National Library of Energy BETA

Sample records for appl phys lett

  1. Comment on “Diffusion of n-type dopants in germanium” [Appl. Phys. Rev. 1, 011301 (2014)

    SciTech Connect (OSTI)

    Cowern, N. E. B. Simdyankin, S.; Goss, J. P.; Napolitani, E.; De Salvador, D.; Bruno, E.; Mirabella, S.; Ahn, C.; Bennett, N. S.

    2015-09-15

    The authors of the above paper call into question recent evidence on the properties of self-interstitials, I, in Ge [Cowern et al., Phys. Rev. Lett. 110, 155501 (2013)]. We show that this judgment stems from invalid model assumptions during analysis of data on B marker-layer diffusion during proton irradiation, and that a corrected analysis fully supports the reported evidence. As previously stated, I-mediated self-diffusion in Ge exhibits two distinct regimes of temperature, T: high-T, dominated by amorphous-like mono-interstitial clusters—i-morphs—with self-diffusion entropy ≈30 k, and low-T, where transport is dominated by simple self-interstitials. In a transitional range centered on 475 °C both mechanisms contribute. The experimental I migration energy of 1.84 ± 0.26 eV reported by the Münster group based on measurements of self-diffusion during irradiation at 550 °C < T < 680 °C further establishes our proposed i-morph mechanism.

  2. Response to “Comment on ‘Twin symmetry texture of energetically condensed niobium thin films on sapphire substrate’ ” [J. Appl. Phys. 112, 016101 (2012)

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

    Zhao, X.; Philips, L.; Reece, C. E.; Seo, Kang; Krishnan, M.; Valderrama, E.

    2012-07-01

    Welander is correct about the misidentified crystal-directions in the top-view sapphire lattice (Fig. 4 [Zhao et al., J. Appl. Phys. 110, 033523 (2011)]). He is also correct about the misorientation of the pole figures in Fig. 4. In Fig. 1 of this response, we have corrected these errors. Perhaps because of these errors, Welander misconstrued our discussion of the Nbcrystal growth as claiming a new 3D registry. That was not our intention. Rather, we wished to highlight the role of energetic condensation that drives low-defect crystal growth by a combination of non-equilibrium sub-plantation that disturbs the substrate lattice and thermalmore » annealing that annihilates defects and promotes large-grain crystal growth.« less

  3. Comment on “Dimpling in critical current density vs. magnetic field angle in YBa{sub 2}Cu{sub 3}O{sub 7} films irradiated with 3-MeV gold ions” [J. Appl. Phys. 114, 233911 (2013)

    SciTech Connect (OSTI)

    Long, N. J. Wimbush, S. C.

    2014-04-07

    We provide an alternative explanation for the results of Matsui et al. [J. Appl. Phys. 114, 233911 (2013)] by considering the effects of disorder on flux pinning.

  4. Comment on A study of vertical and in-plane electron mobility due to interface roughness scattering at low temperature in InAs-GaSb superlattices [J. Appl. Phys. 114, 053712 (2013)

    SciTech Connect (OSTI)

    Szmulowicz, F.

    2014-04-14

    The purpose of this comment is to point out that the paper by Safa, Asgari, and Faraone [J. Appl. Phys. 114, 053712 (2013)] (SAF) on electronic transport in superlattices contains a number of errors in physics and execution. By dealing with a finite number of periods and forcing the wave function to be zero at the upper and lower boundaries of the superlattice stack, SAF have turned the system into a quantum well for which the momentum along the growth axis is not a good quantum number, so that the bands in the growth direction are flat and the corresponding carrier velocities and vertical mobilities are zero. A number of other errors allow the authors to get nonzero results and to reach conclusions that qualitatively mirror those of Szmulowicz, Haugan, Elhamri, and Brown [Phys. Rev. B 84, 155307 (2011)].

  5. Comment on Magnetic field mediated low-temperature resistivity upturn in electron-doped La{sub 1?x}Hf{sub x}MnO{sub 3} manganite oxides [J. Appl. Phys. 112, 123710 (2012)

    SciTech Connect (OSTI)

    Rozenberg, E.

    2014-01-21

    In a recent paper, Guo et al. [J. Appl. Phys. 112, 123710 (2012)] reported on characteristic features of the temperature (T) and magnetic field (H) dependences of electrical resistivity (?) in polycrystalline La{sub 1?x}Hf{sub x}MnO{sub 3} (x?=?0.2 and 0.3) manganites. In particular, shallow minima were observed at some T{sub min} below 100?K on ?(T) curves. Application of an external H???5?T leads first to a decrease in the T{sub min} value, while this value increases notably at H?>?0.75?T. The authors attributed this complex behavior to competitive electron-electron interaction and Kondo-like spin dependent scattering of carriers. It is shown in the comment that such interpretation is very questionable due to the fundamental inapplicability of this approach for analysis of low-T conductivity in polycrystalline manganites. It seems that the most likely reason for the appearance of the low temperature minima on ?(T) curves and their evolution upon field application is the well known grain boundary effects in magnetically and structurally inhomogeneous samples.

  6. Comment on "Radicalicity: A scale to compare reactivities of radicals" (Chem. Phys. Lett. 618 (2015) 99-101)*

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

    Poutsma, Marvin L.

    2016-04-21

    The recently proposed term radicalicity was described as a measure of the reactivity of a free radical Q*, i.e., a kinetic quantity. Here it is shown that in fact it is simply a frame-shifted version of the well-known bond dissociation energy, a thermodynamic quantity. Hence its use is discouraged.

  7. Comparing Apples to Apples: Benchmarking Electrocatalysts for...

    Office of Science (SC) Website

    Comparing Apples to Apples: Benchmarking Electrocatalysts for Solar Water-Splitting Devices Basic Energy Sciences (BES) BES Home About Research Facilities Science Highlights ...

  8. Atmos. Chem. Phys., 16, 3449-3462, ...

    Office of Scientific and Technical Information (OSTI)

    ... Phys., 13, 11187-11194, doi:10.5194acp-13-11187-2013,2013. Seinfeld, J. H. and Pandis, S. N.: Atmospheric chemistry and physics: from air pollution to climate change, John Wiley ...

  9. Atmos. Chem. Phys., 16, 715-738, ...

    Office of Scientific and Technical Information (OSTI)

    ... Phys., 15, 1633- 1646, doi:10.5194acp-15-1633-2015, 2015. Seinfeld, J. H. and Pandis, S. N.: Atmospheric Chemistry and Physics: From Air Pollution to Climate Change, John Wiley ...

  10. Erratum: Evidence of b-jet quenching in PbPb collisions at sNN=2.76TeV [Phys. Rev. Lett. 113 , 132301 (2014)

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

    Chatrchyan, S.

    2015-07-10

    In our Letter, there was a component of the statistical uncertainty from the simulated PbPb Monte Carlo samples. This uncertainty was not propagated to all of the results. Figures 3 and 4 have been updated to reflect this source of uncertainty. In this case, the statistical uncertainties remain smaller than the systematic uncertainties in all cases such that the conclusions of the Letter are unaltered.

  11. untitled

    Office of Scientific and Technical Information (OSTI)

    ... Equilibrium magnetic states in individual hemispherical permalloy caps. Appl. Phys. Lett. 101, 132419 (2012). 34. Albrecht, M. et al. Magnetic multilayers on nanospheres. Nat. ...

  12. About APPLE II Operation

    SciTech Connect (OSTI)

    Schmidt, T.; Zimoch, D.

    2007-01-19

    The operation of an APPLE II based undulator beamline with all its polarization states (linear horizontal and vertical, circular and elliptical, and continous variation of the linear vector) requires an effective description allowing an automated calculation of gap and shift parameter as function of energy and operation mode. The extension of the linear polarization range from 0 to 180 deg. requires 4 shiftable magnet arrrays, permitting use of the APU (adjustable phase undulator) concept. Studies for a pure fixed gap APPLE II for the SLS revealed surprising symmetries between circular and linear polarization modes allowing for simplified operation. A semi-analytical model covering all types of APPLE II and its implementation will be presented.

  13. Yuankun Cai

    Office of Scientific and Technical Information (OSTI)

    ... Lett., 89 (2006) 263512. 6 R. Meerheim, R. Nitsche, K. Leo, Appl. Phys. Lett., 93 (2008) 043310. 7 A. Dodabalapur, L.J. Rothberg, R. H. Jordan, T. M. Miller, R. E. Slusher, J. ...

  14. Apple Strength Issues

    SciTech Connect (OSTI)

    Syn, C

    2009-12-22

    Strength of the apple parts has been noticed to decrease, especially those installed by the new induction heating system since the LEP campaign started. Fig. 1 shows the ultimate tensile strength (UTS), yield strength (YS), and elongation of the installed or installation-simulated apples on various systems. One can clearly see the mean values of UTS and YS of the post-LEP parts decreased by about 8 ksi and 6 ksi respectively from those of the pre-LEP parts. The slight increase in elongation seen in Fig.1 can be understood from the weak inverse relationship between the strength and elongation in metals. Fig.2 shows the weak correlation between the YS and elongation of the parts listed in Fig. 1. Strength data listed in Figure 1 were re-plotted as histograms in Figs. 3 and 4. Figs. 3a and 4a show histograms of all UTS and YS data. Figs. 3b and 4b shows histograms of pre-LEP data and Figs. 3c and 4c of post-LEP data. Data on statistical scatter of tensile strengths have been rarely published by material suppliers. Instead, only the minimum 'guaranteed' strength data are typically presented. An example of strength distribution of aluminum 7075-T6 sheet material, listed in Fig. 5, show that its scatter width of both UTS and YS for a single sheet can be about 6 ksi and for multi-lot scatter can be as large as 11 ksi even though the sheets have been produced through well-controlled manufacturing process. By approximating the histograms shown in Figs. 3 and 4 by a Gaussian or similar type of distribution curves, one can plausibly see the strength reductions in the later or more recent apples. The pre-LEP data in Figs. 3b and 4b show wider scatter than the post-LEP data in Figs. 3c and 4c and seem to follow the binomial distribution of strength indicating that the apples might have been made from two different lots of material, either from two different vendors or from two different melts of perhaps slightly different chemical composition by a single vendor. The post

  15. Comment on 'A planar refractive x-ray lens made of nanocrystalline diamond'[J. Appl. Phys. 108, 123107 (2010)

    SciTech Connect (OSTI)

    Kroon, R. E.

    2013-05-28

    The material LuAG (lutetium aluminium garnet) has been confused with LAG (lanthanum aluminium garnet). In general, aluminium garnet phases only occur for the smaller trivalent metal cations and LAG is not known to have been synthesized.

  16. Corrigendum to “Suppression of Υ production in d+Au and Au+Au collisions at √ SNN = 200 GeV" [Phys. Lett. B 735 (2014) 127-137

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

    Adamczyk, L.

    2015-04-01

    We report measurements of Υ meson production in p + p, d + Au, and Au+Au collisions using the STAR detector at RHIC. We compare the Υ yield to the measured cross section in p + p collisions in order to quantify any modifications of the yield in cold nuclear matter using d + Au data and in hot nuclear matter using Au+Au data separated into three centrality classes. Our p + p measurement is based on three times the statistics of our previous result. We obtain a nuclear modification factor for Upsilon (1S + 2S + 3S) in themore »rapidity range |y| dAu = 0.79 ± 0.24(stat.) ± 0.03(syst.) ± 0.10(p + p syst.). A comparison with models including shadowing and initial state parton energy loss indicates the presence of additional cold-nuclear matter suppression. Similarly, in the top 10% most-central Au + Au collisions, we measure a nuclear modification factor of R AA = 0.49 ±0.1(stat.) ±0.02(syst.) ±0.06(p + p syst.), which is a larger suppression factor than that seen in cold nuclear matter. Our results are consistent with complete suppression of excited-state Upsilon mesons in Au + Au collisions. The additional suppression in Au + Au is consistent with the level expected in model calculations that include the presence of a hot, deconfined Quark–Gluon Plasma. However, understanding the suppression seen in d + Au is still needed before any definitive statements about the nature of the suppression in Au + Au can be made.« less

  17. Corrigendum to Suppression of ? production in d+Au and Au+Au collisions at ? SNN = 200 GeV" [Phys. Lett. B 735 (2014) 127-137

    SciTech Connect (OSTI)

    Adamczyk, L.

    2015-04-01

    We report measurements of ? meson production in p + p, d + Au, and Au+Au collisions using the STAR detector at RHIC. We compare the ? yield to the measured cross section in p + p collisions in order to quantify any modifications of the yield in cold nuclear matter using d + Au data and in hot nuclear matter using Au+Au data separated into three centrality classes. Our p + p measurement is based on three times the statistics of our previous result. We obtain a nuclear modification factor for Upsilon (1S + 2S + 3S) in the rapidity range |y| < 1 in d + Au collisions of RdAu = 0.79 0.24(stat.) 0.03(syst.) 0.10(p + p syst.). A comparison with models including shadowing and initial state parton energy loss indicates the presence of additional cold-nuclear matter suppression. Similarly, in the top 10% most-central Au + Au collisions, we measure a nuclear modification factor of R AA = 0.49 0.1(stat.) 0.02(syst.) 0.06(p + p syst.), which is a larger suppression factor than that seen in cold nuclear matter. Our results are consistent with complete suppression of excited-state Upsilon mesons in Au + Au collisions. The additional suppression in Au + Au is consistent with the level expected in model calculations that include the presence of a hot, deconfined QuarkGluon Plasma. However, understanding the suppression seen in d + Au is still needed before any definitive statements about the nature of the suppression in Au + Au can be made.

  18. Corrigendum to “Suppression of Υ production in d+Au and Au+Au collisions at √ SNN = 200 GeV" [Phys. Lett. B 735 (2014) 127-137

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

    Adamczyk, L.

    2015-04-01

    We report measurements of Υ meson production in p + p, d + Au, and Au+Au collisions using the STAR detector at RHIC. We compare the Υ yield to the measured cross section in p + p collisions in order to quantify any modifications of the yield in cold nuclear matter using d + Au data and in hot nuclear matter using Au+Au data separated into three centrality classes. Our p + p measurement is based on three times the statistics of our previous result. We obtain a nuclear modification factor for Upsilon (1S + 2S + 3S) in themore » rapidity range |y| < 1 in d + Au collisions of RdAu = 0.79 ± 0.24(stat.) ± 0.03(syst.) ± 0.10(p + p syst.). A comparison with models including shadowing and initial state parton energy loss indicates the presence of additional cold-nuclear matter suppression. Similarly, in the top 10% most-central Au + Au collisions, we measure a nuclear modification factor of R AA = 0.49 ±0.1(stat.) ±0.02(syst.) ±0.06(p + p syst.), which is a larger suppression factor than that seen in cold nuclear matter. Our results are consistent with complete suppression of excited-state Upsilon mesons in Au + Au collisions. The additional suppression in Au + Au is consistent with the level expected in model calculations that include the presence of a hot, deconfined Quark–Gluon Plasma. However, understanding the suppression seen in d + Au is still needed before any definitive statements about the nature of the suppression in Au + Au can be made.« less

  19. Feasibility of utilizing apple pomace

    SciTech Connect (OSTI)

    Stapleton, J.

    1983-06-01

    Apple pomace, the solid residue from juice production, is a solid waste problem in the Hudson Valley. This study investigates possibilities for converting it to a resource. The characteristics of the region's apple growing and processing industries are examined at length, including their potential for converting waste biomass. The properties of apple pomace are described. From interviews with Hudson Valley apple processors the following information is presented: quantities of pomace produced; seasonality of production; disposal procedures, costs, and revenues; trends in juice production; and attitudes toward alternatives. Literature research resulted in a list of more than 25 end uses for apple pomace of which eight were selected for analysis. Landfilling, landspreading, composting, animal feed, direct burning, gasification, anaerobic digestion (methane generation), and fermentation (ethanol production) were analyzed with regard to technical availability, regulatory and environmental impact, attitudes toward end use, and energetic and economic feasibility (See Table 19). The study recommends (1) a pilot anaerobic digestion plant be set up, (2) the possibility of extracting methane from the Marlborough landfill be investigated, (3) a study of the mid-Hudson waste conversion potential be conducted, and (4) an education program in alternative waste management be carried out for the region's industrial and agricultural managers.

  20. Connecting your Apple to Octopus 7600's

    SciTech Connect (OSTI)

    Barton, G.W. Jr.

    1983-01-17

    In UCID-19588, Communicating between the Apple and the Wang, we described how to take Apple DOS text files and send them to the Wang, and how to return Wang files to the Apple. It is also possible to use your Apple as an Octopus terminal, and to exchange files with Octopus 7600's. Presumably, you can also talk to the Crays, or any other part of the system. This connection has another virtue. It eliminates one of the terminals in your office.

  1. Energy accounting of apple processing operations

    SciTech Connect (OSTI)

    Romero, R.; Singh, R.P.; Brown, D.

    1981-01-01

    A thermal-energy accounting study was conducted at an apple processing plant. An analysis is given of thermal energy use and thermal efficiencies of an apple-juice single-effect evaporator and an apple-sauce cooker. 3 refs.

  2. Erratum: "'Water-cycle' mechanism for writing and erasingnanostructur...

    Office of Scientific and Technical Information (OSTI)

    Erratum: "'Water-cycle' mechanism for writing and erasing nanostructures at the LaAlO3SrTiO3 interface" Appl. Phys. Lett. 97, 173110 (2010) Citation Details In-Document Search ...

  3. NREL: Photovoltaics Research - Hao-Chih Yuan

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

    Yuan, "Multi-scale surface texture to improve blue response of nanoporous black silicon solar cells," to appear in Appl. Phys. Lett. J. Oh, T.G. Deutsch, H.-C. Yuan, and H.M....

  4. Erratum: "Impact of symmetry on the ferroelectric properties...

    Office of Scientific and Technical Information (OSTI)

    Impact of symmetry on the ferroelectric properties of CaTiO3 thin films" Appl. Phys. Lett. 106, 162904 (2015) Citation Details In-Document Search Title: Erratum: "Impact of ...

  5. Beamline 6-ID-B,C Publications

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

    of electron doped manganites," S. Middey, M. Kareev, D. Meyers, X. Liu, Y. Cao, S. Tripathi, D. Yazici, M.B. Maple, P.J. Ryan, J.W. Freeland, J. Chakhalian, Appl. Phys. Lett....

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

    Office of Scientific and Technical Information (OSTI)

    Title: Ultrafast Terahertz-Induced Response of GeSbTe Phase-Change Materials ... Resource Relation: Journal Name: Appl. Phys. Lett.; Journal Volume: 104; Journal Issue: 25 Research ...

  7. V-191: Apple Mac OS X Multiple Vulnerabilities | Department of...

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

    1: Apple Mac OS X Multiple Vulnerabilities V-191: Apple Mac OS X Multiple Vulnerabilities July 3, 2013 - 6:00am Addthis PROBLEM: Apple has issued a security update for Mac OS X...

  8. Appling County, Georgia: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    Georgia Appling County Pellets Places in Appling County, Georgia Baxley, Georgia Graham, Georgia Surrency, Georgia Retrieved from "http:en.openei.orgw...

  9. Production of alcohol from apple pomace

    SciTech Connect (OSTI)

    Hang, Y.D.; Lee, C.Y.; Woodams, E.E.; Cooley, H.J.

    1981-12-01

    Production of ethyl alcohol from apple pomace with a Montrachet strain of Saccharomyces cerevisiae is described. More than 43 grams of the ethyl alcohol could be produced per kg of apple pomace fermented at 30 degrees Celcius in 24 hours. The fermentation efficiency of this process was approximately 89%. (Refs. 9).

  10. Ergonomic evaluation of the Apple Adjustable Keyboard

    SciTech Connect (OSTI)

    Tittiranonda, P.; Burastero, S.; Shih, M.; Rempel, D.

    1994-05-01

    This study presents an evaluation of the Apple Adjustable Keyboard based on subjective preference and observed joint angles during typing. Thirty five keyboard users were asked to use the Apple adjustable keyboard for 7--14 days and rate the various characteristics of the keyboard. Our findings suggest that the most preferred opening angles range from 11--20{degree}. The mean ulnar deviation on the Apple Adjustable keyboard is 11{degree}, compared to 16{degree} on the standard keyboard. The mean extension was decreased from 24{degree} to 16{degree} when using the adjustable keyboard. When asked to subjectively rate the adjustable keyboard in comparison to the standard, the average subject felt that the Apple Adjustable Keyboard was more comfortable and easier to use than the standard flat keyboard.

  11. Response to Comment on Velocity boundary conditions at a tokamak resistive wall [Phys. Plasmas 21, 094701 (2014)

    SciTech Connect (OSTI)

    Strauss, H. R.

    2014-09-15

    A response is given to Comment on Velocity boundary conditions at a tokamak resistive wall? [Phys. Plasmas 21, 094701 (2014)].

  12. Production of fuels and chemicals from apple pomace

    SciTech Connect (OSTI)

    Hang, Y.D.

    1987-03-01

    Nearly 36 million tons of apples are produced annually in the US. Approximately 45% of the total US apple production is used for processing purposes. The primary by-product of apple processing is apple pomace. It consists of the presscake resulting from pressing apples for juice or cider, including the presscake obtained in pressing peel and core wastes generated in the manufacture of apple sauce or slices. More than 500 food processing plants in the US produce a total of about 1.3 million metric tons of apple pomace each year, and it is likely that annual disposal fees exceed $10 million. Apple pomace has the potential to be used for the production of fuels (ethanol and biogas containing 60% methane) and food-grade chemicals. These uses will be reviewed in this article.

  13. Communicating between the Apple and the Wang

    SciTech Connect (OSTI)

    Barton, G.W., Downey, R.

    1982-10-26

    This manual covers what the beginner needs to know in order to transfer files between an Apple's Microcomputer and a Wang's OIS Word Processor. We have also tried to indicate where the experienced user might want to look for additional details. We cover the use of Apple Writer )(, VisiTerm, VisiCalc, and EasyWriter Professional. For us, the two most useful connections are from Applewriter to Wang and from Visicalc to Wang. From Wang to Apple Writer via Visiterm may have some value. Files can be transferred by VisiTerm to Wang, but they arrive with RETURNS in the middle of words, which have to be edited out, so we do not recommend it. We describe how to go from EasyWriter to Wang, but we do not know how to go from Wang to EasyWriter. We see no reason to go from Wang to VisiCalc, so we haven't thought about it. All instructions are given for a typical configuration of the Apple, namely the one on which this manual was composed. It is detailed in the section on Hardware and Software.

  14. Innovative Hydropower Technology Now Powering an Apple Data Center |

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

    Department of Energy Innovative Hydropower Technology Now Powering an Apple Data Center Innovative Hydropower Technology Now Powering an Apple Data Center November 24, 2015 - 9:43am Addthis Innovative Hydropower Technology Now Powering an Apple Data Center Sarah Wagoner Sarah Wagoner Communications Specialist, Wind and Water Power Technologies Office Above: Completed Intake Structure. Water from the irrigation canal is divided in two as it approaches the plant. The existing drop structure

  15. V-115: Apple iOS Bugs Let Local Users Gain Elevated Privileges...

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

    5: Apple iOS Bugs Let Local Users Gain Elevated Privileges V-115: Apple iOS Bugs Let Local Users Gain Elevated Privileges March 20, 2013 - 12:08am Addthis PROBLEM: Apple iOS Bugs...

  16. V-113: Apple Safari Bugs Let Remote Users Execute Arbitrary Code...

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

    3: Apple Safari Bugs Let Remote Users Execute Arbitrary Code V-113: Apple Safari Bugs Let Remote Users Execute Arbitrary Code March 18, 2013 - 1:53am Addthis PROBLEM: Apple Safari...

  17. Apple Valley, California: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    Apple Valley, California: Energy Resources Jump to: navigation, search Equivalent URI DBpedia Coordinates 34.5008311, -117.1858759 Show Map Loading map... "minzoom":false,"map...

  18. Comment on 'Stimulated Raman scattering of laser from periodically spaced nanoparticles' [Phys. Plasmas 16, 093106 (2009)

    SciTech Connect (OSTI)

    Maraghechi, B.; Chakhmachi, A.

    2010-08-15

    Parashar [Phys. Plasmas 16, 093106 (2009)] studied the Raman backscattering of electromagnetic waves from nanoparticle lattice. We have demonstrated that the uncoupled dispersion curves have incorrect cutoff frequencies and the electromagnetic dispersion curves do not have correct asymptotic behavior at large frequencies. It has been shown that Parashar obtained an incorrect diagram of the growth rate for which the pump wave frequency goes below the cutoff frequency of the electromagnetic wave. Correct diagrams for the Raman backscattering as well as forward scattering are presented. It has been shown that backscattering has a larger maximum growth rate. We also found no instability if scattered radiation belongs to the lower branch of the dispersion curves.

  19. Erratum: Evidence of b-jet quenching in PbPb collisions at sNN=2.76TeV [Phys. Rev. Lett. 113 , 132301 (2014)

    SciTech Connect (OSTI)

    Chatrchyan, S.

    2015-07-10

    In our Letter, there was a component of the statistical uncertainty from the simulated PbPb Monte Carlo samples. This uncertainty was not propagated to all of the results. Figures 3 and 4 have been updated to reflect this source of uncertainty. In this case, the statistical uncertainties remain smaller than the systematic uncertainties in all cases such that the conclusions of the Letter are unaltered.

  20. Comment on Stationary self-focusing of Gaussian laser beam in relativistic thermal quantum plasma [Phys. Plasmas 20, 072703 (2013)

    SciTech Connect (OSTI)

    Habibi, M.; Ghamari, F.

    2014-06-15

    Patil and Takale in their recent article [Phys. Plasmas 20, 072703 (2013)], by evaluating the quantum dielectric response in thermal quantum plasma, have modeled the relativistic self-focusing of Gaussian laser beam in a plasma. We have found that there are some important shortcomings and fundamental mistakes in Patil and Takale [Phys. Plasmas 20, 072703 (2013)] that we give a brief description about them and refer readers to important misconception about the use of the Fermi temperature in quantum plasmas, appearing in Patil and Takale [Phys. Plasmas 20, 072703 (2013)].

  1. Comment on “Effects of damping solitary wave in a viscosity bounded plasma” [Phys. Plasmas 21, 022118 (2014)

    SciTech Connect (OSTI)

    Ghosh, Uday Narayan Chatterjee, Prasanta; Roychoudhury, Rajkumar

    2015-07-15

    Recently Gun Li et al. discussed “Effects of damping solitary wave in a viscosity bounded plasma” [Phys. Plasmas 21, 022118 (2014)]. The paper contains some serious errors which have been pointed out in this Comment.

  2. PyDecay/GraphPhys: A Unified Language and Storage System for Particle Decay Process Descriptions

    SciTech Connect (OSTI)

    Dunietz, Jesse N.; /MIT /SLAC

    2011-06-22

    To ease the tasks of Monte Carlo (MC) simulation and event reconstruction (i.e. inferring particle-decay events from experimental data) for long-term BaBar data preservation and analysis, the following software components have been designed: a language ('GraphPhys') for specifying decay processes, common to both simulation and data analysis, allowing arbitrary parameters on particles, decays, and entire processes; an automated visualization tool to show graphically what decays have been specified; and a searchable database storage mechanism for decay specifications. Unlike HepML, a proposed XML standard for HEP metadata, the specification language is designed not for data interchange between computer systems, but rather for direct manipulation by human beings as well as computers. The components are interoperable: the information parsed from files in the specification language can easily be rendered as an image by the visualization package, and conversion between decay representations was implemented. Several proof-of-concept command-line tools were built based on this framework. Applications include building easier and more efficient interfaces to existing analysis tools for current projects (e.g. BaBar/BESII), providing a framework for analyses in future experimental settings (e.g. LHC/SuperB), and outreach programs that involve giving students access to BaBar data and analysis tools to give them a hands-on feel for scientific analysis.

  3. From: Nicholas Ammann [mailto:nammann@apple.com]

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

    Wednesday, June 20, 2012 8:12 AM To: Exparte Communications Subject: Energy Conservation Standards for Battery Chargers and External Power Supplies; Proposed Rule Making - Ex Parte Communication Apple Inc. met with DOE to discuss the notice of proposed rule making the Department sent out regarding battery chargers and external power supplies. Below is a list of topics that Apple discussed with DOE. - Discussion regarding Battery Charger product Class 8 and that it does not scale with battery

  4. Celebrating Clean Energy Manufacturing in the Big Apple | Department of

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

    Energy Celebrating Clean Energy Manufacturing in the Big Apple Celebrating Clean Energy Manufacturing in the Big Apple June 15, 2016 - 10:51am Addthis Dr. Mark Johnson (left), Director of the Energy Department’s Advanced Manufacturing Office, moderates a panel on shared infrastructure and innovation ecosystems. Dr. Mark Johnson (left), Director of the Energy Department's Advanced Manufacturing Office, moderates a panel on shared infrastructure and innovation ecosystems. Dr. Dave

  5. New SRC APPLE ll Variable Polarization Beamline

    SciTech Connect (OSTI)

    M Severson; M Bissen; M Fisher; G Rogers; R Reininger; M Green; D Eisert; B Tredinnick

    2011-12-31

    SRC has recently commissioned a new Varied Line-Spacing Plane Grating Monochromator (VLS-PGM) utilizing as its source a 1 m long APPLE II insertion device in short-straight-section 9 of the Aladdin storage ring. The insertion device reliably delivers horizontal, vertical, and right and left circularly polarized light to the beamline. Measurements from an in situ polarimeter can be used for undulator corrections to compensate for depolarizing effects of the beamline. The beamline has only three optical elements and covers the energy range from 11.1 to 270 eV using two varied line-spacing gratings. A plane mirror rotates to illuminate the gratings at the correct angle to cancel the defocus term at all photon energies. An exit slit and elliptical-toroid refocusing mirror complete the beamline. Using a 50 {mu}m exit slit, the beamline provides moderate to high resolution, with measured flux in the mid 10{sup 12} (photons/s/200 mA) range, and a spot size of 400 {mu}m horizontal by 30 {mu}m vertical.

  6. V-020: Apple QuickTime Multiple Flaws Let Remote Users Execute...

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

    0: Apple QuickTime Multiple Flaws Let Remote Users Execute Arbitrary Code V-020: Apple QuickTime Multiple Flaws Let Remote Users Execute Arbitrary Code November 9, 2012 - 6:00am...

  7. U-239: Apple iPhone SMS Processing Flaw Lets Remote Users Spoof...

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

    U-165: Apple iOS Bugs Let Remote Users Execute Arbitrary Code and Spoof Address Bar URLs T-676: Apple iOS Certificate Chain Validation Flaw Lets Certain Remote Users Access or ...

  8. Using the Apple LaserWriter at ANL

    SciTech Connect (OSTI)

    Errion, S.M.; Thommes, M.M. Caruthers, C.M.

    1987-09-01

    Using the Apple LaserWriter at ANL (ANL/TM 452) explains how Argonne computer users (with CMS, MVS, or VAX/VMS accounts) can print quality text and graphics on the Apple LaserWriter. Currently, applications at Argonne that are compatible with the Apple LaserWriter include Waterloo Script, CA/ISSCO graphics software (i.e., Cuechart, Tellagraf, and Disspla), SAS/Graph, ANSYS (version 4.2), and some personal computer test and graphics software. This manual does not attempt to cover use of the Apple LaserWriter with other applications, though some information on the handling of PostScript-compatible files may be valid for other applications. Refer to the documentation of those applications to learn how they work with the Apple LaserWriter. Most of the information in this manual applies to the Allied Linotype L300P typesetter in Building 222. However, the typesetter is not a high volume output device and should be used primarily for high quality (1250 and 2500 dots per inch) final copy output for Laboratory publications prior to making printing plates. You should print all drafts and proof pages on LaserWriers or other printers compatible with the PostScript page description language. Consult with Graphic Arts (at extension 2-5603) to determine the availability of the typesetter for printing the final copy of your document or graphics application. Since the Apple LaserWriter itself produces good quality output (300 dots per inch), we expect that most internal documents consisting of test or graphics will continue to be printed at LaserWriters distributed throughout the Laboratory. 5 figs., 2 tabs.

  9. V-137: Apple Mac OS X update for Java | Department of Energy

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

    7: Apple Mac OS X update for Java V-137: Apple Mac OS X update for Java April 18, 2013 - 6:00am Addthis PROBLEM: Apple Mac OS X update for Java PLATFORM: Mac OS X 10.6, OS X Lion...

  10. DOE - NNSA/NFO -- News & Views Apple II

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

    Typical American Community Destroyed at Nevada National Security Site Photo - Apple II test, house on Yucca Flat On May 5, 1955 a 29-kiloton device named "Apple II" was detonated from a 500-foot tower on Yucca Flat. It was the second nationally televised nuclear test associated with an extensive civil effects program. The first shot was "Annie" on March 17, 1953. Annie was part of a civil effects test named Operation Cue, conducted by the Federal Civil Defense Administration

  11. Firm develops own EMS built on Apple computer

    SciTech Connect (OSTI)

    Pospisil, R.

    1982-04-05

    Firestone Fibers and Textile Co. programmed a $2000 desktop Apple II computer and special electronic panels designed by the engineering staff to perform process control and other energy-management functions. The system should reduce natural gas consumption 40% and save the company up to $75,000 a year by reducing the amount of hot air exhausted from fabric-treating ovens. The system can be expanded to control lights and space-conditioning equipment. The company is willing to negotiate with other firms to market the panels. The Apple II was chosen because it has a high capacity for data acquisition and testing and because of the available software. (DCK)

  12. T-673: Apple Safari Multiple Flaws Let Remote Users Execute Arbitrary Code, Conduct Cross-Site Scripting Attacks

    Broader source: Energy.gov [DOE]

    Apple Safari Multiple Flaws Let Remote Users Execute Arbitrary Code, Conduct Cross-Site Scripting Attacks

  13. Comment on A case study on the scaling of 1/f noise: La{sub 2?3}Sr{sub 1?3}MnO{sub 3} thin films [J. Appl. Phys. 113, 094901 (2013)

    SciTech Connect (OSTI)

    Barone, C. Pagano, S.; Mchin, L.; Guillet, B.; Routoure, J.-M.

    2014-03-21

    The problem of non-standard scaling of the 1/f noise in thin manganite films was revisited in the above paper, suggesting the quantum theory of fundamental flicker noise for the interpretation of the unusual dependence of the normalized Hooge parameter on the sample volume. Experimental evidence has been reported, showing that in these materials such volume dependence is, instead, an artifact of extrinsic noise sources, e.g., contact noise. Moreover, the proposed theoretical model implies a linear temperature dependence of the Hooge parameter, which is against the experimental data reported here. Based on these arguments, it is possible to conclude that the quantum theory of fundamental flicker noise cannot be applied to the case of La{sub 2?3}Sr{sub 1?3}MnO{sub 3} thin films.

  14. Comment on “Towards high efficiency thin-film crystalline silicon solar cells: The roles of light trapping and non-radiative recombinations” [J. Appl. Phys. 115, 094501 (2014)

    SciTech Connect (OSTI)

    Abenante, L.

    2015-01-14

    In the above paper, an analytical approach including a new solution to the differential diffusion equation in illuminated quasi-neutral regions (QNR) is exploited to calculate the short-circuit current density (J{sub sc}), open-circuit voltage (V{sub oc}), fill factor (FF), and efficiency (η) of light-trapping (LT) c-Si solar cells with a given structure. Comparisons with numerical results calculated by the Silvaco ATLAS device simulator in the same LT cells show that the analytical results are systematically overestimated. According to the authors, the inaccuracies in J{sub sc}, V{sub oc}, and η are due to the fact that assuming ideal collection from space-charge region (SCR) and using the superposition approximation introduce systematic errors into analytical models. In this comment, an analytical approach using reported solutions to the transport equations in QNR and SCR, where ideal collection from SCR is assumed and the superposition approximation is used, is shown to agree with both the Silvaco and PC1d numerical approaches in calculating J{sub sc}, V{sub oc}, and η, in the same LT devices as considered in the commented paper. Reasons for the inaccuracies detected in the commented paper are suggested.

  15. Use of an Apple IIe microcomputer for pyrolysis data acquisition

    SciTech Connect (OSTI)

    Not Available

    1988-02-01

    An Apple IIe microcomputer is being used to collect data and to control a pyrolysis system. Pyrolysis data for bitumen and kerogen are widely used to estimate source rock maturity. For a detailed analysis of kinetic parameters, however, data must be obtained more precisely than for routine pyrolysis. The authors discuss the program which controls the temperature ramp of the furnace that heats the sample, and collects data from a thermocouple in the furnace and from the flame ionization detector measuring evolved hydrocarbons. These data are stored on disk for later use by programs that display the results of the experiment or calculate kinetic parameters. The program is written in Applesoft BASIC with subroutines in Apple assembler for speed and efficiency.

  16. Mercury residues in south Florida apple snails (Pomacea paludosa)

    SciTech Connect (OSTI)

    Eisemann, J.D.; Beyer, W.N.; Morton, A.; Bennetts, R.E.

    1997-05-01

    Mercury concentrations in the sediments of south Florida wetlands have increased three fold in the last century. Because south Florida is home to many endemic and endangered species, it is important to understand the potential impacts of mercury in this ecosystem`s food web. Recent research by Malley et al. has shown mollusks to be sensitive indicators of methyl mercury which can reflect small differences in background methyl mercury concentrations. In this study, we attempted to determine if the apple snail (Pomacea paludosa) or its eggs are good indicators of bioavailable mercury. Then, using the apple snail as an indicator, we attempted to determine geographic differences in the concentrations of mercury in south Florida. 12 refs., 1 fig., 1 tab.

  17. From: Nicholas Ammann [mailto:nammann@apple.com]

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

    Tuesday, July 16, 2013 4:35 PM To: Exparte Communications Subject: Request for Information on Evaluating New Products for the Battery Chargers and External Power Supply Rulemaking - Ex Parte Communication Below are a list of topics that Apple Inc. discussed with DOE. - Timeline for the effective date of the DOE battery charger efficiency regulation and the external power supply regulation. - Flexibility of DOE Battery Charger efficiency mark, including using software or package as an alternate

  18. Comment on 'The diatomic dication CuZn{sup 2+} in the gas phase' [J. Chem. Phys. 135, 034306 (2011)

    SciTech Connect (OSTI)

    Fiser, Jiri; Diez, Reinaldo Pis; Franzreb, Klaus; Alonso, Julio A.

    2013-02-21

    In this Comment, the density functional theory (DFT) calculations carried out by Diez et al. [J. Chem. Phys. 135, 034306 (2011)] are revised within the framework of the coupled-cluster single double triple method. These more sophisticated calculations allow us to show that the {sup 2}{Sigma}{sup +} electronic ground state of CuZn{sup 2+}, characterized as the metastable ground state by DFT calculations, is a repulsive state instead. The {sup 2}{Delta} and {sup 2}{Pi} metastable states of CuZn{sup 2+}, on the other hand, should be responsible for the formation mechanism of the dication through the near-resonant electron transfer CuZn{sup +}+ Ar{sup +}{yields} CuZn{sup 2+}+ Ar reaction.

  19. Eur. Phys. J. C

    Office of Scientific and Technical Information (OSTI)

    ... arranged in a close-packed array held by a copper structure. The detectors are arranged in planes of 4 crystals each, with PTFE spacers that secure crystals to the copper frames. ...

  20. Eur. Phys. J. C

    Office of Scientific and Technical Information (OSTI)

    ... This is a very strong motivation for next generation experiments to exploit high ... nu- clei have provided a strong motivation to pursue another, extremely ...

  1. Atmos. Chem. Phys.,

    Office of Scientific and Technical Information (OSTI)

    ... organ- ics, through activity coefficients ... i.e., the chem- ical and physical processes that change ... all other stations were measuring for about a month or less. ...

  2. Plasma Phys. Control. Fusion

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

    38 (1996) A213-A225. Printed in the UK Measurement of magnetic fluctuation-induced heat transport in tokamaks and RFP G Fiksel, Roger D Bengtson†, M Cekic, D Den Hartog, S C Prager, P Pribyl‡, J Sarff, C Sovinec, M R Stoneking, R J Taylor‡, P W Terry, G R Tynan‡ and A J Wootton† Department of Physics University of Wisconsin - Madison, Madison, WI 53706, USA Abstract. The local electron energy flux produced by magnetic fluctuations has been measured directly in the edge plasma (r/a >

  3. U-170: Apple QuickTime Multiple Flaws Let Remote Users Execute Arbitrary Code

    Broader source: Energy.gov [DOE]

    Multiple vulnerabilities were reported in Apple QuickTime. A remote user can cause arbitrary code to be executed on the target user's system.

  4. U-239: Apple iPhone SMS Processing Flaw Lets Remote Users Spoof SMS Source

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

    Addresses | Department of Energy 39: Apple iPhone SMS Processing Flaw Lets Remote Users Spoof SMS Source Addresses U-239: Apple iPhone SMS Processing Flaw Lets Remote Users Spoof SMS Source Addresses August 20, 2012 - 7:00am Addthis PROBLEM: Apple iPhone SMS Processing Flaw Lets Remote Users Spoof SMS Source Addresses PLATFORM: Version(s): 6 beta 4 and prior versions ABSTRACT: A remote user can spoof SMS source addresses. Reference LINKS: SecurityTracker Alert ID: 1027410 Apple.com PCMag.com

  5. T-634: Apple Mac OS X MacDefender Fake Antivirus Malicious Software

    Office of Energy Efficiency and Renewable Energy (EERE)

    Apple Mac OS X users could infect their systems after visiting a malicious web page. Reports suggest that the Apple Safari web browser could allow automatic download and execution of the JavaScript-based malware because of an incorrectly set security option in Safari.

  6. Preparing the BESSY APPLE Undulators for Top-Up Operation

    SciTech Connect (OSTI)

    Bahrdt, J.; Frentrup, W.; Gaupp, A.; Scheer, M.

    2007-01-19

    BESSY plans to go to topping up operation in the near future. A high injection efficiency is essential to avoid particle losses inside the undulator magnets and to ensure a low radiation background in the beamlines. Dynamic and static multipoles of the insertion devices have to be minimized to accomplish this requirement. APPLE II devices show strong dynamic multipoles in the elliptical and vertical polarization mode. Measurements before and after shimming of these multipoles are presented. The static multipoles of the BESSY UE56-2 which are due to systematic block inhomgeneities have successfully been shimmed recovering the full dynamic aperture.

  7. Note: Derivation of two-photon circular dichroism—Addendum to “Two-photon circular dichroism” [J. Chem. Phys. 62, 1006 (1975)

    SciTech Connect (OSTI)

    Friese, Daniel H.

    2015-09-07

    This addendum shows the detailed derivation of the fundamental equations for two-photon circular dichroism which are given in a very condensed form in the original publication [I. Tinoco, J. Chem. Phys. 62, 1006 (1975)]. In addition, some minor errors are corrected and some of the derivations in the original publication are commented.

  8. Response to Comment on Magnetic geometry and physics of advanced divertors: The X-divertor and the snowflake? [Phys. Plasmas 21, 054701 (2014)

    SciTech Connect (OSTI)

    Kotschenreuther, Mike; Valanju, Prashant; Covele, Brent; Mahajan, Swadesh

    2014-05-15

    Relying on coil positions relative to the plasma, the Comment on Magnetic geometry and physics of advanced divertors: The X-divertor and the snowflake? [Phys. Plasmas 21, 054701 (2014)], emphasizes a criterion for divertor characterization that was critiqued to be ill posed [M. Kotschenreuther et al., Phys. Plasmas 20, 102507 (2013)]. We find that no substantive physical differences flow from this criteria. However, using these criteria, the successful NSTX experiment by Ryutov et al. [Phys. Plasmas 21, 054701 (2014)] has the coil configuration of an X-divertor (XD), rather than a snowflake (SF). On completing the divertor index (DI) versus distance graph for this NSTX shot (which had an inexplicably missing region), we find that the DI is like an XD for most of the outboard wetted divertor plate. Further, the proximity condition, used to define an SF [M. Kotschenreuther et al., Phys. Plasmas 20, 102507 (2013)], does not have a substantive physics basis to override metrics based on flux expansion and line length. Finally, if the criteria of the comment are important, then the results of NSTX-like experiments could have questionable applicability to reactors.

  9. T-676: Apple iOS Certificate Chain Validation Flaw Lets Certain Remote

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

    Users Access or Modify SSL/TLS Sessions | Department of Energy 76: Apple iOS Certificate Chain Validation Flaw Lets Certain Remote Users Access or Modify SSL/TLS Sessions T-676: Apple iOS Certificate Chain Validation Flaw Lets Certain Remote Users Access or Modify SSL/TLS Sessions July 26, 2011 - 1:06am Addthis PROBLEM: A vulnerability was reported in Apple iOS. A remote user with the ability to conduct a man-in-the-middle attack can access or modify SSL/TLS sessions. PLATFORM: iOS 4.2.5

  10. Solid state fermentation system for production of ethanol from apple pomace

    SciTech Connect (OSTI)

    Hang, Y.D.; Lee, C.Y.; Woodams, E.E.

    1982-01-01

    A solid state fermentation system for the production of ethanol from apple pomace with a Montrachet strain of Saccharomyces cerevisiae is described. The yields of ethanol varied from about 29 g to more than 40 g/kg of apple pomace, depending on the samples fermented. Separation of up to 99% of the ethanol from spent qpple pomace was achieved with a rotary vacuum evaporator. Alcohol fermentation of apple pomace might be an efficient method of alleviating waste disposal problems with the concomitant production of ethanol.

  11. A Fixed Gap APPLE II Undulator for SLS

    SciTech Connect (OSTI)

    Schmidt, T.; Imhof, A.; Ingold, G.; Jakob, B.; Vollenweider, C.

    2007-01-19

    To vary the polarization vector of an APPLE II undulator continuously from 0 - 180 deg., all four magnet arrays need to be movable. Following the adjustable-phase undulator approach by R. Carr, a 3.4 m long fixed gap undulator for SLS with a gap of 11.6 mm has been constructed. It will be installed in fall 2006. The gap drive is replaced by a pair-wise shift of the magnet arrays to change the energy, while the polarization is changed by shifts of diagonal arrays. The high injection efficiency and standard operation top-up mode at the SLS allows this simplified undulator design. The design as well as the operational aspects will be discussed.

  12. The Macolumn: Desperately seeking software. [Geologic software for the Apple Macintosh

    SciTech Connect (OSTI)

    Busbey, A.B.

    1988-08-01

    The Apple Macintosh has been available since 1984, but there has been little development of commercial geological software for it. The author briefly reviews what geological software is available for the Macintosh

  13. Experimental study of multichromatic terahertz wave propagation through planar micro-channels

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

    Shin, Young-Min -Min; Northern Illinois Univ., Dekalb, IL; Fermi National Accelerator Lab.; Baig, Anisullah; Barchfeld, Robert; Gamzina, Diana; Barnett, Larry R.; Luhmann, Jr., Neville C.

    2012-04-10

    Previous theoretical and numerical studies [Y. M. Shin and L. R. Barnett, Appl. Phys. Lett. 92, 091501 (2008) and Y. M. Shin et al., Appl. Phys. Lett. 93, 221504 (2008)] have reported that a planar micro-channel with an asymmetric corrugation array supports strongly confined propagation of broadband THz plasmonic waves. The highly broad spectral response is experimentally demonstrated in the near-THz regime of 0.19-0.265 THz. Signal reflection and transmission tests on the three designed micro-channels including directional couplers resulted in a full-width-half-maximum bandwidth of ~ 50-60GHz with an insertion loss of approximately -5 dB, which is in good agreement withmore » simulation data. As a result, these micro-structures can be utilized for free electron beam and electronic/optic integrated devices« less

  14. A possibility for using an APPLE undulator to generate a photon beam with transverse optical modes.

    SciTech Connect (OSTI)

    Sasaki, S.; McNulty, I.; Shimada, T.; JAEA

    2008-01-01

    We investigate use of an APPLE-type undulator for generating Laguerre-Gaussian (LG) and Hermite-Gaussian (HG) mode beams. We find that the second harmonic radiation in the circular mode corresponds to an LG beam with l=1, and the second harmonic in the linear mode corresponds to an HG beam with l=1. The combination of an APPLE undulator and conventional monochromator optics may provide an opportunity for a new type of experimental research in the synchrotron radiation community.

  15. Comment on General rotating quantum vortex filaments in the low-temperature Svistunov model of the local induction approximation [Phys. Fluids 26, 065105 (2014)

    SciTech Connect (OSTI)

    Hietala, Niklas Hnninen, Risto

    2014-11-15

    Van Gorder considers a formulation of the local induction approximation, which allows the vortex to move in the direction of the reference axis [General rotating quantum vortex filaments in the low-temperature Svistunov model of the local induction approximation, Phys. Fluids 26, 065105 (2014)]. However, in his analytical and numerical study he does not use it. A mistake in the torsion of a helical vortex is also corrected.

  16. Response to Comment on Stationary self-focusing of Gaussian laser beam in relativistic thermal quantum plasma [Phys. Plasmas 21, 064701 (2014)

    SciTech Connect (OSTI)

    Patil, S. D.; Takale, M. V.

    2014-06-15

    Habibi and Ghamari have presented a Comment on our paper [Phys. Plasmas 20, 072703 (2013)] by examining quantum dielectric response in thermal quantum plasma. They have modeled the relativistic self-focusing of Gaussian laser beam in cold and warm quantum plasmas and reported that self-focusing length does not change in both situations. In this response, we have reached the following important conclusions about the comment itself.

  17. Response to Comment on General rotating quantum vortex filaments in the low-temperature Svistunov model of the local induction approximation [Phys. Fluids 26, 119101 (2014)

    SciTech Connect (OSTI)

    Van Gorder, Robert A.

    2014-11-15

    In R. A. Van Gorder, General rotating quantum vortex filaments in the low-temperature Svistunov model of the local induction approximation, Phys. Fluids 26, 065105 (2014) I discussed properties of generalized vortex filaments exhibiting purely rotational motion under the low-temperature Svistunov model of the local induction approximation. Such solutions are stationary in terms of translational motion. In the Comment [N. Hietala, Comment on General rotating quantum vortex filaments in the low-temperature Svistunov model of the local induction approximation [Phys. Fluids 26, 065105 (2014)], Phys. Fluids 26, 119101 (2014)], the author criticizes my paper for not including translational motion (although it was clearly stated that the filament motion was assumed rotational). As it turns out, if one is interested in studying the geometric structure of solutions (which was the point of my paper), one obtains the needed qualitative results on the structure of such solutions by studying the purely rotational case. Nevertheless, in this Response I shall discuss the vortex filaments that have both rotational and translational motions. I then briefly discuss why one might want to study such generalized rotating filament solutions, in contrast to simple the standard helical or planar examples (which are really special cases). I also discuss how one can study the time evolution of filaments which exhibit more complicated dynamics than pure translation and rotation. Doing this, one can study non-stationary solutions which initially appear purely rotational and gradually display other dynamics as the filaments evolve.

  18. Effects of acid rain on apple tree productivity and fruit quality

    SciTech Connect (OSTI)

    Forsline, P.L.; Musselman, R.C.; Kender, W.J.; Dee, R.J.

    1983-01-01

    Mature 'McIntosh', 'Empire', and 'Golden Delicious' apple trees (Malus domestica Borkh.) were sprayed with simulated acid rain solutions in the pH range of 2.5 to 5.5 at full bloom in 1980 and in 1981. In 1981, weekly sprays were applied at pH 2.75 and pH 3.25. Necrotic lesions developed on apple petals at pH 2.5 with slight injury appearing at pH 3.0 and pH 3.5. Apple foliage had no acid rain lesions at any of the pH levels tested. Pollen germination was reduced at ph 2.5 in 'Empire'. Slight fruit set reduction at pH 2.5 was observed in 'McIntosh'. The incidence of russetting on 'Golden Delicious' fruits was ameliorated by the presence of rain-exclusion chambers but was not affected by acid rain. With season-long sprays at pH 2.75, there was a slight delay in maturity and lower weight of 'McIntosh' apples. Even at the lowest pH levels no detrimental effects of simulated acid rain were found on apple tree productivity and fruit quality when measured as fruit set, seed number per fruit, and fruit size and appearance.

  19. Comment on Motion of a helical vortex filament in superfluid {sup 4}He under the extrinsic form of the local induction approximation [Phys. Fluids 25, 085101 (2013)

    SciTech Connect (OSTI)

    Hietala, Niklas Hnninen, Risto

    2014-01-15

    We comment on the paper by Van Gorder [Motion of a helical vortex filament in superfluid {sup 4}He under the extrinsic form of the local induction approximation, Phys. Fluids 25, 085101 (2013)]. We point out that the flow of the normal fluid component parallel to the vortex will often lead into the DonnellyGlaberson instability, which will cause the amplification of the Kelvin wave. We explain why the comparison to local nonlinear equation is unreasonable, and remark that neglecting the motion in the x-direction is not reasonable for a Kelvin wave with an arbitrary wavelength and amplitude. The correct equations in the general case are also derived.

  20. Comment on “Generalized dispersion relation for electron Bernstein waves in a non-Maxwellian magnetized anisotropic plasma” [Phys. Plasmas 17, 102114 (2010)

    SciTech Connect (OSTI)

    Sharifi, M. Parvazian, A.

    2015-02-15

    In a recent paper [Deeba et al., Phys. Plasmas 17, 102114 (2010)], a generalized dielectric constant for the electron Bernstein waves using non-Maxwellian distribution functions was derived in a collisionless, uniform magnetized plasma. Using the Neumann series expansion for the products of Bessel functions, Deeba, Ahmad, and Murtaza derived the dispersion relations for both kappa and the generalized (r, q) distributions in a straightforward manner. However, their results are questionable, since the Neumann series expansion for the products of Bessel functions is valid for small argument, while for perpendicular propagation, it is necessary to evaluate special integrands for small as well as large arguments.

  1. Prickett and Lonnquist aquifer simulation program for the Apple II minicomputer

    SciTech Connect (OSTI)

    Hull, L.C.

    1983-02-01

    The Prickett and Lonnquist two-dimensional groundwater model has been programmed for the Apple II minicomputer. Both leaky and nonleaky confined aquifers can be simulated. The model was adapted from the FORTRAN version of Prickett and Lonnquist. In the configuration presented here, the program requires 64 K bits of memory. Because of the large number of arrays used in the program, and memory limitations of the Apple II, the maximum grid size that can be used is 20 rows by 20 columns. Input to the program is interactive, with prompting by the computer. Output consists of predicted lead values at the row-column intersections (nodes).

  2. Comment on “Rethinking first-principles electron transport theories with projection operators: The problems caused by partitioning the basis set” [J. Chem. Phys. 139, 114104 (2013)

    SciTech Connect (OSTI)

    Brandbyge, Mads

    2014-05-07

    In a recent paper Reuter and Harrison [J. Chem. Phys. 139, 114104 (2013)] question the widely used mean-field electron transport theories, which employ nonorthogonal localized basis sets. They claim these can violate an “implicit decoupling assumption,” leading to wrong results for the current, different from what would be obtained by using an orthogonal basis, and dividing surfaces defined in real-space. We argue that this assumption is not required to be fulfilled to get exact results. We show how the current/transmission calculated by the standard Greens function method is independent of whether or not the chosen basis set is nonorthogonal, and that the current for a given basis set is consistent with divisions in real space. The ambiguity known from charge population analysis for nonorthogonal bases does not carry over to calculations of charge flux.

  3. U-121: Apple iOS Bugs Let Remote Users Execute Arbitrary Code...

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

    ID: 1026774 Apple Security Updates About the security content of iOS 5.1 Software Update CVE-2012-0641, CVE-2012-0642, CVE-2012-0643, CVE-2011-3453, CVE-2012-0644, CVE-2012-0585,...

  4. Effects of acid rain on apple tree productivity and fruit quality

    SciTech Connect (OSTI)

    Forsline, P.L.; Musselman, R.C.; Kender, W.J.; Dee, R.J.

    1983-01-01

    Mature McIntosh, Empire, and Golden Delicious apple trees (Malus domestica) were sprayed with simulated acid rain solutions in the pH range of 2.5 to 5.5 at full bloom in 1980 and 1981. In 1981, weekly sprays were applied at pH 2.75 and pH 3.25. Necrotic lesions developed on apple petals at pH 2.5 with slight injury appearing at pH 3.0 and 3.5. Apple foliage had no acid rain lesions at any of the pH levels tested. Pollen germination was reduced at pH 2.5 in Empire. Slight fruit set reduction at pH 2.5 was observed in McIntosh. Even at the lowest pH levels no detrimental effects of simulated acid rain were found on apple tree productivity and fruit quality when measured as fruit set, seed number per fruit, and fruit size and appearance.

  5. U-165: Apple iOS Bugs Let Remote Users Execute Arbitrary Code and Spoof Address Bar URLs

    Broader source: Energy.gov [DOE]

    Two vulnerabilities were reported in Apple iOS. A remote user can cause arbitrary code to be executed on the target user's system. A remote user can spoof the address bar URL.

  6. The Macolumn - the plot thickens. [Review of a Apple Macintosh geologic software package and using a plotter with a Macintosh

    SciTech Connect (OSTI)

    Bushey, A.B. )

    1990-04-01

    Several geologic software packages are for the Apple Macintosh are reviewed along with an section on using a plotter with the Macintosh. The plotter is a CalComp Artisan 1025 8-pen plotter.

  7. Comment on Magnetic geometry and physics of advanced divertors: The X-divertor and the snowflake [Phys. Plasmas 20, 102507 (2013)

    SciTech Connect (OSTI)

    Ryutov, D. D. Cohen, R. H.; Rognlien, T. D.; Soukhanovskii, V. A.; Umansky, M. V.

    2014-05-15

    In the recently published paper Magnetic geometry and physics of advanced divertors: The X-divertor and the snowflake [Phys. Plasmas 20, 102507 (2013)], the authors raise interesting and important issues concerning divertor physics and design. However, the paper contains significant errors: (a) The conceptual framework used in it for the evaluation of divertor quality is reduced to the assessment of the magnetic field structure in the outer Scrape-Off Layer. This framework is incorrect because processes affecting the pedestal, the private flux region and all of the divertor legs (four, in the case of a snowflake) are an inseparable part of divertor operation. (b) The concept of the divertor index focuses on only one feature of the magnetic field structure and can be quite misleading when applied to divertor design. (c) The suggestion to rename the divertor configurations experimentally realized on NSTX (National Spherical Torus Experiment) and DIII-D (Doublet III-D) from snowflakes to X-divertors is not justified: it is not based on comparison of these configurations with the prototypical X-divertor, and it ignores the fact that the NSTX and DIII-D poloidal magnetic field geometries fit very well into the snowflake two-null prescription.

  8. Response of a fluid-immersed microcantilever close to a deformable body

    SciTech Connect (OSTI)

    Clarke, R. J.; Lee, T. C.; Cater, J. E.; Bachtiar, V.; Minton, J.

    2015-03-07

    The importance of hydrodynamics upon the response of a microcantilever immersed in a viscous fluid has been well established [J. E. Sader, J. Appl. Phys. 84, 64 (1998); C. A. Eysden and J. E. Sader, J. Appl. Phys. 101, 044908 (2007)]. It has previously been shown that the presence of a nearby rigid planar surface can significantly alter a microcantilever's non-contact response, through microcantilever–surface hydrodynamic interactions [C. P. Green and J. E. Sader, Phys. Fluids 17, 073102 (2005); C. P. Green and J. E. Sader, J. Appl. Phys. 98, 114913 (2005); R. J. Clarke et al., J. Fluid Mech. 545, 397426 (2005); R. J. Clarke et al., Phys. Rev. Lett. 96, 050801 (2006).]. In cases where the nearby surface is a finite-sized deformable body, such as in noncontact microrheology measurements, we expect to see further changes in the microcantilever's response. Hence, we here compute the thermal spectra of several microcantilevers in the presence of different compliant samples that have the characteristics of soft biological fibres. Our findings demonstrate that the elastohydrodynamic regime can substantially dictate the extent to which the compliance of a given body is evident in the microcantilever's thermal spectra, and suggest that certain nondimensional quantities should lie within particular, ranges for this to be the case. We expect these findings to be of interest in areas such as Atomic Force Microscopy, microsensing, and non-contact microrheology.

  9. The Macolumn - the Mac gets geophysical. [A review of geophysical software for the Apple Macintosh computer

    SciTech Connect (OSTI)

    Busbey, A.B. )

    1990-02-01

    Seismic Processing Workshop, a program by Parallel Geosciences of Austin, TX, is discussed in this column. The program is a high-speed, interactive seismic processing and computer analysis system for the Apple Macintosh II family of computers. Also reviewed in this column are three products from Wilkerson Associates of Champaign, IL. SubSide is an interactive program for basin subsidence analysis; MacFault and MacThrustRamp are programs for modeling faults.

  10. Evaluation of laboratory-scale in-vessel co-composting of tobacco and apple waste

    SciTech Connect (OSTI)

    Kop?i?, Nina Vukovi? Domanovac, Marija; Ku?i?, Dajana; Briki, Felicita

    2014-02-15

    Highlights: Apple and tobacco waste mixture was efficiently composted during 22 days. Physicalchemical and microbiological properties of the mixture were suitable the process. Evaluation of selected mathematical model showed good prediction of the temperature. The temperature curve was a mirror image of the oxygen concentration curve. The peak values of the temperature were occurred 9.5 h after the peak oxygen consumption. - Abstract: Efficient composting process requires set of adequate parameters among which physicalchemical properties of the composting substrate play the key-role. Combining different types of biodegradable solid waste it is possible to obtain a substrate eligible to microorganisms in the composting process. In this work the composting of apple and tobacco solid waste mixture (1:7, dry weight) was explored. The aim of the work was to investigate an efficiency of biodegradation of the given mixture and to characterize incurred raw compost. Composting was conducted in 24 L thermally insulated column reactor at airflow rate of 1.1 L min{sup ?1}. During 22 days several parameters were closely monitored: temperature and mass of the substrate, volatile solids content, C/N ratio and pH-value of the mixture and oxygen consumption. The composting of the apple and tobacco waste resulted with high degradation of the volatile solids (53.1%). During the experiment 1.76 kg of oxygen was consumed and the C/N ratio of the product was 11.6. The obtained temperature curve was almost a mirror image of the oxygen concentration curve while the peak values of the temperature were occurred 9.5 h after the peak oxygen consumption.

  11. Characterization of the Support and Drive System of the PETRA III APPLE Undulator

    SciTech Connect (OSTI)

    Bahrdt, J.; Baecker, H.-J.; Frentrup, W.; Gaupp, A.; Gottschlich, S.; Kuhn, C.; Scheer, M.; Schulz, B.; Gast, M.; Englisch, U.; Schoeps, A.; Tischer, M.

    2010-06-23

    Helmholtzzentrum Berlin has built an APPLE II undulator for the storage ring PETRA III. The device has a total length of 5m and a minimum gap of 11mm. The high magnetic forces in particular in the inclined mode have been analyzed by means of finite element methods (FEM). Specific mechanic components such as flexible joints have been optimized to cope with the gap- and shift-dependent 3D-forces and a sophisticated control and drive system has been implemented. After completion of the device, detailed laser interferometer measurements for all operation modes have been performed. The data are compared to the FEM simulations.

  12. Microsoft PowerPoint - Xiao_NanoLett-2013.pptx

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

    of GaS nanosheet photodetectors made on SiO 2 Si substrates and flexible polyethylene terephthalate (PET) substrates exhibit a photo-responsivity at 254nm up to 4.2 AW...

  13. Microsoft PowerPoint - NanoLett_Strelcov_2013.pptx

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

    and electric-field-driven resistance changes in Ca-BFO. The FORC-IV is shown to be a simple, powerful and flexible method for studying electrochemical activity of materials at...

  14. Microsoft PowerPoint - Chen_NanoLett-2013.pptx

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

    for producing individual and dispersible MCNs, including MCNs, HMCNs, and YSMCNs. The synthesis with high yield (76.6%) can be carried out on a relatively large scale (grams) by...

  15. Microsoft PowerPoint - NanoLett_Zhang_2013.pptx

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

    quasi-1D electronic transport in nanowires and nanowire arrays by combining epitaxial synthesis, 4-probe STM measurements, phenomelogical modeling and first-principles electronic...

  16. U-264: Apple OS X Lets Remote Users Execute Arbitrary Code and Local Users Gain Elevated Privileges

    Office of Energy Efficiency and Renewable Energy (EERE)

    Several vulnerabilities were reported in Apple OS X. A remote user can execute arbitrary code on the target system. A remote user can obtain a password hash in certain cases. A local user can obtain elevated privileges on the target system. A local user can obtain password keystrokes.

  17. Nanobumps on silicon created with polystyrene spheres and 248 or 308 nm laser pulses

    SciTech Connect (OSTI)

    Piparia, Reema; Rothe, Erhard W.; Baird, R. J.

    2006-11-27

    Huang et al. [Appl. Phys. Lett. 86, 161911 (2005)] formed arrays of nanobumps on a silicon substrate. They applied a 248 nm laser pulse to a surface monolayer of 1-{mu}m-diameter polystyrene spheres. The authors first replicated their experiment with 248 nm light. But when 308 nm pulses were applied instead, the nanobumps had a different shape and composition. At 248 nm, much of the laser light is absorbed in the polystyrene, which serves to quickly distort, melt, and ablate the sphere. At 308 nm, very little light is absorbed. The nanobumps from 248 nm radiation are organic polymers, while those formed with 308 nm pulses are silicon based.

  18. Experimental demonstration of laser to x-ray conversion enhancements with low density gold targets

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

    Shang, Wanli; Yang, Jiamin; Zhang, Wenhai; Li, Zhichao; Deng, Bo; Dong, Yunsong; Zhu, Tuo; Huang, Chengwu; Zhan, Xiayu; Mei, Yu; et al

    2016-02-12

    The enhancement of laser to x-ray conversion efficiencies using low density gold targets [W. L. Shang, J. M. Yang, and Y. S. Dong, Appl. Phys. Lett. 102, 094105 (2013)] is demonstrated. Laser to x-ray conversion efficiencies with 6.3% and 12% increases are achieved with target densities of 1 and 0.25 g/cm3, when compared with that of a solid gold target (19.3 g/cm3). Experimental data and numerical simulations are in good agreement. Lastly, the enhancement is caused by larger x-ray emission zone lengths formed in low density targets, which is in agreement with the simulation results.

  19. 2006 Publications Resulting from the Use of NERSC Resources

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

    6 2006 Publications Resulting from the Use of NERSC Resources On their Allocation Year 2007 ERCAP Request Forms Principal Investigators reported 1,437 refereed publications (published or submitted) for the preceding 12 months, based on using, at least in part, NERSC resources. A PI Mowfak Al-Jassim Y. Yan, M.M. Al-Jassim, and S.-H. Wei Doping of ZnO with group-IB elements Appl. Phys. Lett. In press (2006) Y. Yan, R. Noufi, and M.M. Al-Jassim Grain-Boundary Physics in Polycrystalline CuInSe2

  20. 2007 Publications Resulting from the Use of NERSC Resources

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

    7 2007 Publications Resulting from the Use of NERSC Resources On their Allocation Year 2008 ERCAP Request Forms Principal Investigators reported 1,464 refereed publications (published or submitted) for the preceding 12 months, based on using, at least in part, NERSC resources. A PI Mowfak Al-Jassim Y. Yan, J. L. F. Da Silva, S.-H. Wei, and M. Al-Jassim, "Atomic structure of In2O3ZnO system" Appl. Phys. Lett. 90, 261904 (2007). Y. Yan, J. Li, S.-H. Wei, and M. Al-Jassim, A possible

  1. Realization of an all optical exciton-polariton router

    SciTech Connect (OSTI)

    Marsault, Félix; Nguyen, Hai Son; Tanese, Dimitrii; Lemaître, Aristide; Galopin, Elisabeth; Sagnes, Isabelle; Amo, Alberto

    2015-11-16

    We report on the experimental realization of an all optical router for exciton-polaritons. This device is based on the design proposed by Flayac and Savenko [Appl. Phys. Lett. 103, 201105 (2013)], in which a zero-dimensional island is connected through tunnel barriers to two periodically modulated wires of different periods. Selective transmission of polaritons injected in the island, into either of the two wires, is achieved by tuning the energy of the island state across the band structure of the modulated wires. We demonstrate routing of ps polariton pulses using an optical control beam which controls the energy of the island quantum states, thanks to polariton-exciton interactions.

  2. Structure of a Rhamnogalacturonan Fragment from Apple Pectin: Implications for Pectin Architecture

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

    Wu, Xiangmei; Mort, Andrew

    2014-01-01

    A comore » mmercial apple pectin was sequentially digested with the cloned enzymes endopolygalacturonase, galactanase, arabinofuranosidase, xylogalacturonase, and rhamnogalacturonan hydrolase. The rhamnogalacturonan hydrolase-generated oligosaccharides were separated by ultrafiltration, anion exchange, and size-exclusion chromatography. Fractions from the ion exchange chromatography were pooled, lyophilized, and screened by MALDI-TOF MS. An oligosaccharide (RGP14P3) was identified and its structure, α -D-Gal p A- ( 1 → 2 ) - α -L-Rha p - ( 1 → 4 ) - α -D-Gal p A- ( 1 → 2 ) - α -L-Rha p - ( 1 → 4 ) - α -D-Gal p A, determined by 1D and 2D NMR spectrometry. This oligosaccharide probably represents a direct connection between homogalacturonan and rhamnogalacturonan in pectin. Alternatively, it could indicate that the nonreducing end of rhamnogalacturonan starts with a galacturonic acid residue.« less

  3. ATLAS note ATL-COM-PHYS-2009.

    SciTech Connect (OSTI)

    Chekanov, S.; Boomsma, J.; High Energy Physics

    2009-12-22

    The program InvMass has been developed to perform a general model-independent search for new particles using the ATLAS detector at the Large Hadron Collider (LHC), a proton-proton collider at CERN. The search is performed by examining statistically significant variations from the Standard Model predictions in exclusive event classes classified according to the number of identified objects. The program, called InvMass, finds all relevant particle groups identified with the ATLAS detector and analyzes their production rates, invariant masses and the total transverse momenta. The generic code of InvMass can easily be adapted for any particle types identified with the ATLAS detector. Several benchmark tests are presented.

  4. Atmos. Chem. Phys., 16, 4967-4986, ...

    Office of Scientific and Technical Information (OSTI)

    ... to source regions, impacting trans- portation (road vehicles and airports), military operations and photovoltaic energy production (see, e.g., Schroedter- Homscheidt et al., 2013). ...

  5. Atmos. Chem. Phys., 16, 4283-4305, ...

    Office of Scientific and Technical Information (OSTI)

    ... et al., 2007; Kang et al., 2007, 2011; Smith et al., 2009; Mas- soli etal., 2010; ... from a local excited state (Phillips and Smith, 2015), which is likely to result in low ...

  6. Atmos. Chem. Phys., 16, 5427-5451, ...

    Office of Scientific and Technical Information (OSTI)

    ... C., Docherty, K. S., Ulbrich, I. M., Grieshop, A. P., Robinson, A. L., Duplissy, J., Smith, J. D., Wil- son, K. R., Lanz, V A., Hueglin, C., Sun, Y. L., Tian, J., Laak- sonen, ...

  7. Atmos. Chem. Phys., 16, 5203-5227, ...

    Office of Scientific and Technical Information (OSTI)

    ... Meteorol., 6, 129- 150, 1974. Betts, A.: Chapter 4 The Physics and Parameterization of Moist Atmospheric Convection, in: Trade Cumulus: Observations and Modeling, edited by: Smith, ...

  8. Atmos. Chem. Phys., 16, 5853-5866, ...

    Office of Scientific and Technical Information (OSTI)

    ... Model study of the cross-tropopause transport of biomass burning pollution, Atmos. Chem. ... production of atomic nitrogen and oxygen by relativistic proton impact in air, J. Chem. ...

  9. Atmos. Chem. Phys., 16, 2611-2629, ...

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

    ... The narrower range of AIDA efficien- cies reinforces this point: this spectrum describes ... The range of efficien- cies is limited when there is no competition for water vapor ...

  10. Atmos. Chem. Phys., 15, 3831-3850, ...

    Office of Scientific and Technical Information (OSTI)

    ... This discrepancy, especially at high altitudes, may be caused, in part, by insufficient rainout (e.g., Wang etal., 2013). To improve our understanding about air pollution in the ...

  11. Atmos. Chem. Phys., 15, 153-172, ...

    Office of Scientific and Technical Information (OSTI)

    ... The three participating WRF-Chem models (PNNL, IOWA, and UW) show somewhat differing cloud characteris- tics but are similar in some other respects. Since they use dif- ferent PBL ...

  12. Microsoft Word - AdvMat Radaelli text+SI_appeal.doc

    Office of Scientific and Technical Information (OSTI)

    ... Lett. 97, 227201 (2006); V. Skumryev, V. Laukhin, I. Fina, X. Marti, F. Sanchez, M. Gospodinov and J. Fontcuberta, Phys. Rev. Lett. 106, 057206 (2011); X. He, Y. Wang, N. Wu, A. N. ...

  13. When worlds collide - Mac to MS-DOS. [Data transfer to and from Apple Macintosh computers and MS-DOS based personal computers

    SciTech Connect (OSTI)

    Busbey, A.B.

    1989-04-01

    A number of methods and products, both hardware and software, to allow data exchange between Apple Macintosh computers and MS-DOS based systems. These included serial null modem connections, MS-DOS hardware and/or software emulation, MS-DOS disk-reading hardware and networking.

  14. Study of Row Phase Dependent Skew Quadrupole Fields in Apple-II Type EPUs at the ALS

    SciTech Connect (OSTI)

    Steier, C.; Marks, S.; Prestemon, Soren; Robin, David; Schlueter, Ross; Wolski, Andrzej

    2004-05-07

    Since about 5 years, Apple-II type Elliptically Polarizing Undulators (EPU) have been used very successfully at the ALS to generate high brightness photon beams with arbitrary polarization. However, both EPUs installed so far cause significant changes of the vertical beamsize, especially when the row phase is changed to change the polarization of the photons emitted. Detailed measurements indicate this is caused by a row phase dependent skew quadrupole term in the EPUs. Magnetic measurements revealed the same effect for the third EPU to be installed later this year. All measurements to identify and quantify the effect with beam will be presented, as well as some results of magnetic bench measurements and numeric field simulations.

  15. Fine Structure Studies in Proton Emission

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

    (2006). " Fine Structure in Proton Emission from 145 Tm discovered with the Novel technique of Digital Signal Processing" M. Karny, et al., Phys. Rev. Lett. 90, 012502 (2003)....

  16. ARPES Provides Direct Evidence of Spin-Wave Coupling

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

    D. Schrupp, E. Rotenberg, K. Rossnagel, H. Koh, P. Blaha, and R. Claessen, "Electronic quasiparticle renormalization on the spin wave energy scale," Phys. Rev. Lett. 92, 097205...

  17. Comment on ''Scaling Laws of Turbulence and Heating of Fast Solar Wind: The Role of Density Fluctuations''

    SciTech Connect (OSTI)

    Forman, M. A.; Smith, C. W.; Vasquez, B. J.

    2010-05-07

    A Comment on the Letter by V. Carbone et al. Phys. Rev. Lett. 103, 061102 (2009). The authors of the Letter offer a Reply.

  18. Vladimir Stoica

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

    Etalon", Phys. Rev. Lett. 110, 086109 (2013). Y. Li, V.A. Stoica, L. Endicott, G. Wang, C. Uher, and R. Clarke, "Coherent optical phonon spectroscopy studies of...

  19. Purification of 1-aminocyclopropane-1-carboxylate synthase from apple fruits using s-adenosyl (3,4 sup 14 C)-methionine (SAM) as a probe

    SciTech Connect (OSTI)

    Yip, Wingkip; Dong, Jianguo,; Yang, Shang Fa )

    1989-04-01

    Tomato ACC synthase is inactivated by its substrate SAM, with the moiety of aminobutyrate being covalently linked to ACC synthase during the catalytic reactions. A partial purified ACC synthase (the catalytic activity 100 {mu}mol/h{center dot}mg protein) from pellets of apple extract was incubated with (3,4{sup 14}C) SAM. Only one radioactive peak was revealed in a C-4 reverse phase HPLC and one radioactive band on SDS-PAGE with an M.W. of 48 kDa. Apple ACC synthase in native form is resistant to V8, {alpha}-chromtrypsin and carboxylpeptidase A digestion, but effectively inactivated by trypsin and ficin, as demonstrated by both the activity assay and SAM labeling. The radioactive protein cut from the SDS-PAGE was injected to three mice, two of the mice showed responses to the protein in western blot analysis. The antibodies from mice is currently under characterization.

  20. U. S. Government purposes. ANL-HEP-CP-88-42

    Office of Scientific and Technical Information (OSTI)

    ... D6,177 (1972). 12. M. S. Goodman et al., Phys. Rev. Lett. 47, 293 (1981). 13. J. D. Bjorken, Phys. Rev. 1T9, 1547 (1969); R. P. Feynman, Photon-Hadron Inter- actions, Benjamin, New ...

  1. Neutrino Theory

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

    interactions, Phys.Lett. B 594, 347 (2004). A. Friedland and C. Lunardini, A Test of tau neutrino interactions with atmospheric neutrinos and K2K, Phys.Rev. D 72, 053009...

  2. Enhancement of lanthanide evaporation by complexation: Dysprosium tri-iodide mixed with indium iodide and thulium tri-iodide mixed with thallium iodide

    SciTech Connect (OSTI)

    Curry, J. J.; Henins, A.; Hardis, J. E.; Estupin, E. G.; Lapatovich, W. P.; Shastri, S. D.

    2013-09-28

    The vapors in equilibrium with condensates of DyI{sub 3}, DyI{sub 3}/InI, TmI{sub 3}, and TmI{sub 3}/TlI were observed over the temperature range from 900 K to 1400 K using x-ray induced fluorescence. The total densities of each element (Dy, Tm, In, Tl, and I) in the vapor, summed over all atomic and molecular species, were determined. Dramatic enhancements in the total vapor densities of Dy and Tm were observed in the vapors over DyI{sub 3}/InI and TmI{sub 3}/TlI as compared to the vapors over pure DyI{sub 3} and pure TmI{sub 3}, respectively. An enhancement factor exceeding 10 was observed for Dy at T? 1020 K, decreasing to 0 at T? 1250 K. An enhancement factor exceeding 20 was observed for Tm at T? 1040 K, decreasing to 0 at T? 1300 K. Such enhancements are expected from the formation of the vapor-phase hetero-complexes DyInI{sub 4} and TmTlI{sub 4}. Numerical simulations of the thermo-chemical equilibrium suggest the importance of additional complexes in liquid phases. A description of the measurement technique is given. Improvements in the absolute calibration lead to an approximately 40% correction to previously reported preliminary results [J. J. Curry et al., Chem. Phys. Lett. 507, 52 (2011); Appl. Phys. Lett. 100, 083505 (2012)].

  3. SciTech Connect:

    Office of Scientific and Technical Information (OSTI)

    Stanford U., Appl. Phys. Dept. SLAC" Name Name ORCID Search Authors Type: All BookMonograph ConferenceEvent Journal Article Miscellaneous Patent Program Document Software...

  4. Reorientation of the crystalline planes in confined single crystal nickel nanorods induced by heavy ion irradiation

    SciTech Connect (OSTI)

    Misra, Abha; Tyagi, Pawan K.; Rai, Padmnabh; Misra, D. S.; Ghatak, Jay; Satyam, P. V.; Avasthi, D. K.

    2006-08-28

    In a recent letter Tyagi et al. [Appl. Phys. Lett. 86, 253110 (2005)] have reported the special orientation of nickel planes inside multiwalled carbon nanotubes (MWCNTs) with respect to the tube axis. Heavy ion irradiation has been performed with 1.5 MeV Au{sup 2+} and 100 MeV Au{sup 7+} ions on these nickel filled MWCNTs at fluences ranging from 10{sup 12} to 10{sup 15} ions/cm{sup 2} at room temperature. Ion-induced modifications have been studied using high-resolution transmission electron microscopy. The diffraction pattern and the lattice imaging showed the presence of ion-induced planar defects on the tube walls and completely amorphized encapsulated nickel nanorods. The results are discussed in terms of thermal spike model.

  5. Early stage time evolution of a dense nanosecond microdischarge used in fast optical switching applications

    SciTech Connect (OSTI)

    Levko, Dmitry; Raja, Laxminarayan L.

    2015-12-15

    The mechanism of high-voltage nanosecond microdischarges is studied by the self-consistent two-dimensional Particle-in-Cell/Monte Carlo Collisions model. These microdischarges were recently proposed for use as fast switches of visible light in Bataller et al. [Appl. Phys. Lett. 105, 223501 (2014)]. The microdischarge is found to develop in two stages. The first stage is associated with the electrons initially seeded in the cathode-anode gap. These electrons lead to the formation of a cathode-directed streamer. The second stage starts when the secondary electron emission from the cathode begins. In this stage, a rather dense plasma (∼10{sup 16 }cm{sup −3}) is generated which results in the narrow cathode sheath. The electric field in this sheath exceeds the critical electric field which is necessary for the runaway electrons generation. We have found that the presence of these energetic electrons is crucial for the discharge maintenance.

  6. Absorbance and fluorometric sensing with capillary wells microplates

    SciTech Connect (OSTI)

    Tan, Han Yen; Cheong, Brandon Huey-Ping; Neild, Adrian; Wah Ng, Tuck; Liew, Oi Wah

    2010-12-15

    Detection and readout from small volume assays in microplates are a challenge. The capillary wells microplate approach [Ng et al., Appl. Phys. Lett. 93, 174105 (2008)] offers strong advantages in small liquid volume management. An adapted design is described and shown here to be able to detect, in a nonimaging manner, fluorescence and absorbance assays minus the error often associated with meniscus forming at the air-liquid interface. The presence of bubbles in liquid samples residing in microplate wells can cause inaccuracies. Pipetting errors, if not adequately managed, can result in misleading data and wrong interpretations of assay results; particularly in the context of high throughput screening. We show that the adapted design is also able to detect for bubbles and pipetting errors during actual assay runs to ensure accuracy in screening.

  7. Memory-bit selection and recording by rotating fields in vortex-core cross-point architecture

    SciTech Connect (OSTI)

    Yu, Y. -S.; Jung, H.; Lee, K. -S.; Fischer, P.; Kim, S. -K.

    2010-10-21

    In one of our earlier studies [Appl. Phys. Lett. 92, 022509 (2008)], we proposed a concept of robust information storage, recording and readout, which can be implementaed in nonvolatile magnetic random-access memories and is based on the energetically degenerated twofold ground states of vortex-core magnetizations. In the present study, we experimentally demonstrate reliable memory-bit selection and information recording in vortex-core cross-point architecture, specifically using a two-by-two vortex-state disk array. In order to efficiently switch a vortex core positioned at the intersection of crossed electrodes, two orthogonal addressing electrodes are selected, and then two Gaussian pulse currents of optimal pulse width and time delay are applied. Such tailored pulse-type rotating magnetic fields which occurs only at the selected intersection is prerequisite for a reliable memory-bit selection and low-power-consumption recording of information in the existing cross-point architecture.

  8. Passivation of deep level states caused by misfit dislocations in InGaAs on patterned GaAs

    SciTech Connect (OSTI)

    Matragrano, M.J.; Watson, G.P.; Ast, D.G. ); Anderson, T.J.; Pathangey, B. )

    1993-03-22

    Deep level transient spectroscopy (DLTS) and cathodoluminescence (CL) were used to study the hydrogen passivation of misfit dislocations in In[sub 0.06]Ga[sub 0.94]As/GaAs heterostructures. The CL observations indicate that hydrogen plasma exposure passivates most, but not all, of the dark line defects existing in the specimen prior to hydrogenation. The concentration of deep level defect states that cannot be passivated is below the detection limit of the DLTS instrument (approximately 4[times]10[sup 12] cm[sup [minus]3]). We find the passivation is stable after anneals at temperatures as high as 600 [degree]C, indicating that hydrogen passivation of misfit dislocations is at least as stable as that of the isolated point defect studied previously with DLTS [W. C. Dautremont-Smith, J. C. Nabity, V. Swaminathan, M. Stavola, J. Chevalier, C. W. Tu, and S. J. Pearton, Appl. Phys. Lett. [bold 49] 1098 (1986)].

  9. Ab Initio Coupled-Cluster Effective Interactions for the Shell...

    Office of Scientific and Technical Information (OSTI)

    Record 10.1103PhysRevLett.113.142502 http:dx.doi.org10.1103PhysRevLett.113.142502 Have feedback or suggestions for a way to improve these results? Save Share this Record ...

  10. Electron Elevator: Excitations across the Band Gap via a Dynamical...

    Office of Scientific and Technical Information (OSTI)

    Record 10.1103PhysRevLett.116.043201 http:dx.doi.org10.1103PhysRevLett.116.043201 Have feedback or suggestions for a way to improve these results? Save Share this Record ...

  11. Hall_B

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

    N∆ Transition Form Factor & Multipoles The CEBAF Large Acceptance Spectrometer (CLAS) www.jlab.org K. Joo et al., Phys. Rev. Lett. 88 (2002) 122001 F.X. Girod et al. (CLAS Collaboration), Phys. Rev. Lett. 100 (2008) 162002 L. El Fassi et al. (CLAS Collaboration), submitted for publication (2011)

  12. Microsoft PowerPoint - Gong_CNMS User Project Highlight_NanoLett...

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

    band gap of molybdenum disulfide has been tuned between 1.85 and 1.60 eV by changing Se concentration. Controlling and quantifying dopant concentration within each atomic layer...

  13. Microsoft PowerPoint - Ahn_2014_CNMSStaffScienceHighlight_ACSMacroLett...

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

    exclusion chromatography (SEC), small-angle neutron scattering (SANS), and coarse-grained molecular dynamics (CG-MD) simulations. Multiple aliquots were collected at various...

  14. Microsoft PowerPoint - Sacci_2015_UserProjectHighlight_NanoLett...

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

    Lithium dendrite formation is a major safety concern existing in Li-ion and Li-metal batteries. In situ ec-STEM (a liquid cell electron microscopy based characterization method)...

  15. Microsoft PowerPoint - OHern_2014_CNMS_UserScienceHighlight_NanoLett...

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

    1 1 1 Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States 2 Center for Nanophase Materials Sciences, Oak...

  16. Microsoft PowerPoint - Li_2014_CNMSUserProjectHighlight_NanoLett...

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

    work shows that the conformational dependence of the Coulomb charging energy of a nanocluster leads to a giant electroresistance, where charging induced conformational...

  17. Microsoft PowerPoint - NanoLett_2013_Highlight-Thermovoltage...

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

    response due to electron scattering effect at defects and boundaries in graphene. It provides a rare glimpse of thermal-electrical energy conversion process at an...

  18. Microsoft PowerPoint - Tian_2015_UserProjectHighlight_NanoLett

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

    A new aspect of graphene chemistry in terms of a special chemical bonding between the giant graphene "molecules" is demonstrated through rigorous theoretical calculations....

  19. Microsoft PowerPoint - Belianinov_2015_UserProjectHighlight_NanoLett...

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

    of Physics, Vilnius University, Vilnius, Lithuania LT-01513 3a Institute for Problems of Material Sciences, 3b Institute of Physics, National Academy of Sciences of Ukraine, Kyiv,...

  20. Apple latent spherical virus vectors for reliable and effective virus-induced gene silencing among a broad range of plants including tobacco, tomato, Arabidopsis thaliana, cucurbits, and legumes

    SciTech Connect (OSTI)

    Igarashi, Aki; Yamagata, Kousuke; Sugai, Tomokazu; Takahashi, Yukari; Sugawara, Emiko; Tamura, Akihiro; Yaegashi, Hajime; Yamagishi, Noriko; Takahashi, Tsubasa; Isogai, Masamichi; Takahashi, Hideki; Yoshikawa, Nobuyuki

    2009-04-10

    Apple latent spherical virus (ALSV) vectors were evaluated for virus-induced gene silencing (VIGS) of endogenous genes among a broad range of plant species. ALSV vectors carrying partial sequences of a subunit of magnesium chelatase (SU) and phytoene desaturase (PDS) genes induced highly uniform knockout phenotypes typical of SU and PDS inhibition on model plants such as tobacco and Arabidopsis thaliana, and economically important crops such as tomato, legume, and cucurbit species. The silencing phenotypes persisted throughout plant growth in these plants. In addition, ALSV vectors could be successfully used to silence a meristem gene, proliferating cell nuclear antigen and disease resistant N gene in tobacco and RCY1 gene in A. thaliana. As ALSV infects most host plants symptomlessly and effectively induces stable VIGS for long periods, the ALSV vector is a valuable tool to determine the functions of interested genes among a broad range of plant species.

  1. Comment on 'Undamped electrostatic plasma waves'[Phys. Plasmas...

    Office of Scientific and Technical Information (OSTI)

    scenario, however, at least four ingredients are mandatory. Several corrections of the conventional body of thought about the proper kinetic wave description are proposed. ...

  2. Microsoft PowerPoint - Ievlev_NaturePhys_2013.pptx

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

    now widely using in acoustic, nonlinear optical and emergent data storage devices. As such, the investigation of the polarization reversal mechanisms on the level of a single...

  3. Recent HRIBF Research - Deviations from U(5) Symmetry in 116Cd

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

    B297, 19 (1992). 15. S. Juutinen, et al., Phys. Lett. B386, 80 (1996). 16. R. M. A. L. Petit, et al., J. Phys. G 20, 1955 (1994). 17. M. D'eleze, et al., Nucl. Phys. A551, 269...

  4. Interpreting the behavior of a quarter-wave transmission line resonator in a magnetized plasma

    SciTech Connect (OSTI)

    Gogna, G. S. Turner, M. M.; Karkari, S. K.

    2014-12-15

    The quarter wave resonator immersed in a strongly magnetized plasma displays two possible resonances occurring either below or above its resonance frequency in vacuum, f{sub o}. This fact was demonstrated in our recent articles [G. S. Gogna and S. K. Karkari, Appl. Phys. Lett. 96, 151503 (2010); S. K. Karkari, G. S. Gogna, D. Boilson, M. M. Turner, and A. Simonin, Contrib. Plasma Phys. 50(9), 903 (2010)], where the experiments were carried out over a limited range of magnetic fields at a constant electron density, n{sub e}. In this paper, we present the observation of dual resonances occurring over the frequency scan and find that n{sub e} calculated by considering the lower resonance frequency is 25%–30% smaller than that calculated using the upper resonance frequency with respect to f{sub o}. At a given magnetic field strength, the resonances tend to shift away from f{sub o} as the background density is increased. The lower resonance tends to saturate when its value approaches electron cyclotron frequency, f{sub ce}. Interpretation of these resonance conditions are revisited by examining the behavior of the resonance frequency response as a function of n{sub e}. A qualitative discussion is presented which highlights the practical application of the hairpin resonator for interpreting n{sub e} in a strongly magnetized plasma.

  5. A Delicate Universe: Compactification Obstacles to D-brane Inflation...

    Office of Scientific and Technical Information (OSTI)

    10.1103PhysRevLett.99.141601; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA) Country of Publication: United States Language: ...

  6. Isomerism in Metal-Organic Frameworks: "Framework Isomers" |...

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

    Isomerism in Metal-Organic Frameworks: "Framework Isomers" Previous Next List Trevor A. Makal, Andrey A. Yakovenko, and Hong-Cai Zhou, J. Phys. Chem. Lett., 2011, 2 (14), pp ...

  7. 2015 Publications | Stanford Synchrotron Radiation Lightsource

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

    Phys. 118, 085707 (2015), doi: 10.10631.4928812 D. E. Acevedo-Cartagena, J. Zhu, E. ... Substrates", ACS Macro Lett. 4, 483 (2015), doi: 10.1021acsmacrolett.5b00038 J. C. ...

  8. Comment on the APEX {ital e}{sup +}{ital e}{sup {minus}} Experiment

    SciTech Connect (OSTI)

    Cowan, T.E.; Greenberg, J.S.

    1996-09-01

    A Comment on the Letter by I. Ahmad, {ital et} {ital al}., Phys. Rev. Lett. {bold 75}, 2658 (1995). The authors of the Letter offer a Reply. {copyright} {ital 1996 The American Physical Society.}

  9. MiniBooNE Nuebar Data Release

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

    Event Excess in the MiniBooNE Search for bar numu rightarrow bar nue Oscillations", arXiv:1007.1150 hep-ex,Phys.Rev.Lett.105,181801 (2010) The following MiniBooNE...

  10. Tomographic

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

    ... Phys. Lett. 91, 113106 2007. 8 K. Thompson, D. Lawrence, D. J. Larson, J. D. Olson, T. F. Kelly, and B. Gorman, Ultramicroscopy 107, 131 2007. 9 D. J. Larson, D. T. Foord, ...

  11. ABSTRACTS OF PAPERS PUBLISHED

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

    ... Makinaga, S. Goko, H. Akimune, T. Yamagata, H. Toyokawa, T. Matsumoto, H. Harano, S. Hohara, Y.-W. Lui, S. Hilaire, S. Peru, and A.J. Koning, Phys. Rev. Lett. 100, 162502 (2008). ...

  12. Comment on ''Phase Diagram of an Impurity in the Spin-1/ 2 Chain: Two-Channel Kondo Effect versus Curie Law''

    SciTech Connect (OSTI)

    Zvyagin, A. A.

    2001-07-30

    A Comment on the Letter by Sebatian Eggert, David P. Gustafsson, and Stefan Rommer Phys.Rev.Lett.86, 516 (2001). The authors of the Letter offer a Reply.

  13. ABSORPTION OF HARD AND THERMAL PHOTONS IN A QUARK-GLUON PLASMA...

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

    * 1 R. J. Fries, B. Muller, D. K. Srivastava, "High-energy photons from passage of jets through quark gluon plasma", Phys. Rev. Lett. 90, 132301 (2003). * 2 P.B. Arnold,...

  14. Papers Published April 1, 1996 - March 31, 1997

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

    E. Norbeck, D.E. Russ, M. Steiner, B. Stone, A.M. Vander Molen, G.D. Westfall, L.B. Yang, and S.J. Yennello Phys. Rev. Lett. 76, 1026 (1997) Entrance channel mass asymmetry...

  15. This manuscript has been authored ...

    Office of Scientific and Technical Information (OSTI)

    ... and C. Ocal, Nano Lett. 10, 3828 (2010). 9 A. Sawa, Materials today 11, 28 (2008). 10 S. Piskunov, E. Heifets, T. Jacob, E.A. Kotomin, D.E. Ellis, and E. Spohr, Phys. Rev. ...

  16. Lensless Imaging of Magnetic Nanostructures

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

    Gambino, S. Mangin, S. Roy, and P. Fischer, "X-ray diffraction microscopy of magnetic structures," Phys. Rev. Lett. 107, 033904 (2011). ALS Science Highlight 244 ALSNews Vol. 329...

  17. Direct Imaging of Asymmetric Magnetization Reversal

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

    and H. Ohldag, "Direct imaging of asymmetric magnetization reversal in exchange-biased FeMnPd bilayers by x-ray photoemission electron microscopy," Phys. Rev. Lett. 94, 107203...

  18. Lensless Imaging of Magnetic Nanostructures

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

    I. McNulty, R. Gambino, S. Mangin, S. Roy, and P. Fischer, "X-ray diffraction microscopy of magnetic structures," Phys. Rev. Lett. 107, 033904 (2011). ALS Science Highlight 244...

  19. Direct Imaging of Asymmetric Magnetization Reversal

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

    H. Ohldag, "Direct imaging of asymmetric magnetization reversal in exchange-biased FeMnPd bilayers by x-ray photoemission electron microscopy," Phys. Rev. Lett. 94, 107203 (2005...

  20. Time-Resolved Study of Bonding in Liquid Carbon

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

    Lindenberg, O.R. Monteiro, Z. Chang, R.W. Lee, and R.W. Falcone, "Bonding in liquid carbon studied by time-resolved x-ray absorption spectroscopy," Phys. Rev. Lett. 94 057407 (2005...

  1. Synopsis: Getting Under the Neutron Skin (Physics) | Jefferson Lab

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

    Synopsis: Getting Under the Neutron Skin (Physics) External Link: http://physics.aps.org/synopsis-for/10.1103/PhysRevLett.108.112502 By jlab_admin on Thu, 2012-03-15

  2. UNIRIB Publications: 2007 Bibliography

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

    J.H. Hamilton, J.K. Hwang, S. Ilyushkin, A. Korgul, W. Krolas, K. Li, R.D. Page, D. Simpson and J.A. Winger, Phys. Rev. Lett. 98, 212501 (2007) ConferencesMeetings Development...

  3. PAPERS PUBLISHED / 2006-2007 Progress in Research / Cyclotron...

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

    ... Comment on breakup densities of hot nuclei V. Viola, K. Kwiatkowski, S.J. Yennello, and J.B. Natowitz Phys. Lett. B 637, 176 (2006) Light ion-induced multifragmentation: The ISiS ...

  4. MiniBooNE Nue Data Release

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

    Neutrino Appearance at the m2 1 eV2 Scale", arXiv:0704.1500 hep-ex, Phys. Rev. Lett. 98, 231801 (2007) The following MiniBooNE information from the first oscillation paper in...

  5. MiniBooNE LowE Data Release

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

    Excess of Electron-Like Events From a 1 GeV Neutrino Beam", arXiv:0812.2243 hep-ex, Phys. Rev. Lett. 102, 101802 (2009) The following MiniBooNE information from the 2009...

  6. NREL: Energy Sciences - Su-Huai Wei

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

    Wei, S.-H. (2013). "Origin of the variation of exciton binding energy in semiconductors." Phys. Rev. Lett. (110); p. 016402. http:prl.aps.orgabstractPRLv110i1e016402. Huang,...

  7. MiniBooNE Numu/Numubar Disappearance Data Release

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

    for muon neutrino and antineutrino disappearance in MiniBooNE", arXiv:0903.2465 hep-ex, Phys. Rev. Lett. 103, 061802 (2009) The following MiniBooNE information from the 2009 numu...

  8. MiniBooNE Nuebar Data Release

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

    Electron Anti-Neutrino Appearance at the m2 1 eV2 Scale", arXiv:0904.1958 hep-ex, Phys. Rev. Lett. 103, 111801 (2009) The following MiniBooNE information from the 2009...

  9. UNIRIB Publications: 2013 Bibliography

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

    S.V. Paulauskas, A.V. Ramayya, J.A. Winger, M. Wolinska-Cichock and E.F. Zganjar, Phys. Rev. Lett. 109, 112501 (2012) Low-lying collective states in 120Cd populated by...

  10. Can't We All Just Get Along? | The Ames Laboratory

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

    P. C. Canfield, and Y. Furukawa Article Link: http:dx.doi.org10.1103PhysRevLett.115.137001 Journal Name: Physical Review Letters Volume: 115 Year: 2015 Page Number(s): 137001...

  11. Search for: All records | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    ... a few years back in perovskite MTiO3 (M Fe, Mn, Ni) Fennie, Phys. Rev. Lett. 100, 167203 (2008). We set out to stabilize this metastable perovskite structure by growing ...

  12. Strain-dependence Of The Structure And Ferroic Properties Of...

    Office of Scientific and Technical Information (OSTI)

    a few years back in perovskite MTiO3 (M Fe, Mn, Ni) Fennie, Phys. Rev. Lett. 100, 167203 (2008). We set out to stabilize this metastable perovskite structure by growing ...

  13. Field effect in the quantum Hall regime of a high mobility graphene wire

    SciTech Connect (OSTI)

    Barraud, C., E-mail: cbarraud@phys.ethz.ch, E-mail: clement.barraud@univ-paris-diderot.fr; Choi, T.; Ihn, T.; Ensslin, K. [Solid State Physics Laboratory, ETH Zrich, CH-8093 Zrich (Switzerland); Butti, P.; Shorubalko, I. [Swiss Federal Laboratories of Materials Science and Technologies, EMPA Elect. Metrol. Reliabil. Lab., CH-8600 Dbendorf (Switzerland); Taniguchi, T.; Watanabe, K. [National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044 (Japan)

    2014-08-21

    In graphene-based electronic devices like in transistors, the field effect applied thanks to a gate electrode allows tuning the charge density in the graphene layer and passing continuously from the electron to the hole doped regime across the Dirac point. Homogeneous doping is crucial to understand electrical measurements and for the operation of future graphene-based electronic devices. However, recently theoretical and experimental studies highlighted the role of the electrostatic edge due to fringing electrostatic field lines at the graphene edges [P. Silvestrov and K. Efetov, Phys. Rev. B 77, 155436 (2008); F. T. Vasko and I. V. Zozoulenko, Appl. Phys. Lett. 97, 092115 (2010)]. This effect originates from the particular geometric design of the samples. A direct consequence is a charge accumulation at the graphene edges giving a value for the density, which deviates from the simple picture of a plate capacitor and also varies along the width of the graphene sample. Entering the quantum Hall regime would, in principle, allow probing this accumulation thanks to the extreme sensitivity of this quantum effect to charge density and the charge distribution. Moreover, the presence of an additional and counter-propagating edge channel has been predicted [P. Silvestrov and K. Efetov, Phys. Rev. B 77, 155436 (2008)] giving a fundamental aspect to this technological issue. In this article, we investigate this effect by tuning a high mobility graphene wire into the quantum Hall regime in which charge carriers probe the electrostatic potential at high magnetic field close to the edges. We observe a slight deviation to the linear shift of the quantum Hall plateaus with magnetic field and we study its evolution for different filling factors, which correspond to different probed regions in real space. We discuss the possible origins of this effect including an increase of the charge density towards the edges.

  14. appl_household2001.pdf

    U.S. Energy Information Administration (EIA) Indexed Site

    Appliances Tables (Million U.S. Households; 60 pages, 240 kb) Contents Pages HC5-1a. Appliances by Climate Zone, Million U.S. Households, 2001 5 HC5-2a. Appliances by Year of Construction, Million U.S. Households, 2001 5 HC5-3a. Appliances by Household Income, Million U.S. Households, 2001 5 HC5-4a. Appliances by Type of Housing Unit, Million U.S. Households, 2001 5 HC5-5a. Appliances by Type of Owner-Occupied Housing Unit, Million U.S. Households, 2001 5 HC5-6a. Appliances by Type of Rented

  15. appl_household2001.pdf

    U.S. Energy Information Administration (EIA) Indexed Site

    0a. Appliances by Midwest Census Region, Million U.S. Households, 2001 Appliance Types and Characteristics RSE Column Factor: Total U.S. Midwest Census Region RSE Row Factors Total Census Division East North Central West North Central 0.5 1.0 1.2 1.5 Total .............................................................. 107.0 24.5 17.1 7.4 NE Kitchen Appliances Cooking Appliances Oven ......................................................... 101.7 23.8 16.6 7.2 NE 1

  16. appl_household2001.pdf

    U.S. Energy Information Administration (EIA) Indexed Site

    1a. Appliances by South Census Region, Million U.S. Households, 2001 Appliance Types and Characteristics RSE Column Factor: Total U.S. South Census Region RSE Row Factors Total Census Division South Atlantic East South Central West South Central 0.5 0.8 1.1 1.4 1.5 Total .............................................................. 107.0 38.9 20.3 6.8 11.8 NE Kitchen Appliances Cooking Appliances Oven ......................................................... 101.7 36.2 19.4 6.4 10.3 1.5 1

  17. appl_household2001.pdf

    U.S. Energy Information Administration (EIA) Indexed Site

    2a. Appliances by West Census Region, Million U.S. Households, 2001 Appliance Types and Characteristics RSE Column Factor: Total U.S. West Census Region RSE Row Factors Total Census Division Mountain Pacific 0.5 1.0 1.7 1.2 Total .............................................................. 107.0 23.3 6.7 16.6 NE Kitchen Appliances Cooking Appliances Oven ......................................................... 101.7 22.1 6.6 15.5 1.1 1

  18. appl_household2001.pdf

    U.S. Energy Information Administration (EIA) Indexed Site

    a. Appliances by Climate Zone, Million U.S. Households, 2001 Appliance Types and Characteristics RSE Column Factor: Total Climate Zone 1 RSE Row Factors Fewer than 2,000 CDD and -- 2,000 CDD or More and Fewer than 4,000 HDD More than 7,000 HDD 5,500 to 7,000 HDD 4,000 to 5,499 HDD Fewer than 4,000 HDD 0.4 1.9 1.1 1.1 1.2 1.1 Total .................................................. 107.0 9.2 28.6 24.0 21.0 24.1 7.8 Kitchen Appliances Cooking Appliances Oven

  19. appl_household2001.pdf

    U.S. Energy Information Administration (EIA) Indexed Site

    2a. Appliances by Year of Construction, Million U.S. Households, 2001 Appliance Types and Characteristics RSE Column Factor: Total Year of Construction RSE Row Factors 1990 to 2001 1 1980 to 1989 1970 to 1979 1960 to 1969 1950 to 1959 1949 or Before 0.4 1.5 1.2 1.1 1.2 1.1 0.9 Total ............................................... 107.0 15.5 18.2 18.8 13.8 14.2 26.6 4.2 Kitchen Appliances Cooking Appliances Oven ........................................... 101.7 14.3 17.2 17.8 12.9 13.7 25.9 4.2 1

  20. appl_household2001.pdf

    U.S. Energy Information Administration (EIA) Indexed Site

    4a. Appliances by Type of Housing Unit, Million U.S. Households, 2001 Appliance Types and Characteristics RSE Column Factor: Total Type of Housing Unit RSE Row Factors Single-Family Apartments in Buildings With Mobile Home Two to Four Units Five or More Units 0.4 0.5 1.7 1.6 1.9 Total ............................................... 107.0 73.7 9.5 17.0 6.8 4.2 Kitchen Appliances Cooking Appliances Oven ........................................... 101.7 69.1 9.4 16.7 6.6 4.3 1

  1. appl_household2001.pdf

    U.S. Energy Information Administration (EIA) Indexed Site

    5a. Appliances by Type of Owner-Occupied Housing Unit, Million U.S. Households, 2001 Appliance Types and Characteristics RSE Column Factor: Total Owner- Occupied Units Type of Owner-Occupied Housing Unit RSE Row Factors Single-Family Apartments in Buildings With Mobile Home Two to Four Units Five or More Units 0.3 0.4 2.1 3.1 1.3 Total ............................................... 72.7 63.2 2.1 1.8 5.7 6.7 Kitchen Appliances Cooking Appliances Oven ...........................................

  2. appl_household2001.pdf

    U.S. Energy Information Administration (EIA) Indexed Site

    6a. Appliances by Type of Rented Housing Unit, Million U.S. Households, 2001 Appliance Types and Characteristics RSE Column Factor: Total Rented Units Type of Rented Housing Unit RSE Row Factors Single-Family Apartments in Buildings With Mobile Home Two to Four Units Five or More Units 0.5 0.8 1.1 0.9 2.5 Total ............................................... 34.3 10.5 7.4 15.2 1.1 6.9 Kitchen Appliances Cooking Appliances Oven ........................................... 33.4 10.1 7.3 14.9 1.1

  3. appl_household2001.pdf

    U.S. Energy Information Administration (EIA) Indexed Site

    2001 Appliance Types and Characteristics RSE Column Factor: Total U.S. Four Most Populated States RSE Row Factors New York California Texas Florida 0.4 1.2 1.1 1.4 1.3 Total .............................................................. 107.0 7.1 12.3 7.7 6.3 NE Kitchen Appliances Cooking Appliances Oven ......................................................... 101.7 6.9 11.4 6.7 6.1 1.6 1 .............................................................. 95.2 6.2 10.7 6.3 6.0 2.1 2 or More

  4. appl_household2001.pdf

    U.S. Energy Information Administration (EIA) Indexed Site

    8a. Appliances by Urban/Rural Location, Million U.S. Households, 2001 Appliance Types and Characteristics RSE Column Factor: Total Urban/Rural Location 1 RSE Row Factors City Town Suburbs Rural 0.5 0.9 1.4 1.2 1.3 Total .............................................................. 107.0 49.9 18.0 21.2 17.9 4.1 Kitchen Appliances Cooking Appliances Oven ......................................................... 101.7 47.5 17.5 19.9 16.8 4.2 1

  5. appl_household2001.pdf

    U.S. Energy Information Administration (EIA) Indexed Site

    9a. Appliances by Northeast Census Region, Million U.S. Households, 2001 Appliance Types and Characteristics RSE Column Factor: Total U.S. Northeast Census Region RSE Row Factors Total Census Division Middle Atlantic New England 0.5 1.0 1.3 1.6 Total .............................................................. 107.0 20.3 14.8 5.4 NE Kitchen Appliances Cooking Appliances Oven ......................................................... 101.7 19.6 14.5 5.2 1.1 1

  6. appl_household2001.pdf

    U.S. Energy Information Administration (EIA) Indexed Site

    RSE Column Factor: Total 2001 Household Income Below Poverty Line Eli- gible for Fed- eral ... RSE Column Factor: Total 2001 Household Income Below Poverty Line Eli- gible for Fed- eral ...

  7. To be submitted to Appl

    Office of Scientific and Technical Information (OSTI)

    retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide ...

  8. Search for: All records | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    ... Fermi Surface And Quasiparticle Excitations of Sr2RhO4 Baumberger, F. ; Ingle, N.J.C. ; Meevasana, W. ; Shen, K.M. ; Lu, D.H. ; Stanford U., Appl. Phys. Dept. SLAC, SSRL ; Perry, ...

  9. Coherency Does Not Equate to Stability

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

    to Stability As-grown nanotwin (NT) copper (A) SEM image. (B) An edge-on inverse ... M. Kumar, "Topological view of the thermal stability of nanotwinned copper", Appl. Phys. ...

  10. Dielectric Resonator Metamasurfaces: Optical Magnetism Emission...

    Office of Scientific and Technical Information (OSTI)

    ... Laboratories Phase-locked Time Domain Spectroscopy 35s, 1350 nm 90s, 1550 nm Gate: 15s, 1050 nm Fiber Laser Svster AOM Lock-in Amplifier Sampling Oscilloscope WP Appl. Phys. ...

  11. Joint MiniBooNE, SciBooNE Disappearance Analysis Gary Cheng Warren Huelsnitz

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

    MiniBooNE, SciBooNE Disappearance Analysis Gary Cheng Warren Huelsnitz Columbia University Los Alamos National Lab Fermilab 31 Aug 2012 Friday, August 31, 2012 Acknowledgements * Teppei Katori * Joe Grange * Zarko Pavlovic * Kendall Mahn and Yasuhiro Nakajima 2 * Muon Neutrino CCQE Cross Section Analysis (Phys. Rev. D81, 092005 (2010)) * Neutrino Contamination in Antineutrino Mode (Phys. Rev. D84, 072005 (2011) and arXiv: 1107.5327) * Electron Neutrino (Antineutrino) Appearance (Phys. Rev. Lett.

  12. Rarefaction windows in a high-power impulse magnetron sputtering plasma

    SciTech Connect (OSTI)

    Palmucci, Maria; Britun, Nikolay; Konstantinidis, Stephanos; Snyders, Rony; Materia Nova Research Center, Parc Initialis, B-7000 Mons

    2013-09-21

    The velocity distribution function of the sputtered particles in the direction parallel to the planar magnetron cathode is studied by spatially- and time-resolved laser-induced fluorescence spectroscopy in a short-duration (20 ?s) high-power impulse magnetron sputtering discharge. The experimental evidence for the neutral and ionized sputtered particles to have a constant (saturated) velocity at the end of the plasma on-time is demonstrated. The velocity component parallel to the target surface reaches the values of about 5 km/s for Ti atoms and ions, which is higher that the values typically measured in the direct current sputtering discharges before. The results point out on the presence of a strong gas rarefaction significantly reducing the sputtered particles energy dissipation during a certain time interval at the end of the plasma pulse, referred to as rarefaction window in this work. The obtained results agree with and essentially clarify the dynamics of HiPIMS discharge studied during the plasma off-time previously in the work: N. Britun, Appl. Phys. Lett. 99, 131504 (2011)

  13. Optimization of the output and efficiency of a high power cascaded arc hydrogen plasma source

    SciTech Connect (OSTI)

    Vijvers, W. A. J.; Gils, C. A. J. van; Goedheer, W. J.; Meiden, H. J. van der; Veremiyenko, V. P.; Westerhout, J.; Lopes Cardozo, N. J.; Rooij, G. J. van; Schram, D. C.

    2008-09-15

    The operation of a cascaded arc hydrogen plasma source was experimentally investigated to provide an empirical basis for the scaling of this source to higher plasma fluxes and efficiencies. The flux and efficiency were determined as a function of the input power, discharge channel diameter, and hydrogen gas flow rate. Measurements of the pressure in the arc channel show that the flow is well described by Poiseuille flow and that the effective heavy particle temperature is approximately 0.8 eV. Interpretation of the measured I-V data in terms of a one-parameter model shows that the plasma production is proportional to the input power, to the square root of the hydrogen flow rate, and is independent of the channel diameter. The observed scaling shows that the dominant power loss mechanism inside the arc channel is one that scales with the effective volume of the plasma in the discharge channel. Measurements on the plasma output with Thomson scattering confirm the linear dependence of the plasma production on the input power. Extrapolation of these results shows that (without a magnetic field) an improvement in the plasma production by a factor of 10 over where it was in van Rooij et al. [Appl. Phys. Lett. 90, 121501 (2007)] should be possible.

  14. Normal and abnormal evolution of argon metastable density in high-density plasmas

    SciTech Connect (OSTI)

    Seo, B. H.; Kim, J. H.; You, S. J.

    2015-05-15

    A controversial problem on the evolution of Ar metastable density as a function of electron density (increasing trend versus decreasing trend) was resolved by discovering the anomalous evolution of the argon metastable density with increasing electron density (discharge power), including both trends of the metastable density [Daltrini et al., Appl. Phys. Lett. 92, 061504 (2008)]. Later, by virtue of an adequate physical explanation based on a simple global model, both evolutions of the metastable density were comprehensively understood as part of the abnormal evolution occurring at low- and high-density regimes, respectively, and thus the physics behind the metastable evolution has seemed to be clearly disclosed. In this study, however, a remarkable result for the metastable density behavior with increasing electron density was observed: even in the same electron density regime, there are both normal and abnormal evolutions of metastable-state density with electron density depending on the measurement position: The metastable density increases with increasing electron density at a position far from the inductively coupled plasma antenna but decreases at a position close to the antenna. The effect of electron temperature, which is spatially nonuniform in the plasma, on the electron population and depopulation processes of Argon metastable atoms with increasing electron density is a clue to understanding the results. The calculated results of the global model, including multistep ionization for the argon metastable state and measured electron temperature, are in a good agreement with the experimental results.

  15. Identification of nitrogen- and host-related deep-level traps in n-type GaNAs and their evolution upon annealing

    SciTech Connect (OSTI)

    Gelczuk, ?.; Henini, M.

    2014-07-07

    Deep level traps in as-grown and annealed n-GaNAs layers (doped with Si) of various nitrogen concentrations (N=0.2%, 0.4%, 0.8%, and 1.2%) were investigated by deep level transient spectroscopy. In addition, optical properties of GaNAs layers were studied by photoluminescence and contactless electroreflectance. The identification of N- and host-related traps has been performed on the basis of band gap diagram [Kudrawiec, Appl. Phys. Lett. 101, 082109 (2012)], which assumes that the activation energy of electron traps of the same microscopic nature decreases with the rise of nitrogen concentration in accordance with the N-related shift of the conduction band towards trap levels. The application of this diagram has allowed to investigate the evolution of donor traps in GaNAs upon annealing. In general, it was observed that the concentration of N- and host-related traps decreases after annealing and PL improves very significantly. However, it was also observed that some traps are generated due to annealing. It explains why the annealing conditions have to be carefully optimized for this material system.

  16. Electronic and optical properties of single excitons and biexcitons in type-II quantum dot nanocrystals

    SciTech Connect (OSTI)

    Koc, Fatih; Sahin, Mehmet E-mail: mehsahin@gmail.com

    2014-05-21

    In this study, a detailed investigation of the electronic and optical properties (i.e., binding energies, absorption wavelength, overlap of the electron-hole wave functions, recombination oscillator strength, etc.) of an exciton and a biexciton in CdTe/CdSe core/shell type-II quantum dot heterostructures has been carried out in the frame of the single band effective mass approximation. In order to determine the electronic properties, we have self-consistently solved the Poisson-Schrdinger equations in the Hartree approximation. We have considered all probable Coulomb interaction effects on both energy levels and also on the corresponding wave functions for both single exciton and biexciton. In addition, we have taken into account the quantum mechanical exchange-correlation effects in the local density approximation between same kinds of particles for biexciton. Also, we have examined the effect of the ligands and dielectric mismatch on the electronic and optical properties. We have used a different approximation proposed by Sahin and Koc [Appl. Phys. Lett. 102, 183103 (2013)] for the recombination oscillator strength of the biexciton for bound and unbound cases. The results obtained have been presented comparatively as a function of the shell thicknesses and probable physical reasons in behind of the results have been discussed in a detail.

  17. Coalescence-controlled and coalescence-free growth regimes during deposition of pulsed metal vapor fluxes on insulating surfaces

    SciTech Connect (OSTI)

    L, B.; Mnger, E. P.; Sarakinos, K.

    2015-04-07

    The morphology and physical properties of thin films deposited by vapor condensation on solid surfaces are predominantly set by the processes of island nucleation, growth, and coalescence. When deposition is performed using pulsed vapor fluxes, three distinct nucleation regimes are known to exist depending on the temporal profile of the flux. These regimes can be accessed by tuning deposition conditions; however, their effect on film microstructure becomes marginal when coalescence sets in and erases morphological features obtained during nucleation. By preventing coalescence from being completed, these nucleation regimes can be used to control microstructure evolution and thus access a larger palette of film morphological features. Recently, we derived the quantitative criterion to stop coalescence during continuous metal vapor flux deposition on insulating surfaceswhich typically yields 3-dimensional growthby describing analytically the competition between island growth by atomic incorporation and the coalescence rate of islands [L et al., Appl. Phys. Lett. 105, 163107 (2014)]. Here, we develop the analytical framework for entering a coalescence-free growth regime for metal vapor deposition on insulating substrates using pulsed vapor fluxes, showing that there exist three distinct criteria for suppressing coalescence that correspond to the three nucleation regimes of pulsed vapor flux deposition. The theoretical framework developed herein is substantiated by kinetic Monte Carlo growth simulations. Our findings highlight the possibility of using atomistic nucleation theory for pulsed vapor deposition to control morphology of thin films beyond the point of island density saturation.

  18. Convergence of shock waves generated by underwater electrical explosion of cylindrical wire arrays between different boundary geometries

    SciTech Connect (OSTI)

    Yanuka, D.; Zinowits, H. E.; Krasik, Ya. E.; Kozlov, M.

    2015-10-15

    The results of experiments and numerical simulations of a shock wave propagating between either conical or parabolic bounding walls are presented. The shock wave was generated by a microsecond timescale underwater electrical explosion of a cylindrical wire array supplied by a current pulse having an amplitude of ∼230 kA and a rise time of ∼1 μs. It is shown that with the same energy density deposition into the exploding wire array, the shock wave converges faster between parabolic walls, and as a result, the pressure in the vicinity of convergence is ∼2.3 times higher than in the case of conical walls. The results obtained are compared to those of earlier experiments [Antonov et al., Appl. Phys. Lett. 102, 124104 (2013)] with explosions of spherical wire arrays. It is shown that at a distance of ∼400 μm from the implosion origin the pressure obtained in the current experiments is higher than for the case of spherical wire arrays.

  19. Bulk and surface half-metallicity: The case of D0{sub 3}-type Mn{sub 3}Ge

    SciTech Connect (OSTI)

    Liu, Hao; Gao, G. Y. Hu, Lei; Ni, Yun; Zu, Fengxia; Zhu, Sicong; Wang, Shuling; Yao, K. L.

    2014-01-21

    Motivated by the experimental realization of D0{sub 22}-type Mn{sub 3}Ge (001) films [Kurt et al. Appl. Phys. Lett. 101, 132410 (2012)] and the structural stability of D0{sub 3}-type Heusler alloy Mn{sub 3}Ge [Zhang et al. J. Phys.: Condens. Matter 25, 206006 (2013)], we use the first-principles calculations based on the full potential linearized augmented plane-wave method to investigate the electronic and magnetic properties of D0{sub 3}-type Heusler alloy Mn{sub 3}Ge and its (001) surface. We show that bulk D0{sub 3}-Mn{sub 3}Ge is a half-metallic ferromagnet with the minority-spin energy gap of 0.52 eV and the magnetic moment of 1.00 μ{sub B} per formula unit. The bulk half-metallicity is preserved at the pure Mn-terminated (001) surface due to the large exchange split, but the MnGe-terminated (001) surface destroys the bulk half-metallicity. We also reveal that the surface stabilities are comparable between the D0{sub 3}-Mn{sub 3}Ge (001) and the experimental D0{sub 22}-Mn{sub 3}Ge (001), which indicates the feasibility to grow the Mn{sub 3}Ge (001) films with D0{sub 3} phase other than D0{sub 22} one. The surface half-metallicity and stability make D0{sub 3}-Mn{sub 3}Ge a promising candidate for spintronic applications.

  20. Critical view to ''IGEX {sup 76}Ge neutrinoless double-beta decay experiment: Prospects for next generation experiments''

    SciTech Connect (OSTI)

    Klapdor-Kleingrothaus, H.V.; Dietz, A. [Max-Planck-Institut fuer Kernphysik, Postfach 10 39 80, D-69029 Heidelberg (Germany); Krivosheina, I. V. [Max-Planck-Institut fuer Kernphysik, Postfach 10 39 80, D-69029 Heidelberg (Germany); Radiophysical-Research Institute, Nishnii-Novgorod (Russian Federation)

    2004-10-01

    Recently, a paper entitled 'The IGEX {sup 76}Ge neutrinoless double-beta decay experiment: Prospects for next generation experiments' has been published [Phys. Rev. D 65, 092007 (2002)]. In view of the recently reported evidence for neutrinoless double-beta decay [Mod. Phys. Lett. A 16, 2409 (2001).; Found. Phys. 31, 1181 (2002); Phys. Lett. B 586, 198 (2004).], it is particularly unfortunate that the IGEX paper is rather incomplete in its presentation. We would like to point out in this Comment that and why it would be highly desirable to make more details about the experimental conditions and the analysis of IGEX available. We list some of the main points, which require further explanation. We also point to an arithmetic mistake in the analysis of the IGEX data, the consequence of which are too high half-life limits given in that paper.

  1. Probabilistic programmable quantum processors with multiple copies of program states

    SciTech Connect (OSTI)

    Brazier, Adam; Buzek, Vladimir; Knight, Peter L.

    2005-03-01

    We examine the execution of general U(1) transformations on programmable quantum processors. We show that, with only the minimal assumption of availability of copies of the 1-qubit program state, the apparent advantage of existing schemes proposed by G. Vidal et al. [Phys. Rev. Lett. 88, 047905 (2002)] and M. Hillery et al. [Phys. Rev. A 65, 022301 (2003)] to execute a general U(1) transformation with greater probability using complex program states appears not to hold.

  2. Phonon-deficit effect in superconductors in a strong microwave field

    SciTech Connect (OSTI)

    Gulyan, A.M.; Zharkov, G.F.

    1981-08-20

    The phonon flux from a thin superconducting film irradiated by a microwave field is derived. It is shown that in intense microwave fields, as in the case of weak fields, studied previously )A. M. Gulian (Gulyan) and G. F. Zharkov, Phys. Lett. 80A, 79 (1980); Zh. Eksp. Teor. Fiz. 80, 303 (1981) (Sov. Phys. JETP 53, 154 (1981))), phonons are not emitted in a narrow spectral interval of phonon frequencies and are instead absorbed from the heat reservoir by the film.

  3. Appling County Pellets | Open Energy Information

    Open Energy Info (EERE)

    County Pellets Place: Graham, Georgia Zip: 31513 Sector: Biomass Product: Producer of wood pellets and other biomass products located in Georgia. Coordinates: 47.055765,...

  4. Public Data Set: High Confinement Mode and Edge Localized Mode Characteristics in a Near-Unity Aspect Ratio Tokamak

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Thome, Kathreen E. [University of Wisconsin-Madison] (ORCID:0000000248013922); Bongard, Michael W. [University of Wisconsin-Madison] (ORCID:0000000231609746); Barr, Jayson L. [University of Wisconsin-Madison] (ORCID:0000000177685931); Bodner, Grant M. [University of Wisconsin-Madison] (ORCID:0000000324979172); Burke, Marcus G. [University of Wisconsin-Madison] (ORCID:0000000176193724); Fonck, Raymond J. [University of Wisconsin-Madison] (ORCID:0000000294386762); Kriete, David M. [University of Wisconsin-Madison] (ORCID:0000000236572911); Perry, Justin M. [University of Wisconsin-Madison] (ORCID:0000000171228609); Schlossberg, David J. [University of Wisconsin-Madison] (ORCID:0000000287139448)

    2016-04-27

    This data set contains openly-documented, machine readable digital research data corresponding to figures published in K.E. Thome et al., 'High Confinement Mode and Edge Localized Mode Characteristics in a Near-Unity Aspect Ratio Tokamak,' Phys. Rev. Lett. 116, 175001 (2016).

  5. Structures and stability of metal-doped GenM (n = 9, 10) clusters

    Office of Scientific and Technical Information (OSTI)

    ... Chem. 13, i73 (2oo2). 19 J. G. Han, Chem. Phys. 286, i8i (2oo3). 20 V. Kumar, A. K. Singh, and Y. Kawazoe, Nano Lett. 4, 677 (2oo4). 21 D. Bandyopadhyay, P. Kaur, and P. Sen, J. ...

  6. Zahirul Islam

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

    Revealed by X-Ray Diffraction in Pulsed Magnetic Fields," J.P.C. Ruff, J.-H. Chu, H.-H. Kuo, R.K. Das, H. Nojiri, I.R. Fisher, Z. Islam, Phys. Rev. Lett. 109, 027004 (2012)....

  7. Nuclear magnetic resonance implementation of a quantum clock synchronization algorithm

    SciTech Connect (OSTI)

    Zhang Jingfu; Long, G.C; Liu Wenzhang; Deng Zhiwei; Lu Zhiheng

    2004-12-01

    The quantum clock synchronization (QCS) algorithm proposed by Chuang [Phys. Rev. Lett. 85, 2006 (2000)] has been implemented in a three qubit nuclear magnetic resonance quantum system. The time difference between two separated clocks can be determined by measuring the output states. The experimental realization of the QCS algorithm also demonstrates an application of the quantum phase estimation.

  8. Electromagnetic model for near-field microwave microscope with atomic resolution: Determination of tunnel junction impedance

    SciTech Connect (OSTI)

    Reznik, Alexander N.

    2014-08-25

    An electrodynamic model is proposed for the tunneling microwave microscope with subnanometer space resolution as developed by Lee et al. [Appl. Phys. Lett. 97, 183111 (2010)]. Tip-sample impedance Z{sub a} was introduced and studied in the tunneling and non-tunneling regimes. At tunneling breakdown, the microwave current between probe and sample flows along two parallel channels characterized by impedances Z{sub p} and Z{sub t} that add up to form overall impedance Z{sub a}. Quantity Z{sub p} is the capacitive impedance determined by the near field of the probe and Z{sub t} is the impedance of the tunnel junction. By taking into account the distance dependences of effective tip radius r{sub 0}(z) and tunnel resistance R{sub t}(z)?=?Re[Z{sub t}(z)], we were able to explain the experimentally observed dependences of resonance frequency f{sub r}(z) and quality factor Q{sub L}(z) of the microscope. The obtained microwave resistance R{sub t}(z) and direct current tunnel resistance R{sub t}{sup dc}(z) exhibit qualitatively similar behavior, although being largely different in both magnitude and the characteristic scale of height dependence. Interpretation of the microwave images of the atomic structure of test samples proved possible by taking into account the inductive component of tunnel impedance ImZ{sub t}?=??L{sub t}. Relation ?L{sub t}/R{sub t}???0.235 was obtained.

  9. Route to polarization switching induced by optical injection in vertical-cavity surface-emitting lasers

    SciTech Connect (OSTI)

    Sciamanna, M.; Panajotov, K.

    2006-02-15

    We perform a theoretical investigation of the polarization dynamics in a vertical-cavity surface-emitting laser (VCSEL) subject to orthogonal optical injection, i.e., the injected field has a linear polarization (LP) orthogonal to that of the free-running VCSEL. In agreement with previous experiments [Z. G. Pan et al., Appl. Phys. Lett. 63, 2999 (1993)], an increase of the injection strength may lead to a polarization switching accompanied by an injection locking. We find that this route to polarization switching is typically accompanied by a cascade of bifurcations to wave-mixing dynamics and time-periodic and possibly chaotic regimes. A detailed mapping of the polarization dynamics in the plane of the injection parameters (detuning, injection strength) unveils a large richness of dynamical scenarios. Of particular interest is the existence of another injection-locked solution for which the two LP modes both lock to the master laser frequency, i.e., an elliptically polarized injection-locked (EPIL) steady state. Modern continuation techniques allow us to unveil an unfolding mechanism of the EPIL solution as the detuning varies and also to link the existence of the EPIL solution to a resonance condition between the master laser frequency and the free-running frequency of the normally depressed LP mode in the slave laser. We furthermore report an additional case of bistability, in which the EPIL solution may coexist with the second injection-locked solution (the one being locked to the master polarization). This case of bistability is a result of the interaction between optical injection and the two-polarization-mode characteristics of VCSEL devices.

  10. Geralyn "Sam" Zeller

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

    Reference From: Lipari et al., Phys. Rev. Lett. 74, 4384 (1995) Quasi Elastic Scattering: Author Title Reference L.A. Ahrens et al. "Determination of the Neutrino Fluxes in the Brookhaven Wide-Band Beam" Phys. Rev. D34, 75 (1986) N.J. Baker et al. "Quasi-Elastic Neutrino Scattering: A Measurement of the Weak Nucleon Axial-Vector Form Factor" Phys. Rev. D23, 2499 (1981) C. Bleve et al. "Effects of Nuclear Re-Interactions in Quasi-Elastic Neutrino-Nucleus Scattering"

  11. Discrete kinetic eigenmode spectra of electron plasma oscillations in weakly collisional plasma: A numerical study

    SciTech Connect (OSTI)

    Black, Carrie; Ng, C. S.

    2013-01-15

    It has been demonstrated that in the presence of weak collisions, described by the Lenard-Bernstein (LB) collision operator, the Landau-damped solutions become true eigenmodes of the system and constitute a complete set [C.-S. Ng et al., Phys. Rev. Lett. 83, 1974 (1999) and C. S. Ng et al., Phys. Rev. Lett. 96, 065002 (2004)]. We present numerical results from an Eulerian Vlasov code that incorporates the Lenard-Bernstein collision operator [A. Lenard and I. B. Bernstein, Phys. Rev. 112, 1456 (1958)]. The effect of collisions on the numerical recursion phenomenon seen in Vlasov codes is discussed. The code is benchmarked against exact linear eigenmode solutions in the presence of weak collisions, and a spectrum of Landau-damped solutions is determined within the limits of numerical resolution. Tests of the orthogonality and the completeness relation are presented.

  12. Center for Materials at Irradiation and Mechanical Extremes:...

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

    M. T. Whittaker, R. E. Muenchausen, and R. C. Sze, "Crystal Growth and Optical Characterization of Cerium-doped Lu1.8Y0.2SiO5," J. Appl. Phys., 8812 (2000), pp. 7360-7362. J....

  13. VI-1 PAPERS PUBLISHED

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

    1 - March 31, 2012 Isoscalar giant resonances in 48 Ca, Y.-W. Lui, D. H. Youngblood, S. Shlomo, X. Chen, Y. Tokimoto, Krishichayan, M. Anders, and J. Button, Phys. Rev. C 83, 044327 (2011). Experimental validation of the largest calculated isospin-symmetry-breaking effect in a superallowed Fermi decay, D. Melconian, S. Triambak, C. Bordeanu, A. Garcia, J.C. Hardy, V.E. Iacob, N. Nica, H.I. Park, G. Tabacaru, L. Trache, I.S. Towner, R.E. Tribble and Y. Zhai, Phys. Rev. Lett. 107, 182301 (2011).

  14. Miami2010_miniboone_hray.pptx

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

    Miami 2010 MINIBOONE ν µ ν e ν e ν µ 2008! Miami 2010 -BUFTU 3FTVMUT GSPN .JOJ#PP/& ) 3BZ H. Ray, University of Florida Miami 2010 *OUSJHVF JO 0TDJMMBUJPO 3FTVMUT .JOJ#PP/& NPUJWBUFE CZ BO PCTFSWFE FYDFTT PG F JO B CFBN -4/% FYQFSJNFOU JO T 6TFE $$2& JOUFSBDUJPO F Q è F O &YDFTT )JHIMZ DPOUSPWFSTJBM SFTVMU H. Ray, University of Florida Phys. Rev. Lett. 77:3082-3085 (1996) Phys. Rev. C 58:2489-2511 (1998) Miami 2010 -4/% UPP NBOZ NBTTFT H. Ray, University of Florida LSND

  15. PAPERS PUBLISHED April 1, 2011 - March 31, 2012

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

    1 - March 31, 2012 Isoscalar giant resonances in 48Ca Y.-W. Lui, D. H. Youngblood, S. Shlomo, X. Chen, Y. Tokimoto, Krishichayan, M. Anders, and J. Button Phys. Rev. C 83, 044327 (2011) Experimental validation of the largest calculated isospin-symmetry-breaking effect in a superallowed Fermi decay D. Melconian, S. Triambak, C. Bordeanu, A. Garcia, J.C. Hardy, V.E. Iacob, N. Nica, H.I. Park, G. Tabacaru, L. Trache, I.S. Towner, R.E. Tribble and Y. Zhai Phys. Rev. Lett. 107, 182301 (2011) Precise

  16. MINERvA Publications

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

    MINERvA Publications "Neutrino Flux Predictions for the NuMI Beam" "First evidence of coherent K+ meson production in neutrino-nucleus scattering" Phys. Rev. Lett. 117, 061802 (2016) "Measurement of K+ production in charged-current νμ interactions" Phys. Rev. D 94, 012002 (2016) "Cross sections for neutrino and antineutrino induced pion production on hydrocarbon in the few-GeV region using MINERvA" accepted for publication by PRD "Evidence for

  17. Beneficial role of noise in artificial neural networks

    SciTech Connect (OSTI)

    Monterola, Christopher; Saloma, Caesar; Zapotocky, Martin

    2008-06-18

    We demonstrate enhancement of neural networks efficacy to recognize frequency encoded signals and/or to categorize spatial patterns of neural activity as a result of noise addition. For temporal information recovery, noise directly added to the receiving neurons allow instantaneous improvement of signal-to-noise ratio [Monterola and Saloma, Phys. Rev. Lett. 2002]. For spatial patterns however, recurrence is necessary to extend and homogenize the operating range of a feed-forward neural network [Monterola and Zapotocky, Phys. Rev. E 2005]. Finally, using the size of the basin of attraction of the networks learned patterns (dynamical fixed points), a procedure for estimating the optimal noise is demonstrated.

  18. Kinetic simulations and reduced modeling of longitudinal sideband instabilities in non-linear electron plasma waves

    SciTech Connect (OSTI)

    Brunner, S.; Berger, R. L.; Cohen, B. I.; Hausammann, L.; Valeo, E. J.

    2014-10-01

    Kinetic Vlasov simulations of one-dimensional finite amplitude Electron Plasma Waves are performed in a multi-wavelength long system. A systematic study of the most unstable linear sideband mode, in particular its growth rate γ and quasi- wavenumber δk, is carried out by scanning the amplitude and wavenumber of the initial wave. Simulation results are successfully compared against numerical and analytical solutions to the reduced model by Kruer et al. [Phys. Rev. Lett. 23, 838 (1969)] for the Trapped Particle Instability (TPI). A model recently suggested by Dodin et al. [Phys. Rev. Lett. 110, 215006 (2013)], which in addition to the TPI accounts for the so-called Negative Mass Instability because of a more detailed representation of the trapped particle dynamics, is also studied and compared with simulations.

  19. Kinetic simulations and reduced modeling of longitudinal sideband instabilities in non-linear electron plasma waves

    SciTech Connect (OSTI)

    Brunner, S. Hausammann, L.; Berger, R. L. Cohen, B. I.; Valeo, E. J.

    2014-10-15

    Kinetic Vlasov simulations of one-dimensional finite amplitude Electron Plasma Waves are performed in a multi-wavelength long system. A systematic study of the most unstable linear sideband mode, in particular its growth rate ? and quasi- wavenumber ?k, is carried out by scanning the amplitude and wavenumber of the initial wave. Simulation results are successfully compared against numerical and analytical solutions to the reduced model by Kruer et al. [Phys. Rev. Lett. 23, 838 (1969)] for the Trapped Particle Instability (TPI). A model recently suggested by Dodin et al. [Phys. Rev. Lett. 110, 215006 (2013)], which in addition to the TPI accounts for the so-called Negative Mass Instability because of a more detailed representation of the trapped particle dynamics, is also studied and compared with simulations.

  20. Collimated proton acceleration in light sail regime with a tailored pinhole target

    SciTech Connect (OSTI)

    Wang, H. Y.; Zepf, M.; Yan, X. Q.

    2014-06-15

    A scheme for producing collimated protons from laser interactions with a diamond-like-carbon?+?pinhole target is proposed. The process is based on radiation pressure acceleration in the multi-species light-sail regime [B. Qiao et al., Phys. Rev. Lett. 105, 155002 (2010); T. P. Yu et al., Phys. Rev. Lett. 105, 065002 (2010)]. Particle-in-cell simulations demonstrate that transverse quasistatic electric field at TV/m level can be generated in the pinhole. The transverse electric field suppresses the transverse expansion of protons effectively, resulting in a higher density and more collimated proton beam compared with a single foil target. The dependence of the proton beam divergence on the parameters of the pinhole is also investigated.

  1. VOLUME

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

    Evidence of Stabilization in the Z-Pinch U. Shumlak, R. P. Golingo, and B. A. Nelson University of Washington, Aerospace and Energetics Research Program, Seattle, Washington 98195-2250 D. J. Den Hartog* Sterling Scientific, Inc., Madison, Wisconsin (Received 11 June 2001; published 29 October 2001) Theoretical studies have predicted that the Z-pinch can be stabilized with a sufficiently sheared axial flow [U. Shumlak and C. W. Hartman, Phys. Rev. Lett. 75, 3285 (1995)]. A Z-pinch experiment is

  2. X marks the spot: Researchers confirm novel method for controlling plasma

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

    rotation to improve fusion performance | Princeton Plasma Physics Lab X marks the spot: Researchers confirm novel method for controlling plasma rotation to improve fusion performance By Raphael Rosen June 23, 2015 Tweet Widget Google Plus One Share on Facebook Representative plasma geometries, with the X-point location circled in red / Reprinted from T. Stoltzfus-Dueck et al., Phys. Rev. Lett. 114, 245001 (2015). Copyright 2015 by the American Physical Society. Representative plasma

  3. X marks the spot: Researchers confirm novel method for controlling plasma

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

    rotation to improve fusion performance | Princeton Plasma Physics Lab X marks the spot: Researchers confirm novel method for controlling plasma rotation to improve fusion performance By Raphael Rosen June 23, 2015 Tweet Widget Google Plus One Share on Facebook Representative plasma geometries, with the X-point location circled in red / Reprinted from T. Stoltzfus-Dueck et al., Phys. Rev. Lett. 114, 245001 (2015). Copyright 2015 by the American Physical Society. Representative plasma

  4. The effect of elementary reactions on solitary waves in dusty plasmas

    SciTech Connect (OSTI)

    Tahraoui, A.; Annou, R.

    2012-01-15

    The conditions of existence of solitons have been determined by Wang et al.[Phys. Lett. A 339, 96 (2005)], in negative ions containing dusty plasmas where Boltzmannian ions and electrons are assumed. The study is revisited taking into account actual elementary reactions in plasma conditions, viz., particles attachment by grains as well as neutrals and electron impact ionization of neutrals. Dust charge variation is self-consistently introduced leading to the Boltzmannian approximation relaxation.

  5. Reply to comment on ''New limits on intrinsic charm in the nucleon from global analysis of parton distribution''

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

    Jimenez-Delgado, Pedro; Hobbs, Timothy J.; Londergan, J. T.; Melnitchouk, Wally

    2016-01-05

    We reply to the Comment of Brodsky and Gardner on our paper "New limits on intrinsic charm in the nucleon from global analysis of parton distributions" [Phys. Rev. Lett. 114, 082002 (2015)]. We address a number of incorrect claims made about our fitting methodology, and elaborate how global QCD analysis of all available high-energy data provides no evidence for a large intrinsic charm component of the nucleon.

  6. Quantum Theory for Cold Avalanche Ionization in Solids

    SciTech Connect (OSTI)

    Deng, H. X.; Zu, X. T.; Xiang, X.; Sun, K.

    2010-09-10

    A theory of photon-assisted impact ionization in solids is presented. Our theory makes a quantum description of the new impact ionization--cold avalanche ionization recently reported by P. P. Rajeev, M. Gertsvolf, P. B. Corkum, and D. M. Rayner [Phys. Rev. Lett. 102, 083001 (2009)]. The present theory agrees with the experiments and can be reduced to the traditional impact ionization expression in the absence of a laser.

  7. Positive field-cooled dc susceptibility in granular superconductors interpreted through numerical simulations on a simple Josephson-junction-array model

    SciTech Connect (OSTI)

    Auletta, C.; Raiconi, G.; De Luca, R.; Pace, S.

    1995-05-01

    We have performed numerical simulations of a field-cooled dc susceptibility experiment carried out for granular superconductors by modeling these systems with a simple Josephson-junction array proposed by the authors. By this analysis the temperature dependence of the positive field-cooled susceptibility at very low values of the applied magnetic field, observed by Braunisch {ital et} {ital al}. [Phys. Rev. Lett. 68, 1908 (1992)] for some ceramic superonductors, has been reproduced and interpreted.

  8. 15.01.16 RH Perovskite Solar Cells - JCAP

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

    Fabrication of High Efficiency Perovskite Solar Cells Li, Y., Cooper, J. K., Buonsanti, R., Giannini, G., Liu, Y., Toma, F. M. & Sharp, I. D. Fabrication of Planar Heterojunction Perovskite Solar Cells by Controlled Low-Pressure Vapor Annealing. J. Phys. Chem. Lett ., 6, 493-499, DOI: 10.1021/jz502720a (2015). Scientific Achievement A new synthetic method based on low-pressure and reduced-temperature vapor annealing was developed and demonstrated to yield efficient hybrid halide perovskites

  9. Structural and Vibrational Properties of Liquid Water from van der Waals

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

    Density Functionals | Argonne Leadership Computing Facility Structural and Vibrational Properties of Liquid Water from van der Waals Density Functionals Authors: Zhang, C., Wu, J., Gygi, F., Galli, G. We present results for the structural and vibrational properties of the water molecule, water dimer, and liquid water at the experimental equilibrium density, as obtained with several van der Waals density functionals. The functional form originally proposed by Dion et al. [ Phys. Rev. Lett.

  10. Reddy, J. S.; Kale, T. S.; Balaji, G.; Chandrasekaran, A.; Thayumanavan, S*

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

    Reddy, J. S.; Kale, T. S.; Balaji, G.; Chandrasekaran, A.; Thayumanavan, S* Effect of Fluorinated Substituents on Electro- chemical and Charge Transport Properties Reddy, J. S.et al. J. Phys. Chem. Lett. 2011, 2, 648-654. (DOI: 10.1021/jz200126s) Small molecule semiconductors based on cyclopenta-dithiophene (CPD) hole conductors were electronically "tuned" by incorporation of electron withdrawing groups, including fluorinated substituents. Conversion of an otherwise p-type material

  11. Suppression of quantum chaos in a quantum computer hardware

    SciTech Connect (OSTI)

    Lages, J.; Shepelyansky, D. L. [Laboratoire de Physique Theorique, UMR 5152 du CNRS, Universite Paul Sabatier, 31062 Toulouse Cedex 4 (France)

    2006-08-15

    We present numerical and analytical studies of a quantum computer proposed by the Yamamoto group in Phys. Rev. Lett. 89, 017901 (2002). The stable and quantum chaos regimes in the quantum computer hardware are identified as a function of magnetic field gradient and dipole-dipole couplings between qubits on a square lattice. It is shown that a strong magnetic field gradient leads to suppression of quantum chaos.

  12. U-202: Apple QuickTime Multiple Stack Overflow Vulnerabilities

    Broader source: Energy.gov [DOE]

    Visiting a maliciously crafted website may lead to an unexpected application termination or arbitrary code execution.

  13. ENERGY COMMISSION APPL.lCATION FOR SOURCE MATERIAL LICENSE

    Office of Legacy Management (LM)

    ... MATERIAL LICENSE . Pursuant to the Atomic Energy Act of 1954, and Title 10, Code of ... specified in Section 183 of the Atotic Energy Act of 1954 and is subject to all ...

  14. Crunching Solar Numbers: The Big Apple Uses Big Data

    Broader source: Energy.gov [DOE]

    The City University of New York (CUNY) and its partners developed an analytics-based approach that makes it easier to spot key solar market indicators such as new permit applications and...

  15. AMR Power Private Ltd APPL | Open Energy Information

    Open Energy Info (EERE)

    Hyderabad, Andhra Pradesh, India Zip: 560 034 Sector: Hydro Product: Hyderabad-based small hydro project developer. Coordinates: 17.6726, 77.5971 Show Map Loading map......

  16. Backed apple? Metropolitan New York in the greenhouse

    SciTech Connect (OSTI)

    Hill, D.

    1997-12-31

    Steps to mitigate global climate change are being negotiated internationally, but it is on the local level that its effects will be felt and actions are taken. Like many midlatitude coastal cities, metropolitan New York could expect serious consequences from global warming: killing hot spells, worsened ozone pollution, uncertain water supply, and inundation of its waterfront from higher sea level and violent storms. Seen at the local level, the opportunities and limitations of measures to mitigate or adapt to climate change become explicit. Indirect local effects from changes elsewhere in the world must also be considered.

  17. From: Nicholas Ammann [mailto:nammann@apple.com

    Office of Environmental Management (EM)

    on Evaluating New Products for the Battery Chargers and External Power Supply ... for the effective date of the DOE battery charger efficiency regulation and the ...

  18. Innovative Hydropower Technology Now Powering an Apple Data Center...

    Office of Environmental Management (EM)

    bypass extra flow, and the newly-constructed plant intake structure (background) routes water into the penstock and on to the hydroEngine. Image courtesy of Natel Energy. The...

  19. Westinghouse, DOE see apples, oranges in IG staffing report

    SciTech Connect (OSTI)

    Lobsenz, G.

    1994-03-01

    The operator of the Energy Department's Savannah River weapons plant has at least 1,800 more employees than it needs, and could save $400 million over a five-year period by cutting its staff accordingly, a DOE inspector general study says. Most of the boat - 1,206 employees - was attributed to excessive numbers of managers, with the inspector general concluding that Westinghouse Savannah River Co. had roughly twice as many layers of management than two other DOE weapons contractors. The study also concluded that Westinghouse in fiscal year 1992 significantly understated its actual staffing levels in reports to DOE, failing to disclose 1,765 full-time employees or the equivalent hours worked. Through such underreporting Westinghouse was able to [open quotes]circumvent staffing ceilings established by the department,[close quotes] the study added. Overall, DOE Inspector General John Layton said Westinghouse's staff levels substantially exceeded those needed for efficient operation of the South Carolina nuclear weapons facility. Layton based his analysis on efficiency standards attained by other DOE weapons plant contractors, such as Martin Marietta Energy Systems at DOE's Oak Ridge, Tenn., plant and EG G Rocky Flats, as well as widely utilized worker performance requirements used by the Navy and private sector companies that perform work similar to that done at Savannah River.

  20. U-022: Apple QuickTime Multiple Vulnerabilities

    Broader source: Energy.gov [DOE]

    A remote user can create a file that, when loaded by the target user, will execute arbitrary code on the target user's system.

  1. Property:Incentive/ApplDsc | Open Energy Information

    Open Energy Info (EERE)

    (Vermont) + Commercial +, Industrial + 4 401 Certification (Vermont) + Industrial +, Utility + A AEP (Central and North) - CitySmart Program (Texas) + Commercial +, Industrial...

  2. Apples with apples: accounting for fuel price risk in comparisons of gas-fired and renewable generation

    SciTech Connect (OSTI)

    Bolinger, Mark; Wiser, Ryan

    2003-12-18

    For better or worse, natural gas has become the fuel of choice for new power plants being built across the United States. According to the US Energy Information Administration (EIA), natural gas combined-cycle and combustion turbine power plants accounted for 96% of the total generating capacity added in the US between 1999 and 2002--138 GW out of a total of 144 GW. Looking ahead, the EIA expects that gas-fired technology will account for 61% of the 355 GW new generating capacity projected to come on-line in the US up to 2025, increasing the nationwide market share of gas-fired generation from 18% in 2002 to 22% in 2025. While the data are specific to the US, natural gas-fired generation is making similar advances in other countries as well. Regardless of the explanation for (or interpretation of) the empirical findings, however, the basic implications remain the same: one should not blindly rely on gas price forecasts when comparing fixed-price renewable with variable-price gas-fired generation contracts. If there is a cost to hedging, gas price forecasts do not capture and account for it. Alternatively, if the forecasts are at risk of being biased or out of tune with the market, then one certainly would not want to use them as the basis for resource comparisons or investment decisions if a more certain source of data (forwards) existed. Accordingly, assuming that long-term price stability is valued, the most appropriate way to compare the levelized cost of these resources in both cases would be to use forward natural gas price data--i.e. prices that can be locked in to create price certainty--as opposed to uncertain natural gas price forecasts. This article suggests that had utilities and analysts in the US done so over the sample period from November 2000 to November 2003, they would have found gas-fired generation to be at least 0.3-0.6 cents/kWh more expensive (on a levelized cost basis) than otherwise thought. With some renewable resources, in particular wind power, now largely competitive with gas-fired generation in the US (including the impact of the federal production tax credit and current high gas prices), a margin of 0.3-0.6 cents/kWh may in some cases be enough to sway resource decisions in favor of renewables.

  3. Mesoscale Simulations of Coarsening in GB Networks

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

    Mukul Kumar is the Principal Investigator for Mesoscale Simulations of Coarsening in GB Networks LLNL BES Programs Highlight Mesoscale Simulations of Coarsening in GB Networks The Phase Field Model evolves a grain boundary network with realistic network correlations, as seeded by a group-theory-based Monte Carlo model M. Tang, B. W. Reed, and M. Kumar, J. Appl. Phys. 112, 043505 (2012) V. Bulatov, B. W. Reed, and M. Kumar; "Grain boundary energy function for FCC metals," Physical

  4. Exploring magnetized liner inertial fusion with a semi-analytic model

    SciTech Connect (OSTI)

    McBride, Ryan D.; Slutz, Stephen A.; Vesey, Roger A.; Gomez, Matthew R.; Sefkow, Adam B.; Hansen, Stephanie B.; Knapp, Patrick F.; Schmit, Paul F.; Geissel, Matthias; Harvey-Thompson, Adam James; Jennings, Christopher Ashley; Harding, Eric C.; Awe, Thomas James; Rovang, Dean C.; Hahn, Kelly D.; Martin, Matthew R.; Cochrane, Kyle R.; Peterson, Kyle J.; Rochau, Gregory A.; Porter, John L.; Stygar, William A.; Campbell, Edward Michael; Nakhleh, Charles W.; Herrmann, Mark C.; Cuneo, Michael E.; Sinars, Daniel B.

    2016-01-01

    In this study, we explore magnetized liner inertial fusion (MagLIF) [S. A. Slutz et al., Phys. Plasmas 17, 056303 (2010)] using a semi-analytic model [R. D. McBride and S. A. Slutz, Phys. Plasmas 22, 052708 (2015)]. Specifically, we present simulation results from this model that: (a) illustrate the parameter space, energetics, and overall system efficiencies of MagLIF; (b) demonstrate the dependence of radiative loss rates on the radial fraction of the fuel that is preheated; (c) explore some of the recent experimental results of the MagLIF program at Sandia National Laboratories [M. R. Gomez et al., Phys. Rev. Lett. 113, 155003 (2014)]; (d) highlight the experimental challenges presently facing the MagLIF program; and (e) demonstrate how increases to the preheat energy, fuel density, axial magnetic field, and drive current could affect future MagLIF performance.

  5. Exploring magnetized liner inertial fusion with a semi-analytic model

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

    McBride, Ryan D.; Slutz, Stephen A.; Vesey, Roger A.; Gomez, Matthew R.; Sefkow, Adam B.; Hansen, Stephanie B.; Knapp, Patrick F.; Schmit, Paul F.; Geissel, Matthias; Harvey-Thompson, Adam James; et al

    2016-01-01

    In this study, we explore magnetized liner inertial fusion (MagLIF) [S. A. Slutz et al., Phys. Plasmas 17, 056303 (2010)] using a semi-analytic model [R. D. McBride and S. A. Slutz, Phys. Plasmas 22, 052708 (2015)]. Specifically, we present simulation results from this model that: (a) illustrate the parameter space, energetics, and overall system efficiencies of MagLIF; (b) demonstrate the dependence of radiative loss rates on the radial fraction of the fuel that is preheated; (c) explore some of the recent experimental results of the MagLIF program at Sandia National Laboratories [M. R. Gomez et al., Phys. Rev. Lett. 113,more » 155003 (2014)]; (d) highlight the experimental challenges presently facing the MagLIF program; and (e) demonstrate how increases to the preheat energy, fuel density, axial magnetic field, and drive current could affect future MagLIF performance.« less

  6. Publisher's Note: Level structure 18Ne and its importance in the 14O(α,p)17F reaction rate [Phys. Rev. C 86, 025801(2012)

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

    Almaraz-Calderon, S.; Tan, W. P.; Aprahamian, A.; Bucher, B.; Roberts, A.; Wiescher, M.; Brune, C. R.; Massey, T. N.; Ozkan, N.; Guray, R. T.; et al

    2012-08-10

    The level structure of 18Ne above the α-decay threshold has been studied using the 16O(3He,n) reaction. A coincidence measurement of neutrons and charged particles decaying from populated states in 18Ne has been made. Decay branching ratios were measured for six resonances and used to calculate the 14O(α,p)17F reaction rate which is a measure of one of two breakout paths from the Hot CNO cycle. As a result, the new experimental information combined with previous experimental and theoretical information, provides a more accurate calculation of the reaction rate.

  7. Comment on C. W. Wong, Maxwell equations and the redundant gauge degree of freedom 2009 Eur. J. Phys. 30, 1401-1416

    SciTech Connect (OSTI)

    Jackson, John David

    2009-10-22

    In the paper cited in the title, the author makes the claim that in classical electromagnetic theory the longitudinal electric field is instantaneous, corresponding to action at a distance, contrary to popular and correct belief. We point out that the determination of the speed of propagation of electromagnetic fields requires specification of the initial condition of the sources or equivalent. The Coulomb field of a stationary point charge proves nothing. We describe in detail a simple example to illustrate the universal onset of the static 'instantaneous' regime throughout a region of space that expands with the speed of light.

  8. Antihydrogen Trapped in the ALPHA Experiment

    ScienceCinema (OSTI)

    None

    2011-04-25

    In 2010 the ALPHA collaboration succeeded in trapping antihydrogen atoms for the first time.[i]  Stored antihydrogen promises to be a unique tool for making high precision measurements of the structure of this first anti-atom. Achieving this milestone presented several substantial experimental challenges and this talk will describe how they were overcome.   The unique design features of the ALPHA apparatus will be explained.[ii]  These allow a high intensity positron source and an antiproton imaging detector similar to the one used in the ATHENA[iii] experiment to be combined with an innovative magnet design of the anti-atom trap. This seeks to minimise the perturbations to trapped charged particles which may cause particle loss and heating[iv].   The diagnostic techniques used to measure the diameter, number, density, and temperatures of both plasmas will be presented as will the methods developed to actively compress and cool of both plasma species to sizes and temperatures [v],[vi], [vii] where trapping attempts with a reasonable chance of success can be tried.   The results of the successful trapping experiments will be outlined as well as some subsequent experiments to improve the trapping rate and storage time. [i] 'Trapped antihydrogen' G.B. Andresen et al., Nature 468, 673 (2010) [ii]'A Magnetic Trap for Antihydrogen Confinement' W. Bertsche et al., Nucl. Instr. Meth. Phys. Res. A566, 746 (2006) [iii] Production and detection of cold antihydrogen atoms M.Amoretti et al., Nature 419, 456 (2002). [iv]' Antihydrogen formation dynamics in a multipolar neutral anti-atom trap' G.B. Andresen et al., Phys. Lett. B 685, 141 (2010) [v]' Evaporative Cooling of Antiprotons to Cryogenic Temperatures',                                   G.B. Andresen et al. Phys. Rev. Lett 105, 013003 (2010) [vi]'Compression of Antiproton Clouds for Antihydrogen Trapping' G. B. Andresen et al. Phys. Rev. Lett 100, 203401 (2008) [vii]  'Autoresonant

  9. Auxiliary field formalism for dilute fermionic atom gases with tunable interactions

    SciTech Connect (OSTI)

    Mihaila, Bogdan; Chien, Chih-Chun; Timmermans, Eddy; Dawson, John F.; Cooper, Fred

    2011-05-15

    We develop the auxiliary field formalism corresponding to a dilute system of spin-1/2 fermions. This theory represents the Fermi counterpart of the Bose-Einstein condensation (BEC) theory developed recently by F. Cooper et al. [Phys. Rev. Lett. 105, 240402 (2010)] to describe a dilute gas of Bose particles. Assuming tunable interactions, this formalism is appropriate for the study of the crossover from the regime of Bardeen-Cooper-Schriffer (BCS) pairing to the regime of BEC in ultracold fermionic atom gases. We show that when applied to the Fermi case at zero temperature, the leading-order auxiliary field (LOAF) approximation gives the same equations as obtained in the standard BCS variational picture. At finite temperature, LOAF leads to the theory discussed by Sa de Melo, Randeria, and Engelbrecht [Phys. Rev. Lett. 71, 3202 (1993); Phys. Rev. B 55, 15153 (1997)]. As such, LOAF provides a unified framework to study the interacting Fermi gas. The mean-field results discussed here can be systematically improved on by calculating the one-particle irreducible action corrections, order by order.

  10. Higher velocity, high-foot implosions on the National Ignition Facility laser

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

    Callahan, D. A.; Hurricane, O. A.; Hinkel, D. E.; Döppner, T.; Ma, T.; Park, H. -S.; Barrios Garcia, M. A.; Berzak Hopkins, L. F.; Casey, D. T.; Cerjan, C. J.; et al

    2015-05-15

    By increasing the velocity in “high foot” implosions [Dittrich et al., Phys. Rev. Lett. 112, 055002 (2014); Park et al., Phys. Rev. Lett. 112, 055001 (2014); Hurricane et al., Nature 506, 343 (2014); Hurricane et al., Phys. Plasmas 21, 056314 (2014)] on the National Ignition Facility laser, we have nearly doubled the neutron yield and the hotspot pressure as compared to the implosions reported upon last year. The implosion velocity has been increased using a combination of the laser (higher power and energy), the hohlraum (depleted uranium wall material with higher opacity and lower specific heat than gold hohlraums), andmore » the capsule (thinner capsules with less mass). We find that the neutron yield from these experiments scales systematically with a velocity-like parameter of the square root of the laser energy divided by the ablator mass. By connecting this parameter with the inferred implosion velocity (v), we find that for shots with primary yield >1e15 neutrons, the total yield ~ v⁹˙⁴. This increase is considerably faster than the expected dependence for implosions without alpha heating ( ~v⁵˙⁹) and is additional evidence that these experiments have significant alpha heating.« less

  11. Higher velocity, high-foot implosions on the National Ignition Facility laser

    SciTech Connect (OSTI)

    Callahan, D. A.; Hurricane, O. A.; Hinkel, D. E.; Döppner, T.; Ma, T.; Park, H. -S.; Barrios Garcia, M. A.; Berzak Hopkins, L. F.; Casey, D. T.; Cerjan, C. J.; Dewald, E. L.; Dittrich, T. R.; Edwards, M. J.; Haan, S. W.; Hamza, A. V.; Kline, J. L.; Knauer, J. P.; Kritcher, A. L.; Landen, O. L.; LePape, S.; MacPhee, A. G.; Milovich, J. L.; Nikroo, A.; Pak, A. E.; Patel, P. K.; Rygg, J. R.; Ralph, J. E.; Salmonson, J. D.; Spears, B. K.; Springer, P. T.; Tommasini, R.; Benedetti, L. R.; Bionta, R. M.; Bond, E. J.; Bradley, D. K.; Caggiano, J. A.; Field, J. E.; Fittinghoff, D. N.; Frenje, J.; Gatu Johnson, M.; Grim, G. P.; Hatarik, R.; Merrill, F. E.; Nagel, S. R.; Izumi, N.; Khan, S. F.; Town, R. P. J.; Sayre, D. B.; Volegov, P.; Wilde, C. H.

    2015-05-15

    By increasing the velocity in “high foot” implosions [Dittrich et al., Phys. Rev. Lett. 112, 055002 (2014); Park et al., Phys. Rev. Lett. 112, 055001 (2014); Hurricane et al., Nature 506, 343 (2014); Hurricane et al., Phys. Plasmas 21, 056314 (2014)] on the National Ignition Facility laser, we have nearly doubled the neutron yield and the hotspot pressure as compared to the implosions reported upon last year. The implosion velocity has been increased using a combination of the laser (higher power and energy), the hohlraum (depleted uranium wall material with higher opacity and lower specific heat than gold hohlraums), and the capsule (thinner capsules with less mass). We find that the neutron yield from these experiments scales systematically with a velocity-like parameter of the square root of the laser energy divided by the ablator mass. By connecting this parameter with the inferred implosion velocity (v), we find that for shots with primary yield >1e15 neutrons, the total yield ~ v⁹˙⁴. This increase is considerably faster than the expected dependence for implosions without alpha heating ( ~v⁵˙⁹) and is additional evidence that these experiments have significant alpha heating.

  12. Higher velocity, high-foot implosions on the National Ignition Facility laser

    SciTech Connect (OSTI)

    Callahan, D. A.; Hurricane, O. A.; Hinkel, D. E.; Dppner, T.; Ma, T.; Park, H.-S.; Barrios Garcia, M. A.; Berzak Hopkins, L. F.; Casey, D. T.; Cerjan, C. J.; Dewald, E. L.; Dittrich, T. R.; Edwards, M. J.; Haan, S. W.; Hamza, A. V.; Kritcher, A. L.; Landen, O. L.; LePape, S.; MacPhee, A. G.; Milovich, J. L.; and others

    2015-05-15

    By increasing the velocity in high foot implosions [Dittrich et al., Phys. Rev. Lett. 112, 055002 (2014); Park et al., Phys. Rev. Lett. 112, 055001 (2014); Hurricane et al., Nature 506, 343 (2014); Hurricane et al., Phys. Plasmas 21, 056314 (2014)] on the National Ignition Facility laser, we have nearly doubled the neutron yield and the hotspot pressure as compared to the implosions reported upon last year. The implosion velocity has been increased using a combination of the laser (higher power and energy), the hohlraum (depleted uranium wall material with higher opacity and lower specific heat than gold hohlraums), and the capsule (thinner capsules with less mass). We find that the neutron yield from these experiments scales systematically with a velocity-like parameter of the square root of the laser energy divided by the ablator mass. By connecting this parameter with the inferred implosion velocity (v), we find that for shots with primary yield >1 10{sup 15} neutrons, the total yield ??v{sup 9.4}. This increase is considerably faster than the expected dependence for implosions without alpha heating (?v{sup 5.9}) and is additional evidence that these experiments have significant alpha heating.

  13. An in-flight radiography platform to measure hydrodynamic instability growth in inertial confinement fusion capsules at the National Ignition Facility

    SciTech Connect (OSTI)

    Raman, K. S.; Smalyuk, V. A.; Casey, D. T.; Haan, S. W.; Hurricane, O. A.; Kroll, J. J.; Peterson, J. L.; Remington, B. A.; Robey, H. F.; Clark, D. S.; Hammel, B. A.; Landen, O. L.; Marinak, M. M.; Munro, D. H.; Salmonson, J.; Hoover, D. E.; Nikroo, A.; Peterson, K. J.

    2014-07-15

    A new in-flight radiography platform has been established at the National Ignition Facility (NIF) to measure RayleighTaylor and RichtmyerMeshkov instability growth in inertial confinement fusion capsules. The platform has been tested up to a convergence ratio of 4. An experimental campaign is underway to measure the growth of pre-imposed sinusoidal modulations of the capsule surface, as a function of wavelength, for a pair of ignition-relevant laser drives: a low-foot drive representative of what was fielded during the National Ignition Campaign (NIC) [Edwards et al., Phys. Plasmas 20, 070501 (2013)] and the new high-foot [Dittrich et al., Phys. Rev. Lett. 112, 055002 (2014); Park et al., Phys. Rev. Lett. 112, 055001 (2014)] pulse shape, for which the predicted instability growth is much lower. We present measurements of Legendre modes 30, 60, and 90 for the NIC-type, low-foot, drive, and modes 60 and 90 for the high-foot drive. The measured growth is consistent with model predictions, including much less growth for the high-foot drive, demonstrating the instability mitigation aspect of this new pulse shape. We present the design of the platform in detail and discuss the implications of the data it generates for the on-going ignition effort at NIF.

  14. Higher velocity, high-foot implosions on the National Ignition Facility laser

    SciTech Connect (OSTI)

    Callahan, D. A.; Hurricane, O. A.; Hinkel, D. E.; Dppner, T.; Ma, T.; Park, H. -S.; Barrios Garcia, M. A.; Berzak Hopkins, L. F.; Casey, D. T.; Cerjan, C. J.; Dewald, E. L.; Dittrich, T. R.; Edwards, M. J.; Haan, S. W.; Hamza, A. V.; Kline, J. L.; Knauer, J. P.; Kritcher, A. L.; Landen, O. L.; LePape, S.; MacPhee, A. G.; Milovich, J. L.; Nikroo, A.; Pak, A. E.; Patel, P. K.; Rygg, J. R.; Ralph, J. E.; Salmonson, J. D.; Spears, B. K.; Springer, P. T.; Tommasini, R.; Benedetti, L. R.; Bionta, R. M.; Bond, E. J.; Bradley, D. K.; Caggiano, J. A.; Field, J. E.; Fittinghoff, D. N.; Frenje, J.; Gatu Johnson, M.; Grim, G. P.; Hatarik, R.; Merrill, F. E.; Nagel, S. R.; Izumi, N.; Khan, S. F.; Town, R. P. J.; Sayre, D. B.; Volegov, P.; Wilde, C. H.

    2015-05-15

    By increasing the velocity in high foot implosions [Dittrich et al., Phys. Rev. Lett. 112, 055002 (2014); Park et al., Phys. Rev. Lett. 112, 055001 (2014); Hurricane et al., Nature 506, 343 (2014); Hurricane et al., Phys. Plasmas 21, 056314 (2014)] on the National Ignition Facility laser, we have nearly doubled the neutron yield and the hotspot pressure as compared to the implosions reported upon last year. The implosion velocity has been increased using a combination of the laser (higher power and energy), the hohlraum (depleted uranium wall material with higher opacity and lower specific heat than gold hohlraums), and the capsule (thinner capsules with less mass). We find that the neutron yield from these experiments scales systematically with a velocity-like parameter of the square root of the laser energy divided by the ablator mass. By connecting this parameter with the inferred implosion velocity (v), we find that for shots with primary yield >1e15 neutrons, the total yield ~ v???. This increase is considerably faster than the expected dependence for implosions without alpha heating ( ~v???) and is additional evidence that these experiments have significant alpha heating.

  15. Neutrino CCQE Data Release Page

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

    Neutrino CCQE Data Release Page "Measurement of Muon Neutrino Quasi-Elastic Scattering on a Hydrocarbon Target at Ev ~ 3.5 GeV" Phys. Rev. Lett. 111 (2013) 022502, hep-ex/1305.2243 Data Ancillary data files for this result are given here, and supercede the ones originally associated with the arXiv entry: they have been updated with MINERvA's best estimate of the NuMI neutrino flux. The available data files have the following format: The columns are Q2 bins, first the 8 neutrino and

  16. Nuclear Target Ratios data release page

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

    Nuclear Target Ratios data release page "Measurement of ratios of muon neutrino charged-current cross sections on C, Fe, and Pb to CH at neutrino energies 2-20 GeV" Phys. Rev. Lett. 112 (2014) 231801, hep-ex/1403.2103. Data Anciliary files for this result can be found at http://arxiv.org/src/1403.2103v4/anc Anciliary Files include: Cross section ratios as a function of Bjorken x Cross Section ratio as a function of neutrino energy Target Masses used in the experiment Neutrino Flux used

  17. Sensitivity of ultracold-atom scattering experiments to variation of the fine-structure constant

    SciTech Connect (OSTI)

    Borschevsky, A.; Beloy, K.; Flambaum, V. V.; Schwerdtfeger, P.

    2011-05-15

    We present numerical calculations for cesium and mercury to estimate the sensitivity of the scattering length to the variation of the fine-structure constant {alpha}. The method used follows the ideas of Chin and Flambaum [Phys. Rev. Lett. 96, 230801 (2006)], where the sensitivity to the variation of the electron-to-proton mass ratio {beta} was considered. We demonstrate that for heavy systems, the sensitivity to the variation of {alpha} is of the same order of magnitude as to the variation of {beta}. Near narrow Feshbach resonances, the enhancement of the sensitivity may exceed nine orders of magnitude.

  18. Electron Neutrino CCQE Data Release Page

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

    Electron Neutrino CCQE Data Release Page Measurement of electron neutrino quasielastic and quasielastic-like scattering on hydrocarbon at ⟨Eν⟩ = 3.6 GeV Phys. Rev. Lett. 116, 081802 (2016) and hep-ex/1509.05729 Data Ancillary files for this result are available at http://arxiv.org/src/1509.05729v6/anc The available data files are: Cross Section as a function of Electron Angle Cross Section as a function of Electron Energy Cross Section as a function of Q2 Covariance Matrix as a function of

  19. FES BER HEP NP BES ASCR

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

    December 2015 NERSC Science Highlights Science Highlights December 2015 Chemistry Simula'ons run at NERSC lead to the predic'on of a new phase of superionic ice, a special form of ice that could exist on Uranus and Neptune (Roberto Car , Princeton U., Nature Comm.) Fusion Energy 3D simula'ons run at NERSC help gain new insights into fusion plasma behavior that will improve the ability to stabilize a tokamak reactor (S. Jardin , Princeton Plasma Physics Lab, Phys. Rev. Lett.) High Energy &

  20. Structural physical approximations of unphysical maps and generalized quantum measurements

    SciTech Connect (OSTI)

    Fiurasek, Jaromir

    2002-11-01

    We investigate properties of the structural physical approximation (SPA) of the partial transposition map recently introduced by Horodecki and Ekert [Phys. Rev. Lett. 89, 127902 (2002)]. We focus on the case of two-qubit states and show that in this case the map has the structure of a generalized quantum measurement followed by the preparation of a suitable output state. We also introduce SPA for a map that transforms two copies of density matrix of a single qubit onto a square of that matrix. We prove that also this map is essentially a generalized quantum measurement.

  1. On the Colbeck–Renner theorem

    SciTech Connect (OSTI)

    Landsman, Klaas

    2015-12-15

    In three papers, Colbeck and Renner [Nat. Commun. 2, 411 (2011); Phys. Rev. Lett. 108, 150402 (2012); e-print arXiv:1208.4123] argued that “no alternative theory compatible with quantum theory and satisfying the freedom of choice assumption can give improved predictions.” We give a more precise version of the formulation and proof of this remarkable claim. Our proof broadly follows theirs, which relies on physically well motivated axioms, but to fill in some crucial details, certain technical assumptions have had to be added, whose physical status seems somewhat obscure.

  2. A practical guide to density matrix embedding theory in quantum chemistry

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

    Wouters, Sebastian; Jimenez-Hoyos, Carlos A.; Sun, Qiming; Chan, Garnet K.-L.

    2016-05-09

    Density matrix embedding theory (DMET) (Knizia, G.; Chan, G. K.-L. Phys. Rev. Lett. 2012, 109, 186404) provides a theoretical framework to treat finite fragments in the presence of a surrounding molecular or bulk environment, even when there is significant correlation or entanglement between the two. In this work, we give a practically oriented and explicit description of the numerical and theoretical formulation of DMET. We also describe in detail how to perform self-consistent DMET optimizations. Furthermore, we explore different embedding strategies with and without a self-consistency condition in hydrogen rings, beryllium rings, and a sample SN2 reaction.

  3. Antineutrino CCQE Data Release Page

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

    Antineutrino CCQE Data Release Page "Measurement of Muon Antineutrino Quasi-Elastic Scattering on a Hydrocarbon Target at Ev ~ 3.5 GeV" Phys. Rev. Lett. 111 (2013) 022501, hep-ex/1305.2234 Data Ancillary data files for this result are given here, and supercede the ones originally associated with the arXiv entry: they have been updated with MINERvA's best estimate of the NuMI neutrino flux. The available data files have the following format: The columns are Q2 bins, first the 8 neutrino

  4. Does the orbit-averaged theory require a scale separation between periodic orbit size and perturbation correlation length?

    SciTech Connect (OSTI)

    Zhang, Wenlu; Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026; Department of Physics and Astronomy, University of California, Irvine, California 92697 ; Lin, Zhihong; Fusion Simulation Center, Peking University, Beijing 100871

    2013-10-15

    Using the canonical perturbation theory, we show that the orbit-averaged theory only requires a time-scale separation between equilibrium and perturbed motions and verifies the widely accepted notion that orbit averaging effects greatly reduce the microturbulent transport of energetic particles in a tokamak. Therefore, a recent claim [Hauff and Jenko, Phys. Rev. Lett. 102, 075004 (2009); Jenko et al., ibid. 107, 239502 (2011)] stating that the orbit-averaged theory requires a scale separation between equilibrium orbit size and perturbation correlation length is erroneous.

  5. Effects of nonthermal electrons on plasma expansion into vacuum

    SciTech Connect (OSTI)

    Bennaceur-Doumaz, D. Bara, D.; Benkhelifa, E.; Djebli, M.

    2015-01-28

    The expansion of semi-infinite plasma into vacuum is analyzed with a hydrodynamic model for cold ions assuming electrons modelled by a kappa-type distribution. Similarly to Mora study of a plasma expansion into vacuum [P. Mora, Phys. Rev. Lett. 90, 185002 (2003)], we formulated empirical expressions for the electric field strength, velocity, and position of the ion front in one-dimensional nonrelativistic, collisionless isothermally expanding plasma. Analytic expressions for the maximum ion energy and the spectrum of the accelerated ions in the plasma were derived and discussed to highlight the electron nonthermal effects on enhancing the ion acceleration in plasma expansion into vacuum.

  6. Anomalous diffusion and Tsallis statistics in an optical lattice

    SciTech Connect (OSTI)

    Lutz, Eric

    2003-05-01

    We point out a connection between anomalous transport in an optical lattice and Tsallis' generalized statistics. Specifically, we show that the momentum equation for the semiclassical Wigner function which describes atomic motion in the optical potential, belongs to a class of transport equations recently studied by Borland [Phys. Lett. A 245, 67 (1998)]. The important property of these ordinary linear Fokker-Planck equations is that their stationary solutions are exactly given by Tsallis distributions. An analytical expression of the Tsallis index q in terms of the microscopic parameters of the quantum-optical problem is given and the spatial coherence of the atomic wave packets is discussed.

  7. Sequential generation of matrix-product states in cavity QED

    SciTech Connect (OSTI)

    Schoen, C.; Hammerer, K.; Wolf, M. M.; Cirac, J. I.; Solano, E.

    2007-03-15

    We study the sequential generation of entangled photonic and atomic multiqubit states in the realm of cavity QED. We extend the work of C. Schoen et al. [Phys. Rev. Lett. 95, 110503 (2005)], where it was shown that all states generated in a sequential manner can be classified efficiently in terms of matrix-product states. In particular, we consider two scenarios: photonic multiqubit states sequentially generated at the cavity output of a single-photon source and atomic multiqubit states generated by their sequential interaction with the same cavity mode.

  8. Inline CBET Model Including SRS Backscatter

    SciTech Connect (OSTI)

    Bailey, David S.

    2015-06-26

    Cross-beam energy transfer (CBET) has been used as a tool on the National Ignition Facility (NIF) since the first energetics experiments in 2009 to control the energy deposition in ignition hohlraums and tune the implosion symmetry. As large amounts of power are transferred between laser beams at the entrance holes of NIF hohlraums, the presence of many overlapping beat waves can lead to stochastic ion heating in the regions where laser beams overlap [P. Michel et al., Phys. Rev. Lett. 109, 195004 (2012)]. Using the CBET gains derived in this paper, we show how to implement these equations in a ray-based laser source for a rad-hydro code.

  9. Dynamical generation of phase-squeezed states in two-component Bose-Einstein condensates

    SciTech Connect (OSTI)

    Jin, G. R.; An, Y.; Yan, T.; Lu, Z. S. [Department of Physics, Beijing Jiaotong University, Beijing 100044 (China)

    2010-12-15

    As an ''input'' state of a linear (Mach-Zehnder or Ramsey) interferometer, the phase-squeezed state proposed by Berry and Wiseman exhibits the best sensitivity approaching to the Heisenberg limit [Phys. Rev. Lett. 85, 5098 (2000)]. Similar with the Berry and Wiseman's state, we find that two kinds of phase-squeezed states can be generated dynamically with atomic Bose-Einstein condensates confined in a symmetric double-well potential, which shows squeezing along spin operator S{sub y} and antisqueezing along S{sub z}, leading to subshot-noise phase estimation.

  10. Vacuum-induced Berry phases in single-mode Jaynes-Cummings models

    SciTech Connect (OSTI)

    Liu, Yu; Wei, L. F.; Jia, W. Z. [Quantum Optoelectronics Laboratory, School of Physics and Technology, Southwest Jiaotong University, Chengdu 610031 (China); Liang, J. Q. [Institute of Theoretical Physics and Department of Physics, Shanxi University, Taiyuan 030006 (China)

    2010-10-15

    Motivated by work [Phys. Rev. Lett. 89, 220404 (2002)] for detecting the vacuum-induced Berry phases with two-mode Jaynes-Cummings models (JCMs), we show here that, for a parameter-dependent single-mode JCM, certain atom-field states also acquired photon-number-dependent Berry phases after the parameter slowly changed and eventually returned to its initial value. This geometric effect related to the field quantization still exists, even if the field is kept in its vacuum state. Specifically, a feasible Ramsey interference experiment with a cavity quantum electrodynamics system is designed to detect the vacuum-induced Berry phase.

  11. Experimental evidence for collisional shock formation via two obliquely merging supersonic plasma jets

    SciTech Connect (OSTI)

    Merritt, Elizabeth C. Adams, Colin S.; University of New Mexico, Albuquerque, New Mexico 87131 ; Moser, Auna L.; Hsu, Scott C. Dunn, John P.; Miguel Holgado, A.; Gilmore, Mark A.

    2014-05-15

    We report spatially resolved measurements of the oblique merging of two supersonic laboratory plasma jets. The jets are formed and launched by pulsed-power-driven railguns using injected argon, and have electron density ?10{sup 14}?cm{sup ?3}, electron temperature ?1.4?eV, ionization fraction near unity, and velocity ?40?km/s just prior to merging. The jet merging produces a few-cm-thick stagnation layer, as observed in both fast-framing camera images and multi-chord interferometer data, consistent with collisional shock formation [E. C. Merritt et al., Phys. Rev. Lett. 111, 085003 (2013)].

  12. MiniBooNE LowE Data Release

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

    Unexplained Excess of Electron-Like Events From a 1 GeV Neutrino Beam", arXiv:0812.2243 [hep-ex], Phys. Rev. Lett. 102, 101802 (2009) The following MiniBooNE information from the 2009 updated nue oscillation paper is made available to the public: Energy Range for Default Oscillation Fit (475 MeV - 3000 MeV reconstructed neutrino energy) 1D array of bin boundaries in electron neutrino reconstructed neutrino energy 1D array of observed electron neutrino candidate events per reconstructed

  13. MiniBooNE Nue Data Release

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

    Neutrino Appearance at the Δm2 ~1 eV2 Scale", arXiv:0704.1500 [hep-ex], Phys. Rev. Lett. 98, 231801 (2007) The following MiniBooNE information from the first oscillation paper in 2007 is made available to the public: Energy Range for Default Oscillation Fit (475 MeV - 3000 MeV reconstructed neutrino energy) ntuple file of official MiniBooNE sin2(2theta) sensitivity and upper limit curves as a function of Dm2, for a 2-neutrino muon-to-electron oscillation fit, and 90% and 3sigma confidence

  14. MiniBooNE Nuebar Data Release

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

    Search for Electron Anti-Neutrino Appearance at the Δm2 ~1 eV2 Scale", arXiv:0904.1958 [hep-ex], Phys. Rev. Lett. 103, 111801 (2009) The following MiniBooNE information from the 2009 nuebar appearance paper is made available to the public: Energy Range: 475 MeV - 3000 MeV reconstructed neutrino energy ntuple file of MiniBooNE sin2(2theta) sensitivity and upper limit curves as a function of Dm2, for a 2-neutrino muon-to-electron antineutrino oscillation fit, and 90% and 3sigma confidence

  15. MiniBooNE Numu/Numubar Disappearance Data Release

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

    A Search for muon neutrino and antineutrino disappearance in MiniBooNE", arXiv:0903.2465 [hep-ex], Phys. Rev. Lett. 103, 061802 (2009) The following MiniBooNE information from the 2009 numu and numubar disappearance paper is made available to the public: Numu Disappearance ntuple file of MiniBooNE numu 90% confidence level sensitivity as a function of Dm2, for a 2-neutrino numu -> nux ocillation fit. The file contains 141 rows, with two columns: Dm2 value in the range 0.4 < Dm2 (eV2)

  16. Decoherence-free evolution of time-dependent superposition states of two-level systems and thermal effects

    SciTech Connect (OSTI)

    Prado, F. O.; Duzzioni, E. I. [Universidade Federal de Uberlandia, Caixa Postal 593, 38400-902 Uberlandia, Minas Geraisn (Brazil); Almeida, N. G. de [Instituto de Fisica, Universidade Federal de Goias, 74001-970, Goiania, Goias (Brazil); Moussa, M. H. Y. [Instituto de Fisica de Sao Carlos, Universidade de Sao Paulo, Caixa Postal 369, 13560-970 Sao Carlos, Sao Paulo (Brazil); Villas-Boas, C. J. [Departamento de Fisica, Universidade Federal de Sao Carlos, P.O. Box 676, 13565-905 Sao Carlos, Sao Paulo (Brazil)

    2011-07-15

    In this paper we detail some results advanced in a recent letter [Prado et al., Phys. Rev. Lett. 102, 073008 (2009).] showing how to engineer reservoirs for two-level systems at absolute zero by means of a time-dependent master equation leading to a nonstationary superposition equilibrium state. We also present a general recipe showing how to build nonadiabatic coherent evolutions of a fermionic system interacting with a bosonic mode and investigate the influence of thermal reservoirs at finite temperature on the fidelity of the protected superposition state. Our analytical results are supported by numerical analysis of the full Hamiltonian model.

  17. Frustrated quantum phase diffusion and increased coherence of solitons due to nonlocality

    SciTech Connect (OSTI)

    Batz, Sascha; Peschel, Ulf

    2011-03-15

    We investigate the quantum properties of solitons with nonlocal self-interaction. We find significant changes when compared to the local interaction. Quantum phase diffusion of nonlocal solitons is always reduced with respect to the local interaction and vanishes in the strongly nonlocal limit. Thus, coherence is increased in the nonlocal case. Furthermore, we compare the intrinsic quantum wave packet spreading to the recently discussed classical Gordon-Haus effect for nonlocal solitons [V. Folli and C. Conti, Phys. Rev. Lett. 104, 193901 (2010)].

  18. Lattice QCD | Argonne Leadership Computing Facility

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

    form factor for the decay of a kaon into a pion and two leptons The form factor for the decay of a kaon into a pion and two leptons. It yields the most precise determination so far of the CKM matrix element, |Vus|. Credit: A. Bazavov et al., Phys.Rev. Lett. 112 (2014) 112001; e-Print: arXiv:1312.1228 Lattice QCD PI Name: Paul Mackenzie PI Email: mackenzie@fnal.gov Institution: Fermilab Allocation Program: INCITE Allocation Hours at ALCF: 180 Million Year: 2015 Research Domain: Physics For this

  19. Lattice QCD | Argonne Leadership Computing Facility

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

    The form factor for the decay of a kaon into a pion and two leptons The form factor for the decay of a kaon into a pion and two leptons. It yields the most precise determination so far of the CKM matrix element, |Vus|. A. Bazavov et al., Phys.Rev. Lett. 112 (2014) 112001; e-Print: arXiv:1312.1228 Lattice QCD PI Name: Paul Mackenzie PI Email: mackenzie@fnal.gov Institution: Fermilab Allocation Program: INCITE Allocation Hours at ALCF: 180 Million Year: 2016 Research Domain: Physics For this

  20. Local content of bipartite qubit correlations

    SciTech Connect (OSTI)

    Branciard, Cyril; Gisin, Nicolas [Group of Applied Physics, University of Geneva, 1211 Geneva (Switzerland); Scarani, Valerio [Centre for Quantum Technologies and Department of Physics, National University of Singapore, 117543 Singapore (Singapore)

    2010-02-15

    One of the last open problems concerning two qubits in a pure state is to find the exact local content of their correlation, in the sense of Elitzur, Popescu, and Rohrlich (EPR2) [A. C. Elitzur, S. Popescu, and D. Rohrlich, Phys. Lett. A162, 25 (1992)]. We propose an EPR2 decomposition that allows us to prove, for a wide range of states |{psi}({theta})>=cos{theta}|00>+sin{theta}|11>, that their local content is p{sub L}({theta})=cos2{theta}. We also share reflections on how to possibly extend this result to all two-qubit pure states.

  1. 2006 Publications | Stanford Synchrotron Radiation Lightsource

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

    6 Publications Journal Papers Y. Acremann, J. P. Strachan, V. Chembrolu, S. D. Andrews, T. Tyliszczak, J. A. Katine, M. J. Carey, B. M. Clemens, H. C. Siegmann and J. Stöhr, "Time-resolved Imaging of Spin Transfer Switching: Beyond the Macrospin Concept", Phys. Rev. Lett. 96, 217202 (2006) O. S. Alexeev, A. Siani, G. Lafaye, C. T. Williams, H. J. Ploehn and M. D. Amiridis, "EXAFS Characterization of Dendrimer-Pt Nanocomposites Used for the Preparation of Pt/g-Al2O3

  2. 2008 Publications Resulting from the Use of NERSC Resources

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

    8 2008 Publications Resulting from the Use of NERSC Resources On their Allocation Year 2009 ERCAP Request Forms Principal Investigators reported 1,487 refereed publications (published or submitted) for the preceding 12 months, based on using, at least in part, NERSC resources. A PI Mowfak Al-Jassim Juarez L. F. Da Silva, Yanfa Yan, and Su-Huai Wei, Rules of Structure Formation for the Homologous InMO3(ZnO)n Compounds Phys. Rev. Lett. 100, 255501 (2008). Yanfa Yan and S.-H. Wei, Doping asymmetry

  3. 2011 Publications | Argonne National Laboratory

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

    1 Publications 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 Antonio D. and Lopez O."Micromechanical Magnetometers Based on Clamped-clamped High-Q Nonlinear Resonators ,"IEEE Conf. Proc. Solid-State Sensors, Actuators and Microsystems (2011) (Link) Aschauer U. J. and Selloni A., "Structure of the Rutile TiO2(011) Surface in Aqueous Environment," Phys. Rev. Lett., 106, 166102-166105 (2011) (Link) Awuah S. G., Polreis

  4. Using an iterative eigensolver to compute vibrational energies with phase-spaced localized basis functions

    SciTech Connect (OSTI)

    Brown, James Carrington, Tucker

    2015-07-28

    Although phase-space localized Gaussians are themselves poor basis functions, they can be used to effectively contract a discrete variable representation basis [A. Shimshovitz and D. J. Tannor, Phys. Rev. Lett. 109, 070402 (2012)]. This works despite the fact that elements of the Hamiltonian and overlap matrices labelled by discarded Gaussians are not small. By formulating the matrix problem as a regular (i.e., not a generalized) matrix eigenvalue problem, we show that it is possible to use an iterative eigensolver to compute vibrational energy levels in the Gaussian basis.

  5. Optimized pulse sequences for suppressing unwanted transitions in quantum systems

    SciTech Connect (OSTI)

    Schroeder, C. A.; Agarwal, G. S.

    2011-01-15

    We investigate the nature of the pulse sequence so that unwanted transitions in quantum systems can be inhibited optimally. For this purpose we show that the sequence of pulses proposed by Uhrig [Phys. Rev. Lett. 98, 100504 (2007)] in the context of inhibition of environmental dephasing effects is optimal. We derive exact results for inhibiting the transitions and confirm the results numerically. We posit a very significant improvement by usage of the Uhrig sequence over an equidistant sequence in decoupling a quantum system from unwanted transitions. The physics of inhibition is the destructive interference between transition amplitudes before and after each pulse.

  6. Scaling of Sweet-Parker reconnection with secondary islands

    SciTech Connect (OSTI)

    Cassak, P. A.; Shay, M. A.; Drake, J. F.

    2009-12-15

    Sweet-Parker (collisional) magnetic reconnection at high Lundquist number is modified by secondary islands. Daughton et al. [Phys. Rev. Lett. 103, 065004 (2009)] suggested the Sweet-Parker model governs the fragmented current sheet segments. If true, the reconnection rate would increase by the square root of the number of secondary islands. High Lundquist number resistive magnetohydrodynamic simulations are presented which agree, in a time-averaged sense, with the predicted scaling. This result may have important implications for energy storage before a solar eruption and its subsequent release.

  7. Publications | ANSER Center | Argonne-Northwestern National Laboratory

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

    Publications Home > Publications 2012 2011 2010 Jin, S.; Zhang, J.; Schaller, R.D.; Rajh, T.; Wiederrecht, G. P.; "Ultrafast Charge Separation from Highly Reductive ZnTe/CdSe Type II Quantum Dots." J. Phys. Chem. Lett., 2012, 3, 2052. 10.1021/jz3008886 Rybtchinski, B.; Wasielewski, M. R. "Artificial Photosynthesis for Solar Energy Conversion." in Fundamentals of Materials for Energy and Environmental Sustainability, Eds. Ginley, D. S., Cahen, D. 2012., Materials Research

  8. Analysis of the spin Hall effect in CuIr alloys: Combined approach of density functional theory and Hartree-Fock approximation

    SciTech Connect (OSTI)

    Xu, Zhuo Gu, Bo; Mori, Michiyasu; Maekawa, Sadamichi; Ziman, Timothy

    2015-05-07

    We analyze the spin Hall effect in CuIr alloys in theory by the combined approach of the density functional theory (DFT) and Hartree-Fock (HF) approximation. The spin Hall angle (SHA) is obtained to be negative without the local correlation effects. After including the local correlation effects of the 5d orbitals of Ir impurities, the SHA becomes positive with realistic correlation parameters and consistent with experiment [Niimi et al., Phys. Rev. Lett. 106, 126601 (2011)]. Moreover, our analysis shows that the DFT + HF approach is a convenient and general method to study the influence of local correlation effects on the spin Hall effect.

  9. Coherent Pion data release page

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

    Coherent Pion data release page "Measurement of Coherent Production of π± in Neutrino and Anti-Neutrino Beams on Carbon from E_nu of 1.5 to 20 GeV" Phys. Rev. Lett. 113 (2014) 261802, hep-ex/1409.3835 Data Ancillary data files for this result are available on arXiv at http://arxiv.org/src/1409.3835/anc.< /li> Among the available data files are: Scale factors (obtained from background fits) applied to different GENIE 2.6.2 background sources. Fractional systematic uncertainties

  10. Supersymmetric analysis of the Dirac-Weyl operator within PT symmetry

    SciTech Connect (OSTI)

    Ye?ilta?, zlem

    2014-08-15

    Two-dimensional effective Hamiltonian for a massless Dirac electron interacting with a hyperbolic magnetic field is discussed within PT symmetry. Factorization method and polynomial procedures are used to solve Dirac equation for the constant Fermi velocity and the effective potential which is complex Scarf II potential. The more general effective Scarf II potential models are also obtained within pseudo-supersymmetry. Finally, an extension of Panella and Roy's work [Phys. Lett. A 376, 25802583 (2012)] to the both PT symmetric and real Scarf II partner potentials is given using the position dependent Fermi velocity.

  11. Restricted thermalization for two interacting atoms in a multimode harmonic waveguide

    SciTech Connect (OSTI)

    Yurovsky, V. A.; Olshanii, M. [School of Chemistry, Tel Aviv University, IL-69978 Tel Aviv (Israel); Department of Physics, University of Massachusetts Boston, Boston, Massachusetts 02125 (United States)

    2010-04-15

    In this article, we study the thermalizability of a system consisting of two atoms in a circular, transversely harmonic waveguide in the multimode regime. While showing some signatures of quantum-chaotic behavior, the system fails to reach a thermal equilibrium in a relaxation from an initial state, even when the interaction between the atoms is infinitely strong. We relate this phenomenon to the previously addressed unattainability of a complete quantum chaos in the Seba billiard [P. Seba, Phys. Rev. Lett. 64, 1855 (1990)], and we conjecture the absence of a complete thermalization to be a generic property of integrable quantum systems perturbed by a nonintegrable but well-localized perturbation.

  12. ABSTRACTS FOR PAPERS SUBMITTED

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

    FOR PAPERS SUBMITTED April 1, 2001 - March 31, 2002 Mid-rapidity and Λ Λ Production in Au+Au Collisions at NN S = 103 GeV STAR Collaboration Phys. Rev. Lett. (submitted) We report the first measurement of strange ( and anti-strange ) Λ ) Λ ( baryon production from NN S = 130 GeV Au + Au collisions at the Relativistic Heavy Ion Collider (RHIC). Rapidity density and transverse mass distributions at mid-rapidity are presented as a function of centrality. The yield of ( and ) Λ ) (Λ hyperons

  13. Effect of {alpha} variation on the vibrational spectrum of Sr{sub 2}

    SciTech Connect (OSTI)

    Beloy, K.; Hauser, A. W.; Borschevsky, A.; Schwerdtfeger, P.; Flambaum, V. V.

    2011-12-15

    We consider the effect of {alpha} variation on the vibrational spectrum of Sr{sub 2} in the context of a planned experiment to test the stability of {mu}{identical_to}m{sub e}/m{sub p} using optically trapped Sr{sub 2} molecules [Zelevinsky et al., Phys. Rev. Lett. 100, 043201 (2008); Kotochigova et al., Phys. Rev. A 79, 012504 (2009)]. We find the prospective experiment to be 3 to 4 times less sensitive to fractional variation in {alpha} as it is to fractional variation in {mu}. Depending on the precision ultimately achieved by the experiment, this result may give justification for the neglect of {alpha} variation or, alternatively, may call for its explicit consideration in the interpretation of experimental results.

  14. Demonstration of fuel hot-spot pressure in excess of 50 Gbar for direct-drive, layered deuterium-tritium implosions on OMEGA

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

    Regan, S. P.; Goncharov, V. N.; Igumenshchev, I. V.; Sangster, T. C.; Betti, R.; Bose, A.; Boehly, T. R.; Bonino, M. J.; Campbell, E. M.; Cao, D.; et al

    2016-07-07

    A record fuel hot-spot pressure Phs = 56±7 Gbar was inferred from x-ray and nuclear diagnostics for direct-drive inertial confinement fusion cryogenic, layered deuterium–tritium implosions on the 60-beam, 30-kJ, 351-nm OMEGA Laser System. When hydrodynamically scaled to the energy of the National Ignition Facility (NIF), these implosions achieved a Lawson parameter ~60% of the value required for ignition [A. Bose et al., Phys. Rev. E (in press)], similar to indirect-drive implosions [R. Betti et al., Phys. Rev. Lett. 114, 255003 (2015)], and nearly half of the direct-drive ignition-threshold pressure. Relative to symmetric, one-dimensional simulations, the inferred hot-spot pressure is ~40%more » lower. Furthermore, three-dimensional simulations suggest that low-mode distortion of the hot spot seeded by laser-drive nonuniformity and target-positioning error reduces target performance.« less

  15. On the question of hysteresis in Hall magnetohydrodynamic reconnection

    SciTech Connect (OSTI)

    Sullivan, Brian P.; Bhattacharjee, A.; Huang Yimin

    2010-11-15

    Controversy has been raised regarding the cause of hysteresis, or bistability, of solutions to the equations that govern the geometry of the reconnection region in Hall magnetohydrodynamic (MHD) systems. This brief communication presents a comparison of the frameworks within which this controversy has arisen and illustrates that the Hall MHD hysteresis originally discovered numerically by Cassak et al. [Phys. Rev. Lett. 95, 235002 (2005)] is a different phenomenon from that recently reported by Zocco et al. [Phys. Plasmas 16, 110703 (2009)] on the basis of analysis and simulations in electron MHD with finite electron inertia. We demonstrate that the analytic prediction of hysteresis in EMHD does not describe or explain the hysteresis originally reported in Hall MHD, which is shown to persist even in the absence of electron inertia.

  16. Pressure effects on the optical conductivity of Kondo insulators

    SciTech Connect (OSTI)

    Zhang, Sun

    2001-06-01

    The effects of pressure on the optical conductivity of Kondo insulators are studied in the framework of the slave-boson mean-field theory under the coherent potential approximation. A unified picture is presented for both the hole-type Kondo insulators [H. Okamura , Phys. Rev. B >58, R7496 (1998)] and the electron-type Kondo insulators [B. Bucher , Phys. Rev. Lett. >72, 522 (1994)]. The density of states of f electrons under the applied pressure and its variation with the concentration of the impurity doping are calculated self-consistently. The Kondo temperature and the optical conductivity are obtained, in agreement with the experiments qualitatively. The two contrasting pressure-dependent effects for the hole-type Kondo insulators and the electron-type Kondo insulators are also given as predictions for further observations.

  17. The Ginibre evolution in the large-N limit

    SciTech Connect (OSTI)

    Tribe, Roger Zaboronski, Oleg

    2014-06-15

    We analyse statistics of the real eigenvalues of gl(N, R)-valued Brownian motion (the Ginibre evolution) in the limit of large N. In particular, we calculate the limiting two-time correlation function of spin variables associated with real eigenvalues of the Ginibre evolution. We also show how the formalism of spin variables can be used to compute the fixed time correlation functions of real eigenvalues discovered originally by Forrester and Nagao [“Eigenvalue statistics of the real Ginibre ensemble,” Phys. Rev. Lett. 99(5), 050603 (2007)] and Borodin and Sinclair [“The Ginibre ensemble of real random matrices and its scaling limits,” Commun. Math. Phys. 291(1), 177–224 (2009)].

  18. Topological degeneracy of non-Abelian states for dummies

    SciTech Connect (OSTI)

    Oshikawa, Masaki . E-mail: oshikawa@issp.u-tokyo.ac.jp; Kim, Yong Baek; Shtengel, Kirill; Nayak, Chetan; Tewari, Sumanta

    2007-06-15

    We present a physical construction of degenerate groundstates of the Moore-Read Pfaffian states, which exhibits non-Abelian statistics, on general Riemann surface with genus g. The construction is given by a generalization of the recent argument [M.O., T. Senthil, Phys. Rev. Lett. 96 (2006) 060601] which relates fractionalization and topological order. The nontrivial groundstate degeneracy obtained by Read and Green [Phys. Rev. B 61 (2000) 10267] based on differential geometry is reproduced exactly. Some restrictions on the statistics, due to the fractional charge of the quasiparticle are also discussed. Furthermore, the groundstate degeneracy of the p + ip superconductor in two dimensions, which is closely related to the Pfaffian states, is discussed with a similar construction.

  19. Three-dimensional modeling and analysis of a high energy density Kelvin-Helmholtz experiment

    SciTech Connect (OSTI)

    Raman, K. S.; Hurricane, O. A.; Park, H.-S.; Remington, B. A.; Robey, H.; Smalyuk, V. A.; Drake, R. P.; Krauland, C. M.; Kuranz, C. C.; Hansen, J. F.; Harding, E. C.

    2012-09-15

    A recent series of experiments on the OMEGA laser provided the first controlled demonstration of the Kelvin-Helmholtz (KH) instability in a high-energy-density physics context [E. C. Harding et al., Phys. Rev. Lett. 103, 045005, (2009); O. A. Hurricane et al., Phys. Plasmas 16, 056305, (2009)]. We present 3D simulations which resolve previously reported discrepancies between those experiments and the 2D simulation used to design them. Our new simulations reveal a three-dimensional mechanism behind the low density 'bubble' structures which appeared in the experimental x-ray radiographs at late times but were completely absent in the 2D simulations. We also demonstrate that the three-dimensional expansion of the walls of the target is sufficient to explain the 20% overprediction by 2D simulation of the late-time growth of the KH rollups. The implications of these results for the design of future experiments are discussed.

  20. Neutron yield enhancement in laser-induced deuterium-deuterium fusion using a novel shaped target

    SciTech Connect (OSTI)

    Zhao, J. R.; Chen, L. M. Li, Y. T.; Li, F.; Zhu, B. J.; Li, Yan. F.; Liao, G. Q.; Huang, K.; Ma, Y.; Li, Yi. F.; Zhang, X. P.; Fu, C. B.; Yuan, D. W.; Zhang, K.; Han, B.; Zhao, G.; Rhee, Y. J.; Liu, C.; Xiong, J.; Huang, X. G.; and others

    2015-06-15

    Neutron yields have direct correlation with the energy of incident deuterons in experiments of laser deuterated target interaction [Roth et al., Phys. Rev. Lett. 110, 044802 (2013) and Higginson et al., Phys. Plasmas 18, 100703 (2011)], while deuterated plasma density is also an important parameter. Experiments at the Shenguang II laser facility have produced neutrons with energy of 2.45 MeV using d (d, n) He reaction. Deuterated foil target and K-shaped target were employed to study the influence of plasma density on neutron yields. Neutron yield generated by K-shaped target (nearly 10{sup 6}) was two times higher than by foil target because the K-shaped target results in higher density plasma. Interferometry and multi hydro-dynamics simulation confirmed the importance of plasma density for enhancement of neutron yields.

  1. A verification of the gyrokinetic microstability codes GEM, GYRO, and GS2

    SciTech Connect (OSTI)

    Bravenec, R. V.; Chen, Y.; Wan, W.; Parker, S.; Candy, J.

    2013-10-15

    A previous publication [R. V. Bravenec et al., Phys. Plasmas 18, 122505 (2011)] presented favorable comparisons of linear frequencies and nonlinear fluxes from the Eulerian gyrokinetic codes gyro[J. Candy and R. E. Waltz, J. Comput. Phys. 186, 545 (2003)] and gs2[W. Dorland et al., Phys. Rev. Lett. 85, 5579 (2000)]. The motivation was to verify the codes, i.e., demonstrate that they correctly solve the gyrokinetic-Maxwell equations. The premise was that it is highly unlikely for both codes to yield the same incorrect results. In this work, we add the Lagrangian particle-in-cell code gem[Y. Chen and S. Parker, J. Comput. Phys. 220, 839 (2007)] to the comparisons, not simply to add another code, but also to demonstrate that the codes' algorithms do not matter. We find good agreement of gem with gyro and gs2 for the plasma conditions considered earlier, thus establishing confidence that the codes are verified and that ongoing validation efforts for these plasma parameters are warranted.

  2. PAPERS PUBLISHED April 1, 2010 - March 31, 2011

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

    0 - March 31, 2011 Tests of nuclear half-lives as a function of the host medium and temperature: refutation of recent claims J.C. Hardy, J.R. Goodwin, V.V. Golovko and V.E. Iacob Appl. Rad. and Isot. 68, 1550 (2010). Superallowed nuclear β decay: symmetry breaking, CVC and CKM unitarity J.C. Hardy and I.S. Towner Nucl. Phys. A 844, 138c (2010). Precise half-life measurement of the superallowed β+ emitter 26Si V.E. Iacob, J.C. Hardy, A. Banu, L. Chen, V.V. Golovko, J. Goodwin, V. Horvat, N.

  3. 2007 Publications | Argonne National Laboratory

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

    7 Publications 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 Abel E., Matan K., Chou F., Isaacs E., Moncton D., Sinn H., Alatas A., and Lee Y., "X-ray Scattering study of the spin-Peierls transition and soft phonon behavior in TiOCI," Phys. Rev. B, 76 (2007) Ahn W., Sheeley S. A., Rajh T., and Cropek D. M., "Photocatalytic Reduction of 4-Nitrophenol with Arginine-Modified Titanium Dioxide Nanoparticles," Appl. Catal.

  4. ABSTRACTS OF PAPERS PUBLISHED

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

    0 - March 31, 2011 Tests of nuclear half-lives as a function of host temperature: refutation of recent claims, J.C. Hardy, J.R. Goodwin, V.V. Golovko and V.E. Iacob, Appl. Rad. and Isot. 68, 1550 (2010). Superallowed nuclear β decay: symmetry breaking, CVC and CKM unitarity, J.C. Hardy and I.S. Towner, Nucl. Phys. A 844, 138c (2010). Precise half-life measurement of the superallowed β + emitter 26 Si, V.E. Iacob, J.C. Hardy, A. Banu, L. Chen, V.V. Golovko, J. Goodwin, V. Horvat, N. Nica, H.I.

  5. Fusion proton diagnostic for the C-2 field reversed configuration

    SciTech Connect (OSTI)

    Magee, R. M. Clary, R.; Korepanov, S.; Smirnov, A.; Garate, E.; Knapp, K.; Tkachev, A.

    2014-11-15

    Measurements of the flux of fusion products from high temperature plasmas provide valuable insights into the ion energy distribution, as the fusion reaction rate is a very sensitive function of ion energy. In C-2, where field reversed configuration plasmas are formed by the collision of two compact toroids and partially sustained by high power neutral beam injection [M. Binderbauer et al., Phys. Rev. Lett. 105, 045003 (2010); M. Tuszewski et al., Phys. Rev. Lett. 108, 255008 (2012)], measurements of DD fusion neutron flux are used to diagnose ion temperature and study fast ion confinement and dynamics. In this paper, we will describe the development of a new 3 MeV proton detector that will complement existing neutron detectors. The detector is a large area (50?cm{sup 2}), partially depleted, ion implanted silicon diode operated in a pulse counting regime. While the scintillator-based neutron detectors allow for high time resolution measurements (?100 kHz), they have no spatial or energy resolution. The proton detector will provide 10 cm spatial resolution, allowing us to determine if the axial distribution of fast ions is consistent with classical fast ion theory or whether anomalous scattering mechanisms are active. We will describe in detail the diagnostic design and present initial data from a neutral beam test chamber.

  6. Understanding the dynamics of photoionization-induced nonlinear effects and solitons in gas-filled hollow-core photonic crystal fibers

    SciTech Connect (OSTI)

    Saleh, Mohammed F.; Biancalana, Fabio

    2011-12-15

    We present the details of our previously formulated model [Saleh et al., Phys. Rev. Lett. 107, 203902 (2011)] that governs pulse propagation in hollow-core photonic crystal fibers filled by an ionizable gas. By using perturbative methods, we find that the photoionization process induces the opposite phenomenon of the well-known Raman self-frequency redshift of solitons in solid-core glass fibers, as was recently experimentally demonstrated [Hoelzer et al., Phys. Rev. Lett. 107, 203901 (2011)]. This process is only limited by ionization losses, and leads to a constant acceleration of solitons in the time domain with a continuous blueshift in the frequency domain. By applying the Gagnon-Belanger gauge transformation, multipeak ''inverted gravitylike'' solitary waves are predicted. We also demonstrate that the pulse dynamics shows the ejection of solitons during propagation in such fibers, analogous to what happens in conventional solid-core fibers. Moreover, unconventional long-range nonlocal interactions between temporally distant solitons, unique of gas plasma systems, are predicted and studied. Finally, the effects of higher-order dispersion coefficients and the shock operator on the pulse dynamics are investigated, showing that the conversion efficiency of resonant radiation into the deep UV can be improved via plasma formation.

  7. Optimisation of geometrical ratchets for spin-current amplification

    SciTech Connect (OSTI)

    Abdullah, Ranjdar M.; Vick, Andrew J.; Murphy, Benedict A.; Hirohata, Atsufumi

    2015-05-07

    A two-dimensional model is used to study the geometrical effects of a nonmagnetic (NM) nanowire upon a spin-polarised electron current in a lateral spin-valve structure. We found that the implemented ratchet shapes at the centre of the NM have a crucial effect on the diffusive rate for up- and down-spin electrons along the wire, which leads to the amplification of non-local spin-current signals. By using our simple model, the geometries have been optimised. The calculated spin-current signals are in good qualitative agreement with our recent experimental results [Abdullah et al., J. Phys. D: Appl. Phys. 47, 482001(FTC) (2014)]. Our model may be very useful to evaluate such a geometrical effect on spin-polarised electron transport.

  8. The influence of the secondary electron induced asymmetry on the electrical asymmetry effect in capacitively coupled plasmas

    SciTech Connect (OSTI)

    Korolov, Ihor; Derzsi, Aranka; Donkó, Zoltán; Schulze, Julian

    2013-08-05

    In geometrically symmetric capacitive radio-frequency plasmas driven by two consecutive harmonics, a dc self-bias can be generated as a function of the phase shift between the driving frequencies via the Electrical Asymmetry Effect (EAE). Recently, the Secondary Electron Asymmetry Effect (SEAE) was discovered (Lafleur et al., J. Phys. D: Appl. Phys. 46, 135201 (2013)): unequal secondary electron emission coefficients at both electrodes were found to induce an asymmetry in single-frequency capacitive plasmas. Here, we investigate the simultaneous presence of both effects, i.e., a dual-frequency plasma driven by two consecutive harmonics with different electrode materials. We find that the superposition of the EAE and the SEAE is generally non-linear, i.e., the asymmetries generated by each individual effect do not simply add up at all phases. The control ranges of the dc self-bias and the mean ion energy can be enlarged, if both effects are combined.

  9. Single-shot electron bunch length measurements using a spatial electro-optical autocorrelation interferometer

    SciTech Connect (OSTI)

    Suetterlin, Daniel; Erni, Daniel; Schlott, Volker; Sigg, Hans; Jaeckel, Heinz; Murk, Axel

    2010-10-15

    A spatial, electro-optical autocorrelation (EOA) interferometer using the vertically polarized lobes of coherent transition radiation (CTR) has been developed as a single-shot electron bunch length monitor at an optical beam port downstream the 100 MeV preinjector LINAC of the Swiss Light Source. This EOA monitor combines the advantages of step-scan interferometers (high temporal resolution) [D. Mihalcea et al., Phys. Rev. ST Accel. Beams 9, 082801 (2006) and T. Takahashi and K. Takami, Infrared Phys. Technol. 51, 363 (2008)] and terahertz-gating technologies [U. Schmidhammer et al., Appl. Phys. B: Lasers Opt. 94, 95 (2009) and B. Steffen et al., Phys. Rev. ST Accel. Beams 12, 032802 (2009)] (fast response), providing the possibility to tune the accelerator with an online bunch length diagnostics. While a proof of principle of the spatial interferometer was achieved by step-scan measurements with far-infrared detectors, the single-shot capability of the monitor has been demonstrated by electro-optical correlation of the spatial CTR interference pattern with fairly long (500 ps) neodymium-doped yttrium aluminum garnet (Nd:YAG) laser pulses in a ZnTe crystal. In single-shot operation, variations of the bunch length between 1.5 and 4 ps due to different phase settings of the LINAC bunching cavities have been measured with subpicosecond time resolution.

  10. U-165: Apple iOS Bugs Let Remote Users Execute Arbitrary Code...

    Energy Savers [EERE]

    iOS. A remote user can cause arbitrary code to be executed on the target user's system. ... A remote user can create a specially crafted file that, when loaded by the target user, ...

  11. T-654: Apple QuickTime Multiple Bugs Let Remote Users Execute Arbitrary

    Broader source: Energy.gov [DOE]

    A remote user can create a specially crafted file that, when loaded by the target user, will execute arbitrary code on the target system. The code will run with the privileges of the target user.

  12. T-529: Apple Mac OS PackageKit Distribution Script Remote Code Execution Vulnerability

    Broader source: Energy.gov [DOE]

    A format string issue exists in PackageKit's handling of distribution scripts. A man-in-the-middle attacker may be able to cause an unexpected application termination or arbitrary code execution when Software Update checks for new updates. This issue is addressed through improved validation of distribution scripts. This issue does not affect systems prior to Mac OS X v10.6.

  13. U-036: Apple iOS Bugs Let Remote Users Execute Arbitrary Code

    Broader source: Energy.gov [DOE]

    A remote user can create content that, when loaded by the target user, will execute arbitrary code on or obtain potentially sensitive information from the target user's system.

  14. U-170: Apple QuickTime Multiple Flaws Let Remote Users Execute...

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

    overflow CVE-2012-0670. A specially crafted '.pict' file can trigger a memory corruption error CVE-2012-0671. Impact: A remote user can create a file that, when loaded by...

  15. V-171: Apple Safari Bugs Let Remote Users Execute Arbitrary Code...

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

    specially crafted HTML that, when loaded by the target user, will trigger a memory corruption error and execute arbitrary code on the target system CVE-2013-1009,...

  16. V-164: Apple QuickTime Multiple Flaws Let Remote Users Execute...

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

    1) An unspecified error when handling TeXML files can be exploited to cause memory corruption. 2) A boundary error when handling H.263 encoded movie files can be exploited to...

  17. T-673: Apple Safari Multiple Flaws Let Remote Users Execute Arbitrary...

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

    specially crafted HTML that, when loaded by the target user, will trigger a memory corruption error and execute arbitrary code on the target system - CVE-2010-1823,...

  18. U-222: Apple Safari Bugs Let Remote Users Execute Arbitrary Code...

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

    specially crafted HTML that, when loaded by the target user, will trigger a memory corruption error and execute arbitrary code on the target system CVE-2011-3016, CVE-2011-3021,...

  19. T-676: Apple iOS Certificate Chain Validation Flaw Lets Certain...

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

    T-727:Microsoft Windows SSLTLS Protocol Flaw Lets Remote Users Decryption Sessions U-259: RSA BSAFE SSL-C Lets Remote Users Decrypt SSLTLS Traffic and SSL Buffer Overflow Lets ...

  20. Response to Comment on Motion of a helical vortex filament in superfluid {sup 4}He under the extrinsic form of the local induction approximation [Phys. Fluids 26, 019101 (2014)

    SciTech Connect (OSTI)

    Van Gorder, Robert A.

    2014-01-15

    I agree with the authors regarding their comments on the Donnelly-Glaberson instability for such helical filaments as those obtained in my paper. I also find merit in their derivation of the quantum LIA (local induction approximation) in the manner of the LIA of Boffetta et al. However, I disagree with the primary criticisms of Hietala and Hnninen. In particular, though they suggest LIA and local nonlinear equation modes are not comparable since the former class of models contains superfluid friction parameters, note that since these parameters are small one may take them to zero and consider a qualitative comparison of the models (which is what was done in my paper). Second, while Hietala and Hnninen criticize certain assumptions made in my paper (and the paper of Shivamoggi where the model comes from) since the results break-down when Ak ? ?, note that in my paper I state that any deviations from the central axis along which the filament is aligned must be sufficiently bounded in variation. Therefore, it was already acknowledged that Ak(=|?{sub x}|) should be sufficiently bounded, precluding the Ak ? ? case. I also show that, despite what Hietala and Hnninen claim, the dispersion relation obtained in my paper is consistent with LIA, where applicable. Finally, while Hietala and Hnninen claim that the dispersion parameter should be complex valued, I show that their dispersion relation is wrong, since it was derived incorrectly (they assume the complex modulus of the potential function is constant, yet then use this to obtain a potential function with non-constant modulus)

  1. Comment on ''The velocity field due to an oscillating plate in an Oldroyd-B fluid'' by C.C. Hopkins and J.R. de Bruyn [Can. J. Phys. 92, 533 (2014)

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

    Christov, Ivan C.

    2015-09-11

    We correct certain errors and ambiguities in the recent pedagogical article by Hopkins and de Bruyn. The early-time asymptotics of the solution to the transient version of Stokes’ second problem for an Oldroyd-B fluid in a half-space is presented, as Appendix A, to complement the late-time asymptotics given by Hopkins and de Bruyn.

  2. Erratum: Measurement of azimuthal asymmetries in inclusive production of hadron pairs in e⁺e⁻ annihilation at √s=10.58 GeV [Phys. Rev. D 78, 032011 (2008)

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

    Seidl, R.; Grosse Perdekamp, M.; Ogawa, A.; Adachi, I.; Aihara, H.; Bahinipati, S.; Bakich, A. M.; Bartel, W.; Bitenc, U.; Bondar, A.; et al

    2012-08-09

    In the original article, it was found in Monte Carlo simulations that the reconstructed A₀ results are roughly consistent with the generated asymmetries, while the A₁₂ results systematically underestimate the generated asymmetries. This underestimation can be attributed to the difference between the reconstructed thrust axis and the original quark-antiquark axis. The corresponding correction factors are 1.6 ± 0.04 for the A₁₂ results and 1.11 ± 0.05 for the A₀ results. Because of a flaw in the original analysis program, these correction factors were not applied to the AUC-type asymmetries in Table V as well as in some figures. In addition,more » a small mistake in the error propagation in the charm correction resulted in slightly underestimated statistical uncertainties. These omissions affect all but the charm asymmetry results. The correct central values are therefore given in Tables IV and V of this Erratum. The systematic uncertainties of the original publication remain unchanged.« less

  3. Erratum: Evolution of precipitate morphology during heat treatment and its implications for the superconductivity in KxFe1.6+ySe2 single crystals [Phys. Rev. B 86 , 144507 (2012)

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

    Liu, Y.; Xing, Q.; Dennis, K. W.; McCallum, R. W.; Lograsso, T. A.

    2015-08-14

    In this article, we study the relationship between precipitate morphology and superconductivity in KxFe1.6+ySe2 single crystals grown by self-flux method. Scanning electron microscopy (SEM) measurements revealed that the superconducting phase forms a network in the samples quenched above iron vacancy order-disorder transition temperature Ts, whereas it aggregates into micrometer-sized rectangular bars and aligns as disconnected chains in the furnace-cooled samples.

  4. Combining density functional and incremental post-Hartree-Fock approaches for van der Waals dominated adsorbate-surface interactions: Ag{sub 2}/graphene

    SciTech Connect (OSTI)

    Lara-Castells, María Pilar de; Mitrushchenkov, Alexander O.; Stoll, Hermann

    2015-09-14

    A combined density functional (DFT) and incremental post-Hartree-Fock (post-HF) approach, proven earlier to calculate He-surface potential energy surfaces [de Lara-Castells et al., J. Chem. Phys. 141, 151102 (2014)], is applied to describe the van der Waals dominated Ag{sub 2}/graphene interaction. It extends the dispersionless density functional theory developed by Pernal et al. [Phys. Rev. Lett. 103, 263201 (2009)] by including periodic boundary conditions while the dispersion is parametrized via the method of increments [H. Stoll, J. Chem. Phys. 97, 8449 (1992)]. Starting with the elementary cluster unit of the target surface (benzene), continuing through the realistic cluster model (coronene), and ending with the periodic model of the extended system, modern ab initio methodologies for intermolecular interactions as well as state-of-the-art van der Waals-corrected density functional-based approaches are put together both to assess the accuracy of the composite scheme and to better characterize the Ag{sub 2}/graphene interaction. The present work illustrates how the combination of DFT and post-HF perspectives may be efficient to design simple and reliable ab initio-based schemes in extended systems for surface science applications.

  5. Bell-Plesset effects in Rayleigh-Taylor instability of finite-thickness spherical and cylindrical shells

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

    Velikovich, A. L.; Schmit, P. F.

    2015-12-28

    Bell-Plesset (BP) effects account for the influence of global convergence or divergence of the fluid flow on the evolution of the interfacial perturbations embedded in the flow. The development of the Rayleigh-Taylor instability in radiation-driven spherical capsules and magnetically-driven cylindrical liners necessarily includes a significant contribution from BP effects due to the time dependence of the radius, velocity, and acceleration of the unstable surfaces or interfaces. An analytical model is presented that, for an ideal incompressible fluid and small perturbation amplitudes, exactly evaluates the BP effects in finite-thickness shells through acceleration and deceleration phases. The time-dependent dispersion equations determining themore » “instantaneous growth rate” are derived. It is demonstrated that by integrating this approximate growth rate over time, one can accurately evaluate the number of perturbation e-foldings during the inward acceleration phase of the implosion. As a result, in the limit of small shell thickness, exact thin-shell perturbationequations and approximate thin-shell dispersion equations are obtained, generalizing the earlier results [E. G. Harris, Phys. Fluids 5, 1057 (1962); E. Ott, Phys. Rev. Lett. 29, 1429 (1972); A. B. Bud'ko et al., Phys. Fluids B 2, 1159 (1990)].« less

  6. Transitions to improved confinement regimes induced by changes in heating in zero-dimensional models for tokamak plasmas

    SciTech Connect (OSTI)

    Zhu, H.; Chapman, S. C.; Dendy, R. O.; Itoh, K.

    2014-06-15

    It is shown that rapid substantial changes in heating rate can induce transitions to improved energy confinement regimes in zero-dimensional models for tokamak plasma phenomenology. We examine for the first time the effect of step changes in heating rate in the models of Kim and Diamond [Phys. Rev. Lett. 90, 185006 (2003)] and Malkov and Diamond [Phys. Plasmas 16, 012504 (2009)], which nonlinearly couple the evolving temperature gradient, micro-turbulence, and a mesoscale flow; and in the extension of Zhu et al. [Phys. Plasmas 20, 042302 (2013)], which couples to a second mesoscale flow component. The temperature gradient rises, as does the confinement time defined by analogy with the fusion context, while micro-turbulence is suppressed. This outcome is robust against variation of heating rise time and against introduction of an additional variable into the model. It is also demonstrated that oscillating changes in heating rate can drive the level of micro-turbulence through a period-doubling path to chaos, where the amplitude of the oscillatory component of the heating rate is the control parameter.

  7. Bell-Plesset effects in Rayleigh-Taylor instability of finite-thickness spherical and cylindrical shells

    SciTech Connect (OSTI)

    Velikovich, A. L.; Schmit, P. F.

    2015-12-28

    Bell-Plesset (BP) effects account for the influence of global convergence or divergence of the fluid flow on the evolution of the interfacial perturbations embedded in the flow. The development of the Rayleigh-Taylor instability in radiation-driven spherical capsules and magnetically-driven cylindrical liners necessarily includes a significant contribution from BP effects due to the time dependence of the radius, velocity, and acceleration of the unstable surfaces or interfaces. An analytical model is presented that, for an ideal incompressible fluid and small perturbation amplitudes, exactly evaluates the BP effects in finite-thickness shells through acceleration and deceleration phases. The time-dependent dispersion equations determining the “instantaneous growth rate” are derived. It is demonstrated that by integrating this approximate growth rate over time, one can accurately evaluate the number of perturbation e-foldings during the inward acceleration phase of the implosion. As a result, in the limit of small shell thickness, exact thin-shell perturbationequations and approximate thin-shell dispersion equations are obtained, generalizing the earlier results [E. G. Harris, Phys. Fluids 5, 1057 (1962); E. Ott, Phys. Rev. Lett. 29, 1429 (1972); A. B. Bud'ko et al., Phys. Fluids B 2, 1159 (1990)].

  8. Anomalous momentum and energy transfer rates for electrostatic ion-cyclotron turbulence in downward auroral-current regions of the Earth's magnetosphere. III

    SciTech Connect (OSTI)

    Jasperse, John R.; Basu, Bamandas; Lund, Eric J.; Grossbard, Neil

    2010-06-15

    Recently, a new multimoment fluid theory was developed for inhomogeneous, nonuniformly magnetized plasma in the guiding-center and gyrotropic approximation that includes the effect of electrostatic, turbulent, wave-particle interactions (see Jasperse et al. [Phys. Plasmas 13, 072903 (2006); ibid.13, 112902 (2006)]). In the present paper, which is intended as a sequel, it is concluded from FAST satellite data that the electrostatic ion-cyclotron turbulence that appears is due to the operation of an electron, bump-on-tail-driven ion-cyclotron instability for downward currents in the long-range potential region of the Earth's magnetosphere. Approximate closed-form expressions for the anomalous momentum and energy transfer rates for the ion-cyclotron turbulence are obtained. The turbulent, inhomogeneous, nonuniformly magnetized, multimoment fluid theory given above, in the limit of a turbulent, homogeneous, uniformly magnetized, quasisteady plasma, yields the well-known formula for the anomalous resistivity given by Gary and Paul [Phys. Rev. Lett. 26, 1097 (1971)] and Tange and Ichimaru [J. Phys. Soc. Jpn. 36, 1437 (1974)].

  9. Spectral geometry of {kappa}-Minkowski space

    SciTech Connect (OSTI)

    D'Andrea, Francesco

    2006-06-15

    After recalling Snyder's idea [Phys. Rev. 71, 38 (1947)] of using vector fields over a smooth manifold as 'coordinates on a noncommutative space', we discuss a two-dimensional toy-model whose 'dual' noncommutative coordinates form a Lie algebra: this is the well-known {kappa}-Minkowski space [Phys. Lett. B 334, 348 (1994)]. We show how to improve Snyder's idea using the tools of quantum groups and noncommutative geometry. We find a natural representation of the coordinate algebra of {kappa}-Minkowski as linear operators on an Hilbert space (a major problem in the construction of a physical theory), study its 'spectral properties', and discuss how to obtain a Dirac operator for this space. We describe two Dirac operators. The first is associated with a spectral triple. We prove that the cyclic integral of Dimitrijevic et al. [Eur. Phys. J. C 31, 129 (2003)] can be obtained as Dixmier trace associated to this triple. The second Dirac operator is equivariant for the action of the quantum Euclidean group, but it has unbounded commutators with the algebra.

  10. Effect of {alpha} variation on a prospective experiment to detect variation of m{sub e}/m{sub p} in diatomic molecules

    SciTech Connect (OSTI)

    Beloy, K.; Borschevsky, A.; Schwerdtfeger, P.; Flambaum, V. V.

    2011-10-15

    We consider the influence of variation in the fine structure constant {alpha} on a promising experiment proposed by DeMille et al. to search for variation in the electron-to-proton mass ratio {mu} using diatomic molecules [DeMille et al., Phys. Rev. Lett. 100, 043202 (2008)]. The proposed experiment involves spectroscopically probing the splitting between two nearly degenerate vibrational levels supported by different electronic potentials. Here we demonstrate that this splitting may be equally or more sensitive to variation in {alpha} as to variation in {mu}. For the anticipated experimental precision, this implies that the {alpha} variation may not be negligible, as previously assumed, and further suggests that the method could serve as a competitive means to search for {alpha} variation as well.

  11. Sign of coupling in barrier-separated Bose-Einstein condensates and stability of double-ring systems

    SciTech Connect (OSTI)

    Brand, J.; Haigh, T. J.; Zuelicke, U.

    2010-02-15

    We revisit recent claims about the instability of nonrotating tunnel coupled annular Bose-Einstein condensates leading to the emergence of angular momentum Josephson oscillation [Phys. Rev. Lett. 98, 050401 (2007)]. It was predicted that all stationary states with uniform density become unstable in certain parameter regimes. By careful analysis, we arrive at a different conclusion. We show that there is a stable nonrotating and uniform ground state for any value of the tunnel coupling and repulsive interactions. The instability of an excited state with {pi} phase difference between the condensates can be interpreted in terms of the familiar snake instability. We further discuss the sign of the tunnel coupling through a separating barrier, which carries significance for the nature of the stationary states. It is found to always be negative for physical reasons.

  12. Energy-dependent crossover from anisotropic to isotropic magnetic dispersion in lightly-doped La1.96Sr0.04CuO4

    SciTech Connect (OSTI)

    Matsuda, Masaaki; Granroth, Garrett E; Fujita, M.; Yamada, K.; Tranquada, John M.

    2013-01-01

    Inelastic neutron scattering experiments have been performed on lightly-doped La$_{1.96}$Sr$_{0.04}$CuO$_{4}$, which shows diagonal incommensurate spin correlations at low temperatures. We previously reported that this crystal, with a single orthorhombic domain, exhibits the ``hourglass" dispersion at low energies [Phys. Rev. Lett. 101, 197001 (2008)]. In this paper, we investigate in detail the energy evolution of the magnetic excitations up to 65 meV. It is found that the anisotropic excitations at low energies, dispersing only along the spin modulation direction, crossover to an isotropic, conical dispersion that resembles spin waves in the parent compound La$_2$CuO$_{4}$. The change from two-fold to full symmetry on crossing the waist of the hourglass reproduces behavior first identified in studies of underdoped YBa$_2$Cu$_3$O$_{6+x}$. We discuss the significance of these results.

  13. Robustness of fractional quantum Hall states with dipolar atoms in artificial gauge fields

    SciTech Connect (OSTI)

    Grass, T.; Baranov, M. A.; Lewenstein, M.

    2011-10-15

    The robustness of fractional quantum Hall states is measured as the energy gap separating the Laughlin ground state from excitations. Using thermodynamic approximations for the correlation functions of the Laughlin state and the quasihole state, we evaluate the gap in a two-dimensional system of dipolar atoms exposed to an artificial gauge field. For Abelian fields, our results agree well with the results of exact diagonalization for small systems but indicate that the large value of the gap predicted [Phys. Rev. Lett. 94, 070404 (2005)] was overestimated. However, we are able to show that the small gap found in the Abelian scenario dramatically increases if we turn to non-Abelian fields squeezing the Landau levels.

  14. Theoretical study of Raman chirped adiabatic passage by X-ray absorption spectroscopy: Highly excited electronic states and rotational effects

    SciTech Connect (OSTI)

    Engin, Selma; Sisourat, Nicolas Selles, Patricia; Taïeb, Richard; Carniato, Stéphane

    2014-06-21

    Raman Chirped Adiabatic Passage (RCAP) is an efficient method to climb the vibrational ladder of molecules. It was shown on the example of fixed-in-space HCl molecule that selective vibrational excitation can thus be achieved by RCAP and that population transfer can be followed by X-ray Photoelectron spectroscopy [S. Engin, N. Sisourat, P. Selles, R. Taïeb, and S. Carniato, Chem. Phys. Lett. 535, 192–195 (2012)]. Here, in a more detailed analysis of the process, we investigate the effects of highly excited electronic states and of molecular rotation on the efficiency of RCAP. Furthermore, we propose an alternative spectroscopic way to monitor the transfer by means of X-ray absorption spectra.

  15. Study of the stability of Z-pinch implosions with different initial density profiles

    SciTech Connect (OSTI)

    Rousskikh, A. G.; Zhigalin, A. S.; Labetskaya, N. A.; Chaikovsky, S. A.; Yushkov, G. Yu.; Oreshkin, V. I.; Batrakov, A. V.; Tomsk Polytechnic University, Tomsk ; Baksht, R. B.; Tel-Aviv University, Tel Aviv

    2014-05-15

    Stability of metal-puff Z pinches was studied experimentally. Experiments were carried out on a facility producing a load current up to 450 kA with a rise time of 450?ns. In a metal-puff Z pinch, the plasma shell is produced due to evaporation of the electrode material during the operation of a vacuum arc. In the experiment to be reported, a single-shell and a shell-on-jet pinch load with magnesium electrodes were used. Two-dimensional, 3 ns gated, visible-light images were taken at different times during the implosion. When the shell was formed from a collimated plasma flow with small radial divergence, RayleighTaylor (RT) instability typical of gas-puff implosions was recorded. The RT instability was completely suppressed in a mode where the initial density distribution of the shell approached a tailored density profile [A. L. Velikovich et al., Phys. Rev. Lett. 77, 853 (1996)].

  16. Electromagnetic nonlinear gyrokinetics with polarization drift

    SciTech Connect (OSTI)

    Duthoit, F.-X.; Hahm, T. S.; Wang, Lu

    2014-08-15

    A set of new nonlinear electromagnetic gyrokinetic Vlasov equation with polarization drift and gyrokinetic Maxwell equations is systematically derived by using the Lie-transform perturbation method in toroidal geometry. For the first time, we recover the drift-kinetic expression for parallel acceleration [R. M. Kulsrud, in Basic Plasma Physics, edited by A. A. Galeev and R. N. Sudan (North-Holland, Amsterdam, 1983)] from the nonlinear gyrokinetic equations, thereby bridging a gap between the two formulations. This formalism should be useful in addressing nonlinear ion Compton scattering of intermediate-mode-number toroidal Alfvén eigenmodes for which the polarization current nonlinearity [T. S. Hahm and L. Chen, Phys. Rev. Lett. 74, 266 (1995)] and the usual finite Larmor radius effects should compete.

  17. Core conditions for alpha heating attained in direct-drive inertial confinement fusion

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

    Bose, A.; Woo, K. M.; Betti, R.; Campbell, E. M.; Mangino, D.; Christopherson, A. R.; McCrory, R. L.; Nora, R.; Regan, S. P.; Goncharov, V. N.; et al

    2016-07-07

    Here, it is shown that direct-drive implosions on the OMEGA laser have achieved core conditions that would lead to significant alpha heating at incident energies available on the National Ignition Facility (NIF) scale. The extrapolation of the experimental results from OMEGA to NIF energy assumes only that the implosion hydrodynamic efficiency is unchanged at higher energies. This approach is independent of the uncertainties in the physical mechanism that degrade implosions on OMEGA, and relies solely on a volumetric scaling of the experimentally observed core conditions. It is estimated that the current best-performing OMEGA implosion [Regan et al., Phys. Rev. Lett.more » 117, 025001 (2016)] extrapolated to a 1.9 MJ laser driver with the same illumination configuration and laser-target coupling would produce 125 kJ of fusion energy with similar levels of alpha heating observed in current highest performing indirect-drive NIF implosions.« less

  18. Intrinsic momentum generation by a combined neoclassical and turbulence mechanism in diverted DIII-D plasma edge

    SciTech Connect (OSTI)

    Seo, Janghoon; Choe, W.; Chang, C. S.; Ku, S.; Kwon, J. M.; Mller, Stefan H.

    2014-09-15

    Fluid Reynolds stress from turbulence has usually been considered to be responsible for the anomalous toroidal momentum transport in tokamak plasma. Experiment by Mller et al. [Phys. Rev. Lett. 106, 115001 (2011)], however, reported that neither the observed edge rotation profile nor the inward momentum transport phenomenon at the edge region of an H-mode plasma could be explained by the fluid Reynolds stress measured with reciprocating Langmuir-probe. The full-function gyrokinetic code XGC1 is used to explain, for the first time, Mller et al.'s experimental observations. It is discovered that, unlike in the plasma core, the fluid Reynolds stress from turbulence is not sufficient for momentum transport physics in plasma edge. The turbulent neoclassical physics arising from the interaction between kinetic neoclassical orbit dynamics and plasma turbulence is key in the tokamak edge region across the plasma pedestal into core.

  19. Dynamical mean-field theory and weakly non-linear analysis for the phase separation of active Brownian particles

    SciTech Connect (OSTI)

    Speck, Thomas; Menzel, Andreas M.; Bialké, Julian; Löwen, Hartmut

    2015-06-14

    Recently, we have derived an effective Cahn-Hilliard equation for the phase separation dynamics of active Brownian particles by performing a weakly non-linear analysis of the effective hydrodynamic equations for density and polarization [Speck et al., Phys. Rev. Lett. 112, 218304 (2014)]. Here, we develop and explore this strategy in more detail and show explicitly how to get to such a large-scale, mean-field description starting from the microscopic dynamics. The effective free energy emerging from this approach has the form of a conventional Ginzburg-Landau function. On the coarsest scale, our results thus agree with the mapping of active phase separation onto that of passive fluids with attractive interactions through a global effective free energy (motility-induced phase transition). Particular attention is paid to the square-gradient term necessary for the phase separation kinetics. We finally discuss results from numerical simulations corroborating the analytical results.

  20. On the nature of kinetic electrostatic electron nonlinear (KEEN) waves

    SciTech Connect (OSTI)

    Dodin, I. Y.; Fisch, N. J.

    2014-03-15

    An analytical theory is proposed for the kinetic electrostatic electron nonlinear (KEEN) waves originally found in simulations by Afeyan et al. [arXiv:1210.8105]. We suggest that KEEN waves represent saturated states of the negative mass instability (NMI) reported recently by Dodin et al. [Phys. Rev. Lett. 110, 215006 (2013)]. Due to the NMI, trapped electrons form macroparticles that produce field oscillations at harmonics of the bounce frequency. At large enough amplitudes, these harmonics can phase-lock to the main wave and form stable nonlinear dissipationless structures that are nonstationary but otherwise similar to Bernstein-Greene-Kruskal modes. The theory explains why the formation of KEEN modes is sensitive to the excitation scenario and yields estimates that agree with the numerical results of Afeyan et al. A new type of KEEN wave may be possible at even larger amplitudes of the driving field than those used in simulations so far.

  1. Study of electron trapping by a transversely ellipsoidal bubble in the laser wake-field acceleration

    SciTech Connect (OSTI)

    Cho, Myung-Hoon; Kim, Young-Kuk; Hur, Min Sup

    2013-09-15

    We present electron trapping in an ellipsoidal bubble which is not well explained by the spherical bubble model by [Kostyukov et al., Phys. Rev. Lett. 103, 175003 (2009)]. The formation of an ellipsoidal bubble, which is elongated transversely, frequently occurs when the spot size of the laser pulse is large compared to the plasma wavelength. First, we introduce the relation between the bubble size and the field slope inside the bubble in longitudinal and transverse directions. Then, we provide an ellipsoidal model of the bubble potential and investigate the electron trapping condition by numerical integration of the equations of motion. We found that the ellipsoidal model gives a significantly less restrictive trapping condition than that of the spherical bubble model. The trapping condition is compared with three-dimensional particle-in-cell simulations and the electron trajectory in test potential simulations.

  2. Nonlinear interferometry with Bose-Einstein condensates

    SciTech Connect (OSTI)

    Tacla, Alexandre B. [Center for Quantum Information and Control, MSC 07-4220, University of New Mexico, Albuquerque, New Mexico 87131-0001 (United States); Boixo, Sergio [Institute for Quantum Information, California Institute of Technology, Pasadena, California 91125 (United States); Datta, Animesh [Clarendon Laboratory, Department of Physics, University of Oxford, OX1 3PU (United Kingdom); Shaji, Anil [School of Physics, Indian Institute of Science Education and Research, College of Engineering Trivandrum Campus, Thiruvananthapuram, Kerala 695016 (India); Caves, Carlton M. [Center for Quantum Information and Control, MSC 07-4220, University of New Mexico, Albuquerque, New Mexico 87131-0001 (United States); School of Mathematics and Physics, University of Queensland, Brisbane, Queensland 4072 (Australia)

    2010-11-15

    We analyze a proposed experiment [Boixo et al., Phys. Rev. Lett. 101, 040403 (2008)] for achieving sensitivity scaling better than 1/N in a nonlinear Ramsey interferometer that uses a two-mode Bose-Einstein condensate (BEC) of N atoms. We present numerical simulations that confirm the analytical predictions for the effect of the spreading of the BEC ground-state wave function on the ideal 1/N{sup 3/2} scaling. Numerical integration of the coupled, time-dependent, two-mode Gross-Pitaevskii equations allows us to study the several simplifying assumptions made in the initial analytic study of the proposal and to explore when they can be justified. In particular, we find that the two modes share the same spatial wave function for a length of time that is sufficient to run the metrology scheme.

  3. Kondo-type transport through a quantum dot under magnetic fields

    SciTech Connect (OSTI)

    Dong, Bing; Lei, X. L.

    2001-06-15

    In this paper, we investigate the Kondo correlation effects on linear and nonlinear transport in a quantum dot connected to reservoirs under finite magnetic fields, using the slave-boson mean field approach suggested by Kotliar and Ruckenstein [Phys. Rev. Lett. >57, 1362 (1986)]. A brief comparison between the present formulation and other slave-boson formulation is presented to justify this approach. The numerical results show that the linear conductance near electron-hole symmetry is suppressed by the application of the magnetic fields, but an anomalous enhancement is predicted in the nonsymmetry regime. The effect of external magnetic fields on the nonlinear differential conductances is discussed for the Kondo system. A significant reduction of the peak splitting is observed due to the strong Kondo correlation, which agrees well with experimental data.

  4. Vibrational Feshbach resonances in near threshold HOCO{sup -} photodetachment: a theoretical study

    SciTech Connect (OSTI)

    Miyabe, Shungo; Haxton, Dan; Lawler, Keith; Orel, Ann; McCurdy, Bill; Rescigno, Tom

    2011-03-02

    The results of a theoretical study of HOCO{sup ?} photodetachment are presented, with a view toward understanding the origin of two peaks observed by Lu and Continetti (Phys. Rev. Lett. 99, 113005 (2007)) in the photoelectron kinetic energy spectrum very close to threshold. It is shown that the peaks can be attributed to vibrational Feshbach resonances of dipole-bound trans-HOCO{sup ?}, and not s- and p-wave shape resonances as previously assumed. Fixed-nuclei variational electron-HOCO scattering calculations are used to compute photodetachment cross sections and laboratory-frame photoelectron angular distributions. The calculations show a broad A??(#25;{pi}*)-shape resonance several eV above threshold.

  5. Fixed conditions for achieving the real-valued partition function of one-dimensional Gross-Pitaevskii equation coupled with time-dependent potential

    SciTech Connect (OSTI)

    Prayitno, T. B.

    2014-03-24

    We have imposed the conditions in order to preserve the real-valued partition function in the case of onedimensional Gross-Pitaevskii equation coupled by time-dependent potential. In this case we have solved the Gross-Pitaevskii equation by means of the time-dependent perturbation theory by extending the previous work of Kivshar et al. [Phys. Lett A 278, 225–230 (2001)]. To use the method, we have treated the equation as the macroscopic quantum oscillator and found that the expression of the partition function explicitly has complex values. In fact, we have to choose not only the appropriate functions but also the suitable several values of the potential to keep the real-valued partition function.

  6. Anisotropy of radiation emitted from planar wire arrays

    SciTech Connect (OSTI)

    Kantsyrev, V. L.; Esaulov, A. A.; Safronova, A. S.; Williamson, K. M.; Osborne, G. C.; Shrestha, I. K.; Weller, M. E.; Shlyaptseva, V. V.; Chuvatin, A. S.; Rudakov, L. I.; Velikovich, A.

    2013-07-15

    The planar wire array (PWA) is a promising load for new multi-source inertial confinement fusion (ICF) hohlraums [B. Jones et al., Phys. Rev. Lett. 104, 125001 (2010)]. The hohlraum radiation symmetry is an important issue for ICF. It was found that extreme ultraviolet and sub-keV photon emission from PWAs may have considerable anisotropy in the load azimuthal plane. This experimental result is obtained on the UNR 1–1.7 MA Zebra generator. The time-dependent anisotropy effect is detected. This feature is studied in 2D numerical simulations and can be explained by initial anisotropy of implosion of those non-cylindrical loads radiating essentially as surface sources in sub-keV quanta and also by radiation absorption in cold magnetized plasma tails forming in the direction of magnetic compression.

  7. Particle-in-cell simulations of laser beat-wave magnetization of dense plasmas

    SciTech Connect (OSTI)

    Welch, D. R.; Genoni, T. C.; Thoma, C.; Rose, D. V.; Hsu, S. C.

    2014-03-15

    The interaction of two lasers with a difference frequency near that of the ambient plasma frequency produces beat waves that can resonantly accelerate thermal electrons. These beat waves can be used to drive electron current and thereby embed magnetic fields into the plasma [Welch et al., Phys. Rev. Lett. 109, 225002 (2012)]. In this paper, we present two-dimensional particle-in-cell simulations of the beat-wave current-drive process over a wide range of angles between the injected lasers, laser intensities, and plasma densities. We discuss the application of this technique to the magnetization of dense plasmas, motivated in particular by the problem of forming high-β plasma targets in a standoff manner for magneto-inertial fusion. The feasibility of a near-term experiment embedding magnetic fields using lasers with micron-scale wavelengths into a ∼10{sup 18} cm{sup −3}-density plasma is assessed.

  8. Mid-infrared pump-related electric-field domains in GaAs/(Al,Ga)As quantum-cascade structures for terahertz lasing without population inversion

    SciTech Connect (OSTI)

    Giehler, M.; Wienold, M.; Schrottke, L.; Hey, R.; Grahn, H. T.; Pavlov, S. G.; Huebers, H.-W.; Winnerl, S.; Schneider, H.

    2011-11-15

    We investigate the effect of mid-infrared (MIR) pumping on the transport properties of GaAs/(Al,Ga)As terahertz (THz) quantum lasers (TQLs), which rely on quantum coherence effects of intersubband transitions. Aiming at THz lasing at elevated temperatures, we extend the concept of THz gain with and without population inversion of a single, MIR-pumped, electrically driven THz stage proposed by Waldmueller et al.[Phys. Rev. Lett. 99, 117401 (2007)] to an entire TQL. However, experiments using a CO{sub 2} as well as a free-electron laser and numerical simulations show that this resonant MIR pumping causes a negative differential conductivity (NDC) in addition to the NDC caused by sequential tunneling. Lasing of these TQLs is prevented by the formation of electric-field domains below the resonance field strength for gain of each single THz stage.

  9. Nonlinear oscillations and waves in an arbitrary mass ratio cold plasma

    SciTech Connect (OSTI)

    Verma, Prabal Singh

    2011-12-15

    It is well known that nonlinear standing oscillations in an arbitrary mass ratio cold plasma always phase mix away. However, there exist nonlinear electron-ion traveling wave solutions, which do not exhibit phase mixing because they have zero ponderomotive force. The existence of these waves has been demonstrated using a perturbation method. Moreover, it is shown that cold plasma BGK waves [Albritton et al., Nucl. Fusion 15, 1199 (1975)] phase mix away if ions are allowed to move and the scaling of phase mixing is found to be different from earlier work [Sengupta et al., Phys. Rev. Lett. 82, 1867 (1999)]. Phase mixing of these waves has been further verified in 1-D particle in cell simulation.

  10. The study of electromagnetic cusp solitons

    SciTech Connect (OSTI)

    Verma, Deepa; Das, Amita; Kaw, Predhiman; Tiwari, Sanat Kumar

    2015-01-15

    The formation of a cusp structure in the envelope of electromagnetic solitons for electron-ion plasma at the ion wave breaking point has been shown by Farina and Bulanov [Phys. Rev. Lett. 86, 5289 (2001)]. The analytical form of the cusp structure has been obtained here. The analytical form of the cusp is shown to compare well with the exact numerically obtained solutions. Such cusp solitons occurring at the ion wave breaking point may have relevance to ion acceleration mechanism. In an effort towards studying the dynamical stability of such structures, the time evolution studies have been carried out which show that the structure survives for several plasma periods. However, ultimately it breaks apart due to the instability associated with the forward Raman scattering.

  11. Radiating subdispersive fractional optical solitons

    SciTech Connect (OSTI)

    Fujioka, J. Espinosa, A.; Rodríguez, R. F.; Malomed, B. A.

    2014-09-01

    It was recently found [Fujioka et al., Phys. Lett. A 374, 1126 (2010)] that the propagation of solitary waves can be described by a fractional extension of the nonlinear Schrödinger (NLS) equation which involves a temporal fractional derivative (TFD) of order α > 2. In the present paper, we show that there is also another fractional extension of the NLS equation which contains a TFD with α < 2, and in this case, the new equation describes the propagation of radiating solitons. We show that the emission of the radiation (when α < 2) is explained by resonances at various frequencies between the pulses and the linear modes of the system. It is found that the new fractional NLS equation can be derived from a suitable Lagrangian density, and a fractional Noether's theorem can be applied to it, thus predicting the conservation of the Hamiltonian, momentum and energy.

  12. Dust acoustic dressed soliton with dust charge fluctuations

    SciTech Connect (OSTI)

    Asgari, H.; Muniandy, S. V.; Wong, C. S.

    2010-06-15

    Modeling of dust acoustic solitons observed in dusty plasma experiment [Bandyopadhyay et al., Phys. Rev. Lett. 101, 065006 (2008)] using the Korteweg-de Vries (KdV) equation showed significant discrepancies in the regime of large amplitudes (or high soliton speed). In this paper, higher order perturbation corrections to the standard KdV soliton are proposed and the resulting dressed soliton is shown to describe the experimental data better, in particular, at high soliton speed. The effects of dust charge fluctuations on the dust acoustic dressed soliton in a dusty plasma system are also investigated. The KdV equation and a linear inhomogeneous equation, governing the evolution of first and second order potentials, respectively, are derived for the system by using reductive perturbation technique. Renormalization procedure is used to obtain nonsecular solutions of these coupled equations. The characteristics of dust acoustic dressed solitons with and without dust charge fluctuations are discussed.

  13. Toward protocols for quantum-ensured privacy and secure voting

    SciTech Connect (OSTI)

    Bonanome, Marianna; Buzek, Vladimir; Ziman, Mario; Hillery, Mark

    2011-08-15

    We present a number of schemes that use quantum mechanics to preserve privacy, in particular, we show that entangled quantum states can be useful in maintaining privacy. We further develop our original proposal [see M. Hillery, M. Ziman, V. Buzek, and M. Bielikova, Phys. Lett. A 349, 75 (2006)] for protecting privacy in voting, and examine its security under certain types of attacks, in particular dishonest voters and external eavesdroppers. A variation of these quantum-based schemes can be used for multiparty function evaluation. We consider functions corresponding to group multiplication of N group elements, with each element chosen by a different party. We show how quantum mechanics can be useful in maintaining the privacy of the choices group elements.

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

    SciTech Connect (OSTI)

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

    2014-07-15

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

  15. Fracton contribution to the optical linewidth in glasses

    SciTech Connect (OSTI)

    Lyo, S.K.; Orbach, R.

    1984-02-15

    We use the previous formalism of Lyo (Phys. Rev. Lett. 48, 688 (1982)) for optical linewidths of paramagnetic impurities in glasses to include the effects of fractal excitations (fractons). We find the optical-linewidth temperature dependence for interactions between the two-level systems and the optically active center of dipole-quadrupole and quadrupole-quadrupole character to be T/sup( 1+d//4) and T/sup( 1+2d//5), respectively, where d is the spectral dimensionality of Alexander and Orbach. Use of the percolating network value for d, (4/3), predicts a temperature dependence T/sup 1.33/ for the former coupling in reasonable agreement with very recent experimental results of Voelker and collaborators in organic glasses.

  16. Simulations of x-ray speckle-based dark-field and phase-contrast imaging with a polychromatic beam

    SciTech Connect (OSTI)

    Zdora, Marie-Christine; Thibault, Pierre; Pfeiffer, Franz; Zanette, Irene

    2015-09-21

    Following the first experimental demonstration of x-ray speckle-based multimodal imaging using a polychromatic beam [I. Zanette et al., Phys. Rev. Lett. 112(25), 253903 (2014)], we present a simulation study on the effects of a polychromatic x-ray spectrum on the performance of this technique. We observe that the contrast of the near-field speckles is only mildly influenced by the bandwidth of the energy spectrum. Moreover, using a homogeneous object with simple geometry, we characterize the beam hardening artifacts in the reconstructed transmission and refraction angle images, and we describe how the beam hardening also affects the dark-field signal provided by speckle tracking. This study is particularly important for further implementations and developments of coherent speckle-based techniques at laboratory x-ray sources.

  17. Calculating nonlocal optical properties of structures with arbitrary shape.

    SciTech Connect (OSTI)

    McMahon, J. M.; Gray, S. K.; Schatz, G. C.; Northwestern Univ.

    2010-07-16

    In a recent Letter [J. M. McMahon, S. K. Gray, and G. C. Schatz, Phys. Rev. Lett. 103, 097403 (2009)], we outlined a computational method to calculate the optical properties of structures with a spatially nonlocal dielectric function. In this paper, we detail the full method and verify it against analytical results for cylindrical nanowires. Then, as examples of our method, we calculate the optical properties of Au nanostructures in one, two, and three dimensions. We first calculate the transmission, reflection, and absorption spectra of thin films. Because of their simplicity, these systems demonstrate clearly the longitudinal (or volume) plasmons characteristic of nonlocal effects, which result in anomalous absorption and plasmon blueshifting. We then study the optical properties of spherical nanoparticles, which also exhibit such nonlocal effects. Finally, we compare the maximum and average electric field enhancements around nanowires of various shapes to local theory predictions. We demonstrate that when nonlocal effects are included, significant decreases in such properties can occur.

  18. Interaction of Josephson Junction and Distant Vortex in Narrow Thin-Film Superconducting Strips

    SciTech Connect (OSTI)

    Kogan, V. G.; Mints, R. G.

    2014-01-31

    The phase difference between the banks of an edge-type planar Josephson junction crossing the narrow thin-film strip depends on wether or not vortices are present in the junction banks. For a vortex close to the junction this effect has been seen by Golod, Rydh, and Krasnov [Phys. Rev. Lett. 104, 227003 (2010)], who showed that the vortex may turn the junction into ? type. It is shown here that even if the vortex is far away from the junction, it still changes the 0 junction to a ? junction when situated close to the strip edges. Within the approximation used, the effect is independent of the vortex-junction separation, a manifestation of the topology of the vortex phase which extends to macroscopic distances of superconducting coherence.

  19. Confined quantum time of arrival for the vanishing potential

    SciTech Connect (OSTI)

    Galapon, Eric A.; Caballar, Roland F.; Bahague, Ricardo

    2005-12-15

    We give full account of our recent report in E. A. Galapon, R. Caballar, and R. Bahague, Phys. Rev. Lett. 93, 180406 (2004), where it is shown that formulating the free quantum time of arrival problem in a segment of the real line suggests rephrasing the quantum time of arrival problem to finding a complete set of states that evolve to unitarily arrive at a given point at a definite time. For a spatially confined particle, here it is shown explicitly that the problem admits a solution in the form of an eigenvalue problem of a class of compact and self-adjoint time of arrival operators derived by a quantization of the classical time of arrival. The eigenfunctions of these operators are numerically demonstrated to unitarily arrive at the origin at their respective eigenvalues.

  20. Low energy properties of the Kondo chain in the RKKY regime

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

    D. H. Schimmel; Tsvelik, A. M.; Yevtushenko, O. M.

    2016-05-03

    We study the Kondo chain in the regime of high spin concentration where the low energy physics is dominated by the Ruderman–Kittel–Kasuya–Yosida interaction. As has been recently shown (Tsvelik and Yevtushenko 2015 Phys. Rev. Lett. 115 216402), this model has two phases with drastically different transport properties depending on the anisotropy of the exchange interaction. In particular, the helical symmetry of the fermions is spontaneously broken when the anisotropy is of the easy plane type. This leads to a parametrical suppression of the localization effects. In the present paper we substantially extend the previous theory, in particular, by analyzing amore » competition of forward- and backward- scattering, including into the theory short range electron interactions and calculating spin correlation functions. In conclusion, we discuss applicability of our theory and possible experiments which could support the theoretical findings.« less

  1. Electronic and magnetic properties of epitaxial perovskite SrCrO3(001)

    SciTech Connect (OSTI)

    Zhang, Hongliang; Du, Yingge; Sushko, Petr; Bowden, Mark E.; Shutthanandan, V.; Qiao, Liang; Cao, Guixin; Gai, Zheng; Sallis, Shawn; Piper, L.F.J.; Chambers, Scott A.

    2015-06-24

    We have investigated the intrinsic properties of SrCrO3 epitaxial thin films synthesized by molecular beam epitaxy. We find compelling evidence that SrCrO3 is a correlated metal. X-ray photoemission valence band and O K-edge x-ray absorption spectra indicate a strongly hybridized Cr3d-O2p state crossing the Fermi level, leading to metallic behavior. Comparison between valence band spectra near the Fermi level and the densities of states calculated using density functional theory (DFT) also suggests the presence of coherent and incoherent states and points to a strong electron-electron correlation effects. The magnetic susceptibility can be described by Pauli paramagnetism at temperatures above 100 K, but reveals antiferromagnetic behavior at lower temperatures resulting from orbital ordering as suggested by Ortega-San-Martin et al. [Phys. Rev. Lett. 99, 255701 (2007)].

  2. Dust-acoustic shock formation in dusty plasmas with non-thermal ions

    SciTech Connect (OSTI)

    Asgari, H.; Muniandy, S. V.; Wong, C. S.

    2013-01-15

    In this study, the nonlinear Burgers equation in the presence of the dust charge fluctuation is derived and the shock-like solution is determined. It is well known that in order to have a monotonic or oscillatory shock wave, a source of dissipation is needed. By using the experimental data reported in the laboratory observation of self-excited dust-acoustic shock waves [Heinrich et al., Phys. Rev. Lett. 103, 115002 (2009)], it is shown that dust charge fluctuation can be considered as a candidate for the source of dissipation needed for the dust-acoustic shock formation. By examining the effects of non-thermal ions on dust-acoustic shock's characteristics, a possible theoretical explanation for the discrepancies observed between theory and experiment is proposed.

  3. Enhanced spin Hall effect by electron correlations in CuBi alloys

    SciTech Connect (OSTI)

    Gu, Bo Xu, Zhuo; Mori, Michiyasu; Maekawa, Sadamichi; Ziman, Timothy

    2015-05-07

    A recent experiment in CuBi alloys obtained a large spin Hall angle (SHA) of −0.24 (Niimi et al., Phys. Rev. Lett. 109, 156602 (2012)). We find that the SHA can be dramatically enhanced by Bi impurities close to the Cu surface. The mechanisms of this enhancement are two-fold. One is that the localized impurity state on surface has a decreased hybridization and combined with Coulomb correlation effect. The other comes from the low-dimensional state of conduction electrons on surface, which results in a further enhancement of skew scattering by impurities. Furthermore, we note that a discrepancy in sign of SHA between the experiment and previous theories is simply caused by different definitions of SHA. This re-establishes skew scattering as the essential mechanism underlying the spin Hall effect in CuBi alloys.

  4. Instability Control in a Staged Z-pinch

    SciTech Connect (OSTI)

    Frank J. WESSEL

    2011-04-22

    A \\Staged Z-Pinch” is a fusion-energy concept in which stored-electric energy is first converted into plasma-liner-kinetic energy, and then transferred to a coaxialtarget plasma [H. U. Rahman, F. J. Wessel, and N. Rostoker, Phys. Rev. Lett. 74, p. 714(1996)]. Proper choice of the liner and target materials, and their initial radii and mass densities, leads to dynamic stabilization, current amplification, and shock heating of the target. Simulations suggest that this configuration has merit as a alternative inertial-confinement-fusion concept, and may provide an energy release exceeding thermonuclear break-even, if tested on one of many newer pulsed power systems, for example those located at Sandia National Laboratories.

  5. Scaling of Dynamic Spin Correlations in BaCu2(Si0.5Ge0.5)2O7

    SciTech Connect (OSTI)

    Zheludev, Andrey I; Masuda, T.; Dhalenne, G.; Revcolevschi, A.; Frost, C.; Perring, T. G.

    2007-01-01

    The magnetic dynamic structure factor of the one-dimensional S=1/2 chain system BaCu{sub 2}(Si{sub 0.5}Ge{sub 0.5}){sub 2}O{sub 7} is studied in a wide range of energy transfers and temperatures. Contrary to previous erroneous reports [T. Masuda et al., Phys. Rev. Lett. 93, 077206 (2004)], the scaling properties observed in the range 0.5-25 meV are found to be fully consistent with expectations for a Luttinger spin liquid. At higher energies, a breakdown of scaling laws is observed and attributed to lattice effects. The results are complementary to those found in literature for other S=1/2 chain compounds, such as KCuF{sub 3} and Cu benzoate.

  6. Urea and deuterium mixtures at high pressures

    SciTech Connect (OSTI)

    Donnelly, M. Husband, R. J.; Frantzana, A. D.; Loveday, J. S.; Bull, C. L.; Klotz, S.

    2015-03-28

    Urea, like many network forming compounds, has long been known to form inclusion (guest-host) compounds. Unlike other network formers like water, urea is not known to form such inclusion compounds with simple molecules like hydrogen. Such compounds if they existed would be of interest both for the fundamental insight they provide into molecular bonding and as potential gas storage systems. Urea has been proposed as a potential hydrogen storage material [T. A. Strobel et al., Chem. Phys. Lett. 478, 97 (2009)]. Here, we report the results of high-pressure neutron diffraction studies of urea and D{sub 2} mixtures that indicate no inclusion compound forms up to 3.7 GPa.

  7. Three-body scattering theory without knowledge of exact asymptotic boundary conditions

    SciTech Connect (OSTI)

    Shakeshaft, Robin

    2009-07-15

    We formulate the theory of three-body scattering without explicit reference to exact asymptotic boundary conditions on the wave function. The transition rate and amplitude are expressed as volume integrals of the resolvent, which are insensitive to the region of asymptotically large distances. The physical branch of the resolvent is selected through the arrow of time, which is required to point forward in each subchannel. This is accomplished by first expressing the resolvent as an integral over time and then making a conformal transformation of each half of the time plane onto a unit disk. The physical branch corresponds to a path of integration in the upper half of the disk. We have tested the method, using a real discrete basis, by calculating the total cross section for singlet S-wave electron impact ionization of atomic hydrogen; our results are in reasonable agreement overall with the landmark results of Bartlet and Stelbovics [Phys. Rev. Lett. 93, 233201 (2004)].

  8. Entropic uncertainty relations and locking: Tight bounds for mutually unbiased bases

    SciTech Connect (OSTI)

    Ballester, Manuel A.; Wehner, Stephanie

    2007-02-15

    We prove tight entropic uncertainty relations for a large number of mutually unbiased measurements. In particular, we show that a bound derived from the result by Maassen and Uffink [Phys. Rev. Lett. 60, 1103 (1988)] for two such measurements can in fact be tight for up to {radical}(d) measurements in mutually unbiased bases. We then show that using more mutually unbiased bases does not always lead to a better locking effect. We prove that the optimal bound for the accessible information using up to {radical}(d) specific mutually unbiased bases is log d/2, which is the same as can be achieved by using only two bases. Our result indicates that merely using mutually unbiased bases is not sufficient to achieve a strong locking effect and we need to look for additional properties.

  9. Quantum interference within the complex quantum Hamilton-Jacobi formalism

    SciTech Connect (OSTI)

    Chou, Chia-Chun; Sanz, Angel S.; Miret-Artes, Salvador; Wyatt, Robert E.

    2010-10-15

    Quantum interference is investigated within the complex quantum Hamilton-Jacobi formalism. As shown in a previous work [Phys. Rev. Lett. 102 (2009) 250401], complex quantum trajectories display helical wrapping around stagnation tubes and hyperbolic deflection near vortical tubes, these structures being prominent features of quantum caves in space-time Argand plots. Here, we further analyze the divergence and vorticity of the quantum momentum function along streamlines near poles, showing the intricacy of the complex dynamics. Nevertheless, despite this behavior, we show that the appearance of the well-known interference features (on the real axis) can be easily understood in terms of the rotation of the nodal line in the complex plane. This offers a unified description of interference as well as an elegant and practical method to compute the lifetime for interference features, defined in terms of the average wrapping time, i.e., considering such features as a resonant process.

  10. Extended Coherence Time on the Clock Transition of Optically Trapped Rubidium

    SciTech Connect (OSTI)

    Kleine Buening, G.; Will, J.; Ertmer, W.; Rasel, E.; Klempt, C.; Arlt, J.; Ramirez-Martinez, F.; Rosenbusch, P.; Piechon, F.

    2011-06-17

    Optically trapped ensembles are of crucial importance for frequency measurements and quantum memories but generally suffer from strong dephasing due to inhomogeneous density and light shifts. We demonstrate a drastic increase of the coherence time to 21 s on the magnetic field insensitive clock transition of {sup 87}Rb by applying the recently discovered spin self-rephasing [C. Deutsch et al., Phys. Rev. Lett. 105, 020401 (2010)]. This result confirms the general nature of this new mechanism and thus shows its applicability in atom clocks and quantum memories. A systematic investigation of all relevant frequency shifts and noise contributions yields a stability of 2.4x10{sup -11{tau}-1/2}, where {tau} is the integration time in seconds. Based on a set of technical improvements, the presented frequency standard is predicted to rival the stability of microwave fountain clocks in a potentially much more compact setup.

  11. Relativistic general-order coupled-cluster method for high-precision calculations: Application to the Al{sup +} atomic clock

    SciTech Connect (OSTI)

    Kallay, Mihaly; Nataraj, H. S.; Sahoo, B. K.; Das, B. P.; Visscher, Lucas

    2011-03-15

    We report the implementation of a general-order relativistic coupled-cluster method for performing high-precision calculations of atomic and molecular properties. As a first application, the black-body radiation shift of the Al{sup +} clock has been estimated precisely. The computed shift relative to the frequency of the 3s{sup 2} {sup 1}S{sub 0}{sup e}{yields}3s3p {sup 3}P{sub 0}{sup o} clock transition given by (-3.66{+-}0.60)x10{sup -18} calls for an improvement over the recent measurement with a reported result of (-9{+-}3)x10{sup -18}[Phys. Rev. Lett. 104, 070802 (2010)].

  12. Bite the apple, get driven out of the garden: A risky story telling at the ASME town meeting

    SciTech Connect (OSTI)

    Majumdar, K.C.

    1994-11-01

    Risk, the all-encompassing four-letter word became a widely used household cliche and an institutional mantra in the nineties. Risk analysis models from the Garden of Eden to the Capitol Hill lawn have made a number of sharp paradigm shifts to evolve itself as a decision-making tool from individual risk perception to societal risk-based regulatory media. Risk always coexists with benefit and is arbitrated by costs. Risk-benefit analysis has been in use in business and industry in economic ventures for a long time. Only recently risk management in its current state of development, evolved as a regulatory tool for controlling large technological systems that have potential impacts on the health and safety of the public and on the sustainability of the ecology and the environment. This paper summarizes the evolution of the risk management concepts and models in industry and the regulatory agencies in the US over the last three decades. It also discusses the benefits and limitations of this evolving discipline as it is applied to high-risk technologies from the nuclear power plant and petrochemical industry, etc. to nuclear weapons technology.

  13. Automation of a high-speed imaging setup for differential viscosity measurements

    SciTech Connect (OSTI)

    Hurth, C.; Duane, B.; Whitfield, D.; Smith, S.; Nordquist, A.; Zenhausern, F.

    2013-12-28

    We present the automation of a setup previously used to assess the viscosity of pleural effusion samples and discriminate between transudates and exudates, an important first step in clinical diagnostics. The presented automation includes the design, testing, and characterization of a vacuum-actuated loading station that handles the 2 mm glass spheres used as sensors, as well as the engineering of electronic Printed Circuit Board (PCB) incorporating a microcontroller and their synchronization with a commercial high-speed camera operating at 10 000 fps. The hereby work therefore focuses on the instrumentation-related automation efforts as the general method and clinical application have been reported earlier [Hurth et al., J. Appl. Phys. 110, 034701 (2011)]. In addition, we validate the performance of the automated setup with the calibration for viscosity measurements using water/glycerol standard solutions and the determination of the viscosity of an “unknown” solution of hydroxyethyl cellulose.

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

    SciTech Connect (OSTI)

    Oks, Efim; Anders, Andre

    2010-10-19

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

  15. Regular perturbation solution of the Elenbaas-Heller equation

    SciTech Connect (OSTI)

    Shaw, B.D.

    2006-02-01

    The Elenbaas-Heller equation is nondimensionalized and solved using regular perturbation theory to provide closed-form analytical solutions to describe structures of cylindrically symmetrical steady electric arc discharges with negligible radiant heat transfer. Based on available data, it is assumed that the electrical conductivity varies with the heat-flux potential in an Arrhenius fashion. The leading-order solution is equivalent to an asymptotic solution proposed by Kuiken [J. Appl. Phys. 58, 1833 (1991)]. Higher-order terms are also derived in the present paper, and it is shown that quantitatively accurate analytical solutions can be developed when higher-order terms are included. Analysis shows that appreciable Joule heating is restricted to an inner zone when a dimensionless parameter is large relative to unity, leading to arc-channel models suggested by previous investigators.

  16. An efficient method for unfolding kinetic pressure driven VISAR data

    SciTech Connect (OSTI)

    Mark Harry Hess; Peterson, Kyle; Harvey-Thompson, Adam James

    2015-08-18

    Velocity Interferometer System for Any Reflector (VISAR) [Barker and Hollenbach, J. Appl. Phys. 43, 4669 (1972)] is a well-known diagnostic that is employed on many shock physics and pulsed-power experiments. With the VISAR diagnostic, the velocity on the surface of any metal flyer can be found. For most experiments employing VISAR, either a kinetic pressure [Grady, Mech. Mater. 29, 181 (1998)] or a magnetic pressure [Lemke et al., Intl J. Impact Eng. 38, 480 (2011)] drives the motion of the flyer. Moreover, reliable prediction of the time-dependent pressure is often a critical component to understanding the physics of these experiments. Although VISAR can provide a precise measurement of a flyer’s surface velocity, the real challenge of this diagnostic implementation is using this velocity to unfold the time-dependent pressure. The purpose of this study is to elucidate a new method for quickly and reliably unfolding VISAR data.

  17. Final Task Report on NRF Measurements of Photon Scattering Resonances in Plutonium at the High Voltage Research Laboratory of MIT

    SciTech Connect (OSTI)

    Johnson, M S; McNabb, D P; Norman, E B

    2007-02-23

    Conclusions of this report are that there are 13 new transitions associated with NRF states in {sup 239}Pu that have been discovered. These resonances are between 2- and 2.5-MeV relative to the ground state in {sup 239}Pu. The strengths of most these resonances are between 15 and 20 eV b. This approximately is the strength required for using the transmission detection method for NRF [Pruet et al J. Appl. Phys. 99 12310 (2006)] for six-sigma alarm confidence levels. Future measurements on {sup 239}Pu at higher photon energies are necessary to probe for NRF strengths at higher energies. Such resonances may be more advantageous to the NRF technique with FINDER if they are stronger or if the mean free path of these energetic photons is longer.

  18. Electroactive-Zone Extension in Flow-Battery Stacks

    SciTech Connect (OSTI)

    Smith, KC; Brunini, VE; Dong, YJ; Chiang, YM; Carter, WC

    2014-11-20

    Flowable suspensions that conduct both electrons and ions can enable the use of energy-dense electroactive species in flow batteries [M. Duduta et al., Adv. Energy Mater., 1, 511 (2011); Z. Li et al., Phys. Chem. Chem. Phys., 15, 15,833 (2013); F. Fan et al., Nano Lett., 14, 2210 (2014)]. In comparison with conventional flow batteries where electrochemical reactions are confined to a fixed current-collector region, electronically conductive flow electrodes permit electrochemical reactions to extend outside of the physical confines of the stack. We have measured and modeled how mixed-conduction enables an electroactive zone (EAZ, in which electrochemical reactions occur) that is of greater spatial extent than current collectors, the extension being termed side zone, SZ. Electrochemical reactions in SZs can reduce coulombic and energetic efficiency. Here we show that for realistic suspension properties and operating conditions, the added inefficiency is small in practice, and can be further mitigated by using appropriate operating conditions and/or materials choices. For the specific example of a non-aqueous Li4Ti5O12 suspension, we show that EAZ extension contributes less than 1% additional efficiency loss at C/10 rates for current collectors greater than 20 mm long. (C) 2014 Elsevier Ltd. All rights reserved.

  19. Response calculations based on an independent particle system with the exact one-particle density matrix: Polarizabilities

    SciTech Connect (OSTI)

    Giesbertz, K. J. H.; Gritsenko, O. V.; Pohang University of Science and Technology, Department of Chemistry, San 31, Hyojadong, Namgu, Pohang 790-784 ; Baerends, E. J.; Pohang University of Science and Technology, Department of Chemistry, San 31, Hyojadong, Namgu, Pohang 790-784; Department of Chemistry, Faculty of Science, King Abdulaziz University, Jeddah 21589

    2014-05-14

    Recently, we have demonstrated that the problems finding a suitable adiabatic approximation in time-dependent one-body reduced density matrix functional theory can be remedied by introducing an additional degree of freedom to describe the system: the phase of the natural orbitals [K. J. H. Giesbertz, O. V. Gritsenko, and E. J. Baerends, Phys. Rev. Lett. 105, 013002 (2010); K. J. H. Giesbertz, O. V. Gritsenko, and E. J. Baerends, J. Chem. Phys. 133, 174119 (2010)]. In this article we will show in detail how the frequency-dependent response equations give the proper static limit (ω → 0), including the perturbation in the chemical potential, which is required in static response theory to ensure the correct number of particles. Additionally we show results for the polarizability for H{sub 2} and compare the performance of two different two-electron functionals: the phase-including Löwdin–Shull functional and the density matrix form of the Löwdin–Shull functional.

  20. Communication: A combined periodic density functional and incremental wave-function-based approach for the dispersion-accounting time-resolved dynamics of {sup 4}He nanodroplets on surfaces: {sup 4}He/graphene

    SciTech Connect (OSTI)

    Lara-Castells, María Pilar de; Stoll, Hermann; Civalleri, Bartolomeo; Causà, Mauro; Voloshina, Elena; Mitrushchenkov, Alexander O.; Pi, Martí

    2014-10-21

    In this work we propose a general strategy to calculate accurate He–surface interaction potentials. It extends the dispersionless density functional approach recently developed by Pernal et al. [Phys. Rev. Lett. 103, 263201 (2009)] to adsorbate-surface interactions by including periodic boundary conditions. We also introduce a scheme to parametrize the dispersion interaction by calculating two- and three-body dispersion terms at coupled cluster singles and doubles and perturbative triples (CCSD(T)) level via the method of increments [H. Stoll, J. Chem. Phys. 97, 8449 (1992)]. The performance of the composite approach is tested on {sup 4}He/graphene by determining the energies of the low-lying selective adsorption states, finding an excellent agreement with the best available theoretical data. Second, the capability of the approach to describe dispersionless correlation effects realistically is used to extract dispersion effects in time-dependent density functional simulations on the collision of {sup 4}He droplets with a single graphene sheet. It is found that dispersion effects play a key role in the fast spreading of the {sup 4}He nanodroplet, the evaporation-like process of helium atoms, and the formation of solid-like helium structures. These characteristics are expected to be quite general and highly relevant to explain experimental measurements with the newly developed helium droplet mediated deposition technique.

  1. Realistic exact solution for the exterior field of a rotating neutron star

    SciTech Connect (OSTI)

    Pachon, Leonardo A.; Rueda, Jorge A.; Sanabria-Gomez, Jose D.

    2006-05-15

    A new six-parametric, axisymmetric, and asymptotically flat exact solution of Einstein-Maxwell field equations having reflection symmetry is presented. It has arbitrary physical parameters of mass, angular momentum, mass-quadrupole moment, current octupole moment, electric charge, and magnetic dipole, so it can represent the exterior field of a rotating, deformed, magnetized, and charged object; some properties of the closed-form analytic solution such as its multipolar structure, electromagnetic fields, and singularities are also presented. In the vacuum case, this analytic solution is matched to some numerical interior solutions representing neutron stars, calculated by Berti and Stergioulas [E. Berti and N. Stergioulas, Mon. Not. R. Astron. Soc. 350, 1416 (2004)], imposing that the multipole moments be the same. As an independent test of accuracy of the solution to describe exterior fields of neutron stars, we present an extensive comparison of the radii of innermost stable circular orbits (ISCOs) obtained from the Berti and Stergioulas numerical solutions, the Kerr solution [R. P. Kerr, Phys. Rev. Lett. 11, 237 (1963)], the Hartle and Thorne solution [J. B. Hartle and K. S. Thorne, Astrophys. J. 153, 807 (1968)], an analytic series expansion derived by Shibata and Sasaki [M. Shibata and M. Sasaki, Phys. Rev. D 58, 104011 (1998)], and our exact solution. We found that radii of ISCOs from our solution fits better than others with realistic numerical interior solutions.

  2. Instability growth for magnetized liner inertial fusion seeded by electro-thermal, electro-choric, and material strength effects

    SciTech Connect (OSTI)

    Pecover, J. D.; Chittenden, J. P.

    2015-10-15

    A critical limitation of magnetically imploded systems such as magnetized liner inertial fusion (MagLIF) [Slutz et al., Phys. Plasmas 17, 056303 (2010)] is the magneto-Rayleigh-Taylor (MRT) instability which primarily disrupts the outer surface of the liner. MagLIF-relevant experiments have showed large amplitude multi-mode MRT instability growth growing from surface roughness [McBride et al., Phys. Rev. Lett. 109, 135004 (2012)], which is only reproduced by 3D simulations using our MHD code Gorgon when an artificially azimuthally correlated initialisation is added. We have shown that the missing azimuthal correlation could be provided by a combination of the electro-thermal instability (ETI) and an “electro-choric” instability (ECI); describing, respectively, the tendency of current to correlate azimuthally early in time due to temperature dependent Ohmic heating; and an amplification of the ETI driven by density dependent resistivity around vapourisation. We developed and implemented a material strength model in Gorgon to improve simulation of the solid phase of liner implosions which, when applied to simulations exhibiting the ETI and ECI, gave a significant increase in wavelength and amplitude. Full circumference simulations of the MRT instability provided a significant improvement on previous randomly initialised results and approached agreement with experiment.

  3. Analyticity constraints on the Landshoff-Donnachie fit to total cross sections

    SciTech Connect (OSTI)

    Block, M. M.; Halzen, F.

    2006-12-01

    Landshoff and Donnachie [A. Donnachie and P. V. Landshoff, Phys. Lett. B 296, 227 (1992).; P. V. Landshoff, hep-ph/0509240] parametrize the energy behavior of pp and pp scattering cross sections with five parameters, using: {sigma}{sup +}=56.08s{sup -0.4525}+21.70s{sup 0.0808} for pp, {sigma}{sup -}=98.39s{sup -0.4525}+21.70s{sup 0.0808} for pp. Using the four analyticity constraints of Block and Halzen [M. M. Block and F. Halzen, Phys. Rev. D 72, 036006 (2005).], we simultaneously fit the Landshoff-Donnachie form to the same sieved set of pp and pp cross section and {rho} data that Block and Halzen used for a very good fit to a ln{sup 2}s parametrization. We show that the satisfaction of the analyticity constraints will require modification of the Landshoff-Donnachie parametrization for lower energies, thus altering its inherent appeal of simplicity and universality.

  4. Electronically Nonadiabatic Dynamics via Semiclassical Initial Value Methods

    SciTech Connect (OSTI)

    Miller, William H.

    2008-12-11

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

  5. Better band gaps with asymptotically corrected local exchange potentials

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

    Singh, Prashant; Harbola, Manoj K.; Hemanadhan, M.; Mookerjee, Abhijit; Johnson, D. D.

    2016-02-22

    In this study, we formulate a spin-polarized van Leeuwen and Baerends (vLB) correction to the local density approximation (LDA) exchange potential [R. van Leeuwen and E. J. Baerends, Phys. Rev. A 49, 2421 (1994)] that enforces the ionization potential (IP) theorem following T. Stein et al. [Phys. Rev. Lett. 105, 266802 (2010)]. For electronic-structure problems, the vLB correction replicates the behavior of exact-exchange potentials, with improved scaling and well-behaved asymptotics, but with the computational cost of semilocal functionals. The vLB + IP correction produces a large improvement in the eigenvalues over those from the LDA due to correct asymptotic behaviormore » and atomic shell structures, as shown in rare-gas, alkaline-earth, zinc-based oxides, alkali halides, sulfides, and nitrides. In half-Heusler alloys, this asymptotically corrected LDA reproduces the spin-polarized properties correctly, including magnetism and half-metallicity. We also consider finite-sized systems [e.g., ringed boron nitride (B12N12) and graphene (C24)] to emphasize the wide applicability of the method.« less

  6. Nonlinear electronic excitations in crystalline solids using meta-generalized gradient approximation and hybrid functional in time-dependent density functional theory

    SciTech Connect (OSTI)

    Sato, Shunsuke A.; Taniguchi, Yasutaka; Shinohara, Yasushi; Yabana, Kazuhiro

    2015-12-14

    We develop methods to calculate electron dynamics in crystalline solids in real-time time-dependent density functional theory employing exchange-correlation potentials which reproduce band gap energies of dielectrics; a meta-generalized gradient approximation was proposed by Tran and Blaha [Phys. Rev. Lett. 102, 226401 (2009)] (TBm-BJ) and a hybrid functional was proposed by Heyd, Scuseria, and Ernzerhof [J. Chem. Phys. 118, 8207 (2003)] (HSE). In time evolution calculations employing the TB-mBJ potential, we have found it necessary to adopt the predictor-corrector step for a stable time evolution. We have developed a method to evaluate electronic excitation energy without referring to the energy functional which is unknown for the TB-mBJ potential. For the HSE functional, we have developed a method for the operation of the Fock-like term in Fourier space to facilitate efficient use of massive parallel computers equipped with graphic processing units. We compare electronic excitations in silicon and germanium induced by femtosecond laser pulses using the TB-mBJ, HSE, and a simple local density approximation (LDA). At low laser intensities, electronic excitations are found to be sensitive to the band gap energy: they are close to each other using TB-mBJ and HSE and are much smaller in LDA. At high laser intensities close to the damage threshold, electronic excitation energies do not differ much among the three cases.

  7. Error analyses on some typically approximate solutions of residual stress within a thin film on a substrate

    SciTech Connect (OSTI)

    Zhang, X.C.; Xu, B.S.; Wang, H.D.; Wu, Y.X.

    2005-09-01

    Stoney's equation and subsequent modifications and some approximations are widely used to evaluate the macrostress within a film on a substrate, though some of these solutions are only applicable for thin films. The purpose of this paper is to review the considerable efforts devoted to the analysis of residual stresses in a single-layer film in the last century and recent years and to estimate the errors involved in using these formulas. The following are some of the important results that can be obtained. (1) The exact solution for the residual stress can be expressed in terms of Stoney's equation [Proc. R. Soc. London A82, 172 (1909)] and a correction factor (1+{sigma}{eta}{sup 3})/(1+{eta}), where {sigma},{eta} are the ratios of the elastic modulus and the thickness of the film to those of the substrate, respectively. (2) When the thickness ratio of the film and the substrate is less than 0.1, Stoney's equation and Roell's approximation [J. Appl. Phys. 47, 3224 (1976)] do not cause serious errors. (3) The approximation proposed by Vilms and Kerps [J. Appl. Phys. 53, 1536 (1982)] is an improved modification for Stoney's equation and can be applicable when {eta}{<=}0.3. (4) The approximations proposed by Brenner and Senderoff [J. Res. Natl. Bur. Stand. 42, 105 (1949)] and Teixeira [Thin Solid Films 392, 276 (2001)] can lead to serious errors and should be avoided. (5) The approximation based on the assumption of constant elastic modulus is only applicable for a ratio of {eta}{<=}0.01 and can be very misleading.

  8. Correlating sampling and intensity statistics in nanoparticle diffraction experiments

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

    Öztürk, Hande; Yan, Hanfei; Hill, John P.; Noyan, I. Cevdet

    2015-07-28

    It is shown in a previous article [Öztürk, Yan, Hill & Noyan (2014).J. Appl. Cryst.47, 1016–1025] that the sampling statistics of diffracting particle populations within a polycrystalline ensemble depended on the size of the constituent crystallites: broad X-ray peak breadths enabled some nano-sized particles to contribute more than one diffraction spot to Debye–Scherrer rings. Here it is shown that the equations proposed by Alexander, Klug & Kummer [J. Appl. Phys.(1948),19, 742–753] (AKK) to link diffracting particle and diffracted intensity statistics are not applicable if the constituent crystallites of the powder are below 10 nm. In this size range, (i) themore » one-to-one correspondence between diffracting particles and Laue spots assumed in the AKK analysis is not satisfied, and (ii) the crystallographic correlation between Laue spots originating from the same grain invalidates the assumption that all diffracting plane normals are randomly oriented and uncorrelated. Such correlation produces unexpected results in the selection of diffracting grains. For example, three or more Laue spots from a given grain for a particular reflection can only be observed at certain wavelengths. In addition, correcting the diffracted intensity values by the traditional Lorentz term, 1/cos θ, to compensate for the variation of particles sampled within a reflection band does not maintain fidelity to the number of poles contributing to the diffracted signal. A new term, cos θB/cos θ, corrects this problem.« less

  9. A full-dimensional multilayer multiconfiguration time-dependent Hartree study on the ultraviolet absorption spectrum of formaldehyde oxide

    SciTech Connect (OSTI)

    Meng, Qingyong, E-mail: mengqingyong@dicp.ac.cn [State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, 116023 Dalian (China); Meyer, Hans-Dieter, E-mail: hans-dieter.meyer@pci.uni-heidelberg.de [Theoretische Chemie, Physikalisch-Chemisches Institut, Ruprecht-Karls Universitt Heidelberg, Im Neuenheimer Feld 229, D-69120 Heidelberg (Germany)

    2014-09-28

    Employing the multilayer multiconfiguration time-dependent Hartree (ML-MCTDH) method in conjunction with the multistate multimode vibronic coupling Hamiltonian (MMVCH) model, we perform a full dimensional (9D) quantum dynamical study on the simplest Criegee intermediate, formaldehyde oxide, in five lower-lying singlet electronic states. The ultraviolet (UV) spectrum is then simulated by a Fourier transform of the auto-correlation function. The MMVCH model is built based on extensive MRCI(8e,8o)/aug-cc-pVTZ calculations. To ensure a fast convergence of the final calculations, a large number of ML-MCTDH test calculations is performed to find an appropriate multilayer separations (ML-trees) of the ML-MCTDH nuclear wave functions, and the dynamical calculations are carefully checked to ensure that the calculations are well converged. To compare the computational efficiency, standard MCTDH simulations using the same Hamiltonian are also performed. A comparison of the MCTDH and ML-MCTDH calculations shows that even for the present not-too-large system (9D here) the ML-MCTDH calculations can save a considerable amount of computational resources while producing identical spectra as the MCTDH calculations. Furthermore, the present theoretical B{sup ~} {sup 1}A{sup ?}?X{sup ~} {sup 1}A{sup ?} UV spectral band and the corresponding experimental measurements [J. M. Beames, F. Liu, L. Lu, and M. I. Lester, J. Am. Chem. Soc. 134, 2004520048 (2012); L. Sheps, J. Phys. Chem. Lett. 4, 42014205 (2013); W.-L. Ting, Y.-H. Chen, W. Chao, M. C. Smith, and J. J.-M. Lin, Phys. Chem. Chem. Phys. 16, 1043810443 (2014)] are discussed. To the best of our knowledge, this is the first theoretical UV spectrum simulated for this molecule including nuclear motion beyond an adiabatic harmonic approximation.

  10. More light on the 2ν{sub 5} Raman overtone of SF{sub 6}: Can a weak anisotropic spectrum be due to a strong transition anisotropy?

    SciTech Connect (OSTI)

    Kremer, D.; Rachet, F.; Chrysos, M.

    2014-01-21

    Long known as a fully polarized band with a near vanishing depolarization ratio [η{sub s} = 0.05, W. Holzer and R. Ouillon, Chem. Phys. Lett. 24, 589 (1974)], the 2ν{sub 5} Raman overtone of SF{sub 6} has so far been considered as of having a prohibitively weak anisotropic spectrum [D. P. Shelton and L. Ulivi, J. Chem. Phys. 89, 149 (1988)]. Here, we report the first anisotropic spectrum of this overtone, at room temperature and for 13 gas densities ranging between 2 and 27 amagat. This spectrum is 10 times broader and 50 times weaker than the isotropic counterpart of the overtone [D. Kremer, F. Rachet, and M. Chrysos, J. Chem. Phys. 138, 174308 (2013)] and its profile much more sensitive to pressure effects than the profile of the isotropic spectrum. From our measurements an accurate value for the anisotropy matrix-element |〈000020|Δα|000000〉| was derived and this value was found to be comparable to that of the mean-polarizability ((000020), α{sup ¯} (000000)). Among other conclusions our study offers compelling evidence that, in Raman spectroscopy, highly polarized bands or tiny depolarization ratios are not necessarily incompatible with large polarizability anisotropy transition matrix-elements. Our findings and the way to analyze them suggest that new strategies should be developed on the basis of the complementarity inherent in independent incoherent Raman experiments that run with two different incident-beam polarizations, and on concerted efforts to ab initio calculate accurate data for first and second polarizability derivatives. Values for these derivatives are still rarities in the literature of SF{sub 6}.

  11. Chaotic dynamics around astrophysical objects with nonisotropic stresses

    SciTech Connect (OSTI)

    Dubeibe, F. L.; Pachon, Leonardo A.; Sanabria-Gomez, Jose D.

    2007-01-15

    The existence of chaotic behavior for the geodesics of the test particles orbiting compact objects is a subject of much current research. Some years ago, Gueron and Letelier [Phys. Rev. E 66, 046611 (2002)] reported the existence of chaotic behavior for the geodesics of the test particles orbiting compact objects like black holes induced by specific values of the quadrupolar deformation of the source using as models the Erez--Rosen solution and the Kerr black hole deformed by an internal multipole term. In this work, we are interested in the study of the dynamic behavior of geodesics around astrophysical objects with intrinsic quadrupolar deformation or nonisotropic stresses, which induces nonvanishing quadrupolar deformation for the nonrotating limit. For our purpose, we use the Tomimatsu-Sato spacetime [Phys. Rev. Lett. 29 1344 (1972)] and its arbitrary deformed generalization obtained as the particular vacuum case of the five parametric solution of Manko et al. [Phys. Rev. D 62, 044048 (2000)] characterizing the geodesic dynamics throughout the Poincare sections method. We found only regular motion for the geodesics in the Tomimatsu-Sato {delta}=2 solution. Additionally, using the deformed generalization of Tomimatsu-Sato {delta}=2 solution given by Manko et al. we found chaotic motion for oblate deformation instead of prolate deformation, which is in contrast to the results by Gueron and Letelier. It opens the possibility that the particles forming the accretion disk around a large variety of different astrophysical bodies (nonprolate, e.g., neutron stars) could exhibit chaotic dynamics. We also conjecture that the existence of an arbitrary deformation parameter is necessary for the existence of chaotic dynamics.

  12. Magneto thermal conductivity of superconducting Nb with intermediate level of impurity

    SciTech Connect (OSTI)

    L.S. Sharath Chandra, M.K. Chattopadhyay, S.B. Roy, V.C. Sahni, G.R. Myneni

    2012-03-01

    Niobium materials with intermediate purity level are used for fabrication of superconducting radio frequency cavities (SCRF), and thermal conductivity is an important parameter influencing the performance of such SCRF cavities. We report here the temperature and magnetic field dependence of thermal conductivity {kappa} for superconducting niobium (Nb) samples, for which the electron mean free path I{sub e}, the phonon mean free path I{sub g}, and the vortex core diameter 2r{sub C} are of the same order of magnitude. The measured thermal conductivity is analyzed using the effective gap model (developed for I{sub e} >> 2r{sub C} (Dubeck et al 1963 Phys. Rev. Lett. 10 98)) and the normal core model (developed for I{sub e} << 2r{sub C} (Ward and Dew-Hughes 1970 J. Phys. C: Solid St. Phys. 3 2245)). However, it is found that the effective gap model is not suitable for low temperatures when I{sub e} {approx} 2r{sub C}. The normal core model, on the other hand, is able to describe {kappa}(T,H) over the entire temperature range except in the field regime between H{sub C1} and H{sub C2} i.e. in the mixed state. It is shown that to understand the complete behavior of {kappa} in the mixed state, the scattering of quasi-particles from the vortex cores and the intervortex quasi-particle tunneling are to be invoked. The quasi-particle scattering from vortices for the present system is understood in terms of the framework of Sergeenkov and Ausloos (1995 Phys. Rev. B 52 3614) extending their approach to the case of Nb. The intervortex tunneling is understood within the framework of Schmidbauer et al (1970 Z. Phys. 240 30). Analysis of the field dependence of thermal conductivity shows that while the quasi-particle scattering from vortices dominates in the low fields, the intervortex quasi-particle tunneling dominates in high fields. Analysis of the temperature dependence of thermal conductivity shows that while the quasi-particle scattering is dominant at low temperatures, the

  13. A framework for modeling the detailed optical response of thick...

    Office of Scientific and Technical Information (OSTI)

    ; Paris U., VI-VII ; Claver, Chuck ; NOAO, Tucson ; Doherty, Peter ; Harvard U., Phys. ... Part. Phys. ; Stubbs, Christopher ; Harvard U., Phys. Dept. less Publication Date: ...

  14. More Mac software and connections

    SciTech Connect (OSTI)

    Busbey, A.B.

    1988-11-01

    This column briefly reviews several geologic software packaged designed for Apple Macintosh. In addition, it discusses methods of networking Apple Macintosh computers.

  15. Sandia National Laboratories: Working with Sandia: Just in Time...

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

    Just in Time Contracts Commodity Descriptions of Commodity Items APPLE COMPUTERS APPLE COMPUTERS (MAC) AUTO PARTS ELECTRICALMECH AUTOEQUIP PARTS (RESTRICTED) BOOKS INFORMATIONAL...

  16. Demonstration of thermonuclear conditions in magnetized liner inertial fusion experiments

    SciTech Connect (OSTI)

    Gomez, Matthew R.; Slutz, Stephen A.; Sefkow, Adam B.; Hahn, Kelly D.; Hansen, Stephanie B.; Knapp, Patrick F.; Schmit, Paul F.; Ruiz, Carlos L.; Sinars, Daniel Brian; Harding, Eric C.; Jennings, Christopher A.; Awe, Thomas James; Geissel, Matthias; Rovang, Dean C.; Smith, Ian C.; Chandler, Gordon A.; Cooper, Gary Wayne; Cuneo, Michael Edward; Harvey-Thompson, Adam James; Herrmann, Mark C.; Hess, Mark Harry; Lamppa, Derek C.; Martin, Matthew R.; McBride, Ryan D.; Peterson, Kyle J.; Porter, John L.; Rochau, Gregory A.; Savage, Mark E.; Schroen, Diana G.; Stygar, William A.; Vesey, Roger Alan

    2015-04-29

    In this study, the magnetized liner inertial fusion concept [S. A. Slutz et al., Phys. Plasmas17, 056303 (2010)] utilizes a magnetic field and laser heating to relax the pressure requirements of inertial confinement fusion. The first experiments to test the concept [M. R. Gomez et al., Phys. Rev. Lett. 113, 155003 (2014)] were conducted utilizing the 19 MA, 100 ns Z machine, the 2.5 kJ, 1 TW Z Beamlet laser, and the 10 T Applied B-field on Z system. Despite an estimated implosion velocity of only 70 km/s in these experiments, electron and ion temperatures at stagnation were as high as 3 keV, and thermonuclear deuterium-deuterium neutron yields up to 2 1012 have been produced. X-ray emission from the fuel at stagnation had widths ranging from 50 to 110 ?m over a roughly 80% of the axial extent of the target (68 mm) and lasted approximately 2 ns. X-ray yields from these experiments are consistent with a stagnation density of the hot fuel equal to 0.20.4 g/cm3. In these experiments, up to 5 1010 secondary deuterium-tritium neutrons were produced. Given that the areal density of the plasma was approximately 12 mg/cm2, this indicates the stagnation plasma was significantly magnetized, which is consistent with the anisotropy observed in the deuterium-tritium neutron spectra. Control experiments where the laser and/or magnetic field were not utilized failed to produce stagnation temperatures greater than 1 keV and primary deuterium-deuterium yields greater than 1010. An additional control experiment where the fuel contained a sufficient dopant fraction to substantially increase radiative losses also failed to produce a relevant stagnation temperature. The results of these experiments are consistent with a thermonuclear neutron source.

  17. Ternary eutectic dendrites: Pattern formation and scaling properties

    SciTech Connect (OSTI)

    Rátkai, László; Szállás, Attila; Pusztai, Tamás; Mohri, Tetsuo; Gránásy, László

    2015-04-21

    Extending previous work [Pusztai et al., Phys. Rev. E 87, 032401 (2013)], we have studied the formation of eutectic dendrites in a model ternary system within the framework of the phase-field theory. We have mapped out the domain in which two-phase dendritic structures grow. With increasing pulling velocity, the following sequence of growth morphologies is observed: flat front lamellae → eutectic colonies → eutectic dendrites → dendrites with target pattern → partitionless dendrites → partitionless flat front. We confirm that the two-phase and one-phase dendrites have similar forms and display a similar scaling of the dendrite tip radius with the interface free energy. It is also found that the possible eutectic patterns include the target pattern, and single- and multiarm spirals, of which the thermal fluctuations choose. The most probable number of spiral arms increases with increasing tip radius and with decreasing kinetic anisotropy. Our numerical simulations confirm that in agreement with the assumptions of a recent analysis of two-phase dendrites [Akamatsu et al., Phys. Rev. Lett. 112, 105502 (2014)], the Jackson-Hunt scaling of the eutectic wavelength with pulling velocity is obeyed in the parameter domain explored, and that the natural eutectic wavelength is proportional to the tip radius of the two-phase dendrites. Finally, we find that it is very difficult/virtually impossible to form spiraling two-phase dendrites without anisotropy, an observation that seems to contradict the expectations of Akamatsu et al. Yet, it cannot be excluded that in isotropic systems, two-phase dendrites are rare events difficult to observe in simulations.

  18. Demonstration of thermonuclear conditions in magnetized liner inertial fusion experiments

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

    Gomez, Matthew R.; Slutz, Stephen A.; Sefkow, Adam B.; Hahn, Kelly D.; Hansen, Stephanie B.; Knapp, Patrick F.; Schmit, Paul F.; Ruiz, Carlos L.; Sinars, Daniel Brian; Harding, Eric C.; et al

    2015-04-29

    In this study, the magnetized liner inertial fusion concept [S. A. Slutz et al., Phys. Plasmas17, 056303 (2010)] utilizes a magnetic field and laser heating to relax the pressure requirements of inertial confinement fusion. The first experiments to test the concept [M. R. Gomez et al., Phys. Rev. Lett. 113, 155003 (2014)] were conducted utilizing the 19 MA, 100 ns Z machine, the 2.5 kJ, 1 TW Z Beamlet laser, and the 10 T Applied B-field on Z system. Despite an estimated implosion velocity of only 70 km/s in these experiments, electron and ion temperatures at stagnation were as highmore » as 3 keV, and thermonuclear deuterium-deuterium neutron yields up to 2 × 1012 have been produced. X-ray emission from the fuel at stagnation had widths ranging from 50 to 110 μm over a roughly 80% of the axial extent of the target (6–8 mm) and lasted approximately 2 ns. X-ray yields from these experiments are consistent with a stagnation density of the hot fuel equal to 0.2–0.4 g/cm3. In these experiments, up to 5 ×1010 secondary deuterium-tritium neutrons were produced. Given that the areal density of the plasma was approximately 1–2 mg/cm2, this indicates the stagnation plasma was significantly magnetized, which is consistent with the anisotropy observed in the deuterium-tritium neutron spectra. Control experiments where the laser and/or magnetic field were not utilized failed to produce stagnation temperatures greater than 1 keV and primary deuterium-deuterium yields greater than 1010. An additional control experiment where the fuel contained a sufficient dopant fraction to substantially increase radiative losses also failed to produce a relevant stagnation temperature. The results of these experiments are consistent with a thermonuclear neutron source.« less

  19. Open-field host specificity test of Gratiana boliviana (Coleoptera: Chrysomelidae), a biological control agent of tropical soda apple (Solanaceae) in the United States

    SciTech Connect (OSTI)

    Gandolfo, D.; McKay, F.; Medal, J.C.; Cuda, J.P.

    2007-03-15

    An open-field experiment was conducted to assess the suitability of the South American leaf feeding beetle Gratiana boliviana Spaeth for biological control of Solanum viarum Dunal in the USA. An open-field test with eggplant, Solanum melongena L., was conducted on the campus of the University of Buenos Aires, Argentina, and a S. viarum control plot was established 40 km from the campus. One hundred adult beetles were released in each plot at the beginning of the experiment during the vegetative stage of the plants, and forty additional beetles were released in the S. melongena plot at the flowering stage. All the plants in each plot were checked twice a week and the number of adults, immatures, and eggs recorded. Results showed almost a complete rejection of eggplant by G. boliviana. No noticeable feeding damage was ever recorded on eggplant. The experiment was ended when the eggplants started to senesce or were severely damaged by whiteflies and spider mites. The results of this open-field experiment corroborate previous quarantine/laboratory host-specificity tests indicating that a host range expansion of G. boliviana to include eggplant is highly unlikely. Gratiana boliviana was approved for field release in May 2003 in the USA. To date, no non-target effects have been observed either on eggplant or native species of Solanum. (author) [Spanish] Una prueba de campo fue conducida para evaluar la especificidad del escarabajo suramericano defoliador Gratiana boliviana Spaeth para control biologico de Solanum viarum Dunal en los Estados Unidos. La prueba con berenjena se realizo en el campo experimental de la Universidad de Buenos Aires, Argentina, y una parcela control con S. viarum fue establecida a 40 km. Cien escarabajos adultos fueron liberados en cada parcela al inicio del experimento durante la fase vegetativa, y cuarenta escarabajos adicionales fueron liberados en la parcela de berenjena durante la floracion. Todas las plantas en cada parcela fueron inspeccionadas dos veces a la semana y el numero de adultos, larvas, y posturas fueron registrados. Resultados indicaron un casi completo rechazo de la berenjena por G. boliviana. Ningun dano visible de defoliacion en la berenjena fue detectado. Las pruebas concluyeron cuando las plantas de berenjena alcazaron su madurez o fueron severamente danadas por mosca blanca y acaros. Resultados corroboran previas pruebas de especificidad en laboratorio/cuarentena que indican que la berenjena no es un hospedero de G. boliviana y que la posibilidad de llegar a ser una plaga de este cultivo es muy remota. Gratiana boliviana fue aprobado para ser liberado en el campo en mayo del 2003. Ningun dano ha sido observado hasta la fecha a plantas no blanco. (author)

  20. MOBILE4. 1: Highway-vehicle mobile-source emission-factor model (Apple MacIntosh version) (for microcomputers). Model-Simulation

    SciTech Connect (OSTI)

    Not Available

    1991-08-01

    MOBILE4.1 is the latest revision to EPA's highway vehicle mobile source emission factor model. Relative to MOBILE4, it contains numerous revisions and provides the user with additional options for modeling highway vehicle emission factors. it will calculate emission factors for hydrocarbons (HC), carbon monoxide, (CO), and oxides of nitrogen (NOx) from highway motor vehicles. It calculates emission factors for eight individual vehicle types, in two regions of the country (low and high altitude). The emission factors depend on various conditions such as ambient temperature, fuel volatility, speed, and mileage accrual rates. It will estimate emission factors for any calendar year between 1960 and 2020 inclusive. The 25 most recent model years are considered in operation in each calendar year. EPA is requiring that states and others preparing emission inventories for nonattainment areas for CO and ozone to use MOBILE4.1 in the development of the base year 1990 emission inventories required under the Clean Air Act of 1990.

  1. Correlating sampling and intensity statistics in nanoparticle diffraction experiments

    SciTech Connect (OSTI)

    Öztürk, Hande; Yan, Hanfei; Hill, John P.; Noyan, I. Cevdet

    2015-07-28

    It is shown in a previous article [Öztürk, Yan, Hill & Noyan (2014).J. Appl. Cryst.47, 1016–1025] that the sampling statistics of diffracting particle populations within a polycrystalline ensemble depended on the size of the constituent crystallites: broad X-ray peak breadths enabled some nano-sized particles to contribute more than one diffraction spot to Debye–Scherrer rings. Here it is shown that the equations proposed by Alexander, Klug & Kummer [J. Appl. Phys.(1948),19, 742–753] (AKK) to link diffracting particle and diffracted intensity statistics are not applicable if the constituent crystallites of the powder are below 10 nm. In this size range, (i) the one-to-one correspondence between diffracting particles and Laue spots assumed in the AKK analysis is not satisfied, and (ii) the crystallographic correlation between Laue spots originating from the same grain invalidates the assumption that all diffracting plane normals are randomly oriented and uncorrelated. Such correlation produces unexpected results in the selection of diffracting grains. For example, three or more Laue spots from a given grain for a particular reflection can only be observed at certain wavelengths. In addition, correcting the diffracted intensity values by the traditional Lorentz term, 1/cos θ, to compensate for the variation of particles sampled within a reflection band does not maintain fidelity to the number of poles contributing to the diffracted signal. A new term, cos θB/cos θ, corrects this problem.

  2. AFV CoverSheet

    Office of Scientific and Technical Information (OSTI)

    ... Lett., 105,107003 (2010). 8 A. E. Bohmer, P. Burger, F. Hardy, T. Wolf, P. Schweiss, R. ... Lett., 98, 57010 (2012). 14 S. Drotziger, P. Schweiss, K. Grube, T. Wolf, P. Adelmann, C. ...

  3. LBL-25687

    Office of Scientific and Technical Information (OSTI)

    ... Rev. Lett. 43, 1892 (1979). 64. G. R. Stewart, Z. Flak, J. 0. Willis, and D. L. Smith, Phya. Rev. Lett. 52, 679 (1984). 65. Valence Instabilities and Related Harrow Band ...

  4. Secure quantum private information retrieval using phase-encoded queries

    SciTech Connect (OSTI)

    Olejnik, Lukasz

    2011-08-15

    We propose a quantum solution to the classical private information retrieval (PIR) problem, which allows one to query a database in a private manner. The protocol offers privacy thresholds and allows the user to obtain information from a database in a way that offers the potential adversary, in this model the database owner, no possibility of deterministically establishing the query contents. This protocol may also be viewed as a solution to the symmetrically private information retrieval problem in that it can offer database security (inability for a querying user to steal its contents). Compared to classical solutions, the protocol offers substantial improvement in terms of communication complexity. In comparison with the recent quantum private queries [Phys. Rev. Lett. 100, 230502 (2008)] protocol, it is more efficient in terms of communication complexity and the number of rounds, while offering a clear privacy parameter. We discuss the security of the protocol and analyze its strengths and conclude that using this technique makes it challenging to obtain the unconditional (in the information-theoretic sense) privacy degree; nevertheless, in addition to being simple, the protocol still offers a privacy level. The oracle used in the protocol is inspired both by the classical computational PIR solutions as well as the Deutsch-Jozsa oracle.

  5. Enhanced sensitivity to the time variation of the fine-structure constant and m{sub p}/m{sub e} in diatomic molecules: A closer examination of silicon monobromide

    SciTech Connect (OSTI)

    Beloy, K.; Borschevsky, A.; Schwerdtfeger, P.; Flambaum, V. V.

    2010-08-15

    Recently it was pointed out that transition frequencies in certain diatomic molecules have an enhanced sensitivity to variations in the fine-structure constant {alpha} and the proton-to-electron mass ratio m{sub p}/m{sub e} due to a near cancellation between the fine structure and vibrational interval in a ground electronic multiplet [V. V. Flambaum and M. G. Kozlov, Phys. Rev. Lett. 99, 150801 (2007)]. One such molecule possessing this favorable quality is silicon monobromide. Here we take a closer examination of SiBr as a candidate for detecting variations in {alpha} and m{sub p}/m{sub e}. We analyze the rovibronic spectrum by employing the most accurate experimental data available in the literature and perform ab initio calculations to determine the precise dependence of the spectrum on variations in {alpha}. Furthermore, we calculate the natural linewidths of the rovibronic levels, which place a fundamental limit on the accuracy to which variations may be determined.

  6. Kinetic mix mechanisms in shock-driven inertial confinement fusion implosions

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

    Rinderknecht, H. G.; Sio, H.; Li, C. K.; Hoffman, N.; Zylstra, A. B.; Rosenberg, M. J.; Frenje, J. A.; Gatu Johnson, M.; Seguin, F. H.; Petrasso, R. D.; et al

    2014-05-19

    Shock-driven implosions of thin-shell capsules, or ''exploding pushers,'' generate low-density, high-temperature plasmas in which hydrodynamic instability growth is negligible and kinetic effects can play an important role. Data from implosions of thin deuterated-plastic shells with hydroequivalent D3He gas fills ranging from pure deuterium to pure 3He [H. G. Rinderknecht et al., Phys. Rev. Lett. 112, 135001 (2014)] were obtained to evaluate non-hydrodynamic fuel-shell mix mechanisms. Simulations of the experiments including reduced ion kinetic models support ion diffusion as an explanation for these data. Several additional kinetic mechanisms are investigated and compared to the data to determine which are important inmore » the experiments. Shock acceleration of shell deuterons is estimated to introduce mix less than or comparable to the amount required to explain the data. Beam-target mechanisms are found to produce yields at most an order of magnitude less than the observations« less

  7. Nonequilibrium fixed points in longitudinally expanding scalar theories: Infrared cascade, Bose condensation and a challenge for kinetic theory

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

    Berges, J.; Schlichting, S.; Boguslavski, K.; Venugopalan, R.

    2015-11-05

    In [Phys. Rev. Lett. 114, 061601 (2015)], we reported on a new universality class for longitudinally expanding systems, encompassing strongly correlated non-Abelian plasmas and N-component self-interacting scalar field theories. Using classical-statistical methods, we showed that these systems share the same self-similar scaling properties for a wide range of momenta in a limit where particles are weakly coupled but their occupancy is high. Here we significantly expand on our previous work and delineate two further self-similar regimes. One of these occurs in the deep infrared (IR) regime of very high occupancies, where the nonequilibrium dynamics leads to the formation of amore » Bose-Einstein condensate. The universal IR scaling exponents and the spectral index characterizing the isotropic IR distributions are described by an effective theory derived from a systematic large-N expansion at next-to-leading order. Remarkably, this effective theory can be cast as a vertex-resummed kinetic theory. The other novel self-similar regime occurs close to the hard physical scale of the theory, and sets in only at later times. In this study, we argue that the important role of the infrared dynamics ensures that key features of our results for scalar and gauge theories cannot be reproduced consistently in conventional kinetic theory frameworks.« less

  8. Low-energy inverse photoemission spectroscopy using a high-resolution grating spectrometer in the near ultraviolet range

    SciTech Connect (OSTI)

    Yoshida, Hiroyuki

    2013-10-15

    An inverse photoemission spectroscopy (IPES) apparatus using a Czerny-Turner grating spectrometer is demonstrated. Previous IPES instruments based on grating spectrometers used a concave grating and operated in the vacuum ultraviolet range. The reflectance of such gratings is lower than 20% and the aberration cannot be finely corrected leading to an energy resolution of up to 0.1 eV. In the present study, employing the low energy IPES regime [H. Yoshida, Chem. Phys. Lett. 539–540, 180 (2012)], incident electrons with a kinetic energy below 5 eV are used, while photon emission in the range of between 250 and 370 nm is analyzed with a 10-cm Czerny-Turner grating spectrometer. The signal intensity is at least 30 times higher than the previous apparatus. The resolution of photon detection is set at 0.07 eV though the ultimate resolution is one order of magnitude higher. The experiment is performed both by sweeping the electron energy (isochromat mode) and by simultaneously analyzing the photon of whole wavelength range (tunable photon energy mode)

  9. Monoclinic nanodomains in morphotropic phase boundary Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}–PbTiO{sub 3}

    SciTech Connect (OSTI)

    Sato, Y.; Hirayama, T.; Ikuhara, Y.

    2014-02-24

    Crystalline structure is a fundamental characteristic of many materials, and drastic changes in properties may accompany crystal phase transitions. A prominent example of this is the morphotropic phase boundary of (Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}-PbTiO{sub 3}) single crystal, a region that exhibits a high piezoelectric effect. Although the highest piezoelectricity is often attributed to a monoclinic crystal phase, formation of ferroelectric nanodomains (NDs) complicates understanding of this crystal structure. In this Letter, we report dedicated transmission electron microscopy and electron diffraction analysis to understand the crystal structure at the ND level. Splitting of diffraction spots, caused by very small lattice distortion in the NDs, is important to understanding crystal structure and has been unambiguously observed. The results can be explained by monoclinic phase NDs. Combining these results with our previous findings on ND dynamics [Sato et al. Phys. Rev. Lett. 107, 187601 (2011)], monoclinic NDs can potentially make a considerable contribution to the piezoelectricity in these materials.

  10. Positive semidefinite tensor factorizations of the two-electron integral matrix for low-scaling ab initio electronic structure

    SciTech Connect (OSTI)

    Hoy, Erik P.; Mazziotti, David A.

    2015-08-14

    Tensor factorization of the 2-electron integral matrix is a well-known technique for reducing the computational scaling of ab initio electronic structure methods toward that of Hartree-Fock and density functional theories. The simplest factorization that maintains the positive semidefinite character of the 2-electron integral matrix is the Cholesky factorization. In this paper, we introduce a family of positive semidefinite factorizations that generalize the Cholesky factorization. Using an implementation of the factorization within the parametric 2-RDM method [D. A. Mazziotti, Phys. Rev. Lett. 101, 253002 (2008)], we study several inorganic molecules, alkane chains, and potential energy curves and find that this generalized factorization retains the accuracy and size extensivity of the Cholesky factorization, even in the presence of multi-reference correlation. The generalized family of positive semidefinite factorizations has potential applications to low-scaling ab initio electronic structure methods that treat electron correlation with a computational cost approaching that of the Hartree-Fock method or density functional theory.

  11. Magnetic excitations in the spin-1/2 triangular-lattice antiferromagnet Cs2CuBr4

    SciTech Connect (OSTI)

    Zvyagin, S. A.; Ozerov, M.; Kamenskyi, D.; Wosnitza, J.; Krzystek, J.; Yoshizawa, D.; Hagiwara, M.; Hu, Rongwei; Ryu, Hyejin; Petrovic, C.; Zhitomirsky, M. E.

    2015-11-27

    We present on high- field electron spin resonance (ESR) studies of magnetic excitations in the spin- 1/2 triangular-lattice antiferromagnet Cs2CuBr4. Frequency- field diagrams of ESR excitations are measured for different orientations of magnetic fields up to 25 T. We show that the substantial zero- field energy gap, Δ ≈ 9.5 K, observed in the low-temperature excitation spectrum of Cs2CuBr4 [Zvyagin et al:, Phys. Rev. Lett. 112, 077206 (2014)], is present well above TN. Noticeably, the transition into the long-range magnetically ordered phase does not significantly affect the size of the gap, suggesting that even below TN the high-energy spin dynamics in Cs2CuBr4 is determined by short-range-order spin correlations. The experimental data are compared with results of model spin-wave-theory calculations for spin-1/2 triangle-lattice antiferromagnet.

  12. High field nuclear magnetic resonance in transition metal substituted BaFe{sub 2}As{sub 2}

    SciTech Connect (OSTI)

    Garitezi, T. M. Lesseux, G. G.; Rosa, P. F. S.; Adriano, C.; Pagliuso, P. G.; Urbano, R. R.; Reyes, A. P.; Kuhns, P. L.

    2014-05-07

    We report high field {sup 75}As nuclear magnetic resonance (NMR) measurements on Co and Cu substituted BaFe{sub 2}As{sub 2} single crystals displaying same structural/magnetic transition T{sub 0}≃128  K. From our anisotropy studies in the paramagnetic state, we strikingly found virtually identical quadrupolar splitting and consequently the quadrupole frequency ν{sub Q}≃2.57(1)  MHz for both compounds, despite the claim that each Cu delivers 2 extra 3d electrons in BaFe{sub 2}As{sub 2} compared to Co substitution. These results allow us to conclude that a subtle change in the crystallographic structure, particularly in the Fe–As tetrahedra, must be the most probable tuning parameter to determine T{sub 0} in this class of superconductors rather than electronic doping. Furthermore, our NMR data around T{sub 0} suggest coexistence of tetragonal/paramagnetic and orthorhombic/antiferromagnetic phases between the structural and the spin density wave magnetic phase transitions, similarly to what was reported for K-doped BaFe{sub 2}As{sub 2} [Urbano et al., Phys. Rev. Lett. 105, 107001 (2010)].

  13. Electric field determination in the plasma-antenna boundary of a lower-hybrid wave launcher in Tore Supra through dynamic Stark-effect spectroscopy

    SciTech Connect (OSTI)

    Martin, Elijah H.; Goniche, M.; Klepper, C. Christopher; Hillairet, J.; Isler, Ralph C.; Bottereau, C.; Colas, L.; Ekedahl, A.; Panayotis, S.; Pegourie, B.; Lotte, Ph.; Colledani, G.; Caughman, J. B. O.; Harris, Jeffrey H.; Hillis, Donald Lee; Shannon, S.C.; Clairet, F.; Litaudon, X.

    2015-04-22

    Interaction of radio-frequency (RF) waves with the plasma in the near-field of a high-power wave launcher is now seen to be important, both in understanding the channeling of these waves through the plasma boundary and in avoiding power losses in the edge. In a recent Letter a direct non-intrusive measurement of a near antenna RF electric field in the range of lower hybrid (LH) frequencies ($E_{LH}$) was announced (Phys. Rev. Lett., 110:215005, 2013). The measurement was achieved through the fitting of Balmer series deuterium spectral lines utilizing a time dependent (dynamic) Stark effect model. In this article, the processing of the spectral data is discussed in detail and applied to a larger range of measurements and the accuracy and limitations of the experimental technique is investigated. We find through an analysis of numerous Tore Supra pulses that good quantitative agreement exists between the measured and full-wave modeled $E_{LH}$ when the launched power exceeds 0.5MW. For low power the measurement becomes formidable utilizing the implemented passive spectroscopic technique because the spectral noise overwhelms the effect of the RF electric field on the line profile. Additionally, effects of the ponderomotive force are suspected at sufficiently high power.

  14. Surface collective modes in the topological insulators Bi2Se3 and Bi0.5Sb1.5Te3-xSex

    SciTech Connect (OSTI)

    Kogar, A.; Gu, G.; Vig, S.; Thaler, A.; Wong, M. H.; Xiao, Y.; Reig-i-Plessis, D.; Cho, G. Y.; Valla, T.; Pan, Z.; Schneeloch, J.; Zhong, R.; Hughes, T. L.; MacDougall, G. J.; Chiang, T. -C.; Abbamonte, P.

    2015-12-15

    In this study, we used low-energy, momentum-resolved inelastic electron scattering to study surface collective modes of the three-dimensional topological insulators Bi2Se3 and Bi0.5Sb1.5Te3-xSex. Our goal was to identify the “spin plasmon” predicted by Raghu and co-workers [Phys. Rev. Lett. 104, 116401 (2010)]. Instead, we found that the primary collective mode is a surface plasmon arising from the bulk, free carriers in these materials. This excitation dominates the spectral weight in the bosonic function of the surface χ''(q,ω) at THz energy scales, and is the most likely origin of a quasiparticle dispersion kink observed in previous photoemission experiments. Our study suggests that the spin plasmon may mix with this other surface mode, calling for a more nuanced understanding of optical experiments in which the spin plasmon is reported to play a role.

  15. Empirical formulas for direct double ionization by bare ions: Z = - 1 to 92

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

    DuBois, R. D.; Santos, A. C. F.; Manson, S. T.

    2014-11-25

    Experimental cross sections and cross-section ratios reported in the literature for direct double ionization of the outer shells of helium, neon, and argon atoms resulting from bare ions ranging from protons to uranium and for antiprotons are analyzed in terms of a first- and second-order interference model originally proposed by McGuire [J. H. McGuire, Phys. Rev. Lett. 49, 1153 (1982)]. Empirical formulas for the various contributions to double ionization plus information about the phase difference between the first- and second-order mechanisms are extracted from the data. Projectile and target scalings are also extracted. Total cross sections and their ratios determinedmore » using these formulas and scalings are shown to be in very good agreement with experimental data for lower-Z projectiles and impact velocities larger than 1 a.u. For very-high-Z projectiles, the amount of double ionization is overestimated, probably due to saturation of probabilities that is not accounted for in scaling formulas.« less

  16. Solenoid-free Plasma Startup in NSTX using Coaxial Helicity Injection

    SciTech Connect (OSTI)

    Roger Raman; Thomas R. Jarboe; Michael G. Bell; Dennis Mueller; Brian A. Nelson; Benoit LeBlanc; Charles Bush; Masayoshi Nagata; Ted Biewer

    2005-01-03

    The favorable properties of the Spherical Torus (ST) arise from its very small aspect ratio. However, small aspect ratio devices have very restricted space for a substantial central solenoid. Thus methods for initiating the plasma current without relying on induction from a central solenoid are essential for the viability of the ST concept. Coaxial Helicity Injection (CHI) is a promising candidate for solenoid-free plasma startup in a ST. Recent experiments on the HIT-II ST at the University of Washington, have demonstrated the capability of a new method, referred to as transient CHI, to produce a high quality, closed-flux equilibrium that has then been coupled to induction, with a reduced requirement for transformer flux [R. Raman, T.R. Jarboe, B.A. Nelson, et al., Phys. Rev. Lett. 90 (February 2003) 075005-1]. An initial test of this method on the National Spherical Torus Experiment (NSTX) has produced about 140 kA of toroidal current. Modifications are now underway to improve capability for transient CHI in NSTX.

  17. Models of the elastic x-ray scattering feature for warm dense aluminum

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

    Starrett, Charles Edward; Saumon, Didier

    2015-09-03

    The elastic feature of x-ray scattering from warm dense aluminum has recently been measured by Fletcher et al. [Nature Photonics 9, 274 (2015)] with much higher accuracy than had hitherto been possible. This measurement is a direct test of the ionic structure predicted by models of warm dense matter. We use the method of pseudoatom molecular dynamics to predict this elastic feature for warm dense aluminum with temperatures of 1–100 eV and densities of 2.7–8.1g/cm3. We compare these predictions to experiments, finding good agreement with Fletcher et al. and corroborating the discrepancy found in analyses of an earlier experiment ofmore » Ma et al. [Phys. Rev. Lett. 110, 065001 (2013)]. Lastly, we also evaluate the validity of the Thomas-Fermi model of the electrons and of the hypernetted chain approximation in computing the elastic feature and find them both wanting in the regime currently probed by experiments.« less

  18. Models of the elastic x-ray scattering feature for warm dense aluminum

    SciTech Connect (OSTI)

    Starrett, Charles Edward; Saumon, Didier

    2015-09-03

    The elastic feature of x-ray scattering from warm dense aluminum has recently been measured by Fletcher et al. [Nature Photonics 9, 274 (2015)] with much higher accuracy than had hitherto been possible. This measurement is a direct test of the ionic structure predicted by models of warm dense matter. We use the method of pseudoatom molecular dynamics to predict this elastic feature for warm dense aluminum with temperatures of 1–100 eV and densities of 2.7–8.1g/cm3. We compare these predictions to experiments, finding good agreement with Fletcher et al. and corroborating the discrepancy found in analyses of an earlier experiment of Ma et al. [Phys. Rev. Lett. 110, 065001 (2013)]. Lastly, we also evaluate the validity of the Thomas-Fermi model of the electrons and of the hypernetted chain approximation in computing the elastic feature and find them both wanting in the regime currently probed by experiments.

  19. The tokamak density limit: A thermo-resistive disruption mechanism

    SciTech Connect (OSTI)

    Gates, D. A.; Brennan, D. P.; Delgado-Aparicio, L.; White, R. B.

    2015-06-15

    The behavior of magnetic islands with 3D electron temperature and the corresponding 3D resistivity effects on growth are examined for islands with near-zero net heating in the island interior. We refer to the resulting class of non-linearities as thermo-resistive effects. In particular, the effects of varying impurity mix on the previously proposed local island onset threshold [Gates and Delgado-Aparicio, Phys. Rev. Lett. 108, 165004 (2012)] are examined and shown to be consistent with the well established experimental scalings for tokamaks at the density limit. A surprisingly simple semi-analytic theory is developed which imposes the effects of heating/cooling in the island interior as well as the effects of island geometry. For the class of current profiles considered, it is found that a new term that accounts for the thermal effects of island asymmetry is required in the modified Rutherford equation. The resultant model is shown to exhibit a robust onset of a rapidly growing tearing mode—consistent with the disruption mechanism observed at the density limit in tokamaks. A fully non-linear 3D cylindrical calculation is performed that simulates the effect of net island heating/cooling by raising/suppressing the temperature in the core of the island. In both the analytic theory and the numerical simulation, the sudden threshold for rapid growth is found to be due to an interaction between three distinct thermal non-linearities which affect the island resistivity, thereby modifying the growth dynamics.

  20. Kinetic mix mechanisms in shock-driven inertial confinement fusion implosions

    SciTech Connect (OSTI)

    Rinderknecht, H. G.; Sio, H.; Li, C. K.; Zylstra, A. B.; Rosenberg, M. J.; Frenje, J. A.; Gatu Johnson, M.; Séguin, F. H.; Petrasso, R. D.; Hoffman, N.; Kagan, G.; Molvig, K.; Betti, R.; Yu Glebov, V.; Meyerhofer, D. D.; Sangster, T. C.; Seka, W.; Stoeckl, C.; Bellei, C.; Amendt, P.; and others

    2014-05-15

    Shock-driven implosions of thin-shell capsules, or “exploding pushers,” generate low-density, high-temperature plasmas in which hydrodynamic instability growth is negligible and kinetic effects can play an important role. Data from implosions of thin deuterated-plastic shells with hydroequivalent D{sup 3}He gas fills ranging from pure deuterium to pure {sup 3}He [H. G. Rinderknecht et al., Phys. Rev. Lett. 112, 135001 (2014)] were obtained to evaluate non-hydrodynamic fuel-shell mix mechanisms. Simulations of the experiments including reduced ion kinetic models support ion diffusion as an explanation for these data. Several additional kinetic mechanisms are investigated and compared to the data to determine which are important in the experiments. Shock acceleration of shell deuterons is estimated to introduce mix less than or comparable to the amount required to explain the data. Beam-target mechanisms are found to produce yields at most an order of magnitude less than the observations.

  1. Analytical estimate of phase mixing time of longitudinal Akhiezer-Polovin waves

    SciTech Connect (OSTI)

    Mukherjee, Arghya Sengupta, Sudip

    2014-11-15

    Phase mixing of a longitudinal Akhiezer-Polovin wave subjected to a small amplitude longitudinal perturbation and its eventual breaking is studied analytically. It is well known that longitudinal Akhiezer-Polovin wave subjected to arbitrarily small longitudinal perturbation breaks via the process of phase mixing at an amplitude well below its limiting amplitude [Verma et al., Phys. Rev. Lett. 108, 125005 (2012)]. We analytically show that the phase mixing time (breaking time, ω{sub p}τ{sub mix}) scales with β (phase velocity) and u{sub m}(maximum fluid velocity) as ω{sub p}τ{sub mix}∼(2πβ)/(3δ) [1/u{sub m}{sup 2}−1/4], where δ is the amplitude of velocity perturbation and ω{sub p} is the non-relativistic plasma frequency. This analytical dependence of phase mixing time on β, u{sub m}, and δ is further verified using numerical simulations based on Dawson sheet model.

  2. Investigation into the semimagic nature of the tin isotopes through electromagnetic moments

    SciTech Connect (OSTI)

    Allmond, J. M.; Stuchbery, A. E.; Galindo-Uribarri, A.; Padilla-Rodal, E.; Radford, D. C.; Batchelder, J. C.; Bingham, C. R.; Howard, M. E.; Liang, J. F.; Manning, B.; Pain, S. D.; Stone, N. J.; Varner, R. L.; Yu, C. -H.

    2015-10-19

    A complete set of electromagnetic moments, B(E2;0+1 2+1), Q(2+1), and g(2+1), have been measured from Coulomb excitation of semi-magic 112,114,116,118,120,122,124Sn (Z = 50) on natural carbon and titanium targets. The magnitude of the B(E2) values, measured to a precision of ~4%, disagree with a recent lifetime study [Phys. Lett. B 695, 110 (2011)] that employed the Doppler- shift attenuation method. The B(E2) values show an overall enhancement compared with recent theoretical calculations and a clear asymmetry about midshell, contrary to naive expectations. A new static electric quadrupole moment, Q(2+1), has been measured for 114Sn. The static quadrupole moments are generally consistent with zero but reveal an enhancement near midshell; this had not been previously observed. The magnetic dipole moments are consistent with previous measurements and show a near monotonic decrease in value with neutron number. The current theory calculations fail to reproduce the electromagnetic moments of the tin isotopes. The role of 2p-2h and 4p-4h intruders, which are lowest in energy at mid shell and outside of current model spaces, needs to be investigated in the future.

  3. Investigation into the semimagic nature of the tin isotopes through electromagnetic moments

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

    Allmond, J. M.; Stuchbery, A. E.; Galindo-Uribarri, A.; Padilla-Rodal, E.; Radford, D. C.; Batchelder, J. C.; Bingham, C. R.; Howard, M. E.; Liang, J. F.; Manning, B.; et al

    2015-10-19

    A complete set of electromagnetic moments, B(E2;0+1 2+1), Q(2+1), and g(2+1), have been measured from Coulomb excitation of semi-magic 112,114,116,118,120,122,124Sn (Z = 50) on natural carbon and titanium targets. The magnitude of the B(E2) values, measured to a precision of ~4%, disagree with a recent lifetime study [Phys. Lett. B 695, 110 (2011)] that employed the Doppler- shift attenuation method. The B(E2) values show an overall enhancement compared with recent theoretical calculations and a clear asymmetry about midshell, contrary to naive expectations. A new static electric quadrupole moment, Q(2+1), has been measured for 114Sn. The static quadrupole moments are generallymore » consistent with zero but reveal an enhancement near midshell; this had not been previously observed. The magnetic dipole moments are consistent with previous measurements and show a near monotonic decrease in value with neutron number. The current theory calculations fail to reproduce the electromagnetic moments of the tin isotopes. The role of 2p-2h and 4p-4h intruders, which are lowest in energy at mid shell and outside of current model spaces, needs to be investigated in the future.« less

  4. Ablation dynamics in coiled wire-array Z-pinches

    SciTech Connect (OSTI)

    Hall, G. N.; Lebedev, S. V.; Suzuki-Vidal, F.; Swadling, G.; Chittenden, J. P.; Bland, S. N.; Harvey-Thompson, A.; Knapp, P. F.; Blesener, I. C.; McBride, R. D.; Chalenski, D. A.; Blesener, K. S.; Greenly, J. B.; Pikuz, S. A.; Shelkovenko, T. A.; Hammer, D. A.; Kusse, B. R.

    2013-02-15

    Experiments to study the ablation dynamics of coiled wire arrays were performed on the MAGPIE generator (1 MA, 240 ns) at Imperial College, and on the COBRA generator at Cornell University's Laboratory of Plasma Studies (1 MA, 100 ns). The MAGPIE generator was used to drive coiled wires in an inverse array configuration to study the distribution of ablated plasma. Using interferometry to study the plasma distribution during the ablation phase, absolute quantitative measurements of electron line density demonstrated very high density contrasts between coiled ablation streams and inter-stream regions many millimetres from the wire. The measured density contrasts for a coiled array were many times greater than that observed for a conventional array with straight wires, indicating that a much greater axial modulation of the ablated plasma may be responsible for the unique implosion dynamics of coiled arrays. Experiments on the COBRA generator were used to study the complex redirection of plasma around a coiled wire that gives rise to the ablation structure exhibited by coiled arrays. Observations of this complex 3D plasma structure were used to validate the current model of coiled array ablation dynamics [Hall et al., Phys. Rev. Lett. 100, 065003 (2008)], demonstrating irrefutably that plasma flow from the wires behaves as predicted. Coiled wires were observed to ablate and implode in the same manner on both machines, indicating that current rise time should not be an issue for the scaling of coiled arrays to larger machines with fast current rise times.

  5. Surface collective modes in the topological insulators Bi2Se3 and Bi0.5Sb1.5Te3-xSex

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

    Kogar, A.; Gu, G.; Vig, S.; Thaler, A.; Wong, M. H.; Xiao, Y.; Reig-i-Plessis, D.; Cho, G. Y.; Valla, T.; Pan, Z.; et al

    2015-12-15

    In this study, we used low-energy, momentum-resolved inelastic electron scattering to study surface collective modes of the three-dimensional topological insulators Bi2Se3 and Bi0.5Sb1.5Te3-xSex. Our goal was to identify the “spin plasmon” predicted by Raghu and co-workers [Phys. Rev. Lett. 104, 116401 (2010)]. Instead, we found that the primary collective mode is a surface plasmon arising from the bulk, free carriers in these materials. This excitation dominates the spectral weight in the bosonic function of the surface χ''(q,ω) at THz energy scales, and is the most likely origin of a quasiparticle dispersion kink observed in previous photoemission experiments. Our study suggestsmore » that the spin plasmon may mix with this other surface mode, calling for a more nuanced understanding of optical experiments in which the spin plasmon is reported to play a role.« less

  6. Incommensurate magnetic ordering in Cu{sub 2}Te{sub 2}O{sub 5}X{sub 2} (X=Cl,Br) studied by single crystal neutron diffraction

    SciTech Connect (OSTI)

    Zaharko, O.; Roennow, H.; Mesot, J.; Crowe, S. J.; Paul, D. McK.; Brown, P. J.; Daoud-Aladine, A.; Meents, A.; Wagner, A.; Prester, M.; Berger, H.

    2006-02-01

    Polarized and unpolarized neutron-diffraction studies have been carried out on single crystals of the coupled spin tetrahedra systems Cu{sub 2}Te{sub 2}O{sub 5}X{sub 2} (X=Cl,Br). A model of the magnetic structure associated with the propagation vectors k{sup '}{sub Cl}{approx_equal}(-0.150,0.422,(1/2)) and k{sup '}{sub Br}{approx_equal}(-0.172,0.356,(1/2)) and stable below T{sub N}=18 K for X=Cl and T{sub N}=11 K for X=Br is proposed. A feature of the model, common to both the bromide and chloride, is a canted coplanar motif for the four Cu{sup 2+} spins on each tetrahedron which rotates on a helix from cell to cell following the propagation vector. The Cu{sup 2+} magnetic moment determined for X=Br,0.395(5){mu}{sub B}, is significantly less than for X=Cl,0.88(1){mu}{sub B} at 2 K. The magnetic structure of the chloride associated with the wave vector k{sup '} differs from that determined previously for the wave vector k{approx_equal}(0.150,0.422,(1/2)) [O. Zaharko et al., Phys. Rev. Lett. 93, 217206(E) (2004)].

  7. Kinetic mix mechanisms in shock-driven inertial confinement fusion implosions

    SciTech Connect (OSTI)

    Rinderknecht, H. G.; Sio, H.; Li, C. K.; Hoffman, N.; Zylstra, A. B.; Rosenberg, M. J.; Frenje, J. A.; Gatu Johnson, M.; Seguin, F. H.; Petrasso, R. D.; Betti, R.; Yu Glebov, V.; Meyerhofer, D. D.; Sangster, T. C.; Seka, W.; Stoeckl, C.; Kagan, G.; Molvig, K.; Bellei, C.; Amendt, P.; Landen, O.; Rygg, J. R.; Smalyuk, V. A.; Wilks, S.; Greenwood, A.; Nikroo, A.

    2014-05-19

    Shock-driven implosions of thin-shell capsules, or ''exploding pushers,'' generate low-density, high-temperature plasmas in which hydrodynamic instability growth is negligible and kinetic effects can play an important role. Data from implosions of thin deuterated-plastic shells with hydroequivalent D3He gas fills ranging from pure deuterium to pure 3He [H. G. Rinderknecht et al., Phys. Rev. Lett. 112, 135001 (2014)] were obtained to evaluate non-hydrodynamic fuel-shell mix mechanisms. Simulations of the experiments including reduced ion kinetic models support ion diffusion as an explanation for these data. Several additional kinetic mechanisms are investigated and compared to the data to determine which are important in the experiments. Shock acceleration of shell deuterons is estimated to introduce mix less than or comparable to the amount required to explain the data. Beam-target mechanisms are found to produce yields at most an order of magnitude less than the observations

  8. Two-dimensional studies of relativistic electron beam plasma instabilities in an inhomogeneous plasma

    SciTech Connect (OSTI)

    Shukla, Chandrasekhar; Das, Amita; Patel, Kartik

    2015-11-15

    Relativistic electron beam propagation in plasma is fraught with several micro instabilities like two stream, filamentation, etc., in plasma. This results in severe limitation of the electron transport through a plasma medium. Recently, however, there has been an experimental demonstration of improved transport of Mega Ampere of electron currents (generated by the interaction of intense laser with solid target) in a carbon nanotube structured solid target [G. Chatterjee et al., Phys. Rev. Lett. 108, 235005 (2012)]. This then suggests that the inhomogeneous plasma (created by the ionization of carbon nanotube structured target) helps in containing the growth of the beam plasma instabilities. This manuscript addresses this issue with the help of a detailed analytical study and 2-D Particle-In-Cell simulations. The study conclusively demonstrates that the growth rate of the dominant instability in the 2-D geometry decreases when the plasma density is chosen to be inhomogeneous, provided the scale length 1/k{sub s} of the inhomogeneous plasma is less than the typical plasma skin depth (c/ω{sub 0}) scale. At such small scale lengths channelization of currents is also observed in simulation.

  9. Electric field determination in the plasma-antenna boundary of a lower-hybrid wave launcher in Tore Supra through dynamic Stark-effect spectroscopy

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

    Martin, Elijah H.; Goniche, M.; Klepper, C. Christopher; Hillairet, J.; Isler, Ralph C.; Bottereau, C.; Colas, L.; Ekedahl, A.; Panayotis, S.; Pegourie, B.; et al

    2015-04-22

    Interaction of radio-frequency (RF) waves with the plasma in the near-field of a high-power wave launcher is now seen to be important, both in understanding the channeling of these waves through the plasma boundary and in avoiding power losses in the edge. In a recent Letter a direct non-intrusive measurement of a near antenna RF electric field in the range of lower hybrid (LH) frequencies (more » $$E_{LH}$$) was announced (Phys. Rev. Lett., 110:215005, 2013). The measurement was achieved through the fitting of Balmer series deuterium spectral lines utilizing a time dependent (dynamic) Stark effect model. In this article, the processing of the spectral data is discussed in detail and applied to a larger range of measurements and the accuracy and limitations of the experimental technique is investigated. We find through an analysis of numerous Tore Supra pulses that good quantitative agreement exists between the measured and full-wave modeled $$E_{LH}$$ when the launched power exceeds 0.5MW. For low power the measurement becomes formidable utilizing the implemented passive spectroscopic technique because the spectral noise overwhelms the effect of the RF electric field on the line profile. Additionally, effects of the ponderomotive force are suspected at sufficiently high power.« less

  10. Kinetic model of force-free current sheets with non-uniform temperature

    SciTech Connect (OSTI)

    Kolotkov, D. Y.; Nakariakov, V. M.; Vasko, I. Y.

    2015-11-15

    The kinetic model of a one-dimensional force-free current sheet (CS) developed recently by Harrison and Neukirch [Phys. Rev. Lett. 102(13), 135003 (2009)] predicts uniform distributions of the plasma temperature and density across the CS. However, in realistic physical systems, inhomogeneities of these plasma parameters may arise quite naturally due to the boundary conditions or local plasma heating. Moreover, as the CS spatial scale becomes larger than the characteristic kinetic scales (the regime often referred to as the MHD limit), it should be possible to set arbitrary density and temperature profiles. Thus, an advanced model has to allow for inhomogeneities of the macroscopic plasma parameters across the CS, to be consistent with the MHD limit. In this paper, we generalise the kinetic model of a force-free current sheet, taking into account the inhomogeneity of the density and temperature across the CS. In the developed model, the density may either be enhanced or depleted in the CS central region. The temperature profile is prescribed by the density profile, keeping the plasma pressure uniform across the CS. All macroscopic parameters, as well as the distribution functions for the protons and electrons, are determined analytically. Applications of the developed model to current sheets observed in space plasmas are discussed.

  11. Practicality of magnetic compression for plasma density control

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

    Gueroult, Renaud; Fisch, Nathaniel J.

    2016-03-16

    Here, plasma densification through magnetic compression has been suggested for time-resolved control of the wave properties in plasma-based accelerators [P. F. Schmit and N. J. Fisch, Phys. Rev. Lett. 109, 255003 (2012)]. Using particle in cell simulations with real mass ratio, the practicality of large magnetic compression on timescales shorter than the ion gyro-period is investigated. For compression times shorter than the transit time of a compressional Alfven wave across the plasma slab, results show the formation of two counter-propagating shock waves, leading to a highly non-uniform plasma density profile. Furthermore, the plasma slab displays large hydromagnetic like oscillations aftermore » the driving field has reached steady state. Peak compression is obtained when the two shocks collide in the mid-plane. At this instant, very large plasma heating is observed, and the plasmaβ is estimated to be about 1. Although these results point out a densification mechanism quite different and more complex than initially envisioned, these features still might be advantageous in particle accelerators.« less

  12. Relativistic plasma expansion with Maxwell-Juettner distribution

    SciTech Connect (OSTI)

    Huang, Yongsheng; Wang, Naiyan; Tang, Xiuzhang; Shi, Yijin

    2013-11-15

    A self-similar analytical solution is proposed to describe the relativistic ion acceleration with the local Maxwell-Juettner relativistic distribution electrons. It is an alternative to the existing static model [M. Passoni and M. Lontano, Phys. Rev. Lett. 101, 115001 (2008)], which exploits a limited solution for the acceleration potential. With our model, the potential is finite naturally and has an upper limitation proportional to the square root of the electron temperature. The divergent potential in the non-relativistic case is the linear items of the Taylor expansion of that obtained relativistic one here. The energy distribution of ions and the dependence of the ion momentum on the acceleration time are obtained analytically. Maximum ion energy has an upper limitation decided by the finite potential difference. In the ultra-relativistic region, the ion energy at the ion front is proportional to t{sup 4/5} and the energy of the ions behind the ion front is proportional to t{sup 2/3} since the field there is shielded by the ions beyond them and the field at the ion front is the most intense.

  13. Magnetic excitations in the spin-1/2 triangular-lattice antiferromagnet Cs2CuBr4

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

    Zvyagin, S. A.; Ozerov, M.; Kamenskyi, D.; Wosnitza, J.; Krzystek, J.; Yoshizawa, D.; Hagiwara, M.; Hu, Rongwei; Ryu, Hyejin; Petrovic, C.; et al

    2015-11-27

    We present on high- field electron spin resonance (ESR) studies of magnetic excitations in the spin- 1/2 triangular-lattice antiferromagnet Cs2CuBr4. Frequency- field diagrams of ESR excitations are measured for different orientations of magnetic fields up to 25 T. We show that the substantial zero- field energy gap, Δ ≈ 9.5 K, observed in the low-temperature excitation spectrum of Cs2CuBr4 [Zvyagin et al:, Phys. Rev. Lett. 112, 077206 (2014)], is present well above TN. Noticeably, the transition into the long-range magnetically ordered phase does not significantly affect the size of the gap, suggesting that even below TN the high-energy spin dynamicsmore » in Cs2CuBr4 is determined by short-range-order spin correlations. The experimental data are compared with results of model spin-wave-theory calculations for spin-1/2 triangle-lattice antiferromagnet.« less

  14. Spin filtering in a double quantum dot device: Numerical renormalization group study of the internal structure of the Kondo state

    SciTech Connect (OSTI)

    Vernek, E.; Bsser, C. A.; Anda, E. V.; Feiguin, A. E.; Martins, G. B.

    2014-03-31

    A double quantum dot device, connected to two channels that only interact through interdot Coulomb repulsion, is analyzed using the numerical renormalization group technique. Using a two-impurity Anderson model, and realistic parameter values [S. Amasha, A. J. Keller, I. G. Rau, A. Carmi, J. A. Katine, H. Shtrikman, Y. Oreg, and D. Goldhaber-Gordon, Phys. Rev. Lett. 110, 046604 (2013)], it is shown that, by applying a moderate magnetic field and independently adjusting the gate potential of each quantum dot at half-filling, a spin-orbital SU(2) Kondo state can be achieved where the Kondo resonance originates from spatially separated parts of the device. Our results clearly link this spatial separation effect to currents with opposing spin polarizations in each channel, i.e., the device acts as a spin filter. In addition, an experimental probe of this polarization effect is suggested, pointing to the exciting possibility of experimentally probing the internal structure of an SU(2) Kondo state.

  15. Elementary excitations and universal interaction in Bose-Einstein condensates at large scattering lengths

    SciTech Connect (OSTI)

    Sarjonen, R.; Saarela, M.; Mazzanti, F.

    2011-10-15

    We present a theoretical analysis of excitation modes in Bose-Einstein condensates of ultracold alkali-metal gases for large scattering lengths, showing clear deviations from the Bogoliubov prediction as seen by Papp et al.[Phys. Rev. Lett. 101, 135301 (2008)]. We construct the atom-atom interaction by deriving the T matrix of such systems from two coupled (open and closed) channels assuming that the Feshbach resonance dominates the latter. We calculate molecular bound-state energies as a function of the magnetic field and compare with available experiments. The s-wave phase shifts determine the local effective interaction with long-ranged repulsion and short-ranged attraction. We show that it becomes a universal function at large scattering lengths. Finally, we use this interaction to characterize the ground-state and elementary excitations of {sup 85}Rb, {sup 87}Rb, and {sup 23}Na gases. Good agreement with line shift experiments in {sup 85}Rb is achieved. We find that, at large scattering lengths, Bragg scattering experiments could directly measure the momentum dependence of the effective two-body potential.

  16. Lubricating bacteria model for the growth of bacterial colonies exposed to ultraviolet radiation

    SciTech Connect (OSTI)

    Zhang Shengli; Zhang Lei; Liang Run; Zhang Erhu; Liu Yachao; Zhao Shumin

    2005-11-01

    In this paper, we study the morphological transition of bacterial colonies exposed to ultraviolet radiation by modifying the bacteria model proposed by Delprato et al. Our model considers four factors: the lubricant fluid generated by bacterial colonies, a chemotaxis initiated by the ultraviolet radiation, the intensity of the ultraviolet radiation, and the bacteria's two-stage destruction rate with given radiation intensities. Using this modified model, we simulate the ringlike pattern formation of the bacterial colony exposed to uniform ultraviolet radiation. The following is shown. (1) Without the UV radiation the colony forms a disklike pattern and reaches a constant front velocity. (2) After the radiation is switched on, the bacterial population migrates to the edge of the colony and forms a ringlike pattern. As the intensity of the UV radiation is increased the ring forms faster and the outer velocity of the colony decreases. (3) For higher radiation intensities the total population decreases, while for lower intensities the total population increases initially at a small rate and then decreases. (4) After the UV radiation is switched off, the bacterial population grows both outward as well as into the inner region, and the colony's outer front velocity recovers to a constant value. All these results agree well with the experimental observations [Phys. Rev. Lett. 87, 158102 (2001)]. Along with the chemotaxis, we find that lubricant fluid and the two-stage destruction rate are critical to the dynamics of the growth of the bacterial colony when exposed to UV radiation, and these were not previously considered.

  17. Velocity Interferometer blanking due to preheating in a double pulse planar experiment

    SciTech Connect (OSTI)

    Laffite, S.; Combis, P.; Clerouin, J.; Recoules, V.; Rousseaux, C.; Videau, L.; Baton, S. D.; Koenig, M.

    2014-08-15

    Optical diagnostics, such as VISAR (Velocity Interferometer System for Any Reflector) or SOP (Streaked Optical Pyrometry), have become essential in shock timing experiments. Their high precision allows for accurate measurements of shock velocities, chronometry, and brightness temperature. However, in some instances, these measurements can be compromised. In planar shock coalescence experiments recently performed at the LULI facility [Baton et al., Phys. Rev. Lett. 108, 195002 (2012)], VISAR signal loss was observed. In these experiments, a strong shock launched by a high-intensity spike catches up with a previously shock launched by an earlier, low-intensity beam. The disappearance of the VISAR signal is attributed to a preheating of the coronal plasma by x-rays generated by the high intensity spike. The signal does not disappear if the high-intensity spike starts after VISAR probe beam begins to reflect off of the first shock. The VISAR diagnostic, modeled using an assessment of the optical index in quartz, compares favorably to experimental results. This provides evidence that x-ray preheating can cause blanking of the VISAR signal in quartz.

  18. Nonequilibrium fixed points in longitudinally expanding scalar theories: Infrared cascade, Bose condensation and a challenge for kinetic theory

    SciTech Connect (OSTI)

    Berges, J.; Schlichting, S.; Boguslavski, K.; Venugopalan, R.

    2015-11-05

    In [Phys. Rev. Lett. 114, 061601 (2015)], we reported on a new universality class for longitudinally expanding systems, encompassing strongly correlated non-Abelian plasmas and N-component self-interacting scalar field theories. Using classical-statistical methods, we showed that these systems share the same self-similar scaling properties for a wide range of momenta in a limit where particles are weakly coupled but their occupancy is high. Here we significantly expand on our previous work and delineate two further self-similar regimes. One of these occurs in the deep infrared (IR) regime of very high occupancies, where the nonequilibrium dynamics leads to the formation of a Bose-Einstein condensate. The universal IR scaling exponents and the spectral index characterizing the isotropic IR distributions are described by an effective theory derived from a systematic large-N expansion at next-to-leading order. Remarkably, this effective theory can be cast as a vertex-resummed kinetic theory. The other novel self-similar regime occurs close to the hard physical scale of the theory, and sets in only at later times. In this study, we argue that the important role of the infrared dynamics ensures that key features of our results for scalar and gauge theories cannot be reproduced consistently in conventional kinetic theory frameworks.

  19. Langmuir probe diagnostic suite in the C-2 field-reversed configuration

    SciTech Connect (OSTI)

    Roche, T. Armstrong, S.; Knapp, K.; Slepchenkov, M.; Sun, X.

    2014-11-15

    Several in situ probes have been designed and implemented into the diagnostic array of the C-2 field-reversed configuration (FRC) at Tri Alpha Energy [M. Tuszewski et al. (the TAE Team), Phys. Rev. Lett. 108, 255008 (2012)]. The probes are all variations on the traditional Langmuir probe. They include linear arrays of triple probes, linear arrays of single-tipped swept probes, a multi-faced Gundestrup probe, and an ion-sensitive probe. The probes vary from 5 to 7 mm diameter in size to minimize plasma perturbations. They also have boron nitride outer casings that prevent unwanted electrical breakdown and reduce the introduction of impurities. The probes are mounted on motorized linear-actuators allowing for programmatic scans of the various plasma parameters over the course of several shots. Each probe has a custom set of electronics that allows for measurement of the desired signals. High frequency ( > 5MHz) analog optical-isolators ensure that plasma parameters can be measured at sub-microsecond time scales while providing electrical isolation between machine and data acquisition systems. With these probes time-resolved plasma parameters (temperature, density, spatial potential, flow, and electric field) can be directly/locally measured in the FRC jet and edge/scrape-off layer.

  20. Using high-intensity laser-generated energetic protons to radiograph directly driven implosions

    SciTech Connect (OSTI)

    Zylstra, A. B.; Li, C. K.; Rinderknecht, H. G.; Seguin, F. H.; Petrasso, R. D.; Stoeckl, C.; Meyerhofer, D. D.; Nilson, P.; Sangster, T. C.; Le Pape, S.; Mackinnon, A.; Patel, P.

    2012-01-15

    The recent development of petawatt-class lasers with kilojoule-picosecond pulses, such as OMEGA EP [L. Waxer et al., Opt. Photonics News 16, 30 (2005)], provides a new diagnostic capability to study inertial-confinement-fusion (ICF) and high-energy-density (HED) plasmas. Specifically, petawatt OMEGA EP pulses have been used to backlight OMEGA implosions with energetic proton beams generated through the target normal sheath acceleration (TNSA) mechanism. This allows time-resolved studies of the mass distribution and electromagnetic field structures in ICF and HED plasmas. This principle has been previously demonstrated using Vulcan to backlight six-beam implosions [A. J. Mackinnon et al., Phys. Rev. Lett. 97, 045001 (2006)]. The TNSA proton backlighter offers better spatial and temporal resolution but poorer spatial uniformity and energy resolution than previous D{sup 3}He fusion-based techniques [C. Li et al., Rev. Sci. Instrum. 77, 10E725 (2006)]. A target and the experimental design technique to mitigate potential problems in using TNSA backlighting to study full-energy implosions is discussed. The first proton radiographs of 60-beam spherical OMEGA implosions using the techniques discussed in this paper are presented. Sample radiographs and suggestions for troubleshooting failed radiography shots using TNSA backlighting are given, and future applications of this technique at OMEGA and the NIF are discussed.

  1. Intrinsic torque reversals induced by magnetic shear effects on the turbulence spectrum in tokamak plasmas

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

    Lu, Z. X.; Wang, W. X.; Diamond, P. H.; Tynan, G.; Ethier, S.; Gao, C.; Rice, J.

    2015-05-04

    We report that intrinsic torque, which can be generated by turbulent stresses, can induce toroidal rotation in a tokamak plasma at rest without direct momentum injection. Reversals in intrinsic torque have been inferred from the observation of toroidal velocity changes in recent lower hybrid current drive (LHCD) experiments. Here we focus on understanding the cause of LHCD-induced intrinsic torque reversal using gyrokinetic simulations and theoretical analyses. A new mechanism for the intrinsic torque reversal linked to magnetic shear (sˆ) effects on the turbulence spectrum is identified. This reversal is a consequence of the ballooning structure at weak sˆ . Basedmore » on realistic profiles from the Alcator C-Mod LHCD experiments, simulations demonstrate that the intrinsic torque reverses for weak sˆ discharges and that the value of sˆ crit is consistent with the experimental results sˆ expcrit [Rice et al., Phys. Rev. Lett. 111, 125003 (2013)]. In conclusion, the consideration of this intrinsic torque feature in our work is important for the understanding of rotation profile generation at weak and its consequent impact on macro-instability stabilization and micro-turbulence reduction, which is crucial for ITER. It is also relevant to internal transport barrier formation at negative or weakly positive sˆ .« less

  2. Large-amplitude solitons in gravitationally balanced quantum plasmas

    SciTech Connect (OSTI)

    Akbari-Moghanjoughi, M.

    2014-08-15

    Using the quantum fluid model for self-gravitating quantum plasmas with the Bernoulli pseudopotential method and taking into account the relativistic degeneracy effect, it is shown that gravity-induced large-amplitude density rarefaction solitons can exist in gravitationally balanced quantum plasmas. These nonlinear solitons are generated due to the force imbalance between the gravity and the quantum fluid pressure via local density perturbations, similar to that on shallow waters. It is found that both the fluid mass-density and the atomic-number of the constituent ions have significant effect on the amplitude and width of these solitonic profiles. Existence of a large-scale gravity-induced solitonic activities on neutron-star surface, for instance, can be a possible explanation for the recently proposed resonant shattering mechanism [D. Tsang et al., Phys. Rev. Lett. 108, 011102 (2012)] causing the intense short gamma ray burst phenomenon, in which release of ≃10{sup 46}–10{sup 47} ergs would be possible from the surface. The resonant shattering of the crust in a neutron star has been previously attributed to the crust-core interface mode and the tidal surface tensions. We believe that current model can be a more natural explanation for the energy liberation by solitonic activities on the neutron star surfaces, without a requirement for external mergers like other neutron stars or black holes for the crustal shatter.

  3. Electric field determination in the plasma-antenna boundary of a lower-hybrid wave launcher in Tore Supra through dynamic Stark-effect spectroscopy

    SciTech Connect (OSTI)

    Martin, Elijah H; Goniche, M.; Klepper, C Christopher; Hillairet, J.; Isler, Ralph C; Caughman, J. B. O.; Colas, L.; Ekedahl, A.; Colledani, G.; Lotte, Ph.; Litaudon, X; Hillis, Donald Lee; Harris, Jeffrey H

    2015-01-01

    Interaction of radio-frequency (RF) waves with the plasma in the near-field of a high-power wave launcher is now seen to be important, both in understanding the channeling of these waves through the plasma boundary and in avoiding power losses in the edge. In a recent Letter a direct non-intrusive measurement of a near antenna RF electric field in the range of lower hybrid (LH) frequencies ($E_{LH}$) was announced (Phys. Rev. Lett., 110:215005, 2013). The measurement was achieved through the fitting of Balmer series deuterium spectral lines utilizing a time dependent (dynamic) Stark effect model. In this article, the processing of the spectral data is discussed in detail and applied to a larger range of measurements and the accuracy and limitations of the experimental technique is investigated. It was found through an analysis of numerous Tore Supra pulses that good quantitative agreement exists between the measured and full-wave modeled $E_{LH}$ when the launched power exceeds 0.5MW. For low power the measurement becomes formidable utilizing the implemented passive spectroscopic technique because the spectral noise overwhelms the effect of the RF electric field on the line profile. Additionally, effects of the ponderomotive force are suspected at sufficiently high power.

  4. Fluctuating and dissipative dynamics of dark solitons in quasicondensates

    SciTech Connect (OSTI)

    Cockburn, S. P.; Proukakis, N. P.; Nistazakis, H. E.; Frantzeskakis, D. J.; Horikis, T. P.; Kevrekidis, P. G.

    2011-10-15

    The fluctuating and dissipative dynamics of matter-wave dark solitons within harmonically trapped, partially condensed Bose gases is studied both numerically and analytically. A study of the stochastic Gross-Pitaevskii equation, which correctly accounts for density and phase fluctuations at finite temperatures, reveals dark-soliton decay times to be lognormally distributed at each temperature, thereby characterizing the previously predicted long-lived soliton trajectories within each ensemble of numerical realizations [S. P. Cockburn et al., Phys. Rev. Lett. 104, 174101 (2010)]. Expectation values for the average soliton lifetimes extracted from these distributions are found to agree well with both numerical and analytic predictions based upon the dissipative Gross-Pitaevskii model (with the same ab initio damping). Probing the regime for which 0.8 k{sub B}T<{mu}<1.6 k{sub B}T, we find average soliton lifetimes to scale with temperature as {tau}{approx}T{sup -4}, in agreement with predictions previously made for the low-temperature regime k{sub B}T<<{mu}. The model is also shown to capture the experimentally relevant decrease in the visibility of an oscillating soliton due to the presence of background fluctuations.

  5. Plasma response to electron energy filter in large volume plasma device

    SciTech Connect (OSTI)

    Sanyasi, A. K.; Awasthi, L. M.; Mattoo, S. K.; Srivastava, P. K.; Singh, S. K.; Singh, R.; Kaw, P. K. [Institute for Plasma Research, Gandhinagar, 382 428 Gujarat (India)] [Institute for Plasma Research, Gandhinagar, 382 428 Gujarat (India)

    2013-12-15

    An electron energy filter (EEF) is embedded in the Large Volume Plasma Device plasma for carrying out studies on excitation of plasma turbulence by a gradient in electron temperature (ETG) described in the paper of Mattoo et al. [S. K. Mattoo et al., Phys. Rev. Lett. 108, 255007 (2012)]. In this paper, we report results on the response of the plasma to the EEF. It is shown that inhomogeneity in the magnetic field of the EEF switches on several physical phenomena resulting in plasma regions with different characteristics, including a plasma region free from energetic electrons, suitable for the study of ETG turbulence. Specifically, we report that localized structures of plasma density, potential, electron temperature, and plasma turbulence are excited in the EEF plasma. It is shown that structures of electron temperature and potential are created due to energy dependence of the electron transport in the filter region. On the other hand, although structure of plasma density has origin in the particle transport but two distinct steps of the density structure emerge from dominance of collisionality in the source-EEF region and of the Bohm diffusion in the EEF-target region. It is argued and experimental evidence is provided for existence of drift like flute Rayleigh-Taylor in the EEF plasma.

  6. Sensitivity of transitions in internal rotor molecules to a possible variation of the proton-to-electron mass ratio

    SciTech Connect (OSTI)

    Jansen, Paul; Ubachs, Wim; Bethlem, Hendrick L.; Kleiner, Isabelle; Xu, Li-Hong

    2011-12-15

    Recently, methanol was identified as a sensitive target system to probe variations of the proton-to-electron mass ratio {mu}[Jansen et al., Phys. Rev. Lett. 106, 100801 (2011)]. The high sensitivity of methanol originates from the interplay between overall rotation and hindered internal rotation of the molecule; that is, transitions that convert internal rotation energy into overall rotation energy, or vice versa, have an enhanced sensitivity coefficient, K{sub {mu}}. As internal rotation is a common phenomenon in polyatomic molecules, it is likely that other molecules display similar or even larger effects. In this paper we generalize the concepts that form the foundation of the high sensitivity in methanol and use this to construct an approximate model which makes it possible to estimate the sensitivities of transitions in internal rotor molecules with C{sub 3v} symmetry, without performing a full calculation of energy levels. We find that a reliable estimate of transition sensitivities can be obtained from the three rotational constants (A, B, and C) and three torsional constants (F, V{sub 3}, and {rho}). This model is verified by comparing obtained sensitivities for methanol, acetaldehyde, acetamide, methyl formate, and acetic acid with a full analysis of the molecular Hamiltonian. Of the molecules considered, methanol is by far the most suitable candidate for laboratory and cosmological tests searching for a possible variation of {mu}.

  7. Analysis of depolarization ratios of ClNO{sub 2} dissolved in methanol

    SciTech Connect (OSTI)

    Trimithioti, Marilena; Hayes, Sophia C.; Akimov, Alexey V.; Department of Chemistry, Brookhaven National Laboratory, Upton, New York 11973 ; Prezhdo, Oleg V.

    2014-01-07

    A detailed analysis of the resonance Raman depolarization ratio dispersion curve for the NO symmetric stretch of nitryl chloride in methanol at excitation wavelengths spanning the D absorption band is presented. The depolarization ratios are modeled using the time-dependent formalism for Raman scattering with contributions from two excited states (2{sup 1}A{sub 1} and 3{sup 1}B{sub 1}), which are taken as linearly dissociative along the ClN coordinate. The analysis focuses on the interplay between different types of broadening revealing the importance of inhomogenous broadening in determining the relative contributions of the two electronic transitions. We find that the transition dipole moment (M) for 2{sup 1}A{sub 1} is greater than for 3{sup 1}B{sub 1}, in agreement with gas phase calculations in the literature [A. Lesar, M. Hdoscek, M. Muhlhauser, and S. D. Peyerimhoff, Chem. Phys. Lett. 383, 84 (2004)]. However, we find that the polarity of the solvent influences the excited state energetics, leading to a reversal in the ordering of these two states with 3{sup 1}B{sub 1} shifting to lower energies. Molecular dynamics simulations along with linear response and ab initio calculations support the evidence extracted from resonance Raman intensity analysis, providing insights on ClNO{sub 2} electronic structure, solvation effects in methanol, and the source of broadening, emphasizing the importance of a contribution from inhomogeneous linewidth.

  8. Orbital-selective Mott phases of a one-dimensional three-orbital Hubbard model studied using computational techniques

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

    Liu, Guangkun; Kaushal, Nitin; Liu, Shaozhi; Bishop, Christopher B.; Wang, Yan; Johnston, Steve; Alvarez, Gonzalo; Moreo, Adriana; Dagotto, Elbio R.

    2016-06-24

    A recently introduced one-dimensional three-orbital Hubbard model displays orbital-selective Mott phases with exotic spin arrangements such as spin block states [J. Rincón et al., Phys. Rev. Lett. 112, 106405 (2014)]. In this paper we show that the constrained-path quantum Monte Carlo (CPQMC) technique can accurately reproduce the phase diagram of this multiorbital one-dimensional model, paving the way to future CPQMC studies in systems with more challenging geometries, such as ladders and planes. The success of this approach relies on using the Hartree-Fock technique to prepare the trial states needed in CPQMC. In addition, we study a simplified version of themore » model where the pair-hopping term is neglected and the Hund coupling is restricted to its Ising component. The corresponding phase diagrams are shown to be only mildly affected by the absence of these technically difficult-to-implement terms. This is confirmed by additional density matrix renormalization group and determinant quantum Monte Carlo calculations carried out for the same simplified model, with the latter displaying only mild fermion sign problems. Lastly, we conclude that these methods are able to capture quantitatively the rich physics of the several orbital-selective Mott phases (OSMP) displayed by this model, thus enabling computational studies of the OSMP regime in higher dimensions, beyond static or dynamic mean-field approximations.« less

  9. Strain-dependence Of The Structure And Ferroic Properties Of Epitaxial Ni-1 (-) Ti-x(1) (-) O-y(3) Thin Films Grown On Sapphire Substrates

    SciTech Connect (OSTI)

    Varga, Tamas; Droubay, Timothy C.; Bowden, Mark E.; Stephens, Sean A.; Manandhar, Sandeep; Shutthanandan, V.; Colby, Robert J.; Hu, Dehong; Shelton, William A.; Chambers, Scott A.

    2015-03-01

    Polarization-induced weak ferromagnetism has been predicted a few years back in perovskite MTiO3 (M = Fe, Mn, Ni) [Fennie, Phys. Rev. Lett. 100, 167203 (2008)]. We set out to stabilize this metastable perovskite structure by growing NiTiO3 epitaxially on sapphire Al2O3 (001) substrate, and to control the polar and magnetic properties via strain. Epitaxial Ni1-xTi1-yO3 films of different Ni/Ti ratios and thicknesses were deposited on Al2O3 substrates by pulsed laser deposition at different temperatures, and characterized using several techniques. The effect of film thickness, deposition temperature, and film stoichiometry on lattice strain, film structure, and physical properties was investigated. Our structural data from x-ray diffraction, electron microscopy, and x-ray absorption spectroscopy shows that substrate-induced strain has a marked effect on the structure and crystalline quality of the films. Physical property measurements reveal a dependence of the Nel transition and lattice polarization on strain, and highlight our ability to control the ferroic properties in NiTiO3 thin films by film stoichiometry and thickness.

  10. Strain-dependence Of The Structure And Ferroic Properties Of Epitaxial NiTiO3 Thin Films Grown On Different Substrates

    SciTech Connect (OSTI)

    Varga, Tamas; Droubay, Timothy C.; Bowden, Mark E.; Kovarik, Libor; Hu, Dehong; Chambers, Scott A.

    2015-08-14

    Polarization-induced weak ferromagnetism has been predicted a few years back in perovskite MTiO3 (M = Fe, Mn, Ni) [Fennie, Phys. Rev. Lett. 100, 167203 (2008)]. We set out to stabilize this metastable perovskite structure by growing NiTiO3 epitaxially on different substrates, and to investigate the dependence of polar and magnetic properties on strain. Epitaxial NiTiO3 films were deposited on Al2O3, Fe2O3, and LiNbO3 substrates by pulsed laser deposition, and characterized using several techniques. The effect of substrate choice on lattice strain, film structure, and physical properties was investigated. Our structural data from x-ray diffraction and electron microscopy shows that substrate-induced strain has a marked effect on the structure and crystalline quality of the films. Physical property measurements reveal a dependence of the weak ferromagnetism and lattice polarization on strain, and highlight our ability to control the ferroic properties in NiTiO3 thin films by the choice of substrate. Our results are also consistent with the theoretical prediction that the ferromagnetism in acentric NiTiO3 is polarization-induced. From the substrates studied here, the perovskite substrate LiNbO3 proved to be the most promising one for strong multiferroism.

  11. On Properties of Compressional Alfven Eigenmode Instability Driven by Superalfvinic Ions

    SciTech Connect (OSTI)

    N.N. Gorelenkov; C.Z. Cheng

    2002-02-06

    Properties of the instability of Compressional Alfven Eigenmodes (CAE) in tokamak plasmas are studied in the cold plasma approximation with an emphasis on the instability driven by the energetic minority Ion Cyclotron Resonance Heating (ICRH) ions. We apply earlier developed theory [N.N. Gorelenkov and C.Z. Cheng, Nuclear Fusion 35 (1995) 1743] to compare two cases: Ion Cyclotron Emission (ICE) driven by charged fusion products and ICRH Minority driven ICE (MICE) [J. Cottrell, Phys. Rev. Lett. (2000)] recently observed on JET [Joint European Torus]. Particularly in MICE spectrum, only instabilities with even harmonics of deuterium-cyclotron frequency at the low-field-side plasma edge were reported. Odd deuterium-cyclotron frequency harmonics of ICE spectrum between the cyclotron harmonics of protons can be driven only via the Doppler-shifted cyclotron wave-particle resonance of CAEs with fusion products, but are shown to be damped due to the electron Landau damping in experiments on MI CE. Excitation of odd harmonics of MICE with high-field-side heating is predicted. Dependencies of the instability on the electron temperature is studied and is shown to be strong. Low electron temperature is required to excite odd harmonics in MICE.

  12. Measurement of partonic nuclear effects in deep-inelastic neutrino scattering using MINERvA

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

    Mousseau, J.

    2016-04-19

    Here, the MINERvA Collaboration reports a novel study of neutrino-nucleus charged-current deep inelastic scattering (DIS) using the same neutrino beam incident on targets of polystyrene, graphite, iron, and lead. Results are presented as ratios of C, Fe, and Pb to CH. The ratios of total DIS cross sections as a function of neutrino energy and flux-integrated differential cross sections as a function of the Bjorken scaling variable x are presented in the neutrino-energy range of 5–50 GeV. Based on the predictions of charged-lepton scattering ratios, good agreement is found between the data and prediction at medium x and low neutrino energy.more » However, the ratios appear to be below predictions in the vicinity of the nuclear shadowing region, x < 0.1. This apparent deficit, reflected in the DIS cross-section ratio at high Eν, is consistent with previous MINERvA observations [B. Tice (MINERvA Collaboration), Phys. Rev. Lett. 112, 231801 (2014).] and with the predicted onset of nuclear shadowing with the axial-vector current in neutrino scattering.« less

  13. A Thermodynamically-Consistent Non-Ideal Stochastic Hard-Sphere Fluid

    SciTech Connect (OSTI)

    Donev, A; Alder, B J; Garcia, A L

    2009-08-03

    A grid-free variant of the Direct Simulation Monte Carlo (DSMC) method is proposed, named the Isotropic DSMC (I-DSMC) method, that is suitable for simulating collision-dominated dense fluid flows. The I-DSMC algorithm eliminates all grid artifacts from the traditional DSMC algorithm and is Galilean invariant and microscopically isotropic. The stochastic collision rules in I-DSMC are modified to introduce a non-ideal structure factor that gives consistent compressibility, as first proposed in [Phys. Rev. Lett. 101:075902 (2008)]. The resulting Stochastic Hard Sphere Dynamics (SHSD) fluid is empirically shown to be thermodynamically identical to a deterministic Hamiltonian system of penetrable spheres interacting with a linear core pair potential, well-described by the hypernetted chain (HNC) approximation. We develop a kinetic theory for the SHSD fluid to obtain estimates for the transport coefficients that are in excellent agreement with particle simulations over a wide range of densities and collision rates. The fluctuating hydrodynamic behavior of the SHSD fluid is verified by comparing its dynamic structure factor against theory based on the Landau-Lifshitz Navier-Stokes equations. We also study the Brownian motion of a nano-particle suspended in an SHSD fluid and find a long-time power-law tail in its velocity autocorrelation function consistent with hydrodynamic theory and molecular dynamics calculations.

  14. Laser-induced magnetic fields in ICF capsules, Final Report, DE-FG02-08ER85128, Phase 1

    SciTech Connect (OSTI)

    Lindman, Erick L

    2009-11-05

    Laser-induced magnetic fields in ICF capsules Final Report, DE-FG02-08ER85128, Phase 1 E. L. LINDMAN, Otowi Technical Services, Los Alamos, NM. The performance of an inertial-confinement-fusion (ICF) capsule can be improved by inserting a magnetic field into it before compressing it [Kirkpatrick, et al., Fusion Technol. 27, 205 (1995)]. To obtain standoff in an ICF power generator, a method of inserting the field without the use of low-inductance leads attached to the capsule is desired. A mechanism for generating such a field using a laser was discovered in Japan [Sakagami, et al., Phys. Rev. Lett. 42, 839 (1979), Kolodner and Yablonovitch, Phys. Rev. Lett. 43, 1402 (1979)] and studied at Los Alamos in the 1980s [M. A. Yates, et al., Phys. Rev. Lett. 49, 1702 (1982); Forslund and Brackbill, Phys. Rev. Lett. 48, 1614 (1982)]. In this mechanism, a p-polarized laser beam strikes a solid target producing hot electrons that are accelerated away from the target surface by resonant absorption. An electric field is created that returns the hot electrons to the target. But, they do not return to the target along the same trajectory on which they left. The resulting current produces a toroidal magnetic field that was observed to spread over a region outside the hot spot with a radius of a millimeter. No experimental measurements of the magnetic field strength were performed. Estimates from computer simulation suggest that field strengths in the range of 1 to 10 Mega gauss (100 to 1000 Tesla) were obtained outside of the laser spot. To use this mechanism to insert a magnetic field into an ICF capsule, the capsule must be redesigned. In one approach, a central conductor is added, a toroidal gap is cut in the outer wall and the DT fuel is frozen on the inner surface of the capsule. The capsule is dropped into the reaction chamber and struck first with the laser that generates the magnetic field. The laser hot spot is positioned at the center of the toroidal gap. As the

  15. On the stability of the disordered molecular alloy phase of ammonia hemihydrate

    SciTech Connect (OSTI)

    Wilson, C. W.; Bull, C. L.; Stinton, G. W.; Amos, D. M.; Donnelly, M.-E.; Loveday, J. S.

    2015-03-07

    The disordered-molecular-alloy phase (DMA) of ammonia hydrates [J. S. Loveday and R. J. Nelmes, Phys. Rev. Lett. 83, 4329 (1999)] is unique in that it has substitutional disorder of ammonia and water over the molecular sites of a body centred cubic lattice. Whilst this structure has been observed in ammonia di- and mono-hydrate compositions, it has not been conclusively observed in the ammonia hemihydrate system. This work presents investigations of the structural behaviour of ammonia hemihydrate as a function of P and T. The indications of earlier studies [Ma et al. RSC Adv. 2, 4290 (2012)] that the DMA structure could be produced by compression of ammonia hemihydrate above 20 GPa at ambient temperature are confirmed. In addition, the DMA structure was found to form reversibly both from the melt, and on warming of ammonia hemihydrate phase-II, in the pressure range between 4 and 8 GPa. The route used to make the DMA structure from ammonia mono- and di-hydrates—compression at 170 K to 6 GPa followed by warming to ambient temperature—was found not to produce the DMA structure for ammonia hemihydrate. These results provide the first strong evidence that DMA is a thermodynamically stable form. A high-pressure phase diagram for ammonia hemihydrate is proposed which has importance for planetary modelling.

  16. Propagation speed of rotation signals for field lines undergoing magnetic reconnection

    SciTech Connect (OSTI)

    Lapenta, Giovanni; Goldman, Martin; Newman, David; Markidis, Stefano

    2013-10-15

    Reconnection is associated with two bending of the magnetic field lines. Considering the usual plane of a 2D reconnection simulation, the first bending is in-plane and produces the needed topological changes by bringing oppositely directed filed lines in proximity. The second is typical of fast reconnection and is out of plane, leading to the formation of the Hall magnetic field. This second rotation has recently been observed to proceed at superAlfvénic speeds and to carry substantial energy fluxes (Shay et al., Phys. Rev. Lett. 107, 065001 (2011)). We revisit these rotations with a new diagnostics based on dispersing a multitude of virtual probes into a kinetic simulation, akin the approach of multi spacecraft missions. The results of the new diagnostics are compared with the theory of characteristics applied to the two fluid model. The comparison of virtual probes and the method of characteristics confirm the findings relative to the out of plane rotation and uncover the existence of two families of characteristics. Both are observed in the simulation. The early stage of reconnection develops on the slower compressional branch and the later faster phase develops on the faster torsional branch. The superAlfvénic signal is only relevant in the second phase.

  17. Slow dynamics in an azopolymer molecular layer studied by x-ray photon correlation spectroscopy

    SciTech Connect (OSTI)

    Orsi, D.; Fluerasu, A.; Cristofolini, L.; Fontana, M.P.; Pontecorvo, E.; Caronna, C.; Zontone, F.; Madsen, A.

    2010-09-23

    We report the results of x-ray photon correlation spectroscopy (XPCS) experiments on multilayers of a photosensitive azo-polymer which can be softened by photoisomerization. Time correlation functions have been measured at different temperatures and momentum transfers (q) and under different illumination conditions (dark, UV or visible). The correlation functions are well described by the Kohlrausch-Williams-Watts (KWW) form with relaxation times that are proportional to q{sup -1}. The characteristic relaxation times follow the same Vogel-Fulcher-Tammann law describing the bulk viscosity of this polymer. The out-of-equilibrium relaxation dynamics following a UV photoperturbation are accelerated, which is in agreement with a fluidification effect previously measured by rheology. The transient dynamics are characterized by two times correlation function, and dynamical heterogeneity is evidenced by calculating the variance {chi} of the degree of correlation as a function of ageing time. A clear peak in {chi} appears at a well defined time {tau}{sub C} which scales with q{sup -1} and with the ageing time, in a similar fashion as previously reported in colloidal suspensions [O. Dauchot et al. Phys. Rev. Lett. 95 265701 (2005)]. From an accurate analysis of the correlation functions we could demonstrate a temperature and light dependent cross-over from compressed KWW to simple exponential behavior.

  18. Modeling of 10 GeV-1 TeV laser-plasma accelerators using Lorentz booster simulations

    SciTech Connect (OSTI)

    Vay, J.-L.; Geddes, C.G.R.; Esarey, E.; Esarey, E.; Leemans, W.P.; Cormier-Michel, E.; Grote, D.P.

    2011-12-01

    Modeling of laser-plasma wakefield accelerators in an optimal frame of reference [J.-L. Vay, Phys. Rev. Lett. 98 130405 (2007)] allows direct and e#14;fficient full-scale modeling of deeply depleted and beam loaded laser-plasma stages of 10 GeV-1 TeV (parameters not computationally accessible otherwise). This verifies the scaling of plasma accelerators to very high energies and accurately models the laser evolution and the accelerated electron beam transverse dynamics and energy spread. Over 4, 5 and 6 orders of magnitude speedup is achieved for the modeling of 10 GeV, 100 GeV and 1 TeV class stages, respectively. Agreement at the percentage level is demonstrated between simulations using different frames of reference for a 0.1 GeV class stage. Obtaining these speedups and levels of accuracy was permitted by solutions for handling data input (in particular particle and laser beams injection) and output in a relativistically boosted frame of reference, as well as mitigation of a high-frequency instability that otherwise limits effectiveness.

  19. Atomic interactions in precision interferometry using Bose-Einstein condensates

    SciTech Connect (OSTI)

    Jamison, Alan O.; Gupta, Subhadeep; Kutz, J. Nathan

    2011-10-15

    We present theoretical tools for predicting and reducing the effects of atomic interactions in Bose-Einstein condensate (BEC) interferometry experiments. To address mean-field shifts during free propagation, we derive a robust scaling solution that reduces the three-dimensional Gross-Pitaevskii equation to a set of three simple differential equations valid for any interaction strength. To model the other common components of a BEC interferometer--condensate splitting, manipulation, and recombination--we generalize the slowly varying envelope reduction, providing both analytic handles and dramatically improved simulations. Applying these tools to a BEC interferometer to measure the fine structure constant, {alpha}[S. Gupta, K. Dieckmann, Z. Hadzibabic, and D. E. Pritchard, Phys. Rev. Lett. 89, 140401 (2002)], we find agreement with the results of the original experiment and demonstrate that atomic interactions do not preclude measurement to better than part-per-billion accuracy, even for atomic species with relatively large scattering lengths. These tools help make BEC interferometry a viable choice for a broad class of precision measurements.

  20. Solid phase stability of molybdenum under compression: Sound velocity measurements and first-principles calculations

    SciTech Connect (OSTI)

    Zhang, Xiulu; Liu, Zhongli; Jin, Ke; Xi, Feng; Yu, Yuying; Tan, Ye; Dai, Chengda; Cai, Lingcang

    2015-02-07

    The high-pressure solid phase stability of molybdenum (Mo) has been the center of a long-standing controversy on its high-pressure melting. In this work, experimental and theoretical researches have been conducted to check its solid phase stability under compression. First, we performed sound velocity measurements from 38 to 160 GPa using the two-stage light gas gun and explosive loading in backward- and forward-impact geometries, along with the high-precision velocity interferometry. From the sound velocities, we found no solid-solid phase transition in Mo before shock melting, which does not support the previous solid-solid phase transition conclusion inferred from the sharp drops of the longitudinal sound velocity [Hixson et al., Phys. Rev. Lett. 62, 637 (1989)]. Then, we searched its structures globally using the multi-algorithm collaborative crystal structure prediction technique combined with the density functional theory. By comparing the enthalpies of body centered cubic structure with those of the metastable structures, we found that bcc is the most stable structure in the range of 0–300 GPa. The present theoretical results together with previous ones greatly support our experimental conclusions.

  1. First principles molecular dynamics without self-consistent field optimization

    SciTech Connect (OSTI)

    Souvatzis, Petros; Niklasson, Anders M. N.

    2014-01-28

    We present a first principles molecular dynamics approach that is based on time-reversible extended Lagrangian Born-Oppenheimer molecular dynamics [A. M. N. Niklasson, Phys. Rev. Lett. 100, 123004 (2008)] in the limit of vanishing self-consistent field optimization. The optimization-free dynamics keeps the computational cost to a minimum and typically provides molecular trajectories that closely follow the exact Born-Oppenheimer potential energy surface. Only one single diagonalization and Hamiltonian (or Fockian) construction are required in each integration time step. The proposed dynamics is derived for a general free-energy potential surface valid at finite electronic temperatures within hybrid density functional theory. Even in the event of irregular functional behavior that may cause a dynamical instability, the optimization-free limit represents a natural starting guess for force calculations that may require a more elaborate iterative electronic ground state optimization. Our optimization-free dynamics thus represents a flexible theoretical framework for a broad and general class of ab initio molecular dynamics simulations.

  2. Coupled cluster channels in the homogeneous electron gas

    SciTech Connect (OSTI)

    Shepherd, James J. E-mail: jamesjshepherd@gmail.com; Henderson, Thomas M.; Scuseria, Gustavo E.

    2014-03-28

    We discuss diagrammatic modifications to the coupled cluster doubles (CCD) equations, wherein different groups of terms out of rings, ladders, crossed-rings, and mosaics can be removed to form approximations to the coupled cluster method, of interest due to their similarity with various types of random phase approximations. The finite uniform electron gas (UEG) is benchmarked for 14- and 54-electron systems at the complete basis set limit over a wide density range and performance of different flavours of CCD is determined. These results confirm that rings generally overcorrelate and ladders generally undercorrelate; mosaics-only CCD yields a result surprisingly close to CCD. We use a recently developed numerical analysis [J. J. Shepherd and A. Grneis, Phys. Rev. Lett. 110, 226401 (2013)] to study the behaviours of these methods in the thermodynamic limit. We determine that the mosaics, on forming the Brueckner one-body Hamiltonian, open a gap in the effective one-particle eigenvalues at the Fermi energy. Numerical evidence is presented which shows that methods based on this renormalisation have convergent energies in the thermodynamic limit including mosaic-only CCD, which is just a renormalised MP2. All other methods including only a single channel, namely, ladder-only CCD, ring-only CCD, and crossed-ring-only CCD, appear to yield divergent energies; incorporation of mosaic terms prevents this from happening.

  3. Shapiro-like resonance in ultracold molecule production via an oscillating magnetic field

    SciTech Connect (OSTI)

    Liu Bin; Fu Libin; Liu Jie

    2010-01-15

    We study the process of the production of ultracold molecules from ultracold atoms using a sinusoidally oscillating magnetic-field modulation. Our study is based on a two-mode mean-field treatment of the problem. When the magnetic field is resonant roughly with the molecular binding energy, Shapiro-like resonances are observed. Their resonance profiles are well fitted by the Lorentzian functions. The linewidths depend on both the amplitude and the duration of the applied modulations and are found to be dramatically broadened by the thermal dephasing effect. The resonance centers shift due to both the many-body effect and the finite temperature effect. Our theory is consistent with a recent experiment [S. T. Thompson, E. Hodby, and C. E. Wieman, Phys. Rev. Lett. 95, 190404 (2005)]. Our model predicts a 1/3 ceiling for the molecular production yield in uncondensed ultracold atomic clouds for a long coupling time, while for condensed atoms the optimal conversion yield could be beyond the limit.

  4. Fabrication Of Surface Bumps On A Capsule To Simulate Fill Tube...

    Office of Scientific and Technical Information (OSTI)

    The bumps were characterized using interference microscopy and AFM. Authors: Letts, S ; ... FABRICATION; HYDRODYNAMICS; INSTABILITY; MASS DEFECT; MICROSCOPY; PLASMA; POLYMERS

  5. Role of spall in microstructure evolution during laser-shock-driven rapid undercooling and resolidification

    SciTech Connect (OSTI)

    Colvin, Jeffrey D.; Jankowski, Alan F.; Kumar, Mukul; MoberlyChan, Warren J.; Reed, Bryan W.; Paisley, Dennis L.; Tierney, Thomas E.

    2009-01-01

    We previously reported [Colvin et al., J. Appl. Phys. 101, 084906 (2007)] on the microstructure morphology of pure Bi metal subjected to rapid laser-shock-driven melting and subsequent resolidification upon release of pressure, where the estimated effective undercooling rates were of the order of 10{sup 9}-10{sup 10} K/s. More recently, we repeated these experiments, but with a Bi/Zn alloy (Zn atomic fraction of 2%-4%) instead of elemental Bi and with a change in target design to suppress spall in the Bi/Zn samples. We observed a similar microstructure morphology in the two sets of experiments, with initially columnar grains recrystallizing to larger equiaxed grains. The Bi samples, however, exhibited micron-scale dendrites on the spall surfaces, whereas there were no dendritic structures anywhere in the nonspalled Bi/Zn, even down to the nanometer scale as observed by transmission electron microscopy. We present the simulations and the interferometry data that show that the samples in the two sets of experiments followed nearly identical hydrodynamic and thermodynamic paths apart from the presence of (probably partially liquid) spall in pure Bi. Simulations also show that the spall occurs right at the moving phase front and, hence, the spall itself cuts off the principal direction for latent heat dissipation across the phase boundary. We suggest that it is the liquid spall itself that creates the conditions for dendrite formation.

  6. Current constriction of high-current vacuum arc in vacuum interrupters

    SciTech Connect (OSTI)

    Wang Lijun; Jia Shenli; Zhang Ling; Yang Dingge; Shi Zongqian; Gentils, Francois; Jusselin, Benoit

    2008-03-15

    Compared with previous paper [L. Wang et al., J. Appl. Phys. 100, 113304 (2006)], higher-current vacuum arc is simulated and analyzed based on magnetohydrodynamics model, and current constriction phenomenon in arc column is mainly paid attention to and analyzed in this paper. According to simulation results, it can be found that significant current constriction only appears near anode regions for lower-current vacuum arc. However, with the increase of arc current, current constriction also appears near the cathode side, and with the further increase of arc current, current constriction near the cathode side can become more significant than that near the anode side. The current constriction near the cathode side can be mainly caused by very high current level. The increase of axial magnetic field (AMF) strength will inhibit current constriction in the whole arc column. For influence of AMF distribution, saddle-shaped distributed AMF can more efficiently inhibit current constriction of arc column than bell-shaped AMF. The phenomenon of current constriction near the cathode side has also been found by many experiments, which also can verify the correctness of simulation results.

  7. Monoxides of small terbium clusters: A density functional theory investigation

    SciTech Connect (OSTI)

    Zhang, G. L.; Yuan, H. K. Chen, H.; Kuang, A. L.; Li, Y.; Wang, J. Z.; Chen, J.

    2014-12-28

    To investigate the effect of oxygen atom on the geometrical structures, electronic, and magnetic properties of small terbium clusters, we carried out the first-principles calculations on Tb{sub n}O (n = 1-14) clusters. The capping of an oxygen atom on one trigonal-facet of Tb{sub n} structures is always favored energetically, which can significantly improve the structural stability. The far-infrared vibrational spectroscopies are found to be different from those of corresponding bare clusters, providing a distinct signal to detect the characteristic structures of Tb{sub n}O clusters. The primary effect of oxygen atom on magnetic properties is to change the magnetic orderings among Tb atoms and to reduce small of local magnetic moments of the O-coordinated Tb atoms, both of which serve as the key reasons for the experimental magnetic evolution of an oscillating behavior. These calculations are consistent with, and help to account for, the experimentally observed magnetic properties of monoxide Tb{sub n}O clusters [C. N. Van Dijk et al., J. Appl. Phys. 107, 09B526 (2010)].

  8. An efficient method for unfolding kinetic pressure driven VISAR data

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

    Mark Harry Hess; Peterson, Kyle; Harvey-Thompson, Adam James

    2015-08-18

    Velocity Interferometer System for Any Reflector (VISAR) [Barker and Hollenbach, J. Appl. Phys. 43, 4669 (1972)] is a well-known diagnostic that is employed on many shock physics and pulsed-power experiments. With the VISAR diagnostic, the velocity on the surface of any metal flyer can be found. For most experiments employing VISAR, either a kinetic pressure [Grady, Mech. Mater. 29, 181 (1998)] or a magnetic pressure [Lemke et al., Intl J. Impact Eng. 38, 480 (2011)] drives the motion of the flyer. Moreover, reliable prediction of the time-dependent pressure is often a critical component to understanding the physics of these experiments.more » Although VISAR can provide a precise measurement of a flyer’s surface velocity, the real challenge of this diagnostic implementation is using this velocity to unfold the time-dependent pressure. The purpose of this study is to elucidate a new method for quickly and reliably unfolding VISAR data.« less

  9. Reinvestigation of high pressure polymorphism in hafnium metal

    SciTech Connect (OSTI)

    Pandey, K. K. Sharma, Surinder M.; Gyanchandani, Jyoti; Dey, G. K.; Somayazulu, M.; Sikka, S. K.

    2014-06-21

    There has been a recent controversy about the high pressure polymorphism of Hafnium (Hf). Unlike, the earlier known ??? structural transition at 38??8?GPa, at ambient temperature, Hrubiak et al. [J. Appl. Phys. 111, 112612 (2012)] did not observe it till 51?GPa. They observed this transition only at elevated temperatures. We have reinvestigated the room temperature phase diagram of Hf, employing x-ray diffraction (XRD) and DFT based first principles calculations. Experimental investigations have been carried out on several pure and impure Hf samples and also with different pressure transmitting media. Besides demonstrating the significant role of impurity levels on the high pressure phase diagram of Hf, our studies re-establish room temperature ??? transition at high pressures, even in quasi-hydrostatic environment. We observed this transition in pure Hf with equilibrium transition pressure P{sub o}?=?44.5?GPa; however, with large hysteresis. The structural sequence, transition pressures, the lattice parameters, the c/a ratio and its variation with compression for the ? and ? phases as predicted by our ab-initio scalar relativistic (SR) calculations are found to be in good agreement with our experimental results of pure Hf.

  10. Micromagnetic simulations of spin-wave normal modes and the spin-transfer-torque driven magnetization dynamics of a ferromagnetic cross

    SciTech Connect (OSTI)

    Pramanik, Tanmoy Roy, Urmimala; Register, Leonard F.; Banerjee, Sanjay K.; Tsoi, Maxim

    2014-05-07

    We studied spin-transfer-torque (STT) switching of a cross-shaped magnetic tunnel junction in a recent report [Roy et al., J. Appl. Phys. 113, 223904 (2013)]. In that structure, the free layer is designed to have four stable energy states using the shape anisotropy of a cross. STT switching showed different regions with increasing current density. Here, we employ the micromagnetic spectral mapping technique in an attempt to understand how the asymmetry of cross dimensions and spin polarization direction of the injected current affect the magnetization dynamics. We compute spatially averaged frequency-domain spectrum of the time-domain magnetization dynamics in the presence of the current-induced STT term. At low currents, the asymmetry of polarization direction and that of the arms are observed to cause a splitting of the excited frequency modes. Higher harmonics are also observed, presumably due to spin-wave wells caused by the regions of spatially non-uniform effective magnetic field. The results could be used towards designing a multi-bit-per-cell STT-based random access memory with an improved storage density.

  11. Shock-induced irreversible transition from {alpha}-quartz to CaCl{sub 2}-like silica

    SciTech Connect (OSTI)

    Berterretche, P.; Resseguier, T. de; Hallouin, M.; Petitet, J. P.

    2004-10-15

    Previous analyses of quartz samples recovered after being submitted to laser shocks of very short duration (nanosecond order) have shown the presence of CaCl{sub 2}-like silica [T. de Resseguier, P. Berterretche, M. Hallouin, and J. P. Petitet, J. Appl. Phys. 94, 2123 (2003)]. To date, this transition has never been observed under shocks of longer duration (microsecond order) generated by explosives or plate impacts. While this phase is produced from stishovite under static compression at very high pressure (above 50 GPa) and disappears on pressure release, it is observed after low pressure laser shocks (below 5 GPa) and it is quenched to ambient conditions. The origins of these differences are still unclear. This paper presents complementary laser shock experiments involving setups to provide additional information on the influence of various shock parameters. The results suggest a direct transition from {alpha}-quartz to CaCl{sub 2}-type silica following a diffusionless mechanism involving high shear strains. They also show the presence of vitreous silica characterized by an 'organized' ringlike structure, and we propose that this amorphous phase is an intermediate structure between the quartz lattice and grains of the high-pressure phase.

  12. RECOVERY ACT: MULTIMODAL IMAGING FOR SOLAR CELL MICROCRACK DETECTION

    SciTech Connect (OSTI)

    Janice Hudgings; Lawrence Domash

    2012-02-08

    Undetected microcracks in solar cells are a principal cause of failure in service due to subsequent weather exposure, mechanical flexing or diurnal temperature cycles. Existing methods have not been able to detect cracks early enough in the production cycle to prevent inadvertent shipment to customers. This program, sponsored under the DOE Photovoltaic Supply Chain and Cross-Cutting Technologies program, studied the feasibility of quantifying surface micro-discontinuities by use of a novel technique, thermoreflectance imaging, to detect surface temperature gradients with very high spatial resolution, in combination with a suite of conventional imaging methods such as electroluminescence. The project carried out laboratory tests together with computational image analyses using sample solar cells with known defects supplied by industry sources or DOE National Labs. Quantitative comparisons between the effectiveness of the new technique and conventional methods were determined in terms of the smallest detectable crack. Also the robustness of the new technique for reliable microcrack detection was determined at various stages of processing such as before and after antireflectance treatments. An overall assessment is that the new technique compares favorably with existing methods such as lock-in thermography or ultrasonics. The project was 100% completed in Sept, 2010. A detailed report of key findings from this program was published as: Q.Zhou, X.Hu, K.Al-Hemyari, K.McCarthy, L.Domash and J.Hudgings, High spatial resolution characterization of silicon solar cells using thermoreflectance imaging, J. Appl. Phys, 110, 053108 (2011).

  13. Spectral monodromy of non-self-adjoint operators

    SciTech Connect (OSTI)

    Phan, Quang Sang

    2014-01-15

    In the present paper, we build a combinatorial invariant, called the “spectral monodromy” from the spectrum of a single (non-self-adjoint) h-pseudodifferential operator with two degrees of freedom in the semi-classical limit. Our inspiration comes from the quantum monodromy defined for the joint spectrum of an integrable system of n commuting self-adjoint h-pseudodifferential operators, given by S. Vu Ngoc [“Quantum monodromy in integrable systems,” Commun. Math. Phys. 203(2), 465–479 (1999)]. The first simple case that we treat in this work is a normal operator. In this case, the discrete spectrum can be identified with the joint spectrum of an integrable quantum system. The second more complex case we propose is a small perturbation of a self-adjoint operator with a classical integrability property. We show that the discrete spectrum (in a small band around the real axis) also has a combinatorial monodromy. The main difficulty in this case is that we do not know the description of the spectrum everywhere, but only in a Cantor type set. In addition, we also show that the corresponding monodromy can be identified with the classical monodromy, defined by J. Duistermaat [“On global action-angle coordinates,” Commun. Pure Appl. Math. 33(6), 687–706 (1980)].

  14. Characterization of electrically-active defects in ultraviolet light-emitting diodes with laser-based failure analysis techniques

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

    Miller, Mary A.; Tangyunyong, Paiboon; Edward I. Cole, Jr.

    2016-01-12

    In this study, laser-based failure analysis techniques demonstrate the ability to quickly and non-intrusively screen deep ultraviolet light-emitting diodes(LEDs) for electrically-active defects. In particular, two laser-based techniques, light-induced voltage alteration and thermally-induced voltage alteration, generate applied voltage maps (AVMs) that provide information on electrically-active defect behavior including turn-on bias, density, and spatial location. Here, multiple commercial LEDs were examined and found to have dark defect signals in the AVM indicating a site of reduced resistance or leakage through the diode. The existence of the dark defect signals in the AVM correlates strongly with an increased forward-bias leakage current. This increasedmore » leakage is not present in devices without AVM signals. Transmission electron microscopyanalysis of a dark defect signal site revealed a dislocation cluster through the pn junction. The cluster included an open core dislocation. Even though LEDs with few dark AVM defect signals did not correlate strongly with power loss, direct association between increased open core dislocation densities and reduced LED device performance has been presented elsewhere [M. W. Moseley et al., J. Appl. Phys. 117, 095301 (2015)].« less

  15. Nonstationary stochastic charge fluctuations of a dust particle in plasmas

    SciTech Connect (OSTI)

    Shotorban, B.

    2011-06-15

    Stochastic charge fluctuations of a dust particle that are due to discreteness of electrons and ions in plasmas can be described by a one-step process master equation [T. Matsoukas and M. Russell, J. Appl. Phys. 77, 4285 (1995)] with no exact solution. In the present work, using the system size expansion method of Van Kampen along with the linear noise approximation, a Fokker-Planck equation with an exact Gaussian solution is developed by expanding the master equation. The Gaussian solution has time-dependent mean and variance governed by two ordinary differential equations modeling the nonstationary process of dust particle charging. The model is tested via the comparison of its results to the results obtained by solving the master equation numerically. The electron and ion currents are calculated through the orbital motion limited theory. At various times of the nonstationary process of charging, the model results are in a very good agreement with the master equation results. The deviation is more significant when the standard deviation of the charge is comparable to the mean charge in magnitude.

  16. Propagation of gamma rays and production of free electrons in air

    SciTech Connect (OSTI)

    Dimant, Y. S.; Nusinovich, G. S.; Romero-Talamas, C. A.; Granatstein, V. L.; Sprangle, P.; Penano, J.

    2012-10-15

    This paper is devoted to the analysis of production of free electrons in air by gamma-rays leaking from radioactive materials. A model based on the Klein-Nishina scattering theory is used to calculate scattering cross sections and approximate the electron production rate. The model includes the effects of primary gamma-quanta radiated by the source as well as that scattered in air. Comparison of the model with the mcnpx kinetic code (http://mcnpx.lanl.gov/) in a sample problem shows excellent agreement. The motivation for this research comes from the recently proposed concept of remote detection of concealed radioactive materials [V. L. Granatstein and G. S. Nusinovich, J. Appl. Phys. 108, 063304 (2010)]. The concept is based on the breakdown in air at the focal point of a high-power beam of electromagnetic waves produced by a THz gyrotron with a 10-20 {mu}s pulse. The presence of a radioactive material can greatly exceed the production rate of free electrons over the natural background rate. Additional electrons act as seeds to initiate the breakdown and create sufficiently dense plasma at the focal region. The dense plasma can then be remotely detected as an unambiguous effect of the concealed radioactive material.

  17. Band alignment in visible-light photo-active CoO/SrTiO{sub 3} (001) heterostructures

    SciTech Connect (OSTI)

    Seo, Hosung; Demkov, Alexander A.

    2014-12-28

    Epitaxial oxide heterostructures are of fundamental interest in a number of problems ranging from oxide electronics to model catalysts. The epitaxial CoO/SrTiO{sub 3} (001) heterostructure on Si(001) has been recently studied as a model oxide catalyst for water splitting under visible light irradiation (Ngo et al., J. Appl. Phys. 114, 084901 (2013)). We use density functional theory to investigate the valence band offset at the CoO/SrTiO{sub 3} (001) interface. We examine the mechanism of charge transfer and dielectric screening at the interface and demonstrate that charge transfer is mediated by the metal-induced gap states in SrTiO{sub 3}, while the dielectric screening at the interface is largely governed by the ionic polarization of under-coordinated oxygen. Based on this finding, we argue that strain relaxation in CoO plays a critical role in determining the band offset. We find that the offsets of 1.36–1.10 eV, calculated in the Schottky-limit are in excellent agreement with the experimental value of 1.20 eV. In addition, we investigate the effect of the Hubbard correction, applied on the Co 3d states, on the dipole layer and potential shift at the interface.

  18. Unbound Particles in Dark Matter Halos (Journal Article) | SciTech...

    Office of Scientific and Technical Information (OSTI)

    Authors: Behroozi, Peter S. ; KIPAC, Menlo Park Stanford U., Phys. Dept. SLAC ; Loeb, Abraham ; Harvard U. ; Wechsler, Risa H. ; KIPAC, Menlo Park Stanford U., Phys. Dept. ...

  19. 2008 Publications | Stanford Synchrotron Radiation Lightsource

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

    ... Iron Centers in Model Systems: Theoretical and Experimental Trends", Phys. ... Core-Shell Nanoparticle Electrocatalysts for Use in PEM Fuel Cell Cathodes", J. Phys. Chem. ...

  20. Energy Conservation Standards for Battery Chargers and External Power Supplies; Proposed Rule Making- Ex Parte Communication

    Broader source: Energy.gov [DOE]

    Apple Inc. met with DOE to discuss the notice of proposed rule making the Department sent out regarding battery chargers and external power supplies.  Below is a list of topics that Apple discussed...

  1. From: Nicholas Ammann [mailto:nammann@me.com

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

    EERE-2014-BT-TP-0043 RIN 1904-AD36 On 12192014, Apple Inc. met with DOE to discuss the ... point and data collection Nicholas Ammann Apple Federal Government Affairs (o) ...

  2. Strong-field and attosecond physics in solids

    SciTech Connect (OSTI)

    Ghimire, Shambhu; Ndabashimiye, Georges; DiChiara, Anthony D.; Sistrunk, Emily; Stockman, Mark I.; Agostini, Pierre; DiMauro, Louis F.; Reis, David A.

    2014-10-08

    We review the status of strong-field and attosecond processes in bulk transparent solids near the Keldysh tunneling limit. For high enough fields and low-frequency excitations, the optical and electronic properties of dielectrics can be transiently and reversibly modified within the applied pulse. In Ghimire et al (2011 Phys. Rev. Lett. 107 167407) non-parabolic band effects were seen in photon-assisted tunneling experiments in ZnO crystals in a strong mid-infrared field. Using the same ZnO crystals, Ghimire et al (2011 Nat. Phys. 7 138–41) reported the first observation of non-pertubative high harmonics, extending well above the bandgap into the vacuum ultraviolet. Recent experiments by Schubert et al (2014 Nat. Photonics 8 119–23) showed a carrier envelope phase dependence in the harmonic spectrum in strong-field 30 THz driven GaSe crystals which is the most direct evidence yet of the role of sub-cycle electron dynamics in solid-state harmonic generation. The harmonic generation mechanism is different from the gas phase owing to the high density and periodicity of the crystal. For example, this results in a linear dependence of the high-energy cutoff with the applied field in contrast to the quadratic dependence in the gas phase. Sub-100 attosecond pulses could become possible if the harmonic spectrum can be extended into the extreme ultraviolet (XUV). Here we report harmonics generated in bulk MgO crystals, extending to $\\sim 26$ eV when driven by ~35 fs, 800 nm pulses focused to a ~1 VÅ$^{-1}$ peak field. The fundamental strong-field and attosecond response also leads to Wannier–Stark localization and reversible semimetallization as seen in the sub-optical cycle behavior of XUV absorption and photocurrent experiments on fused silica by Schiffrin et al (2013 Nature 493 70–4) and Schultze et al (2013 Nature 493 75–8). These studies are advancing our understanding of fundamental strong-field and attosecond physics in solids with potential applications

  3. Transferability and accuracy by combining dispersionless density functional and incremental post-Hartree-Fock theories: Noble gases adsorption on coronene/graphene/graphite surfaces

    SciTech Connect (OSTI)

    Lara-Castells, María Pilar de Bartolomei, Massimiliano; Mitrushchenkov, Alexander O.; Stoll, Hermann

    2015-11-21

    The accuracy and transferability of the electronic structure approach combining dispersionless density functional theory (DFT) [K. Pernal et al., Phys. Rev. Lett. 103, 263201 (2009)] with the method of increments [H. Stoll, J. Chem. Phys. 97, 8449 (1992)], are validated for the interaction between the noble-gas Ne, Ar, Kr, and Xe atoms and coronene/graphene/graphite surfaces. This approach uses the method of increments for surface cluster models to extract intermonomer dispersion-like (2- and 3-body) correlation terms at coupled cluster singles and doubles and perturbative triples level, while periodic dispersionless density functionals calculations are performed to estimate the sum of Hartree-Fock and intramonomer correlation contributions. Dispersion energy contributions are also obtained using DFT-based symmetry-adapted perturbation theory [SAPT(DFT)]. An analysis of the structure of the X/surface (X = Ne, Ar, Kr, and Xe) interaction energies shows the excellent transferability properties of the leading intermonomer correlation contributions across the sequence of noble-gas atoms, which are also discussed using the Drude oscillator model. We further compare these results with van der Waals-(vdW)-corrected DFT-based approaches. As a test of accuracy, the energies of the low-lying nuclear bound states supported by the laterally averaged X/graphite potentials (X = {sup 3}He, {sup 4}He, Ne, Ar, Kr, and Xe) are calculated and compared with the best estimations from experimental measurements and an atom-bond potential model using the ab initio-assisted fine-tuning of semiempirical parameters. The bound-state energies determined differ by less than 6–7 meV (6%) from the atom-bond potential model. The crucial importance of including incremental 3-body dispersion-type terms is clearly demonstrated, showing that the SAPT(DFT) approach effectively account for these terms. With the deviations from the best experimental-based estimations smaller than 2.3 meV (1.9%), the

  4. Strong-field and attosecond physics in solids

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

    Ghimire, Shambhu; Ndabashimiye, Georges; DiChiara, Anthony D.; Sistrunk, Emily; Stockman, Mark I.; Agostini, Pierre; DiMauro, Louis F.; Reis, David A.

    2014-10-08

    We review the status of strong-field and attosecond processes in bulk transparent solids near the Keldysh tunneling limit. For high enough fields and low-frequency excitations, the optical and electronic properties of dielectrics can be transiently and reversibly modified within the applied pulse. In Ghimire et al (2011 Phys. Rev. Lett. 107 167407) non-parabolic band effects were seen in photon-assisted tunneling experiments in ZnO crystals in a strong mid-infrared field. Using the same ZnO crystals, Ghimire et al (2011 Nat. Phys. 7 138–41) reported the first observation of non-pertubative high harmonics, extending well above the bandgap into the vacuum ultraviolet. Recent experiments by Schubert et al (2014 Nat. Photonics 8 119–23) showed a carrier envelope phase dependence in the harmonic spectrum in strong-field 30 THz driven GaSe crystals which is the most direct evidence yet of the role of sub-cycle electron dynamics in solid-state harmonic generation. The harmonic generation mechanism is different from the gas phase owing to the high density and periodicity of the crystal. For example, this results in a linear dependence of the high-energy cutoff with the applied field in contrast to the quadratic dependence in the gas phase. Sub-100 attosecond pulses could become possible if the harmonic spectrum can be extended into the extreme ultraviolet (XUV). Here we report harmonics generated in bulk MgO crystals, extending tomore » $$\\sim 26$$ eV when driven by ~35 fs, 800 nm pulses focused to a ~1 VÅ$$^{-1}$$ peak field. The fundamental strong-field and attosecond response also leads to Wannier–Stark localization and reversible semimetallization as seen in the sub-optical cycle behavior of XUV absorption and photocurrent experiments on fused silica by Schiffrin et al (2013 Nature 493 70–4) and Schultze et al (2013 Nature 493 75–8). These studies are advancing our understanding of fundamental strong-field and attosecond physics in solids with potential

  5. Understanding the dynamics and energetics of magnetic reconnection in a laboratory plasma: Review of recent progress on selected fronts

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

    Yamada, Masaaki; Yoo, Jongsoo; Myers, Clayton E.

    2016-05-11

    Here, magnetic reconnection is a fundamental process at work in laboratory, space, and astrophysical plasmas, in which magnetic field lines change their topology and convert magnetic energy to plasma particles by acceleration and heating. One of the most important problems in reconnection research has been to understand why reconnection occurs so much faster than predicted by magnetohydrodynamics theory. Following the recent pedagogical review of this subject [Yamada et al., Rev. Mod. Phys. 82, 603 (2010)], this paper presents a review of more recent discoveries and findings in the research of fast magnetic reconnection in laboratory, space, and astrophysical plasmas. Inmore » spite of the huge difference in physical scales, we find remarkable commonality between the characteristics of the magnetic reconnection in laboratory and space plasmas. In this paper, we will focus especially on the energy flow, a key feature of the reconnection process. In particular, the experimental results on the energy conversion and partitioning in a laboratory reconnection layer [Yamada et al., Nat. Commun. 5, 4474 (2014)] are discussed and compared with quantitative estimates based on two-fluid analysis. In the Magnetic ReconnectionExperiment, we find that energy deposition to electrons is localized near the X-point and is mostly from the electric field component perpendicular to the magnetic field. The mechanisms of ion acceleration and heating are also identified, and a systematic and quantitative study on the inventory of converted energy within a reconnection layer with a well-defined but variable boundary. The measured energy partition in a reconnection region of similar effective size (L ≈ 3 ion skin depths) of the Earth's magneto-tail [Eastwood et al., Phys. Rev. Lett. 110, 225001 (2013)] is notably consistent with our laboratory results. Finally, to study the global aspects of magnetic reconnection, we have carried out a laboratory experiment on the stability criteria for

  6. Demonstration of thermonuclear conditions in magnetized liner inertial fusion experiments

    SciTech Connect (OSTI)

    Gomez, Matthew R.; Slutz, Stephen A.; Sefkow, Adam B.; Hahn, Kelly D.; Hansen, Stephanie B.; Knapp, Patrick F.; Schmit, Paul F.; Ruiz, Carlos L.; Sinars, Daniel Brian; Harding, Eric C.; Jennings, Christopher A.; Awe, Thomas James; Geissel, Matthias; Rovang, Dean C.; Smith, Ian C.; Chandler, Gordon A.; Cooper, Gary Wayne; Cuneo, Michael Edward; Harvey-Thompson, Adam James; Herrmann, Mark C.; Mark Harry Hess; Lamppa, Derek C.; Martin, Matthew R.; McBride, Ryan D.; Peterson, Kyle J.; Porter, John L.; Rochau, Gregory A.; Savage, Mark E.; Schroen, Diana G.; Stygar, William A.; Vesey, Roger Alan

    2015-04-29

    In this study, the magnetized liner inertial fusion concept [S. A. Slutz et al., Phys. Plasmas17, 056303 (2010)] utilizes a magnetic field and laser heating to relax the pressure requirements of inertial confinement fusion. The first experiments to test the concept [M. R. Gomez et al., Phys. Rev. Lett. 113, 155003 (2014)] were conducted utilizing the 19 MA, 100 ns Z machine, the 2.5 kJ, 1 TW Z Beamlet laser, and the 10 T Applied B-field on Z system. Despite an estimated implosion velocity of only 70 km/s in these experiments, electron and ion temperatures at stagnation were as high as 3 keV, and thermonuclear deuterium-deuterium neutron yields up to 2 × 1012 have been produced. X-ray emission from the fuel at stagnation had widths ranging from 50 to 110 μm over a roughly 80% of the axial extent of the target (6–8 mm) and lasted approximately 2 ns. X-ray yields from these experiments are consistent with a stagnation density of the hot fuel equal to 0.2–0.4 g/cm3. In these experiments, up to 5 ×1010 secondary deuterium-tritium neutrons were produced. Given that the areal density of the plasma was approximately 1–2 mg/cm2, this indicates the stagnation plasma was significantly magnetized, which is consistent with the anisotropy observed in the deuterium-tritium neutron spectra. Control experiments where the laser and/or magnetic field were not utilized failed to produce stagnation temperatures greater than 1 keV and primary deuterium-deuterium yields greater than 1010. An additional control experiment where the fuel contained a sufficient dopant fraction to substantially increase radiative losses also failed to produce a relevant stagnation temperature. The results of these experiments are consistent with a thermonuclear neutron source.

  7. Demonstration of thermonuclear conditions in magnetized liner inertial fusion experiments

    SciTech Connect (OSTI)

    Gomez, M. R.; Slutz, S. A.; Sefkow, A. B.; Hahn, K. D.; Hansen, S. B.; Knapp, P. F.; Schmit, P. F.; Ruiz, C. L.; Sinars, D. B.; Harding, E. C.; Jennings, C. A.; Awe, T. J.; Geissel, M.; Rovang, D. C.; Smith, I. C.; Chandler, G. A.; Cooper, G. W.; Cuneo, M. E.; Harvey-Thompson, A. J.; Hess, M. H.; and others

    2015-05-15

    The magnetized liner inertial fusion concept [S. A. Slutz et al., Phys. Plasmas 17, 056303 (2010)] utilizes a magnetic field and laser heating to relax the pressure requirements of inertial confinement fusion. The first experiments to test the concept [M. R. Gomez et al., Phys. Rev. Lett. 113, 155003 (2014)] were conducted utilizing the 19 MA, 100 ns Z machine, the 2.5 kJ, 1 TW Z Beamlet laser, and the 10 T Applied B-field on Z system. Despite an estimated implosion velocity of only 70 km/s in these experiments, electron and ion temperatures at stagnation were as high as 3 keV, and thermonuclear deuterium-deuterium neutron yields up to 2 × 10{sup 12} have been produced. X-ray emission from the fuel at stagnation had widths ranging from 50 to 110 μm over a roughly 80% of the axial extent of the target (6–8 mm) and lasted approximately 2 ns. X-ray yields from these experiments are consistent with a stagnation density of the hot fuel equal to 0.2–0.4 g/cm{sup 3}. In these experiments, up to 5 × 10{sup 10} secondary deuterium-tritium neutrons were produced. Given that the areal density of the plasma was approximately 1–2 mg/cm{sup 2}, this indicates the stagnation plasma was significantly magnetized, which is consistent with the anisotropy observed in the deuterium-tritium neutron spectra. Control experiments where the laser and/or magnetic field were not utilized failed to produce stagnation temperatures greater than 1 keV and primary deuterium-deuterium yields greater than 10{sup 10}. An additional control experiment where the fuel contained a sufficient dopant fraction to substantially increase radiative losses also failed to produce a relevant stagnation temperature. The results of these experiments are consistent with a thermonuclear neutron source.

  8. Formation of superheavy elements in cold fusion reactions

    SciTech Connect (OSTI)

    Smolanczuk, Robert

    2001-04-01

    We calculate the formation cross sections of transactinides (superheavy elements), as well as heavy actinides (No and Lr), which have been or might be obtained in fusion reactions with the evaporation of only one neutron. We use both more realistic fusion barrier and survival probability of the compound nucleus in comparison with the original phenomenological model [Phys. Rev. C 59, 2634 (1999)] that prompted the Berkeley experiment on the synthesis of a new superheavy element 118 [Phys. Rev. Lett. 83, 1104 (1999)]. Calculations are performed for asymmetric and symmetric target-projectile combinations and for reactions with stable and radioactive-ion beams. The formation cross sections measured at GSI-Darmstadt for transactinides and heavy actinides, as well as that for superheavy element 118 reported by the LBNL-Berkeley group, are reproduced within a factor of 2.4, on average. Based on the obtained relatively large cross sections, we predict that optimal reactions with stable beams for the synthesis of so far unobserved superheavy elements 119, 120, and 121 are {sup 209}Bi({sup 86}Kr, 1n){sup 294}119, {sup 208}Pb({sup 88}Sr, 1n){sup 295}120, and {sup 209}Bi({sup 88}Sr, 1n){sup 296}121, respectively. This is because of the magic of both the target and the projectile that leads to larger Q value and, consequently, lower effective fusion barrier with larger transmission probability. The same effect is responsible for relatively large cross sections predicted for the symmetric reactions {sup 136}Xe({sup 124}Sn, 1n){sup 259}Rf, {sup 136}Xe({sup 136}Xe, 1n){sup 271}Hs,{sup 138}Ba({sup 136}Xe, 1n){sup 273}110, and {sup 140}Ce({sup 136}Xe, 1n){sup 275}112. Although shell effects in the magic nuclei {sup 124}Sn, {sup 136}Xe, {sup 138}Ba, and {sup 140}Ce are not as strong as in {sup 208}Pb and {sup 209}Bi, they act on both the target and the projectile and lead to the prediction of measurable cross sections.

  9. Assessment of ion kinetic effects in shock-driven inertial confinement fusion (ICF) implosions using fusion burn imaging

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

    Rosenberg, M. J.; Séguin, F. H.; Amendt, P. A.; Atzeni, S.; Rinderknecht, H. G.; Hoffman, N. M.; Zylstra, A. B.; Li, C. K.; Sio, H.; Gatu Johnson, M.; et al

    2015-06-02

    The significance and nature of ion kinetic effects in D³He-filled, shock-driven inertial confinement fusion implosions are assessed through measurements of fusion burn profiles. Over this series of experiments, the ratio of ion-ion mean free path to minimum shell radius (the Knudsen number, NK) was varied from 0.3 to 9 in order to probe hydrodynamic-like to strongly kinetic plasma conditions; as the Knudsen number increased, hydrodynamic models increasingly failed to match measured yields, while an empirically-tuned, first-step model of ion kinetic effects better captured the observed yield trends [Rosenberg et al., Phys. Rev. Lett. 112, 185001 (2014)]. Here, spatially resolved measurementsmore » of the fusion burn are used to examine kinetic ion transport effects in greater detail, adding an additional dimension of understanding that goes beyond zero-dimensional integrated quantities to one-dimensional profiles. In agreement with the previous findings, a comparison of measured and simulated burn profiles shows that models including ion transport effects are able to better match the experimental results. In implosions characterized by large Knudsen numbers (NK ~ 3), the fusion burn profiles predicted by hydrodynamics simulations that exclude ion mean free path effects are peaked far from the origin, in stark disagreement with the experimentally observed profiles, which are centrally peaked. In contrast, a hydrodynamics simulation that includes a model of ion diffusion is able to qualitatively match the measured profile shapes. Therefore, ion diffusion or diffusion-like processes are identified as a plausible explanation of the observed trends, though further refinement of the models is needed for a more complete and quantitative understanding of ion kinetic effects.« less

  10. Radiation sources with planar wire arrays and planar foils for inertial confinement fusion and high energy density physics research

    SciTech Connect (OSTI)

    Kantsyrev, V. L.; Safronova, A. S.; Esaulov, A. A.; Shrestha, I.; Astanovitsky, A.; Osborne, G. C.; Shlyaptseva, V. V.; Weller, M. E.; Keim, S.; Stafford, A.; Cooper, M.; Chuvatin, A. S.; Rudakov, L. I.; Velikovich, A. L.

    2014-03-15

    This article reports on the joint success of two independent lines of research, each of them being a multi-year international effort. One of these is the development of innovative sources, such as planar wire arrays (PWAs). PWAs turned out to be a prolific radiator, which act mainly as a resistor, even though the physical mechanism of efficient magnetic energy conversion into radiation still remains unclear. We review the results of our extensive studies of PWAs. We also report the new results of the experimental comparison PWAs with planar foil liners (another promising alternative to wire array loads at multi-mega-ampere generators). Pioneered at UNR, the PWA Z-pinch loads have later been tested at the Sandia National Laboratories (SNL) on the Saturn generator, on GIT-12 machine in Russia, and on the QiangGuang-1 generator in China, always successfully. Another of these is the drastic improvement in energy efficiency of pulsed-power systems, which started in early 1980s with Zucker's experiments at Naval Research Laboratory (NRL). Successful continuation of this approach was the Load Current Multiplier (LCM) proposed by Chuvatin in collaboration with Rudakov and Weber from NRL. The 100?ns LCM was integrated into the Zebra generator, which almost doubled the plasma load current, from 0.9 to 1.7 MA. The two above-mentioned innovative approaches were used in combination to produce a new compact hohlraum radiation source for ICF, as jointly proposed by SNL and UNR [Jones et al., Phys. Rev. Lett. 104, 125001 (2010)]. The first successful proof-of-the-principle experimental implementation of new hohlraum concept at university-scale generator Zebra/LCM is demonstrated. A numerical simulation capability with VisRaD code (from PRISM Co.) established at UNR allowed for the study of hohlraum coupling physics and provides the possibility of optimization of a new hohlraum. Future studies are discussed.

  11. Coupled-oscillator theory of dispersion and Casimir-Polder interactions

    SciTech Connect (OSTI)

    Berman, P. R.; Ford, G. W.; Milonni, P. W.

    2014-10-28

    We address the question of the applicability of the argument theorem (of complex variable theory) to the calculation of two distinct energies: (i) the first-order dispersion interaction energy of two separated oscillators, when one of the oscillators is excited initially and (ii) the Casimir-Polder interaction of a ground-state quantum oscillator near a perfectly conducting plane. We show that the argument theorem can be used to obtain the generally accepted equation for the first-order dispersion interaction energy, which is oscillatory and varies as the inverse power of the separation r of the oscillators for separations much greater than an optical wavelength. However, for such separations, the interaction energy cannot be transformed into an integral over the positive imaginary axis. If the argument theorem is used incorrectly to relate the interaction energy to an integral over the positive imaginary axis, the interaction energy is non-oscillatory and varies as r{sup ?4}, a result found by several authors. Rather remarkably, this incorrect expression for the dispersion energy actually corresponds to the nonperturbative Casimir-Polder energy for a ground-state quantum oscillator near a perfectly conducting wall, as we show using the so-called remarkable formula for the free energy of an oscillator coupled to a heat bath [G. W. Ford, J. T. Lewis, and R. F. OConnell, Phys. Rev. Lett. 55, 2273 (1985)]. A derivation of that formula from basic results of statistical mechanics and the independent oscillator model of a heat bath is presented.

  12. Heavy fermion Ce{sub 3}Co{sub 4}Sn{sub 13} compound under pressure

    SciTech Connect (OSTI)

    Collave, J. R.; Borges, H. A.; Ramos, S. M.; Hering, E. N.; Mendona-Ferreira, L.; Pagliuso, P. G.

    2015-05-07

    The non-magnetic heavy fermion compound Ce{sub 3}Co{sub 4}Sn{sub 13} was studied under pressure. We report single crystalline measurements of electrical resistivity as a function of temperature ?(T) under pressure. Some characteristic features related to a structural transition (T{sub S}), crystalline field effects (T{sub CEF}), and a low temperature maximum (T{sub max}), possibly connected simultaneously to the onset of Kondo lattice coherence and short range magnetic correlations, were identified in the ?(T) data. A pressure-temperature phase diagram with T{sub S} and T{sub max} was constructed by mapping these features. Like for most Ce-based heavy fermion compounds, T{sub max} moves to higher temperatures with pressure, indicating that it is related to the Kondo energy scale, due to the increase of hybridization induced by pressure. On the other hand, T{sub S}, associated to a superlattice distortion and probably combined with a charge density wave transition, decreases as a function of pressure. However, differently from the Sr{sub 3?x}Ca{sub x}Ir{sub 4}Sn{sub 13} system, where a superlattice quantum phase transition is observed [L. E. Klintberg et al., Phys. Rev. Lett. 109, 237?008 (2012)], in Ce{sub 3}Co{sub 4}Sn{sub 13} T{sub S}???154?K, at ambient pressure (P?=?0), seems to stabilize at around 143?K for P???19 kilobars. We also investigated ?(T) in external magnetic fields, at P?=?0. Negative magnetoresistance and increase of T{sub max} are observed, suggesting suppression of low temperature short range magnetic correlations.

  13. Assessment of ion kinetic effects in shock-driven inertial confinement fusion (ICF) implosions using fusion burn imaging

    SciTech Connect (OSTI)

    Rosenberg, M. J.; Séguin, F. H.; Amendt, P. A.; Atzeni, S.; Rinderknecht, H. G.; Hoffman, N. M.; Zylstra, A. B.; Li, C. K.; Sio, H.; Gatu Johnson, M.; Frenje, J. A.; Petrasso, R. D.; Glebov, V. Yu.; Stoeckl, C.; Seka, W.; Marshall, F. J.; Delettrez, J. A.; Sangster, T. C.; Betti, R.; Wilks, S. C.; Pino, J.; Kagan, G.; Molvig, K.; Nikroo, A.

    2015-06-02

    The significance and nature of ion kinetic effects in D³He-filled, shock-driven inertial confinement fusion implosions are assessed through measurements of fusion burn profiles. Over this series of experiments, the ratio of ion-ion mean free path to minimum shell radius (the Knudsen number, NK) was varied from 0.3 to 9 in order to probe hydrodynamic-like to strongly kinetic plasma conditions; as the Knudsen number increased, hydrodynamic models increasingly failed to match measured yields, while an empirically-tuned, first-step model of ion kinetic effects better captured the observed yield trends [Rosenberg et al., Phys. Rev. Lett. 112, 185001 (2014)]. Here, spatially resolved measurements of the fusion burn are used to examine kinetic ion transport effects in greater detail, adding an additional dimension of understanding that goes beyond zero-dimensional integrated quantities to one-dimensional profiles. In agreement with the previous findings, a comparison of measured and simulated burn profiles shows that models including ion transport effects are able to better match the experimental results. In implosions characterized by large Knudsen numbers (NK ~ 3), the fusion burn profiles predicted by hydrodynamics simulations that exclude ion mean free path effects are peaked far from the origin, in stark disagreement with the experimentally observed profiles, which are centrally peaked. In contrast, a hydrodynamics simulation that includes a model of ion diffusion is able to qualitatively match the measured profile shapes. Therefore, ion diffusion or diffusion-like processes are identified as a plausible explanation of the observed trends, though further refinement of the models is needed for a more complete and quantitative understanding of ion kinetic effects.

  14. Assessment of ion kinetic effects in shock-driven inertial confinement fusion implosions using fusion burn imaging

    SciTech Connect (OSTI)

    Rosenberg, M. J. Séguin, F. H.; Rinderknecht, H. G.; Zylstra, A. B.; Li, C. K.; Sio, H.; Johnson, M. Gatu; Frenje, J. A.; Petrasso, R. D.; Amendt, P. A.; Wilks, S. C.; Pino, J.; Atzeni, S.; Hoffman, N. M.; Kagan, G.; Molvig, K.; Glebov, V. Yu.; Stoeckl, C.; Seka, W.; Marshall, F. J.; and others

    2015-06-15

    The significance and nature of ion kinetic effects in D{sup 3}He-filled, shock-driven inertial confinement fusion implosions are assessed through measurements of fusion burn profiles. Over this series of experiments, the ratio of ion-ion mean free path to minimum shell radius (the Knudsen number, N{sub K}) was varied from 0.3 to 9 in order to probe hydrodynamic-like to strongly kinetic plasma conditions; as the Knudsen number increased, hydrodynamic models increasingly failed to match measured yields, while an empirically-tuned, first-step model of ion kinetic effects better captured the observed yield trends [Rosenberg et al., Phys. Rev. Lett. 112, 185001 (2014)]. Here, spatially resolved measurements of the fusion burn are used to examine kinetic ion transport effects in greater detail, adding an additional dimension of understanding that goes beyond zero-dimensional integrated quantities to one-dimensional profiles. In agreement with the previous findings, a comparison of measured and simulated burn profiles shows that models including ion transport effects are able to better match the experimental results. In implosions characterized by large Knudsen numbers (N{sub K} ∼ 3), the fusion burn profiles predicted by hydrodynamics simulations that exclude ion mean free path effects are peaked far from the origin, in stark disagreement with the experimentally observed profiles, which are centrally peaked. In contrast, a hydrodynamics simulation that includes a model of ion diffusion is able to qualitatively match the measured profile shapes. Therefore, ion diffusion or diffusion-like processes are identified as a plausible explanation of the observed trends, though further refinement of the models is needed for a more complete and quantitative understanding of ion kinetic effects.

  15. High-rate Plastic Deformation of Nanocrystalline Tantalum to Large Strains: Molecular Dynamics Simulation

    SciTech Connect (OSTI)

    Rudd, R E

    2009-02-05

    Recent advances in the ability to generate extremes of pressure and temperature in dynamic experiments and to probe the response of materials has motivated the need for special materials optimized for those conditions as well as a need for a much deeper understanding of the behavior of materials subjected to high pressure and/or temperature. Of particular importance is the understanding of rate effects at the extremely high rates encountered in those experiments, especially with the next generation of laser drives such as at the National Ignition Facility. Here we use large-scale molecular dynamics (MD) simulations of the high-rate deformation of nanocrystalline tantalum to investigate the processes associated with plastic deformation for strains up to 100%. We use initial atomic configurations that were produced through simulations of solidification in the work of Streitz et al [Phys. Rev. Lett. 96, (2006) 225701]. These 3D polycrystalline systems have typical grain sizes of 10-20 nm. We also study a rapidly quenched liquid (amorphous solid) tantalum. We apply a constant volume (isochoric), constant temperature (isothermal) shear deformation over a range of strain rates, and compute the resulting stress-strain curves to large strains for both uniaxial and biaxial compression. We study the rate dependence and identify plastic deformation mechanisms. The identification of the mechanisms is facilitated through a novel technique that computes the local grain orientation, returning it as a quaternion for each atom. This analysis technique is robust and fast, and has been used to compute the orientations on the fly during our parallel MD simulations on supercomputers. We find both dislocation and twinning processes are important, and they interact in the weak strain hardening in these extremely fine-grained microstructures.

  16. Assessment of ion kinetic effects in shock-driven inertial confinement fusion (IFC) implosions using fusion burn imaging

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

    Rosenberg, M. J.; Sguin, F. H.; Amendt, P. A.; Atzeni, S.; Rinderknecht, H. G.; Hoffman, N. M.; Zylstra, A. B.; Li, C. K.; Sio, H.; Gatu Johnson, M.; et al

    2015-06-02

    The significance and nature of ion kinetic effects in DHe-filled, shock-driven inertial confinement fusion implosions are assessed through measurements of fusion burn profiles. Over this series of experiments, the ratio of ion-ion mean free path to minimum shell radius (the Knudsen number, NK) was varied from 0.3 to 9 in order to probe hydrodynamic-like to strongly kinetic plasma conditions; as the Knudsen number increased, hydrodynamic models increasingly failed to match measured yields, while an empirically-tuned, first-step model of ion kinetic effects better captured the observed yield trends [Rosenberg et al., Phys. Rev. Lett. 112, 185001 (2014)]. Here, spatially resolved measurementsmoreof the fusion burn are used to examine kinetic ion transport effects in greater detail, adding an additional dimension of understanding that goes beyond zero-dimensional integrated quantities to one-dimensional profiles. In agreement with the previous findings, a comparison of measured and simulated burn profiles shows that models including ion transport effects are able to better match the experimental results. In implosions characterized by large Knudsen numbers (NK ~ 3), the fusion burn profiles predicted by hydrodynamics simulations that exclude ion mean free path effects are peaked far from the origin, in stark disagreement with the experimentally observed profiles, which are centrally peaked. In contrast, a hydrodynamics simulation that includes a model of ion diffusion is able to qualitatively match the measured profile shapes. Therefore, ion diffusion or diffusion-like processes are identified as a plausible explanation of the observed trends, though further refinement of the models is needed for a more complete and quantitative understanding of ion kinetic effects.less

  17. Order-parameter-aided temperature-accelerated sampling for the exploration of crystal polymorphism and solid-liquid phase transitions

    SciTech Connect (OSTI)

    Yu, Tang-Qing Vanden-Eijnden, Eric; Chen, Pei-Yang; Chen, Ming; Samanta, Amit; Tuckerman, Mark

    2014-06-07

    The problem of predicting polymorphism in atomic and molecular crystals constitutes a significant challenge both experimentally and theoretically. From the theoretical viewpoint, polymorphism prediction falls into the general class of problems characterized by an underlying rough energy landscape, and consequently, free energy based enhanced sampling approaches can be brought to bear on the problem. In this paper, we build on a scheme previously introduced by two of the authors in which the lengths and angles of the supercell are targeted for enhanced sampling via temperature accelerated adiabatic free energy dynamics [T. Q. Yu and M. E. Tuckerman, Phys. Rev. Lett. 107, 015701 (2011)]. Here, that framework is expanded to include general order parameters that distinguish different crystalline arrangements as target collective variables for enhanced sampling. The resulting free energy surface, being of quite high dimension, is nontrivial to reconstruct, and we discuss one particular strategy for performing the free energy analysis. The method is applied to the study of polymorphism in xenon crystals at high pressure and temperature using the Steinhardt order parameters without and with the supercell included in the set of collective variables. The expected fcc and bcc structures are obtained, and when the supercell parameters are included as collective variables, we also find several new structures, including fcc states with hcp stacking faults. We also apply the new method to the solid-liquid phase transition in copper at 1300 K using the same Steinhardt order parameters. Our method is able to melt and refreeze the system repeatedly, and the free energy profile can be obtained with high efficiency.

  18. Ultrashort x-ray backlighters and applications

    SciTech Connect (OSTI)

    Umstadter, D., University of Michigan

    1997-08-01

    Previously, using ultrashort laser pulses focused onto solid targets, we have experimentally studied a controllable ultrafast broadband radiation source in the extreme ultraviolet for time-resolved dynamical studies in ultrafast science [J. Workman, A. Maksimchuk, X. Llu, U. Ellenberger, J. S. Coe, C.-Y. Chien, and D. Umstadter, ``Control of Bright Picosecond X-Ray Emission from Intense Sub- Picosecond Laser-Plasma Interactions,`` Phys. Rev. Lett. 75, 2324 (1995)]. Once armed with a bright ultrafast broadband continuum x-ray source and appropriate detectors, we used the source as a backlighter to study a remotely produced plasma. The application of the source to a problem relevant to high-density matter completes the triad: creating and controlling, efficiently detecting, and applying the source. This work represented the first use of an ultrafast laser- produced x-ray source as a time-resolving probe in an application relevant to atomic, plasma and high-energy-density matter physics. Using the x-ray source as a backlighter, we adopted a pump-probe geometry to investigate the dynamic changes in electronic structure of a thin metallic film as it is perturbed by an ultrashort laser pulse. Because the laser deposits its energy in a skin depth of about 100 {Angstrom} before expansion occurs, up to gigabar pressure shock waves lasting picosecond in duration have been predicted to form in these novel plasmas. This raises the possibility of studying high- energy-density matter relevant to inertial confinement fusion (ICF) and astrophysics in small-scale laboratory experiments. In the past, time-resolved measurements of K-edge shifts in plasmas driven by nanosecond pulses have been used to infer conditions in highly compressed materials. In this study, we used 100-fs laser pulses to impulsively drive shocks into a sample (an untamped 1000 {Angstrom} aluminum film on 2000 {Angstrom} of parylene-n), measuring L-edge shifts.

  19. The double-gradient magnetic instability: Stabilizing effect of the guide field

    SciTech Connect (OSTI)

    Korovinskiy, D. B. Semenov, V. S.; Ivanova, V. V.; Divin, A. V.; Erkaev, N. V.; Artemyev, A. V.; Lapenta, G.; Markidis, S.; Biernat, H. K.

    2015-01-15

    The role of the dawn-dusk magnetic field component in stabilizing of the magnetotail flapping oscillations is investigated in the double-gradient model framework (Erkaev et al., Phys. Rev. Lett. 99, 235003 (2007)), extended for the magnetotail-like configurations with non-zero guide field B{sub y}. Contribution of the guide field is examined both analytically and by means of linearized 2-dimensional (2D) and non-linear 3-dimensional (3D) MHD modeling. All three approaches demonstrate the same properties of the instability: stabilization of current sheet oscillations for short wavelength modes, appearing of the typical (fastest growing) wavelength λ{sub peak} of the order of the current sheet width, decrease of the peak growth rate with increasing B{sub y} value, and total decay of the mode for B{sub y}∼0.5 in the lobe magnetic field units. Analytical solution and 2D numerical simulations claim also the shift of λ{sub peak} toward the longer wavelengths with increasing guide field. This result is barely visible in 3D simulations. It may be accounted for the specific background magnetic configuration, the pattern of tail-like equilibrium provided by approximated solution of the conventional Grad-Shafranov equation. The configuration demonstrates drastically changing radius of curvature of magnetic field lines, R{sub c}. This, in turn, favors the “double-gradient” mode (λ > R{sub c}) in one part of the sheet and classical “ballooning” instability (λ < R{sub c}) in another part, which may result in generation of a “combined” unstable mode.

  20. Streamlining the Nuclear Force | U.S. DOE Office of Science ...

    Office of Science (SC) Website

    ... Lett. 110, 192502 (2013) Related Links NUCLEI (NUclear Computational Low-Energy Initiative) SciDAC project External link Highlight Categories Program: ASCR, NP PerformerFacility: ...