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Sample records for ultrafast physics molecular

  1. New 'Molecular Movie' Reveals Ultrafast Chemistry in Motion

    SciTech Connect (OSTI)

    Minitti, Michael

    2015-06-22

    Scientists for the first time tracked ultrafast structural changes, captured in quadrillionths-of-a-second steps, as ring-shaped gas molecules burst open and unraveled. Ring-shaped molecules are abundant in biochemistry and also form the basis for many drug compounds. The study points the way to a wide range of real-time X-ray studies of gas-based chemical reactions that are vital to biological processes.

  2. QUANTUM MECHANICS, GENERAL PHYSICS; 74 ATOMIC AND MOLECULAR PHYSICS...

    Office of Scientific and Technical Information (OSTI)

    of model atoms in fields Milonni, P.W. 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 74 ATOMIC AND MOLECULAR PHYSICS; ATOMS; OPTICAL MODELS; QUANTUM MECHANICS;...

  3. Physical mechanisms of SiN{sub x} layer structuring with ultrafast lasers by direct and confined laser ablation

    SciTech Connect (OSTI)

    Rapp, S.; Heinrich, G.; Wollgarten, M.; Huber, H. P.; Schmidt, M.

    2015-03-14

    In the production process of silicon microelectronic devices and high efficiency silicon solar cells, local contact openings in thin dielectric layers are required. Instead of photolithography, these openings can be selectively structured with ultra-short laser pulses by confined laser ablation in a fast and efficient lift off production step. Thereby, the ultrafast laser pulse is transmitted by the dielectric layer and absorbed at the substrate surface leading to a selective layer removal in the nanosecond time domain. Thermal damage in the substrate due to absorption is an unwanted side effect. The aim of this work is to obtain a deeper understanding of the physical laser-material interaction with the goal of finding a damage-free ablation mechanism. For this, thin silicon nitride (SiN{sub x}) layers on planar silicon (Si) wafers are processed with infrared fs-laser pulses. Two ablation types can be distinguished: The known confined ablation at fluences below 300 mJ/cm{sup 2} and a combined partial confined and partial direct ablation at higher fluences. The partial direct ablation process is caused by nonlinear absorption in the SiN{sub x} layer in the center of the applied Gaussian shaped laser pulses. Pump-probe investigations of the central area show ultra-fast reflectivity changes typical for direct laser ablation. Transmission electron microscopy results demonstrate that the Si surface under the remaining SiN{sub x} island is not damaged by the laser ablation process. At optimized process parameters, the method of direct laser ablation could be a good candidate for damage-free selective structuring of dielectric layers on absorbing substrates.

  4. Navigating Space-Time with Ultrafast Exciton Photolithography or

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    Scintillating Near-fields to Follow Dynamic Processes in Molecular Materials | MIT-Harvard Center for Excitonics Navigating Space-Time with Ultrafast Exciton Photolithography or Scintillating Near-fields to Follow Dynamic Processes in Molecular Materials May 5, 2015 at 4:30pm/ rm: 4-370 Naomi Ginsberg University of California/Department of Chemistry and Physics nsginsberg abstract: A cross-cutting theme in my research group is to examine dynamic processes in spatially-heterogeneous condensed

  5. PARTICLE ACCELERATORS; 74 ATOMIC AND MOLECULAR PHYSICS; ATOMS...

    Office of Scientific and Technical Information (OSTI)

    74 ATOMIC AND MOLECULAR PHYSICS; ATOMS; ELECTRONS; HELIUM; LIGHT SOURCES; RADIATIONS; STORAGE RINGS; SYNCHROTRONS SYNCHROTRON RADIATION SYNCHROTRONLIGHT SOURCES QUANTUM CHAOS...

  6. Ultrafast electron transfer at organic semiconductor interfaces: Importance of molecular orientation

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

    Ayzner, Alexander L.; Nordlund, Dennis; Kim, Do -Hwan; Bao, Zhenan; Toney, Michael F.

    2014-12-04

    Much is known about the rate of photoexcited charge generation in at organic donor/acceptor (D/A) heterojunctions overaged over all relative arrangements. However, there has been very little experimental work investigating how the photoexcited electron transfer (ET) rate depends on the precise relative molecular orientation between D and A in thin solid films. This is the question that we address in this work. We find that the ET rate depends strongly on the relative molecular arrangement: The interface where the model donor compound copper phthalocyanine is oriented face-on with respect to the fullerene C60 acceptor yields a rate that is approximatelymore » 4 times faster than that of the edge-on oriented interface. Our results suggest that the D/A electronic coupling is significantly enhanced in the face-on case, which agrees well with theoretical predictions, underscoring the importance of controlling the relative interfacial molecular orientation.« less

  7. Ultrafast electron transfer at organic semiconductor interfaces: Importance of molecular orientation

    SciTech Connect (OSTI)

    Ayzner, Alexander L.; Nordlund, Dennis; Kim, Do -Hwan; Bao, Zhenan; Toney, Michael F.

    2014-12-04

    Much is known about the rate of photoexcited charge generation in at organic donor/acceptor (D/A) heterojunctions overaged over all relative arrangements. However, there has been very little experimental work investigating how the photoexcited electron transfer (ET) rate depends on the precise relative molecular orientation between D and A in thin solid films. This is the question that we address in this work. We find that the ET rate depends strongly on the relative molecular arrangement: The interface where the model donor compound copper phthalocyanine is oriented face-on with respect to the fullerene C60 acceptor yields a rate that is approximately 4 times faster than that of the edge-on oriented interface. Our results suggest that the D/A electronic coupling is significantly enhanced in the face-on case, which agrees well with theoretical predictions, underscoring the importance of controlling the relative interfacial molecular orientation.

  8. Ultrafast Laser Diagnostics for Energetic-Material Ignition Mechanisms...

    Office of Scientific and Technical Information (OSTI)

    for Physics-Based Model Development. Citation Details In-Document Search Title: Ultrafast Laser Diagnostics for Energetic-Material Ignition Mechanisms: Tools for Physics-Based ...

  9. Ultrafast Core-Hole Induced Dynamics in Water

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    isotope substitution experiments and molecular dynamics simulations, researchers from Sweden, Germany, and the U.S. have shown that the ultrafast (0- to 10-fs) dissociation...

  10. MAUI: Modeling, Analysis, and Ultrafast Imaging | Argonne National...

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

    interfaces. Our goal is to integrate ultrafast time-resolved imaging with large-scale molecular dynamics modeling and in situ data analysis and visualization. This will allow...

  11. Physics with fast molecular-ion beams

    SciTech Connect (OSTI)

    Kanter, E.P.

    1980-01-01

    Fast (MeV) molecular-ion beams provide a unique source of energetic projectile nuclei which are correlated in space and time. The recognition of this property has prompted several recent investigations of various aspects of the interactions of these ions with matter. High-resolution measurements on the fragments resulting from these interactions have already yielded a wealth of new information on such diverse topics as plasma oscillations in solids and stereochemical structures of molecular ions as well as a variety of atomic collision phenomena. The general features of several such experiments will be discussed and recent results will be presented.

  12. Ultrafast X-Ray Coherent Control

    SciTech Connect (OSTI)

    Reis, David

    2009-05-01

    This main purpose of this grant was to develop the nascent #12;eld of ultrafast x-ray science using accelerator-based sources, and originally developed from an idea that a laser could modulate the di#11;racting properties of a x-ray di#11;racting crystal on a fast enough time scale to switch out in time a shorter slice from the already short x-ray pulses from a synchrotron. The research was carried out primarily at the Advanced Photon Source (APS) sector 7 at Argonne National Laboratory and the Sub-Picosecond Pulse Source (SPPS) at SLAC; in anticipation of the Linac Coherent Light Source (LCLS) x-ray free electron laser that became operational in 2009 at SLAC (all National User Facilities operated by BES). The research centered on the generation, control and measurement of atomic-scale dynamics in atomic, molecular optical and condensed matter systems with temporal and spatial resolution . It helped develop the ultrafast physics, techniques and scienti#12;c case for using the unprecedented characteristics of the LCLS. The project has been very successful with results have been disseminated widely and in top journals, have been well cited in the #12;eld, and have laid the foundation for many experiments being performed on the LCLS, the world's #12;rst hard x-ray free electron laser.

  13. Ultrafast Laser Diagnostics for Energetic-Material Ignition Mechanisms:

    Office of Scientific and Technical Information (OSTI)

    Tools for Physics-Based Model Development. (Technical Report) | SciTech Connect Technical Report: Ultrafast Laser Diagnostics for Energetic-Material Ignition Mechanisms: Tools for Physics-Based Model Development. Citation Details In-Document Search Title: Ultrafast Laser Diagnostics for Energetic-Material Ignition Mechanisms: Tools for Physics-Based Model Development. We present the results of an LDRD project to develop diagnostics to perform fundamental measurements of material properties

  14. Ultrafast Photovoltaic Response in Ferroelectric Nanolayers ...

    Office of Scientific and Technical Information (OSTI)

    Ultrafast Photovoltaic Response in Ferroelectric Nanolayers Citation Details In-Document Search Title: Ultrafast Photovoltaic Response in Ferroelectric Nanolayers Authors:...

  15. Ultrafast Core-Hole Induced Dynamics in Water

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

    Ultrafast Core-Hole Induced Dynamics in Water Ultrafast Core-Hole Induced Dynamics in Water Print Wednesday, 22 February 2006 00:00 A thorough understanding of the chemical processes that are initiated when radiation interacts with aqueous systems is essential for many diverse fields, from condensed matter physics to medicine to environmental science. An incoming photon with enough energy to produce a core hole in a water molecule sets off motions that can affect bonding configurations, which in

  16. Ultrafast observation of shocked states in a precompressed material

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Ultrafast observation of shocked states in a precompressed material Citation Details In-Document Search Title: Ultrafast observation of shocked states in a precompressed material Authors: Armstrong, M R ; Crowhurst, J C ; Bastea, S ; Zaug, J M Publication Date: 2010-07-08 OSTI Identifier: 1117984 Report Number(s): LLNL-JRNL-442472 DOE Contract Number: W-7405-ENG-48 Resource Type: Journal Article Resource Relation: Journal Name: Journal of Applied Physics,

  17. 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.

  18. Ultrafast laser diagnostics to investigate initiation fundamentals...

    Office of Scientific and Technical Information (OSTI)

    Ultrafast laser diagnostics to investigate initiation fundamentals in energetic materials. Citation Details In-Document Search Title: Ultrafast laser diagnostics to investigate ...

  19. Spectroscopy of complex molecular systems: Physics on an exciton cake-walk

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

    | MIT-Harvard Center for Excitonics of complex molecular systems: Physics on an exciton cake-walk November 29, 2011 at 3pm/36-428 Jasper Knoester Zernike Institute for Advanced Materials, University of Groningen, Netherlands j_knoester Abstract: The concept of excitons, collective excited states, is well-known in solid-state physics. It was first developed by Frenkel in the 1930's to explain the absorption spectrum of perfect molecular crystals, in which case the excitons are simple Bloch

  20. Ultrafast Probes for Dirac Materials Yarotski, Dmitry Anatolievitch...

    Office of Scientific and Technical Information (OSTI)

    Science(36) Material Science; topological insulators, ultrafast spectroscopy, graphene Material Science; topological insulators, ultrafast spectroscopy, graphene Abstract...

  1. Ultrafast Transformations in Superionic Nanocrystals

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

    (Journal Article) | SciTech Connect Journal Article: Ultrafast Terahertz-Induced Response of GeSbTe Phase-Change Materials Citation Details In-Document Search Title: Ultrafast Terahertz-Induced Response of GeSbTe Phase-Change Materials Authors: Shu, Michael J. ; Zalden, Peter ; Chen, Frank ; Weems, Ben ; Chatzakis, Ioannis ; Xiong, Feng ; Jeyasingh, Rakesh ; Hoffmann, Matthias C. ; Pop, Eric ; Wong, H.-S.Philip ; Wuttig, Matthias ; Lindenberg, Aaron M. Publication Date: 2014-07-08 OSTI

  2. Ultrafast Transformations in Superionic Nanocrystals

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

    Ultrafast Transformations in Superionic Nanocrystals Ultrafast Transformations in Superionic Nanocrystals Print Wednesday, 29 January 2014 00:00 A superionic material is a multi-component solid with simultaneous characteristics of both a solid and a liquid. Above a critical temperature associated with a structural phase transition, one of the atomic species in the material will exhibit liquid-like ionic conductivity and dynamic disorder within the rigid crystalline structure of the other.

  3. Molecular photoionization studies of nucleobases and correlated systems

    SciTech Connect (OSTI)

    Poliakoff, Erwin D.

    2015-03-11

    We proposed molecular photoionization studies in order to probe correlated events in fundamental scattering phenomena. In particular, we suggested that joint theoretical-experimental studies would provide a window into the microscopic aspects that are of central importance in AMO and chemical physics generally, and would generate useful data for wide array of important DOE topics, such as ultrafast dynamics, high harmonic generation, and probes of nonadiabatic processes. The unifying theme is that correlations between electron scattering dynamics and molecular geometry highlight inherently molecular aspects of the photoelectron behavior.

  4. Ultrafast scanning probe microscopy

    DOE Patents [OSTI]

    Weiss, Shimon; Chemla, Daniel S.; Ogletree, D. Frank; Botkin, David

    1995-01-01

    An ultrafast scanning probe microscopy method for achieving subpicosecond-temporal resolution and submicron-spatial resolution of an observation sample. In one embodiment of the present claimed invention, a single short optical pulse is generated and is split into first and second pulses. One of the pulses is delayed using variable time delay means. The first pulse is then directed at an observation sample located proximate to the probe of a scanning probe microscope. The scanning probe microscope produces probe-sample signals indicative of the response of the probe to characteristics of the sample. The second pulse is used to modulate the probe of the scanning probe microscope. The time delay between the first and second pulses is then varied. The probe-sample response signal is recorded at each of the various time delays created between the first and second pulses. The probe-sample response signal is then plotted as a function of time delay to produce a cross-correlation of the probe sample response. In so doing, the present invention provides simultaneous subpicosecond-temporal resolution and submicron-spatial resolution of the sample.

  5. Ultrafast scanning probe microscopy

    DOE Patents [OSTI]

    Weiss, S.; Chemla, D.S.; Ogletree, D.F.; Botkin, D.

    1995-05-16

    An ultrafast scanning probe microscopy method is described for achieving subpicosecond-temporal resolution and submicron-spatial resolution of an observation sample. In one embodiment of the present claimed invention, a single short optical pulse is generated and is split into first and second pulses. One of the pulses is delayed using variable time delay means. The first pulse is then directed at an observation sample located proximate to the probe of a scanning probe microscope. The scanning probe microscope produces probe-sample signals indicative of the response of the probe to characteristics of the sample. The second pulse is used to modulate the probe of the scanning probe microscope. The time delay between the first and second pulses is then varied. The probe-sample response signal is recorded at each of the various time delays created between the first and second pulses. The probe-sample response signal is then plotted as a function of time delay to produce a cross-correlation of the probe sample response. In so doing, the present invention provides simultaneous subpicosecond-temporal resolution and submicron-spatial resolution of the sample. 6 Figs.

  6. Ultrafast Nanoplasmonics: Toward Coherently Controlled Chemistry at the

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

    Time-space Limit | MIT-Harvard Center for Excitonics Ultrafast Nanoplasmonics: Toward Coherently Controlled Chemistry at the Time-space Limit November 3, 2015 at 4:30 PM/ RLE Allen 36-462* Tamar Seideman Department of Chemistry, Northwestern University, Illinois seideman Electronics has long reached the molecular scale; not only do single-molecule junctions exhibit interesting conduction behaviors that have no analog in macroscopic electronics, they can also be tailored to induce a variety

  7. Ultrafast Core-Hole Induced Dynamics in Water

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

    Ultrafast Core-Hole Induced Dynamics in Water Print A thorough understanding of the chemical processes that are initiated when radiation interacts with aqueous systems is essential for many diverse fields, from condensed matter physics to medicine to environmental science. An incoming photon with enough energy to produce a core hole in a water molecule sets off motions that can affect bonding configurations, which in turn affect subsequent chemical-reaction pathways. However, it is a fundamental

  8. Ultrafast Core-Hole Induced Dynamics in Water

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

    Ultrafast Core-Hole Induced Dynamics in Water Print A thorough understanding of the chemical processes that are initiated when radiation interacts with aqueous systems is essential for many diverse fields, from condensed matter physics to medicine to environmental science. An incoming photon with enough energy to produce a core hole in a water molecule sets off motions that can affect bonding configurations, which in turn affect subsequent chemical-reaction pathways. However, it is a fundamental

  9. Ultrafast Core-Hole Induced Dynamics in Water

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

    Ultrafast Core-Hole Induced Dynamics in Water Print A thorough understanding of the chemical processes that are initiated when radiation interacts with aqueous systems is essential for many diverse fields, from condensed matter physics to medicine to environmental science. An incoming photon with enough energy to produce a core hole in a water molecule sets off motions that can affect bonding configurations, which in turn affect subsequent chemical-reaction pathways. However, it is a fundamental

  10. Ultrafast Core-Hole Induced Dynamics in Water

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

    Ultrafast Core-Hole Induced Dynamics in Water Print A thorough understanding of the chemical processes that are initiated when radiation interacts with aqueous systems is essential for many diverse fields, from condensed matter physics to medicine to environmental science. An incoming photon with enough energy to produce a core hole in a water molecule sets off motions that can affect bonding configurations, which in turn affect subsequent chemical-reaction pathways. However, it is a fundamental

  11. Ultrafast Core-Hole Induced Dynamics in Water

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

    Ultrafast Core-Hole Induced Dynamics in Water Print A thorough understanding of the chemical processes that are initiated when radiation interacts with aqueous systems is essential for many diverse fields, from condensed matter physics to medicine to environmental science. An incoming photon with enough energy to produce a core hole in a water molecule sets off motions that can affect bonding configurations, which in turn affect subsequent chemical-reaction pathways. However, it is a fundamental

  12. Physical aspects of the structure and function of helicases as rotary molecular motors

    SciTech Connect (OSTI)

    Pikin, S. A.

    2009-11-15

    Helicases were shown to have common physical properties with rotary molecular motors, such as F{sub 0}F{sub 1}-ATP synthase and type I restriction-modification (RM) enzymes. The necessary conditions for action of molecular motors are chirality, the presence of the C{sub 2} (or lower) symmetry axis within rather large atomic groups, and polarization properties. The estimates were made for the material parameters of helicases, which translocate DNA due to moving chiral kinks without DNA cleavage and are characterized by higher viscosity, low mobility, and smaller chiral kinetic coefficients than type II RM enzymes. This paper discusses the efficiency of helicases with opposite polarities that drive DNA translocation in opposite directions.

  13. Ultrafast Probes for Dirac Materials (Technical Report) | SciTech...

    Office of Scientific and Technical Information (OSTI)

    Ultrafast Probes for Dirac Materials Citation Details In-Document Search Title: Ultrafast Probes for Dirac Materials You are accessing a document from the Department of Energy's ...

  14. Plasmas, Dielectrics and the Ultrafast: First Science and Operational...

    Office of Scientific and Technical Information (OSTI)

    Plasmas, Dielectrics and the Ultrafast: First Science and Operational Experience at FACET Citation Details In-Document Search Title: Plasmas, Dielectrics and the Ultrafast: First ...

  15. Ultrafast laser diagnostics for studies of shock initiation in...

    Office of Scientific and Technical Information (OSTI)

    Ultrafast laser diagnostics for studies of shock initiation in energetic materials. Citation Details In-Document Search Title: Ultrafast laser diagnostics for studies of shock ...

  16. Ultrafast Optical Microscopy of Single Monolayer Molybdenum Disulfide...

    Office of Scientific and Technical Information (OSTI)

    Ultrafast Optical Microscopy of Single Monolayer Molybdenum Disulfide Flakes Citation Details In-Document Search Title: Ultrafast Optical Microscopy of Single Monolayer Molybdenum ...

  17. Ultrafast Laser Fabrication: a Rapid Prototyping Capability for...

    Office of Scientific and Technical Information (OSTI)

    Technical Report: Ultrafast Laser Fabrication: a Rapid Prototyping Capability for CINT Citation Details In-Document Search Title: Ultrafast Laser Fabrication: a Rapid Prototyping ...

  18. Ultrafast Laser Fabrication: a Rapid Prototyping Capability for...

    Office of Scientific and Technical Information (OSTI)

    Technical Report: Ultrafast Laser Fabrication: a Rapid Prototyping Capability for CINT Citation Details In-Document Search Title: Ultrafast Laser Fabrication: a Rapid Prototyping...

  19. Ultrafast chirped optical waveform recorder using a time microscope...

    Office of Scientific and Technical Information (OSTI)

    Data Explorer Search Results Ultrafast chirped optical waveform recorder using a time microscope Title: Ultrafast chirped optical waveform recorder using a time microscope A new ...

  20. Ultrafast chirped optical waveform recorder using a time microscope...

    Office of Scientific and Technical Information (OSTI)

    Ultrafast chirped optical waveform recorder using a time microscope Title: Ultrafast chirped optical waveform recorder using a time microscope A new technique for capturing both ...

  1. Surface modified CFx cathode material for ultrafast discharge...

    Office of Scientific and Technical Information (OSTI)

    Surface modified CFx cathode material for ultrafast discharge and high energy density Prev Next Title: Surface modified CFx cathode material for ultrafast discharge and high...

  2. Indirect excitation of ultrafast demagnetization (Journal Article) |

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect Indirect excitation of ultrafast demagnetization Citation Details In-Document Search Title: Indirect excitation of ultrafast demagnetization Does the excitation of ultrafast magnetization require direct interaction between the photons of the optical pump pulse and the magnetic layer? Here, we demonstrate unambiguously that this is not the case. For this we have studied the magnetization dynamics of a ferromagnetic cobalt/palladium multilayer capped by an IR-opaque aluminum

  3. Cavity-Enhanced Transient Absorption Spectroscopy: Ultrafast...

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    Cavity-Enhanced Transient Absorption Spectroscopy: Ultrafast Spectroscopy goes Ultra-Sensitive Wednesday, November 11, 2015 - 3:00pm SLAC, Redtail Hawk Conference Room 108A...

  4. Indirect excitation of ultrafast demagnetization

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

    Vodungbo, Boris; Tudu, Bahrati; Perron, Jonathan; Delaunay, Renaud; Müller, Leonard; Berntsen, Magnus H.; Grübel, Gerhard; Malinowski, Grégory; Weier, Christian; Gautier, Julien; et al

    2016-01-06

    Does the excitation of ultrafast magnetization require direct interaction between the photons of the optical pump pulse and the magnetic layer? Here, we demonstrate unambiguously that this is not the case. For this we have studied the magnetization dynamics of a ferromagnetic cobalt/palladium multilayer capped by an IR-opaque aluminum layer. Upon excitation with an intense femtosecond-short IR laser pulse, the film exhibits the classical ultrafast demagnetization phenomenon although only a negligible number of IR photons penetrate the aluminum layer. In comparison with an uncapped cobalt/palladium reference film, the initial demagnetization of the capped film occurs with a delayed onset andmore » at a slower rate. Both observations are qualitatively in line with energy transport from the aluminum layer into the underlying magnetic film by the excited, hot electrons of the aluminum film. As a result, our data thus confirm recent theoretical predictions.« less

  5. Ultrafast Transformations in Superionic Nanocrystals

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

    Ultrafast Transformations in Superionic Nanocrystals Print A superionic material is a multi-component solid with simultaneous characteristics of both a solid and a liquid. Above a critical temperature associated with a structural phase transition, one of the atomic species in the material will exhibit liquid-like ionic conductivity and dynamic disorder within the rigid crystalline structure of the other. Discovered by Michael Faraday almost 200 years ago, superionic materials today hold promise

  6. Ultrafast Transformations in Superionic Nanocrystals

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

    Ultrafast Transformations in Superionic Nanocrystals Print A superionic material is a multi-component solid with simultaneous characteristics of both a solid and a liquid. Above a critical temperature associated with a structural phase transition, one of the atomic species in the material will exhibit liquid-like ionic conductivity and dynamic disorder within the rigid crystalline structure of the other. Discovered by Michael Faraday almost 200 years ago, superionic materials today hold promise

  7. Ultrafast Transformations in Superionic Nanocrystals

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

    Ultrafast Transformations in Superionic Nanocrystals Print A superionic material is a multi-component solid with simultaneous characteristics of both a solid and a liquid. Above a critical temperature associated with a structural phase transition, one of the atomic species in the material will exhibit liquid-like ionic conductivity and dynamic disorder within the rigid crystalline structure of the other. Discovered by Michael Faraday almost 200 years ago, superionic materials today hold promise

  8. Ultrafast Transformations in Superionic Nanocrystals

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

    Ultrafast Transformations in Superionic Nanocrystals Print A superionic material is a multi-component solid with simultaneous characteristics of both a solid and a liquid. Above a critical temperature associated with a structural phase transition, one of the atomic species in the material will exhibit liquid-like ionic conductivity and dynamic disorder within the rigid crystalline structure of the other. Discovered by Michael Faraday almost 200 years ago, superionic materials today hold promise

  9. Ultrafast Transformations in Superionic Nanocrystals

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

    Ultrafast Transformations in Superionic Nanocrystals Print A superionic material is a multi-component solid with simultaneous characteristics of both a solid and a liquid. Above a critical temperature associated with a structural phase transition, one of the atomic species in the material will exhibit liquid-like ionic conductivity and dynamic disorder within the rigid crystalline structure of the other. Discovered by Michael Faraday almost 200 years ago, superionic materials today hold promise

  10. Phonon-assisted tunneling and two-channel Kondo physics in molecular junctions

    SciTech Connect (OSTI)

    Dias Da Silva, Luis G; Dagotto, Elbio R

    2009-01-01

    The interplay between vibrational modes and Kondo physics is a fundamental aspect of transport properties of correlated molecular conductors. We present theoretical results for a single molecule in the Kondo regime connected to left and right metallic leads, creating the usual coupling to a conduction channel with left-right parity even. A center-of-mass vibrational mode introduces an additional phonon-assisted tunneling through the antisymmetric odd channel. A non-Fermi-liquid fixed point, reminiscent of the two-channel Kondo effect, appears at a critical value of the phonon-mediated coupling strength. Our numerical renormalization-group calculations for this system reveal non-Fermi-liquid behavior at low temperatures over lines of critical points. Signatures of this strongly correlated state are prominent in the thermodynamic properties and in the linear conductance.

  11. Ultrafast Laser Facility - Virtual Tour | Photosynthetic Antenna Research

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    Center Ultrafast Laser Facility - Virtual Tour December 10, 2015 Ultrafast Laser Facility - Virtual Tour A look at the technology and science in the Ultrafast lab PARC Research Scientist Darek Niedzwiedzki hosted a virtual tour of the Ultrafast Laser Facility for St. Louis University High School students. Special thanks to teacher Nhan Pham for joining us! News/Media Videos

  12. Indirect excitation of ultrafast demagnetization

    Office of Scientific and Technical Information (OSTI)

    opEN Indirect excitation of ultrafast demagnetization Boris Vodungbo1,2, Bahrati Tudu1,2, Jonathan Perron1,2, Renaud Delaunay1,2, Leonard Muller3, Magnus H. Berntsen3, Gerhard Grubel3,4, Gregory Malinowski5, Christian Weier6, Recelved: 03 September 2015 Julien Gautier7, Guillaume Lambert7, Philippe Zeitoun7, Christian Gutt8, Emmanuelle Jal9, Acce ted: 01 December 2015 Alexander H. Reid9, Patrick W. Granitzka9,10, Nicolas Jaouen11, Georgi L. Dakovski12, CCeP e : eCem er Stefan Moeller12, Michael

  13. Physics

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    Physics Physics Print Because a large proportion of ALS experiments are "physics" experiments, it's useful to separate them into two categories - one focused on MaterialsCondensed ...

  14. Physics

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    Group (PDG) Organizations American Institute of Physics (AIP) American Physical Society (APS) Institute of Physics (IOP) SPIE - International society for optics and photonics Top...

  15. Ultrafast pulsed laser utilizing broad bandwidth laser glass

    DOE Patents [OSTI]

    Payne, S.A.; Hayden, J.S.

    1997-09-02

    An ultrafast laser uses a Nd-doped phosphate laser glass characterized by a particularly broad emission bandwidth to generate the shortest possible output pulses. The laser glass is composed primarily of P{sub 2}O{sub 5}, Al{sub 2}O{sub 3} and MgO, and possesses physical and thermal properties that are compatible with standard melting and manufacturing methods. The broad bandwidth laser glass can be used in modelocked oscillators as well as in amplifier modules. 7 figs.

  16. Ultrafast pulsed laser utilizing broad bandwidth laser glass

    DOE Patents [OSTI]

    Payne, Stephen A.; Hayden, Joseph S.

    1997-01-01

    An ultrafast laser uses a Nd-doped phosphate laser glass characterized by a particularly broad emission bandwidth to generate the shortest possible output pulses. The laser glass is composed primarily of P.sub.2 O.sub.5, Al.sub.2 O.sub.3 and MgO, and possesses physical and thermal properties that are compatible with standard melting and manufacturing methods. The broad bandwidth laser glass can be used in modelocked oscillators as well as in amplifier modules.

  17. Interfacial effects revealed by ultrafast relaxation dynamics...

    Office of Scientific and Technical Information (OSTI)

    Title: Interfacial effects revealed by ultrafast relaxation dynamics in BiFeO 3 YBa 2 Cu 3 O 7 bilayers Authors: Springer, D. ; Nair, Saritha K. ; He, Mi ; Lu, C. L. ; Cheong, S. ...

  18. An ultrafast carbon nanotube terahertz polarisation modulator

    SciTech Connect (OSTI)

    Docherty, Callum J.; Stranks, Samuel D.; Habisreutinger, Severin N.; Joyce, Hannah J.; Herz, Laura M.; Nicholas, Robin J.; Johnston, Michael B.

    2014-05-28

    We demonstrate ultrafast modulation of terahertz radiation by unaligned optically pumped single-walled carbon nanotubes. Photoexcitation by an ultrafast optical pump pulse induces transient terahertz absorption in nanowires aligned parallel to the optical pump. By controlling the polarisation of the optical pump, we show that terahertz polarisation and modulation can be tuned, allowing sub-picosecond modulation of terahertz radiation. Such speeds suggest potential for semiconductor nanowire devices in terahertz communication technologies.

  19. Ultrafast Spectroscopy of Warm Dense Matter

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

    Ultrafast Probes for Dirac Materials Citation Details In-Document Search Title: Ultrafast Probes for Dirac Materials Authors: Yarotski, Dmitry Anatolievitch [1] + Show Author Affiliations Los Alamos National Laboratory Publication Date: 2015-03-12 OSTI Identifier: 1172825 Report Number(s): LA-UR-15-21802 DOE Contract Number: AC52-06NA25396 Resource Type: Technical Report Research Org: Los Alamos National Laboratory (LANL) Sponsoring Org: UCRP Country of Publication: United States Language:

  20. Ultrafast Spectroscopy of Warm Dense Matter

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

    Ultrafast Spectroscopy of Warm Dense Matter Ultrafast Spectroscopy of Warm Dense Matter Print Wednesday, 25 April 2012 00:00 Being neither solid, liquid, gas, nor plasma, warm dense matter (WDM) occupies a no man's land in the map of material phases. Its temperature can range between that of planetary cores (tens of thousands K) to that of stellar cores (hundreds of thousands K). Not only is it prevalent throughout the universe, it is relevant to inertial confinement fusion (ICF) and material

  1. Ultrafast terahertz gating of the polarization and giant nonlinear...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Ultrafast terahertz gating of the polarization and giant nonlinear optical response in BiFeO3 thin films Citation Details In-Document Search Title: Ultrafast ...

  2. Physics

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

    Physics Print Because a large proportion of ALS experiments are "physics" experiments, it's useful to separate them into two categories - one focused on MaterialsCondensed Matter, ...

  3. Electronic/photonic interfaces for ultrafast data processing...

    Office of Scientific and Technical Information (OSTI)

    and hybrid integration processes, two key elements of an ultrafast data processor. ... TRANSMISSION; TECHNOLOGY ASSESSMENT Numerical analysis-Data processing.; ...

  4. UPGRADING METHANE USING ULTRA-FAST THERMAL SWING ADSORPTION

    SciTech Connect (OSTI)

    Anna Lee Tonkovich

    2004-01-01

    The purpose of this project is to design and demonstrate an approach to upgrade low-BTU methane streams from coal mines to pipeline-quality natural gas. The objective of Phase I of the project was to assess the feasibility of upgrading low-Btu methane streams using ultra-fast thermal swing adsorption (TSA) using Velocys' modular microchannel process technology. The project is on schedule and under budget. For Task 1.1, the open literature, patent information, and vendor contacts were surveyed to identify adsorbent candidates for experimental validation and subsequent demonstration in an MPT-based ultra-fast TSA separation for methane upgrading. The leading candidates for preferential adsorption of methane over nitrogen are highly microporous carbons. A Molecular Gate{trademark} zeolite from Engelhard Corporation has emerged as a candidate. For Task 1.2, experimental evaluation of adsorbents was initiated, and data were collected on carbon (MGN-101) from PICA, Inc. This carbon demonstrated a preferential capacity for methane over nitrogen, as well as a reasonable thermal swing differential capacity for a 90% methane and 10% nitrogen mixture. A similar methane swing capacity at 2 psig was measured. The mixture composition is relevant because gob gas contains nearly 85% methane and must be purified to 97% methane for pipeline quality.

  5. Ultrafast pulse radiolysis using a terawatt laser wakefield accelerator

    SciTech Connect (OSTI)

    Oulianov, Dmitri A.; Crowell, Robert A.; Gosztola, David J.; Shkrob, Ilya A.; Korovyanko, Oleg J.; Rey-de-Castro, Roberto C.

    2007-03-01

    We report ultrafast pulse radiolysis transient absorption (TA) spectroscopy measurements from the Terawatt Ultrafast High Field Facility (TUHFF) at Argonne National Laboratory. TUHFF houses a 20 TW Ti:sapphire laser system that generates 2.5 nC subpicosecond pulses of multi-mega-electron-volt electrons at 10 Hz using laser wakefield acceleration. The system has been specifically optimized for kinetic TA measurements in a pump-probe fashion. This requires averaging over many shots which necessitates stable, reliable generation of electron pulses. The latter were used to generate excess electrons in pulse radiolysis of liquid water and concentrated solutions of perchloric acid. The hydronium ions in the acidic solutions react with the hydrated electrons resulting in the rapid decay of the transient absorbance at 800 nm on the picosecond time scale. Normalization of the TA signal leads to an improvement in the signal to noise ratio by a factor of 5 to 6. Due the pointing instability of the laser this improvement was limited to a 5 to 10 min acquisition period, requiring periodic recalibration and realignment. Time resolution, defined by the rise time of TA signal from hydrated electron in pulse radiolysis of liquid water, of a few picoseconds, has been demonstrated. The current time resolution is determined primarily by the physical dimensions of the sample and the detection sensitivity. Subpicosecond time resolution can be achieved by using thinner samples, more sensitive detection techniques, and improved electron beam quality.

  6. Physics

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

    Physics user facilities and resources Lujan Neutron Scattering Center Proton ... battlefield MRI, which uses ultra-low-field magnetic resonance imaging to create images of ...

  7. Ultrafast Materials and Chemical Sciences FOA | U.S. DOE Office...

    Office of Science (SC) Website

    Ultrafast Materials and Chemical Sciences FOA Basic Energy Sciences (BES) BES Home About ... Funding Opportunities Ultrafast Materials and Chemical Sciences FOA Print Text Size: A A A ...

  8. Ultrafast X-ray Phase-Enhanced Microimaging for Visualizing Fuel...

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

    Ultrafast X-ray Phase-Enhanced Microimaging for Visualizing Fuel Injection Process and Diesel Sprays Ultrafast X-ray Phase-Enhanced Microimaging for Visualizing Fuel Injection ...

  9. Ultrafast photodetectors allow direct observation of multiple electrons

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

    generated by a single photon Ultrafast photodetectors Ultrafast photodetectors allow direct observation of multiple electrons generated by a single photon The new technique involves monitoring photocurrent transients in specially engineered photodetectors that provide very high temporal resolution of only 50 picoseconds. September 11, 2015 Andrew Fidler of Los Alamos National Laboratory examines an ultrafast photodetector used to measure quantum dot carrier multiplication in real time.

  10. Ultrafast transient grating radiation to optical image converter (Patent) |

    Office of Scientific and Technical Information (OSTI)

    DOEPatents Data Explorer Search Results Ultrafast transient grating radiation to optical image converter Title: Ultrafast transient grating radiation to optical image converter A high sensitivity transient grating ultrafast radiation to optical image converter is based on a fixed transmission grating adjacent to a semiconductor substrate. X-rays or optical radiation passing through the fixed transmission grating is thereby modulated and produces a small periodic variation of refractive index

  11. Ultrafast Optical Microscopy of Single Monolayer Molybdenum Disulfide

    Office of Scientific and Technical Information (OSTI)

    Flakes (Journal Article) | SciTech Connect Ultrafast Optical Microscopy of Single Monolayer Molybdenum Disulfide Flakes Citation Details In-Document Search Title: Ultrafast Optical Microscopy of Single Monolayer Molybdenum Disulfide Flakes We performed ultrafast optical microscopy on single flakes of atomically thin CVD-grown molybdenum disulfide, using non-degenerate femtosecond pump-probe spectroscopy to excite and probe carriers above and below the indirect and direct band gaps. These

  12. Ultrafast laser diagnostics to investigate initiation fundamentals in

    Office of Scientific and Technical Information (OSTI)

    energetic materials. (Technical Report) | SciTech Connect Technical Report: Ultrafast laser diagnostics to investigate initiation fundamentals in energetic materials. Citation Details In-Document Search Title: Ultrafast laser diagnostics to investigate initiation fundamentals in energetic materials. We present the results of a two year early career LDRD project, which has focused on the development of ultrafast diagnostics to measure temperature, pressure and chemical change during the shock

  13. Ultrafast kinetics subsequent to shock in an unreacted, oxygen...

    Office of Scientific and Technical Information (OSTI)

    and hydrogen peroxide Citation Details In-Document Search Title: Ultrafast kinetics subsequent to shock in an unreacted, oxygen balanced mixture of nitromethane and hydrogen ...

  14. Ultrafast kinetics subsequent to shock compression in an oxygen...

    Office of Scientific and Technical Information (OSTI)

    to shock compression in an oxygen-balanced mixture of nitromethane and hydrogen peroxide Citation Details In-Document Search Title: Ultrafast kinetics subsequent to shock ...

  15. Ultrafast kinetics subsequent to shock in an unreacted, oxygen...

    Office of Scientific and Technical Information (OSTI)

    shock in an unreacted, oxygen balanced mixture of nitromethane and hydrogen peroxide Citation Details In-Document Search Title: Ultrafast kinetics subsequent to shock in an ...

  16. Ultrafast optical control of magnetization dynamics in polycrystalline...

    Office of Scientific and Technical Information (OSTI)

    bismuth doped iron garnet thin films Citation Details In-Document Search Title: Ultrafast optical control of magnetization dynamics in polycrystalline bismuth doped iron ...

  17. Ultrafast Structural Rearrangements in the MLCT Excited State...

    Office of Scientific and Technical Information (OSTI)

    These results provide guidance for future x-ray structural studies on ultrafast time scale, as well as for synthesis towards its applications in solar energy conversion. less ...

  18. Ultrafast Structural Rearrangements in the MLCT Excited State...

    Office of Scientific and Technical Information (OSTI)

    Ultrafast Structural Rearrangements in the MLCT Excited State for Copper(I) ... previous laser-initiated time-resolved x-ray absorption spectroscopy (LITR-XAS) results. ...

  19. Prospects for Electron Imaging with Ultrafast Time Resolution...

    Office of Scientific and Technical Information (OSTI)

    Service, Springfield, VA at www.ntis.gov. Many pivotal aspects of material science, biomechanics, and chemistry would benefit from nanometer imaging with ultrafast time resolution....

  20. Atomic and molecular physics and data activities for astrophysics at Oak Ridge National Laboratory

    SciTech Connect (OSTI)

    Jeffery, D.J.; Kristic, P.S.; Liu, W.; Schultz, D.R.; Stancil, P.C.

    1998-04-01

    The atomic astrophysics group at ORNL produces, collects, evaluates, and disseminates atomic and molecular data relevant to astrophysics and actively models various astrophysical environments utilizing this information. With the advent of the World Wide Web, these data are also being placed on-line to facilitate their use by end-users. In this brief report, the group`s recent activities in data production and in modeling are highlighted. For example, the authors describe recent calculations of elastic and transport cross sections relevant to ionospheric and heliospheric studies, charge transfer between metal ions and metal atoms and novel supernova nebular spectra modeling, ion-molecule collision data relevant to planetary atmospheres and comets, and data for early universe modeling.

  1. Ultra-fast framing camera tube

    DOE Patents [OSTI]

    Kalibjian, Ralph (1051 Batavia Ave., Livermore, CA 94550)

    1981-01-01

    An electronic framing camera tube features focal plane image dissection and synchronized restoration of the dissected electron line images to form two-dimensional framed images. Ultra-fast framing is performed by first streaking a two-dimensional electron image across a narrow slit, thereby dissecting the two-dimensional electron image into sequential electron line images. The dissected electron line images are then restored into a framed image by a restorer deflector operated synchronously with the dissector deflector. The number of framed images on the tube's viewing screen is equal to the number of dissecting slits in the tube. The distinguishing features of this ultra-fast framing camera tube are the focal plane dissecting slits, and the synchronously-operated restorer deflector which restores the dissected electron line images into a two-dimensional framed image. The framing camera tube can produce image frames having high spatial resolution of optical events in the sub-100 picosecond range.

  2. Quantum Transport Effects and Coherent Ultrafast Multidimensional

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

    Spectroscopy of Light Harvesting Photosynthetic Complexes | MIT-Harvard Center for Excitonics Transport Effects and Coherent Ultrafast Multidimensional Spectroscopy of Light Harvesting Photosynthetic Complexes March 16, 2010 at 3pm/36-428 Shaul Mukamel Department of Chemistry, University of California, Irvine shaul_001 abstract: The harvesting of solar energy and its conversion to chemical energy is essential for all forms of life. Whether quantum effects persist in the energy transport is

  3. Ultrafast Spectroscopy of Warm Dense Matter

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

    Ultrafast Spectroscopy of Warm Dense Matter Print Being neither solid, liquid, gas, nor plasma, warm dense matter (WDM) occupies a no man's land in the map of material phases. Its temperature can range between that of planetary cores (tens of thousands K) to that of stellar cores (hundreds of thousands K). Not only is it prevalent throughout the universe, it is relevant to inertial confinement fusion (ICF) and material performance under extreme conditions. However, because of its extreme

  4. Ultrafast Spectroscopy of Warm Dense Matter

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

    Ultrafast Spectroscopy of Warm Dense Matter Print Being neither solid, liquid, gas, nor plasma, warm dense matter (WDM) occupies a no man's land in the map of material phases. Its temperature can range between that of planetary cores (tens of thousands K) to that of stellar cores (hundreds of thousands K). Not only is it prevalent throughout the universe, it is relevant to inertial confinement fusion (ICF) and material performance under extreme conditions. However, because of its extreme

  5. Ultrafast Structural Dynamics in Combustion Relevant Model Systems

    SciTech Connect (OSTI)

    Weber, Peter M.

    2014-03-31

    The research project explored the time resolved structural dynamics of important model reaction system using an array of novel methods that were developed specifically for this purpose. They include time resolved electron diffraction, time resolved relativistic electron diffraction, and time resolved Rydberg fingerprint spectroscopy. Toward the end of the funding period, we also developed time-resolved x-ray diffraction, which uses ultrafast x-ray pulses at LCLS. Those experiments are just now blossoming, as the funding period expired. In the following, the time resolved Rydberg Fingerprint Spectroscopy is discussed in some detail, as it has been a very productive method. The binding energy of an electron in a Rydberg state, that is, the energy difference between the Rydberg level and the ground state of the molecular ion, has been found to be a uniquely powerful tool to characterize the molecular structure. To rationalize the structure sensitivity we invoke a picture from electron diffraction: when it passes the molecular ion core, the Rydberg electron experiences a phase shift compared to an electron in a hydrogen atom. This phase shift requires an adjustment of the binding energy of the electron, which is measurable. As in electron diffraction, the phase shift depends on the molecular, geometrical structure, so that a measurement of the electron binding energy can be interpreted as a measurement of the molecules structure. Building on this insight, we have developed a structurally sensitive spectroscopy: the molecule is first elevated to the Rydberg state, and the binding energy is then measured using photoelectron spectroscopy. The molecules structure is read out as the binding energy spectrum. Since the photoionization can be done with ultrafast laser pulses, the technique is inherently capable of a time resolution in the femtosecond regime. For the purpose of identifying the structures of molecules during chemical reactions, and for the analysis of molecular species in the hot environments of combustion processes, there are several features that make the Rydberg ionization spectroscopy uniquely useful. First, the Rydberg electrons orbit is quite large and covers the entire molecule for most molecular structures of combustion interest. Secondly, the ionization does not change vibrational quantum numbers, so that even complicated and large molecules can be observed with fairly well resolved spectra. In fact, the spectroscopy is blind to vibrational excitation of the molecule. This has the interesting consequence for the study of chemical dynamics, where the molecules are invariably very energetic, that the molecular structures are observed unobstructed by the vibrational congestion that dominates other spectroscopies. This implies also that, as a tool to probe the time-dependent structural dynamics of chemically interesting molecules, Rydberg spectroscopy may well be better suited than electron or x-ray diffraction. With recent progress in calculating Rydberg binding energy spectra, we are approaching the point where the method can be evolved into a structure determination method. To implement the Rydberg ionization spectroscopy we use a molecular beam based, time-resolved pump-probe multi-photon ionization/photoelectron scheme in which a first laser pulse excites the molecule to a Rydberg state, and a probe pulse ionizes the molecule. A time-of-flight detector measures the kinetic energy spectrum of the photoelectrons. The photoelectron spectrum directly provides the binding energy of the electron, and thereby reveals the molecules time-dependent structural fingerprint. Only the duration of the laser pulses limits the time resolution. With a new laser system, we have now reached time resolutions better than 100 fs, although very deep UV wavelengths (down to 190 nm) have slightly longer instrument functions. The structural dynamics of molecules in Rydberg-excited states is obtained by delaying the probe ionization photon from the pump photon; the structural dynamics of molecules in their ground state or e

  6. Femtosecond laser studies of ultrafast intramolecular processes

    SciTech Connect (OSTI)

    Hayden, C.

    1993-12-01

    The goal of this research is to better understand the detailed mechanisms of chemical reactions by observing, directly in time, the dynamics of fundamental chemical processes. In this work femtosecond laser pulses are used to initiate chemical processes and follow the progress of these processes in time. The authors are currently studying ultrafast internal conversion and subsequent intramolecular relaxation in unsaturated hydrocarbons. In addition, the authors are developing nonlinear optical techniques to prepare and monitor the time evolution of specific vibrational motions in ground electronic state molecules.

  7. Ultrafast Laser Facility | Photosynthetic Antenna Research Center

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

    | SciTech Connect Dynamic Response of Single Crystal PETN and Beta-HMX Citation Details In-Document Search Title: Ultrafast Dynamic Response of Single Crystal PETN and Beta-HMX Authors: Zaug, J M ; Armstrong, M R ; Crowhurst, J C ; Feranti, L ; Swan, R ; Gross, R ; Teshlich, N E ; Wall, M ; Austin, R A ; Fried, L E Publication Date: 2014-06-30 OSTI Identifier: 1149550 Report Number(s): LLNL-CONF-656341 DOE Contract Number: DE-AC52-07NA27344 Resource Type: Conference Resource Relation:

  8. Ultrafast transient reflectance of epitaxial semiconducting perovskite thin films

    SciTech Connect (OSTI)

    Smolin, S. Y.; Guglietta, G. W.; Baxter, J. B. E-mail: smay@coe.drexel.edu; Scafetta, M. D.; May, S. J. E-mail: smay@coe.drexel.edu

    2014-07-14

    Ultrafast pump-probe transient reflectance (TR) spectroscopy was used to study carrier dynamics in an epitaxial perovskite oxide thin film of LaFeO{sub 3} (LFO) with a thickness of 40 unit cells (16?nm) grown by molecular beam epitaxy on (LaAlO{sub 3}){sub 0.3}(Sr{sub 2}AlTaO{sub 6}){sub 0.7} (LSAT). TR spectroscopy shows two negative transients in reflectance with local maxima at ?2.5?eV and ?3.5?eV which correspond to two optical transitions in LFO as determined by ellipsometry. The kinetics at these transients were best fit with an exponential decay model with fast (540 ps), medium (?200 ps), and slow (??3?ns) components that we attribute mainly to recombination of photoexcited carriers. Moreover, these reflectance transients did not completely decay within the observable time window, indicating that ?10% of photoexcited carriers exist for at least 3?ns. This work illustrates that TR spectroscopy can be performed on thin (<20?nm) epitaxial oxide films to provide a quantitative understanding of recombination lifetimes, which are important parameters for the potential utilization of perovskite films in photovoltaic and photocatalytic applications.

  9. Apparatus and method for characterizing ultrafast polarization varying optical pulses

    DOE Patents [OSTI]

    Smirl, Arthur; Trebino, Rick P.

    1999-08-10

    Practical techniques are described for characterizing ultrafast potentially ultraweak, ultrashort optical pulses. The techniques are particularly suited to the measurement of signals from nonlinear optical materials characterization experiments, whose signals are generally too weak for full characterization using conventional techniques.

  10. New Algorithm Enables Faster Simulations of Ultrafast Processes

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

    Ultrafast Processes Opens the Door for Real-Time Simulations in Atomic-Level Materials ... Numerical simulations in real time provide the best way to study these processes, but such ...

  11. Molecular Foundry

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

    The new ultrafast laser lab uses second harmonic generation imaging to probe the plasmonic enhancement frequency response of these and other photonic and plasmonic structures. ...

  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. Electronic/photonic interfaces for ultrafast data processing. (Technical

    Office of Scientific and Technical Information (OSTI)

    Report) | SciTech Connect Technical Report: Electronic/photonic interfaces for ultrafast data processing. Citation Details In-Document Search Title: Electronic/photonic interfaces for ultrafast data processing. This report summarizes a 3-month program that explored the potential areas of impact for electronic/photonic integration technologies, as applied to next-generation data processing systems operating within 100+ Gb/s optical networks. The study included a technology review that

  14. Ultrafast chirped optical waveform recorder using a time microscope

    Office of Scientific and Technical Information (OSTI)

    (Patent) | DOEPatents Data Explorer Search Results Ultrafast chirped optical waveform recorder using a time microscope Title: Ultrafast chirped optical waveform recorder using a time microscope A new technique for capturing both the amplitude and phase of an optical waveform is presented. This technique can capture signals with many THz of bandwidths in a single shot (e.g., temporal resolution of about 44 fs), or be operated repetitively at a high rate. That is, each temporal window (or

  15. New Algorithm Enables Faster Simulations of Ultrafast Processes

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

    Algorithm Enables Faster Simulations of Ultrafast Processes New Algorithm Enables Faster Simulations of Ultrafast Processes Opens the Door for Real-Time Simulations in Atomic-Level Materials Research February 20, 2015 Contact: Rachel Berkowitz, 510-486-7254, rberkowitz@lbl.gov femtosecondalgorithm copy Model of ion (Cl) collision with atomically thin semiconductor (MoSe2). Collision region is shown in blue and zoomed in; red points show initial positions of Cl. The simulation calculates the

  16. Plasmas, Dielectrics and the Ultrafast: First Science and Operational

    Office of Scientific and Technical Information (OSTI)

    Experience at FACET (Conference) | SciTech Connect Conference: Plasmas, Dielectrics and the Ultrafast: First Science and Operational Experience at FACET Citation Details In-Document Search Title: Plasmas, Dielectrics and the Ultrafast: First Science and Operational Experience at FACET FACET (Facility for Advanced Accelerator and Experimental Tests) is an accelerator R&D test facility that has been recently constructed at SLAC National Accelerator Laboratory. The facility provides 20 GeV,

  17. Ultrafast Laser Diagnostics to Investigate Initiation Fundamentals in

    Office of Scientific and Technical Information (OSTI)

    Energetic Materials. (Conference) | SciTech Connect Conference: Ultrafast Laser Diagnostics to Investigate Initiation Fundamentals in Energetic Materials. Citation Details In-Document Search Title: Ultrafast Laser Diagnostics to Investigate Initiation Fundamentals in Energetic Materials. Abstract not provided. Authors: Farrow, Darcie ; Kearney, Sean Patrick ; Scoglietti, Daniel Publication Date: 2011-08-01 OSTI Identifier: 1143441 Report Number(s): SAND2011-5736C 481988 DOE Contract Number:

  18. Ultrafast Laser Fabrication: a Rapid Prototyping Capability for CINT

    Office of Scientific and Technical Information (OSTI)

    (Technical Report) | SciTech Connect Technical Report: Ultrafast Laser Fabrication: a Rapid Prototyping Capability for CINT Citation Details In-Document Search Title: Ultrafast Laser Fabrication: a Rapid Prototyping Capability for CINT Authors: McCulloch, Quinn [1] ; Dattelbaum, Andrew M. [1] ; Nath, Pulak [1] + Show Author Affiliations Los Alamos National Laboratory Publication Date: 2013-03-04 OSTI Identifier: 1067392 Report Number(s): LA-UR-13-21541 DOE Contract Number: AC52-06NA25396

  19. Ultrafast all-optical manipulation of interfacial magnetoelectric coupling

    Office of Scientific and Technical Information (OSTI)

    (Technical Report) | SciTech Connect SciTech Connect Search Results Technical Report: Ultrafast all-optical manipulation of interfacial magnetoelectric coupling Citation Details In-Document Search Title: Ultrafast all-optical manipulation of interfacial magnetoelectric coupling Authors: Sheu, Yu-Miin [1] + Show Author Affiliations Los Alamos National Laboratory [Los Alamos National Laboratory Publication Date: 2014-04-24 OSTI Identifier: 1129830 Report Number(s): LA-UR-14-22829 DOE Contract

  20. Ultrafast optical control of magnetization dynamics in polycrystalline

    Office of Scientific and Technical Information (OSTI)

    bismuth doped iron garnet thin films (Journal Article) | SciTech Connect Ultrafast optical control of magnetization dynamics in polycrystalline bismuth doped iron garnet thin films Citation Details In-Document Search Title: Ultrafast optical control of magnetization dynamics in polycrystalline bismuth doped iron garnet thin films Controlling the magnetization dynamics on the femtosecond timescale is of fundamental importance for integrated opto-spintronic devices. For industrial

  1. Ultrafast carriers dynamics in filled-skutterudites

    SciTech Connect (OSTI)

    Guo, Liang; Xu, Xianfan; Salvador, James R.

    2015-06-08

    Carrier dynamics of filled-skutterudites, an important class of thermoelectric materials, is investigated using ultrafast optical spectroscopy. By tuning the wavelength of the probe laser, charge transfers at different electronic energy levels are interrogated. Analysis based on the Kramers-Kronig relation explains the complex spectroscopy data, which is mainly due to band filling caused by photo-excited carriers and free carrier absorption. The relaxation time of hot carriers is found to be about 0.40.6 ps, depending on the electronic energy level, and the characteristic time for carrier-phonon equilibrium is about 0.95 ps. These studies of carrier dynamics, which fundamentally determines the transport properties of thermoelectric material, can provide guidance for the design of materials.

  2. An ultrafast silicon nanoplasmonic ballistic triode

    SciTech Connect (OSTI)

    Greig, S. R. Elezzabi, A. Y.

    2014-12-15

    A nanoscale three terminal silicon based nanoplasmonic triode is proposed as a nanometer transistor. The device is suitable for monolithic integration with complementary-metal-oxide-semiconductor technology. Due to the highly spatially inhomogeneous, highly confined nanoplasmonic mode, electrons generated through two-photon absorption in the silicon are ponderomotively accelerated towards the copper anode producing an output current. Application of a negative grid voltage allows for control of the output current. The nanoplasmonic triode is able to achieve output current as high as 628?mA/?m on an ultrafast timescale of 150 fs in a compact footprint of 0.07??m{sup 2}. Reduction of the plasmonic field strength allows for a CMOS compatible current of 11.7?mA/?m. The results demonstrate the potential for the compact optical control of current useful for applications in high-speed, high current switching, and amplification.

  3. Ultrafast Dynamic Response of Single Crystal PETN and Beta-HMX...

    Office of Scientific and Technical Information (OSTI)

    Conference: Ultrafast Dynamic Response of Single Crystal PETN and Beta-HMX Citation Details In-Document Search Title: Ultrafast Dynamic Response of Single Crystal PETN and Beta-HMX...

  4. Ultrafast resonant soft x-ray diffraction dynamics of the charge...

    Office of Scientific and Technical Information (OSTI)

    Ultrafast resonant soft x-ray diffraction dynamics of the charge density wave in TbTe 3 ... Title: Ultrafast resonant soft x-ray diffraction dynamics of the charge density wave in ...

  5. Ultrafast spin exchange-coupling torque via photo-excited charge-transfer

    Office of Scientific and Technical Information (OSTI)

    processes (Journal Article) | DOE PAGES Ultrafast spin exchange-coupling torque via photo-excited charge-transfer processes Title: Ultrafast spin exchange-coupling torque via photo-excited charge-transfer processes In this study, optical control of spin is of central importance in the research of ultrafast spintronic devices utilizing spin dynamics at short time scales. Recently developed optical approaches such as ultrafast demagnetization, spin-transfer and spin-orbit torques open new

  6. Ultrafast spin exchange-coupling torque via photo-excited charge-transfer

    Office of Scientific and Technical Information (OSTI)

    processes (Journal Article) | SciTech Connect Ultrafast spin exchange-coupling torque via photo-excited charge-transfer processes Citation Details In-Document Search Title: Ultrafast spin exchange-coupling torque via photo-excited charge-transfer processes In this study, optical control of spin is of central importance in the research of ultrafast spintronic devices utilizing spin dynamics at short time scales. Recently developed optical approaches such as ultrafast demagnetization,

  7. In the OSTI Collections: Ultrafast Processes | OSTI, US Dept of Energy,

    Office of Scientific and Technical Information (OSTI)

    Office of Scientific and Technical Information Ultrafast Processes Article Acknowledgement: Dr. William N. Watson, Physicist DOE Office of Scientific and Technical Information Examples of ultrafast chemical and electronic processes Further examples of electronic processes Chemical reactions from shock waves Ultrafast instruments References Research Organizations Reports available through OSTI's SciTech Connect Patent available through OSTI's DOepatents Additional References Because the atoms

  8. Impact system for ultrafast synchrotron experiments

    SciTech Connect (OSTI)

    Jensen, B. J.; Owens, C. T.; Ramos, K. J.; Yeager, J. D.; Saavedra, R. A.; Luo, S. N.; Hooks, D. E.; Iverson, A. J.; Fezzaa, K.

    2013-01-15

    The impact system for ultrafast synchrotron experiments, or IMPULSE, is a 12.6-mm bore light-gas gun (<1 km/s projectile velocity) designed specifically for performing dynamic compression experiments using the advanced imaging and X-ray diffraction methods available at synchrotron sources. The gun system, capable of reaching projectile velocities up to 1 km/s, was designed to be portable for quick insertion/removal in the experimental hutch at Sector 32 ID-B of the Advanced Photon Source (Argonne, IL) while allowing the target chamber to rotate for sample alignment with the beam. A key challenge in using the gun system to acquire dynamic data on the nanosecond time scale was synchronization (or bracketing) of the impact event with the incident X-ray pulses (80 ps width). A description of the basic gun system used in previous work is provided along with details of an improved launch initiation system designed to significantly reduce the total system time from launch initiation to impact. Experiments were performed to directly measure the gun system time and to determine the gun performance curve for projectile velocities ranging from 0.3 to 0.9 km/s. All results show an average system time of 21.6 {+-} 4.5 ms, making it possible to better synchronize the gun system and detectors to the X-ray beam.

  9. All-Optical Molecular Orientation

    SciTech Connect (OSTI)

    Oda, Keita; Hita, Masafumi; Minemoto, Shinichirou; Sakai, Hirofumi [Department of Physics, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)

    2010-05-28

    We report clear evidence of all-optical orientation of carbonyl sulfide molecules with an intense nonresonant two-color laser field in the adiabatic regime. The technique relies on the combined effects of anisotropic hyperpolarizability interaction and anisotropic polarizability interaction and does not rely on the permanent dipole interaction with an electrostatic field. It is demonstrated that the molecular orientation can be controlled simply by changing the relative phase between the two wavelength fields. The present technique brings researchers a new steering tool of gaseous molecules and will be quite useful in various fields such as electronic stereodynamics in molecules and ultrafast molecular imaging.

  10. Ultrafast electron diffraction from aligned molecules

    SciTech Connect (OSTI)

    Centurion, Martin

    2015-08-17

    The aim of this project was to record time-resolved electron diffraction patterns of aligned molecules and to reconstruct the 3D molecular structure. The molecules are aligned non-adiabatically using a femtosecond laser pulse. A femtosecond electron pulse then records a diffraction pattern while the molecules are aligned. The diffraction patterns are then be processed to obtain the molecular structure.

  11. The role of collective motion in the ultrafast charge transfer in van der Waals heterostructures

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

    Wang, Han; Bang, Junhyeok; Sun, Yiyang; Liang, Chen; Damien, West; Meunier, Vincent; Zhang, Prof. Shengbai

    2016-01-01

    The success of van der Waals (vdW) heterostructures, made of graphene, metal dichalcogenides, and other layered materials, hinges on the understanding of charge transfer across the interface as the foundation for new device concepts and applications. In contrast to conventional heterostructures, where a strong interfacial coupling is essential to charge transfer, recent experimental findings indicate that vdW heterostructues can exhibit ultra-fast charge transfer despite the weak binding of the heterostructure. Using time-dependent density functional theory molecular dynamics, we identify a strong dynamic coupling between the vdW layers associated with charge transfer. This dynamic coupling results in rapid nonlinear coherent chargemore » oscillations which constitute a purely electronic phenomenon and are shown to be a general feature of vdW heterostructures provided they have a critical minimum dipole coupling. Application to MoS2/WS2 heterostructure yields good agreement with experiment, indicating near complete charge transfer within a timescale of 100 fs.The success of van der Waals heterostructures made of graphene, metal dichalcogenides and other layered materials, hinges on the understanding of charge transfer across the interface as the foundation for new device concepts and applications. In contrast to conventional heterostructures, where a strong interfacial coupling is essential to charge transfer, recent experimental findings indicate that van der Waals heterostructues can exhibit ultrafast charge transfer despite the weak binding of these heterostructures. Here we find, using time-dependent density functional theory molecular dynamics, that the collective motion of excitons at the interface leads to plasma oscillations associated with optical excitation. By constructing a simple model of the van der Waals heterostructure, we show that there exists an unexpected criticality of the oscillations, yielding rapid charge transfer across the interface. Application to the MoS2/WS2 heterostructure yields good agreement with experiments, indicating near complete charge transfer within a timescale of 100 fs.« less

  12. Apparatus and method for characterizing ultrafast polarization varying optical pulses

    DOE Patents [OSTI]

    Smirl, A.; Trebino, R.P.

    1999-08-10

    Practical techniques are described for characterizing ultrafast potentially ultraweak, ultrashort optical pulses. The techniques are particularly suited to the measurement of signals from nonlinear optical materials characterization experiments, whose signals are generally too weak for full characterization using conventional techniques. 2 figs.

  13. CHEMICAL AND PHYSICAL CONDITIONS IN MOLECULAR CLOUD CORE DC 000.4-19.5 (SL42) IN CORONA AUSTRALIS

    SciTech Connect (OSTI)

    Hardegree-Ullman, E.; Whittet, D. C. B.; Harju, J.; Juvela, M.; Sipilae, O.; Hotzel, S.

    2013-01-20

    Chemical reactions in starless molecular clouds are heavily dependent on interactions between gas phase material and solid phase dust and ices. We have observed the abundance and distribution of molecular gases in the cold, starless core DC 000.4-19.5 (SL42) in Corona Australis using data from the Swedish ESO Submillimeter Telescope. We present column density maps determined from measurements of C{sup 18}O (J = 2-1, 1-0) and N{sub 2}H{sup +} (J = 1-0) emission features. Herschel data of the same region allow a direct comparison to the dust component of the cloud core and provide evidence for gas phase depletion of CO at the highest extinctions. The dust color temperature in the core calculated from Herschel maps ranges from roughly 10.7 to 14.0 K. This range agrees with the previous determinations from Infrared Space Observatory and Planck observations. The column density profile of the core can be fitted with a Plummer-like density distribution approaching n(r) {approx} r {sup -2} at large distances. The core structure deviates clearly from a critical Bonnor-Ebert sphere. Instead, the core appears to be gravitationally bound and to lack thermal and turbulent support against the pressure of the surrounding low-density material: it may therefore be in the process of slow contraction. We test two chemical models and find that a steady-state depletion model agrees with the observed C{sup 18}O column density profile and the observed N(C{sup 18}O) versus A{sub V} relationship.

  14. Towards simultaneous measurements of electronic and structural properties in ultra-fast x-ray free electron laser absorption spectroscopy experiments

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

    Gaudin, J.; Fourment, C.; Cho, B. I.; Engelhorn, K.; Galtier, E.; Harmand, M.; Leguay, P. M.; Lee, H. J.; Nagler, B.; Nakatsutsumi, M.; et al

    2014-04-17

    The rapidly growing ultrafast science with X-ray lasers unveils atomic scale processes with unprecedented time resolution bringing the so called “molecular movie” within reach. X-ray absorption spectroscopy is one of the most powerful x-ray techniques providing both local atomic order and electronic structure when coupled with ad-hoc theory. Collecting absorption spectra within few x-ray pulses is possible only in a dispersive setup. We demonstrate ultrafast time-resolved measurements of the LIII-edge x-ray absorption near-edge spectra of irreversibly laser excited Molybdenum using an average of only few x-ray pulses with a signal to noise ratio limited only by the saturation level ofmore » the detector. The simplicity of the experimental set-up makes this technique versatile and applicable for a wide range of pump-probe experiments, particularly in the case of non-reversible processes.« less

  15. Towards simultaneous measurements of electronic and structural properties in ultra-fast x-ray free electron laser absorption spectroscopy experiments

    SciTech Connect (OSTI)

    Gaudin, J.; Fourment, C.; Cho, B. I.; Engelhorn, K.; Galtier, E.; Harmand, M.; Leguay, P. M.; Lee, H. J.; Nagler, B.; Nakatsutsumi, M.; Ozkan, C.; Strmer, M.; Toleikis, S.; Tschentscher, Th.; Heimann, P. A.; Dorchies, F.

    2014-04-17

    The rapidly growing ultrafast science with X-ray lasers unveils atomic scale processes with unprecedented time resolution bringing the so called molecular movie within reach. X-ray absorption spectroscopy is one of the most powerful x-ray techniques providing both local atomic order and electronic structure when coupled with ad-hoc theory. Collecting absorption spectra within few x-ray pulses is possible only in a dispersive setup. We demonstrate ultrafast time-resolved measurements of the LIII-edge x-ray absorption near-edge spectra of irreversibly laser excited Molybdenum using an average of only few x-ray pulses with a signal to noise ratio limited only by the saturation level of the detector. The simplicity of the experimental set-up makes this technique versatile and applicable for a wide range of pump-probe experiments, particularly in the case of non-reversible processes.

  16. The ALS X-Ray Streak Camera: Bringing the Ultrafast and Ultrasmall into

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

    Focus The ALS X-Ray Streak Camera: Bringing the Ultrafast and Ultrasmall into Focus Print Studying the world of the ultrasmall and the ultrafast is at the frontier of scientific research. Two x-ray approaches can be used for ultrafast examinations. The first entails developing sources that have short x-ray pulses such as free-electron lasers and slicing sources, which will provide the ultrafast temporal information. The other approach is to develop a detector that is fast enough to resolve

  17. The ALS X-Ray Streak Camera: Bringing the Ultrafast and Ultrasmall into

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

    Focus The ALS X-Ray Streak Camera: Bringing the Ultrafast and Ultrasmall into Focus Print Studying the world of the ultrasmall and the ultrafast is at the frontier of scientific research. Two x-ray approaches can be used for ultrafast examinations. The first entails developing sources that have short x-ray pulses such as free-electron lasers and slicing sources, which will provide the ultrafast temporal information. The other approach is to develop a detector that is fast enough to resolve

  18. The ALS X-Ray Streak Camera: Bringing the Ultrafast and Ultrasmall into

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

    Focus The ALS X-Ray Streak Camera: Bringing the Ultrafast and Ultrasmall into Focus Print Studying the world of the ultrasmall and the ultrafast is at the frontier of scientific research. Two x-ray approaches can be used for ultrafast examinations. The first entails developing sources that have short x-ray pulses such as free-electron lasers and slicing sources, which will provide the ultrafast temporal information. The other approach is to develop a detector that is fast enough to resolve

  19. The ALS X-Ray Streak Camera: Bringing the Ultrafast and Ultrasmall into

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

    Focus The ALS X-Ray Streak Camera: Bringing the Ultrafast and Ultrasmall into Focus The ALS X-Ray Streak Camera: Bringing the Ultrafast and Ultrasmall into Focus Print Wednesday, 26 March 2008 00:00 Studying the world of the ultrasmall and the ultrafast is at the frontier of scientific research. Two x-ray approaches can be used for ultrafast examinations. The first entails developing sources that have short x-ray pulses such as free-electron lasers and slicing sources, which will provide the

  20. Ultrafast spin exchange-coupling torque via photo-excited charge...

    Office of Scientific and Technical Information (OSTI)

    Recently developed optical approaches such as ultrafast demagnetization, spin-transfer and spin-orbit torques open new pathways to manipulate spin through its interaction with ...

  1. The ALS X-Ray Streak Camera: Bringing the Ultrafast and Ultrasmall into

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

    Focus The ALS X-Ray Streak Camera: Bringing the Ultrafast and Ultrasmall into Focus Print Studying the world of the ultrasmall and the ultrafast is at the frontier of scientific research. Two x-ray approaches can be used for ultrafast examinations. The first entails developing sources that have short x-ray pulses such as free-electron lasers and slicing sources, which will provide the ultrafast temporal information. The other approach is to develop a detector that is fast enough to resolve

  2. The ALS X-Ray Streak Camera: Bringing the Ultrafast and Ultrasmall into

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

    Focus The ALS X-Ray Streak Camera: Bringing the Ultrafast and Ultrasmall into Focus Print Studying the world of the ultrasmall and the ultrafast is at the frontier of scientific research. Two x-ray approaches can be used for ultrafast examinations. The first entails developing sources that have short x-ray pulses such as free-electron lasers and slicing sources, which will provide the ultrafast temporal information. The other approach is to develop a detector that is fast enough to resolve

  3. Molecular Foundry

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

    David Prendergast David Prendergast Director, Theory of Nanostructured Materials dgprendergast@lbl.gov 510.486.4948 personal website Biography Education 2002 Ph.D., Physics, University College Cork, Ireland 1999 B.Sc., Physics and Mathematics, University College Cork, Ireland Research Interests My research focuses on employing and developing first-principles electronic structure theory and molecular dynamics simulations on high-performance computing infrastructure to reveal energy relevant

  4. Ultrafast electron transport across nano gaps in nanowire circuits

    SciTech Connect (OSTI)

    Potma, Eric O.

    2015-07-31

    In this Program we aim for a closer look at electron transfer through single molecules. To achieve this, we use ultrafast laser pulses to time stamp an electron tunneling event in a molecule that is connected between two metallic electrodes, while reading out the electron current. A key aspect of this project is the use of metallic substrates with plasmonic activity to efficiently manipulate the tunneling probability. The first Phase of this program is concerned with developing highly sensitive tools for the ultrafast optical manipulation of tethered molecules through the evanescent surface field of plasmonic substrates. The second Phase of the program aims to use these tools for exercising control over the electron tunneling probability.

  5. Erdemir receives patent for ultra-fast surface hardening technology |

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

    Argonne National Laboratory Erdemir receives patent for ultra-fast surface hardening technology By Payal Marathe * August 11, 2015 Tweet EmailPrint The metal components that make up industrial machines are subject to tremendous wear and tear. But a newly patented technology by Distinguished Fellow Ali Erdemir and his team at the U.S. Department of Energy's Argonne National Laboratory could greatly extend the lifetime of mechanical parts. To protect machinery and increase longevity, several

  6. Ultrafast Laser Diagnostics for Studies of Shock Initiation in Energetic

    Office of Scientific and Technical Information (OSTI)

    Materials. (Conference) | SciTech Connect for Studies of Shock Initiation in Energetic Materials. Citation Details In-Document Search Title: Ultrafast Laser Diagnostics for Studies of Shock Initiation in Energetic Materials. Abstract not provided. Authors: Farrow, Darcie ; Kearney, Sean Patrick ; Jilek, Brook Anton ; Urayama, Junji ; Kohl, Ian Thomas Publication Date: 2013-06-01 OSTI Identifier: 1115245 Report Number(s): SAND2013-5254C 478660 DOE Contract Number: AC04-94AL85000 Resource

  7. Ultrafast Laser Diagnostics to Investigate Initiation in Energetic

    Office of Scientific and Technical Information (OSTI)

    Materials. (Conference) | SciTech Connect to Investigate Initiation in Energetic Materials. Citation Details In-Document Search Title: Ultrafast Laser Diagnostics to Investigate Initiation in Energetic Materials. Abstract not provided. Authors: Farrow, Darcie Publication Date: 2012-01-01 OSTI Identifier: 1118319 Report Number(s): SAND2012-0257C 481469 DOE Contract Number: AC04-94AL85000 Resource Type: Conference Resource Relation: Conference: NW external LDRD review held January 18, 2012 in

  8. Ultrafast Terahertz Probes of Interacting Dark Excitons in

    Office of Scientific and Technical Information (OSTI)

    Chirality-Specific Semiconducting Single-Walled Carbon Nanotubes (Journal Article) | SciTech Connect Terahertz Probes of Interacting Dark Excitons in Chirality-Specific Semiconducting Single-Walled Carbon Nanotubes Citation Details In-Document Search Title: Ultrafast Terahertz Probes of Interacting Dark Excitons in Chirality-Specific Semiconducting Single-Walled Carbon Nanotubes Authors: Luo, Liang ; Chatzakis, Ioannis ; Patz, Aaron ; Wang, Jigang Publication Date: 2015-03-13 OSTI

  9. Ultrafast kinetics subsequent to shock in an unreacted, oxygen balanced

    Office of Scientific and Technical Information (OSTI)

    mixture of nitromethane and hydrogen peroxide (Conference) | SciTech Connect kinetics subsequent to shock in an unreacted, oxygen balanced mixture of nitromethane and hydrogen peroxide Citation Details In-Document Search Title: Ultrafast kinetics subsequent to shock in an unreacted, oxygen balanced mixture of nitromethane and hydrogen peroxide Authors: Armstrong, M R ; Zaug, J M ; Grant, C D ; Crowhurst, J C ; Bastea, S Publication Date: 2014-06-24 OSTI Identifier: 1149544 Report Number(s):

  10. Ultrafast Chemistry under Nonequilibrium Conditions and the Shock to Deflagration Transition at the Nanoscale

    SciTech Connect (OSTI)

    Wood, Mitchell A.; Cherukara, Mathew J.; Kober, Edward M.; Strachan, Alejandro

    2015-06-13

    We use molecular dynamics simulations to describe the chemical reactions following shock-induced collapse of cylindrical pores in the high-energy density material RDX. For shocks with particle velocities of 2 km/s we find that the collapse of a 40 nm diameter pore leads to a deflagration wave. Molecular collisions during the collapse lead to ultrafast, multistep chemical reactions that occur under nonequilibrium conditions. WE found that exothermic products formed during these first few picoseconds prevent the nanoscale hotspot from quenching. Within 30 ps, a local deflagration wave develops. It propagates at 0.25 km/s and consists of an ultrathin reaction zone of only ~5 nm, thus involving large temperature and composition gradients. Contrary to the assumptions in current models, a static thermal hotspot matching the dynamical one in size and thermodynamic conditions fails to produce a deflagration wave indicating the importance of nonequilibrium loading in the criticality of nanoscale hot spots. These results provide insight into the initiation of reactive decomposition.

  11. Ultrafast Chemistry under Nonequilibrium Conditions and the Shock to Deflagration Transition at the Nanoscale

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

    Wood, Mitchell A.; Cherukara, Mathew J.; Kober, Edward M.; Strachan, Alejandro

    2015-06-13

    We use molecular dynamics simulations to describe the chemical reactions following shock-induced collapse of cylindrical pores in the high-energy density material RDX. For shocks with particle velocities of 2 km/s we find that the collapse of a 40 nm diameter pore leads to a deflagration wave. Molecular collisions during the collapse lead to ultrafast, multistep chemical reactions that occur under nonequilibrium conditions. WE found that exothermic products formed during these first few picoseconds prevent the nanoscale hotspot from quenching. Within 30 ps, a local deflagration wave develops. It propagates at 0.25 km/s and consists of an ultrathin reaction zone ofmore » only ~5 nm, thus involving large temperature and composition gradients. Contrary to the assumptions in current models, a static thermal hotspot matching the dynamical one in size and thermodynamic conditions fails to produce a deflagration wave indicating the importance of nonequilibrium loading in the criticality of nanoscale hot spots. These results provide insight into the initiation of reactive decomposition.« less

  12. Ultra-fast Laser Synthesis of Nanopore Arrays in Silicon for Bio-molecule Separation and Detection

    SciTech Connect (OSTI)

    Tringe, J W; Ileri, N; Letant, S E; Stroeve, P; Shirk, M; Zaidi, S; Balhorn, R L; Siders, C W

    2008-02-07

    We demonstrate that interference of ultra-fast pulses of laser light can create regular patterns in thin silicon membranes that are compatible with the formation of a uniform array of nanopores. The spacing and size of these pores can be tuned by changing the laser energy, wavelength and number of ultra-short pulses. Short pulses and wavelengths ({approx}550 nm and smaller) are needed to define controllable nanoscale features in silicon. Energy must be localized in time and space to produce the etching, ablation or amorphization effects over the {approx}100 nm length scales appropriate for definition of single pores. Although in this brief study pattern uniformity was limited by laser beam quality, a complementary demonstration reported here used continuous-wave interferometric laser exposure of photoresist to show the promise of the ultra-fast approach for producing uniform pore arrays. The diameters of these interferometrically-defined features are significantly more uniform than the diameters of pores in state-of-the-art polycarbonate track etch membranes widely used for molecular separations.

  13. Identification of the dominant photochemical pathways and mechanistic insights to the ultrafast ligand exchange of Fe(CO)5 to Fe(CO)4EtOH

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

    Kunnus, K.; Josefsson, I.; Rajkovic, I.; Schreck, S.; Quevedo, W.; Beye, M.; Weniger, C.; Grübel, S.; Scholz, M.; Nordlund, D.; et al

    2016-02-09

    We utilized femtosecond time-resolved resonant inelastic X-ray scattering and ab initio theory to study the transient electronic structure and the photoinduced molecular dynamics of a model metal carbonyl photocatalyst Fe(CO)5 in ethanol solution. We propose mechanistic explanation for the parallel ultrafast intra-molecular spin crossover and ligation of the Fe(CO)4 which are observed following a charge transfer photoexcitation of Fe(CO)5 as reported in our previous study [Wernet et al., Nature 520, 78 (2015)]. We find that branching of the reaction pathway likely happens in the 1A1 state of Fe(CO)4. A sub-picosecond time constant of the spin crossover from 1B2 tomore » 3B2 is rationalized by the proposed 1B2 → 1A1 → 3B2 mechanism. Ultrafast ligation of the 1B2 Fe(CO)4 state is significantly faster than the spin-forbidden and diffusion limited ligation process occurring from the 3B2 Fe(CO)4 ground state that has been observed in the previous studies. We propose that the ultrafast ligation occurs via 1B2 → 1A1 → 1A' Fe(CO)4EtOH pathway and the time scale of the 1A1 Fe(CO)4 state ligation is governed by the solute-solvent collision frequency. In conclusion, our study emphasizes the importance of understanding the interaction of molecular excited states with the surrounding environment to explain the relaxation pathways of photoexcited metal carbonyls in solution.« less

  14. Condensed Phase and Interfacial Molecular Science | U.S. DOE...

    Office of Science (SC) Website

    Condensed Phase and Interfacial Molecular Science Chemical Sciences, Geosciences, & ... emphasizes molecular understanding of chemical, physical, and electron-driven processes ...

  15. Ultrafast Optical Microscopy of Single Monolayer Molybdenum Disulfide Flakes

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

    Seo, Minah; Yamaguchi, Hisato; Mohite, Aditya D.; Boubanga-Tombet, Stephane; Blancon, Jean-Christophe; Najmaei, Sina; Ajayan, Pulickel M.; Lou, Jun; Taylor, Antoinette J.; Prasankumar, Rohit P.

    2016-02-15

    We performed ultrafast optical microscopy on single flakes of atomically thin CVD-grown molybdenum disulfide, using non-degenerate femtosecond pump-probe spectroscopy to excite and probe carriers above and below the indirect and direct band gaps. These measurements reveal the influence of layer thickness on carrier dynamics when probing near the band gap. Furthermore, fluence-dependent measurements indicate that carrier relaxation is primarily influenced by surface-related defect and trap states after above-bandgap photoexcitation. Furthermore, the ability to probe femtosecond carrier dynamics in individual flakes can thus give much insight into light-matter interactions in these two-dimensional nanosystems.

  16. Ultrafast carrier capture in InGaAs quantum posts

    SciTech Connect (OSTI)

    Talbayev, Diyar; Taylor, Antoinette J; Stehr, D; Morris, C M; Wagner, M; Kim, H C; Schneider, H; Petroff, P M; Sherwin, M S

    2009-01-01

    To explore the capture dynamics of photoexcited carriers in semiconductor quantum posts, optical pump - THz probe and time-resolved photoluminescence spectroscopy were performed. The results of the THz experiment show that after ultrafast excitation, electrons relax within a few picoseconds into the quantum posts, which are acting as efficient traps. The saturation of the quantum post states, probed by photoluminescence, was reached approximately at ten times the quantum post density in the samples. The results imply that quantum posts are posts highly attractive nanostructures for future device applications.

  17. Driving magnetic order in a manganite by ultrafast lattice excitation.

    SciTech Connect (OSTI)

    Forst, M.; Tobey, R. I.; Wall, S.; Bromberger, H.; Khanna, V.; Cavalieri, A. L.; Chuang, Y.-D.; Lee, W. S.; Moore, R.; Schlotter, W. F.; Turner, J. J.; Krupin, O.; Trigo, M.; Zheng, H.; Mitchell, J. F.; Dhesi, S. S.; Hill, J. P.; Cavalleri, A.

    2011-01-01

    Femtosecond midinfrared pulses are used to directly excite the lattice of the single-layer manganite La{sub 0.5}Sr{sub 1.5}MnO{sub 4}. Magnetic and orbital orders, as measured by femtosecond resonant soft x-ray diffraction with an x-ray free-electron laser, are reduced within a few picoseconds. This effect is interpreted as a displacive exchange quench, a prompt shift in the equilibrium value of the magnetic- and orbital-order parameters after the lattice has been distorted. Control of magnetism through ultrafast lattice excitation may be of use for high-speed optomagnetism.

  18. Ultrafast laser control of backward superfluorescence towards standoff sensing

    SciTech Connect (OSTI)

    Ariunbold, Gombojav O.; Sautenkov, Vladimir A.; Rostovtsev, Yuri V.; Scully, Marlan O.

    2014-01-13

    We study infrared backward cooperative emission in a rubidium vapor induced by ultrafast two-photon optical excitations. The laser coherent control of the backward emission is demonstrated by using a pair of 100 fs pulses with a variable time delay. The temporal variation (quantum beat) of the backward beam intensity due to interference of atomic transitions in the rubidium atomic level system 5S-5P-5D is produced and controlled. Based on the obtained experimental results, we discuss possible applications of the developed approach for creation of an effective “guide star” in the sodium atomic layer in the upper atmosphere (mesosphere)

  19. Rise Time Measurement for Ultrafast X-Ray Pulses

    DOE Patents [OSTI]

    Celliers, Peter M.; Weber, Franz A.; Moon, Stephen J.

    2005-04-05

    A pump-probe scheme measures the rise time of ultrafast x-ray pulses. Conventional high speed x-ray diagnostics (x-ray streak cameras, PIN diodes, diamond PCD devices) do not provide sufficient time resolution to resolve rise times of x-ray pulses on the order of 50 fs or less as they are being produced by modern fast x-ray sources. Here, we are describing a pump-probe technique that can be employed to measure events where detector resolution is insufficient to resolve the event. The scheme utilizes a diamond plate as an x-ray transducer and a p-polarized probe beam.

  20. Rise time measurement for ultrafast X-ray pulses

    DOE Patents [OSTI]

    Celliers, Peter M.; Weber, Franz A.; Moon, Stephen J.

    2005-04-05

    A pump-probe scheme measures the rise time of ultrafast x-ray pulses. Conventional high speed x-ray diagnostics (x-ray streak cameras, PIN diodes, diamond PCD devices) do not provide sufficient time resolution to resolve rise times of x-ray pulses on the order of 50 fs or less as they are being produced by modern fast x-ray sources. Here, we are describing a pump-probe technique that can be employed to measure events where detector resolution is insufficient to resolve the event. The scheme utilizes a diamond plate as an x-ray transducer and a p-polarized probe beam.

  1. Ultrafast Shock Initiation of Exothermic Chemistry in Hydrogen Peroxide

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Shock Initiation of Exothermic Chemistry in Hydrogen Peroxide Citation Details In-Document Search Title: Ultrafast Shock Initiation of Exothermic Chemistry in Hydrogen Peroxide Authors: Armstrong, M R ; Zaug, J M ; Goldman, N ; Crowhurst, J C ; Howard, W M ; Carter, J A ; Kashgarian, M ; Chesser, J M ; Barbee, T W ; Bastea, S Publication Date: 2012-06-17 OSTI Identifier: 1202899 Report Number(s): LLNL-JRNL-605214 DOE Contract Number: DE-AC52-07NA27344

  2. Ultrafast terahertz gating of the polarization and giant nonlinear optical

    Office of Scientific and Technical Information (OSTI)

    response in BiFeO3 thin films (Journal Article) | SciTech Connect Title: Ultrafast terahertz gating of the polarization and giant nonlinear optical response in BiFeO3 thin films In this article, terahertz pulses are applied as an all-optical bias to ferroelectric thin-film BiFeO3 while monitoring the time-dependent ferroelectric polarization through its nonlinear optical response. Modulations in the intensity of the second harmonic light generated by the film correspond to on-off ratios of

  3. Ultrafast terahertz gating of the polarization and giant nonlinear optical

    Office of Scientific and Technical Information (OSTI)

    response in BiFeO3 thin films (Journal Article) | SciTech Connect This content will become publicly available on September 21, 2016 Title: Ultrafast terahertz gating of the polarization and giant nonlinear optical response in BiFeO3 thin films Terahertz pulses are applied as an all-optical bias to ferroelectric thin-film BiFeO3 while monitoring the time-dependent ferroelectric polarization through its nonlinear optical response. Modulations in the intensity of the second harmonic light

  4. Quantum Hooke's Law to classify pulse laser induced ultrafast melting

    SciTech Connect (OSTI)

    Hu, Hao; Ding, Hepeng; Liu, Feng

    2015-02-03

    Ultrafast crystal-to-liquid phase transition induced by femtosecond pulse laser excitation is an interesting material's behavior manifesting the complexity of light-matter interaction. There exist two types of such phase transitions: one occurs at a time scale shorter than a picosecond via a nonthermal process mediated by electron-hole plasma formation; the other at a longer time scale via a thermal melting process mediated by electron-phonon interaction. However, it remains unclear what material would undergo which process and why? Here, by exploiting the property of quantum electronic stress (QES) governed by quantum Hooke's law, we classify the transitions by two distinct classes of materials: the faster nonthermal process can only occur in materials like ice having an anomalous phase diagram characterized with dTm/dP < 0, where Tm is the melting temperature and P is pressure, above a high threshold laser fluence; while the slower thermal process may occur in all materials. Especially, the nonthermal transition is shown to be induced by the QES, acting like a negative internal pressure, which drives the crystal into a super pressing state to spontaneously transform into a higher-density liquid phase. Our findings significantly advance fundamental understanding of ultrafast crystal-to-liquid phase transitions, enabling quantitative a priori predictions.

  5. Quantum Hooke's Law to classify pulse laser induced ultrafast melting

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

    Hu, Hao; Ding, Hepeng; Liu, Feng

    2015-02-03

    Ultrafast crystal-to-liquid phase transition induced by femtosecond pulse laser excitation is an interesting material's behavior manifesting the complexity of light-matter interaction. There exist two types of such phase transitions: one occurs at a time scale shorter than a picosecond via a nonthermal process mediated by electron-hole plasma formation; the other at a longer time scale via a thermal melting process mediated by electron-phonon interaction. However, it remains unclear what material would undergo which process and why? Here, by exploiting the property of quantum electronic stress (QES) governed by quantum Hooke's law, we classify the transitions by two distinct classes ofmore » materials: the faster nonthermal process can only occur in materials like ice having an anomalous phase diagram characterized with dTm/dP < 0, where Tm is the melting temperature and P is pressure, above a high threshold laser fluence; while the slower thermal process may occur in all materials. Especially, the nonthermal transition is shown to be induced by the QES, acting like a negative internal pressure, which drives the crystal into a “super pressing” state to spontaneously transform into a higher-density liquid phase. Our findings significantly advance fundamental understanding of ultrafast crystal-to-liquid phase transitions, enabling quantitative a priori predictions.« less

  6. Ultrafast Structural Rearrangements in the MLCT Excited State for Copper(I)

    Office of Scientific and Technical Information (OSTI)

    bis-Phenanthrolines in Solution (Journal Article) | SciTech Connect Ultrafast Structural Rearrangements in the MLCT Excited State for Copper(I) bis-Phenanthrolines in Solution Citation Details In-Document Search Title: Ultrafast Structural Rearrangements in the MLCT Excited State for Copper(I) bis-Phenanthrolines in Solution Ultrafast excited state structural dynamics of [Cu{sup I}(dmp){sub 2}]{sup +} (dmp = 2,9-dimethyl-1,10-phenanthroline) have been studied to identify structural origins

  7. Phase-contrast imaging using ultrafast x-rays in laser-shocked materials

    SciTech Connect (OSTI)

    Workman, Jonathan B; Cobble, James A; Flippo, Kirk; Gautier, Donald C; Montgomery, David S; Offermann, Dustin T

    2010-01-01

    High-energy x-rays, > 10-keV, can be efficiently produced from ultrafast laser target interactions with many applications to dense target materials in Inertial Confinement Fusion (ICF) and High-Energy Density Physics (HEDP). These same x-rays can also be applied to measurements of low-density materials inside high-density hohlraum environments. In the experiments presented, high-energy x-ray images of laser-shocked polystyrene are produced through phase contrast imaging. The plastic targets are nominally transparent to traditional x-ray absorption but show detailed features in regions of high density gradients due to refractive effects often called phase contrast imaging. The 200-TW Trident laser is used both to produce the x-ray source and to shock the polystyrene target. X-rays at 17-keV produced from 2-ps, 100-J laser interactions with a 12-micron molybdenum wire are used to produce a small source size, required for optimizing refractive effects. Shocks are driven in the 1-mm thick polystyrene target using 2-ns, 250-J, 532-nm laser drive with phase plates. X-ray images of shocks compare well to 1-D hydro calculations, HELIOS-CR.

  8. Ultrafast Terahertz-Induced Response of GeSbTe Phase-Change Materials...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Ultrafast Terahertz-Induced Response of GeSbTe Phase-Change Materials Citation Details In-Document ... Publication Date: 2014-07-08 OSTI Identifier: 1136695 Report ...

  9. 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.

  10. Ultrafast terahertz-induced response of GeSbTe phase-change materials...

    Office of Scientific and Technical Information (OSTI)

    Title: Ultrafast terahertz-induced response of GeSbTe phase-change materials The time-reso... pulses as a means of biasing phase-change materials on a sub-picosecond time-scale. ...

  11. Role of grain size on the martensitic transformation and ultra-fast

    Office of Scientific and Technical Information (OSTI)

    superelasticity in shape memory alloys (Journal Article) | DOE PAGES Role of grain size on the martensitic transformation and ultra-fast superelasticity in shape memory alloys This content will become publicly available on May 30, 2017 « Prev Next » Title: Role of grain size on the martensitic transformation and ultra-fast superelasticity in shape memory alloys Authors: Morrison, Keith R. ; Cherukara, Mathew J. ; Kim, Hojin ; Strachan, Alejandro Publication Date: 2015-08-01 OSTI

  12. Minute-MOFs: Ultrafast Synthesis of M2(dobpdc) Metal-Organic Frameworks

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

    from Divalent Metal Oxide Colloidal Nanocrystals | Center for Gas SeparationsRelevant to Clean Energy Technologies | Blandine Jerome Minute-MOFs: Ultrafast Synthesis of M2(dobpdc) Metal-Organic Frameworks from Divalent Metal Oxide Colloidal Nanocrystals Previous Next List Maserati, Lorenzo; Meckler, Stephen M.; Li, Changyi; and Helms, Brett A. Minute-MOFs: Ultrafast Synthesis of M2(dobpdc) Metal-Organic Frameworks from Divalent Metal Oxide Colloidal Nanocrystals. Chem. Mater., 28, 1581-1588

  13. Ultrafast Probes for Dirac Materials (Technical Report) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    Ultrafast Probes for Dirac Materials Citation Details In-Document Search Title: Ultrafast Probes for Dirac Materials Authors: Yarotski, Dmitry Anatolievitch [1] + Show Author Affiliations Los Alamos National Laboratory Publication Date: 2015-03-12 OSTI Identifier: 1172825 Report Number(s): LA-UR-15-21802 DOE Contract Number: AC52-06NA25396 Resource Type: Technical Report Research Org: Los Alamos National Laboratory (LANL) Sponsoring Org: UCRP Country of Publication: United States Language:

  14. Ultrafast kinetics subsequent to shock compression in an oxygen-balanced

    Office of Scientific and Technical Information (OSTI)

    mixture of nitromethane and hydrogen peroxide (Journal Article) | SciTech Connect Journal Article: Ultrafast kinetics subsequent to shock compression in an oxygen-balanced mixture of nitromethane and hydrogen peroxide Citation Details In-Document Search Title: Ultrafast kinetics subsequent to shock compression in an oxygen-balanced mixture of nitromethane and hydrogen peroxide Authors: Armstrong, M R ; Zaug, J M ; Grant, C D ; Crowhurst, J C ; Bastea, S Publication Date: 2014-03-03 OSTI

  15. 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 mission. This workshop built on previous workshops and included three breakout sessions identifying scientific challenges in biology, biogeochemistry, catalysis, and materials science frontier areas of fundamental science that underpin energy and environmental science that would significantly benefit from ultrafast transmission electron microscopy (UTEM). In addition, the current status of time-resolved electron microscopy was examined, and the technologies that will enable future advances in spatio-temporal resolution were identified in a fourth breakout session.

  16. William R. Wiley Environmental Molecular Sciences Laboratory...

    Office of Science (SC) Website

    to unravel the interactions of physical, chemical and biological processes that underpin ... and simulate atomic- and molecular-level biological, chemical and physical processes. ...

  17. Ultrafast transient grating radiation to optical image converter

    DOE Patents [OSTI]

    Stewart, Richard E; Vernon, Stephen P; Steel, Paul T; Lowry, Mark E

    2014-11-04

    A high sensitivity transient grating ultrafast radiation to optical image converter is based on a fixed transmission grating adjacent to a semiconductor substrate. X-rays or optical radiation passing through the fixed transmission grating is thereby modulated and produces a small periodic variation of refractive index or transient grating in the semiconductor through carrier induced refractive index shifts. An optical or infrared probe beam tuned just below the semiconductor band gap is reflected off a high reflectivity mirror on the semiconductor so that it double passes therethrough and interacts with the radiation induced phase grating therein. A small portion of the optical beam is diffracted out of the probe beam by the radiation induced transient grating to become the converted signal that is imaged onto a detector.

  18. Ultrafast dynamic ellipsometry and spectroscopy of laser shocked materials

    SciTech Connect (OSTI)

    Mcgrane, Shawn David [Los Alamos National Laboratory; Bolme, Cindy B [Los Alamos National Laboratory; Whitley, Von H [Los Alamos National Laboratory; Moore, David S [Los Alamos National Laboratory

    2010-01-01

    Shock waves create extreme states of matter with very high pressures, temperatures, and volumetric compressions, at an exceedingly rapid rate of change. We review how to use a beamsplitter and a note card to turn a typical chirp pulse amplified femtosecond laser system into an ultrafast shock dynamics machine. Open scientific questions that can be addressed with such an apparatus are described. We report on the development of several single shot time resolved diagnostics needed to answer these questions. These single shot diagnostics are expected to be broadly applicable to other types of laser ablation experiments. Experimental results measured from shocked material dynamics of several systems are detailed. Finally, we report on progress towards using transient absorption as a measure of electronic excitation and coherent Raman as a picosecond probe of temperature in shock compressed condensed matter.

  19. Ultrafast stimulated Raman parallel adiabatic passage by shaped pulses

    SciTech Connect (OSTI)

    Dridi, G.; Guerin, S.; Hakobyan, V.; Jauslin, H. R.; Eleuch, H.

    2009-10-15

    We present a general and versatile technique of population transfer based on parallel adiabatic passage by femtosecond shaped pulses. Their amplitude and phase are specifically designed to optimize the adiabatic passage corresponding to parallel eigenvalues at all times. We show that this technique allows the robust adiabatic population transfer in a Raman system with the total pulse area as low as 3{pi}, corresponding to a fluence of one order of magnitude below the conventional stimulated Raman adiabatic passage process. This process of short duration, typically picosecond and subpicosecond, is easily implementable with the modern pulse shaper technology and opens the possibility of ultrafast robust population transfer with interesting applications in quantum information processing.

  20. Ultrafast observation of shocked states in a precompressed material...

    Office of Scientific and Technical Information (OSTI)

    Subject: 71 CLASSICAL AND QUANTUMM MECHANICS, GENERAL PHYSICS; 36 MATERIALS SCIENCE; 37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY Word Cloud More Like This Full Text ...

  1. Ultrafast Shock Initiation of Exothermic Chemistry in Hydrogen...

    Office of Scientific and Technical Information (OSTI)

    Language: English Subject: 71 CLASSICAL AND QUANTUMM MECHANICS, GENERAL PHYSICS; 36 MATERIALS SCIENCE; 42 ENGINEERING; 37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY

  2. Ultrafast observation of shocked states in a precompressed material...

    Office of Scientific and Technical Information (OSTI)

    Resource Type: Journal Article Resource Relation: Journal Name: ... MECHANICS, GENERAL PHYSICS; 36 MATERIALS SCIENCE; 37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY

  3. ULTRAFAST OUTFLOWS: GALAXY-SCALE ACTIVE GALACTIC NUCLEUS FEEDBACK

    SciTech Connect (OSTI)

    Wagner, A. Y.; Umemura, M.; Bicknell, G. V.

    2013-01-20

    We show, using global three-dimensional grid-based hydrodynamical simulations, that ultrafast outflows (UFOs) from active galactic nuclei (AGNs) result in considerable feedback of energy and momentum into the interstellar medium (ISM) of the host galaxy. The AGN wind interacts strongly with the inhomogeneous, two-phase ISM consisting of dense clouds embedded in a tenuous, hot, hydrostatic medium. The outflow floods through the intercloud channels, sweeps up the hot ISM, and ablates and disperses the dense clouds. The momentum of the UFO is primarily transferred to the dense clouds via the ram pressure in the channel flow, and the wind-blown bubble evolves in the energy-driven regime. Any dependence on UFO opening angle disappears after the first interaction with obstructing clouds. On kpc scales, therefore, feedback by UFOs operates similarly to feedback by relativistic AGN jets. Negative feedback is significantly stronger if clouds are distributed spherically rather than in a disk. In the latter case, the turbulent backflow of the wind drives mass inflow toward the central black hole. Considering the common occurrence of UFOs in AGNs, they are likely to be important in the cosmological feedback cycles of galaxy formation.

  4. Isotopically Enriched Films and Nanostructures by Ultrafast Pulsed Laser Deposition

    SciTech Connect (OSTI)

    Peter Pronko

    2004-12-13

    This project involved a systematic study to apply newly discovered isotopic enrichment effects in laser ablation plumes to the fabrication of isotopically engineered thin films, superlattices, and nanostructures. The approach to this program involved using ultrafast lasers as a method for generating ablated plasmas that have preferentially structured isotopic content in the body of the ablation plasma plumes. In examining these results we have attempted to interpret the observations in terms of a plasma centrifuge process that is driven by the internal electro-magnetic fields of the plasma itself. The research plan involved studying the following phenomena in regard to the ablation plume and the isotopic mass distribution within it: (1) Test basic equations of steady state centrifugal motion in the ablation plasma. (2) Investigate angular distribution of ions in the ablation plasmas. (3) Examine interactions of plasma ions with self-generated magnetic fields. (3) Investigate ion to neutral ratios in the ablation plasmas. (5) Test concepts of plasma pumping. (6) Fabricate isotopically enriched nanostructures.

  5. Extension - Upgrading Methane Using Ultra-Fast Thermal Swing Adsorption

    SciTech Connect (OSTI)

    Anna Lee Tonkovich

    2008-08-11

    The need for cost effective technologies for upgrading coal mine methane to pipeline quality natural gas is becoming ever greater. The current work presents and investigates a new approach to reduce the impact of the most costly step in the conventional technology, nitrogen rejection. The proposed approach is based on the Velocys microchannel platform, which is being developed to commercialize compact and cost efficient chemical processing technology. For this separation, ultra fast thermal swing sorption is enabled by the very high rates of heat and mass transfer inherent in microchannel processing. In a first phase of the project solid adsorbents were explored. Feasibility of ultrafast thermal swing was demonstrated but the available adsorbents had insufficient differential methane capacity to achieve the required commercial economics. In a second phase, ionic liquids were adopted as absorbents of choice, and experimental work and economic analyses, performed to gauge their potential, showed promise for this novel alternative. Final conclusions suggest that a combination of a required cost target for ionic liquids or a methane capacity increase or a combination of both is required for commercialization.

  6. Fourth International Conference on High Energy Density Physics

    SciTech Connect (OSTI)

    Beg, Farhat

    2015-01-06

    The Fourth International Conference on High Energy Density Physics (ICHED 2013) was held in Saint Malo, France, at the Palais du Grand Large on 25-28 June 2013 (http://web.luli.polytechnique.fr/ICHED2013/). This meeting was the fourth in a series which was first held in 2008. This conference covered all the important aspects of High Energy Density Physics including fundamental topics from strong-field physics to creating new states of matter (including radiation-dominated, high-pressure quantum and relativistic plasmas) and ultra-fast lattice dynamics on the timescale of atomic transitions.

  7. Physics Division annual report - 1998

    SciTech Connect (OSTI)

    1999-09-07

    Summaries are given of progress accomplished for the year in the following areas: (1) Heavy-Ion Nuclear Physics Research; (2) Operation and Development of Atlas; (3) Medium-Energy Nuclear Physics Research; (4) Theoretical Physics Research; and (5) Atomic and Molecular Physics Research.

  8. Interfacial effects revealed by ultrafast relaxation dynamics in BiFeO 3 /

    Office of Scientific and Technical Information (OSTI)

    YBa 2 Cu 3 O 7 bilayers (Journal Article) | SciTech Connect Interfacial effects revealed by ultrafast relaxation dynamics in BiFeO 3 / YBa 2 Cu 3 O 7 bilayers Citation Details In-Document Search This content will become publicly available on February 11, 2017 Title: Interfacial effects revealed by ultrafast relaxation dynamics in BiFeO 3 / YBa 2 Cu 3 O 7 bilayers Authors: Springer, D. ; Nair, Saritha K. ; He, Mi ; Lu, C. L. ; Cheong, S. A. ; Wu, T. ; Panagopoulos, C. ; Chia, Elbert E. M. ;

  9. Laser-induced short-range disorder in aluminum revealed by ultrafast electron diffuse scattering

    SciTech Connect (OSTI)

    Zhu, Pengfei; Chen, Jie; Li, Runze; Chen, Long; Cao, Jianming; Sheng, Zhengming; Zhang, Jie; Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190

    2013-12-02

    We report ultrafast electron diffuse scattering intensity (DSI) measurement in order to study the structural response of aluminum to femtosecond laser excitation. In this measurement, the evolutions of DSI and Bragg peak intensities after the laser excitation are measured and compared in the time domain. Their differences suggest that two kinds of lattice disorder, short-range and long-range, are triggered simultaneously. The former, induced by electron excitation, arises and decays with a faster rate than the latter which is subject to lattice heating. The results presented show that the time-resolved DSI measurements provide complementary insights to the ultrafast diffraction measurements.

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

    SciTech Connect (OSTI)

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

    2014-05-14

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

  11. Ultrafast Dynamic Response of Single Crystal PETN and Beta-HMX (Conference)

    Office of Scientific and Technical Information (OSTI)

    | SciTech Connect Conference: Ultrafast Dynamic Response of Single Crystal PETN and Beta-HMX Citation Details In-Document Search Title: Ultrafast Dynamic Response of Single Crystal PETN and Beta-HMX Authors: Zaug, J M ; Armstrong, M R ; Crowhurst, J C ; Feranti, L ; Swan, R ; Gross, R ; Teshlich, N E ; Wall, M ; Austin, R A ; Fried, L E Publication Date: 2014-06-30 OSTI Identifier: 1149550 Report Number(s): LLNL-CONF-656341 DOE Contract Number: DE-AC52-07NA27344 Resource Type: Conference

  12. Ultrafast charge localization in a stripe-phase nickelate (Journal Article)

    Office of Scientific and Technical Information (OSTI)

    | SciTech Connect Ultrafast charge localization in a stripe-phase nickelate Citation Details In-Document Search Title: Ultrafast charge localization in a stripe-phase nickelate × You are accessing a document from the Department of Energy's (DOE) SciTech Connect. This site is a product of DOE's Office of Scientific and Technical Information (OSTI) and is provided as a public service. Visit OSTI to utilize additional information resources in energy science and technology. A paper copy of this

  13. Ultrafast resonant soft x-ray diffraction dynamics of the charge density

    Office of Scientific and Technical Information (OSTI)

    wave in TbTe 3 (Journal Article) | SciTech Connect Ultrafast resonant soft x-ray diffraction dynamics of the charge density wave in TbTe 3 Citation Details In-Document Search This content will become publicly available on January 24, 2017 Title: Ultrafast resonant soft x-ray diffraction dynamics of the charge density wave in TbTe 3 Authors: Moore, R. G. ; Lee, W. S. ; Kirchman, P. S. ; Chuang, Y. D. ; Kemper, A. F. ; Trigo, M. ; Patthey, L. ; Lu, D. H. ; Krupin, O. ; Yi, M. ; Reis, D. A. ;

  14. Ultrafast terahertz-induced response of GeSbTe phase-change materials

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect terahertz-induced response of GeSbTe phase-change materials Citation Details In-Document Search Title: Ultrafast terahertz-induced response of GeSbTe phase-change materials The time-resolved ultrafast electric field-driven response of crystalline and amorphous GeSbTe films has been measured all-optically, pumping with single-cycle terahertz pulses as a means of biasing phase-change materials on a sub-picosecond time-scale. Utilizing the near-band-gap

  15. Ultrafast Core-Hole Induced Dynamics in Water

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

    Waters If you look deeply enough at even the stillest of waters, as deep as the molecular level, you will find a surprisingly turbulent, dynamic universe. The water...

  16. Ultrafast Core-Hole Induced Dynamics in Water

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

    with pump-probe measurements. Using a combination of isotope substitution experiments and molecular dynamics simulations, researchers from Sweden, Germany, and the U.S. have shown...

  17. Ultrafast spin exchange-coupling torque via photo-excited charge-transfer processes

    SciTech Connect (OSTI)

    Ma, X.; Fang, F.; Li, Q.; Zhu, J.; Yang, Y.; Wu, Y. Z.; Zhao, H. B.; Lüpke, G.

    2015-10-28

    In this study, optical control of spin is of central importance in the research of ultrafast spintronic devices utilizing spin dynamics at short time scales. Recently developed optical approaches such as ultrafast demagnetization, spin-transfer and spin-orbit torques open new pathways to manipulate spin through its interaction with photon, orbit, charge or phonon. However, these processes are limited by either the long thermal recovery time or the low-temperature requirement. Here we experimentally demonstrate ultrafast coherent spin precession via optical charge-transfer processes in the exchange-coupled Fe/CoO system at room temperature. The efficiency of spin precession excitation is significantly higher and the recovery time of the exchange-coupling torque is much shorter than for the demagnetization procedure, which is desirable for fast switching. The exchange coupling is a key issue in spin valves and tunnelling junctions, and hence our findings will help promote the development of exchange-coupled device concepts for ultrafast coherent spin manipulation.

  18. Decoupling Bulk and Surface Contributions in Water- Splitting Photocatalysts by In Situ Ultrafast Spectroscopy

    SciTech Connect (OSTI)

    Appavoo, Kannatassen; Mingzhao, Liu; Black, Charles T.; Sfeir, Matthew Y.

    2015-05-10

    By performing ultrafast emission spectroscopy in an operating, bias-controlled photoelectrochemical cell, we distinguish between bulk (charge transport) and surface (chemical reaction) recombination processes in a nanostructured photocatalyst and correlate its electronic properties directly with its incident-photon-to-current efficiency.

  19. DEVELOPMENT OF NEW MID-INFRARED ULTRAFAST LASER SOURCES FOR COMPACT COHERENT X-RAY SOURCES

    SciTech Connect (OSTI)

    Sterling Backus

    2012-05-14

    In this project, we proposed to develop laser based mid-infrared lasers as a potentially robust and reliable source of ultrafast pulses in the mid-infrared region of the spectrum, and to apply this light source to generating bright, coherent, femtosecond-to-attosecond x-ray beams.

  20. Ultrafast dynamics of liquid water: Energy relaxation and transfer processes of the OH stretch and the HOH bend

    SciTech Connect (OSTI)

    Imoto, Sho; Xantheas, Sotiris S.; Saito, Shinji

    2015-08-27

    The vibrational energy relaxation and transfer processes of the OH stretching and the HOH bending vibrations in liquid water are investigated via the theoretical calculation of the pump-probe spectra obtained from non-equilibrium molecular dynamics simulations with the TTM3-F interaction potential. The excitation of the OH stretch induces an instantaneous response of the high frequency librational motions in the 600-1000 cm-1 range. In addition, the excess energy of the OH stretch of a water molecule quickly transfers to the OH stretches of molecules in its first hydration shell with a time constant of ~50 fs, followed by relaxation to the HOH bends of the surrounding molecules with a time constant of 230 fs. The excitation of the HOH bend also results in the ultrafast excitation of the high frequency librational motions. The energy of the excited HOH bend of a water molecule decays, with a time constant of 200 fs, mainly to the relaxation of the HOH bends of its surrounding molecules. The energies of the HOH bends were found to transfer quickly to the intermolecular motions via the coupling with the high frequency librational motions. The excess energy of the OH stretch or the HOH bend relaxes to the high frequency intermolecular librational motions and eventually to the hot ground state with a time scale of ~1 ps via the coupling with the librational and translational motions. The energy relaxation and transfer processes were found to depend on the local hydrogen bonding network; the relaxations of the excess energy of the OH stretch and the HOH bend of four- and five-coordinated molecules are faster than those of a three-coordinated molecule due to the delocalization of the vibrational motions of the former (four- and five-coordinated molecules) compared to those of the later (three-coordinated molecules). The present results highlight the importance of the high frequency intermolecular librational modes in facilitating the ultrafast energy relaxation process in liquid water via their strong nonlinear couplings with the intramolecular OH stretching and HOH bending vibrations. S.S.X. acknowledges the support of the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences. Pacific Northwest National Laboratory (PNNL) is a multiprogram national laboratory operated for DOE by Battelle. The calculation was carried out using the computing resources at the Research Center for Computational Science in Okazaki, Japan.

  1. Molecular Foundry

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

    ... Revealing the Fluctuations of Flexible DNA in 3D First-of-their-kind images by Molecular ... Electronic Landscapes of Molecular Nanostructures: Mapping States for Charge Transfer with ...

  2. Molecular Dynameomics

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

    Dynameomics Molecular Dynameomics DaggettHiResWhitebg.png Key Challenges: Perform molecular dynamics simulations to characterize both native (i.e. biologically active) and...

  3. Proton chemical shift tensors determined by 3D ultrafast MAS double-quantum NMR spectroscopy

    SciTech Connect (OSTI)

    Zhang, Rongchun; Mroue, Kamal H.; Ramamoorthy, Ayyalusamy

    2015-10-14

    Proton NMR spectroscopy in the solid state has recently attracted much attention owing to the significant enhancement in spectral resolution afforded by the remarkable advances in ultrafast magic angle spinning (MAS) capabilities. In particular, proton chemical shift anisotropy (CSA) has become an important tool for obtaining specific insights into inter/intra-molecular hydrogen bonding. However, even at the highest currently feasible spinning frequencies (110–120 kHz), {sup 1}H MAS NMR spectra of rigid solids still suffer from poor resolution and severe peak overlap caused by the strong {sup 1}H–{sup 1}H homonuclear dipolar couplings and narrow {sup 1}H chemical shift (CS) ranges, which render it difficult to determine the CSA of specific proton sites in the standard CSA/single-quantum (SQ) chemical shift correlation experiment. Herein, we propose a three-dimensional (3D) {sup 1}H double-quantum (DQ) chemical shift/CSA/SQ chemical shift correlation experiment to extract the CS tensors of proton sites whose signals are not well resolved along the single-quantum chemical shift dimension. As extracted from the 3D spectrum, the F1/F3 (DQ/SQ) projection provides valuable information about {sup 1}H–{sup 1}H proximities, which might also reveal the hydrogen-bonding connectivities. In addition, the F2/F3 (CSA/SQ) correlation spectrum, which is similar to the regular 2D CSA/SQ correlation experiment, yields chemical shift anisotropic line shapes at different isotropic chemical shifts. More importantly, since the F2/F1 (CSA/DQ) spectrum correlates the CSA with the DQ signal induced by two neighboring proton sites, the CSA spectrum sliced at a specific DQ chemical shift position contains the CSA information of two neighboring spins indicated by the DQ chemical shift. If these two spins have different CS tensors, both tensors can be extracted by numerical fitting. We believe that this robust and elegant single-channel proton-based 3D experiment provides useful atomistic-level structural and dynamical information for a variety of solid systems that possess high proton density.

  4. REVEALING THE PHYSICAL PROPERTIES OF MOLECULAR GAS IN ORION WITH A LARGE-SCALE SURVEY IN J = 2-1 LINES OF {sup 12}CO, {sup 13}CO, AND C{sup 18}O

    SciTech Connect (OSTI)

    Nishimura, Atsushi; Tokuda, Kazuki; Kimura, Kimihiro; Muraoka, Kazuyuki; Maezawa, Hiroyuki; Ogawa, Hideo; Onishi, Toshikazu [Department of Physical Science, Graduate School of Science, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531 (Japan); Dobashi, Kazuhito; Shimoikura, Tomomi [Department of Astronomy and Earth Sciences, Tokyo Gakugei University, 4-1-1 Nukuikita-machi, Koganei, Tokyo 184-8501 (Japan); Mizuno, Akira [Solar-terrestrial Environment Laboratory, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601 (Japan); Fukui, Yasuo, E-mail: atsushi.nishimura@nao.ac.jp [Department of Physics and Astrophysics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8602 (Japan)

    2015-01-01

    We present fully sampled ?3' resolution images of {sup 12}CO(J=2-1), {sup 13}CO(J=2-1), and C{sup 18}O(J=2-1) emission taken with the newly developed 1.85 m millimeter-submillimeter telescope over the entire area of the Orion A and B giant molecular clouds. The data were compared with J=1-0 of the {sup 12}CO, {sup 13}CO, and C{sup 18}O data taken with the Nagoya 4 m telescope and the NANTEN telescope at the same angular resolution to derive the spatial distributions of the physical properties of the molecular gas. We explore the large velocity gradient formalism to determine the gas density and temperature using line combinations of {sup 12}CO(J=2-1), {sup 13}CO(J=2-1), and {sup 13}CO(J=1-0) assuming a uniform velocity gradient and abundance ratio of CO. The derived gas density is in the range of 500 to 5000 cm{sup 3}, and the derived gas temperature is mostly in the range of 20 to 50 K along the cloud ridge with a temperature gradient depending on the distance from the star forming region. We found that the high-temperature region at the cloud edge faces the H II region, indicating that the molecular gas is interacting with the stellar wind and radiation from the massive stars. In addition, we compared the derived gas properties with the young stellar objects distribution obtained with the Spitzer telescope to investigate the relationship between the gas properties and the star formation activity therein. We found that the gas density and star formation efficiency are positively well correlated, indicating that stars form effectively in the dense gas region.

  5. Ultrafast Core-Hole Induced Dynamics in Water

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

    aqueous systems is essential for many diverse fields, from condensed matter physics to medicine to environmental science. An incoming photon with enough energy to produce a core...

  6. Prospects for Electron Imaging with Ultrafast Time Resolution...

    Office of Scientific and Technical Information (OSTI)

    Sponsoring Org: USDOE Country of Publication: United States Language: English Subject: 71 CLASSICAL AND QUANTUMM MECHANICS, GENERAL PHYSICS; 36 MATERIALS SCIENCE; CHEMISTRY;...

  7. Ultrafast Terahertz Probes of Interacting Dark Excitons inChirality...

    Office of Scientific and Technical Information (OSTI)

    GrantContract Number: AC02-07CH11358 Type: Publisher's Accepted Manuscript Journal Name: Physical Review Letters Additional Journal Information: Journal Volume: 114; Journal ...

  8. Ultrafast kinetics subsequent to shock compression in an oxygen...

    Office of Scientific and Technical Information (OSTI)

    DOE Contract Number: DE-AC52-07NA27344 Resource Type: Journal Article Resource Relation: Journal Name: Journal of Physical Chemistry A, vol. 118, no. 32, August 14, 2014, pp. ...

  9. Ultrafast Shock Initiation of Exothermic Chemistry in Hydrogen...

    Office of Scientific and Technical Information (OSTI)

    DOE Contract Number: DE-AC52-07NA27344 Resource Type: Journal Article Resource Relation: Journal Name: Journal of Physical Chemistry A, na, na, October 8, 2013, pp. 13051 Research ...

  10. Ultrafast Power Processor for Smart Grid Power Module Development

    SciTech Connect (OSTI)

    MAITRA, ARINDAM; LITWIN, RAY; lai, Jason; Syracuse, David

    2012-12-30

    This project’s goal was to increase the switching speed and decrease the losses of the power semiconductor devices and power switch modules necessary to enable Smart Grid energy flow and control equipment such as the Ultra-Fast Power Processor. The primary focus of this project involves exploiting the new silicon-based Super-GTO (SGTO) technology and build on prototype modules already being developed. The prototype super gate-turn-off thyristor (SGTO) has been tested fully under continuously conducting and double-pulse hard-switching conditions for conduction and switching characteristics evaluation. The conduction voltage drop measurement results indicate that SGTO has excellent conduction characteristics despite inconsistency among some prototype devices. Tests were conducted with two conditions: (1) fixed gate voltage and varying anode current condition, and (2) fixed anode current and varying gate voltage condition. The conduction voltage drop is relatively a constant under different gate voltage condition. In terms of voltage drop as a function of the load current, there is a fixed voltage drop about 0.5V under zero current condition, and then the voltage drop is linearly increased with the current. For a 5-kV voltage blocking device that may operate under 2.5-kV condition, the projected voltage drop is less than 2.5 V under 50-A condition, or 0.1%. If the device is adopted in a converter operating under soft-switching condition, then the converter can achieve an ultrahigh efficiency, typically above 99%. The two-pulse switching test results indicate that SGTO switching speed is very fast. The switching loss is relatively low as compared to that of the insulated-gate-bipolar-transistors (IGBTs). A special phenomenon needs to be noted is such a fast switching speed for the high-voltage switching tends to create an unexpected Cdv/dt current, which reduces the turn-on loss because the dv/dt is negative and increases the turn-off loss because the dv/dt is positive. As a result, the turn-on loss at low current is quite low, and the turn-off loss at low current is relatively high. The phenomenon was verified with junction capacitance measurement along with the dv/dt calculation. Under 2-kV test condition, the turn-on and turn-off losses at 25-A is about 3 and 9 mJ, respectively. As compared to a 4.5-kV, 60-A rated IGBT, which has turn-on and turn-off losses about 25 and 20 mJ under similar test condition, the SGTO shows significant switching loss reduction. The switching loss depends on the switching frequency, but under hard-switching condition, the SGTO is favored to the IGBT device. The only concern is during low current turn-on condition, there is a voltage bump that can translate to significant power loss and associated heat. The reason for such a current bump is not known from this study. It is necessary that the device manufacturer perform though test and provide the answer so the user can properly apply SGTO in pulse-width-modulated (PWM) converter and inverter applications.

  11. PHYSICAL SCIENCES, Physics Phase

    Office of Scientific and Technical Information (OSTI)

    SCIENCES, Physics Phase competition in trisected superconducting dome I. M. Vishik, 1, 2 M Hashimoto, 3 R.-H. He, 4 W. S. Lee, 1, 2 F. Schmitt, 1, 2 D. H. Lu, 3 R. G. Moore, 1...

  12. Plasma Physics

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

    Plasma Physics (P-24) is committed to scientific excellence in basic and applied research. Our breadth and depth in experimental high energy density physics and plasma physics is ...

  13. Morphological changes in ultrafast laser ablation plumes with varying spot size

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

    Harilal, S. S.; Diwakar, P. K.; Polek, M. P.; Phillips, M. C.

    2015-06-04

    We investigated the role of spot size on plume morphology during ultrafast laser ablation of metal targets. Our results show that the spatial features of fs LA plumes are strongly dependent on the focal spot size. Two-dimensional self-emission images showed that the shape of the ultrafast laser ablation plumes changes from spherical to cylindrical with an increasing spot size from 100 to 600 ?m. The changes in plume morphology and internal structures are related to ion emission dynamics from the plasma, where broader angular ion distribution and faster ions are noticed for the smallest spot size used. The present resultsmoreclearly show that the morphological changes in the plume with spot size are independent of laser pulse width.less

  14. Time-domain sampling of x-ray pulses using an ultrafast sample response

    SciTech Connect (OSTI)

    Gaal, P.; Shayduk, R.; Schick, D.; Herzog, M.; Bojahr, A.; Goldshteyn, J.; Navirian, H. A.; Leitenberger, W.; Vrejoiu, I.; Khakhulin, D.; Wulff, M.; Bargheer, M.

    2012-12-10

    We employ the ultrafast response of a 15.4 nm thin SrRuO{sub 3} layer grown epitaxially on a SrTiO{sub 3} substrate to perform time-domain sampling of an x-ray pulse emitted from a synchrotron storage ring. Excitation of the sample with an ultrashort laser pulse triggers coherent expansion and compression waves in the thin layer, which turn the diffraction efficiency on and off at a fixed Bragg angle during 5 ps. This is significantly shorter than the duration of the synchrotron x-ray pulse of 100 ps. Cross-correlation measurements of the ultrafast sample response and the synchrotron x-ray pulse allow to reconstruct the x-ray pulse shape.

  15. Ablation experiment and threshold calculation of titanium alloy irradiated by ultra-fast pulse laser

    SciTech Connect (OSTI)

    Zheng, Buxiang; Jiang, Gedong; Wang, Wenjun Wang, Kedian; Mei, Xuesong; State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an 710054

    2014-03-15

    The interaction between an ultra-fast pulse laser and a material's surface has become a research hotspot in recent years. Micromachining of titanium alloy with an ultra-fast pulse laser is a very important research direction, and it has very important theoretical significance and application value in investigating the ablation threshold of titanium alloy irradiated by ultra-fast pulse lasers. Irradiated by a picosecond pulse laser with wavelengths of 1064 nm and 532 nm, the surface morphology and feature sizes, including ablation crater width (i.e. diameter), ablation depth, ablation area, ablation volume, single pulse ablation rate, and so forth, of the titanium alloy were studied, and their ablation distributions were obtained. The experimental results show that titanium alloy irradiated by a picosecond pulse infrared laser with a 1064 nm wavelength has better ablation morphology than that of the green picosecond pulse laser with a 532 nm wavelength. The feature sizes are approximately linearly dependent on the laser pulse energy density at low energy density and the monotonic increase in laser pulse energy density. With the increase in energy density, the ablation feature sizes are increased. The rate of increase in the feature sizes slows down gradually once the energy density reaches a certain value, and gradually saturated trends occur at a relatively high energy density. Based on the linear relation between the laser pulse energy density and the crater area of the titanium alloy surface, and the Gaussian distribution of the laser intensity on the cross section, the ablation threshold of titanium alloy irradiated by an ultra-fast pulse laser was calculated to be about 0.109 J/cm{sup 2}.

  16. Lattice and Carrier Dynamics in Quantum-Confined Materials on Ultrafast

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

    Timescales | MIT-Harvard Center for Excitonics Lattice and Carrier Dynamics in Quantum-Confined Materials on Ultrafast Timescales April 3, 2014 at 3pm/36-428 Richard Schaller Department of Chemistry, Northwestern University, Argonne National Laboratory richard-schaller_000 Abstract: Excess carrier energy, which many aim to utilize for advanced energy conversion technologies, rapidly dissipates from electrons and holes in both bulk and quantum confined semiconductors despite expectation of

  17. Ultrafast Terahertz-Induced Response of GeSbTe Phase-Change Materials

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Terahertz-Induced Response of GeSbTe Phase-Change Materials Citation Details In-Document Search Title: Ultrafast Terahertz-Induced Response of GeSbTe Phase-Change Materials Authors: Shu, Michael J. ; Zalden, Peter ; Chen, Frank ; Weems, Ben ; Chatzakis, Ioannis ; Xiong, Feng ; Jeyasingh, Rakesh ; Hoffmann, Matthias C. ; Pop, Eric ; Wong, H.-S.Philip ; Wuttig, Matthias ; Lindenberg, Aaron M. Publication Date: 2014-07-08 OSTI Identifier: 1136695 Report

  18. Molecular Foundry

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

    Mike Brady ed_barnard Joint Molecular Foundry/ALS Project Scientist mabrady@lbl.gov 510.486.6548

  19. Molecular Science

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

    Molecular Science NETL's Molecular Science competency provides technology-enabling computational and experimental insight into the atomic-level processes occurring in condensed matter and gas phase systems or at the heterogeneous surface-gas interfaces used for energy applications. Research includes molecular optimization as well as both classical and high-throughput material design, specifically: Molecular Optimization Development and application of new computational approaches in the general

  20. Nuclear Physics

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

    Science Programs Office of Science Nuclear Physics science-innovationassetsimagesicon-science.jpg Nuclear Physics Enabling remarkable discoveries and tools that ...

  1. Physics Division annual review, April 1, 1988--March 31, 1989

    SciTech Connect (OSTI)

    Thayer, K.J.

    1989-08-01

    This document discusses the following main topics: Research at Atlas; Operation and Development of Atlas; Medium-Energy Nuclear Physics and Weak Interactions; Theoretical Nuclear Physics; Interactions of Fast Atomic and Molecular Ions with Solid and Gaseous Targets; Atomic Physics at Synchrotron Light Sources; Atomic Physics at Atlas and the ECR Source; Theoretical Atomic Physics; High-Resolution Laser-rf Spectroscopy of Atomic and Molecular Beams; and Fast Ion-Beam/Laser Studies of Atomic and Molecular Structure.

  2. Molecular Foundry

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

    EVENTS ARCHIVE The Molecular Foundry regularly offers seminars and events that feature compelling research and information for those who investigate at the nanoscale. Seminars occur on Tuesdays at 11:00 am, in Building 67, Room 3111 unless otherwise noted. < seminars and events Molecular Foundry 10th Anniversary Symposium and Dinner On March 24, 2016, the Molecular Foundry will be celebrating the 10th anniversary of the dedication of its iconic building with a full day scientific symposium

  3. Molecular Foundry

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

    Flatter and Faster: Transition Metal Dichalcogendies at the Molecular Foundry (Part II) Brain Imaging and Optical Manipulation Active Nanointerfaces for Electrochemistry SAXS-WAXS...

  4. Molecular Foundry

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

    The abundance of interfaces allows the directing of transport for efficient energy storage and conversion. Electron donors and acceptors at interfaces Molecular level design and ...

  5. Molecular Foundry

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

    ... "'Thinking,' 'Exchanging,' and 'Making' necessary links in creating ground-breaking science inspired SmithGroup's design for the Molecular Foundry in Berkeley, California. The ...

  6. Molecular Foundry

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

    The insight gained guides the design and optimization of new nanostructured materials for molecular-scale electronics, solar harvesting, water-splitting, carbon capture and ...

  7. Molecular Foundry

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

    31, 2016 Instrument Scheduler Nanofabrication Instrument Scheduler User Program The Molecular Foundry user program gives researchers access to expertise and equipment for...

  8. Molecular Foundry

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

    Publications Advanced Materials Special Issue The Molecular Foundry publication database lists peer-reviewed work that has resulted from internal and user research. New...

  9. Molecular Foundry

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

    Dmitry Soustin dmitry User Program Administrator dsoustin@lbl.gov 510.486.7687 Biography Dmitry Soustin is the Molecular Foundry's User Program Administrator. In this role, Dmitry...

  10. Molecular Foundry

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

    Theory of Nanostructured Materials jbneaton@lbl.gov 510.486.4527 personal website Biography Jeffrey B. Neaton is Director of the Molecular Foundry, a Department of Energy...

  11. Subatomic Physics

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

    5 Subatomic Physics We play a major role in large-scale scientific collaborations around the world, performing nuclear physics experiments that advance the understanding of the ...

  12. Physics Division annual review, April 1, 1991--March 31, 1992

    SciTech Connect (OSTI)

    Henning, W.F.

    1992-08-01

    This report contains brief discusses on topics in the following areas: Research at atlas; operation and development of atlas; medium-energy nuclear physics and weak interactions; theoretical nuclear physics; and atomic and molecular physics research.

  13. The Behavior of Hydrogen Under Extreme Conditions on Ultrafast Timescales (A "Life at the Frontiers of Energy Research" contest entry from the 2011 Energy Frontier Research Centers (EFRCs) Summit and Forum)

    SciTech Connect (OSTI)

    Mao, Ho-kwang; EFree Staff

    2011-05-01

    'The Behavior of Hydrogen Under Extreme Conditions on Ultrafast Timescales ' was submitted by the Center for Energy Frontier Research in Extreme Environments (EFree) to the 'Life at the Frontiers of Energy Research' video contest at the 2011 Science for Our Nation's Energy Future: Energy Frontier Research Centers (EFRCs) Summit and Forum. Twenty-six EFRCs created short videos to highlight their mission and their work. EFree is directed by Ho-kwang Mao at the Carnegie Institute of Washington and is a partnership of scientists from thirteen institutions.The Office of Basic Energy Sciences in the U.S. Department of Energy's Office of Science established the 46 Energy Frontier Research Centers (EFRCs) in 2009. These collaboratively-organized centers conduct fundamental research focused on 'grand challenges' and use-inspired 'basic research needs' recently identified in major strategic planning efforts by the scientific community. The overall purpose is to accelerate scientific progress toward meeting the nation's critical energy challenges. The mission of Energy Frontier Research in Extreme Environments is 'to accelerate the discovery and creation of energy-relevant materials using extreme pressures and temperatures.' Research topics are: catalysis (CO{sub 2}, water), photocatalysis, solid state lighting, optics, thermelectric, phonons, thermal conductivity, solar electrodes, fuel cells, superconductivity, extreme environment, radiation effects, defects, spin dynamics, CO{sub 2} (capture, convert, store), greenhouse gas, hydrogen (fuel, storage), ultrafast physics, novel materials synthesis, and defect tolerant materials.

  14. The Behavior of Hydrogen Under Extreme Conditions on Ultrafast Timescales (A "Life at the Frontiers of Energy Research" contest entry from the 2011 Energy Frontier Research Centers (EFRCs) Summit and Forum)

    ScienceCinema (OSTI)

    Mao, Ho-kwang (Director, Center for Energy Frontier Research in Extreme Environments); EFree Staff

    2011-11-02

    'The Behavior of Hydrogen Under Extreme Conditions on Ultrafast Timescales ' was submitted by the Center for Energy Frontier Research in Extreme Environments (EFree) to the 'Life at the Frontiers of Energy Research' video contest at the 2011 Science for Our Nation's Energy Future: Energy Frontier Research Centers (EFRCs) Summit and Forum. Twenty-six EFRCs created short videos to highlight their mission and their work. EFree is directed by Ho-kwang Mao at the Carnegie Institute of Washington and is a partnership of scientists from thirteen institutions.The Office of Basic Energy Sciences in the U.S. Department of Energy's Office of Science established the 46 Energy Frontier Research Centers (EFRCs) in 2009. These collaboratively-organized centers conduct fundamental research focused on 'grand challenges' and use-inspired 'basic research needs' recently identified in major strategic planning efforts by the scientific community. The overall purpose is to accelerate scientific progress toward meeting the nation's critical energy challenges. The mission of Energy Frontier Research in Extreme Environments is 'to accelerate the discovery and creation of energy-relevant materials using extreme pressures and temperatures.' Research topics are: catalysis (CO{sub 2}, water), photocatalysis, solid state lighting, optics, thermelectric, phonons, thermal conductivity, solar electrodes, fuel cells, superconductivity, extreme environment, radiation effects, defects, spin dynamics, CO{sub 2} (capture, convert, store), greenhouse gas, hydrogen (fuel, storage), ultrafast physics, novel materials synthesis, and defect tolerant materials.

  15. Ultrafast dynamics of liquid water: Frequency fluctuations of the OH stretch and the HOH bend

    SciTech Connect (OSTI)

    Imoto, Sho; Xantheas, Sotiris S.; Saito, Shinji

    2013-07-28

    Frequency fluctuations of the OH stretch and the HOH bend in liquid water are reported from the third-order response function evaluated using the TTM3-F potential for water. The simulated two-dimensional infrared (IR) spectra of the OH stretch are similar to previously reported theoretical results. The present study suggests that the frequency fluctuation of the HOH bend is faster than that of the OH stretch. The ultrafast loss of the frequency correlation of the HOH bend is due to the strong couplings with the OH stretch as well as the intermolecular hydrogen bond bend.

  16. Ultrafast spectroscopy of super high frequency mechanical modes of doubly clamped beams

    SciTech Connect (OSTI)

    Ristow, Oliver; Merklein, Moritz; Grossmann, Martin; Hettich, Mike; Schubert, Martin; Bruchhausen, Axel; Scheer, Elke; Dekorsy, Thomas; Barretto, Elaine C. S.; Grebing, Jochen; Erbe, Artur; Mounier, Denis; Gusev, Vitalyi

    2013-12-02

    We use ultrafast pump-probe spectroscopy to study the mechanical vibrations in the time domain of doubly clamped silicon nitride beams. Beams with two different clamping conditions are investigated. Finite element method calculations are performed to analyse the mode spectra of both structures. By calculating the strain integral on the surface of the resonators, we are able to reproduce the effect of the detection mechanism and identify all the measured modes. We show that our spectroscopy technique combined with our modelling tools allow the investigation of several different modes in the super high frequency range (3-30?GHz) and above, bringing more information about the vibration modes of nanomechanical resonators.

  17. Ultrafast Terahertz-Induced Response of GeSbTe Phase-Change Materials

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Terahertz-Induced Response of GeSbTe Phase-Change Materials Citation Details In-Document Search Title: Ultrafast Terahertz-Induced Response of GeSbTe Phase-Change Materials × You are accessing a document from the Department of Energy's (DOE) SciTech Connect. This site is a product of DOE's Office of Scientific and Technical Information (OSTI) and is provided as a public service. Visit OSTI to utilize additional information resources in energy science and

  18. Differential ultrafast all-optical switching of the resonances of a micropillar cavity

    SciTech Connect (OSTI)

    Thyrrestrup, Henri Yce, Emre; Ctistis, Georgios; Vos, Willem L.; Claudon, Julien; Grard, Jean-Michel

    2014-09-15

    We perform frequency- and time-resolved all-optical switching of a GaAs-AlAs micropillar cavity using an ultrafast pump-probe setup. The switching is achieved by two-photon excitation of free carriers. We track the cavity resonances in time with a high frequency resolution. The pillar modes exhibit simultaneous frequency shifts, albeit with markedly different maximum switching amplitudes and relaxation dynamics. These differences stem from the non-uniformity of the free carrier density in the micropillar, and are well understood by taking into account the spatial distribution of injected free carriers, their spatial diffusion and surface recombination at micropillar sidewalls.

  19. Explosive photodissociation of methane induced by ultrafast intense laser

    SciTech Connect (OSTI)

    Kong Fanao; Luo Qi; Xu Huailiang; Sharifi, Mehdi; Song Di; Chin, See Leang

    2006-10-07

    A new type of molecular fragmentation induced by femtosecond intense laser at the intensity of 2x10{sup 14} W/cm{sup 2} is reported. For the parent molecule of methane, ethylene, n-butane, and 1-butene, fluorescence from H (n=3{yields}2), CH (A {sup 2}{delta}, B {sup 2}{sigma}{sup -}, and C {sup 2}{sigma}{sup +}{yields}X {sup 2}{pi}), or C{sub 2} (d {sup 3}{pi}{sub g}{yields}a {sup 3}{pi}{sub u}) is observed in the spectrum. It shows that the fragmentation is a universal property of neutral molecule in the intense laser field. Unlike breaking only one or two chemical bonds in conventional UV photodissociation, the fragmentation caused by the intense laser undergoes vigorous changes, breaking most of the bonds in the molecule, like an explosion. The fragments are neutral species and cannot be produced through Coulomb explosion of multiply charged ion. The laser power dependence of CH (A{yields}X) emission of methane on a log-log scale has a slope of 10{+-}1. The fragmentation is thus explained as multiple channel dissociation of the superexcited state of parent molecule, which is created by multiphoton excitation.

  20. Molecular Foundry

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

    Agenda March 24, 2016 Lawrence Berkeley National Laboratory AGENDA Registration 8:30 am - 9:00 am The Molecular Foundry's History and Impact 9:00 am - 10:30 am Jeff Neaton, Molecular Foundry Welcome Paul Alivisatos, Berkeley Lab/UC Berkeley The Creation of the Molecular Foundry Michael Witherell, Berkeley Lab Berkeley Lab Impact Brian Schowengerdt, Magic Leap Industry Impact Representative Mike Honda (D-CA) National Impact Break 10:30 am - 11:00 am Session 1: Functional Nanointerfaces 11:00 am -

  1. Molecular Foundry

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

    in 1983 to maintain a forefront research center for electron microscopy with state-of-the-art instrumentation and expertise. Merged with the Molecular Foundry in 2014 to take...

  2. Molecular Foundry

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

    Meg Holm Meg Senior Administrator mcholm@lbl.gov 510.486.5135 Biography Meg is the Molecular Foundry's Senior Administrator. In this role, she supervises the Foundry budget...

  3. Molecular Foundry

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

    Alison Hatt allison User Program Director ajhatt@lbl.gov 510.486.7154 Biography Alison Hatt is the Director of the User Program at the Molecular Foundry and a former Foundry...

  4. Molecular Foundry

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

    Gil Torres Gil Torres gjtorres@lbl.gov 510.486.4395 Biography Gil is the Building Manager for MSD in buildings 62, 66, 2, 30, JCAP and the Molecular Foundry. Gil supports Foundry...

  5. Molecular Foundry

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

    Alex Weber-Bargioni Weber-Bargioni Staff Scientist, Imaging and Manipulation of Nanostructures afweber-bargioni@lbl.gov 510.486.4026 personal website Biography Education University of Konstanz, Germany Physics B.S., 2001 Portland State University Physics M.S., 2003 University of British Columbia Physics Ph.D., 2007 Lawrence Berkeley Nat. Lab Material Science PostDoc 2008-2010 Research Interests Dr. Weber-Bargioni's research revolves around understanding fundamental opto electronic processes at

  6. Molecular Foundry

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

    Gang (Gary) Ren Ren Staff Scientist, Imaging and Manipulation of Nanostructures gren@lbl.gov 510.495.2375 personal website Biography Education B.A., Theoretical Physics, Lanzhou University, China, 1986-1990 M.S., Theoretical Physics (General relativity and gauge theory), Lanzhou University, China, 1990-1993, Advisor: Prof. Yi-shi Duan. Thesis: "Theory and Application of 2+1 Dimensional Topological Current" Ph.D. Material Physics (Electron microscopy), Univ. of Science and Technology

  7. Molecular Foundry

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

    See the Foundry's full equipment list Organic and Macromolecular Synthesis Capabilities & Tools Instrument Scheduler Major Instruments and Capabilities AB SCIEX TF4800 MALDI TOF-TOF Mass Spectrometer This instrument is the tandem time-of-flight mass spectrometer systems, providing the excellent level of molecular mass coverage in the range of molecular masses 500 and 150,000 Da, high throughput, and confidence in both qualitative and quantitative analyses. The analyzer combines all of the

  8. Molecular Foundry

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

    Molecular Foundry Advanced Materials Special Issue Advanced Materials Cover Art The multidisciplinary science that is central to the Molecular Foundry's mission is well represented throughout the October 14, 2015 special issue of Advanced Materials. In three Review articles, we highlight recent areas of particular innovation and promise at the Foundry: the development of advanced electron tomography for both hard and soft materials with near-atomic resolution, the creation of designer biomimetic

  9. Molecular Foundry

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

    Behzad Rad Rad Senior Scientific Engineering Associate, Biological Nanostructures BRad@lbl.gov 510.486.5795 Biography Education Postdoctoral Fellow Molecular Foundry Lawrence Berkeley National Labs Ph.D. in Biophysics University of California at Davis Dissertation Title: "The Unwinding Mechanism of the E. coli RecQ helicase" Dissertation Advisor: Dr. Stephen C. Kowalczykowski Bachelor's in Molecular and Cellular Biology University of California at Berkeley Expertise Behzad's interests

  10. Molecular Foundry

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

    Media and Resources MEDIA Molecular Foundry Youtube Channel Berkeley Lab Youtube Channel Berkeley Lab Photo Archive Webcam The Molecular Foundry and its users benefit from its location at Berkeley Lab within the Bay Area's vibrant scientific ecosystem. The expansive views serve to fuel the imagination and build connections among the Foundry's diverse research community. Baycam Click here for a full screen view from our webcam. RESOURCES Style Guide PDF 308 KB Logos Signature Preferred 41 KB ZIP

  11. Molecular Foundry

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

    Lab; Professor of Physics UC Berkeley 66 Auditorium 9:30 am Keynote Address The BRAIN Initiative and Nanoscience abstract Ralph Greenspan Director, Center for Brain...

  12. Capturing ultrafast photoinduced local structural distortions of BiFeO3

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

    Wen, Haidan; Sassi, Michel JPC; Luo, Zhenlin; Adamo, Carolina; Schlom, Darrell; Rosso, Kevin M.; Zhang, Xiaoyi

    2015-10-14

    The interaction of light with materials is an intensively studied research forefront, in which the coupling of radiation energy to selective degrees of freedom offers contact-free tuning of functionalities on ultrafast time scales. Capturing the fundamental processes and understanding the mechanism of photoinduced structural rearrangement are essential to applications such as photo-active actuators and efficient photovoltaic devices. Using ultrafast x-ray absorption spectroscopy aided by density functional theory calculations, we reveal the local structural arrangement around the transition metal atom in a unit cell of the photoferroelectric archetype BiFeO3 film. The out-of-plane elongation of the unit cell is accompanied by themore » in-plane shrinkage with minimal change of interaxial lattice angles upon photoexcitation. This uniaxial elastic deformation of the unit cell is driven by localized electric field as a result of photoinduced charge separation, in contrast to a global lattice constant increase and lattice angle variations as a result of heating. The finding of a photoinduced elastic unit cell deformation elucidates a microscopic picture of photocarrier-mediated nonequilibrium processes in polar materials.« less

  13. CITIUS: An infrared-extreme ultraviolet light source for fundamental and applied ultrafast science

    SciTech Connect (OSTI)

    Grazioli, C.; Gauthier, D.; Ivanov, R.; De Ninno, G.; Elettra Sincrotrone Trieste, Trieste ; Callegari, C.; Spezzani, C.; Ciavardini, A.; Coreno, M.; Institute of Inorganic Methodologies and Plasmas , Montelibretti, Roma ; Frassetto, F.; Miotti, P.; Poletto, L.; Golob, D.; Kivimäki, A.; Mahieu, B.; Service des Photons Atomes et Molécules, Commissariat à l'Energie Atomique, Centre d'Etudes de Saclay, Bâtiment 522, 91191 Gif-sur-Yvette ; Bučar, B.; Merhar, M.; Polo, E.; Ressel, B.

    2014-02-15

    We present the main features of CITIUS, a new light source for ultrafast science, generating tunable, intense, femtosecond pulses in the spectral range from infrared to extreme ultraviolet (XUV). The XUV pulses (about 10{sup 5}-10{sup 8} photons/pulse in the range 14-80 eV) are produced by laser-induced high-order harmonic generation in gas. This radiation is monochromatized by a time-preserving monochromator, also allowing one to work with high-resolution bandwidth selection. The tunable IR-UV pulses (10{sup 12}-10{sup 15} photons/pulse in the range 0.4-5.6 eV) are generated by an optical parametric amplifier, which is driven by a fraction of the same laser pulse that generates high order harmonics. The IR-UV and XUV pulses follow different optical paths and are eventually recombined on the sample for pump-probe experiments. We also present the results of two pump-probe experiments: with the first one, we fully characterized the temporal duration of harmonic pulses in the time-preserving configuration; with the second one, we demonstrated the possibility of using CITIUS for selective investigation of the ultra-fast dynamics of different elements in a magnetic compound.

  14. H.sub.2O doped WO.sub.3, ultra-fast, high-sensitivity hydrogen sensors

    DOE Patents [OSTI]

    Liu, Ping; Tracy, C. Edwin; Pitts, J. Roland; Lee, Se-Hee

    2011-03-22

    An ultra-fast response, high sensitivity structure for optical detection of low concentrations of hydrogen gas, comprising: a substrate; a water-doped WO.sub.3 layer coated on the substrate; and a palladium layer coated on the water-doped WO.sub.3 layer.

  15. Frontiers for Discovery in High Energy Density Physics

    SciTech Connect (OSTI)

    Davidson, R. C.; Katsouleas, T.; Arons, J.; Baring, M.; Deeney, C.; Di Mauro, L.; Ditmire, T.; Falcone, R.; Hammer, D.; Hill, W.; Jacak, B.; Joshi, C.; Lamb, F.; Lee, R.; Logan, B. G.; Melissinos, A.; Meyerhofer, D.; Mori, W.; Murnane, M.; Remington, B.; Rosner, R.; Schneider, D.; Silvera, I.; Stone, J.; Wilde, B.; Zajc. W.

    2004-07-20

    The report is intended to identify the compelling research opportunities of high intellectual value in high energy density physics. The opportunities for discovery include the broad scope of this highly interdisciplinary field that spans a wide range of physics areas including plasma physics, laser and particle beam physics, nuclear physics, astrophysics, atomic and molecular physics, materials science and condensed matter physics, intense radiation-matter interaction physics, fluid dynamics, and magnetohydrodynamics

  16. Charge exchange molecular ion source

    DOE Patents [OSTI]

    Vella, Michael C.

    2003-06-03

    Ions, particularly molecular ions with multiple dopant nucleons per ion, are produced by charge exchange. An ion source contains a minimum of two regions separated by a physical barrier and utilizes charge exchange to enhance production of a desired ion species. The essential elements are a plasma chamber for production of ions of a first species, a physical separator, and a charge transfer chamber where ions of the first species from the plasma chamber undergo charge exchange or transfer with the reactant atom or molecules to produce ions of a second species. Molecular ions may be produced which are useful for ion implantation.

  17. Molecular fountain.

    SciTech Connect (OSTI)

    Strecker, Kevin E.; Chandler, David W.

    2009-09-01

    A molecular fountain directs slowly moving molecules against gravity to further slow them to translational energies that they can be trapped and studied. If the molecules are initially slow enough they will return some time later to the position from which they were launched. Because this round trip time can be on the order of a second a single molecule can be observed for times sufficient to perform Hz level spectroscopy. The goal of this LDRD proposal was to construct a novel Molecular Fountain apparatus capable of producing dilute samples of molecules at near zero temperatures in well-defined user-selectable, quantum states. The slowly moving molecules used in this research are produced by the previously developed Kinematic Cooling technique, which uses a crossed atomic and molecular beam apparatus to generate single rotational level molecular samples moving slowly in the laboratory reference frame. The Kinematic Cooling technique produces cold molecules from a supersonic molecular beam via single collisions with a supersonic atomic beam. A single collision of an atom with a molecule occurring at the correct energy and relative velocity can cause a small fraction of the molecules to move very slowly vertically against gravity in the laboratory. These slowly moving molecules are captured by an electrostatic hexapole guiding field that both orients and focuses the molecules. The molecules are focused into the ionization region of a time-of-flight mass spectrometer and are ionized by laser radiation. The new molecular fountain apparatus was built utilizing a new design for molecular beam apparatus that has allowed us to miniaturize the apparatus. This new design minimizes the volumes and surface area of the machine allowing smaller pumps to maintain the necessary background pressures needed for these experiments.

  18. Ultrafast dynamics of strong-field dissociative ionization ofCH2Br2 probed by femtosecond soft x-ray transient absorptionspectroscopy

    SciTech Connect (OSTI)

    Loh, Zhi-Heng; Leone, Stephen R.

    2008-01-15

    Femtosecond time-resolved soft x-ray transient absorption spectroscopy based on a high-order harmonic generation source is used to investigate the dissociative ionization of CH{sub 2}Br{sub 2} induced by 800 nm strong-field irradiation. At moderate peak intensities (2.0 x 10{sup 14} W/cm{sup 2}), strong-field ionization is accompanied by ultrafast C-Br bond dissociation, producing both neutral Br ({sup 2}P{sub 3/2}) and Br* ({sup 2}P{sub 1/2}) atoms together with the CH{sub 2}Br{sup +} fragment ion. The measured rise times for Br and Br* are 130 {+-} 22 fs and 74 {+-} 10 fs, respectively. The atomic bromine quantum state distribution shows that the Br/Br* population ratio is 8.1 {+-} 3.8 and that the Br {sup 2}P{sub 3/2} state is not aligned. The observed product distribution and the timescales of the photofragment appearances suggest that multiple field-dressed potential energy surfaces are involved in the dissociative ionization process. In addition, the transient absorption spectrum of CH{sub 2}Br{sub 2}{sup +} suggests that the alignment of the molecule relative to the polarization axis of the strong-field ionizing pulse determines the electronic symmetry of the resulting ion; alignment of the Br-Br, H-H, and C{sub 2} axis of the molecule along the polarization axis results in the production of the ion {tilde X}({sup 2}B{sub 2}), {tilde B}({sup 2}B{sub 1}) and {tilde C}({sup 2}A{sub 1}) states, respectively. At higher peak intensities (6.2 x 10{sup 14} W/cm{sup 2}), CH{sub 2}Br{sub 2}{sup +} undergoes sequential ionization to form the metastable CH{sub 2}Br{sub 2}{sup 2+} dication. These results demonstrate the potential of core-level probing with high-order harmonic transient absorption spectroscopy for studying ultrafast molecular dynamics.

  19. Planetary Physics

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

    Planetary Physics Some of the most intriguing NIF experiments test the physics believed to determine the structures of planets down to their cores, both in our solar system and ...

  20. Interface-assisted molecular spintronics

    SciTech Connect (OSTI)

    Raman, Karthik V.

    2014-09-15

    Molecular spintronics, a field that utilizes the spin state of organic molecules to develop magneto-electronic devices, has shown an enormous scientific activity for more than a decade. But, in the last couple of years, new insights in understanding the fundamental phenomena of molecular interaction on magnetic surfaces, forming a hybrid interface, are presenting a new pathway for developing the subfield of interface-assisted molecular spintronics. The recent exploration of such hybrid interfaces involving carbon based aromatic molecules shows a significant excitement and promise over the previously studied single molecular magnets. In the above new scenario, hybridization of the molecular orbitals with the spin-polarized bands of the surface creates new interface states with unique electronic and magnetic character. This study opens up a molecular-genome initiative in designing new handles to functionalize the spin dependent electronic properties of the hybrid interface to construct spin-functional tailor-made devices. Through this article, we review this subject by presenting a fundamental understanding of the interface spin-chemistry and spin-physics by taking support of advanced computational and spectroscopy tools to investigate molecular spin responses with demonstration of new interface phenomena. Spin-polarized scanning tunneling spectroscopy is favorably considered to be an important tool to investigate these hybrid interfaces with intra-molecular spatial resolution. Finally, by addressing some of the recent findings, we propose novel device schemes towards building interface tailored molecular spintronic devices for applications in sensor, memory, and quantum computing.

  1. Effective Analysis of NGS Metagenomic Data with Ultra-Fast Clustering Algorithms (MICW - Metagenomics Informatics Challenges Workshop: 10K Genomes at a Time)

    ScienceCinema (OSTI)

    Li, Weizhong [San Diego Supercomputer Center

    2013-01-22

    San Diego Supercomputer Center's Weizhong Li on "Effective Analysis of NGS Metagenomic Data with Ultra-fast Clustering Algorithms" at the Metagenomics Informatics Challenges Workshop held at the DOE JGI on October 12-13, 2011.

  2. Molecular Foundry

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

    P. James Schuck Schuck Facility Director, Imaging and Manipulation of Nanostructures PJSchuck@lbl.gov 510.486.4822 personal website Biography Education Stanford University, Postdoctoral Fellow, Department of Chemistry, Advisor: W. E. Moerner, 2003-2006 Yale University, Ph.D., Department of Applied Physics, Advisor: R. D. Grober, Dissertation titled "Three-Dimensional Imaging Spectroscopy of the III-Nitride Material System", 2003 Yale University, M.S., Department of Applied Physics,

  3. Molecular Foundry

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

    Peter Ercius Staff Scientist, NCEM percius@lbl.gov 510.486.4634 Biography Peter Ercius graduated from Cornell University with a B.S. in applied and engineering physics in 2003. He remained at Cornell and completed a Ph.D. in applied and engineering physics with Professor David Muller in 2009. His dissertation project involved three-dimensional imaging of semiconductor devices using STEM. He then joined NCEM as a collaborative postdoctoral researcher for 2 years to implement electron tomography

  4. Ultrafast Control of Magnetism in Ferromagnetic Semiconductors via Photoexcited Transient Carriers

    SciTech Connect (OSTI)

    Cotoros, Ingrid A.

    2008-12-12

    The field of spintronics offers perspectives for seamless integration of coupled and inter-tunable electrical and magnetic properties in a single device. For integration of the spin degree of freedom with current electronic technology, new semiconductors are needed that show electrically-tunable magnetic properties at room temperature and above. Dilute magnetic semiconductors derived from III-V compounds, like GaMnAs and InMnAs, show coupled and tunable magnetic, transport, and optical properties, due to the fact that their ferromagnetism is hole-mediated. These unconventional materials are ideal systems for manipulating the magnetic order by changing the carrier polarization, population density, and energy band distribution of the complementary subsystem of holes. This is the main theme we cover in this thesis. In particular, we develop a unique setup by use of ultraviolet pump, near-infrared probe femtosecond laser pulses, that allows for magneto-optical Kerr effect (MOKE) spectroscopy experiments. We photo-excite transient carriers in our samples, and measure the induced transient magnetization dynamics. One set of experiments performed allowed us to observe for the first time enhancement of the ferromagnetic order in GaMnAs, on an ultrafast time scale of hundreds of picoseconds. The corresponding transient increase of Curie temperature (Tc, the temperature above which a ferromagnetic material loses its permanent magnetism) of about 1 K for our experimental conditions is a very promising result for potential spintronics applications, especially since it is seconded by observation of an ultrafast ferromagnetic to paramagnetic phase transition above Tc. In a different set of experiments, we"write" the magnetization in a particular orientation in the sample plane. Using an ultrafast scheme, we alter the distribution of holes in the system and detect signatures of the particular memory state in the subsequent magnetization dynamics, with unprecedented hundreds of femtosecond detection speed. The femtosecond cooperative magnetic phenomena presented here further our understanding of Mn-hole correlations in III-V dilute magnetic semiconductors, and may well represent universal principles of a large class of carrier-mediated ferromagnetic materials. Thus they offer perspectives for future terahertz (1012 Hz) speed"spintronic" functional devices.

  5. Molecular Foundry

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

    Liana Klivansky Klivansky Principal Scientific Engineering Associate, Organic and Macromolecular Synthesis LMKlivansky@lbl.gov 510.486.4199 Biography Education B.Sc.(HONS) Chemistry, Monash University, Victoria, Australia, 1990 Previous Professional Positions Principal Scientific Engineering Associate, Molecular Foundry, Lawrence Berkeley National Laboratory, 2006 - present Research Associate, Chiron Corp. Emeryville, CA, 1998 - 2006 Research Associate, Chiron Mimotopes, Victoria, Australia,

  6. Graphene nanoribbon molecular sensor based on inelastic transport...

    Office of Scientific and Technical Information (OSTI)

    Citation Details In-Document Search Title: Graphene nanoribbon molecular sensor based on ... School of Physics, Trinity College Dublin, Dublin 2 (Ireland) Instituto de Fsica, ...

  7. Theoretical Physics

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

    HEP Theoretical Physics Understanding discoveries at the Energy, Intensity, and Cosmic Frontiers Get Expertise Rajan Gupta (505) 667-7664 Email Bruce Carlsten (505) 667-5657 Email HEP Theory at Los Alamos The Theoretical High Energy Physics group at Los Alamos National Laboratory is active in a number of diverse areas of research. Their primary areas of interest are in physics beyond the Standard Model, cosmology, dark matter, lattice quantum chromodynamics, neutrinos, the fundamentals of

  8. Nuclear Physics

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

    Nuclear Physics /science-innovation/_assets/images/icon-science.jpg Nuclear Physics Enabling remarkable discoveries and tools that transform our understanding of energy and matter and advance national, economic, and energy security. Isotopes» A roadmap of matter that will help unlock the secrets of how the universe is put together The DOE Office of Science's Nuclear Physics (NP) program supports the experimental and theoretical research needed to create this roadmap. This quest requires a broad

  9. Efficient terahertz-wave generation and its ultrafast optical modulation in charge ordered organic ferroelectrics

    SciTech Connect (OSTI)

    Itoh, Hirotake Iwai, Shinichiro; Itoh, Keisuke; Goto, Kazuki; Yamamoto, Kaoru; Yakushi, Kyuya

    2014-04-28

    Efficient terahertz (THz) wave generation in strongly correlated organic compounds ?-(ET){sub 2}I{sub 3} and ??-(ET){sub 2}IBr{sub 2} (ET:bis(ethylenedithio)-tetrathiafulvalene) was demonstrated. The spontaneous polarization induced by charge ordering or electronic ferroelectricity was revealed to trigger the THz-wave generation via optical rectification; the estimated 2nd-order nonlinear optical susceptibility for ?-(ET){sub 2}I{sub 3} is over 70 times larger than that for prototypical THz-source ZnTe. Ultrafast (<1 ps) and sensitive (?40%) photoresponse of the THz wave was observed for ?-(ET){sub 2}I{sub 3}, which is attributable to photoinduced quenching of the polarization accompanied by insulator(ferroelectric)-to-metal transition. Modulation of the THz wave was observed for ??-(ET){sub 2}IBr{sub 2} upon the poling procedure, indicating the alignment of polar domains.

  10. Terahertz Spectroscopy of Low-Dimensional Nanomaterials: Nonlinear Emission and Ultrafast Electrodynamics

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

    Luo, Liang; Wang, Jigang

    2016-01-01

    Nonlinear and non-equilibrium properties of low-dimensional quantum materials are fundamental in nanoscale science yet transformative in nonlinear imaging/photonic technology today. These have been poorly addressed in many nano-materials despite of their well-established equilibrium optical and transport properties. The development of ultrafast terahertz (THz) sources and nonlinear spectroscopy tools facilitates understanding these issues and reveals a wide range of novel nonlinear and quantum phenomena that are not expected in bulk solids or atoms. In this paper, we discuss our recent discoveries in two model photonic and electronic nanostructures to solve two outstanding questions: (1) how to create nonlinear broadband terahertz emittersmore » using deeply subwavelength nanoscale meta-atom resonators? (2) How to access one-dimensional (1D) dark excitons and their non-equilibrium correlated states in single-walled carbon nanotubes (SWMTs)?« less

  11. 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

  12. Ultrafast carrier dynamics in the large-magnetoresistance material WTe2

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

    Dai, Y. M.; Bowlan, J.; Li, H.; Miao, H.; Wu, S. F.; Kong, W. D.; Shi, Y. G.; Trugman, S. A.; Zhu, J. -X.; Ding, H.; et al

    2015-10-07

    In this study, ultrafast optical pump-probe spectroscopy is used to track carrier dynamics in the large-magnetoresistance material WTe2. Our experiments reveal a fast relaxation process occurring on a subpicosecond time scale that is caused by electron-phonon thermalization, allowing us to extract the electron-phonon coupling constant. An additional slower relaxation process, occurring on a time scale of ~5–15 ps, is attributed to phonon-assisted electron-hole recombination. As the temperature decreases from 300 K, the time scale governing this process increases due to the reduction of the phonon population. However, below ~50 K, an unusual decrease of the recombination time sets in, mostmore » likely due to a change in the electronic structure that has been linked to the large magnetoresistance observed in this material.« less

  13. Ultrafast dynamics of type-II GaSb/GaAs quantum dots

    SciTech Connect (OSTI)

    Komolibus, K.; Piwonski, T.; Gradkowski, K.; Reyner, C. J.; Liang, B.; Huffaker, D. L.; Huyet, G.; Houlihan, J.

    2015-01-19

    In this paper, room temperature two-colour pump-probe spectroscopy is employed to study ultrafast carrier dynamics in type-II GaSb/GaAs quantum dots. Our results demonstrate a strong dependency of carrier capture/escape processes on applied reverse bias voltage, probing wavelength and number of injected carriers. The extracted timescales as a function of both forward and reverse bias may provide important information for the design of efficient solar cells and quantum dot memories based on this material. The first few picoseconds of the dynamics reveal a complex behaviour with an interesting feature, which does not appear in devices based on type-I materials, and hence is linked to the unique carrier capture/escape processes possible in type-II structures.

  14. Terahertz Spectroscopy of Low-Dimensional Nanomaterials: Nonlinear Emission and Ultrafast Electrodynamics

    SciTech Connect (OSTI)

    Luo, Liang; Wang, Jigang

    2016-01-01

    Nonlinear and non-equilibrium properties of low-dimensional quantum materials are fundamental in nanoscale science yet transformative in nonlinear imaging/photonic technology today. These have been poorly addressed in many nano-materials despite of their well-established equilibrium optical and transport properties. The development of ultrafast terahertz (THz) sources and nonlinear spectroscopy tools facilitates understanding these issues and reveals a wide range of novel nonlinear and quantum phenomena that are not expected in bulk solids or atoms. In this paper, we discuss our recent discoveries in two model photonic and electronic nanostructures to solve two outstanding questions: (1) how to create nonlinear broadband terahertz emitters using deeply subwavelength nanoscale meta-atom resonators? (2) How to access one-dimensional (1D) dark excitons and their non-equilibrium correlated states in single-walled carbon nanotubes (SWMTs)?

  15. 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.

  16. Ultrafast terahertz-induced response of GeSbTe phase-change materials

    SciTech Connect (OSTI)

    Shu, Michael J.; Zalden, Peter; Chen, Frank; Weems, Ben; Chatzakis, Ioannis; Xiong, Feng; Jeyasingh, Rakesh; Pop, Eric; Philip Wong, H.-S.; Hoffmann, Matthias C.; Wuttig, Matthias; Lindenberg, Aaron M.

    2014-06-23

    The time-resolved ultrafast electric field-driven response of crystalline and amorphous GeSbTe films has been measured all-optically, pumping with single-cycle terahertz pulses as a means of biasing phase-change materials on a sub-picosecond time-scale. Utilizing the near-band-gap transmission as a probe of the electronic and structural response below the switching threshold, we observe a field-induced heating of the carrier system and resolve the picosecond-time-scale energy relaxation processes and their dependence on the sample annealing condition in the crystalline phase. In the amorphous phase, an instantaneous electroabsorption response is observed, quadratic in the terahertz field, followed by field-driven lattice heating, with Ohmic behavior up to 200 kV/cm.

  17. Physical Sciences

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

    and the universe around us. Physics Division researchers are studying these interactions from the outermost reaches of the cosmos, to the innermost confines of subatomic particles....

  18. physical security

    National Nuclear Security Administration (NNSA)

    5%2A en Physical Security Systems http:nnsa.energy.govaboutusourprogramsnuclearsecurityphysicalsecuritysystems

  19. Theoretical Physics

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

    Their primary areas of interest are in physics beyond the Standard Model, cosmology, dark matter, lattice quantum chromodynamics, neutrinos, the fundamentals of quantum field ...

  20. Production of high molecular weight polylactic acid

    DOE Patents [OSTI]

    Bonsignore, P.V.

    1995-11-28

    A degradable high molecular weight poly(lactic acid) is described. The poly(lactic acid) has a terminal end group of one of carboxyl or hydroxyl groups with low molecular weight poly(lactic acid) units coupled with linking agents of di-isocyanates, bis-epoxides, bis-oxazolines and bis-ortho esters. The resulting high molecular weight poly(lactic acid) can be used for applications taking advantage of the improved physical properties.

  1. Production of high molecular weight polylactic acid

    DOE Patents [OSTI]

    Bonsignore, Patrick V.

    1995-01-01

    A degradable high molecular weight poly(lactic acid). A poly(lactic acid) has a terminal end group of one of carboxyl or hydroxyl groups with low molecular weight poly(lactic acid) units coupled with linking agents of di-isocyanates, bis-epoxides, bis-oxazolines and bis-ortho esters. The resulting high molecular weight poly(lactic acid) can be used for applications taking advantage of the improved physical properties.

  2. Molecular Foundry

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

    See the Foundry's full equipment list Nanofabrication Capabilities & Tools Instrument Scheduler Major Capabilities: Instruments and Labs Zeiss Crossbeam 1540 EsB The Molecular Foundry Zeiss Cross-beam is one of the most versatile lithographic and inspection tools allowing fabrication of complex prototypes for nanoelectronics, nano-optical antenna, modifying scanning probe tips, rapid electrical contacting and many other applications. The 1500XB Cross Beam combines the Gemini field emission

  3. Molecular Foundry

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

    Branden Brough Branden Director of Strategy and External Relations bbrough@lbl.gov 510.486.4206 Biography Branden Brough is the Molecular Foundry's Director of Strategy and External Relations. In this role, Dr. Brough is responsible for the organization's strategic planning and management. He also facilitates internal and external communications to promote the Foundry's mission and showcase its accomplishments to the DOE, the nanoscience research community and the public. Before joining the

  4. Molecular Foundry

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

    Emory Chan Brand Staff Scientist, Inorganic Nanostructures EMChan@lbl.gov 510.486.7874 personal website Biography Education Postdoctoral fellow, Molecular Foundry with Dr. Delia Milliron Ph. D., Chemistry, UC Berkeley with Prof. Paul Alivisatos and Prof. Richard Mathies, B. S., Chemistry, Stanford University with Prof. Hongjie Dai Expertise Dr. Chan's expertise lies in the combinatorial and high-throughput synthesis of colloidal inorganic nanoparticles. As part of the Foundry's Combinatorial

  5. Molecular Foundry

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

    Rita Garcia Brand Principal Research Associate, Biological Nanostructures Facility RLGarcia@lbl.gov 510.486.4125 Biography Education B.A. Molecular Biology, Scripps College, Claremont, CA, 2005 Previous Professional Positions Principal Research Associate, Lawrence Berkeley National Lab, Berkeley, CA, May 2009 - present Office Manager, Microsoft, San Francisco, CA, August 2008 - December 2008 Office Manager, Powerset, Inc., San Francisco, CA, January 2007 - July 2008 Post-Baccalaureate Intramural

  6. Molecular Foundry

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

    Tracy Mattox TMMattox Senior Scientific Engineering Associate, Inorganic Nanostructures TMMattox@lbl.gov 510.495.2649 Biography Education M.S. in Chemistry, Miami University, 2006 B.S. in Chemistry, University of Portland, 2003 Tracy Mattox has been a member of the Inorganic Facility at the Molecular Foundry as a Scientific Engineering Associate since 2007. Expertise Tracy's main focus is assisting users with their research projects (helping design reactions and analyze results). She is well

  7. Molecular Foundry

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

    User Guide Download the complete Users' Guide (PDF) Submit a Proposal Learn about the Molecular Foundry and its user program Explore Foundry capabilities and plan your proposal Prepare responses to proposal questions Create and submit your proposal through the online proposal portal After your proposal is approved* Complete secondary safety screening Become a badged LBNL "affiliate" Contact your assigned Foundry scientist When you arrive* Go to your appointment with the Affiliate

  8. Molecular Foundry

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

    Molecular Foundry User Policies and Definitions Download the complete User Policies and Definitions (PDF) Guiding principles Safety Costs 50/50 staff time model User proposal types Proposal questions and evaluation criteria Proposal Review Board (PRB) and review process User agreements with Berkeley Lab Access to other user facilities at LBNL Final project report Publications and acknowledgement User feedback and end-of-project survey Users' Executive Committee (UEC) Scientific Advisory Board

  9. Molecular Foundry

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

    and Dinner On March 24, 2016, the Molecular Foundry celebrated the 10th anniversary of the dedication of its iconic building with a full day scientific symposium and dinner event. This celebration recognized the Foundry's major scientific and operational milestones and looked forward to the promising future of nanoscience. Leaders from Congress, DOE, academia, industry, and Berkeley Lab joined prominent Foundry users and staff, both past and present, to participate in this celebration.

  10. Browse by Discipline -- E-print Network Subject Pathways: Physics...

    Office of Scientific and Technical Information (OSTI)

    ... Mesquita Alencar) - Departamento de Fsica Geral, Universidade de So Paulo ... Academia Sinica, Institute of Atomic and Molecular Sciences, High-Field Physics and ...

  11. Molecular Foundry

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

    SEMINARS ARCHIVE The Molecular Foundry regularly offers seminars and events that feature compelling research and information for those who investigate at the nanoscale. Seminars occur on Tuesdays at 11:00 am, in Building 67, Room 3111 unless otherwise noted. < seminars and events Tuesday, May 10, 2016 at 11am On the Optical and Magnetic Properties of Ln3+ Based Nanoparticles for Bio-Imaging Frank van Veggel, University of Victoria [MORE] Tuesday, May 3, 2016 at 11am On the Nature of

  12. Molecular Foundry

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

    Caroline M. Ajo-Franklin Ajo-Franklin Staff Scientist, Biological Nanostructures cajo-franklin@lbl.gov 510.486.4299 personal website Biography Dr. Ajo-Franklin has been a Staff Scientist at the Molecular Foundry since 2007. Before that, she received her Ph.D. in Chemistry from Stanford University with Prof. Steve Boxer and was a post-doctoral fellow with Prof. Pam Silver in the Department of Systems Biology at Harvard Medical School. Dr. Ajo-Franklin is fascinated by the incredible, diverse

  13. Physical Scientist

    Broader source: Energy.gov [DOE]

    The Office of Science is the single largest supporter of basic research in the physical sciences in the United States, providing more than 40 percent of total funding for this vital area of...

  14. Molecular Foundry

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

    Adam Schwartzberg SSchwartzberg Staff Engineer, Nanofabrication AMSchwartzberg@lbl.gov 831.247.4932 Biography Dr. Schwartzberg is a Bay Area and California native, growing up in the East Bay Area. He performed both his undergraduate and Ph.D. work at UC Santa Cruz under Professor Jin Z. Zhang in Physical Chemistry. While at Santa Cruz, he also worked at Lawrence Livermore National Labs as a graduate research fellow under Professor Thomas Huser. In graduate school, his work focused on metal

  15. Molecular Foundry

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

    Christian Kisielowski Staff Scientist, NCEM cfkisielowski@lbl.gov 510.486.4716 Biography Christian Kisielowski was awarded his PhD in natural sciences and his habilitation in physics performing spectroscopic studies on defects in semiconductors at the University of Cologne, Germany in 1985 and 1990, respectively. Thereafter, he joined AT&T Bell Laboratories (1991 - 1994) where he established a new quantitative method for image analyses in high resolution electron microscopy (QUANTITEM). From

  16. Molecular Foundry

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

    Colin Ophus Project Scientist, NCEM clophus@lbl.gov 510.486.5663 Biography Colin Ophus received his PhD in Materials Engineering from the University of Alberta in Canada. There he studied the growth of polycrystalline and amorphous metal thin films with deposition experiments and simulations. He has used microfabrication techniques including physical and chemical vapor deposition, chemical etching, and optical and electron beam lithography. He is also proficient in analysis techniques including

  17. Molecular Foundry

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

    D. Frank Ogletree Ogletree Staff Engineer, Imaging and Manipulation of Nanostructures dfogletree@lbl.gov 510.486.4862 Biography Education Postdoctoral Research Fellow with Miquel Salmeron developing ultra-high vacuum scanning tunneling microscopy in the Materials and Chemical Sciences Division, Lawrence Berkeley Laboratory, 1987 - 1988. Ph.D. in Experimental Solid State Physics, 1986, University of California, Berkeley, California. Thesis title: "Extending the Range of Low Energy Electron

  18. Molecular Foundry

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

    Shaul Aloni Svec Staff Engineer, Inorganic Nanostructures/Imaging and Manipulation of Nanostructures saloni@lbl.gov 510.486.7452 Biography Education 2001 Weizmann Institute of Science, Rechovot, Israel Ph.D. in Chemical Physics, Awarded Finberg prize for outstanding graduate research 1995 Ben-Gurion University of the Negev, Beer-Sheva, Israel M. Sc. in Materials Science and Engineering, Summa Cum Laude 1992 Ben-Gurion University of the Negev, Beer-Sheva, Israel B. Sc. in Materials Science and

  19. Molecular Foundry

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

    Stefano Cabrini Stefano Cabrini Facility Director, Nanofabrication scabrini@lbl.gov 510.486.7339 Biography Education Ph.D. in PHYSICS (Laurea degree), University of Rome "La Sapienza", Thesis entitled: "Theoretical - numerical analysis of Free Electron Laser systems operating in saturation regime." Advisors: Prof. F. De Martini - Univ of Rome; Dr G. Dattoli, Dr E. Sabia - C.R.E. ENEA Frascati (Rome) Past Professional Positions 2003 - 2006. Senior Scientist (Primo ricercatore)

  20. Molecular Foundry

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

    Stephen Whitelam Whitelam Staff Scientist, Theory of Nanostructured Materials swhitelam@lbl.gov 510.495.2769 personal website Biography Steve Whitelam got his Ph.D. in theoretical physics in 2004 from Oxford University, where he used statistical mechanics to study the dynamics of model glass-forming liquids. He was supervised by Juan P. Garrahan and David Sherrington. From 2004 - 2007 he did a postdoc with Phillip Geissler at UC Berkeley, using theory and simulation to study protein complex

  1. Plasma Physics

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

    Plasma Physics Almost all of the observable matter in the universe is in the plasma state. Formed at high temperatures, plasmas consist of freely moving ions and free electrons. They are often called the "fourth state of matter" because their unique physical properties distinguish them from solids, liquids and gases. Plasma densities and temperatures vary widely, from the cold gases of interstellar space to the extraordinarily hot, dense cores of stars and inside a detonating nuclear

  2. Committee on Atomic, Molecular and Optical Sciences

    SciTech Connect (OSTI)

    Lancaster, James

    2015-06-30

    The Committee on Atomic, Molecular, and Optical Sciences (CAMOS) is a standing activity of the National Research Council (NRC) that operates under the auspices of the Board on Physics and Astronomy. CAMOS is one of five standing committees of the BPA that are charged with assisting it in achieving its goals—monitoring the health of physics and astronomy, identifying important new developments at the scientific forefronts, fostering interactions with other fields, strengthening connections to technology, facilitating effective service to the nation, and enhancing education in physics. CAMOS provides these capabilities for the atomic, molecular and optical (AMO) sciences.

  3. Flavor Physics

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

    Flavor Physics and CP Violation Conference, Bled, 2007 1 The Search for ν µ → ν e Oscillations at MiniBooNE H. A. Tanaka, for the MiniBooNE collaboration Department of Physics, Joseph Henry Laboratories, Princeton University, Princeton, New Jersey, 08544 United States of America MiniBooNE (Mini Booster Neutrino Experiment) searches for the ν µ → ν e oscillations with ∆m 2 ∼ 1 eV 2 /c 4 indicated by the LSND experiment. The LSND evidence, when taken with the solar and atmospheric

  4. Teaching symmetry in the introductory physics curriculum

    SciTech Connect (OSTI)

    Hill, C. T.; Lederman, L. M.

    2000-01-01

    Modern physics is largely defined by fundamental symmetry principles and Noether's Theorem. Yet these are not taught, or rarely mentioned, to beginning students, thus missing an opportunity to reveal that the subject of physics is as lively and contemporary as molecular biology, and as beautiful as the arts. We prescribe a symmetry module to insert into the curriculum, of a week's length.

  5. Surface modified CFx cathode material for ultrafast discharge and high energy density

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

    Dai, Yang; Zhu, Yimei; Cai, Sendan; Wu, Lijun; Yang, Weijing; Xie, Jingying; Wen, Wen; Zheng, Jin-Cheng; Zheng, Yi

    2014-11-10

    Li/CFx primary possesses the highest energy density of 2180 W h kg⁻¹ among all primary lithium batteries. However, a key limitation for the utility of this type of battery is in its poor rate capability because the cathode material, CFx, is an intrinsically poor electronic conductor. Here, we report on our development of a controlled process of surface de-fluorination under mild hydrothermal conditions to modify the highly fluorinated CFx. The modified CFx, consisting of an in situ generated shell component of F-graphene layers, possesses good electronic conductivity and removes the transporting barrier for lithium ions, yielding a high-capacity performance andmore » an excellent rate-capability. Indeed, a capacity of 500 mA h g⁻¹ and a maximum power density of 44 800 W kg⁻¹ can be realized at the ultrafast rate of 30 C (24 A g⁻¹), which is over one order of magnitude higher than that of the state-of-the-art primary lithium-ion batteries.« less

  6. Surface modified CFx cathode material for ultrafast discharge and high energy density

    SciTech Connect (OSTI)

    Dai, Yang; Zhu, Yimei; Cai, Sendan; Wu, Lijun; Yang, Weijing; Xie, Jingying; Wen, Wen; Zheng, Jin-Cheng; Zheng, Yi

    2014-11-10

    Li/CFx primary possesses the highest energy density of 2180 W h kg⁻¹ among all primary lithium batteries. However, a key limitation for the utility of this type of battery is in its poor rate capability because the cathode material, CFx, is an intrinsically poor electronic conductor. Here, we report on our development of a controlled process of surface de-fluorination under mild hydrothermal conditions to modify the highly fluorinated CFx. The modified CFx, consisting of an in situ generated shell component of F-graphene layers, possesses good electronic conductivity and removes the transporting barrier for lithium ions, yielding a high-capacity performance and an excellent rate-capability. Indeed, a capacity of 500 mA h g⁻¹ and a maximum power density of 44 800 W kg⁻¹ can be realized at the ultrafast rate of 30 C (24 A g⁻¹), which is over one order of magnitude higher than that of the state-of-the-art primary lithium-ion batteries.

  7. Ultrafast nanolaser device for detecting cancer in a single live cell.

    SciTech Connect (OSTI)

    Gourley, Paul Lee; McDonald, Anthony Eugene

    2007-11-01

    Emerging BioMicroNanotechnologies have the potential to provide accurate, realtime, high throughput screening of live tumor cells without invasive chemical reagents when coupled with ultrafast laser methods. These optically based methods are critical to advancing early detection, diagnosis, and treatment of disease. The first year goals of this project are to develop a laser-based imaging system integrated with an in- vitro, live-cell, micro-culture to study mammalian cells under controlled conditions. In the second year, the system will be used to elucidate the morphology and distribution of mitochondria in the normal cell respiration state and in the disease state for normal and disease states of the cell. In this work we designed and built an in-vitro, live-cell culture microsystem to study mammalian cells under controlled conditions of pH, temp, CO2, Ox, humidity, on engineered material surfaces. We demonstrated viability of cell culture in the microsystem by showing that cells retain healthy growth rates, exhibit normal morphology, and grow to confluence without blebbing or other adverse influences of the material surfaces. We also demonstrated the feasibility of integrating the culture microsystem with laser-imaging and performed nanolaser flow spectrocytometry to carry out analysis of the cells isolated mitochondria.

  8. Physical Protection

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2009-07-23

    This Manual establishes requirements for the physical protection of interests under the U.S. Department of Energys (DOEs) purview ranging from facilities, buildings, Government property, and employees to national security interests such as classified information, special nuclear material (SNM), and nuclear weapons. Cancels Section A of DOE M 470.4-2 Chg 1. Canceled by DOE O 473.3.

  9. Molecular separation method and apparatus

    DOE Patents [OSTI]

    Villa-Aleman, Eliel

    1996-01-01

    A method and apparatus for separating a gaseous mixture of chemically identical but physically different molecules based on their polarities. The gaseous mixture of molecules is introduced in discrete quantities into the proximal end of a porous glass molecular. The molecular sieve is exposed to microwaves to excite the molecules to a higher energy state from a lower energy state, those having a higher dipole moment being excited more than those with a lower energy state. The temperature of the sieve kept cold by a flow of liquid nitrogen through a cooling jacket so that the heat generated by the molecules colliding with the material is transferred away from the material. The molecules thus alternate between a higher energy state and a lower one, with the portion of molecules having the higher dipole moment favored over the others. The former portion can then be extracted separately from the distal end of the molecular sieve.

  10. Molecular separation method and apparatus

    DOE Patents [OSTI]

    Villa-Aleman, E.

    1996-04-09

    A method and apparatus are disclosed for separating a gaseous mixture of chemically identical but physically different molecules based on their polarities. The gaseous mixture of molecules is introduced in discrete quantities into the proximal end of a porous glass molecular sieve. The molecular sieve is exposed to microwaves to excite the molecules to a higher energy state from a lower energy state, those having a higher dipole moment being excited more than those with a lower energy state. The temperature of the sieve kept cold by a flow of liquid nitrogen through a cooling jacket so that the heat generated by the molecules colliding with the material is transferred away from the material. The molecules thus alternate between a higher energy state and a lower one, with the portion of molecules having the higher dipole moment favored over the others. The former portion can then be extracted separately from the distal end of the molecular sieve. 2 figs.

  11. Capturing Molecular Motion with Relativistic Electrons | U.S...

    Office of Science (SC) Website

    This results demonstrate a temporal resolution sufficient to directly image chemical ... This new instrument will be used to image the ultrafast evolution of chemical reactions ...

  12. 2012 ATOMIC AND MOLECULAR INTERACTIONS GORDON RESEARCH CONFERENCE AND GORDON RESEARCH SEMINAR, JULY 15-20, 2012

    SciTech Connect (OSTI)

    Zwier, Timothy

    2012-07-20

    At the 2012 Atomic and Molecular Interactions Gordon Conference, there will be talks in several broadly defined and partially overlapping areas: ? Intramolecular and single-collision reaction dynamics; ? Photophysics and photochemistry of excited states; ? Clusters, aerosols and solvation; ? Interactions at interfaces; ? Conformations and folding of large molecules; ? Interactions under extreme conditions of temperature and pressure. The theme of the Gordon Research Seminar on Atomic & Molecular Interactions, in keeping with the tradition of the Atomic and Molecular Interactions Gordon Research Conference, is far-reaching and involves fundamental research in the gas and condensed phases along with application of these ideas to practical chemical fields. The oral presentations, which will contain a combination of both experiment and theory, will focus on four broad categories: ? Ultrafast Phenomena; ? Excited States, Photoelectrons, and Photoions; ? Chemical Reaction Dynamics; ? Biomolecules and Clusters.

  13. Physics Division News

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

    PADSTE ADEPS Physics Physics Division News Physics Division News Discover more about the wide-ranging scope of Physics Division science and technology. Contact Us ADEPS ...

  14. Physical Protection

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2005-08-26

    This Manual establishes requirements for the physical protection of safeguards and security interests. Copies of Section B, Safeguards and Security Alarm Management System, which contains Unclassified Controlled Nuclear Information, and Appendix 1, Security Badge Specifications, which contains Official Use Only information, are only available, by request, from the program manager, Protection Program Operations, 301-903-6209. Chg 1, dated 3/7/06. Cancels: DOE M 473.1-1 and DOE M 471.2-1B

  15. Physical Protection

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2005-08-26

    Establishes requirements for the physical protection of safeguards and security interests. Copies of Section B, Safeguards and Security Alarm Management System, which contains Unclassified Controlled Nuclear Information, and Appendix 1, Security Badge Specifications, which contains Official Use Only information, are only available, by request, from the program manager, Protection Program Operations, 301-903-6209. Cancels: DOE M 473.1-1 and DOE M 471.2-1B.

  16. Ultrafast spin tunneling and injection in coupled nanostructures of InGaAs quantum dots and quantum well

    SciTech Connect (OSTI)

    Yang, Xiao-Jie Kiba, Takayuki; Yamamura, Takafumi; Takayama, Junichi; Subagyo, Agus; Sueoka, Kazuhisa; Murayama, Akihiro

    2014-01-06

    We investigate the electron-spin injection dynamics via tunneling from an In{sub 0.1}Ga{sub 0.9}As quantum well (QW) to In{sub 0.5}Ga{sub 0.5}As quantum dots (QDs) in coupled QW-QDs nanostructures. These coupled nanostructures demonstrate ultrafast (5 to 20 ps) spin injection into the QDs. The degree of spin polarization up to 45% is obtained in the QDs after the injection, essentially depending on the injection time. The spin injection and conservation are enhanced with thinner barriers due to the stronger electronic coupling between the QW and QDs.

  17. Physics Division annual report, April 1, 1993--March 31, 1994

    SciTech Connect (OSTI)

    Thayer, K.J.; Henning, W.F.

    1994-08-01

    This is the Argonne National Laboratory Physics Division Annual Report for the period April 1, 1993 to March 31, 1994. It summarizes work done in a number of different fields, both on site, and at other facilities. Chapters describe heavy ion nuclear physics research, operation and development of the ATLAS accelerator, medium-energy nuclear physics research, theoretical physics, and atomic and molecular physics research.

  18. Structural Molecular Biology, SSRL

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

    Highlights Training Workshops & Summer Schools Summer Students Structural Molecular Biology Illuminating Biological Structures at the Atomic and Molecular Levels Your browser...

  19. Laser plasma x-ray source for ultrafast time-resolved x-ray absorption spectroscopy

    SciTech Connect (OSTI)

    Miaja-Avila, L.; O'Neil, G. C.; Uhlig, J.; Cromer, C. L.; Dowell, M. L.; Jimenez, R.; Hoover, A. S.; Silverman, K. L.; Ullom, J. N.

    2015-03-02

    We describe a laser-driven x-ray plasma source designed for ultrafast x-ray absorption spectroscopy. The source is comprised of a 1 kHz, 20 W, femtosecond pulsed infrared laser and a water target. We present the x-ray spectra as a function of laser energy and pulse duration. Additionally, we investigate the plasma temperature and photon flux as we vary the laser energy. We obtain a 75 μm FWHM x-ray spot size, containing ~106 photons/s, by focusing the produced x-rays with a polycapillary optic. Since the acquisition of x-ray absorption spectra requires the averaging of measurements from >107 laser pulses, we also present data on the source stability, including single pulse measurements of the x-ray yield and the x-ray spectral shape. In single pulse measurements, the x-ray flux has a measured standard deviation of 8%, where the laser pointing is the main cause of variability. Further, we show that the variability in x-ray spectral shape from single pulses is low, thus justifying the combining of x-rays obtained from different laser pulses into a single spectrum. Finally, we show a static x-ray absorption spectrum of a ferrioxalate solution as detected by a microcalorimeter array. Altogether, our results demonstrate that this water-jet based plasma source is a suitable candidate for laboratory-based time-resolved x-ray absorption spectroscopy experiments.

  20. Ultrafast dark-field surface inspection with hybrid-dispersion laser scanning

    SciTech Connect (OSTI)

    Yazaki, Akio; Kim, Chanju; Chan, Jacky; Mahjoubfar, Ata; Goda, Keisuke; Watanabe, Masahiro; Jalali, Bahram

    2014-06-23

    High-speed surface inspection plays an important role in industrial manufacturing, safety monitoring, and quality control. It is desirable to go beyond the speed limitation of current technologies for reducing manufacturing costs and opening a new window onto a class of applications that require high-throughput sensing. Here, we report a high-speed dark-field surface inspector for detection of micrometer-sized surface defects that can travel at a record high speed as high as a few kilometers per second. This method is based on a modified time-stretch microscope that illuminates temporally and spatially dispersed laser pulses on the surface of a fast-moving object and detects scattered light from defects on the surface with a sensitive photodetector in a dark-field configuration. The inspector's ability to perform ultrafast dark-field surface inspection enables real-time identification of difficult-to-detect features on weakly reflecting surfaces and hence renders the method much more practical than in the previously demonstrated bright-field configuration. Consequently, our inspector provides nearly 1000 times higher scanning speed than conventional inspectors. To show our method's broad utility, we demonstrate real-time inspection of the surface of various objects (a non-reflective black film, transparent flexible film, and reflective hard disk) for detection of 10??m or smaller defects on a moving target at 20?m/s within a scan width of 25?mm at a scan rate of 90.9?MHz. Our method holds promise for improving the cost and performance of organic light-emitting diode displays for next-generation smart phones, lithium-ion batteries for green electronics, and high-efficiency solar cells.

  1. Laser plasma x-ray source for ultrafast time-resolved x-ray absorption spectroscopy

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

    Miaja-Avila, L.; O'Neil, G. C.; Uhlig, J.; Cromer, C. L.; Dowell, M. L.; Jimenez, R.; Hoover, A. S.; Silverman, K. L.; Ullom, J. N.

    2015-03-02

    We describe a laser-driven x-ray plasma source designed for ultrafast x-ray absorption spectroscopy. The source is comprised of a 1 kHz, 20 W, femtosecond pulsed infrared laser and a water target. We present the x-ray spectra as a function of laser energy and pulse duration. Additionally, we investigate the plasma temperature and photon flux as we vary the laser energy. We obtain a 75 μm FWHM x-ray spot size, containing ~106 photons/s, by focusing the produced x-rays with a polycapillary optic. Since the acquisition of x-ray absorption spectra requires the averaging of measurements from >107 laser pulses, we also presentmore » data on the source stability, including single pulse measurements of the x-ray yield and the x-ray spectral shape. In single pulse measurements, the x-ray flux has a measured standard deviation of 8%, where the laser pointing is the main cause of variability. Further, we show that the variability in x-ray spectral shape from single pulses is low, thus justifying the combining of x-rays obtained from different laser pulses into a single spectrum. Finally, we show a static x-ray absorption spectrum of a ferrioxalate solution as detected by a microcalorimeter array. Altogether, our results demonstrate that this water-jet based plasma source is a suitable candidate for laboratory-based time-resolved x-ray absorption spectroscopy experiments.« less

  2. Ultrafast Multiphoton Pump-probe Photoemission Excitation Pathways in Rutile TiO2(110)

    SciTech Connect (OSTI)

    Argondizzo, Adam; Cui, Xuefeng; Wang, Cong; Sun, Huijuan; Shang, Honghui; Zhao, Jin; Petek, Hrvoje

    2015-04-27

    We investigate the spectroscopy and photoinduced electron dynamics within the conduction band of reduced rutile TiO2(110) surface by multiphoton photoemission (mPP) spectroscopy with wavelength tunable ultrafast (!20 fs) laser pulse excitation. Tuning the mPP photon excitation energy between 2.9 and 4.6 eV reveals a nearly degenerate pair of new unoccupied states located at 2.73 ± 0.05 and 2.85 ± 0.05 eV above the Fermi level, which can be analyzed through the polarization and sample azimuthal orientation dependence of the mPP spectra. Based on the calculated electronic structure and optical transition moments, as well as related spectroscopic evidence, we assign these resonances to transitions between Ti 3d bands of nominally t2g and eg symmetry, which are split by crystal field. The initial states for the optical transition are the reduced Ti3+ states of t2g symmetry populated by formation oxygen vacancy defects, which exist within the band gap of TiO2. Furthermore,we studied the electron dynamics within the conduction band of TiO2 by three-dimensional time-resolved pump-probe interferometric mPP measurements. The spectroscopic and time-resolved studies reveal competition between 2PP and 3PP processes where the t2g-eg transitions in the 2PP process saturate, and are overtaken by the 3PP process initiated by the band-gap excitation from the valence band of TiO2.

  3. Hadron physics

    SciTech Connect (OSTI)

    Bunce, G.

    1984-05-30

    Is all hadronic physics ultimately describable by QCD. Certainly, many disparate phenomena can be understood within the QCD framework. Also certainly, there are important questions which are open, both theoretically (little guidance, as yet) and experimentally, regarding confinement. Are there dibaryons, baryonium, glueballs. In addition, there are experimental results which at present do not have an explanation. This talk, after a short section on QCD successes and difficulties, will emphasize two experimental topics which have recent results - glueball spectroscopy and exclusive reactions at large momentum transfer. Both are experimentally accessible in the AGS/LAMPF II/AGS II/TRIUMF II/SIN II energy domain.

  4. Applied Mathematics and Plasma Physics

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

    5 Applied Mathematics and Plasma Physics Maintaining mathematic, theory, modeling, and simulation capabilities in a broad set of areas Leadership Group Leader Pieter Swart Email Deputy Group Leader (Acting) Luis Chacon Email Contact Us Administrator Charlotte Lehman Email Electron density simulation Electron density from an orbital-free quantum molecular dynamics simulation for a warm dense plasma of deuterium at density 10 g/cc and temperature 10 eV. Mathematical, theory, modeling, and

  5. Calculating time-resolved differential absorbance spectra for ultrafast pump-probe experiments with surface hopping trajectories

    SciTech Connect (OSTI)

    Petit, Andrew S.; Subotnik, Joseph E.

    2014-10-21

    We report a surface hopping approach for modeling the full time- and frequency-resolved differential absorbance spectra (beyond the inhomogenous limit) obtained in ultrafast pump-probe experiments. In our approach, we combine dynamical information obtained from ensembles of classical trajectories propagated on the ground and on the excited potential energy surfaces to directly calculate optical response functions and hence spectral lineshapes. We demonstrate that our method is exact for the model problem of two shifted harmonic potentials with identical harmonic frequencies in the absence of electronic relaxation. We then consider a model three state system with electronic relaxation and show that our method is able to capture the effects of nonadiabatic excited state dynamics on the time-dependent differential absorbance spectra. Furthermore, by comparing our spectra against those spectra calculated with either an (1) inhomogenous expression, (2) ground-state Kubo theory, or (3) excited-state Kubo theory, we show that including dynamical information from both the ground and excited potential energy surfaces significantly improves the reliability of the semiclassical approximations. As such, our surface hopping method should find immediate use in modeling the time-dependent differential abosrbance spectra of ultrafast pump-probe experiments.

  6. Physics Topics - MST - UW Plasma Physics

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

    Physics Topics UW Madison Madison Symmetric Torus Physics Topics MST HomeGraduate Student InformationLinksTourControl and Auxiliary SystemsPhysics TopicsDeviceResearch MissionMST ...

  7. Physics of Cancer | Princeton Plasma Physics Lab

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

    MBG Auditorium Physics of Cancer Professor Wolfgang Losert, Associate Professor, and ... PDF icon Wolfgang Losert Bio.pdf Physics of Cancer Contact Information ...

  8. High Energy Physics

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

    High Energy Physics science-innovationassetsimagesicon-science.jpg High Energy Physics Investigating the field of high energy physics through experiments that strengthen our ...

  9. Uranium molecular laser isotope separation

    SciTech Connect (OSTI)

    Jensen, R.J.; Sullivan, A.

    1982-01-01

    The Molecular Laser Isotope Separation program is moving into the engineering phase, and it is possible to determine in some detail the plant cost terms involved in the process economics. A brief description of the MLIS process physics is given as a motivation to the engineering and economics discussion. Much of the plant cost arises from lasers and the overall optical system. In the paper, the authors discuss lasers as operating units and systems, along with temporal multiplexing and Raman shifting. Estimates of plant laser costs are given.

  10. Saturday Morning Physics - Talks

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

    Further information online Contemporary Physics Education Project The Particle Adventure Particle Physics - Education and Outreach (Fermilab) CERN (Education Website) Wikipedia: ...

  11. Role of nuclear dynamics in the Asymmetric molecular-frame photoelectron angular distributions for C 1s photoejection from CO{sub 2}

    SciTech Connect (OSTI)

    Miyabe, Shungo; Haxton, Dan; Rescigno, Tom; McCurdy, Bill

    2010-11-30

    We report the results of semiclassical calculations of the asymmetric molecular-frame photoelectron angular distributions for C 1s ionization of CO{sub 2} measured with respect to the CO{sup +} and O{sup +} ions produced by subsequent Auger decay, and show how the decay event can be used to probe ultrafast molecular dynamics of the transient cation. The fixed-nuclei photoionization amplitudes were constructed using variationally obtained electron-molecular ion scattering wave functions. The amplitudes are then used in a semiclassical manner to investigate their dependence on the nuclear dynamics of the cation. The method introduced here can be used to study other core-level ionization events.

  12. Cost effective nanostructured copper substrates prepared with ultrafast laser pulses for explosives detection using surface enhanced Raman scattering

    SciTech Connect (OSTI)

    Hamad, Syed; Podagatlapalli, G. Krishna; Soma, Venugopal Rao E-mail: soma-venu@yahoo.com; Mohiddon, Md. Ahamad

    2014-06-30

    Ultrafast laser pulses induced surface nanostructures were fabricated on a copper (Cu) target through ablation in acetone, dichloromethane, acetonitrile, and chloroform. Surface morphological information accomplished from the field emission scanning electron microscopic data demonstrated the diversities of ablation mechanism in each case. Fabricated Cu substrates were utilized exultantly to investigate the surface plasmon (localized and propagating) mediated enhancements of different analytes using surface enhance Raman scattering (SERS) studies. Multiple utility of these substrates were efficiently demonstrated by collecting the SERS data of Rhodamine 6G molecule and two different secondary explosive molecules such as 5-amino-3-nitro-l,2,4-triazole and trinitrotoluene on different days which were weeks apart. We achieved significant enhancement factors of >10{sup 5} through an easily adoptable cleaning procedure.

  13. High quality single shot ultrafast MeV electron diffraction from a photocathode radio-frequency gun

    SciTech Connect (OSTI)

    Fu, Feichao; Liu, Shengguang; Zhu, Pengfei; Xiang, Dao Zhang, Jie; Cao, Jianming

    2014-08-15

    A compact ultrafast electron diffractometer, consisting of an s-band 1.6 cell photocathode radio-frequency gun, a multi-function changeable sample chamber, and a sensitive relativistic electron detector, was built at Shanghai Jiao Tong University. High-quality single-shot transmission electron diffraction patterns have been recorded by scattering 2.5 MeV electrons off single crystalline gold and polycrystalline aluminum samples. The high quality diffraction pattern indicates an excellent spatial resolution, with the ratio of the diffraction ring radius over the ring rms width beyond 10. The electron pulse width is estimated to be about 300 fs. The high temporal and spatial resolution may open new opportunities in various areas of sciences.

  14. Ultrafast time-resolved spectroscopy of the light-harvesting complex 2 (LH2) from the photosynthetic bacterium Thermochromatium tepidum

    SciTech Connect (OSTI)

    Niedzwiedzki, Dariusz M.; Fuciman, Marcel; Kobayashi, Masayuki; Frank, Harry A.; Blankenship, Robert E.

    2011-10-08

    The light-harvesting complex 2 from the thermophilic purple bacterium Thermochromatium tepidum was purified and studied by steady-state absorption and fluorescence, sub-nanosecond-time-resolved fluorescence and femtosecond time-resolved transient absorption spectroscopy. The measurements were performed at room temperature and at 10 K. The combination of both ultrafast and steady-state optical spectroscopy methods at ambient and cryogenic temperatures allowed the detailed study of carotenoid (Car)-to-bacteriochlorophyll (BChl) as well BChl-to-BChl excitation energy transfer in the complex. The studies show that the dominant Cars rhodopin (N = 11) and spirilloxanthin (N = 13) do not play a significant role as supportive energy donors for BChl a. This is related with their photophysical properties regulated by long ?-electron conjugation. On the other hand, such properties favor some of the Cars, particularly spirilloxanthin (N = 13) to play the role of the direct quencher of the excited singlet state of BChl.

  15. System and method for ultrafast optical signal detecting via a synchronously coupled anamorphic light pulse encoded laterally

    DOE Patents [OSTI]

    Heebner, John E.

    2010-08-03

    In one general embodiment, a method for ultrafast optical signal detecting is provided. In operation, a first optical input signal is propagated through a first wave guiding layer of a waveguide. Additionally, a second optical input signal is propagated through a second wave guiding layer of the waveguide. Furthermore, an optical control signal is applied to a top of the waveguide, the optical control signal being oriented diagonally relative to the top of the waveguide such that the application is used to influence at least a portion of the first optical input signal propagating through the first wave guiding layer of the waveguide. In addition, the first and the second optical input signals output from the waveguide are combined. Further, the combined optical signals output from the waveguide are detected. In another general embodiment, a system for ultrafast optical signal recording is provided comprising a waveguide including a plurality of wave guiding layers, an optical control source positioned to propagate an optical control signal towards the waveguide in a diagonal orientation relative to a top of the waveguide, at least one optical input source positioned to input an optical input signal into at least a first and a second wave guiding layer of the waveguide, and a detector for detecting at least one interference pattern output from the waveguide, where at least one of the interference patterns results from a combination of the optical input signals input into the first and the second wave guiding layer. Furthermore, propagation of the optical control signal is used to influence at least a portion of the optical input signal propagating through the first wave guiding layer of the waveguide.

  16. Ultrafast spin exchange-coupling torque via photo-excited charge...

    Office of Scientific and Technical Information (OSTI)

    ... manipulation of magnetic order. Rev. Modern Phys. 82, 2731-2784 (2010). 17. Ju, G., ... DEFG02-04ER46127. The work at the Department of Physics, Fudan University, was supported ...

  17. Progress at LAMPF (Los Alamos Meson Physics Facility), January--December 1989

    SciTech Connect (OSTI)

    Poelakker, K.

    1990-12-01

    This report contains brief papers on research conducted at the lampf facility in the following areas: nuclear and particle physics; astrophysics; atomic and molecular physics; materials science; nuclear chemistry; radiation effects and radioisotope production.

  18. Carl A. Gagliardi PHYSICS

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

    A. Gagliardi PHYSICS Fundamental interactions and nuclear astrophysics - Fellow, American Physical Society - Distinguished Achievement Award in Teaching, AFS, - Texas A&M John C. Hardy PHYSICS Fundamental interactions and exotic nuclei - Fellow, Royal Society of Canada - Fellow, American Physical Society Che Ming Ko PHYSICS Theoretical hadron physics and heavy-ion collisions - Humboldt Research Award - Fellow, American Physical Society Joseph B. Natowitz CHEMISTRY Heavy-ion reaction

  19. Plasma physics | Princeton Plasma Physics Lab

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

    physics Subscribe to RSS - Plasma physics The study of plasma, a partially-ionized gas that is electrically conductive and able to be confined within a magnetic field, and how it ...

  20. Partnership for Edge Physics Simulation (EPSI)

    SciTech Connect (OSTI)

    Schroder, Peter

    2015-02-11

    We propose to develop advanced simulation codes, based upon an extreme parallelism, first principles kinetic approach, to address the challenges associated with the edge region of magnetically confined plasmas. This work is relevant to both existing magnetic fusion facilities and essential for next-generation burning plasma experiments, such as ITER where success is critically dependent upon H-mode operation achieving an edge pedestal of sufficient height for good core plasma performance without producing deleterious large scale edge localized instabilities. The plasma edge presents a well-known set of multi-physics, multi-scale problems involving complex 3D magnetic geometry. Perhaps the greatest computational challenge is the lack of scale separation – temporal scales for drift waves, Alfven waves, ELM dynamics for example have strong overlap. Similar overlap occurs on the spatial scales for the ion poloidal gyro-radius, drift wave and pedestal width. The traditional approach of separating fusion problems into weakly interacting spatial or temporal domains clearly breaks down in the edge. A full kinetic model (full-f model) must be solved to understand and predict the edge physics including non-equilibrium thermodynamic issues arising from the magnetic topology (the open field lines producing a spatially sensitive velocity hole), plasma wall interactions, neutral and atomic physics. The plan here is to model these phenomena within a comprehensive first principles set of equations without the need for the insurmountable multiple-codes coupling issues by building on the XGC1 code developed under the SciDAC Proto-FSP Center for Plasma Edge Simulation (CPES). This proposal includes the critical participants in the XGC1 development. We propose enhancing the capability of XGC1 by including all the important turbulence physics contained in kinetic ion and electron electromagnetic dynamics, by extending the PIC technology to incorporate several positive features found in the Eulerian grid technology, combining the coarse grained XGC0 code into it with a multiscale projective time integration technique to be developed in the project for experimental time scale simulation of the edge multi-physics, and by implementing modern computational technologies to move forward with the extreme scale heterogeneous hardware/software platform development. Ultra-fast edge localized instabilities, involving compressional Alven modes, will be studied using a proper MHD or two-fluid codes employing kinetic closure information from XGC. The proposed research integrates the most important physical processes on overlapping temporal and spatial scales, to study (i) transitions and thresholds for enhanced confinement regimes, (ii) the predictive understanding of the edge pedestal formation, structure and dynamics, (iii) the effect of the edge plasma on the core confinement, (iv) the physics of Edge Localized Modes and their suppression or mitigation via external control techniques, and (v) the heat load on the material wall. Our approach will implement physical models that are valid in their relevant collisionality regimes for current experiments and future burning plasma devices. Comparisons with experimental data will be made at multiple levels including characterization of turbulence dynamics, flux-gradient responses in the energy, particle and momentum channels, and observations of global phenomena such as L-H transitions, momentum generation, ELM dynamics, ELM-free regimes and the tokamak density limit. The proposal team has established strong connections, through joint membership, with other organizations that will be critical for success. These include FASTMath, SUPER and QUEST Institutes respectively for meshing tools and solvers; code performance tuning and uncertainty quantification as well as a proposed Data Management and Visualization Institute.. We will also be teaming with ongoing fusion SciDAC’s: CSWPI for RF-edge plasmas interactions; CEMM for the M3D MHD simulations and with PEPSC for incorporation of energetic particle physics. Finally, the team includes representatives from each of the major U.S. experimental facilities who will coordinate the validation program and the development of synthetic diagnostics.

  1. Ultrafast laser and swift heavy ion irradiation: Response of Gd{sub 2}O{sub 3} and ZrO{sub 2} to intense electronic excitation

    SciTech Connect (OSTI)

    Rittman, Dylan R.; Tracy, Cameron L.; Cusick, Alex B.; Abere, Michael J.; Yalisove, Steven M.; Torralva, Ben; Ewing, Rodney C.

    2015-04-27

    In order to investigate the response of materials to extreme conditions, there are several approaches to depositing extremely high concentrations of energy into very small volumes of material, including ultrafast laser and swift heavy ion (SHI) irradiation. In this study, crystalline-to-crystalline phase transformations in cubic Gd{sub 2}O{sub 3} and monoclinic ZrO{sub 2} have been investigated using ultrafast laser irradiation. The phases produced by the extreme conditions of irradiation were characterized by grazing incidence x-ray diffraction (GIXRD) and Raman spectroscopy. Gd{sub 2}O{sub 3} exhibited a cubic-to-monoclinic phase transformation, as evidenced by the appearance of the monoclinic (402{sup }), (003), (310), and (112{sup }) peaks in the GIXRD pattern and of four A{sub g} and three B{sub g} Raman modes. ZrO{sub 2} underwent a monoclinic-to-tetragonal phase transformation, as evidenced by the emergence of the tetragonal (101) peak in the GIXRD pattern and of E{sub g} and A{sub 1g} Raman modes. The new phases formed by ultrafast laser irradiation are high temperature polymorphs of the two materials. No evidence of amorphization was seen in the GIXRD data, though Raman spectroscopy indicated point defect accumulation. These results are identical to those produced by irradiation with SHIs, which also deposit energy in materials primarily through electronic excitation. The similarity in damage process and material response between ultrafast laser and SHI irradiation suggests a fundamental relationship between these two techniques.

  2. Nuclear Physics: Experiment Research

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    Physics justification: The main focus of the HELIOS research program is the study of ... Physics justification: Spectroscopy following the decay of nuclear ground states and ...

  7. ORISE: Health Physics Training

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    Health Physics Training Student performs an analysis during an ORAU health physics training course Training and educating a highly skilled workforce that can meet operational ...

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    Health physics services Nuclear power plant The Oak Ridge Institute for Science and Education (ORISE) offers comprehensive health physics services in a number of technical areas ...

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    advantage of new physics opportunities with a suitable suite of experimental equipment. ... focus on delineating the goals of the physics program for the next decade, and on ...

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    Physics Topics: Meetings Talks given at the Science & Technology Review 2004 Larry Cardman: Science Overview and the Experimental Program ppt | pdf Tony Thomas: Nuclear Physics ...

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    Missoula, MT, USA 8 Princeton Plasma Physics Laboratory, Princeton, NJ, USA Received ... can be produced in two quite different physics regimes: standard-confinement plasmas ...

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    Safety Tom Mullen, Physics Division Safety Engineer. Please Note: If you have any comments or concerns regarding safety at ATLAS, please contact the Physics Division Safety ...

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    Free-Electron Laser (FEL) Medical Imaging Physics Topics Campaigns The Structure of the Nuclear Building Blocks The Structure of Nuclei Symmetry Tests in Nuclear Physics Meetings ...

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    Working Groups - Session 1 - Focus on Physics 1: Nuclear Structure (Auditorium) ... Working Groups - Session 1 - Focus on Physics Nuclear Structure Nuclear reactions and ...

  1. Experimental Physical Sciences

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    in Physics, Chair ASM International, Board of Trustees Association for Iron & Steel Technology, Board of Directors National Science Foundation, Condensed Matter Physics, Program...

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    Our Mission Our Mission The SSRL Structural Molecular Biology program operates as a integrated resource and has three primary areas (or cores) of technological research and...

  4. TH-A-18C-04: Ultrafast Cone-Beam CT Scatter Correction with GPU-Based Monte Carlo Simulation

    SciTech Connect (OSTI)

    Xu, Y; Bai, T; Yan, H; Ouyang, L; Wang, J; Pompos, A; Jiang, S; Jia, X; Zhou, L

    2014-06-15

    Purpose: Scatter artifacts severely degrade image quality of cone-beam CT (CBCT). We present an ultrafast scatter correction framework by using GPU-based Monte Carlo (MC) simulation and prior patient CT image, aiming at automatically finish the whole process including both scatter correction and reconstructions within 30 seconds. Methods: The method consists of six steps: 1) FDK reconstruction using raw projection data; 2) Rigid Registration of planning CT to the FDK results; 3) MC scatter calculation at sparse view angles using the planning CT; 4) Interpolation of the calculated scatter signals to other angles; 5) Removal of scatter from the raw projections; 6) FDK reconstruction using the scatter-corrected projections. In addition to using GPU to accelerate MC photon simulations, we also use a small number of photons and a down-sampled CT image in simulation to further reduce computation time. A novel denoising algorithm is used to eliminate MC scatter noise caused by low photon numbers. The method is validated on head-and-neck cases with simulated and clinical data. Results: We have studied impacts of photo histories, volume down sampling factors on the accuracy of scatter estimation. The Fourier analysis was conducted to show that scatter images calculated at 31 angles are sufficient to restore those at all angles with <0.1% error. For the simulated case with a resolution of 512×512×100, we simulated 10M photons per angle. The total computation time is 23.77 seconds on a Nvidia GTX Titan GPU. The scatter-induced shading/cupping artifacts are substantially reduced, and the average HU error of a region-of-interest is reduced from 75.9 to 19.0 HU. Similar results were found for a real patient case. Conclusion: A practical ultrafast MC-based CBCT scatter correction scheme is developed. The whole process of scatter correction and reconstruction is accomplished within 30 seconds. This study is supported in part by NIH (1R01CA154747-01), The Core Technology Research in Strategic Emerging Industry, Guangdong, China (2011A081402003)

  5. High Energy Physics and Nuclear Physics Network Requirements...

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  6. Physical Biosciences | U.S. DOE Office of Science (SC)

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    Physical Biosciences Chemical Sciences, Geosciences, & Biosciences (CSGB) Division CSGB Home About Research Areas Energy Frontier Research Centers (EFRCs) DOE Energy Innovation Hubs Reports and Activities Science Highlights Principal Investigators' Meetings BES Home Research Areas Physical Biosciences Print Text Size: A A A FeedbackShare Page This research area combines experimental and computational tools from the physical sciences with biochemistry and molecular biology. A fundamental

  7. Nuclear Physics: Experiment Research

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  8. SC e-journals, Physics

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    ... in Physics - OAJ Review of Physics in Technology Reviews of Geophysics Reviews of Modern Physics Rheologica Acta Russian Physics Journal Science Science and Technology of Advanced ...

  9. The 2011 Dynamics of Molecular Collisions Conference

    SciTech Connect (OSTI)

    Nesbitt, David J.

    2011-07-11

    The Dynamics of Molecular Collisions Conference focuses on all aspects of molecular collisions--experimental & theoretical studies of elastic, inelastic, & reactive encounters involving atoms, molecules, ions, clusters, & surfaces--as well as half collisions--photodissociation, photo-induced reaction, & photodesorption. The scientific program for the meeting in 2011 included exciting advances in both the core & multidisciplinary forefronts of the study of molecular collision processes. Following the format of the 2009 meeting, we also invited sessions in special topics that involve interfacial dynamics, novel emerging spectroscopies, chemical dynamics in atmospheric, combustion & interstellar environments, as well as a session devoted to theoretical & experimental advances in ultracold molecular samples. Researchers working inside & outside the traditional core topics of the meeting are encouraged to join the conference. We invite contributions of work that seeks understanding of how inter & intra-molecular forces determine the dynamics of the phenomena under study. In addition to invited oral sessions & contributed poster sessions, the scientific program included a formal session consisting of five contributed talks selected from the submitted poster abstracts. The DMC has distinguished itself by having the Herschbach Medal Symposium as part of the meeting format. This tradition of the Herschbach Medal was first started in the 2007 meeting chaired by David Chandler, based on a generous donation of funds & artwork design by Professor Dudley Herschbach himself. There are two such awards made, one for experimental & one for theoretical contributions to the field of Molecular Collision Dynamics, broadly defined. The symposium is always held on the last night of the meeting & has the awardees are asked to deliver an invited lecture on their work. The 2011 Herschbach Medal was dedicated to the contributions of two long standing leaders in Chemical Physics, Professor Yuan T. Lee & Professor George Schatz. Professor Lees research has been based on the development & use of advanced chemical kinetics & molecular beams to investigate & manipulate the behavior of fundamental chemical reactions. Lees work has been recognized by many awards, including the Nobel Prize for Chemistry in 1986, as well as Sloan Fellow, Dreyfus Scholar, Fellowship in the American Academy of Arts & Sciences, Fellowship in the American Physical Society, Guggenheim Fellow, Member National Academy of Sciences, Member Academia Sinica, E.O. Lawrence Award, Miller Professor, Berkeley, Fairchild Distinguished Scholar, Harrison Howe Award, Peter Debye Award, & the National Medal of Science. Lee also has served as the President of the Academia Sinica in Taiwan (ROC). Professor Schatzs research group is interested in using theory & computation to describe physical phenomena in a broad range of applications relevant to chemistry, physics, biology & engineering. Among the types of applications that we interested are: optical properties of nanoparticles & nanoparticle assemblies; using theory to model polymer properties; DNA structure, thermodynamics & dynamics; modeling self assembly & nanopatterning; & gas phase reaction dynamics. Among his many awards & distinctions have been appointment as an Alfred P. Sloan Research Fellow, Camille & Henry Dreyfus Teacher-Scholar, the Fresenius Award, Fellow of the American Physical Society, the Max Planck Research Award, Fellowship in the American Association for the Advancement of Science, & election to the International Academy of Quantum Molecular Sciences & the American Academy of Arts & Sciences. Dr Schatz is also lauded for his highly successful work as Editor for the Journal of Physical Chemistry. We requested $10,000 from DOE in support of this meeting. The money was distributed widely among the student & post doctoral fellows & some used to attract the very best scientists in the field. The organizers were committed to encouraging women & minorities as well as encourage the field of Chemical Physics in scientific

  10. NuSTAR REVEALS RELATIVISTIC REFLECTION BUT NO ULTRA-FAST OUTFLOW IN THE QUASAR PG 1211+143

    SciTech Connect (OSTI)

    Zoghbi, A.; Miller, J. M.; Walton, D. J.; Stern, D.; Harrison, F. A.; Fabian, A. C.; Reynolds, C. S.; Boggs, S. E.; Craig, W.; Christensen, F. E.; Hailey, C. J.; Zhang, W. W.

    2015-02-01

    We report on four epochs of observations of the quasar PG 1211+143 using NuSTAR. The net exposure time is 300 ks. Prior work on this source found suggestive evidence of an ultra-fast outflow (UFO) in the Fe K band with a velocity of approximately 0.1c. The putative flow would carry away a high-mass flux and kinetic power, with broad implications for feedback and black hole--galaxy co-evolution. NuSTAR detects PG 1211+143 out to 30 keV, meaning that the continuum is well-defined both through and above the Fe K band. A characteristic relativistic disk reflection spectrum is clearly revealed via a broad Fe K emission line and Compton back-scattering curvature. The data offer only weak constraints on the spin of the black hole. A careful search for UFOs shows no significant absorption feature above 90% confidence. The limits are particularly tight when relativistic reflection is included. We discuss the statistics and the implications of these results in terms of connections between accretion onto quasars, Seyferts, and stellar-mass black holes, and feedback into their host environments.

  11. Optimization of chemical compositions in low-carbon Al-killed enamel steel produced by ultra-fast continuous annealing

    SciTech Connect (OSTI)

    Dong, Futao; Du, Linxiu; Liu, Xianghua; Xue, Fei

    2013-10-15

    The influence of Mn,S and B contents on microstructural characteristics, mechanical properties and hydrogen trapping ability of low-carbon Al-killed enamel steel was investigated. The materials were produced and processed in a laboratory and the ultra-fast continuous annealing processing was performed using a continuous annealing simulator. It was found that increasing Mn,S contents in steel can improve its hydrogen trapping ability which is attributed by refined ferrite grains, more dispersed cementite and added MnS inclusions. Nevertheless, it deteriorates mechanical properties of steel sheet. Addition of trace boron results in both good mechanical properties and significantly improved hydrogen trapping ability. The boron combined with nitrogen segregating at grain boundaries, cementite and MnS inclusions, provides higher amount of attractive hydrogen trapping sites and raises the activation energy for hydrogen desorption from them. - Highlights: We study microstructures and properties in low-carbon Al-killed enamel steel. Hydrogen diffusion coefficients are measured to reflect fish-scale resistance. Manganese improves hydrogen trapping ability but decrease deep-drawing ability. Boron improves both hydrogen trapping ability and deep-drawing ability. Both excellent mechanical properties and fish-scale resistance can be matched.

  12. Study of beam loading and its compensation in the Compact Ultrafast Terahertz Free-Electron Laser injector linac

    SciTech Connect (OSTI)

    Lal, Shankar Pant, K. K.

    2014-12-15

    The RF properties of an accelerating structure, and the pulse structure and charge per bunch in the electron beam propagating through it are important parameters that determine the impact of beam loading in the structure. The injector linac of the Compact Ultrafast Terahertz Free-Electron Laser (CUTE-FEL) has been operated with two different pulse structures during initial commissioning experiments and the effect of beam loading on the accelerated electron beam parameters has been studied analytically for these two pulse structures. This paper discusses the analytical study of beam loading in a Standing Wave, Plane Wave Transformer linac employed in the CUTE-FEL setup, and a possible technique for its compensation for the electron beam parameters of the CUTE-FEL. A parametric study has been performed to study beam loading for different beam currents and to optimize injection time of the electron beam to compensate beam loading. Results from the parametric study have also been used to explain previously observed results from acceleration experiments in the CUTE-FEL setup.

  13. Coherent orbital waves during an Ultrafast Photo-induced Isulator-metal Transition in a magnetoresistive manganite

    SciTech Connect (OSTI)

    ULTRAS-INFM-CNR Dipartimento di Fisica, Politecnico di Milano, Italy; Department of Physics - Cavalleri Group, Clarendon Laboratory, University of Oxford, U.K.; Correlated Electron Research Center, Tsukuba, Japan; Schoenlein, Robert William; Polli, D.; Rini, M.; Wall, S.; Schoenlein, R.W.; Tomioka, Y.; Tokura, Y.; Cerullo, G.; Cavalleri, A.

    2007-06-01

    Photo-excitation can drive strongly correlated electron insulators into competing conducting phases1,2, resulting in giant and ultrafast changes of their electronic and magnetic properties. The underlying non-equilibrium dynamics involve many degrees of freedom at once, whereby sufficiently short optical pulses can trigger the corresponding collective modes of the solid along temporally coherent pathways. The characteristic frequencies of these modes range between the few GHz of acoustic vibrations3 to the tens or even hundreds of THz for purely electronic excitations. Virtually all experiments so far have used 100 fs or longer pulses, detecting only comparatively slow lattice dynamics4,5. Here, we use sub-10-fs optical pulses to study the photo-induced insulator-metal transition in the magneto-resistive manganite Pr0.7Ca0.3MnO3. At room temperature, we find that the time-dependent pathway towards the metallic phase is accompanied by coherent 31 THz oscillations of the optical reflectivity, significantly faster than all lattice vibrations. These high-frequency oscillations are suggestive of coherent orbital waves6,7, crystal-field excitations triggered here by impulsive stimulated Raman scattering. Orbital waves are likely to be initially localized to the small polarons of this room-temperature manganite, coupling to other degrees of freedom at longer times, as photo-domains coalesce into a metallic phase.

  14. Ultrafast electrochemical preparation of graphene/CoS nanosheet counter electrodes for efficient dye-sensitized solar cells

    SciTech Connect (OSTI)

    Zhu, Chongyang; Zhu, Yimei; Min, Huihua; Xu, Feng; Chen, Jing; Dong, Hui; Tong, Ling; Sun, Litao

    2015-10-05

    Utilizing inexpensive, high-efficiency counter electrodes (CEs) to replace the traditional platinum counterparts in dye-sensitized solar cells (DSSCs) is worthwhile. In this paper, we detail how we synchronously prepared composite CEs of CoS nanosheet arrays and reduced graphene oxide (rGO) layers for the first time via a low temperature, ultrafast one-step electrochemical strategy. With this approach, the whole fabrication process of the composite CEs was only a small percentage of the average time (~15 hours) using other methods. The DSSC assembled with the rGO–CoS composite CE achieved an enhanced power conversion efficiency (PCE) of 8.34%, which is dramatically higher than 6.27% of pure CoS CE-based DSSC and even exceeds 7.50% of Pt CE-based DSSC. The outstanding PCE breakthrough is undoubtedly attributed to the enhancement in electrocatalytic ability of the rGO–CoS composite CE due to the incorporation of highly conducting rGO layers and the GO layers-induced growth of CoS nanosheet arrays with higher density and larger surface area. Therefore, lower charge-transfer resistance and higher exchange current density can be achieved as corroborated by the electrochemical impedance spectra (EIS) and Tafel polarization curves (TPCs). As a result, further experiments also proved that the electrochemical strategy exhibited its universality of fabricating other graphene-enhanced chalcogenide functional composite films.

  15. Ultrafast electrochemical preparation of graphene/CoS nanosheet counter electrodes for efficient dye-sensitized solar cells

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

    Zhu, Chongyang; Zhu, Yimei; Min, Huihua; Xu, Feng; Chen, Jing; Dong, Hui; Tong, Ling; Sun, Litao

    2015-10-05

    Utilizing inexpensive, high-efficiency counter electrodes (CEs) to replace the traditional platinum counterparts in dye-sensitized solar cells (DSSCs) is worthwhile. In this paper, we detail how we synchronously prepared composite CEs of CoS nanosheet arrays and reduced graphene oxide (rGO) layers for the first time via a low temperature, ultrafast one-step electrochemical strategy. With this approach, the whole fabrication process of the composite CEs was only a small percentage of the average time (~15 hours) using other methods. The DSSC assembled with the rGO–CoS composite CE achieved an enhanced power conversion efficiency (PCE) of 8.34%, which is dramatically higher than 6.27%more » of pure CoS CE-based DSSC and even exceeds 7.50% of Pt CE-based DSSC. The outstanding PCE breakthrough is undoubtedly attributed to the enhancement in electrocatalytic ability of the rGO–CoS composite CE due to the incorporation of highly conducting rGO layers and the GO layers-induced growth of CoS nanosheet arrays with higher density and larger surface area. Therefore, lower charge-transfer resistance and higher exchange current density can be achieved as corroborated by the electrochemical impedance spectra (EIS) and Tafel polarization curves (TPCs). As a result, further experiments also proved that the electrochemical strategy exhibited its universality of fabricating other graphene-enhanced chalcogenide functional composite films.« less

  16. Dr. James H. Glownia | U.S. DOE Office of Science (SC)

    Office of Science (SC) Website

    and application of ultrafast laser based experimental techniques to study complex ultrafast dynamic, nonlinear and coherent phenomena in atomic, molecular and material systems. ...

  17. Research | Argonne National Laboratory

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

    and Ultrafast Imaging Integrating ultrafast time-resolved imaging with large-scale molecular dynamics modeling and in situ data analysis and visualization in order to...

  18. Single shot ultrafast dynamic ellipsometry (UDE) of laser-driven shocks in single crystal explosives

    SciTech Connect (OSTI)

    Whitley, Von H; Mcgrane, Shawn D; Moore, David S; Eakins, Dan E; Bolme, Cindy A

    2009-01-01

    We report on the first experiments to measure states in shocked energetic single crystals with dynamic ellipsometry. We demonstrate that these ellipsometric techniques can produce reasonable Hugoniot values using small amounts of crystalline RDX and PETN. Pressures, particle velocities and shock velocities obtained using shocked ellipsometry are comparable to those found using gas-gun flyer plates and molecular dynamics calculations. The adaptation of the technique from uniform thin films of polymers to thick non-perfect crystalline materials was a significant achievement. Correct sample preparation proved to be a crucial component. Through trial and error, we were able to resolve polishing issues, sample quality problems, birefringence effects and mounting difficulties that were not encountered using thin polymer films.

  19. Shock and Detonation Physics at Los Alamos National Laboratory

    SciTech Connect (OSTI)

    Robbins, David L; Dattelbaum, Dana M; Sheffield, Steve A

    2012-08-22

    WX-9 serves the Laboratory and the Nation by delivering quality technical results, serving customers that include the Nuclear Weapons Program (DOE/NNSA), the Department of Defense, the Department of Homeland Security and other government agencies. The scientific expertise of the group encompasses equations-of-state, shock compression science, phase transformations, detonation physics including explosives initiation, detonation propagation, and reaction rates, spectroscopic methods and velocimetry, and detonation and equation-of-state theory. We are also internationally-recognized in ultra-fast laser shock methods and associated diagnostics, and are active in the area of ultra-sensitive explosives detection. The facility capital enabling the group to fulfill its missions include a number of laser systems, both for laser-driven shocks, and spectroscopic analysis, high pressure gas-driven guns and powder guns for high velocity plate impact experiments, explosively-driven techniques, static high pressure devices including diamond anvil cells and dilatometers coupled with spectroscopic probes, and machine shops and target fabrication facilities.

  20. THE DARK MOLECULAR GAS

    SciTech Connect (OSTI)

    Wolfire, Mark G.; Hollenbach, David; McKee, Christopher F. E-mail: dhollenbach@seti.or

    2010-06-20

    The mass of molecular gas in an interstellar cloud is often measured using line emission from low rotational levels of CO, which are sensitive to the CO mass, and then scaling to the assumed molecular hydrogen H{sub 2} mass. However, a significant H{sub 2} mass may lie outside the CO region, in the outer regions of the molecular cloud where the gas-phase carbon resides in C or C{sup +}. Here, H{sub 2} self-shields or is shielded by dust from UV photodissociation, whereas CO is photodissociated. This H{sub 2} gas is 'dark' in molecular transitions because of the absence of CO and other trace molecules, and because H{sub 2} emits so weakly at temperatures 10 K molecular component. This component has been indirectly observed through other tracers of mass such as gamma rays produced in cosmic-ray collisions with the gas and far-infrared/submillimeter wavelength dust continuum radiation. In this paper, we theoretically model this dark mass and find that the fraction of the molecular mass in this dark component is remarkably constant ({approx}0.3 for average visual extinction through the cloud A-bar{sub V{approx_equal}}8) and insensitive to the incident ultraviolet radiation field strength, the internal density distribution, and the mass of the molecular cloud as long as A-bar{sub V}, or equivalently, the product of the average hydrogen nucleus column and the metallicity through the cloud, is constant. We also find that the dark mass fraction increases with decreasing A-bar{sub V}, since relatively more molecular H{sub 2} material lies outside the CO region in this case.

  1. Optical Modulation of Molecular Conductance

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

    Transient absorption spectra of these molecular layers are consistent with formation of a long-lived charge separated state, a finding with implications for the design of molecular ...

  2. Theoretical Condensed Matter Physics | U.S. DOE Office of Science...

    Office of Science (SC) Website

    Core research areas include quantum materials, materials discovery, out-of-equilibrium and ultrafast response, and materials relevant to efficient energy conversion, and ...

  3. Fermilab | Science | Particle Physics

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    Particle Physics photo At Fermilab, a robust scientific program pursues answers to key questions about the laws of nature and the cosmos. The challenge of particle physics is to ...

  4. Physics Informed Machine Learning

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

    Physics Informed Machine Learning Physics Informed Machine Learning WHEN: Jan 19, 2016 8:00 AM - Jan 22, 2016 4:00 PM WHERE: Inn at Loretto, Santa Fe CATEGORY: Science TYPE: ...

  5. INSTITUTE OF PHYSICS PUBLISHING

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

    and C.B. Forest 1 Department of Physics, University of Wisconsin, 1150 University ... The plasma physics of the problem is entirely described by the 2 2 spectral surface ...

  6. Argonne Physics Division - ATLAS

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

    It is supported by the Office of Nuclear Physics of the Department of Energy. The Users ... main goals and is aligned with i the US Nuclear Physics long-range plan priorities. ...

  7. Argonne Physics Division - ATLAS

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

    In addition, the role of ATLAS for the low-energy nuclear physics community needs to be ... The facility and its users are encouraged by the DOE Office of Nuclear Physics to look ...

  8. Future Physics | Jefferson Lab

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

    Future Physics March 5, 2009 In late January, we held a meeting of our Physics Advisory Committee, PAC34 to be precise. We had two primary goals for the PAC, one related to the ...

  9. Argonne Physics Division - ATLAS

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

    The ATLAS User Group shall be formed from the members of the nuclear physics, nuclear chemistry and atomic physics community who are past, present, or potential users of the ATLAS ...

  10. Argonne Physics Division - ATLAS

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

    Office of Nuclear Physics at the Department of Energy to upgrade the capabilities of ATLAS in the area of physics with rare isotopes. A copy of the proposal for the CAlifornium...

  11. Princeton Plasma Physics Laboratory

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

    Plasma Physics Laboratory P.O. Box 451 Princeton, NJ 08543-0451 GPS: 100 Stellarator Road Princeton, NJ 08540 www.pppl.gov 2015 Princeton Plasma Physics Laboratory. A...

  12. MST - UW Plasma Physics

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

    The Madison Symmetric Torus produces hot plasma for research in plasma physics and fusion power generation, the energy source of the sun. Located in the Physics Department of the ...

  13. Physics Informed Machine Learning

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

    Physics Informed Machine Learning Physics Informed Machine Learning WHEN: Jan 19, 2016 8:00 AM - Jan 22, 2016 4:00 PM WHERE: Inn at Loretto, Santa Fe CATEGORY: Science TYPE:...

  14. ORISE: Health Physics Training

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

    Health Physics Training Student performs an analysis during an ORAU health physics training course Training and educating a highly skilled workforce that can meet operational commitments in the areas of radiation and health physics is an essential part of protecting your workers, the public and the environment. ORAU, the managing contractor of the Oak Ridge Institute for Science and Education, offers hands-on, laboratory-based training courses in a variety of health physics areas. Training

  15. Introduction to Neutrino Physics

    SciTech Connect (OSTI)

    Linares, Edgar Casimiro

    2009-04-30

    I present a basic introduction to the physics of the neutrino, with emphasis on experimental results and developments.

  16. American Physical Society Awards

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

    Physical Society Awards American Physical Society (APS) is one of the most important professional societies for gauging the quality of R&D done at the Laboratory. The APS sponsors a number of awards including the John Dawson Award of Excellence in Plasma Physics, James Clerk Maxwell Prize for Plasma Physics, as well as Dinstinguised Lectuerer and Doctoral Dissertation prizes. Name Year Name of Award and Citation Yu-hsin Chen 2012 Marshall N. Rosenbluth Outstanding Doctoral Thesis For

  17. How to Popularize Physics

    ScienceCinema (OSTI)

    Simmons, Elizabeth [Michigan State University, East Landing, Michigan, United States

    2009-09-01

    This talk discusses the whys and hows of educational outreach and presents examples from several fields of physics.

  18. American Physical Society awards

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

    awards fellowships to Los Alamos scientists December 18, 2012 American Physical Society Awards Fellowships to Los Alamos Scientists LOS ALAMOS, NEW MEXICO, December 18, 2012-Ten scientists at Los Alamos National Laboratory are being inducted into the ranks of fellowship in the American Physical Society (APS) for 2012. The criterion for election as an APS Fellow is exceptional contributions to the physics enterprise; such as performing outstanding physics research, important applications of

  19. DISCOVERY OF ULTRA-FAST OUTFLOWS IN A SAMPLE OF BROAD-LINE RADIO GALAXIES OBSERVED WITH SUZAKU

    SciTech Connect (OSTI)

    Tombesi, F.; Sambruna, R. M.; Mushotzky, R. F.; Braito, V.; Ballo, L.; Cappi, M.

    2010-08-10

    We present the results of a uniform and systematic search for blueshifted Fe K absorption lines in the X-ray spectra of five bright broad-line radio galaxies observed with Suzaku. We detect, for the first time in radio-loud active galactic nuclei (AGNs) at X-rays, several absorption lines at energies greater than 7 keV in three out of five sources, namely, 3C 111, 3C 120, and 3C 390.3. The lines are detected with high significance according to both the F-test and extensive Monte Carlo simulations. Their likely interpretation as blueshifted Fe XXV and Fe XXVI K-shell resonance lines implies an origin from highly ionized gas outflowing with mildly relativistic velocities, in the range v {approx_equal} 0.04-0.15c. A fit with specific photoionization models gives ionization parameters in the range log {xi} {approx_equal} 4-5.6 erg s{sup -1} cm and column densities of N {sub H} {approx_equal} 10{sup 22}-10{sup 23} cm{sup -2}. These characteristics are very similar to those of the ultra-fast outflows (UFOs) previously observed in radio-quiet AGNs. Their estimated location within {approx}0.01-0.3 pc of the central super-massive black hole suggests a likely origin related with accretion disk winds/outflows. Depending on the absorber covering fraction, the mass outflow rate of these UFOs can be comparable to the accretion rate and their kinetic power can correspond to a significant fraction of the bolometric luminosity and is comparable to their typical jet power. Therefore, these UFOs can play a significant role in the expected feedback from the AGN to the surrounding environment and can give us further clues on the relation between the accretion disk and the formation of winds/jets in both radio-quiet and radio-loud AGNs.

  20. Luu, T; Platter, L 73 NUCLEAR PHYSICS AND RADIATION PHYSICS;...

    Office of Scientific and Technical Information (OSTI)

    constraints from Big Bang nucleosynthesis Bedaque, P; Luu, T; Platter, L 73 NUCLEAR PHYSICS AND RADIATION PHYSICS; DEUTERIUM; FIELD THEORIES; NUCLEAR PHYSICS; NUCLEOSYNTHESIS;...

  1. Substructured multibody molecular dynamics.

    SciTech Connect (OSTI)

    Grest, Gary Stephen; Stevens, Mark Jackson; Plimpton, Steven James; Woolf, Thomas B. (Johns Hopkins University, Baltimore, MD); Lehoucq, Richard B.; Crozier, Paul Stewart; Ismail, Ahmed E.; Mukherjee, Rudranarayan M. (Rensselaer Polytechnic Institute, Troy, NY); Draganescu, Andrei I.

    2006-11-01

    We have enhanced our parallel molecular dynamics (MD) simulation software LAMMPS (Large-scale Atomic/Molecular Massively Parallel Simulator, lammps.sandia.gov) to include many new features for accelerated simulation including articulated rigid body dynamics via coupling to the Rensselaer Polytechnic Institute code POEMS (Parallelizable Open-source Efficient Multibody Software). We use new features of the LAMMPS software package to investigate rhodopsin photoisomerization, and water model surface tension and capillary waves at the vapor-liquid interface. Finally, we motivate the recipes of MD for practitioners and researchers in numerical analysis and computational mechanics.

  2. Low-power, ultrafast, and dynamic all-optical tunable plasmonic analog to electromagnetically induced transparency in two resonators side-coupled with a waveguide system

    SciTech Connect (OSTI)

    Wang, Boyun; Wang, Tao Li, Xiaoming; Han, Xu; Zhu, Youjiang

    2015-06-07

    We theoretically and numerically investigate a low-power, ultrafast, and dynamic all-optical tunable plasmonic analog to electromagnetically induced transparency (EIT) in two nanodisk resonators side-coupled to a metal-insulator-metal plasmonic waveguide system. The optical Kerr effect is enhanced by the slow light effect of the plasmonic EIT-like effect and the plasmonic waveguide based on graphene-Ag composite material structures with giant effective Kerr nonlinear coefficient. The optical Kerr effect modulation method is applied to improve tuning rate with response time of subpicoseconds or even femtoseconds. With dynamically tuning the propagation phase of the plasmonic waveguide, π-phase shift of the transmission spectrum in the plasmonic EIT-like system is achieved under excitation of a pump light with an intensity as low as 5.85 MW/cm{sup 2}. The group delay is controlled between 0.09 and 0.4 ps. All observed schemes are analyzed rigorously through finite-difference time-domain simulations and coupled-mode formalism. Results show a new direction toward the low power consumption and ultrafast responses of integration plasmonic photonic devices and all-optical dynamical storage of light devices in optical communication and quantum information processing.

  3. Linewidth of the harmonics in a microwave frequency comb generated by focusing a mode-locked ultrafast laser on a tunneling junction

    SciTech Connect (OSTI)

    Hagmann, Mark J.; Stenger, Frank S.; Yarotski, Dmitry A.

    2013-12-14

    Previous analyses suggest that microwave frequency combs (MFCs) with harmonics having extremely narrow linewidths could be produced by photodetection with a mode-locked ultrafast laser. In the MFC generated by focusing a passively mode-locked ultrafast laser on a tunneling junction, 200 harmonics from 74.254 MHz to 14.85 GHz have reproducible measured linewidths approximating the 1 Hz resolution bandwidth (RBW) of the spectrum analyzer. However, in new measurements at a RBW of 0.1 Hz, the linewidths are distributed from 0.12 to 1.17 Hz. Measurements and analysis suggest that, because the laser is not stabilized, the stochastic drift in the pulse repetition rate is the cause for the distribution in measured linewidths. It appears that there are three cases in which the RBW is (1) greater than, (2) less than, or (3) comparable with the intrinsic linewidth. The measured spectra in the third class are stochastic and may show two or more peaks at a single harmonic.

  4. Physics | Department of Energy

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

    Physics Physics On January 13, 2012, Lawrence Berkeley National Laboratory senior scientist Dr. Saul Perlmutter spoke with Energy Department staff about his research that earned him a 2011 Nobel Prize in Physics. Featured Dark Energy Cam: Fermilab Expands Understanding of Expanding Universe Researchers at Fermi National Lab team stand beside the 570-megapixels, five-ton Dark Energy camera, which will be capable of measuring the expansion of the universe - and developing better models about how

  5. ORISE: Health physics services

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

    Health physics services Nuclear power plant The Oak Ridge Institute for Science and Education (ORISE) offers comprehensive health physics services in a number of technical areas for the U.S. Department of Energy (DOE) and U.S. Nuclear Regulatory Commission (NRC), as well as other federal and state agencies. From radiological facility audits and reviews to dose modeling and technical evaluations, ORISE is nationally-recognized for its health physics support to decontamination and decommissioning

  6. physics-based-html

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

    physical security Physical Security Systems After the 9/11 terrorist attacks, NNSA took steps to protect its critical facilities from vehicle bombs and strengthened its facilities against attacks. NNSA has begun consolidating its nuclear weapons material which reduces the number of targets to be protected. It has hardened its

    Physics-based High-Resolution Numerical Modeling of Bridge Foundation Scour

  7. American Physical Society Fellows

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

    American Physical Society Fellows American Physical Society (APS) Fellowships recognize those who have made advances in knowledge through original research or have made significant and innovative contributions in the application of physics to science and technology. Each year, no more than one-half of one percent of APS's current membership is recognized by their peers for election to the status of Fellow. The hundred-year-old society numbers tens of thousands of physicists worldwide. Name Year

  8. Self-doped molecular composite battery electrolytes

    DOE Patents [OSTI]

    Harrup, Mason K.; Wertsching, Alan K.; Stewart, Frederick F.

    2003-04-08

    This invention is in solid polymer-based electrolytes for battery applications. It uses molecular composite technology, coupled with unique preparation techniques to render a self-doped, stabilized electrolyte material suitable for inclusion in both primary and secondary batteries. In particular, a salt is incorporated in a nano-composite material formed by the in situ catalyzed condensation of a ceramic precursor in the presence of a solvated polymer material, utilizing a condensation agent comprised of at least one cation amenable to SPE applications. As such, the counterion in the condensation agent used in the formation of the molecular composite is already present as the electrolyte matrix develops. This procedure effectively decouples the cation loading levels required for maximum ionic conductivity from electrolyte physical properties associated with condensation agent loading levels by utilizing the inverse relationship discovered between condensation agent loading and the time domain of the aging step.

  9. Molecular Foundry Bay Cam

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

    Baycam The Molecular Foundry is a Department of Energy-funded nanoscience research facility at Berkeley Lab that provides users from around the world with access to cutting-edge expertise and instrumentation in a collaborative, multidisciplinary environment. twitter instagram facebook

  10. Nuclear Physics: Experiment Research

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

    Free Electron Laser (FEL) Medical Imaging Physics Topics Campaigns Meetings Recent Talks Archived Talks Additional Information Computing at JLab Operations Logbook Experiment ...

  11. Physical Protection Program Manual

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2002-12-23

    Supplements DOE O 473.1, by establishing requirements for the physical protection of safeguards and security interests. Cancels: DOE M 5632.1C-1

  12. Internships for Physics Majors

    Broader source: Energy.gov [DOE]

    Fermilab's IPM program offers ten-week summer internships to outstanding undergraduate physics majors. This program has been developed to familiarize students with opportunities at the frontiers of...

  13. Furth Plasma Physics Library | Princeton Plasma Physics Lab

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

    Safety & Health Furth Plasma Physics Library Lab Leadership Organization Chart ... Safety & Health Furth Plasma Physics Library Lab Leadership Organization Chart ...

  14. Nuclear & Particle Physics, Astrophysics, Cosmology

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

    Nuclear & Particle Physics science-innovationassetsimagesicon-science.jpg Nuclear & Particle Physics, Astrophysics, Cosmology National security depends on science and ...

  15. Organization | Princeton Plasma Physics Lab

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

    Careers Human Resources Directory Environment, Safety & Health Furth Plasma Physics ... Safety & Health Furth Plasma Physics Library Lab Leadership Organization Chart ...

  16. Physical Hydrogen Storage

    Broader source: Energy.gov [DOE]

    Physical storage is the most mature hydrogen storage technology. The current near-term technology for onboard automotive physical hydrogen storage is 350 and 700 bar (5,000 and 10,000 psi) nominal working-pressure compressed gas vessels—that is, "tanks."

  17. Probing Interactions in Complex Molecular Systems through Ordered Assembly

    SciTech Connect (OSTI)

    De Yoreo, J J; Bartelt, M C; Orme, C A; Villacampa, A; Weeks, B L; Miller, A E

    2002-01-31

    Emerging from the machinery of epitaxial science and chemical synthesis, is a growing emphasis on development of self-organized systems of complex molecular species. The nature of self-organization in these systems spans the continuum from simple crystallization of large molecules such as dendrimers and proteins, to assembly into large organized networks of nanometer-scale structures such as quantum dots or nanoparticles. In truth, self-organization in complex molecular systems has always been a central feature of many scientific disciplines including fields as diverse as structural biology, polymer science and geochemistry. But over the past decade, changes in those fields have often been marked by the degree to which researchers are using molecular-scale approaches to understand the hierarchy of structures and processes driven by this ordered assembly. At the same time, physical scientists have begun to use their knowledge of simple atomic and molecular systems to fabricate synthetic self-organized systems. This increasing activity in the field of self-organization is testament to the success of the physical and chemical sciences in building a detailed understanding of crystallization and epitaxy in simple atomic and molecular systems, one that is soundly rooted in thermodynamics and chemical kinetics. One of the fundamental challenges of chemistry and materials science in the coming decades is to develop a similarly well-founded physical understanding of assembly processes in complex molecular systems. Over the past five years, we have successfully used in situ atomic force microscopy (AFM) to investigate the physical controls on single crystal epitaxy from solutions for a wide range of molecular species. More recently, we have combined this method with grazing incidence X-ray diffraction and kinetic Monte Carlo modeling in order to relate morphology to surface atomic structure and processes. The purpose of this proposal was to extend this approach to assemblies of three classes of ''super molecular'' nanostructured materials. These included (1) dendrimers, (2) DNA bonded nano-particles, and (3) colloids, all of which form solution-based self-organizing systems. To this end, our goals were, first, to learn how to modify models of epitaxy in small molecule systems so that they are useful, efficient, and applicable to assembly of super-molecular species; and, second, to learn how systematic variations in the structure and bonding of the building blocks affect the surface kinetics and energetics that control the assembly process and the subsequent dynamic behavior of the assembled structures. AFM imaging provided experimental data on morphology and kinetics, while kinetic Monte Carlo (KMC) simulations related these data to molecular-scale processes and features.

  18. Physical Uncertainty Bounds (PUB)

    SciTech Connect (OSTI)

    Vaughan, Diane Elizabeth; Preston, Dean L.

    2015-03-19

    This paper introduces and motivates the need for a new methodology for determining upper bounds on the uncertainties in simulations of engineered systems due to limited fidelity in the composite continuum-level physics models needed to simulate the systems. We show that traditional uncertainty quantification methods provide, at best, a lower bound on this uncertainty. We propose to obtain bounds on the simulation uncertainties by first determining bounds on the physical quantities or processes relevant to system performance. By bounding these physics processes, as opposed to carrying out statistical analyses of the parameter sets of specific physics models or simply switching out the available physics models, one can obtain upper bounds on the uncertainties in simulated quantities of interest.

  19. Molecular-beam scattering

    SciTech Connect (OSTI)

    Vernon, M.F.

    1983-07-01

    The molecular-beam technique has been used in three different experimental arrangements to study a wide range of inter-atomic and molecular forces. Chapter 1 reports results of a low-energy (0.2 kcal/mole) elastic-scattering study of the He-Ar pair potential. The purpose of the study was to accurately characterize the shape of the potential in the well region, by scattering slow He atoms produced by expanding a mixture of He in N/sub 2/ from a cooled nozzle. Chapter 2 contains measurements of the vibrational predissociation spectra and product translational energy for clusters of water, benzene, and ammonia. The experiments show that most of the product energy remains in the internal molecular motions. Chapter 3 presents measurements of the reaction Na + HCl ..-->.. NaCl + H at collision energies of 5.38 and 19.4 kcal/mole. This is the first study to resolve both scattering angle and velocity for the reaction of a short lived (16 nsec) electronic excited state. Descriptions are given of computer programs written to analyze molecular-beam expansions to extract information characterizing their velocity distributions, and to calculate accurate laboratory elastic-scattering differential cross sections accounting for the finite apparatus resolution. Experimental results which attempted to determine the efficiency of optically pumping the Li(2/sup 2/P/sub 3/2/) and Na(3/sup 2/P/sub 3/2/) excited states are given. A simple three-level model for predicting the steady-state fraction of atoms in the excited state is included.

  20. Ultrafast optical pump-probe spectroscopy is used to reveal the coexistence of coupled antiferromagnetic (AFM)/ferroelectric (FE) and ferromagnetic (FM) orders in multiferroic TbMnO3 films, which can guide researchers in creating new kinds of multiferroic materials.

    SciTech Connect (OSTI)

    Qi, Jingbo; Zhu, Jianxin; Trugman, Stuart A.; Taylor, Antoinette; Jia, Quanxi; Prasankumar, Rohit

    2012-07-06

    Multiferroic materials have attracted much interest in the past decade, due not only to their novel device applications, but also their manifestations of coupling and interactions between different order parameters (particularly electric polarization and magnetic order). Recently, much attention has been focused on perovskite manganites, RMnO{sub 3} (R = rare earth ions), due to the discovery of a large magnetoelectric effect in these materials. The first member of this family to be discovered was TbMnO{sub 3} (TMO), which is now well established as a typical magnetoelectric multiferroic. Extensive experimental and theoretical studies have already been done on single crystal TMO (SC-TMO). In brief, SC-TMO, with a distorted orthorhombic perovskite structure, has an antiferromagnetic (AFM) phase transition at T{sub N} {approx}40 K with sinusoidally ordered Mn moments. Below T{sub FE} {approx} 28 K, ferroelectric (FE) order develops owing to the appearance of cycloidal spiral spin structure. In contrast, there are relatively few reports describing the properties of TMO thin films (typically grown on SrTiO{sub 3} (STO) substrates). In general, thin films can enable new functionality in materials, as their physical parameters can be changed by modifying their structure via strain imposed by the substrate. Strain in particular has the potential to directly couple FE and FM orders, which is very rare. This could benefit electronic device applications by providing low power consumption, high speed operation, and greater electric/magnetic field controllability. Previous investigations of magnetic properties in TMO films revealed an unexpected ferromagnetic (FM) order, in contrast to SC-TMO. However, several important questions regarding these films are still unanswered for instance: (1) What mechanism induces FM order? (2) Can FM, sinusoidal AFM and spiral AFM (or FE) orders coexist? (3) Can FM order be coupled to FE order? To fully understand these unique materials, experimental techniques capable of dynamically unraveling the interplay between these degrees of freedom on an ultrafast timescale are needed. Here, we use ultrafast optical pump-probe spectroscopy to reveal coexisting coupled magnetic orders in epitaxial TMO thin films grown on (001)-STO, which were not observed in previous work. Our temperature (T)-dependent transient differential reflectivity ({Delta}R/R) measurements show clear signatures of sinusoidal AFM, spiral AFM (FE) and FM phases developing as the film thickness changes. We carry out first-principle density functional theory (DFT) calculations to explain the coupling between AFM/FE and FM orders. These results reveal that the coupling between different magnetic orders observed in our multiferroic TMO thin films may offer greater control of functionality as compared to bulk single crystal multiferroics.

  1. Toward a constructive physics

    SciTech Connect (OSTI)

    Noyes, H.P.; Gefwert, C.; Manthey, M.J.

    1983-06-01

    We argue that the discretization of physics which has occurred thanks to the advent of quantum mechanics has replaced the continuum standards of time, length and mass which brought physics to maturity by counting. The (arbitrary in the sense of conventional dimensional analysis) standards have been replaced by three dimensional constants: the limiting velocity c, the unit of action h, and either a reference mass (eg m/sub p/) or a coupling constant (eg G related to the mass scale by hc/(2..pi..Gm/sub p//sup 2/) approx. = 1.7 x 10/sup 38/). Once these physical and experimental reference standards are accepted, the conventional approach is to connect physics to mathematics by means of dimensionless ratios. But these standards now rest on counting rather than ratios, and allow us to think of a fourth dimensionless mathematical concept, which is counting integers. According to constructive mathematics, counting has to be understood before engaging in the practice of mathematics in order to avoid redundancy. In its strict form constructive mathematics allows no completed infinities, and must provide finite algorithms for the computation of any acceptable concept. This finite requirement in constructive mathematics is in keeping with the practice of physics when that practice is restricted to hypotheses which are testable in a finite time. In this paper we attempt to outline a program for physics which will meet these rigid criteria while preserving, in so far as possible, the successes that conventional physics has already achieved.

  2. Courses on Beam Physics

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

    a foundation course on accelerator physics and associated technologies. The US-CERN-Japan-Russia Joint Accelerator School The purpose of the US-CERN-Japan-Russia joint school...

  3. Physical Protection Program

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2002-12-23

    Establishes Department of Energy management objectives, requirements and responsibilities for the physical protection of safeguards and security interests. Cancels DOE 5632.1C. Canceled by DOE O 470.4.

  4. Physics Division annual review, 1 April 1987--31 March 1988

    SciTech Connect (OSTI)

    Not Available

    1988-06-01

    This paper contains a description of the research project at Argonne National Laboratory over the past year (4/11/87--3/31/88). The major sections of this report in nuclear physics are: research at ATLAS; operation and development of TLAS: medium-energy nuclear physics and weak interactions; and theoretical nuclei physics. The major sections in atomic physics are: high-resolution laser-rf spectroscopy with beams of atoms, molecules and ions; beam-foil research, ion-beam laser interactions, and collision dynamics of heavy ions; interactions of fast atomic and molecular ions with solid and gaseous target; theoretical atomic physics; atomic physics at ATLAS; atomic physics using a synchrotron light source; and molecular structures and dynamics from coulomb-explosion measurements. (LSP)

  5. UNIRIB: Physics Topics

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

    Physics Topics Research Capitalizing on the strengths of nine collaborating research universities and the world-class equipment available at the Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge National Laboratory (ORNL), the University Radioactive Ion Beam (UNIRIB) consortium is conducting research at the forefront of nuclear physics. UNIRIB, a division of the Oak Ridge Institute for Science and Education (ORISE), brings together researchers from around the world to study the

  6. Nuclear Physics: Experiment Research

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

    Colloquium Experiment Research User/Researcher Information print version Research Highlights Public Interest Nuclear Physics Accelerator Free Electron Laser (FEL) Medical Imaging Physics Topics Campaigns Meetings Recent Talks Archived Talks Additional Information Computing at JLab Operations Logbook Accelerator and Experimental Schedule Memos & Information Short Term Schedule (MCC Whiteboard) Nominal Dates for Bi-annual Beam Time Requests Forms for Beam Time Requests and Experiment

  7. LANSCE Weapons Physics

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

    7 LANSCE Weapons Physics Fortune 500 companies and weapons designers alike rely on our internationally recognized nuclear physics and materials science expertise as well as our one-of-a-kind experimental tools. Contact Us Group Leader Gus Sinnis Email Deputy Group Leader Fredrik Tovesson Email Deputy Group Leader and Experimental Area Manager Charles Kelsey Email Group Office (505) 665-5390 Time Projection Chamber at LANSCE Researcher making measurements of fission cross sections on the Time

  8. Neutrino Oscillation Physics

    SciTech Connect (OSTI)

    Kayser, Boris

    2012-06-01

    To complement the neutrino-physics lectures given at the 2011 International School on Astro Particle Physics devoted to Neutrino Physics and Astrophysics (ISAPP 2011; Varenna, Italy), at the 2011 European School of High Energy Physics (ESHEP 2011; Cheila Gradistei, Romania), and, in modified form, at other summer schools, we present here a written description of the physics of neutrino oscillation. This description is centered on a new way of deriving the oscillation probability. We also provide a brief guide to references relevant to topics other than neutrino oscillation that were covered in the lectures. Neutrinos and photons are by far the most abundant elementary particles in the universe. Thus, if we would like to comprehend the universe, we must understand the neutrinos. Of course, studying the neutrinos is challenging, since the only known forces through which these electrically-neutral leptons interact are the weak force and gravity. Consequently, interactions of neutrinos in a detector are very rare events, so that very large detectors and intense neutrino sources are needed to make experiments feasible. Nevertheless, we have confirmed that the weak interactions of neutrinos are correctly described by the Standard Model (SM) of elementary particle physics. Moreover, in the last 14 years, we have discovered that neutrinos have nonzero masses, and that leptons mix. These discoveries have been based on the observation that neutrinos can change from one 'flavor' to another - the phenomenon known as neutrino oscillation. We shall explain the physics of neutrino oscillation, deriving the probability of oscillation in a new way. We shall also provide a very brief guide to references that can be used to study some major neutrino-physics topics other than neutrino oscillation.

  9. Palm Physics Page

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

    Palm Physics Page ** We no longer support this website. This is a preliminary group of Palm applications/databases that are intended to serve the interests of atomic, nuclear and particle physics. Applications Periodic Table: Shareware version of the periodic table with basic chemical properties of the elements.(Download) Particle Data Book: From the Particle Data Group at LBL. (Download) Heavy Ion Fusion Calculator: Compute available energy, Coulomb energy, maximum angular momentum for compound

  10. Computational Physics and Methods

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

    2 Computational Physics and Methods Performing innovative simulations of physics phenomena on tomorrow's scientific computing platforms Growth and emissivity of young galaxy hosting a supermassive black hole as calculated in cosmological code ENZO and post-processed with radiative transfer code AURORA. image showing detailed turbulence simulation, Rayleigh-Taylor Turbulence imaging: the largest turbulence simulations to date Advanced multi-scale modeling Turbulence datasets Density iso-surfaces

  11. American Physical Society

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

    Los Alamos scientists honored by American Physical Society November 12, 2015 LOS ALAMOS, N.M., Nov. 12, 2015-Ten Los Alamos National Laboratory scientists are new Fellows of the American Physical Society. Tariq Aslam, Steven Batha, Eric Bauer, Hou-Tong Chen, Diego Alejandro Dalvit, Dinh Nguyen, Alan Perelson, Filip Ronning, Alexander Saunders and Glen Wurden were named this week by the national organization. "We're extremely pleased that the technical accomplishments of our talented staff

  12. Ultrafast carrier dynamics in the large-magnetoresistance material WTe2

    SciTech Connect (OSTI)

    Dai, Y. M.; Bowlan, J.; Li, H.; Miao, H.; Wu, S. F.; Kong, W. D.; Shi, Y. G.; Trugman, S. A.; Zhu, J. -X.; Ding, H.; Taylor, A. J.; Yarotski, D. A.; Prasankumar, R. P.

    2015-10-07

    In this study, ultrafast optical pump-probe spectroscopy is used to track carrier dynamics in the large-magnetoresistance material WTe2. Our experiments reveal a fast relaxation process occurring on a subpicosecond time scale that is caused by electron-phonon thermalization, allowing us to extract the electron-phonon coupling constant. An additional slower relaxation process, occurring on a time scale of ~5–15 ps, is attributed to phonon-assisted electron-hole recombination. As the temperature decreases from 300 K, the time scale governing this process increases due to the reduction of the phonon population. However, below ~50 K, an unusual decrease of the recombination time sets in, most likely due to a change in the electronic structure that has been linked to the large magnetoresistance observed in this material.

  13. Effect of carrier recombination on ultrafast carrier dynamics in thin films of the topological insulator Bi{sub 2}Se{sub 3}

    SciTech Connect (OSTI)

    Glinka, Yuri D.; Babakiray, Sercan; Johnson, Trent A.; Holcomb, Mikel B.; Lederman, David

    2014-10-27

    Transient reflectivity (TR) from thin films (6–40 nm thick) of the topological insulator Bi{sub 2}Se{sub 3} revealed ultrafast carrier dynamics, which suggest the existence of both radiative and non-radiative recombination between electrons residing in the upper cone of initially unoccupied high energy Dirac surface states (SS) and holes residing in the lower cone of occupied low energy Dirac SS. The modeling of measured TR traces allowed us to conclude that recombination is induced by the depletion of bulk electrons in films below ∼20 nm thick due to the charge captured on the surface defects. We predict that such recombination processes can be observed using time-resolved photoluminescence techniques.

  14. High efficiency, high quality x-ray optic based on ellipsoidally bent highly oriented pyrolytic graphite crystal for ultrafast x-ray diffraction experiments

    SciTech Connect (OSTI)

    Uschmann, I.; Nothelle, U.; Foerster, E.; Arkadiev, V.; Langhoff, N.; Antonov, A.; Grigorieva, I.; Steinkopf, R.; Gebhardt, A

    2005-08-20

    By the use of a thin highly oriented pyrolytic graphite crystal (HOPG) bent to a high-performance ellipsoidal shape it was possible to focus monochromatic x-rays of 4.5 keV photon energy with an efficiency of 0.0033, which is 30 times larger than for previously used bent crystals. Isotropic TiK{sub a}lpha radiation of a 150 {mu}m source was focused onto a 450 {mu}m spot. The size of the focal spot can be explained by broadening due to the mosaic crystal rocking curve. The rocking curve width (FWHM) of the thin graphite foil was determined to 0.11 deg. . The estimated temporal broadening of an ultrashort Kalpha pulse by the crystal is not larger than 300 fs. These properties make the x-ray optic very attractive for ultrafast time-resolved x-ray measurements.

  15. 2D heterodyne-detected sum frequency generation study on the ultrafast vibrational dynamics of H{sub 2}O and HOD water at charged interfaces

    SciTech Connect (OSTI)

    Inoue, Ken-ichi; Singh, Prashant C.; Nihonyanagi, Satoshi; Tahara, Tahei; Yamaguchi, Shoichi

    2015-06-07

    Two-dimensional heterodyne-detected vibrational sum-frequency generation (2D HD-VSFG) spectroscopy is applied to study the ultrafast vibrational dynamics of water at positively charged aqueous interfaces, and 2D HD-VSFG spectra of cetyltrimethylammonium bromide (CTAB)/water interfaces in the whole hydrogen-bonded OH stretch region (3000 cm{sup ?1} ? ?{sub pump} ? 3600 cm{sup ?1}) are measured. 2D HD-VSFG spectrum of the CTAB/isotopically diluted water (HOD-D{sub 2}O) interface exhibits a diagonally elongated bleaching lobe immediately after excitation, which becomes round with a time constant of ?0.3 ps due to spectral diffusion. In contrast, 2D HD-VSFG spectrum of the CTAB/H{sub 2}O interface at 0.0 ps clearly shows two diagonal peaks and their cross peaks in the bleaching region, corresponding to the double peaks observed at 3230 cm{sup ?1} and 3420 cm{sup ?1} in the steady-state HD-VSFG spectrum. Horizontal slices of the 2D spectrum show that the relative intensity of the two peaks of the bleaching at the CTAB/H{sub 2}O interface gradually change with the change of the pump frequency. We simulate the pump-frequency dependence of the bleaching feature using a model that takes account of the Fermi resonance and inhomogeneity of the OH stretch vibration, and the simulated spectra reproduce the essential features of the 2D HD-VSFG spectra of the CTAB/H{sub 2}O interface. The present study demonstrates that heterodyne detection of the time-resolved VSFG is critically important for studying the ultrafast dynamics of water interfaces and for unveiling the underlying mechanism.

  16. Physics Topics - Rotating Wall Machine - UW Plasma Physics

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

    Physics Topics UW Madison Line Tied Reconnection Experiment Physics Topics LTRX HomeResearch MissionLTRX DevicePhysics TopicsDiagnosticsLTRX GalleryLTRX People CPLA Home Directory ...

  17. The Intersection of Physics and Biology

    ScienceCinema (OSTI)

    Liphardt, Jan [University of California, Berkeley, California, United States

    2010-09-01

    In April 1953, Watson and Crick largely defined the program of 20th century biology: obtaining the blueprint of life encoded in the DNA. Fifty years later, in 2003, the sequencing of the human genome was completed. Like any major scientific breakthrough, the sequencing of the human genome raised many more questions than it answered. I'll brief you on some of the big open problems in cell and developmental biology, and I'll explain why approaches, tools, and ideas from the physical sciences are currently reshaping biological research. Super-resolution light microscopies are revealing the intricate spatial organization of cells, single-molecule methods show how molecular machines function, and new probes are clarifying the role of mechanical forces in cell and tissue function. At the same time, Physics stands to gain beautiful new problems in soft condensed matter, quantum mechanics, and non-equilibrium thermodynamics.

  18. The encyclopedia of physics. Third edition

    SciTech Connect (OSTI)

    Bescancon, R.M.

    1985-01-01

    This encyclopedia contains 350 articles which have been selected to give adequate representation to all branches of the subject, with emphasis on new and sophisticated concepts. A special feature of this encyclopedia is its arrangement of material. Articles on the main divisions of physics are written for readers with little background in the subject, articles on subdivisions are aimed at those with more knowledge, and articles on finer division are geared to users with farily sound backgrounds in physics and mathematics. Among the topics given new or expanded coverage are gauge theories, quantum chromodynamics, electroweak theory, and grand unified theories. Readers will also find new information on particle theory, biomedical instrumentation, molecular biology, quarks and pulsars, laser fusion, and volcanology.

  19. MOLECULAR VACUUM PUMP

    DOE Patents [OSTI]

    Eckberg, E.E.

    1960-09-27

    A multiple molecular vacuum pump capable of producing a vacuum of the order of 10/sup -9/ mm Hg is described. The pump comprises a casing of an aggregate of paired and matched cylindrical plates, a recessed portion on one face of each plate concentrically positioned formed by a radially extending wall and matching the similarly recessed portion of its twin plate of that pair of plates and for all paired and matched plates; a plurality of grooves formed in the radially extending walls of each and all recesses progressing in a spiral manner from their respective starting points out at the periphery of the recess inwardly to the central area; a plurality of rotors rotatably mounted to closely occupy the spaces as presented by the paired and matched recesses between all paired plates; a hollowed drive-shaft perforated at points adjacent to the termini of all spiral grooves; inlet ports at the starting points of all grooves and through all plates at common points to each respectively; and a common outlet passage presented by the hollow portion of the perforated hollowed drive-shaft of the molecular pump. (AEC)

  20. Heteropolymer freezing and design: Towards physical models of protein folding

    SciTech Connect (OSTI)

    Pande, Vijay S. [Chemistry Department, Stanford University, Stanford, California 94305-5080 (United States)] [Chemistry Department, Stanford University, Stanford, California 94305-5080 (United States); Grosberg, Alexander Yu. [Department of Physics, University of Minnesota, Minneapolis, Minnesota 55455 (United States)] [Department of Physics, University of Minnesota, Minneapolis, Minnesota 55455 (United States); Tanaka, Toyoichi [Department of Physics and Center for Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)] [Department of Physics and Center for Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    2000-01-01

    Protein folding has become one of the most actively studied problems in modern molecular biophysics. Approaches to the problem combine ideas from the physics of disordered systems, polymer physics, and molecular biology. Much can be learned from the statistical properties of model heteropolymers, the chain molecules having different monomers in irregular sequences. Even in highly evolved proteins, there is a strong random element in the sequences, which gives rise to a statistical ensemble of sequences for a given folded shape. Simple analytic models give rise to phase transitions between random, glassy, and folded states, depending on the temperature T and the design temperature T{sup des} of the ensemble of sequences. Besides considering the analytic results obtainable in a random-energy model and in the Flory mean-field model of polymers, the article reports on confirming numerical simulations. (c) 2000 The American Physical Society.

  1. PLASMA PHYSICS AND FUSION TECHNOLOGY; GRAPHITE; CREEP; PHYSICAL...

    Office of Scientific and Technical Information (OSTI)

    creep of graphite) Kennedy, C.R. 36 MATERIALS SCIENCE; 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; GRAPHITE; CREEP; PHYSICAL RADIATION EFFECTS; JAPAN; MEETINGS; TRAVEL; ASIA; CARBON;...

  2. Gogny, D; Schunck, N 73 NUCLEAR PHYSICS AND RADIATION PHYSICS...

    Office of Scientific and Technical Information (OSTI)

    of low energy fission: fragment properties Younes, W; Gogny, D; Schunck, N 73 NUCLEAR PHYSICS AND RADIATION PHYSICS Abstract not provided Lawrence Livermore National Laboratory...

  3. QCD and Hadron Physics

    SciTech Connect (OSTI)

    Brodsky, Stanley J.; Deshpande, Abhay L.; Gao, Haiyan; McKeown, Robert D.; Meyer, Curtis A.; Meziani, Zein-Eddine; Milner, Richard G.; Qiu, Jianwei; Richards, David G.; Roberts, Craig D.

    2015-02-26

    This White Paper presents the recommendations and scientific conclusions from the Town Meeting on QCD and Hadronic Physics that took place in the period 13-15 September 2014 at Temple University as part of the NSAC 2014 Long Range Planning process. The meeting was held in coordination with the Town Meeting on Phases of QCD and included a full day of joint plenary sessions of the two meetings. The goals of the meeting were to report and highlight progress in hadron physics in the seven years since the 2007 Long Range Plan (LRP07), and present a vision for the future by identifying the key questions and plausible paths to solutions which should define the next decade. The introductory summary details the recommendations and their supporting rationales, as determined at the Town Meeting on QCD and Hadron Physics, and the endorsements that were voted upon. The larger document is organized as follows. Section 2 highlights major progress since the 2007 LRP. It is followed, in Section 3, by a brief overview of the physics program planned for the immediate future. Finally, Section 4 provides an overview of the physics motivations and goals associated with the next QCD frontier: the Electron-Ion-Collider.

  4. Particle physics and cosmology

    SciTech Connect (OSTI)

    Kolb, E.W.

    1986-10-01

    This series of lectures is about the role of particle physics in physical processes that occurred in the very early stages of the bug gang. Of particular interest is the role of particle physics in determining the evolution of the early Universe, and the effect of particle physics on the present structure of the Universe. The use of the big bang as a laboratory for placing limits on new particle physics theories will also be discussed. Section 1 reviews the standard cosmology, including primordial nucleosynthesis. Section 2 reviews the decoupling of weakly interacting particles in the early Universe, and discusses neutrino cosmology and the resulting limits that may be placed on the mass and lifetime of massive neutrinos. Section 3 discusses the evolution of the vacuum through phase transitions in the early Universe and the formation of topological defects in the transitions. Section 4 covers recent work on the generation of the baryon asymmetry by baryon-number violating reactions in Grand Unified Theories, and mentions some recent work on baryon number violation effects at the electroweak transition. Section 5 is devoted to theories of cosmic inflation. Finally, Section 6 is a discussion of the role of extra spatial dimensions in the evolution of the early Universe. 78 refs., 32 figs., 6 tabs.

  5. FTP archives for physics

    SciTech Connect (OSTI)

    Trunec, D.; Brablec, A.; Kapicka, V.

    1995-12-31

    We have established archives for programs, data, papers etc. in physics (mainly for plasma physics). The archives are located at computer ftp.muni.cz in the directory pub/muni.cz/physics. These archives can be reached by anonymous FTP or by gopher server gopher.muni.cz (147.251.4.33). At the present time, programs for PC, cross sections for electrons, swarm parameters and rate constants stored are in the archives. We would like to collect the programs for calculations in physics (mainly for PC). We suppose that each program should have a testing example and some description. We would also like to collect physical constants and experimental or theoretical data (e.g. cross sections, swarm parameters and rate constants), which are important for other calculation or for comparison with the results of others studies. Interested scholars are invited to sent us their programs, data, preprints and reports for these archives. All files in the archives are in public domain and can be obtained using computer network Internet.

  6. Ultrafast neutron detector

    DOE Patents [OSTI]

    Wang, Ching L.

    1987-01-01

    The invention comprises a neutron detector (50) of very high temporal resolution that is particularly well suited for measuring the fusion reaction neutrons produced by laser-driven inertial confinement fusion targets. The detector comprises a biased two-conductor traveling-wave transmission line (54, 56, 58, 68) having a uranium cathode (60) and a phosphor anode (62) as respective parts of the two conductors. A charge line and Auston switch assembly (70, 72, 74) launch an electric field pulse along the transmission line. Neutrons striking the uranium cathode at a location where the field pulse is passing, are enabled to strike the phosphor anode and produce light that is recorded on photographic film (64). The transmission line may be variously configured to achieve specific experimental goals.

  7. Ultrafast neutron detector

    DOE Patents [OSTI]

    Wang, C.L.

    1985-06-19

    A neutron detector of very high temporal resolution is described. It may be used to measure distributions of neutrons produced by fusion reactions that persist for times as short as about 50 picoseconds.

  8. Timeline | Princeton Plasma Physics Lab

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

    Project Matterhorn's first linear device, L-1, begins operation for the study of basic plasma physics. 1959 The first Princeton doctoral degree in plasma physics is awarded. Since ...

  9. Neutrino Physics AAPT Strand Day

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

    Physics AAPT Strand Day NSTA Regional, 2005 Jocelyn Monroe, Columbia University 1. What Is ... quark (FNAL) The Standard Model New Physics (Relatively Speaking) 1900s: e discovered ...

  10. Nuclear Physics: Archived Talks - Accelerator

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

    Free Electron Laser (FEL) Medical Imaging Physics Topics Campaigns Meetings Recent Talks ... Additional Information Computing at JLab Operations Logbook Physics Topics: Archived Talks ...

  11. Physics and Chemistry of Materials

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

    1 Physics and Chemistry of Materials Developing new science and technologies needed for ... Fundamental and applied theoretical research on the physics and chemistry of materials The ...

  12. ORISE: Applied health physics projects

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

    Applied health physics projects The Oak Ridge Institute for Science and Education (ORISE) provides applied health physics services to government agencies needing technical support ...

  13. Physics Beyond the Standard Model

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

    Physics Beyond the Standard Model 1663 Los Alamos science and technology magazine Latest Issue:October 2015 past issues All Issues submit Physics Beyond the Standard Model...

  14. Assessment of Molecular Modeling & Simulation

    SciTech Connect (OSTI)

    2002-01-03

    This report reviews the development and applications of molecular and materials modeling in Europe and Japan in comparison to those in the United States. Topics covered include computational quantum chemistry, molecular simulations by molecular dynamics and Monte Carlo methods, mesoscale modeling of material domains, molecular-structure/macroscale property correlations like QSARs and QSPRs, and related information technologies like informatics and special-purpose molecular-modeling computers. The panel's findings include the following: The United States leads this field in many scientific areas. However, Canada has particular strengths in DFT methods and homogeneous catalysis; Europe in heterogeneous catalysis, mesoscale, and materials modeling; and Japan in materials modeling and special-purpose computing. Major government-industry initiatives are underway in Europe and Japan, notably in multi-scale materials modeling and in development of chemistry-capable ab-initio molecular dynamics codes.

  15. J. Plasma Physics:

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

    Plasma Physics: page 1 of 18. c Cambridge University Press 2015 doi:10.1017/S0022377815000471 1 Prospects for observing the magnetorotational instability in the plasma Couette experiment K. Flanagan 1 †, M. Clark 1 , C. Collins 1,2 , C. M. Cooper 1 , I. V. Khalzov 1,3 , J. Wallace 1 and C. B. Forest 1 1 Department of Physics, University of Wisconsin, Madison, WI 53706, USA 2 University of California Irvine, Irvine, CA 92697, USA 3 National Research Centre 'Kurchatov Institute', Moscow, 123182,

  16. PHYSICAL REVIEW E

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

    PHYSICAL REVIEW E 85, 066315 (2012) Role of large-scale velocity fluctuations in a two-vortex kinematic dynamo E. J. Kaplan, 1,2,* B. P. Brown, 1,2 K. Rahbarnia, 1,2 and C. B. Forest 1,2 1 Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, Wisconsin 53706, USA 2 Center for Magnetic-Self Organization in Laboratory and Astrophysical Plasmas, University of Wisconsin-Madison, 21 North Park Street, Madison, Wisconsin 53715, USA (Received 10 April 2012; revised

  17. Princeton Plasma Physics Laboratory

    SciTech Connect (OSTI)

    Not Available

    1990-01-01

    This report discusses the following topics: principal parameters achieved in experimental devices fiscal year 1990; tokamak fusion test reactor; compact ignition tokamak; Princeton beta experiment- modification; current drive experiment-upgrade; international collaboration; x-ray laser studies; spacecraft glow experiment; plasma processing: deposition and etching of thin films; theoretical studies; tokamak modeling; international thermonuclear experimental reactor; engineering department; project planning and safety office; quality assurance and reliability; technology transfer; administrative operations; PPPL patent invention disclosures for fiscal year 1990; graduate education; plasma physics; graduate education: plasma science and technology; science education program; and Princeton Plasma Physics Laboratory reports fiscal year 1990.

  18. Mysteries of 'molecular machines' revealed

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

    Mysteries of 'molecular machines' revealed Mysteries of 'molecular machines' revealed Scientists are making it easier for pharmaceutical companies and researchers to see the detailed inner workings of molecular machines. December 22, 2014 A picture of a membrane protein called cysZ determined with Phenix software using data that could not previously be analyzed. A picture of a membrane protein called cysZ determined with Phenix software using data that could not previously be analyzed. Contact

  19. Electron Trapping by Molecular Vibration

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

    Electron Trapping by Molecular Vibration Electron Trapping by Molecular Vibration Print Wednesday, 27 April 2005 00:00 In photoelectron spectroscopy experiments performed at the ALS, a group of researchers has found that electronic transitions normally thought to be forbidden can in fact be excited in conjunction with certain types of molecular vibrations. Specifically, they found that when the symmetry of a linear triatomic molecule is broken by asymmetric vibrational modes, photoelectrons can

  20. Lubricant characterization by molecular simulation

    SciTech Connect (OSTI)

    Moore, J.D.; Cui, S.T.; Cummings, P.T.; Cochran, H.D.

    1997-12-01

    The authors have reported the calculation of the kinematic viscosity index of squalane from nonequilibrium molecular dynamics simulations. This represents the first accurate quantitative prediction of this measure of lubricant performance by molecular simulation. Using the same general alkane potential model, this computational approach offers the possibility of predicting the performance of potential lubricants prior to synthesis. Consequently, molecular simulation is poised to become an important tool for future lubricant development.

  1. Electron Trapping by Molecular Vibration

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

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

  2. Operational health physics training

    SciTech Connect (OSTI)

    1992-06-01

    The initial four sections treat basic information concerning atomic structure and other useful physical quantities, natural radioactivity, the properties of {alpha}, {beta}, {gamma}, x rays and neutrons, and the concepts and units of radiation dosimetry (including SI units). Section 5 deals with biological effects and the risks associated with radiation exposure. Background radiation and man-made sources are discussed next. The basic recommendations of the ICRP concerning dose limitations: justification, optimization (ALARA concepts and applications) and dose limits are covered in Section seven. Section eight is an expanded version of shielding, and the internal dosimetry discussion has been extensively revised to reflect the concepts contained in the MIRD methodology and ICRP 30. The remaining sections discuss the operational health physics approach to monitoring radiation. Individual sections include radiation detection principles, instrument operation and counting statistics, health physics instruments and personnel monitoring devices. The last five sections deal with the nature of, operation principles of, health physics aspects of, and monitoring approaches to air sampling, reactors, nuclear safety, gloveboxes and hot cells, accelerators and x ray sources. Decontamination, waste disposal and transportation of radionuclides are added topics. Several appendices containing constants, symbols, selected mathematical topics, and the Chart of the Nuclides, and an index have been included.

  3. High energy physics

    SciTech Connect (OSTI)

    Kernan, A.; Shen, B.C.; Ma, E.

    1997-07-01

    This proposal is for the continuation of the High Energy Physics program at the University of California at Riverside. In hadron collider physics the authors will complete their transition from experiment UA1 at CERN to the DZERO experiment at Fermilab. On experiment UA1 their effort will concentrate on data analysis at Riverside. At Fermilab they will coordinate the high voltage system for all detector elements. They will also carry out hardware/software development for the D0 muon detector. The TPC/Two-Gamma experiment has completed its present phase of data-taking after accumulating 160 pb{sup {minus}}1 of luminosity. The UC Riverside group will continue data and physics analysis and make minor hardware improvement for the high luminosity run. The UC Riverside group is participating in design and implementation of the data acquisition system for the OPAL experiment at LEP. Mechanical and electronics construction of the OPAL hadron calorimeter strip readout system is proceeding on schedule. Data analysis and Monte Carlo detector simulation efforts are proceeding in preparation for the first physics run when IEP operation comenses in fall 1989.

  4. Physics overview of AVLIS

    SciTech Connect (OSTI)

    Solarz, R.W.

    1985-02-01

    Atomic vapor laser isotope separation (AVLIS) represents the largest-scale potential application of tunable lasers that has received serious attention within the chemical physics community. For over a decade the US Department of Energy has funded an aggressive program in AVLIS at Lawrence Livermore National Laboratory. After extensive research, the underlying physical principles have been identified and optimized, the major technology components have been developed, and the integrated enrichment performance of the process has been tested under realistic conditions. The central physical processes are outlined, progress to date on the technology elements is reviewed, and scaling laws that can be used to scope out new applications are fomulated. The two primary applications of major interest to the Department of Energy are the production of light-water reactor fuel and the conversion of fuel-grade plutonium to weapons-grade material. In FY 1984 the total AVLIS funding level for these two missions was approximately $150M. In addition to these primary missions, a variety of applications exist that all potentially use a common base of AVLIS technology. These include missions such as the enrichment of mercury isotopes to improve fluorescent lamp efficiency, the enrichment of iodine isotopes for medical isotope use, and the cleanup of strontium from defense waste for recovering strontium isotopes for radio-thermal mechanical generators. We will see that the ability to rapidly assess the economic and technical feasibility of each mission is derived from the general applicability of AVLIS physics and AVLIS technology.

  5. Physics Teachers Workshop

    ScienceCinema (OSTI)

    Huggins, DaNel; Calhoun, John; Palmer, Alyson; Thorpe, Steve; Vanderveen, Anne;

    2013-05-28

    INL is looking for the nation's top high school physics teachers to attend our July workshop in Idaho Falls. Participants get to learn from nuclear researchers, tour facilities including a research reactor and interact with peers from across the country. You can learn more about INL projects at http://www.facebook.com/idahonationallaboratory

  6. RESEARCH IN PARTICLE PHYSICS

    SciTech Connect (OSTI)

    Kearns, Edward

    2013-07-12

    This is the final report for the Department of Energy Grant to Principal Investigators in Experimental and Theoretical Particle Physics at Boston University. The research performed was in the Energy Frontier at the LHC, the Intensity Frontier at Super-Kamiokande and T2K, the Cosmic Frontier and detector R&D in dark matter detector development, and in particle theory.

  7. FSU High Energy Physics

    SciTech Connect (OSTI)

    Prosper, Harrison B.; Adams, Todd; Askew, Andrew; Berg, Bernd; Blessing, Susan K.; Okui, Takemichi; Owens, Joseph F.; Reina, Laura; Wahl, Horst D.

    2014-12-01

    The High Energy Physics group at Florida State University (FSU), which was established in 1958, is engaged in the study of the fundamental constituents of matter and the laws by which they interact. The group comprises theoretical and experimental physicists, who sometimes collaborate on projects of mutual interest. The report highlights the main recent achievements of the group. Significant, recent, achievements of the group’s theoretical physicists include progress in making precise predictions in the theory of the Higgs boson and its associated processes, and in the theoretical understanding of mathematical quantities called parton distribution functions that are related to the structure of composite particles such as the proton. These functions are needed to compare data from particle collisions, such as the proton-proton collisions at the CERN Large Hadron Collider (LHC), with theoretical predictions. The report also describes the progress in providing analogous functions for heavy nuclei, which find application in neutrino physics. The report highlights progress in understanding quantum field theory on a lattice of points in space and time (an area of study called lattice field theory), the progress in constructing several theories of potential new physics that can be tested at the LHC, and interesting new ideas in the theory of the inflationary expansion of the very early universe. The focus of the experimental physicists is the Compact Muon Solenoid (CMS) experiment at CERN. The report, however, also includes results from the D0 experiment at Fermilab to which the group made numerous contributions over a period of many years. The experimental group is particularly interested in looking for new physics at the LHC that may provide the necessary insight to extend the standard model (SM) of particle physics. Indeed, the search for new physics is the primary task of contemporary particle physics, one motivated by the need to explain certain facts, such as the non-zero neutrino masses or the overwhelming astrophysical evidence for an invisible form of matter, called dark matter, that has had a marked effect on the evolution of structure in the universe. The report highlights the main, recent, experimental achievements of the experimental group, which include the investigation of properties of the W and Z bosons; the search for new heavy stable charged particles and the search for a proposed property of nature called supersymmetry in proton-proton collisions that yield high energy photons. In addition, we report a few results from a more general search for supersymmetry at the LHC, initiated by the group. The report also highlights the group's significant contributions, both theoretical and experimental, to the 2012 discovery of the Higgs boson and the measurement of its properties.

  8. Structure of Molecular Thin Films for Organic Electronics | Stanford

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

    Synchrotron Radiation Lightsource Structure of Molecular Thin Films for Organic Electronics Friday, April 6, 2012 - 1:00pm SSRL Conference Room 137-322 Bert Nickel, Physics Faculty and CeNS, Ludwig-Maximilians-University, München Thin films made out of conjugated small molecules and polymers exhibit very interesting semiconducting properties. While some applications such as light emitting diodes (OLED) are already on the market, other application such as solar cells, integrated circuits,

  9. LHC forward physics

    SciTech Connect (OSTI)

    Cartiglia, N.; Royon, C.

    2015-10-02

    The goal of this report is to give a comprehensive overview of the rich field of forward physics, with a special attention to the topics that can be studied at the LHC. The report starts presenting a selection of the Monte Carlo simulation tools currently available, chapter 2, then enters the rich phenomenology of QCD at low, chapter 3, and high, chapter 4, momentum transfer, while the unique scattering conditions of central exclusive production are analyzed in chapter 5. The last two experimental topics, Cosmic Ray and Heavy Ion physics are presented in the chapter 6 and 7 respectively. Chapter 8 is dedicated to the BFKL dynamics, multiparton interactions, and saturation. The report ends with an overview of the forward detectors at LHC. Each chapter is correlated with a comprehensive bibliography, attempting to provide to the interested reader with a wide opportunity for further studies.

  10. Nuclear Physics | Jefferson Lab

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

    Nuclear Physics Scientists from across the country and around the world use the Thomas Jefferson National Accelerator Facility to advance mankind's understanding of the atom's nucleus. To probe nuclei, scientists use continuous beams of high-energy electrons from the lab's Continuous Electron Beam Accelerator Facility, or CEBAF, and the advanced particle-detection and ultra-high-speed data acquisition equipment in CEBAF's four experimental halls. Jefferson Lab has both theoretical and

  11. Princeton Plasma Physics Laboratory:

    SciTech Connect (OSTI)

    Phillips, C.A.

    1986-01-01

    This paper discusses progress on experiments at the Princeton Plasma Physics Laboratory. The projects and areas discussed are: Principal Parameters Achieved in Experimental Devices, Tokamak Fusion Test Reactor, Princeton Large Torus, Princeton Beta Experiment, S-1 Spheromak, Current-Drive Experiment, X-ray Laser Studies, Theoretical Division, Tokamak Modeling, Spacecraft Glow Experiment, Compact Ignition Tokamak, Engineering Department, Project Planning and Safety Office, Quality Assurance and Reliability, and Administrative Operations.

  12. Nuclear Physics Review

    SciTech Connect (OSTI)

    Walker-Loud, Andre

    2014-11-01

    Anchoring low-energy nuclear physics to the fundamental theory of strong interactions remains an outstanding challenge. I review the current progress and challenges of the endeavor to use lattice QCD to bridge this connection. This is a particularly exciting time for this line of research as demonstrated by the spike in the number of different collaborative efforts focussed on this problem and presented at this conference. I first digress and discuss the 2013 Ken Wilson Award.

  13. Emergency Response Health Physics

    SciTech Connect (OSTI)

    Mena, RaJah; Pemberton, Wendy; Beal, William

    2012-05-01

    Health physics is an important discipline with regard to understanding the effects of radiation on human health; however, there are major differences between health physics for research or occupational safety and health physics during a large-scale radiological emergency. The deployment of a U.S. Department of Energy/National Nuclear Security Administration (DOE/NNSA) monitoring and assessment team to Japan in the wake of the March 2011 accident at Fukushima Daiichi Nuclear Power Plant yielded a wealth of lessons on these difference. Critical teams (CMOC (Consequence Management Outside the Continental U.S.) and CMHT (Consequence Management Home Team) ) worked together to collect, compile, review, and analyze radiological data from Japan to support the response needs of and answer questions from the Government of Japan, the U.S. military in Japan, the U.S. Embassy and U.S. citizens in Japan, and U.S. citizens in America. This paper addresses the unique challenges presented to the health physicist or analyst of radiological data in a large-scale emergency. A key lesson learned was that public perception and the availability of technology with social media requires a diligent effort to keep the public informed of the science behind the decisions in a manner that is meaningful to them.

  14. University of Washington, Nuclear Physics Laboratory annual report, 1995

    SciTech Connect (OSTI)

    1995-04-01

    The Nuclear Physics Laboratory of the University of Washington supports a broad program of experimental physics research. The current program includes in-house research using the local tandem Van de Graff and superconducting linac accelerators and non-accelerator research in double beta decay and gravitation as well as user-mode research at large accelerator and reactor facilities around the world. This book is divided into the following areas: nuclear astrophysics; neutrino physics; nucleus-nucleus reactions; fundamental symmetries and weak interactions; accelerator mass spectrometry; atomic and molecular clusters; ultra-relativistic heavy ion collisions; external users; electronics, computing, and detector infrastructure; Van de Graff, superconducting booster and ion sources; nuclear physics laboratory personnel; degrees granted for 1994--1995; and list of publications from 1994--1995.

  15. Nuclear Physics Laboratory, University of Washington annual report

    SciTech Connect (OSTI)

    1998-04-01

    The Nuclear Physics Laboratory at the University of Washington in Seattle pursues a broad program of nuclear physics. These activities are conducted locally and at remote sites. The current programs include in-house research using the local tandem Van de Graaff and superconducting linac accelerators and non-accelerator research in solar neutrino physics at the Sudbury Neutrino Observatory in Canada and at SAGE in Russia, and gravitation as well as user-mode research at large accelerators and reactor facilities around the world. Summaries of the individual research projects are included. Areas of research covered are: fundamental symmetries, weak interactions and nuclear astrophysics; neutrino physics; nucleus-nucleus reactions; ultra-relativistic heavy ions; and atomic and molecular clusters.

  16. Molecular Science Research Center annual report

    SciTech Connect (OSTI)

    Knotek, M.L.

    1991-01-01

    The Chemical Structure and Dynamics group is studying chemical kinetics and reactions dynamics of terrestrial and atmospheric processes as well as the chemistry of complex waste forms and waste storage media. Staff are using new laser systems and surface-mapping techniques in combination with molecular clusters that mimic adsorbate/surface interactions. The Macromolecular Structure and Dynamics group is determining biomolecular structure/function relationships for processes the control the biological transformation of contaminants and the health effects of toxic substances. The Materials and Interfaces program is generating information needed to design and synthesize advanced materials for the analysis and separation of mixed chemical waste, the long-term storage of concentrated hazardous materials, and the development of chemical sensors for environmental monitoring of various organic and inorganic species. The Theory, Modeling, and Simulation group is developing detailed molecular-level descriptions of the chemical, physical, and biological processes in natural and contaminated systems. Researchers are using the full spectrum of computational techniques. The Computer and Information Sciences group is developing new approaches to handle vast amounts of data and to perform calculations for complex natural systems. The EMSL will contain a high-performance computing facility, ancillary computing laboratories, and high-speed data acquisition systems for all major research instruments.

  17. Molecular dynamics simulations of microscale fluid transport

    SciTech Connect (OSTI)

    Wong, C.C.; Lopez, A.R.; Stevens, M.J.; Plimpton, S.J.

    1998-02-01

    Recent advances in micro-science and technology, like Micro-Electro-Mechanical Systems (MEMS), have generated a group of unique liquid flow problems that involve characteristic length scales of a Micron. Also, in manufacturing processes such as coatings, current continuum models are unable to predict microscale physical phenomena that appear in these non-equilibrium systems. It is suspected that in these systems, molecular-level processes can control the interfacial energy and viscoelastic properties at the liquid/solid boundary. A massively parallel molecular dynamics (MD) code has been developed to better understand microscale transport mechanisms, fluid-structure interactions, and scale effects in micro-domains. Specifically, this MD code has been used to analyze liquid channel flow problems for a variety of channel widths, e.g. 0.005-0.05 microns. This report presents results from MD simulations of Poiseuille flow and Couette flow problems and addresses both scaling and modeling issues. For Poiseuille flow, the numerical predictions are compared with existing data to investigate the variation of the friction factor with channel width. For Couette flow, the numerical predictions are used to determine the degree of slip at the liquid/solid boundary. Finally, the results also indicate that shear direction with respect to the wall lattice orientation can be very important. Simulation results of microscale Couette flow and microscale Poiseuille flow for two different surface structures and two different shear directions will be presented.

  18. Bright, Coherent, Ultrafast Soft X-Ray Harmonics Spanning the Water Window from a Tabletop Light Source

    SciTech Connect (OSTI)

    Chen, M.-C.; Arpin, P.; Popmintchev, T.; Gerrity, M.; Zhang, B.; Seaberg, M.; Popmintchev, D.; Murnane, M. M.; Kapteyn, H. C.

    2010-10-22

    We demonstrate fully phase-matched high harmonic emission spanning the water window spectral region important for nano- and bioimaging and a breadth of materials and molecular dynamics studies. We also generate the broadest bright coherent bandwidth ({approx_equal}300 eV) to date from any light source, small or large, that is consistent with a single subfemtosecond burst. The harmonic photon flux at 0.5 keV is 10{sup 3} higher than demonstrated previously. This work extends bright, spatially coherent, attosecond pulses into the soft x-ray region for the first time.

  19. HIV Molecular Immunology 2014

    SciTech Connect (OSTI)

    Yusim, Karina; Korber, Bette Tina Marie; Barouch, Dan; Koup, Richard; de Boer, Rob; Moore, John P.; Brander, Christian; Haynes, Barton F.; Walker, Bruce D.

    2015-02-03

    HIV Molecular Immunology is a companion volume to HIV Sequence Compendium. This publication, the 2014 edition, is the PDF version of the web-based HIV Immunology Database (http://www.hiv.lanl.gov/content/immunology/). The web interface for this relational database has many search options, as well as interactive tools to help immunologists design reagents and interpret their results. In the HIV Immunology Database, HIV-specific B-cell and T-cell responses are summarized and annotated. Immunological responses are divided into three parts, CTL, T helper, and antibody. Within these parts, defined epitopes are organized by protein and binding sites within each protein, moving from left to right through the coding regions spanning the HIV genome. We include human responses to natural HIV infections, as well as vaccine studies in a range of animal models and human trials. Responses that are not specifically defined, such as responses to whole proteins or monoclonal antibody responses to discontinuous epitopes, are summarized at the end of each protein section. Studies describing general HIV responses to the virus, but not to any specific protein, are included at the end of each part. The annotation includes information such as crossreactivity, escape mutations, antibody sequence, TCR usage, functional domains that overlap with an epitope, immune response associations with rates of progression and therapy, and how specific epitopes were experimentally defined. Basic information such as HLA specificities for T-cell epitopes, isotypes of monoclonal antibodies, and epitope sequences are included whenever possible. All studies that we can find that incorporate the use of a specific monoclonal antibody are included in the entry for that antibody. A single T-cell epitope can have multiple entries, generally one entry per study. Finally, maps of all defined linear epitopes relative to the HXB2 reference proteins are provided.

  20. Emergency Response Health Physics

    SciTech Connect (OSTI)

    Mena, R., Pemberton, W., Beal, W.

    2012-05-01

    Health physics is an important discipline with regard to understanding the effects of radiation on human health. Topics of discussion included in this manuscript are related to responding to a radiation emergency, and the necessary balance between desired high accuracy laboratory results and rapid turnaround requirements. Considerations are addressed for methodology with which to provide the most competent solutions despite challenges presented from incomplete datasets and, at times, limited methodology. An emphasis is placed on error and uncertainty of sample analysis results, how error affects products, and what is communicated in the final product.

  1. INSTITUTE OF PHYSICS PUBLISHING

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

    4 (2004) 162-171 PII: S0029-5515(04)72612-5 Equilibrium reconstruction in the Madison Symmetric Torus reversed field pinch J.K. Anderson, C.B. Forest, T.M. Biewer a , J.S. Sarff and J.C. Wright b Department of Physics, University of Wisconsin, Madison, WI 53706, USA Received 21 December 2002, accepted for publication 18 November 2003 Published 17 December 2003 Online at stacks.iop.org/NF/44/162 (DOI: 10.1088/0029-5515/44/1/018) Abstract A non-linear Grad-Shafranov toroidal equilibrium

  2. Theoretical High Energy Physics

    SciTech Connect (OSTI)

    Christ, Norman H.; Weinberg, Erick J.

    2014-07-14

    we provide reports from each of the six faculty supported by the Department of Energy High Energy Physics Theory grant at Columbia University. Each is followed by a bibliography of the references cited. A complete list of all of the publications in the 12/1/2010-04/30/2014 period resulting from research supported by this grant is provided in the following section. The final section lists the Ph.D. dissertations based on research supported by the grant that were submitted during this period.

  3. Argonne Physics Division - ATLAS

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

    Experiment Safety Considerations at ATLAS For onsite emergencies, call 911 on the internal phones (or 252-1911 on cell phones) Equipment Safety Reviews are required whenever new equipment is brought in for an experiment. The review is conducted by the Physics Division safety committee. If you plan to bring in your own detectors or other equipment for an experiment, it will need to reviewed. If a safety review is required for your equipment, you will need to fill out a Hazard Analysis form. Forms

  4. Renormalization and plasma physics

    SciTech Connect (OSTI)

    Krommes, J.A.

    1980-02-01

    A review is given of modern theories of statistical dynamics as applied to problems in plasma physics. The derivation of consistent renormalized kinetic equations is discussed, first heuristically, later in terms of powerful functional techniques. The equations are illustrated with models of various degrees of idealization, including the exactly soluble stochastic oscillator, a prototype for several important applications. The direct-interaction approximation is described in detail. Applications discussed include test particle diffusion and the justification of quasilinear theory, convective cells, E vector x B vector turbulence, the renormalized dielectric function, phase space granulation, and stochastic magnetic fields.

  5. Neutrino Physics at Fermilab

    ScienceCinema (OSTI)

    Saoulidou, Niki

    2010-01-08

    Neutrino oscillations provide the first evidence for physics beyond the Standard Model. I will briefly overview the neutrino "hi-story", describing key discoveries over the past decades that shaped our understanding of neutrinos and their behavior. Fermilab was, is and hopefully will be at the forefront of the accelerator neutrino experiments.  NuMI, the most powerful accelerator neutrino beam in the world has ushered us into the era of precise measurements. Its further upgrades may give a chance to tackle the remaining mysteries of the neutrino mass hierarchy and possible CP violation.

  6. 2010 Atomic & Molecular Interactions Gordon Research Conference

    SciTech Connect (OSTI)

    Todd Martinez

    2010-07-23

    The Atomic and Molecular Interactions Gordon Conferences is justifiably recognized for its broad scope, touching on areas ranging from fundamental gas phase and gas-condensed matter collision dynamics, to laser-molecule interactions, photophysics, and unimolecular decay processes. The meeting has traditionally involved scientists engaged in fundamental research in gas and condensed phases and those who apply these concepts to systems of practical chemical and physical interest. A key tradition in this meeting is the strong mixing of theory and experiment throughout. The program for 2010 conference continues these traditions. At the 2010 AMI GRC, there will be talks in 5 broadly defined and partially overlapping areas of intermolecular interactions and chemical dynamics: (1) Photoionization and Photoelectron Dynamics; (2) Quantum Control and Molecules in Strong Fields; (3) Photochemical Dynamics; (4) Complex Molecules and Condensed Phases; and (5) Clusters and Reaction Dynamics. These areas encompass many of the most productive and exciting areas of chemical physics, including both reactive and nonreactive processes, intermolecular and intramolecular energy transfer, and photodissociation and unimolecular processes. Gas phase dynamics, van der Waals and cluster studies, laser-matter interactions and multiple potential energy surface phenomena will all be discussed.

  7. TURBULENCE DECAY AND CLOUD CORE RELAXATION IN MOLECULAR CLOUDS

    SciTech Connect (OSTI)

    Gao, Yang; Law, Chung K.; Xu, Haitao

    2015-02-01

    The turbulent motion within molecular clouds is a key factor controlling star formation. Turbulence supports molecular cloud cores from evolving to gravitational collapse and hence sets a lower bound on the size of molecular cloud cores in which star formation can occur. On the other hand, without a continuous external energy source maintaining the turbulence, such as in molecular clouds, the turbulence decays with an energy dissipation time comparable to the dynamic timescale of clouds, which could change the size limits obtained from Jean's criterion by assuming constant turbulence intensities. Here we adopt scaling relations of physical variables in decaying turbulence to analyze its specific effects on the formation of stars. We find that the decay of turbulence provides an additional approach for Jeans' criterion to be achieved, after which gravitational infall governs the motion of the cloud core. This epoch of turbulence decay is defined as cloud core relaxation. The existence of cloud core relaxation provides a more complete understanding of the effect of the competition between turbulence and gravity on the dynamics of molecular cloud cores and star formation.

  8. Apparatus for molecular weight separation

    DOE Patents [OSTI]

    Smith, Richard D. (Richland, WA); Liu, Chuanliang (Haverhill, MA)

    2001-01-01

    The present invention relates generally to an apparatus and method for separating high molecular weight molecules from low molecular weight molecules. More specifically, the invention relates to the use of microdialysis for removal of the salt (low molecular weight molecules) from a nucleotide sample (high molecular weight molecules) for ESI-MS analysis. The dialysis or separation performance of the present invention is improved by (1) increasing dialysis temperature thereby increasing desalting efficiency and improving spectrum quality; (2) adding piperidine and imidazole to the dialysis buffer solution and reducing charge states and further increasing detection sensitivity for DNA; (3) using low concentrations (0-2.5 mM NH4OAc) of dialysis buffer and shifting the DNA negative ions to higher charge states, producing a nearly 10-fold increase in detection sensitivity and a slightly decreased desalting efficiency, (4) conducting a two-stage separation or (5) any combination of (1), (2), (3) and (4).

  9. Possible Demonstration of a Polaronic Bose-Einstein(-Mott) Condensate in UO2(+x) by Ultrafast THz Spectroscopy and Microwave Dissipation

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

    Conradson, Steven D.; Gilbertson, Steven M.; Daifuku, Stephanie L.; Kehl, Jeffrey A.; Durakiewicz, Tomasz; Andersson, David A.; Bishop, Alan R.; Byler, Darrin D.; Maldonado, Pablo; Oppeneer, Peter M.; et al

    2015-10-16

    Bose-Einstein condensates (BECs) composed of polarons would be an advance because they would combine coherently charge, spin, and a crystal lattice. Following our earlier report of unique structural and spectroscopic properties, we now identify potentially definitive evidence for polaronic BECs in photo- and chemically doped UO2(+x) on the basis of exceptional coherence in the ultrafast time dependent terahertz absorption and microwave spectroscopy results that show collective behavior including dissipation patterns whose precedents are condensate vortex and defect disorder and condensate excitations. Furthermore, that some of these signatures of coherence in an atom-based system extend to ambient temperature suggests a novelmore »mechanism that could be a synchronized, dynamical, disproportionation excitation, possibly via the solid state analog of a Feshbach resonance that promotes the coherence. Such a mechanism would demonstrate that the use of ultra-low temperatures to establish the BEC energy distribution is a convenience rather than a necessity, with the actual requirement for the particles being in the same state that is not necessarily the ground state attainable by other means. Interestingly, a macroscopic quantum object created by chemical doping that can persist to ambient temperature and resides in a bulk solid would be revolutionary in a number of scientific and technological fields.« less

  10. Excited state carrier dynamics in CdS{sub x}Se{sub 1-x} semisconductor alloys as studied by ultrafast fluorescence spectroscopy

    SciTech Connect (OSTI)

    Gadd, S.E.

    1995-08-01

    This dissertation discusses studies of the electron-hole pair dynamics of CdS{sub x}Se{sub 1-x} semiconductor alloys for the entire compositional range from x = 1 to x = 0 as examined by the ultrafast fluorescence techniques of time correlated single photon counting and fluorescence upconversion. Specifically, samples with x = 1, .75, .5, .25, and 0 were studied each at a spread of wavelengths about its respective emission maximum which varies according to {lambda} = 718nm - 210x nm. The decays of these samples were found to obey a Kohlrausch distribution, exp [(t/{tau}){sup {beta}}], with the exponent 3 in the range .5-.7 for the alloys. These results are in agreement with those expected for localization due to local potential variations resulting from the random distribution of sulfur and selenium atoms on the element VI A sub-lattice. This localization can be understood in terms of Anderson localization of the holes in states whose energy distribution tails into the forbidden energy band-gap. Because these states have energy dependent lifetimes, the carriers can decay via many parallel channels. This distribution of channels is the ultimate source of the Kohlrausch form of the fluorescence decays.

  11. Possible Demonstration of a Polaronic Bose-Einstein(-Mott) Condensate in UO2(+x) by Ultrafast THz Spectroscopy and Microwave Dissipation

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

    Conradson, Steven D.; Gilbertson, Steven M.; Daifuku, Stephanie L.; Kehl, Jeffrey A.; Durakiewicz, Tomasz; Andersson, David A.; Bishop, Alan R.; Byler, Darrin D.; Maldonado, Pablo; Oppeneer, Peter M.; et al

    2015-10-16

    Bose-Einstein condensates (BECs) composed of polarons would be an advance because they would combine coherently charge, spin, and a crystal lattice. Following our earlier report of unique structural and spectroscopic properties, we now identify potentially definitive evidence for polaronic BECs in photo- and chemically doped UO2(+x) on the basis of exceptional coherence in the ultrafast time dependent terahertz absorption and microwave spectroscopy results that show collective behavior including dissipation patterns whose precedents are condensate vortex and defect disorder and condensate excitations. Furthermore, that some of these signatures of coherence in an atom-based system extend to ambient temperature suggests a novelmore » mechanism that could be a synchronized, dynamical, disproportionation excitation, possibly via the solid state analog of a Feshbach resonance that promotes the coherence. Such a mechanism would demonstrate that the use of ultra-low temperatures to establish the BEC energy distribution is a convenience rather than a necessity, with the actual requirement for the particles being in the same state that is not necessarily the ground state attainable by other means. Interestingly, a macroscopic quantum object created by chemical doping that can persist to ambient temperature and resides in a bulk solid would be revolutionary in a number of scientific and technological fields.« less

  12. Inquiring Minds - Questions About Physics

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

    You Wrote: One day I was sitting in my living room, reading a book on physics, an idea ... This is, specifically, a question about dimensional physics (that's probably not the real ...

  13. Electron Trapping by Molecular Vibration

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

    Electron Trapping by Molecular Vibration Print In photoelectron spectroscopy experiments performed at the ALS, a group of researchers has found that electronic transitions normally thought to be forbidden can in fact be excited in conjunction with certain types of molecular vibrations. Specifically, they found that when the symmetry of a linear triatomic molecule is broken by asymmetric vibrational modes, photoelectrons can become temporarily trapped by the molecule before ultimately escaping,

  14. Electron Trapping by Molecular Vibration

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

    Electron Trapping by Molecular Vibration Print In photoelectron spectroscopy experiments performed at the ALS, a group of researchers has found that electronic transitions normally thought to be forbidden can in fact be excited in conjunction with certain types of molecular vibrations. Specifically, they found that when the symmetry of a linear triatomic molecule is broken by asymmetric vibrational modes, photoelectrons can become temporarily trapped by the molecule before ultimately escaping,

  15. Electron Trapping by Molecular Vibration

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

    Electron Trapping by Molecular Vibration Print In photoelectron spectroscopy experiments performed at the ALS, a group of researchers has found that electronic transitions normally thought to be forbidden can in fact be excited in conjunction with certain types of molecular vibrations. Specifically, they found that when the symmetry of a linear triatomic molecule is broken by asymmetric vibrational modes, photoelectrons can become temporarily trapped by the molecule before ultimately escaping,

  16. Electron Trapping by Molecular Vibration

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

    Electron Trapping by Molecular Vibration Print In photoelectron spectroscopy experiments performed at the ALS, a group of researchers has found that electronic transitions normally thought to be forbidden can in fact be excited in conjunction with certain types of molecular vibrations. Specifically, they found that when the symmetry of a linear triatomic molecule is broken by asymmetric vibrational modes, photoelectrons can become temporarily trapped by the molecule before ultimately escaping,

  17. Synchrotrons Explore Water's Molecular Mysteries

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

    Synchrotrons Explore Water's Molecular Mysteries Synchrotrons Explore Water's Molecular Mysteries Print Friday, 01 February 2013 00:00 In experiments at SLAC National Accelerator Laboratory and Lawrence Berkeley National Laboratory's Advanced Light Source, scientists observed a surprisingly dense form of water that remained liquid well beyond its typical freezing point. Researchers applied a superthin coating of water-no deeper than a few molecules-to the surface of a barium fluoride crystal.

  18. Chemical Dynamics, Molecular Energetics, and Kinetics at the Synchrotron

    SciTech Connect (OSTI)

    Leone, Stephen R.; Ahmed, Musahid; Wilson, Kevin R.

    2010-03-14

    Scientists at the Chemical Dynamics Beamline of the Advanced Light Source in Berkeley are continuously reinventing synchrotron investigations of physical chemistry and chemical physics with vacuum ultraviolet light. One of the unique aspects of a synchrotron for chemical physics research is the widely tunable vacuum ultraviolet light that permits threshold ionization of large molecules with minimal fragmentation. This provides novel opportunities to assess molecular energetics and reaction mechanisms, even beyond simple gas phase molecules. In this perspective, significant new directions utilizing the capabilities at the Chemical Dynamics Beamline are presented, along with an outlook for future synchrotron and free electron laser science in chemical dynamics. Among the established and emerging fields of investigations are cluster and biological molecule spectroscopy and structure, combustion flame chemistry mechanisms, radical kinetics and product isomer dynamics, aerosol heterogeneous chemistry, planetary and interstellar chemistry, and secondary neutral ion-beam desorption imaging of biological matter and materials chemistry.

  19. Molecular modeling of responsive polymer films

    SciTech Connect (OSTI)

    Tagliazucchi, Mario; Calvo, Ernesto J; Szleifer, Igal

    2010-06-29

    In this perspective, we have shown three different cases of responsive polymers at surfaces where the properties of the surface can be varied in response to cues from the bulk solution or in the presence of an external field. The most important conclusion in all three cases is that the chemical reaction equilibrium, physical interactions and molecular organization are strongly coupled, and it is imperative to consider the global and local changes that occur to the surface structure and properties due to this coupling. In particular acid-base and redox equilibrium are very different in polymer-modified surfaces than in the corresponding bulk solutions. Moreover, the definition of apparent redox potentials and apparent pKaresults from the averaging over highly inhomogeneous values,and, therefore, they do not necessarily represent the state of the layer and the local values and their variation are very important for the design of functional surfaces. The very large variation on chemical equilibrium results from the optimization of all the interactions. The picture that emerges is that trying to deduce what the final state of the system is by looking at the individual optimization of each contribution leads to qualitative incorrect assumptions and only the minimization of the complete free energy leads to the proper behavior in these complex systems.In the cases where domain formation is possible in grafted weak polyacid layers charge regulation may lead to regimes of coexistence between aggregates with relatively low fraction of charged polymer segments surrounded by highly stretched chains that have a relatively high fraction of charged groups.Therefore, one can control the state of charge, local electrostatic potential and local pH in all three dimensions with im-portant gradients on length scales of nanometers. For hydrophobic redox polymers we show how the application of an electrode potential can lead to changes in the structure and type of morphological aggregates that can form on the surface.Again, these structures result from the optimization of chemical redox equilibrium, conformational entropy, electrostatic and hydrophobic interactions. Furthermore, changes in domains structure can manifest themselves in the capacitance-potential curves and then provide a link between macroscopic measurements and the formation of nanoscopic domains. It is clear that chemical engineers are in a unique position to use these switchable surfaces in the molecular design of sensors, biosensors, separation devices, microfluidic devices with on-off environmental switches and drug delivery systems among many others. Finally, we want to stress that the application of molecular theories, where the coupling between chemical equilibrium, physical interactions and molecular organization are explicitly included provide with quantitative predictions of the layers properties, as compared with experimental observations, and enable the fundamental understanding of the observed behavior. Moreover, the theory provides with a detailed microscopic picture and should be used as an integral part in the design of functional and responsive surfaces. It is important to emphasize that the molecular approaches are not exact, and, therefore, there is a need to continue their development and the incorporation of improved approximations to further broaden their applicability.

  20. Princeton Plasma Physics Laboratory News

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

    archive Princeton Plasma Physics Laboratory news feed en PPPL physicists simulate innovative method for starting up tokamaks without...

  1. Protein Structure Suggests Role as Molecular Adapter

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

    Protein Structure Suggests Role as Molecular Adapter Print To split and copy DNA during replication, all cellular organisms use a multicomponent molecular machine known as the...

  2. Institute for Molecular Engineering | Argonne National Laboratory

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

    for Molecular Engineering explores innovative technologies that address fundamental societal problems through advances in nanoscale manipulation and design at a molecular scale. ...

  3. PIA - Environmental Molecular Sciences Laboratory (EMSL) User...

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

    Molecular Sciences Laboratory (EMSL) User System (ESU) PDF icon PIA - Environmental Molecular Sciences Laboratory (EMSL) User System (ESU) More Documents & Publications PIA - WEB ...

  4. Protein Structure Suggests Role as Molecular Adapter

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

    Structure Suggests Role as Molecular Adapter Print To split and copy DNA during replication, all cellular organisms use a multicomponent molecular machine known as the...

  5. Connecting the Molecular and the Continuum Scales

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

    range of phenomena, from climate change to contaminant remediation. Accomplishments: Used molecular dynamics (MD) simulations to determine molecular-scale diffusion coefficients of...

  6. Atomic and molecular collision processes: Progress report for the period January 1, 1985-November 30, 1986

    SciTech Connect (OSTI)

    Norcross, D.W.

    1986-07-31

    The past year's progress in a long-term program of code development and high precision calculations for electron and positron collisions with atoms, atomic ions, and molecules is summarized. In electron-ion collisions, the primary concern is with the fundamental physics of the process that controls excitation in high temperature plasmas. In the molecular work, we pursue accurate calculations of ro-vibrational excitation of polyatomic molecules, by both electrons and positrons, and the structure of molecular negative ions. 16 refs.

  7. Attosecond Light and Science at the Time-scale of the Electron - Coherent X-Rays from Tabletop Ultrafast Lasers

    ScienceCinema (OSTI)

    Margaret, Murnane [University of Colorado, Boulder and NIST

    2010-09-01

    Ever since the invention of the laser 50 years ago and its application in nonlinear optics, scientists have been striving to extend coherent laser beams into the x-ray region of the spectrum. Very recently however, the prospects for tabletop coherent sources at very short wavelengths, even in the hard x-ray region of the spectrum at wavelengths < 1nm, have brightened considerably. This advance is possible by taking nonlinear optics techniques to an extreme - physics that is the direct result of a new ability to manipulate electrons on the fastest, attosecond, time-scales of our natural world. Several applications have already been demonstrated, including making a movie of how electrons rearrange in a chemical bond changes shape as a molecule breaks apart, following how fast a magnetic material can flip orientation, understanding how fast heat flows in a nanocircuit, or building a microscope without lenses. Nature 460, 1088 (2009); Science 317, 775 (2007); Physical Review Letters 103, 257402 (2009); Nature Materials 9, 26 (2010); Nature 463, 214 (2010); Science 322, 1207 (2008).

  8. Statistical physics ""Beyond equilibrium

    SciTech Connect (OSTI)

    Ecke, Robert E

    2009-01-01

    The scientific challenges of the 21st century will increasingly involve competing interactions, geometric frustration, spatial and temporal intrinsic inhomogeneity, nanoscale structures, and interactions spanning many scales. We will focus on a broad class of emerging problems that will require new tools in non-equilibrium statistical physics and that will find application in new material functionality, in predicting complex spatial dynamics, and in understanding novel states of matter. Our work will encompass materials under extreme conditions involving elastic/plastic deformation, competing interactions, intrinsic inhomogeneity, frustration in condensed matter systems, scaling phenomena in disordered materials from glasses to granular matter, quantum chemistry applied to nano-scale materials, soft-matter materials, and spatio-temporal properties of both ordinary and complex fluids.

  9. Physics Integration KErnels (PIKE)

    Energy Science and Technology Software Center (OSTI)

    2014-07-31

    Pike is a software library for coupling and solving multiphysics applications. It provides basic interfaces and utilities for performing code-to-code coupling. It provides simple “black-box” Picard iteration methods for solving the coupled system of equations including Jacobi and Gauss-Seidel solvers. Pike was developed originally to couple neutronics and thermal fluids codes to simulate a light water nuclear reactor for the Consortium for Simulation of Light-water Reactors (CASL) DOE Energy Innovation Hub. The Pike library containsmore » no physics and just provides interfaces and utilities for coupling codes. It will be released open source under a BSD license as part of the Trilinos solver framework (trilinos.org) which is also BSD. This code provides capabilities similar to other open source multiphysics coupling libraries such as LIME, AMP, and MOOSE.« less

  10. VLHC accelerator physics

    SciTech Connect (OSTI)

    Michael Blaskiewicz et al.

    2001-11-01

    A six-month design study for a future high energy hadron collider was initiated by the Fermilab director in October 2000. The request was to study a staged approach where a large circumference tunnel is built that initially would house a low field ({approx}2 T) collider with center-of-mass energy greater than 30 TeV and a peak (initial) luminosity of 10{sup 34} cm{sup -2}s{sup -1}. The tunnel was to be scoped, however, to support a future upgrade to a center-of-mass energy greater than 150 TeV with a peak luminosity of 2 x 10{sup 34} cm{sup -2} sec{sup -1} using high field ({approx} 10 T) superconducting magnet technology. In a collaboration with Brookhaven National Laboratory and Lawrence Berkeley National Laboratory, a report of the Design Study was produced by Fermilab in June 2001. 1 The Design Study focused on a Stage 1, 20 x 20 TeV collider using a 2-in-1 transmission line magnet and leads to a Stage 2, 87.5 x 87.5 TeV collider using 10 T Nb{sub 3}Sn magnet technology. The article that follows is a compilation of accelerator physics designs and computational results which contributed to the Design Study. Many of the parameters found in this report evolved during the study, and thus slight differences between this text and the Design Study report can be found. The present text, however, presents the major accelerator physics issues of the Very Large Hadron Collider as examined by the Design Study collaboration and provides a basis for discussion and further studies of VLHC accelerator parameters and design philosophies.

  11. Quantum computations with atoms in optical lattices: Marker qubits and molecular interactions

    SciTech Connect (OSTI)

    Calarco, T.; Dorner, U.; Zoller, P.; Julienne, P.S.; Williams, C.J.

    2004-07-01

    We develop a scheme for quantum computation with neutral atoms, based on the concept of 'marker' atoms, i.e., auxiliary atoms that can be efficiently transported in state-independent periodic external traps to operate quantum gates between physically distant qubits. This allows for relaxing a number of experimental constraints for quantum computation with neutral atoms in microscopic potential, including single-atom laser addressability. We discuss the advantages of this approach in a concrete physical scenario involving molecular interactions.

  12. Research in Neutrino Physics

    SciTech Connect (OSTI)

    Busenitz, Jerome

    2014-09-30

    Research in Neutrino Physics We describe here the recent activities of our two groups over the first year of this award (effectively November 2010 through January 2012) and our proposed activities and associated budgets for the coming grant year. Both of our groups are collaborating on the Double Chooz reactor neutrino experiment and are playing major roles in calibration and analysis. A major milestone was reached recently: the collaboration obtained the first result on the search for 13 based on 100 days of data from the far detector. Our data indicates that 13 is not zero; specifically the best fit of the neutrino oscillation hypothesis to our data gives sin2 (2 13) = 0.086 ± 0.041 (stat) ± 0.030 (syst) The null oscillation hypothesis is excluded at the 94.6% C.L. This result1 has been submitted to Physical Review Letters. As we continue to take data with the far detector in the coming year, in parallel with completing the construction of the near lab and installing the near detector, we expect the precision of our measurement to improve as we gather significantly more statistics, gain better control of backgrounds through use of partial power data and improved event selection, and better understand the detector energy scale and detection efficiency from calibration data. With both detectors taking data starting in the second half of 2013, we expect to further drive down the uncertainty on our measurement of sin2 (2 13) to less than 0.02. Stancu’s group is also collaborating on the MiniBooNE experiment. Data taking is scheduled to continue through April, by which time 1.18 × 1021 POT is projected. The UA group is playing a leading role in the measurement of antineutrino cross sections, which should be the subject of a publication later this year as well as of Ranjan Dharmapalan’s Ph.D. thesis, which he is expected to defend by the end of this year. It is time to begin working on projects which will eventually succeed Double Chooz and MiniBooNE as the main foci of our efforts. The Stancu group plans to become re–involved in LBNE and possibly also to join NO A, and the Busenitz group has begun to explore joining a direct dark matter search.

  13. Experimental Particle Physics

    SciTech Connect (OSTI)

    Rosenfeld, Carl; Mishra, Sanjib R.; Petti, Roberto; Purohit, Milind V.

    2014-08-31

    The high energy physics group at the University of South Carolina, under the leadership of Profs. S.R. Mishra, R. Petti, M.V. Purohit, J.R. Wilson (co-PI's), and C. Rosenfeld (PI), engaged in studies in "Experimental Particle Physics." The group collaborated with similar groups at other universities and at national laboratories to conduct experimental studies of elementary particle properties. We utilized the particle accelerators at the Fermi National Accelerator Laboratory (Fermilab) in Illinois, the Stanford Linear Accelerator Center (SLAC) in California, and the European Center for Nuclear Research (CERN) in Switzerland. Mishra, Rosenfeld, and Petti worked predominantly on neutrino experiments. Experiments conducted in the last fifteen years that used cosmic rays and the core of the sun as a source of neutrinos showed conclusively that, contrary to the former conventional wisdom, the "flavor" of a neutrino is not immutable. A neutrino of flavor "e," "mu," or "tau," as determined from its provenance, may swap its identity with one of the other flavors -- in our jargon, they "oscillate." The oscillation phenomenon is extraordinarily difficult to study because neutrino interactions with our instruments are exceedingly rare -- they travel through the earth mostly unimpeded -- and because they must travel great distances before a substantial proportion have made the identity swap. Three of the experiments that we worked on, MINOS, NOvA, and LBNE utilize a beam of neutrinos from an accelerator at Fermilab to determine the parameters governing the oscillation. Two other experiments that we worked on, NOMAD and MIPP, provide measurements supportive of the oscillation experiments. Good measurements of the neutrino oscillation parameters may constitute a "low energy window" on related phenomena that are otherwise unobservable because they would occur only at energies way above the reach of conceivable accelerators. Purohit and Wilson participated in the BaBar experiment, which collected data at SLAC until 2008. They continued to analyze the voluminous BaBar data with an emphasis on precision tests of Quantum Chromodynamics and on properties of the "eta_B," a bottom quark paired in a meson with a strange quark. The ATLAS experiment became the principal research focus for Purohit. One of the world's largest pieces of scientific equipment, ATLAS observes particle collisions at the highest-energy particle accelerator ever built, the Large Hadron Collider (LHC) at CERN. Our efforts on ATLAS included participation in the commissioning, calibration, and installation of components called "CSCs". The unprecedented energy of 14 TeV enabled the ATLAS and CMS collaborations to declare discovery of the famous Higgs particle in 2012.

  14. Health Physics Support Assistant | Princeton Plasma Physics Lab

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

    Saville Requisition Number: 1500691 POSITIONAL SUMMARY: To support the Health Physics Dosimeter program, records management (both archival and electronic) and to backup the ES&HS...

  15. Few-body physics

    SciTech Connect (OSTI)

    Briceno, Raul

    2015-05-01

    Few-body hadronic observables play an essential role in a wide number of processes relevant for both particle and nuclear physics. In order for Lattice QCD to offer insight into the interpretation of few-body states, a theoretical infrastructure must be developed to map Euclidean-time correlation functions to the desired Minkowski-time few-body observables. In this talk, I will first review the formal challenges associated with the studies of such systems via Lattice QCD, as first introduced by Maiani and Testa, and then review methodology to circumvent said limitations. The first main example of the latter is the formalism of Luscher to analyze elastic scattering and a second is the method of Lellouch & Luscher to analyze weak decays. I will then proceed to discus recent theoretical generalizations of these frameworks that allow for the determination of scattering amplitudes, resonances, transition and elastic form factors. Finally, I will outline outstanding problems, including those that are now beginning to be addressed.

  16. Particle physics---Experimental

    SciTech Connect (OSTI)

    Lord, J.J.; Boynton, P.E.; Burnett, T.H.; Wilkes, R.J.

    1991-08-21

    We are continuing a research program in particle astrophysics and high energy experimental particle physics. We have joined the DUMAND Collaboration, which is constructing a deep undersea astrophysical neutrino detector near Hawaii. Studies of high energy hadronic interactions using emulsion chamber techniques were also continued, using balloon flight exposures to ultra-high cosmic ray nuclei (JACEE) and accelerator beams. As members of the DUMAND Collaboration, we have responsibility for development a construction of critical components for the deep undersea neutrino detector facility. We have designed and developed the acoustical positioning system required to permit reconstruction of muon tracks with sufficient precision to meet the astrophysical goals of the experiment. In addition, we are making significant contributions to the design of the database and triggering system to be used. Work has been continuing in other aspects of the study of multiparticle production processes in nuclei. We are participants in a joint US/Japan program to study nuclear interactions at energies two orders of magnitude greater than those of existing accelerators, using balloon-borne emulsion chambers. On one of the flights we found two nuclear interactions of multiplicity over 1000 -- one with a multiplicity of over 2000 and pseudorapidity density {approximately} 800 in the central region. At the statistical level of the JACEE experiment, the frequency of occurrence of such events is orders of magnitude too large. We have continued our ongoing program to study hadronic interactions in emulsions exposed to high energy accelerator beams.

  17. Integrated Multiscale Modeling of Molecular Computing Devices

    SciTech Connect (OSTI)

    Weinan E

    2012-03-29

    The main bottleneck in modeling transport in molecular devices is to develop the correct formulation of the problem and efficient algorithms for analyzing the electronic structure and dynamics using, for example, the time-dependent density functional theory. We have divided this task into several steps. The first step is to developing the right mathematical formulation and numerical algorithms for analyzing the electronic structure using density functional theory. The second step is to study time-dependent density functional theory, particularly the far-field boundary conditions. The third step is to study electronic transport in molecular devices. We are now at the end of the first step. Under DOE support, we have made subtantial progress in developing linear scaling and sub-linear scaling algorithms for electronic structure analysis. Although there has been a huge amount of effort in the past on developing linear scaling algorithms, most of the algorithms developed suffer from the lack of robustness and controllable accuracy. We have made the following progress: (1) We have analyzed thoroughly the localization properties of the wave-functions. We have developed a clear understanding of the physical as well as mathematical origin of the decay properties. One important conclusion is that even for metals, one can choose wavefunctions that decay faster than any algebraic power. (2) We have developed algorithms that make use of these localization properties. Our algorithms are based on non-orthogonal formulations of the density functional theory. Our key contribution is to add a localization step into the algorithm. The addition of this localization step makes the algorithm quite robust and much more accurate. Moreover, we can control the accuracy of these algorithms by changing the numerical parameters. (3) We have considerably improved the Fermi operator expansion (FOE) approach. Through pole expansion, we have developed the optimal scaling FOE algorithm.

  18. Molecular resonance phenomena. [Calculation of resonance widths

    SciTech Connect (OSTI)

    Hazi, A.U.

    1980-01-01

    It is attempted to show that the Stieltjes-moment-theory provides a practical and a reasonably accurate method for calculating the widths of molecular resonances. The method seems to possess a number of advantages for molecular applications, since it avoids the explicit construction of continuum wavefunctions. It is very simple to implement the technique numerically, because it requires only existing bound-state electronic structure codes. Through the use of configuration interaction techniques, many-electron correlation and polarization effects can be included in the description of both the resonance and the non-resonant background continuum. To illustrate the utility and the accuracy of the Stieltjes-moment-theory technique, used in conjunction with configuration interaction (CI) wave functions, recent applications to the /sup 1/..sigma../sub u/(1sigma/sub u/ 2sigma/sub g/) autoionizing resonance state of H/sub 2/ and the well known /sup 2/PI/sub g/ state of N/sub 2//sup -/ are discussed. The choices of the one-electron basis sets and the types of many-electron configurations appropriate for these two cases are described. Also, guidelines for the selection of the projection operators defining the resonant and non-resonant subspaces in the case of both Feshbach and shape-resonances are given. The numerical results indicate that the Stieltjes-moment-theory technique, which employs L/sup 2/ basis functions exclusively, produces as accurate resonance parameters as can be extracted from direct electron-molecule scattering calculations, provided approximately the same approximations are used to describe important physical effects such as target polarization. Furthermore the method provides sufficiently accurate fixed-nuclei electronic resonance parameters to be used in ab initio calculation of resonant vibrational excitation cross sections. (WHK)

  19. High Energy Physics Division, ANL Lattice QCD

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

    Energy Physics Division, ANL Lattice QCD in extreme environments D. K. Sinclair (HEP, Argonne) J. B. Kogut (Physics, Illinois) D. Toublan (Physics, Illinois) 1 Lattice QCD Quantum ...

  20. PHYSICAL INVENTORY LISTING | Department of Energy

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

    PHYSICAL INVENTORY LISTING PHYSICAL INVENTORY LISTING Form supports nuclear materials control and accountability. PDF icon PHYSICAL INVENTORY LISTING More Documents & Publications ...