the U(VI), Np(VI) and Pu(VI) complexes are 27.1 {plus minus} 0.3, 64.7 {plus minus} 3.3 and 706 {plus minus} 29. The variation of k with temperature was used to calculate the values of {Delta}H{sup +} = 53 and 42 kJ/M; and {Delta}S{sup +} = {minus}40 and {minus}71 J/M-K for the uranyl and neptunyl systems, respectively. A plausible reaction scheme for the exchange reaction is considered. The influence of these slow carbonate exchange reactions on selected electron transfer reactions is noted. 19 refs., 4 figs., 2 tabs.

  15. Structural aspects of the solvation shell of lysine and acetylated lysine: A Car-Parrinello and classical molecular dynamics investigation

    SciTech Connect (OSTI)

    Carnevale, V.; Raugei, S.

    2009-12-14

    Lysine acetylation is a post-translational modification, which modulates the affinity of protein-protein and/or protein-DNA complexes. Its crucial role as a switch in signaling pathways highlights the relevance of charged chemical groups in determining the interactions between water and biomolecules. A great effort has been recently devoted to assess the reliability of classical molecular dynamics simulations in describing the solvation properties of charged moieties. In the spirit of these investigations, we performed classical and Car-Parrinello molecular dynamics simulations on lysine and acetylated-lysine in aqueous solution. A comparative analysis between the two computational schemes is presented with a focus on the first solvation shell of the charged groups. An accurate structural analysis unveils subtle, yet statistically significant, differences which are discussed in connection to the significant electronic density charge transfer occurring between the solute and the surrounding water molecules.

  16. Characterizing multiple solutions to the time-energy canonical commutation relation via internal symmetries

    SciTech Connect (OSTI)

    Caballar, Roland Cristopher F.; Ocampo, Leonard R.; Galapon, Eric A.

    2010-06-15

    Internal symmetries can be used to classify multiple solutions to the time-energy canonical commutation relation (TE-CCR). The dynamical behavior of solutions to the TE-CCR possessing particular internal symmetries involving time reversal differ significantly from solutions to the TE-CCR without those particular symmetries, implying a connection between the internal symmetries of a quantum system, its internal unitary dynamics, and the TE-CCR.

  17. Aggregation of heteropolyanions in aqueous solutions exhibiting short-range attractions and long-range repulsions

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

    Bera, Mrinal K.; Qiao, Baofu; Seifert, Soenke; Burton-Pye, Benjamin P.; Monica Olvera de la Cruz; Antonio, Mark R.

    2015-12-15

    Charged colloids and proteins in aqueous solutions interact via short-range attractions and long-range repulsions (SALR) and exhibit complex structural phases. These include homogeneously dispersed monomers, percolated monomers, clusters, and percolated clusters. We report the structural architectures of simple charged systems in the form of spherical, Keggin-type heteropolyanions (HPAs) by small-angle X-ray scattering (SAXS) and molecular dynamics (MD) simulations. Structure factors obtained from the SAXS measurements show that the HPAs interact via SALR. Concentration and temperature dependences of the structure factors for HPAs with –3e (e is the charge of an electron) charge are consistent with a mixture of nonassociated monomersmore » and associated randomly percolated monomers, whereas those for HPAs with –4e and –5e charges exhibit only nonassociated monomers in aqueous solutions. Our experiments show that the increase in magnitude of the charge of the HPAs increases their repulsive interactions and inhibits their aggregation in aqueous solutions. MD simulations were done to reveal the atomistic scale origins of SALR between HPAs. As a result, the short-range attractions result from water or proton-mediated hydrogen bonds between neighboring HPAs, whereas the long-range repulsions are due to the distributions of ions surrounding the HPAs.« less

  18. Sandia National Laboratories: Rad-Hard Electronics and Trusted Services

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

    Rad-Hard Electronics and Trusted Services Sensors Sandia's Microsystems Center affords access to trusted resources and facilities for research and development, design, layout, fabrication, characterization, packaging, and test Custom Solutions Trusted Electronic Microsystems The Sandia National Laboratories Microsystems Engineering and Sciences Applications (MESA) complex has achieved Defense MicroElectronics Activity (DMEA) Category 1A Trust Accreditation for trusted services including design,

  19. Electronic Coupling Dependence of Ultrafast Interfacial Electron...

    Office of Scientific and Technical Information (OSTI)

    Electron Transfer on Nanocrystalline Thin Films and Single Crystal Lian, Tianquan 14 SOLAR ENERGY The long-term goal of the proposed research is to understand electron transfer...

  20. Low-Cost Solutions for Dynamic Window Material | Department of...

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

    & Publications Atmospheric Pressure Deposition for Electrochromic Windows Nanolens Window Coatings for Daylighting Advanced Facades, Daylighting, and Complex Fenestration Systems

  1. Low-Cost Solutions for Dynamic Window Material

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

    ... we use "terminated cluster growth". * Nanoparticles (copper, vanadium) have been synthesized and analyzed * First oxide nanoparticles have been made and deposited as a film ...

  2. Mega-electron-volt ultrafast electron diffraction at SLAC National Accelerator Laboratory

    SciTech Connect (OSTI)

    Weathersby, S. P.; Brown, G.; Centurion, M.; Chase, T. F.; Coffee, R.; Corbett, J.; Eichner, J. P.; Frisch, J. C.; Fry, A. R.; Gühr, M.; Hartmann, N.; Hast, C.; Hettel, R.; Jobe, R. K.; Jongewaard, E. N.; Lewandowski, J. R.; Li, R. K.; Lindenberg, A. M.; Makasyuk, I.; May, J. E.; McCormick, D.; Nguyen, M. N.; Reid, A. H.; Shen, X.; Sokolowski-Tinten, K.; Vecchione, T.; Vetter, S. L.; Wu, J.; Yang, J.; Dürr, H. A.; Wang, X. J.

    2015-07-01

    Ultrafast electron probes are powerful tools, complementary to x-ray free-electron lasers, used to study structural dynamics in material, chemical, and biological sciences. High brightness, relativistic electron beams with femtosecond pulse duration can resolve details of the dynamic processes on atomic time and length scales. SLAC National Accelerator Laboratory recently launched the Ultrafast Electron Diffraction (UED) and microscopy Initiative aiming at developing the next generation ultrafast electron scattering instruments. As the first stage of the Initiative, a mega-electron-volt (MeV) UED system has been constructed and commissioned to serve ultrafast science experiments and instrumentation development. The system operates at 120-Hz repetition rate with outstanding performance. In this paper, we report on the SLAC MeV UED system and its performance, including the reciprocal space resolution, temporal resolution, and machine stability.

  3. Simulation Results of a Feedback Control System to Damp Electron Cloud Single-Bunch Transverse Instabilities In The Cern SPS

    SciTech Connect (OSTI)

    Secondo, R.; Vay, J. L.; Venturini, M.; Fox, J. D.; Rivetta, C. H.; Hofle, W.

    2011-03-28

    Transverse Single-Bunch Instabilities due to the Electron Cloud effect are limiting the operation at high current of the SPS at CERN. Recently a high-bandwidth Feedback System has been proposed as a possible solution to stabilize the beam and is currently under study. We analyze the dynamics of the bunch actively damped with a simple model of the Feedback in the macro-particle code WARP, in order to investigate the limitations of the System such as the minimum amount of power required to maintain stability. We discuss the feedback model, report on simulation results and present our plans for further development of the numerical model.

  4. Slow Dynamics of Orbital Domains in Manganite

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

    Slow Dynamics of Orbital Domains in Manganite Slow Dynamics of Orbital Domains in Manganite Print Wednesday, 25 June 2008 00:00 At the ALS, an international team of researchers has used low-energy coherent x rays to extract new knowledge about the correlated motion of groups of self-assembled, outer-lying electrons in the extremely complex electronic system found in manganites. The manganite family of materials has puzzled physicists for years by defying standard models for the motion of

  5. Ion aggregation in high salt solutions. III. Computational vibrational spectroscopy of HDO in aqueous salt solutions

    SciTech Connect (OSTI)

    Choi, Jun-Ho; Lim, Sohee; Chon, Bonghwan; Cho, Minhaeng; Kim, Heejae; Kim, Seongheun

    2015-05-28

    The vibrational frequency, frequency fluctuation dynamics, and transition dipole moment of the OD stretch mode of HDO molecule in aqueous solutions are strongly dependent on its local electrostatic environment and hydrogen-bond network structure. Therefore, the time-resolved vibrational spectroscopy the OD stretch mode has been particularly used to investigate specific ion effects on water structure. Despite prolonged efforts to understand the interplay of OD vibrational dynamics with local water hydrogen-bond network and ion aggregate structures in high salt solutions, still there exists a gap between theory and experiment due to a lack of quantitative model for accurately describing OD stretch frequency in high salt solutions. To fill this gap, we have performed numerical simulations of Raman scattering and IR absorption spectra of the OD stretch mode of HDO in highly concentrated NaCl and KSCN solutions and compared them with experimental results. Carrying out extensive quantum chemistry calculations on not only water clusters but also ion-water clusters, we first developed a distributed vibrational solvatochromic charge model for the OD stretch mode in aqueous salt solutions. Furthermore, the non-Condon effect on the vibrational transition dipole moment of the OD stretch mode was fully taken into consideration with the charge response kernel that is non-local polarizability density. From the fluctuating OD stretch mode frequencies and transition dipole vectors obtained from the molecular dynamics simulations, the OD stretch Raman scattering and IR absorption spectra of HDO in salt solutions could be calculated. The polarization effect on the transition dipole vector of the OD stretch mode is shown to be important and the asymmetric line shapes of the OD stretch Raman scattering and IR absorption spectra of HDO especially in highly concentrated NaCl and KSCN solutions are in quantitative agreement with experimental results. We anticipate that this

  6. Three-dimensional dust-ion-acoustic rogue waves in a magnetized dusty pair-ion plasma with nonthermal nonextensive electrons and opposite polarity dust grains

    SciTech Connect (OSTI)

    Guo, Shimin Mei, Liquan

    2014-08-15

    Dust-ion-acoustic (DIA) rogue waves are investigated in a three-dimensional magnetized plasma containing nonthermal electrons featuring Tsallis distribution, both positive and negative ions, and immobile dust grains having both positive and negative charges. Via the reductive perturbation method, a (3?+?1)-dimensional nonlinear Schrdinger (NLS) equation is derived to govern the dynamics of the DIA wave packets. The modulation instability of DIA waves described by the (3?+?1)-dimensional NLS equation is investigated. By means of the similarity transformation and symbolic computation, both the first- and second-order rogue wave solutions of the (3?+?1)-dimensional NLS equation are constructed in terms of rational functions. Moreover, the dynamics properties and the effects of plasma parameters on the nonlinear structures of rogue waves are discussed in detail. The results could be useful for understanding the physical mechanism of rogue waves in laboratory experiments where pair-ion plasmas with electrons and dust grains can be found.

  7. 2013 R&D 100 Award: Movie-mode electron microscope captures nanoscale

    ScienceCinema (OSTI)

    Lagrange, Thomas; Reed, Bryan

    2014-07-21

    A new instrument developed by LLNL scientists and engineers, the Movie Mode Dynamic Transmission Electron Microscope (MM-DTEM), captures billionth-of-a-meter-scale images with frame rates more than 100,000 times faster than those of conventional techniques. The work was done in collaboration with a Pleasanton-based company, Integrated Dynamic Electron Solutions (IDES) Inc. Using this revolutionary imaging technique, a range of fundamental and technologically important material and biological processes can be captured in action, in complete billionth-of-a-meter detail, for the first time. The primary application of MM-DTEM is the direct observation of fast processes, including microstructural changes, phase transformations and chemical reactions, that shape real-world performance of nanostructured materials and potentially biological entities. The instrument could prove especially valuable in the direct observation of macromolecular interactions, such as protein-protein binding and host-pathogen interactions. While an earlier version of the technology, Single Shot-DTEM, could capture a single snapshot of a rapid process, MM-DTEM captures a multiframe movie that reveals complex sequences of events in detail. It is the only existing technology that can capture multiple electron microscopy images in the span of a single microsecond.

  8. Energy: elusive solutions

    SciTech Connect (OSTI)

    Velocci, T.

    1980-08-01

    The author states that America's seven-year search for answers to the energy crisis has produced more promise than substance. In fact, the US is even more dependent on imported oil today than it was in 1973 when the Arabs slapped on their economy-busting embargo. US imports have risen from 35% then to 40% now of daily oil consumption. The price of a barrel has doubled since last year and US product is sagging. Synthetic fuels from oil shale and coal deposits and conservation are still seen as the only solution to US independence from OPEC nations. (PSB)

  9. Boltzmann-Electron Model in Aleph.

    SciTech Connect (OSTI)

    Hughes, Thomas Patrick; Hooper, Russell

    2014-11-01

    We apply the Boltzmann-electron model in the electrostatic, particle-in-cell, finite- element code Aleph to a plasma sheath. By assuming a Boltzmann energy distribution for the electrons, the model eliminates the need to resolve the electron plasma fre- quency, and avoids the numerical %22grid instability%22 that can cause unphysical heating of electrons. This allows much larger timesteps to be used than with kinetic electrons. Ions are treated with the standard PIC algorithm. The Boltzmann-electron model re- quires solution of a nonlinear Poisson equation, for which we use an iterative Newton solver (NOX) from the Trilinos Project. Results for the spatial variation of density and voltage in the plasma sheath agree well with an analytic model

  10. Dirac solutions for quaternionic potentials

    SciTech Connect (OSTI)

    De Leo, Stefano Giardino, Sergio

    2014-02-15

    The Dirac equation is solved for quaternionic potentials, i?V{sub 0} + j?W{sub 0} (V{sub 0}?R , W{sub 0}?C). The study shows two different solutions. The first one contains particle and anti-particle solutions and leads to the diffusion, tunneling, and Klein energy zones. The standard solution is recovered taking the complex limit of this solution. The second solution, which does not have a complex counterpart, can be seen as a V{sub 0}-antiparticle or |W{sub 0}|-particle solution.

  11. Three-temperature plasma shock solutions with gray radiation diffusion

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

    Johnson, Bryan M.; Klein, Richard I.

    2016-04-19

    Here we discuss the effects of radiation on the structure of shocks in a fully ionized plasma are investigated by solving the steady-state fluid equations for ions, electrons, and radiation. The electrons and ions are assumed to have the same bulk velocity but separate temperatures, and the radiation is modeled with the gray diffusion approximation. Both electron and ion conduction are included, as well as ion viscosity. When the material is optically thin, three-temperature behavior occurs. When the diffusive flux of radiation is important but radiation pressure is not, two-temperature behavior occurs, with the electrons strongly coupled to the radiation.more » Since the radiation heats the electrons on length scales that are much longer than the electron–ion Coulomb coupling length scale, these solutions resemble radiative shock solutions rather than plasma shock solutions that neglect radiation. When radiation pressure is important, all three components are strongly coupled. Results with constant values for the transport and coupling coefficients are compared to a full numerical simulation with a good match between the two, demonstrating that steady shock solutions constitute a straightforward and comprehensive verification test methodology for multi-physics numerical algorithms.« less

  12. Non-adiabatic molecular dynamics by accelerated semiclassical Monte Carlo

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

    White, Alexander J.; Gorshkov, Vyacheslav N.; Tretiak, Sergei; Mozyrsky, Dmitry

    2015-07-07

    Non-adiabatic dynamics, where systems non-radiatively transition between electronic states, plays a crucial role in many photo-physical processes, such as fluorescence, phosphorescence, and photoisomerization. Methods for the simulation of non-adiabatic dynamics are typically either numerically impractical, highly complex, or based on approximations which can result in failure for even simple systems. Recently, the Semiclassical Monte Carlo (SCMC) approach was developed in an attempt to combine the accuracy of rigorous semiclassical methods with the efficiency and simplicity of widely used surface hopping methods. However, while SCMC was found to be more efficient than other semiclassical methods, it is not yet as efficientmore » as is needed to be used for large molecular systems. Here, we have developed two new methods: the accelerated-SCMC and the accelerated-SCMC with re-Gaussianization, which reduce the cost of the SCMC algorithm up to two orders of magnitude for certain systems. In many cases shown here, the new procedures are nearly as efficient as the commonly used surface hopping schemes, with little to no loss of accuracy. This implies that these modified SCMC algorithms will be of practical numerical solutions for simulating non-adiabatic dynamics in realistic molecular systems.« less

  13. Non-adiabatic molecular dynamics by accelerated semiclassical Monte Carlo

    SciTech Connect (OSTI)

    White, Alexander J.; Gorshkov, Vyacheslav N.; Tretiak, Sergei; Mozyrsky, Dmitry

    2015-07-07

    Non-adiabatic dynamics, where systems non-radiatively transition between electronic states, plays a crucial role in many photo-physical processes, such as fluorescence, phosphorescence, and photoisomerization. Methods for the simulation of non-adiabatic dynamics are typically either numerically impractical, highly complex, or based on approximations which can result in failure for even simple systems. Recently, the Semiclassical Monte Carlo (SCMC) approach was developed in an attempt to combine the accuracy of rigorous semiclassical methods with the efficiency and simplicity of widely used surface hopping methods. However, while SCMC was found to be more efficient than other semiclassical methods, it is not yet as efficient as is needed to be used for large molecular systems. Here, we have developed two new methods: the accelerated-SCMC and the accelerated-SCMC with re-Gaussianization, which reduce the cost of the SCMC algorithm up to two orders of magnitude for certain systems. In many cases shown here, the new procedures are nearly as efficient as the commonly used surface hopping schemes, with little to no loss of accuracy. This implies that these modified SCMC algorithms will be of practical numerical solutions for simulating non-adiabatic dynamics in realistic molecular systems.

  14. Electron beam generation in Tevatron electron lenses

    SciTech Connect (OSTI)

    Kamerdzhiev, V.; Kuznetsov, G.; Shiltsev, V.; Solyak, N.; Tiunov, M.; /Novosibirsk, IYF

    2006-08-01

    New type of high perveance electron guns with convex cathode has been developed. Three guns described in this article are built to provide transverse electron current density distributions needed for Electron Lenses for beam-beam compensation in the Tevatron collider. The current distribution can be controlled either by the gun geometry or by voltage on a special control electrode located near cathode. We present the designs of the guns and report results of beam measurements on the test bench. Because of their high current density and low transverse temperature of electrons, electron guns of this type can be used in electron cooling and beam-beam compensation devices.

  15. Microsoft Word - Advanced Solution Verification of CFD Solutions for LES of GTRF_Rider_August23.docx

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

    VUQ.VVDA.P4.03 Jim Stewart SNL Completed: 8/31/2012 CASL-U-2012-0132-000 Advanced Solution Verification of CFD Solutions for LES o f R elevance t o GTRF Estimates. William J. Rider and James R. Kamm Sandia N ational L aboratories Albuquerque, NM 87185 August 31, 2012 SAND 2 012---7199P Summary The purpose of this work is to d emonstrate advanced solution verification (i.e., numerical error estimation) techniques on computational fluid dynamics simulations of interest to CASL. The specific case

  16. Optically pulsed electron accelerator

    DOE Patents [OSTI]

    Fraser, J.S.; Sheffield, R.L.

    1985-05-20

    An optically pulsed electron accelerator can be used as an injector for a free electron laser and comprises a pulsed light source, such as a laser, for providing discrete incident light pulses. A photoemissive electron source emits electron bursts having the same duration as the incident light pulses when impinged upon by same. The photoemissive electron source is located on an inside wall of a radiofrequency-powered accelerator cell which accelerates the electron burst emitted by the photoemissive electron source.

  17. Optically pulsed electron accelerator

    DOE Patents [OSTI]

    Fraser, John S.; Sheffield, Richard L.

    1987-01-01

    An optically pulsed electron accelerator can be used as an injector for a free electron laser and comprises a pulsed light source, such as a laser, for providing discrete incident light pulses. A photoemissive electron source emits electron bursts having the same duration as the incident light pulses when impinged upon by same. The photoemissive electron source is located on an inside wall of a radio frequency powered accelerator cell which accelerates the electron burst emitted by the photoemissive electron source.

  18. Slow Dynamics of Orbital Domains in Manganite

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

    Slow Dynamics of Orbital Domains in Manganite Print At the ALS, an international team of researchers has used low-energy coherent x rays to extract new knowledge about the correlated motion of groups of self-assembled, outer-lying electrons in the extremely complex electronic system found in manganites. The manganite family of materials has puzzled physicists for years by defying standard models for the motion of electrons in crystals. By controlling the properties of the incident x rays, the

  19. Slow Dynamics of Orbital Domains in Manganite

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

    Slow Dynamics of Orbital Domains in Manganite Print At the ALS, an international team of researchers has used low-energy coherent x rays to extract new knowledge about the correlated motion of groups of self-assembled, outer-lying electrons in the extremely complex electronic system found in manganites. The manganite family of materials has puzzled physicists for years by defying standard models for the motion of electrons in crystals. By controlling the properties of the incident x rays, the

  20. Slow Dynamics of Orbital Domains in Manganite

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

    Slow Dynamics of Orbital Domains in Manganite Print At the ALS, an international team of researchers has used low-energy coherent x rays to extract new knowledge about the correlated motion of groups of self-assembled, outer-lying electrons in the extremely complex electronic system found in manganites. The manganite family of materials has puzzled physicists for years by defying standard models for the motion of electrons in crystals. By controlling the properties of the incident x rays, the

  1. Slow Dynamics of Orbital Domains in Manganite

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

    Slow Dynamics of Orbital Domains in Manganite Print At the ALS, an international team of researchers has used low-energy coherent x rays to extract new knowledge about the correlated motion of groups of self-assembled, outer-lying electrons in the extremely complex electronic system found in manganites. The manganite family of materials has puzzled physicists for years by defying standard models for the motion of electrons in crystals. By controlling the properties of the incident x rays, the

  2. Slow Dynamics of Orbital Domains in Manganite

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

    Slow Dynamics of Orbital Domains in Manganite Print At the ALS, an international team of researchers has used low-energy coherent x rays to extract new knowledge about the correlated motion of groups of self-assembled, outer-lying electrons in the extremely complex electronic system found in manganites. The manganite family of materials has puzzled physicists for years by defying standard models for the motion of electrons in crystals. By controlling the properties of the incident x rays, the

  3. Slow Dynamics of Orbital Domains in Manganite

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

    Slow Dynamics of Orbital Domains in Manganite Print At the ALS, an international team of researchers has used low-energy coherent x rays to extract new knowledge about the correlated motion of groups of self-assembled, outer-lying electrons in the extremely complex electronic system found in manganites. The manganite family of materials has puzzled physicists for years by defying standard models for the motion of electrons in crystals. By controlling the properties of the incident x rays, the

  4. Dynamics of gauge field inflation

    SciTech Connect (OSTI)

    Alexander, Stephon; Jyoti, Dhrubo; Kosowsky, Arthur; Marcianò, Antonino

    2015-05-05

    We analyze the existence and stability of dynamical attractor solutions for cosmological inflation driven by the coupling between fermions and a gauge field. Assuming a spatially homogeneous and isotropic gauge field and fermion current, the interacting fermion equation of motion reduces to that of a free fermion up to a phase shift. Consistency of the model is ensured via the Stückelberg mechanism. We prove the existence of exactly one stable solution, and demonstrate the stability numerically. Inflation arises without fine tuning, and does not require postulating any effective potential or non-standard coupling.

  5. Theoretical studies of electronically excited states

    SciTech Connect (OSTI)

    Besley, Nicholas A.

    2014-10-06

    Time-dependent density functional theory is the most widely used quantum chemical method for studying molecules in electronically excited states. However, excited states can also be computed within Kohn-Sham density functional theory by exploiting methods that converge the self-consistent field equations to give excited state solutions. The usefulness of single reference self-consistent field based approaches for studying excited states is demonstrated by considering the calculation of several types of spectroscopy including the infrared spectroscopy of molecules in an electronically excited state, the rovibrational spectrum of the NO-Ar complex, core electron binding energies and the emission spectroscopy of BODIPY in water.

  6. Dynamics of high temperature plasmas. Final report

    SciTech Connect (OSTI)

    Dialetis, D.; Finn, J.; Freund, H.; Mondelli, A.; Ott, E.

    1985-10-01

    Contents include: envelope model for beam transport and focusing in an induction linac; high-current accelerators; free-electron laser studies; laser beat-wave particle acceleration; orbitron maser design; electron-beam stability in the modified betatron; relativistic electron beam diode design; free electron laser application to xuv production and particle acceleration; high-current betatron with stellarator fields; a bumpy-torus betatron; design and operation of a collective millimeter-wave free-electron laser; study of gain, bandwidth, and tunability of a millimeter-wave free-electron laser operating in the collective regime; nonlinear analysis of free-electron-laser amplifiers with axial guide fields; unstable electrostatic beam modes in free-electron-laser systems; three-dimensional theory of free electron lasers with an axial guide field; three-dimensional theory of the free-electron laser in the collective regime; rapid electron beam accelerators; excitation of the plasma waves in the laser beat wave accelerator; dynamics of space-charge waves in the laser beat wave accelerator; finite larmor radius diocotron instability; one dimensional models for relativistic electron beam diode design; collective instabilities and high-gain regime in a free electron laser; and free electron lasers for the xuv spectral region.

  7. Electronic cooling using thermoelectric devices

    SciTech Connect (OSTI)

    Zebarjadi, M.

    2015-05-18

    Thermoelectric coolers or Peltier coolers are used to pump heat in the opposite direction of the natural heat flux. These coolers have also been proposed for electronic cooling, wherein the aim is to pump heat in the natural heat flux direction and from hot spots to the colder ambient temperature. In this manuscript, we show that for such applications, one needs to use thermoelectric materials with large thermal conductivity and large power factor, instead of the traditionally used high ZT thermoelectric materials. We further show that with the known thermoelectric materials, the active cooling cannot compete with passive cooling, and one needs to explore a new set of materials to provide a cooling solution better than a regular copper heat sink. We propose a set of materials and directions for exploring possible materials candidates suitable for electronic cooling. Finally, to achieve maximum cooling, we propose to use thermoelectric elements as fins attached to copper blocks.

  8. Aqueous Solution Vessel Thermal Model Development II

    SciTech Connect (OSTI)

    Buechler, Cynthia Eileen

    2015-10-28

    The work presented in this report is a continuation of the work described in the May 2015 report, “Aqueous Solution Vessel Thermal Model Development”. This computational fluid dynamics (CFD) model aims to predict the temperature and bubble volume fraction in an aqueous solution of uranium. These values affect the reactivity of the fissile solution, so it is important to be able to calculate them and determine their effects on the reaction. Part A of this report describes some of the parameter comparisons performed on the CFD model using Fluent. Part B describes the coupling of the Fluent model with a Monte-Carlo N-Particle (MCNP) neutron transport model. The fuel tank geometry is the same as it was in the May 2015 report, annular with a thickness-to-height ratio of 0.16. An accelerator-driven neutron source provides the excitation for the reaction, and internal and external water cooling channels remove the heat. The model used in this work incorporates the Eulerian multiphase model with lift, wall lubrication, turbulent dispersion and turbulence interaction. The buoyancy-driven flow is modeled using the Boussinesq approximation, and the flow turbulence is determined using the k-ω Shear-Stress-Transport (SST) model. The dispersed turbulence multiphase model is employed to capture the multiphase turbulence effects.

  9. A Community of Electrons

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

    plutonium's missing magnetism also provides a groundbreaking insight into the overall nature of matter. November 20, 2015 A Community of Electrons With electronic correlations,...

  10. Controlling Graphene's Electronic Structure

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

    Controlling Graphene's Electronic Structure Print Graphene, because of its unusual electron properties, reduced dimensionality, and scale, has enormous potential for use in...

  11. Electron Microscopy Center

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

    Electron Microscopy Center Argonne Home > EMC > EMC Home Electron Microscopy Center Web Site has moved This page has moved to http:www.anl.govcnmgroupelectron-microscopy-cente...

  12. Photodissociation Dynamics

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

    Photodissociation Dynamics - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us Employee Locator Energy & Climate Secure & Sustainable Energy Future Stationary Power Energy Conversion Efficiency Solar Energy Wind Energy Water Power Supercritical CO2 Geothermal Natural Gas Safety, Security & Resilience of the Energy Infrastructure Energy Storage Nuclear Power & Engineering Grid Modernization Battery Testing Nuclear Energy Defense Waste Management Programs Advanced

  13. Suntech Energy Solutions Formerly EI Solutions | Open Energy...

    Open Energy Info (EERE)

    Place: Pasadena, California Zip: 91103 Sector: Solar Product: A California-based solar power systems integrator and installer. References: Suntech Energy Solutions...

  14. Sierra Structural Dynamics User's Notes

    SciTech Connect (OSTI)

    Reese, Garth M.

    2015-10-19

    Sierra/SD provides a massively parallel implementation of structural dynamics finite element analysis, required for high fidelity, validated models used in modal, vibration, static and shock analysis of weapons systems. This document provides a users guide to the input for Sierra/SD. Details of input specifications for the different solution types, output options, element types and parameters are included. The appendices contain detailed examples, and instructions for running the software on parallel platforms.

  15. Cryptosystems based on chaotic dynamics

    SciTech Connect (OSTI)

    McNees, R.A.; Protopopescu, V.; Santoro, R.T.; Tolliver, J.S.

    1993-08-01

    An encryption scheme based on chaotic dynamics is presented. This scheme makes use of the efficient and reproducible generation of cryptographically secure pseudo random numbers from chaotic maps. The result is a system which encrypts quickly and possesses a large keyspace, even in small precision implementations. This system offers an excellent solution to several problems including the dissemination of key material, over the air rekeying, and other situations requiring the secure management of information.

  16. Better Buildings Residential Program Solution Center Demonstration |

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

    Department of Energy Residential Program Solution Center Demonstration Better Buildings Residential Program Solution Center Demonstration Better Buildings Residential Program Solution Center Demonstration from the U.S. Department of Energy. Solution Center Demo (2.8 MB) More Documents & Publications Building Science Solutions … Faster and Better Presentation: Better Buildings Residential Program Solution Center Presentation: Better Buildings Residential Program Solution Center

  17. Generation of Femtosecond Electron Pulses

    SciTech Connect (OSTI)

    Jinamoon, V.; Kusoljariyakul, K.; Rimjaem, S.; Saisut, J.; Thongbai, C.; Vilaithong, T.; Rhodes, M.W.; Wichaisirimongkol, P.; Chumphongphan, S.; Wiedemann, H.; /SLAC, SSRL

    2005-05-09

    At the Fast Neutron Research Facility (FNRF), Chiang Mai University (Thailand), the SURIYA project has been established aiming to produce femtosecond electron pulses utilizing a combination of an S-band thermionic rf gun and a magnetic bunch compressor ({alpha}-magnet). A specially designed rf-gun has been constructed to obtain optimum beam characteristics for the best bunch compression. Simulation results show that bunch lengths as short as about 50 fs rms can be expected at the experimental station. The electron bunch lengths will be determined using autocorrelation of coherent transition radiation (TR) through a Michelson interferometer. The paper discusses beam dynamics studies, design, fabrication and cold tests of the rf-gun as well as presents the project current status and forth-coming experiments.

  18. Electron Cloud Effects in Accelerators

    SciTech Connect (OSTI)

    Furman, M.A.

    2012-11-30

    Abstract We present a brief summary of various aspects of the electron-cloud effect (ECE) in accelerators. For further details, the reader is encouraged to refer to the proceedings of many prior workshops, either dedicated to EC or with significant EC contents, including the entire ?ECLOUD? series [1?22]. In addition, the proceedings of the various flavors of Particle Accelerator Conferences [23] contain a large number of EC-related publications. The ICFA Beam Dynamics Newsletter series [24] contains one dedicated issue, and several occasional articles, on EC. An extensive reference database is the LHC website on EC [25].

  19. The Solvation Structure of Mg Ions in Dichloro Complex Solutions from

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

    First-Principles Molecular Dynamics and Simulated X-ray Absorption Spectra - Joint Center for Energy Storage Research September 22, 2014, Research Highlights The Solvation Structure of Mg Ions in Dichloro Complex Solutions from First-Principles Molecular Dynamics and Simulated X-ray Absorption Spectra The coordination of a Mg-ion dimer complex extracted from solution phase simulations at room temperature indicating 4- and 5-fold coordination of Mg ions (orange) by Cl counterions (green) and

  20. Instabilities of optical solitons and Hamiltonian singular solutions in a medium of finite extension

    SciTech Connect (OSTI)

    Assemat, E.; Picozzi, A.; Jauslin, H. R.; Sugny, D.

    2011-07-15

    We analyze the role of soliton solutions and Hamiltonian singularities in the dynamics of counterpropagating waves in a medium of finite spatial extension. The soliton solution can become unstable due to the finite extension of the system. We show that the spatiotemporal dynamics then relaxes toward a Hamiltonian singular state of a nature different than that of the soliton state. This phenomenon can be explained through a geometrical analysis of the singularities of the stationary Hamiltonian system.

  1. Electronic Transitions in f-electron Metals at High Pressures...

    Office of Scientific and Technical Information (OSTI)

    Technical Report: Electronic Transitions in f-electron Metals at High Pressures: Citation Details In-Document Search Title: Electronic Transitions in f-electron Metals at High ...

  2. Financing Solutions | Department of Energy

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

    Financing Solutions Financing Solutions Transitioning to a clean energy economy requires innovative financing solutions that enable state, local, and tribal governments to invest in clean energy technologies. However, the clean energy puzzle can be daunting, especially when it comes to financing. With that in mind this website aims to provide an overview of financing as it pertains to state, local, and tribal governments who are designing and implementing clean energy financing programs. Learn

  3. Employment Solutions Division (HC-13)

    Broader source: Energy.gov [DOE]

    This division develops and implements innovative HCM business solutions relating to corporate recruiting, organizational and workforce development, workforce and succession planning, talent...

  4. MPower Solutions | Open Energy Information

    Open Energy Info (EERE)

    Dundee,, United Kingdom Zip: DD2 4UH Product: MPower Solutions is one Europe's largest battery manufacturers supplying over 500,000 batteries every month. MPower provides optimised...

  5. SBY Solutions | Open Energy Information

    Open Energy Info (EERE)

    Jump to: navigation, search Name: SBY Solutions Place: Israel Zip: 42836 Sector: Solar Product: Solar panel installer, mainly focusing on rooftops. References: SBY...

  6. Extraordinary vacuum black string solutions

    SciTech Connect (OSTI)

    Kim, Hyeong-Chan; Lee, Jungjai

    2008-01-15

    In addition to the boosted static solution there are two other classes of stationary stringlike solutions of the vacuum Einstein equation in (4+1) dimensions. Each class is characterized by three parameters of mass, tension, and momentum flow along the fifth coordinate. We analyze the metric properties of one of the two classes, which was previously assumed to be naked singular, and show that the solution spectrum contains black string and wormhole in addition to the known naked singularity as the momentum flow to mass ratio increases. Interestingly, there does not exist new zero momentum solution in these cases.

  7. Biofuel Solutions | Open Energy Information

    Open Energy Info (EERE)

    developer, which had been developing one plant in Fairmont, Minnesota and another in Wood River, Biofuel Energy LLC took over plant development of Biofuel Solutions' projects in...

  8. DEVELOPMENT Solutions | Open Energy Information

    Open Energy Info (EERE)

    Product: DEVELOPMENT Solutions (DS) supports investors to realise projects with sustainable applications, including in the areas of environment, energy efficiency, water...

  9. Extracting alcohols from aqueous solutions

    DOE Patents [OSTI]

    Compere, Alicia L.; Googin, John M.; Griffith, William L.

    1984-01-01

    Hydrocarbon and surfactants are contacted with a solution of alcohol and water to extract the alcohol into the hydrocarbon-surfactant mixture.

  10. Cleantech Solutions | Open Energy Information

    Open Energy Info (EERE)

    New York Zip: 10023 Region: Northeast - NY NJ CT PA Area Sector: Efficiency Product: Energy efficiency solutions and consumption monitoring systems for buildings Website:...

  11. RWE Solutions | Open Energy Information

    Open Energy Info (EERE)

    RWE Solutions Place: Neu-Isenburg, Germany Zip: 63263 Sector: Solar Product: Germany-based, subsidiary of RWE AG plans, builds and manages energy infrastructure for utilities...

  12. Dow Building Solutions | Open Energy Information

    Open Energy Info (EERE)

    Dow Building Solutions Jump to: navigation, search Name: Dow Building Solutions Place: Midland, MI Website: www.dowbuildingsolutions.com References: Dow Building Solutions1...

  13. Future Energy Solutions | Open Energy Information

    Open Energy Info (EERE)

    Solutions Jump to: navigation, search Name: Future Energy Solutions Place: Didcot, United Kingdom Zip: OX11 0QR Product: Future Energy Solutions is a sustainable energy...

  14. Carbon Solutions Group | Open Energy Information

    Open Energy Info (EERE)

    Solutions Group Jump to: navigation, search Name: Carbon Solutions Group Place: Chicago, Illinois Zip: 60601 Sector: Carbon Product: Carbon Solutions Group collaborates with...

  15. ECO Solutions LLC | Open Energy Information

    Open Energy Info (EERE)

    ECO Solutions LLC Jump to: navigation, search Name: ECO Solutions, LLC Place: Chatsworth, Georgia Zip: 30705 Product: ECO Solutions operates a biodiesel plant in Georgia with a...

  16. Energy Capital Solutions | Open Energy Information

    Open Energy Info (EERE)

    Capital Solutions Jump to: navigation, search Logo: Energy Capital Solutions Name: Energy Capital Solutions Address: 2651 North Harwood Street, Suite 410 Place: Dallas, Texas Zip:...

  17. Solar Choice Solutions Inc | Open Energy Information

    Open Energy Info (EERE)

    Choice Solutions Inc Jump to: navigation, search Name: Solar Choice Solutions Inc. Place: Calabasas, California Zip: 91302 Sector: Solar Product: Solar Choice Solutions Inc. is an...

  18. Institute for Environmental Solutions | Open Energy Information

    Open Energy Info (EERE)

    Environmental Solutions Jump to: navigation, search Logo: Institute for Environmental Solutions Name: Institute for Environmental Solutions Address: 761 Newport St. Place: Denver,...

  19. Mechanical Solutions Inc | Open Energy Information

    Open Energy Info (EERE)

    Mechanical Solutions Inc Jump to: navigation, search Name: Mechanical Solutions Inc Place: New York Product: New York-based contractor. References: Mechanical Solutions Inc1 This...

  20. Chevron Energy Solutions | Open Energy Information

    Open Energy Info (EERE)

    Chevron Energy Solutions Jump to: navigation, search Logo: Chevron Energy Solutions Name: Chevron Energy Solutions Address: 345 California Street, 18th Floor Place: San Francisco,...

  1. AFV Solutions Inc | Open Energy Information

    Open Energy Info (EERE)

    Solutions Inc Place: Mesa, Arizona Zip: 85210 Product: AFV Solutions is a manufacturer of electric-hybrid buses and energy conversion systems for cars. References: AFV Solutions...

  2. Wind Park Solutions Arcadia | Open Energy Information

    Open Energy Info (EERE)

    Park Solutions Arcadia Jump to: navigation, search Name: Wind Park Solutions Arcadia Place: Big Sandy, Montana Sector: Wind energy Product: JV between Wind Park Solutions America...

  3. High conductivity electrolyte solutions and rechargeable cells incorporating such solutions

    DOE Patents [OSTI]

    Angell, C.A.; Zhang, S.S.; Xu, K.

    1998-10-20

    This invention relates generally to electrolyte solvents for use in liquid or rubbery polymer electrolyte solutions as are used, for example, in electrochemical devices. More specifically, this invention relates to sulfonyl/phospho-compound electrolyte solvents and sulfonyl/phospho-compound electrolyte solutions incorporating such solvents. 9 figs.

  4. High conductivity electrolyte solutions and rechargeable cells incorporating such solutions

    DOE Patents [OSTI]

    Angell, Charles Austen (Mesa, AZ); Zhang, Sheng-Shui (Tucson, AZ); Xu, Kang (Tempe, AZ)

    1998-01-01

    This invention relates generally to electrolyte solvents for use in liquid or rubbery polymer electrolyte solutions as are used, for example, in electrochemical devices. More specifically, this invention relates to sulfonyl/phospho-compound electrolyte solvents and sulfonyl/phospho-compound electrolyte solutions incorporating such solvents.

  5. Temperature Profile of the Solution Vessel of an Accelerator-Driven Subcritical Fissile Solution System

    SciTech Connect (OSTI)

    Klein, Steven Karl; Determan, John C.

    2015-09-14

    Dynamic System Simulation (DSS) models of fissile solution systems have been developed and verified against a variety of historical configurations. DSS techniques have been applied specifically to subcritical accelerator-driven systems using fissile solution fuels of uranium. Initial DSS models were developed in DESIRE, a specialized simulation scripting language. In order to tailor the DSS models to specifically meet needs of system designers they were converted to a Visual Studio implementation, and one of these subsequently to National Instrument’s LabVIEW for human factors engineering and operator training. Specific operational characteristics of subcritical accelerator-driven systems have been examined using a DSS model tailored to this particular class using fissile fuel.

  6. Multispacecraft observations of the electron current sheet, neighboring magnetic islands, and electron acceleration during magnetotail reconnection

    SciTech Connect (OSTI)

    Chen Lijen; Bessho, Naoki; Bhattacharjee, Amitava; Lefebvre, Bertrand; Vaith, Hans; Puhl-Quinn, Pamela; Torbert, Roy; Asnes, Arne; Fazakerley, Andrew; Khotyaintsev, Yuri; Daly, Patrick

    2009-05-15

    Open questions concerning structures and dynamics of diffusion regions and electron acceleration in collisionless magnetic reconnection are addressed based on data from the four-spacecraft mission Cluster and particle-in-cell simulations. Using time series of electron distribution functions measured by the four spacecraft, distinct electron regions around a reconnection layer are mapped out to set the framework for studying diffusion regions. A spatially extended electron current sheet (ecs), a series of magnetic islands, and bursts of energetic electrons within islands are identified during magnetotail reconnection with no appreciable guide field. The ecs is collocated with a layer of electron-scale electric fields normal to the ecs and pointing toward the ecs center plane. Both the observed electron and ion densities vary by more than a factor of 2 within one ion skin depth north and south of the ecs, and from the ecs into magnetic islands. Within each of the identified islands, there is a burst of suprathermal electrons whose fluxes peak at density compression sites [L.-J. Chen et al., Nat. Phys. 4, 19 (2008)] and whose energy spectra exhibit power laws with indices ranging from 6 to 7.3. These results indicate that the in-plane electric field normal to the ecs can be of the electron scale at certain phases of reconnection, electrons and ions are highly compressible within the ion diffusion region, and for reconnection involving magnetic islands, primary electron acceleration occurs within the islands.

  7. Scattering Dynamics

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

    Scattering Dynamics - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us Employee Locator Energy & Climate Secure & Sustainable Energy Future Stationary Power Energy Conversion Efficiency Solar Energy Wind Energy Water Power Supercritical CO2 Geothermal Natural Gas Safety, Security & Resilience of the Energy Infrastructure Energy Storage Nuclear Power & Engineering Grid Modernization Battery Testing Nuclear Energy Defense Waste Management Programs Advanced Nuclear

  8. Rheological Behavior of Xanthan Gum Solution Related to Shear Thinning Fluid Delivery for Subsurface Remediation

    SciTech Connect (OSTI)

    Zhong, Lirong; Oostrom, Martinus; Truex, Michael J.; Vermeul, Vincent R.; Szecsody, James E.

    2013-01-15

    Xanthan gum, a biopolymer, forms shear thinning fluids which can be used as delivery media to improve the distribution of remedial amendments injected into heterogeneous subsurface environments. The rheological behavior of the shear thinning solution needs to be known to develop an appropriate design for field injection. In this study, the rheological properties of xanthan gum solutions were obtained under various chemical and environmental conditions relevant to delivery of remedial amendments to groundwater. Higher xanthan concentration raised the absolute solution viscosity and increased the degree of shear thinning. Addition of remedial amendments (e.g., phosphate, sodium lactate, ethyl lactate) caused the dynamic viscosity of xanthan gum to decrease, but the solutions maintained shear-thinning properties. Use of simple salt (e.g. Na+, Ca2+) to increase the solution ionic strength also decreased the dynamic viscosity of xanthan and the degree of shear thinning, although the effect is a function of xanthan gum concentration and diminished as the xanthan gum concentration was increased. At high xanthan concentration, addition of salt to the solution increased dynamic viscosity. In the absence of sediments, xanthan gum solutions maintain their viscosity properties for months. However, xanthan gum solutions were shown to lose dynamic viscosity over a period of days to weeks when contacted with saturated site sediment. Loss of viscosity is attributed to physical and biodegradation processes.

  9. Controlling Molecular Ordering in Solution-State Conjugated Polymers

    SciTech Connect (OSTI)

    Zhu, Jiahua; Han, Youngkyu; Kumar, Rajeev; Hong, Kunlun; Bonnesen, Peter V.; Sumpter, Bobby G.; Smith, Gregory Scott; Ivanov, Ilia N.; Do, Changwoo

    2015-07-17

    Rationally encoding molecular interactions that can control the assembly structure and functional expression in solution of conjugated polymers holds great potential for enabling optimal organic optoelectronic and sensory materials. In this work, we show that thermally-controlled and surfactant-guided assembly of water-soluble conjugated polymers in aqueous solution is a simple and effective strategy to generate optoelectronic materials with desired molecular ordering. We have studied a conjugated polymer consisting of a hydrophobic thiophene backbone and hydrophilic, thermo-responsive ethylene oxide side groups, which shows a step-wise, multi-dimensional assembly in water. By incorporating the polymer into phase-segregated domains of an amphiphilic surfactant in solution, we demonstrate that both chain conformation and degree of molecular ordering of the conjugated polymer can be tuned in hexagonal, micellar and lamellar phases of the surfactant solution. The controlled molecular ordering in conjugated polymer assembly is demonstrated as a key factor determining the electronic interaction and optical function.

  10. A novel solution-phase route for the synthesis of crystalline silver nanowires

    SciTech Connect (OSTI)

    Liu Yang; Chu Ying . E-mail: chuying@nenu.edu.cn; Yang Likun; Han Dongxue; Lue Zhongxian

    2005-10-06

    A unique solution-phase route was devised to synthesize crystal Ag nanowires with high aspect-ratio (8-10 nm in diameter and length up to 10 {mu}m) by the reduction of AgNO{sub 3} with Vitamin C in SDS/ethanol solution. The resultant nanoproducts were characterized by transmission electron microscope (TEM), X-ray diffraction (XRD) and electron diffraction (ED). A soft template mechanism was put forward to interpret the formation of metal Ag nanowires.

  11. A divide-conquer-recombine algorithmic paradigm for large spatiotemporal quantum molecular dynamics simulations

    SciTech Connect (OSTI)

    Shimojo, Fuyuki; Hattori, Shinnosuke; Department of Physics, Kumamoto University, Kumamoto 860-8555 ; Kalia, Rajiv K.; Mou, Weiwei; Nakano, Aiichiro; Nomura, Ken-ichi; Rajak, Pankaj; Vashishta, Priya; Kunaseth, Manaschai; National Nanotechnology Center, Pathumthani 12120 ; Ohmura, Satoshi; Department of Physics, Kumamoto University, Kumamoto 860-8555; Department of Physics, Kyoto University, Kyoto 606-8502 ; Shimamura, Kohei; Department of Physics, Kumamoto University, Kumamoto 860-8555; Department of Applied Quantum Physics and Nuclear Engineering, Kyushu University, Fukuoka 819-0395

    2014-05-14

    We introduce an extension of the divide-and-conquer (DC) algorithmic paradigm called divide-conquer-recombine (DCR) to perform large quantum molecular dynamics (QMD) simulations on massively parallel supercomputers, in which interatomic forces are computed quantum mechanically in the framework of density functional theory (DFT). In DCR, the DC phase constructs globally informed, overlapping local-domain solutions, which in the recombine phase are synthesized into a global solution encompassing large spatiotemporal scales. For the DC phase, we design a lean divide-and-conquer (LDC) DFT algorithm, which significantly reduces the prefactor of the O(N) computational cost for N electrons by applying a density-adaptive boundary condition at the peripheries of the DC domains. Our globally scalable and locally efficient solver is based on a hybrid real-reciprocal space approach that combines: (1) a highly scalable real-space multigrid to represent the global charge density; and (2) a numerically efficient plane-wave basis for local electronic wave functions and charge density within each domain. Hybrid space-band decomposition is used to implement the LDC-DFT algorithm on parallel computers. A benchmark test on an IBM Blue Gene/Q computer exhibits an isogranular parallel efficiency of 0.984 on 786 432 cores for a 50.3 × 10{sup 6}-atom SiC system. As a test of production runs, LDC-DFT-based QMD simulation involving 16 661 atoms is performed on the Blue Gene/Q to study on-demand production of hydrogen gas from water using LiAl alloy particles. As an example of the recombine phase, LDC-DFT electronic structures are used as a basis set to describe global photoexcitation dynamics with nonadiabatic QMD (NAQMD) and kinetic Monte Carlo (KMC) methods. The NAQMD simulations are based on the linear response time-dependent density functional theory to describe electronic excited states and a surface-hopping approach to describe transitions between the excited states. A series of

  12. TREATMENT OF AMMONIUM NITRATE SOLUTIONS

    DOE Patents [OSTI]

    Boyer, T.W.; MacHutchin, J.G.; Yaffe, L.

    1958-06-10

    The treatment of waste solutions obtained in the processing of neutron- irradiated uranium containing fission products and ammonium nitrate is described. The object of this process is to provide a method whereby the ammonium nitrate is destroyed and removed from the solution so as to permit subsequent concentration of the solution.. In accordance with the process the residual nitrate solutions are treated with an excess of alkyl acid anhydride, such as acetic anhydride. Preferably, the residual nitrate solution is added to an excess of the acetic anhydride at such a rate that external heat is not required. The result of this operation is that the ammonium nitrate and acetic anhydride react to form N/sub 2/ O and acetic acid.

  13. Polarized X-Rays Reveal Molecular Alignment in Printed Electronics

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

    Polarized X-Rays Reveal Molecular Alignment in Printed Electronics Polarized X-Rays Reveal Molecular Alignment in Printed Electronics Print Wednesday, 31 October 2012 00:00 The printing of electronic devices using giant roll-to-roll presses or inkjet-style printers has recently been made possible by the development of solution-processable organic materials with optoelectronic properties. Organic light-emitting diodes (OLEDs) are already being produced commercially, and sensors, organic thin-film

  14. Conference Agenda: Residential Energy Efficiency Solutions 2012...

    Office of Environmental Management (EM)

    Conference Agenda: Residential Energy Efficiency Solutions 2012 Conference Agenda: Residential Energy Efficiency Solutions 2012 Presents conference agenda including a general ...

  15. Effects of hot electron inertia on electron-acoustic solitons and double layers

    SciTech Connect (OSTI)

    Verheest, Frank; Hellberg, Manfred A.

    2015-07-15

    The propagation of arbitrary amplitude electron-acoustic solitons and double layers is investigated in a plasma containing cold positive ions, cool adiabatic and hot isothermal electrons, with the retention of full inertial effects for all species. For analytical tractability, the resulting Sagdeev pseudopotential is expressed in terms of the hot electron density, rather than the electrostatic potential. The existence domains for Mach numbers and hot electron densities clearly show that both rarefactive and compressive solitons can exist. Soliton limitations come from the cool electron sonic point, followed by the hot electron sonic point, until a range of rarefactive double layers occurs. Increasing the relative cool electron density further yields a switch to compressive double layers, which ends when the model assumptions break down. These qualitative results are but little influenced by variations in compositional parameters. A comparison with a Boltzmann distribution for the hot electrons shows that only the cool electron sonic point limit remains, giving higher maximum Mach numbers but similar densities, and a restricted range in relative hot electron density before the model assumptions are exceeded. The Boltzmann distribution can reproduce neither the double layer solutions nor the switch in rarefactive/compressive character or negative/positive polarity.

  16. The behavior of the electron plasma boundary in ultraintense laser–highly overdense plasma interaction

    SciTech Connect (OSTI)

    Sánchez-Arriaga, G.; Sanz, J.; Debayle, A.; Lehmann, G.

    2014-12-15

    The structural stability of the laser/plasma interaction is discussed, for the case of a linearly polarized laser beam interacting with a solid at normal incidence. Using a semi-analytical cold fluid model, the dynamics of the electron plasma boundary (EPB), usually related to the high-order harmonic generation and laser absorption, are presented. While the well-known J × B plasma oscillations at two times the laser frequency are recovered by the model, several other periodic in time stable solutions exist for exactly the same value of the physical parameters. This novel behavior highlights the importance of the laser pulse history among other factors. Some important features, such as the synchronization between the incident laser and the EPB oscillation, depend on the solution under consideration. A description of the possible types of stable oscillations in a parametric plane involving plasma density and laser amplitude is presented. The semi-analytical model is compared with particle-in-cell and semi-Lagrangian Vlasov simulations. They show that, among all the stable solutions, the plasma preferentially evolves to a state with the EPB oscillating twice faster than the laser. The effect of the plasma temperature and the existence of a ramp in the ion density profile are also discussed.

  17. Standing electromagnetic solitons in hot ultra-relativistic electron-positron plasmas

    SciTech Connect (OSTI)

    Heidari, E.; Aslaninejad, M.; Eshraghi, H.; Rajaee, L.

    2014-03-15

    Using a one-dimensional self-consistent fluid model, we investigate standing relativistic bright solitons in hot electron-positron plasmas. The positron dynamics is taken into account. A set of nonlinear coupled differential equations describing the evolution of electromagnetic waves in fully relativistic two-fluid plasma is derived analytically and solved numerically. As a necessary condition for the existence of standing solitons the system should be relativistic. For the case of ultra-relativistic plasma, we investigate non-drifting bright solitary waves. Detailed discussions of the acceptable solutions are presented. New single hump non-trivial symmetric solutions for the scalar potential were found, and single and multi-nodal symmetric and anti-symmetric solutions for the vector potential are presented. It is shown that for a fixed value of the fluid velocity excited modes with more zeros in the profile of the vector potential show a higher magnitude for the scalar potential. An increase in the plasma fluid velocity also increases the magnitude of the scalar potential. Furthermore, the Hamiltonian and the first integral of the system are given.

  18. Kinetic simulations and reduced modeling of longitudinal sideband instabilities in non-linear electron plasma waves

    SciTech Connect (OSTI)

    Brunner, S.; Berger, R. L.; Cohen, B. I.; Hausammann, L.; Valeo, E. J.

    2014-10-01

    Kinetic Vlasov simulations of one-dimensional finite amplitude Electron Plasma Waves are performed in a multi-wavelength long system. A systematic study of the most unstable linear sideband mode, in particular its growth rate γ and quasi- wavenumber δk, is carried out by scanning the amplitude and wavenumber of the initial wave. Simulation results are successfully compared against numerical and analytical solutions to the reduced model by Kruer et al. [Phys. Rev. Lett. 23, 838 (1969)] for the Trapped Particle Instability (TPI). A model recently suggested by Dodin et al. [Phys. Rev. Lett. 110, 215006 (2013)], which in addition to the TPI accounts for the so-called Negative Mass Instability because of a more detailed representation of the trapped particle dynamics, is also studied and compared with simulations.

  19. Kinetic simulations and reduced modeling of longitudinal sideband instabilities in non-linear electron plasma waves

    SciTech Connect (OSTI)

    Brunner, S. Hausammann, L.; Berger, R. L. Cohen, B. I.; Valeo, E. J.

    2014-10-15

    Kinetic Vlasov simulations of one-dimensional finite amplitude Electron Plasma Waves are performed in a multi-wavelength long system. A systematic study of the most unstable linear sideband mode, in particular its growth rate ? and quasi- wavenumber ?k, is carried out by scanning the amplitude and wavenumber of the initial wave. Simulation results are successfully compared against numerical and analytical solutions to the reduced model by Kruer et al. [Phys. Rev. Lett. 23, 838 (1969)] for the Trapped Particle Instability (TPI). A model recently suggested by Dodin et al. [Phys. Rev. Lett. 110, 215006 (2013)], which in addition to the TPI accounts for the so-called Negative Mass Instability because of a more detailed representation of the trapped particle dynamics, is also studied and compared with simulations.

  20. RHIC electron lenses upgrades

    SciTech Connect (OSTI)

    Gu, X.; Altinbas, Z.; Bruno, D.; Binello, S.; Costanzo, M.; Drees, A.; Fischer, W.; Gassner, D. M.; Hock, J.; Hock, K.; Harvey, M.; Luo, Y.; Marusic, A.; Mi, C.; Mernick, K.; Minty, M.; Michnoff, R.; Miller, T. A.; Pikin, A. I.; Robert-Demolaize, G.; Samms, T.; Shrey, T. C.; Schoefer, V.; Tan, Y.; Than, R.; Thieberger, P.; White, S. M.

    2015-05-03

    In the Relativistic Heavy Ion Collider (RHIC) 100 GeV polarized proton run in 2015, two electron lenses were used to partially compensate for the head-on beam-beam effect for the first time. Here, we describe the design of the current electron lens, detailing the hardware modifications made after the 2014 commissioning run with heavy ions. A new electron gun with 15-mm diameter cathode is characterized. The electron beam transverse profile was measured using a YAG screen and fitted with a Gaussian distribution. During operation, the overlap of the electron and proton beams was achieved using the electron backscattering detector in conjunction with an automated orbit control program.

  1. Development of an (e,2e) electron momentum spectroscopy apparatus using an ultrashort pulsed electron gun

    SciTech Connect (OSTI)

    Yamazaki, M.; Kasai, Y.; Oishi, K.; Nakazawa, H.; Takahashi, M.

    2013-06-15

    An (e,2e) apparatus for electron momentum spectroscopy (EMS) has been developed, which employs an ultrashort-pulsed incident electron beam with a repetition rate of 5 kHz and a pulse duration in the order of a picosecond. Its instrumental design and technical details are reported, involving demonstration of a new method for finding time-zero. Furthermore, EMS data for the neutral Ne atom in the ground state measured by using the pulsed electron beam are presented to illustrate the potential abilities of the apparatus for ultrafast molecular dynamics, such as by combining EMS with the pump-and-probe technique.

  2. ASYMMETRIC ELECTRON DISTRIBUTIONS IN THE SOLAR WIND

    SciTech Connect (OSTI)

    Rha, Kicheol; Ryu, Chang-Mo [Department of Physics, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of)] [Department of Physics, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of); Yoon, Peter H. [Institute for Physical Science and Technology, University of Maryland, College Park, MD 20742 (United States)] [Institute for Physical Science and Technology, University of Maryland, College Park, MD 20742 (United States)

    2013-09-20

    A plausible mechanism responsible for producing asymmetric electron velocity distribution functions in the solar wind is investigated by means of one-dimensional electrostatic particle-in-cell (PIC) simulation. A recent paper suggests that the variation in the ion-to-electron temperature ratio influences the nonlinear wave-particle dynamics such that it results in the formation of asymmetric distributions. The present PIC code simulation largely confirms this finding, but quantitative differences between the weak turbulence formalism and the present PIC simulation are also found, suggesting the limitation of the analytical method. The inter-relationship between the asymmetric electron distribution and the ion-to-electron temperature ratio may be a new useful concept for the observation.

  3. Generation of Femtosecond Electron And Photon Pulses

    SciTech Connect (OSTI)

    Thongbai, C.; Jinamoon, V.; Kangrang, M.; Kusoljariyakul, K.; Rimjaem, S.; Saisut, J.; Vilaithong, T.; Rhodes, M.W.; Wichaisirimongkol, P.; Wiedemann, H.; /SLAC

    2006-03-17

    Femtosecond (fs) electron and photon pulses become a tool of increasing importance to study dynamics in ultrafast processes. Such short electron pulses can be generated from a system consisting of a thermionic-cathode RF-gun and a magnetic bunch compressor. The fs electron pulses can be used directly or used as a source to produce equally short electromagnetic radiation pulses via certain kind of radiation production processes. At the Fast Neutron Research Facility (FNRF), Thailand, we are especially interested in production of radiation in Farinfrared and X-ray regime. In the far-infrared wavelengths, the radiation emitted from fs electron pulses is emitted coherently resulting high intensity radiation. In the X-ray regime, development of fs X-ray sources is crucial for application in ultrafast sciene.

  4. MECHANICS OF CRACK BRIDGING UNDER DYNAMIC LOADS

    SciTech Connect (OSTI)

    N. SRIDHAR; ET AL

    2001-02-01

    A bridging law for fiber reinforced composites under dynamic crack propagation conditions has been derived. Inertial effects in the mechanism of fiber pullout during dynamic propagation of a bridged crack are critically examined for the first time. By reposing simple shear lag models of pullout as problems of dynamic wave propagation, the effect of the frictional coupling between the fibers and the matrix is accounted for in a fairly straightforward way. The solutions yield the time-dependent relationship between the crack opening displacement and the bridging traction. Engineering criteria and the role of material and geometrical parameters for significant inertial effects are identified.

  5. Parallel Implementation of Power System Dynamic Simulation

    SciTech Connect (OSTI)

    Jin, Shuangshuang; Huang, Zhenyu; Diao, Ruisheng; Wu, Di; Chen, Yousu

    2013-07-21

    Dynamic simulation of power system transient stability is important for planning, monitoring, operation, and control of electrical power systems. However, modeling the system dynamics and network involves the computationally intensive time-domain solution of numerous differential and algebraic equations (DAE). This results in a transient stability implementation that may not maintain the real-time constraints of an online security assessment. This paper presents a parallel implementation of the dynamic simulation on a high-performance computing (HPC) platform using parallel simulation algorithms and computation architectures. It enables the simulation to run even faster than real time, enabling the look-ahead capability of upcoming stability problems in the power grid.

  6. Catalac free electron laser

    DOE Patents [OSTI]

    Brau, Charles A. (Los Alamos, NM); Swenson, Donald A. (Los Alamos, NM); Boyd, Jr., Thomas J. (Los Alamos, NM)

    1982-01-01

    A catalac free electron laser using a rf linac (catalac) which acts as a catalyst to accelerate an electron beam in an initial pass through the catalac and decelerate the electron beam during a second pass through the catalac. During the second pass through the catalac, energy is extracted from the electron beam and transformed to energy of the accelerating fields of the catalac to increase efficiency of the device. Various embodiments disclose the use of post linacs to add electron beam energy extracted by the wiggler and the use of supplementary catalacs to extract energy at various energy peaks produced by the free electron laser wiggler to further enhance efficiency of the catalac free electron laser. The catalac free electron laser can be used in conjunction with a simple resonator, a ring resonator or as an amplifier in conjunction with a master oscillator laser.

  7. Relativistic electron beam generator

    DOE Patents [OSTI]

    Mooney, L.J.; Hyatt, H.M.

    1975-11-11

    A relativistic electron beam generator for laser media excitation is described. The device employs a diode type relativistic electron beam source having a cathode shape which provides a rectangular output beam with uniform current density.

  8. Catalac free electron laser

    DOE Patents [OSTI]

    Brau, C.A.; Swenson, D.A.; Boyd, T.J. Jr.

    1979-12-12

    A catalac free electron laser using a rf linac (catalac) which acts as a catalyst to accelerate an electron beam in an initial pass through the catalac and decelerate the electron beam during a second pass through the catalac is described. During the second pass through the catalac, energy is extracted from the electron beam and transformed to energy of the accelerating fields of the catalac to increase efficiency of the device. Various embodiments disclose the use of post linacs to add electron beam energy extracted by the wiggler and the use of supplementary catalacs to extract energy at various energy peaks produced by the free electron laser wiggler to further enhance efficiency of the catalac free electron laser. The catalac free electron laser can be used in conjunction with a simple resonator, a ring resonator, or as an amplifier in conjunction with a master oscillator laser.

  9. Thermodynamics of Electron Flow in the Bacterial Deca-heme Cytochrome MtrF

    SciTech Connect (OSTI)

    Breuer, Marian; Zarzycki, Piotr P.; Blumberger, Jochen; Rosso, Kevin M.

    2012-07-01

    Electron transporting multiheme cytochromes are essential to the metabolism of microbes that inhabit soils and carry out important biogeochemical processes. Recently the first crystal structure of a prototype bacterial deca-heme cytochrome (MtrF) has been resolved and its electrochemistry characterized. However, the molecular details of electron conductance along heme chains in the cytochrome are difficult to access via experiment due to the nearly identical chemical nature of the heme cofactors. Here we employ large-scale molecular dynamics simulations to compute the reduction potentials of the ten hemes of MtrF in aqueous solution. We find that as a whole they fall within a range of about 0.3 V in agreement with experiment. Individual reduction potentials give rise to a free energy profile for electron conduction that is approximately symmetric with respect to the center of the protein. Our calculations indicate that there is no significant potential bias along the orthogonal octa- and tetra-heme chains suggesting that under aqueous conditions MtrF is a nearly reversible two-dimensional conductor.

  10. Decision-making in structure solution using Bayesian estimates of map quality: the PHENIX autosol wizard

    SciTech Connect (OSTI)

    Terwilliger, Thomas C; Adams, Paul D; Read, Randy J; Mccoy, Airlie J

    2008-01-01

    Ten measures of experimental electron-density-map quality are examined and the skewness of electron density is found to be the best indicator of actual map quality. A Bayesian approach to estimating map quality is developed and used in the PHENIX AutoSol wizard to make decisions during automated structure solution.

  11. Sunflower Solutions | Open Energy Information

    Open Energy Info (EERE)

    tracking systems maker for PV modules targeted at installations in the developing world. References: Sunflower Solutions1 This article is a stub. You can help OpenEI by...

  12. Cold Climate Building Enclosure Solutions

    Office of Scientific and Technical Information (OSTI)

    Enclosure Solutions Jan Kosny, Ali Fallahi, and Nitin Shukla Fraunhofer CSE January 2013 NOTICE This report was prepared as an account of work sponsored by an agency of the...

  13. Power Electronics Block Set

    Energy Science and Technology Software Center (OSTI)

    2008-12-31

    The software consists of code that will allow rapid prototyping of advanced power electronics for use in renewable energy systems.

  14. Controlling Graphene's Electronic Structure

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

    Controlling Graphene's Electronic Structure Print Graphene, because of its unusual electron properties, reduced dimensionality, and scale, has enormous potential for use in ultrafast electronic transistors. It exhibits high conductivity and an anomalous quantum Hall effect (a phenomenon exhibited by certain semiconductor devices at low temperatures and high magnetic fields). Among its novel properties, graphene's electrical charge carriers (electrons and holes) move through a solid with

  15. Controlling Graphene's Electronic Structure

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

    Controlling Graphene's Electronic Structure Print Graphene, because of its unusual electron properties, reduced dimensionality, and scale, has enormous potential for use in ultrafast electronic transistors. It exhibits high conductivity and an anomalous quantum Hall effect (a phenomenon exhibited by certain semiconductor devices at low temperatures and high magnetic fields). Among its novel properties, graphene's electrical charge carriers (electrons and holes) move through a solid with

  16. Controlling Graphene's Electronic Structure

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

    Controlling Graphene's Electronic Structure Print Graphene, because of its unusual electron properties, reduced dimensionality, and scale, has enormous potential for use in ultrafast electronic transistors. It exhibits high conductivity and an anomalous quantum Hall effect (a phenomenon exhibited by certain semiconductor devices at low temperatures and high magnetic fields). Among its novel properties, graphene's electrical charge carriers (electrons and holes) move through a solid with

  17. Controlling Graphene's Electronic Structure

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

    Controlling Graphene's Electronic Structure Print Graphene, because of its unusual electron properties, reduced dimensionality, and scale, has enormous potential for use in ultrafast electronic transistors. It exhibits high conductivity and an anomalous quantum Hall effect (a phenomenon exhibited by certain semiconductor devices at low temperatures and high magnetic fields). Among its novel properties, graphene's electrical charge carriers (electrons and holes) move through a solid with

  18. Controlling Graphene's Electronic Structure

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

    Controlling Graphene's Electronic Structure Print Graphene, because of its unusual electron properties, reduced dimensionality, and scale, has enormous potential for use in ultrafast electronic transistors. It exhibits high conductivity and an anomalous quantum Hall effect (a phenomenon exhibited by certain semiconductor devices at low temperatures and high magnetic fields). Among its novel properties, graphene's electrical charge carriers (electrons and holes) move through a solid with

  19. Controlling Graphene's Electronic Structure

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

    Controlling Graphene's Electronic Structure Print Graphene, because of its unusual electron properties, reduced dimensionality, and scale, has enormous potential for use in ultrafast electronic transistors. It exhibits high conductivity and an anomalous quantum Hall effect (a phenomenon exhibited by certain semiconductor devices at low temperatures and high magnetic fields). Among its novel properties, graphene's electrical charge carriers (electrons and holes) move through a solid with

  20. Controlling Graphene's Electronic Structure

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

    Controlling Graphene's Electronic Structure Controlling Graphene's Electronic Structure Print Wednesday, 25 April 2007 00:00 Graphene, because of its unusual electron properties, reduced dimensionality, and scale, has enormous potential for use in ultrafast electronic transistors. It exhibits high conductivity and an anomalous quantum Hall effect (a phenomenon exhibited by certain semiconductor devices at low temperatures and high magnetic fields). Among its novel properties, graphene's

  1. Multiscale reactive molecular dynamics | Argonne Leadership Computing

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

    Facility reactive molecular dynamics Authors: Chris KnighT, Gerrick E. Lindberg, Gregory A. Voth Many processes important to chemistry, materials science, and biology cannot be described without considering electronic and nuclear-level dynamics and their coupling to slower, cooperative motions of the system. These inherently multiscale problems require computationally efficient and accurate methods to converge statistical properties. In this paper, a method is presented that uses data

  2. Comprehensive Water-Efficiency Solutions

    SciTech Connect (OSTI)

    McMordie Stoughton, Kate

    2015-07-15

    Energy performance contracts can be an effective way to integrate comprehensive water-efficient technologies and solutions into energy efficiency projects. Current practices often miss key opportunities to incorporate a full suite of water measures primarily because a comprehensive approach is not taken in the assessment. This article provides information on how to develop a comprehensive water project that leads to innovative solutions and potential for large water reduction.

  3. Cosmological solution moduli of bigravity

    SciTech Connect (OSTI)

    Yılmaz, Nejat Tevfik

    2015-09-29

    We construct the complete set of metric-configuration solutions of the ghost-free massive bigravity for the scenario in which the g−metric is the Friedmann-Lemaitre-Robertson-Walker (FLRW) one, and the interaction Lagrangian between the two metrics contributes an effective ideal fluid energy-momentum tensor to the g-metric equations. This set corresponds to the exact background cosmological solution space of the theory.

  4. Cesium recovery from aqueous solutions

    DOE Patents [OSTI]

    Goodhall, C. A.

    1960-09-13

    A process for recovering cesium from aqueous solutions is given in which precipitation on zinc ferricyanide is used. The precipitation is preferably carried out in solutions containing at least 0.0004M zinc ferricyanide, an acidity ranging from 0.2N mineral acid to 0.61N acid deficiency, and 1 to 2.5M aluminum nitrate. (D.L.C.)

  5. Quasi-linear analysis of the extraordinary electron wave destabilized by runaway electrons

    SciTech Connect (OSTI)

    Pokol, G. I.; Kmr, A.; Budai, A.; Stahl, A.; Flp, T.

    2014-10-15

    Runaway electrons with strongly anisotropic distributions present in post-disruption tokamak plasmas can destabilize the extraordinary electron (EXEL) wave. The present work investigates the dynamics of the quasi-linear evolution of the EXEL instability for a range of different plasma parameters using a model runaway distribution function valid for highly relativistic runaway electron beams produced primarily by the avalanche process. Simulations show a rapid pitch-angle scattering of the runaway electrons in the high energy tail on the 1001000??s time scale. Due to the wave-particle interaction, a modification to the synchrotron radiation spectrum emitted by the runaway electron population is foreseen, exposing a possible experimental detection method for such an interaction.

  6. Kathy Prestridge-Physics' solutions for energy independence

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

    Kathy Prestridge Kathy Prestridge-Physics' solutions for energy independence She leads a team whose high-resolution experiments in fluid dynamics have been applied to weapon design, astrophysics and inertial confinement fusion (ICF)-the power of the sun. March 19, 2014 Kathy Prestridge In college at Princeton and then U.C. San Diego where she obtained her doctorate, Prestridge studied applied mechanics and aerospace engineering. At Los Alamos, she researches the behavior of materials in extreme

  7. Energy transfer dynamics in trimers and aggregates of light-harvesting...

    Office of Scientific and Technical Information (OSTI)

    Energy transfer dynamics in trimers and aggregates of light-harvesting complex II probed by 2D electronic spectroscopy Citation Details In-Document Search Title: Energy transfer ...

  8. ICFA Beam Dynamics Newsletter

    SciTech Connect (OSTI)

    Ben-Zvi I.; Kuczewski A.; Altinbas, Z.; Beavis, D.; Belomestnykh,; Dai, J. et al

    2012-07-01

    The Collider-Accelerator Department at Brookhaven National Laboratory is building a high-brightness 500 mA capable Energy Recovery Linac (ERL) as one of its main R&D thrusts towards eRHIC, the polarized electron - hadron collider as an upgrade of the operating RHIC facility. The ERL is in final assembly stages, with injection commisioning starting in October 2012. The objective of this ERL is to serve as a platform for R&D into high current ERL, in particular issues of halo generation and control, Higher-Order Mode (HOM) issues, coherent emissions for the beam and high-brightness, high-power beam generation and preservation. The R&D ERL features a superconducting laser-photocathode RF gun with a high quantum efficiency photoccathode served with a load-lock cathode delivery system, a highly damped 5-cell accelerating cavity, a highly flexible single-pass loop and a comprehensive system of beam instrumentation. In this ICFA Beam Dynamics Newsletter article we will describe the ERL in a degree of detail that is not usually found in regular publications. We will discuss the various systems of the ERL, following the electrons from the photocathode to the beam dump, cover the control system, machine protection etc and summarize with the status of the ERL systems.

  9. Estimating the uncertainty in underresolved nonlinear dynamics

    SciTech Connect (OSTI)

    Chorin, Alelxandre; Hald, Ole

    2013-06-12

    The Mori-Zwanzig formalism of statistical mechanics is used to estimate the uncertainty caused by underresolution in the solution of a nonlinear dynamical system. A general approach is outlined and applied to a simple example. The noise term that describes the uncertainty turns out to be neither Markovian nor Gaussian. It is argued that this is the general situation.

  10. Integrated Network Decompositions and Dynamic Programming for Graph Optimization (INDDGO)

    Energy Science and Technology Software Center (OSTI)

    2012-05-31

    The INDDGO software package offers a set of tools for finding exact solutions to graph optimization problems via tree decompositions and dynamic programming algorithms. Currently the framework offers serial and parallel (distributed memory) algorithms for finding tree decompositions and solving the maximum weighted independent set problem. The parallel dynamic programming algorithm is implemented on top of the MADNESS task-based runtime.

  11. Dynamic Simulation over Long Time Periods with 100% Solar Generation.

    SciTech Connect (OSTI)

    Concepcion, Ricky James; Elliott, Ryan Thomas

    2015-12-01

    This project aimed to identify the path forward for dynamic simulation tools to accommodate these needs by characterizing the properties of power systems (with high PV penetration), analyzing how these properties affect dynamic simulation software, and offering solutions for potential problems.

  12. Electron-doping of graphene-based devices by hydrazine

    SciTech Connect (OSTI)

    Feng, Tingting; Xie, Dan; Wang, Dongxia; Wen, Lang; Wu, Mengqiang

    2014-12-14

    A facile and effective technique to tune the electronic properties of graphene is essential to facilitate the flexibility of graphene-based device performances. Here, the use of hydrazine as a solution-processable and effective n-type dopant for graphene is described. By dropping hydrazine solutions at different concentrations on a graphene surface, the Dirac point of graphene can be remarkably tuned. The transport behavior of graphene can be changed from p-type to n-type accordingly, demonstrating the controllable and adjustable doping effect of the hydrazine solutions. Accompanying the Dirac point shift is an enhanced hysteretic behavior of the graphene conductance, indicating an increasing trap state density induced by the hydrazine adsorbates. The electron-doping of graphene by the hydrazine solutions can be additionally confirmed with graphene/p-type silicon heterojunctions. The decrease of the junction current after the hydrazine treatment demonstrates an increase of the junction barrier between graphene and silicon, which is essentially due to the electron-doping of graphene and the resultant upshift of the Fermi level. Finally, partially doped graphene is realized and its electrical property is studied to demonstrate the potential of the hydrazine solutions to selectively electron-doping graphene for future electronic applications.

  13. Soliton solutions of the 3D Gross-Pitaevskii equation by a potential control method

    SciTech Connect (OSTI)

    Fedele, R.; Eliasson, B.; Shukla, P. K.; Haas, F.; Jovanovic, D.; De Nicola, S.

    2010-12-14

    We present a class of three-dimensional solitary waves solutions of the Gross-Pitaevskii (GP) equation, which governs the dynamics of Bose-Einstein condensates (BECs). By imposing an external controlling potential, a desired time-dependent shape of the localized BEC excitation is obtained. The stability of some obtained localized solutions is checked by solving the time-dependent GP equation numerically with analytic solutions as initial conditions. The analytic solutions can be used to design external potentials to control the localized BECs in experiment.

  14. Future of Electron Scattering and Diffraction

    SciTech Connect (OSTI)

    Hall, Ernest; Stemmer, Susanne; Zheng, Haimei; Zhu, Yimei; Maracas, George

    2014-02-25

    spectroscopy with high spatial resolution without damaging their structure. The strong interaction of electrons with matter allows high-energy electron pulses to gather structural information before a sample is damaged. Electron ScatteringImaging, diffraction, and spectroscopy are the fundamental capabilities of electron-scattering instruments. The DOE BES-funded TEAM (Transmission Electron Aberration-corrected Microscope) project achieved unprecedented sub-atomic spatial resolution in imaging through aberration-corrected transmission electron microscopy. To further advance electron scattering techniques that directly enable groundbreaking science, instrumentation must advance beyond traditional two-dimensional imaging. Advances in temporal resolution, recording the full phase and energy spaces, and improved spatial resolution constitute a new frontier in electron microscopy, and will directly address the BES Grand Challenges, such as to “control the emergent properties that arise from the complex correlations of atomic and electronic constituents” and the “hidden states” “very far away from equilibrium”. Ultrafast methods, such as the pump-probe approach, enable pathways toward understanding, and ultimately controlling, the chemical dynamics of molecular systems and the evolution of complexity in mesoscale and nanoscale systems. Central to understanding how to synthesize and exploit functional materials is having the ability to apply external stimuli (such as heat, light, a reactive flux, and an electrical bias) and to observe the resulting dynamic process in situ and in operando, and under the appropriate environment (e.g., not limited to UHV conditions). To enable revolutionary advances in electron scattering and science, the participants of the workshop recommended three major new instrumental developments: A. Atomic-Resolution Multi-Dimensional Transmission Electron Microscope: This instrument would provide quantitative information over the entire real space

  15. Frontiers of in situ electron microscopy

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

    Zheng, Haimei; Zhu, Yimei; Meng, Shirley Ying

    2015-01-01

    In situ transmission electron microscopy (TEM) has become an increasingly important tool for materials characterization. It provides key information on the structural dynamics of a material during transformations and the correlation between structure and properties of materials. With the recent advances in instrumentation, including aberration corrected optics, sample environment control, the sample stage, and fast and sensitive data acquisition, in situ TEM characterization has become more and more powerful. In this article, a brief review of the current status and future opportunities of in situ TEM is included. It also provides an introduction to the six articles covered by inmore » this issue of MRS Bulletin explore the frontiers of in situ electron microscopy, including liquid and gas environmental TEM, dynamic four-dimensional TEM, nanomechanics, ferroelectric domain switching studied by in situ TEM, and state-of-the-art atomic imaging of light elements (i.e., carbon atoms) and individual defects.« less

  16. Average dynamics of a finite set of coupled phase oscillators

    SciTech Connect (OSTI)

    Dima, Germn C. Mindlin, Gabriel B.

    2014-06-15

    We study the solutions of a dynamical system describing the average activity of an infinitely large set of driven coupled excitable units. We compared their topological organization with that reconstructed from the numerical integration of finite sets. In this way, we present a strategy to establish the pertinence of approximating the dynamics of finite sets of coupled nonlinear units by the dynamics of its infinitely large surrogate.

  17. Electronics Stewardship | Department of Energy

    Office of Environmental Management (EM)

    Electronics Stewardship Electronics Stewardship Mission The team promotes sustainable management of LM's electronic equipment, as deemed appropriate for LM operations and approved ...

  18. Electron emitting filaments for electron discharge devices

    DOE Patents [OSTI]

    Leung, K.N.; Pincosy, P.A.; Ehlers, K.W.

    1983-06-10

    Electrons are copiously emitted by a device comprising a loop-shaped filament made of lanthanum hexaboride. The filament is directly heated by an electrical current produced along the filament by a power supply connected to the terminal legs of the filament. To produce a filament, a diamond saw or the like is used to cut a slice from a bar made of lanthanum hexaboride. The diamond saw is then used to cut the slice into the shape of a loop which may be generally rectangular, U-shaped, hairpin-shaped, zigzag-shaped, or generally circular. The filaments provide high electron emission at a relatively low operating temperature, such as 1600/sup 0/C. To achieve uniform heating, the filament is formed with a cross section which is tapered between the opposite ends of the filament to compensate for nonuniform current distribution along the filament due to the emission of electrons from the filament.

  19. Electron emitting filaments for electron discharge devices

    DOE Patents [OSTI]

    Leung, Ka-Ngo; Pincosy, Philip A.; Ehlers, Kenneth W.

    1988-01-01

    Electrons are copiously emitted by a device comprising a loop-shaped filament made of lanthanum hexaboride. The filament is directly heated by an electrical current produced along the filament by a power supply connected to the terminal legs of the filament. To produce a filament, a diamond saw or the like is used to cut a slice from a bar made of lanthanum hexaboride. The diamond saw is then used to cut the slice into the shape of a loop which may be generally rectangular, U-shaped, hairpin-shaped, zigzag-shaped, or generally circular. The filaments provide high electron emission at a relatively low operating temperature, such as 1600.degree. C. To achieve uniform heating, the filament is formed with a cross section which is tapered between the opposite ends of the filament to compensate for non-uniform current distribution along the filament due to the emission of electrons from the filament.

  20. Electron Elevator: Excitations across the Band Gap via a Dynamical...

    Office of Scientific and Technical Information (OSTI)

    Record 10.1103PhysRevLett.116.043201 http:dx.doi.org10.1103PhysRevLett.116.043201 Have feedback or suggestions for a way to improve these results? Save Share this Record ...

  1. Electron dynamics in intense laser fields with Bohmian trajectories...

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

    extension, as the characteristic features of high order harmonic generation spectrum. ... In this case, the resulting patterns in the high-order harmonic generation and the above ...

  2. Longitudinal dynamics of twin electron bunches in the Linac Coherent...

    Office of Scientific and Technical Information (OSTI)

    OSTI Identifier: 1181464 GrantContract Number: AC02-76SF00515 Type: Published Article Journal Name: Physical Review Special Topics - Accelerators and Beams Additional Journal ...

  3. Individual identification of free hole and electron dynamics...

    Office of Scientific and Technical Information (OSTI)

    as an understanding of this behavior is essential for improving the performance of solar cells composed of CIGS thin films. A characteristic double-peak structure due to the...

  4. Single-Particle Dynamics in Electron Storage Rings with Extremely...

    Office of Scientific and Technical Information (OSTI)

    They have become essential facilities to study high-energy physics and material and medical sciences. To further increase the luminosity of colliders or the brightness of ...

  5. Interfacial electron transfer dynamics of photosensitized zinc oxide nanoclusters

    SciTech Connect (OSTI)

    Murakoshi, Kei; Yanagida, Shozo; Capel, M.

    1997-06-01

    The authors have prepared and characterized photosensitized zinc oxide (ZnO) nanoclusters, dispersed in methanol, using carboxylated coumarin dyes for surface adsorption. Femtosecond time-resolved emission spectroscopy allows the authors to measure the photo-induced charge carrier injection rate constant from the adsorbed photosensitizer to the n-type semiconductor nanocluster. These results are compared with other photosensitized semiconductors.

  6. Electron Transfer Dynamics in Efficient Molecular Solar Cells

    SciTech Connect (OSTI)

    Meyer, Gerald John

    2014-10-01

    This research provided new mechanistic insights into surface mediated photochemical processes relevant to solar energy conversion. In this past three years our research has focused on oxidation photo-redox chemistry and on the role surface electric fields play on basic spectroscopic properties of molecular-semiconductor interfaces. Although this research as purely fundamental science, the results and their interpretation have relevance to applications in dye sensitized and photogalvanic solar cells as well as in the storage of solar energy in the form of chemical bonds.

  7. Single-Particle Dynamics in Electron Storage Rings with Extremely...

    Office of Scientific and Technical Information (OSTI)

    we have refined transfer maps of common elements in storage rings and developed a new method to compute the resonance driving terms as they are built up along a beamline....

  8. Electrodialysis operation with buffer solution

    DOE Patents [OSTI]

    Hryn, John N.; Daniels, Edward J.; Krumdick, Greg K.

    2009-12-15

    A new method for improving the efficiency of electrodialysis (ED) cells and stacks, in particular those used in chemical synthesis. The process entails adding a buffer solution to the stack for subsequent depletion in the stack during electrolysis. The buffer solution is regenerated continuously after depletion. This buffer process serves to control the hydrogen ion or hydroxide ion concentration so as to protect the active sites of electrodialysis membranes. The process enables electrodialysis processing options for products that are sensitive to pH changes.

  9. Building America Solution Center Webinar

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

    Webinar July 22, 2015 Put New Tools and Content on the Building America Solution Center to Work for You! CHRISSI ANTONOPOULOS Pacific NW National Laboratory 2 | Building America eere.energy.gov 2015 has been an exciting year for the Building America Solution Center! Along with continuous content additions, there are many new features we'd like to share with you: * EPA Indoor airPLUS checklist manager * A new sales tool * Over 80 videos * Existing homes expanded content and navigation Overview 3

  10. TrueWind Solutions | Open Energy Information

    Open Energy Info (EERE)

    TrueWind Solutions Jump to: navigation, search Name: TrueWind Solutions Place: Albany, NY Website: www.awstruepower.com References: TrueWind Solutions1 Information About...

  11. Electron localization of anions probed by nitrile vibrations

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

    Mani, Tomoyasu; Grills, David C.; Newton, Marshall D.; Miller, John R.

    2015-08-02

    Localization and delocalization of electrons is a key concept in chemistry, and is one of the important factors determining the efficiency of electron transport through organic conjugated molecules, which have potential to act as “molecular wires”. This, in turn, substantially influences the efficiencies of organic solar cells and other molecular electronic devices. It is also necessary to understand the electronic energy landscape and the dynamics of electrons through molecular chain that govern their transport capabilities in one-dimensional conjugated chains so that we can better define the design principles of conjugated molecules for their applications. We show that nitrile ν(C≡N) vibrationsmore » respond to the degree of electron localization in nitrile-substituted organic anions by utilizing time-resolved infrared (TRIR) detection combined with pulse radiolysis. Measurements of a series of aryl nitrile anions allow us to construct a semi-empirical calibration curve between the changes in the ν(C≡N) IR shifts and the changes in the electronic charges from the neutral to the anion states in the nitriles; more electron localization in the nitrile anion results in larger IR shifts. Furthermore, the IR linewidth in anions can report a structural change accompanying changes in the electronic density distribution. Probing the shift of the nitrile ν(C≡N) IR vibrational bands enables us to determine how the electron is localized in anions of nitrile-functionalized oligofluorenes, considered as organic mixed-valence compounds. We estimate the diabatic electron transfer distance, electronic coupling strengths, and energy barriers in these organic mixed-valence compounds. The analysis reveals a dynamic picture, showing that the electron is moving back and forth within the oligomers with a small activation energy of ≤ kBT, likely controlled by the movement of dihedral angles between monomer units. Thus, implications for the electron transport capability

  12. Electron localization of anions probed by nitrile vibrations

    SciTech Connect (OSTI)

    Mani, Tomoyasu; Grills, David C.; Newton, Marshall D.; Miller, John R.

    2015-08-02

    Localization and delocalization of electrons is a key concept in chemistry, and is one of the important factors determining the efficiency of electron transport through organic conjugated molecules, which have potential to act as molecular wires. This, in turn, substantially influences the efficiencies of organic solar cells and other molecular electronic devices. It is also necessary to understand the electronic energy landscape and the dynamics of electrons through molecular chain that govern their transport capabilities in one-dimensional conjugated chains so that we can better define the design principles of conjugated molecules for their applications. We show that nitrile ?(C?N) vibrations respond to the degree of electron localization in nitrile-substituted organic anions by utilizing time-resolved infrared (TRIR) detection combined with pulse radiolysis. Measurements of a series of aryl nitrile anions allow us to construct a semi-empirical calibration curve between the changes in the ?(C?N) IR shifts and the changes in the electronic charges from the neutral to the anion states in the nitriles; more electron localization in the nitrile anion results in larger IR shifts. Furthermore, the IR linewidth in anions can report a structural change accompanying changes in the electronic density distribution. Probing the shift of the nitrile ?(C?N) IR vibrational bands enables us to determine how the electron is localized in anions of nitrile-functionalized oligofluorenes, considered as organic mixed-valence compounds. We estimate the diabatic electron transfer distance, electronic coupling strengths, and energy barriers in these organic mixed-valence compounds. The analysis reveals a dynamic picture, showing that the electron is moving back and forth within the oligomers with a small activation energy of ? kBT, likely controlled by the movement of dihedral angles between monomer units. Thus, implications for the electron transport capability in

  13. Electron localization of anions probed by nitrile vibrations

    SciTech Connect (OSTI)

    Mani, Tomoyasu; Grills, David C.; Newton, Marshall D.; Miller, John R.

    2015-08-02

    Localization and delocalization of electrons is a key concept in chemistry, and is one of the important factors determining the efficiency of electron transport through organic conjugated molecules, which have potential to act as “molecular wires”. This, in turn, substantially influences the efficiencies of organic solar cells and other molecular electronic devices. It is also necessary to understand the electronic energy landscape and the dynamics of electrons through molecular chain that govern their transport capabilities in one-dimensional conjugated chains so that we can better define the design principles of conjugated molecules for their applications. We show that nitrile ν(C≡N) vibrations respond to the degree of electron localization in nitrile-substituted organic anions by utilizing time-resolved infrared (TRIR) detection combined with pulse radiolysis. Measurements of a series of aryl nitrile anions allow us to construct a semi-empirical calibration curve between the changes in the ν(C≡N) IR shifts and the changes in the electronic charges from the neutral to the anion states in the nitriles; more electron localization in the nitrile anion results in larger IR shifts. Furthermore, the IR linewidth in anions can report a structural change accompanying changes in the electronic density distribution. Probing the shift of the nitrile ν(C≡N) IR vibrational bands enables us to determine how the electron is localized in anions of nitrile-functionalized oligofluorenes, considered as organic mixed-valence compounds. We estimate the diabatic electron transfer distance, electronic coupling strengths, and energy barriers in these organic mixed-valence compounds. The analysis reveals a dynamic picture, showing that the electron is moving back and forth within the oligomers with a small activation energy of ≤ kBT, likely controlled by the movement of dihedral angles between monomer units. Thus, implications for the electron transport

  14. Field emission electron source

    DOE Patents [OSTI]

    Zettl, Alexander Karlwalter; Cohen, Marvin Lou

    2000-01-01

    A novel field emitter material, field emission electron source, and commercially feasible fabrication method is described. The inventive field emission electron source produces reliable electron currents of up to 400 mA/cm.sup.2 at 200 volts. The emitter is robust and the current it produces is not sensitive to variability of vacuum or the distance between the emitter tip and the cathode. The novel emitter has a sharp turn-on near 100 volts.

  15. Ceramic Electron Multiplier

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

    Comby, G.

    1996-10-01

    The Ceramic Electron Multipliers (CEM) is a compact, robust, linear and fast multi-channel electron multiplier. The Multi Layer Ceramic Technique (MLCT) allows to build metallic dynodes inside a compact ceramic block. The activation of the metallic dynodes enhances their secondary electron emission (SEE). The CEM can be used in multi-channel photomultipliers, multi-channel light intensifiers, ion detection, spectroscopy, analysis of time of flight events, particle detection or Cherenkov imaging detectors. (auth)

  16. Electronic Recordkeeping System Questionnaire

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

    5 (04/2015) U.S. DEPARTMENT OF ENERGY Electronic Recordkeeping System Questionnaire INSTRUCTIONS: System owners should work in consultation with their organization's records contacts to ensure the accurate completion of a separate questionnaire for each electronic recordkeeping system. Federal regulations require proper address of recordkeeping requirements and disposition before approving new electronic information systems (EIS) or enhancements to existing EISes. OMB Circular A-130 requires

  17. Controlling Graphene's Electronic Structure

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

    spectroscopy (ARPES) at ALS Beamline 7.0.1, a team of scientists from the ALS and Germany characterized the electronic band structure and successfully controlled the gap...

  18. Laser spectroscopy and dynamics of transient species

    SciTech Connect (OSTI)

    Clouthier, D.J.

    1993-12-01

    The goal of this program is to study the vibrational and electronic spectra and excited state dynamics of a number of transient sulfur and oxygen species. A variety of supersonic jet techniques, as well as high resolution FT-IR and intracavity dye laser spectroscopy, have been applied to these studies.

  19. Funding Opportunity Webinar - Advancing Solutions to Improve...

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

    Advancing Solutions to Improve Energy Efficiency of Commercial Buildings Funding Opportunity Webinar - Advancing Solutions to Improve Energy Efficiency of Commercial Buildings View ...

  20. Advanced Hydro Solutions | Open Energy Information

    Open Energy Info (EERE)

    Hydro Solutions Jump to: navigation, search Name: Advanced Hydro Solutions Place: Fairlawn, Ohio Zip: 44333 Sector: Hydro Product: Ohio-based company seeking to develop...

  1. Island Energy Solutions | Open Energy Information

    Open Energy Info (EERE)

    search Name: Island Energy Solutions Place: Kailua, Hawaii Zip: 96734 Product: Island Energy Solutions, Inc. is an electrical contracting company, based out of Kailua, Oahu,...

  2. Understanding and Manipulating Solution Chemistry of Polysulfides...

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

    Understanding and Manipulating Solution Chemistry of Polysulfides for Lithium Sulfur Batteries (Top)Fundamental details regarding the solution chemistry of polysulfides in organic ...

  3. Freedom Energy Solutions LLC | Open Energy Information

    Open Energy Info (EERE)

    Energy Solutions LLC Jump to: navigation, search Name: Freedom Energy Solutions LLC Place: Westminster, Maryland Zip: 21157 Sector: Geothermal energy, Solar Product: Retailer and...

  4. Conservation Resource Solutions | Open Energy Information

    Open Energy Info (EERE)

    Solutions Jump to: navigation, search Name: Conservation Resource Solutions Place: Cumming, Georgia Zip: 30040 Sector: Services Product: String representation "Conservation Re ......

  5. Bio Solutions Manufacturing Inc | Open Energy Information

    Open Energy Info (EERE)

    Solutions Manufacturing Inc Jump to: navigation, search Name: Bio Solutions Manufacturing Inc Place: Las Vegas, Nevada Zip: 89103 Product: Waste-to-energy bioremediation developer....

  6. First Carbon Solutions | Open Energy Information

    Open Energy Info (EERE)

    Solutions Jump to: navigation, search Name: First Carbon Solutions Place: Bethesda, Maryland Product: To be completed... Coordinates: 40.020185, -81.073819 Show Map Loading...

  7. Clean Energy Solutions Center | Open Energy Information

    Open Energy Info (EERE)

    Center Jump to: navigation, search Logo: Clean Energy Solutions Center Name Clean Energy Solutions Center AgencyCompany Organization Clean Energy Ministerial Sector Energy Focus...

  8. Quantum Energy Solutions | Open Energy Information

    Open Energy Info (EERE)

    Solutions Jump to: navigation, search Name: Quantum Energy Solutions Place: Rancho Cordova, California Zip: 95742 Product: California-based energy management company that was...

  9. AG Solutions Inc | Open Energy Information

    Open Energy Info (EERE)

    navigation, search Name: AG Solutions Inc. Place: Gladstone, Michigan Product: 10Mgpy biodiesel producer in Gladstone, Michigan. References: AG Solutions Inc.1 This article is a...

  10. Biodiesel Solutions Inc | Open Energy Information

    Open Energy Info (EERE)

    Solutions Inc Jump to: navigation, search Name: Biodiesel Solutions Inc Place: Sparks, Nevada Zip: 89431 Product: Designs and manufactures processing equipment and accessories to...

  11. Challenges and Solutions for Multifamily Modeling | Department...

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

    Challenges and Solutions for Multifamily Modeling Challenges and Solutions for Multifamily Modeling This presentation was delivered at the U.S. Department of Energy Building ...

  12. Officials Establish Training Institute, Creating Enterprise Solution...

    Office of Environmental Management (EM)

    Officials Establish Training Institute, Creating Enterprise Solution for Worker Safety Officials Establish Training Institute, Creating Enterprise Solution for Worker Safety March ...

  13. Presentation: Better Buildings Residential Program Solution Center...

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

    Presentation: Better Buildings Residential Program Solution Center, from the U.S. Department of Energy's Better Buildings Neighborhood Program, April 2014. Solution Center Overview...

  14. Eco Power Solutions | Open Energy Information

    Open Energy Info (EERE)

    Power Solutions Jump to: navigation, search Name: Eco Power Solutions Place: Quincy, Massachusetts Zip: 2169 Product: Massachusetts-based, energy recovery and emission control...

  15. Eco Sustainable Solutions Ltd | Open Energy Information

    Open Energy Info (EERE)

    Sustainable Solutions Ltd Jump to: navigation, search Name: Eco Sustainable Solutions Ltd Place: Dorset, United Kingdom Zip: BH23 6BG Sector: Biomass Product: Focused on organics...

  16. Smarter Grid Solutions | Open Energy Information

    Open Energy Info (EERE)

    Smarter Grid Solutions Jump to: navigation, search Name: Smarter Grid Solutions Place: United Kingdom Product: String representation "The SGS technol ... the technology." is too...

  17. Reaction Engineering Solutions Ltd | Open Energy Information

    Open Energy Info (EERE)

    Ltd Jump to: navigation, search Name: Reaction Engineering Solutions Ltd. Place: Cambridge, United Kingdom Zip: CB4 3QG Product: PUk-based, provider of computational solutions...

  18. Atlantic Energy Solutions | Open Energy Information

    Open Energy Info (EERE)

    Atlantic Energy Solutions Place: Foxboro, Massachusetts Sector: Efficiency, Renewable Energy Product: Atlantic Energy Solutions provides energy auditing for its customers and...

  19. Technology Market Solutions | Open Energy Information

    Open Energy Info (EERE)

    Solutions Jump to: navigation, search Name: Technology & Market Solutions Place: Fairfax Station, Virginia Zip: 22039 Product: A consulting practice concentrating on technological,...

  20. Solution Capital Partners | Open Energy Information

    Open Energy Info (EERE)

    Solution Capital Partners Jump to: navigation, search Name: Solution Capital Partners Place: New York Zip: NY 10036 Product: A New York-based investment firm active in the...

  1. Regional Climate Vulnerabilities and Resilience Solutions | Department...

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

    Regional Climate Vulnerabilities and Resilience Solutions Regional Climate Vulnerabilities and Resilience Solutions This interactive map is not viewable in your browser. Please ...

  2. Eco Alternative Energy Solutions | Open Energy Information

    Open Energy Info (EERE)

    Solutions Jump to: navigation, search Name: Eco Alternative Energy Solutions Place: Puerto Rico Product: Puerto Rico-based majority owner of joint venture Pevafersa America, which...

  3. Energy Options Solutions | Open Energy Information

    Open Energy Info (EERE)

    Energy Options & Solutions Place: Ann Arbor, Michigan Zip: 48103 Product: Michigan-based alternative energy consultant. References: Energy Options & Solutions1 This article is a...

  4. Duke Energy Generation Services formerly Cinergy Solutions |...

    Open Energy Info (EERE)

    Generation Services formerly Cinergy Solutions Jump to: navigation, search Name: Duke Energy Generation Services (formerly Cinergy Solutions) Place: Cincinatti, Ohio Zip: 45202...

  5. PowerIt Solutions | Open Energy Information

    Open Energy Info (EERE)

    Place: Seattle, Washington Zip: 98104 Product: Powerit Solutions provides energy demand response and demand control solutions for industrial and commercial applications....

  6. M S Solutions | Open Energy Information

    Open Energy Info (EERE)

    Solutions Jump to: navigation, search Name: MS Solutions Place: Burdwan, West Bengal, India Sector: Biomass Product: Burdwan-based biomass cogenration project developer....

  7. Econic Renewable Energy Solutions | Open Energy Information

    Open Energy Info (EERE)

    Econic Renewable Energy Solutions Jump to: navigation, search Name: Econic Renewable Energy Solutions Place: Norfolk, United Kingdom Zip: NR 105PQ Sector: Renewable Energy Product:...

  8. Renewable Energy Solutions, LLC | Open Energy Information

    Open Energy Info (EERE)

    Solutions, LLC Jump to: navigation, search Name: Renewable Energy Solutions, LLC Place: Fairfield, California Zip: 94534 Region: Bay Area Sector: Services Year Founded: 2008...

  9. International Environmental Solutions IES | Open Energy Information

    Open Energy Info (EERE)

    Environmental Solutions IES Jump to: navigation, search Name: International Environmental Solutions (IES) Place: Romoland, California Zip: 92585 Product: It is an environmentally...

  10. Better Buildings Residential Program Solution Center Demonstration...

    Energy Savers [EERE]

    Residential Program Solution Center Demonstration Better Buildings Residential Program ... Residential Program Solution Center Demonstration from the U.S. Department of Energy. ...

  11. Better Buildings Residential Program Solution Center Demonstration...

    Office of Environmental Management (EM)

    Webinar Better Buildings Residential Program Solution Center Demonstration Webinar Demonstration webinar slides for Better Buildings Residential Program Solution Center, November 19, ...

  12. Enisolar Energy Solutions | Open Energy Information

    Open Energy Info (EERE)

    Solutions Jump to: navigation, search Name: Enisolar Energy Solutions Place: Istanbul, Turkey Sector: Wind energy Product: Turkey-based wind, PV, and hybrid system integrator; also...

  13. Guardian Energy Management Solutions | Open Energy Information

    Open Energy Info (EERE)

    Guardian Energy Management Solutions Jump to: navigation, search Name: Guardian Energy Management Solutions Address: 753 Forest Street, Suite 110 Place: Marlborough, Massachusetts...

  14. Atlas Material Testing Solutions | Open Energy Information

    Open Energy Info (EERE)

    Atlas Material Testing Solutions Jump to: navigation, search Name: Atlas Material Testing Solutions Place: Chicago, IL Zip: 60613 Website: atlas-mts.com Coordinates: 41.9529209,...

  15. Global Power Solutions LLC | Open Energy Information

    Open Energy Info (EERE)

    Global Power Solutions LLC Jump to: navigation, search Name: Global Power Solutions LLC Place: Colorado Zip: CO 80401 Sector: Geothermal energy Product: String representation...

  16. Ebony Solutions UK | Open Energy Information

    Open Energy Info (EERE)

    Ebony Solutions UK Jump to: navigation, search Name: Ebony Solutions UK Place: Northwich, Cheshire, United Kingdom Zip: CW8 2SX Product: A UK biodiesel manufacturer. References:...

  17. Solar Electric Solutions LLC | Open Energy Information

    Open Energy Info (EERE)

    Electric Solutions LLC Jump to: navigation, search Name: Solar Electric Solutions, LLC Place: Woodland Hills, California Zip: 91364 Sector: Solar Product: California-based...

  18. Energy Solutions Co Ltd | Open Energy Information

    Open Energy Info (EERE)

    Energy Solutions Co Ltd Jump to: navigation, search Name: Energy Solutions Co Ltd Place: Seoul, Korea (Republic) Sector: Efficiency Product: A Korean builderengineering contractor...

  19. BFC Solutions Limited | Open Energy Information

    Open Energy Info (EERE)

    BFC Solutions Limited Jump to: navigation, search Name: BFC Solutions Limited Place: Taunton, England, United Kingdom Zip: TA1 PEJ Sector: Carbon Product: Somerset-based...

  20. PNE Renewable Solutions JV | Open Energy Information

    Open Energy Info (EERE)

    PNE Renewable Solutions JV Jump to: navigation, search Name: PNE & Renewable Solutions JV Place: Delaware Sector: Wind energy Product: Delaware-based limited liability company and...

  1. EQuilibrium Solutions Inc | Open Energy Information

    Open Energy Info (EERE)

    EQuilibrium Solutions Inc Jump to: navigation, search Name: eQuilibrium Solutions Inc Place: Boston, Massachusetts Zip: 2215 Sector: Carbon, Efficiency Product: Boston-based...

  2. Solargen Solutions UK | Open Energy Information

    Open Energy Info (EERE)

    Solargen Solutions UK Jump to: navigation, search Name: Solargen Solutions UK Place: United Kingdom Zip: NP 44 3AS Sector: Renewable Energy, Solar Product: String representation...

  3. Washington TRU Solutions Inc | Open Energy Information

    Open Energy Info (EERE)

    Washington TRU Solutions Inc Jump to: navigation, search Name: Washington TRU Solutions, Inc. Place: Carlsbad, New Mexico Zip: 88220 Product: New Mexico-based managing and...

  4. Advanced Combustion Concepts - Enabling Systems and Solutions...

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

    Combustion Concepts - Enabling Systems and Solutions (ACCESS) for High Efficiency Light Duty Vehicles Advanced Combustion Concepts - Enabling Systems and Solutions (ACCESS) for ...

  5. Solar amp Electric Solutions | Open Energy Information

    Open Energy Info (EERE)

    Electric Solutions Jump to: navigation, search Name: Solar & Electric Solutions Place: Santa Cruz, California Zip: 95062 Sector: Solar Product: Small solar installation firm in...

  6. Global Warming Solutions Inc previously Southern Investments...

    Open Energy Info (EERE)

    Solutions Inc previously Southern Investments Inc Jump to: navigation, search Name: Global Warming Solutions Inc (previously Southern Investments Inc) Place: Houston, Texas...

  7. Consolidated Edison Solutions, Inc. ESCO Qualification Sheet...

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

    Sheet Consolidated Edison Solutions, Inc. ESCO Qualification Sheet Document outlines the energy service company (ESCO) qualifications for ConEdison Solutions. PDF icon ces

  8. Nextreme Thermal Solutions Inc | Open Energy Information

    Open Energy Info (EERE)

    Nextreme Thermal Solutions Inc Jump to: navigation, search Name: Nextreme Thermal Solutions Inc Place: North Carolina Zip: 27709-3981 Product: String representation "Manufactures...

  9. 2016 Midwest Energy Solutions Conference

    Broader source: Energy.gov [DOE]

    Once a year, MEEA invites all energy stakeholders to gather at our annual Midwest Energy Solutions Conference to raise awareness and reinforce the importance of energy efficiency in the Midwest. MES is about celebrating accomplishments in energy efficiency, as well as laying out the efficiency program and policy landscape for the coming year.

  10. 2016 Midwest Energy Solutions Conference

    Broader source: Energy.gov [DOE]

    The Midwest Energy Efficiency Alliance invites all energy stakeholders to gather at the annual Midwest Energy Solutions Conference to raise awareness and reinforce the importance of energy efficiency in the Midwest. This annual conference is about celebrating accomplishments and inspirations in energy efficiency, as well as laying out the efficiency program and policy landscape for the coming year.

  11. Molecular dynamics simulations of the effects of salts on the aggregation properties of benzene in water.

    SciTech Connect (OSTI)

    Smith, P. E.

    2003-07-16

    The specific aims of the project were: to provide an atomic level description of the interactions between benzene, water and ions in solutions. To determine the degree of association between two benzene molecules in aqueous and salt solutions. To investigate the structure and dynamics of the interface between benzene and water or salt solution.

  12. Analysis of the Fisher solution

    SciTech Connect (OSTI)

    Abdolrahimi, Shohreh; Shoom, Andrey A.

    2010-01-15

    We study the d-dimensional Fisher solution which represents a static, spherically symmetric, asymptotically flat spacetime with a massless scalar field. The solution has two parameters, the mass M and the 'scalar charge' {Sigma}. The Fisher solution has a naked curvature singularity which divides the spacetime manifold into two disconnected parts. The part which is asymptotically flat we call the Fisher spacetime, and another part we call the Fisher universe. The d-dimensional Schwarzschild-Tangherlini solution and the Fisher solution belong to the same theory and are dual to each other. The duality transformation acting in the parameter space (M,{Sigma}) maps the exterior region of the Schwarzschild-Tangherlini black hole into the Fisher spacetime which has a naked timelike singularity, and interior region of the black hole into the Fisher universe, which is an anisotropic expanding-contracting universe and which has two spacelike singularities representing its 'big bang' and 'big crunch'. The big bang singularity and the singularity of the Fisher spacetime are radially weak in the sense that a 1-dimensional object moving along a timelike radial geodesic can arrive to the singularities intact. At the vicinity of the singularity the Fisher spacetime of nonzero mass has a region where its Misner-Sharp energy is negative. The Fisher universe has a marginally trapped surface corresponding to the state of its maximal expansion in the angular directions. These results and derived relations between geometric quantities of the Fisher spacetime, the Fisher universe, and the Schwarzschild-Tangherlini black hole may suggest that the massless scalar field transforms the black hole event horizon into the naked radially weak disjoint singularities of the Fisher spacetime and the Fisher universe which are 'dual to the horizon'.

  13. Dissociative electron attachment studies on acetone

    SciTech Connect (OSTI)

    Prabhudesai, Vaibhav S. Tadsare, Vishvesh; Ghosh, Sanat; Gope, Krishnendu; Davis, Daly; Krishnakumar, E.

    2014-10-28

    Dissociative electron attachment (DEA) to acetone is studied in terms of the absolute cross section for various fragment channels in the electron energy range of 020 eV. H{sup ?} is found to be the most dominant fragment followed by O{sup ?} and OH{sup ?} with only one resonance peak between 8 and 9 eV. The DEA dynamics is studied by measuring the angular distribution and kinetic energy distribution of fragment anions using Velocity Slice Imaging technique. The kinetic energy and angular distribution of H{sup ?} and O{sup ?} fragments suggest a many body break-up for the lone resonance observed. The ab initio calculations show that electron is captured in the multi-centered anti-bonding molecular orbital which would lead to a many body break-up of the resonance.

  14. Predissociation dynamics of lithium iodide

    SciTech Connect (OSTI)

    Schmidt, H.; Vangerow, J. von; Stienkemeier, F.; Mudrich, M.; Bogomolov, A. S.; Baklanov, A. V.; Reich, D. M.; Skomorowski, W.; Koch, C. P.

    2015-01-28

    The predissociation dynamics of lithium iodide (LiI) in the first excited A-state is investigated for molecules in the gas phase and embedded in helium nanodroplets, using femtosecond pump-probe photoionization spectroscopy. In the gas phase, the transient Li{sup +} and LiI{sup +} ion signals feature damped oscillations due to the excitation and decay of a vibrational wave packet. Based on high-level ab initio calculations of the electronic structure of LiI and simulations of the wave packet dynamics, the exponential signal decay is found to result from predissociation predominantly at the lowest avoided X-A potential curve crossing, for which we infer a coupling constant V{sub XA} = 650(20) cm{sup −1}. The lack of a pump-probe delay dependence for the case of LiI embedded in helium nanodroplets indicates fast droplet-induced relaxation of the vibrational excitation.

  15. Electronic Mail Analysis Capability

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2001-01-08

    Establishes the pilot program to test the Department of Energy (DOE) Electronic Mail Analysis Capability (EMAC), which will be used to monitor and analyze outgoing and incoming electronic mail (e-mail) from the National Nuclear Security Administration (NNSA) and DOE laboratories that are engaged in nuclear weapons design or work involving special nuclear material. No cancellation.

  16. Effect of Coulomb interaction on multi-electronwave packet dynamics

    SciTech Connect (OSTI)

    Shiokawa, T.; Takada, Y.; Konabe, S.; Hatsugai, Y.; Muraguchi, M.; Endoh, T.; Shiraishi, K.

    2013-12-04

    We have investigated the effect of Coulomb interaction on electron transport in a one-dimensional nanoscale structure using a multi-electron wave packet approach. To study the time evolution, we numerically solve the time-dependent Hartree-Fock equation, finding that the electron wave packet dynamics strongly depends on the Coulomb interaction strength. When the Coulomb interaction is large, each electron wave packet moves separately in the presence of an electric field. With weak Coulomb interaction, however, the electron wave packets overlap, forming and moving as one collective wave packet.

  17. The solution combustion synthesis of nanophosphors

    SciTech Connect (OSTI)

    Tornga, Stephanie C

    2009-01-01

    Nanophosphors are defined as nano-sized (1-100mn), insulating, inorganic materials that emit light under particle or electromagnetic excitation. Their unique luminescence properties provide an excellent potential for applications in radiation detection and imaging. Herein, solution combustion synthesis (SCS) is presented as a method to prepare nanophosphor powders, while X-ray diffraction (XRD), transmission electron microscopy (TEM), photoluminescence (PL), photoluminescence excitation (PLE), and other techniques were used to characterize their structural and optical properties. The goal of this work is to synthesize bright, high-quality powders of nanophosphors, consolidate them into bulk materials and study their structural and optical properties using XRD, TEM, PL, and PLE. SCS is of interest because it is a robust, inexpensive, and facile technique, which yields a significant amount of a wide variety of oxide materials, in a short amount of time. Several practical nanophosphors were synthesized and investigated in this work, including simple oxides such as Y{sub 2}O{sub 3}:Bi, Y{sub 2}O{sub 3}:Tb, Y{sub 2}O{sub 3}:Eu and Gd{sub 2}O{sub 3}:Eu, complex oxides such as Gd{sub 2}SiO{sub 5}:Ce, Y{sub 2}SiO{sub 5}:Ce, Lu{sub 2}SiO{sub 5}:Ce, Zn{sub 2}SiO{sub 4}:Mn, and Y{sub 3}Al{sub 5}O{sub 12}:Ce. Results demonstrate that altering the processing parameters such as water content of the precursor solution, ignition temperature, fuel type and amount, and post-synthesis annealing can significantly improve light output, and that it is possible to optimize the luminescence output of oxyorthosilicates by reducing the amount of silica in the precursor mixture.

  18. High brightness electron accelerator

    DOE Patents [OSTI]

    Sheffield, Richard L.; Carlsten, Bruce E.; Young, Lloyd M.

    1994-01-01

    A compact high brightness linear accelerator is provided for use, e.g., in a free electron laser. The accelerator has a first plurality of acclerating cavities having end walls with four coupling slots for accelerating electrons to high velocities in the absence of quadrupole fields. A second plurality of cavities receives the high velocity electrons for further acceleration, where each of the second cavities has end walls with two coupling slots for acceleration in the absence of dipole fields. The accelerator also includes a first cavity with an extended length to provide for phase matching the electron beam along the accelerating cavities. A solenoid is provided about the photocathode that emits the electons, where the solenoid is configured to provide a substantially uniform magnetic field over the photocathode surface to minimize emittance of the electons as the electrons enter the first cavity.

  19. Electron: Cluster interactions

    SciTech Connect (OSTI)

    Scheidemann, A.A.; Kresin, V.V.; Knight, W.D.

    1994-02-01

    Beam depletion spectroscopy has been used to measure absolute total inelastic electron-sodium cluster collision cross sections in the energy range from E {approximately} 0.1 to E {approximately} 6 eV. The investigation focused on the closed shell clusters Na{sub 8}, Na{sub 20}, Na{sub 40}. The measured cross sections show an increase for the lowest collision energies where electron attachment is the primary scattering channel. The electron attachment cross section can be understood in terms of Langevin scattering, connecting this measurement with the polarizability of the cluster. For energies above the dissociation energy the measured electron-cluster cross section is energy independent, thus defining an electron-cluster interaction range. This interaction range increases with the cluster size.

  20. Electrons and Mirror Symmetry

    SciTech Connect (OSTI)

    Kumar, Krishna

    2007-04-04

    The neutral weak force between an electron and a target particle, mediated by the Z boson, can be isolated by measuring the fractional change under a mirror reflection of the scattering probability of relativistic longitudinally polarized electrons off unpolarized targets. This technique yields neutral weak force measurements at a length scale of 1 femtometer, in contrast to high energy collider measurements that probe much smaller length scales. Study of the variation of the weak force over a range of length scales provides a stringent test of theory, complementing collider measurements. We describe a recent measurement of the neutral weak force between two electrons by the E158 experiment at the Stanford Linear Accelerator Center. While the weak force between an electron and positron has been extensively studied, that between two electrons had never directly been measured. We conclude by discussing prospects for even more precise measurements at future facilities.

  1. Electrons and Mirror Symmetry

    ScienceCinema (OSTI)

    Kumar, Krishna

    2009-09-01

    The neutral weak force between an electron and a target particle, mediated by the Z boson, can be isolated by measuring the fractional change under a mirror reflection of the scattering probability of relativistic longitudinally polarized electrons off unpolarized targets. This technique yields neutral weak force measurements at a length scale of 1 femtometer, in contrast to high energy collider measurements that probe much smaller length scales. Study of the variation of the weak force over a range of length scales provides a stringent test of theory, complementing collider measurements. We describe a recent measurement of the neutral weak force between two electrons by the E158 experiment at the Stanford Linear Accelerator Center. While the weak force between an electron and positron has been extensively studied, that between two electrons had never directly been measured. We conclude by discussing prospects for even more precise measurements at future facilities.

  2. Computational Fluid Dynamics Library

    Energy Science and Technology Software Center (OSTI)

    2005-03-04

    CFDLib05 is the Los Alamos Computational Fluid Dynamics LIBrary. This is a collection of hydrocodes using a common data structure and a common numerical method, for problems ranging from single-field, incompressible flow, to multi-species, multi-field, compressible flow. The data structure is multi-block, with a so-called structured grid in each block. The numerical method is a Finite-Volume scheme employing a state vector that is fully cell-centered. This means that the integral form of the conservation lawsmore » is solved on the physical domain that is represented by a mesh of control volumes. The typical control volume is an arbitrary quadrilateral in 2D and an arbitrary hexahedron in 3D. The Finite-Volume scheme is for time-unsteady flow and remains well coupled by means of time and space centered fluxes; if a steady state solution is required, the problem is integrated forward in time until the user is satisfied that the state is stationary.« less

  3. Simulations of Gaussian electron guns for RHIC electron lens

    SciTech Connect (OSTI)

    Pikin, A.

    2014-02-28

    Simulations of two versions of the electron gun for RHIC electron lens are presented. The electron guns have to generate an electron beam with Gaussian radial profile of the electron beam density. To achieve the Gaussian electron emission profile on the cathode we used a combination of the gun electrodes and shaping of the cathode surface. Dependence of electron gun performance parameters on the geometry of electrodes and the margins for electrodes positioning are presented.

  4. Propagation of three-dimensional electron-acoustic solitary waves

    SciTech Connect (OSTI)

    Shalaby, M.; El-Sherif, L. S.; El-Labany, S. K.; Sabry, R.

    2011-06-15

    Theoretical investigation is carried out for understanding the properties of three-dimensional electron-acoustic waves propagating in magnetized plasma whose constituents are cold magnetized electron fluid, hot electrons obeying nonthermal distribution, and stationary ions. For this purpose, the hydrodynamic equations for the cold magnetized electron fluid, nonthermal electron density distribution, and the Poisson equation are used to derive the corresponding nonlinear evolution equation, Zkharov-Kuznetsov (ZK) equation, in the small- but finite- amplitude regime. The ZK equation is solved analytically and it is found that it supports both solitary and blow-up solutions. It is found that rarefactive electron-acoustic solitary waves strongly depend on the density and temperature ratios of the hot-to-cold electron species as well as the nonthermal electron parameter. Furthermore, there is a critical value for the nonthermal electron parameter, which decides whether the electron-acoustic solitary wave's amplitude is decreased or increased by changing various plasma parameters. Importantly, the change of the propagation angles leads to miss the balance between the nonlinearity and dispersion; hence, the localized pulses convert to explosive/blow-up pulses. The relevance of this study to the nonlinear electron-acoustic structures in the dayside auroral zone in the light of Viking satellite observations is discussed.

  5. REMOVAL OF CHLORIDE FROM AQUEOUS SOLUTIONS

    DOE Patents [OSTI]

    Schulz, W.W.

    1959-08-01

    The removal of chlorides from aqueons solutions is described. The process involves contacting the aqueous chloride containing solution with a benzene solution about 0.005 M in phenyl mercuric acetate whereby the chloride anions are taken up by the organic phase and separating the organic phase from the aqueous solutions.

  6. Energy solutions?Director Eric Isaacs

    ScienceCinema (OSTI)

    Eric ISaacs

    2013-06-05

    Argonne's Director Eric Isaacs talks about the laboratory's efforts for creating new, clean energy solutions.

  7. Polarized X-Rays Reveal Molecular Alignment in Printed Electronics

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

    Polarized X-Rays Reveal Molecular Alignment in Printed Electronics Print The printing of electronic devices using giant roll-to-roll presses or inkjet-style printers has recently been made possible by the development of solution-processable organic materials with optoelectronic properties. Organic light-emitting diodes (OLEDs) are already being produced commercially, and sensors, organic thin-film transistors (OTFTs), and organic photovoltaics (OPVs) are also well on their way to commercial

  8. Polarized X-Rays Reveal Molecular Alignment in Printed Electronics

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

    Polarized X-Rays Reveal Molecular Alignment in Printed Electronics Print The printing of electronic devices using giant roll-to-roll presses or inkjet-style printers has recently been made possible by the development of solution-processable organic materials with optoelectronic properties. Organic light-emitting diodes (OLEDs) are already being produced commercially, and sensors, organic thin-film transistors (OTFTs), and organic photovoltaics (OPVs) are also well on their way to commercial

  9. Polarized X-Rays Reveal Molecular Alignment in Printed Electronics

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

    Polarized X-Rays Reveal Molecular Alignment in Printed Electronics Print The printing of electronic devices using giant roll-to-roll presses or inkjet-style printers has recently been made possible by the development of solution-processable organic materials with optoelectronic properties. Organic light-emitting diodes (OLEDs) are already being produced commercially, and sensors, organic thin-film transistors (OTFTs), and organic photovoltaics (OPVs) are also well on their way to commercial

  10. Polarized X-Rays Reveal Molecular Alignment in Printed Electronics

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

    Polarized X-Rays Reveal Molecular Alignment in Printed Electronics Print The printing of electronic devices using giant roll-to-roll presses or inkjet-style printers has recently been made possible by the development of solution-processable organic materials with optoelectronic properties. Organic light-emitting diodes (OLEDs) are already being produced commercially, and sensors, organic thin-film transistors (OTFTs), and organic photovoltaics (OPVs) are also well on their way to commercial

  11. Polarized X-Rays Reveal Molecular Alignment in Printed Electronics

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

    Polarized X-Rays Reveal Molecular Alignment in Printed Electronics Print The printing of electronic devices using giant roll-to-roll presses or inkjet-style printers has recently been made possible by the development of solution-processable organic materials with optoelectronic properties. Organic light-emitting diodes (OLEDs) are already being produced commercially, and sensors, organic thin-film transistors (OTFTs), and organic photovoltaics (OPVs) are also well on their way to commercial

  12. Polarized X-Rays Reveal Molecular Alignment in Printed Electronics

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

    Polarized X-Rays Reveal Molecular Alignment in Printed Electronics Print The printing of electronic devices using giant roll-to-roll presses or inkjet-style printers has recently been made possible by the development of solution-processable organic materials with optoelectronic properties. Organic light-emitting diodes (OLEDs) are already being produced commercially, and sensors, organic thin-film transistors (OTFTs), and organic photovoltaics (OPVs) are also well on their way to commercial

  13. Polarized X-Rays Reveal Molecular Alignment in Printed Electronics

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

    Polarized X-Rays Reveal Molecular Alignment in Printed Electronics Print The printing of electronic devices using giant roll-to-roll presses or inkjet-style printers has recently been made possible by the development of solution-processable organic materials with optoelectronic properties. Organic light-emitting diodes (OLEDs) are already being produced commercially, and sensors, organic thin-film transistors (OTFTs), and organic photovoltaics (OPVs) are also well on their way to commercial

  14. Polarized X-Rays Reveal Molecular Alignment in Printed Electronics

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

    Polarized X-Rays Reveal Molecular Alignment in Printed Electronics Print The printing of electronic devices using giant roll-to-roll presses or inkjet-style printers has recently been made possible by the development of solution-processable organic materials with optoelectronic properties. Organic light-emitting diodes (OLEDs) are already being produced commercially, and sensors, organic thin-film transistors (OTFTs), and organic photovoltaics (OPVs) are also well on their way to commercial

  15. The integration of cryogenic cooling systems with superconducting electronic systems

    SciTech Connect (OSTI)

    Green, Michael A.

    2003-07-01

    The need for cryogenic cooling has been critical issue that has kept superconducting electronic devices from reaching the market place. Even though the performance of the superconducting circuit is superior to silicon electronics, the requirement for cryogenic cooling has put the superconducting devices at a disadvantage. This report will talk about the various methods for refrigerating superconducting devices. Cryocooler types will be compared for vibration, efficiency, and cost. Some solutions to specific problems of integrating cryocoolers to superconducting devices are presented.

  16. Electrochromic Salts, Solutions, and Devices

    DOE Patents [OSTI]

    Burrell, Anthony K.; Warner, Benjamin P.; McClesky, T. Mark

    2008-11-11

    Electrochromic salts. Electrochromic salts of dicationic viologens such as methyl viologen and benzyl viologen associated with anions selected from bis(trifluoromethylsulfonyl)imide, bis(perfluoroethylsulfonyl)imide, and tris(trifluoromethylsulfonyl)methide are produced by metathesis with the corresponding viologen dihalide. They are highly soluble in molten quarternary ammonium salts and together with a suitable reductant provide electrolyte solutions that are used in electrochromic windows.

  17. Electrochromic Salts, Solutions, and Devices

    DOE Patents [OSTI]

    Burrell, Anthony K.; Warner, Benjamin P.; McClesky, T. Mark

    2008-10-14

    Electrochromic salts. Electrochromic salts of dicationic viologens such as methyl viologen and benzyl viologen associated with anions selected from bis(trifluoromethylsulfonyl)imide, bis(perfluoroethylsulfonyl)imide, and tris(trifluoromethylsulfonyl)methide are produced by metathesis with the corresponding viologen dihalide. They are highly soluble in molten quarternary ammonium salts and together with a suitable reductant provide electrolyte solutions that are used in electrochromic windows.

  18. Electrochromic salts, solutions, and devices

    DOE Patents [OSTI]

    Burrell, Anthony K.; Warner, Benjamin P.; McClesky,7,064,212 T. Mark

    2006-06-20

    Electrochromic salts. Electrochromic salts of dicationic viologens such as methyl viologen and benzyl viologen associated with anions selected from bis(trifluoromethylsulfonyl)imide, bis(perfluoroethylsulfonyl)imide, and tris(trifluoromethylsulfonyl)methide are produced by metathesis with the corresponding viologen dihalide. They are highly soluble in molten quarternary ammonium salts and together with a suitable reductant provide electrolyte solutions that are used in electrochromic windows.

  19. Clean Energy Solutions Center (Presentation)

    SciTech Connect (OSTI)

    Reategui, S.

    2012-07-01

    The Clean Energy Ministerial launched the Clean Energy Solutions Center in April, 2011 for major economy countries, led by Australia and U.S. with other CEM partners. Partnership with UN-Energy is extending scope to support all developing countries: 1. Enhance resources on policies relating to energy access, small to medium enterprises (SMEs), and financing programs; 2. Offer expert policy assistance to all countries; 3. Expand peer to peer learning, training, and deployment and policy data for developing countries.

  20. Electrons trajectories around a bubble regime in intense laser plasma interaction

    SciTech Connect (OSTI)

    Lu, Ding; Xie, Bai-Song; Ali Bake, Muhammad; Sang, Hai-Bo; Zhao, Xue-Yan; Wu, Hai-Cheng

    2013-06-15

    Some typical electrons trajectories around a bubble regime in intense laser plasma interaction are investigated theoretically. By considering a modification of the fields and ellipsoid bubble shape due to the presence of residual electrons in the bubble regime, we study in detail the electrons nonlinear dynamics with or without laser pulse. To examine the electron dynamical behaviors, a set of typical electrons, which locate initially at the front of the bubble, on the transverse edge and at the bottom of the bubble respectively, are chosen for study. It is found that the range of trapped electrons in the case with laser pulse is a little narrower than that without laser pulse. The partial phase portraits for electrons around the bubble are presented numerically and their characteristic behaviors are discussed theoretically. Implication of our results on the high quality electron beam generation is also discussed briefly.