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


1

Precise and ultrafast molecular sieving through graphene oxide membranes  

E-Print Network [OSTI]

There has been intense interest in filtration and separation properties of graphene-based materials that can have well-defined nanometer pores and exhibit low frictional water flow inside them. Here we investigate molecular permeation through graphene oxide laminates. They are vacuum-tight in the dry state but, if immersed in water, act as molecular sieves blocking all solutes with hydrated radii larger than 4.5A. Smaller ions permeate through the membranes with little impedance, many orders of magnitude faster than the diffusion mechanism can account for. We explain this behavior by a network of nanocapillaries that open up in the hydrated state and accept only species that fit in. The ultrafast separation of small salts is attributed to an 'ion sponge' effect that results in highly concentrated salt solutions inside graphene capillaries.

R. K. Joshi; P. Carbone; F. C. Wang; V. G. Kravets; Y. Su; I. V. Grigorieva; H. A. Wu; A. K. Geim; R. R. Nair

2014-01-14T23:59:59.000Z

2

Hydrogen Bond Migration between Molecular Sites Observed with Ultrafast 2D IR Chemical Exchange Spectroscopy  

E-Print Network [OSTI]

Hydrogen Bond Migration between Molecular Sites Observed with Ultrafast 2D IR Chemical ExchangeVed: January 12, 2010 Hydrogen-bonded complexes between phenol and phenylacetylene are studied using ultrafast hydrogen bonding acceptor sites (phenyl or acetylene) that compete for hydrogen bond donors in solution

Fayer, Michael D.

3

Dynamics of Functionalized Surface Molecular Monolayers Studied with Ultrafast Infrared Vibrational Spectroscopy  

E-Print Network [OSTI]

Dynamics of Functionalized Surface Molecular Monolayers Studied with Ultrafast Infrared Vibrational by excitation transfer and molecular reorientation. The HDTG experiments show no evidence of anisotropy decay of molecular monolayers depend on the structure and dynamics of the surface-attached molecules. New tools

Fayer, Michael D.

4

Non-adiabatic molecular dynamics simulation of ultrafast solar cell electron transfer  

E-Print Network [OSTI]

confinement devices [1­5]. Solar cells of the Graetzel type [6,7] are based on dye sensitized nanocrystalline in solar cells, photocatalysis and photoelectrolysis. The electronic structure of the dye cell; Ultrafast electron transfer; Non-adiabatic molecular dynamics simulation; Dye sensitized titanium

5

Modified ultrafast thermometer UFT-M and temperature measurements during Physics of Stratocumulus Top (POST)  

E-Print Network [OSTI]

al. : Modified ultrafast thermometer UFT-M and temperatureR. : A new ultrafast thermometer for airborne measurementsof some airborne thermometers in clouds, J. Atmos. Ocean.

Kumala, W.; Haman, K. E; Kopec, M. K; Khelif, D.; Malinowski, S. P

2013-01-01T23:59:59.000Z

6

Ultraslow dissociation of the H{sub 2}{sup +} molecular ion via two-color ultrafast laser pulses  

SciTech Connect (OSTI)

We report a mode of dissociative ionization in an intense two-color laser field. When bond softened by the superposition of 800 and 400 nm ultrafast laser pulses in a narrow intensity range, H{sub 2}{sup +} molecular ions experience ultraslow dissociation. This near-zero kinetic-energy release is supported by theoretical simulations and two-color field-dressed adiabatic potential curves. Furthermore, we show that the shift to lower energy of a known bond-softened peak can be explained by the influence of a two-color field-induced potential well. Such ultraslow dissociation can facilitate ultrafast time-resolved spectroscopy of molecules.

Moser, B.; Gibson, G. N. [Department of Physics, University of Connecticut, Storrs, Connecticut 06269 (United States)

2009-10-15T23:59:59.000Z

7

Coherent lattice and molecular dynamics in ultrafast single-shot spectroscopy  

E-Print Network [OSTI]

This thesis focuses on the development, refinement, and application of dual- echelon single-shot ultrafast spectroscopy to the study of coherent nuclear motion in condensed phase systems. The general principles of the ...

Poulin, Peter Roland, 1973-

2005-01-01T23:59:59.000Z

8

AGN-driven winds on all scales in Markarian 231: from hot nuclear ultra-fast up to kpc-extended molecular outflow  

E-Print Network [OSTI]

We present the best sensitivity and angular resolution maps of the molecular disk and outflow of Mrk231, obtained with IRAM/PdBI, and an analysis of archival Chandra and NuSTAR data. We constrain the physical properties of both the molecular disk and outflow, the presence of a highly-ionized ultra-fast nuclear wind, and their connection. The CO(2-1) outflow has a size of ~1 kpc, and extends in all directions around the nucleus, being more prominent along the south-west to north-east direction, suggesting a wide-angle biconical geometry. Its maximum projected velocity is nearly constant out to ~1 kpc, thus implying that the density of the outflowing material must decrease from the nucleus outwards as ~ r^-2. This suggests that either a large part of the gas leaves the flow during its expansion, or that the bulk of the outflow has not yet reached ~1 kpc, implying a limit on its age of ~ 1 Myr. The mass and energy rates of the molecular outflow are dM/dt(OF)=[500-1000] Msun/yr and dE(kin,OF)/dt=[7-10] 10^43 erg/...

Feruglio, C; Carniani, S; Piconcelli, E; Zappacosta, L; Bongiorno, A; Cicone, C; Maiolino, R; Marconi, A; Menci, N; Puccetti, S; Veilleux, S

2015-01-01T23:59:59.000Z

9

Ultrafast Excited-State Dynamics in the Green Fluorescent Protein Variant S65T/ H148D. 2. Unusual Photophysical Properties  

E-Print Network [OSTI]

Ultrafast Excited-State Dynamics in the Green Fluorescent Protein Variant S65T/ H148D. 2. Unusual, California 94305-5080, and Institute of Molecular Biology and Department of Physics, UniVersity of Oregon of this variant at pH 5.6 by ultrafast fluorescence upconversion spectroscopy. Following excitation at 400 nm

Boxer, Steven G.

10

Measuring molecular electric dipoles using trapped atomic ions and ultrafast laser pulses  

E-Print Network [OSTI]

We study a hybrid quantum system composed of an ion and an electric dipole. We show how a trapped ion can be used to measure the small electric field generated by a classical dipole. We discuss the application of this scheme to measure the electric dipole moment of cold polar molecules, whose internal state can be controlled with ultrafast laser pulses, by trapping them in the vicinity of a trapped ion.

Jordi Mur-Petit; Juan José García-Ripoll

2015-01-12T23:59:59.000Z

11

Comparative investigation of third- and fifth-harmonic generation in atomic and molecular gases driven by midinfrared ultrafast laser pulses  

SciTech Connect (OSTI)

We report on the comparative experimental investigation on third- and fifth-harmonic generation (THG and FHG) in atomic and molecular gases driven by midinfrared ultrafast laser pulses at a wavelength of {approx}1500 nm. We observe that the conversion efficiencies of both the THG and FHG processes saturate at similar peak intensities close to {approx}1.5 x 10{sup 14} W/cm{sup 2} for argon, nitrogen, and air, whose ionization potentials are close to each other. Near the saturation intensity, the ratio of yields of the FHG and THG reaches {approx}10{sup -1} for all the gases. Our results show that high-order Kerr effect seems to exist; however, contribution from the fourth-order Kerr refractive index coefficient alone is insufficient to balance the Kerr self-focusing without the assistance of plasma generation.

Ni Jielei; Yao Jinping; Zeng Bin; Chu Wei; Li Guihua; Zhang Haisu; Jing Chenrui [State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, P.O. Box 800-211, Shanghai 201800 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100039 (China); Chin, S. L. [Department of Physics, Engineering Physics and Optics, and Center for Optics, Photonics and Laser (COPL), Laval University, Laval, Quebec, G1K 7P4 (Canada); Cheng, Y.; Xu, Z. [State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, P.O. Box 800-211, Shanghai 201800 (China)

2011-12-15T23:59:59.000Z

12

Ultrafast Laser Diagnostics for Energetic-Material Ignition Mechanisms: Tools for Physics-Based Model Development.  

SciTech Connect (OSTI)

We present the results of an LDRD project to develop diagnostics to perform fundamental measurements of material properties during shock compression of condensed phase materials at micron spatial scales and picosecond time scales. The report is structured into three main chapters, which each focus on a different diagnostic devel opment effort. Direct picosecond laser drive is used to introduce shock waves into thin films of energetic and inert materials. The resulting laser - driven shock properties are probed via Ultrafast Time Domain Interferometry (UTDI), which can additionally be used to generate shock Hugoniot data in tabletop experiments. Stimulated Raman scattering (SRS) is developed as a temperature diagnostic. A transient absorption spectroscopy setup has been developed to probe shock - induced changes during shock compressio n. UTDI results are presented under dynamic, direct - laser - drive conditions and shock Hugoniots are estimated for inert polystyrene samples and for the explosive hexanitroazobenzene, with results from both Sandia and Lawrence Livermore presented here. SRS a nd transient absorption diagnostics are demonstrated on static thin - film samples, and paths forward to dynamic experiments are presented.

Kearney, Sean P.; Jilek, Brook Anton; Kohl, Ian Thomas; Farrow, Darcie; Urayama, Junji

2014-11-01T23:59:59.000Z

13

Ultrafast probing of ejection dynamics of Rydberg atoms and molecular fragments from electronically excited helium nanodroplets  

SciTech Connect (OSTI)

The ejection dynamics of Rydberg atoms and molecular fragments from electronically excited helium nanodroplets are studied with time-resolved extreme ultraviolet ion imaging spectroscopy. At excitation energies of 23.6 {+-} 0.2 eV, Rydberg atoms in n= 3 and n= 4 states are ejected on different time scales and with significantly different kinetic energy distributions. Specifically, n= 3 Rydberg atoms are ejected with kinetic energies as high as 0.85 eV, but their appearance is delayed by approximately 200 fs. In contrast, n= 4 Rydberg atoms appear within the time resolution of the experiment with considerably lower kinetic energies. Major features in the Rydberg atom kinetic energy distributions for both principal quantum numbers can be described within a simple elastic scattering model of localized perturbed atomic Rydberg atoms that are expelled from the droplet due to their repulsive interaction with the surrounding helium bath. Time-dependent kinetic energy distributions of He{sub 2}{sup +} and He{sub 3}{sup +} ions are presented that support the formation of molecular ions in an indirect droplet ionization process and the ejection of neutral Rydberg dimers on a similar time scale as the n= 3 Rydberg atoms.

Buenermann, Oliver; Kornilov, Oleg; Neumark, Daniel M. [Ultrafast X-ray Science Laboratory, Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Department of Chemistry, University of California, Berkeley, California 94720 (United States); Haxton, Daniel J.; Gessner, Oliver [Ultrafast X-ray Science Laboratory, Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Leone, Stephen R. [Ultrafast X-ray Science Laboratory, Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Department of Chemistry, University of California, Berkeley, California 94720 (United States); Department of Physics, University of California, Berkeley, California 94720 (United States)

2012-12-07T23:59:59.000Z

14

Ultrafast X-Ray Coherent Control  

SciTech Connect (OSTI)

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.

Reis, David

2009-05-01T23:59:59.000Z

15

Physics with fast molecular-ion beams  

SciTech Connect (OSTI)

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.

Kanter, E.P.

1980-01-01T23:59:59.000Z

16

Ultrafast gas switching experiments  

SciTech Connect (OSTI)

We describe recent experiments which studied the physics of ultrafast gas breakdown under the extreme overvoltages which occur when a high pressure gas switch is pulse charged to hundreds of kV in 1 ns or less. The highly overvolted peaking gaps produce powerful electromagnetic pulses with risetimes < 100 ps which can be used for ultrawideband radar systems, particle accelerators, laser drivers, bioelectromagnetic studies, electromagnetic effects testing, and for basic studies of gas breakdown physics. We have produced and accurately measured pulses with 50 to 100 ps risetimes to peak levels of 75 to 160 kV at pulse repetition frequencies (PRF) to I kHz. A unique gas switch was developed to hold off hundreds of kV with parasitic inductance less than I nH. An advanced diagnostic system using Fourier compensation was developed to measure single-shot risetimes below 35 ps. The complete apparatus is described and wave forms are presented. The measured data are compared with a theoretical model which predicts key features including dependence on gas species and pressure. We have applied this technology to practical systems driving ultrawideband radiating antennas and bounded wave simulators. For example, we have developed a thyristor/pulse transformer based system using a highly overvolted cable switch. This pulser driving a Sandia- designed TEM cell, provides an ultra wideband impulse with < 200 ps risetime to the test object at a PRF > 1 kHz at > 100 kV/m E field.

Frost, C.A.; Martin, T.H.; Patterson, P.E.; Rinehart, L.F.; Rohwein, G.J.; Roose, L.D.; Aurand, J.F.; Buttram, M.T.

1996-11-01T23:59:59.000Z

17

Applied Statistical Physics Molecular Engineering Conference Puerto Vallarta, Mexico, 24-29 August 2003  

E-Print Network [OSTI]

of the sessions: Complex Fluids: Equilibrium and Dynamics, Nano-biotechnology, Nanoscience, Quantum EngineeringFOREWORD Applied Statistical Physics Molecular Engineering Conference Puerto Vallarta, Mexico, 24, RS, Brazil The Second International Conference on `Applied Statistical Physics: Molecular Engineering

Barbosa, Marcia C. B.

18

Coherent ultrafast pulse synthesis between an optical parametric oscillator and a laser  

E-Print Network [OSTI]

Coherent ultrafast pulse synthesis between an optical parametric oscillator and a laser Jinghua Sun* and Derryck T. Reid Ultrafast Optics Group, School of Engineering and Physical Sciences, Heriot 13, 2009 We have demonstrated coherent pulse synthesis between the carrier-envelope, phase

19

Ultrafast Spectroscopy of Correlated Electron Systems  

E-Print Network [OSTI]

full, non-zero bandwidth of an ultrafast pulse with itself.amplifier delivers ultrafast pulses of 45 fs at a repetitionthe “rectification” of an ultrafast optical pulse will have

Schmid, Benjamin Andrew

2009-01-01T23:59:59.000Z

20

Faculty Position Atomic, Molecular and Optical Physics The Columbia University Department of Physics seeks to appoint an assistant professor  

E-Print Network [OSTI]

Faculty Position Atomic, Molecular and Optical Physics The Columbia University Department November 1, 2014 and continue until the position is filled. Columbia University is an Equal Opportunity research program, continuing the long Columbia record of outstanding accomplishment in science. Applicants

Qian, Ning

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


21

Plasmonic enhanced ultrafast switch.  

SciTech Connect (OSTI)

Ultrafast electronic switches fabricated from defective material have been used for several decades in order to produce picosecond electrical transients and TeraHertz radiation. Due to the ultrashort recombination time in the photoconductor materials used, these switches are inefficient and are ultimately limited by the amount of optical power that can be applied to the switch before self-destruction. The goal of this work is to create ultrafast (sub-picosecond response) photoconductive switches on GaAs that are enhanced through plasmonic coupling structures. Here, the plasmonic coupler primarily plays the role of being a radiation condenser which will cause carriers to be generated adjacent to metallic electrodes where they can more efficiently be collected.

Subramania,Ganapathi Subramanian; Reno, John Louis; Passmore, Brandon Scott; Harris, Tom.; Shaner, Eric Arthur; Barrick, Todd A.

2009-09-01T23:59:59.000Z

22

Ptychographic ultrafast pulse reconstruction  

E-Print Network [OSTI]

We demonstrate a new ultrafast pulse reconstruction modality which is somewhat reminiscent of frequency resolved optical gating but uses a modified setup and a conceptually different reconstruction algorithm that is derived from ptychography. Even though it is a second order correlation scheme it shows no time ambiguity. Moreover, the number of spectra to record is considerably smaller than in most other related schemes which, together with a robust algorithm, leads to extremely fast convergence of the reconstruction.

Spangenberg, D; Brügmann, M H; Feurer, T

2014-01-01T23:59:59.000Z

23

PHYSICS OF CHEMORECEPTION HOWARD C. BERG AND EDWARD M. PURCELL, Department ofMolecular,  

E-Print Network [OSTI]

PHYSICS OF CHEMORECEPTION HOWARD C. BERG AND EDWARD M. PURCELL, Department ofMolecular, Cellular, and Developmental Biology, University ofColorado, Boulder, Colorado 80309 and the Department ofPhysics, Harvard. In these circumstances, what are the physical limitations on the cell's ability to sense and respond to changes in its

Voigt, Chris

24

Hue Sun Chan Departments of Biochemistry, of Molecular Genetics, and of Physics  

E-Print Network [OSTI]

Hue Sun Chan Departments of Biochemistry, of Molecular Genetics, and of Physics University. --Hue Sun Chan, University of Toronto #12;Experimental criteria from: calorimetry: HvH/Hcal 1 chevron

Chan, Hue Sun

25

Ultrafast optical parametric processes in photonic crystal fibers: fundamentals and applications  

E-Print Network [OSTI]

of ultrafast optical pulses . . . . . . . . .copropagating ultrafast optical pulses”, Appl. Phys. Lett.Additionally, the ultrafast pump pulses can experience

Gu, Chenji

2012-01-01T23:59:59.000Z

26

Ultrafast Transformations in Superionic Nanocrystals  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLasDelivered energy consumption by sectorlong version) The0 -ITER'sUltrafastUltrafastUltrafast

27

Ultrafast Transformations in Superionic Nanocrystals  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched Ferromagnetism in Layeredof2014 EIA Energy40081AEnergyUltrafastUltrafastUltrafast

28

Ultrafast scanning tunneling microscopy  

SciTech Connect (OSTI)

I have developed an ultrafast scanning tunneling microscope (USTM) based on uniting stroboscopic methods of ultrafast optics and scanned probe microscopy to obtain nanometer spatial resolution and sub-picosecond temporal resolution. USTM increases the achievable time resolution of a STM by more than 6 orders of magnitude; this should enable exploration of mesoscopic and nanometer size systems on time scales corresponding to the period or decay of fundamental excitations. USTM consists of a photoconductive switch with subpicosecond response time in series with the tip of a STM. An optical pulse from a modelocked laser activates the switch to create a gate for the tunneling current, while a second laser pulse on the sample initiates a dynamic process which affects the tunneling current. By sending a large sequence of identical pulse pairs and measuring the average tunnel current as a function of the relative time delay between the pulses in each pair, one can map the time evolution of the surface process. USTM was used to measure the broadband response of the STM`s atomic size tunnel barrier in frequencies from tens to hundreds of GHz. The USTM signal amplitude decays linearly with the tunnel junction conductance, so the spatial resolution of the time-resolved signal is comparable to that of a conventional STM. Geometrical capacitance of the junction does not appear to play an important role in the measurement, but a capacitive effect intimately related to tunneling contributes to the measured signals and may limit the ultimate resolution of the USTM.

Botkin, D.A. [California Univ., Berkeley, CA (United States). Dept. of Physics]|[Lawrence Berkeley Lab., CA (United States)

1995-09-01T23:59:59.000Z

29

Ultrafast studies of organometallic photochemistry: the mechanism of carbon-hydrogen bond activation in solution  

E-Print Network [OSTI]

watts [2]. These "ultrafast pulses" can be used to resolveof the directions that ultrafast pulse research has taken inand a separate ultrafast visible pulse to detect ultrafast

Broomberg, Steven E.

2010-01-01T23:59:59.000Z

30

Ultrafast Transformations in Superionic Nanocrystals  

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

The research team looked at copper sulfide nanodiscs (10 nm in diameter) using ultrafast x-ray pump-probe techniques. The samples were photoexcited with 400-nm laser...

31

Ultrafast Switching of Coherent Electronic Excitation: Great Promise for Reaction Control  

E-Print Network [OSTI]

With the advent of femtosecond laser pulses the temporal aspect of the interplay of light and molecular dynamics pulses [4] are the suitable tools to exert microscopic control on molecular dynamics at the quantum levelUltrafast Switching of Coherent Electronic Excitation: Great Promise for Reaction Control

Peinke, Joachim

32

Ultrafast optics For optics and photonics course,  

E-Print Network [OSTI]

ultrafast and ultrashort generally describe pulses of widths in the nanosecond to femtosecond, or shorterUltrafast optics For optics and photonics course, Spring 2012 By :Alireza Moheghi Ultrafast optics, regimes. · Interest in ultrashort optical pulses began with the invention of the laser, · Ultrashort

Palffy-Muhoray, Peter

33

High-Pulse-Energy Ultrafast Laser for  

E-Print Network [OSTI]

High-Pulse-Energy Ultrafast Laser for Spectroscopy & Micromachining PROBLEM THIS TECHNOLOGY SOLVES. In addition to the OPO, a custom designed ultrafast pump source, provides high pulse energy (.res.hw.ac.uk Professor Derryck Reid (Principal Investigator) www.ultrafast.hw.ac.uk BENEFITS & APPLICATIONS: · High pulse

Painter, Kevin

34

Ultrafast scanning probe microscopy  

DOE Patents [OSTI]

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.

Weiss, Shimon (El Cerrito, CA); Chemla, Daniel S. (Kensington, CA); Ogletree, D. Frank (El Cerrito, CA); Botkin, David (San Francisco, CA)

1995-01-01T23:59:59.000Z

35

Ultrafast scanning probe microscopy  

DOE Patents [OSTI]

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.

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

1995-05-16T23:59:59.000Z

36

Ultrafast Transformations in Superionic Nanocrystals  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLasDelivered energy consumption by sectorlong version) The0 -ITER'sUltrafastUltrafast

37

Ultrafast Transformations in Superionic Nanocrystals  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched Ferromagnetism in Layeredof2014 EIA Energy40081AEnergyUltrafastUltrafast

38

MOLECULAR PHYSICS, 1999, VOL. 97, NO. 7, 897 905 Dynamics and hydrogen bonding in liquid ethanol  

E-Print Network [OSTI]

MOLECULAR PHYSICS, 1999, VOL. 97, NO. 7, 897± 905 Dynamics and hydrogen bonding in liquid ethanol L of liquid ethanol at three temperatures have been carried out. The hydrogen bonding states of ethanol measurements of the frequency-dependent dielectric permittivity of liquid ethanol. 1. Introduction A detailed

Saiz, Leonor

39

Ultrafast optical pulse shaping: A tutorial review Andrew M. Weiner  

E-Print Network [OSTI]

Ultrafast optical pulse shaping: A tutorial review Andrew M. Weiner Purdue University, School 2011 Keywords: Ultrafast optics Pulse shaping Femtosecond optics Coherent control Optical signal programmable reshapingof ultrafast pulses, or generation of arbitrary optical waveforms, according to user

Purdue University

40

Stabilized Ultrafast Pulse Generation and Optical Frequency Combs Techniques  

E-Print Network [OSTI]

Stabilized Ultrafast Pulse Generation and Optical Frequency Combs ­ Techniques and Applications Diodes ­ Review Ultrafast Dynamics ­ Breathing Mode (Dispersion Managed Cavity) · High Pulse Energy to Make Short Pulses - Review Ultrafast Dynamics- - Dispersion Managed (Breathing Mode) MLL #12

Van Stryland, Eric

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


41

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

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

Data Science Modeling and Simulation Multimodal Imaging MAUI: Modeling, Analysis, and Ultrafast Imaging MAUI: Modeling, Analysis, and Ultrafast Imaging Project Goals...

42

Ultrafast Phenomena XIV, pp. 650-654 , Springer, Berlin (2005). 650 Ultrafast Dynamics of Light Transmission  

E-Print Network [OSTI]

of ultrafast pulse propagation through nano-hole arrays reported a 10-fs delay in transmission [6 of ultrafast light propagation through plasmonic nano-crystals using light pulses much shorter than the SPPUltrafast Phenomena XIV, pp. 650-654 , Springer, Berlin (2005). 650 Ultrafast Dynamics of Light

Peinke, Joachim

43

Investigations of ultrafast nuclear response induced by resonant and nonresonant laser pulses  

E-Print Network [OSTI]

Investigations of ultrafast nuclear response induced by resonant and nonresonant laser pulses Anand by ultrashort laser pulses interacting with a two electronic level molecular system. Fully quantum mechanical to implement. The behavior of the first two moments with respect to various parameters such as the pulse

Kumar, Anand T.N.

44

NANO EXPRESS Open Access Ultrafast nano-oscillators based on interlayer-  

E-Print Network [OSTI]

NANO EXPRESS Open Access Ultrafast nano-oscillators based on interlayer- bridged carbon nanoscrolls nano-oscillators based on carbon nanoscrolls (CNSs) using molecular dynamics simulations. Initiated of gigahertz. We demonstrate an effective strategy to reduce the dissipation of the CNS-based nano

Li, Teng

45

Ultrafast infrared studies of chemical reaction dynamics in room-temperature liquids  

E-Print Network [OSTI]

ultrafast pulses ..analyses of the ultrafast pulses. (a) A spectral analysis ofExperimentally, an ultrafast UV pulse dissociates a photo

Yang, H.

2011-01-01T23:59:59.000Z

46

Femtosecond pulse imaging: ultrafast optical oscilloscope  

E-Print Network [OSTI]

Femtosecond pulse imaging: ultrafast optical oscilloscope P. C. Sun, Y. T. Mazurenko,* and Y as well as our ability to detect the shape of the ul- trashort pulses that can be seen as an ultrafast 12, 1996 A nonlinear optical processor that is capable of real-time conversion of a femtosecond pulse

Fainman, Yeshaiahu

47

Delayed Ultrafast X-ray Auger Probing (DUXAP) of Nucleobase Ultraviolet Photoprotection  

E-Print Network [OSTI]

We present a new method for ultrafast spectroscopy of molecular photoexcited dynamics. The technique uses a pair of femtosecond pulses: a photoexcitation pulse initiating excited state dynamics followed by a soft x-ray (SXR) probe pulse that core ionizes certain atoms inside the molecule. We observe the Auger decay of the core hole as a function of delay between the photoexcitation and SXR pulses. The core hole decay is particularly sensitive to the local valence electrons near the core and shows new types of propensity rules, compared to dipole selection rules in SXR absorption or emission spectroscopy. We apply the delayed ultrafast x-ray Auger probing (DUXAP) method to the specific problem of nucleobase photoprotection to demonstrate its potential. The ultraviolet photoexcited \\pi\\pi* states of nucleobases are prone to chemical reactions with neighboring bases. To avoid this, the single molecules funnel the \\pi\\pi* population to lower lying electronic states on an ultrafast timescale under violation of the...

McFarland, B K; Miyabe, S; Tarantelli, F; Aguilar, A; Berrah, N; Bostedt, C; Bozek, J; Bucksbaum, P H; Castagna, J C; Coffee, R; Cryan, J; Fang, L; Feifel, R; Gaffney, K; Glownia, J; Martinez, T; Mucke, M; Murphy, B; Natan, A; Osipov, T; Petrovic, V; Schorb, S; Schultz, Th; Spector, L; Swiggers, M; Tenney, I; Wang, S; White, W; White, J; Gühr, M

2013-01-01T23:59:59.000Z

48

Ultrafast Transformations in Superionic Nanocrystals  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched Ferromagnetism in Layeredof2014 EIAUltrafast Transformations in SuperionicUltrafast

49

Ultrafast Strong-Field Vibrational Dynamics Studied by Femtosecond Extreme-Ultraviolet Transient Absorption Spectroscopy  

E-Print Network [OSTI]

to yield a compressed, ultrafast pulse close to the originalspectral width of the ultrafast optical pulses, delivering

Hosler, Erik Robert

2013-01-01T23:59:59.000Z

50

Ultrafast pulsed laser utilizing broad bandwidth laser glass  

DOE Patents [OSTI]

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.

Payne, Stephen A. (Castro Valley, CA); Hayden, Joseph S. (Clarks Summit, PA)

1997-01-01T23:59:59.000Z

51

Ultrafast pulsed laser utilizing broad bandwidth laser glass  

DOE Patents [OSTI]

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.

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

1997-09-02T23:59:59.000Z

52

4th-International Symposium on Ultrafast Surface Science - Final Report  

SciTech Connect (OSTI)

The 4-th International Symposium on Ultrafast Surface Dynamics (UDS4) was held at the Telluride Summer Research Center on June 22-27, 2003. The International Organizing Committee consisting of Hrvoje Petek (USA), Xiaoyang Zhu (USA), Pedro Echenique (Spain) and Maki Kawai (Japan) brought together a total of 51 participants 16 of whom were from Europe, 10 from Japan, and 25 from the USA. The focus of the conference was on ultrafast electron or light induced processes at well-defined surfaces. Ultrafast surface dynamics concerns the transfer of charge and energy at solid surfaces on the femtosecond time scale. These processes govern rates of fundamental steps in surface reactions, interfacial electron transfer in molecular electronics, and relaxation in spin transport. Recent developments in femtosecond laser technology make it possible to measure by a variety of nonlinear optical techniques directly in the time domain the microscopic rates underlying these interfacial processes. Parallel progress in scanning probe microscopy makes it possible at a single molecular level to perform the vibrational and electronic spectroscopy measurements, to induce reactions with tunneling electrons, and to observe their outcome. There is no doubt that successful development in the field of ultrafast surface dynamics will contribute to many important disciplines.

Hrvoje Petek

2005-01-26T23:59:59.000Z

53

Ultrafast Spectroscopy of Warm Dense Matter  

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

a plasma. Therefore, to probe a warm dense state undergoing a nonreversible process, an ultrafast technique faster than the ALS pulse duration (70 ps) and a single-shot...

54

Ultrafast Optical Pulses: Synthesis and Applications  

E-Print Network [OSTI]

This dissertation is devoted to ultrafast waveform synthesis using coherent Raman sidebands with the assistance of pulse shapers based on acousto-optic programmable dispersive ?lter (AOPDF) or deformable mirror (DM). Ultrashort optical science has...

Wang, Kai

2013-12-11T23:59:59.000Z

55

An ultrafast carbon nanotube terahertz polarisation modulator  

SciTech Connect (OSTI)

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.

Docherty, Callum J.; Stranks, Samuel D.; Habisreutinger, Severin N.; Joyce, Hannah J.; Herz, Laura M.; Nicholas, Robin J.; Johnston, Michael B., E-mail: m.johnston@physics.ox.ac.uk [Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford OX1 3PU (United Kingdom)

2014-05-28T23:59:59.000Z

56

Ultrafast infrared studies of complex ligand rearrangements in solution  

SciTech Connect (OSTI)

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

Payne, Christine K.

2003-05-31T23:59:59.000Z

57

Nanoscience on the Timescale of Electrons Ultrafast Spectroscopy of Nanomaterials  

E-Print Network [OSTI]

Nanoscience on the Timescale of Electrons Ultrafast Spectroscopy of Nanomaterials Pat Kambhampati with it??? ·How does it actually work??? #12;Nanoscience on the Ultrafast Timescale Pat Kambhampati, Mc? #12;Nanoscience on the Ultrafast Timescale Pat Kambhampati, McGill Chemistry Nanomaterial based

Kambhampati, Patanjali

58

Broadband laser cooling of trapped atoms with ultrafast pulses  

E-Print Network [OSTI]

Broadband laser cooling of trapped atoms with ultrafast pulses B. B. Blinov,* R. N. Kohn, Jr., M. J ions in an rf trap using ultrafast pulses from a mode-locked laser. The temperature of a single ion On the other hand, an ultrafast laser whose pulse is a few picoseconds long will naturally have a bandwidth

Blinov, Boris

59

Ultrafast x-rays: radiographing magnetism Project overview  

E-Print Network [OSTI]

, head of the ultrafast magnetism group. Stanford PULSE is a worldwide renowned centre for ultrafast1 Ultrafast x-rays: radiographing magnetism Project overview The main purpose of the proposed, it is now possible to achieve x-ray pulses that are a few femtoseconds long and that are focused within

Haviland, David

60

UPGRADING METHANE USING ULTRA-FAST THERMAL SWING ADSORPTION  

SciTech Connect (OSTI)

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.

Anna Lee Tonkovich

2004-01-01T23:59:59.000Z

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


61

Mehak Mehta November 21st Role of water on molecular mobility and physical stability of amorphous state  

E-Print Network [OSTI]

Mehak Mehta November 21st 2013 Role of water on molecular mobility and physical stability of amorphous state The chemical instability of pharmaceuticals can often be predicted based on accelerated the glass transition temperature (Tg), i.e. in the glassy state. Thus, from a practical stand point

Thomas, David D.

62

Ultrafast Spectroscopy of Warm Dense Matter  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched Ferromagnetism in Layeredof2014 EIA Energy40081AEnergyUltrafast LaserUltrafast

63

Ultrafast Spectroscopy of Warm Dense Matter  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched Ferromagnetism in Layeredof2014 EIA Energy40081AEnergyUltrafastUltrafast Spectroscopy

64

The Physical Conditions in a Pre Super Star Cluster Molecular Cloud in the Antennae Galaxies  

E-Print Network [OSTI]

We present an analysis of the physical conditions in an extreme molecular cloud in the Antennae merging galaxies. This cloud has properties consistant with those required to form a globular cluster. We have obtained ALMA CO and 870$\\mu$m observations of the Antennae galaxy system with $\\sim 0".5$ resolution. This cloud stands out in the data with a radius of $\\lesssim 24$~pc and mass of $>5\\times 10^6$~M$_\\odot$. The cloud appears capable of forming a globular cluster, but the lack of associated thermal radio emission indicates that star formation has not yet altered the environment. The lack of thermal radio emission places the cloud in an early stage of evolution, which we expect to be short-lived ($\\lesssim 1$~Myr) and thus rare. Given its mass and kinetic energy, for the cloud to be confined (as its appearance strongly suggests) it must be subject to an external pressure of P/$k_B \\gtrsim 10^8$~K~cm$^{-3}$ -- 10,000 times higher than typical interstellar pressure. This would support theories that high pre...

Johnson, K E; Indebetouw, R; Brogan, C L; Whitmore, B C; Hibbard, J; Sheth, K; Evans, A

2015-01-01T23:59:59.000Z

65

PURDUE UNIVERSITY ULTRAFAST OPTICS & OPTICAL FIBER COMMUNICATIONS LABORATORY Photonic RF Waveform Synthesis,  

E-Print Network [OSTI]

PURDUE UNIVERSITY ULTRAFAST OPTICS & OPTICAL FIBER COMMUNICATIONS LABORATORY Photonic RF Waveform, Shijun Xiao Funding from ARO, DARPA, and NSF #12;PURDUE UNIVERSITY ULTRAFAST OPTICS & OPTICAL FIBER performance (spectral engineering, dispersion compensation) #12;PURDUE UNIVERSITY ULTRAFAST OPTICS & OPTICAL

Purdue University

66

PURDUE UNIVERSITY ULTRAFAST OPTICS AND OPTICAL FIBER COMMUNICATIONS LABORATORY Femtosecond Pulse  

E-Print Network [OSTI]

as new pulse sequence processing functionalities. #12;PURDUE UNIVERSITY ULTRAFAST OPTICS AND OPTICAL UNIVERSITY ULTRAFAST OPTICS AND OPTICAL FIBER COMMUNICATIONS LABORATORY CLEO 2002 One Guide ­ One PulsePURDUE UNIVERSITY ULTRAFAST OPTICS AND OPTICAL FIBER COMMUNICATIONS LABORATORY CLEO 2002

Purdue University

67

Adaptive feedback control of ultrafast semiconductor nonlinearities J. Kunde,a)  

E-Print Network [OSTI]

that adaptive feedback optical pulse shaping can be used to control ultrafast semiconductor nonlinearities insight into the interaction of semiconduc- tors and ultrafast optical pulses. Specifically, we develop spectroscopy. More- over, the optimized pulse shape can substantially enhance ultrafast semiconductor

Keller, Ursula

68

Spatio-temporal mapping of ablated species in ultrafast laser-produced graphite plasmas  

SciTech Connect (OSTI)

We studied the spatial and temporal distributions of ionic, neutral, and molecular species generated by femtosecond laser produced plasma under varying ambient nitrogen gas pressures. Plasmas were generated by irradiating planar graphite targets using 40 fs pulses of 800 nm radiation from a Ti:Sapphire laser. The results show that in the presence of an ambient gas, the molecular species spatial extension and lifetime are directly correlated to the evolution of excited ions. The present studies also provide valuable insights into the evolution history of various species and their excitation during ultrafast laser ablation.

Al-Shboul, K. F.; Harilal, S. S.; Hassanein, A. [Center for Materials Under Extreme Environment, School of Nuclear Engineering, Purdue University, West Lafayette, Indiana 47907 (United States)

2012-05-28T23:59:59.000Z

69

Attosecond timing the ultrafast charge-transfer process in atomic collisions  

SciTech Connect (OSTI)

By solving the three-dimensional, time-dependent Schroedinger equation, we have demonstrated that the ultrafast charge-transfer process in ion-atom collisions can be mapped out with attosecond extreme uv (xuv) pulses. During the dynamic-charge transfer from the target atom to the projectile ion, the electron coherently populates the two sites of both nuclei, which can be viewed as a 'short-lived' molecular state. A probing attosecond xuv pulse can instantly unleash the delocalized electron from such a ''transient molecule,'' so that the resulting photoelectron may exhibit a ''double-slit'' interference. On the contrary, either reduced or no photoelectron interference will occur if the attosecond xuv pulse strikes well before or after the collision. Therefore, by monitoring the photoelectron interference visibility, one can precisely time the ultrafast charge-transfer process in atomic collisions with time-delayed attosecond xuv pulses.

Hu, S. X. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States)

2011-04-15T23:59:59.000Z

70

Ultrafast Control of Magnetism in Ferromagnetic Semiconductors via Photoexcited Transient Carriers  

E-Print Network [OSTI]

Magneto-Optics in Nickel: Magnetism or Optics? ” Phys. Rev.Ultrafast Control of Magnetism in FerromagneticFall 2008 Ultrafast Control of Magnetism in Ferromagnetic

Cotoros, Ingrid A.

2009-01-01T23:59:59.000Z

71

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...

72

Ultrafast Diagnostics for Electron Beams from Laser Plasma Accelerators  

E-Print Network [OSTI]

Laser, Plasma, Accelerator, Diagnostic PACS: 52.25.0s,Leemans, "Charge Diagnostics for Laser Plasma Accelerators,"Ultrafast Diagnostics for Electron Beams from Laser Plasma

Matlis, N. H.

2011-01-01T23:59:59.000Z

73

Suppression of Magnetic State Decoherence Using Ultrafast Optical Pulses  

E-Print Network [OSTI]

It is shown that the magnetic state decoherence produced by collisions in a thermal vapor can be suppressed by the application of a train of ultrafast optical pulses.

C. Search; P. R. Berman

2000-03-01T23:59:59.000Z

74

Ultrafast charge localization in a stripe-phase nickelate  

E-Print Network [OSTI]

21 . The ability of ultrafast optical pulses to suppress theultrafast response of the mid-IR conductivity to femtosecond optical excitation. Pump pulses

Coslovich, Giacomo

2013-01-01T23:59:59.000Z

75

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...

76

Ultrafast Excited-State Dynamics in the Green Fluorescent Protein Variant S65T/ H148D. 1. Mutagenesis and Structural Studies,  

E-Print Network [OSTI]

Articles Ultrafast Excited-State Dynamics in the Green Fluorescent Protein Variant S65T/ H148D. 1 Kanchanawong,# William Childs,# Steven G. Boxer,# and S. James Remington*,§ Institute of Molecular Biology chromophores, respectively. Excitation of either band leads to green emission. In wt-GFP, excitation of band

Boxer, Steven G.

77

Ultrafast Pulse Shaping Approaches to Quantum Computing  

E-Print Network [OSTI]

Quantum computing exploits the quantum-mechanical nature of matter to exist in multiple possible states simultaneously. This new approach promises to revolutionize the present form of computing. As an approach to quantum computing, we discuss ultrafast laser pulse shaping, in particular, the acousto-optic modulator based Fourier-Transform pulse-shaper, which has the ability to modulate tunable high power ultrafast laser pulses. We show that optical pulse shaping is an attractive route to quantum computing since shaped pulses can be transmitted over optical hardware and the same infrastructure can be used for computation and optical information transfer. We also address the problem of extending coherence-times for optically induced processes.

Debabrata Goswami

2003-12-24T23:59:59.000Z

78

Laser cooling with ultrafast pulse trains  

E-Print Network [OSTI]

We propose a new laser cooling method for atomic species whose level structure makes traditional laser cooling difficult. For instance, laser cooling of hydrogen requires vacuum-ultraviolet laser light, while multielectron atoms need laser light at many widely separated frequencies. These restrictions can be eased by laser cooling on two-photon transitions with ultrafast pulse trains. Laser cooling of hydrogen, antihydrogen, and carbon appears feasible, and extension of the technique to molecules may be possible.

David Kielpinski

2003-06-14T23:59:59.000Z

79

Ultrafast Spectroscopy of Warm Dense Matter  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLasDelivered energy consumption by sectorlong version) The0 -ITER'sUltrafast

80

Ultrafast Structural Dynamics in Combustion Relevant Model Systems  

SciTech Connect (OSTI)

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 molecule’s 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 molecule’s 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 electron’s 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 molecule’s 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

Weber, Peter M. [Brown University

2014-03-31T23:59:59.000Z

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


81

Technical Report Ultrafast X-ray Science at the Sub-Picosecond Pulse Source  

E-Print Network [OSTI]

1 Technical Report Ultrafast X-ray Science at the Sub-Picosecond Pulse Source Kelly J. Gaffney ultrafast phenomena. These techniques involve excitation of a sample with an ultrafast laser pump pulse, USA The ultrafast, high brightness x-ray free electron laser (XFEL) sources of the future have

Wechsler, Risa H.

82

Controlled Coherent Excitations in a Single Cadmium Ion with an Ultrafast Laser  

E-Print Network [OSTI]

of ultrafast pulses in a Ramsey interferometer. This ultrafast coupling is vital in a scheme for generationControlled Coherent Excitations in a Single Cadmium Ion with an Ultrafast Laser by Rudolph Nicolas: Controlled Coherent Excitations in a Single Cadmium Ion with an Ultrafast Laser written by R. N. Kohn Jr. has

Monroe, Christopher

83

Ultrafast X-ray Diffraction Theory Jianshu Cao* and Kent R. Wilson  

E-Print Network [OSTI]

notablely using ultrafast optical pump-probe pulses. Unfortunately, except for a few favorable cases of a sample is initiated by an ultrafast optical laser pulse and then probed by an ultrafast X-ray pulse initiated by the optical pump pulse in real time and real space.9-11 From a simple viewpoint, ultrafast X

Cao, Jianshu

84

Ultrafast extended x-ray absorption fine structure ,,EXAFS...--theoretical considerations  

E-Print Network [OSTI]

13­20 to generate ultrafast x-ray pulses, however, the prospect of ultrafast EXAFS seems encouragingUltrafast extended x-ray absorption fine structure ,,EXAFS...--theoretical considerations Frank L by the recent experimental demonstration of ultrafast x-ray absorption spectroscopy, we present a framework

Cao, Jianshu

85

DIRECT SPACE-TO-TIME PULSE SHAPING FOR ULTRAFAST OPTICAL  

E-Print Network [OSTI]

DIRECT SPACE-TO-TIME PULSE SHAPING FOR ULTRAFAST OPTICAL WAVEFORM GENERATION A Thesis Submitted ago. To the students, past and present, post-docs, and visitors of the Ultrafast Optics & Optical me what it is that I love about this work. The experimental optical pulse train generation devices

Purdue University

86

Ultrafast lasers in the femtosecond regime: generation, amplification  

E-Print Network [OSTI]

Ultrafast lasers in the femtosecond regime: generation, amplification and measurement Pedro can be explored. Ultrafast elec- tromagnetic fields are one of those tools, as they allow the probing is divided in two parts one that deals with the generation and amplification of ultrashort pulses the second

87

Information processing with longitudinal spectral decomposition of ultrafast pulses  

E-Print Network [OSTI]

Information processing with longitudinal spectral decomposition of ultrafast pulses Robert E of waveforms depending on whether their frequency response is or is not known a priori. Ultrafast pulses prove synthesis and detection relying on longitudinal spectral decomposition of subpicosecond optical pulses

Fainman, Yeshaiahu

88

Radiological and Environmental Research Division annual report, October 1979-September 1980: fundamental molecular physics and chemistry  

SciTech Connect (OSTI)

Research is reported on the physics and chemistry of atoms, ions, and molecules, especially their interactions with external agents such as photons and electrons. Individual items from the report were prepared separately for the data base. (GHT)

Not Available

1981-09-01T23:59:59.000Z

89

Ultrafast electron beam imaging of femtosecond laser-induced plasma Junjie Li, Xuan Wang, Zhaoyang Chen, Richard Clinite, Samuel S. Mao et al.  

E-Print Network [OSTI]

, Beijing 100190, China and Department of Physics, Shanghai Jiao Tong University, Shanghai 200240, China in the early stage of laser ablation of a copper target are investigated in real time by making ultrafast have been a subject of intensive investigation in recent years ow- ing to its importance in a wide

Cao, Jianming

90

Femtosecond laser studies of ultrafast intramolecular processes  

SciTech Connect (OSTI)

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.

Hayden, C. [Sandia National Laboratories, Livermore, CA (United States)

1993-12-01T23:59:59.000Z

91

High Resolution, Ultrafast SFG Vibrational Spectroscopy | EMSL  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-SeriesFlickr FlickrGuidedCH2M HILLAdministration |BasicResolution, Ultrafast

92

Ultrafast Laser Facility | Photosynthetic Antenna Research Center  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched Ferromagnetism in Layeredof2014 EIA Energy40081AEnergyUltrafast Laser Facility

93

Ultrafast Spectroscopy of Warm Dense Matter  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched Ferromagnetism in Layeredof2014 EIA Energy40081AEnergyUltrafast Laser

94

Ultrafast Spectroscopy of Warm Dense Matter  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched Ferromagnetism in Layeredof2014 EIA Energy40081AEnergyUltrafast

95

Applications of Ultrafast Terahertz Pulses for Intra-Excitonic Spectroscopy of Quasi-2D Electron-Hole Gases  

E-Print Network [OSTI]

Applications of Ultrafast Terahertz Pulses for Intra-the utilization of ultrafast terahertz (THz) pulses for theUltrafast Terahertz” 250-kHz Ti:Sapphire Regenerative Amplifier System Pulse

Kaindl, Robert A.; Carnahan, Marc A.; Hagele, Daniel; Chemla, D.S.

2006-01-01T23:59:59.000Z

96

Techniques for synchronization of X-Ray pulses to the pump laser in an ultrafast X-Ray facility  

E-Print Network [OSTI]

synchronization of ultrafast x-ray pulses produced in theAccurate timing of ultrafast x-ray probe pulses emitted fromOF X-RAY PULSES TO THE PUMP LASER IN AN ULTRAFAST X-RAY

Corlett, J.N.; Doolittle, L.; Schoenlein, R.; Staples, J.; Wilcox, R.; Zholents, A.

2003-01-01T23:59:59.000Z

97

Synchronization of x-ray pulses to the pump laser in an ultrafast x-ray facility  

E-Print Network [OSTI]

Accurate timing of ultrafast x-ray probe pulses emitted fromOF X-RAY PULSES TO THE PUMP LASER IN AN ULTRAFAST X-RAY

Corlett, J.N.; Barry, W.; Byrd, J.M.; Schoenlein, R.; Zholents, A.

2002-01-01T23:59:59.000Z

98

Space charge effects in ultrafast electron diffraction and imaging  

SciTech Connect (OSTI)

Understanding space charge effects is central for the development of high-brightness ultrafast electron diffraction and microscopy techniques for imaging material transformation with atomic scale detail at the fs to ps timescales. We present methods and results for direct ultrafast photoelectron beam characterization employing a shadow projection imaging technique to investigate the generation of ultrafast, non-uniform, intense photoelectron pulses in a dc photo-gun geometry. Combined with N-particle simulations and an analytical Gaussian model, we elucidate three essential space-charge-led features: the pulse lengthening following a power-law scaling, the broadening of the initial energy distribution, and the virtual cathode threshold. The impacts of these space charge effects on the performance of the next generation high-brightness ultrafast electron diffraction and imaging systems are evaluated.

Tao Zhensheng; Zhang He; Duxbury, P. M.; Berz, Martin; Ruan, Chong-Yu [Physics and Astronomy Department, Michigan State University, East Lansing, Michigan 48824-2320 (United States)

2012-02-15T23:59:59.000Z

99

Apparatus and method for characterizing ultrafast polarization varying optical pulses  

DOE Patents [OSTI]

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.

Smirl, Arthur (1020 Cherry La. Northwest, Iowa City, IA 52240); Trebino, Rick P. (425 Mulqueeny St., Livermore, CA 94550)

1999-08-10T23:59:59.000Z

100

High-performance laser processing using manipulated ultrafast laser pulses  

SciTech Connect (OSTI)

We employ manipulated ultrafast laser pulses to realize microprocessing with high-performance. Efficient microwelding of glass substrates by irradiation by a double-pulse train of ultrafast laser pulses is demonstrated. The bonding strength of two photostructurable glass substrates welded by double-pulse irradiation was evaluated to be 22.9 MPa, which is approximately 22% greater than that of a sample prepared by conventional irradiation by a single pulse train. Additionally, the fabrication of hollow microfluidic channels with a circular cross-sectional shape embedded in fused silica is realized by spatiotemporally focusing the ultrafast laser beam. We show both theoretically and experimentally that the spatiotemporal focusing of ultrafast laser beam allows for the creation of a three-dimensionally symmetric spherical peak intensity distribution at the focal spot.

Sugioka, Koji; Cheng Ya; Xu Zhizhan; Hanada, Yasutaka; Midorikawa, Katsumi [RIKEN - Advanced Science Institute, Wako, Saitama 351-0198 (Japan); State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences (China); RIKEN - Advanced Science Institute, Wako, Saitama 351-0198 (Japan)

2012-07-30T23:59:59.000Z

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


101

Controlling ultrafast currents by the non-linear photogalvanic effect  

E-Print Network [OSTI]

We theoretically investigate the effect of broken inversion symmetry on the generation and control of ultrafast currents in a transparent dielectric (SiO2) by strong femto-second optical laser pulses. Ab-initio simulations based on time-dependent density functional theory predict ultrafast DC currents that can be viewed as a non-linear photogalvanic effect. Most surprisingly, the direction of the current undergoes a sudden reversal above a critical threshold value of laser intensity I_c ~ 3.8*10^13 W/cm2. We trace this switching to the transition from non-linear polarization currents to the tunneling excitation regime. We demonstrate control of the ultrafast currents by the time delay between two laser pulses. We find the ultrafast current control by the non-linear photogalvanic effect to be remarkably robust and insensitive to laser-pulse shape and carrier-envelope phase.

Georg Wachter; Shunsuke A. Sato; Christoph Lemell; Xiao-Min Tong; Kazuhiro Yabana; Joachim Burgdörfer

2015-03-20T23:59:59.000Z

102

Electron-nuclear correlations for photo-induced dynamics in molecular dimers  

E-Print Network [OSTI]

January 2004; accepted 11 March 2004 Ultrafast photoinduced dynamics of electronic excitation in molecularElectron-nuclear correlations for photo-induced dynamics in molecular dimers Dmitri S. Kilin, Yuri dimers is drastically affected by the dynamic reorganization of inter- and intra- molecular nuclear

103

Laser safety information for the Atomic, Molecular and Optical (AMO) Physics Labs at Lehigh University modified from the laser safety program developed by the office of Environmental  

E-Print Network [OSTI]

1 Laser safety information for the Atomic, Molecular and Optical (AMO) Physics Labs at Lehigh University modified from the laser safety program developed by the office of Environmental Health and Safety using the following reference materials: I. American National Standards for Safe Use of Lasers - ANSI Z

Huennekens, John

104

Ultrafast Optics and Optical Fiber Communications Laboratory http://purcell.ecn.purdue.edu/~fsoptics/  

E-Print Network [OSTI]

Ultrafast Optics and Optical Fiber Communications Laboratory http, A. M. Weiner Purdue University C. Lin Avanex Corporation Conference on Lasers and Electro Optics;Ultrafast Optics and Optical Fiber Communications Laboratory http://purcell.ecn.purdue.edu/~fsoptics/ 2

Purdue University

105

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

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

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...

106

Ultrafast imaging of complex systems in 3-D at near atomic resolution...  

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

on ultrafast timescales using extremely intense X-ray free-electron laser (XFEL) pulses. One important step toward ultrafast imaging of samples with a single X-ray shot is...

107

Ultrafast optical pulse manipulation in three dimensional-resolved microscope imaging and microfabrication  

E-Print Network [OSTI]

The availability of lasers with femtosecond, ultrafast light pulses provides new opportunities and challenges in instrument design. This thesis addresses three aspects of utilizing ultrafast light pulses in two-photon ...

Kim, Daekeun, Ph. D. Massachusetts Institute of Technology

2009-01-01T23:59:59.000Z

108

Investigation on properties of ultrafast switching in a bulk gallium arsenide avalanche semiconductor switch  

SciTech Connect (OSTI)

Properties of ultrafast switching in a bulk gallium arsenide (GaAs) avalanche semiconductor switch based on semi-insulating wafer, triggered by an optical pulse, were analyzed using physics-based numerical simulations. It has been demonstrated that when a voltage with amplitude of 5.2?kV is applied, after an exciting optical pulse with energy of 1??J arrival, the structure with thickness of 650??m reaches a high conductivity state within 110 ps. Carriers are created due to photons absorption, and electrons and holes drift to anode and cathode terminals, respectively. Static ionizing domains appear both at anode and cathode terminals, and create impact-generated carriers which contribute to the formation of electron-hole plasma along entire channel. When the electric field in plasma region increases above the critical value (?4?kV/cm) at which the electrons drift velocity peaks, a domain comes into being. An increase in carrier concentration due to avalanche multiplication in the domains reduces the domain width and results in the formation of an additional domain as soon as the field outside the domains increases above ?4?kV/cm. The formation and evolution of multiple powerfully avalanching domains observed in the simulations are the physical reasons of ultrafast switching. The switch exhibits delayed breakdown with the characteristics affected by biased electric field, current density, and optical pulse energy. The dependence of threshold energy of the exciting optical pulse on the biased electric field is discussed.

Hu, Long, E-mail: hulong-1226@126.com [Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Xi'an Jiaotong University, Xi'an 710049 (China); Science and Technology on High Power Microwave Laboratory, Northwest Institute of Nuclear Technology, Xi'an 710024 (China); Su, Jiancang; Ding, Zhenjie; Hao, Qingsong; Yuan, Xuelin [Science and Technology on High Power Microwave Laboratory, Northwest Institute of Nuclear Technology, Xi'an 710024 (China)

2014-03-07T23:59:59.000Z

109

A grazing incidence x-ray streak camera for ultrafast, single-shot measurements  

E-Print Network [OSTI]

provided by UV pulses derived from an ultrafast laser. Dueultrafast dynamics using a single synchrotron x-ray pulse.

Feng, Jun

2010-01-01T23:59:59.000Z

110

Physics  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation Desert Southwest RegionatSearch Welcome to theNews & Blog »Physics Physics Print Because

111

Physics  

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

Physics A B C D E F G H I J K L M N O P Q R S T U V W X Y Z A'Hearn, Michael F. - Department of Astronomy, University of Maryland at College Park Aalberts, Daniel P. - Department...

112

Ultrafast X-ray Absorption Spectroscopy using Laser-Driven Electron X-ray Sources (LEXS)  

E-Print Network [OSTI]

: ultrafast x-rays, x-ray absorption spectroscopy, terawatt lasers, ultrafast reaction dynamics, atomic motion atomic motion by scrutinizing the changes in x- ray absorption spectra during reactions. FirstUltrafast X-ray Absorption Spectroscopy using Laser-Driven Electron X-ray Sources (LEXS) Guangjun

Guo, Ting

113

Plasmonic Near-Electric Field Enhancement Effects in Ultrafast Photoelectron Emission: Correlated Spatial and Laser Polarization  

E-Print Network [OSTI]

ABSTRACT: Electron emission from single, supported Ag nanocubes excited with ultrafast laser pulses ( = 800 irradiated with ultrafast laser pulses at a photon energy (Eph) below the material work functionPlasmonic Near-Electric Field Enhancement Effects in Ultrafast Photoelectron Emission: Correlated

Mohseni, Hooman

114

ULTRAFAST OPTICS AND OPTICAL FIBER COMMUNICATIONS LABORATORYLEOS 2003 Multiple Output Channel  

E-Print Network [OSTI]

DSTAWG DST Pulse Shaper Fiber ports Imaging optics U.S. Quarter #12;ULTRAFAST OPTICS AND OPTICAL FIBER;ULTRAFAST OPTICS AND OPTICAL FIBER COMMUNICATIONS LABORATORYLEOS 2003 One Guide ­ One Pulse Pulses slab Loss-engineering to control relative pulse amplitude. #12;ULTRAFAST OPTICS AND OPTICAL FIBER

Purdue University

115

Optical coherence and beamspread in ultrafast-laser pulsetrain-burst hole drilling  

E-Print Network [OSTI]

advantages over single-pulse laser processing of materials and biological tissues. Ultrafast lasers are often material, as is sometimes the case for nanosecond-pulse ablation; further, pulsetrain-bursts of ultrafast of ultrafast laser pulses, at a repetition rate of 1 MHz or greater, is less likely to leave cracks or residual

Marjoribanks, Robin S.

116

Title of dissertation: ULTRAFAST CONTROL OF SPIN AND MOTION IN TRAPPED IONS  

E-Print Network [OSTI]

, I report here on the first experiments using ultrafast laser pulses to control the internalABSTRACT Title of dissertation: ULTRAFAST CONTROL OF SPIN AND MOTION IN TRAPPED IONS Jonathan and external states of a single trapped ion. I begin with experiments in ultrafast spin control, showing how

Monroe, Christopher

117

Proceedings of SPIE, Vol. 5825, 118-138 (2005) Ultrafast coherent spectroscopy of single semiconductor  

E-Print Network [OSTI]

ultrafast optical pulses to probe and control coherent polarizations. In this article, we review our recentProceedings of SPIE, Vol. 5825, 118-138 (2005) Ultrafast coherent spectroscopy of single work on combining ultrafast spectroscopy and near-field microscopy to probe the nonlinear optical

Peinke, Joachim

118

Characterization of a liquid-crystal ultrafast pulse shaper for ultra-broadband applications  

E-Print Network [OSTI]

Characterization of a liquid-crystal ultrafast pulse shaper for ultra-broadband applications pulse shaping Spatial light modulators Ultrafast optics Femtosecond pulses a b s t r a c t By combining in revised form 22 January 2014 Accepted 28 January 2014 Available online 6 February 2014 Keywords: Ultrafast

119

Single pulse ultrafast laser imprinting of axial dot arrays in bulk glasses C. Mauclair,1,  

E-Print Network [OSTI]

Single pulse ultrafast laser imprinting of axial dot arrays in bulk glasses C. Mauclair,1, A sam- ples were irradiated with 160 fs pulses from an 800 nm Ti:Sapphire amplified ultrafast laser.mauclair@univ-st-etienne.fr Compiled December 20, 2010 Ultrafast laser processing of bulk transparent materials can significantly gain

Paris-Sud XI, Université de

120

Breathing coherent phonons and caps fragmentation in carbon nanotubes following ultrafast laser pulses  

E-Print Network [OSTI]

driven by ultrafast laser pulses.1­3 The necessary conditions for generating such coherent phonons are i is larger than the duration of currently available ultrafast pulses. ii Measurements4­7 determinedBreathing coherent phonons and caps fragmentation in carbon nanotubes following ultrafast laser

Dumitrica,Traian

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


121

Generation of mega-electron-volt electron beams by an ultrafast intense laser pulse  

E-Print Network [OSTI]

Generation of mega-electron-volt electron beams by an ultrafast intense laser pulse Xiaofang Wang emission from the interaction of an ultrafast ( 29 fs), intense ( 1018 W/cm2 ) laser pulse with underdense of such an ultrafast laser pulse with matter and possible new approaches to MeV electron generation. In this paper we

Umstadter, Donald

122

Parametric cascade downconverter for intense ultrafast mid-infrared generation beyond the ManleyRowe  

E-Print Network [OSTI]

codes: 190.2620, 190.4970, 320.7160, 320.7110. Intense and ultrafast optical pulses (durations typ of optical sources that directly produce ultrafast intense pulses at long wavelengths. One technique that has from in- tense ultrafast pulses in the near infrared 800 nm . Recent results that produce intense

Boyer, Edmond

123

Fourier information optics for the ultrafast time domain Andrew M. Weiner  

E-Print Network [OSTI]

of ultrafast pulses. These examples exploit time­ frequency Fourier techniques to perform matched filtering processing of ultrafast pulsed signals, in close analogy with the spatial Fourier techniques used by LeithFourier information optics for the ultrafast time domain Andrew M. Weiner School of Electrical

Purdue University

124

Control of ultrafast electron dynamics with shaped femtosecond laser pulses: from atoms to solids  

E-Print Network [OSTI]

Control of ultrafast electron dynamics with shaped femtosecond laser pulses: from atoms to solids;1. Introduction In coherent control shaped femtosecond laser pulses are used as a tool to steer the ultrafast focus on advanced control of ultrafast electron dynamics with shaped femtosecond laser pulses

Peinke, Joachim

125

Physics  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - September 2006Photovoltaic Theory and Modeling Los AlamosAerosol.Physics

126

Physics  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassive Solar Home Design Passive SolarCenter |Photoinduced2Zoe Martin'sPhysics Print

127

Impact system for ultrafast synchrotron experiments  

SciTech Connect (OSTI)

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.

Jensen, B. J.; Owens, C. T.; Ramos, K. J.; Yeager, J. D.; Saavedra, R. A.; Luo, S. N.; Hooks, D. E. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Iverson, A. J. [National Security Technologies, Los Alamos, New Mexico 87544 (United States); Fezzaa, K. [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

2013-01-15T23:59:59.000Z

128

Ultrafast Nonlinear Spectroscopy of Semiconducting Carbon Nanotubes  

E-Print Network [OSTI]

metallic nanotubes . . . . . . . . . . . . . . . . . Carbon2 Carbon Nanotubes Physical and ElectronicStructure of Carbon Nanotubes . . . . . . . . . .

Graham, Matthew Werden

2010-01-01T23:59:59.000Z

129

Ultrafast Nonlinear Spectroscopy of Semiconducting Carbon Nanotubes  

E-Print Network [OSTI]

2 Carbon Nanotubes Physical andElectronic Structure of Carbon Nanotubes . . . . . . . . . .Photophysics in Semiconducting Carbon Nanotubes . . . . .

Graham, Matthew Werden

2010-01-01T23:59:59.000Z

130

Ultrafast energy transfer from rigid, branched side-chains into a conjugated, alternating copolymer  

SciTech Connect (OSTI)

We present the synthesis and characterization of a benzodithiophene/thiophene alternating copolymer decorated with rigid, singly branched pendant side chains. We characterize exciton migration and recombination dynamics in these molecules in tetrahydrofuran solution, using a combination of static and time-resolved spectroscopies. As control experiments, we also measure electronic relaxation dynamics in isolated molecular analogues of both the side chain and polymer moieties. We employ semi-empirical and time-dependent density functional theory calculations to show that photoexcitation of the decorated copolymer using 395 nm laser pulses results in excited states primarily localized on the pendant side chains. We use ultrafast transient absorption spectroscopy to show that excitations are transferred to the polymer backbone faster than the instrumental response function, ?250 fs.

Griffin, Graham B.; Rolczynski, Brian S.; Linkin, Alexander; McGillicuddy, Ryan D.; Engel, Gregory S., E-mail: gsengel@uchicago.edu [Department of Chemistry, The James Franck Institute, Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637 (United States); Lundin, Pamela M. [Department of Chemical Engineering, Stanford University, Stauffer III, 381 North-South Mall, Stanford, California 94305 (United States) [Department of Chemical Engineering, Stanford University, Stauffer III, 381 North-South Mall, Stanford, California 94305 (United States); A. R. Smith Department of Chemistry, Appalachian State University, 417 CAP Building, 525 Rivers Street, Boone, North Carolina 28608 (United States); Bao, Zhenan [Department of Chemical Engineering, Stanford University, Stauffer III, 381 North-South Mall, Stanford, California 94305 (United States)] [Department of Chemical Engineering, Stanford University, Stauffer III, 381 North-South Mall, Stanford, California 94305 (United States)

2014-01-21T23:59:59.000Z

131

Optical Damage Threshold of Silicon for Ultrafast Infrared Pulses  

SciTech Connect (OSTI)

While silicon has several properties making it an attractive material for structure-based laser-driven acceleration, its optical damage threshold, a key parameter for high-gradient acceleration, has been unknown. Here we present measurements of the optical damage threshold of crystalline silicon for ultrafast pulses in the mid-infrared. The wavelengths tested span a range from the telecommunications band at 1550 nm extending longer toward the two-photon absorption threshold at around 2200 nm. We discuss the prevailing theories of ultrafast optical breakdown, describe the experimental setup and preliminary results, and propose a relevant performance parameter for candidate accelerator structures.

Cowan, B.; /SLAC

2006-09-07T23:59:59.000Z

132

Ultrafast reduction of the total magnetization in iron  

SciTech Connect (OSTI)

Surprisingly, if a ferromagnet is exposed to an ultrafast laser pulse, its apparent magnetization is reduced within less than a picosecond. Up to now, the total magnetization, i.e., the average spin polarization of the whole valence band, was not detectable on a sub-picosecond time scale. Here, we present experimental data, confirming the ultrafast reduction of the total magnetization. Soft x-ray pulses from the free electron laser in Hamburg (FLASH) extract polarized cascade photoelectrons from an iron layer excited by a femtosecond laser pulse. The spin polarization of the emitted electrons is detected by a Mott spin polarimeter.

Fognini, A., E-mail: afognini@phys.ethz.ch; Michlmayr, T. U.; Salvatella, G.; Vaterlaus, A.; Acremann, Y., E-mail: acremann@solid.phys.ethz.ch [Laboratory for Solid State Physics, Otto-Stern-Weg 1, ETH Zurich, 8093 Zurich (Switzerland); Wetli, C. [Multifunktionale Ferroische Mat., Vladimir-Prelog-Weg 1-5/10, ETH Zurich, 8093 Zurich (Switzerland); Ramsperger, U.; Bähler, T.; Pescia, D. [Laboratory for Solid State Physics, Auguste-Piccard-Hof 1, ETH Zurich, 8093 Zurich (Switzerland); Sorgenfrei, F.; Beye, M.; Eschenlohr, A.; Pontius, N.; Föhlisch, A. [Institut für Methoden und Instrumentierung der Forschung mit Synchrotronstrahlung, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, 12489 Berlin (Germany); Stamm, C. [Institut für Methoden und Instrumentierung der Forschung mit Synchrotronstrahlung, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, 12489 Berlin (Germany); Department of Materials, ETH Zurich, Hönggerbergring 64, 8093 Zurich (Switzerland); Hieke, F.; Dell'Angela, M.; Wurth, W. [Institut für Experimentalphysik and Center for Free-Electron Laser Science, Universität Hamburg, 22607 Hamburg (Germany); Jong, S. de; Dürr, H. A. [SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); and others

2014-01-20T23:59:59.000Z

133

Ultrafast Core-Hole Induced Dynamics in Water  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched Ferromagnetism in Layeredof2014 EIA Energy40081AEnergy StorageUltrafastUltrafast

134

Characterization of iso-CF{sub 2}I{sub 2} in frequency and ultrafast time domains  

SciTech Connect (OSTI)

The photolysis of diiododifluoromethane (CF{sub 2}I{sub 2}) in condensed phases was studied by a combination of matrix isolation and ultrafast time-resolved spectroscopy, in concert with ab initio calculations. Photolysis at wavelengths of 355 or 266 nm of CF{sub 2}I{sub 2}:Ar samples (1:5000) held at {approx}8 K yielded iso-CF{sub 2}I{sub 2} (F{sub 2}C-I-I), a metastable isomer of CF{sub 2}I{sub 2}, characterized here for the first time. The infrared (IR) spectra of this isomer were recorded in matrix experiments, and the derived positions of the C-F stretching modes are in very good agreement with the predictions of high level ab initio calculations, which show that the iso-form is a minimum on the CF{sub 2}I{sub 2} ground state potential energy surface. The formation of this isomer following 350 nm excitation of CF{sub 2}I{sub 2} in room temperature CCl{sub 4} solutions was monitored through its intense C-F stretching mode by means of ultrafast time-resolved IR absorption. Together, matrix isolation and ultrafast IR absorption experiments suggest that the formation of iso-CF{sub 2}I{sub 2} occurs via recombination of CF{sub 2}I radical and I atom. Ultrafast IR experiments detect a delayed rise of iso-CF{sub 2}I-I absorption, placing an upper limit of 400 fs for the C-I bond dissociation and primary geminate recombination processes. The product absorption spectrum recorded 1 ns after 350 nm excitation of CF{sub 2}I{sub 2} in solution is virtually identical to the visible absorption spectrum of iso-CF{sub 2}I{sub 2} trapped in matrix isolation experiments [with subtracted I{sub 2}(X) absorption]. The formation of this isomer in solution at room temperature has direct dynamic implications for the ultrafast production of molecular iodine from electronically excited CF{sub 2}I{sub 2}.

El-Khoury, Patrick Z.; Tarnovsky, Alexander N. [Department of Chemistry and Center for Photochemical Sciences, Bowling Green State University, Bowling Green, Ohio 43403-0001 (United States); George, Lisa; Kalume, Aimable; Reid, Scott A. [Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53201-1881 (United States); Ault, Bruce S. [Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221-0172 (United States)

2010-03-28T23:59:59.000Z

135

Molecular Dynamics of Methanol Monocation (CH3OH+ ) in Strong  

E-Print Network [OSTI]

ultrafast hydrogen migration.7,8 The 38 fs 800 nm pump pulse produced methanol monocation, and a probe pulseMolecular Dynamics of Methanol Monocation (CH3OH+ ) in Strong Laser Fields Bishnu Thapa and H surfaces of methanol neutral, monocation, and singlet and triplet dication were explored using the CBS

Schlegel, H. Bernhard

136

PURDUE UNIVERSITY ULTRAFAST OPTICS & OPTICAL FIBER COMMUNICATIONS LABORATORYA.M. Weiner Andrew M. Weiner, Jason McKinney*, and Shijun Xiao  

E-Print Network [OSTI]

PURDUE UNIVERSITY ULTRAFAST OPTICS & OPTICAL FIBER COMMUNICATIONS LABORATORYA.M. Weiner Andrew M affiliation: Naval Research Labs #12;PURDUE UNIVERSITY ULTRAFAST OPTICS & OPTICAL FIBER COMMUNICATIONS bandwidth #12;PURDUE UNIVERSITY ULTRAFAST OPTICS & OPTICAL FIBER COMMUNICATIONS LABORATORYA.M. Weiner

Purdue University

137

Attosecond X-Ray Pulses for Molecular Electronic Dynamics  

E-Print Network [OSTI]

techniques for ultrafast laser pulse characterization. Thethe ultrafast evolution of the driver pulse intensity, weisolated pulse production will enable probing of ultrafast

Abel, Mark Joseph

2010-01-01T23:59:59.000Z

138

Ultra-Fast Photodiodes for Terahertz Generation E. Rouvalis1  

E-Print Network [OSTI]

Ultra-Fast Photodiodes for Terahertz Generation E. Rouvalis1 , C. C. Renaud1 and A. J. Seeds1 1 Photodiode is realised as a broadband and high-efficiency photomixer while the frequency response advantage-power photomixers is essential. 2. Travelling-Wave Uni-Travelling Carrier Photodiode (TW-UTC-PD). Bandwidth

Haddadi, Hamed

139

Science Challenge Computational modeling of ultrafast digital electronics  

E-Print Network [OSTI]

properties in response to the needs of a particular device or situation. These smart electronics have the potential to lead to entirely new generations of electronic devices--such as military and civilian Science Challenge ­ Computational modeling of ultrafast digital electronics · To understand how

Freericks, Jim

140

Ultrafast Digital Electronics: Optimizing the speed of a  

E-Print Network [OSTI]

Ultrafast Digital Electronics: Optimizing the speed of a Josephson junction J. K. Freericks and P, Georgetown University, Josephson Junction talk, 2000 #12;Josephson Tunnel Junctions · A Superconductor to "punch-through"). J. K. Freericks, Georgetown University, Josephson Junction talk, 2000 S I S I I V V Ic

Freericks, Jim

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


141

Ultrafast photochemistry of methyl hydroperoxide on ice particles  

E-Print Network [OSTI]

Ultrafast photochemistry of methyl hydroperoxide on ice particles M. A. Kambouresa , S. AOOH, on water clusters produces a surprisingly wide range of products on a subpicosecond time scale | photodissociation Photoinduced processes at surfaces of water or ice are of interest in atmospheric chemistry

Nizkorodov, Sergey

142

Apparatus and method for characterizing ultrafast polarization varying optical pulses  

DOE Patents [OSTI]

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.

Smirl, A.; Trebino, R.P.

1999-08-10T23:59:59.000Z

143

Unraveling shock-induced chemistry using ultrafast lasers  

SciTech Connect (OSTI)

The exquisite time synchronicity between shock and diagnostics needed to unravel chemical events occurring in picoseconds has been achieved using a shaped ultrafast laser pulse to both drive the shocks and interrogate the sample via a multiplicity of optical diagnostics. The shaped laser drive pulse can produce well-controlled shock states of sub-ns duration with sub-10 ps risetimes, sufficient for investigation offast reactions or phase transformations in a thin layer with picosecond time resolution. The shock state is characterized using ultrafast dynamic ellipsometry (UDE) in either planar or Gaussian spatial geometries, the latter allowing measurements of the equation of state of materials at a range of stresses in a single laser pulse. Time-resolved processes in materials are being interrogated using UDE, ultrafast infrared absorption, ultrafast UV/visible absorption, and femtosecond stimulated Raman spectroscopy. Using these tools we showed that chemistry in an energetic thin film starts only after an induction time of a few tens of ps, an observation that allows differentiation between proposed shock-induced reaction mechanisms. These tools are presently being applied to a variety of energetic and reactive sample systems, from nitromethane and carbon disulfide, to microengineered interfaces in tunable energetic mixtures. Recent results will be presented, and future trends outlined.

Moore, David Steven [Los Alamos National Laboratory

2010-12-06T23:59:59.000Z

144

Structural Dynamics of a Catalytic Monolayer Probed by Ultrafast  

E-Print Network [OSTI]

REPORTS Structural Dynamics of a Catalytic Monolayer Probed by Ultrafast 2D IR Vibrational Echoes in solutions. Here, we extend the technique to probing the interfacial dynamics and structure of a silica. The structural dynamics, as reported on by a carbonyl stretch vibration of the surface-bound complex, have

Fayer, Michael D.

145

Ultrafast Digital Electronics: Optimizing the speed of a  

E-Print Network [OSTI]

Ultrafast Digital Electronics: Optimizing the speed of a Josephson junction J. K. Freericks and P of Naval Research Preprint: cond-mat/0001269 J. K. Freericks, Georgetown University, Josephson Junction symmetry (examples include YBCO and BSCCO). J. K. Freericks, Georgetown University, Josephson Junction talk

Freericks, Jim

146

Effect of damping on the laser induced ultrafast switching in rare earth-transition metal alloys  

SciTech Connect (OSTI)

In this paper, we present simulations of thermally induced magnetic switching in ferrimagnetic systems performed with a Landau-Lifshitz-Bloch (LLB) equation for damping constant in a wide range of values. We have systematically studied the GdFeCo ferrimagnet with various concentrations of Gd and compared for some values of parameters the LLB results with atomistic simulations. The agreement is remarkably good, which shows that the dynamics described by the ferrimagnetic LLB is a reasonable approximation of this complex physical phenomenon. As an important element, we show that the LLB is able to also describe the intermediate formation of a ferromagnetic state which seems to be essential to understand laser induced ultrafast switching. The study reveals the fundamental role of damping during the switching process.

Oniciuc, Eugen; Stoleriu, Laurentiu; Cimpoesu, Dorin; Stancu, Alexandru, E-mail: alstancu@uaic.ro [Faculty of Physics and CARPATH Center, “Alexandru Ioan Cuza” University, 700506 Iasi (Romania)

2014-06-02T23:59:59.000Z

147

Advances in Ultrafast Control and Probing of Correlated-Electron Materials  

SciTech Connect (OSTI)

In this paper, we present recent results on ultrafast control and probing of strongly correlated-electron materials. We focus on magnetoresistive manganites, applying excitation and probing wavelengths that cover the mid-IR to the soft X-rays. In analogy with near-equilibrium filling and bandwidth control of phase transitions, our approach uses both visible and mid-IR pulses to stimulate the dynamics by exciting either charges across electronic bandgaps or specific vibrational resonances. X-rays are used to unambiguously measure the microscopic electronic, orbital, and structural dynamics. Our experiments dissect and separate the nonequilibrium physics of these compounds, revealing the complex interplay and evolution of spin, lattice, charge, and orbital degrees of freedoms in the time domain.

Wall, Simon; Rini, Matteo; Dhesi, Sarnjeet S.; Schoenlein, Robert W.; Cavalleri, Andrea

2011-02-01T23:59:59.000Z

148

Snapshots of the retarded interaction of charge carriers with ultrafast fluctuations in cuprates  

E-Print Network [OSTI]

One of the pivotal questions in the physics of high-temperature superconductors is whether the low-energy dynamics of the charge carriers is mediated by bosons with a characteristic timescale. This issue has remained elusive since electronic correlations are expected to dramatically speed up the electron-boson scattering processes, confining them to the very femtosecond timescale that is hard to access even with state-of-the-art ultrafast techniques. Here we simultaneously push the time resolution and the frequency range of transient reflectivity measurements up to an unprecedented level that enables us to directly observe the 16 fs build-up of the effective electron-boson interaction in hole-doped copper oxides. This extremely fast timescale is in agreement with numerical calculations based on the t-J model and the repulsive Hubbard model, in which the relaxation of the photo-excited charges is achieved via inelastic scattering with short-range antiferromagnetic excitations.

Conte, S Dal; Golež, D; Mierzejewski, M; Soavi, G; Peli, S; Banfi, F; Ferrini, G; Comin, R; Ludbrook, B M; Chauviere, L; Zhigadlo, N D; Eisaki, H; Greven, M; Lupi, S; Damascelli, A; Brida, D; Capone, M; Bon?a, J; Cerullo, G; Giannetti, C

2015-01-01T23:59:59.000Z

149

The ATLAS 3D project - XVI. Physical parameters and spectral line energy distributions of the molecular gas in gas-rich early-type galaxies  

E-Print Network [OSTI]

[Abridged] We present a detailed study of the physical properties of the molecular gas in a sample of 18 molecular gas-rich early-type galaxies (ETGs) from the ATLAS$ 3D sample. Our goal is to better understand the star formation processes occurring in those galaxies, starting here with the dense star-forming gas. We use existing integrated $^{12}$CO(1-0, 2-1), $^{13}$CO(1-0, 2-1), HCN(1-0) and HCO$^{+}$(1-0) observations and present new $^{12}$CO(3-2) single-dish data. From these, we derive for the first time the average kinetic temperature, H$_{2}$ volume density and column density of the emitting gas, this using a non-LTE theoretical model. Since the CO lines trace different physical conditions than of those the HCN and HCO$^{+}$ lines, the two sets of lines are treated separately. We also compare for the first time the predicted CO spectral line energy distributions (SLEDs) and gas properties of our molecular gas-rich ETGs with those of a sample of nearby well-studied disc galaxies. The gas excitation con...

Bayet, Estelle; Davis, Timothy A; Young, Lisa M; Crocker, Alison F; Alatalo, Katherine; Blitz, Leo; Bois, Maxime; Bournaud, Frédéric; Cappellari, Michele; Davies, Roger L; de Zeeuw, P T; Duc, Pierre-Alain; Emsellem, Eric; Khochfar, Sadegh; Krajnovi?, Davor; Kuntschner, Harald; McDermid, Richard M; Morganti, Raffaella; Naab, Thorsten; Oosterloo, Tom; Sarzi, Marc; Scott, Nicholas; Serra, Paolo; Weijmans, Anne-Marie

2012-01-01T23:59:59.000Z

150

PHYSICAL REVIEW A 83, 063419 (2011) Electromagnetically induced transparency in an open V-type molecular system  

E-Print Network [OSTI]

for Theoretical Physics (NITheP) Stellenbosch 7600, South Africa 3 Department of Physics, 16 Memorial Drive East theoretical model we employ the density matrix formalism, as well as perturbative methods for obtaining-type system is of special interest because no population trapping is involved. Thus, such a system can be used

Huennekens, John

151

E-Print Network 3.0 - all-optical ultrafast muon Sample Search...  

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

not been reported because of silicon's weak ultrafast nonlinearity. We have demonstrated intensity Source: Hochberg, Michael - Department of Electrical Engineering, University of...

152

INSTITUTE OF PHYSICS PUBLISHING JOURNAL OF PHYSICS B: ATOMIC, MOLECULAR AND OPTICAL PHYSICS J. Phys. B: At. Mol. Opt. Phys. 36 (2003) 41274143 PII: S0953-4075(03)64763-2  

E-Print Network [OSTI]

in molecular gases, focusing on collisional excitation of molecularrotationaland ro conservation and the vector dynamics associated with rotational excitation. It is pointed out. In particular, for swarms of electrons or ions in molecular gases, it is clear that excitation of rotational

Morrison, Michael A.

153

Spectral Noise Correlations of an Ultrafast Frequency Comb  

E-Print Network [OSTI]

Cavity-based noise detection schemes are combined with ultrafast pulse shaping as a means to diagnose the spectral correlations of both the amplitude and phase noise of an ultrafast frequency comb. The comb is divided into ten spectral regions, and the distribution of noise as well as the correlations between all pairs of spectral regions are measured against the quantum limit. These correlations are then represented in the form of classical noise matrices, which furnish a complete description of the underlying comb dynamics. Their eigendecomposition reveals a set of theoretically predicted, decoupled noise modes that govern the dynamics of the comb. Finally, the matrices contain the information necessary to deduce macroscopic noise properties of the comb.

Roman Schmeissner; Jonathan Roslund; Claude Fabre; Nicolas Treps

2014-10-16T23:59:59.000Z

154

Ultrafast time-division demultiplexing of polarization-entangled photons  

E-Print Network [OSTI]

Maximizing the information transmission rate through quantum channels is essential for practical implementation of quantum communication. Time-division multiplexing is an approach for which the ultimate rate requires the ability to manipulate and detect single photons on ultrafast timescales while preserving their quantum correlations. Here we demonstrate the demultiplexing of a train of pulsed single photons using time-to-frequency conversion while preserving their polarization entanglement with a partner photon. Our technique converts a pulse train with 2.69 ps spacing to a frequency comb with 307 GHz spacing which may be resolved using diffraction techniques. Our work enables ultrafast multiplexing of quantum information with commercially available single-photon detectors.

John M. Donohue; Jonathan Lavoie; Kevin J. Resch

2014-10-16T23:59:59.000Z

155

Ultrafast dynamics of excitons in tetracene single crystals  

SciTech Connect (OSTI)

Ultrafast exciton dynamics in free standing 200 nm thin tetracene single crystals were studied at room temperature by femtosecond transient absorption spectroscopy in the visible spectral range. The complex spectrally overlapping transient absorption traces of single crystals were systematically deconvoluted. From this, the ultrafast dynamics of the ground, excited, and transition states were identified including singlet exciton fission into two triplet excitons. Fission is generated through both, direct fission of higher singlet states S{sub n} on a sub-picosecond timescale, and thermally activated fission of the singlet exciton S{sub 1} on a 40 ps timescale. The high energy Davydov component of the S{sub 1} exciton is proposed to undergo fission on a sub-picoseconds timescale. At high density of triplet excitons their mutual annihilation (triplet-triplet annihilation) occurs on a <10 ps timescale.

Birech, Zephania; Schwoerer, Heinrich, E-mail: heso@sun.ac.za [Laser Research Institute, Stellenbosch University, Stellenbosch 7600 (South Africa)] [Laser Research Institute, Stellenbosch University, Stellenbosch 7600 (South Africa); Schwoerer, Markus [Department of Physics, University of Bayreuth, Bayreuth (Germany)] [Department of Physics, University of Bayreuth, Bayreuth (Germany); Schmeiler, Teresa; Pflaum, Jens [Experimental Physics VI, University of Würzburg and Bavarian Center for Applied Energy Research, Würzburg (Germany)] [Experimental Physics VI, University of Würzburg and Bavarian Center for Applied Energy Research, Würzburg (Germany)

2014-03-21T23:59:59.000Z

156

Broadband laser cooling of trapped atoms with ultrafast pulses  

E-Print Network [OSTI]

We demonstrate broadband laser cooling of atomic ions in an rf trap using ultrafast pulses from a modelocked laser. The temperature of a single ion is measured by observing the size of a time-averaged image of the ion in the known harmonic trap potential. While the lowest observed temperature was only about 1 K, this method efficiently cools very hot atoms and can sufficiently localize trapped atoms to produce near diffraction-limited atomic images.

B. B. Blinov; R. N. Kohn Jr.; M. J. Madsen; P. Maunz; D. L. Moehring; C. Monroe

2005-07-07T23:59:59.000Z

157

Ultrafast Time-Resolved Electron Diffraction with Megavolt Electron Beams  

SciTech Connect (OSTI)

An rf photocathode electron gun is used as an electron source for ultrafast time-resolved pump-probe electron diffraction. We observed single-shot diffraction patterns from a 160 nm Al foil using the 5.4 MeV electron beam from the Gun Test Facility at the Stanford Linear Accelerator. Excellent agreement with simulations suggests that single-shot diffraction experiments with a time resolution approaching 100 fs are possible.

Hastings, J.B.; /SLAC; Rudakov, F.M.; /Brown U.; Dowell, D.H.; Schmerge, J.F.; /SLAC; Cardoza, J.D.; /Brown U.; Castro, J.M.; Gierman, S.M.; Loos, H.; /SLAC; Weber, P.M.; /Brown U.

2006-10-24T23:59:59.000Z

158

Femtosecond-scale response of GaAs to ultrafast laser pulses Traian Dumitrica* and Roland E. Allen  

E-Print Network [OSTI]

Femtosecond-scale response of GaAs to ultrafast laser pulses Traian Dumitrica* and Roland E. Allen ordinary heating of the sample by phonon emission, there is convinc- ing evidence that ultrafast pulses of the initial stages of the interaction of a laser pulse with a semiconductor, which show that ultrafast disor

Allen, Roland E.

159

1966 JOURNAL OF LIGHTWAVE TECHNOLOGY, VOL. 15, NO. 10, OCTOBER 1997 Mode Conversion of Ultrafast Pulses by Grating  

E-Print Network [OSTI]

conversion of an ultrafast, ultrawide-bandwidth optical pulse propagating in a layered di- electric waveguide for an ultrafast six-cycle optical pulse over that achieved with standard uniform grating convertors. Index Terms--Dielectric waveguides, FDTD, mode conversion, mode extraction, numerical modeling, ultrafast optical pulses. I

Ziolkowski, Richard W.

160

Ultrafast charge localization in a stripe-phase nickelate  

SciTech Connect (OSTI)

Self-organized electronically-ordered phases are a recurring feature in correlated materials, resulting in e.g. fluctuating charge stripes whose role in high-Tc superconductivity is under debate. However, the relevant cause-effect relations between real-space charge correlations and low-energy excitations remain hidden in time-averaged studies. Here, we reveal ultrafast charge localization and lattice vibrational coupling as dynamical precursors of stripe formation in the model compound La1.75Sr0.25NiO4, using ultrafast and equilibrium mid-infrared spectroscopy. The opening of a pseudogap at a crossover temperature T* far above long-range stripe formation establishes the onset of electronic localization which is accompanied by an enhanced Fano asymmetry of Ni-O stretch vibrations. Ultrafast excitation triggers a sub-picosecond dynamics exposing the synchronous modulation of electron-phonon coupling and charge localization. These results illuminate the role of localization in forming the pseudogap in nickelates, opening a path to understanding this mysterious phase in a broad class of complex oxides.

Coslovich, Giacomo; Huber, Bernhard; Lee, Wei-Sheng; Sasagawa, Takao; Hussain, Zahid; Bechtel, Hans A.; Martin, Michael C.; Shen, Zhi-Xun; W. Schoenlein, Robert; A. Kaindl, Robert

2013-08-30T23:59:59.000Z

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


161

RADIATION HEAT TRANSFER IN TISSUE WELDING AND SOLDERING WITH ULTRAFAST LASERS  

E-Print Network [OSTI]

RADIATION HEAT TRANSFER IN TISSUE WELDING AND SOLDERING WITH ULTRAFAST LASERS Kyunghan Kim to incorporate transient radiation heat transfer in tissue welding and soldering with use of ultrafast lasers are performed between laser welding and laser soldering. The use of solder is found to substantially enhance

Guo, Zhixiong "James"

162

HARMONIC CASCADE FEL DESIGNS FOR LUX, A FACILTY FOR ULTRAFAST X-RAY SCIENCE  

E-Print Network [OSTI]

-electron laser (FEL) beamlines which use the har- monic cascade approach to produce coherent XUV & soft X-ray for an integrated system of ultrafast x-ray techniques and lasers, using laser-seeded harmonic cascade FEL's, rfHARMONIC CASCADE FEL DESIGNS FOR LUX, A FACILTY FOR ULTRAFAST X-RAY SCIENCE J. Corlett, W. Fawley

Wurtele, Jonathan

163

Analytic model of electron pulse propagation in ultrafast electron diffraction experiments  

E-Print Network [OSTI]

Analytic model of electron pulse propagation in ultrafast electron diffraction experiments A. M pulses used in ultrafast electron diffraction experiments UED . We assume a Gaussian form to characterize the electron pulse, and derive a system of ordinary differential equations that are solved quickly and easily

Sipe,J. E.

164

Adaptive all-order dispersion compensation of ultrafast laser pulses using dynamic spectral holography  

E-Print Network [OSTI]

Adaptive all-order dispersion compensation of ultrafast laser pulses using dynamic spectral-1396 Received 14 July 1999; accepted for publication 24 September 1999 The time-varying dispersion of ultrafast laser pulses can be self-adaptively stabilized using real-time dynamic spectral holography

Nolte, David D.

165

Ultrafast Dynamics and Phase Changes in Solids Excited by Femtosecond Laser Pulses  

E-Print Network [OSTI]

Ultrafast Dynamics and Phase Changes in Solids Excited by Femtosecond Laser Pulses A thesis pulse excites 1­20% of the valence electrons. We developed a broadband pump-probe technique to measure femtoseconds. The dielectric function provides more information than ever before on the ultrafast electronic

Mazur, Eric

166

Numerical simulations of self-focusing of ultrafast laser pulses Gadi Fibich*  

E-Print Network [OSTI]

Numerical simulations of self-focusing of ultrafast laser pulses Gadi Fibich* School November 2002; published 7 May 2003 Simulation of nonlinear propagation of intense ultrafast laser pulses, space-time focusing, and self-steepening. Our simulations show that, after the asymmetric temporal pulse

Wang, Xiao-Ping

167

Ultrafast control of donor-bound electron spins with single detuned optical pulses  

E-Print Network [OSTI]

LETTERS Ultrafast control of donor-bound electron spins with single detuned optical pulses KAI on microwave sources--can be attained with broadband optical pulses. One promising ultrafast technique uses single broadband pulses detuned from resonance in a three-level system4 . This technique is robust

Loss, Daniel

168

644 OPTICS LETTERS / Vol. 29, No. 6 / March 15, 2004 General ultrafast pulse measurement using the  

E-Print Network [OSTI]

644 OPTICS LETTERS / Vol. 29, No. 6 / March 15, 2004 General ultrafast pulse measurement using the cross-correlation single-shot sonogram technique Derryck T. Reid and Jesus Garduno-Mejia Ultrafast technique offers exact pulse measurement and real-time pulse monitoring via an intuitive time

169

A pulsed electron gun for ultrafast electron diffraction at surfaces A. Janzen,a  

E-Print Network [OSTI]

A pulsed electron gun for ultrafast electron diffraction at surfaces A. Janzen,a B. Krenzer, O The construction of a pulsed electron gun for ultrafast reflection high-energy electron diffraction experiments: a photocathode, consisting of a 10 nm thin Au film deposited onto a sapphire substrate. Electron pulses

von der Linde, D.

170

Laser pulse control of ultrafast heterogeneous electron transfer: A computational study  

E-Print Network [OSTI]

Laser pulse control of ultrafast heterogeneous electron transfer: A computational study Luxia Wang on ultrafast HET given in Refs. 14­16. In the following we will focus on the case where a tailored laser pulse, Germany Received 31 March 2004; accepted 30 July 2004 Laser pulse control of the photoinduced 90 fs charge

Röder, Beate

171

Ultrafast dynamics of the laser-induced solid-to-liquid phase transition in aluminum  

E-Print Network [OSTI]

Ultrafast dynamics of the laser-induced solid-to-liquid phase transition in aluminum A thesis dynamics of the laser-induced solid-to-liquid phase transition in aluminum Eric Mazur Maria Kandyla Abstract This dissertation reports the ultrafast dynamics of aluminum during the solid-to- liquid phase

Mazur, Eric

172

Ultrafast Third Harmonic Micro-spectroscopy Reveals a Two-Photon Resonance in Human Hemoglobin  

E-Print Network [OSTI]

Ultrafast Third Harmonic Micro-spectroscopy Reveals a Two-Photon Resonance in Human Hemoglobin G Golden, CO 80401 Abstract The recently developed technique of ultrafast third harmonic generation (THG states in physiological solutions of human hemoglobin. Keywords: Third Harmonic Generation, Micro

Kleinfeld, David

173

Size-dependent ultrafast structural dynamics inside phospholipid vesicle bilayers measured with 2D IR  

E-Print Network [OSTI]

Size-dependent ultrafast structural dynamics inside phospholipid vesicle bilayers measured with 2D 25, 2013) The ultrafast structural dynamics inside the bilayers of dilauroyl- phosphatidylcholine was used as a vibrational probe and provided information on spectral diffusion (structural dynam- ics

Fayer, Michael D.

174

PHYSICAL REVIEW B 85, 205440 (2012) Inelastic neutron scattering investigations of the quantum molecular dynamics of a H2 molecule  

E-Print Network [OSTI]

PHYSICAL REVIEW B 85, 205440 (2012) Inelastic neutron scattering investigations of the quantum transfer arising from the neutron scattering event has also been investigated. The -dependence spectra investigations using infrared (IR),3,13­15 inelastic neutron scattering (INS),3,16,17 and nuclear magnetic

Turro, Nicholas J.

175

Magnetismo Molecular (Molecular Magentism)  

SciTech Connect (OSTI)

The new synthesis processes in chemistry open a new world of research, new and surprising materials never before found in nature can now be synthesized and, as a wonderful result, observed a series of physical phenomena never before imagined. Among these are many new materials the molecular magnets, the subject of this book and magnetic properties that are often reflections of the quantum behavior of these materials. Aside from the wonderful experience of exploring something new, the theoretical models that describe the behavior these magnetic materials are, in most cases, soluble analytically, which allows us to know in detail the physical mechanisms governing these materials. Still, the academic interest in parallel this subject, these materials have a number of properties that are promising to be used in technological devices, such as in computers quantum magnetic recording, magnetocaloric effect, spintronics and many other devices. This volume will journey through the world of molecular magnets, from the structural description of these materials to state of the art research.

Reis, Mario S [Universidade Federal Fluminense, Brasil; Moreira Dos Santos, Antonio F [ORNL

2010-07-01T23:59:59.000Z

176

Physics high-ranking Journals (category 2) Advances in Physics  

E-Print Network [OSTI]

Physics high-ranking Journals (category 2) Advances in Physics Annual Review of Astronomy and Astrophysics Annual Review of Nuclear and Particle Science Applied Physics Letters Astronomy & Astrophysics Astronomy and Astrophysics Review Astrophysical Journal European Physical Journal D. Atomic, Molecular

177

Physical properties and band structure of reactive molecular beam epitaxy grown oxygen engineered HfO{sub 2{+-}x}  

SciTech Connect (OSTI)

We have conducted a detailed thin film growth structure of oxygen engineered monoclinic HfO{sub 2{+-}x} grown by reactive molecular beam epitaxy. The oxidation conditions induce a switching between (111) and (002) texture of hafnium oxide. The band gap of oxygen deficient hafnia decreases with increasing amount of oxygen vacancies by more than 1 eV. For high oxygen vacancy concentrations, defect bands form inside the band gap that induce optical transitions and p-type conductivity. The resistivity changes by several orders of magnitude as a function of oxidation conditions. Oxygen vacancies do not give rise to ferromagnetic behavior.

Hildebrandt, Erwin; Kurian, Jose; Alff, Lambert [Institute of Materials Science, Technische Universitaet Darmstadt, 64287 Darmstadt (Germany)

2012-12-01T23:59:59.000Z

178

INSTITUTE OF PHYSICS PUBLISHING JOURNAL OF PHYSICS B: ATOMIC, MOLECULAR AND OPTICAL PHYSICS J. Phys. B: At. Mol. Opt. Phys. 37 (2004) R57R88 PII: S0953-4075(04)63251-2  

E-Print Network [OSTI]

of the high-energy storage rings used in high-energy particle physics, in particular LEAR [8], and use mainly, they are usually smaller and require neither high-energy (MeV) accelerators for injecting the beam, nor and nuclear physics, nonlinear dynamics, single component plasmas, mass spectrometry, biophysics, quantum

Zajfman, Daniel

179

Rise Time Measurement for Ultrafast X-Ray Pulses  

DOE Patents [OSTI]

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.

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

2005-04-05T23:59:59.000Z

180

Optical Damage Threshold of Silicon for Ultrafast Infrared Pulses  

SciTech Connect (OSTI)

We present measurements of the optical damage threshold of crystalline silicon in air for ultrafast pulses in the near infrared. The wavelengths tested span a range from the telecommunications band at 1550 nm, extending to 2260 nm. We discuss the motivation for the measurements and give theoretical context. We then describe the experimental setup, diagnostics, and procedure. The results show a breakdown threshold of 0.2J/cm{sup 2} at 1550 nm and 1.06 ps FWHM pulse duration, and a weak dependence on wavelength.

Cowan, Benjamin M.; /Tech-X, Boulder /SLAC

2007-11-28T23:59:59.000Z

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


181

Rise time measurement for ultrafast X-ray pulses  

DOE Patents [OSTI]

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.

Celliers, Peter M. (Berkeley, CA); Weber, Franz A. (Oakland, CA); Moon, Stephen J. (Tracy, CA)

2005-04-05T23:59:59.000Z

182

Photoionisation loading of large Sr+ ion clouds with ultrafast pulses  

E-Print Network [OSTI]

This paper reports on photoionisation loading based on ultrafast pulses of singly-ionised strontium ions in a linear Paul trap. We take advantage of an autoionising resonance of Sr neutral atoms to form Sr+ by two-photon absorption of femtosecond pulses at a wavelength of 431nm. We compare this technique to electron-bombardment ionisation and observe several advantages of photoionisation. It actually allows the loading of a pure Sr+ ion cloud in a low radio-frequency voltage amplitude regime. In these conditions up to 4x10^4 laser-cooled Sr+ ions were trapped.

Sébastien Removille; Romain Dubessy; Quentin Glorieux; Samuel Guibal; Thomas Coudreau; Luca Guidoni; Jean-Pierre Likforman

2008-12-05T23:59:59.000Z

183

Ultrafast laser control of backward superfluorescence towards standoff sensing  

SciTech Connect (OSTI)

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)

Ariunbold, Gombojav O. [Texas A and M University, College Station, Texas 77843 (United States); National University of Mongolia, Ulaanbaatar 210646 (Mongolia); Baylor University, Waco, Texas 76798 (United States); Sautenkov, Vladimir A. [Texas A and M University, College Station, Texas 77843 (United States); Joint Institute for High Temperatures, Russian Academy of Sciences, Moscow 125412 (Russian Federation); P. N. Lebedev Physical Institute, Russian Academy of Sciences, Moscow 119991 (Russian Federation); Rostovtsev, Yuri V. [University of North Texas, Denton, Texas 76203 (United States); Scully, Marlan O. [Texas A and M University, College Station, Texas 77843 (United States); Baylor University, Waco, Texas 76798 (United States); Princeton University, Princeton, New Jersey 08544 (United States)

2014-01-13T23:59:59.000Z

184

Ultrafast Core-Hole Induced Dynamics in Water  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLasDelivered energy consumption by sectorlong version) The0 -ITER'sUltrafast Core-Hole Induced

185

Ultrafast Core-Hole Induced Dynamics in Water  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLasDelivered energy consumption by sectorlong version) The0 -ITER'sUltrafast Core-Hole

186

Ultrafast Core-Hole Induced Dynamics in Water  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched Ferromagnetism in Layeredof2014 EIA Energy40081AEnergy StorageUltrafast Core-Hole

187

Ultrafast Core-Hole Induced Dynamics in Water  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched Ferromagnetism in Layeredof2014 EIA Energy40081AEnergy StorageUltrafast

188

Ultrafast Core-Hole Induced Dynamics in Water  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched Ferromagnetism in Layeredof2014 EIA Energy40081AEnergy Storage EnergyUltrafast

189

Optoacoustic Microscopy for Investigation of Material Nanostructures-Embracing the Ultrasmall, Ultrafast, and the Invisible  

SciTech Connect (OSTI)

The goal of this grant was the development of a new type of scanning acoustic microscope for nanometer resolution ultrasound imaging, based on ultrafast optoacoustics (>GHz). In the microscope, subpicosecond laser pulses was used to generate and detect very high frequency ultrasound with nanometer wavelengths. We report here on the outcome of the 3-year DOE/BES grant which involved the design, multifaceted construction, and proof-of-concept demonstration of an instrument that can be used for quantitative imaging of nanoscale material features – including features that may be buried so as to be inaccessible to conventional lightwave or electron microscopies. The research program has produced a prototype scanning optoacoustic microscope which, in combination with advanced computational modeling, is a system-level new technology (two patents issues) which offer novel means for precision metrology of material nanostructures, particularly those that are of contemporary interest to the frontline micro- and optoelectronics device industry. For accomplishing the ambitious technical goals, the research roadmap was designed and implemented in two phases. In Phase I, we constructed a “non-focusing” optoacoustic microscope instrument (“POAM”), with nanometer vertical (z-) resolution, while limited to approximately 10 micrometer scale lateral recolution. The Phase I version of the instrument which was guided by extensive acoustic and optical numerical modeling of the basic underlying acoustic and optical physics, featured nanometer scale close loop positioning between the optoacoustic transducer element and a nanostructured material sample under investigation. In phase II, we implemented and demonstrated a scanning version of the instrument (“SOAM”) where incident acoustic energy is focused, and scanned on lateral (x-y) spatial scale in the 100 nm range as per the goals of the project. In so doing we developed advanced numerical simulations to provide computational models of the focusing of multi-GHz acoustic waves to the nanometer scale and innovated a series fabrication approaches for a new type of broadband high-frequency acoustic focusing microscope objective by applying methods on nanoimprinting and focused-ion beam techniques. In the following, the Phase I and Phase II instrument development is reported as Section II. The first segment of this section describes the POAM instrument and its development, while including much of the underlying ultrafast acoustic physics which is common to all of our work for this grant. Then, the science and engineering of the SOAM instrument is described, including the methods of fabricating new types of acoustic microlenses. The results section is followed by reports on publications (Section III), Participants (Section IV), and statement of full use of the allocated grant funds (Section V).

Nurmikko, Arto; Humphrey, Maris

2014-07-10T23:59:59.000Z

190

Melting processes of oligomeric ? and ? isotactic polypropylene crystals at ultrafast heating rates  

SciTech Connect (OSTI)

The melting behaviors of ? (stable) and ? (metastable) isotactic polypropylene (iPP) crystals at ultrafast heating rates are simulated with atomistic molecular dynamics method. Quantitative information about the melting processes of ?- and ?-iPP crystals at atomistic level is achieved. The result shows that the melting process starts from the interfaces of lamellar crystal through random dislocation of iPP chains along the perpendicular direction of lamellar crystal structure. In the melting process, the lamellar crystal gradually expands but the corresponding thickness decreases. The analysis shows that the system expansion lags behind the crystallinity decreasing and the lagging extents for ?- and ?-iPP are significantly different. The apparent melting points of ?- and ?-iPP crystals rise with the increase of the heating rate and lamellar crystal thickness. The apparent melting point of ?-iPP crystal is always higher than that of ?-iPP at differently heating rates. Applying the Gibbs-Thomson rule and the scaling property of the melting kinetics, the equilibrium melting points of perfect ?- and ?-iPP crystals are finally predicted and it shows a good agreement with experimental result.

Ji, Xiaojing [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China)] [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); He, Xuehao, E-mail: xhhe@tju.edu.cn, E-mail: scjiang@tju.edu.cn [Department of Chemistry, School of Science, Tianjin University, and Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072 (China)] [Department of Chemistry, School of Science, Tianjin University, and Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072 (China); Jiang, Shichun, E-mail: xhhe@tju.edu.cn, E-mail: scjiang@tju.edu.cn [School of Material, Tianjin University, Tianjin 300072 (China)] [School of Material, Tianjin University, Tianjin 300072 (China)

2014-02-07T23:59:59.000Z

191

Double Wall Carbon Nanotubes for Wide-Band, Ultrafast Pulse Generation  

E-Print Network [OSTI]

Accepted Manuscript: ACS Nano, 2014, 8 (5), pp 4836–4847DOI: 10.1021/nn500767b 1 Double Wall Carbon Nanotubes for Wide-Band, Ultrafast Pulse Generation Tawfique Hasan1,*, Zhipei Sun2, PingHeng Tan3, Daniel Popa1, Emmanuel Flahaut4,5, Edmund J. R... , Polymer Composites, Saturable Absorber, Ultrafast Laser. Accepted Manuscript: ACS Nano, 2014, 8 (5), pp 4836–4847DOI: 10.1021/nn500767b 2 ABSTRACT: We demonstrate wideband ultrafast optical pulse generation at 1, 1.5 and 2?m using a single polymer...

Hasan, Tawfique; Sun, Zhipei; Tan, PingHeng; Popa, Daniel; Flahaut, Emmanuel; Kelleher, Edmund J. R.; Bonaccorso, Francesco; Wang, Fengqiu; Jiang, Zhe; Torrisi, Felice; Privitera, Giulia; Nicolosi, Valeria; Ferrari, Andrea C.

2014-04-15T23:59:59.000Z

192

Optical Nonlinearities and Ultrafast Carrier Dynamics in Semiconductor Quantum Dots  

SciTech Connect (OSTI)

Low-dimensional semiconductors have attracted great interest due to the potential for tailoring their linear and nonlinear optical properties over a wide-range. Semiconductor nanocrystals (NC's) represent a class of quasi-zero-dimensional objects or quantum dots. Due to quantum cordhement and a large surface-to-volume ratio, the linear and nonlinear optical properties, and the carrier dynamics in NC's are significantly different horn those in bulk materials. napping at surface states can lead to a fast depopulation of quantized states, accompanied by charge separation and generation of local fields which significantly modifies the nonlinear optical response in NC's. 3D carrier confinement also has a drastic effect on the energy relaxation dynamics. In strongly confined NC's, the energy-level spacing can greatly exceed typical phonon energies. This has been expected to significantly inhibit phonon-related mechanisms for energy losses, an effect referred to as a phonon bottleneck. It has been suggested recently that the phonon bottleneck in 3D-confined systems can be removed due to enhanced role of Auger-type interactions. In this paper we report femtosecond (fs) studies of ultrafast optical nonlinearities, and energy relaxation and trap ping dynamics in three types of quantum-dot systems: semiconductor NC/glass composites made by high temperature precipitation, ion-implanted NC's, and colloidal NC'S. Comparison of ultrafast data for different samples allows us to separate effects being intrinsic to quantum dots from those related to lattice imperfections and interface properties.

Klimov, V.; McBranch, D.; Schwarz, C.

1998-08-10T23:59:59.000Z

193

Two-Color Ultrafast Photoexcited Scanning Tunneling Microscopy  

SciTech Connect (OSTI)

We report on two-color two-photon photoexcitation of a metal surface driven by ultrafast laser pulses and detected with a scanning tunneling microscope (STM) tip as a proximate anode. Results are presented for two cases: (i) where the tip is retracted from the surface far enough to prohibit tunneling, and (ii) where the tip is within tunneling range of the surface. A delay-modulation technique is implemented to isolate the two-color photoemission from concurrent one-color two-photon photoemission and provide subpicosecond time-resolved detection. When applied with the tip in tunneling range, this approach effectively isolates the two-photon photoexcited current signal from the conventional tunneling current and enables subpicosecond time-resolved detection of the photoexcited surface electrons. The advantage of the two-color approach is highlighted by comparison with the one-color case where optical interference causes thermal modulation of the STM tip length, resulting in tunneling current modulations that are orders of magnitude larger than the current due to photoexcitation of surface electrons. By completely eliminating this interference, and thereby avoiding thermal modulation of the STM tip length, the two-color approach represents an important step toward the ultimate goal of simultaneous subnanometer and subpicosecond measurements of surface electron dynamics by ultrafast-laser-excited STM.

Camillone, N.; Dolocan, A.; Acharya, D.P.; Zahl, P.; Sutter, P.

2011-05-26T23:59:59.000Z

194

Atomic Resolution Coherent Diffractive Imaging and Ultrafast Science  

SciTech Connect (OSTI)

A major scientific challenge is determining the 3-D atomic structure of small nanostructures, including single molecules. Coherent diffractive imaging (CDI) is a promising approach. Recent progress has demonstrated coherent diffraction patterns can be recorded from individual nanostructures and phased to reconstruct their structure. However, overcoming the dose limit imposed by radiation damage is a major obstacle toward the full potential of CDI. One approach is to use ultrafast x-ray or electron pulses. In electron diffraction, amplitudes recorded in a diffraction pattern are unperturbed by lens aberrations, defocus, and other microscope resolution-limiting factors. Sub-A signals are available beyond the information limit of direct imaging. Significant contrast improvement is obtained compared to high-resolution electron micrographs. progress has also been made in developing time-resolved electron diffraction and imaging for the study of ultrafast dynamic processes in materials. This talk will cover these crosscutting issues and the convergence of electron and x-ray diffraction techniques toward structure determination of single molecules.

Zuo, Jian-min (University of Illinois) [University of Illinois

2011-01-12T23:59:59.000Z

195

INSTITUTE OF PHYSICS PUBLISHING JOURNAL OF PHYSICS B: ATOMIC, MOLECULAR AND OPTICAL PHYSICS J. Phys. B: At. Mol. Opt. Phys. 37 (2004) 35513562 PII: S0953-4075(04)81883-2  

E-Print Network [OSTI]

in an accelerating potential Timothy M Roach Physics Department, The College of the Holy Cross, Worcester, MA 01610 #12;3552 T M Roach y gUBU U atoms grating(a) (b) y Figure 1. (a) Cloud of atoms accelerated towards

Roach, Timothy

196

Are water simulation models consistent with steady-state and ultrafast vibrational spectroscopy experiments?  

E-Print Network [OSTI]

Are water simulation models consistent with steady-state and ultrafast vibrational spectroscopy, United States b Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, United States c Department of Chemistry, Stanford University, Stanford, CA 94305, United States Received

Fayer, Michael D.

197

Collective Hydrogen Bond Reorganization in Water Studied with Temperature-Dependent Ultrafast Infrared Spectroscopy  

E-Print Network [OSTI]

We use temperature-dependent ultrafast infrared spectroscopy of dilute HOD in H2O to study the picosecond reorganization of the hydrogen bond network of liquid water. Temperature-dependent two-dimensional infrared (2D IR), ...

Nicodemus, Rebecca A.

198

Ultrafast laser inscription of bistable and reversible waveguides in strontium barium niobate crystals  

E-Print Network [OSTI]

Ultrafast laser inscription of bistable and reversible waveguides in strontium barium niobate optical channel waveguides in strontium barium niobate nonlinear ferroelectric crystals by direct for the fabrication of optical buried waveguides. This would be especially relevant in the ferroelectric strontium

199

Electromagnetically-driven ultra-fast tool servos for diamond turning  

E-Print Network [OSTI]

This thesis presents the design, implementation, and control of a new class of fast tool servos (FTS). The primary thesis contributions include the design and experimental demonstration of: novel ultra-fast electromagnetic ...

Lu, Xiaodong, Ph. D. Massachusetts Institute of Technology

2005-01-01T23:59:59.000Z

200

Release mechanism of octadecyl rhodamine B chloride from Au nanorods by ultrafast laser pulses  

E-Print Network [OSTI]

We investigated the release of octadecyl rhodamine B chloride (R[subscript 18]) loaded onto cetyltrimethylammonium bromide (CTAB) coated gold nanorods (NR) by pulsed ultrafast laser excitation. R[subscript 18] intercalates ...

Alper, Joshua Daniel

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


201

Two photon luminescence from quantum dots using broad and narrowband ultrafast laser pulses  

E-Print Network [OSTI]

Nonlinear optical microscopy (NLOM) offers many advantages when imaging intact biological samples. By using ultrafast lasers in the near infrared and two photon excitation (TPE), signal production is limited to the focal volume and provides...

Balasubramanian, Haribhaskar

2009-05-15T23:59:59.000Z

202

Electron Pulse Compression with a Practical Reflectron Design for Ultrafast Electron Diffraction  

E-Print Network [OSTI]

Ultrafast electron diffraction (UED) is a powerful method for studying time-resolved structural changes. Currently, space-charge-induced temporal broadening prevents obtaining high-brightness electron pulses with sub-100 ...

Wang, Yihua

203

Hydrogen Bond Dynamics Probed with Ultrafast Infrared Heterodyne-Detected Multidimensional Vibrational Stimulated Echoes  

E-Print Network [OSTI]

Hydrogen Bond Dynamics Probed with Ultrafast Infrared Heterodyne-Detected Multidimensional, USA (Received 24 February 2003; published 3 December 2003) Hydrogen bond dynamics are explicated hydrogen bonded network are measured with ultrashort (

Fayer, Michael D.

204

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

SciTech Connect (OSTI)

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.

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

2012-07-25T23:59:59.000Z

205

Two photon luminescence from quantum dots using broad and narrowband ultrafast laser pulses  

E-Print Network [OSTI]

TWO PHOTON LUMINESCENCE FROM QUANTUM DOTS USING BROAD AND NARROWBAND ULTRAFAST LASER PULSES A Thesis by HARIBHASKAR BALASUBRAMANIAN Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE December 2007 Major Subject: Biomedical Engineering TWO PHOTON LUMINESCENCE FROM QUANTUM DOTS USING BROAD AND NARROWBAND ULTRAFAST LASER PULSES A Thesis by HARIBHASKAR...

Balasubramanian, Haribhaskar

2008-10-10T23:59:59.000Z

206

Ultrafast Extreme Ultraviolet Induced Isomerization of Acetylene Cations  

E-Print Network [OSTI]

PHYSICAL REVIEW LETTERS PRL 105, 263002 (2010) week endingAmerican Physical Society PRL 105, 263002 (2010) PHYSICALcould not be distinguished. PRL 105, 263002 (2010) PHYSICAL

Jiang, Y.

2012-01-01T23:59:59.000Z

207

Ultrafast Extreme Ultraviolet Induced Isomerization of Acetylene Cations  

SciTech Connect (OSTI)

Ultrafast isomerization of acetylene cations ([HC = CH]{sup +}) in the low-lying excited A{sup 2}{Sigma}{sub g}{sup +} state, populated by the absorption of extreme ultraviolet (XUV) photons (38 eV), has been observed at the Free Electron Laser in Hamburg, (FLASH). Recording coincident fragments C{sup +} + CH{sub 2}{sup +} as a function of time between XUV-pump and -probe pulses, generated by a split-mirror device, we find an isomerization time of 52 {+-} 15 fs in a kinetic energy release (KER) window of 5.8 < KER < 8 eV, providing clear evidence for the existence of a fast, nonradiative decay channel.

Jiang, Y.; Rudenko, Artem; Herrwerth, O.; Foucar, L.; Kurka, M.; Kuhnel, K.; Lezius, M.; Kling, Matthias; van Tilborg, Jeroen; Belkacem, Ali; Ueda, K.; Dusterer, S.; Treusch, R.; Schroter, Claus-Dieter; Moshammer, Robbert; Ullrich, Joachim

2011-06-17T23:59:59.000Z

208

Ultrafast stimulated Raman parallel adiabatic passage by shaped pulses  

E-Print Network [OSTI]

We present a general and versatile technique of population transfer based on {\\it 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 pico- 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.

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

2009-10-06T23:59:59.000Z

209

Ultrafast electron diffraction with radio-frequency compressed electron pulses  

SciTech Connect (OSTI)

We report on the complete characterization of time resolution in an ultrafast electron diffraction (UED) instrument based on radio-frequency electron pulse compression. The temporal impulse response function of the instrument was determined directly in pump-probe geometry by performing electron-laser pulse cross-correlation measurements using the ponderomotive interaction. With optimal settings, a stable impulse response of 334{+-}10 fs was measured at a bunch charge of 0.1 pC (6.24 Multiplication-Sign 10{sup 5} electrons/pulse); a dramatic improvement compared to performance without pulse compression. Phase stability currently limits the impulse response of the UED diffractometer to the range of 334-500 fs, for bunch charges ranging between 0.1 and 0.6 pC.

Chatelain, Robert P.; Morrison, Vance R.; Godbout, Chris; Siwick, Bradley J. [Departments of Physics and Chemistry, Center for the Physics of Materials, McGill University, Montreal (Canada)

2012-08-20T23:59:59.000Z

210

Ultrafast laser diagnostics to investigate initiation fundamentals in energetic materials.  

SciTech Connect (OSTI)

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 initiation of energetic materials. We compare two single-shot versions of femtosecond rotational CARS to measure nitrogen temperature: chirped-probe-pulse and ps/fs hybrid CARS thermometry. The applicability of measurements to the combustion of energetic materials will be discussed. We have also demonstrated laser shock and particle velocity measurements in thin film explosives using stretched femtosecond laser pulses. We will discuss preliminary results from Al and PETN thin films. Agreement between our results and previous work will be discussed.

Farrow, Darcie; Jilek, Brook Anton; Kohl, Ian Thomas; Kearney, Sean Patrick

2013-08-01T23:59:59.000Z

211

Ultrafast transient grating radiation to optical image converter  

DOE Patents [OSTI]

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.

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

2014-11-04T23:59:59.000Z

212

IOP PUBLISHING JOURNAL OF PHYSICS B: ATOMIC, MOLECULAR AND OPTICAL PHYSICS J. Phys. B: At. Mol. Opt. Phys. 42 (2009) 105201 (5pp) doi:10.1088/0953-4075/42/10/105201  

E-Print Network [OSTI]

of core and valence electron excitation in molecules and the dissociation dynamics under such excitations- coincidence technique may permit reconstruction of the geometry of the excited molecular ion. As an example in excitation into a discrete molecular orbital as a function of the molecular alignment has been studied

Bapat, Bhas

213

Study of the subpicosecond rotational molecular dynamics in liquids  

SciTech Connect (OSTI)

The parameters of the femtosecond vibration-rotation molecular dynamics of liquid acetonitrile CH{sub 3}CN, trimethylacetonitrile (CH{sub 3}){sub 3}CCN, propionitrile CH{sub 3}CH{sub 2}CN, fluoroform CHF{sub 3}, and chloroform CHCl{sub 3} are found by analysing the ultrafast optical Kerr effect. The influence of the molecular structure on the features of rotational (diffusion and libration) motions is studied. It is shown that the distribution of libration frequencies is described by the Maxwell distribution. (laser applications and other topics in quantum electronics)

Nikiforov, V G; Lobkov, Vladimir S [E.K.Zavoisky Physical-Technical Institute, Kazan Scientific Center, Russian Academy of Sciences, Kazan (Russian Federation)

2006-10-31T23:59:59.000Z

214

PHYSICAL REVIEW B 84, 115421 (2011) Efficient terahertz emission from InAs nanowires  

E-Print Network [OSTI]

PHYSICAL REVIEW B 84, 115421 (2011) Efficient terahertz emission from InAs nanowires Denis V, University of New Mexico, Albuquerque, NM 87131, USA 2 Sandia National Laboratories, Albuquerque, NM 87185 measurements of electronic transport on individual nanowires, ultrafast terahertz spectroscopy, and theoretical

Sheik-Bahae, Mansoor

215

Title: Combined passive detection and ultrafast active imaging of cavitation events induced by short pulses of high intensity  

E-Print Network [OSTI]

1 Title: Combined passive detection and ultrafast active imaging of cavitation events induced by short pulses of high intensity ultrasound Authors: Jérôme GATEAU, Jean-François AUBRY, Mathieu PERNOT / INSERM, U979 / Université Denis Diderot, Paris VII Key words: single nucleation events, ultrafast active

Boyer, Edmond

216

Electron-ion relaxation time dependent signal enhancement in ultrafast double-pulse laser-induced breakdown spectroscopy  

E-Print Network [OSTI]

Electron-ion relaxation time dependent signal enhancement in ultrafast double-pulse laser of collinear double-pulse compared to single-pulse ultrafast laser induced breakdown spectroscopy. Our results showed that the significant signal enhancement noticed in the double pulse scheme is strongly correlated

Harilal, S. S.

217

Subnanometer-Scale Measurements of the Interaction of Ultrafast Soft X-Ray Free-Electron-Laser Pulses with Matter  

E-Print Network [OSTI]

lengths greater than 3 A° . This experiment demonstrates that with intense ultrafast pulses, structuralSubnanometer-Scale Measurements of the Interaction of Ultrafast Soft X-Ray Free-Electron-Laser Pulses with Matter Stefan P. Hau-Riege,1,* Henry N. Chapman,1 Jacek Krzywinski,2 Ryszard Sobierajski,2

von der Linde, D.

218

Ultrafast metal-insulator varistors based on tunable Al2O3 tunnel junctions Michael A. Weimer,1,2  

E-Print Network [OSTI]

Ultrafast metal-insulator varistors based on tunable Al2O3 tunnel junctions Michael A. Weimer,1; accepted 4 April 2008; published online 21 April 2008 Ultrafast metal-insulator varistors have been oxide varistors. These characteristics result from the Fowler­Nordheim tunneling of electrons through

George, Steven M.

219

Upgrading Methane Using Ultra-Fast Thermal Swing Adsorption  

SciTech Connect (OSTI)

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 technical feasibility and cost of upgrading low-BTU methane streams using ultra-fast thermal swing adsorption (TSA) using Velocys modular microchannel process technology. The objective of Phase II is to demonstrate the process at the bench-scale. Natural gas upgrading systems have six main unit operations: feed compressor, dehydration unit, nitrogen rejection unit, deoxygenator, carbon dioxide scrubber, and a sales compressor. The NRU is the focus of the development program, and a bench-scale demonstration has been initiated. The Velocys NRU system targets producing methane with greater than 96% purity and at least 90% recovery for final commercial operation. A preliminary cost analysis of the methane upgrading system, including the Velocys NRU, suggests that costs below $2.00 per million (MM) BTU methane may be achieved. The cost for a conventional methane upgrading system is well above $2.30 per MM BTU, as benchmarked in an Environmental Protection Agency study. The project is on schedule and on budget. Task 4, a bench-scale demonstration of the ultra-fast TSA system is complete. Rapid thermal swing of an adsorbent bed using microchannels has been successfully demonstrated and the separation of a 70% methane and 30% nitrogen was purified to 92% methane. The bench-scale demonstration unit was small relative to the system dead volume for the initial phase of experiments and a purge step was added to sweep the dead volume prior to desorbing the bed and measuring purity. A technical and economic feasibility assessment was completed in Task 3. The proposed Velocys technology appears feasible for the methane upgrading market. Evaluated categories include adsorbent selection, rapid-cycle valve selection, microchannel manufacturability assessment, and system design and cost. The selected adsorbent, granular microporous carbon from either Barnaby-Sutcliffe or Calgon, experimentally demonstrated sufficient methane capacity under differential temperature at 100 pounds per square inch gauge. Several valve options were identified, including candidates that can operate millions of cycles between refurbishment. The microchannel adsorber and desorber designs were made using internal Velocys manufacturability standards, and the associated costs are acceptable as included with the complete nitrogen rejection unit (NRU) cost projection. A system design and cost estimate was completed for the NRU section of the methane upgrading system. As integrated into the complete system, the cost is in line with the market requirement.

Anna Lee Tonkovich

2005-07-01T23:59:59.000Z

220

Dynamics of excess electrons in atomic and molecular clusters  

E-Print Network [OSTI]

2.2 Femtosecond laser system Ultrafast pulses are generatedwith ultrafast lasers is that the laser pulse generationultrafast systems, everything which must sync to a laser pulse

Young, Ryan Michael

2011-01-01T23:59:59.000Z

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


221

Quantitative comparison of fuel spray images obtained using ultrafast coherent and incoherent double-pulsed illumination  

E-Print Network [OSTI]

We present a quantitative comparison between the high-pressure fuel spray images obtained experimentally using classical imaging with coherent and incoherent ultrafast illuminations recorded using a compatible CMOS camera. The ultrafast, incoherent illumination source was extracted from the supercontinuum generated by tightly focusing the femtosecond laser pulses in water. The average velocity maps computed using time-correlated image-pairs and spray edge complexity computed using the average curvature scale space maps are compared for the spray images obtained with the two illumination techniques and also for the numerically simulated spray using the coupled volume of fluid and level set method for interface tracking (direct numerical simulation or DNS). The spray images obtained with supercontinuum-derived, incoherent, ultrafast illumination are clearer, since the artifacts arising due to laser speckles and multiple diffraction effects are largely reduced and show a better correlation with the DNS results.

Purwar, Harsh; Idlahcen, Saïd; Rozé, Claude; Blaisot, Jean-Bernard; Ménard, Thibault

2015-01-01T23:59:59.000Z

222

Ultrafast time dynamics studies of periodic lattices with free electron laser radiation  

SciTech Connect (OSTI)

It has been proposed that radiation from free electron laser (FEL) at Hamburg (FLASH) can be used for ultrafast time-resolved x-ray diffraction experiments based on the near-infrared (NIR) pump/FEL probe scheme. Here, investigation probing the ultrafast structural dynamics of periodic nano-crystalline organic matter (silver behenate) with such a scheme is reported. Excitation with a femtosecond NIR laser leads to an ultrafast lattice modification which time evolution has been studied through the scattering of vacuum ultraviolet FEL pulses. The found effect last for 6 ps and underpins the possibility for studying nanoperiodic dynamics down to the FEL source time resolution. Furthermore, the possibility of extending the use of silver behenate (AgBh) as a wavelength and temporal calibration tool for experiments with soft x-ray/FEL sources is suggested.

Quevedo, W.; Busse, G.; Hallmann, J.; More, R.; Petri, M.; Rajkovic, I. [Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Goettingen (Germany); Krasniqi, F.; Rudenko, A. [Max Planck Advanced Study Group at CFEL, Notkestrasse 85, 22607 Hamburg (Germany); Tschentscher, T. [European XFEL GmbH, Albert-Einstein-Ring 19, 22671 Hamburg (Germany); Stojanovic, N.; Duesterer, S.; Treusch, R.; Tolkiehn, M. [HASYLAB at DESY, Notkestrasse 85, 22607 Hamburg (Germany); Techert, S. [Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Goettingen (Germany); Max Planck Advanced Study Group at CFEL, Notkestrasse 85, 22607 Hamburg (Germany)

2012-11-01T23:59:59.000Z

223

Extension - Upgrading Methane Using Ultra-Fast Thermal Swing Adsorption  

SciTech Connect (OSTI)

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.

Anna Lee Tonkovich

2008-08-11T23:59:59.000Z

224

ULTRAFAST OUTFLOWS: GALAXY-SCALE ACTIVE GALACTIC NUCLEUS FEEDBACK  

SciTech Connect (OSTI)

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.

Wagner, A. Y.; Umemura, M. [Center for Computational Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8577 (Japan); Bicknell, G. V., E-mail: ayw@ccs.tsukuba.ac.jp [Research School of Astronomy and Astrophysics, Australian National University, ACT 2611 (Australia)

2013-01-20T23:59:59.000Z

225

Magnetically-Driven Accretion-Disk Winds and Ultra-Fast Outflows in PG1211+143  

E-Print Network [OSTI]

We present a study of X-ray ionization of magnetohydrodynamic (MHD) accretion-disk winds in an effort to constrain the physics underlying the highly-ionized ultra-fast outflows (UFOs) inferred by X-ray absorbers often detected in various sub-classes of Seyfert active galactic nuclei (AGNs). Our primary focus is to show that magnetically-driven outflows are indeed physically plausible candidates for the observed outflows accounting for the AGN absorption properties of the present X-ray spectroscopic observations. Employing a stratified MHD wind launched across the entire AGN accretion disk, we calculate its X-ray ionization and the ensuing X-ray absorption line spectra. Assuming an appropriate ionizing AGN spectrum, we apply our MHD winds to model the absorption features in an {\\it XMM-Newton}/EPIC spectrum of the narrow-line Seyfert, \\pg. We find, through identifying the detected features with Fe K$\\alpha$ transitions, that the absorber has a characteristic ionization parameter of $\\log (\\xi_c [erg~cm~s$^{-1}...

Fukumura, Keigo; Kazanas, Demosthenes; Shrader, Chris; Behar, Ehud; Contopoulos, Ioannis

2015-01-01T23:59:59.000Z

226

An ultrafast phase-change logic device driven by melting processes  

E-Print Network [OSTI]

/device structures are developed with a higher number of resistance levels and resistance-level combinations (11,14). 6 The GST cells have been shown to exhibit ultra-fast Boolean algebraic operations via boosting the energy delivered by electrical-pulse... 1 Title An ultrafast phase-change logic device driven by melting processes Authors D. Loke,1,2,3 J. M. Skelton,1,4 W. J. Wang,5 T. H. Lee,1 R. Zhao,2 T. C. Chong,2,* S. R. Elliott,1,* Affiliations 1Department of Chemistry, University...

Loke, D.; Skelton, J. M.; Wang, W. J.; Lee, T. H.; Zhao, R.; Chong, T. C.; Elliott, S. R.

2014-09-02T23:59:59.000Z

227

A grazing incidence x-ray streak camera for ultrafast, single-shot measurements  

SciTech Connect (OSTI)

An ultrafast x-ray streak camera has been realized using a grazing incidence reflection photocathode. X-rays are incident on a gold photocathode at a grazing angle of 20 degree and photoemitted electrons are focused by a large aperture magnetic solenoid lens. The streak camera has high quantum efficiency, 600fs temporal resolution, and 6mm imaging length in the spectral direction. Its single shot capability eliminates temporal smearing due to sweep jitter, and allows recording of the ultrafast dynamics of samples that undergo non-reversible changes.

Feng, Jun; Engelhorn, K.; Cho, B.I.; Lee, H.J.; Greaves, M.; Weber, C.P.; Falcone, R.W.; Padmore, H. A.; Heimann, P.A.

2010-02-18T23:59:59.000Z

228

Nanoparticle size and morphology control using ultrafast laser induced forward transfer of Ni thin films  

SciTech Connect (OSTI)

We have developed a nanoparticle (NP) printing technique using Ni thin film lift-off from glass substrates after ultrafast irradiation in air. Unique interactions of ultrafast laser pulses with thin films allow for control over NP faceting and size distributions. Control is achieved by changing the laser fluence, film thickness, and film-substrate distance. We demonstrate 20 nm Ni film removal from substrates and rapid NP printing, with size distributions centered at a 6 nm diameter. When the Ni film thickness is lowered to 10 nm, NPs are printed with distributions peaked at a 2 nm diameter.

Murphy, Ryan D. [Applied Physics Program, University of Michigan, Ann Arbor, Michigan 48109 (United States)] [Applied Physics Program, University of Michigan, Ann Arbor, Michigan 48109 (United States); Abere, Michael J.; Schrider, Keegan J.; Yalisove, Steven M. [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States)] [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States); Torralva, Ben [Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor, Michigan 48109 (United States)] [Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor, Michigan 48109 (United States)

2013-08-26T23:59:59.000Z

229

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

SciTech Connect (OSTI)

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.

Li, Run-Ze; Zhu, Pengfei; Chen, Long; Chen, Jie, E-mail: jiec@sjtu.edu.cn, E-mail: jzhang1@sjtu.edu.cn; Sheng, Zheng-Ming; Zhang, Jie, E-mail: jiec@sjtu.edu.cn, E-mail: jzhang1@sjtu.edu.cn [Key Laboratory for Laser Plasmas (Ministry of Education) and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Cao, Jianming [Key Laboratory for Laser Plasmas (Ministry of Education) and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Physics Department and National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310 (United States)

2014-05-14T23:59:59.000Z

230

Generation of sub-30-fs microjoule mid-infrared pulses for ultrafast vibrational  

E-Print Network [OSTI]

compression. http://dx.doi.org/10.1364/OL.38.005008 Understanding ultrafast interactions in solids and con]. The dispersion properties of certain nonlinear optical materials, such as potassium titanyl phosphate (KTP), lithium niobate (LNB), potassium niobate (KNB), and periodically poled stoichiometric lithium tantalate

Borguet, Eric

231

Ultrafast intermolecular energy transfer in heavy water L. Piatkowski,*a  

E-Print Network [OSTI]

Ultrafast intermolecular energy transfer in heavy water L. Piatkowski,*a K. B. Eisenthalb and H. J of the excitation of the OH vibration for different isotopic mixtures of water and heavy water.6 At a low concentration of water in heavy water (o1%) the OH groups are too far apart to show energy transfer within

Eisenthal, Kenneth B.

232

Single ultrafast diffusive conduction based optoelectronic switch for multi-channel operation  

E-Print Network [OSTI]

Single ultrafast diffusive conduction based optoelectronic switch for multi-channel operation Fatih to multi-channel operation, including Green's function diffusive conduction solution and crosstalk conduction based optoelectronic switches that accommodate >100 optical channels (with 2,000mm-2 channel

Miller, David A. B.

233

Atomic-Scale Perspective of Ultrafast Charge Transfer at a Dye-Semiconductor Interface  

E-Print Network [OSTI]

Atomic-Scale Perspective of Ultrafast Charge Transfer at a Dye-Semiconductor Interface Katrin R3 dye molecules and ZnO nanocrystals within the first picosecond after photoexcitation and from the unique perspective of the Ru reporter atom at the center of the dye. A transient chemical shift of the Ru

Neumark, Daniel M.

234

Ultrafast Carrier Dynamics in Exfoliated and Functionalized Calcium Niobate Nanosheets in Water and Methanol  

E-Print Network [OSTI]

Ultrafast Carrier Dynamics in Exfoliated and Functionalized Calcium Niobate Nanosheets in Water trapping and recombination processes in suspensions of exfoliated calcium niobate nanosheets derived from in exfoliated [H1-xCa2Nb3O10]x- nanosheets (x ) 0.15-0.20) and APS-functionalized (TBA,H)- Ca2Nb3O10. We

Osterloh, Frank

235

Internal friction in the ultrafast folding of the tryptophan cage q Linlin Qiu 1  

E-Print Network [OSTI]

Internal friction in the ultrafast folding of the tryptophan cage q Linlin Qiu 1 , Stephen J. Hagen is a diffusional process, and the speed of folding is controlled by the frictional forces that act important source of friction in folding reactions. By contrast, our studies of the folding dynamics

Hagen, Stephen J.

236

Ultrafast Microwave Hydrothermal Synthesis of BiFeO3 Nanoplates Riad Nechache,  

E-Print Network [OSTI]

hydrothermal processes while requiring significantly less time and energy. In addition, we show that microwaveUltrafast Microwave Hydrothermal Synthesis of BiFeO3 Nanoplates Shun Li, Riad Nechache,§ Ivan and very rapid (1­2 min) microwave-assisted hydrothermal approach. We show that the microwave treatment

237

Ultrafast high-pressure AC electro-osmotic pumps for portable biomedical microfluidics  

E-Print Network [OSTI]

Ultrafast high-pressure AC electro-osmotic pumps for portable biomedical microfluidics Chien details the development of an integrated AC electro-osmotic (ACEO) microfluidic pump for dilute (100 mM) biological solutions in separate microfluidic devices, with potential applications in portable

Bazant, Martin Z.

238

Coherent matter waves for ultrafast laser pulse characterization M. Winter, M. Wollenhaupt, T. Baumert *  

E-Print Network [OSTI]

Coherent matter waves for ultrafast laser pulse characterization M. Winter, M. Wollenhaupt, T for the characterization of ultrashort laser pulses using coherent matter waves is demonstrated. We emphasize the anal- ogy theoretically and experimentally and is the basis for our laser pulse character- ization technique. We use

Peinke, Joachim

239

Three envelope approach for ultrafast pulse characterization in a pump-probe experiment  

E-Print Network [OSTI]

Three envelope approach for ultrafast pulse characterization in a pump-probe experiment Balakishore of temporally identical ultrashort pulses at the focal point in a pump-probe experiment for potential use, fundamental, and second harmonic spectra, combined with an error minimization pulse retrieval scheme

240

Broadband conversion in an Yb:KYW-pumped ultrafast optical parametric oscillator with a long  

E-Print Network [OSTI]

Broadband conversion in an Yb:KYW-pumped ultrafast optical parametric oscillator with a long-infrared pulses at 3.5-µm from an optical parametric oscillator incorporating a 25- mm MgO:PPLN crystal and synchronously-pumped by chirped pulses from a fiber-amplified Yb:KYW laser. A long nonlinear crystal permits

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


241

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

SciTech Connect (OSTI)

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.

Sterling Backus

2012-05-14T23:59:59.000Z

242

Ultrafast Material Science Probed Using Coherent X-ray Pulses from High-Harmonic  

E-Print Network [OSTI]

Chapter 7 Ultrafast Material Science Probed Using Coherent X-ray Pulses from High science have made it possible to generate x-ray pulses at the femto- and attosecond frontiers using either-ray pulses paves the way for a completely new generation of experiments that can capture the coupled dynamics

Aeschlimann, Martin

243

OPTI-583: Computational Optics I: Ultrafast pulses and strong-field light-matter interactions.  

E-Print Network [OSTI]

OPTI-583: Computational Optics I: Ultrafast pulses and strong-field light-matter interactions. Time-power femtosecond pulses. Prerequisites: Knowledge of basic electromagnetic theory (e.g. Phys-241). While previous that govern the interaction of ultrashort pulses with var- ious media, and the Numerical methods track

Arizona, University of

244

Water Dynamics in Salt Solutions Studied with Ultrafast Two-Dimensional Infrared (2D IR)  

E-Print Network [OSTI]

Water Dynamics in Salt Solutions Studied with Ultrafast Two-Dimensional Infrared (2D IR RECEIVED ON FEBRUARY 3, 2009 C O N S P E C T U S Water is ubiquitous in nature, but it exists as pure water infrequently. From the ocean to biology, water molecules interact with a wide variety of dissolved species

Fayer, Michael D.

245

Water at the Surfaces of Aligned Phospholipid Multibilayer Model Membranes Probed with Ultrafast Vibrational  

E-Print Network [OSTI]

Water at the Surfaces of Aligned Phospholipid Multibilayer Model Membranes Probed with Ultrafast@stanford.edu Abstract: The dynamics of water at the surface of artificial membranes composed of aligned multibilayers pump-probe spectroscopy. The experiments are performed at various hydration levels, x ) 2 - 16 water

Fayer, Michael D.

246

Optical Deflection and Temporal Characterization of an Ultrafast Laser-Produced Electron Beam  

E-Print Network [OSTI]

Optical Deflection and Temporal Characterization of an Ultrafast Laser-Produced Electron Beam show that the optical pulse with a0 0:5 imparts momentum to the electron beam, causing it to deflect optically driven x-ray sources based on nonlinear Thomson scattering [3­5]. A finite optical pulse imparts

Umstadter, Donald

247

Ultrafast Structural Dynamics Inside Planar Phospholipid Multibilayer Model Cell Membranes Measured with 2D IR  

E-Print Network [OSTI]

Ultrafast Structural Dynamics Inside Planar Phospholipid Multibilayer Model Cell Membranes Measured diffusion caused by the structural dynamics of the membrane from 200 fs to 200 ps as a function structure and an abrupt change in dynamics at 35% cholesterol. The dynamics are independent of cholesterol

Fayer, Michael D.

248

APPLIED PHYSICS APPLIED PHYSICS  

E-Print Network [OSTI]

MSc APPLIED PHYSICS #12;MSc APPLIED PHYSICS This taught Masters course is based on the strong research in Applied Physics in the University's Department of Physics. The department has an impressive photonics and quantum optics, Physics and the Life Sciences, and solid state physics. The knowledge gained

Mottram, Nigel

249

Physics Division annual report - 1998  

SciTech Connect (OSTI)

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.

NONE

1999-09-07T23:59:59.000Z

250

Ultrafast Photocurrent Measurement of the Escape Time of Electrons and Holes from Carbon Nanotube p-i-n Photodiodes  

E-Print Network [OSTI]

Ultrafast photocurrent measurements are performed on individual carbon nanotube p-i-n photodiodes. The photocurrent response to subpicosecond pulses separated by a variable time delay ?t shows strong photocurrent suppression ...

Gabor, Nathaniel M.

251

Long-term stable timing distribution of an ultrafast optical pulse train over multiple fiber links with polarization maintaining output  

E-Print Network [OSTI]

The distribution of an ultrafast optical pulse train over multiple fiber links with long-term stable timing precision within 2 femtoseconds rms is accomplished by integrating a polarization maintaining output with 300 meter ...

Cox, Jonathan A.

252

Upgrading Methane Using Ultra-Fast Thermal Swing Adsorption  

SciTech Connect (OSTI)

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 technical feasibility and cost of upgrading low-BTU methane streams using ultra-fast thermal swing adsorption (TSA) using Velocys modular microchannel process technology. The objective of Phase II is to demonstrate the process at the bench scale. The project is on schedule and on budget. A technical and economic feasibility assessment was completed in Task 3. The proposed Velocys technology appears feasible for the methane upgrading market. Evaluated categories include adsorbent selection, rapid-cycle valve selection, microchannel manufacturability assessment, and system design and cost. The selected adsorbent, granular microporous carbon from either Barnaby-Sutcliffe or Calgon, experimentally demonstrated sufficient methane capacity under differential temperature at 100 pounds per square inch gauge. Several valve options were identified, including candidates that can operate millions of cycles between refurbishment. The microchannel adsorber and desorber designs were made using internal Velocys manufacturability standards, and the associated costs are acceptable as included with the complete nitrogen rejection unit (NRU) cost projection. A system design and cost estimate was completed for the NRU section of the methane upgrading system. As integrated into the complete system, the cost is in line with the market requirement. The system has six main unit operations: feed compressor, dehydration unit, nitrogen rejection unit, deoxygenator, carbon dioxide scrubber, and a sales compressor. The NRU is the focus of the development program, and a bench-scale demonstration will be initiated in the next fiscal year. The Velocys NRU system targets producing methane with greater than 96% purity and at least 90% recovery for final commercial operation. A preliminary cost analysis of the methane upgrading system, including the Velocys NRU, suggests that costs below $2.00 per million (MM) BTU methane may be achieved. The cost for a conventional methane upgrading system is well above $2.30 per MM BTU, as benchmarked in an Environmental Protection Agency study.

Anna Lee Tonkovich

2004-07-01T23:59:59.000Z

253

Hot-electron-driven charge transfer processes on O2 Pt,,111... surface probed by ultrafast extreme-ultraviolet pulses  

E-Print Network [OSTI]

it with an ultrafast laser pulse, charge transfer induced changes in the platinum-oxygen bond were observedHot-electron-driven charge transfer processes on O2 Ã?Pt,,111... surface probed by ultrafast extreme-ultraviolet pulses C. Lei,1, * M. Bauer,2 K. Read,1 R. Tobey,1 Y. Liu,3 T. Popmintchev,1 M. M. Murnane,1 and H. C

Bauer, Michael

254

Ultrafast Optical Packet Switching over Arbitrary Physical Topologies using the Manhattan Street Network  

E-Print Network [OSTI]

Komolafe,O. Harle,D. Cotter,D. Proceedings of the 2001 IEEE International Conference on Communications (ICC) IEEE

Komolafe, O.

255

Journal of Physics B: Atomic, Molecular and Optical Physics J. Phys. B: At. Mol. Opt. Phys. 47 (2014) 075301 (12pp) doi:10.1088/0953-4075/47/7/075301  

E-Print Network [OSTI]

for the analysis of such condensates [4]. The long-range and anisotropic character of the DDI leads to new physical (2014) 075301 (12pp) doi:10.1088/0953-4075/47/7/075301 Bright solitons in Bose­Einstein condensates-dimensional model of a bosonic gas of particles carrying collinear dipole moments which are induced by an external

Gammal, Arnaldo

256

Molecular dynamics of excited state intramolecular proton transfer: 3-hydroxyflavone in solution  

SciTech Connect (OSTI)

The ultrafast enol-keto photoisomerization in the lowest singlet excited state of 3-hydroxyflavone is investigated using classical molecular dynamics in conjunction with empirical valence bond (EVB) potentials for the description of intramolecular interactions, and a molecular mechanics and variable partial charge model, dependent on transferring proton position, for the description of solute-solvent interactions. A parallel multi-level genetic program was used to accurately fit the EVB potential energy surfaces to high level ab initio data. We have studied the excited state intramolecular proton transfer (ESIPT) reaction in three different solvent environments: methylcyclohexane, acetonitrile, and methanol. The effects of the environment on the proton transfer time and the underlying mechanisms responsible for the varied time scales of the ESIPT reaction rates are analyzed. We find that simulations with our EVB potential energy surfaces accurately reproduce experimentally determined reaction rates, fluorescence spectra, and vibrational frequency spectra in all three solvents. Furthermore, we find that the ultrafast ESIPT process results from a combination of ballistic transfer, and intramolecular vibrational redistribution, which leads to the excitation of a set of low frequency promoting vibrational modes. From this set of promoting modes, we find that an O-O in plane bend and a C-H out of plane bend are present in all three solvents, indicating that they are fundamental to the ultrafast proton transfer. Analysis of the slow proton transfer trajectories reveals a solvent mediated proton transfer mechanism, which is diffusion limited.

Bellucci, Michael A.; Coker, David F. [Department of Chemistry, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215 (United States)

2012-05-21T23:59:59.000Z

257

Ultrafast Power Processor for Smart Grid Power Module Development  

SciTech Connect (OSTI)

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.

MAITRA, ARINDAM [EPRI] [EPRI; LITWIN, RAY [EPRI] [EPRI; lai, Jason [Enertronics] [Enertronics; Syracuse, David [Silicon Power] [Silicon Power

2012-12-30T23:59:59.000Z

258

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

SciTech Connect (OSTI)

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.

Gaal, P.; Shayduk, R. [Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH, Wilhelm-Conrad-Roentgen Campus, BESSY II, Albert-Einstein-Str. 15, 12489 Berlin (Germany); Schick, D.; Herzog, M.; Bojahr, A.; Goldshteyn, J.; Navirian, H. A.; Leitenberger, W. [Institut fuer Physik und Astronomie, Universitaet Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam (Germany); Vrejoiu, I. [Max-Planck-Institut fuer Mikrostrukturphysik, Weinberg 2, 06120 Halle (Germany); Khakhulin, D.; Wulff, M. [European Synchrotron Radiation Facility (ESRF), 6 rue Jules Horowitz, 38000 Grenoble (France); Bargheer, M. [Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH, Wilhelm-Conrad-Roentgen Campus, BESSY II, Albert-Einstein-Str. 15, 12489 Berlin (Germany); Institut fuer Physik und Astronomie, Universitaet Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam (Germany)

2012-12-10T23:59:59.000Z

259

Ultrafast Charge Separation and Nongeminate Electron-Hole Recombination in Organic Photovoltaics  

E-Print Network [OSTI]

The mechanism of electron-hole separation in organic solar cells is currently hotly debated. Recent experimental work suggests that these charges can separate on extremely short timescales (<100 fs). This can be understood in terms of delocalised transport within fullerene aggregates, which is thought to emerge on short timescales before vibronic relaxation induces polaron formation. However, in the optimal heterojunction morphology, electrons and holes will often re-encounter each other before reaching the electrodes. If such charges trap and cannot separate, then device efficiency will suffer. Here we extend the theory of ultrafast charge separation to incorporate polaron formation, and find that the same delocalised transport used to explain ultrafast charge separation can account for the suppression of nongeminate recombination in the best devices.

Samuel L Smith; Alex W Chin

2014-06-04T23:59:59.000Z

260

Ultrafast resolution of tunneling delay time ALEXANDRA S. LANDSMAN,,  

E-Print Network [OSTI]

laser physics; (020.4180) Multiphoton processes; (240.7040) Tunneling. http://dx.doi.org/10.1364/OPTICA Vol. 1, No. 5 / November 2014 / Optica 343 #12;Observable 1 is the polarization axis

Keller, Ursula

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


261

Time of flight emission spectroscopy of laser produced nickel plasma: Short-pulse and ultrafast excitations  

SciTech Connect (OSTI)

We report the experimental investigation and comparison of the temporal features of short-pulse (7?ns) and ultrafast (100 fs) laser produced plasmas generated from a solid nickel target, expanding into a nitrogen background. When the ambient pressure is varied in a large range of 10{sup ?6?}Torr to 10{sup 2?}Torr, the plume intensity is found to increase rapidly as the pressure crosses 1?Torr. Time of flight (TOF) spectroscopy of emission from neutral nickel (Ni I) at 361.9?nm (3d{sup 9}({sup 2}D) 4p ? 3d{sup 9}({sup 2}D) 4s transition) reveals two peaks (fast and slow species) in short-pulse excitation and a single peak in ultrafast excitation. The fast and slow peaks represent recombined neutrals and un-ionized neutrals, respectively. TOF emission from singly ionized nickel (Ni II) studied using the 428.5?nm (3p{sup 6}3d{sup 8}({sup 3}P) 4s? 3p{sup 6}3d{sup 9} 4s) transition shows only a single peak for either excitation. Velocities of the neutral and ionic species are determined from TOF measurements carried out at different positions (i.e., at distances of 2?mm and 4?mm, respectively, from the target surface) on the plume axis. Measured velocities indicate acceleration of neutrals and ions, which is caused by the Coulomb pull of the electrons enveloping the plume front in the case of ultrafast excitation. Both Coulomb pull and laser-plasma interaction contribute to the acceleration in the case of short-pulse excitation. These investigations provide new information on the pressure dependent temporal behavior of nickel plasmas produced by short-pulse and ultrafast laser pulses, which have potential uses in applications such as pulsed laser deposition and laser-induced nanoparticle generation.

Smijesh, N.; Chandrasekharan, K. [Laser and Nonlinear Optics Laboratory, Department of Physics, National Institute of Technology Calicut, Calicut 673601 (India); Joshi, Jagdish C.; Philip, Reji, E-mail: reji@rri.res.in [Ultrafast and Nonlinear Optics Lab, Light and Matter Physics Group, Raman Research Institute, Bangalore 560080 (India)

2014-07-07T23:59:59.000Z

262

DeepNet: An Ultrafast Neural Learning Code for Seismic Imaging  

SciTech Connect (OSTI)

A feed-forward multilayer neural net is trained to learn the correspondence between seismic data and well logs. The introduction of a virtual input layer, connected to the nominal input layer through a special nonlinear transfer function, enables ultrafast (single iteration), near-optimal training of the net using numerical algebraic techniques. A unique computer code, named DeepNet, has been developed, that has achieved, in actual field demonstrations, results unattainable to date with industry standard tools.

Barhen, J.; Protopopescu, V.; Reister, D.

1999-07-10T23:59:59.000Z

263

Department of Biological, Chemical and Physical Sciences Department of Biological, Chemical and Physical Sciences  

E-Print Network [OSTI]

; and elementary particle physics, acceler- ator and plasma physics, condensed-matter physics, bio- logical physics for Accelerator and Particle Physics Center for the Molecular Study of Soft and Condensed Matter Research and particle physics are active. Collabo- rative programs are carried on with Fermi National Ac- celerator

Saniie, Jafar

264

Precision lifetime measurements of a single trapped ion with ultrafast laser pulses D. L. Moehring,* B. B. Blinov, D. W. Gidley, R. N. Kohn, Jr., M. J. Madsen, T. D. Sanderson, R. S. Vallery, and C. Monroe  

E-Print Network [OSTI]

Precision lifetime measurements of a single trapped ion with ultrafast laser pulses D. L. Moehring and ultrafast laser technologies, the ion is excited with picosecond laser pulses from a mode-locked laser excited state lifetime of order nanoseconds by an ultrafast laser pulse duration of order picoseconds

Blinov, Boris

265

Generalized model for ultrafast laser induced electron emission from a metal tip  

SciTech Connect (OSTI)

In this paper, we will present a brief review of the recently developed non-equilibrium heating and time dependent tunneling model to study the dynamic processes in using an ultrafast laser to induce electron emission from a metallic tip ranging from the multiphoton to the optical tunneling regime. Due to the short time scale of the ultrafast laser pulse, the lattice is found to be in a non-equilibrium condition and a single temperature model is no longer valid. The ultrafast laser heating enhances the electron emission through both the multiphoton and optical tunneling processes rather than over-barrier emission due to thermal heating. The paper is focused on the methodology of how these two effects (non-equilibrium heating and time-dependent tunneling) are combined in a self-consistent model. The model shows a smooth transition of the emitted charge as a function of laser field, ranging from the multiphoton emission regime at low laser field to the optical tunneling regime at high laser field. The paper will conclude with some discussion of future work.

Ang, L. K. [Singapore University of Technology and Design, Singapore 138682 (Singapore) [Singapore University of Technology and Design, Singapore 138682 (Singapore); School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798 (Singapore); Pant, M. [Singapore University of Technology and Design, Singapore 138682 (Singapore)] [Singapore University of Technology and Design, Singapore 138682 (Singapore)

2013-05-15T23:59:59.000Z

266

Multidiagnostic analysis of ultrafast laser ablation of metals with pulse pair irradiation  

SciTech Connect (OSTI)

Copper targets are irradiated in the ablation regime by pairs of equal, time-delayed collinear laser pulses separated on a timescale going from {approx_equal}2 ps to {approx_equal}2 ns. The ablation plume is characterized by ion probe diagnostic, fast imaging, and temporally and spatially resolved optical emission spectroscopy. The variation in the ablation efficiency with the delay between the pulses is analyzed by measuring the ablation crater profile with a contact profilometer. The second laser pulse modifies the characteristics of the plasma plume produced by the first pulse and the ablation efficiency. The different mechanisms involved in double pulse ultrafast laser ablation are identified and discussed. The experimental findings are interpreted in the frame of a simple model of the interaction of the second pulse with the nascent ablation plume produced by the first pulse. This model yields consistent and quantitative agreement with the experimental findings predicting the observed experimental trends of the ablation depth reduction and ion yield increase with the delay between the pulses, as well as the characteristic timescale of the observed changes. The possibility of controlling the characteristics of the plumes produced during ultrafast laser ablation via an efficient coupling of the energy of the second pulse to the various ablation components produced by the first pulse is of particular interest in ultrafast pulsed laser deposition and microprobe analyses of materials.

Amoruso, S.; Bruzzese, R. [Dipartimento di Scienze Fisiche, Universita degli Studi di Napoli Federico II, Complesso Universitario di Monte S. Angelo, Via Cintia, I-80126 Napoli (Italy); CNR-SPIN, Complesso Universitario di Monte S. Angelo, Via Cintia, I-80126 Napoli (Italy); Wang, X. [CNR-SPIN, Complesso Universitario di Monte S. Angelo, Via Cintia, I-80126 Napoli (Italy); O'Connell, G.; Lunney, J. G. [School of Physics, Trinity College-Dublin, Dublin 2 (Ireland)

2010-12-01T23:59:59.000Z

267

Ultrafast electron cascades in semiconductors driven by intense femtosecond terahertz pulses H. Wen,1 M. Wiczer,3 and A. M. Lindenberg1,2  

E-Print Network [OSTI]

Ultrafast electron cascades in semiconductors driven by intense femtosecond terahertz pulses H. Wen processing. With wavelengths in the far infrared, near­ half-cycle THz pulses can be thought of as ultrafast,1 M. Wiczer,3 and A. M. Lindenberg1,2 1PULSE Institute, Stanford Linear Accelerator Center, Menlo

268

Using femtosecond electron pulses as an imaging tool, we can probe ultrafast dynamics by taking snapshots at different time delays. By using femtosecond electron diffraction (FED),  

E-Print Network [OSTI]

Abstract Using femtosecond electron pulses as an imaging tool, we can probe ultrafast dynamics correlation. Additionally, ultrafast electron shadow imaging (UESI) can explore the dynamics of laser induced System The femtosecond "camera" mentioned above is comprised of an amplified femtosecond pulsed laser

Weston, Ken

269

Development of ultrafast computed tomography of highly transient fuel sprays  

E-Print Network [OSTI]

, such as automotive fuel injection systems. As the worldwide demand for energy grows rapidly, the technologies capable , Sol M. Grunera, b a Department of Physics and b Cornell High Energy Synchrotron Source, Cornell-intake port. Due to the ability to precisely control the injection rate, timing, and combustion of the fuel

Gruner, Sol M.

270

The Whys and Hows of Ultrafast X-ray Science  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched Ferromagnetism in Layered NbS2 andThe MolecularPlaceThe publication of the

271

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)

'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.

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

2011-11-02T23:59:59.000Z

272

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

SciTech Connect (OSTI)

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.

Thayer, K.J. (ed.)

1989-08-01T23:59:59.000Z

273

Ultra-fast outflows (aka UFOs) from AGNs and QSOs  

E-Print Network [OSTI]

During the last decade, strong observational evidence has been accumulated for the existence of massive, high velocity winds/outflows (aka Ultra Fast Outflows, UFOs) in nearby AGNs and in more distant quasars. Here we briefly review some of the most recent developments in this field and discuss the relevance of UFOs for both understanding the physics of accretion disk winds in AGNs, and for quantifying the global amount of AGN feedback on the surrounding medium.

Cappi, M; Giustini, M

2013-01-01T23:59:59.000Z

274

A compact streak camera for 150 fs time resolved measurement of bright pulses in ultrafast electron diffraction  

SciTech Connect (OSTI)

We have developed a compact streak camera suitable for measuring the duration of highly charged subrelativistic femtosecond electron bunches with an energy bandwidth in the order of 0.1%, as frequently used in ultrafast electron diffraction (UED) experiments for the investigation of ultrafast structural dynamics. The device operates in accumulation mode with 50 fs shot-to-shot timing jitter, and at a 30 keV electron energy, the full width at half maximum temporal resolution is 150 fs. Measured durations of pulses from our UED gun agree well with the predictions from the detailed charged particle trajectory simulations.

Kassier, G. H.; Haupt, K.; Erasmus, N.; Rohwer, E. G.; Bergmann, H. M. von; Schwoerer, H. [Laser Research Institute, University of Stellenbosch, Private Bag X1, 7602 Matieland (South Africa); Coelho, S. M. M.; Auret, F. D. [Department of Physics, University of Pretoria, Pretoria 0002 (South Africa)

2010-10-15T23:59:59.000Z

275

Ultrafast laser based coherent control methods for explosives detection  

SciTech Connect (OSTI)

The detection of explosives is a notoriously difficult problem, especially at stand-off, due to their (generally) low vapor pressure, environmental and matrix interferences, and packaging. We are exploring Optimal Dynamic Detection of Explosives (ODD-Ex), which exploits the best capabilities of recent advances in laser technology and recent discoveries in optimal shaping of laser pulses for control of molecular processes to significantly enhance the standoff detection of explosives. The core of the ODD-Ex technique is the introduction of optimally shaped laser pulses to simultaneously enhance sensitivity to explosives signatures while dramatically improving specificity, particularly against matrix materials and background interferences. These goals are being addressed by operating in an optimal non-linear fashion, typically with a single shaped laser pulse inherently containing within it coherently locked control and probe subpulses. Recent results will be presented.

Moore, David Steven [Los Alamos National Laboratory

2010-12-06T23:59:59.000Z

276

Mode-selective vibrational control of charge transport in $?$-conjugated molecular materials  

E-Print Network [OSTI]

The soft character of organic materials leads to strong coupling between molecular nuclear and electronic dynamics. This coupling opens the way to control charge transport in organic electronic devices by inducing molecular vibrational motions. However, despite encouraging theoretical predictions, experimental realization of such control has remained elusive. Here we demonstrate experimentally that photoconductivity in a model organic optoelectronic device can be controlled by the selective excitation of molecular vibrations. Using an ultrafast infrared laser source to create a coherent superposition of vibrational motions in a pentacene/C60 photoresistor, we observe that excitation of certain modes in the 1500-1700 cm$^{-1}$ region leads to photocurrent enhancement. Excited vibrations affect predominantly trapped carriers. The effect depends on the nature of the vibration and its mode-specific character can be well described by the vibrational modulation of intermolecular electronic couplings. Vibrational control thus presents a new tool for studying electron-phonon coupling and charge dynamics in (bio)molecular materials.

Artem A. Bakulin; Robert Lovrin?i?; Yu Xi; Oleg Selig; Huib J. Bakker; Yves L. A. Rezus; Pabitra K. Nayak; Alexandr Fonari; Veaceslav Coropceanu; Jean-Luc Brédas; David Cahen

2015-03-02T23:59:59.000Z

277

Control of molecular rotation in the limit of extreme rotational excitation  

E-Print Network [OSTI]

Laser control of molecular rotation is an area of active research. A number of recent studies has aimed at expanding the reach of rotational control to extreme, previously inaccessible rotational states, as well as controlling the directionality of molecular rotation. Dense ensembles of molecules undergoing ultrafast uni-directional rotation, known as molecular superrotors, are anticipated to exhibit unique properties, from spatially anisotropic diffusion and vortex formation to the creation of powerful acoustic waves and tuneable THz radiation. Here we describe our recent progress in controlling molecular rotation in the regime of high rotational excitation. We review two experimental techniques of producing uni-directional rotational wave packets with a "chiral train" of femtosecond pulses and an "optical centrifuge". Three complementary detection methods, enabling the direct observation, characterization and control of the superrotor states, are outlined: the one based on coherent Raman scattering, and two...

Milner, V

2015-01-01T23:59:59.000Z

278

Broadband electromagnetic response and ultrafast dynamics of few-layer epitaxial graphene  

SciTech Connect (OSTI)

We study the broadband optical conductivity and ultrafast carrier dynamics of epitaxial graphene in the few-layer limit. Equilibrium spectra of nominally buffer, monolayer, and multilayer graphene exhibit significant terahertz and near-infrared absorption, consistent with a model of intra- and interband transitions in a dense Dirac electron plasma. Non-equilibrium terahertz transmission changes after photoexcitation are shown to be dominated by excess hole carriers, with a 1.2-ps mono-exponential decay that refects the minority-carrier recombination time.

Choi, Hyunyong; Borondics, Ferenc; Siegel, David A.; Zhou, Shuyun Y.; Martin, Michael C.; Lanzara, Alessandra; Kaindl, Robert A.

2009-03-26T23:59:59.000Z

279

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

SciTech Connect (OSTI)

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.

Thyrrestrup, Henri, E-mail: h.t.nielsen@utwente.nl; Yüce, Emre; Ctistis, Georgios; Vos, Willem L. [Complex Photonic Systems (COPS), MESA Institute for Nanotechnology, University of Twente, 7500 AE Enschede (Netherlands); Claudon, Julien; Gérard, Jean-Michel, E-mail: jean-michel.gerard@cea.fr [University Grenoble Alpes, INAC-SP2M, Nanophysics and Semiconductors Lab, F-38000 Grenoble (France); CEA, INAC-SP2M, Nanophysics and Semiconductors Lab, F-38000 Grenoble (France)

2014-09-15T23:59:59.000Z

280

Ultrafast magneto-photocurrents in GaAs: Separation of surface and bulk contributions  

E-Print Network [OSTI]

We induce ultrafast magneto-photocurrents in a GaAs crystal employing interband excitation with femtosecond laser pulses at room temperature and non-invasively separate surface and bulk contributions to the overall current response. The separation between the different symmetry contributions is achieved by measuring the simultaneously emitted terahertz radiation for different sample orientations. Excitation intensity and photon energy dependences of the magneto-photocurrents for linearly and circularly polarized excitations reveal an involvement of different microscopic origins, one of which we believe is the inverse Spin-Hall effect. Our experiments are important for a better understanding of the complex momentum-space carrier dynamics in magnetic fields.

Schmidt, Christian B; Tarasenko, Sergey A; Bieler, Mark

2015-01-01T23:59:59.000Z

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


281

Electron Pulse Compression with a Practical Reflectron Design for Ultrafast Electron Diffraction  

E-Print Network [OSTI]

Ultrafast electron diffraction (UED) is a powerful method for studying time-resolved structural changes. Currently, space charge induced temporal broadening prevents obtaining high brightness electron pulses with sub-100 fs durations limiting the range of phenomena that can be studied with this technique. We review the state of the the art of UED in this respect and propose a practical design for reflectron based pulse compression which utilizes only electro-static optics and has a tunable temporal focal point. Our simulation shows that this scheme is capable of compressing an electron pulse containing 100,000 electrons with 60:1 temporal compression ratio.

Wang, Yihua

2013-01-01T23:59:59.000Z

282

Pump-probe imaging of laser-induced periodic surface structures after ultrafast irradiation of Si  

SciTech Connect (OSTI)

Ultrafast pump-probe microscopy has been used to investigate laser-induced periodic surface structure (LIPSS) formation on polished Si surfaces. A crater forms on the surface after irradiation by a 150 fs laser pulse, and a second, subsequent pulse forms LIPSS within the crater. Sequentially delayed images show that LIPSS with a periodicity slightly less than the fundamental laser wavelength of 780 nm appear on Si surfaces ?50 ps after arrival of the second pump laser pulse, well after the onset of melting. LIPSS are observed on the same timescale as material removal, suggesting that their formation involves material ejection.

Murphy, Ryan D. [Applied Physics Program, University of Michigan, Ann Arbor, Michigan 48109 (United States)] [Applied Physics Program, University of Michigan, Ann Arbor, Michigan 48109 (United States); Torralva, Ben [Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor, Michigan 48109 (United States)] [Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor, Michigan 48109 (United States); Adams, David P. [Sandia National Laboratories, Albuquerque, New Mexico 87123 (United States)] [Sandia National Laboratories, Albuquerque, New Mexico 87123 (United States); Yalisove, Steven M. [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States)] [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States)

2013-09-30T23:59:59.000Z

283

Ultrafast X-ray Spectroscopy of Warm Dense Matter | Stanford Synchrotron  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLasDelivered energy consumption by sectorlong version) The0Radiation Lightsource Ultrafast

284

Measurements of Ionic Structure in Shock Compressed Lithium Hydride from Ultrafast X-Ray Thomson Scattering  

SciTech Connect (OSTI)

We present the first ultrafast temporally, spectrally, and angularly resolved x-ray scattering measurements from shock-compressed matter. The experimental spectra yield the absolute elastic and inelastic scattering intensities from the measured density of free electrons. Laser-compressed lithium-hydride samples are well characterized by inelastic Compton and plasmon scattering of a K-alpha x-ray probe providing independent measurements of temperature and density. The data show excellent agreement with the total intensity and structure when using the two-species form factor and accounting for the screening of ion-ion interactions.

Kritcher, A. L. [L-399, Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551 (United States); Department of Nuclear Engineering, University of California Berkeley, Berkeley, California 94709 (United States); Neumayer, P.; Doeppner, T.; Landen, O. L.; Glenzer, S. H. [L-399, Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551 (United States); Brown, C. R. D. [Department of Physics, Imperial College, London SW7 2AZ (United Kingdom); AWE plc., Aldermaston, Reading, RG7 4PR (United Kingdom); Davis, P. [L-399, Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551 (United States); Department of Physics, University of California Berkeley, Berkeley, California 94709 (United States); Falcone, R. W.; Lee, H. J. [Department of Physics, University of California Berkeley, Berkeley, California 94709 (United States); Gericke, D. O.; Vorberger, J.; Wuensch, K. [CFSA, Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Gregori, G. [Department of Physics, Oxford University, Oxford OX1 3PU (United Kingdom); Holst, B.; Redmer, R. [Universitaet Rostock, Institut fuer Physik, D-18051 Rostock (Germany); Morse, E. C. [Department of Nuclear Engineering, University of California Berkeley, Berkeley, California 94709 (United States); Pelka, A.; Roth, M. [Institut fuer Kernphysik, Technische Universitaet Darmstadt, Darmstadt (Germany)

2009-12-11T23:59:59.000Z

285

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

SciTech Connect (OSTI)

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.

Henning, W.F.

1992-08-01T23:59:59.000Z

286

DEPARTMENT OF PHYSICS Physics 32100  

E-Print Network [OSTI]

DEPARTMENT OF PHYSICS Syllabus Physics 32100 Modern Physics for Engineers Designation to one- electron atoms, atomic shell structure and periodic table; nuclear physics, relativity. Prerequisites: Prereq.: Physics 20800 or equivalent, Math 20300 or 20900 (elective for Engineering students

Lombardi, John R.

287

DEPARTMENT OF PHYSICS Physics 21900  

E-Print Network [OSTI]

DEPARTMENT OF PHYSICS Syllabus Physics 21900 Physics for Architecture Students Designation suggested material: Giancoli, Physics, Principles with Applications (6th ed.) (required), Prentice Hall Giancoli, Physics, Principles with Applications, Student Guide (6th ed.) (optional), Prentice Hall Course

Lombardi, John R.

288

DEPARTMENT OF PHYSICS Physics 20300  

E-Print Network [OSTI]

DEPARTMENT OF PHYSICS Syllabus Physics 20300 General Physics Designation: Required Undergraduate Catalog description: For majors in the life sciences (biology, medicine, dentistry, psychology, physical therapy) and for liberal arts students. Fundamental ideas and laws of physics from mechanics to modern

Lombardi, John R.

289

Molecular Biology The molecular biology major at Stetson University is designed for  

E-Print Network [OSTI]

Molecular Biology The molecular biology major at Stetson University is designed for students interested in the interface between the life sciences and physical sciences. Molecular biology is an interdisciplinary science that uses the techniques of biology and chemistry to examine genetic inheritance

Miles, Will

290

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

DOE Patents [OSTI]

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.

Liu, Ping (Denver, CO); Tracy, C. Edwin (Golden, CO); Pitts, J. Roland (Lakewood, CO); Lee, Se-Hee (Lakewood, CO)

2011-03-22T23:59:59.000Z

291

Ultrafast Laser Pulse Control of Exciton Dynamics: A Computational Study on the FMO Ben Bru1ggemann and Volkhard May*  

E-Print Network [OSTI]

Ultrafast Laser Pulse Control of Exciton Dynamics: A Computational Study on the FMO Complex Ben Bru, D-12489 Berlin, Germany ReceiVed: February 4, 2004; In Final Form: May 23, 2004 Femtosecond laser-pulse on the Frenkel exciton model for the bacteriochlorophyll (BChl) Qy-excitations, the laser- pulse-driven exciton

Röder, Beate

292

Free electron properties of metals under ultrafast laser-induced electron-phonon nonequilibrium: a first-principles study  

E-Print Network [OSTI]

Free electron properties of metals under ultrafast laser-induced electron-phonon nonequilibrium CEA-DIF, 91297 Arpajon, France (Dated: April 3, 2014) The electronic behavior of various solid metals modelled based on the free electron classical theory, the free electron number is a key parameter. However

Paris-Sud XI, Université de

293

IEEE Trans Ultrason Ferroelectr Freq Control . Author manuscript Combined passive detection and ultrafast active imaging of cavitation  

E-Print Network [OSTI]

Gateaué ô Abstract The activation of natural gas nuclei to induce larger and ultrafast active imaging over a large volume and with the same multi-element probe. Bubble nucleation ; ultrasonography ; Phantoms, Imaging ; Sheep ; Signal Processing, Computer-Assisted ; Transducers ; Ultrasonography

Paris-Sud XI, Université de

294

Hydrogen Bond Switching among Flavin and Amino Acid Side Chains in the BLUF Photoreceptor Observed by Ultrafast Infrared Spectroscopy  

E-Print Network [OSTI]

Hydrogen Bond Switching among Flavin and Amino Acid Side Chains in the BLUF Photoreceptor Observed hydrogen-bond network with nearby amino acid side chains, including a highly conserved tyrosine and glutamine. The participation of particular amino acid side chains in the ultrafast hydrogen-bond switching

van Stokkum, Ivo

295

Emission dynamics of an expanding ultrafast-laser produced Zn plasma under different ambient pressures  

SciTech Connect (OSTI)

We report time and space resolved spectral measurements of neutral Zn emission from an ultrafast laser produced plasma, generated by the irradiation of a Zn target with laser pulses of 100 femtoseconds duration, carried out in a broad ambient pressure range of 0.05 to 100 Torr. The measurement is done for three different axial positions in the expanding plume. The spectra are rich in neutral Zn (Zn I) emissions at 334.5 nm, 468 nm, 472 nm, 481 nm, and 636 nm, respectively, depicting the characteristic triplet structure of Zn. Fast as well as slow peaks are observed in the time of flight data of 481 nm emission, which arise from recombination and atomic contributions, respectively, occurring at different time scales. Average speeds of the fast atomic species do not change appreciably with ambient pressure. The plasma parameters (electron temperature and number density) are evaluated from the measured optical emission spectra. The rates of ionization and recombination can be enhanced by a double-pulse excitation configuration in which optical energy is coupled to the ultrafast plasma through a delayed laser pulse.

Smijesh, N.; Philip, Reji [Raman Research Institute, C.V. Raman Avenue, Sadashivanagar, Bangalore 560080 (India)] [Raman Research Institute, C.V. Raman Avenue, Sadashivanagar, Bangalore 560080 (India)

2013-09-07T23:59:59.000Z

296

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

SciTech Connect (OSTI)

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.

Grazioli, C.; Gauthier, D.; Ivanov, R.; De Ninno, G. [Laboratory of Quantum Optics, University of Nova Gorica, Nova Gorica (Slovenia) [Laboratory of Quantum Optics, University of Nova Gorica, Nova Gorica (Slovenia); Elettra Sincrotrone Trieste, Trieste (Italy)] [Italy; Callegari, C.; Spezzani, C. [Elettra Sincrotrone Trieste, Trieste (Italy)] [Elettra Sincrotrone Trieste, Trieste (Italy); Ciavardini, A. [Sapienza University, Rome (Italy)] [Sapienza University, Rome (Italy); Coreno, M. [Elettra Sincrotrone Trieste, Trieste (Italy) [Elettra Sincrotrone Trieste, Trieste (Italy); Institute of Inorganic Methodologies and Plasmas (CNR-IMIP), Montelibretti, Roma (Italy); Frassetto, F.; Miotti, P.; Poletto, L. [Institute of Photonics and Nanotechnologies (CNR-IFN), Padova (Italy)] [Institute of Photonics and Nanotechnologies (CNR-IFN), Padova (Italy); Golob, D. [Kontrolni Sistemi d.o.o., Sežana (Slovenia)] [Kontrolni Sistemi d.o.o., Sežana (Slovenia); Kivimäki, A. [Institute of Materials Manufacturing (CNR-IOM), TASC Laboratory, Trieste (Italy)] [Institute of Materials Manufacturing (CNR-IOM), TASC Laboratory, Trieste (Italy); Mahieu, B. [Elettra Sincrotrone Trieste, Trieste (Italy) [Elettra Sincrotrone Trieste, Trieste (Italy); Service des Photons Atomes et Molécules, Commissariat à l'Energie Atomique, Centre d'Etudes de Saclay, Bâtiment 522, 91191 Gif-sur-Yvette (France); Bu?ar, B.; Merhar, M. [Laboratory of Mechanical Processing Technologies, University of Ljubljana, Ljubljana (Slovenia)] [Laboratory of Mechanical Processing Technologies, University of Ljubljana, Ljubljana (Slovenia); Polo, E. [Institute of Organic Synthesis and Photoreactivity (CNR-ISOF), Ferrara (Italy)] [Institute of Organic Synthesis and Photoreactivity (CNR-ISOF), Ferrara (Italy); Ressel, B. [Laboratory of Quantum Optics, University of Nova Gorica, Nova Gorica (Slovenia)] [Laboratory of Quantum Optics, University of Nova Gorica, Nova Gorica (Slovenia)

2014-02-15T23:59:59.000Z

297

Processing and thermal properties of molecularly oriented polymers  

E-Print Network [OSTI]

High molecular weight polymers that are linear in molecular construction can be oriented such that some of their physical properties in the oriented direction are enhanced. For over 50 years polymer orientation and processing ...

Skow, Erik (Erik Dean)

2007-01-01T23:59:59.000Z

298

Nonlinear Ultrafast Spectroscopy of Electron and Energy Transfer in Molecule Complexes  

SciTech Connect (OSTI)

The proposed research program will focus on the development of a unified dynamical theoretical framework for calculating the optical response of molecular assemblies and applying it towards studying the interplay of energy and charge transfer in artificial chromophore-aggregate complexes. Applications will be made to poly (p phenylene vinylene), (PPV) oligomers, several families of stilbenoid aggregates with stacking through a cyclophane group, coupled porphyrin arrays, and energy funneling in phenylacetylene dendrimers. The approach is based on formulating the problem using the density- matrix and developing Liouville-space techniques which provide physical insight and are particularly suitable for computing both coherent and incoherent transport. A physical picture based on collective electronic normal modes which represent the dynamics of the optically-driven reduced single electron density matrix will be established. Femtosecond signals and optical properties will be directly related to the motions of electron-hole pairs in real space, completely avoiding the calculation of many-electron excited-state wavefunctions, thus, considerably reducing computational effort. Vibrational and solvent effects will be incorporated. Guidelines for the synthesis of new donor/bridge/acceptor molecules with desired properties such as carrier transport, optical response time scales and fluorescence quantum yields will be developed. The analogy with Thz emission spectroscopy which probes charge carrier dynamic is in semiconductor superlattices will be explored. A systematic procedure for identifying the electronic coherence sizes which control the transport and optical properties will be developed. Localization of electronic transition density matrices of large molecules will be used to break the description of their optical response into coupled chromophores. The proposal is divided into four parts: (i) Collective-Oscillator Representation of Electronic Excitations in Molecular Assemblies; (ii) Nonlinear Optical Spectroscopy of Coupled Chromophores; (iii) Long-Range Electron Transfer and Transport in Solvents with Complex Spectral Densities; (iv) Probing Exciton-Migration by Coherent Femtosecond Spectroscopies.

Mukamel, Shaul

2006-02-09T23:59:59.000Z

299

Introduction to Accelerated Molecular Dynamics  

SciTech Connect (OSTI)

Molecular Dynamics is the numerical solution of the equations of motion of a set of atoms, given an interatomic potential V and some boundary and initial conditions. Molecular Dynamics is the largest scale model that gives unbiased dynamics [x(t),p(t)] in full atomistic detail. Molecular Dynamics: is simple; is 'exact' for classical dynamics (with respect to a given V); can be used to compute any (atomistic) thermodynamical or dynamical properties; naturally handles complexity -- the system does the right thing at the right time. The physics derives only from the interatomic potential.

Perez, Danny [Los Alamos National Laboratory

2012-07-10T23:59:59.000Z

300

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

ScienceCinema (OSTI)

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.

Li, Weizhong [San Diego Supercomputer Center

2013-01-22T23:59:59.000Z

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


301

alkane molecular ions: Topics by E-print Network  

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

1977-01-01 25 Blackbody thermometry with cold molecular ions and application to ion-based frequency standards Physics Websites Summary: Blackbody thermometry with cold...

302

Distribution Category: Atomic, Molecular, and Chemical Physics  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation Proposed Newcatalyst phasesDataTranslocation oftheAmperometricEnergyDISTRIBUTEDAtomic,

303

How to Calculate Molecular Column Density  

E-Print Network [OSTI]

The calculation of the molecular column density from molecular spectral (rotational or ro-vibrational) transition measurements is one of the most basic quantities derived from molecular spectroscopy. Starting from first principles where we describe the basic physics behind the radiative and collisional excitation of molecules and the radiative transfer of their emission, we derive a general expression for the molecular column density. As the calculation of the molecular column density involves a knowledge of the molecular energy level degeneracies, rotational partition functions, dipole moment matrix elements, and line strengths, we include generalized derivations of these molecule-specific quantities. Given that approximations to the column density equation are often useful, we explore the optically thin, optically thick, and low-frequency limits to our derived general molecular column density relation. We also evaluate the limitations of the common assumption that the molecular excitation temperature is con...

Mangum, Jeffrey G

2015-01-01T23:59:59.000Z

304

Frontiers for Discovery in High Energy Density Physics  

SciTech Connect (OSTI)

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

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.

2004-07-20T23:59:59.000Z

305

Ultrafast Control of Magnetism in Ferromagnetic Semiconductors via Photoexcited Transient Carriers  

SciTech Connect (OSTI)

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.

Cotoros, Ingrid A.

2008-12-12T23:59:59.000Z

306

@Why Physics Comprehensive Physics Major.  

E-Print Network [OSTI]

@Why Physics Comprehensive Physics Major. From the basic laws of physics to the resulting emergent behavior, physics studies what the universe is made of and how it works. As a Physics major that surrounds us, to the structure and evolution of the entire universe. We offer three degrees in Physics

Yoo, S. J. Ben

307

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

SciTech Connect (OSTI)

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.

Itoh, Hirotake, E-mail: hiroitoh@m.tohoku.ac.jp; Iwai, Shinichiro, E-mail: s-iwai@m.tohoku.ac.jp [Department of Physics, Tohoku University, Sendai 980-8578 (Japan); JST, CREST, Sendai 980-8578 (Japan); Itoh, Keisuke; Goto, Kazuki [Department of Physics, Tohoku University, Sendai 980-8578 (Japan); Yamamoto, Kaoru [Department of Applied Physics, Okayama University of Science, Okayama 700-0005 (Japan); Yakushi, Kyuya [Toyota Physical and Chemical Research Institute, Nagakute 480-1192 (Japan)

2014-04-28T23:59:59.000Z

308

A microfluidic flow-cell for the study of the ultrafast dynamics of biological systems  

SciTech Connect (OSTI)

The study of biochemical dynamics by ultrafast spectroscopic methods is often restricted by the limited amount of liquid sample available, while the high repetition rate of light sources can induce photodamage. In order to overcome these limitations, we designed a high flux, sub-ml, capillary flow-cell. While the 0.1 mm thin window of the 0.5 mm cross-section capillary ensures an optimal temporal resolution and a steady beam deviation, the cell-pump generates flows up to ?0.35 ml/s that are suitable to pump laser repetition rates up to ?14 kHz, assuming a focal spot-diameter of 100 ?m. In addition, a decantation chamber efficiently removes bubbles and allows, via septum, for the addition of chemicals while preserving the closed atmosphere. The minimal useable amount of sample is ?250 ?l.

Chauvet, Adrien, E-mail: adrien.chauvet@epfl.ch; Chergui, Majed [Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratoire de Spectroscopie Ultrarapide, ISIC, Faculté des Sciences de Base, Station 6, 1015 Lausanne (Switzerland); Tibiletti, Tania; Caffarri, Stefano [Aix Marseille Université, CNRS, CEA, UMR 7265 Biologie Végétale et Microbiologie Environnementales, 13009 Marseille (France)

2014-10-15T23:59:59.000Z

309

Ultra-fast photoluminescence as a diagnostic for laser damage initiation  

SciTech Connect (OSTI)

Using high-sensitivity confocal time-resolved photoluminescence (CTP) techniques, we report an ultra-fast photoluminescence (40ps-5ns) from impurity-free surface flaws on fused silica, including polished, indented or fractured surfaces of fused silica, and from laser-heated evaporation pits. This fast photoluminescence (PL) is not associated with slower point defect PL in silica which has characteristic decay times longer than 5ns. Fast PL is excited by the single photon absorption of sub-band gap light, and is especially bright in fractures. Regions which exhibit fast PL are strongly absorptive well below the band gap, as evidenced by a propensity to damage with 3.5eV ns-scale laser pulses, making CTP a powerful non-destructive diagnostic for laser damage in silica. The use of CTP to provide insights into the nature of damage precursors and to help develop and evaluate new damage mitigation strategies will be presented.

Laurence, T A; Bude, J D; Shen, N; Miller, P E; Steele, W A; Guss, G; Adams, J J; Wong, L L; Feit, M D; Suratwala, T I

2009-10-30T23:59:59.000Z

310

Evidence for ultra-fast heating in intense-laser irradiated reduced-mass targets  

SciTech Connect (OSTI)

We report on an experiment irradiating individual argon droplets of 20 {mu}m diameter with laser pulses of several Joule energy at intensities of 10{sup 19} W/cm{sup 2}. K-shell emission spectroscopy was employed to determine the hot electron energy fraction and the time-integrated charge-state distribution. Spectral fitting indicates that bulk temperatures up to 160 eV are reached. Modelling of the hot-electron relaxation and generation of K-shell emission with collisional hot-electron stopping only is incompatible with the experimental results, and the data suggest an additional ultra-fast (sub-ps) heating contribution. For example, including resistive heating in the modelling yields a much better agreement with the observed final bulk temperature and qualitatively reproduces the observed charge state distribution.

Neumayer, P.; Gumberidze, A.; Hochhaus, D. C. [ExtreMe Matter Institute EMMI and Research Division, GSI Helmholtzzentrum fuer Schwerionenforschung, 64291 Darmstadt (Germany); Frankfurt Institute for Advanced Studies FIAS, 60438 Frankfurt am Main (Germany); Aurand, B.; Stoehlker, T. [Helmholtzzentrum fuer Schwerionenforschung GSI, 64291 Darmstadt (Germany); Helmholtz Institute Jena, 07743 Jena (Germany); Costa Fraga, R. A.; Kalinin, A. [Institut fuer Kernphysik, J. W. Goethe University Frankfurt, 60438 Frankfurt am Main (Germany); Ecker, B. [Johannes Gutenberg University Mainz, 55099 Mainz (Germany); Helmholtz Institute Jena, 07743 Jena (Germany); Grisenti, R. E. [Institut fuer Kernphysik, J. W. Goethe University Frankfurt, 60438 Frankfurt am Main (Germany); Helmholtzzentrum fuer Schwerionenforschung GSI, 64291 Darmstadt (Germany); Kaluza, M. C. [Helmholtz Institute Jena, 07743 Jena (Germany); IOQ Institute of Optics and Quantum Electronics, University of Jena (Germany); Kuehl, T. [Johannes Gutenberg University Mainz, 55099 Mainz (Germany); Helmholtzzentrum fuer Schwerionenforschung GSI, 64291 Darmstadt (Germany); Helmholtz Institute Jena, 07743 Jena (Germany); Polz, J. [IOQ Institute of Optics and Quantum Electronics, University of Jena (Germany); Reuschl, R. [ExtreMe Matter Institute EMMI and Research Division, GSI Helmholtzzentrum fuer Schwerionenforschung, 64291 Darmstadt (Germany); Winters, D.; Winters, N.; Yin, Z. [Helmholtzzentrum fuer Schwerionenforschung GSI, 64291 Darmstadt (Germany)

2012-12-15T23:59:59.000Z

311

Efficient Photoionization-Loading of Trapped Cadmium Ions with Ultrafast Pulses  

E-Print Network [OSTI]

Atomic cadmium ions are loaded into radiofrequency ion traps by photoionization of atoms in a cadmium vapor with ultrafast laser pulses. The photoionization is driven through an intermediate atomic resonance with a frequency-quadrupled mode-locked Ti:Sapphire laser that produces pulses of either 100 fsec or 1 psec duration at a central wavelength of 229 nm. The large bandwidth of the pulses photoionizes all velocity classes of the Cd vapor, resulting in high loading efficiencies compared to previous ion trap loading techniques. Measured loading rates are compared with a simple theoretical model, and we conclude that this technique can potentially ionize every atom traversing the laser beam within the trapping volume. This may allow the operation of ion traps with lower levels of background pressures and less trap electrode surface contamination. The technique and laser system reported here should be applicable to loading most laser-cooled ion species.

L. Deslauriers; M. Acton; B. B. Blinov; K. -A. Brickman; P. C. Haljan; W. K. Hensinger; D. Hucul; S. Katnik; R. N. Kohn, Jr.; P. J. Lee; M. J. Madsen; P. Maunz; S. Olmschenk; D. L. Moehring; D. Stick; J. Sterk; M. Yeo; K. C. Younge; C. Monroe

2006-08-04T23:59:59.000Z

312

Four-level atomic interferometer driven by shaped ultrafast laser pulses  

SciTech Connect (OSTI)

We analyze the behavior of a four-state, two-path atomic interferometer driven by shaped ultrafast laser pulses. The laser pulses interact with atomic rubidium, exciting the atoms to the 5D state via two intermediate resonances (the 5P{sub 1/2} and 5P{sub 3/2}). The relative phase of the two paths can be modified by applying a varying spectral phase at the wavelength corresponding to one of the resonant transitions for each pathway. We trace out the behavior of the system from the simplest case of weak-field excitation with resonant fields to strong-field excitation with a broadband source. Our measurements and analysis reveal that while interference is observed for all field strengths and spectral widths, the character of the interference changes substantially.

Clow, Stephen; Weinacht, Thomas [Department of Physics, Stony Brook University, Stony Brook, New York 11794 (United States)

2010-08-15T23:59:59.000Z

313

Ultrafast terahertz-induced response of GeSbTe phase-change materials  

SciTech Connect (OSTI)

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.

Shu, Michael J. [Department of Applied Physics, Stanford University, Stanford, California 94305 (United States); Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Zalden, Peter [Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Chen, Frank [Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Department of Electrical Engineering, Stanford University, Stanford, California 94305 (United States); Weems, Ben [Department of Materials Science and Engineering, Stanford University, Stanford, California 94305 (United States); Chatzakis, Ioannis [Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Xiong, Feng; Jeyasingh, Rakesh; Pop, Eric; Philip Wong, H.-S. [Department of Electrical Engineering, Stanford University, Stanford, California 94305 (United States); Hoffmann, Matthias C. [SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Wuttig, Matthias [I. Physikalisches Institut, RWTH Aachen University, 52056 Aachen (Germany); JARA–Fundamentals of Information Technology, RWTH Aachen University, 52056 Aachen (Germany); Lindenberg, Aaron M., E-mail: aaronl@stanford.edu [Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Department of Materials Science and Engineering, Stanford University, Stanford, California 94305 (United States)

2014-06-23T23:59:59.000Z

314

Collinear, two-color optical Kerr effect shutter for ultrafast time-resolved imaging  

E-Print Network [OSTI]

Imaging with ultrashort exposure times is generally achieved with a crossed-beam geometry. In the usual arrangement, an off-axis gating pulse induces birefringence in a medium exhibiting a strong Kerr response (commonly carbon disulfide) which is followed by a polarizer aligned to fully attenuate the on-axis imaging beam. By properly timing the gate pulse, imaging light experiences a polarization change allowing time-dependent transmission through the polarizer to form an ultrashort image. The crossed-beam system is effective in generating short gate times, however, signal transmission through the system is complicated by the crossing angle of the gate and imaging beams. This work presents a robust ultrafast time-gated imaging scheme based on a combination of type-I frequency doubling and a collinear optical arrangement in carbon disulfide. We discuss spatial effects arising from crossed-beam Kerr gating, and examine the imaging spatial resolution and transmission timing affected by collinear activation of th...

Purwar, Harsh; Rozé, Claude; Sedarsky, David; Blaisot, Jean-Bernard

2015-01-01T23:59:59.000Z

315

An ultrafast angle-resolved photoemission apparatus for measuring complex materials  

SciTech Connect (OSTI)

We present technical specifications for a high resolution time- and angle-resolved photoemission spectroscopy setup based on a hemispherical electron analyzer and cavity-dumped solid state Ti:sapphire laser used to generate pump and probe beams, respectively, at 1.48 and 5.93 eV. The pulse repetition rate can be tuned from 209 Hz to 54.3 MHz. Under typical operating settings the system has an overall energy resolution of 23 meV, an overall momentum resolution of 0.003 A{sup -1}, and an overall time resolution of 310 fs. We illustrate the system capabilities with representative data on the cuprate superconductor Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}}. The descriptions and analyses presented here will inform new developments in ultrafast electron spectroscopy.

Smallwood, Christopher L.; Lanzara, Alessandra [Department of Physics, University of California, Berkeley, California 94720 (United States); Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Jozwiak, Christopher [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Zhang Wentao [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

2012-12-15T23:59:59.000Z

316

Ultrafast formation of the benzoic acid triplet upon ultraviolet photolysis and its sequential photodissociation in solution  

SciTech Connect (OSTI)

Time-resolved infrared (TR-IR) absorption spectroscopy in both the femtosecond and nanosecond time domain has been applied to examine the photolysis of benzoic acid in acetonitrile solution following either 267 nm or 193 nm excitation. By combining the ultrafast and nanosecond TR-IR measurements, both the excited states and the photofragments have been detected and key mechanistic insights were obtained. We show that the solvent interaction modifies the excited state relaxation pathways and thus the population dynamics, leading to different photolysis behavior in solution from that observed in the gas phase. Vibrational energy transfer to solvents dissipates excitation energy efficiently, suppressing the photodissociation and depopulating the excited S{sub 2} or S{sub 3} state molecules to the lowest T{sub 1} state with a rate of {approx}2.5 ps after a delayed onset of {approx}3.7 ps. Photolysis of benzoic acid using 267 nm excitation is dominated by the formation of the T{sub 1} excited state and no photofragments could be detected. The results from TR-IR experiments using higher energy of 193 nm indicate that photodissociation proceeds more rapidly than the vibrational energy transfer to solvents and C-C bond fission becomes the dominant relaxation pathway in these experiments as featured by the prominent observation of the COOH photofragments and negligible yield of the T{sub 1} excited state. The measured ultrafast formation of T{sub 1} excited state supports the existence of the surface intersections of S{sub 2}/S{sub 1}, S{sub 2}/T{sub 2}, and S{sub 1}/T{sub 1}/T{sub 2}, and the large T{sub 1} quantum yield of {approx}0.65 indicates the importance of the excited state depopulation to triplet manifold as the key factor affecting the photophysical and photochemical behavior of the monomeric benzoic acid.

Yang Chunfan; Su Hongmei [Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory of Molecular Reaction Dynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Sun Xuezhong; George, Michael W. [School of Chemistry, University of Nottingham, University Park NG7 2RD (United Kingdom)

2012-05-28T23:59:59.000Z

317

physics.illinois.edu The University of Illinois  

E-Print Network [OSTI]

.edu Illinois Physics REU Condensed matter physics Atomic & molecular optics Biophysics High Energy Physicsphysics.illinois.edu The University of Illinois Physics REU Program Kevin Pitts Department of Physics 13-Nov-13 1 http://physics.illinois.edu/undergrad/reu/ Contact/follow me! Email: kpitts@illinois

Ha, Taekjip

318

Reactor Physics  

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

Reactor Physics Reactor and nuclear physics is a key area of research at INL. Much of the research done in reactor physics can be separated into one of three categories:...

319

Frequency modulated few-cycle optical pulse trains induced controllable ultrafast coherent population oscillations in three-level atomic systems  

E-Print Network [OSTI]

We report a study on the ultrafast coherent population oscillations (UCPO) in two level atoms induced by the frequency modulated few-cycle optical pulse train. The phenomenon of UCPO is investigated by numerically solving the optical Bloch equations beyond the rotating wave approximation. We demonstrate that the quantum state of the atoms and the frequency of UCPO may be controlled by controlling the number of pulses in the pulse trains and the pulse repetition time respectively. Moreover, the robustness of the population inversion against the variation of the laser pulse parameters is also investigated. The proposed scheme may be useful for the creation of atoms in selected quantum state for desired time duration and may have potential applications in ultrafast optical switching.

Parvendra Kumar; Amarendra K. Sarma

2012-11-16T23:59:59.000Z

320

DEPARTMENT OF PHYSICS Physics 32300  

E-Print Network [OSTI]

DEPARTMENT OF PHYSICS Syllabus Physics 32300 Quantum Mechanics for Engineers Designation: required for Physics majors in the Applied Physics Option Undergraduate Catalog description: Basic experiments, wave: Physics 20700 and 20800, Math 39100 and Math 39200 Textbook and other suggested material: Scherrer

Lombardi, John R.

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


321

DEPARTMENT OF PHYSICS Physics 42200  

E-Print Network [OSTI]

DEPARTMENT OF PHYSICS Syllabus Physics 42200 Biophysics Designation: Undergraduate Catalog and membranes. In depth study of the physical basis of selected systems including vision, nerve transmission. Prerequisites: Prereq.: 1 yr. of Math, 1 yr. of Physics (elective for Physics Majors and Biomedical Engineering

Lombardi, John R.

322

650-nJ pulses from a cavity-dumped Yb:fiber-pumped ultrafast optical parametric oscillator  

E-Print Network [OSTI]

650-nJ pulses from a cavity-dumped Yb:fiber- pumped ultrafast optical parametric oscillator Tobias.p.lamour@hw.ac.uk Abstract: Sub-250-fs pulses with energies of up to 650 nJ and peak powers up to 2.07 MW were generated from a cavity-dumped optical parametric oscillator, synchronously-pumped at 15.3 MHz with sub-400-fs pulses from

323

Chirped-pulse manipulated carrier dynamics in low-temperature molecular-beam-epitaxy grown GaAs  

SciTech Connect (OSTI)

Chirped pulse controlled carrier dynamics in low-temperature molecular-beam-epitaxy grown GaAs are investigated by degenerate pump-probe technique. Varying the chirped condition of excited pulse from negative to positive increases the carrier relaxation time so as to modify the dispersion and reshape current pulse in time domain. The spectral dependence of carrier dynamics is analytically derived and explained by Shockley-Read Hall model. This observation enables the new feasibility of controlling carrier dynamics in ultrafast optical devices via the chirped pulse excitations.

Lee, Chao-Kuei, E-mail: chuckcklee@yahoo.com [Department of Photonics, National Sun-Yat-Sen University, Kaohsiung 80400, Taiwan (China); Lin, Yuan-Yao [Department of Electrical Engineering, Institute of Photonics Technologies, National Tsing Hua University, Hsinchu 30010, Taiwan (China); Lin, Sung-Hui [Department of Photonics, National Chiao Tung University, Hsinchu 30010, Taiwan (China); Lin, Gong-Ru [Department of Electrical Engineering, Graduate Institute of Photonics and Optoelectronics, National Taiwan University, No. 1, Roosevelt Road, Sec. 4, Taipei 10617, Taiwan (China); Pan, Ci-Ling [Department of Photonics, National Chiao Tung University, Hsinchu 30010, Taiwan (China); Department of Physics, National Tsing Hwa University, Hsinchu 30010, Taiwan (China)

2014-04-28T23:59:59.000Z

324

Industrial Affiliates Day 2006, April 21, 2006 ULTRAFAST NONLINEAR OPTICAL MICROSCOPY  

E-Print Network [OSTI]

of studies, including photochemical reactions, molecular dynamics, micropharmacology and optical memory. History of Two-Photon Molecular Excitation 1905 First Conception: A. Einstein: Creation and Conversion for data storage. Combined with fluorescence microscopy, multiphoton excitation (MPE) provides 3D

Van Stryland, Eric

325

DEPARTMENT OF PHYSICS Physics 35400  

E-Print Network [OSTI]

DEPARTMENT OF PHYSICS Syllabus Physics 35400 Electricity and Magnetism II Designation potentials and radiation, special relativity. 3 HR./WK.; 3 CR. Prerequisites: Prereq.: Physics 35300; pre- or coreq.: Math 39200 (required for Physics majors, except those in the Biomedical Option). Textbook

Lombardi, John R.

326

Ultrafast vectorial and scalar dynamics of ionic clusters: Azobenzene solvated by oxygen  

SciTech Connect (OSTI)

The ultrafast dynamics of clusters of trans-azobenzene anion (A{sup -}) solvated by oxygen molecules was investigated using femtosecond time-resolved photoelectron spectroscopy. The time scale for stripping off all oxygen molecules from A{sup -} was determined by monitoring in real time the transient of the A{sup -} rise, following an 800 nm excitation of A{sup -} (O{sub 2}){sub n}, where n=1-4. A careful analysis of the time-dependent photoelectron spectra strongly suggests that for n>1 a quasi-O{sub 4} core is formed and that the dissociation occurs by a bond cleavage between A{sup -} and conglomerated (O{sub 2}){sub n} rather than a stepwise evaporation of O{sub 2}. With time and energy resolutions, we were able to capture the photoelectron signatures of transient species which instantaneously rise (<100 fs) then decay. The transient species are assigned as charge-transfer complexes: A{center_dot}O{sub 2}{sup -} for A{sup -}O{sub 2} and A{center_dot}O{sub 4}{sup -}{center_dot}(O{sub 2}){sub n-2} for A{sup -}(O{sub 2}){sub n}, where n=2-4. Subsequent to an ultrafast electron recombination, A{sup -} rises with two distinct time scales: a subpicosecond component reflecting a direct bond rupture of the A{sup -}-(O{sub 2}){sub n} nuclear coordinate and a slower component (1.6-36 ps, increasing with n) attributed to an indirect channel exhibiting a quasistatistical behavior. The photodetachment transients exhibit a change in the transition dipole direction as a function of time delay. Rotational dephasing occurs on a time scale of 2-3 ps, with a change in the sign of the transient anisotropy between A{sup -}O{sub 2} and the larger clusters. This behavior is a key indicator of an evolving cluster structure and is successfully modeled by calculations based on the structures and inertial motion of the parent clusters.

Paik, D. Hern; Baskin, J. Spencer; Kim, Nam Joon; Zewail, Ahmed H. [Laboratory for Molecular Sciences, California Institute of Technology, Pasadena, California 91125 and Physical Biology Center for Ultrafast Science and Technology, California Institute of Technology, Pasadena, California 91125 (United States)

2006-10-07T23:59:59.000Z

327

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

SciTech Connect (OSTI)

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.

Zwier, Timothy

2012-07-20T23:59:59.000Z

328

Quantum physics meets biology  

E-Print Network [OSTI]

Quantum physics and biology have long been regarded as unrelated disciplines, describing nature at the inanimate microlevel on the one hand and living species on the other hand. Over the last decades the life sciences have succeeded in providing ever more and refined explanations of macroscopic phenomena that were based on an improved understanding of molecular structures and mechanisms. Simultaneously, quantum physics, originally rooted in a world view of quantum coherences, entanglement and other non-classical effects, has been heading towards systems of increasing complexity. The present perspective article shall serve as a pedestrian guide to the growing interconnections between the two fields. We recapitulate the generic and sometimes unintuitive characteristics of quantum physics and point to a number of applications in the life sciences. We discuss our criteria for a future quantum biology, its current status, recent experimental progress and also the restrictions that nature imposes on bold extrapolations of quantum theory to macroscopic phenomena.

Markus Arndt; Thomas Juffmann; Vlatko Vedral

2009-11-01T23:59:59.000Z

329

physics | EMSL  

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

physics physics Leads No leads are available at this time. 15N2 formation and fast oxygen isotope exchange during pulsed 15N18O exposure of MnOxCeO2. Abstract: Pulsing 15N18O onto...

330

HELIOS-K: An Ultrafast, Open-source Opacity Calculator for Radiative Transfer  

E-Print Network [OSTI]

We present an ultrafast opacity calculator for application to exoplanetary atmospheres, which we name HELIOS-K. It takes a line list as an input, computes the shape of each spectral line (e.g., a Voigt profile) and provides an option for grouping an enormous number of lines into a manageable number of bins. We implement a combination of Algorithm 916 and Gauss-Hermite quadrature to compute the Voigt profile, write the code in CUDA and optimise the computation for graphics processing units (GPUs). We use the k-distribution method to reduce $\\sim 10^5$ to $10^8$ lines to $\\sim 10$ to $10^4$ wavenumber bins, which may then be used for radiative transfer, atmospheric retrieval and general circulation models. We demonstrate that the resampling of the k-distribution function, within each bin, is an insignificant source of error across a broad range of wavenumbers and column masses. By contrast, the choice of line-wing cutoff for the Voigt profile is a significant source of error and affects the value of the compute...

Grimm, Simon L

2015-01-01T23:59:59.000Z

331

Ultrafast control of donor-bound electron spins with single detuned optical pulses  

E-Print Network [OSTI]

The ability to control spins in semiconductors is important in a variety of fields including spintronics and quantum information processing. Due to the potentially fast dephasing times of spins in the solid state [1-3], spin control operating on the picosecond or faster timescale may be necessary. Such speeds, which are not possible to attain with standard electron spin resonance (ESR) techniques based on microwave sources, can be attained with broadband optical pulses. One promising ultrafast technique utilizes single broadband pulses detuned from resonance in a three-level Lambda system [4]. This attractive technique is robust against optical pulse imperfections and does not require a fixed optical reference phase. Here we demonstrate the principle of coherent manipulation of spins theoretically and experimentally. Using this technique, donor-bound electron spin rotations with single-pulse areas exceeding pi/4 and two-pulses areas exceeding pi/2 are demonstrated. We believe the maximum pulse areas attained do not reflect a fundamental limit of the technique and larger pulse areas could be achieved in other material systems. This technique has applications from basic solid-state ESR spectroscopy to arbitrary single-qubit rotations [4, 5] and bang-bang control[6] for quantum computation.

Kai-Mei C. Fu; Susan M. Clark; Charles Santori; M. C. Holland; Colin R. Stanley; Yoshihisa Yamamoto

2008-06-25T23:59:59.000Z

332

Velocity measurements in the near field of a diesel fuel injector by ultrafast imagery  

E-Print Network [OSTI]

This paper examines the velocity profile of fuel issuing from a high-pressure single-orifice diesel injector. Velocities of liquid structures were determined from time-resolved ultrafast shadow images, formed by an amplified two-pulse laser source coupled to a double-frame camera. A statistical analysis of the data over many injection events was undertaken to map velocities related to spray formation near the nozzle outlet as a function of time after start of injection. These results reveal a strong asymmetry in the liquid profile of the test injector, with distinct fast and slow regions on opposite sides of the orifice. Differences of ~100 m/s can be observed between the 'fast' and 'slow' sides of the jet, resulting in different atomization conditions across the spray. On average, droplets are dispersed at a greater distance from the nozzle on the 'fast' side of the flow, and distinct macrostructure can be observed under the asymmetric velocity conditions. The changes in structural velocity and atomization b...

Sedarsky, David; Blaisot, Jean-Bernard; Rozé, Claude

2013-01-01T23:59:59.000Z

333

Electroweak Physics  

E-Print Network [OSTI]

Work on electroweak precision calculations and event generators for electroweak physics studies at current and future colliders is summarized.

W. Hollik

2005-01-26T23:59:59.000Z

334

Physics and Astronomy Department Strategic Plan March 1, 2011  

E-Print Network [OSTI]

Physics and Astronomy Department Strategic Plan March 1, 2011 Executive Summary The Department of Physics & Astronomy performs world-class research and provides state-of-the-art training for students in astronomy, astrophysics, and gravitational physics; atomic/molecular/optical physics, quantum optics

Harms, Kyle E.

335

May 2, 2014 Molecular Physics QCHEM4 To appear in Molecular Physics  

E-Print Network [OSTI]

`ele Laurentb,cm , Keith V. Lawlerc,cn , Sergey V. Levchenkob,co , Ching Yeh Lind , Fenglai Liua , Ester , Christopher F. Williamsg , Vitalii Vanovschib , Sine Yeganehw , Shane R. Yostc,w , Zhi-Qiang Youas,g , Igor. Chipmanag , Christopher J. Cramerab , William A. Goddard IIIah , Mark S. Gordonai , Warren J. Hehrey

Krylov, Anna I.

336

Solution Processed MoS2-PVA Composite for Sub-Bandgap Mode-Locking of a Wideband Tunable Ultrafast Er:Fiber Laser  

E-Print Network [OSTI]

with stable, picosecond pulses, tunable from 1535 nm to 1565 nm 2 Solution Processed MoS2-PVA Composite for Sub-Bandgap Mode-Locking of a Wideband Tunable Ultrafast Er:Fiber Laser Meng Zhang1, Richard C. T. Howe2, Robert I. Woodward1... ! to! relaxation! of! thermalized! electron! and!phonon! distribution! [3].! This! combination! of!properties!makes!MoS2!a!suitable!saturable!absorber!(SA)! for! ultrafast! mode+locked! pulsed! lasers,! with!the! potential! for! pulse! generation! at...

Zhang, Meng; Howe, Richard C. T.; Woodward, Robert I.; Kelleher, Edmund J. R.; Torrisi, Felice; Hu, Guohua; Popov, Sergei V.; Taylor, J. Roy; Hasan, Tawfique

2014-11-11T23:59:59.000Z

337

Physics PhD Mentors at CCNY, 2014 (Please also see faculty and staff profiles on the Physics website)  

E-Print Network [OSTI]

Physics PhD Mentors at CCNY, 2014 (Please also see faculty and staff profiles on the Physics molecular biological physics; electron and proton transfer reactions; solar energy Koder, Ronald koder@sci.ccny.c uny.edu http://web.sci.ccny.cuny.edu/~koder/koder.ht ml experimental biological physics; de novo #12

Lombardi, John R.

338

Electron diffraction using ultrafast electron bunches from a laser-wakefield accelerator at kHz repetition rate  

SciTech Connect (OSTI)

We show that electron bunches in the 50-100 keV range can be produced from a laser wakefield accelerator using 10 mJ, 35 fs laser pulses operating at 0.5 kHz. It is shown that using a solenoid magnetic lens, the electron bunch distribution can be shaped. The resulting transverse and longitudinal coherence is suitable for producing diffraction images from a polycrystalline 10 nm aluminum foil. The high repetition rate, the stability of the electron source, and the fact that its uncorrelated bunch duration is below 100 fs make this approach promising for the development of sub-100 fs ultrafast electron diffraction experiments.

He, Z.-H.; Thomas, A. G. R.; Nees, J. A.; Hou, B.; Krushelnick, K. [Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48106-2099 (United States)] [Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48106-2099 (United States); Beaurepaire, B.; Malka, V.; Faure, J. [Laboratoire d'Optique Appliquee, ENSTA-CNRS-Ecole Polytechnique, UMR 7639, 91761 Palaiseau (France)] [Laboratoire d'Optique Appliquee, ENSTA-CNRS-Ecole Polytechnique, UMR 7639, 91761 Palaiseau (France)

2013-02-11T23:59:59.000Z

339

Ultrafast and selective coherent population transfer in four-level atoms by a single frequency chirped few-cycle pulse  

E-Print Network [OSTI]

We report and propose a simple scheme to achieve the ultrafast and selective population transfer in four-level atoms by utilizing a single frequency chirped few-cycle pulse. It is demonstrated that the almost complete population may be transferred to the preselected state of atoms just by manipulating the so called chirp offset parameter. The robustness of the scheme against the variation of laser pulse parameters is also investigated. The proposed scheme may also be useful for the selective population transfer in molecules.

Parvendra Kumar; Amarendra K. Sarma

2013-03-01T23:59:59.000Z

340

Ultrafast and efficient coherence creation in ?-like atomic systems driven by nonlinearly chirped few-cycle pulses  

E-Print Network [OSTI]

We report an ultrafast and efficient way to create the maximum coherence between the two lower states in a -like atomic systems, driven by two nonlinearly chirped few-cycle pulses. The phenomenon of coherent population trapping and electromagnetically induced population transfer are investigated by solving the appropriate density matrix equations without invoking the rotating wave approximation. The robustness of the scheme for maximum coherence against the variation of the laser parameters are tested numerically. We also demonstrate that the proposed scheme could be used to obtain complete population transfer to an initially empty ground state.

Amarendra K. Sarma; Parvendra Kumar

2011-11-17T23:59:59.000Z

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


341

Molecular Foundry  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation InInformation InExplosion Monitoring:Home|Physics Research High-Energy- Density Go About

342

Modeling Molecular Dynamics from Simulations  

SciTech Connect (OSTI)

Many important processes in biology occur at the molecular scale. A detailed understanding of these processes can lead to significant advances in the medical and life sciences. For example, many diseases are caused by protein aggregation or misfolding. One approach to studying these systems is to use physically-based computational simulations to model the interactions and movement of the molecules. While molecular simulations are computationally expensive, it is now possible to simulate many independent molecular dynamics trajectories in a parallel fashion by using super- or distributed- computing methods such as Folding@Home or Blue Gene. The analysis of these large, high-dimensional data sets presents new computational challenges. In this seminar, I will discuss a novel approach to analyzing large ensembles of molecular dynamics trajectories to generate a compact model of the dynamics. This model groups conformations into discrete states and describes the dynamics as Markovian, or history-independent, transitions between the states. I will discuss why the Markovian state model (MSM) is suitable for macromolecular dynamics, and how it can be used to answer many interesting and relevant questions about the molecular system. I will also discuss many of the computational and statistical challenges in building such a model, such as how to appropriately cluster conformations, determine the statistical reliability, and efficiently design new simulations.

Hinrichs, Nina Singhal (University of Chicago) [University of Chicago

2009-01-28T23:59:59.000Z

343

Role of electron-electron interference in ultrafast time-resolved imaging of electronic wavepackets  

SciTech Connect (OSTI)

Ultrafast time-resolved x-ray scattering is an emerging approach to image the dynamical evolution of the electronic charge distribution during complex chemical and biological processes in real-space and real-time. Recently, the differences between semiclassical and quantum-electrodynamical (QED) theory of light-matter interaction for scattering of ultrashort x-ray pulses from the electronic wavepacket were formally demonstrated and visually illustrated by scattering patterns calculated for an electronic wavepacket in atomic hydrogen [G. Dixit, O. Vendrell, and R. Santra, Proc. Natl. Acad. Sci. U.S.A. 109, 11636 (2012)]. In this work, we present a detailed analysis of time-resolved x-ray scattering from a sample containing a mixture of non-stationary and stationary electrons within both the theories. In a many-electron system, the role of scattering interference between a non-stationary and several stationary electrons to the total scattering signal is investigated. In general, QED and semiclassical theory provide different results for the contribution from the scattering interference, which depends on the energy resolution of the detector and the x-ray pulse duration. The present findings are demonstrated by means of a numerical example of x-ray time-resolved imaging for an electronic wavepacket in helium. It is shown that the time-dependent scattering interference vanishes within semiclassical theory and the corresponding patterns are dominated by the scattering contribution from the time-independent interference, whereas the time-dependent scattering interference contribution do not vanish in the QED theory and the patterns are dominated by the scattering contribution from the non-stationary electron scattering.

Dixit, Gopal [Center for Free-Electron Laser Science, DESY, Notkestrasse 85, D-22607 Hamburg (Germany); Santra, Robin [Center for Free-Electron Laser Science, DESY, Notkestrasse 85, D-22607 Hamburg (Germany); Department of Physics, University of Hamburg, D-20355 Hamburg (Germany)

2013-04-07T23:59:59.000Z

344

Ultrafast heterogeneous electron transfer reactions: Comparative theoretical studies on time- and frequency-domain data  

SciTech Connect (OSTI)

Recent theoretical studies on linear absorption spectra of dye-semiconductor systems [perylene attached to nanostructured TiO{sub 2}, L. Wang et al., J. Phys. Chem. B 109, 9589 (2005)] are extended here in different respects. Since the systems show ultrafast photoinduced heterogeneous electron transfer the time-dependent formulation used to compute the absorbance is also applied to calculate the temporal evolution of the sub-100 fs charge injection dynamics after a 10 fs laser-pulse excitation. These studies complement our recent absorption spectra fit for two perylene bridge-anchor group TiO{sub 2} systems. Moreover, the time-dependent formulation of the absorbance is confronted with a frequency-domain description. The latter underlines the central importance of the self-energy caused by the coupling of the dye levels to the semiconductor band continuum. The used model is further applied to study the effect of different parameters such as (1) the dependence on the reorganization energies of the involved intramolecular transitions, (2) the effect of changing the transfer integral which couples the excited dye state with the band continuum, and (3) the effect of the concrete form of the semiconductor band density of states. Emphasis is also put on the case where the charge injection level of the dye is near or somewhat below the band edge. This nicely demonstrates the change from a structureless absorption to a well-resolved vibrational progression including characteristic shifts of the absorption lines which are a direct measure for the dye-semiconductor coupling.

Wang Luxia; Willig, Frank; May, Volkhard [Institut fuer Physik, Humboldt-Universitaet zu Berlin, Newtonstrasse 15, D-12489 Berlin (Germany); Hahn-Meitner-Institut, Abteilung Dynamik von Genzflaechenreaktionen, Glienicker Strasse 100, 14109 Berlin (Germany); Institut fuer Physik, Humboldt-Universitaet zu Berlin, Newtonstrasse 15, D-12489 Berlin (Germany)

2006-01-07T23:59:59.000Z

345

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

SciTech Connect (OSTI)

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.

Yazaki, Akio [Department of Electrical Engineering, University of California, Los Angeles, California 90095 (United States); Yokohama Research Laboratory, Hitachi, Ltd., Kanagawa 244-0817 (Japan); Kim, Chanju [Department of Electrical Engineering, University of California, Los Angeles, California 90095 (United States); Advanced Photonics Research Institute, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of); Chan, Jacky [Department of Electrical Engineering, University of California, Los Angeles, California 90095 (United States); Mahjoubfar, Ata [Department of Electrical Engineering, University of California, Los Angeles, California 90095 (United States); California NanoSystems Institute, University of California, Los Angeles, California 90095 (United States); Goda, Keisuke, E-mail: goda@chem.s.u-tokyo.ac.jp [Department of Electrical Engineering, University of California, Los Angeles, California 90095 (United States); Department of Chemistry, University of Tokyo, Tokyo 113-0033 (Japan); Watanabe, Masahiro [Yokohama Research Laboratory, Hitachi, Ltd., Kanagawa 244-0817 (Japan); Jalali, Bahram [Department of Electrical Engineering, University of California, Los Angeles, California 90095 (United States); California NanoSystems Institute, University of California, Los Angeles, California 90095 (United States); Department of Bioengineering, University of California, Los Angeles, California 90095 (United States); Department of Surgery, David Geffen School of Medicine, University of California, Los Angeles, California 90095 (United States)

2014-06-23T23:59:59.000Z

346

Physics Fellow  

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

as Institute of Physics Fellow January 18, 2011 LOS ALAMOS, New Mexico, January 18, 2011-Alan Bishop, Los Alamos National Laboratory's associate director for theory, simulation,...

347

Science Challenge Computational modeling of ultrafast digital electronics To understand how large electric fields, such as those from lightning strikes or electronic countermeasures,  

E-Print Network [OSTI]

properties in response to the needs of a particular device or situation. These smart electronics have the potential to lead to entirely new generations of electronic devices--such as military and civilian Science Challenge ­ Computational modeling of ultrafast digital electronics · To understand how

Freericks, Jim

348

Use of Ultrafast Dispersed Pump-Dump-Probe and Pump-Repump-Probe Spectroscopies to Explore the Light-Induced Dynamics of Peridinin in Solution  

E-Print Network [OSTI]

Use of Ultrafast Dispersed Pump-Dump-Probe and Pump-Repump-Probe Spectroscopies to Explore Form: NoVember 14, 2005 Optical pump-induced dynamics of the highly asymmetric carotenoid peridinin in methanol was studied by dispersed pump-probe, pump-dump-probe, and pump-repump-probe transient absorption

van Stokkum, Ivo

349

Ultrafast Infrared Heating Laser Pulse-Induced Micellization Kinetics of Poly(ethylene oxide)-Poly(propylene oxide)-Poly(ethylene oxide) in  

E-Print Network [OSTI]

Ultrafast Infrared Heating Laser Pulse-Induced Micellization Kinetics of Poly(ethylene oxide infrared heating laser pulse (10 ns)-induced temperature jump. The increases in the fluorescenceVersity of Hong Kong, Shatin N.T., Hong Kong ReceiVed June 4, 2007. In Final Form: July 7, 2007 The heating

Liu, Shilin

350

Non-Markovian response of ultrafast coherent electronic ring currents in chiral aromatic molecules in a condensed phase  

SciTech Connect (OSTI)

Results of a theoretical study on non-Markov response for femtosecond laser-driven coherent ring currents in chiral aromatic molecules embedded in a condensed phase are presented. Coherent ring currents are generated by coherent excitation of a pair of quasi-degenerated ?-electronic excited states. The coherent electronic dynamical behaviors are strongly influenced by interactions between the electronic system and phonon bath in a condensed phase. Here, the bath correlation time is not instantaneous but should be taken to be a finite time in ultrashort time-resolved experiments. In such a case, Markov approximation breaks down. A hierarchical master equation approach for an improved semiclassical Drude dissipation model was adopted to examine the non-Markov effects on ultrafast coherent electronic ring currents of (P)-2,2{sup ?}-biphenol in a condensed phase. Time evolution of the coherent ring current derived in the hierarchical master equation approach was calculated and compared with those in the Drude model in the Markov approximation and in the static limit. The results show how non-Markovian behaviors in quantum beat signals of ring currents depend on the Drude bath damping constant. Effects of temperatures on ultrafast coherent electronic ring currents are also clarified.

Mineo, H. [Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan (China)] [Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan (China); Lin, S. H. [Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan (China) [Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan (China); Department of Applied Chemistry, Institute of Molecular Science and Center for Interdisciplinary Molecular Science, National Chiao-Tung University, Hsin-Chu 300, Taiwan (China); Fujimura, Y. [Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan (China) [Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan (China); Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578 (Japan); Xu, J. [Department of Chemistry, Nankai University, Tianjin 300071 (China) [Department of Chemistry, Nankai University, Tianjin 300071 (China); Department of Chemistry, Hong Kong University of Science and Technology, Kowloon (Hong Kong); Xu, R. X. [Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China)] [Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China); Yan, Y. J. [Department of Chemistry, Hong Kong University of Science and Technology, Kowloon (Hong Kong) [Department of Chemistry, Hong Kong University of Science and Technology, Kowloon (Hong Kong); Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China)

2013-12-07T23:59:59.000Z

351

Transition from ultrafast laser photo-electron emission to space charge limited current in a 1D gap  

E-Print Network [OSTI]

A one-dimensional (1D) model has been constructed to study the transition of the time-dependent ultrafast laser photo-electron emission from a flat metallic surface to the space charge limited (SCL) current, including the effect of non-equilibrium laser heating on metals at the ultrafast time scale. At a high laser field, it is found that the space charge effect cannot be ignored and the SCL current emission is reached at a lower value predicted by a short pulse SCL current model that assumed a time-independent emission process. The threshold of the laser field to reach the SCL regime is determined over a wide range of operating parameters. The calculated results agree well with particle-in-cell (PIC) simulation. It is found that the space charge effect is more important for materials with lower work function like tungsten (4.4 eV) as compared to gold (5.4 eV). However for a flat surface, both materials will reach the space charge limited regime at the sufficiently high laser field such as $>$ 5 GV/m with a laser pulse length of tens to one hundred femtoseconds.

Yangjie Liu; L. K. Ang

2014-08-21T23:59:59.000Z

352

Decoding Photosynthesis' Molecular Mysteries  

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

Decoding Photosynthesis' Molecular Mysteries Decoding the Molecular Mysteries of Photosynthesis Understanding the inner workings of photosynthesis is key to building new man-made...

353

Physics & Astronomy Degree options  

E-Print Network [OSTI]

148 Physics & Astronomy Degree options BSc (Single Honours Degrees) Astrophysics Physics MPhys (Single Honours Degrees) Astrophysics Physics Theoretical Physics BSc (Joint Honours Degrees) Physics) Theoretical Physics and Mathematics MSci (Joint Honours Degree) Physics and Chemistry Entrance Requirements

Brierley, Andrew

354

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

SciTech Connect (OSTI)

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.

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

1994-08-01T23:59:59.000Z

355

Molecular weight and molecular weight distribution of kraft lignins  

SciTech Connect (OSTI)

Kraft lignins are the lignin degradation products from kraft pulping. They are complex, heterogeneous polymers with some polar character. The molecular weight of kraft lignins greatly affect the physical properties of black liquors, and are of primary importance in separation from black liquor and in evaluating potential uses. Several purified kraft lignins from slash pine were analyzed for number average molecular weight by vapor pressure osmometry (VPO), for weight average molecular weight by low angle laser light scattering (LALLS), and for the molecular weight distribution by high temperature size exclusion chromatography (SEC). The lignins were run in tetrahydrofuran (THF), N,N-dimethyl formamide (DMF), DMF with 0.1M LiBr, and pyridine at conditions above the Theta temperature. Experimental methods are discussed. The results show that VPO may be used to determine M[sub n] for kraft lignins if the purity of the lignins and the identity of the impurities are known. LALLS can be used to determine M[sub w] for kraft lignins if measurements are made at or above the Theta temperature of the lignin-solvent pair. SEC should be used at temperatures at, or above, the Theta temperature of the lignin-solvent pair. Size separation is highly dependent on the solvent used, and DMF is a much better solvent than THF for high temperature SEC. Future work using moment resolution procedures to derive an accurate calibration curve are also discussed.

Schmidl, W.; Dong, D.; Fricke, A.L. (Univ. of Florida, Gainesville, FL (United States))

1990-01-01T23:59:59.000Z

356

Symposium on molecular and cellular mechanisms of mutagenesis  

SciTech Connect (OSTI)

These proceedings contain abstracts only of the 21 papers presented at the Sympsoium. The papers dealt with molecular mechanisms of mutagenesis and cellular responses to chemical and physical mutagenic agents. (ERB)

Not Available

1981-01-01T23:59:59.000Z

357

accurate dynamic molecular: Topics by E-print Network  

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

18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 How accurate is molecular dynamics? Mathematical Physics (arXiv) Summary: Born-Oppenheimer dynamics is shown to provide...

358

EMSL - physics  

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

physics en 15N2 formation and fast oxygen isotope exchange during pulsed 15N18O exposure of MnOxCeO2. http:www.emsl.pnl.govemslwebpublications15n2-formation-and-fast-oxygen-i...

359

Physical Scientist  

Broader source: Energy.gov [DOE]

A successful candidate in this position will serve as the Senior Headquarters (HQ) Physical Scientist for the Carbon Storage Program. The Carbon Storage Program focuses on the development of...

360

Theoretical Physics  

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

a hierarchy problem? Are there new physical principles at the TeV scale? Is the Higgs boson a fundamental particle or composite, like a pion? What is the final state of...

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


361

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...

362

PREPRINT submitted to Journal of Physics B Electronic structure of the Magnesium hydride  

E-Print Network [OSTI]

PREPRINT submitted to Journal of Physics B Electronic structure of the Magnesium hydride molecular: 31.15.AR,31.15.Ct,31.50.Be,31.50.Df #12; Electronic structure of the Magnesium hydride molecular ion

Recanati, Catherine

363

Physics Based on Physical Monism  

E-Print Network [OSTI]

Based on a physical monism, which holds that the matter and space are classified by not a difference of their kind but a difference of magnitude of their density, I derive the most fundamental equation of motion, which is capable of providing a deeper physical understanding than the known physics. For example, this equation answers to the substantive reason of movement, and Newton's second law, which has been regarded as the definition of force, is derived in a substantive level from this equation. Further, the relativistic energy-mass formula is generalized to include the potential energy term, and the Lorentz force and Maxwell equations are newly derived.

Seong-Dong Kim

2005-09-08T23:59:59.000Z

364

Molecular Dynamics Simulations of Supported Pt Nanoclusters  

E-Print Network [OSTI]

¤Introduction and Background ¤Constructing a Physical Model ¤Details of the Simulation ¤Results and Conclusions · Petroleum reformation · Gasification of biomass for biofuels #12;Previous Investigation of NanoclustersMolecular Dynamics Simulations of Supported Pt Nanoclusters Jeffrey Moore #12;A Brief Outline

Washington at Seattle, University of - Department of Physics, Electroweak Interaction Research Group

365

Hypersonic Molecular Shocks in Star Forming Regions  

E-Print Network [OSTI]

Much emission from star forming regions is from shock-excited gas. Shocks in molecular clouds are still not fully understood, as magnetic fields, dust and chemistry all play significant roles. I review the history, physics and current work in understanding these shocks, and in their possible use as diagnostics of local conditions.

Brand, P W J L

2006-01-01T23:59:59.000Z

366

Hypersonic Molecular Shocks in Star Forming Regions  

E-Print Network [OSTI]

Much emission from star forming regions is from shock-excited gas. Shocks in molecular clouds are still not fully understood, as magnetic fields, dust and chemistry all play significant roles. I review the history, physics and current work in understanding these shocks, and in their possible use as diagnostics of local conditions.

Peter W. J. L. Brand

2006-09-08T23:59:59.000Z

367

REVIEW OF PARTICLE PHYSICS  

E-Print Network [OSTI]

ONLINE PARTICLE PHYSICS INFORMATION 1.3. Particle Physics Information Platforms . . . . . . . . .14. Particle Physics Education and Outreach

Beringer, Juerg

2013-01-01T23:59:59.000Z

368

Review of Particle Physics  

E-Print Network [OSTI]

11. Particle Physics Education Sites . . . . . . . . .ONLINE PARTICLE PHYSICS INFORMATION 1.11. Particle Physics Education Sites . . . . . . . . . . 12.

Nakamura, Kenzo

2010-01-01T23:59:59.000Z

369

Characterization and light-induced dynamics of alkanethiol-capped gold nanoparticles supracrystals by small-angle ultrafast electron diffraction  

E-Print Network [OSTI]

Metal nanoparticles (NPs) are promising candidates for applications from electronics to medicine. Their metallic core provides some key properties, e.g. magnetization, plasmonic response or conductivity, with the ligand molecules providing others like solubility, assembly or interaction with biomolecules. Even more properties can be engineered when these NPs are used as building blocks to form supracrystals. The formation of these supracrystals depends upon a complex interplay between many forces, some stemming from the core, some from the ligand. At present, there is no known approach to characterize the local order of ligand molecules in such complex supracrystals or their dynamics, with a spatial resolution ranging from the NPs cores and their ligands, to the larger scale domains arrangement. Here, we develop a methodology based on small-angle ultrafast electron diffraction to characterize different two-dimensional supracrystals of alkanethiol-coated gold nanoparticles with femtosecond time, sub-nanometer ...

Mancini, Giulia Fulvia; Pennacchio, Francesco; Reguera, Javier; Stellacci, Francesco; Carbone, Fabrizio

2015-01-01T23:59:59.000Z

370

Role of surface states and defects in the ultrafast nonlinear optical properties of CuS quantum dots  

SciTech Connect (OSTI)

We report facile preparation of water dispersible CuS quantum dots (2–4 nm) and nanoparticles (5–11 nm) through a nontoxic, green, one-pot synthesis method. Optical and microstructural studies indicate the presence of surface states and defects (dislocations, stacking faults, and twins) in the quantum dots. The smaller crystallite size and quantum dot formation have significant effects on the high energy excitonic and low energy plasmonic absorption bands. Effective two-photon absorption coefficients measured using 100 fs laser pulses employing open-aperture Z-scan in the plasmonic region of 800 nm reveal that CuS quantum dots are better ultrafast optical limiters compared to CuS nanoparticles.

Mary, K. A. Ann; Unnikrishnan, N. V., E-mail: nvu100@yahoo.com [School of Pure and Applied Physics, Mahatma Gandhi University, Kottayam 686560 (India); Philip, Reji [Light and Matter Physics Group, Raman Research Institute, C.V. Raman Avenue, Sadashivanagar, Bangalore 560080 (India)

2014-07-01T23:59:59.000Z

371

Ultrafast single-electron transfer in coupled quantum dots driven by a few-cycle chirped pulse  

SciTech Connect (OSTI)

We theoretically study the ultrafast transfer of a single electron between the ground states of a coupled double quantum dot (QD) structure driven by a nonlinear chirped few-cycle laser pulse. A time-dependent Schrödinger equation without the rotating wave approximation is solved numerically. We demonstrate numerically the possibility to have a complete transfer of a single electron by choosing appropriate values of chirped rate parameters and the intensity of the pulse. Even in the presence of the spontaneous emission and dephasing processes of the QD system, high-efficiency coherent transfer of a single electron can be obtained in a wide range of the pulse parameters. Our results illustrate the potential to utilize few-cycle pulses for the excitation in coupled quantum dot systems through the nonlinear chirp parameter control, as well as a guidance in the design of experimental implementation.

Yang, Wen-Xing, E-mail: wenxingyang2@126.com [Department of Physics, Southeast University, Nanjing 210096 (China); Institute of Photonics Technologies, National Tsing-Hua University, Hsinchu 300, Taiwan (China); Chen, Ai-Xi [Department of Applied Physics, School of Basic Science, East China Jiaotong University, Nanchang 330013 (China); Bai, Yanfeng [Department of Physics, Southeast University, Nanjing 210096 (China); Lee, Ray-Kuang [Institute of Photonics Technologies, National Tsing-Hua University, Hsinchu 300, Taiwan (China)

2014-04-14T23:59:59.000Z

372

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

SciTech Connect (OSTI)

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.

Hamad, Syed [School of Physics, University of Hyderabad, Prof. C. R. Rao Road, Hyderabad 500046 (India); Podagatlapalli, G. Krishna; Soma, Venugopal Rao, E-mail: svrsp@uohyd.ernet.in, E-mail: soma-venu@yahoo.com [Advanced Center of Research in High Energy Materials (ACRHEM), University of Hyderabad, Prof. C. R. Rao Road, Hyderabad 500046 (India); Mohiddon, Md. Ahamad [Center for Nanotechnology, University of Hyderabad, Prof. C. R. Rao Road, Hyderabad 500046 (India)

2014-06-30T23:59:59.000Z

373

Electron-ion relaxation time dependent signal enhancement in ultrafast double-pulse laser-induced breakdown spectroscopy  

SciTech Connect (OSTI)

We investigated the emission properties of collinear double-pulse compared to single-pulse ultrafast laser induced breakdown spectroscopy. Our results showed that the significant signal enhancement noticed in the double pulse scheme is strongly correlated to the characteristic electron-ion relaxation time and hence to the inter-pulse delays. Spectroscopic excitation temperature analysis showed that the improvement in signal enhancement is caused by the delayed pulse efficient reheating of the pre-plume. The signal enhancement is also found to be related to the upper excitation energy of the selected lines, i.e., more enhancement noticed for lines originating from higher excitation energy levels, indicating reheating is the major mechanism behind the signal improvement.

Harilal, S. S.; Diwakar, P. K.; Hassanein, A. [Center for Materials Under Extreme Environment, School of Nuclear Engineering, Purdue University, West Lafayette, Indiana 47907 (United States)] [Center for Materials Under Extreme Environment, School of Nuclear Engineering, Purdue University, West Lafayette, Indiana 47907 (United States)

2013-07-22T23:59:59.000Z

374

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

SciTech Connect (OSTI)

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.

Fu, Feichao; Liu, Shengguang; Zhu, Pengfei; Xiang, Dao, E-mail: dxiang@sjtu.edu.cn; Zhang, Jie, E-mail: jzhang1@sjtu.edu.cn [Key Laboratory for Laser Plasmas (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Cao, Jianming [Department of Physics and National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310 (United States)

2014-08-15T23:59:59.000Z

375

A table-top, repetitive pulsed magnet for nonlinear and ultrafast spectroscopy in high magnetic fields up to 30 T  

SciTech Connect (OSTI)

We have developed a mini-coil pulsed magnet system with direct optical access, ideally suited for nonlinear and ultrafast spectroscopy studies of materials in high magnetic fields up to 30 T. The apparatus consists of a small coil in a liquid nitrogen cryostat coupled with a helium flow cryostat to provide sample temperatures down to below 10 K. Direct optical access to the sample is achieved with the use of easily interchangeable windows separated by a short distance of ?135 mm on either side of the coupled cryostats with numerical apertures of 0.20 and 0.03 for measurements employing the Faraday geometry. As a demonstration, we performed time-resolved and time-integrated photoluminescence measurements as well as transmission measurements on InGaAs quantum wells.

Noe, G. Timothy; Lee, Joseph; Woods, Gary L. [Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005 (United States)] [Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005 (United States); Nojiri, Hiroyuki [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan)] [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Léotin, Jean [Laboratoire National des Champs Magnétiques Intenses, CNRS-UJF-UPS-INSA, Toulouse (France)] [Laboratoire National des Champs Magnétiques Intenses, CNRS-UJF-UPS-INSA, Toulouse (France); Kono, Junichiro, E-mail: kono@rice.edu [Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005 (United States) [Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005 (United States); Department of Physics and Astronomy, Rice University, Houston, Texas 77005, USA and Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005 (United States)

2013-12-15T23:59:59.000Z

376

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

DOE Patents [OSTI]

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.

Heebner, John E. (Livermore, CA)

2010-08-03T23:59:59.000Z

377

Planetary Physics  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation Desert Southwest RegionatSearch Welcome to theNews & Blog »Physics PhysicsWeek »

378

Plasma Physics  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation Desert Southwest RegionatSearch Welcome to theNews & Blog »Physics PhysicsWeekPlasma

379

Physical Protection  

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

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.

2009-07-23T23:59:59.000Z

380

Epsilon-Near-Zero Al-Doped ZnO for Ultrafast Switching at Telecom Wavelengths: Outpacing the Traditional Amplitude-Bandwidth Trade-Off  

E-Print Network [OSTI]

Transparent conducting oxides have recently gained great attention as CMOS-compatible materials for applications in nanophotonics due to their low optical loss, metal-like behavior, versatile/tailorable optical properties, and established fabrication procedures. In particular, aluminum doped zinc oxide (AZO) is very attractive because its dielectric permittivity can be engineered over a broad range in the near infrared and infrared. However, despite all these beneficial features, the slow (> 100 ps) electron-hole recombination time typical of these compounds still represents a fundamental limitation impeding ultrafast optical modulation. Here we report the first epsilon-near-zero AZO thin films which simultaneously exhibit ultra-fast carrier dynamics (excitation and recombination time below 1 ps) and an outstanding reflectance modulation up to 40% for very low pump fluence levels (< 4 mJ/cm2) at the telecom wavelength of 1.3 {\\mu}m. The unique properties of the demonstrated AZO thin films are the result of...

Kinsey, N; Kim, J; Ferrera, M; Shalaev, V M; Boltasseva, A

2015-01-01T23:59:59.000Z

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


381

Repetition of the shape of the ultrafast self-modulation of the optical absorption spectrum upon varying the energy of pulse of GaAs pumping  

SciTech Connect (OSTI)

Ultrafast self-modulation of the fundamental optical absorption emerges during intense picosecond optical pumping of GaAs and, according to the main assumption, reflects self-oscillations of depletion of electron populations in the conduction band. In this study, the quantitatively confirmed explanation of previously experimentally found cyclic repetition of the form of ultrafast self-modulation of the absorption spectrum upon varying the energy of the pumping pulse and fixed delay between pumping and probing (the measurement of absorption) is given. Repetition of the shape is explained by varying the phase of self-oscillations of the optical absorption. The explanation is based on the previously found experimentally dependence of the frequency of self-oscillations of absorption on the pumping energy. Therefore, this is also a new confirmation of the mentioned dependence (which satisfactorily coincides with a similar calculated dependence of the frequency of self-oscillations of depletion of populations).

Ageeva, N. N.; Bronevoi, I. L., E-mail: bil@cplire.ru; Zabegaev, D. N.; Krivonosov, A. N. [Russian Academy of Sciences, Kotel'nikov Institute of Radio Engineering and Electronics (Russian Federation)

2010-10-15T23:59:59.000Z

382

Low-Temperature Ultrafast Mobility in Systems with Long-Range Repulsive Interactions: M. Hupalo,1  

E-Print Network [OSTI]

and that this is one of the best realizations of an outstanding prediction in theoretical physics, i.e., the ``devil's staircase'' (DS) [1]. As predicted 25 years ago in systems with long-range (LR) repulsive interactions

Zaluska-Kotur, Magdalena

383

Molecular information ratchets   

E-Print Network [OSTI]

In the emerging aield of molecular machines, a molecular ratchet is a chemical system that allows the positional displacement of a submolecular component of be captured and directionally relea ...

Wilson, Adam Christopher

2012-11-28T23:59:59.000Z

384

The effect of cluster formation on mass separation in binary molecular beams  

E-Print Network [OSTI]

The effect of cluster formation on mass separation in binary molecular beams Wei Li,a) M. J composition of a skimmed supersonic binary molecular beam originally consisting of a 20% neon/80% xenon. © 2000 American Institute of Physics. S0021-9606 00 01806-7 I. INTRODUCTION Supersonic molecular beam

Sibener, Steven

385

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

SciTech Connect (OSTI)

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.

Poelakker, K. (ed.)

1990-12-01T23:59:59.000Z

386

JOURNAL OF COMPUTATIONAL PHYSICS 132, 157166 (1997) ARTICLE NO. CP965604  

E-Print Network [OSTI]

JOURNAL OF COMPUTATIONAL PHYSICS 132, 157­166 (1997) ARTICLE NO. CP965604 A Generalized Particle). Then, if xp j there exists one and only one point tion in plasma physics, astrophysics, and molecular

Frey, Pascal

387

Experiments in Physics Physics 1291  

E-Print Network [OSTI]

of the Laboratory The laboratory experiments described in this manual are an important part of your physics course-3 Velocity, Acceleration, and g 35 1-4 Projectile Motion and Conservation of Energy 45 1-5 Conservation. Whenever possible, the material will have been discussed in lecture before you come to the laboratory

Columbia University

388

Experiments in Physics Physics 1291  

E-Print Network [OSTI]

and Conservation of Energy 97 1-9 Standing Waves 105 1-10 Specific Heat and Mechanical Equivalent of Heat 115 #12;#12;Introduction 1-0 General Instructions 1 Purpose of the Laboratory The laboratory experiments described in this manual are an important part of your physics course. Most of the experiments are designed to illustrate

Columbia University

389

Experiments in Physics Physics 1291  

E-Print Network [OSTI]

The laboratory experiments described in this manual are an important part of your physics course. Most-8 Projectile Motion and Conservation of Energy 97 1-9 Standing Waves 105 1-10 Specific Heat and Mechanical Equivalent of Heat 115 #12;#12;Introduction 1-0 General Instructions 1 Purpose of the Laboratory

Columbia University

390

Capturing inhomogeneous broadening of the -CN stretch vibration in a Langmuir monolayer with high-resolution spectra and ultrafast vibrational dynamics in sum-frequency generation vibrational spectroscopy (SFG-VS)  

SciTech Connect (OSTI)

Even though in principle the frequency-domain and time-domain spectroscopic measurement should generate identical information for a given molecular system, inhomogeneous character of surface vibrations in the sum-frequency generation vibrational spectroscopy (SFG-VS) studies has only been studied with the time-domain SFGVS by mapping the decay of the vibrational polarization using ultrafast lasers, due to the lack of SFG vibrational spectra with high enough spectral resolution and accurate enough line shape. Here with recently developed high-resolution broadband SFG-VS (HR-BB-SFG-VS) we show that the inhomogeneous line shape can be obtained in the frequency-domain, for the anchoring CN stretch of the 4-n-octyl-4'-cyanobiphenyl (8CB) Langmuir monolayer at the air-water interface, and that an excellent agreement with the time-domain SFG free-induction-decay (FID) results can be established. We found that the 8CB CN stretch spectrum consists of a single peak centered at 2234.00 + * 0.01 cm-1 with a total line width of 10.9 + - 0.3 cm-1 at half maximum. The Lorentzian contribution accounts only for 4:7 + -0:4 cm-1 to this width and the Gaussian (inhomogeneous) broadening for as much as 8:1+*0:2 cm-1. Polarization analysis of the -CN spectra showed that the -CN group is tilted 57 + - 2 degrees from the surface normal. The large heterogeneity in the -CN spectrum is tentatively attributed to the -CN group interactions with the interfacial water molecules penetrated/accomodated into the 8CB monolayer, a unique phenomenon for the nCB Langmuir monolayers reported previously.

Velarde Ruiz Esparza, Luis A.; Wang, Hongfei

2013-08-28T23:59:59.000Z

391

Hypernuclear physics  

SciTech Connect (OSTI)

A brief overview of progress made in the study of hypernuclear physics is presented. The use of ..lambda..-hypernuclei to study properties of conventional (nonstrange) nuclei is explored. Our knowledge of the hyperon-nucleon force is reviewed. Anecdotal examples of interesting hypernuclear phenomena are discussed. The status of ..sigma..-hypernuclei is considered along with a search for the ''H'' dibaryon. 30 refs., 10 figs.

Gibson, B.F.

1987-01-01T23:59:59.000Z

392

Physical Protection  

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

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.

2005-08-26T23:59:59.000Z

393

Physical Protection  

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

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

2005-08-26T23:59:59.000Z

394

Ultrafast Photooxidation of Mn(II)-Terpyridine Complexes Covalently Attached to TiO2 Nanoparticles  

E-Print Network [OSTI]

-energy conversion by dye-sensitized solar cells,1,2 photocatalysis,3-6 and molecular electronics.7,8 Most previous-cost, high-efficiency solar cell based on Ru-dye sensitization of colloidal TiO2 films.1 Presently, the most studies have been focused on TiO2 nanoparticles sensitized with Ru dyes,9,10 although IET in other

395

Molecular Hydrogen Emission from Protoplanetary Disks  

E-Print Network [OSTI]

We have modeled self-consistently the density and temperature profiles of gas and dust in protoplanetary disks, taking into account irradiation from a central star. Making use of this physical structure, we have calculated the level populations of molecular hydrogen and the line emission from the disks. As a result, we can reproduce the observed strong line spectra of molecular hydrogen from protoplanetary disks, both in the ultraviolet (UV) and the near-infrared, but only if the central star has a strong UV excess radiation.

H. Nomura; T. J. Millar

2005-05-06T23:59:59.000Z

396

Molecular electrostatic potentials by systematic molecular fragmentation  

SciTech Connect (OSTI)

A simple method is presented for estimating the molecular electrostatic potential in and around molecules using systematic molecular fragmentation. This approach estimates the potential directly from the electron density. The accuracy of the method is established for a set of organic molecules and ions. The utility of the approach is demonstrated by estimating the binding energy of a water molecule in an internal cavity in the protein ubiquitin.

Reid, David M.; Collins, Michael A. [Research School of Chemistry, Australian National University, Canberra, ACT 0200 (Australia)] [Research School of Chemistry, Australian National University, Canberra, ACT 0200 (Australia)

2013-11-14T23:59:59.000Z

397

Physics and Astronomy Engineering/Physics Concentration  

E-Print Network [OSTI]

Physics and Astronomy Engineering/Physics Concentration Strongly recommended courses Credits Term Electromagnetic Fields & Waves 3 PHY 3230 Thermal Physics 3 PHY 4020 Computational Methods in Physics.) taken Grade PHY 4620 Optics 4 PHY 3211 Modern Physics II 3 PHY 4730 Analog Circuits 3 PHY 4640 Quantum

Thaxton, Christopher S.

398

Physics and Astronomy Radiation Safety Physics Concentration  

E-Print Network [OSTI]

Physics and Astronomy Radiation Safety Physics Concentration Strongly recommended courses Credits Environucleonics Lab 1 PHY 3211 Modern Physics II 3 PHY 3230 Thermal Physics 3 PHY 4330 Digital Electronics 3 PHY 4820 Medical Physics 3 CHE 1101 Intro. Chemistry I 3 CHE 1110 Intro. Chemistry I Lab 1 CHE 1102 Intro

Thaxton, Christopher S.

399

PHYSICS OF BURNING PHYSICS INACCESSIBLE TO  

E-Print Network [OSTI]

PHYSICS OF BURNING PLASMAS: PHYSICS INACCESSIBLE TO PRESENT FACILITIES FIRE Physics Workshop May 2000 F. Perkins and N. Sauthoff Princeton Plasma Physics Laboratory FIRE Workshop 1 May 2000 #12;OUTLINE · Introduction · Three Classes of Burning Plasma Physics inaccessable to contemporary tokamak

400

Department of Physics Department of Physics  

E-Print Network [OSTI]

Department of Physics Department of Physics Life Sciences Building 3101 S. Dearborn St. Chicago, IL 60616 312.567.3480 www.iit.edu/csl/physics Chair: Grant Bunder The Department of Physics offers B.S., M.S., and Ph.D. degrees in physics. Within the department, there are many opportunities for interdisciplinary

Heller, Barbara

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


401

314 Department of Physics Department of Physics  

E-Print Network [OSTI]

314 Department of Physics Department of Physics Physics, one of the basic sciences, has its origin led to the detailed understanding of a remarkable variety of physical phenomena. Our knowledge now comprehension of the physical world forms an impressive part of the intellectual and cultural heritage of our

Nagle, John F.

402

Physics (Phys) (Department of Physics and Engineering)  

E-Print Network [OSTI]

229Physics Physics (Phys) (Department of Physics and Engineering) McCormick Foundation PROFESSORSILU INSTRUCTOR CUMMING VISITING PROFESSOR BOLLER MAJORS A major in physics leading to a Bachelor of Science degree requires completion of 50 credits including the following: 1. Physics 111, 112, 113, 114, 210, 215

Dresden, Gregory

403

Department of Physics Department of Physics  

E-Print Network [OSTI]

Department of Physics Department of Physics Life Sciences Building 3101 S. Dearborn St. Chicago, IL 60616 312.567.3480 www.iit.edu/csl/physics Chair: Christopher White The Department of Physics offers B.S., M.S., and Ph.D. degrees in physics. Within the department, there are many opportunities

Heller, Barbara

404

Hadron physics  

SciTech Connect (OSTI)

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.

Bunce, G.

1984-05-30T23:59:59.000Z

405

Nuclear Physics  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas Conchas recoveryLaboratory | NationalJohnSecurityControls |Navy Nuclear NavyNuclear Physics

406

January 2010 Physics 3300  

E-Print Network [OSTI]

1 January 2010 Physics 3300 Introduction to Physical Oceanography Instructor: Brad de Young Physics and Physical Oceanography Memorial University, bdeyoung@mun.ca Room C-3000 737-8738 Physics 3300 Introduction to Physical Oceanography deals with the physics of the processes in the ocean, providing an integrating view

deYoung, Brad

407

Computational Physics on Graphics Processing Units  

E-Print Network [OSTI]

The use of graphics processing units for scientific computations is an emerging strategy that can significantly speed up various different algorithms. In this review, we discuss advances made in the field of computational physics, focusing on classical molecular dynamics, and on quantum simulations for electronic structure calculations using the density functional theory, wave function techniques, and quantum field theory.

Ari Harju; Topi Siro; Filippo Federici-Canova; Samuli Hakala; Teemu Rantalaiho

2013-03-06T23:59:59.000Z

408

Particle Physics Booklet 2008  

E-Print Network [OSTI]

212 25. Accelerator physics of colliders ? 26. High-energythe full Review. PARTICLE PHYSICS BOOKLET TABLE OF CONTENTSrev. ) Summary Tables of Particle Physics Gauge and Higgs

et al., C. Amsler

2008-01-01T23:59:59.000Z

409

Center for Beam Physics  

E-Print Network [OSTI]

for Heavy Ion Fusion," Research Trends in Physics, La JollaInternational School of Physics, New York, New York (1992),Professor and Chairman Physics Department University of

Chattopadhyay, S.

2010-01-01T23:59:59.000Z

410

A simple electron time-of-flight spectrometer for ultrafast vacuum ultraviolet photoelectron spectroscopy of liquid solutions  

SciTech Connect (OSTI)

We present a simple electron time of flight spectrometer for time resolved photoelectron spectroscopy of liquid samples using a vacuum ultraviolet (VUV) source produced by high-harmonic generation. The field free spectrometer coupled with the time-preserving monochromator for the VUV at the Artemis facility of the Rutherford Appleton Laboratory achieves an energy resolution of 0.65 eV at 40 eV with a sub 100 fs temporal resolution. A key feature of the design is a differentially pumped drift tube allowing a microliquid jet to be aligned and started at ambient atmosphere while preserving a pressure of 10{sup ?1} mbar at the micro channel plate detector. The pumping requirements for photoelectron (PE) spectroscopy in vacuum are presented, while the instrument performance is demonstrated with PE spectra of salt solutions in water. The capability of the instrument for time resolved measurements is demonstrated by observing the ultrafast (50 fs) vibrational excitation of water leading to temporary proton transfer.

Arrell, C. A., E-mail: christopher.arrell@epfl.ch; Ojeda, J.; Mourik, F. van; Chergui, M. [Laboratory of Ultrafast Spectroscopy, ISIC, Station 6, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne (Switzerland); Sabbar, M.; Gallmann, L.; Keller, U. [Physics Department, ETH Zurich, 8093 Zurich (Switzerland); Okell, W. A.; Witting, T.; Siegel, T.; Diveki, Z.; Hutchinson, S.; Tisch, J. W.G.; Marangos, J. P. [Department of Physics, The Blackett Laboratory, Imperial College, London SW7 2AZ (United Kingdom); Chapman, R. T.; Cacho, C.; Rodrigues, N.; Turcu, I. C.E.; Springate, E. [Central Laser Facility, STFC Rutherford Appleton Laboratory, Oxon OX11 0QX (United Kingdom)

2014-10-15T23:59:59.000Z

411

In-situ weak-beam and polarization control of multidimensional laser sidebands for ultrafast optical switching  

SciTech Connect (OSTI)

All-optical switching has myriad applications in optoelectronics, optical communications, and quantum information technology. To achieve ultrafast optical switching in a compact yet versatile setup, we demonstrate distinct sets of two-dimensional (2D) broadband up-converted multicolor arrays (BUMAs) in a thin type-I ?-barium-borate crystal with two noncollinear near-IR femtosecond pulses at various phase-matching conditions. The unique interaction mechanism is revealed as quadratic spatial solitons (QSSs)-coupled cascaded four-wave mixing (CFWM), corroborated by numerical calculations of the governing phase-matching conditions. Broad and continuous spectral-spatial tunability of the 2D BUMAs are achieved by varying the time delay between the two incident pulses that undergo CFWM interaction, rooted in the chirped nature of the weak white light and the QSSs generation of the intense fundamental beam. The control of 2D BUMAs is accomplished via seeding a weak second-harmonic pulse in situ to suppress the 2D arrays with polarization dependence on the femtosecond timescale that matches the control pulse duration of ?35 fs. A potential application is proposed on femtosecond all-optical switching in an integrated wavelength-time division multiplexing device.

Liu, Weimin; Wang, Liang; Fang, Chong, E-mail: Chong.Fang@oregonstate.edu [Department of Chemistry, Oregon State University, Corvallis, Oregon 97331 (United States)

2014-03-17T23:59:59.000Z

412

Ultrafast Large Area Micropattern Generation in Non-absorbing Polymer Thin-Films by Pulsed Laser Diffraction  

E-Print Network [OSTI]

We report an ultrafast, parallel and beyond-the-master micro-patterning technique for ultrathin (30 nm-400 nm) non-absorbing polymer films by diffraction of a laser light through a two dimensional periodic aperture. The redistribution of laser energy absorbed by the substrate causes self-organization of polymer thin-film in the form of wrinkle like surface relief structures caused by localized melting and freezing of the thin-film. Unlike the conventional laser ablation and laser writing processes, low laser fluence is employed to only passively swell the polymer as a pre-ablative process without the loss of material, and without absorption/reaction with the incident radiation. Self-organization in the thin polymer film aided by the diffraction pattern produces micro-structures made up of thin raised lines. These regular microstructures have far more complex morphologies than the mask geometry and very narrow line widths that can be an order of magnitude smaller than the openings in the mask. The microstructure morphology is easily modulated by changing the film thickness, aperture size and geometry and by changing the diffraction pattern, e.g., by changing the aperture-substrate distance.

Ankur Verma; Ashutosh Sharma; Giridhar U. Kulkarni

2011-01-27T23:59:59.000Z

413

NuSTAR Reveals Relativistic Reflection But No Ultra-Fast Outflow In The Quasar PG 1211+143  

E-Print Network [OSTI]

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' (or, 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 UFO's show 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,...

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

2015-01-01T23:59:59.000Z

414

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

SciTech Connect (OSTI)

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.

Dong, Futao, E-mail: dongft@sina.com [The State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China); Du, Linxiu; Liu, Xianghua [The State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China); Xue, Fei [College of Electrical Engineering, Hebei United University, Tangshan 063000 (China)

2013-10-15T23:59:59.000Z

415

A dynamic and ultrafast group delay tuning mechanism in two microcavities side-coupled with a waveguide system  

SciTech Connect (OSTI)

We theoretically propose a dynamic and ultrafast group delay tuning mechanism in two microcavities side-coupled to a waveguide system through external optical pump beams. The optical Kerr effect modulation method is applied to improve tuning rate with response time of subpicoseconds or even femtoseconds. The group delay of an all-optical analog to electromagnetically induced transparency effect can be controlled by tuning either the frequency of photonic crystal microcavities or the propagation phase of line waveguide. Group delay is controlled between 5.88 and 70.98?ps by dynamically tuning resonant frequencies of the microcavities. Alternatively, the group delay is controlled between 1.86 and 12.08?ps by dynamically tuning the propagation phase of line waveguide. All observed schemes are analyzed rigorously through finite-difference time-domain simulations and coupled-mode formalism. Results show a new direction toward microstructure integration optical pulse trapping and all-optical dynamical storage of light devices in optical communication and quantum information processing.

Wang, Boyun; Wang, Tao, E-mail: wangtao@hust.edu.cn; Tang, Jian; Li, Xiaoming; Zhu, Youjiang [Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074 (China)

2014-10-07T23:59:59.000Z

416

Physics Illinois Undergraduate Programs  

E-Print Network [OSTI]

Physics Illinois Undergraduate Programs Department of Physics College of Engineering University to undergraduate education. Over the last 15 years, in collaboration with our nationally recognized Physics Education Research Group, our faculty has reinvented the way undergraduate physics courses are taught

Gilbert, Matthew

417

Physics 6321 Coastal oceanography  

E-Print Network [OSTI]

Physics 6321 Coastal oceanography · Instructor: Dr. Iakov Afanassiev · Office: Physics C-4065 · email: yakov@physics.mun.ca · Course Times: TBD Room TBD · Office Hours: unlimited · Web Page: http://www.physics

deYoung, Brad

418

High Energy Physics  

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

Basic Energy Science Biological and Environmental Research Fusion Energy Sciences High Energy Physics Nuclear Physics Advanced Scientific Computing Research Pioneering...

419

People's Physics Book The People's Physics Book  

E-Print Network [OSTI]

#12;People's Physics Book The People's Physics Book Authors James H. Dann, Ph.D. James J. Dann. All rights reserved. Textbook Website http://scipp.ucsc.edu/outreach/index2.html #12;People's Physics) "Each discovery, each advance, each increase in the sum of human riches, owes its being to the physical

California at Santa Cruz, University of

420

Physics Procedia 00 (2013) 16 Physics Procedia  

E-Print Network [OSTI]

Physics Procedia 00 (2013) 1­6 Physics Procedia Educating the next generation of Computational Physicists Joan Adler Physics Department, Technion -IIT, Haifa, Israel, 32000 Abstract Many "senior" Computational Physics researchers began their careers perched on of the other vertices of the Landau triangle

Adler, Joan

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


421

People's Physics Book The People's Physics Book  

E-Print Network [OSTI]

People's Physics Book The People's Physics Book Authors James H. Dann, Ph.D. James J. Dann. All rights reserved. Textbook Website http://scipp.ucsc.edu/outreach/index2.html #12;People's Physics) "Each discovery, each advance, each increase in the sum of human riches, owes its being to the physical

California at Santa Cruz, University of

422

Physics and Astronomy Chemical Physics Concentration  

E-Print Network [OSTI]

Physics and Astronomy Chemical Physics Concentration Strongly recommended courses Credits Term Dept Fields & Waves 3 PHY 3230 Thermal Physics 3 PHY 4640 Quantum Mechanics 3 PHY 4020 Computational Methods in Physics & Engineering 3 PHY 4330 Digital Electronics 3 CHE 1101 Intro. Chemistry I 3 CHE 1110 Intro

Thaxton, Christopher S.

423

Physics Procedia 00 (2013) 15 Physics Procedia  

E-Print Network [OSTI]

Physics Procedia 00 (2013) 1­5 Physics Procedia Educating the next generation of Computational Physicists Joan Adler Physics Department, Technion -IIT, Haifa, Israel, 32000 Abstract Many "senior" Computational Physics researchers began their careers perched on of the other vertices of the Landau triangle

Adler, Joan

424

Fundamentals of Plasma Physics  

E-Print Network [OSTI]

of students (from physics, engineering physics, elec- trical engineering, nuclear engineering and other un;PREFACE Plasma physics is a relatively new branch of physics that became a mature science over the last). Thus, plasma physics has developed in large part as a branch of applied or engineering physics

Callen, James D.

425

Ab initio studies of ultrafast x-ray scattering of the photodissociation of iodine  

SciTech Connect (OSTI)

We computationally examine various aspects of the reaction dynamics of the photodissociation and recombination of molecular iodine. We use our recently proposed formalism to calculate time-dependent x-ray scattering signal changes from first principles. Different aspects of the dynamics of this prototypical reaction are studied, such as coherent and noncoherent processes, features of structural relaxation that are periodic in time versus nonperiodic dissociative processes, as well as small electron density changes caused by electronic excitation, all with respect to x-ray scattering. We can demonstrate that wide-angle x-ray scattering offers a possibility to study the changes in electron densities in nonperiodic systems, which render it a suitable technique for the investigation of chemical reactions from a structural dynamics point of view.

Debnarova, Andrea; Techert, Simone [Max Planck Institute for Biophysical Chemistry, 37077 Goettingen, Am Fassberg 11 (Germany); Schmatz, Stefan [Institut fuer Physikalische Chemie, Universitaet Goettingen, 37077 Goettingen, Tammannstr. 6 (Germany)

2010-09-28T23:59:59.000Z

426

Development of Nanofluidic Cells for Ultrafast X-ray Studies of Water  

SciTech Connect (OSTI)

In order to study the molecular structure and dynamics of liquid water with soft x-ray probes, samples with nanoscale dimensions are needed. This paper describes a simple method for preparing nanofluidic water cells. The idea is to confine a thin layer of water between two silicon nitride windows. The windows are 1 mm x 1 mm and 0.5 mm x 0.5 mm in size and have a thickness of 150 nm. The thickness of the water layer was measured experimentally by probing the infrared spectrum of water in the cells with a Fourier Transform InfraRed (FTIR) apparatus and from soft x-ray static measurements at the Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory. Water layers ranging from 10 nm to more than 2 {micro}m were observed. Evidence for changes in the water structure compared to bulk water is observed in the ultrathin cells.

Irizarry, Melvin E.; /Puerto Rico U., Mayaguez /SLAC

2006-08-23T23:59:59.000Z

427

Laser wavelength effects in ultrafast near-field laser nanostructuring of Si  

SciTech Connect (OSTI)

We study the effect of laser wavelength (400 nm and 800 nm) on the near-field processing of crystalline silicon (Si) in the femtosecond (fs) pulse duration regime through sub-wavelength apertures. Distinct differences in the obtained nanostructures are found in each case both in terms of their physical sizes as well as their structure which can be tuned between craters and protrusions. A single or a few fs pulses can deliver enough energy on the substrate to induce sub-diffraction limited surface modification, which is among the smallest ever reported in sub-wavelength apertured Near-field Scanning Optical Microscope (NSOM) schemes.

Zormpa, Vasileia; Mao, Xianglei; Russo, Richard E.

2010-03-18T23:59:59.000Z

428

High-stability time-domain balanced homodyne detector for ultrafast optical pulse applications  

E-Print Network [OSTI]

Low-noise, efficient, phase-sensitive time-domain optical detection is essential for foundational tests of quantum physics based on optical quantum states and the realization of numerous applications ranging from quantum key distribution to coherent classical telecommunications. Stability, bandwidth, efficiency, and signal-to-noise ratio are crucial performance parameters for effective detector operation. Here we present a high-bandwidth, low-noise, ultra-stable time-domain coherent measurement scheme based on balanced homodyne detection ideally suited to characterization of quantum and classical light fields in well-defined ultrashort optical pulse modes.

Merlin Cooper; Christoph Söller; Brian J. Smith

2013-03-25T23:59:59.000Z

429

Laser Control of Dissipative Two-Exciton Dynamics in Molecular Aggregates  

E-Print Network [OSTI]

There are two types of two-photon transitions in molecular aggregates, that is, non-local excitations of two monomers and local double excitations to some higher excited intra-monomer electronic state. As a consequence of the inter-monomer Coulomb interaction these different excitation states are coupled to each other. Higher excited intra-monomer states are rather short-lived due to efficient internal conversion of electronic into vibrational energy. Combining both processes leads to the annihilation of an electronic excitation state, which is a major loss channel for establishing high excitation densities in molecular aggregates. Applying theoretical pulse optimization techniques to a Frenkel exciton model it is shown that the dynamics of two-exciton states in linear aggregates (dimer to tetramer) can be influenced by ultrafast shaped laser pulses. In particular, it is studied to what extent the decay of the two-exciton population by inter-band transitions can be transiently suppressed. Intra-band dynamics is described by a dissipative hierarchy equation approach, which takes into account strong exciton-vibrational coupling in the non-Markovian regime.

Yun-an Yan; Oliver Kühn

2012-07-09T23:59:59.000Z

430

Physical Mapping of Chromosomes: A Combinatorial Problem in Molecular Biology  

E-Print Network [OSTI]

of nucleotides from the set fA; T ; C;Gg. The nucleotides A and T are complementary to each other, as are the nucleotides C and G. Each nucleotide on one strand is bound to a complementary nucleotide on the other strand will cleave a DNA molecule at every site where a certain short sequence of nucleotides occurs. A separation

Alizadeh, Farid

431

Spectroscopy of complex molecular systems: Physics on an exciton...  

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

Jasper Knoester Zernike Institute for Advanced Materials, University of Groningen, Netherlands jknoester Abstract: The concept of excitons, collective excited states, is...

432

Molecular heat pump  

E-Print Network [OSTI]

We propose a novel molecular device that pumps heat against a thermal gradient. The system consists of a molecular element connecting two thermal reservoirs that are characterized by different spectral properties. The pumping action is achieved by applying an external force that periodically modulates molecular levels. This modulation affects periodic oscillations of the internal temperature of the molecule and the strength of its coupling to each reservoir resulting in a net heat flow in the desired direction. The heat flow is examined in the slow and fast modulation limits and for different modulation waveforms, thus making it possible to optimize the device performance.

Dvira Segal; Abraham Nitzan

2005-10-11T23:59:59.000Z

433

Accelerated molecular dynamics methods  

SciTech Connect (OSTI)

The molecular dynamics method, although extremely powerful for materials simulations, is limited to times scales of roughly one microsecond or less. On longer time scales, dynamical evolution typically consists of infrequent events, which are usually activated processes. This course is focused on understanding infrequent-event dynamics, on methods for characterizing infrequent-event mechanisms and rate constants, and on methods for simulating long time scales in infrequent-event systems, emphasizing the recently developed accelerated molecular dynamics methods (hyperdynamics, parallel replica dynamics, and temperature accelerated dynamics). Some familiarity with basic statistical mechanics and molecular dynamics methods will be assumed.

Perez, Danny [Los Alamos National Laboratory

2011-01-04T23:59:59.000Z

434

Investigation of ultrafast photothermal surface expansion and diffusivity in GaAs via laser-induced dynamic gratings  

SciTech Connect (OSTI)

This thesis details the first direct ultrafast measurements of the dynamic thermal expansion of a surface and the temperature dependent surface thermal diffusivity using a two-color reflection transient grating technique. Studies were performed on p-type, n-type, and undoped GaAs(100) samples over a wide range of temperatures. By utilizing a 90 fs ultraviolet probe with visible excitation beams, the effects of interband saturation and carrier dynamics become negligible; thus lattice expansion due to heating and subsequent contraction caused by cooling provided the dominant influence on the probe. At room temperature a rise due to thermal expansion was observed, corresponding to a maximum net displacement of {approximately} 1 {Angstrom} at 32 ps. The diffracted signal was composed of two components, thermal expansion of the surface and heat flow away from the surface, thus allowing a determination of the rate of expansion as well as the surface thermal diffusivity, D{sub S}. By varying the fringe spacing of the grating, this technique has the potential to separate the signal contributions to the expansion of the lattice in the perpendicular and parallel directions. In the data presented here a large fringe spacing was used, thus the dominant contribution to the rising edge of the signal was expansion perpendicular to the surface. Comparison of he results with a straightforward thermal model yields good agreement over a range of temperatures (20--300{degrees}K). Values for D{sub S} in GaAs were measured and found to be in reasonable agreement with bulk values above 50{degrees}K. Below 50{degrees}K, D{sub S} were determined to be up to an order of magnitude slower than the bulk diffusivity due to increased phonon boundary scattering. The applicability and advantages of the TG technique for studying photothermal and photoacoustic phenomena are discussed.

Pennington, D.M.

1992-04-01T23:59:59.000Z

435

B Physics (Experiment)  

E-Print Network [OSTI]

In past few years the flavor physics made important transition from the work on confirmation the standard model of particle physics to the phase of search for effects of a new physics beyond standard model. In this paper we review current state of the physics of b-hadrons with emphasis on results with a sensitivity to new physics.

Michal Kreps

2010-08-02T23:59:59.000Z

436

General Syllabus Physics 45100  

E-Print Network [OSTI]

General Syllabus Physics 45100 Thermodynamics and Statistical Physics Designation: Undergraduate Catalog description: 45100: Thermodynamics and Statistical Physics Temperature; equation of state; work and statistical mechanics; low-temperature physics; the Third Law. 3 HR./Wk.; 3 CR. Prerequisites: Physics 35100

Lombardi, John R.

437

Physics Resources for Teachers  

E-Print Network [OSTI]

Physics Resources for Teachers University of Wisconsin ­ Madison Department of Physics 1150 University Ave. Madison, WI 53706 wonders@physics.wisc.edu (608) 262-2927 Plasma Physics Web Resources Center Plasma Physics Lab http://science-education.pppl.gov/ Coalition for Plasma Science http

Collar, Juan I.

438

Department of Physics High Energy Physics Group  

E-Print Network [OSTI]

Department of Physics High Energy Physics Group Electrical Engineer (Job ref: 0004) The High Energy and experience. A job description and an application form can be obtained from http

439

Theory of Molecular Machines. I. Channel Capacity of Molecular Machines  

E-Print Network [OSTI]

Theory of Molecular Machines. I. Channel Capacity of Molecular Machines running title: Channel Capacity of Molecular Machines Thomas D. Schneider version = 5.76 of ccmm.tex 2004 Feb 3 Version 5.67 was submitted 1990 December 5 Schneider, T. D. (1991). Theory of molecular machines. I. Channel capacity

Schneider, Thomas D.

440

Physics 4: Introductory Physics Electromagnetism and Light  

E-Print Network [OSTI]

Physics 4: Introductory Physics Electromagnetism and Light Professor Jeffrey D. Richman Department: Electromagnetism and Light Welcome to Physics 4! What is your goal in life? If it is to become an engineer or to pursue a career in science, this is a key class for you. Understanding electromagnetism and light

Fygenson, Deborah Kuchnir

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


441

Shock and Detonation Physics at Los Alamos National Laboratory  

SciTech Connect (OSTI)

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.

Robbins, David L [Los Alamos National Laboratory; Dattelbaum, Dana M [Los Alamos National Laboratory; Sheffield, Steve A [Los Alamos National Laboratory

2012-08-22T23:59:59.000Z

442

ENVIRONMENTAL PHYSICS METHODS  

E-Print Network [OSTI]

ENVIRONMENTAL PHYSICS METHODS LABORATORY PRACTICES #12;Foundations of Environmental Science Lecture Enviromental Physics Methods Laboratory Practices #12;Eötvös Loránd University Faculty of Science ENVIRONMENTAL tankönyvsorozat" (KMR Foundations of Environmental Science Lecture Series). KEYWORDS: Environmental physics

Horváth, Ákos

443

E-Print Network 3.0 - assisted molecular beam Sample Search Results  

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

10.1103PhysRevLett.98.103201 PACS numbers: 39.10.+j, 03.75.Be Atomic and molecular beams have... as well as fundamental physics and precision tests 3. The highest brightness...

444

Breaking the Attosecond, Angstrom and TV/M Field Barriers with Ultra-Fast Electron Beams  

SciTech Connect (OSTI)

Recent initiatives at UCLA concerning ultra-short, GeV electron beam generation have been aimed at achieving sub-fs pulses capable of driving X-ray free-electron lasers (FELs) in single-spike mode. This use of very low Q beams may allow existing FEL injectors to produce few-100 attosecond pulses, with very high brightness. Towards this end, recent experiments at the LCLS have produced {approx}2 fs, 20 pC electron pulses. We discuss here extensions of this work, in which we seek to exploit the beam brightness in FELs, in tandem with new developments in cryogenic undulator technology, to create compact accelerator-undulator systems that can lase below 0.15 {angstrom}, or be used to permit 1.5 {angstrom} operation at 4.5 GeV. In addition, we are now developing experiments which use the present LCLS fs pulses to excite plasma wakefields exceeding 1 TV/m, permitting a table-top TeV accelerator for frontier high energy physics applications.

Rosenzweig, James; Andonian, Gerard; Fukasawa, Atsushi; Hemsing, Erik; Marcus, Gabriel; Marinelli, Agostino; Musumeci, Pietro; O'Shea, Brendan; O'Shea, Finn; Pellegrini, Claudio; Schiller, David; Travish, Gil; /UCLA; Bucksbaum, Philip; Hogan, Mark; Krejcik, Patrick; /SLAC; Ferrario, Massimo; /INFN, Rome; Full, Steven; /Penn State U.; Muggli, Patric; /Southern California U.

2012-06-22T23:59:59.000Z

445

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...

446

B Physics: Theory Overview  

E-Print Network [OSTI]

This is an overview of B physics that can be done at the LHC with the purpose of searching for new physics.

David London

2012-07-19T23:59:59.000Z

447

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...

448

Office of Physical Protection  

Broader source: Energy.gov [DOE]

The Office of Physical Protection is comprised of a team of security specialists engaged in providing Headquarters-wide physical protection.

449

Hydrogen bond rearrangements and the motion of charge defects in water viewed using multidimensional ultrafast infrared spectroscopy  

E-Print Network [OSTI]

Compared with other molecular liquids, water is highly structured due to its ability to form up to four hydrogen bonds to its nearest neighbors, resulting in a tetrahedral network of molecules. However, this network is ...

Roberts, Sean T. (Sean Thomas)

2010-01-01T23:59:59.000Z

450

SUPPORTING INFORMATION Molecular Characterization of Organosulfates in Organic  

E-Print Network [OSTI]

of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, Fudan collected on the roof of building of the department of Environmental Science & Engineering, Fudan University, USA c Physical Sciences Division, d William R. Wiley Environmental Molecular Sciences Laboratory

Nizkorodov, Sergey

451

Self-doped molecular composite battery electrolytes  

DOE Patents [OSTI]

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.

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

2003-04-08T23:59:59.000Z

452

HNCO in molecular clouds  

SciTech Connect (OSTI)

In a survey of 18 molecular clouds, HNCO J/sub K/-1K1..-->..J'/sub K/'-1K'1 = 5/sub 05/..-->..4/sub 05/ and 4/sub 04/..-->..3/sub 03/ emission was etected in seven clouds, and possibly in one other. Emission in these transitions originates in high-density regions (n> or approx. =10/sup 6/ cm/sup -3/). The molecule's excitation requirements allow us to derive limits to excitation temperatures an optical depths. We discuss the possibility of clumping with respect to the beam and compare our results with data from other molecular species. The HNCO emission from Sgr A is an ordder of magnitude larger than the other detected sources as is the ratio ..delta..T +- /sub A/(HNCO 5/sub 05/..-->..4/sub 04/)/..delta..T +- /sub A/(C/sup 18/O 1..-->..0). HNCO is probably a constituent of most molecular clouds.

Jackson, J.M.; Armstrong, J.T.; Barrett, A.H.

1984-05-15T23:59:59.000Z

453

Current issue Physics Resources  

E-Print Network [OSTI]

History Physics Education Industrial Outreach Programs that Match Every Interest - Master's Degrees, it became clear that physics master's programs were not easily categorized. The original classification the strengths of physics master's degree programs. Over half of physics departments offer at least one master

Thaxton, Christopher S.

454

PHYSICS 106 Summer 2011  

E-Print Network [OSTI]

PHYSICS 106 Summer 2011 Instructor: Stephanie Magleby (sam25@physics.byu.edu) Office Hours: MWF 2 -3 pm, N311 ESC Office Phone (physics): 422-7056 Office Phone (engineering): 422-8319 TA: Corbin Jacobs [corbinjacobs@gmail.com] Email Corbin with any reading quiz questions or Mastering Physics issues

Hart, Gus

455

Aspects of Unparticle Physics  

E-Print Network [OSTI]

We review some theoretical and experimental issues in unparticle physics, focusing mainly on collider signatures.

Arvind Rajaraman

2008-09-29T23:59:59.000Z

456

Substructured multibody molecular dynamics.  

SciTech Connect (OSTI)

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.

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.

2006-11-01T23:59:59.000Z

457

New results in atomic physics at the Advanced Light Source  

SciTech Connect (OSTI)

The Advanced Light Source is the world's first low-energy third-generation synchrotron radiation source. It has been running reliably and exceeding design specifications since it began operation in October 1993. It is available to a wide community of researchers in many scientific fields, including atomic and molecular science and chemistry. Here, new results in atomic physics at the Advanced Light Source demonstrate the opportunities available in atomic and molecular physics at this synchrotron light source. The unprecedented brightness allows experiments with high flux, high spectral resolution, and nearly 100% linear polarization.

Schlachter, A.S.

1995-01-01T23:59:59.000Z

458

DOCTORAL PROGRAMME MATHEMATICS AND PHYSICS, Subprogramme PHYSICS,  

E-Print Network [OSTI]

Slovenia is producing a significant share of its electricity in nuclear power plant. The doctoral programme of nuclear engineering stems from the requirements of the Nuclear power plant Krsko, Slovenian Nuclear SafetyDOCTORAL PROGRAMME MATHEMATICS AND PHYSICS, Subprogramme PHYSICS, Module NUCLEAR ENGINEERING

?umer, Slobodan

459

Molecular Squares as Molecular Sieves: Size-Selective Transport Through  

E-Print Network [OSTI]

Molecular Squares as Molecular Sieves: Size-Selective Transport Through Porous-Membrane squaresº: cyclic structures typically featuring metal-ion cor- ners and difunctional bridging ligands processes: size-selective molecular transport from a guest-containing solution to one initially free

460

Molecular Gas in Early-type Galaxies  

E-Print Network [OSTI]

toward the center (first seen in the molecular gas in A+3.4 Molecular Gas Mass . . . . . . .of the molecular gas . . . . . . . . . . 2.4.3 Mass of

Alatalo, Katherine Anne

2012-01-01T23:59:59.000Z

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


461

Effect of carrier recombination on ultrafast carrier dynamics in thin films of the topological insulator Bi{sub 2}Se{sub 3}  

SciTech Connect (OSTI)

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.

Glinka, Yuri D., E-mail: ydglinka@mail.wvu.edu [Department of Physics and Astronomy, West Virginia University, Morgantown, West Virginia 26506-6315 (United States); Institute of Physics, National Academy of Sciences of Ukraine, Kiev 03028 (Ukraine); Babakiray, Sercan; Johnson, Trent A.; Holcomb, Mikel B.; Lederman, David [Department of Physics and Astronomy, West Virginia University, Morgantown, West Virginia 26506-6315 (United States)

2014-10-27T23:59:59.000Z

462

First-Principles Simulations of Chemical Reactions in an HCl Molecule Embedded inside a C or BN Nanotube Induced by Ultrafast Laser Pulses  

SciTech Connect (OSTI)

We show by first-principles simulations that ultrafast laser pulses induce different chemical reactions in a molecule trapped inside a nanotube. A strong laser pulse polarized perpendicular to the tube axis induces a giant bond stretch of an encapsulated HCl molecule in semiconducting carbon nanotube or in a BN nanotube. Depending on the initial orientation of the HCl molecule, the subsequent laser-induced dynamics is different: either complete disintegration or rebonding of the HCl molecule. Radial motion of the nanotube is always observed and a vacancy appears on the tube wall when the HCl is perpendicular to the tube axis. Those results are important to analyze confined nanochemistry and to manipulate molecules and nanostructures encapsulated in organic and inorganic nanotubes.

Miyamoto, Yoshiyuki [Green Innovation Research Laboratories, NEC Corporation, 34 Miyukigaoka, Tsukuba 305-8501 (Japan); Zhang Hong [School of Physical Science and Technology, Sichuan University, Chengdu 610065 (China); Rubio, Angel [Nano-Bio Spectroscopy group and ETSF Scientific Development Centre, Department Fisica de Materiales, Universidad del Pais Vasco, Avenida de Tolosa 72, E-20018 San Sebastian (Spain)

2010-12-10T23:59:59.000Z

463

Chemistry 685 (CHE 685) Advanced Organic Chemistry: Organic Reaction Mechanisms and Molecular Interactions  

E-Print Network [OSTI]

Chemistry 685 (CHE 685) Advanced Organic Chemistry: Organic Reaction Mechanisms and Molecular and physical chemistry Course description and rationale CHE685 is a graduate-level organic chemistry course. These two courses focus on physical organic chemistry, which deals with the structure and reactivity

Mather, Patrick T.

464

Cavity-enhanced field-free molecular alignment at high repetition rate  

E-Print Network [OSTI]

Extreme ultraviolet frequency combs are a versatile tool with applications including precision measurement, strong-field physics, and solid-state physics. Here we report on an application of extreme ultraviolet frequency combs and their driving lasers to studying strong-field effects in molecular systems. We perform field-free molecular alignment and high-order hamonic generation with aligned molecules in a gas jet at 154 MHz repetition rate using a high-powered optical frequency comb inside a femtosecond enhancement cavity. The cavity-enhanced system provides means to reach suitable intensities to study field-free molecular alignment and enhance the observable effects of the molecule-field interaction. We observe modulations of the driving field, arising from the nature of impulsive stimulated Raman scattering responsible for coherent molecular rotations. We foresee impact of this work on the study of molecule-based strong-field physics, with improved precision and a more fundamental understanding of the int...

Benko, Craig; Allison, Thomas K; Labaye, François; Ye, Jun

2015-01-01T23:59:59.000Z

465

Probing new physics with flavor physics (and probing flavor physics with new physics)  

E-Print Network [OSTI]

This is a written version of a series of lectures aimed at graduate students and postdoctoral fellows in particle theory/string theory/particle experiment familiar with the basics of the Standard Model. We begin with an overview of flavor physics and its implications for new physics. We emphasize the "new physics flavor puzzle". Then, we give four specific examples of flavor measurements and the lessons that have been (or can be) drawn from them: (i) Charm physics: lessons for supersymmetry from the upper bound on $\\Delta m_D$. (ii) Bottom physics: model independent lessons on the KM mechanism and on new physics in neutral B mixing from $S_{\\psi K_S}$. (iii) Top physics and beyond: testing minimal flavor violation at the LHC. (iv) Neutrino physics: interpreting the data on neutrino masses and mixing within flavor models.

Yosef Nir

2007-08-14T23:59:59.000Z

466

Physics 151 Lecture 1 Physics 207: Lecture 1, Pg 1  

E-Print Network [OSTI]

Page 1 Physics 151 ­ Lecture 1 Physics 207: Lecture 1, Pg 1 Physics 207, Sections: 301/601Physics 207, Sections: 301/601 ­­ 314/614314/614 General Physics IGeneral Physics I MichaelMichael Winokur of the courseScope of the course Begin chapter 1Begin chapter 1 Homepage:Homepage: http://romano.physics

Winokur, Michael

467

Whither Nuclear Physics ?  

E-Print Network [OSTI]

Nuclear Physics has had its ups and downs. However in recent years, bucked up by some new and often puzzling data, it has become a potentially very rich field. We review some of these exciting developments in a few important sectors of nuclear physics. Emphasis shall be on the study of exotic nuclei and the new physics that these nuclei are teaching us.

Syed Afsar Abbas

2008-01-07T23:59:59.000Z

468

in Condensed Matter Physics  

E-Print Network [OSTI]

Master in Condensed Matter Physics ­ Master académique #12;2 #12;3 Students at the University. Condensed matter physics is about explaining and predicting the relationship between the atomic, and broad education in the field of condensed matter physics · introduce you to current research topics

van der Torre, Leon

469

PHYSICS, QUALITATIVE BIBLIOGRAPHY  

E-Print Network [OSTI]

PHYSICS, QUALITATIVE C BIBLIOGRAPHY D. G. Bobrow and R J. Hayes, eds., Artif. Intell. 24," in Gentner and Stevens, 1983, pp. 155--190. J. de Kleer and J. S. Brown "A Qualitative Physics Based.J., 1983. P. Hayes, "The Naive Physics Manifesto," in Hobbs and Moore, 1985, pp 1--36 J R Hobbs and R C

de Kleer, Johan

470

B Physics at LHCb  

E-Print Network [OSTI]

LHCb is a dedicated detector for b physics at the LHC. In this article we present a concise review of the detector design and performance together with the main physics goals and their relevance for a precise test of the Standard Model and search of New Physics beyond it.

Monica Pepe Altarelli; Frederic Teubert

2008-02-13T23:59:59.000Z

471

Quantum Physics Einstein's Gravity  

E-Print Network [OSTI]

Quantum Physics confronts Einstein's Gravity Matt Visser Physics Department Washington University Saint Louis USA Science Saturdays 13 October 2001 #12; Quantum Physics confronts Einstein's Gravity and with Einstein's theory of gravity (the general relativity) is still the single biggest theoretical problem

Visser, Matt

472

Physical Probability Patrick Maher  

E-Print Network [OSTI]

Physical Probability Patrick Maher University of Illinois at Urbana-Champaign October 13, 2007 ABSTRACT. By "physical probability" I mean the empirical concept of probability in or- dinary language-extreme physical probabilities are compatible with determin- ism. Two principles, called specification

Fitelson, Branden

473

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

SciTech Connect (OSTI)

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)

Not Available

1988-06-01T23:59:59.000Z

474

VOLUME 87, NUMBER 8 P H Y S I C A L R E V I E W L E T T E R S 20 AUGUST 2001 Investigation of Ultrafast Laser-Driven Radiative Blast Waves  

E-Print Network [OSTI]

. This is believed to be due to the stabilizing effect of a relatively thick blast wave shell resulting in part from of Ultrafast Laser-Driven Radiative Blast Waves M.J. Edwards,1 A. J. MacKinnon,1 J. Zweiback,1 K. Shigemori,2 D blast waves produced by the deposition of femtosecond laser pulses in gas jets. In high-Z gases

Ditmire, Todd

475

Physics at Strathclyde N. Langford  

E-Print Network [OSTI]

#12;Physics at Strathclyde N. Langford Department of Physics University of Strathclyde #12 and Misconceptions o "There's no money in physics" o "I like the idea of a physics degree but what actual jobs do physics degree is great ­ if you want to teach physics" Untrue Physics leads to engineering NO

Mottram, Nigel

476

Neutrino Oscillation Physics  

E-Print Network [OSTI]

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.

Boris Kayser

2013-12-25T23:59:59.000Z

477

Core Competencies Performing topical research in plasma boundary physics, fueling  

E-Print Network [OSTI]

" in Latin). ORNL and Princeton Plasma Physics Laboratory are co-hosts for the U.S. ITER Project Office the materials science base to develop high- performance structural materials with attractive environmental and safety features. Advanced materials Investigating atomic, molecular, and surface interactions to develop

478

Funding Opportunity: Physics Frontiers Centers (PFC) Sponsor: National Science Foundation  

E-Print Network [OSTI]

investigators or small groups, in an environment in which the collective efforts of the larger group can of Physics: atomic, molecular, optical, plasma, elementary particle, nuclear, astro-, gravitational education, diversity, and public outreach; (3) potential for broader impacts, e.g., impacts on other field

Suzuki, Masatsugu

479

Ultrafast neutron detector  

DOE Patents [OSTI]

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.

Wang, C.L.

1985-06-19T23:59:59.000Z

480

Faculty Position Therapeutic Medical Physics  

E-Print Network [OSTI]

spectroscopy, fluoroscopy, ultrasound, digital radiography, and nuclear medicine. The Colorado State University of subjects in Radiation Therapy Physics, Medical Imaging Physics, and Radiological Physics and Dosimetry

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


481

Molecular Science Computing | EMSL  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation Desert Southwest Regionat Cornell Batteries & Fuel CellsModels fromMolecular Science

482

Molecular Beam Epitaxy | EMSL  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas Conchas recovery challenge fundProject8Mistakes to Avoid MistakesResponseModernMolecular

483

Molecular Beam Kinetics | EMSL  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas Conchas recovery challenge fundProject8Mistakes to AvoidKinetics Molecular Beam Kinetics

484

Part I STATISTICAL PHYSICS 1 Statistical Physics  

E-Print Network [OSTI]

In this first part of the book we shall study aspects of classical statistical physics that every physicist should know, but are not usually treated in elementary thermodynamics courses. Our study will lay the microphysical (particle-scale) foundations for the continuum physics of Parts II—VI. As a central feature of our approach, we shall emphasize the intimate connections between the relativistic formulation of statistical physics and its nonrelativistic limit, and between quantum statistical physics and the classical theory. Throughout, we shall presume that the reader is familiar with elementary thermodynamics, but not with other aspects of statistical physics. In Chap. 2 we will study kinetic theory — the simplest of all formalisms for analyzing systems of huge numbers of particles (e.g., molecules of air, or neutrons diffusing through a nuclear reactor, or photons produced in the big-bang origin of the Universe). In kinetic theory the key concept is the “distribution function ” or “number density of particles in phase space”, N; i.e., the number of particles per unit 3-dimensional volume of ordinary space and per unit 3-dimensional volume of momentum space. Despite first appearances, N turns out to be a geometric, frame-independent entity. This N and the frame-independent laws it

unknown authors

485

Part I STATISTICAL PHYSICS 1 Statistical Physics  

E-Print Network [OSTI]

In this first part of the book we shall study aspects of classical statistical physics that every physicist should know, but are not usually treated in elementary thermodynamics courses. Our study will lay the microphysical (particle-scale) foundations for the continuum physics of Parts II—VI. As a central feature of our approach, we shall emphasize the intimate connections between the relativistic formulation of statistical physics and its nonrelativistic limit, and between quantum statistical physics and the classical theory. Throughout, we shall presume that the reader is familiar with elementary thermodynamics, but not with other aspects of statistical physics. In Chap. 2 we will study kinetic theory — the simplest of all formalisms for analyzing systems of huge numbers of particles (e.g., molecules of air, or neutrons diffusing through a nuclear reactor, or photons produced in the big-bang origin of the Universe). In kinetic theory the key concept is the “distribution function ” or “number density of particles in phase space”, N; i.e., the number of particles per unit 3-dimensional volume of ordinary space and per unit 3-dimensional volume of momentum space. Despite first appearances, N turns out to be a geometric, frame-independent entity. This N and the frame-independent laws it

unknown authors

2004-01-01T23:59:59.000Z

486

Part I STATISTICAL PHYSICS 1 Statistical Physics  

E-Print Network [OSTI]

In this first part of the book we shall study aspects of classical statistical physics that every physicist should know but are not usually treated in elementary thermodynamics courses. This study will lay the microphysical (particle-scale) foundations for the continuum physics of Parts II—VI. Throughout, we shall presume that the reader is familiar with elementary thermodynamics, but not with other aspects of statistical physics. As a central feature of our approach, we shall emphasize the intimate connections between the relativistic formulation of statistical physics and its nonrelativistic limit, and between quantum statistical physics and the classical theory. Chapter 2 will deal with kinetic theory, which is the simplest of all formalisms for studying systems of huge numbers of particles (e.g., molecules of air, or neutrons diffusing through a nuclear reactor, or photons produced in the big-bang origin of the Universe). In kinetic theory the key concept is the “distribution function ” or “number density of particles in phase space”, N; i.e., the number of particles per unit 3-dimensional volume of ordinary space and per unit 3-dimensional volume of momentum space. Despite first appearances, N turns out to be a geometric, frame-independent entity. This N and the laws it obeys provide

unknown authors

487

Ph.D. Physics Program Ph.D. in Physics  

E-Print Network [OSTI]

Ph.D. Physics Program Ph.D. in Physics Department(s) Physics and Astronomy College Sciences Program Assessment Coordinator Michael Pravica pravica@physics.unlv.edu 895-1723 Five-Year Implementation Dates (2010 for physics at the graduate level 4. understand statistical physics at the graduate level 5. perform

Hemmers, Oliver

488

THE PHYSICS MAJOR (Physics and Astronomy & Astrophysics Streams)  

E-Print Network [OSTI]

THE PHYSICS MAJOR (Physics and Astronomy & Astrophysics Streams) Overview: Physics examines, to the behaviour of matter on the subatomic scale - and everything in between. Studying Physics at UWA gives you access to the frontiers of modern physics, built on the pillars of quantum physics and relativity. You

Tobar, Michael

489

Collective coordinates for nuclear spectral densities in energy transfer and femtosecond spectroscopy of molecular aggregates  

E-Print Network [OSTI]

Collective coordinates for nuclear spectral densities in energy transfer and femtosecond collective nuclear coordinates necessary to represent a given set of spectral densities is obtained coordinates phase space. The signatures of excitonic and nuclear motions in ultrafast fluorescence

Mukamel, Shaul

490

Assessment of Molecular Modeling & Simulation  

SciTech Connect (OSTI)

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.

None

2002-01-03T23:59:59.000Z

491

Molecular Gas in Galaxies  

E-Print Network [OSTI]

Knowledge of the molecular component of the ISM is fundamental to understand star formation. The H2 component appears to dominate the gas mass in the inner parts of galaxies, while the HI component dominates in the outer parts. Observation of the CO and other lines in normal and starburst galaxies have questioned the CO-to-H2 conversion factor, and detection of CO in dwarfs have shown how sensitive the conversion f actor is to metallicity. Our knowledge has made great progress in recent years, because of sensitivity and spatial resolution improvements. Large-scale CO maps of nearby galaxies are now available, which extend our knowledge on global properties, radial gradients, and spiral structure of the molecular ISM. Millimetric interferometers reveal high velocity gradients in galaxy nuclei, and formation of embedded structures, like bars within bars. Galaxy interactions are very effective to enhance gas concentrations and trigger starbursts. Nuclear disks or rings are frequently observed, that concentrate the star formation activity. Since the density of starbursting galaxies is strongly increasing with redshift, the CO lines and the mm dust emission are a privileged tool to follow evolution of galaxies and observe the ISM dynamics at high redshift: they could give an answer about the debated question of the star-formation history, since many massive remote starbursts could be dust-enshrouded.

F. Combes

2000-07-21T23:59:59.000Z

492

Heteropolymer freezing and design: Towards physical models of protein folding  

SciTech Connect (OSTI)

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.

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)

2000-01-01T23:59:59.000Z

493

Physics Topics - MST - UW Plasma Physics  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation Desert Southwest RegionatSearch Welcome to theNews & Blog »Physics Physics Print

494

Symmetries in physics  

E-Print Network [OSTI]

The concept of symmetries in physics is briefly reviewed. In the first part of these lecture notes, some of the basic mathematical tools needed for the understanding of symmetries in nature are presented, namely group theory, Lie groups and Lie algebras, and Noether's theorem. In the second part, some applications of symmetries in physics are discussed, ranging from isospin and flavor symmetry to more recent developments involving the interacting boson model and its extension to supersymmetries in nuclear physics.

Roelof Bijker

2005-09-02T23:59:59.000Z

495

QSAR of Progestogens: Use of a Priori and Computed Molecular Descriptors and Molecular Graphics  

E-Print Network [OSTI]

QSAR of Progestogens: Use of a Priori and Computed Molecular Descriptors and Molecular Graphics) and molecular graphics and modeling descriptors were employed. Mo- lecular graphics and modeling studies

Ferreira, Márcia M. C.

496

Physics at LHC  

E-Print Network [OSTI]

The prospects for physics at the LHC are discussed, starting with the foretaste, preparation (and perhaps scoop) provided by the Tevatron, in particular, and then continuing through the successive phases of LHC operation. These include the start-up phase, the early physics runs, the possible search for new physics in double diffraction, the continuation to nominal LHC running, and the possible upgrade of the LHC luminosity. Emphasis is placed on the prospects for Higgs physics and the search for supersymmetry. The progress and discoveries of the LHC will set the time-scale and agenda for the major future accelerator projects that will follow it.

John Ellis

2006-11-17T23:59:59.000Z

497

Cosmology and New Physics  

E-Print Network [OSTI]

A comparison of the standard models in particle physics and in cosmology demonstrates that they are not compatible, though both are well established. Basics of modern cosmology are briefly reviewed. It is argued that the measurements of the main cosmological parameters are achieved through many independent physical phenomena and this minimizes possible interpretation errors. It is shown that astronomy demands new physics beyond the frameworks of the (minimal) standard model in particle physics. More revolutionary modifications of the basic principles of the theory are also discussed.

A. D. Dolgov

2006-06-21T23:59:59.000Z

498

Nuclear Physics from QCD  

E-Print Network [OSTI]

Effective field theories provide a bridge between QCD and nuclear physics. I discuss light nuclei from this perspective, emphasizing the role of fine-tuning.

U. van Kolck

2008-12-20T23:59:59.000Z

499

High Energy Physics  

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

Large Scale Production Computing and Storage Requirements for High Energy Physics: Target 2017 HEPlogo.jpg The NERSC Program Requirements Review "Large Scale Computing and Storage...

500

Advances in Physical Chemistry  

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

Hindawi Publishing Corporation Advances in Physical Chemistry Volume 2011, Article ID 907129, 18 pages doi:10.11552011907129 Review Article Contrast and Synergy between...