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Note: This page contains sample records for the topic "multiple-wavelength anomalous diffraction" from the National Library of EnergyBeta (NLEBeta).
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1

Testing and Comparing the Modified Anomalous Diffraction Approximation  

Science Conference Proceedings (OSTI)

The modified anomalous diffraction approximation (MADA) is used to predict absorption and extinction in water and ice clouds, but it does not predict the scattering phase function or asymmetry parameter g. In conjunction with g parameterizations, ...

David L. Mitchell; Anthony J. Baran; W. P. Arnott; C. Schmitt

2006-11-01T23:59:59.000Z

2

Anomalous X-ray Diffraction Studies for Photovoltaic Applications  

DOE Green Energy (OSTI)

Anomalous X-ray Diffraction (AXRD) has become a useful technique in characterizing bulk and nanomaterials as it provides specific information about the crystal structure of materials. In this project we present the results of AXRD applied to materials for photovoltaic applications: ZnO loaded with Ga and ZnCo{sub 2}O{sub 4} spinel. The X-ray diffraction data collected for various energies were plotted in Origin software. The peaks were fitted using different functions including Pseudo Voigt, Gaussian, and Lorentzian. This fitting provided the integrated intensity data (peaks area values), which when plotted as a function of X-ray energies determined the material structure. For the first analyzed sample, Ga was not incorporated into the ZnO crystal structure. For the ZnCo{sub 2}O{sub 4} spinel Co was found in one or both tetrahedral and octahedral sites. The use of anomalous X-ray diffraction (AXRD) provides element and site specific information for the crystal structure of a material. This technique lets us correlate the structure to the electronic properties of the materials as it allows us to probe precise locations of cations in the spinel structure. What makes it possible is that in AXRD the diffraction pattern is measured at a number of energies near an X-ray absorption edge of an element of interest. The atomic scattering strength of an element varies near its absorption edge and hence the total intensity of the diffraction peak changes by changing the X-ray energy. Thus AXRD provides element specific structural information. This method can be applied to both crystalline and liquid materials. One of the advantages of AXRD in crystallography experiments is its sensitivity to neighboring elements in the periodic tables. This method is also sensitive to specific crystallographic phases and to a specific site in a phase. The main use of AXRD in this study is for transparent conductors (TCs) analysis. TCs are considered to be important materials because of their efficiency and low risk of environmental pollution. These materials are important to solar cells as a result of their remarkable combination of optical and electrical properties, including high electrical conductivity and high optical transparency in the spectrum of visible light. TCs provide a transparent window, which allows sunlight to pass through while also allowing electricity to conduct out of the cell. Spinel materials have the chemical form AB{sub 2}O{sub 4}, and are made of a face-centered cubic (FCC) lattice of oxygen anions and cations in specific interstitial sites. A normal spinel has all A cations on tetrahedral sites and B cations on octahedral sites. In contrast; an inverse spinel has the A and half of the B cations on octahedral sites and the other half of the B cations on tetrahedral sites; a mixed spinel lies between. In the spinel structure, 8 of 64 possible tetrahedral sites and 16 of 32 possible octahedral sites are filled. Normal spinels have particularly high conduction as the linear octahedral chains of B cations likely serve as conduction paths. In this paper we present how the data obtained with AXRD is used to analyze TCs properties as they apply to photovoltaic applications. One of the materials used for this analysis is zinc oxide. It has been loaded with 5% and 10% of Ga, which has an absorption edge of 10367 eV. The peak (100) was measured for the zinc oxide loaded with 10% Ga. In the case of 5% Ga, we measured peaks (100) and (101). With the information provided by the AXRD we can identify if Ga is being incorporated in the ZnO crystal structure. The analysis of 311 plane in the ZnCo{sub 2}O{sub 4} spinel shows if Co is in tetrahedral or octahedral site.

Not Available

2011-06-22T23:59:59.000Z

3

The Absorption of Solar Radiation by Cloud Droplets: An Application of Anomalous Diffraction Theory  

Science Conference Proceedings (OSTI)

In this paper we demonstrate that the anomalous diffraction theory of van de Hulst with some modifications, provides a reasonable approximation of the volume extinction and absorption coefficients. We also show how the shortwave radiative ...

Steven A. Ackerman; Graeme L. Stephens

1987-06-01T23:59:59.000Z

4

Tunnel junction multiple wavelength light-emitting diodes  

DOE Patents (OSTI)

A multiple wavelength LED having a monolithic cascade cell structure comprising at least two p-n junctions, wherein each of said at least two p-n junctions have substantially different band gaps, and electrical connector means by which said at least two p-n junctions may be collectively energized; and wherein said diode comprises a tunnel junction or interconnect. 5 figs.

Olson, J.M.; Kurtz, S.R.

1992-11-24T23:59:59.000Z

5

Tunnel junction multiple wavelength light-emitting diodes  

DOE Patents (OSTI)

A multiple wavelength LED having a monolithic cascade cell structure comprising at least two p-n junctions, wherein each of said at least two p-n junctions have substantially different band gaps, and electrical connector means by which said at least two p-n junctions may be collectively energized; and wherein said diode comprises a tunnel junction or interconnect.

Olson, Jerry M. (Lakewood, CO); Kurtz, Sarah R. (Golden, CO)

1992-01-01T23:59:59.000Z

6

Structure determination of thin CoFe films by anomalous x-ray diffraction  

Science Conference Proceedings (OSTI)

This work reports on the investigation of structure-property relationships in thin CoFe films grown on MgO. Because of the very similar scattering factors of Fe and Co, it is not possible to distinguish the random A2 (W-type) structure from the ordered B2 (CsCl-type) structure with commonly used x-ray sources. Synchrotron radiation based anomalous x-ray diffraction overcomes this problem. It is shown that as grown thin films and 300 K post annealed films exhibit the A2 structure with a random distribution of Co and Fe. In contrast, films annealed at 400 K adopt the ordered B2 structure.

Gloskovskii, Andrei; Stryganyuk, Gregory; Ouardi, Siham [Institut fuer Anorganische und Analytische Chemie, Johannes Gutenberg-Universitaet, 55099 Mainz (Germany); Fecher, Gerhard H.; Felser, Claudia [Institut fuer Anorganische und Analytische Chemie, Johannes Gutenberg-Universitaet, 55099 Mainz (Germany); Max Planck Institute for Chemical Physics of Solids, D-01187 Dresden (Germany); Hamrle, Jaroslav; Pistora, Jaromir [Department of Physics and Nanotechnology Centre, VSB-Technical University of Ostrava, 70833 Ostrava (Czech Republic); Bosu, Subrojati; Saito, Kesami; Sakuraba, Yuya; Takanashi, Koki [Institute for Materials Research (IMR), Tohoku University, Sendai 980-8577 (Japan)

2012-10-01T23:59:59.000Z

7

diffraction  

NLE Websites -- All DOE Office Websites (Extended Search)

appear in different places because they correspond to waves of different wavelength. A classical demonstration of diffraction that more closely resembles some high-energy...

8

Structure of the -Al2O3,,0001... surface from low-energy electron diffraction: Al termination and evidence for anomalously large thermal vibrations  

E-Print Network (OSTI)

Structure of the -Al2O3,,0001... surface from low-energy electron diffraction: Al termination structure of -Al2O3(0001). Sapphire surfaces are prepared in three different ways, and the diffraction, the clearly favored structure has a single Al layer termination and a large first interlayer contraction

Soares, Edmar Avellar

9

Anomalous Magnetohydrodynamics  

E-Print Network (OSTI)

Anomalous symmetries induce currents which can be parallel rather than orthogonal to the hypermagnetic field. Building on the analogy with charged liquids at high magnetic Reynolds numbers, the persistence of anomalous currents is scrutinized for parametrically large conductivities when the plasma approximation is accurate. Different examples in globally neutral systems suggest that the magnetic configurations minimizing the energy density with the constraint that the helicity be conserved coincide, in the perfectly conducting limit, with the ones obtainable in ideal magnetohydrodynamics where the anomalous currents are neglected. It is argued that this is the rationale for the ability of extending to anomalous magnetohydrodynamics the hydromagnetic solutions characterized by finite gyrotropy. The generally covariant aspects of the problem are addressed with particular attention to conformally flat geometries which are potentially relevant for the description of the electroweak plasma prior to the phase transition.

Massimo Giovannini

2013-07-09T23:59:59.000Z

10

Diffraction shaders  

Science Conference Proceedings (OSTI)

Keywords: Fourier transform, Kirchoff theory, diffraction, random processes, rough surface scattering, shading models

Jos Stam

1999-07-01T23:59:59.000Z

11

Anomalous radial transport in tokamak edge plasma  

E-Print Network (OSTI)

1.2 Transport in tokamakAnomalous radial transport model for edge plasma . . . . . .Anomalous transport . . . . . . . . . . . . . . . . . . . .

Bodi, Vasudeva Raghavendra Kowsik

2010-01-01T23:59:59.000Z

12

Anomalous is ubiquitous  

Science Conference Proceedings (OSTI)

Brownian motion is widely considered the quintessential model of diffusion processes-the most elemental random transport processes in Science and Engineering. Yet so, examples of diffusion processes displaying highly non-Brownian statistics-commonly termed 'Anomalous Diffusion' processes-are omnipresent both in the natural sciences and in engineered systems. The scientific interest in Anomalous Diffusion and its applications is growing exponentially in the recent years. In this Paper we review the key statistics of Anomalous Diffusion processes: sub-diffusion and super-diffusion, long-range dependence and the Joseph effect, Levy statistics and the Noah effect, and 1/f noise. We further present a theoretical model-generalizing the Einstein-Smoluchowski diffusion model-which provides a unified explanation for the prevalence of Anomalous Diffusion statistics. Our model shows that what is commonly perceived as 'anomalous' is in effect ubiquitous. - Highlights: > The article provides an overview of Anomalous Diffusion (AD) statistics. > The Einstein-Smoluchowski diffusion model is extended and generalized. > The generalized model universally generates AD statistics. > A unified 'universal macroscopic explanation' for AD statistics is established. > AD statistics are shown to be fundamentally connected to robustness.

Eliazar, Iddo, E-mail: eliazar@post.tau.ac.il [Department of Technology Management, Holon Institute of Technology, P.O. Box 305, Holon 58102 (Israel); Klafter, Joseph, E-mail: klafter@post.tau.ac.il [School of Chemistry, Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978 (Israel)

2011-09-15T23:59:59.000Z

13

Diffractive processes  

SciTech Connect

Recent results on elastic scattering of hadrons, single and double inelastic diffraction, and double Pomeron exchange are reviewed. Comments are made on features of the data that can be simply understood using optical models or the triple Regge model. (auth)

Derrick, M.

1975-01-01T23:59:59.000Z

14

Testing of the Modified Anomalous Diffraction Approximation with...  

NLE Websites -- All DOE Office Websites (Extended Search)

absorption and extinction coefficients, abs and ext , for any particle shape. It is argued here that this simplification not only has computational advantages, but...

15

Beta function and anomalous dimensions  

Science Conference Proceedings (OSTI)

We demonstrate that it is possible to determine the coefficients of an all-orders beta-function linear in the anomalous dimensions using as data the 2-loop coefficients together with the first one of the anomalous dimensions which are universal. The beta function allows us to determine the anomalous dimension of the fermion masses at the infrared fixed point, and the resulting values compare well with the lattice determinations.

Pica, Claudio; Sannino, Francesco [CP3-Origins, University of Southern Denmark, Campusvej 55, DK-5230 Odense M (Denmark)

2011-06-01T23:59:59.000Z

16

Powder Diffraction  

NLE Websites -- All DOE Office Websites (Extended Search)

Powder Diffraction Powder Diffraction Ashfia Huq Spallation Neutron Source Oak Ridge National Laboratory 2 Managed by UT-Battelle for the U.S. Department of Energy Bragg's law W.H. Bragg (1862-1942) W.L. Bragg (1890-1971) *Zinc Blend (fcc not sc) *NaCl (not molecular) *Diamond (two overlapping fcc lattice) Shared 1915 Nobel Prize 3 Managed by UT-Battelle for the U.S. Department of Energy Where are the atoms? X-ray: (l : 10 -9 m - 10 -11 m) l[Å] = 12.398/E ph [keV] Source: * Lab diffractometers * Synchrotron Sources Neutron: (thermal l : 1-4Å) E n [meV] =81.89/ l 2 [Å] Source: * Reactors (fission) * Spallation Source We need wavelength (l) ~ Object size (for condensed matter that is Å) 4 Managed by UT-Battelle for the U.S. Department of Energy

17

Diffraction Shaders  

E-Print Network (OSTI)

The reflection of light from surfaces is a fundamental problem in computer graphics. Although many reflection models have been proposed, few take into account the wave nature of light. In this paper, we derive a new class of reflection models for metallic surfaces that handle the effects of diffraction. Diffraction is a purely wave-like phenomenon and cannot be properly modeled using the ray theory of light alone. A common example of a surface which exhibits diffraction is the compact disk. A characteristic of such surfaces is that they reflect light in a very colorful manner. Our model is also a generalization of most reflection models encountered in computer graphics. In particular, we extend the He-Torrance model to handle anisotropic reflections. This is achieved by rederiving, in a more general setting, results from surface wave physics which were taken for granted by other researchers. Specifically, our use of Fourier analysis has enabled us to tackle the difficult task of analytically computing the Kirchhoff integral of surface scattering.

Jos Stam

1999-01-01T23:59:59.000Z

18

Renewal-anomalous-heterogeneous files  

E-Print Network (OSTI)

Renewal-anomalous-heterogeneous files are solved. A simple file is made of Brownian hard spheres that diffuse stochastically in an effective 1D channel. Generally, Brownian files are heterogeneous: the spheres' diffusion coefficients are distributed and the initial spheres' density is non-uniform. In renewal-anomalous files, the distribution of waiting times for individual jumps is exponential as in Brownian files, yet obeys: {\\psi}_{\\alpha} (t)~t^(-1-{\\alpha}), 0renewal as all the particles attempt to jump at the same time. It is shown that the mean square displacement (MSD) in a renewal-anomalous-heterogeneous file, , obeys, ~[_{nrml}]^{\\alpha}, where _{nrml} is the MSD in the corresponding Brownian file. This scaling is an outcome of an exact relation (derived here) connecting probability density functions of Brownian files and renewal-anomalous files. It is also shown that non-renewal-anomalous files are slower than the corresponding renewal ones.

Ophir Flomenbom

2010-08-13T23:59:59.000Z

19

Multiple wavelength x-ray monochromators  

DOE Patents (OSTI)

An apparatus and method is provided for separating input x-ray radiation containing first and second x-ray wavelengths into spatially separate first and second output radiation which contain the first and second x-ray wavelengths, respectively. The apparatus includes a crystalline diffractor which includes a first set of parallel crystal planes, where each of the planes is spaced a predetermined second distance from one another. The crystalline diffractor also includes a second set of parallel crystal planes inclined at an angle with respect to the first set of crystal planes where each of the planes of the second set of parallel crystal planes is spaced a predetermined second distance from one another. In one embodiment, the crystalline diffractor is comprised of a single crystal. In a second embodiment, the crystalline diffractor is comprised of a stack of two crystals. In a third embodiment, the crystalline diffractor includes a single crystal that is bent for focussing the separate first and second output x-ray radiation wavelengths into separate focal points.

Steinmeyer, P.A.

1991-01-01T23:59:59.000Z

20

Multiple wavelength x-ray monochromators  

DOE Patents (OSTI)

An apparatus and method is provided for separating input x-ray radiation containing first and second x-ray wavelengths into spatially separate first and second output radiation which contain the first and second x-ray wavelengths, respectively. The apparatus includes a crystalline diffractor which includes a first set of parallel crystal planes, where each of the planes is spaced a predetermined second distance from one another. The crystalline diffractor also includes a second set of parallel crystal planes inclined at an angle with respect to the first set of crystal planes where each of the planes of the second set of parallel crystal planes is spaced a predetermined second distance from one another. In one embodiment, the crystalline diffractor is comprised of a single crystal. In a second embodiment, the crystalline diffractor is comprised of a stack of two crystals. In a third embodiment, the crystalline diffractor includes a single crystal that is bent for focussing the separate first and second output x-ray radiation wavelengths into separate focal points.

Steinmeyer, P.A.

1991-12-31T23:59:59.000Z

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


21

Anomalous GPDs in the photon  

E-Print Network (OSTI)

We consider deeply virtual Compton scattering (DVCS) on a photon target, in the generalized Bjorken limit, at the Born order and in the leading logarithmic approximation. This leads us to the extraction of the photon anomalous generalized parton distributions (GPDs) \\cite{url, DVCSphoton}.

S. Friot; B. Pire; L. Szymanowski

2007-10-23T23:59:59.000Z

22

Anomalous-viscosity current drive  

DOE Patents (OSTI)

The present invention relates to a method and apparatus for maintaining a steady-state current for magnetically confining the plasma in a toroidal magnetic confinement device using anomalous viscosity current drive. A second aspect of this invention relates to an apparatus and method for the start-up of a magnetically confined toroidal plasma.

Stix, T.H.; Ono, M.

1986-04-25T23:59:59.000Z

23

Anomalous radial transport in tokamak edge plasma  

E-Print Network (OSTI)

Transport in tokamak plasma . . . . . . . . . . . . . . .of tokamak plasma . . . . . . . . . 1.4 Dissertationtransport model for edge plasma . . . . . . 6.1 Anomalous

Bodi, Vasudeva Raghavendra Kowsik

2010-01-01T23:59:59.000Z

24

Ion temperature gradient instability and anomalous transport  

SciTech Connect

This report discusses experiments in ion temperature gradient instability and anomalous transport in the CLM steady state device. (LSP).

Sen, A.K.

1991-08-01T23:59:59.000Z

25

Does The Pioneer Anomalous Acceleration Really Exist?  

E-Print Network (OSTI)

The analysis of the Pioneer 10 and 11 data demonstrated the presence of an anomalous Doppler frequency blue-shift drift which is interpreted as an anomalous acceleration. The Doppler frequency dirft follows by considering the motions of the Pioneers in the universe, i.e. it is of cosmological origin. There is no anomalous acceleration.

Walter Petry

2005-09-21T23:59:59.000Z

26

Anomalous Radiative Decay of Heavy Higgs Boson  

E-Print Network (OSTI)

The radiative decay width of a heavy Higgs boson $H \\rightarrow W^+W^-\\gamma$ for a {\\it hard} photon is calculated in the Standard Model and its extension with anomalous $\\gamma WW$ couplings. Its dependence on the Higgs mass, the two unknown anomalous couplings, and the photon energy cutoff are studied in detail. We show that this radiative decay of a heavy Higgs is not very sensitive to a wide range of the anomalous couplings compared to the Standard Model result.

Tzu Chiang Yuan

1992-05-27T23:59:59.000Z

27

Electron Backscatter Diffraction  

Science Conference Proceedings (OSTI)

Oct 19, 2011 ... Recent Advances in Structural Characterization of Materials: Electron Backscatter Diffraction Sponsored by: MS&T Organization Program...

28

The investigation of anomalous magnetization in the Raft River...  

Open Energy Info (EERE)

anomalous magnetization in the Raft River valley, Idaho Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: The investigation of anomalous...

29

Diffraction Metrology and Standards  

Science Conference Proceedings (OSTI)

... and X-ray diffraction on two different synchrotron beamlines, at energies of 25 ... that allowed for the calibration of both line position and intensity as a ...

2012-10-09T23:59:59.000Z

30

Diffraction: Stresses and Structures  

Science Conference Proceedings (OSTI)

Aug 6, 2013 ... O. Advanced Neutron and Synchrotron Studies of Materials: Diffraction: Stresses ... of Newcastle; 2ANSTO; 3European Spallation Source (ESS)

31

Diffraction Metrology and Standards  

E-Print Network (OSTI)

. Objective Impact and Customers · Our primary impact is the enhancement of the measurement capability certification. · Primary customers are the International Center for Diffraction Data (ICDD) and X-ray instrument and Engineering Laboratory Diffraction techniques can provide data on a number of sample characteristics

32

Diffraction Results from CDF  

Science Conference Proceedings (OSTI)

We present final results by the CDF II collaboration on diffractive W and Z production, report on the status of ongoing analyses on diffractive dijet production and on rapidity gaps between jets, and briefly summarize results obtained on exclusive production pointing to their relevance to calibrating theoretical models used to predict exclusive Higgs-boson production at the LHC.

Goulianos, Konstantin

2012-04-01T23:59:59.000Z

33

Dirac Kirchhoff diffraction theory  

E-Print Network (OSTI)

Kirchhoff's scalar diffraction theory is applied throughout photon and electron optics. It is based on the stationary electromagnetic or Schr\\"odinger wave equation, and is useful in describing interference phenomena for both light and matter waves. Here, Kirchhoff's diffraction theory is derived from the relativistic Dirac equation, thus reformulated to work on Dirac spinors. The parallels with the "classic" scalar theory are highlighted, and a basic interpretation of the result obtained for the Fraunhofer diffraction limit is given. The goal of this paper is to emphasize the similarity between the two equations on the most fundamental level.

Ruben Van Boxem; Bart Partoens; Jo Verbeeck

2013-03-05T23:59:59.000Z

34

Dirac Kirchhoff diffraction theory  

E-Print Network (OSTI)

Kirchhoff's scalar diffraction theory is applied throughout photon and electron optics. It is based on the stationary electromagnetic or Schr\\"odinger wave equation, and is useful in describing interference phenomena for both light and matter waves. Here, Kirchhoff's diffraction theory is derived from the relativistic Dirac equation, thus reformulated to work on Dirac spinors. The parallels with the "classic" scalar theory are highlighted, and a basic interpretation of the result obtained for the Fraunhofer diffraction limit is given. The goal of this paper is to emphasize the similarity between the two equations on the most fundamental level.

Van Boxem, Ruben; Verbeeck, Jo

2013-01-01T23:59:59.000Z

35

Multilayer dielectric diffraction gratings  

DOE Patents (OSTI)

The design and fabrication of dielectric grating structures with high diffraction efficiency used in reflection or transmission is described. By forming a multilayer structure of alternating index dielectric materials and placing a grating structure on top of the multilayer, a diffraction grating of adjustable efficiency, and variable optical bandwidth can be obtained. Diffraction efficiency into the first order in reflection varying between 1 and 98 percent has been achieved by controlling the design of the multilayer and the depth, shape, and material comprising the grooves of the grating structure. Methods for fabricating these gratings without the use of ion etching techniques are described. 7 figs.

Perry, M.D.; Britten, J.A.; Nguyen, H.T.; Boyd, R.; Shore, B.W.

1999-05-25T23:59:59.000Z

36

Multilayer dielectric diffraction gratings  

DOE Patents (OSTI)

The design and fabrication of dielectric grating structures with high diffraction efficiency used in reflection or transmission is described. By forming a multilayer structure of alternating index dielectric materials and placing a grating structure on top of the multilayer, a diffraction grating of adjustable efficiency, and variable optical bandwidth can be obtained. Diffraction efficiency into the first order in reflection varying between 1 and 98 percent has been achieved by controlling the design of the multilayer and the depth, shape, and material comprising the grooves of the grating structure. Methods for fabricating these gratings without the use of ion etching techniques are described.

Perry, Michael D. (Livermore, CA); Britten, Jerald A. (Oakley, CA); Nguyen, Hoang T. (Livermore, CA); Boyd, Robert (Livermore, CA); Shore, Bruce W. (Livermore, CA)

1999-01-01T23:59:59.000Z

37

Diffraction Analysis of Alloys  

Science Conference Proceedings (OSTI)

Feb 18, 2010 ... Neutron and X-Ray Studies of Advanced Materials III : Diffraction Analysis of Alloys .... at the Advanced Photon Source at Argonne National Laboratory in .... pure Zirconium was performed with the D-DIA apparatus at the APS.

38

Diffraction at TOTEM  

E-Print Network (OSTI)

The TOTEM experiment at the LHC measures the total proton-proton cross section with the luminosity-independent method and the elastic proton-proton cross-section over a wide |t|-range. It also performs a comprehensive study of diffraction, spanning from cross-section measurements of individual diffractive processes to the analysis of their event topologies. Hard diffraction will be studied in collaboration with CMS taking advantage of the large common rapidity coverage for charged and neutral particle detection and the large variety of trigger possibilities even at large luminosities. TOTEM will take data under all LHC beam conditions including standard high luminosity runs to maximize its physics reach. This contribution describes the main features of the TOTEM physics programme including measurements to be made in the early LHC runs. In addition, a novel scheme to extend the diffractive proton acceptance for high luminosity runs by installing proton detectors at IP3 is described.

G. Antchev; P. Aspell; V. Avati; M. G. Bagliesi; V. Berardi; M. Berretti; U. Bottigli; M. Bozzo; E. Brucken; A. Buzzo; F. Cafagna; M. Calicchio; M. G. Catanesi; P. L. Catastini; R. Cecchi; M. A. Ciocci; M. Deile; E. Dimovasili; K. Eggert; V. Eremin; F. Ferro; F. Garcia; S. Giani; V. Greco; J. Heino; T. Hilden; J. Kaspar; J. Kopal; V. Kundrat; K. Kurvinen; S. Lami; G. Latino; R. Lauhakangas; E. Lippmaa; M. Lokajicek; M. Lo Vetere; F. Lucas Rodriguez; M. Macri; G. Magazzu; M. Meucci; S. Minutoli; H. Niewiadomski; E. Noschis; G. Notarnicola; E. Oliveri; F. Oljemark; R. Orava; M. Oriunno; K. Osterberg; P. Palazzi; E. Pedreschi; J. Petajajarvi; M. Quinto; E. Radermacher; E. Radicioni; F. Ravotti; G. Rella; E. Robutti; L. Ropelewski; G. Ruggiero; A. Rummel; H. Saarikko; G. Sanguinetti; A. Santroni; A. Scribano; G. Sette; W. Snoeys; F. Spinella; P. Squillacioti; A. Ster; C. Taylor; A. Trummal; N. Turini; J. Whitmore; J. Wu

2008-12-17T23:59:59.000Z

39

Reflective diffraction grating  

DOE Patents (OSTI)

Reflective diffraction grating. A focused ion beam (FIB) micromilling apparatus is used to store color images in a durable medium by milling away portions of the surface of the medium to produce a reflective diffraction grating with blazed pits. The images are retrieved by exposing the surface of the grating to polychromatic light from a particular incident bearing and observing the light reflected by the surface from specified reception bearing.

Lamartine, Bruce C. (Los Alamos, NM)

2003-06-24T23:59:59.000Z

40

ON THE SOURCE OF ASTROMETRIC ANOMALOUS REFRACTION  

SciTech Connect

More than a century ago, astronomers using transit telescopes to determine precise stellar positions were hampered by an unexplained periodic shifting of the stars they were observing. With the advent of CCD transit telescopes in the past three decades, this unexplained motion, termed 'anomalous refraction' by these early astronomers, is again being observed. Anomalous refraction is described as a low-frequency, large angular scale ({approx}2 Degree-Sign ) motion of the entire image plane with respect to the celestial coordinate system as observed and defined by astrometric catalogs. These motions, of typically several tenths of an arcsecond amplitude with timescales on the order of 10 minutes, are ubiquitous to ground-based drift-scan astrometric measurements regardless of location or telescopes used and have been attributed to the effect of tilting of equal-density layers of the atmosphere. The cause of this tilting has often been attributed to atmospheric gravity waves, but this cause has never been confirmed. Although theoretical models of atmospheric refraction show that atmospheric gravity waves are a plausible cause of anomalous refraction, an observational campaign specifically directed at defining this relationship provides clear evidence that anomalous refraction is not consistent with the passage of atmospheric gravity waves. The source of anomalous refraction is found to be meter-scale, slowly evolving quasi-coherent dynamical structures in the boundary layer below 60 m above ground level.

Taylor, M. Suzanne [Department of Natural and Environmental Sciences, Western State Colorado University, 128 Hurst Hall, Gunnison, CO 81230 (United States); McGraw, John T.; Zimmer, Peter C. [Department of Physics and Astronomy, University of New Mexico, MSC07 4220, Albuquerque, NM 87131 (United States); Pier, Jeffrey R., E-mail: mstaylor@western.edu [Division of Astronomical Sciences, NSF 4201 Wilson Blvd, Arlington, VA 22230 (United States)

2013-03-15T23:59:59.000Z

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


41

EMSL: Capabilities: Spectroscopy and Diffraction  

NLE Websites -- All DOE Office Websites (Extended Search)

Spectroscopy and Diffraction Spectroscopy and Diffraction Additional Information Meet the Spectroscopy and Diffraction Experts Related EMSL User Projects Spectroscopy and Diffraction Tools are Applied to all Science Themes Tutorial: XPS Tools for Surface Analysis Spectroscopy and Diffraction brochure EMSL's suite of spectroscopy and diffraction instruments allows users to study solid-, liquid-, and gas-phase sample structure and composition with remarkable resolution. Ideal for integrated studies, spectrometers and diffractometers are easily coupled with EMSL's computational and modeling capabilities, allowing users to apply a multifaceted research approach for experimental data interpretation and gain fundamental understanding of scientific problems. At EMSL, spectroscopy and diffraction instruments are

42

Nuclear Shadowing and Diffraction  

E-Print Network (OSTI)

The relation between diffraction in lepton-proton collisions and shadowing of nuclear structure functions which arises from Gribov inelastic shadowing, is described. A model realizing such relation, which produces a parameter-free description of experimental data on nuclear structure functions at small $x$, is presented. The application to the description of multiplicities in nuclear collisions is discussed and related to other approaches.

J. L. Albacete; N. Armesto; A. Capella; A. B. Kaidalov; C. A. Salgado

2004-10-12T23:59:59.000Z

43

Neutron Diffraction @ TOPAZ  

NLE Websites -- All DOE Office Websites (Extended Search)

Topaz Guide Bender Topaz Guide Bender Neutron Diffraction @ TOPAZ Workshop on Single Crystal Neutron Diffraction picture 2 September 29 - October 1, 2011 * Spallation Neutron Source * Oak Ridge National Laboratory * Oak Ridge TN, USA TOPAZ 2011 Home Contacts Agenda and Important Deadlines Registration and Payment filler Workshop summary and purpose A workshop on single crystal neutron diffraction will be held at the Spallation Neutron Source at the Oak Ridge National Laboratory (ORNL). It will present invited and contributed talks to showcase cutting edge science and examples where neutron diffraction can make significant contributions; and provide training in neutron structure analysis and sample screening for the preparation of instrument beam-time proposals. TOPAZ is a high resolution wavelength-resolved Laue diffractometer with a versatile sample environment. Commissioning user experiments have demonstrated successfully the instrument capability for structural study of a vitamin B12 derivative, ion distribution in Li-ion battery materials, order and disorder in shape memory intermetallics, magnetic phase transition in multiferroic single crystal and functional thin films. The workshop is directed towards experienced neutron diffraction users and new users alike and encourages members to highlight their research and interest in structure analysis and investigation. The workshop will give opportunity to bring your own single crystal and screen sample quality and scattering power on TOPAZ @ room temperature, to evaluate data collection time and quality for an anticipated experiment. Finally, an opportunity to compose a proposal for neutron beam time (http://neutrons.ornl.gov/users/proposals.shtml) with staff will be provided in the framework of the workshop. The workshop format is well suited for researchers to contribute by showcasing their research and bring their research group or graduate student, who would like to test a single crystal sample. User access training for the ORNL neutron scattering facility will be included. It will be valid for future experiments.

44

The case for anomalous link discovery  

Science Conference Proceedings (OSTI)

In this paper, we describe the challenges inherent to the task of link prediction, and we analyze one reason why many link prediction models perform poorly. Specifically, we demonstrate the effects of the extremely large class skew associated ... Keywords: anomalous link discovery, link prediction, relational learning

Matthew J. Rattigan; David Jensen

2005-12-01T23:59:59.000Z

45

Nonlinear Response to Anomalous Tropical Forcing  

Science Conference Proceedings (OSTI)

We have investigated the nonlinear steady-state response of a barotropic model to an estimate of the observed anomalous tropical divergence forcing for the El Nio winter of 1982/83. The 400 mb climatological flow was made a forced solution of ...

R. J. Haarsma; J. D. Opsteegh

1989-11-01T23:59:59.000Z

46

Investigating Ultrasonic Diffraction Grating Spectroscopy and ...  

Investigating Ultrasonic Diffraction Grating Spectroscopy and Reflection Techniques for Characterization Slurry Properties Investigating Ultrasonic Diffraction Grating

47

SINGLE CRYSTAL NEUTRON DIFFRACTION.  

SciTech Connect

Single-crystal neutron diffraction measures the elastic Bragg reflection intensities from crystals of a material, the structure of which is the subject of investigation. A single crystal is placed in a beam of neutrons produced at a nuclear reactor or at a proton accelerator-based spallation source. Single-crystal diffraction measurements are commonly made at thermal neutron beam energies, which correspond to neutron wavelengths in the neighborhood of 1 Angstrom. For high-resolution studies requiring shorter wavelengths (ca. 0.3-0.8 Angstroms), a pulsed spallation source or a high-temperature moderator (a ''hot source'') at a reactor may be used. When complex structures with large unit-cell repeats are under investigation, as is the case in structural biology, a cryogenic-temperature moderator (a ''cold source'') may be employed to obtain longer neutron wavelengths (ca. 4-10 Angstroms). A single-crystal neutron diffraction analysis will determine the crystal structure of the material, typically including its unit cell and space group, the positions of the atomic nuclei and their mean-square displacements, and relevant site occupancies. Because the neutron possesses a magnetic moment, the magnetic structure of the material can be determined as well, from the magnetic contribution to the Bragg intensities. This latter aspect falls beyond the scope of the present unit; for information on magnetic scattering of neutrons see Unit 14.3. Instruments for single-crystal diffraction (single-crystal diffractometers or SCDs) are generally available at the major neutron scattering center facilities. Beam time on many of these instruments is available through a proposal mechanism. A listing of neutron SCD instruments and their corresponding facility contacts is included in an appendix accompanying this unit.

KOETZLE,T.F.

2001-03-13T23:59:59.000Z

48

Atomic disorder in Heusler Co2MnGe measured by anomalous x-ray diffraction  

SciTech Connect

In ''spintronic'' devices, the spin of the conduction electron is used to control transport properties. A ferromagnet, which has an imbalance in the number of spin-up and spin-down electrons near the Fermi level, plays the role of spin injector or spin filter.

Ravel, Bruce; Cross, Julie O.; Raphael, Mark P.; Harris, Vincent G.; Ramesh, Ramamoorthy; Saraf, Laxmikant V.

2002-05-01T23:59:59.000Z

49

Method for identifying anomalous terrestrial heat flows  

DOE Patents (OSTI)

A method for locating and mapping the magnitude and extent of terrestrial heat-flow anomalies from 5 to 50 times average with a tenfold improved sensitivity over orthodox applications of aerial temperature-sensing surveys as used for geothermal reconnaissance. The method remotely senses surface temperature anomalies such as occur from geothermal resources or oxidizing ore bodies by: measuring the spectral, spatial, statistical, thermal, and temporal features characterizing infrared radiation emitted by natural terrestrial surfaces; deriving from these measurements the true surface temperature with uncertainties as small as 0.05 to 0.5 K; removing effects related to natural temperature variations of topographic, hydrologic, or meteoric origin, the surface composition, detector noise, and atmospheric conditions; factoring out the ambient normal-surface temperature for non-thermally enhanced areas surveyed under otherwise identical environmental conditions; distinguishing significant residual temperature enhancements characteristic of anomalous heat flows and mapping the extent and magnitude of anomalous heat flows where they occur.

Del Grande, Nancy Kerr (San Leandro, CA)

1977-01-25T23:59:59.000Z

50

Results on hard diffractive production  

Science Conference Proceedings (OSTI)

The results of experiments at hadron colliders probing the structure of the pomeron through hard diffraction are reviewed. Some results on deep inelastic diffractive scattering obtained at HERA are also discussed and placed in perspective. By using a properly normalized pomeron flux factor in single diffraction dissociation as dictated by unitarity

Konstantin Goulianos; The CDF Collaboration

1996-01-01T23:59:59.000Z

51

Anomalous Charge Transport in Disordered Organic Semiconductors  

Science Conference Proceedings (OSTI)

Anomalous charge carrier transport in disordered organic semiconductors is studied using fractional differential equations. The connection between index of fractional derivative and dispersion exponent is examined from the perspective of fractional Fokker-Planck equation and its link to the continuous time random walk formalism. The fractional model is used to describe the bi-scaling power-laws observed in the time-of flight photo-current transient data for two different types of organic semiconductors.

Muniandy, S. V.; Woon, K. L. [Department of Physics, University of Malaya, 50603 Kuala Lumpur (Malaysia); Choo, K. Y. [Faculty of Engineering, Multimedia University, 63100 Cyberjaya, Selangor (Malaysia)

2011-03-30T23:59:59.000Z

52

Anomalous and resonance small angle scattering  

SciTech Connect

Significant changes in the small angle scattered intensity can be induced by making measurements with radiation close to an absorption edge of an appropriate atomic species contained in the sample. These changes can be related quantitatively to the real and imaginary anomalous dispersion terms for the scattering factor (x-rays) or scattering length (neutrons). The physics inherent in these anomalous dispersion terms is first discussed before considering how they enter the relevant scattering theory. Two major areas of anomalous scattering research have emerged; macromolecules in solution and unmixing of metallic alloys. Research in each area is reviewed, illustrating both the feasibility and potential of these techniques. All the experimental results reported to date have been obtained with x-rays. However, it is pointed out that the formalism is the same or the analogue experiment with neutrons, and a number of suitable isotopes exist which exhibit resonance in an accessible range of energy. Potential applications of resonance small-angle neutron scatterings are discussed. 8 figs.

Epperson, J.E.; Thiyagarajan, P.

1987-11-01T23:59:59.000Z

53

Anomalous and resonance small angle scattering: Revision  

SciTech Connect

Significant changes in the small angle scattered intensity can be induced by making measurements with radiation close to an absorption edge of an appropriate atomic species contained in the sample. These changes can be related quantitatively to the real and imaginary anomalous dispersion terms for the scattering factor (x-rays) or scattering length (neutrons). The physics inherent in these anomalous dispersion terms is first discussed before considering how they enter the relevant scattering theory. Two major areas of anomalous scattering research have emerged; macromolecules in solution and unmixing of metallic alloys. Research in each area is reviewed, illustrating both the feasibility and potential of these techniques. All the experimental results reported to date have been obtained with x-rays. However, it is pointed out that the formalism is the same for the analogue experiment with neutrons, and a number of suitable isotopes exist which exhibit resonance in an accessible range of energy. Potential applications of resonance small angle neutron scatterings are discussed. 54 refs., 8 figs., 1 tab.

Epperson, J.E.; Thiyagarajan, P.

1987-11-01T23:59:59.000Z

54

Diffraction at HERA  

E-Print Network (OSTI)

Between 1992 and 2007, the HERA accelerator provided $ep$ collisions at center of mass energies beyond $300 \\ {\\rm GeV}$ at the interaction points of the H1 and ZEUS experiments. Interesting results to emerge relate to the newly accessed field of perturbative strong interaction physics at low Bjorken-$x$, where parton densities become extremely large. Questions arise as to how and where non-linear dynamics tame the parton density growth and challenging features such as geometric scaling are observed. Central to this low $x$ physics landscape is a high rate of diffractive processes, in which a colorless exchange takes place and the proton remains intact. A review is given for main results obtained by H1 and ZEUS experiments in this field.

Schoeffel, Laurent

2011-01-01T23:59:59.000Z

55

Anomalous zipping dynamics and forced polymer translocation  

E-Print Network (OSTI)

We investigate by Monte Carlo simulations the zipping and unzipping dynamics of two polymers connected by one end and subject to an attractive interaction between complementary monomers. In zipping, the polymers are quenched from a high temperature equilibrium configuration to a low temperature state, so that the two strands zip up by closing up a "Y"-fork. In unzipping, the polymers are brought from a low temperature double stranded configuration to high temperatures, so that the two strands separate. Simulations show that the unzipping time, $\\tau_u$, scales as a function of the polymer length as $\\tau_u \\sim L$, while the zipping is characterized by anomalous dynamics $\\tau_z \\sim L^\\alpha$ with $\\alpha = 1.37(2)$. This exponent is in good agreement with simulation results and theoretical predictions for the scaling of the translocation time of a forced polymer passing through a narrow pore. We find that the exponent $\\alpha$ is robust against variations of parameters and temperature, whereas the scaling of $\\tau_z$ as a function of the driving force shows the existence of two different regimes: the weak forcing ($\\tau_z \\sim 1/F$) and strong forcing ($\\tau_z$ independent of $F$) regimes. The crossover region is possibly characterized by a non-trivial scaling in $F$, matching the prediction of recent theories of polymer translocation. Although the geometrical setup is different, zipping and translocation share thus the same type of anomalous dynamics. Systems where this dynamics could be experimentally investigated are DNA (or RNA) hairpins: our results imply an anomalous dynamics for the hairpins closing times, but not for the opening times.

Alessandro Ferrantini; Enrico Carlon

2011-02-14T23:59:59.000Z

56

Anomalous Adsorption of Ultrafast Laser Irradiation in Glass ...  

Science Conference Proceedings (OSTI)

Presentation Title, Anomalous Adsorption of Ultrafast Laser Irradiation in Glass ... and is driven by the stress induced by absorption of ultrafast light in glass.

57

Anomalous resistance in high-frequency heating of tokamak plasma  

SciTech Connect

It is shown that induced scattering of electromagnetic waves by ions in a plasma with a longitudinal current can lead to the appearance of an appreciable anomalous resistance.

Parail, V.V.

1976-08-20T23:59:59.000Z

58

Anomalous shear wave attenuation in the shallow crust beneath...  

Open Energy Info (EERE)

the Coso volcanic field, and are coincident with the epicentral locations of recent earthquake swarms. No anomalous attenuation is seen beneath the Coso volcanic field above about...

59

TUTORIALS: Bragg's Law and Diffraction  

Science Conference Proceedings (OSTI)

Jul 8, 2007 ... CITATION: "Bragg's Law and Diffraction: How waves reveal the atomic structure of crystals," Project Java, State University of New York at Stony...

60

NIST Diffraction effects in radiometry  

Science Conference Proceedings (OSTI)

... of the overall effort to understand the role of solar variation in ... diffraction effects at short wavelengths (relevant to spectral power measurements) and ...

2011-01-12T23:59:59.000Z

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


61

Electrically-programmable diffraction grating  

DOE Patents (OSTI)

An electrically-programmable diffraction grating. The programmable grating includes a substrate having a plurality of electrodes formed thereon and a moveable grating element above each of the electrodes. The grating elements are electrostatically programmable to form a diffraction grating for diffracting an incident beam of light as it is reflected from the upper surfaces of the grating elements. The programmable diffraction grating, formed by a micromachining process, has applications for optical information processing (e.g. optical correlators and computers), for multiplexing and demultiplexing a plurality of light beams of different wavelengths (e.g. for optical fiber communications), and for forming spectrometers (e.g. correlation and scanning spectrometers).

Ricco, Antonio J. (Albuquerque, NM); Butler, Michael A. (Albuquerque, NM); Sinclair, Michael B. (Albuquerque, NM); Senturia, Stephen D. (Brookline, MA)

1998-01-01T23:59:59.000Z

62

Diffraction at HFIR  

Science Conference Proceedings (OSTI)

Of the planned suite of powder and single-crystal diffractometers for the HFIR, only two are currently operating, the Neutron Residual Stress Mapping Facility (NRSF2) diffractometer, and the Wide Angle Neutron Diffractometer (WAND). The NSRF2 was recently upgraded and is available to external users via the High Temperature Materials Laboratory (HTML) User Program for studies of stress, texture and phase mapping. The WAND is a flat-cone geometry diffractometer equipped with a curve 1-D PSD, suitable for high intensity powder diffraction (e.g., kinetics, high pressure) and diffuse scattering studies of single-crystals. A rebuild of the old HFIR powder diffractometer, originally located at HB-4 station is now underway, and is expected to begin commissioning by summer 2008. This instrument has a Debye-Scherrer geometry, with a detector bank consisting of 44 3He tubes each with 6' Soller collimators. A four-circle single-crystal diffractometer is located at the HB-3A station, and is slowly being brought back to life after the long hiatus connected to the reactor upgrade. A Letter of Intent to build a quasi-Laue diffractometer, called IMAGINE, in the HFIR Cold Guide Hall has been presented to and endorsed by the Neutron Scattering Science Advisory Committee.

Chakoumakos, Bryan C [ORNL; Fernandez-Baca, Jaime A [ORNL; Garlea, Vasile O [ORNL; Hubbard, Camden R [ORNL; Wang, Xun-Li [ORNL

2008-01-01T23:59:59.000Z

63

Electrically-programmable diffraction grating  

DOE Patents (OSTI)

An electrically-programmable diffraction grating is disclosed. The programmable grating includes a substrate having a plurality of electrodes formed thereon and a moveable grating element above each of the electrodes. The grating elements are electrostatically programmable to form a diffraction grating for diffracting an incident beam of light as it is reflected from the upper surfaces of the grating elements. The programmable diffraction grating, formed by a micromachining process, has applications for optical information processing (e.g. optical correlators and computers), for multiplexing and demultiplexing a plurality of light beams of different wavelengths (e.g. for optical fiber communications), and for forming spectrometers (e.g. correlation and scanning spectrometers). 14 figs.

Ricco, A.J.; Butler, M.A.; Sinclair, M.B.; Senturia, S.D.

1998-05-26T23:59:59.000Z

64

The investigation of anomalous magnetization in the Raft River valley,  

Open Energy Info (EERE)

investigation of anomalous magnetization in the Raft River valley, investigation of anomalous magnetization in the Raft River valley, Idaho Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: The investigation of anomalous magnetization in the Raft River valley, Idaho Details Activities (1) Areas (1) Regions (0) Abstract: Cassia County Idaho; clastic sediments; economic geology; exploration; geophysical methods; geophysical surveys; geothermal energy; gravel; ground methods; Idaho; isothermal remanent magnetization; magnetic anomalies; magnetic methods; magnetic properties; magnetic susceptibility; magnetization; paleomagnetism; Raft River basin; remanent magnetization; sediments; surveys; United States Author(s): Anderson, L.A.; Mabey, D.R. Published: Abstracts - Society of Exploration Geophysicists International

65

Detecting compounded anomalous SNMP situations using cooperative unsupervised pattern recognition  

Science Conference Proceedings (OSTI)

This research employs unsupervised pattern recognition to approach the thorny issue of detecting anomalous network behavior. It applies a connectionist model to identify user behavior patterns and successfully demonstrates that such models respond well ...

Emilio Corchado; lvaro Herrero; Jos Manuel Siz

2005-09-01T23:59:59.000Z

66

Searching for the fourth family quarks through anomalous decays  

Science Conference Proceedings (OSTI)

The flavor democracy hypothesis predicts the existence of the fourth standard model family. Because of the high masses of the fourth family quarks, their anomalous decays could be dominant if certain criteria are met. This will drastically change the search strategy at hadron colliders. We show that the fourth standard model family down quarks with masses up to 400-450 GeV can be observed (or excluded) via anomalous decays by Tevatron.

Sahin, M.; Sultansoy, S.; Turkoz, S. [TOBB University of Economics and Technology, Physics Division, Ankara (Turkey); TOBB University of Economics and Technology, Physics Division, Ankara, Turkey and Institute of Physics, National Academy of Sciences, Baku (Azerbaijan); Ankara University, Department of Physics, Ankara (Turkey)

2010-09-01T23:59:59.000Z

67

Boundary diffraction wave integrals for diffraction modeling of external occulters  

E-Print Network (OSTI)

An occulter is a large diffracting screen which may be flown in conjunction with a telescope to image extrasolar planets. The edge is shaped to minimize the diffracted light in a region beyond the occulter, and a telescope may be placed in this dark shadow to view an extrasolar system with the starlight removed. Errors in position, orientation, and shape of the occulter will diffract additional light into this region, and a challenge of modeling an occulter system is to accurately and quickly model these effects. We present a fast method for the calculation of electric fields following an occulter, based on the concept of the boundary diffraction wave: the 2D structure of the occulter is reduced to a 1D edge integral which directly incorporates the occulter shape, and which can be easily adjusted to include changes in occulter position and shape, as well as the effects of sources---such as exoplanets---which arrive off-axis to the occulter. The structure of a typical implementation of the algorithm is include...

Cady, E

2012-01-01T23:59:59.000Z

68

Diffraction encoded position measuring apparatus  

DOE Patents (OSTI)

When a lightwave passes through a transmission grating, diffracted beams appear at the output or opposite side of the grating that are effectively Doppler shifted in frequency (phase) whereby a detector system can compare the phase of the zero order and higher order beams to obtain an indication of position. Multiple passes through the grating increase resolution for a given wavelength of a laser signal. The resolution can be improved further by using a smaller wavelength laser to generate the grating itself. Since the grating must only have a pitch sufficient to produce diffracted orders, inexpensive, ultraviolet wavelength lasers can be utilized and still obtain high resolution detection. 3 figures.

Tansey, R.J.

1991-09-24T23:59:59.000Z

69

The gravitational cusp anomalous dimension from AdS space  

E-Print Network (OSTI)

Recently a new picture has been developed for examining Wilson lines, and the corresponding anomalous dimensions which govern their renormalization properties. By making a particular coordinate transform, the calculation of the cusp anomalous dimension in QED or QCD can be related to the energy of a pair of static charges in Euclidean Anti-de-Sitter (AdS) space. This paper shows how the same picture can be used to describe Wilson lines in quantum gravity. We show how the relevant cusp anomalous dimension (which has recently been shown to be one loop exact) can be obtained using the Newtonian limit of General Relativity. We also show how both the QED and gravity cases emerge as special cases of a general formulation, and that a continuous parameter exists which interpolates between them. The results may be useful in examining the relations between gauge and gravity theories.

Miller, D J

2012-01-01T23:59:59.000Z

70

The gravitational cusp anomalous dimension from AdS space  

E-Print Network (OSTI)

Recently a new picture has been developed for examining Wilson lines, and the corresponding anomalous dimensions which govern their renormalization properties. By making a particular coordinate transform, the calculation of the cusp anomalous dimension in QED or QCD can be related to the energy of a pair of static charges in Euclidean Anti-de-Sitter (AdS) space. This paper shows how the same picture can be used to describe Wilson lines in quantum gravity. We show how the relevant cusp anomalous dimension (which has recently been shown to be one loop exact) can be obtained using the Newtonian limit of General Relativity. We also show how both the QED and gravity cases emerge as special cases of a general formulation, and that a continuous parameter exists which interpolates between them. The results may be useful in examining the relations between gauge and gravity theories.

D. J. Miller; C. D. White

2012-01-11T23:59:59.000Z

71

Diffraction and central exclusive production at ATLAS  

Science Conference Proceedings (OSTI)

The diffractive physics program for the ATLAS experiment with an emphasis on the central exclusive production is discussed. The key point in this discussion is the need for an unambiguous experimental definition of diffractive signature which would be acceptable and reproducible by theorists. Recent ATLAS results from samples enhanced in diffraction contribution underline this need.

Marek Taevsk; The ATLAS collaboration

2011-01-01T23:59:59.000Z

72

Greenhouse Warming, Decadal Variability, or El Nio? An Attempt to Understand the Anomalous 1990s  

Science Conference Proceedings (OSTI)

The dominant variability modes in the Tropics are investigated and contrasted with the anomalous situation observed during the last few years. The prime quantity analyzed is anomalous sea surface temperature (SST) in the region 30S60N. ...

M. Latif; R. Kleeman; C. Eckert

1997-09-01T23:59:59.000Z

73

Climatology of Anomalous Propagation Radar Echoes in a Coastal Area  

Science Conference Proceedings (OSTI)

Anomalous propagation (AP) of ground-based radar beam results in the detection of ground echoes beyond the horizon. One year of data gathered with an S-band meteorological radar located on the coast in southwest France is used to analyze the ...

Frdric Mesnard; Henri Sauvageot

2010-11-01T23:59:59.000Z

74

Anomalous Transport Processes in Turbulent non-Abelian Plasmas  

E-Print Network (OSTI)

Turbulent color fields, which can arise in the early and late stages of relativistic heavy ion collisions, may contribute significantly to the transport processes in the matter created in these collisions. We review the theory of these anomalous transport processes and discuss their possible phenomenology in the glasma and quasistationary expanding quark-gluon plasma.

Masayuki Asakawa; Steffen A. Bass; Berndt Mller

2010-08-20T23:59:59.000Z

75

Scale-dependent mass anomalous dimension from Dirac eigenmodes  

E-Print Network (OSTI)

We investigate the eigenmodes of the massless Dirac operator to extract the scale-dependent fermion mass anomalous dimension gamma_m(mu). By combining simulations on multiple lattice volumes, and when possible several gauge couplings, we are able to measure the anomalous dimension across a wide range of energy scales. The method that we present is universal and can be applied to any lattice model of interest, including both conformal or chirally broken systems. We consider SU(3) lattice gauge theories with Nf=4, 8 and 12 light or massless fermions. The 4-flavor model behaves as expected for a QCD-like system and demonstrates that systematic effects are manageable in practical lattice calculations. Our 12-flavor results are consistent with the existence of an infrared fixed point, at which we predict the scheme-independent mass anomalous dimension gamma_m^*=0.32(3). For the 8-flavor model we observe a large anomalous dimension across a wide range of energy scales. Further investigation is required to determine whether Nf=8 is chirally broken and walking, or if it possesses a strongly-coupled conformal fixed point.

Anqi Cheng; Anna Hasenfratz; Gregory Petropoulos; David Schaich

2013-01-07T23:59:59.000Z

76

Electrochemical and neutron diffraction measurements of PdD{sub x} cathodes  

DOE Green Energy (OSTI)

Potentiometric and in-situ neutron diffraction measurements have been carried out on PdD{sub x} cathodes in LiOD-saturated D{sub 2}O solution. Open-circuit potentials of the PdD{sub x} electrode after interruption of high-intensity cathodic currents (300--500 mA/cm{sup 2}) showed a more negative potential ({epsilon} = 1010 mV, measured against a Hg/HgO reference electrode) than that expected from the literature. The anomalous potentials were observed for about 10--20 min after current interruption at x > 0.7 concentrations of deuterium. This phenomenon may indicate a metastable phase of the Pd-D system, which may be detected by neutron diffraction. In-situ neutron diffraction measurements, so far, have indicated only the evolution of the known {alpha} and {beta} phases of PdD{sub x}. Successful neutron diffraction measurements in electrochemical cells suggest the viability of this technique for in-situ investigations of metal-hydride battery electrodes in experiments when heavy-water electrolyte is used to model the MH{sub 2}/H{sub 2}O electrode.

Redey, L.; Myles, K.M.; Rotella, F.J.; Richardson, J.W. Jr.; Felcher, G.P.; Hitterman, R.L.; Kleb, R.

1991-12-31T23:59:59.000Z

77

Diffraction gratings used as identifying markers  

DOE Patents (OSTI)

A finely detailed diffraction grating is applied to an object as an identifier or tag which is unambiguous, difficult to duplicate, or remove and transfer to another item, and can be read and compared with prior readings with relative ease. The exact pattern of the diffraction grating is mapped by diffraction moire techniques and recorded for comparison with future readings of the same grating. 7 figures.

Deason, V.A.; Ward, M.B.

1991-03-26T23:59:59.000Z

78

Twenty years of diffraction at the Tevatron  

SciTech Connect

Results on diffractive particle interactions from the Fermilab Tevatron {bar p}p collider are placed in perspective through a QCD inspired phenomenological approach, which exploits scaling and factorization properties observed in data. The results discussed are those obtained by the CDF Collaboration from a comprehensive set of single, double, and multigap soft and hard diffraction processes studied during the twenty year period since 1985, when the CDF diffractive program was proposed and the first Blois Workshop was held.

Goulianos, K.; /Rockefeller U.

2005-10-01T23:59:59.000Z

79

On anomalous diffusion in a plasma in velocity space  

E-Print Network (OSTI)

The problem of anomalous diffusion in momentum space is considered for plasma-like systems on the basis of a new collision integral, which is appropriate for consideration of the probability transition function (PTF) with long tails in momentum space. The generalized Fokker-Planck equation for description of diffusion (in momentum space) of particles (ions, grains etc.) in a stochastic system of light particles (electrons, or electrons and ions, respectively) is applied to the evolution of the momentum particle distribution in a plasma. In a plasma the developed approach is also applicable to the diffusion of particles with an arbitrary mass relation, due to the small characteristic momentum transfer. The cases of an exponentially decreasing in momentum space (including the Boltzmann-like) kernel in the PT-function, as well as the more general kernels, which create the anomalous diffusion in velocity space due to the long tail in the PT-function, are considered. Effective friction and diffusion coefficients f...

Trigger, S A; van Heijst, G J F; Schram, P P J M; Sokolov, I M

2010-01-01T23:59:59.000Z

80

W and Anomalous Single Top Production at HERA  

E-Print Network (OSTI)

The analysis of $W$ production and the search for anomalous single top production is performed with the H1 detector at HERA with an integrated luminosity of 0.5 fb$^{-1}$, consisting of the complete high energy data from the HERA programme. Production cross section measurements of single $W$ production, as well as $W$ polarisation fractions in events containing isolated leptons and missing transverse momentum are also presented. In the context of a search for single top production an upper limit on the top production cross section $\\sigma_{ep\\to etX} < 0.16$ pb is established at the 95% confidence level, corresponding to an upper bound on the anomalous magnetic coupling $\\kappa_{tu\\gamma} < 0.14$.

E. Rizvi; for the H1 Collabortion

2008-07-22T23:59:59.000Z

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


81

Neutron Powder Diffraction Workshop (NPD2011)  

NLE Websites -- All DOE Office Websites (Extended Search)

Workshop Contact Information Instructors Application Form Sample Description HB2A at HFIR POWGEN at SNS filler About the Workshop Neutron powder diffraction is a widely used...

82

Available Technologies: Ultra-High Density Diffraction ...  

The researchers have demonstrated that an extremely high diffraction intensity ... www.lbl.gov/Tech-Transfer/licensing/index ... OF ENERGY OFFICE OF ...

83

Automated Transmission Kikuchi Diffraction for Nanomaterials ...  

Science Conference Proceedings (OSTI)

Presentation Title, Automated Transmission Kikuchi Diffraction for Nanomaterials Characterization in the SEM. Author(s), Scott Sitzman. On-Site Speaker...

84

Anomalous transport due to shear-Alfven waves  

SciTech Connect

The behavior of shear-Alfven eigenmodes and the accompanied anomalous transport have been investigated. In the particle simulation, equilibrium thermal fluctuations associated with the eigenmodes have been observed to nullify the zeroth-order shear near the rational surface through the induced second-order eddy current, and, in turn, give rise to the formation of magnetic islands which cause rapid electron energy transport in the region. The theoretical verification of the observed behavior is discussed.

Lee, W.W.; Chance, M.S.; Okuda, H.

1980-10-01T23:59:59.000Z

85

Anomalous transport and stabilization of collisionless drift-wave instabilities  

SciTech Connect

Extensive numerical simulations have been carried out to study the enhanced transport processes associated with the collisionless drift wave instabilities. The results indicate that the shear is effective in reducing the anomalous particle diffusion as predicted by theory; however, it is less so for the accompanied electron heat transfer. The quasilinear decay of the density profile is found to be the dominant mechanism for the nonlinear saturation. (auth)

Lee, W.W.; Okuda, H.

1975-12-01T23:59:59.000Z

86

Proposed solid-state Faraday anomalous-dispersion optical filter  

Science Conference Proceedings (OSTI)

We propose a Faraday anomalous dispersion optical filter (FADOF) based on a rare-earth ion doped crystal. We present theoretical analyses for the solid-state FADOF transmission. Our theoretical model predicts a maximum transmission efficiency of 71% and a double-peaked transmission spectrum with a bandwidth of 6 GHz under current experimental conditions. Our proposal may have important applications in optical communications.

Lin, Wei-Bin [Key Laboratory of Quantum Information, University of Science and Technology of China, CAS, Hefei 230026 (China); Institute of Laser Technology, Hefei University of Technology, Hefei 230009 (China); Zhou, Zong-Quan; Li, Chuan-Feng; Guo, Guang-Can [Key Laboratory of Quantum Information, University of Science and Technology of China, CAS, Hefei 230026 (China)

2011-11-15T23:59:59.000Z

87

On the origin of the anomalous precession of Mercury's perihelion  

E-Print Network (OSTI)

Action at distance in Newtonian physics is replaced by finite propagation speeds in classical post--Newtonian physics. As a result, the differential equations of motion in Newtonian physics are replaced by functional differential equations, where the delay associated with the finite propagation speed is taken into account. Newtonian equations of motion, with post--Newtonian corrections, are often used to approximate the functional differential equations. In ``On the origin of quantum mechanics'', preprint, physics/0505181, May 2005, a simple atomic model based on a functional differential equation which reproduces the quantized Bohr atomic model was presented. The unique assumption was that the electrodynamic interaction has a finite propagation speed. In ``On the origin of the gravitational quantization: The Titius--Bode Law'', preprint, physics/0507072, Jul 2005, a simple gravitational model based on a functional differential equation which gives a gravitational quantification and an explanation of the modified Titius--Bode law is described. Firstly, in this work, we recall the calculations made by Einstein to arrive at the explanation of the anomalous precession of Mercury's perihelion. Secondly, we recover an ancient work of Gerber in 1898 as a precursor of the retarded theories. In this paper Gerber gave an explanation of the anomalous precession of the Mercury's perihelion in terms of a velocity--dependent potential. In this paper an explanation of the anomalous precession of Mercury's perihelion is given in terms of a simple retarded potential, which, at first order, coincides with Gerber's potential, and which agrees with the author's previous works.

Jaume Gin

2005-10-11T23:59:59.000Z

88

Anomalous Lagrangians and the radiative muon capture in hydrogen  

E-Print Network (OSTI)

The structure of an anomalous Lagrangian of the pi-rho-omega-a_1 system is investigated within the hidden local SU(2)_R x SU(2)_L symmetry approach. The interaction of the external electromagnetic and weak vector and axial-vector fields with the above hadron system is included. The Lagrangian of interest contains the anomalous Wess-Zumino term following from the well known Wess-Zumino-Witten action and six independent homogenous terms. It is characterized by four constants that are to be determined from a fit to the data on various elementary reactions. Present data allows one to extract the constants with a good accuracy. The homogenous part of the Lagrangian has been applied in the study of anomalous processes that could enhance the high energy tail of the spectrum of photons, produced in the radiative muon capture in hydrogen. It should be noted that recently, an intensive search for such enhancement processes has been carried in the literature, in an attempt to resolve the so called "g_P puzzle": an about 50 % difference between the theoretical prediction of the value of the induced pseudoscalar constant g_P and its value extracted from the high energy tail of the photon spectrum, measured in the precision TRIUMF experiment. Here, more details on the studied material are presented and new results, obtained by using the Wess-Zumino term, are provided.

J. Smejkal; E. Truhlik; F. C. Khanna

2005-04-29T23:59:59.000Z

89

Thermostat for neutron-diffraction apparatus  

SciTech Connect

This paper describes a thermostat which has been designed for neutron-diffraction studies. The thermostat does not introduce any distortions into the beam of neutrons diffracted from the specimen. The range of operating temperatures is 300-1300 degrees K and the vacuum is 10/sup -6/ torr. The thermostat permits liquid, solid, and amorphous specimens to be studied.

Kozlov, E.N.; Nikolaev, V.O.; Skovorod'ko, S.N.; Tsirkunova, S.E.

1985-09-01T23:59:59.000Z

90

Evidence for an anomalous like-sign dimuon charge asymmetry  

SciTech Connect

We present a measurement of the like-sign dimuon asymmetry in semileptonic b-hadron decays, performed using 6.1 fb{sup -1} of p{bar p} collisions recorded with the D0 detector at a center-of-mass energy {radical}s = 1.96 TeV at the Fermilab Tevatron collider. This measured value is A{sub sl}{sup b} = [-0.957 {+-} 0.251 (stat) {+-} 0.146 (syst)] %, which disagrees with the Standard Model prediction at a statistical level of 3.2 {sigma}, and provides the first evidence of anomalous CP violation in the mixing of neutral B mesons.

Williams, M.R.J.; /Lancaster U.

2011-01-01T23:59:59.000Z

91

Anomalous Soft Photons Associated with Hadron Production in String Fragmentation  

Science Conference Proceedings (OSTI)

The bosonized QCD2+QED2 system for quarks with two flavors contains QCD2 and QED2 bound states, with an isoscalar photon at about 25 MeV and an isovector (I=1 J_{3}=0) photon at about 44 MeV. Consequently, when a quark and antiquark at the two ends of a string pulls apart from each other at high energies, hadrons and soft photons will be produced simultaneously in the fragmentation of the string. The production of the QED2 soft photons in association with hadrons may explain the anomalous soft photon data in hadron-hadron collisions and e^{+}-e^{-} annihilations at high energies.

Wong, Cheuk-Yin [ORNL

2011-01-01T23:59:59.000Z

92

Three loop MSbar transversity operator anomalous dimensions for fixed moment n <= 8  

E-Print Network (OSTI)

We compute the anomalous dimensions of the transversity operator at three loops in the MSbar scheme for fixed moment n where n n <= 7.

J. A. Gracey

2006-11-07T23:59:59.000Z

93

Anomalous effects due to the inertial anti-gravitational potential of the sun  

E-Print Network (OSTI)

It is introduced inertial anti-gravitational potential into the theory of gravity to stop gravitational collapse at the nuclear density and thus prevent singularities. It is considered effective gravity which includes Newtonian potential and inertial anti-gravitational potential. It is investigated footprints of the effective gravity in the solar system. The inertial anti-gravitational potential of the sun allows to explain the anomalous acceleration of Pioneer 10 and 11, the anomalous increase in the lunar semi-major axis, the residuals of the seasonal variation of the proper angular velocity of the earth, the anomalous increase of the Astronomical Unit, the anomalous shift of the perihelion of mercury.

D. L. Khokhlov

2007-10-31T23:59:59.000Z

94

Anomalous Small-angle Scattering with Soft X-rays at Al and Si K ...  

Science Conference Proceedings (OSTI)

Anomalous Small-angle Scattering with Soft X-rays at Al and Si K Absorption ... and Cooling Cycles in a High Strength Quenched and Tempered Structural Steel.

95

Kinetics of Methane Hydrate Decomposition Studied via in Situ Low Temperature X-ray Powder Diffraction  

SciTech Connect

Gas hydrates are known to have a slowed decomposition rate at ambient pressure and temperatures below the melting point of ice termed self-preservation or anomalous preservation. As hydrate exothermically decomposes, gas is released and water of the clathrate cages transforms into ice. Two regions of slowed decomposition for methane hydrate, 180 200 K and 230 260 K, were observed, and the kinetics were studied by in situ low temperature x-ray powder diffraction. The kinetic constants for ice formation from methane hydrate were determined by the Avrami model within each region and activation energies, Ea, were determined by the Arrhenius plot. Ea determined from the data for 180 200 K was 42 kJ/mol and for 230 260 K was 22 kJ/mol. The higher Ea in the colder temperature range was attributed to a difference in the microstructure of ice between the two regions.

Everett, Susan M [ORNL; Rawn, Claudia J [ORNL; Keffer, David J. [University of Tennessee, Knoxville (UTK); Mull, Derek L [ORNL; Payzant, E Andrew [ORNL; Phelps, Tommy Joe [ORNL

2013-01-01T23:59:59.000Z

96

NORMAL EMISSION PHOTOELECTRON DIFFRACTION STUDIES AT SSRL  

E-Print Network (OSTI)

DIFFRACTION STUDIES AT SSRL S. D. Kevan June 1980 TWO-WEEKDIFFRACTION STUDIES AT SSRL S.D. Kevan Materials andOur group has worked at SSRL using the normal emission

Kevan, S.D.

2013-01-01T23:59:59.000Z

97

Nuclear diffractive structure functions at high energies  

E-Print Network (OSTI)

A future high-energy electron-ion collider would explore the non-linear weakly-coupled regime of QCD, and test the Color Glass Condensate (CGC) approach to high-energy scattering. Hard diffraction in deep inelastic scattering off nuclei will provide many fundamental measurements. In this work, the nuclear diffractive structure function F_{2,A}^D is predicted in the CGC framework, and the features of nuclear enhancement and suppression are discussed.

Marquet, C; Lappi, T; Venugopalan, R

2008-01-01T23:59:59.000Z

98

Nuclear diffractive structure functions at high energies  

E-Print Network (OSTI)

A future high-energy electron-ion collider would explore the non-linear weakly-coupled regime of QCD, and test the Color Glass Condensate (CGC) approach to high-energy scattering. Hard diffraction in deep inelastic scattering off nuclei will provide many fundamental measurements. In this work, the nuclear diffractive structure function F_{2,A}^D is predicted in the CGC framework, and the features of nuclear enhancement and suppression are discussed.

C. Marquet; H. Kowalski; T. Lappi; R. Venugopalan

2008-05-30T23:59:59.000Z

99

Active diffraction gratings: Development and tests  

Science Conference Proceedings (OSTI)

We present the realization and characterization of an active spherical diffraction grating with variable radius of curvature to be used in grazing-incidence monochromators. The device consists of a bimorph deformable mirror on the top of which a diffraction grating with laminar profile is realized by UV lithography. The experimental results show that the active grating can optimize the beam focalization of visible wavelengths through its rotation and focus accommodation.

Bonora, S.; Frassetto, F.; Poletto, L. [Institute of Photonics and Nanotechnologies, National Council for Research of Italy, via Trasea, 7, Padova 35131 (Italy); Zanchetta, E.; Della Giustina, G.; Brusatin, G. [Industrial Engineering Department, University of Padova, Via Marzolo 9, 35131 Padova (Italy)

2012-12-15T23:59:59.000Z

100

Anomalous diffusion and scaling in coupled stochastic processes  

SciTech Connect

Inspired by problems in biochemical kinetics, we study statistical properties of an overdamped Langevin processes with the friction coefficient depending on the state of a similar, unobserved, process. Integrating out the latter, we derive the Pocker-Planck the friction coefficient of the first depends on the state of the second. Integrating out the latter, we derive the Focker-Planck equation for the probability distribution of the former. This has the fonn of diffusion equation with time-dependent diffusion coefficient, resulting in an anomalous diffusion. The diffusion exponent can not be predicted using a simple scaling argument, and anomalous scaling appears as well. The diffusion exponent of the Weiss-Havlin comb model is derived as a special case, and the same exponent holds even for weakly coupled processes. We compare our theoretical predictions with numerical simulations and find an excellent agreement. The findings caution against treating biochemical systems with unobserved dynamical degrees of freedom by means of standandard, diffusive Langevin descritpion.

Bel, Golan [Los Alamos National Laboratory; Nemenman, Ilya [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "multiple-wavelength anomalous diffraction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
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101

Indication of anomalous heat energy production in a reactor device  

E-Print Network (OSTI)

An experimental investigation of possible anomalous heat production in a special type of reactor tube named E-Cat HT is carried out. The reactor tube is charged with a small amount of hydrogen loaded nickel powder plus some additives. The reaction is primarily initiated by heat from resistor coils inside the reactor tube. Measurement of the produced heat was performed with high-resolution thermal imaging cameras, recording data every second from the hot reactor tube. The measurements of electrical power input were performed with a large bandwidth three-phase power analyzer. Data were collected in two experimental runs lasting 96 and 116 hours, respectively. An anomalous heat production was indicated in both experiments. The 116-hour experiment also included a calibration of the experimental set-up without the active charge present in the E-Cat HT. In this case, no extra heat was generated beyond the expected heat from the electric input. Computed volumetric and gravimetric energy densities were found to be far above those of any known chemical source. Even by the most conservative assumptions as to the errors in the measurements, the result is still one order of magnitude greater than conventional energy sources.

Giuseppe Levi; Evelyn Foschi; Torbjrn Hartman; Bo Histad; Roland Pettersson; Lars Tegnr; Hanno Essn

2013-05-16T23:59:59.000Z

102

Anomalous Heat Conduction in One-Dimensional Momentum-Conserving Systems Onuttom Narayan1,2  

E-Print Network (OSTI)

Anomalous Heat Conduction in One-Dimensional Momentum-Conserving Systems Onuttom Narayan1 will obey Fourier's law of conduction j ÿrT; (1) where T is the local temperature and is the heat con but not divergent conduc- tivity [3].) Recently, it has been argued [9] that such anomalous heat conduction occurs

California at Santa Cruz, University of

103

Neutron Diffraction in the Toolbox for Materials Science and ...  

Science Conference Proceedings (OSTI)

Neutron Diffraction Studies of Residual Stresses around Gouges and Gouged Dents in Pipelines Neutron Diffraction Study and EVPSC Modeling of the...

104

High Energy Diffraction Microscopy at the Advanced Photon Source ...  

Science Conference Proceedings (OSTI)

The APS 1-ID beamline is dedicated to high-energy diffraction and the status of the ... High Energy Diffraction Microscopy at the Advanced Photon Source 1-ID...

105

Anomalous evolution of Ar metastable density with electron density in high density Ar discharge  

SciTech Connect

Recently, an anomalous evolution of argon metastable density with plasma discharge power (electron density) was reported [A. M. Daltrini, S. A. Moshkalev, T. J. Morgan, R. B. Piejak, and W. G. Graham, Appl. Phys. Lett. 92, 061504 (2008)]. Although the importance of the metastable atom and its density has been reported in a lot of literature, however, a basic physics behind the anomalous evolution of metastable density has not been clearly understood yet. In this study, we investigated a simple global model to elucidate the underlying physics of the anomalous evolution of argon metastable density with the electron density. On the basis of the proposed simple model, we reproduced the anomalous evolution of the metastable density and disclosed the detailed physics for the anomalous result. Drastic changes of dominant mechanisms for the population and depopulation processes of Ar metastable atoms with electron density, which take place even in relatively low electron density regime, is the clue to understand the result.

Park, Min; Chang, Hong-Young [Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 305-701 (Korea, Republic of); You, Shin-Jae; Kim, Jung-Hyung [Center for Vacuum Technology, Korea Research Institute of Standards and Science, Daejeon, 305-306 (Korea, Republic of); Shin, Yong-Hyeon

2011-10-15T23:59:59.000Z

106

Multiple wavelength time-of-flight sensor based on time-correlated single-photon counting  

E-Print Network (OSTI)

The optical system was based around a commercially available Meade LX200 catadioptric Schmidt a collection fiber and camera in the image plane of the telescope; and c optical routing: an optical routing- get and focused it onto an optical fiber core. This fiber was positioned in the image plane

Buller, Gerald S.

107

Evidence for an anomalous like-sign dimuon charge asymmetry  

Science Conference Proceedings (OSTI)

We measure the charge asymmetry A of like-sign dimuon events in 6.1 fb{sup -1} of pp collisions recorded with the D0 detector at a center-of-mass energy {radical}(s)=1.96 TeV at the Fermilab Tevatron collider. From A, we extract the like-sign dimuon charge asymmetry in semileptonic b-hadron decays: A{sub sl}{sup b}=-0.00957{+-}0.00251 (stat){+-}0.00146 (syst). This result differs by 3.2 standard deviations from the standard model prediction A{sub sl}{sup b}(SM)=(-2.3{sub -0.6}{sup +0.5})x10{sup -4} and provides first evidence of anomalous CP violation in the mixing of neutral B mesons.

Abazov, V. M.; Alexeev, G. D.; Golovanov, G.; Kharzheev, Y. N.; Malyshev, V. L.; Tokmenin, V. V.; Vertogradov, L. S.; Yatsunenko, Y. A. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Abbott, B.; Gutierrez, P.; Hossain, S.; Severini, H.; Skubic, P.; Strauss, M. [University of Oklahoma, Norman, Oklahoma 73019 (United States); Abolins, M.; Benitez, J. A.; Brock, R.; Edmunds, D.; Fisher, W.; Hall, I. [Michigan State University, East Lansing, Michigan 48824 (United States)

2010-08-01T23:59:59.000Z

108

Evidence for an anomalous like-sign dimuon charge asymmetry  

SciTech Connect

The D0 Collaboration has recently measured the charge asymmetry of same-sign dimuon events in 6.1 fb{sup -1} of data collected in p{bar p} collisions at the Fermilab Tevatron collider. This allows the extraction of the same-sign dimuon charge asymmetry in semileptonic b-hadron decays, which is predicted to be extremely small in the standard model. The result is found to differ by 3.2 standard deviations from the standard model value, providing the first evidence for anomalous CP-violation in the mixing of neutral B mesons. The analysis, and the method used to extract the result are described in detail.

Brooijmans, Gustaaf; /Columbia U.

2010-05-01T23:59:59.000Z

109

The restaurant at the end of the random walk: recent developments in the description of anomalous transport by fractional dynamics.  

E-Print Network (OSTI)

The restaurant at the end of the random walk: recent developments in the description of anomalous transport by fractional dynamics.

Metzler, R

2004-01-01T23:59:59.000Z

110

Magnetic Structure Determination from Neutron Diffraction Data  

NLE Websites -- All DOE Office Websites (Extended Search)

logo logo Magnetic Structure Determination from Neutron Diffraction Data September 17 - 20, 2012 logo Oak Ridge National Laboratory - Oak Ridge, Tennessee, USA About the Workshop Program Lecture Notes Useful Links Organizers Travel & Lodging Wireless Networking Photos filler About the Workshop molecule The Magnetic Structure Determination Workshop 2012 concluded on September 20. The aim of this workshop was to enhance the community studying magnetism in materials by learning from experts the essential theoretical foundations to magnetic representation analysis and work through real examples to gain experience in solving and refining magnetic structures from neutron powder and single crystal diffraction data. Invited speakers: Juan Rodríguez-Carvajal (ILL, Grenoble)

111

Deep inelastic scattering and diffraction at HERA  

Science Conference Proceedings (OSTI)

Recent results on deep inelastic scattering and diffraction at HERA obtained by the H1 and ZEUS experiments are presented. The proton structure function F 2 has been measured with the 1994 data in a new kinematic region of Q 2?2 GeV2 and x?4.510?5. The rise in F 2 with decreasing x persists. Results on the determination of the gluon momentum density of the proton are also presented. The diffractive structure function has been measured using large rapidity gap events. The results are interpreted in terms of the pomeron structure.

Johnny S. T. Ng; on behalf of the H1 and ZEUS collaborations

1996-01-01T23:59:59.000Z

112

X-Ray Diffraction on NIF  

SciTech Connect

The National Ignition Facility (NIF) is currently a 192 beam, 1.6 MJ laser. NIF Ramp-Compression Experiments have already made the relevant exo-planet pressure range from 1 to 50 Mbar accessible. We Proposed to Study Carbon Phases by X-Ray Diffraction on NIF. Just a few years ago, ultra-high pressure phase diagrams for materials were very 'simple'. New experiments and theories point out surprising and decidedly complex behavior at the highest pressures considered. High pressures phases of aluminum are also predicted to be complex. Recent metadynamics survey of carbon proposed a dynamic pathway among multiple phases. We need to develop diagnostics and techniques to explore this new regime of highly compressed matter science. X-Ray Diffraction - Understand the phase diagram/EOS/strength/texture of materials to 10's of Mbar. Strategy and physics goals: (1) Powder diffraction; (2) Begin with diamond; (3) Continue with metals etc.; (4) Explore phase diagrams; (5) Develop liquid diffraction; and (6) Reduce background/improve resolution.

Eggert, J H; Wark, J

2012-02-15T23:59:59.000Z

113

DIFFRACTION STUDIES OF ICE Alexe BOSAK  

E-Print Network (OSTI)

as ice-nine [K. Vonnegut, Cat's Cradle] #12;Phase diagram of water #12;Phase diagram of water Here we areDIFFRACTION STUDIES OF ICE Alexeï BOSAK European Synchrotron Radiation Facility #12;Ice as the mild threat ice Ih the only ice in the crust #12;Ice as the absolute weapon Ice IX : melting point 45.8°C

Titov, Anatoly

114

Diffraction gratings used as identifying markers  

DOE Patents (OSTI)

A finely detailed defraction grating is applied to an object as an identifier or tag which is unambiguous, difficult to duplicate, or remove and transfer to another item, and can be read and compared with prior readings with relative ease. The exact pattern of the defraction grating is mapped by diffraction moire techniques and recorded for comparison with future readings of the same grating.

Deason, Vance A. (Idaho Falls, ID); Ward, Michael B. (Idaho Falls, ID)

1991-01-01T23:59:59.000Z

115

Diffractive and Exclusive Production at the Tevatron  

SciTech Connect

Exclusive Higgs production, in which the event consists of nothing but the leading protons and a Higgs boson, has been proposed as a channel in which to study the properties of the Higgs boson at the Large Hadron Collider (LHC). Although we do not expect to observe exclusive Higgs-boson production at the Tevatron, we can observe similar processes which provide a calibration for theoretical predictions of exclusive Higgs production at the LHC. The CDF measurements of exclusive dijet and diphoton production, examples of such processes, are presented in Sec. 2. Single diffraction has been studied extensively at the Tevatron in Run I, including diffractive dijet and W/Z-boson production. New results with extended kinematical reach allowed by the larger Run II dataset are presented in Sec. 3. CDF II includes forward detectors designed for studying diffractive physics. The MiniPlug calorimeters cover the pseudorapidity region 3.5<|{eta}|<5.1. Beam Shower Counters (BSC) surrounding the beampipe in several locations detect particles in the forward region 5.4<|{eta}|<7.4. A spectrometer consisting of three Roman-pot detectors preceded by Tevatron dipoles is used to track diffractive antiprotons which have lost a fraction 0.03<{zeta}<0.10 of the beam momentum.

Convery, M.E.; Collaboration, for the CDF

2008-10-01T23:59:59.000Z

116

Ris-M-2874 Neutron Diffraction Experiments  

E-Print Network (OSTI)

;1. Introduction The nuclear spin systems in metals provide ideal models to test theoretical ideas by experiments Roskilde, Denmark August 1990 #12;Abstract Nuclear spins in silver constitute an ideal antiferromagnetic study the feasibility of neutron diffraction experiments on nuclear magnetic order in silver

117

Detonation Diffraction into a Confined Volume  

E-Print Network (OSTI)

Detonation diffraction has been, and remains, an active area of research. However, detonation diffraction into a confined volume, and specifically the transformation of a planar detonation into a cylindrical detonation, is an area which has received little attention. Experimental work needs to be conducted on detonation diffraction into a confined volume to better understand how the interaction of the diffracted shock wave with a confining wall impacts the detonation diffraction process. Therefore, a facility was constructed to study this problem, and experiments were conducted to determine under what conditions a planar detonation could be successfully transformed into a cylindrical detonation. Four different fuel-oxidizer mixtures, C?H?+ 2.5 O?, C?H?+ 4 O?, C?H?+ 3 O? and H?+ 0.5 O?, were tested in this study using a combination of pressure transducers and soot foil records as diagnostics. Three different regimes of successful transmission; spontaneous re-ignition, continuous reflected re-initiation, and discontinuous reflected re-initiation, were identified. The detonation cell size and the distance from the tube exit to the confining wall, or gap size, were determined to be the most important parameters in the transmission process and a linear correlation for determining whether or not transmission will be successful for a given set of initial conditions was developed for gap sizes between 10 and 35 mm. For gap sizes smaller than 10 mm or gap size larger than 35 mm the linear correlation does not apply. Finally, the results of this study are compared to results on detonation diffraction into a confined volume available in the literature and explanations for any disagreements are given. This study showed that when compared to transmission of a detonation into an unconfined volume, the transmission of a detonation into a confined volume, for the majority of gap sizes, is possible for a wider range of conditions. However, for extremely small gap sizes, when compared to transmission into an unconfined volume, the range of conditions for which successful transmission is possible into a confined volume is actually narrower.

Polley, Nolan Lee

2010-12-01T23:59:59.000Z

118

Anomalous orebody within the Ambrosia Lake trend at Sandstone Mine  

SciTech Connect

The Sandstone Mine contains an anomalous orebody that lacks the characteristic coloring and high gamma-ray expression typically associated with uranium ore in the Ambrosia Lake district. The orebody occurs at the downdip edge of a tongue of hematitic sand in the basal sand unit of the Westwater Canyon Member of the Morrison Formation. The orebody ranges from white to light gray in color. Preliminary analysis indicates the presence of uranophane (Ca(UO/sub 2/)/sub 2/SiO/sub 3/(OH)/sub 2/.5H/sub 2/O), evidently altered from coffinite, which is the predominant uranium mineral in the district. Equivalent U/sub 3/O/sub 8/ indicates that this orebody is relatively recent. Oxidizing meteoric water, which formed a geochemical cell, remobilized uranium minerals in preexisting trend orebodies and deposited the uranium downdip of the furthest extent of this cell. Post-Dakota deformation influenced the course of the migrating meteoric water and the extent of the redox interface controlling the orebody. As sampling and mining lower grades of uranium becomes increasingly more economical, the potential for unknown reserves adjacent to the redox interface should not be overlooked.

Foster, J.F.; Quintanar, R.J.

1980-01-01T23:59:59.000Z

119

Quantum mechanics in fractional and other anomalous spacetimes  

SciTech Connect

We formulate quantum mechanics in spacetimes with real-order fractional geometry and more general factorizable measures. In spacetimes where coordinates and momenta span the whole real line, Heisenberg's principle is proven and the wave-functions minimizing the uncertainty are found. In spite of the fact that ordinary time and spatial translations are broken and the dynamics is not unitary, the theory is in one-to-one correspondence with a unitary one, thus allowing us to employ standard tools of analysis. These features are illustrated in the examples of the free particle and the harmonic oscillator. While fractional (and the more general anomalous-spacetime) free models are formally indistinguishable from ordinary ones at the classical level, at the quantum level they differ both in the Hilbert space and for a topological term fixing the classical action in the path integral formulation. Thus, all non-unitarity in fractional quantum dynamics is encoded in a contribution depending only on the initial and final states.

Calcagni, Gianluca [Max Planck Institute for Gravitational Physics (Albert Einstein Institute), Am Muehlenberg 1, D-14476 Golm (Germany); Instituto de Estructura de la Materia, CSIC, Serrano 121, 28006 Madrid (Spain); Nardelli, Giuseppe [Dipartimento di Matematica e Fisica, Universita Cattolica, via Musei 41, 25121 Brescia (Italy); INFN Gruppo Collegato di Trento, Universita di Trento, 38100 Povo (Trento) (Italy); Scalisi, Marco [Max Planck Institute for Gravitational Physics (Albert Einstein Institute), Am Muehlenberg 1, D-14476 Golm (Germany); Centre for Theoretical Physics, University of Groningen, Nijenborgh 4, 9747 AG Groningen (Netherlands)

2012-10-15T23:59:59.000Z

120

Anomalous North Pacific Atmospheric Circulation and Large Winter Floods in the Southwestern United States  

Science Conference Proceedings (OSTI)

Specific anomalous atmospheric circulation conditions over the North Pacific are conducive to the occurrence of the largest winter floods (?10-yr return period) on rivers in six hydroclimatic subregions of Arizona and southern Utah, Nevada, and ...

Lisa L. Ely; Yehouda Enzel; Daniel R. Cayan

1994-06-01T23:59:59.000Z

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


121

Regional Weather Patterns during Anomalous AirSea Fluxes at the Kuroshio Extension Observatory (KEO)  

Science Conference Proceedings (OSTI)

The weather patterns during periods of anomalous surface fluxes in the Kuroshio recirculation gyre of the western North Pacific are documented. Separate analyses are carried out for the cold season (October March) when the net surface heat flux ...

Nicholas A. Bond; Meghan F. Cronin

2008-04-01T23:59:59.000Z

122

Nature of the Soft Gamma Repeaters and Anomalous X-ray Pulsars  

E-Print Network (OSTI)

I summarize recent developments in the magnetar model of the Soft Gamma Repeaters and Anomalous X-ray Pulsars, give a critical inventory of alternative models for the AXPs, and outline the improved diagnostics expected from present observational efforts.

Christopher Thompson

2001-10-30T23:59:59.000Z

123

Impact of Anomalous Ocean Heat Transport on the North Atlantic Oscillation  

Science Conference Proceedings (OSTI)

Coupled atmosphereocean dynamics in the North Atlantic is studied by means of a simple model, featuring a baroclinic three-dimensional atmosphere coupled to a slab ocean. Anomalous oceanic heat transport due to wind-driven circulation is ...

Fabio DAndrea; Arnaud Czaja; John Marshall

2005-12-01T23:59:59.000Z

124

Objective Identification of Echoes Due to Anomalous Propagation in Weather Radar Data  

Science Conference Proceedings (OSTI)

Serious contamination of weather radar data can occur in atmospheric conditions that cause anomalous propagation of the radar beam. Excessive downward refraction of the beam may be sufficient to cause ground returns (anaprop), which may be ...

J. A. Pamment; B. J. Conway

1998-02-01T23:59:59.000Z

125

Anomalous Near-Field Heat Transfer between a Cylinder and a Perforated Surface  

E-Print Network (OSTI)

We predict that the near-field radiative heat-transfer rate between a cylinder and a perforated surface depends nonmonotonically on their separation. This anomalous behavior, which arises due to evanescent-wave effects, ...

Rodriguez-Wong, Alejandro

126

Coexistence and efficiency of normal and anomalous transport by molecular motors in living cells  

E-Print Network (OSTI)

Recent experiments reveal both passive subdiffusion of various nanoparticles and anomalous active transport of such particles by molecular motors in the molecularly crowded environment of living biological cells. Passive and active microrheology reveals that the origin of this anomalous dynamics is due to the viscoelasticity of the intracellular fluid. How do molecular motors perform in such a highly viscous, dissipative environment? Can we explain the observed co-existence of the anomalous transport of relatively large particles of 100 to 500 nm in size by kinesin motors with the normal transport of smaller particles by the same molecular motors? What is the efficiency of molecular motors in the anomalous transport regime? Here we answer these seemingly conflicting questions and consistently explain experimental findings in a generalization of the well-known continuous diffusion model for molecular motors with two conformational states in which viscoelastic effects are included.

Igor Goychuk; Vasyl O. Kharchenko; R. Metzler

2013-09-26T23:59:59.000Z

127

Forward physics with tagged protons at the LHC: QCD and anomalous couplings  

E-Print Network (OSTI)

We present some physics topics that can be studied at the LHC using proton tagging. We distinguish the QCD (Pomeron structure, BFKL analysis...) from the exploratory physics topics (HIggs boson, anomalous couplings between photons and $W/Z$ bosons

Royon, C

2013-01-01T23:59:59.000Z

128

Physics with tagged protons at the LHC: understanding the Pomeron structure and anomalous coupling studies  

E-Print Network (OSTI)

We describe different physics topics which can be performed at the LHC using tagged intact protons, namely a better understanding of the Pomeron structure in terms of quarks and gluons, and the serach for quartic anomalous couplings.

Royon, C

2013-01-01T23:59:59.000Z

129

Deducing Anomalous Wave Source Regions during the Life Cycles of Persistent Flow Anomalies  

Science Conference Proceedings (OSTI)

Anomalous wave source regions are identified during the life cycles of persistent flow anomalies occurring over the North Pacific and North Atlantic Oceans during boreal winter. These cases project strongly upon the PacificNorth American and ...

Robert X. Black

1997-04-01T23:59:59.000Z

130

The Statistics and Horizontal Structure of Anomalous Weather Regimes in the Community Climate Model  

Science Conference Proceedings (OSTI)

The statistics, horizontal structure, and linear barotropic dynamics of anomalous weather regimes are evaluated in a 15-winter integration of the NCAR Community Climate Model (CCM2). Statistical and ensemble analyses of simulated regimes are ...

Robert X. Black; Katherine J. Evans

1998-04-01T23:59:59.000Z

131

Contributions to the muon's anomalous magnetic moment from a hidden sector  

SciTech Connect

Research Highlights: > Described scenario involving hidden and connector particles that couple to the standard model which could be relevant for dark matter. > Examined constraints on such particles in the case that the SM particle they couple to is the muon. > Found regions of couplings which could explain the discrepancy in the muon's anomalous magnetic moment which differ for different hidden and connector particles' spins. - Abstract: The measurement of the anomalous magnetic moment of the muon provides a stringent test of the standard model and of any physics that lies beyond it. There is currently a deviation of 3.1{sigma} between the standard model prediction for the muon's anomalous magnetic moment and its experimental value. We calculate the contribution to the anomalous magnetic moment in theories where the muon couples to a particle in a hidden sector (that is, uncharged under the standard model) and a connector (which has nontrivial standard model gauge and hidden sector quantum numbers).

McKeen, David, E-mail: mckeen@uvic.ca [Enrico Fermi Institute and Department of Physics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States)

2011-06-15T23:59:59.000Z

132

Application of a Bayesian Classifier of Anomalous Propagation to Single-Polarization Radar Reflectivity Data  

Science Conference Proceedings (OSTI)

A nave Bayes classifier (NBC) was developed to distinguish precipitation echoes from anomalous propagation (anaprop). The NBC is an application of Bayes's theorem, which makes its classification decision based on the class with the maximum a ...

Justin R. Peter; Alan Seed; Peter J. Steinle

2013-09-01T23:59:59.000Z

133

Phase-shifting point diffraction interferometer  

DOE Patents (OSTI)

Disclosed is a point diffraction interferometer for evaluating the quality of a test optic. In operation, the point diffraction interferometer includes a source of radiation, the test optic, a beam divider, a reference wave pinhole located at an image plane downstream from the test optic, and a detector for detecting an interference pattern produced between a reference wave emitted by the pinhole and a test wave emitted from the test optic. The beam divider produces separate reference and test beams which focus at different laterally separated positions on the image plane. The reference wave pinhole is placed at a region of high intensity (e.g., the focal point) for the reference beam. This allows reference wave to be produced at a relatively high intensity. Also, the beam divider may include elements for phase shifting one or both of the reference and test beams.

Medecki, Hector (Berkeley, CA)

1998-01-01T23:59:59.000Z

134

Phase-shifting point diffraction interferometer  

DOE Patents (OSTI)

Disclosed is a point diffraction interferometer for evaluating the quality of a test optic. In operation, the point diffraction interferometer includes a source of radiation, the test optic, a beam divider, a reference wave pinhole located at an image plane downstream from the test optic, and a detector for detecting an interference pattern produced between a reference wave emitted by the pinhole and a test wave emitted from the test optic. The beam divider produces separate reference and test beams which focus at different laterally separated positions on the image plane. The reference wave pinhole is placed at a region of high intensity (e.g., the focal point) for the reference beam. This allows reference wave to be produced at a relatively high intensity. Also, the beam divider may include elements for phase shifting one or both of the reference and test beams. 8 figs.

Medecki, H.

1998-11-10T23:59:59.000Z

135

Diffractive phenomena in high energy processes  

E-Print Network (OSTI)

We review the evolution of the studies of diffractive processes in the strong interaction over the last 60 years. First, we briefly outline the early developments of the theory based on analyticity and unitarity of the S-matrix, including the derivation and exploration of the Regge trajectories and related moving cuts. Special attention is paid to the concept of the Pomeron trajectory introduced for description of total, elastic and diffractive cross sections at high energies and to the emergence of the dynamics of multi-Pomeron interactions.The role of large longitudinal distances and color coherent phenomena for the understanding of inelastic diffraction in hadron-hadron scattering and deep inelastic scattering is emphasized. The connection of these phenomena to the cancellation of the contribution of the Glauber approximation in hadron-nucleus collisions and to the understanding of the Gribov-Glauber approximation is explained. The presence of different scales in perturbative QCD due to masses of heavy quarks has led to the emergence of numerous new phenomena including non-universality of the slopes of Regge trajectories made of light and heavy quarks and non-universal energy dependence of elastic cross sections. The application of the perturbative QCD techniques allowed us to calculate from the first principles the interaction of small transverse size color singlets with hadrons leading to the development of the quantitative theory of hard exclusive reactions and to the successful prediction of many regularities in hard large mass diffraction. It also led to the prediction of the phenomenon of complete transparency of nuclear matter in QCD in special processes. The conflict of perturbative QCD with probability conservation for high energy processes of virtual photon-nucleon scattering is explained. Some properties of the new QCD regime are outlined.

Leonid Frankfurt; Mark Strikman

2013-04-16T23:59:59.000Z

136

Diffraction smoothing aperture for an optical beam  

SciTech Connect

The disclosure is directed to an aperture for an optical beam having an irregular periphery or having perturbations imposed upon the periphery to decrease the diffraction effect caused by the beam passing through the aperture. Such apertures are particularly useful with high power solid state laser systems in that they minimize the problem of self-focusing which frequently destroys expensive components in such systems.

Judd, O' Dean P. (Los Alamos, NM); Suydam, Bergen R. (Los Alamos, NM)

1976-01-01T23:59:59.000Z

137

Diffraction gratings used as identifying markers  

DOE Patents (OSTI)

A finely detailed defraction grating is applied to an object as an identifier or tag which is unambiguous, difficult to duplicate, or remove and transfer to another item, and can be read and compared with prior readings with relative ease. The exact pattern of the defraction grating is mapped by diffraction moire techniques and recorded for comparison with future readings of the same grating. 7 figs.

Deason, V.A.; Ward, M.B.

1989-08-03T23:59:59.000Z

138

Field implementation of geophysical diffraction tomography  

SciTech Connect

Geophysical diffraction tomography is a new technique that shows promise as a tool for quantitative subsurface (below-ground) imaging. The approach being used is based upon the filtered backpropagation algorithm, which is a mathematical extension of the reconstruction software used in conventional X-ray CAT scanners. The difference between this method and existing methods is that the new algorithm rigorously accounts for diffraction effects through an exact inversion of the wave equation. This refinement is necessary in that it admits the use of acoustic and long-wavelength electromagnetic waves, allowing tomography to be taken from the laboratory to the field. ORNL's effort in geophysical diffraction tomography involves reducing the filtered backpropagation algorithm to practice. This requires the design and construction of field instrumentation as well as the development of an improved algorithm. The original algorithm requires the imaged region to be illuminated by plane waves. This requirement simplifies the algorithm but complicates its field implementation in that plane waves are difficult to generate. Consequently, ORNL has been working to generalize the filtered backpropagation algorithm to allow a broader range of incoming wave fields which can more easily be realized in the field. The instrumentation aspects involve the selection of appropriate sonic sources and receivers along with the development of a state-of-art, portable, computer-controlled, multichannel data acquisition system. 5 references, 6 figures.

Witten, A.J.; Stevens, S.S.

1984-01-01T23:59:59.000Z

139

The Diffraction of Kelvin Waves and Bores at Coastal Bends  

Science Conference Proceedings (OSTI)

Bends in coastal mountain ranges may diffract propagating atmospheric Kelvin waves and trapped coastal currents. Analytic solutions exist for the diffraction of both linear Kelvin waves and linear nonrotating gravity waves. Within the context of ...

William C. Skamarock; Joseph B. Klemp; Richard Rotunno

1996-05-01T23:59:59.000Z

140

Diffraction Studies of Irradiated Cladding and Duct Reactor Materials  

Science Conference Proceedings (OSTI)

Symposium, Characterization of Nuclear Reactor Materials and Components with Neutron and Synchrotron Radiation. Presentation Title, Diffraction Studies of...

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


141

Phase-shifting point diffraction interferometer grating designs  

DOE Patents (OSTI)

In a phase-shifting point diffraction interferometer, by sending the zeroth-order diffraction to the reference pinhole of the mask and the first-order diffraction to the test beam window of the mask, the test and reference beam intensities can be balanced and the fringe contrast improved. Additionally, using a duty cycle of the diffraction grating other than 50%, the fringe contrast can also be improved.

Naulleau, Patrick (Oakland, CA); Goldberg, Kenneth Alan (Berkeley, CA); Tejnil, Edita (San Carlos, CA)

2001-01-01T23:59:59.000Z

142

Diffractive Pion Dissociation into ? ? ? + ? ? ? + ? ? at COMPASS  

Science Conference Proceedings (OSTI)

At the COMPASS experiment a sample of ?380000 exclusive events of diffractive pion dissociation on a lead target into a ? ? ? + ? ? ? + ? ? final state has been recorded in 2004. The 5? invariant mass spectrum shows a momentum transfer dependent structure peaking around 1.8? GeV / c 2 . In the (4?) 0 subsystem there is a clear signal for the f 1 (1285) resonance decaying into 4 pions. In this note we describe the data sample and explore the physics potential of this final state.

S. Neubert; The COMPASS collaboration

2010-01-01T23:59:59.000Z

143

Optical-diffraction method for determining crystal orientation  

DOE Patents (OSTI)

Disclosed is an optical diffraction technique for characterizing the three-dimensional orientation of a crystal sample. An arbitrary surface of the crystal sample is texture etched so as to generate a pseudo-periodic diffraction grating on the surface. A laser light beam is then directed onto the etched surface, and the reflected light forms a farfield diffraction pattern in reflection. Parameters of the diffraction pattern, such as the geometry and angular dispersion of the diffracted beam are then related to grating shape of the etched surface which is in turn related to crystal orientation. This technique may be used for examining polycrystalline silicon for use in solar cells.

Sopori, B.L.

1982-05-07T23:59:59.000Z

144

Anomalously High B-Values In The South Flank Of Kilauea Volcano, Hawaii-  

Open Energy Info (EERE)

Anomalously High B-Values In The South Flank Of Kilauea Volcano, Hawaii- Anomalously High B-Values In The South Flank Of Kilauea Volcano, Hawaii- Evidence For The Distribution Of Magma Below Kilauea'S East Rift Zone Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Anomalously High B-Values In The South Flank Of Kilauea Volcano, Hawaii- Evidence For The Distribution Of Magma Below Kilauea'S East Rift Zone Details Activities (1) Areas (1) Regions (0) Abstract: The pattern of b-value of the frequency-magnitude relation, or mean magnitude, varies little in the Kaoiki-Hilea area of Hawaii, and the b-values are normal, with b=0.8 in the top 10 km and somewhat lower values below that depth. We interpret the Kaoiki-Hilea area as relatively stable, normal Hawaiian crust. In contrast, the b-values beneath Kilauea's South

145

Quantum anomalous Hall effect with cold atoms trapped in a square lattice  

E-Print Network (OSTI)

We propose an experimental scheme to realize the quantum anomalous Hall effect in an anisotropic square optical lattice which can be generated from available experimental setups of double-well lattices with minor modifications. A periodic gauge potential induced by atom-light interaction is introduced to give a Peierls phase for the nearest-neighbor site hopping. The quantized anomalous Hall conductivity is investigated by calculating the Chern number as well as the chiral gapless edge states of our system. Furthermore, we show in detail the feasability for its experimental detection through light Bragg scattering of the edge and bulk states with which one can determine the topological phase transition from usual insulating phase to quantum anomalous Hall phase.

Liu, Xiong-Jun; Liu, Xin; Wu, Congjun; Sinova, Jairo

2010-01-01T23:59:59.000Z

146

Anomalous shear wave attenuation in the shallow crust beneath the Coso  

Open Energy Info (EERE)

Anomalous shear wave attenuation in the shallow crust beneath the Coso Anomalous shear wave attenuation in the shallow crust beneath the Coso volcanic region, California Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Anomalous shear wave attenuation in the shallow crust beneath the Coso volcanic region, California Details Activities (1) Areas (1) Regions (0) Abstract: We use seismograms of local earthquakes to image relative shear wave attenuation structure in the shallow crust beneath the region containing the Coso volcanic-geothermal area of eastern California. SV and P wave amplitudes were measured from vertical component seismograms of earthquakes that occurred in the Coso-southern Sierra Nevada region from July 1983 to 1985. Seismograms of 16 small earthquakes show SV amplitudes which are greatly diminished at some azimuths and takeoff angles,

147

BEAMLINE 11-3 Materials Diffraction  

NLE Websites -- All DOE Office Websites (Extended Search)

3 3 CURRENT STATUS: Open SUPPORTED TECHNIQUES: X-ray scattering Thin film diffraction MAIN SCIENTIFIC DISCIPLINES: Materials / Environmental / Biology % TIME GENERAL USE: 100% SCHEDULING: Proposal Submittal and Scheduling Procedures Current SPEAR and Beam Line Schedules SOURCE: 26-pole, 2.0-Tesla ID Side Station BEAM LINE SPECIFICATIONS: energy range resolution DE/E spot size flux angular acceptance focused 12735 eV ~5 x 10-4 3.1 x 0.15 mm Usable 0.15 x 0.15 mm OPTICS: Single-crystal Si, Rh-coated - vertically focusing mirror MONOCHROMATOR: Bent cube-root I_beam Si(311), Side deflecting Monochromator Crystal Glitch Library Crystal changes need to be scheduled and coordinated in advance with BL support staff. ABSORPTION: INSTRUMENTATION: Standard detector: MAR345 Imaging Plate - 345 mm

148

2010 Diffraction Methods in Structural Biology  

Science Conference Proceedings (OSTI)

Advances in basic methodologies have played a major role in the dramatic progress in macromolecular crystallography over the past decade, both in terms of overall productivity and in the increasing complexity of the systems being successfully tackled. The 2010 Gordon Research Conference on Diffraction Methods in Structural Biology will, as in the past, focus on the most recent developments in methodology, covering all aspects of the process from crystallization to model building and refinement, complemented by examples of structural highlights and complementary methods. Extensive discussion will be encouraged and it is hoped that all attendees will participate by giving oral or poster presentations, the latter using the excellent poster display area available at Bates College. The relatively small size and informal atmosphere of the meeting provides an excellent opportunity for all participants, especially younger scientists, to meet and exchange ideas with leading methods developers.

Dr. Ana Gonzalez Phone:650-926-8682

2011-03-10T23:59:59.000Z

149

The Anomalous Nambu-Goldstone Theorem in Relativistic/Nonrelativistic Quantum Field Theory  

E-Print Network (OSTI)

The anomalous Nambu-Goldstone (NG) theorem which is found as a violation of counting law of the number of NG bosons of the normal NG theorem in nonrelativistic and Lorentz-symmetry-violated relativistic theories is studied in detail, with emphasis on its mathematical aspect from Lie algebras, geometry to number theory. The basis of counting law of NG bosons in the anomalous NG theorem is examined by Lie algebras (local) and Lie groups (global). A quasi-Heisenberg algebra is found generically in various symmetry breaking schema of the anomalous NG theorem, and it indicates that it causes a violation/modification of the Heisenberg uncertainty relation in an NG sector which can be experimentally confirmed. The formalism of effective potential is presented for understanding the mechanism of anomalous NG theorem with the aid of our result of Lie algebras. After an investigation on a bosonic kaon condensation model with a finite chemical potential as an explicit Lorentz-symmetry-breaking parameter, a model Lagrangian approach on the anomalous NG theorem is given for our general discussion. Not only the condition of the counting law of true NG bosons, but also the mechanism to generate a mass of massive NG boson is also found by our examination on the kaon condensation model. Furthermore, the generation of a massive mode in the NG sector is understood by the quantum uncertainty relation of the Heisenberg algebra, obtained from a symmetry breaking of a Lie algebra, which realizes in the effective potential of the kaon condensation model. Hence the relation between a symmetry breaking scheme, a Heisenberg algebra, a mode-mode coupling, and the mechanism of mass generation in an NG sector is established. Finally, some relations between the Riemann hypothesis and the anomalous NG theorem are presented.

Tadafumi Ohsaku

2013-12-01T23:59:59.000Z

150

"Pre-Acceleration of Anomalous Cosmic Ray Ions at Recurrent Solar Wind Shocks" Interstellar pickup ions and solar wind ions are two main sources of anomalous cosmic ray (ACR) ions. An important  

E-Print Network (OSTI)

"Pre-Acceleration of Anomalous Cosmic Ray Ions at Recurrent Solar Wind Shocks" Interstellar pickup ions and solar wind ions are two main sources of anomalous cosmic ray (ACR) ions. An important unresolved theoretical issue is how such low-energy seed ions are pre-accelerated to energies sufficiently

Christian, Eric

151

Hadronic Light-by-Light Scattering Contribution to the Muon Anomalous Magnetic Moment  

E-Print Network (OSTI)

We review the current status of theoretical calculations of the hadronic light-by-light scattering contribution to the muon anomalous magnetic moment. Different approaches and related issues such as OPE constraints and large breaking of chiral symmetry are discussed. Combining results of different models with educated guesses on the errors we come to the estimate $$a^{\\rm HLbL}=(10.5\\pm 2.6)\\times 10^{-10}.$$ The text is prepared as a contribution to the {\\it Glasgow White Paper on the present status of the Muon Anomalous Magnetic Moment}.

Joaquim Prades; Eduardo de Rafael; Arkady Vainshtein

2009-01-03T23:59:59.000Z

152

Anomalous Roughening of Curvature-Driven Growth With a Variable Interface Window  

E-Print Network (OSTI)

We studied the curvature-driven roughening of a disk domain pattern with a variable interface window. The relaxation of interface is driven by negative surface tension . When a domain boundary propagates radially at a constant rate, we found that evolution of interface roughness follows scaling dynamic behavior. The local growth exponents are substantially different from the global exponents. Curvature-driven roughening belongs to a new class of anomalous roughening dynamics. However, a different surface tension leads to different global exponents. This is different from that of interface evolution with a fixed-size window, which has universal exponent. The variable growth window leads to a new class of anomalous roughening dynamics.

Yong-Jun Chen; Yuko Nagamine; Tomohiko Yamaguchi; Kenichi Yoshikawa

2012-08-22T23:59:59.000Z

153

Tracking Waves and Vortex Nucleation in Excitable Systems with Anomalous Dispersion N. Manz, C.T. Hamik, and O. Steinbock  

E-Print Network (OSTI)

Tracking Waves and Vortex Nucleation in Excitable Systems with Anomalous Dispersion N. Manz, C of the underlying anomalous dispersion relation. DOI: 10.1103/PhysRevLett.92.248301 PACS numbers: 82.40.Ck, 05.45.­a and physicochemical systems [1,2]. Important examples include neuronal and cardiac tissue as well as gas discharge

Steinbock, Oliver

154

Definition: X-Ray Diffraction (XRD) | Open Energy Information  

Open Energy Info (EERE)

X-Ray Diffraction (XRD) X-Ray Diffraction (XRD) Jump to: navigation, search Dictionary.png X-Ray Diffraction (XRD) X-Ray Diffraction (XRD) is a laboratory-based technique commonly used for identification of crystalline materials and analysis of unit cell dimensions. One of two primary types of XRD analysis (X-ray powder diffraction and single-crystal XRD) is commonly applied to samples to obtain specific information about the crystalline material under investigation. X-ray powder diffraction is widely used in geology, environmental science, material science, and engineering to rapidly identify unknown crystalline substances (typically in less than 20 minutes). A pure, finely ground, and homogenized sample is required for determination of the bulk composition. Additional uses include detailed

155

X-Ray Diffraction (XRD) | Open Energy Information  

Open Energy Info (EERE)

X-Ray Diffraction (XRD) X-Ray Diffraction (XRD) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: X-Ray Diffraction (XRD) Details Activities (0) Areas (0) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Lab Analysis Techniques Exploration Sub Group: Rock Lab Analysis Parent Exploration Technique: Rock Lab Analysis Information Provided by Technique Lithology: Rapid and unambiguous identification of unknown minerals.[1] Stratigraphic/Structural: Hydrological: Thermal: Dictionary.png X-Ray Diffraction (XRD): X-Ray Diffraction (XRD) is a laboratory-based technique commonly used for identification of crystalline materials and analysis of unit cell dimensions. One of two primary types of XRD analysis (X-ray powder diffraction and single-crystal XRD) is commonly applied to samples to

156

Portable X-Ray Diffraction (XRD) | Open Energy Information  

Open Energy Info (EERE)

Portable X-Ray Diffraction (XRD) Portable X-Ray Diffraction (XRD) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Portable X-Ray Diffraction (XRD) Details Activities (0) Areas (0) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Field Techniques Exploration Sub Group: Data Collection and Mapping Parent Exploration Technique: Data Collection and Mapping Information Provided by Technique Lithology: Rapid and unambiguous identification of unknown minerals.[1] Stratigraphic/Structural: Hydrological: Thermal: Dictionary.png Portable X-Ray Diffraction (XRD): Portable X-Ray Diffraction (XRD) is a field-based technique that can be used for identification of crystalline materials and analysis of unit cell dimensions. Portable XRD analysis is similar to X-ray powder diffraction,

157

Advances in 3D Micro-Diffraction with Small Beams.  

Science Conference Proceedings (OSTI)

In-Situ Neutron Diffraction and Crystal Plasticity Modeling of a-Uranium In-Situ Studies of the ... Thermal Residual Stresses and Strains in Depleted Uranium.

158

X-Ray and Neutron Diffraction - Programmaster.org  

Science Conference Proceedings (OSTI)

Oct 20, 2010 ... Strain Determination in Nanoscale Microelectronic Materials Using X-Ray Diffraction: Conal Murray1; 1IBM T.J. Watson Research Center

159

Diffractive Production of Jets and Vector Bosons at the Tevatron  

E-Print Network (OSTI)

Recent results on diffractive dijet and vector boson production and exclusive dijet production from the Collider Detector at Fermilab (CDF) experiment are presented.

Kenichi Hatakeyama; for the CDF Collaboration

2008-12-08T23:59:59.000Z

160

Small-angle Synchrotron Diffraction Study of Partially Gasified Coal ...  

Science Conference Proceedings (OSTI)

Presentation Title, Small-angle Synchrotron Diffraction Study of Partially Gasified Coal Chars. Author(s), Keith Gordon McLennan, Daniel Roberts, Richard...

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


161

Neutron Diffraction Studies of Intercritically Austempered Ductile Irons  

Science Conference Proceedings (OSTI)

... a function of applied stress were determined using neutron diffraction at the NRSF2 at the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory.

162

Diffraction Methods for Measuring Crystal Scale Stress States  

Science Conference Proceedings (OSTI)

... for measuring lattice strains using High Energy x-ray Diffraction Microscopy ( HEDM) techniques at beamline 1-IDC at the Advanced Photon Source (APS).

163

Grain Boundary Deformation Analyzed Via X-Ray Diffraction ...  

Science Conference Proceedings (OSTI)

Modeling the Influence of the Second Phase Particle Spatial Distribution on Recrystallization of AA 7050 Near-Field High Energy X-ray Diffraction Microscopy...

164

Diffraction: Enhanced Light Absorption of Solar Cells and ...  

Sandia National Laboratories Diffraction: Enhanced Light Absorption of Solar Cells and Photodetectors HTTPS://IP.SANDIA.GOV Sandia National Laboratories is a multi ...

165

Anomalous electron trapping by magnetic flux tubes and electric current vortices  

E-Print Network (OSTI)

Anomalous electron trapping by magnetic flux tubes and electric current vortices F. Bentosela, a current vortex in the plane. In this case the flux is zero; there is a pair of bound states for a weak with a nonhomogeneous magnetic field B , and investigate the corresponding Pauli Hamiltonian. We prove a lower bound

166

Sound beyond the speed of light: destructive interference, anomalous dispersion and nonlocality of near field  

E-Print Network (OSTI)

Experimentally fixed sound pulse beyond of light speed in the region of anomalous dispersion [W. M. Robertson, e. a. Appl. Phys. Lett, 90, 014102 (2007)] can be explained, as well as the similar superluminal phenomena, by "the nonlocality in the small" of near electromagnetic field at transferring of relevanted excitations.

Perel'man, M E

2007-01-01T23:59:59.000Z

167

Light supersymmetric axion in an anomalous Abelian extension of the standard model  

Science Conference Proceedings (OSTI)

We present a supersymmetric extension of the standard model (USSM-A) with an anomalous U(1) and Stueckelberg axions for anomaly cancellation, generalizing similar nonsupersymmetric constructions. The model, built by a bottom-up approach, is expected to capture the low-energy supersymmetric description of axionic symmetries in theories with gauged anomalous Abelian interactions, previously explored in the nonsupersymmetric case for scenarios with intersecting branes. The choice of a USSM-like superpotential, with one extra singlet superfield and an extra Abelian symmetry, allows a physical axionlike particle in the spectrum. We describe some general features of this construction and, in particular, the modification of the dark-matter sector which involves both the axion and several neutralinos with an axino component. The axion is expected to be very light in the absence of phases in the superpotential but could acquire a mass which can also be in the few GeV range or larger. In particular, the gauging of the anomalous symmetry allows independent mass/coupling interaction to the gauge fields of this particle, a feature which is absent in traditional (invisible) axion models. We comment on the general implications of our study for the signature of moduli from string theory due to the presence of these anomalous symmetries.

Coriano, Claudio; Guzzi, Marco; Mariano, Antonio; Morelli, Simone [Dipartimento di Fisica, Universita del Salento Via Arnesano 73100 Lecce (Italy) and INFN Sezione di Lecce, Via Arnesano 73100 Lecce (Italy)

2009-08-01T23:59:59.000Z

168

Anomalous subsidence on the rifted volcanic margin of Pakistan: No influence from Deccan plume  

E-Print Network (OSTI)

Anomalous subsidence on the rifted volcanic margin of Pakistan: No influence from Deccan plume, Clifton, Karachi 75600, Pakistan A B S T R A C TA R T I C L E I N F O Article history: Received 28 October

Clift, Peter

169

Anomalous diffusion and ion heating in the presence of electrostatic hydrogen cyclotron instabilities  

DOE Green Energy (OSTI)

One- and two-dimensional simulations have been carried out to study electrostatic ion cyclotron instabilities for a hydrogen plasma in a strong magnetic field. It is found that strong ion heating and anomalous cross-field diffusion comparable to Bohm diffusion take place associated with the instability. Implications of the instability to the recent observations in fusion devices and space plasmas are discussed.

Okuda, H.; Cheng, C.Z.; Lee, W.W.

1980-11-01T23:59:59.000Z

170

The Linearity of the Atmospheric Response to Tropical Pacific Anomalous Forcing  

Science Conference Proceedings (OSTI)

In this paper, the authors show that the effect of a tropical Pacific anomalous forcing can he primarily linear or nonlinear depending on its sign and longitudinal position. Using a nine-level steady-state model both the linear and nonlinear ...

Qing Liu; Cornelius J. F. Schuurmans

1993-05-01T23:59:59.000Z

171

Very Large Aperture Diffractive Space Telescope  

DOE Patents (OSTI)

A very large (10's of meters) aperture space telescope including two separate spacecraft--an optical primary functioning as a magnifying glass and an optical secondary functioning as an eyepiece. The spacecraft are spaced up to several kilometers apart with the eyepiece directly behind the magnifying glass ''aiming'' at an intended target with their relative orientation determining the optical axis of the telescope and hence the targets being observed. The magnifying glass includes a very large-aperture, very-thin-membrane, diffractive lens, e.g., a Fresnel lens, which intercepts incoming light over its full aperture and focuses it towards the eyepiece. The eyepiece has a much smaller, meter-scale aperture and is designed to move along the focal surface of the magnifying glass, gathering up the incoming light and converting it to high quality images. The positions of the two space craft are controlled both to maintain a good optical focus and to point at desired targets.

Hyde, Roderick Allen

1998-04-20T23:59:59.000Z

172

Shaping X-rays by diffractive coded nano-optics  

Science Conference Proceedings (OSTI)

In this paper we report results obtained in the fabrication and use of novel coded diffractive nano-optics that, beyond focusing, can perform new optical functions. In particular, the intensity of light in the space beyond the optical elements can be ... Keywords: X-ray beamshaping, coded diffractive optical element, nano-optics

E. Di Fabrizio; S. Cabrini; D. Cojoc; F. Romanato; L. Businaro; M. Altissimo; B. Kaulich; T. Wilhein; J. Susini; M. De Vittorio; E. Vitale; G. Gigli; R. Cingolani

2003-06-01T23:59:59.000Z

173

X-Ray Diffraction Microscopy of Magnetic Structures  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Diffraction Microscopy of Magnetic Structures Print X-Ray Diffraction Microscopy of Magnetic Structures Print science brief icon Scientists working at ALS Beamline 12.0.2.2 have demonstrated a new x-ray technique for producing short-exposure nanoscale images of the magnetic structure of materials. The new method combines aspects of coherent x-ray diffraction, which can determine 3-D charge distributions, and resonant magnetic scattering, which is sensitive to magnetic structures. Physicists have used coherent x-ray diffraction to measure the electron density of complicated molecules. The formula used to make these calculations contains terms that relate to the electron spin of magnetic atoms, but these terms are traditionally ignored since coherent x-ray diffraction has not been used to retrieve magnetic information. Using the full formula allows for the determination of not only the electron density, but also the magnetic spin distribution and its orientation.

174

LANSCE | Lujan Center | Highlights | In situ neutron diffraction study of  

NLE Websites -- All DOE Office Websites (Extended Search)

In situ neutron diffraction study of CO clathrate hydrate In situ neutron diffraction study of CO clathrate hydrate The structure of a CO clathrate hydrate has been studied for the first time using high-P low-T neutron diffraction. Clathrate Rietveld analysis shows that lattice parameter a (SII cubic clathrate structure) increases with increasing temperature. CO molecules are positionally disordered and off-centered in both large and small cages. Each large cage is occupied by two CO molecules while each small cage is occupied by one CO. A representative neutron diffraction pattern of SII CO clathrate hydrate. Variation of lattice parameter a of CO SII clathrate hydrate as a function of temperature. A representative neutron diffraction pattern of SII CO clathrate hydrate. Variation of lattice parameter a of CO SII clathrate hydrate as a function of temperature.

175

X-Ray Diffraction Microscopy of Magnetic Structures  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Diffraction Microscopy of Magnetic Structures Print X-Ray Diffraction Microscopy of Magnetic Structures Print science brief icon Scientists working at ALS Beamline 12.0.2.2 have demonstrated a new x-ray technique for producing short-exposure nanoscale images of the magnetic structure of materials. The new method combines aspects of coherent x-ray diffraction, which can determine 3-D charge distributions, and resonant magnetic scattering, which is sensitive to magnetic structures. Physicists have used coherent x-ray diffraction to measure the electron density of complicated molecules. The formula used to make these calculations contains terms that relate to the electron spin of magnetic atoms, but these terms are traditionally ignored since coherent x-ray diffraction has not been used to retrieve magnetic information. Using the full formula allows for the determination of not only the electron density, but also the magnetic spin distribution and its orientation.

176

X-Ray Diffraction Microscopy of Magnetic Structures  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Diffraction Microscopy of Magnetic Structures Print X-Ray Diffraction Microscopy of Magnetic Structures Print science brief icon Scientists working at ALS Beamline 12.0.2.2 have demonstrated a new x-ray technique for producing short-exposure nanoscale images of the magnetic structure of materials. The new method combines aspects of coherent x-ray diffraction, which can determine 3-D charge distributions, and resonant magnetic scattering, which is sensitive to magnetic structures. Physicists have used coherent x-ray diffraction to measure the electron density of complicated molecules. The formula used to make these calculations contains terms that relate to the electron spin of magnetic atoms, but these terms are traditionally ignored since coherent x-ray diffraction has not been used to retrieve magnetic information. Using the full formula allows for the determination of not only the electron density, but also the magnetic spin distribution and its orientation.

177

Non-universal, Non-anomalous U(1)' in a Model with Anomaly Mediated SUSY Breaking  

E-Print Network (OSTI)

We construct a Minimum Supersymmetry Standard Model expanded by a non-anomalous family (NAF) U(1)'_{NAF} gauge symmetry. All gauge anomalies are cancelled with no additional exotics other than the three right-handed neutrinos. The FI D-terms associated with the U(1)'_{NAF} symmetry lead to additional positive contributions to slepton squared masses. In a RG invariant way, this thus solves the tachyonic slepton mass problem in Anomaly Mediated Supersymmetry Breaking. In addition, the U(1)'_{NAF} symmetry naturally gives rise to the fermion mass hierarchy and mixing angles, and determines the mass spectrum of the sparticles. Our model also provides a counter example to the previous claim that the only U(1)' that can give rise to realistic fermion mass hierarchy and mixing pattern must be anomalous.

Mu-Chun Chen; Jinrui Huang

2010-11-29T23:59:59.000Z

178

Critical Review of Theoretical Models for Anomalous Effects (Cold Fusion) in Deuterated Metals  

E-Print Network (OSTI)

We briefly summarize the reported anomalous effects in deuterated metals at ambient temperature, commonly known as "Cold Fusion" (CF), with an emphasis on important experiments as well as the theoretical basis for the opposition to interpreting them as cold fusion. Then we critically examine more than 25 theoretical models for CF, including unusual nuclear and exotic chemical hypotheses. We conclude that they do not explain the data.

V. A. Chechin; V. A. Tsarev; M. Rabinowitz; Y. E. Kim

2003-03-22T23:59:59.000Z

179

Mining anomalous events against frequent sequences in surveillance videos from commercial environments  

Science Conference Proceedings (OSTI)

In the UK alone there are currently over 4.2 million operational CCTV cameras, that is virtually one camera for every 14th person, and this figure is increasing at a fast rate throughout the world (especially after the tragic events of 9/11 and 7/7) ... Keywords: Anomalous events mining, Business intelligence, Data mining, Knowledge discovery, Periodicity mining, Sequential pattern mining, Surveillance videos, Video mining

Fahad Anwar; Ilias Petrounias; Tim Morris; Vassilis Kodogiannis

2012-03-01T23:59:59.000Z

180

The Anomalous Magnetic Moment of the Muon and Higgs-Mediated Flavor Changing Neutral Currents  

E-Print Network (OSTI)

In the two-Higgs doublet extension of the standard model, flavor-changing neutral couplings arise naturally. In the lepton sector, the largest such coupling is expected to be $\\mu-\\tau-\\phi#. We consider the effects of this coupling on the anomalous magnetic moment of the muon. The resulting bound on the coupling, unlike previous bounds, is independent of the value of other unknown couplings. It will be significantly improved by the upcoming E821 experiment at Brookhaven National Lab.

Shuquan Nie; Marc Sher

1998-05-19T23:59:59.000Z

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


181

COMMENTS ON ANOMALOUS EFFECTS IN CHARGING OF PD POWDERS WITH HIGH DENSITY HYDROGEN ISOTOPES  

DOE Green Energy (OSTI)

In Kitamura, et al, Pd-containing materials are exposed to isotopes of hydrogen and anomalous results obtained. These are claimed to be a replication of another experiment conducted by Arata and Zhang. Erroneous basic assumptions are pointed out herein that alter the derived conclusions significantly. The final conclusion is that the reported results are likely normal chemistry combined with noise. Thus the claim to have proven that cold fusion is occurring in these systems is both premature and unlikely.

Shanahan, K.

2009-10-01T23:59:59.000Z

182

Roles of Anomalous Tibetan Plateau Warming on the Severe 2008 Winter Storm in Central-Southern China  

Science Conference Proceedings (OSTI)

Anomalous warming occurred over the Tibetan Plateau (TP) before and during the disastrous freezing rain and heavy snow hitting central and southern China in January 2008. The relationship between the TP warming and this extreme event is ...

Qing Bao; Jing Yang; Yimin Liu; Guoxiong Wu; Bin Wang

2010-06-01T23:59:59.000Z

183

Anomalous Cloud-to-Ground Lightning in an F5-Tornado-Producing Supercell Thunderstorm on 28 August 1990  

Science Conference Proceedings (OSTI)

An F5 tornado that devastated Plainfield, Illinois, and environs on 28 August 1990, killing 29 people, is shown to be preduced by a thunderstorm characterized by highly anomalous could-to-ground (CG) lightning activity. Unlike typical summertime ...

Anton Seimon

1993-02-01T23:59:59.000Z

184

Three-dimensional simulations of anomalous absorption of laser radiation by plasma with supercritical density  

Science Conference Proceedings (OSTI)

A three-dimensional (3D) model of the interaction of laser radiation with plasma in the framework of Maxwell-Vlasov equations has been used to calculate the anomalous optical absorption in plasma of supercritical density. The results of calculations confirmed the development of anomalous absorption that was previously revealed by 2D models, which were insufficient for comparison to the experiment. Calculations were performed for a system containing about 10{sup 6} macroparticles that allowed the absorption coefficient and other characteristics of anomalous absorption in plasma with an inhomogeneous surface to be determined as functions of various parameters of the incident radiation and plasma target. Results are analyzed and estimations are obtained for the contributions of ionization processes and pair collisions of electrons, which show that these factors were quite reasonably ignored in the model. All quantitative results are obtained for the third harmonic of neodymium laser ({lambda} = 0.351 {mu}m) at a tenfold excess of the substance density over a critical value for this radiation.

Ginzburg, S. L.; Dyachenko, V. F. [Russian Academy of Sciences, Keldysh Institute for Applied Mathematics (Russian Federation); Imshennik, V. S. [Alikhanov Institute for Theoretical and Experimental Physics (Russian Federation); Paleychik, V. V.

2012-02-15T23:59:59.000Z

185

Anomalous Behavior of D-Layer Preparation Time of the Ionosphere Due to Earthquakes as observed from Malda (India)  

SciTech Connect

The anomalous behavior of D-layer preparation time of the ionosphere are observed only before, during and after the earthquakes, which took place in the neighbouring region by monitoring the Very Low Frequency (VLF) signal using Gyrator II loop antenna. The anomalies were also observed in the sunrise terminator times during seismically active days. These anomalous behavior may be due to the Lithosphere-Ionosphere coupling. These anomalies may be a precursor of earthquake.

Chatterjee, Achintya K.; Nandy, Nilmadhab; Bari, Md. Washimul; Choudhury, Asit K. [Indian Centre for Space Physics (Malda Branch), Atul Market, Malda, West Bengal, Inda, 732101 (India)

2010-10-20T23:59:59.000Z

186

A 3-D numerical study of pinhole diffraction to predict the accuracy of EUV point diffraction interferometry  

SciTech Connect

A 3-D electromagnetic field simulation is used to model the propagation of extreme ultraviolet (EUV), 13-nm, light through sub-1500 {Angstrom} dia pinholes in a highly absorptive medium. Deviations of the diffracted wavefront phase from an ideal sphere are studied within 0.1 numerical aperture, to predict the accuracy of EUV point diffraction interferometersused in at-wavelength testing of nearly diffraction-limited EUV optical systems. Aberration magnitudes are studied for various 3-D pinhole models, including cylindrical and conical pinhole bores.

Goldberg, K.A. [Lawrence Berkeley National Lab., CA (United States)]|[California Univ., Berkeley, CA (United States). Dept. of Physics; Tejnil, E. [California Univ., Berkeley, CA (United States). Dept. of Electrical Engineering and Computer Sciences; Bokor, J. [Lawrence Berkeley National Lab., CA (United States)]|[California Univ., Berkeley, CA (United States). Dept. of Electrical Engineering and Computer Sciences

1995-12-01T23:59:59.000Z

187

Clifford G. Shull, Neutron Diffraction, Hydrogen Atoms, and Neutron  

Office of Scientific and Technical Information (OSTI)

Clifford Shull, Neutron Diffraction, and Neutron Scattering Clifford Shull, Neutron Diffraction, and Neutron Scattering Resources with Additional Information Clifford G. Shull was awarded the 1994 Nobel Prize in Physics "for the development of the neutron diffraction technique". 'Professor Shull's prize was awarded for his pioneering work in neutron scattering, a technique that reveals where atoms are within a material like ricocheting bullets reveal where obstacles are in the dark. Clifford Shull Photo Courtesy of Oak Ridge National Laboratory When a beam of neutrons is directed at a given material, the neutrons bounce off, or are scattered by, atoms in the sample being investigated. The neutrons' directions change, depending on the location of the atoms they hit, and a diffraction pattern of the atoms' positions can then be obtained.

188

Biological Imaging by Soft X-Ray Diffraction Microscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Biological Imaging by Soft X-Ray Diffraction Microscopy Print Biological Imaging by Soft X-Ray Diffraction Microscopy Print Electron and x-ray microscopes are a valuable tool for both the life and materials sciences, but they are limited in their ability to image with nanometer-scale resolution in three dimensions nonperiodic objects that are several microns in size. To fill this gap, the technique of coherent x-ray diffraction imaging now under development takes advantage of the penetrating power of x rays while simultaneously removing the limitations imposed by lens-based optical systems. Researchers from Stony Brook University, in collaboration with scientists at the ALS and Cornell University, have taken a large step in this direction by using a lensless x-ray diffraction microscope to image a freeze-dried yeast cell to better than 30-nm resolution. Images were made at several angular orientations of the cell.

189

Definition: Portable X-Ray Diffraction (XRD) | Open Energy Information  

Open Energy Info (EERE)

Definition Definition Edit with form History Facebook icon Twitter icon » Definition: Portable X-Ray Diffraction (XRD) Jump to: navigation, search Dictionary.png Portable X-Ray Diffraction (XRD) Portable X-Ray Diffraction (XRD) is a field-based technique that can be used for identification of crystalline materials and analysis of unit cell dimensions. Portable XRD analysis is similar to X-ray powder diffraction, which has traditionally been used in geology, environmental science, material science, and engineering to rapidly identify unknown crystalline substances. Portable XRD analysis allows for simpler sample preparation, faster analytical times than traditional methods (less than 2 minutes), and can be performed at the sampling site in the field. A pure, finely ground

190

Biological Imaging by Soft X-Ray Diffraction Microscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Biological Imaging by Soft X-Ray Diffraction Microscopy Print Biological Imaging by Soft X-Ray Diffraction Microscopy Print Electron and x-ray microscopes are a valuable tool for both the life and materials sciences, but they are limited in their ability to image with nanometer-scale resolution in three dimensions nonperiodic objects that are several microns in size. To fill this gap, the technique of coherent x-ray diffraction imaging now under development takes advantage of the penetrating power of x rays while simultaneously removing the limitations imposed by lens-based optical systems. Researchers from Stony Brook University, in collaboration with scientists at the ALS and Cornell University, have taken a large step in this direction by using a lensless x-ray diffraction microscope to image a freeze-dried yeast cell to better than 30-nm resolution. Images were made at several angular orientations of the cell.

191

Biological Imaging by Soft X-Ray Diffraction Microscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Biological Imaging by Soft X-Ray Diffraction Microscopy Print Biological Imaging by Soft X-Ray Diffraction Microscopy Print Electron and x-ray microscopes are a valuable tool for both the life and materials sciences, but they are limited in their ability to image with nanometer-scale resolution in three dimensions nonperiodic objects that are several microns in size. To fill this gap, the technique of coherent x-ray diffraction imaging now under development takes advantage of the penetrating power of x rays while simultaneously removing the limitations imposed by lens-based optical systems. Researchers from Stony Brook University, in collaboration with scientists at the ALS and Cornell University, have taken a large step in this direction by using a lensless x-ray diffraction microscope to image a freeze-dried yeast cell to better than 30-nm resolution. Images were made at several angular orientations of the cell.

192

Overcoming the far-field diffraction limit via absorbance modulation  

E-Print Network (OSTI)

Diffraction limits the resolution of far-field lithography and imaging to about half of the wavelength, which greatly limits the capability of optical techniques. The proposed technique with absorbance modulation aims to ...

Tsai, Hsin-Yu Sidney

2011-01-01T23:59:59.000Z

193

Biological Imaging by Soft X-Ray Diffraction Microscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Biological Imaging by Soft X-Ray Diffraction Microscopy Print Electron and x-ray microscopes are a valuable tool for both the life and materials sciences, but they are limited in...

194

Single and Central Diffractive Higgs Production at the LHC  

Science Conference Proceedings (OSTI)

The single and central diffractive production of the Standard Model Higgs boson is computed using the diffractive factorization formalism, taking into account a parametrization for the Pomeron structure function provided by the H1 Collaboration. We compute the cross sections at NLO accuracy for the gluon fusion process, since it is the leading mechanism for the Higgs boson production. The gap survival probability is also introduced to include the rescattering corrections due to spectator particles present in the interaction. The diffractive ratios are predicted for proton-proton collisions at the LHC, since the beam luminosity is favorable to the Higgs boson detection. These results provide updated estimations for the fraction of single and central diffractive events in the LHC kinematical regime.

Ducati, M. B. Gay; Machado, M. M.; Silveira, G. G. [High Energy Physics Phenomenology Group, GFPAE, IF-UFRGS, Caixa Postal 15051, CEP 91501-970, Porto Alegre, RS (Brazil)

2011-07-15T23:59:59.000Z

195

Exclusive diffractive processes in electron-ion collisions  

E-Print Network (OSTI)

We present a new technique to calculate the cross-section for diffractive vector meson production and DVCS in electron-ion collisions based on the dipole model. The measurement of these processes can provide valuable information on non-linear QCD phenomena, such as gluon saturation, and is the the only known way to gain insight into the spatial distribution of gluons in nuclei. We present predictions of differential cross-section distribution $d\\sigma/dQ^2$ and $d\\sigma/dt$ for $J/\\psi$ and $\\phi$ meson production for diffractive processes of heavy nuclei and demonstrate the feasibility of extracting the gluon source distribution of heavy nuclei, F(b), from coherent diffraction. We briefly introduce a new event generator based on our method that can be used for studying exclusive diffractive processes at a future electron-ion collider.

Tobias Toll; Thomas Ullrich

2012-11-13T23:59:59.000Z

196

Diffraction of Continental Shelf Waves by Irregular Alongshore Geometry  

Science Conference Proceedings (OSTI)

Diffraction of continental shelf waves by irregular alongshore geometry, such as ridges, canyons and bumps, is examined. The full barotropic, shelf-wave equation is treated, and the solutions include forward and back scattering, and a description ...

Dong-Ping Wang

1980-08-01T23:59:59.000Z

197

Biological Imaging by Soft X-Ray Diffraction Microscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Biological Imaging by Soft X-Ray Diffraction Microscopy Print Biological Imaging by Soft X-Ray Diffraction Microscopy Print Electron and x-ray microscopes are a valuable tool for both the life and materials sciences, but they are limited in their ability to image with nanometer-scale resolution in three dimensions nonperiodic objects that are several microns in size. To fill this gap, the technique of coherent x-ray diffraction imaging now under development takes advantage of the penetrating power of x rays while simultaneously removing the limitations imposed by lens-based optical systems. Researchers from Stony Brook University, in collaboration with scientists at the ALS and Cornell University, have taken a large step in this direction by using a lensless x-ray diffraction microscope to image a freeze-dried yeast cell to better than 30-nm resolution. Images were made at several angular orientations of the cell.

198

Diffractive element in extreme-UV lithography condenser  

DOE Patents (OSTI)

Condensers having a mirror with a diffraction grating in projection lithography using extreme ultra-violet significantly enhances critical dimension control. The diffraction grating has the effect of smoothing the illumination at the camera's entrance pupil with minimum light loss. Modeling suggests that critical dimension control for 100 nm features can be improved from 3 nm to less than about 0.5 nm.

Sweatt, William C. (Albuquerque, NM); Ray-Chaudhuri, Avijit (Livermore, CA)

2001-01-01T23:59:59.000Z

199

Diffractive element in extreme-UV lithography condenser  

DOE Patents (OSTI)

Condensers having a mirror with a diffraction grating in projection lithography using extreme ultra-violet significantly enhances critical dimension control. The diffraction grating has the effect of smoothing the illumination at the camera's entrance pupil with minimum light loss. Modeling suggests that critical dimension control for 100 nm features can be improved from 3 nm to less than about 0.5 nm.

Sweatt, William C. (Albuquerque, NM); Ray-Chaudhurl, Avijit K. (Livermore, CA)

2000-01-01T23:59:59.000Z

200

Atomic Resolution Coherent Diffractive Imaging and Ultrafast Science  

Science Conference Proceedings (OSTI)

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

Zuo, Jian-min [University of Illinois

2011-01-12T23:59:59.000Z

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


201

When effective theories predict: the inevitability of Mercury's anomalous perihelion precession  

E-Print Network (OSTI)

If the concepts underlying Effective Theory were appreciated from the earliest days of Newtonian gravity, Le Verrier's announcement in 1845 of the anomalous perihelion precession of Mercury would have been no surprise. Furthermore, the size of the effect could have been anticipated through "naturalness" arguments well before the definitive computation in General Relativity. Thus, we have an illustration of how Effective Theory concepts can guide us in extending our knowledge to "new physics", and not just in how to reduce larger theories to restricted (e.g., lower energy) domains.

James D. Wells

2011-06-08T23:59:59.000Z

202

Quantum Anomalous Hall Effect in Hg_1-yMn_yTe Quantum Wells  

SciTech Connect

The quantum Hall effect is usually observed when the two-dimensional electron gas is subjected to an external magnetic field, so that their quantum states form Landau levels. In this work we predict that a new phenomenon, the quantum anomalous Hall effect, can be realized in Hg{sub 1-y}Mn{sub y}Te quantum wells, without the external magnetic field and the associated Landau levels. This effect arises purely from the spin polarization of the Mn atoms, and the quantized Hall conductance is predicted for a range of quantum well thickness and the concentration of the Mn atoms. This effect enables dissipationless charge current in spintronics devices.

Liu, Chao-Xing; /Tsinghua U., Beijing /Stanford U., Phys. Dept.; Qi, Xiao-Liang; /Stanford U., Phys. Dept.; Dai, Xi; Fang, Zhong; /Beijing, Inst. Phys.; Zhang, Shou-Cheng; /Stanford U., Phys. Dept.

2010-03-19T23:59:59.000Z

203

Exploring anomalous top interactions via the final lepton in ttbar productions/decays at hadron colliders  

E-Print Network (OSTI)

We study momentum distributions of the final-state charged lepton in ppbar/pp --> ttbar --> l^+ X (l=e or mu) at hadron colliders, i.e., Tevatron and Large Hadron Collider (LHC) in order to explore possible new-physics effects in the top-quark sector. Assuming general model-independent ttbar g + ttbar gg and tbW interactions beyond the standard model, we first derive analytical formulas for the corresponding parton-parton processes. We then compute the lepton angular, energy and transverse-momentum distributions in ppbar/pp collisions to clarify how they are affected by those anomalous couplings.

Zenro HIOKI; Kazumasa OHKUMA

2011-04-07T23:59:59.000Z

204

Femtosecond laser pulse filamentation under anomalous dispersion in fused silica. Part 1. Numerical investigation  

SciTech Connect

We report the results of investigation of femtosecond laser pulse filamentation in fused silica by varying the wavelength in the range from 800 to 2300 nm. It is shown that in the case of the anomalous group-velocity dispersion, a sequence of 'light bullets' with a high spatial and temporal localisation of the light field is formed along the filament. The relation of the formation and propagation of light bullets with the formation of an isolated anti-Stokes wing of the supercontinuum spectrum is established. (nonlinear optical phenomena)

Smetanina, E O; Kompanets, V O; Chekalin, Sergei V; Kandidov, V P

2012-10-31T23:59:59.000Z

205

Search for Anomalous Production of Events with Two Photons and Additional Energetic Objects at CDF  

SciTech Connect

The authors present results of a search for anomalous production of two photons together with an electron, muon, {tau} lepton, missing transverse energy, or jets using p{bar p} collision data from 1.1-2.0 fb{sup -1} of integrated luminosity collected by the Collider Detector at Fermilab (CDF). The event yields and kinematic distributions are examined for signs for new physics without favoring a specific model of new physics. The results are consistent with the standard model expectations. The search employs several new analysis techniques that significantly reduce instrumental backgrounds in channels with an electron and missing transverse energy.

Aaltonen, T.; /Helsinki Inst. of Phys.; Adelman, J.; /Chicago U., EFI; Alvarez Gonzalez, B.; /Oviedo U. /Cantabria Inst. of Phys.; Amerio, S.; /Padua U. /INFN, Padua; Amidei, D.; /Michigan U.; Anastassov, A.; /Northwestern U.; Annovi, A.; /Frascati; Antos, J.; /Comenius U. /Kosice, IEF; Apollinari, G.; /Fermilab; Apresyan, A.; /Purdue U.; Arisawa, T.; /Waseda U. /Dubna, JINR

2009-10-01T23:59:59.000Z

206

Anomalous heat-kernel decay for random walk among polynomial lower tail random conductances  

E-Print Network (OSTI)

We consider the nearest-neighbor simple random walk on $\\Z^{d}$, $d\\geq 4$, driven by a field of i.i.d. random nearest-neighbor conductances $\\omega_{xy}\\in[0,1]$. Our aim is to derive estimates of the heat-kernel decay in a case where ellipticity assumption is absent. We consider the case of independant conductances with polynomial tail near 0 and obtain for almost every environment an anomalous lower bound on the heat-kernel.

Boukhadra, Omar

2008-01-01T23:59:59.000Z

207

The strongest cosmic magnets: Soft Gamma-ray Repeaters and Anomalous X-ray Pulsars  

E-Print Network (OSTI)

Two classes of X-ray pulsars, the Anomalous X-ray Pulsars and the Soft Gamma-ray Repeaters, have been recognized in the last decade as the most promising candidates for being magnetars: isolated neutron stars powered by magnetic energy. I review the observational properties of these objects, focussing on the most recent results, and their interpretation in the magnetar model. Alternative explanations, in particular those based on accretion from residual disks, are also considered. The possible relations between these sources and other classes of neutron stars and astrophysical objects are also discussed.

Mereghetti, Sandro

2008-01-01T23:59:59.000Z

208

The strongest cosmic magnets: Soft Gamma-ray Repeaters and Anomalous X-ray Pulsars  

E-Print Network (OSTI)

Two classes of X-ray pulsars, the Anomalous X-ray Pulsars and the Soft Gamma-ray Repeaters, have been recognized in the last decade as the most promising candidates for being magnetars: isolated neutron stars powered by magnetic energy. I review the observational properties of these objects, focussing on the most recent results, and their interpretation in the magnetar model. Alternative explanations, in particular those based on accretion from residual disks, are also considered. The possible relations between these sources and other classes of neutron stars and astrophysical objects are also discussed.

Sandro Mereghetti

2008-04-01T23:59:59.000Z

209

Horizontal, Anomalous U(1) Symmetry for the More Minimal Supersymmetric Standard Model  

E-Print Network (OSTI)

We construct explicit examples with a horizontal, ``anomalous'' $U(1)$ gauge group, which, in a supersymmetric extension of the standard model, reproduce qualitative features of the fermion spectrum and CKM matrix, and suppress FCNC and proton decay rates without the imposition of global symmetries. We review the motivation for such ``more'' minimal supersymmetric standard models and their predictions for the sparticle spectrum. There is a mass hierarchy in the scalar sector which is the inverse of the fermion mass hierarchy. We show in detail why DeltaS = 2 FCNC are suppressed when compared with naive estimates for nondegenerate squarks.

Ann E. Nelson; David Wright

1997-02-18T23:59:59.000Z

210

Photon Sciences | Beamlines | XPD: X-ray Powder Diffraction  

NLE Websites -- All DOE Office Websites (Extended Search)

XPD: X-ray Powder Diffraction XPD: X-ray Powder Diffraction Poster | Fact Sheet | Preliminary Design Report Scientific Scope XPD is a tunable facility with the ability to collect diffraction data at high x-ray energies (40keV-80keV), offering rapid acquisition (millisecond) and high angular resolution capabilities on the same instrument. XPD addresses future scientific challenges in, for example, hydrogen storage, CO2 sequestration, advanced structural ceramics, catalysis, and materials processing. Such materials of high technological value often are complex, nanostructured and heterogeneous. The scientific grand challenge is to obtain robust and quantitative (micro)structural information, not only in the ground state at ambient conditions, but also in situ or in operando with varying temperature, pressure, magnetic/electric/stress

211

Magnetic Structure Analysis from Neutron Powder Diffraction Data Using GSAS  

NLE Websites -- All DOE Office Websites (Extended Search)

Magnetic Structure Analysis from Neutron Powder Diffraction Data Using GSAS Magnetic Structure Analysis from Neutron Powder Diffraction Data Using GSAS This set of web pages provides reference information from the Magnetic Structure Analysis from Neutron Powder Diffraction Data Using GSAS workshop presented at the 2006 American Conference on Neutron Scattering held in St. Charles, IL, June 18-22, 2006. Workshop Schedule: 9:00-9:05 am: Introduction (B.H. Toby) 9:05-9:50 am: History, Color symmetry & Shubnikov space groups (B. Chakoumous) Lecture notes: History and Color symmetry & Shubnikov space groups 9:50-10:20 am: Magnetic extinctions classes & common magnetic structure types (R.B. Von Dreele) Lecture Notes Break 10:50-11:45 am: Overview of representational analysis & FullProf implementation (L.C. Chapon) Lecture Notes and Accompanying files

212

Low-energy positron diffraction from GaAs(110)  

Science Conference Proceedings (OSTI)

Intensities of 16 beams of near normal incidence positrons have been measured at {ital T}=120 K and analyzed using a multiple scattering model of the low-energy positron diffraction (LEPD) process. Excellent correspondence between the measured and calculated intensities is obtained for a reconstruction that is primarily a bond-length-conserving rotation of the top layer, with As relaxed outward and Ga inward with a tilt angle {omega}{sub 1} = 28.6 {plus minus} 3{degree}, confirming the results of previous structure analyses for this surface. The quality of the description of the measured intensities, as measured by the x-ray {ital R} factor, is significantly better for LEPD than for low-energy electron diffraction. This result is attributed to the repulsive character of the positron-ion core potential and a resulting more surface sensitive diffraction process for LEPD.

Lessor, D.L. (Pacific Northwest Laboratory, K5-17 ISB-1, Richland, Washington 99352 (United States)); Duke, C.B. (Xerox Webster Research Center, 800 Phillips Road, 0114-38D, Webster, New York 14580 (United States)); Chen, X.M.; Brandes, G.R.; Canter, K.F. (Department of Physics, Brandeis University, Waltham, Massachusetts 02254 (United States)); Ford, W.K. (Advanced Materials Center and Department of Physics, Montana State University, Bozeman, Montana 59717 (United States))

1992-07-01T23:59:59.000Z

213

Hand held phase-shifting diffraction moire interferometer  

DOE Patents (OSTI)

An interferometer in which a coherent beam of light is generated within a remote case and transmitted to a hand held unit tethered to said remote case, said hand held unit having optical elements for directing a pair of mutually coherent collimated laser beams at a diffraction grating. Data from the secondary or diffracted beams are then transmitted to a separate video and data acquisition system for recording and analysis for load induced deformation or for identification purposes. Means are also provided for shifting the phase of one incident beam relative to the other incident beam and being controlled from within said remote case.

Deason, Vance A. (Idaho Falls, ID); Ward, Michael B. (Idaho Falls, ID)

1994-01-01T23:59:59.000Z

214

Soft Classification of Diffractive Interactions at the LHC  

SciTech Connect

Multivariate machine learning techniques provide an alternative to the rapidity gap method for event-by-event identification and classification of diffraction in hadron-hadron collisions. Traditionally, such methods assign each event exclusively to a single class producing classification errors in overlap regions of data space. As an alternative to this so called hard classification approach, we propose estimating posterior probabilities of each diffractive class and using these estimates to weigh event contributions to physical observables. It is shown with a Monte Carlo study that such a soft classification scheme is able to reproduce observables such as multiplicity distributions and relative event rates with a much higher accuracy than hard classification.

Kuusela, Mikael; Malmi, Eric [Division of Elementary Particle Physics, Department of Physics, PO Box 64, FI-00014 University of Helsinki (Finland); Department of Information and Computer Science, Aalto University School of Science and Technology, PO Box 15400, FI-00076 Aalto (Finland); Orava, Risto [Helsinki Institute of Physics, PO Box 64, FI-00014 University of Helsinki (Finland); Division of Elementary Particle Physics, Department of Physics, PO Box 64, FI-00014 University of Helsinki (Finland); Vatanen, Tommi [Helsinki Institute of Physics, PO Box 64, FI-00014 University of Helsinki (Finland); Department of Information and Computer Science, Aalto University School of Science and Technology, PO Box 15400, FI-00076 Aalto (Finland)

2011-07-15T23:59:59.000Z

215

Hand held phase-shifting diffraction Moire interferometer  

DOE Patents (OSTI)

An interferometer is described in which a coherent beam of light is generated within a remote case and transmitted to a hand held unit tethered to said remote case, said hand held unit having optical elements for directing a pair of mutually coherent collimated laser beams at a diffraction grating. Data from the secondary or diffracted beams are then transmitted to a separate video and data acquisition system for recording and analysis for load induced deformation or for identification purposes. Means are also provided for shifting the phase of one incident beam relative to the other incident beam and being controlled from within said remote case. 4 figs.

Deason, V.A.; Ward, M.B.

1994-09-20T23:59:59.000Z

216

CONSTRAINTS ON FREE-FREE EMISSION FROM ANOMALOUS MICROWAVE EMISSION SOURCES IN THE PERSEUS MOLECULAR CLOUD  

SciTech Connect

We present observations performed with the Green Bank Telescope at 1.4 and 5 GHz of three strips coincident with the anomalous microwave emission features previously identified in the Perseus molecular cloud at 33 GHz with the Very Small Array. With these observations we determine the level of the low frequency ({approx}1-5 GHz) emission. We do not detect any significant extended emission in these regions and we compute conservative 3{sigma} upper limits on the fraction of free-free emission at 33 GHz of 27%, 12%, and 18% for the three strips, indicating that the level of the emission at 1.4 and 5 GHz cannot account for the emission observed at 33 GHz. Additionally, we find that the low frequency emission is not spatially correlated with the emission observed at 33 GHz. These results indicate that the emission observed in the Perseus molecular cloud at 33 GHz, is indeed in excess over the low frequency emission, hence confirming its anomalous nature.

Tibbs, C. T. [Spitzer Science Center, California Institute of Technology, Pasadena, CA 91125 (United States); Paladini, R. [NASA Herschel Science Center, California Institute of Technology, Pasadena, CA 91125 (United States); Dickinson, C.; Davies, R. D.; Davis, R. J.; Watson, R. A. [Jodrell Bank Centre for Astrophysics, School of Physics and Astronomy, The University of Manchester, Manchester M13 9PL (United Kingdom); Mason, B. S. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States); Casassus, S. [Departamento de Astronomia, Universidad de Chile, Casilla 36-D, Santiago (Chile); Cleary, K., E-mail: ctibbs@ipac.caltech.edu [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States)

2013-06-20T23:59:59.000Z

217

Muon anomalous magnetic moment constraints on supersymmetric U(1){sup '} models  

Science Conference Proceedings (OSTI)

We study the anomalous magnetic moment of the muon in supersymmetric E{sub 6} models and generic U(1){sup '} models to probe the model reactions and to find constraints on the large parameter space of these models. For future searches, by imposing the existing bounds coming from collider searches and theoretical considerations upon the U(1){sup '} model parameters, we examine the lightest Higgs boson mass m{sub h} and the mass of the additional Z boson m{sub Z{sub 2}} in such singlet extensions of the MSSM. We observed that not only supersymmetric E{sub 6} models but also generic U(1){sup '} models are sensitive to the imposition of the considered bounds. Indeed, without the muon anomaly constraints E{sub 6} models and generic U(1){sup '} models can predict m{sub h} as large as {approx}150 GeV and {approx}180 GeV, respectively. However, in addition to the mentioned constraints when a 1{sigma} range for the anomalous magnetic moment of the muon is considered, we observe that generic U(1){sup '} models do not favor the mass of the lightest Higgs boson to be larger than 140 GeV; it should be smaller than 135 GeV in E{sub 6} models.

Cincioglu, Elif; Solmaz, Saime; Solmaz, Levent; Hicyilmaz, Yasar [Department of Physics, Balikesir University, TR10145, Balikesir (Turkey); Kirca, Zerrin [Department of Physics, Balikesir University, TR10145, Balikesir (Turkey); Department of Physics, Uludag University, TR16000, Bursa (Turkey); Sert, Hale [Department of Physics, Izmir Institute of Technology, TR35430, Izmir (Turkey)

2010-09-01T23:59:59.000Z

218

Search for anomalous ZZ{gamma} and Z{gamma}{gamma} couplings with D0  

Science Conference Proceedings (OSTI)

A direct test of the Standard Model by searching for anomalous ZZ{gamma} and Z{gamma}{gamma} couplings is presented. The authors analyze p{bar p} {yields} ll{gamma} + X, (l = e,{mu}) events at {radical}s = 1.8 TeV with the D0d detector at the Fermilab Tevatron Collider. A fit to the transverse energy spectrum of the photon in the signal events, based on the data set corresponding to an integrated luminosity of 13.9 pb{sup {minus}1} (13.3 pb{sup {minus}1}) for the electron (muon) channel, yields the following 95% CL limits on the anomalous CP-conserving ZZ{gamma} couplings: -1.9 < h{sub 30}{sup Z} < 1.8 (h{sub 40}{sup Z} = 0), and -0.5 < h{sub 40}{sup Z} < 0.5 ({sub 30}{sup Z} = 0), for a form-factor scale {Lambda} = 500 GeV. Limits on the Z{gamma}{gamma} couplings and CP-violating couplings are also discussed.

Landsberg, G.

1995-05-01T23:59:59.000Z

219

AN EMPIRICAL EXPLANATION OF THE ANOMALOUS INCREASES IN THE ASTRONOMICAL UNIT AND THE LUNAR ECCENTRICITY  

Science Conference Proceedings (OSTI)

The subject of this paper is the empirically determined anomalous secular increases of the astronomical unit, of the order of some cm yr{sup -1}, and of the eccentricity of the lunar orbit, of the order of 10{sup -12} yr{sup -1}. The aim is to find an empirical explanation of both anomalies as far as their orders of magnitude are concerned. The methods employed are working out perturbatively with the Gauss equations the secular effects on the semi-major axis a and the eccentricity e of a test particle orbiting a central body acted upon by a small anomalous radial acceleration A proportional to the radial velocity v{sub r} of the particle-body relative motion. The results show that non-vanishing secular variations and (e) occur. If the magnitude of the coefficient of proportionality of the extra-acceleration is of the same order of magnitude as the Hubble parameter H{sub 0} = 7.47 x 10{sup -11} yr{sup -1} at the present epoch, they are able to explain both astrometric anomalies without contradicting other existing observational determinations for the Moon and the other planets of the solar system. Finally, it is concluded that the extra-acceleration might be of cosmological origin, provided that the relative radial particle-body motion is accounted for in addition to that due to the cosmological expansion only. Further data analyses should confirm or disprove the existence of both astrometric anomalies as genuine physical phenomena.

Iorio, L., E-mail: lorenzo.iorio@libero.it [Viale Unita di Italia 68 70125 Bari (Italy)

2011-09-15T23:59:59.000Z

220

Biological Imaging by Soft X-Ray Diffraction Microscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Biological Imaging by Soft X-Ray Biological Imaging by Soft X-Ray Diffraction Microscopy Biological Imaging by Soft X-Ray Diffraction Microscopy Print Wednesday, 30 November 2005 00:00 Electron and x-ray microscopes are a valuable tool for both the life and materials sciences, but they are limited in their ability to image with nanometer-scale resolution in three dimensions nonperiodic objects that are several microns in size. To fill this gap, the technique of coherent x-ray diffraction imaging now under development takes advantage of the penetrating power of x rays while simultaneously removing the limitations imposed by lens-based optical systems. Researchers from Stony Brook University, in collaboration with scientists at the ALS and Cornell University, have taken a large step in this direction by using a lensless x-ray diffraction microscope to image a freeze-dried yeast cell to better than 30-nm resolution. Images were made at several angular orientations of the cell.

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221

X-ray diffraction data for plutonium compounds  

Science Conference Proceedings (OSTI)

This work is a compilation of x-ray diffraction information relating to powder photographs of plutonium compounds. The information is presented in a format and style substantially as recommended by the International Centre for Diffraction Data. The Los Alamos National Laboratory has been very much involved in the study of the properties of plutonium and its compounds. During the past 45 years the Powder Diffraction File of the Laboratory has grown to more than 20,000 films. F.H. Ellinger and his coworkers have used this data to establish a large number of plutonium binary phase diagrams. A phase diagram, however, should never be regarded as really complete as new techniques of alloy preparation or x-ray and optical metallography continually discover new phases that must be incorporated in the diagram. In addition to the phase diagrams, the crystal structure of a number of plutonium intermetallic compounds have been determined at Los Alamos. Due to the importance of plutonium as a representative of the actinide series of elements, it is deemed advisable to have available information on the x-ray diffraction of plutonium and its compounds for the purpose of identification of these materials. It is hoped that the information presented here will be of value in this regard.

Roof, R.B.

1989-10-01T23:59:59.000Z

222

Single-molecule electron diffraction imaging with charge replacement  

E-Print Network (OSTI)

We investigate the possibility of non-destructive electron diffraction imaging of a single molecule to determine its structure. The molecular specimen will be held on a free-standing sheet of graphene. Due to the high conductivity of graphene, electrons lost by ionization would be rapidly replaced, enabling repeated nondestructive interrogation. Limits of resolution, maximum particle size and required electron flux are assessed.

Fill, E E; Raizen, M

2008-01-01T23:59:59.000Z

223

Diffractive Higgs production at LHC: A case study  

SciTech Connect

We discuss the case of the diffractive Higgs production at LHC. Aim of this talk is to propose the method of using Fracture Functions as an alternative to the ones already present in the literature. We discuss some of the questions involved and the main related issues.

Trentadue, Luca [Dipartimento di Fisica, Universita di Parma, Parma and INFN, Sezione di Milano Bicocca, Milano (Italy)

2012-10-23T23:59:59.000Z

224

Diffraction, Saturation and pp Cross Sections at the LHC  

E-Print Network (OSTI)

Results from the large hadron collider (LHC) show that no available Monte Carlo simulation incorporates our pre-LHC knowledge of soft and hard diffraction in a way that could be reliably extrapolated to LHC energies. As a simulation is needed to establish triggers, perform underlying event corrections and calculate acceptances, the lack of a robust simulation affects all measurements at the LHC. Particularly affected are the measurements of processes with large diffractive rapidity gaps, which constitute about one quarter of the inelastic cross section. In this paper, a previously described phenomenological model based on a saturation effect observed in single diffraction dissociation in pre-LHC data, validated by its successful application to several diffractive processes, is used to predict the total and total-inelastic proton-proton cross sections at the LHC. The prediction for the total-inelastic cross section at a center of mass collision energy of 7 TeV is compared with recent results from ATLAS and CMS.

Konstantin Goulianos

2011-05-25T23:59:59.000Z

225

Diffracted light from latent images in photoresist for exposure control  

DOE Patents (OSTI)

In microelectronics manufacturing, an arrangement for monitoring and control of exposure of an undeveloped photosensitive layer on a structure susceptible to variations in optical properties in order to attain the desired critical dimension for the pattern to be developed in the photosensitive layer. This is done by ascertaining the intensities for one or more respective orders of diffracted power for an incident beam of radiation corresponding to the desired critical dimension for the photosensitive layer as a function of exposure time and optical properties of the structure, illuminating the photosensitive layer with a beam of radiation of one or more frequencies to which the photosensitive layer is not exposure-sensitive, and monitoring the intensities of the orders of diffracted radiation due to said illumination including at least the first order of diffracted radiation thereof, such that when said predetermined intensities for the diffracted orders are reached during said illumination of photosensitive layer, it is known that a pattern having at least approximately the desired critical dimension can be developed on the photosensitive layer.

Bishop, Kenneth P. (Rio Rancho, NM); Brueck, Steven R. J. (Albuquerque, NM); Gaspar, Susan M. (Albuquerque, NM); Hickman, Kirt C. (Albuquerque, NM); McNeil, John R. (Albuquerque, NM); Naqvi, S. Sohail H. (Albuquerque, NM); Stallard, Brian R. (Albuquerque, NM); Tipton, Gary D. (Albuquerque, NM)

1997-01-01T23:59:59.000Z

226

Anomalous zones in Gulf Coast Salt domes with special reference to Big Hill, TX, and Weeks Island, LA  

Science Conference Proceedings (OSTI)

Anomalous features in Gulf Coast Salt domes exhibit deviations from normally pure salt and vary widely in form from one dome to the next, ranging considerably in length and width. They have affected both conventional and solution mining in several ways. Gas outbursts, insolubles, and potash (especially carnallite) have led to the breakage of tubing in a number of caverns, and caused irregular shapes of many caverns through preferential leaching. Such anomalous features essentially have limited the lateral extent of conventional mining at several salt mines, and led to accidents and even the closing of several other mines. Such anomalous features, are often aligned in anomalous zones, and appear to be related to diapiric processes of salt dome development. Evidence indicates that anomalous zones are found between salt spines, where the differential salt intrusion accumulates other materials: Anhydrite bands which are relatively strong, and other, weaker impurities. Shear zones and fault displacement detected at Big Hill and Weeks Island domes have not yet had any known adverse impacts on SPR oil storage, but new caverns at these sites conceivably may encounter some potentially adverse conditions. Seismic reflection profiles at Big Hill dome have shown numerous fractures and faults in the caprock, and verified the earlier recognition of a major shear zone transecting the entire salt stock and forming a graben in the overlying caprock. Casing that is placed in such zones can be at risk. Knowledge of these zones should create awareness of possible effects rather than preclude the future emplacement of caverns. To the extent possible, major anomalous zones and salt stock boundaries should be avoided. Shear zones along overhangs may be particularly hazardous, and otherwise unknown valleys in the top of salt may occur along shear zones. These zones often can be mapped geophysically, especially with high-resolution seismic techniques.

Neal, J.T. [Sandia National Labs., Albuquerque, NM (United States); Magorian, T.R. [Magorian (Thomas R.), Amherst, NY (United States); Thoms, R.L. [AGM, Inc., College Station, TX (United States); Autin, W.J.; McCulloh, R.P. [Louisiana Geological Survey, Baton Rouge, LA (United States); Denzler, S.; Byrne, K.O. [Acres International Corp., Amherst, NY (United States)

1993-07-01T23:59:59.000Z

227

Anomalously low thermal conductivity and thermoelectric properties of new cationic clathrates in the Sn-In-As-I system  

Science Conference Proceedings (OSTI)

Single-crystal samples of cationic clathrates in the Sn-In-As-I system with different indium contents have been synthesized. Their crystal structure has been analyzed and their thermoelectric properties have been measured. These compounds are found to be n-type semiconductors with high absolute values of the Seebeck coefficient (S = 400-600 {mu}V/K) and anomalously low thermal conductivity ({kappa} {materials. The reasons for the anomalously low thermal conductivity of these semiconductors are discussed and ways for optimizing their thermoelectric properties are shown.

Shevelkov, A. V.; Kelm, E. A.; Olenev, A. V. [Moscow State University, Faculty of Chemistry (Russian Federation); Kulbachinskii, V. A., E-mail: kulb@mig.phys.msu.ru; Kytin, V. G. [Moscow State University, Faculty of Physics (Russian Federation)

2011-11-15T23:59:59.000Z

228

Investigation of Sludge Batch 3 (Macrobatch 4) Glass Sample Anomalous Behavior  

Science Conference Proceedings (OSTI)

Two Defense Waste Processing Facility (DWPF) glass samples from Sludge Batch 3 (SB3) (Macrobatch 4) were received by the Savannah River National Laboratory (SRNL) on February 23, 2005. One sample, S02244, was designated for the Product Consistency Test (PCT) and elemental and radionuclide analyses. The second sample, S02247, was designated for archival storage. The samples were pulled from the melter pour stream during the feeding of Melter Feed Tank (MFT) Batch 308 and therefore roughly correspond to feed from Slurry Mix Evaporator (SME) Batches 306-308. During the course of preparing sample S02244 for PCT and other analyses two observations were made which were characterized as ''unusual'' or anomalous behavior relative to historical observations of glasses prepared for the PCT. These observations ultimately led to a series of scoping tests in order to determine more about the nature of the behavior and possible mechanisms. The first observation was the behavior of the ground glass fraction (-100 +200 mesh) for PCT analysis when contacted with deionized water during the washing phase of the PCT procedure. The behavior was analogous to that of an organic compound in the presence of water: clumping, floating on the water surface, and crawling up the beaker walls. In other words, the glass sample did not ''wet'' normally, displaying a hydrophobic behavior in water. This had never been seen before in 18 years SRNL PCT tests on either radioactive or non-radioactive glasses. Typical glass behavior is largely to settle to the bottom of the water filled beaker, though there may be suspended fines which result in some cloudiness to the wash water. The typical appearance is analogous to wetting sand. The second observation was the presence of faint black rings at the initial and final solution levels in the Teflon vessels used for the mixed acid digestion of S02244 glass conducted for compositional analysis. The digestion is composed of two stages, and at both the intermediate and the final content levels in the digestion vessel the rings were present. The rings had not been seen previously during glass digestions and were not present in the Analytical Reference Glass (ARG) standard samples digested, in separate vessels, along with the DWPF glass. What follows in this report are the results and analyses from various scoping experiments done in order to explain the anomalous behavior observed with DWPF glass S02244, along with a comparison with tests on sample S02247 where the anomalous wetting behavior was not observed.

Bannochie, C. J.; Bibler, N. E.; Peeler, D. K.

2005-08-15T23:59:59.000Z

229

AMI OBSERVATIONS OF THE ANOMALOUS MICROWAVE EMISSION IN THE PERSEUS MOLECULAR CLOUD  

SciTech Connect

We present observations of the known anomalous microwave emission region, G159.6-18.5, in the Perseus molecular cloud at 16 GHz performed with the Arcminute Microkelvin Imager Small Array. These are the highest angular resolution observations of G159.6-18.5 at microwave wavelengths. By combining these microwave data with infrared observations between 5.8 and 160 {mu}m from the Spitzer Space Telescope, we investigate the existence of a microwave-infrared correlation on angular scales of {approx}2'. We find that the overall correlation appears to increase toward shorter infrared wavelengths, which is consistent with the microwave emission being produced by electric dipole radiation from small, spinning dust grains. We also find that the microwave-infrared correlation peaks at 24 {mu}m (6.7{sigma}), suggesting that the microwave emission is originating from a population of stochastically heated small interstellar dust grains rather than polycyclic aromatic hydrocarbons.

Tibbs, C. T. [Spitzer Science Center, California Institute of Technology, Pasadena, CA 91125 (United States); Scaife, A. M. M. [School of Physics and Astronomy, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom); Dickinson, C.; Davies, R. D.; Davis, R. J.; Watson, R. A. [Jodrell Bank Centre for Astrophysics, School of Physics and Astronomy, The University of Manchester, Manchester M13 9PL (United Kingdom); Paladini, R. [NASA Herschel Science Center, California Institute of Technology, Pasadena, CA 91125 (United States); Grainge, K. J. B., E-mail: ctibbs@ipac.caltech.edu [Astrophysics Group, Cavendish Laboratory, J J Thomson Avenue, Cambridge CB3 0HE (United Kingdom)

2013-05-10T23:59:59.000Z

230

Search for anomalous production of multiple leptons in association with $W$ and $Z$ bosons at CDF  

Science Conference Proceedings (OSTI)

This paper presents a search for anomalous production of multiple low-energy leptons in association with a W or Z boson using events collected at the CDF experiment corresponding to 5.1 fb{sup -1} of integrated luminosity. This search is sensitive to a wide range of topologies with low-momentum leptons, including those with the leptons near one another. The observed rates of production of additional electrons and muons are compared with the standard model predictions. No indications of phenomena beyond the standard model are found. A 95% confidence level limit is presented on the production cross section for a benchmark model of supersymmetric hidden-valley Higgs production. Particle identification efficiencies are also provided to enable the calculation of limits on additional models.

Aaltonen, T.; /Helsinki Inst. of Phys.; Alvarez Gonzalez, B.; /Oviedo U. /Cantabria Inst. of Phys.; Amerio, S.; /INFN, Padua; Amidei, D.; /Michigan U.; Anastassov, A.; /Northwestern U. /Fermilab; Annovi, A.; /Frascati; Antos, J.; /Comenius U.; Apollinari, G.; /Fermilab; Appel, J.A.; /Fermilab; Arisawa, T.; /Waseda U.; Artikov, A.; /Dubna, JINR /Texas A-M

2012-02-01T23:59:59.000Z

231

Lattice dynamics and anomalous softening in the YbFe4Sb12 skutterudite  

SciTech Connect

The lattice dynamics of the filled skutterudite YbFe{sub 4}Sb{sub 12} was studied by resonant ultrasound spectroscopy and an anomalous softening in the temperature dependence of the elastic constants at {approx}50 K was observed. This anomaly can not be explained by the dynamics of the filler, in contrast to other filled skutterudites. We have further investigated the origin of this anomaly using macroscopic and microscopic measurements. A rearrangement of the spectral weight of the Yb phonon states was observed in the temperature dependence of the density of phonon states, obtained by inelastic neutron scattering. We suggest that the anomaly is due to a change of the Yb valence state and that the anomaly and the phonon spectral weight rearrangement have the same origin.

Mochel, A. [Julich Center for Neutron Science, Julich, Germany; Sergueev, I. [European Synchrotron Radiation Facility (ESRF); Wille, H. -C. [European Synchrotron Radiation Facility (ESRF); Voigt, J. [Julich Center for Neutron Science, Julich, Germany; Prager, M. [Julich Center for Neutron Science, Julich, Germany; Stone, Matthew B [ORNL; Sales, Brian C [ORNL; Guguchia, Z. [Tbilisi State University, Tbilisi, Georgia; Shengelaya, A. [Tbilisi State University, Tbilisi, Georgia; Keppens, V. [University of Tennessee, Knoxville (UTK); Hermann, Raphael P. [Forschungszentrum Julich, Julich, Germany

2011-01-01T23:59:59.000Z

232

Anomalous Corrosion Behavior of Stainless Steels under SOFC Interconnect Exposure Conditions  

Science Conference Proceedings (OSTI)

In low temperature SOFC stacks, oxidation resistant alloys such as ferritic stainless steels have been proposed as candidate materials for the interconnect, which is simultaneously exposed to a fuel on the anode side and an oxidant on the cathode side. The corrosion behavior of ferritic stainless steels under these dual atmosphere exposure conditions was investigated in a specifically designed apparatus. It was discovered that, under the simultaneous exposure, the oxide scale formed on the airside of the sample was significantly different from scales formed when the alloy was exposed to air only. It appeared that the anomalous corrosion behavior during the simultaneous dual exposure was due to hydrogen transport through the bulk alloy from the fuel side to the air side.

Yang, Z Gary; Walker, Matthew S.; Singh, Prabhakar; Stevenson, Jeffry W.

2003-07-23T23:59:59.000Z

233

Anomalous skin effects in relativistic parallel propagating weakly magnetized electron plasma waves  

SciTech Connect

Fully relativistic analysis of anomalous skin effects for parallel propagating waves in a weakly magnetized electron plasma is presented and general expressions for longitudinal and transverse permittivites are derived. It is found that the penetration depth for R- and L-waves increases as we move from non-relativistic to highly relativistic regime. The ambient magnetic field reduces/enhances the skin effects for R-wave/L-wave as the strength of the field is increased. In general, the weak magnetic field effects are pronounced for the weakly relativistic regime as compared with other relativistic cases. The results are also graphically illustrated. On switching off the magnetic field, previous results for field free case are retrieved [A. F. Alexandrov, A. S. Bogdankevich, and A. A. Rukhadze, Priniples of Plasma Electrodynamics (Springer-Verlag, Berlin, Heidelberg, 1984), Vol. 9, p. 106].

Abbas, Gohar; Bashir, M. F. [Salam Chair in Physics, G. C. University, Lahore 54000 (Pakistan); Department of Physics, G. C. University, Lahore 54000 (Pakistan); Murtaza, G. [Salam Chair in Physics, G. C. University, Lahore 54000 (Pakistan)

2011-10-15T23:59:59.000Z

234

Anomalous electron heating and energy balance in an ion beam generated plasma  

DOE Green Energy (OSTI)

The plasma described in this report is generated by a 15 to 34 kV ion beam, consisting primarily of protons, passing through an H/sub 2/ gas cell neutralizer. Plasma ions (or ion-electron pairs) are produced by electron capture from (or ionization of) gas molecules by beam ions and atoms. An explanation is provided for the observed anomalous behavior of the electron temperature (T/sub e/): a step-lite, nearly two-fold jump in T/sub e/ as the beam current approaches that which minimizes beam angular divergence; insensitivity of T/sub e/ to gas pressure; and the linear relation of T/sub e/ to beam energy.

Guethlein, G.

1987-04-01T23:59:59.000Z

235

Hadronic light-by-light scattering contribution to the muon anomalous magnetic moment revisited  

E-Print Network (OSTI)

We discuss hadronic light-by-light scattering contribution to the muon anomalous magnetic moment a_\\mu^{\\rm lbl}, paying particular attention to the consistent matching between the short- and the long-distance behavior of the light-by-light scattering amplitude. We argue that the short-distance QCD imposes strong constraints on this amplitude overlooked in previous analyses. We find that accounting for these constraints leads to approximately 50 per cent increase in the central value of a_\\mu^{\\rm lbl}, compared to existing estimates. The hadronic light-by-light scattering contribution becomes a_\\mu^{\\rm lbl}=136(25) \\times 10^{-11}, thereby shifting the Standard Model prediction closer to the experimental value.

Kirill Melnikov; Arkady Vainshtein

2003-12-16T23:59:59.000Z

236

Entropy of the Nordic electricity market: anomalous scaling, spikes, and mean-reversion  

E-Print Network (OSTI)

The electricity market is a very peculiar market due to the large variety of phenomena that can affect the spot price. However, this market still shows many typical features of other speculative (commodity) markets like, for instance, data clustering and mean reversion. We apply the diffusion entropy analysis (DEA) to the Nordic spot electricity market (Nord Pool). We study the waiting time statistics between consecutive spot price spikes and find it to show anomalous scaling characterized by a decaying power-law. The exponent observed in data follows a quite robust relationship with the one implied by the DEA analysis. We also in terms of the DEA revisit topics like clustering, mean-reversion and periodicities. We finally propose a GARCH inspired model but for the price itself. Models in the context of stochastic volatility processes appear under this scope to have a feasible description.

Perello, J; Montero, M; Palatella, L; Simonsen, I; Masoliver, Jaume; Montero, Miquel; Palatella, Luigi; Perello, Josep; Simonsen, Ingve

2006-01-01T23:59:59.000Z

237

Fractal Location and Anomalous Diffusion Dynamics for Oil Wells from the KY Geological Survey  

E-Print Network (OSTI)

Utilizing data available from the Kentucky Geonet (KYGeonet.ky.gov) the fossil fuel mining locations created by the Kentucky Geological Survey geo-locating oil and gas wells are mapped using ESRI ArcGIS in Kentucky single plain 1602 ft projection. This data was then exported into a spreadsheet showing latitude and longitude for each point to be used for modeling at different scales to determine the fractal dimension of the set. Following the porosity and diffusivity studies of Tarafdar and Roy1 we extract fractal dimensions of the fossil fuel mining locations and search for evidence of scaling laws for the set of deposits. The Levy index is used to determine a match to a statistical mechanically motivated generalized probability function for the wells. This probability distribution corresponds to a solution of a dynamical anomalous diffusion equation of fractional order that describes the Levy paths which can be solved in the diffusion limit by the Fox H function ansatz.

Andrew, Keith; Andrew, Kevin A

2009-01-01T23:59:59.000Z

238

Atmospheric Hydrology of the Anomalous 2002 Indian Summer Monsoon Program in Atmospheric and Oceanic Sciences, University of Colorado, Boulder, Colorado  

E-Print Network (OSTI)

Atmospheric Hydrology of the Anomalous 2002 Indian Summer Monsoon J. FASULLO Program in Atmospheric, in final form 7 April 2005) ABSTRACT The 2002 Indian summer monsoon season is unique because of its in which ENSO events fail to be associated with significant monsoon anomalies. In this study, atmospheric

Fasullo, John

239

Matrix at slow roll: On the equivalence of the energy spectrum and anomalous dimensions for Yang-Mills models  

E-Print Network (OSTI)

We analyze the low energy limit of the massive version of a BFSS-like matrix model and show that in this limit it is equivalent to the matrix model introduced for description of the spectrum of anomalous dimensions for local gauge invariant composite operators in $\\mathcal{N}=4$ super Yang-Mills

Sochichiu, Corneliu

2010-01-01T23:59:59.000Z

240

Phase-shifting point diffraction interferometer mask designs  

DOE Patents (OSTI)

In a phase-shifting point diffraction interferometer, different image-plane mask designs can improve the operation of the interferometer. By keeping the test beam window of the mask small compared to the separation distance between the beams, the problem of energy from the reference beam leaking through the test beam window is reduced. By rotating the grating and mask 45.degree., only a single one-dimensional translation stage is required for phase-shifting. By keeping two reference pinholes in the same orientation about the test beam window, only a single grating orientation, and thus a single one-dimensional translation stage, is required. The use of a two-dimensional grating allows for a multiplicity of pinholes to be used about the pattern of diffracted orders of the grating at the mask. Orientation marks on the mask can be used to orient the device and indicate the position of the reference pinholes.

Goldberg, Kenneth Alan (Berkeley, CA)

2001-01-01T23:59:59.000Z

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


241

X-Ray Diffraction Project Final Report, Fiscal Year 2006  

SciTech Connect

An x-ray diffraction diagnostic system was developed for determining real-time shock-driven lattice parameter shifts in single crystals at the gas gun at TA-IV at Sandia National Laboratories (SNL). The signal-to-noise ratio and resolution of the system were measured using imaging plates as the detector and by varying the slit width. This report includes tests of the x-ray diffraction system using a phosphor coupled to a charge-coupled device (CCD) camera by a coherent fiber-optic bundle. The system timing delay was measured with a newly installed transistor-transistor logic (TTL) bypass designed to reduce the x-ray delay time. The axial misalignment of the Bragg planes was determined with respect to the optical axis for a set of eight LiF [lithium fluoride] crystals provided by SNL to determine their suitability for gas gun experiments.

Dane V. Morgan

2006-10-01T23:59:59.000Z

242

Search of anomalous $Wtb$ couplins in single top quark prodution at D0  

SciTech Connect

The large mass of the top quark, close to the electroweak symmetry-breaking scale, makes it a good candidate for probing physics beyond the Standard Model, including possible anomalous couplings. D0 has made measurements of single top quark production using 5.4 fb{sup -1} of integrated luminosity. We examine the data to study the Lorentz structure of the Wtb coupling. We find that the data prefer the left-handed vector coupling and set upper limits on the anomalous couplings. In 2009, the electroweak single top quark production was observed by the D0 and CDF collaborations. Electroweak production of top quarks at the Tevatron proceeds mainly via the decay of a time-like virtual W boson accompanied by a bottom quark in the s-channel (tb = t{bar b} + {bar t}b), or via the exchange of a space-like virtual W boson between a light quark and a bottom quark in the t-channel (tqb = tq{bar b} + {bar t}qb, where q refers to the light quark). For a top quark mass of 172.5 GeV, The Standard Model (SM) prediction of single top production rate at next-to-leading order with soft-gluon contributions at next-to-next-to-leading order are 1.04 {+-} 0.04 pb (s-channel) and 2.26 {+-} 0.12 pb (t-channel). The large mass of the top quark implies that it has large couplings to the electroweak symmetry breaking sector of the SM and may have non-standard interactions with the weak gauge bosons. Single top quark production provides a unique probe to study the interactions of the top quark with the W boson.

Joshi, Jyoti; Beri, Suman; /Panjab U.

2011-12-01T23:59:59.000Z

243

HIGH-PRECISION ASTROMETRY WITH A DIFFRACTIVE PUPIL TELESCOPE  

SciTech Connect

Astrometric detection and mass determination of Earth-mass exoplanets require sub-{mu}as accuracy, which is theoretically possible with an imaging space telescope using field stars as an astrometric reference. The measurement must, however, overcome astrometric distortions, which are much larger than the photon noise limit. To address this issue, we propose to generate faint stellar diffraction spikes using a two-dimensional grid of regularly spaced small dark spots added to the surface of the primary mirror (PM). Accurate astrometric motion of the host star is obtained by comparing the position of the spikes to the background field stars. The spikes do not contribute to scattered light in the central part of the field and therefore allow unperturbed coronagraphic observation of the star's immediate surroundings. Because the diffraction spikes are created on the PM and imaged on the same focal plane detector as the background stars, astrometric distortions affect equally the diffraction spikes and the background stars and are therefore calibrated. We describe the technique, detail how the data collected by the wide-field camera are used to derive astrometric motion, and identify the main sources of astrometric error using numerical simulations and analytical derivations. We find that the 1.4 m diameter telescope, 0.3 deg{sup 2} field we adopt as a baseline design achieves 0.2 {mu}as single measurement astrometric accuracy. The diffractive pupil concept thus enables sub-{mu}as astrometry without relying on the accurate pointing, external metrology, or high-stability hardware required with previously proposed high-precision astrometry concepts.

Guyon, Olivier; Eisner, Josh A.; Angel, Roger; Woolf, Neville J. [Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States); Bendek, Eduardo A.; Milster, Thomas D. [College of Optical Sciences, University of Arizona, Tucson, AZ 85721 (United States); Mark Ammons, S. [Lawrence Livermore National Laboratory, Physics Division L-210, 7000 East Ave., Livermore, CA 94550 (United States); Shao, Michael; Shaklan, Stuart; Levine, Marie; Nemati, Bijan [Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Pitman, Joe [Exploration Sciences, P.O. Box 24, Pine, CO 80470 (United States); Woodruff, Robert A. [2081 Evergreen Avenue, Boulder, CO 80304 (United States); Belikov, Ruslan, E-mail: guyon@naoj.org [NASA Ames Research Center, Moffett Field, CA 94035 (United States)

2012-06-01T23:59:59.000Z

244

X-ray diffraction data for plutonium compounds  

Science Conference Proceedings (OSTI)

This work is a compilation of x-ray diffraction information relating to powder photographs of plutonium compounds. The information is presented in a format and style substantially as recommended by the International Center for Diffraction Data. Los Alamos National Laboratory has been involved in the study of the properties of plutonium and its compounds. During the past 45 years, the Powder Diffraction File of the Laboratory has grown to more than 20,000 films. F.H. Ellinger and his coworkers have used this data to establish a large number of plutonium binary phase diagrams. These phase diagrams have been published in a special report of the Laboratory, LA-3870, Constitution of Plutonium Alloys,'' authored by F.H. Ellinger, W.N. Miner, D.R. O'Boyle, and F.W. Schonfeld. A phase diagram, however, should never be regarded as really complete as new techniques of alloy preparation or x-ray and optical metallography continually discover new phases that must be incorporated in the diagram. In addition to the phase diagrams, the crystal structures of a number of plutonium intermetallic compounds have been determined at Los Alamos and published in the general literature by D.T. Cromer, A.C. Larson, and R.B. Roof over the last 35 years.

Roof, R.B.

1991-06-01T23:59:59.000Z

245

Improvement of Laser Damage Resistance and Diffraction Efficiency of Multilayer Dielectric Diffraction Gratings by HF-Etchback Linewidth Tailoring  

Science Conference Proceedings (OSTI)

Multilayer dielectric (MLD) diffraction gratings for Petawatt-class laser systems possess unique laser damage characteristics. Details of the shape of the grating lines and the concentration of absorbing impurities on the surface of the grating structures both have strong effects on laser damage threshold. It is known that electric field enhancement in the solid material comprising the grating lines varies directly with the linewidth and inversely with the line height for equivalent diffraction efficiency. Here, they present an overview of laser damage characteristics of MLD gratings, and describe a process for post-processing ion-beam etched grating lines using very dilute buffered hydrofluoric acid solutions. This process acts simultaneously to reduce grating linewidth and remove surface contaminants, thereby improving laser damage thresholds through two pathways.

Nguyen, H T; Larson, C C; Britten, J A

2010-10-28T23:59:59.000Z

246

Single-particle structure determination by correlations of snapshot X-ray diffraction patterns  

DOE Data Explorer (OSTI)

This deposition includes the diffraction images generated by the paired polystyrene spheres in random orientations. These images were used to determine and phase the single particle diffraction volume from their autocorrelation functions.

Starodub, D.

247

Femtosecond diffractive imaging with a soft-X-ray free-electron...  

NLE Websites -- All DOE Office Websites (Extended Search)

diffractive imaging with a soft-X-ray free-electron laser We have demonstrated flash diffractive imaging of nanostructures using pulses from the first soft-X-ray free-electron...

248

Structure and Dynamics of Cholesterol-Containing Polyunsaturated Lipid Membranes Studied by Neutron Diffraction and NMR  

E-Print Network (OSTI)

by Neutron Diffraction and NMR Mihaela Mihailescu Olivierwas carried out by neutron diffraction, 2 H-NMR and 13C-MAS NMR. Scattering length distribution func- tions of

Mihailescu, Mihaela; Soubias, Olivier; Worcester, David; White, Stephen H.; Gawrisch, Klaus

2011-01-01T23:59:59.000Z

249

In-Situ Neutron-Diffraction Study of a Ferritic Superalloy during ...  

Science Conference Proceedings (OSTI)

The neutron diffraction experiments were conducted at VULCAN diffractometer, Spallation Neutron Source, ORNL, with the state-of-art thermomechanical...

250

Two-Dimensional X-ray Diffraction for Advanced Materials Analysis  

Science Conference Proceedings (OSTI)

Deformation Of Shape Memory Alloys Under Biaxial Loading .... Software Tools for the Monitoring, Analysis and Interpretation of Engineering Neutron Diffraction

251

Femtosecond diffractive imaging with a soft-X-ray free-electron laser  

DOE Data Explorer (OSTI)

The diffraction pattern of this entry corresponds to the one shown in **figure 2a** of the corresponding citation.

Chapman, H. N.

252

Palladium deuteride formation in the cathode of an electrochemical cell: An in situ neutron diffraction study  

DOE Green Energy (OSTI)

In this report, neutron diffraction of palladium cathodes is utilized to reveal palladium deuteride formation within the crystal structure of the metal. The experiment described in this report demonstrates the efficacy of neutron powder diffraction as a tool for structural studies of metal deuterides/hydrides and the feasibility of in situ diffraction measurements from a working electrochemical cell. (JL)

Rotella, F.J.; Richardson, J.W. Jr.; Redey, L.; Felcher, G.P.; Hitterman, R.L.; Kleb, R.

1991-12-31T23:59:59.000Z

253

Emittance Adapter for a Diffraction Limited Synchrotron Radiation Source  

Science Conference Proceedings (OSTI)

We investigate the possibility of reaching very small horizontal and vertical emittances inside an undulator in a storage ring, by means of a local exchange of the apparent horizontal and vertical emittances, performed with a combination of skew quadrupoles and one solenoid in a dedicated insertion line in the storage ring. The insertion leaves the ring parameters and its optical properties unaffected. This scheme could greatly relax the emittance requirements for a diffraction limited synchrotron light source. The lattice derivation and design is described.

Chao, Alexander Wu; /SLAC; Raimondi, Pantaleo; /Frascati

2012-03-01T23:59:59.000Z

254

Lithium atom interferometer using laser diffraction : description and experiments  

E-Print Network (OSTI)

We have built and operated an atom interferometer of the Mach-Zehnder type. The atomic wave is a supersonic beam of lithium seeded in argon and the mirrors and beam-splitters for the atomic wave are based on elastic Bragg diffraction on laser standing waves at 671 nm. We give here a detailed description of our experimental setup and of the procedures used to align its components. We then present experimental signals, exhibiting atomic interference effects with a very high visibility, up to 84.5 %. We describe a series of experiments testing the sensitivity of the fringe visibility to the main alignment defects and to the magnetic field gradient.

Alain Miffre; Marion Jacquey; Matthias Bchner; Grard Trenec; Jacques Vigue

2004-10-22T23:59:59.000Z

255

Diffraction crystals for sagittally focusing x-rays  

DOE Patents (OSTI)

The invention is a new type of diffraction crystal designed for sagittally focusing photons of various energies. The invention is based on the discovery that such focusing is not obtainable with conventional crystals because of distortion resulting from anticlastic curvature. The new crystal comprises a monocrystalline base having a front face contoured for sagittally focusing photons and a back face provided with rigid, upstanding, stiffening ribs restricting anticlastic curvature. When mounted in a suitable bending device, the reflecting face of the crystal can be adjusted to focus photons having any one of a range of energies.

Ice, G.E.; Sparks, C.J. Jr.

1982-06-07T23:59:59.000Z

256

Coherent Diffraction Radiation Longitudinal Beam Profile Monitor for CTF3  

E-Print Network (OSTI)

A setup for the investigation of Coherent Diffraction Radiation (CDR) from a conducting screen as a tool for noninvasive longitudinal electron beam profile diagnostics has been designed and installed in the Combiner Ring Measurement (CRM) line of the CLIC Test Facility (CTF3, CERN). In this report the status of the monitor development and results on the interferometric measurements of CDR spectra are presented. The CDR signal correlation with an RF pickup and a streak camera is reported. The future plans for the system improvements are also discussed

Micheler, Maximilian; Boorman, Gary; Karataev, Pavel; Lekomtsev, Konstantin; Molloy, Stephen; Corsini, Roberto; Dabrowski, Anne; Lefevre, Thibaut

2010-01-01T23:59:59.000Z

257

The three dimensional X-ray diffraction technique  

SciTech Connect

This introductory tutorial describes the so called 3 dimensional X-ray diffraction (3DXRD) technique, which allows bulk non-destructive structural characterizations of crystalline materials. The motivations and history behind the development of this technique are described and its potentials are sketched. Examples of the use of the technique are given and future trends and developments are suggested. The primary aim of the paper is to give 3DXRD novices an easy introduction to the technique and to describe a way from a dream to reality and new results.

Jensen, D. Juul; Poulsen, H.F. (Denmark)

2012-10-24T23:59:59.000Z

258

Diffraction crystal for sagittally focusing x-rays  

DOE Patents (OSTI)

The invention is a new type of diffraction crystal designed for sagittally focusing photons of various energies. The invention is based on the discovery that such focusing is not obtainable with conventional crystals because of distortion resulting from anticlastic curvature. The new crystal comprises a monocrystalline base having a front face contoured for sagittally focusing photons and a back face provided with rigid, upstanding, stiffening ribs restricting anticlastic curvature. When mounted in a suitable bending device, the reflecting face of the crystal can be adjusted to focus photons having any one of a range of energies.

Ice, Gene E. (Oak Ridge, TN); Sparks, Jr., Cullie J. (Oak Ridge, TN)

1984-01-01T23:59:59.000Z

259

Recovering partial conservation of axial current in diffractive neutrino scattering  

E-Print Network (OSTI)

A model of diffractive neutrino scattering is formulated in terms of the chiral hadronic current which is conserved in the limit of vanishing pion mass. This current has the correct singularity structure and, naturally, does not lead to contradictions with a partial conservation of the axial current (PCAC). In that respect we differ from earlier work in the literature, where a breakdown of PCAC had been reported. We show that such a breakdown of PCAC is an artifact of the hadronic current non-conservation in the model developed there.

V. A. Novikov; V. R. Zoller

2013-04-10T23:59:59.000Z

260

Beamline 8.2.2  

NLE Websites -- All DOE Office Websites (Extended Search)

2 Print 2 Print Berkeley Center for Structural Biology (BCSB) Multiple-Wavelength Anomalous Diffraction (MAD) and Macromolecular Crystallography (MX) GENERAL BEAMLINE INFORMATION Operational Yes Proposal cycle Proposals for Structural Biology Beamlines (2-month cycle) Source characteristics Superbend (5.0 T, single pole) Energy range 5-16 keV Monochromator Double crystal, Si(111) Measured flux (1.9 GeV, 400 mA) 3.0 x 1011 photons/sec Resolving power (E/ΔE) 7,000 Divergence (max at sample) 3.0(h) x 0.5(v) mrad Measured spot size at sample (FWHM) 100 µm Endstations Minihutch Detectors 3x3 CCD array (ADSC Q315) Sample format Single crystals of biological molecules Sample preparation Support labs available Sample environment Ambient or ~100 K Special notes Computers for data processing and analysis are available

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


261

Beamline 8.2.2  

NLE Websites -- All DOE Office Websites (Extended Search)

2 Print 2 Print Berkeley Center for Structural Biology (BCSB) Multiple-Wavelength Anomalous Diffraction (MAD) and Macromolecular Crystallography (MX) GENERAL BEAMLINE INFORMATION Operational Yes Proposal cycle Proposals for Structural Biology Beamlines (2-month cycle) Source characteristics Superbend (5.0 T, single pole) Energy range 5-16 keV Monochromator Double crystal, Si(111) Measured flux (1.9 GeV, 400 mA) 3.0 x 1011 photons/sec Resolving power (E/ΔE) 7,000 Divergence (max at sample) 3.0(h) x 0.5(v) mrad Measured spot size at sample (FWHM) 100 µm Endstations Minihutch Detectors 3x3 CCD array (ADSC Q315) Sample format Single crystals of biological molecules Sample preparation Support labs available Sample environment Ambient or ~100 K Special notes Computers for data processing and analysis are available

262

Beamline 5.0.2  

NLE Websites -- All DOE Office Websites (Extended Search)

2 Print 2 Print Berkeley Center for Structural Biology (BCSB) Multiple-wavelength anomalous diffraction (MAD) and monochromatic protein crystallography Scientific discipline: Structural biology GENERAL BEAMLINE INFORMATION Operational Yes Proposal cycle Proposals for Structural Biology Beamlines (2-month cycle) Source characteristics 11.4-cm period wiggler (W11) Energy range 5-16 keV Monochromator Double-crystal, Si(111) liquid N2 cooled Measured flux at 12.4 keV 8.0 x 1011 photons/s at 400-mA ring current, with 1.5-mrad convergence and 100-µm pinhole collimator Resolving power (E/ΔE) 7,000 Divergence at sample 3.0(h) x 0.4 (v) mrad (user selectable) Spot size 25-125 µm (user selectable) Endstations Standard hutch Characteristics Single axis, air bearing goniometer; CCD detector, low-temperature system

263

Beamline 8.2.1  

NLE Websites -- All DOE Office Websites (Extended Search)

1 Print 1 Print Berkeley Center for Structural Biology (BCSB) Multiple-Wavelength Anomalous Diffraction (MAD) and Macromolecular Crystallography (MX) Scientific discipline: Structural biology GENERAL BEAMLINE INFORMATION Operational Yes Proposal cycle Proposals for Structural Biology Beamlines (2-month cycle) Source characteristics Superbend magnet (5.0 T, single pole) Energy range 5-16 keV Monochromator Double crystal, Si(111) Measured flux (1.9 GeV, 400 mA) 3.0 x 1011 photons/sec Resolving power (E/ΔE) 7,000 Divergence (max at sample) 3.0 (h) x 0.5 (v) mrad Measured spot size (FWHM) 100 µm Endstations Minihutch Detectors 3x3 CCD array (ADSC Q315R) Sample format Single crystals of biological molecules Sample preparation Support labs available Sample environment Ambient or ~100 K

264

Beamline 8.3.1  

NLE Websites -- All DOE Office Websites (Extended Search)

3.1 Print 3.1 Print Multiple-wavelength anomalous diffraction (MAD) and macromolecular crystallography (MX) Scientific discipline: Structural biology GENERAL BEAMLINE INFORMATION Operational Yes Proposal cycle Proposals for Structural Biology Beamlines (2-month cycle) Source characteristics Superbend magnet (5.0 tesla, single pole) Energy range 5-17 keV (1% max flux) Monochromator Double flat crystal, Si(111) Measured flux (1.9 GeV, 400 mA) 2.5 x 1011 at 11 keV Resolving power (E/ΔE) 7,000 Divergence (max at sample) 3.0 (h) x 0.35 (v) mrad Endstations Minihutch Detectors 3 x 3 CCD array (ADSC Q315r) Measured spot size at sample (FWHM) 0.120 (h) x 0.108 (v) mm Sample format Single crystals of biological molecules. Crystallization tray goniometer available with prior arrangement.

265

Beamline 5.0.2  

NLE Websites -- All DOE Office Websites (Extended Search)

5.0.2 5.0.2 Beamline 5.0.2 Print Tuesday, 20 October 2009 08:35 Berkeley Center for Structural Biology (BCSB) Multiple-wavelength anomalous diffraction (MAD) and monochromatic protein crystallography Scientific discipline: Structural biology GENERAL BEAMLINE INFORMATION Operational Yes Proposal cycle Proposals for Structural Biology Beamlines (2-month cycle) Source characteristics 11.4-cm period wiggler (W11) Energy range 5-16 keV Monochromator Double-crystal, Si(111) liquid N2 cooled Measured flux at 12.4 keV 8.0 x 1011 photons/s at 400-mA ring current, with 1.5-mrad convergence and 100-µm pinhole collimator Resolving power (E/ΔE) 7,000 Divergence at sample 3.0(h) x 0.4 (v) mrad (user selectable) Spot size 25-125 µm (user selectable) Endstations Standard hutch Characteristics

266

Beamline 8.2.1  

NLE Websites -- All DOE Office Websites (Extended Search)

1 Print 1 Print Berkeley Center for Structural Biology (BCSB) Multiple-Wavelength Anomalous Diffraction (MAD) and Macromolecular Crystallography (MX) Scientific discipline: Structural biology GENERAL BEAMLINE INFORMATION Operational Yes Proposal cycle Proposals for Structural Biology Beamlines (2-month cycle) Source characteristics Superbend magnet (5.0 T, single pole) Energy range 5-16 keV Monochromator Double crystal, Si(111) Measured flux (1.9 GeV, 400 mA) 3.0 x 1011 photons/sec Resolving power (E/ΔE) 7,000 Divergence (max at sample) 3.0 (h) x 0.5 (v) mrad Measured spot size (FWHM) 100 µm Endstations Minihutch Detectors 3x3 CCD array (ADSC Q315R) Sample format Single crystals of biological molecules Sample preparation Support labs available Sample environment Ambient or ~100 K

267

Beamline 5.0.2  

NLE Websites -- All DOE Office Websites (Extended Search)

2 Print 2 Print Berkeley Center for Structural Biology (BCSB) Multiple-wavelength anomalous diffraction (MAD) and monochromatic protein crystallography Scientific discipline: Structural biology GENERAL BEAMLINE INFORMATION Operational Yes Proposal cycle Proposals for Structural Biology Beamlines (2-month cycle) Source characteristics 11.4-cm period wiggler (W11) Energy range 5-16 keV Monochromator Double-crystal, Si(111) liquid N2 cooled Measured flux at 12.4 keV 8.0 x 1011 photons/s at 400-mA ring current, with 1.5-mrad convergence and 100-µm pinhole collimator Resolving power (E/ΔE) 7,000 Divergence at sample 3.0(h) x 0.4 (v) mrad (user selectable) Spot size 25-125 µm (user selectable) Endstations Standard hutch Characteristics Single axis, air bearing goniometer; CCD detector, low-temperature system

268

Beamline 8.2.2  

NLE Websites -- All DOE Office Websites (Extended Search)

2 Print 2 Print Berkeley Center for Structural Biology (BCSB) Multiple-Wavelength Anomalous Diffraction (MAD) and Macromolecular Crystallography (MX) GENERAL BEAMLINE INFORMATION Operational Yes Proposal cycle Proposals for Structural Biology Beamlines (2-month cycle) Source characteristics Superbend (5.0 T, single pole) Energy range 5-16 keV Monochromator Double crystal, Si(111) Measured flux (1.9 GeV, 400 mA) 3.0 x 1011 photons/sec Resolving power (E/ΔE) 7,000 Divergence (max at sample) 3.0(h) x 0.5(v) mrad Measured spot size at sample (FWHM) 100 µm Endstations Minihutch Detectors 3x3 CCD array (ADSC Q315) Sample format Single crystals of biological molecules Sample preparation Support labs available Sample environment Ambient or ~100 K Special notes Computers for data processing and analysis are available

269

Beamline 5.0.2  

NLE Websites -- All DOE Office Websites (Extended Search)

2 Print 2 Print Berkeley Center for Structural Biology (BCSB) Multiple-wavelength anomalous diffraction (MAD) and monochromatic protein crystallography Scientific discipline: Structural biology GENERAL BEAMLINE INFORMATION Operational Yes Proposal cycle Proposals for Structural Biology Beamlines (2-month cycle) Source characteristics 11.4-cm period wiggler (W11) Energy range 5-16 keV Monochromator Double-crystal, Si(111) liquid N2 cooled Measured flux at 12.4 keV 8.0 x 1011 photons/s at 400-mA ring current, with 1.5-mrad convergence and 100-µm pinhole collimator Resolving power (E/ΔE) 7,000 Divergence at sample 3.0(h) x 0.4 (v) mrad (user selectable) Spot size 25-125 µm (user selectable) Endstations Standard hutch Characteristics Single axis, air bearing goniometer; CCD detector, low-temperature system

270

Beamline 5.0.2  

NLE Websites -- All DOE Office Websites (Extended Search)

2 Print 2 Print Berkeley Center for Structural Biology (BCSB) Multiple-wavelength anomalous diffraction (MAD) and monochromatic protein crystallography Scientific discipline: Structural biology GENERAL BEAMLINE INFORMATION Operational Yes Proposal cycle Proposals for Structural Biology Beamlines (2-month cycle) Source characteristics 11.4-cm period wiggler (W11) Energy range 5-16 keV Monochromator Double-crystal, Si(111) liquid N2 cooled Measured flux at 12.4 keV 8.0 x 1011 photons/s at 400-mA ring current, with 1.5-mrad convergence and 100-µm pinhole collimator Resolving power (E/ΔE) 7,000 Divergence at sample 3.0(h) x 0.4 (v) mrad (user selectable) Spot size 25-125 µm (user selectable) Endstations Standard hutch Characteristics Single axis, air bearing goniometer; CCD detector, low-temperature system

271

Beamline 8.2.2  

NLE Websites -- All DOE Office Websites (Extended Search)

2 Print 2 Print Berkeley Center for Structural Biology (BCSB) Multiple-Wavelength Anomalous Diffraction (MAD) and Macromolecular Crystallography (MX) GENERAL BEAMLINE INFORMATION Operational Yes Proposal cycle Proposals for Structural Biology Beamlines (2-month cycle) Source characteristics Superbend (5.0 T, single pole) Energy range 5-16 keV Monochromator Double crystal, Si(111) Measured flux (1.9 GeV, 400 mA) 3.0 x 1011 photons/sec Resolving power (E/ΔE) 7,000 Divergence (max at sample) 3.0(h) x 0.5(v) mrad Measured spot size at sample (FWHM) 100 µm Endstations Minihutch Detectors 3x3 CCD array (ADSC Q315) Sample format Single crystals of biological molecules Sample preparation Support labs available Sample environment Ambient or ~100 K Special notes Computers for data processing and analysis are available

272

Beamline 8.2.2  

NLE Websites -- All DOE Office Websites (Extended Search)

2 Print 2 Print Berkeley Center for Structural Biology (BCSB) Multiple-Wavelength Anomalous Diffraction (MAD) and Macromolecular Crystallography (MX) GENERAL BEAMLINE INFORMATION Operational Yes Proposal cycle Proposals for Structural Biology Beamlines (2-month cycle) Source characteristics Superbend (5.0 T, single pole) Energy range 5-16 keV Monochromator Double crystal, Si(111) Measured flux (1.9 GeV, 400 mA) 3.0 x 1011 photons/sec Resolving power (E/ΔE) 7,000 Divergence (max at sample) 3.0(h) x 0.5(v) mrad Measured spot size at sample (FWHM) 100 µm Endstations Minihutch Detectors 3x3 CCD array (ADSC Q315) Sample format Single crystals of biological molecules Sample preparation Support labs available Sample environment Ambient or ~100 K Special notes Computers for data processing and analysis are available

273

Beamline 8.2.2  

NLE Websites -- All DOE Office Websites (Extended Search)

2 Print 2 Print Berkeley Center for Structural Biology (BCSB) Multiple-Wavelength Anomalous Diffraction (MAD) and Macromolecular Crystallography (MX) GENERAL BEAMLINE INFORMATION Operational Yes Proposal cycle Proposals for Structural Biology Beamlines (2-month cycle) Source characteristics Superbend (5.0 T, single pole) Energy range 5-16 keV Monochromator Double crystal, Si(111) Measured flux (1.9 GeV, 400 mA) 3.0 x 1011 photons/sec Resolving power (E/ΔE) 7,000 Divergence (max at sample) 3.0(h) x 0.5(v) mrad Measured spot size at sample (FWHM) 100 µm Endstations Minihutch Detectors 3x3 CCD array (ADSC Q315) Sample format Single crystals of biological molecules Sample preparation Support labs available Sample environment Ambient or ~100 K Special notes Computers for data processing and analysis are available

274

Beamline 8.2.1  

NLE Websites -- All DOE Office Websites (Extended Search)

1 Print 1 Print Berkeley Center for Structural Biology (BCSB) Multiple-Wavelength Anomalous Diffraction (MAD) and Macromolecular Crystallography (MX) Scientific discipline: Structural biology GENERAL BEAMLINE INFORMATION Operational Yes Proposal cycle Proposals for Structural Biology Beamlines (2-month cycle) Source characteristics Superbend magnet (5.0 T, single pole) Energy range 5-16 keV Monochromator Double crystal, Si(111) Measured flux (1.9 GeV, 400 mA) 3.0 x 1011 photons/sec Resolving power (E/ΔE) 7,000 Divergence (max at sample) 3.0 (h) x 0.5 (v) mrad Measured spot size (FWHM) 100 µm Endstations Minihutch Detectors 3x3 CCD array (ADSC Q315R) Sample format Single crystals of biological molecules Sample preparation Support labs available Sample environment Ambient or ~100 K

275

Beamline 8.3.1  

NLE Websites -- All DOE Office Websites (Extended Search)

1 Print 1 Print Multiple-wavelength anomalous diffraction (MAD) and macromolecular crystallography (MX) Scientific discipline: Structural biology GENERAL BEAMLINE INFORMATION Operational Yes Proposal cycle Proposals for Structural Biology Beamlines (2-month cycle) Source characteristics Superbend magnet (5.0 tesla, single pole) Energy range 5-17 keV (1% max flux) Monochromator Double flat crystal, Si(111) Measured flux (1.9 GeV, 400 mA) 2.5 x 1011 at 11 keV Resolving power (E/ΔE) 7,000 Divergence (max at sample) 3.0 (h) x 0.35 (v) mrad Endstations Minihutch Detectors 3 x 3 CCD array (ADSC Q315r) Measured spot size at sample (FWHM) 0.120 (h) x 0.108 (v) mm Sample format Single crystals of biological molecules. Crystallization tray goniometer available with prior arrangement.

276

Beamline 8.2.2  

NLE Websites -- All DOE Office Websites (Extended Search)

2 Print 2 Print Berkeley Center for Structural Biology (BCSB) Multiple-Wavelength Anomalous Diffraction (MAD) and Macromolecular Crystallography (MX) GENERAL BEAMLINE INFORMATION Operational Yes Proposal cycle Proposals for Structural Biology Beamlines (2-month cycle) Source characteristics Superbend (5.0 T, single pole) Energy range 5-16 keV Monochromator Double crystal, Si(111) Measured flux (1.9 GeV, 400 mA) 3.0 x 1011 photons/sec Resolving power (E/ΔE) 7,000 Divergence (max at sample) 3.0(h) x 0.5(v) mrad Measured spot size at sample (FWHM) 100 µm Endstations Minihutch Detectors 3x3 CCD array (ADSC Q315) Sample format Single crystals of biological molecules Sample preparation Support labs available Sample environment Ambient or ~100 K Special notes Computers for data processing and analysis are available

277

Beamline 8.3.1  

NLE Websites -- All DOE Office Websites (Extended Search)

1 Print 1 Print Multiple-wavelength anomalous diffraction (MAD) and macromolecular crystallography (MX) Scientific discipline: Structural biology GENERAL BEAMLINE INFORMATION Operational Yes Proposal cycle Proposals for Structural Biology Beamlines (2-month cycle) Source characteristics Superbend magnet (5.0 tesla, single pole) Energy range 5-17 keV (1% max flux) Monochromator Double flat crystal, Si(111) Measured flux (1.9 GeV, 400 mA) 2.5 x 1011 at 11 keV Resolving power (E/ΔE) 7,000 Divergence (max at sample) 3.0 (h) x 0.35 (v) mrad Endstations Minihutch Detectors 3 x 3 CCD array (ADSC Q315r) Measured spot size at sample (FWHM) 0.120 (h) x 0.108 (v) mm Sample format Single crystals of biological molecules. Crystallization tray goniometer available with prior arrangement.

278

Beamline 8.2.2  

NLE Websites -- All DOE Office Websites (Extended Search)

2 Print 2 Print Berkeley Center for Structural Biology (BCSB) Multiple-Wavelength Anomalous Diffraction (MAD) and Macromolecular Crystallography (MX) GENERAL BEAMLINE INFORMATION Operational Yes Proposal cycle Proposals for Structural Biology Beamlines (2-month cycle) Source characteristics Superbend (5.0 T, single pole) Energy range 5-16 keV Monochromator Double crystal, Si(111) Measured flux (1.9 GeV, 400 mA) 3.0 x 1011 photons/sec Resolving power (E/ΔE) 7,000 Divergence (max at sample) 3.0(h) x 0.5(v) mrad Measured spot size at sample (FWHM) 100 µm Endstations Minihutch Detectors 3x3 CCD array (ADSC Q315) Sample format Single crystals of biological molecules Sample preparation Support labs available Sample environment Ambient or ~100 K Special notes Computers for data processing and analysis are available

279

Beamline 8.2.1  

NLE Websites -- All DOE Office Websites (Extended Search)

1 Print 1 Print Berkeley Center for Structural Biology (BCSB) Multiple-Wavelength Anomalous Diffraction (MAD) and Macromolecular Crystallography (MX) Scientific discipline: Structural biology GENERAL BEAMLINE INFORMATION Operational Yes Proposal cycle Proposals for Structural Biology Beamlines (2-month cycle) Source characteristics Superbend magnet (5.0 T, single pole) Energy range 5-16 keV Monochromator Double crystal, Si(111) Measured flux (1.9 GeV, 400 mA) 3.0 x 1011 photons/sec Resolving power (E/ΔE) 7,000 Divergence (max at sample) 3.0 (h) x 0.5 (v) mrad Measured spot size (FWHM) 100 µm Endstations Minihutch Detectors 3x3 CCD array (ADSC Q315R) Sample format Single crystals of biological molecules Sample preparation Support labs available Sample environment Ambient or ~100 K

280

Beamline 8.3.1  

NLE Websites -- All DOE Office Websites (Extended Search)

1 Print 1 Print Multiple-wavelength anomalous diffraction (MAD) and macromolecular crystallography (MX) Scientific discipline: Structural biology GENERAL BEAMLINE INFORMATION Operational Yes Proposal cycle Proposals for Structural Biology Beamlines (2-month cycle) Source characteristics Superbend magnet (5.0 tesla, single pole) Energy range 5-17 keV (1% max flux) Monochromator Double flat crystal, Si(111) Measured flux (1.9 GeV, 400 mA) 2.5 x 1011 at 11 keV Resolving power (E/ΔE) 7,000 Divergence (max at sample) 3.0 (h) x 0.35 (v) mrad Endstations Minihutch Detectors 3 x 3 CCD array (ADSC Q315r) Measured spot size at sample (FWHM) 0.120 (h) x 0.108 (v) mm Sample format Single crystals of biological molecules. Crystallization tray goniometer available with prior arrangement.

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


281

Beamline 5.0.2  

NLE Websites -- All DOE Office Websites (Extended Search)

2 Print 2 Print Berkeley Center for Structural Biology (BCSB) Multiple-wavelength anomalous diffraction (MAD) and monochromatic protein crystallography Scientific discipline: Structural biology GENERAL BEAMLINE INFORMATION Operational Yes Proposal cycle Proposals for Structural Biology Beamlines (2-month cycle) Source characteristics 11.4-cm period wiggler (W11) Energy range 5-16 keV Monochromator Double-crystal, Si(111) liquid N2 cooled Measured flux at 12.4 keV 8.0 x 1011 photons/s at 400-mA ring current, with 1.5-mrad convergence and 100-µm pinhole collimator Resolving power (E/ΔE) 7,000 Divergence at sample 3.0(h) x 0.4 (v) mrad (user selectable) Spot size 25-125 µm (user selectable) Endstations Standard hutch Characteristics Single axis, air bearing goniometer; CCD detector, low-temperature system

282

Aspects of jet quenching as a diffractive phenomenon  

E-Print Network (OSTI)

We argue that the collisional aspects of jet quenching in a high energy nuclear collision are perhaps best understood as a diffractive phenomenon. The jet has a large energy, and acquires momentum transverse to its axis more effectively by multiple soft collisions than by few hard scatterings (as known from analogous systems such as $J/\\psi$ production at Hera). Such regime of large E and small momentum transfer is characteristically dominated by the pomeron. From this insight we estimate the jet quenching parameter in the hadron medium (largely a pion gas) at the end of the collision, which is naturally small and increases with temperature in line with the gas density. The treatment of diffraction in the quark-gluon plasma/liquid phase is beset with uncertainties, but we provide a couple of preliminary guesses that suggest indeed that the pomeron-mediated interactions are very relevant and provide a further handle on the jet quenching parameter, that perturbation theory seems to underestimate. Finally, the ocasional hard collisions produce features characteristic of a L\\'evy flight in the ${\\bf q}_\\perp^2$ plane perpendicular to the jet axis. We suggest one- and two-particle ${\\bf q}_\\perp$ correlations as interesting experimental probes.

Carlos Hidalgo-Duque; Felipe J. Llanes-Estrada

2013-09-27T23:59:59.000Z

283

Diffraction of surface wave on conducting rectangular wedge  

E-Print Network (OSTI)

Diffraction of a surface wave on a rectangular wedge with impedance faces is studied using the Sommerfeld-Malyuzhinets technique. An analog of Landau's bypass rule in the theory of plasma waves is introduced for selection of a correct branch of the Sommerfeld integral, and the exact solution is given in terms of imaginary error function. The formula derived is valid both in the near-field and far-wave zones. It is shown that a diffracted surface wave is completely scattered into freely propagating electromagnetic waves and neither reflected nor transmitted surface waves are generated in case of bare metals which have positive real part of surface impedance. The scattered waves propagate predominantly at a grazing angle along the direction of propagation of the incident surface wave and mainly in the upper hemisphere regarding the wedge face. The profile of radiated intensity is nonmonotonic and does not resemble the surface wave profile which exponentially evanesces with the distance from the wedge face. Comparison with experiments carried out in the terahertz spectral range at Novosibirsk free electron laser has shown a good agreement of the theory and the experiments.

Igor A. Kotelnikov; Vasily V. Gerasimov; Boris A. Knyazev

2013-01-16T23:59:59.000Z

284

Electron backscatter diffraction of plutonium-gallium alloys  

Science Conference Proceedings (OSTI)

At Los Alamos National Laboratory a recent experimental technique has been developed to characterize reactive metals, including plutonium arid cerium, using electron backscatter diffraction (EBSD). Microstructural characterization of plutonium and its alloys by EBSD had been previously elusive primarily because of the extreme toxicity and rapid surface oxidation rate associated with plutonium metal. The experimental techniques, which included ion-sputtering the metal surface using a scanning auger microprobe (SAM) followed by vacuum transfer of the sample from the SAM to the scanning electron microscope (SEM), used to obtain electron backscatter diffraction Kikuchi patterns (EBSPs) and orientation maps for plutonium-gallium alloys are described and the initial microstructural observations based on the analysis are discussed. Combining the SEM and EBSD observations, the phase transformation behavior between the {delta} and {var_epsilon} structures was explained. This demonstrated sample preparation and characterization technique is expected to be a powerful means to further understand phase transformation behavior, orientation relationships, and texlure in the complicated plutonium alloy systems.

Boehlert, C. J. (Carl J.); Zocco, T. G. (Thomas G.); Schulze, R. K. (Roland K.); Mitchell, J. N. (Jeremy N.); Pereyra, R. A. (Ramiro A.)

2002-01-01T23:59:59.000Z

285

Aspects of jet quenching as a diffractive phenomenon  

E-Print Network (OSTI)

We argue that the collisional aspects of jet quenching in a high energy nuclear collision are perhaps best understood as a diffractive phenomenon. The jet has a large energy, and acquires momentum transverse to its axis more effectively by multiple soft collisions than by few hard scatterings (as known from analogous systems such as $J/\\psi$ production at Hera). Such regime of large E and small momentum transfer is characteristically dominated by the pomeron. From this insight we estimate the jet quenching parameter in the hadron medium (largely a pion gas) at the end of the collision, which is naturally small and increases with temperature in line with the gas density. The treatment of diffraction in the quark-gluon plasma/liquid phase is beset with uncertainties, but we provide a couple of preliminary guesses that suggest indeed that the pomeron-mediated interactions are very relevant and provide a further handle on the jet quenching parameter, that perturbation theory seems to underestimate. Finally, the o...

Hidalgo-Duque, Carlos

2013-01-01T23:59:59.000Z

286

Aspects of jet quenching as a diffractive phenomenon  

E-Print Network (OSTI)

We argue that the collisional aspects of jet quenching in a high energy nuclear collision are perhaps best understood as a diffractive phenomenon. The jet has a large energy, and acquires momentum transverse to its axis more effectively by multiple soft collisions than by few hard scatterings (as known from analogous systems such as J/psi production at Hera). Such regime of large E and small momentum transfer is characteristically dominated by the pomeron. From this insight we estimate the jet quenching parameter in the hadron medium (largely a pion gas) at the end of the collision, which is naturally small and increases with temperature in line with the gas density. The treatment of diffraction in the quark-gluon plasma/liquid phase is beset with uncertainties, but we provide a couple of preliminary guesses that suggest indeed that the pomeron-mediated interactions are very relevant and provide a further handle on the jet quenching parameter, that perturbation theory seems to underestimate. Finally, the ocasional hard collisions produce features characteristic of a L\\`evy flight in the q_perp^2 plane perpendicular to the jet axis. We suggest one- and two-particle q_perp correlations as interesting experimental probes.

Carlos Hidalgo-Duque; Felipe J. Llanes-Estrada

2013-09-27T23:59:59.000Z

287

High temperature metallic diffraction gratings and process of manufacturing same  

DOE Patents (OSTI)

This invention is comprised of a method of applying diffraction gratings or images directly to the surface of a substrate wherein the gratings or images are capable of withstanding high temperatures, pressures, humidity and other such conditions related to materials testing. The method includes coating the surface of the substrate with an uniform layer of metal which is then overlaid with a layer of photo-resist material. Next, after contacting the photo-resist material with a master image containing regions of opacity and transparency, electromagnetic radiation is directed through the master image to expose the photo-resist material such that a contact print of the master image is produced on the photo-resist material. Then, after removing the master image, the photo-resist material is developed so as to remove unhardened portions thereof and leave corresponding portions of the metal layer uncovered. Finally, after removing or etching the uncovered portions of the metal layer, the remaining photo-resist material is removed to produce a metallic diffraction grating or image of predetermined size and pattern on the surface of the substrate.

Deason, V.A.; Hsu, Karen M.; Miller, R.L.

1993-12-31T23:59:59.000Z

288

A single diffractive optical element for implementing spectrum-splitting and beam-concentration functions simultaneously with high diffraction efficiency  

E-Print Network (OSTI)

In this paper, a novel method is proposed, and employed to design a single diffractive optical element (DOE) for implementing spectrum-splitting and beam-concentration (SSBC) functions simultaneously. We develop an optimization algorithm, through which the SSBC DOE can be optimized within an arbitrary thickness range, according to the limitations of modern photolithography technology. Theoretical simulation results reveal that the designed SSBC DOE has a high optical focusing efficiency. It is expected that the designed SSBC DOE should have practical applications in high-efficiency solar cell systems.

Ye, Jia-Sheng; Huang, Qing-Li; Dong, Bi-Zhen; Zhang, Yan; Yang, Guo-Zhen

2013-01-01T23:59:59.000Z

289

Astrophysics of the Soft Gamma Repeaters and Anomalous X-Ray Pulsars  

E-Print Network (OSTI)

I summarize the recent advances in our understanding of the Soft Gamma Repeaters: in particular their spin behavior, persistent emission and hyper-Eddington outbursts. The giant flares on 5 March 1979 and 27 August 1998 provide compelling physical evidence for magnetic fields stronger than 10 B_{QED} = 4.4 x 10^{14} G, consistent with the rapid spindown detected in two of these sources. The persistent X-ray emission and variable spindown of the 6-12 s Anomalous X-ray Pulsars are compared and contrasted with those of the SGRs, and the case made for a close connection between the two types of sources. Their collective properties point to the existence of {\\it magnetars}: neutron stars in which a decaying magnetic field (rather than accretion or rotation) is the dominant source of energy for radiative and particle emissions. Observational tests of the magnetar model are outlined, along with current ideas about the trigger of SGR outbursts, new evidence for the trapped fireball model, and the influence of QED processes on X-ray spectra and lightcurves. A critical examination is made of coherent radio emission from bursting strong-field neutron stars. I conclude with an overview of the genetic connection between neutron star magnetism and the violent fluid motions in a collapsing supernova core.

Christopher Thompson

2000-10-02T23:59:59.000Z

290

Higgs mass and muon anomalous magnetic moment in supersymmetric models with vectorlike matters  

SciTech Connect

We study the muon anomalous magnetic moment (muon g-2) and the Higgs boson mass in a simple extension of the minimal supersymmetric (SUSY) standard model with extra vectorlike matters, in the frameworks of gauge-mediated SUSY breaking (GMSB) models and gravity mediation (mSUGRA) models. It is shown that the deviation of the muon g-2 and a relatively heavy Higgs boson can be simultaneously explained in large tan{beta} region. (i) In GMSB models, the Higgs mass can be more than 135 GeV (130 GeV) in the region where the muon g-2 is consistent with the experimental value at the 2{sigma} (1{sigma}) level, while maintaining the perturbative coupling unification. (ii) In the case of mSUGRA models with universal soft masses, the Higgs mass can be as large as about 130 GeV when the muon g-2 is consistent with the experimental value at the 2{sigma} level. In both cases, the Higgs mass can be above 140 GeV if the g-2 constraint is not imposed.

Endo, Motoi; Hamaguchi, Koichi [Department of Physics, University of Tokyo, Tokyo 113-0033 (Japan); Institute for the Physics and Mathematics of the Universe (IPMU), University of Tokyo, Chiba, 277-8583 (Japan); Iwamoto, Sho; Yokozaki, Norimi [Department of Physics, University of Tokyo, Tokyo 113-0033 (Japan)

2011-10-01T23:59:59.000Z

291

Tests of hadronic vacuum polarization fits for the muon anomalous magnetic moment  

E-Print Network (OSTI)

We construct a physically motivated model for the isospin-one non-strange vacuum polarization function Pi(Q^2) based on a spectral function given by vector-channel OPAL data from hadronic tau decays for energies below the tau mass and a successful parametrization, employing perturbation theory and a model for quark-hadron duality violations, for higher energies. Using a covariance matrix and Q^2 values from a recent lattice simulation, we then generate fake data for Pi(Q^2) and use it to test fitting methods currently employed on the lattice for extracting the hadronic vacuum polarization contribution to the muon anomalous magnetic moment. This comparison reveals a systematic error much larger than the few-percent total error sometimes claimed for such extractions in the literature. In particular, we find that errors deduced from fits using a Vector Meson Dominance ansatz are misleading, typically turning out to be much smaller than the actual discrepancy between the fit and exact model results. The use of a ...

Golterman, Maarten; Peris, Santiago

2013-01-01T23:59:59.000Z

292

Anomalous kinetic energy of a system of dust particles in a gas discharge plasma  

SciTech Connect

The system of equations of motion of dust particles in a near-electrode layer of a gas discharge has been formulated taking into account fluctuations of the charge of a dust particle and the features of the nearelectrode layer of the discharge. The molecular dynamics simulation of the system of dust particles has been carried out. Performing a theoretical analysis of the simulation results, a mechanism of increasing the average kinetic energy of dust particles in the gas discharge plasma has been proposed. According to this mechanism, the heating of the vertical oscillations of dust particles is initiated by induced oscillations generated by fluctuations of the charge of dust particles, and the energy transfer from vertical to horizontal oscillations can be based on the parametric resonance phenomenon. The combination of the parametric and induced resonances makes it possible to explain an anomalously high kinetic energy of dust particles. The estimate of the frequency, amplitude, and kinetic energy of dust particles are close to the respective experimental values.

Norman, G. E., E-mail: norman@ihed.ras.ru; Stegailov, V. V., E-mail: stegailov@gmail.com; Timofeev, A. V., E-mail: timofeevalvl@gmail.com [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)

2011-11-15T23:59:59.000Z

293

Brownian motion and anomalous diffusion revisited via a fractional Langevin equation  

E-Print Network (OSTI)

In this paper we revisit the Brownian motion on the basis of {the fractional Langevin equation which turns out to be a particular case of the generalized Langevin equation introduced by Kubo in 1966. The importance of our approach is to model the Brownian motion more realistically than the usual one based on the classical Langevin equation, in that it takes into account also the retarding effects due to hydrodynamic back-flow, i.e. the added mass and the Basset memory drag. We provide the analytical expressions of the correlation functions (both for the random force and the particle velocity) and of the mean squared particle displacement. The random force has been shown to be represented by a superposition of the usual white noise with a "fractional" noise. The velocity correlation function is no longer expressed by a simple exponential but exhibits a slower decay, proportional to t^{-3/2} for long times, which indeed is more realistic. Finally, the mean squared displacement is shown to maintain, for sufficiently long times, the linear behaviour which is typical of normal diffusion, with the same diffusion coefficient of the classical case. However, the Basset history force induces a retarding effect in the establishing of the linear behaviour, which in some cases could appear as a manifestation of anomalous diffusion to be correctly interpreted in experimental measurements.

Francesco Mainardi; Antonio Mura; Francesco Tampieri

2010-04-20T23:59:59.000Z

294

Brownian Motion in a Speckle Light Field: Tunable Anomalous Diffusion and Deterministic Optical Manipulation  

E-Print Network (OSTI)

The motion of particles in random potentials occurs in several natural phenomena ranging from the mobility of organelles within a biological cell to the diffusion of stars within a galaxy. A Brownian particle moving in the random optical potential associated to a speckle, i.e., a complex interference pattern generated by the scattering of coherent light by a random medium, provides an ideal mesoscopic model system to study such phenomena. Here, we derive a theory for the motion of a Brownian particle in a speckle and, in particular, we identify its universal characteristic timescale levering on the universal properties of speckles. This theoretical insight permits us to identify several interesting unexplored phenomena and applications. As an example of the former, we show the possibility of tuning anomalous diffusion continuously from subdiffusion to superdiffusion. As an example of the latter, we show the possibility of harnessing the speckle memory effect to perform some basic deterministic optical manipulation tasks such as guiding and sorting by employing random speckles, which might broaden the perspectives of optical manipulation for real-life applications by providing a simple and cost-effective technique.

Giorgio Volpe; Giovanni Volpe; Sylvain Gigan

2013-04-04T23:59:59.000Z

295

Relative Contributions of the Indian Ocean and Local SST Anomalies to the Maintenance of the Western North Pacific Anomalous Anticyclone during the El Nio Decaying Summer  

Science Conference Proceedings (OSTI)

To investigate the relative role of the cold SST anomaly (SSTA) in the western North Pacific (WNP) or Indian Ocean basin mode (IOBM) in maintaining an anomalous anticyclone over the western North Pacific (WNPAC) during the El Nio decaying summer,...

Bo Wu; Tim Li; Tianjun Zhou

2010-06-01T23:59:59.000Z

296

Anomalous Temperature Regimes during the Cool Season: Long-term Trends, Low Frequency Mode Modulation and Representation in CMIP5 Simulations  

Science Conference Proceedings (OSTI)

During boreal winter, anomalous temperature regimes (ATRs), including cold air outbreaks (CAOs) and warm waves (WWs), provide important societal influences upon the US. The current study analyzes reanalysis and model data for the period 1949 to ...

Rebecca M. Westby; Yun-Young Lee; Robert X. Black

297

Comment on the article ``UCN anomalous losses and the UCN capture cross section on material defects'' by A. Serebrov et al  

E-Print Network (OSTI)

We present correct solution of the problem about a scattering of the neutron on a point-like defect existing in a medium and show that this mechanism cannot explain anomalous losses of UCN in storage bottles.

A. L. Barabanov; K. V. Protasov

2005-07-08T23:59:59.000Z

298

Bruker Workshop on Single Crystal X-Ray Diffraction  

NLE Websites -- All DOE Office Websites (Extended Search)

Diagnosis and Treatment of Problem Structures: Diagnosis and Treatment of Problem Structures: A Bruker Workshop on Single Crystal X-Ray Diffraction May 30, 2008 Chemistry Department University of Tennessee Knoxville, TN This meeting focuses on the scientific resources of four ORNL user facilities funded by the DOE Office of Basic Energy Sciences. Who Should Attend Synopsis Goals Scheduled Agenda Workshop Materials Confirmed Speakers Important Dates Registration - now open Location - Directions and Map Sponsors Organizing and Local Committee Contacts Relevant Literature, References, Websites Local Information Bruker - UT Workshop Who Should Attend? The Workshop is directed to the newcomer as well as the experienced user of a Bruker Apex / Apex-II system and SHELX software. It will concentrate on hard to solve and/or refine problem structures. We envision it to be

299

Extending Resonant Diffraction to Very High Energies for Structural Studies  

NLE Websites -- All DOE Office Websites (Extended Search)

Tuning the Collective Properties of Artificial Nanoparticle Supercrystals Tuning the Collective Properties of Artificial Nanoparticle Supercrystals The Workings of a Key Staph Enzyme and How to Block It Simple Lithium Is Good For Many Surprises Science Highlights Archives: 2013 | 2012 | 2011 | 2010 2009 | 2008 | 2007 | 2006 2005 | 2004 | 2003 | 2002 2001 | 2000 | 1998 | Subscribe to APS Science Highlights rss feed Extending Resonant Diffraction to Very High Energies for Structural Studies of Complex Materials MARCH 15, 2011 Bookmark and Share Systems investigated using the high-energy resonant PDF method: the (dis)ordered phases of Cu3Au, PtPd random-alloy and core-shell nanoparticles (upper part), and the BiFeO3 perovskite structure (undistorted and distorted; lower part). Researchers utilizing the U.S. Department of Energy's Argonne Advanced

300

3-dimensional imaging system using crystal diffraction lenses  

DOE Patents (OSTI)

A device for imaging a plurality of sources of x-ray and gamma-ray radiation is provided. Diffracting crystals are used for focussing the radiation and directing the radiation to a detector which is used for analyzing their addition to collect data as to the location of the source of radiation. A computer is used for converting the data to an image. The invention also provides for a method for imaging x-ray and gamma radiation by supplying a plurality of sources of radiation; focussing the radiation onto a detector; analyzing the focused radiation to collect data as to the type and location of the radiation; and producing an image using the data.

Smither, Robert K. (Hinsdale, IL)

1999-01-01T23:59:59.000Z

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


301

Synchrotron X-ray diffraction studies of phase transitions and mechanical properties of nanocrystalline materials at high pressure  

Science Conference Proceedings (OSTI)

The behavior of nanocrystals under extreme pressure was investigated using synchrotron x-ray diffraction. A major part of this investigation was the testing of a prototype synchrotron endstation on a bend magnet beamline at the Advanced Light Source for high pressure work using a diamond anvil cell. The experiments conducted and documented here helped to determine issues of efficiency and accuracy that had to be resolved before the construction of a dedicated ''super-bend'' beamline and endstation. The major conclusions were the need for a cryo-cooled monochromator and a fully remote-controllable pressurization system which would decrease the time to change pressure and greatly reduce the error created by the re-placement of the diamond anvil cell after each pressure change. Two very different types of nanocrystal systems were studied, colloidal iron oxide (Fe{sub 2}O{sub 3}) and thin film TiN/BN. Iron oxide nanocrystals were found to have a transition from the {gamma} to the {alpha} structure at a pressure strongly dependent on the size of the nanocrystals, ranging from 26 GPa for 7.2 nm nanocrystals to 37 GPa for 3.6 nm nanocrystals. All nanocrystals were found to remain in the {alpha} structure even after release of pressure. The transition pressure was also found, for a constant size (5.7 nm) to be strongly dependent on the degree of aggregation of the nanocrystals, increasing from 30 GPa for completely dissolved nanocrystals to 45 GPa for strongly aggregated nanocrystals. Furthermore, the x-ray diffraction pattern of the pressure induced {alpha} phase demonstrated a decrease in intensity for certain select peaks. Together, these observations were used to make a complete picture of the phase transition in nanocrystalline systems. The size dependence of the transition was interpreted as resulting from the extremely high surface energy of the {alpha} phase which would increase the thermodynamic offset and thereby increase the kinetic barrier to transition that must be overridden with pressure. The anomalous intensities in the x-ray diffraction patterns were interpreted as being the result of stacking faults, indicating that the mechanism of transition proceeds by the sliding of {gamma}(111) planes to form {alpha}(001) planes. The increasing transition pressure for more aggregated samples may be due to a positive activation volume, retarding the transition for nanocrystals with less excess (organic) volume available to them. The lack of a reverse transition upon decompression makes this interpretation more difficult because of the lack of an observable hysteresis, and it is therefore difficult to ascertain kinetic effects for certain. In the case TiN/BN nanocomposite systems, it was found that the bulk modulus (B{sub 0}) of the TiN nanoparticles was not correlated to the observed hardness or Young's modulus of the macroscopic thin film. This indicates that the origin of the observed super-hard nature of these materials is not due to any change in the Ti-N interatomic potential. Rather, the enhanced hardness must be due to nano-structural effects. It was also found that during pressurization the TiN nanoparticles developed a great deal of strain. This strain can be related to defects induced in individual nanoparticles which generates strain in adjacent particles due to the highly coupled nature of the system.

Prilliman, Gerald Stephen

2003-09-01T23:59:59.000Z

302

Anomalous critical behaviour in the polymer collapse transition of three-dimensional lattice trails  

E-Print Network (OSTI)

Trails (bond-avoiding walks) provide an alternative lattice model of polymers to self-avoiding walks, and adding self-interaction at multiply visited sites gives a model of polymer collapse. Recently, a two-dimensional model (triangular lattice) where doubly and triply visited sites are given different weights was shown to display a rich phase diagram with first and second order collapse separated by a multi-critical point. A kinetic growth process of trails (KGT) was conjectured to map precisely to this multi-critical point. Two types of low temperature phases, globule and crystal-like, were encountered. Here, we investigate the collapse properties of a similar extended model of interacting lattice trails on the simple cubic lattice with separate weights for doubly and triply visited sites. Again we find first and second order collapse transitions dependent on the relative sizes of the doubly and triply visited energies. However we find no evidence of a low temperature crystal-like phase with only the globular phase in existence. Intriguingly, when the ratio of the energies is precisely that which separates the first order from the second-order regions anomalous finite-sized scaling appears. At the finite size location of the rounded transition clear evidence exists for a first order transition that persists in the thermodynamic limit. This location moves as the length increases, with its limit apparently at the point that maps to a KGT. However, if one fixes the temperature to sit at exactly this KGT point then only a critical point can be deduced from the data. The resolution of this apparent contradiction lies in the breaking of crossover scaling and the difference in the shift and transition width (crossover) exponents.

Andrea Bedini; Aleksander L Owczarek; Thomas Prellberg

2011-11-11T23:59:59.000Z

303

ANOMALOUS LOW STATES AND LONG-TERM VARIABILITY IN THE BLACK HOLE BINARY LMC X-3  

Science Conference Proceedings (OSTI)

Rossi X-ray Timing Explorer observations of the black hole binary LMC X-3 reveal an extended very low X-ray state lasting from 2003 December 13 until 2004 March 18, unprecedented both in terms of its low luminosity (>15 times fainter than ever before seen in this source) and long duration ({approx}3 times longer than a typical low/hard state excursion). During this event little to no source variability is observed on timescales of {approx}hours-weeks, and the X-ray spectrum implies an upper limit of 1.2 Multiplication-Sign 10{sup 35} erg s{sup -1}. Five years later another extended low state occurs, lasting from 2008 December 11 until 2009 June 17. This event lasts nearly twice as long as the first, and while significant variability is observed, the source remains reliably in the low/hard spectral state for the {approx}188 day duration. These episodes share some characteristics with the 'anomalous low states' in the neutron star binary Her X-1. The average period and amplitude of the variability of LMC X-3 have different values between these episodes. We characterize the long-term variability of LMC X-3 before and after the two events using conventional and nonlinear time series analysis methods, and show that, as is the case in Her X-1, the characteristic amplitude of the variability is related to its characteristic timescale. Furthermore, the relation is in the same direction in both systems. This suggests that a similar mechanism gives rise to the long-term variability, which in the case of Her X-1 is reliably modeled with a tilted, warped precessing accretion disk.

Smale, Alan P.; Boyd, Patricia T., E-mail: alan.smale@nasa.gov, E-mail: padi.boyd@nasa.gov [Astrophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

2012-09-10T23:59:59.000Z

304

Cryptotomography: reconstructing 3D Fourier intensities from randomly oriented single-shot diffraction patterns  

Science Conference Proceedings (OSTI)

These 2000 single-shot diffraction patterns include were either background-scattering only or hits (background-scattering plus diffraction signal from sub-micron ellipsoidal particles at random, undetermined orientations). Candidate hits were identified by eye, and the remainder were presumed as background. 54 usable, background-subtracted hits in this set (procedure in referenced article) were used to reconstruct the 3D diffraction intensities of the average ellipsoidal particle.

2011-08-01T23:59:59.000Z

305

Cryptotomography: reconstructing 3D Fourier intensities from randomly oriented single-shot diffraction patterns  

DOE Data Explorer (OSTI)

These 2000 single-shot diffraction patterns include were either background-scattering only or hits (background-scattering plus diffraction signal from sub-micron ellipsoidal particles at random, undetermined orientations). Candidate hits were identified by eye, and the remainder were presumed as background. 54 usable, background-subtracted hits in this set (procedure in referenced article) were used to reconstruct the 3D diffraction intensities of the average ellipsoidal particle.

Loh, Ne-Te Duane

306

In-Situ Neutron Diffraction Study of Porous NiO-YSZ Composite ...  

Science Conference Proceedings (OSTI)

Presentation Title, In-Situ Neutron Diffraction Study of Porous NiO-YSZ Composite ... Gas Turbines of the Future: Hydrogen and Oxy-Combustion Environments.

307

In-situ neutron diffraction and crystal plasticity modeling of ?-Uranium  

Science Conference Proceedings (OSTI)

The present study uses a combination of in-situ neutron diffraction and crystal plasticity modeling to elucidate the deformation mechanisms active in ?-Uranium.

308

Neutron Diffraction Studies of the Tri-axial Stress Distribution in ...  

Science Conference Proceedings (OSTI)

Here neutron diffraction strain scanning, originally developed for residual stress measurements, is applied to the stress distribution in granular materials under a...

309

Neutron diffraction measurements of residual stresses in welds fabricated from highly anisotropic materials  

NLE Websites -- All DOE Office Websites (Extended Search)

neutron diffraction to neutron diffraction to engineering problems T.M. Holden Northern Stress Technologies Deep River, Ontario, Canada Oak Ridge National Laboratory, 13 nd June 2011 Reference material * "Introduction to the characterization of residual stress by neutron diffraction". M.T. Hutchings, P.J. Withers, T.M. Holden and T. Lorentzen, (Taylor and Francis: Boca Raton) 2005 * "Introduction to diffraction in Materials Science and Engineering", A.D. Krawitz (John Wiley and Sons ,Inc.: New York) 2001 * "Non-destructive testing-Standard Test Method for

310

Production of spin-3 mesons in diffractive DIS  

E-Print Network (OSTI)

We calculate the amplitudes of J^{PC}=3^{--} meson production in diffractive DIS within the k_t-factorization approach, with a particular attention paid to the rho_3(1690) meson. We find that at all Q^2 the rho_3(1690) production cross section is 2-5 times smaller than the rho(1700) production cross section, which is assumed to be a pure D-wave state. Studying sigma_L and sigma_T separately, we observe domination of rho_3 in sigma_L and domination of rho(1700) in sigma_T and offer an explanation of this behavior in simple terms. We also find very strong contributions -- sometimes even domination -- of the s-channel helicity violating amplitudes. The typical color dipole sizes probed in rho_3 production are shown to be larger than those in the ground state rho production, and the energy dependence of rho_3 cross section turns out to be much flatter than the rho production cross section. All the conclusions about the relative behavior of rho_3(1690) and rho(1700) mesons are numerically stable against variations of input parameters.

F. Caporale; I. P. Ivanov

2005-04-16T23:59:59.000Z

311

Hadron spectroscopy in diffractive and central production processes at COMPASS  

SciTech Connect

COMPASS is a fixed-target experiment using secondary high-energetic hadron beams provided by the CERN SPS. In 2008 and 2009, a large amount of data has been collected with a 190 GeV/c pion beam for the investigation of the hadron spectrum in diffractive and central production processes. A big variety of observed final states, including {pi}{sup -}{pi}{sup +}{pi}{sup -}, {pi}{sup -}{pi}{sup 0}{pi}{sup 0}, {pi}{sup -}{eta}{eta}, {pi}{sup -}K{sub s}K{sub s}, {pi}{sup -}K{sup +}K{sup -}, K{sup -}{pi}{sup +}{pi}{sup -}, and centrally produced 4{pi}, is being analysed. The potential for systematic spectroscopic studies especially concerning the existence and nature of spin-exotic, hybrid and glueball states is discussed. In addition, we show the first results from the data set collected with a proton beam in 2008. These data indicate the chance of COMPASS to contribute to the field of baryon spectroscopy.

Jasinski, Prometeusz Kryspin [Institut fuer Kernphysik, 55128 - Mainz University (Germany)

2011-07-15T23:59:59.000Z

312

Lifting Slepton Masses with a Non-universal, Non-anomalous U(1)'_{NAF} in Anomaly Mediated SUSY breaking  

E-Print Network (OSTI)

We extend the Minimum Supersymmetry Standard Model by a non-anomalous family (NAF) U(1)'_{NAF} gauge symmetry. All gauge anomalies are cancelled with no additional exotics other than the three right-handed neutrinos. The FI D-terms associated with the U(1)'_{NAF} symmetry lead to additional positive contributions to slepton squared masses. In a RG invariant way, this thus solves the tachyonic slepton mass problem in Anomaly Mediated Supersymmetry Breaking. In addition, the U (1)'_{NAF} symmetry naturally gives rise to the fermion mass hierarchy and mixing angles, and determines the mass spectrum of the sparticles.

Mu-Chun Chen; Jinrui Huang

2010-11-01T23:59:59.000Z

313

Atom trapping in a bottle beam created by a diffractive optical element  

E-Print Network (OSTI)

A diffractive optical element (DOE) has been fabricated for creating blue detuned atomic bottle beam traps. The DOE integrates several diffractive lenses for trap creation and imaging of atomic fluorescence. We characterize the performance of the DOE and demonstrate trapping of cold Cesium atoms inside a bottle beam.

V. V. Ivanov; J. A. Isaacs; M. Saffman; S. A. Kemme; A. R. Ellis; G. R. Brady; J. R. Wendt; G. W. Biedermann; S. Samora

2013-05-23T23:59:59.000Z

314

Electron diffraction patterns with thermal diffuse scattering maxima around Kikuchi lines  

SciTech Connect

Transmission electron diffraction patterns of silicon with thermal diffuse maxima around Kikuchi lines, which are analogs of the maxima of thermal diffuse electron scattering around point reflections, have been recorded. Diffuse maxima are observed only around Kikuchi lines with indices that are forbidden for the silicon structure. The diffraction conditions for forming these maxima are discussed.

Karakhanyan, R. K., E-mail: rkarakhanyan@yandex.ru; Karakhanyan, K. R. [Yerevan State University (Armenia)

2011-01-15T23:59:59.000Z

315

Identification of Compounds and Phases Using X-Ray Powder Diffraction  

Science Conference Proceedings (OSTI)

Table 1(a)   Identification of powder diffraction pattern from Al 2 O 3 using the Hanawalt search method...pattern from Al 2 O 3 using the Hanawalt search method The diffracting angles and intensities (area under each peak)

316

Model independent pre-processing of X-ray powder diffraction profiles  

Science Conference Proceedings (OSTI)

Precise knowledge of X-ray diffraction profile shape is crucial in the investigation of the properties of matter in crystals powder. Line-broadening analysis is the fourth pre-processing step in most of the full powder pattern fitting softwares. The ... Keywords: Hankel--Lanczos singular value decomposition (HLSVD), Morphological filtering, X-ray powder diffraction

M. Ladisa; A. Lamura; T. Laudadio; G. Nico

2007-01-01T23:59:59.000Z

317

Atom trapping in a bottle beam created by a diffractive optical element  

E-Print Network (OSTI)

A diffractive optical element (DOE) has been fabricated for creating blue detuned atomic bottle beam traps. The DOE integrates several diffractive lenses for trap creation and imaging of atomic fluorescence. We characterize the performance of the DOE and demonstrate trapping of cold Cesium atoms inside a bottle beam.

Ivanov, V V; Saffman, M; Kemme, S A; Ellis, A R; Brady, G R; Wendt, J R; Biedermann, G W; Samora, S

2013-01-01T23:59:59.000Z

318

Detection of Anomalous Reactor Activity Using Antineutrino Count Rate Evolution Over the Course of a Reactor Cycle  

E-Print Network (OSTI)

This paper analyzes the sensitivity of antineutrino count rate measurements to changes in the fissile content of civil power reactors. Such measurements may be useful in IAEA reactor safeguards applications. We introduce a hypothesis testing procedure to identify statistically significant differences between the antineutrino count rate evolution of a standard 'baseline' fuel cycle and that of an anomalous cycle, in which plutonium is removed and replaced with an equivalent fissile worth of uranium. The test would allow an inspector to detect anomalous reactor activity, or to positively confirm that the reactor is operating in a manner consistent with its declared fuel inventory and power level. We show that with a reasonable choice of detector parameters, the test can detect replacement of 73 kg of plutonium in 90 days with 95% probability, while controlling the false positive rate at 5%. We show that some improvement on this level of sensitivity may be expected by various means, including use of the method in conjunction with existing reactor safeguards methods. We also identify a necessary and sufficient daily antineutrino count rate to achieve the quoted sensitivity, and list examples of detectors in which such rates have been attained.

Vera Bulaevskaya; Adam Bernstein

2010-09-11T23:59:59.000Z

319

Oxygen adsorption on the Ru(1010) surface: Anomalous coverage dependence  

E-Print Network (OSTI)

Oxygen adsorption onto Ru(1010) results in the formation of two ordered overlayers, i.e. a c(24)-2O and a (21)pg-2O phase, which were analyzed by low-energy electron diffraction (LEED) and density functional theory (DFT) calculation. In addition, the vibrational properties of these overlayers were studied by high-resolution electron loss spectroscopy. In both phases, oxygen occupies the threefold coordinated hcp site along the densely packed rows on an otherwise unreconstructed surface, i.e. the O atoms are attached to two atoms in the first Ru layer Ru(1) and to one Ru atom in the second layer Ru(2), forming zigzag chains along the troughs. While in the low-coverage c(24)-O phase, the bond lengths of O to Ru(1) and Ru(2) are 2.08 ?A and 2.03 ?A, respectively, corresponding bond lengths in the high-coverage (21)-2O phase are 2.01 ?A and 2.04 ?A(LEED). Although the adsorption energy decreases by 220 meV with O coverage (DFT calculations), we observe experimentally a shortening of the Ru(1)-O bond length with O coverage. This effect could not be reconciled with the present DFT-GGA calculations. The ?(Ru-O) stretch mode is found at 67 meV [c(24)-2O] and 64 meV [(21)pg-2O]. I.

S. Schwegmann; A. P. Seitsonen; V. De Renzi; H. Dietrich; H. Bludau; M. Gierer; H. Over; K. Jacobi; M. Scheffler; G. Ertl

1997-01-01T23:59:59.000Z

320

Two-loop soft anomalous dimensions for single top quark associated production with a W{sup -} or H{sup -}  

SciTech Connect

I present results for the two-loop soft anomalous dimensions for associated production of a single top quark with a W boson or a charged Higgs boson. The calculation uses expressions for the massive cusp anomalous dimension, which are presented in different forms, and it allows soft-gluon resummation at next-to-next-to-leading-logarithm (NNLL) accuracy. From the NNLL resummed cross section I derive approximate NNLO cross sections for bg{yields}tW{sup -} and bg{yields}tH{sup -} at LHC energies of 7, 10, and 14 TeV.

Kidonakis, Nikolaos [Kennesaw State University, Physics no. 1202, 1000 Chastain Road, Kennesaw, Georgia 30144-5591 (United States)

2010-09-01T23:59:59.000Z

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321

Electron Backscatter Diffraction (EBSD) Characterization of Uranium and Uranium Alloys  

SciTech Connect

Electron backscatter diffraction (EBSD) was used to examine the microstructures of unalloyed uranium, U-6Nb, U-10Mo, and U-0.75Ti. For unalloyed uranium, we used EBSD to examine the effects of various processes on microstructures including casting, rolling and forming, recrystallization, welding, and quasi-static and shock deformation. For U-6Nb we used EBSD to examine the microstructural evolution during shape memory loading. EBSD was used to study chemical homogenization in U-10Mo, and for U-0.75Ti, we used EBSD to study the microstructure and texture evolution during thermal cycling and deformation. The studied uranium alloys have significant microstructural and chemical differences and each of these alloys presents unique preparation challenges. Each of the alloys is prepared by a sequence of mechanical grinding and polishing followed by electropolishing with subtle differences between the alloys. U-6Nb and U-0.75Ti both have martensitic microstructures and both require special care in order to avoid mechanical polishing artifacts. Unalloyed uranium has a tendency to rapidly oxidize when exposed to air and a two-step electropolish is employed, the first step to remove the damaged surface layer resulting from the mechanical preparation and the second step to passivate the surface. All of the alloying additions provide a level of surface passivation and different one and two step electropolishes are employed to create good EBSD surfaces. Because of its low symmetry crystal structure, uranium exhibits complex deformation behavior including operation of multiple deformation twinning modes. EBSD was used to observe and quantify twinning contributions to deformation and to examine the fracture behavior. Figure 1 shows a cross section of two mating fracture surfaces in cast uranium showing the propensity of deformation twinning and intergranular fracture largely between dissimilarly oriented grains. Deformation of U-6Nb in the shape memory regime occurs by the motion of twin boundaries formed during the martensitic transformation. Deformation actually results in a coarsening of the microstructure making EBSD more practical following a limited amount of strain. Figure 2 shows the microstructure resulting from 6% compression. Casting of U-10Mo results in considerable chemical segregation as is apparent in Figure 2a. The segregation subsists through rolling and heat treatment processes as shown in Figure 2b. EBSD was used to study the effects of homogenization time and temperature on chemical heterogeneity. It was found that times and temperatures that result in a chemically homogeneous microstructure also result in a significant increase in grain size. U-0.75Ti forms an acicular martinsite as shown in Figure 4. This microstructure prevails through cycling into the higher temperature solid uranium phases.

McCabe, Rodney J. [Los Alamos National Laboratory; Kelly, Ann Marie [Los Alamos National Laboratory; Clarke, Amy J. [Los Alamos National Laboratory; Field, Robert D. [Los Alamos National Laboratory; Wenk, H. R. [University of California, Berkeley

2012-07-25T23:59:59.000Z

322

VOLUME 88, NUMBER 22 P H Y S I C A L R E V I E W L E T T E R S 3 JUNE 2002 Excitable Front Geometry in Reaction-Diffusion Systems with Anomalous Dispersion  

E-Print Network (OSTI)

in Reaction-Diffusion Systems with Anomalous Dispersion Oliver Steinbock Florida State University, Department-dimensional excitable systems with anomalous dispersion provide a discrete set of interpulse distances for the stable structures are observed in a variety of experiments on gas discharge systems, chemical reactions, and living

Steinbock, Oliver

323

Bragg diffraction using a 100 ps 17.5 keV x-ray backlighter and the Bragg diffraction imager  

Science Conference Proceedings (OSTI)

A new diagnostic for measuring Bragg diffraction of petawatt-generated high-energy x rays off a laser-compressed crystal was designed and tested successfully at the Omega EP laser facility on static Mo and Ta (111) oriented single crystal samples using a 17.5 keV Mo K{alpha} backlighter. The Bragg diffraction imager consists of a heavily shielded enclosure and a precisely positioned beam block attached to the enclosure by an aluminum arm. Fuji image plates are used as the x-ray detectors. The diffraction from Mo and Ta (222) crystal planes was clearly detected with a high signal-to-noise. This technique will be applied to shock- and quasi-isentropically loaded single crystals on the Omega EP laser.

Maddox, B. R.; Park, H.-S.; Hawreliak, J.; Elsholz, A.; Van Maren, R.; Remington, B. A. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Comley, A. [AWE, Reading, Berkshire RG7 4PR (United Kingdom); Wark, J. S. [Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford, OX1 3PU (United Kingdom)

2010-10-15T23:59:59.000Z

324

Transient x-ray diffraction and its application to materials science and x-ray optics  

SciTech Connect

Time resolved x-ray diffraction and scattering have been applied to the measurement of a wide variety of physical phenomena from chemical reactions to shock wave physics. Interest in this method has heightened in recent years with the advent of versatile, high power, pulsed x-ray sources utilizing laser plasmas, electron beams and other methods. In this article, we will describe some of the fundamentals involved in time resolved x-ray diffraction, review some of the history of its development, and describe some recent progress in the field. In this article we will emphasize the use of laser-plasmas as the x-ray source for transient diffraction.

Hauer, A.A.; Kopp, R.; Cobble, J.; Kyrala, G.; Springer, R. [and others

1997-12-01T23:59:59.000Z

325

Three-fold diffraction symmetry in epitaxial graphene and the SiC substrate  

SciTech Connect

The crystallographic symmetries and spatial distribution of stacking domains in graphene films on 6H-SiC(0001) have been studied by low energy electron diffraction (LEED) and dark field imaging in a low energy electron microscope (LEEM). We find that the graphene diffraction spots from 2 and 3 atomic layers of graphene have 3-fold symmetry consistent with AB (Bernal or rhombohedral) stacking of the layers. On the contrary, graphene diffraction spots from the buffer layer and monolayer graphene have apparent 6-fold symmetry, although the 3-fold nature of the satellite spots indicates a more complex periodicity in the graphene sheets.

Siegel, D A; Zhou, S Y; El Gabaly, F; Schmid, A K; McCarty, K F; Lanzara, A

2009-12-10T23:59:59.000Z

326

ALICE diffractive physics in p-p and Pb-Pb collisions at the LHC  

SciTech Connect

The ALICE experiment at the Large Hadron Collider LHC is presently being commissioned. ALICE consists of a central barrel, a muon spectrometer and neutron calorimeters at 0 deg. Additional detectors for event classification and trigger purposes are located on both sides of the central barrel. The geometry of the ALICE detector allows the implementation of a diffractive double gap trigger by requiring two or more tracks in the central barrel but no activity in the event classification detectors. Some selected diffractive physics channels are discussed which become accessible by a double gap trigger. The interest of such diffractive measurements in proton-proton as well as in lead-lead collisions is outlined.

Schicker, R. [Phys. Inst., Philosophenweg 12, 69120 Heidelberg (Germany)

2009-03-23T23:59:59.000Z

327

X-ray Absorption and Diffraction Studies of the Mixed-phase State of (CrxV1-x)2O3  

Science Conference Proceedings (OSTI)

X-ray diffraction and vanadium x-ray absorption near-edge structure (XANES) data have been obtained for (V{sub 1-x}Cr{sub x}){sub 2}O{sub 3} samples containing several concentrations of Cr, crossing the metal-insulator transition boundary. For single-phase single-crystal samples our theoretical results are generally in good qualitative agreement with our experimental single-crystal XANES, for both crystal orientations relative to the incident-beam electric vector. However, an anomalous peak occurs for both orientations in the K pre-edge of the single-crystal sample containing 1.2% Cr, a paramagnetic insulator sample that is in the concentration regime corresponding to the room-temperature two-phase (coexistence) region of the phase diagram. Upon increasing the temperature of the 0.4% Cr powdered material to 400 K so that one enters the two-phase region of the phase diagram, a similar peak appears and then diminishes at 600 K. These results, as well as experiments done by others involving room-temperature and low-temperature XANES of a 1.1% Cr sample, suggest that this feature in the V pre-edge structure is associated with the appearance under some circumstances of a small amount of highly distorted VO{sub 6} octahedra in the interface region between coexisting metal and insulating phases. Finally, we find that, for the two-phase regime, the concentration ratio of the metal-to-insulating phase varies between different regions from a sample batch of uniform composition made by the skull melting method.

D Pease; A Frenkel; V Krayzman; T Huang; P Shanthakumar; J Budnick; P Metcalf; F Chudnovsky; E Stern

2011-12-31T23:59:59.000Z

328

Bragg diffraction using a 100ps 17.5 keV x-ray backlighter and the Bragg Diffraction Imager  

Science Conference Proceedings (OSTI)

A new diagnostic for measuring Bragg diffraction from a laser-driven crystal using a 100ps 17.5 kV x-ray backlighter source is designed and tested successfully at the Omega EP laser facility on static Mo and Ta single crystal samples using a Mo Ka backlighter. The Bragg Diffraction Imager (BDI) consists of a heavily shielded enclosure and a precisely positioned beam block, attached to the main enclosure by an Aluminum arm. Image plate is used as the x-ray detector. The diffraction lines from Mo and Ta planes are clearly detected with a high signal-to-noise using the 17.5 keV and 19.6 keV characteristic lines generated by a petawatt-driven Mo foil. This technique will be applied to shock and ramp-loaded single crystals on the Omega EP laser. Pulsed x-ray diffraction of shock- and ramp-compressed materials is an exciting new technique that can give insight into the dynamic behavior of materials at ultra-high pressure not achievable by any other means to date. X-ray diffraction can be used to determine not only the phase and compression of the lattice at high pressure, but by probing the lattice compression on a timescale equal to the 3D relaxation time of the material, information about dislocation mechanics, including dislocation multiplication rate and velocity, can also be derived. Both Bragg, or reflection, and Laue, or transmission, diffraction have been developed for shock-loaded low-Z crystalline structures such as Cu, Fe, and Si using nano-second scale low-energy implosion and He-{alpha} x-ray backlighters. However, higher-Z materials require higher x-ray probe energies to penetrate the samples, such as in Laue, or probe deep enough into the target, as in the case of Bragg diffraction. Petawatt laser-generated K{alpha} x-ray backlighters have been developed for use in high-energy radiography of dense targets and other HED applications requiring picosecond-scale burst of hard x-rays. While short pulse lasers are very efficient at producing high-energy x-rays, the characteristic x-rays produced in these thin foil targets are superimposed on a broad bremsstrahlung background and can easily saturate a detector if careful diagnostic shielding and experimental geometry are not implemented. A new diagnostic has been designed to measure Bragg diffraction from laser-driven crystal targets using characteristic x-rays from a short-pulse laser backlighter on the Omega EP laser. The Bragg Diffraction Imager, or BDI, is a TIM-mounted instrument consisting of a heavily shielded enclosure made from 3/8-inch thick Heavymet (W-Fe-Ni alloy) and a precisely positioned beam bock, attached to the main enclosure by an Aluminum arm. The beam block is made of 1-inch thick, Al-coated Heavymet and serves to block the x-rays directly from the petawatt backlight, while allowing the diffraction x-rays from the crystal to pass to the enclosure. A schematic of the BDI is shown in Fig. 1a. Image plates are used as the x-ray detector and are loaded through the top of the diagnostic in an Aluminum, light-tight cartridge. The front of the enclosure can be fitted with various filters to maximize the diffraction signal-to-noise.

Maddox, B R; Park, H; Hawreliak, J; Comley, A; Elsholz, A; Van Maren, R; Remington, B A; Wark, J

2010-05-13T23:59:59.000Z

329

Lattice dynamics and anomalous softening in the YbFe[subscript 4]Sb[subscript 12] skutterudite  

SciTech Connect

The lattice dynamics of the filled skutterudite YbFe{sub 4}Sb{sub 12} was studied by resonant ultrasound spectroscopy and an anomalous softening in the temperature dependence of the elastic constants at {approx} 50 K was observed. This anomaly can not be explained by the dynamics of the filler, in contrast to other filled skutterudites. We have further investigated the origin of this anomaly using macroscopic and microscopic measurements. A rearrangement of the spectral weight of the Yb phonon states was observed in the temperature dependence of the density of phonon states, obtained by inelastic neutron scattering. We suggest that the anomaly is due to a change of the Yb valence state and that the anomaly and the phonon spectral weight rearrangement have the same origin.

Mchel, A.; Sergueev, I.; Wille, H.-C.; Voigt, J.; Prager, M.; Stone, M.B.; Sales, B.C.; Guguchia, Z.; Shengelaya, A.; Keppens, V.; Hermann, R.P. (DESY); (Tennessee-K); (Julich); (ORNL); (Tbilisi); (ESRF)

2012-04-02T23:59:59.000Z

330

Anomalously Slow Cross Symmetry Phase Relaxation, Thermalized Non-Equilibrated Matter and Quantum Computing Beyond the Quantum Chaos Border  

E-Print Network (OSTI)

Thermalization in highly excited quantum many-body system does not necessarily mean a complete memory loss of the way the system was formed. This effect may pave a way for a quantum computing, with a large number of qubits $n\\simeq 100$--1000, far beyond the quantum chaos border. One of the manifestations of such a thermalized non-equilibrated matter is revealed by a strong asymmetry around 90$^\\circ $ c.m. of evaporating proton yield in the Bi($\\gamma$,p) photonuclear reaction. The effect is described in terms of anomalously slow cross symmetry phase relaxation in highly excited quantum many-body systems with exponentially large Hilbert space dimensions. In the above reaction this phase relaxation is about eight orders of magnitude slower than energy relaxation (thermalization).

M. Bienert; J. Flores; S. Yu. Kun; T. H. Seligman

2006-02-27T23:59:59.000Z

331

Observation of Anomalous Line Shape of ?(3770) Production and Measurements of Branching Fractions for J/?, ?(3686) and ?(3770)?K 0 /K *0 X  

Science Conference Proceedings (OSTI)

We observe an obviously anomalous line shape of the cross sections for e + e ? ? hadrons and e + e ? ?DD? in the energy region between 3.700 and 3.872 GeV. They are inconsistent with the explanation for only one simple ?(3770) resonance in the range from 3.70 to 3.87 GeV

Gang Rong; The BES collaboration

2010-01-01T23:59:59.000Z

332

Correlelations between the Anomalous Behaviour of the Ionosphere and the Seismic Events for VTX-MALDA VLF Propagation  

SciTech Connect

One of the most important application of the VLF signals is that it contains possible information about the lithosphere-ionosphere coupling. In other words, in near future, it may be possible to predict seismic events by judging signatures of VLF signals. In this paper, we present the result of the monitoring of the VLF signals collected in the Malda branch of ICSP, located in Malda, West Bengal, for four years (2005, 2007-09) and we try to find out the co-relations, if any, between the ionospheric activities and the earthquakes. Here we use that VLF signals which are transmitted from the VTX station (18.2 KHz), located near Vijayanarayanam in Tamilnadu, about 2290 km away from the receiver. To find out the co-relation of the ionospheric activities with the seismic events such as earthquake, first we have to study the average signal throughout the year. For this, we plot the so-called standardized calibration curve using the four years data. Here we use a total of 481 no. of data. To establish the co-relation between the ionospheric activities and the seismic events, we use the data of the year 2008 and we found that the deviations of the anomalous data are co-related with the seismic event. We found that the highest deviation takes place one day prior to the seismic events. We also calculated the 'D-layer preparation time'(DLPT) and the 'D-layer disappearance time'(DLDT) for the data of 2008 and tried to establish the co-relation between the anomalous DLPT and DLDT with the seismic events, if any. We compare our result with the VLF signals received from other places.

Ray, Suman; Sasmal, S. [Indian Centre for Space Physics, 43 Chalantika, Garia Station Road, Kolkata 700084 (India); Chakrabarti, S. K. [Indian Centre for Space Physics, 43 Chalantika, Garia Station Road, Kolkata 700084 (India); S. N. Bose National Centre for Basic Sciences, JD Block, Salt Lake, Kolkata 700098 (India); Choudhury, A. K. [Indian Centre for Space Physics, Malda Branch, Atul Market, Malda 731101 (India)

2010-10-20T23:59:59.000Z

333

Wave Forces on Offshore Structures: Nonlinear Wave Diffraction by Large Cylinders  

Science Conference Proceedings (OSTI)

A nonlinear theory of wave diffraction is presented and used to evaluate the forces exerted On a cylinder of large diameter. A perturbation technique has been used to solve the problem with the inclusion of second-order terms. Analytical ...

M. Rahman; H. S. Heaps

1983-12-01T23:59:59.000Z

334

Observation of diffraction with the CMS experiment at the Large Hadron Collider  

E-Print Network (OSTI)

A clear evidence of inclusive diffraction observed by the CMS detector at the Large Hadron Collider in minimum bias events at $\\sqrt{s}=$0.9 TeV, 2.36 TeV is presented. The observed diffractive signal is dominated by inclusive single-diffractive dissociation and can be identified by the presence of a Large Rapidity Gap that extends over the forward region of the CMS detector. A comparison of the data with Monte Carlo predictions provided by PYTHIA6 and PHOJET generators is given. In addition, first observation of the single-diffractive production of di-jets at $\\sqrt{s}=$7 TeV is presented.

Dmytro Volyanskyy

2011-02-03T23:59:59.000Z

335

Neutron Powder Diffraction of the Mg6Pd and Mg6Pd + Fe ...  

Science Conference Proceedings (OSTI)

To improve magnesium's hydrogen absorption properties, palladium was ball milled ... hydrogen in three disproportional reactions; Mg6Pd + 2.35H2 + energy ... In-situ Chemistry Mapping of Hydrogen Storage Materials by Neutron Diffraction.

336

Lattice motions from THz phonon-polaritons measured with femtosecond x-ray diffraction  

Science Conference Proceedings (OSTI)

We use femtosecond x-ray diffraction to measure the coherent lattice displacements associated with the excitation and propagation of THz phonon polaritons in LiTaO3.

Schoenlein, Robert William; Cavalleri, A.; Wall, S.; Simpson, C.; Statz, E.; Ward, D.W.; Nelson, K.A.; Schoenlein, R.W.; Rini, M.; Dean, N.; Khalil, M.

2006-08-07T23:59:59.000Z

337

Electrochemical in-situ reaction cell for X-ray scattering, diffraction and spectroscopy  

DOE Green Energy (OSTI)

An electrochemical in-situ reaction cell for hard X-ray experiments with battery electrodes is described. Applications include the small angle scattering, diffraction, and near-edge spectroscopy of lithium manganese oxide electrodes.

Braun, Artur; Granlund, Eric; Cairns, Elton J.

2003-01-27T23:59:59.000Z

338

Temperature and TimeResolved XRay Powder Diffraction X14A EERE sponsored PRT beamline  

E-Print Network (OSTI)

Temperature and TimeResolved XRay Powder Diffraction X14A EERE sponsored PRT beamline Objective, in ambience or with gas flow Capabilities: X14A, EERE-sponsored PRT beamline · High photon flux: typically 9x

Homes, Christopher C.

339

Powder diffraction in materials science using the KENS cold-neutron source  

SciTech Connect

Since superconductivity fever spread around the world, neutron powder diffraction has become very popular and been widely used by crystallographers, physicists, chemists, mineralogists, and materials scientists. The purpose of present paper is to show, firstly, important characteristics of time-of-flight TOF powder diffraction using cold-neutron source in the study of materials science, and, secondly, recent studies on the structure and function of batteries at the Neutron Science Laboratory (KENS) in the High Energy Accelerator Research Organization (KEK).

Kamiyama, T.; Oikawa, K. [Univ. of Tsukuba (Japan). Inst. of Materials Science; Akiba, E. [National Inst. of Materials and Chemical Research, Tsukuba (Japan)] [and others

1997-12-01T23:59:59.000Z

340

Investigation of Renal Stones by X-ray and Neutron Diffraction  

SciTech Connect

Renal stones were investigated by X-ray diffraction. The obtained results showed only one crystal phase in every sample. With the aim to verify eventual availability of second phase (under 3 volume %) the same renal stones were investigated by neutron diffraction. The neutron spectra proved that additional crystal phase was absent in the renal stones. The obtained results are scientific-practical, in aid of the medicine, especially in the case of renal stone disease.

Baeva, M.; Boianova, A. [Institute of Solid State Physics-BAS, 1784 Sofia (Bulgaria); Beskrovnyi, A. I.; Shelkova, I. [Joint Institute of Nuclear Research, Dubna (Russian Federation)

2007-04-23T23:59:59.000Z

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


341

In Situ High-Pressure X-ray Diffraction Study of H2O Ice VII  

DOE Green Energy (OSTI)

Ice VII was examined over the entire range of its pressure stability by a suite of x-ray diffraction techniques in order to understand a number of unexplained characteristics of its high-pressure behavior. Axial and radial polycrystalline (diamond anvil cell) x-ray diffraction measurements reveal a splitting of diffraction lines accompanied by changes in sample texture and elastic anisotropy. In situ laser heating of polycrystalline samples resulted in the sharpening of diffraction peaks due to release of nonhydrostatic stresses but did not remove the splitting. Radial diffraction measurements indicate changes in strength of the material at this pressure. Taken together, these observations provide evidence for a transition in ice VII near 14 GPa involving changes in the character of the proton order/disorder. The results are consistent with previous reports of changes in phase boundaries and equation of state at this pressure. The transition can be interpreted as ferroelastic with the appearance of spontaneous strain that vanishes at the hydrogen bond symmetrization transition near 60 GPa.

Somayazulu,M.; Shu, J.; Zha, C.; Goncharov, A.; Tschauner, O.; Mao, H.; Hemley, R.

2008-01-01T23:59:59.000Z

342

Resonant Enhancement of Charge Density Wave Diffraction in the Rare-Earth Tri-Tellurides  

SciTech Connect

We performed resonant soft X-ray diffraction on known charge density wave (CDW) compounds, rare earth tri-tellurides. Near the M{sub 5} (3d - 4f) absorption edge of rare earth ions, an intense diffraction peak is detected at a wavevector identical to that of CDW state hosted on Te{sub 2} planes, indicating a CDW-induced modulation on the rare earth ions. Surprisingly, the temperature dependence of the diffraction peak intensity demonstrates an exponential increase at low temperatures, vastly different than that of the CDW order parameter. Assuming 4f multiplet splitting due to the CDW states, we present a model to calculate X-ray absorption spectrum and resonant profile of the diffraction peak, agreeing well with experimental observations. Our results demonstrate a situation where the temperature dependence of resonant X-ray diffraction peak intensity is not directly related to the intrinsic behavior of the order parameter associated with the electronic order, but is dominated by the thermal occupancy of the valence states.

Lee, W.S.; Sorini, A.P.; Yi, M.; Chuang, Y.D.; Moritz, B.; Yang, W.L.; Chu, J.-H.; Kuo, H.H.; Gonzalez, A.G.Cruz; Fisher, I.R.; Hussain, Z.; Devereau, T.P.; Shen, Z.X.

2012-05-15T23:59:59.000Z

343

The early development of neutron diffraction: Science in the wings of the Manhattan Project  

Science Conference Proceedings (OSTI)

Although neutron diffraction was first observed using radioactive decay sources shortly after the discovery of the neutron, it was only with the availability of higher intensity neutron beams from the first nuclear reactors, constructed as part of the Manhattan project, that systematic investigation of Bragg scattering became possible. Remarkably, at a time when the war effort was singularly focused on the development of the atomic bomb, groups working at Oak Ridge and Chicago carried out key measurements and recognized the future utility of neutron diffraction quite independent of its contributions to the measurements of nuclear cross sections. Ernest O. Wollan, Lyle B. Borst, and Walter H. Zinn were all able to observe neutron diffraction in 1944 using the X-10 graphite reactor and the CP-3 heavy water reactor.

Mason, Thom [ORNL; Gawne, Timothy J [ORNL; Nagler, Stephen E [ORNL; Nestor, Margaret Boone {Bonnie} [ORNL; Carpenter, John M [ORNL

2012-01-01T23:59:59.000Z

344

Neutron diffraction measurements of residual stresses in friction stir welding: a review  

Science Conference Proceedings (OSTI)

Significant amounts of residual stresses are often generated during welding and result in critical degradation of the structural integrity and performance of components. Neutron diffraction has become a well established technique for the determination of residual stresses in welds because of the unique deep penetration, three-dimensional mapping capability, and volume averaged bulk measurements characteristic of the scattering neutron beam. Friction stir welding has gained prominence in recent years. The authors reviewed a number of neutron diffraction measurements of residual stresses in friction stir welds and highlighted examples addressing how the microstructures and residual stresses are correlated with each other. An example of in situ neutron diffraction measurement result shows the evolution of the residual stresses during welding.

Woo, Wan Chuck [ORNL; Feng, Zhili [ORNL; Wang, Xun-Li [ORNL; David, Stan A [ORNL

2011-01-01T23:59:59.000Z

345

Performance characteristics needed for protein crystal diffraction x-ray detectors.  

Science Conference Proceedings (OSTI)

During the 1990's, macromolecular crystallography became progressively more dependent on synchrotrons X-ray sources for diffraction data collection. Detectors of this diffraction data at synchrotrons beamlines have evolved over the decade, from film to image phosphor plates, and then to CCD systems. These changes have been driven by the data quality and quantity improvements each newer detector technology provided. The improvements have been significant. It is likely that newer detector technologies will be adopted at synchrotron beamlines for crystallographic diffraction data collection in the future, but these technologies will have to compete with existing CCD detector systems which are already excellent and are getting incrementally better in terms of size, speed, efficiency, and resolving power. Detector development for this application at synchrotrons must concentrate on making systems which are bigger and faster than CCDs and which can capture weak data more efficiently. And there is a need for excellent detectors which are less expensive than CCD systems.

Westbrook, E. M.

1999-09-21T23:59:59.000Z

346

Search for anomalous production of prompt like-sign lepton pairs at $\\sqrt{s}$ = 7 TeV with the ATLAS detector  

E-Print Network (OSTI)

An inclusive search for anomalous production of two prompt, isolated leptons with the same electric charge is presented. The search is performed in a data sample corresponding to 4.7 fb-1 of integrated luminosity collected in 2011 at $\\sqrt{s}$ = 7 TeV with the ATLAS detector at the LHC. Pairs of leptons (ee, emu, and mumu) with large transverse momentum are selected, and the dilepton invariant mass distribution is examined for any deviation from the Standard Model expectation. No excess is found, and upper limits on the production cross section of like-sign lepton pairs from physics processes beyond the Standard Model are placed as a function of the dilepton invariant mass within a fiducial region close to the experimental selection criteria. The 95% confidence level upper limits on the cross section of anomalous ee, emu, or mumu production range between 1.7 fb and 64 fb depending on the dilepton mass and flavour combination.

Aad, Georges; Abbott, Brad; Abdallah, Jalal; Abdel Khalek, Samah; Abdelalim, Ahmed Ali; Abdinov, Ovsat; Aben, Rosemarie; Abi, Babak; Abolins, Maris; AbouZeid, Ossama; Abramowicz, Halina; Abreu, Henso; Acerbi, Emilio; Acharya, Bobby Samir; Adamczyk, Leszek; Adams, David; Addy, Tetteh; Adelman, Jahred; Adomeit, Stefanie; Adragna, Paolo; Adye, Tim; Aefsky, Scott; Aguilar-Saavedra, Juan Antonio; Agustoni, Marco; Aharrouche, Mohamed; Ahlen, Steven; Ahles, Florian; Ahmad, Ashfaq; Ahsan, Mahsana; Aielli, Giulio; Akdogan, Taylan; kesson, Torsten Paul Ake; Akimoto, Ginga; Akimov, Andrei; Alam, Mohammad; Alam, Muhammad Aftab; Albert, Justin; Albrand, Solveig; Aleksa, Martin; Aleksandrov, Igor; Alessandria, Franco; Alexa, Calin; Alexander, Gideon; Alexandre, Gauthier; Alexopoulos, Theodoros; Alhroob, Muhammad; Aliev, Malik; Alimonti, Gianluca; Alison, John; Allbrooke, Benedict; Allport, Phillip; Allwood-Spiers, Sarah; Almond, John; Aloisio, Alberto; Alon, Raz; Alonso, Alejandro; Alonso, Francisco; Alvarez Gonzalez, Barbara; Alviggi, Mariagrazia; Amako, Katsuya; Amelung, Christoph; Ammosov, Vladimir; Amor Dos Santos, Susana Patricia; Amorim, Antonio; Amram, Nir; Anastopoulos, Christos; Ancu, Lucian Stefan; Andari, Nansi; Andeen, Timothy; Anders, Christoph Falk; Anders, Gabriel; Anderson, Kelby; Andreazza, Attilio; Andrei, George Victor; Andrieux, Marie-Laure; Anduaga, Xabier; Anger, Philipp; Angerami, Aaron; Anghinolfi, Francis; Anisenkov, Alexey; Anjos, Nuno; Annovi, Alberto; Antonaki, Ariadni; Antonelli, Mario; Antonov, Alexey; Antos, Jaroslav; Anulli, Fabio; Aoki, Masato; Aoun, Sahar; Aperio Bella, Ludovica; Apolle, Rudi; Arabidze, Giorgi; Aracena, Ignacio; Arai, Yasuo; Arce, Ayana; Arfaoui, Samir; Arguin, Jean-Francois; Arik, Engin; Arik, Metin; Armbruster, Aaron James; Arnaez, Olivier; Arnal, Vanessa; Arnault, Christian; Artamonov, Andrei; Artoni, Giacomo; Arutinov, David; Asai, Shoji; Asfandiyarov, Ruslan; Ask, Stefan; sman, Barbro; Asquith, Lily; Assamagan, Ketevi; Astbury, Alan; Atkinson, Markus; Aubert, Bernard; Auge, Etienne; Augsten, Kamil; Aurousseau, Mathieu; Avolio, Giuseppe; Avramidou, Rachel Maria; Axen, David; Azuelos, Georges; Azuma, Yuya; Baak, Max; Baccaglioni, Giuseppe; Bacci, Cesare; Bach, Andre; Bachacou, Henri; Bachas, Konstantinos; Backes, Moritz; Backhaus, Malte; Badescu, Elisabeta; Bagnaia, Paolo; Bahinipati, Seema; Bai, Yu; Bailey, David; Bain, Travis; Baines, John; Baker, Oliver Keith; Baker, Mark; Baker, Sarah; Banas, Elzbieta; Banerjee, Piyali; Banerjee, Swagato; Banfi, Danilo; Bangert, Andrea Michelle; Bansal, Vikas; Bansil, Hardeep Singh; Barak, Liron; Baranov, Sergei; Barbaro Galtieri, Angela; Barber, Tom; Barberio, Elisabetta Luigia; Barberis, Dario; Barbero, Marlon; Bardin, Dmitri; Barillari, Teresa; Barisonzi, Marcello; Barklow, Timothy; Barlow, Nick; Barnett, Bruce; Barnett, Michael; Baroncelli, Antonio; Barone, Gaetano; Barr, Alan; Barreiro, Fernando; Barreiro Guimares da Costa, Joo; Barrillon, Pierre; Bartoldus, Rainer; Barton, Adam Edward; Bartsch, Valeria; Basye, Austin; Bates, Richard; Batkova, Lucia; Batley, Richard; Battaglia, Andreas; Battistin, Michele; Bauer, Florian; Bawa, Harinder Singh; Beale, Steven; Beau, Tristan; Beauchemin, Pierre-Hugues; Beccherle, Roberto; Bechtle, Philip; Beck, Hans Peter; Becker, Anne Kathrin; Becker, Sebastian; Beckingham, Matthew; Becks, Karl-Heinz; Beddall, Andrew; Beddall, Ayda; Bedikian, Sourpouhi; Bednyakov, Vadim; Bee, Christopher; Beemster, Lars; Begel, Michael; Behar Harpaz, Silvia; Behera, Prafulla; Beimforde, Michael; Belanger-Champagne, Camille; Bell, Paul; Bell, William; Bella, Gideon; Bellagamba, Lorenzo; Bellina, Francesco; Bellomo, Massimiliano; Belloni, Alberto; Beloborodova, Olga; Belotskiy, Konstantin; Beltramello, Olga; Benary, Odette; Benchekroun, Driss; Bendtz, Katarina; Benekos, Nektarios; Benhammou, Yan; Benhar Noccioli, Eleonora; Benitez Garcia, Jorge-Armando; Benjamin, Douglas; Benoit, Mathieu; Bensinger, James; Benslama, Kamal; Bentvelsen, Stan; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Berghaus, Frank; Berglund, Elina; Beringer, Jrg; Bernat, Pauline; Bernhard, Ralf; Bernius, Catrin; Berry, Tracey; Bertella, Claudia; Bertin, Antonio; Bertolucci, Federico; Besana, Maria Ilaria; Besjes, Geert-Jan; Besson, Nathalie; Bethke, Siegfried; Bhimji, Wahid; Bianchi, Riccardo-Maria; Bianco, Michele; Biebel, Otmar; Bieniek, Stephen Paul; Bierwagen, Katharina; Biesiada, Jed; Biglietti, Michela; Bilokon, Halina; Bindi, Marcello; Binet, Sebastien; Bingul, Ahmet; Bini, Cesare; Biscarat, Catherine; Bittner, Bernhard

2012-01-01T23:59:59.000Z

347

Science as an Anomaly-Driven Enterprise: A Computational Approach to Generating Acceptable Theory Revisions in the Face of Anomalous Data  

E-Print Network (OSTI)

Anomalous data lead to scientific discoveries. Although machine learning systems can be forced to resolve anomalous data, these systems use general learning algorithms to do so. To determine whether anomaly-driven approaches to discovery produce more accurate models than the standard approaches, we built a program called Kalpana. We also used Kalpana to explore means for identifying those anomaly resolutions that are acceptable to domain experts. Our experiments indicated that anomaly-driven approaches can lead to a richer set of model revisions than standard methods. Additionally we identified semantic and syntactic measures that are significantly correlated with the acceptability of model revisions. These results suggest that by interpreting data within the context of a model and by interpreting model revisions within the context of domain knowledge, discovery systems can more readily suggest accurate and acceptable anomaly resolutions.

Will Bridewell; Will Bridewell Phd

2004-01-01T23:59:59.000Z

348

Evidence for nascent equilibrium nuclei as progenitors of anomalous transformation kinetics in a Pu-Ga alloy  

SciTech Connect

By alloying Pu with Ga, the face-centered-cubic {delta} phase can be retained down to room temperature in a metastable configuration, which ultimately yields to chemical driving forces by undergoing the {delta} {yields} {alpha}' isothermal martensitic transformation below M{sub s} {approx} = -100 C. This transformation is found to exhibit anomalous transformation kinetics, the nature of which has remained elusive for over 30 years. Recently, a 'conditioning' treatment - an isothermal hold above M{sub s} - has been shown to dramatically affect the amount of {alpha}' phase formed during the transformation. Herein, we report evidence that the conditioning treatment induces the lower-C of the double-C curve, and we furthermore implicate the classical nucleation of equilibrium phases within the conditioning range as the underlying mechanism behind conditioning in Pu-Ga alloys. This mechanism should not be rigorously exclusive to plutonium alloys as it arises from the proximity between the retained metastable phase and the low-energy equilibrium phases.

Jeffries, J R; Blobaum, K M; Wall, M A; Schwartz, A J

2009-05-27T23:59:59.000Z

349

Combination of searches for anomalous top quark couplings with 5.4 fb(-1) of p(p)over-bar collisions  

SciTech Connect

We present measurements of the tWb coupling form factors using information from electroweak single top quark production and from the helicity of W bosons from top quark decays in t{bar t} events. We set upper limits on anomalous tWb coupling form factors using data collected with the D0 detector at the Tevatron p{bar p} collider corresponding to an integrated luminosity of 5.4 fb{sup -1}.

Abazov V. M.; Abbott, B.; Acharya, B. S.; Adams, M.; Adams, T.; Alexeev, G. D.; Alkhazov, G.; Alton, A.; Alverson, G.; Aoki, M.; Askew, A.; Atkins, S.; Augsten, K.; Avila, C.; Badaud, F.; Bagby, L.; Baldin, B.; Bandurin, D. V.; Banerjee, S.; Barberis, E.; Baringer, P.; Barreto, J.; Bartlett, J. F.; Bassler, U.; Bazterra, V.; Bean, A.; Begalli, M.; Bellantoni, L.; Beri, S. B.; Bernardi, G.; Bernhard, R.; Bertram, I.; Besancon, M.; Beuselinck, R.; Bezzubov, V. A.; Bhat, P. C.; Bhatia, S.; Bhatnagar, V.; Blazey, G.; Blessing, S.; Bloom, K.; Boehnlein, A.; Boline, D.; Boos, E. E.; Borissov, G.; Bose, T.; Brandt, A.; Brandt, O.; Brock, R.; Brooijmans, G.; Bross, A.; Brown, D.; Brown, J.; Bu, X. B.; Buehler, M.; Buescher, V.; Bunichev, V.; Burdin, S.; Buszello, C. P.; Camacho-Perez, E.; Casey, B. C. K.; Castilla-Valdez, H.; Caughron, S.; Chakrabarti, S.; Chakraborty, D.; Chan, K. M.; Chandra, A.; Chapon, E.; Chen, G.; Chevalier-Thery, S.; Cho, D. K.; Cho, S. W.; Choi, S.; Choudhary, B.; Cihangir, S.; Claes, D.; Clutter, J.; Cooke, M.; Cooper, W. E.; Corcoran, M.; Couderc, F.; Cousinou, M. -C.; Croc, A.; Cutts, D.; Das, A.; Davies, G.; de Jong, S. J.; De La Cruz-Burelo, E.; Deliot, F.; Demina, R.; Denisov, D.; Denisov, S. P.; Desai, S.; Deterre, C.; DeVaughan, K.; Diehl, H. T.; Diesburg, M.; Ding, P. F.; Dominguez, A.; Dubey, A.; Dudko, L. V.; Duggan, D.; Duperrin, A.; Dutt, S.; Dyshkant, A.; Eads, M.; Edmunds, D.; Ellison, J.; Elvira, V. D.; Enari, Y.; Evans, H.; Evdokimov, A.; Evdokimov, V. N.; Facini, G.; Feng, L.; Ferbel, T.; Fiedler, F.; Filthaut, F.; Fisher, W.; Fisk, H. E.; Fortner, M.; Fox, H.; Fuess, S.; Garcia-Bellido, A.; Garcia-Gonzalez, J. A.; Garcia-Guerra, G. A.; Gavrilov, V.; Gay, P.; Geng, W.; Gerbaudo, D.; Gerber, C. E.; Gershtein, Y.; Ginther, G.; Golovanov, G.; Goussiou, A.; Grannis, P. D.; Greder, S.; Greenlee, H.; Grenier, G.; Gris, Ph; Grivaz, J-F; Grohsjean, A.; Gruenendahl, S.; Gruenewald, M. W.; Guillemin, T.; Gutierrez, G.; Gutierrez, P.; Haas, A.; Hagopian, S.; Haley, J.; Han, L.; Harder, K.; Harel, A.; Hauptman, J. M.; Hays, J.; Head, T.; Hebbeker, T.; Hedin, D.; Hegab, H.; Heinson, A. P.; Heintz, U.; Hensel, C.; Heredia-De La Cruz, I.; Herner, K.; Hesketh, G.; Hildreth, M. D.; Hirosky, R.; Hoang, T.; Hobbs, J. D.; Hoeneisen, B.; Hohlfeld, M.; Howley, I.; Hubacek, Z.; Hynek, V.; Lashvili, I.; Ilchenko, Y.; Illingworth, R.; Ito, A. S.; Jabeen, S.; Jaffe, M.; Jayasinghe, A.; Jesik, R.; Johns, K.; Johnson, E.; Johnson, M.; Jonckheere, A.; Jonsson, P.; Joshi, J.; Jung, A. W.; Juste, A.; Kaadze, K.; Kajfasz, E.; Karmanov, D.; Kasper, P. A.; Katsanos, I.; Kehoe, R.; Kermiche, S.; Khalatyan, N.; Khanov, A.; Kharchilava, A.; Kharzheev, Y. N.; Kiselevich, I.; Kohli, J. M.; Kozelov, A. V.; Kraus, J.; Kulikov, S.; Kumar, A.; Kupco, A.; Kurca, T.; Kuzmin, V. A.; Lammers, S.; Landsberg, G.; Lebrun, P.; Lee, H. S.; Lee, S. W.; Lee, W. M.; Lellouch, J.; Li, H.; Li, L.; Li, Q. Z.; Lim, J. K.; Lincoln, D.; Linnemann, J.; Lipaev, V. V.; Lipton, R.; Liu, H.; Liu, Y.; Lobodenko, A.; Lokajicek, M.; de Sa, R. Lopes; Lubatti, H. J.; Luna-Garcia, R.; Lyon, A. L.; Maciel, A. K. A.; Madar, R.; Magana-Villalba, R.; Malik, S.; Malyshev, V. L.; Maravin, Y.; Martinez-Ortega, J.; McCarthy, R.; McGivern, C. L.; Meijer, M. M.; Melnitchouk, A.; Menezes, D.; Mercadante, P. G.; Merkin, M.; Meyer, A.; Meyer, J.; et al.

2012-07-09T23:59:59.000Z

350

Na NMR Evidence for Charge Order and Anomalous Magnetism in NaxCoO2 I. R. Mukhamedshin,1,* H. Alloul,1,  

E-Print Network (OSTI)

23 Na NMR Evidence for Charge Order and Anomalous Magnetism in NaxCoO2 I. R. Mukhamedshin,1,* H are studied by 23Na NMR and SQUID magnetometry. In nominal 0:50 x 0:70 solid state reacted samples,6] with the magnetic prop- erties. In a pioneering work, two 59Co NMR signals attributed to nonmagnetic Co3 sites were

Paris-Sud 11, Université de

351

Enclosed Chambers for Humidity Control And Sample Containment in Fiber Diffraction  

Science Conference Proceedings (OSTI)

A chamber and stretch frame for making fibers for diffraction is described. The chamber is made from a simple plastic cuvette with silicon nitride windows. It is suitable for maintaining constant humidity during fiber drying and data collection, and allows stretching of the fiber and exposure to magnetic fields during sample preparation. If necessary, it provides primary containment for toxic and infectious biological materials. The chamber has been used in fiber diffraction experiments with filamentous plant viruses and a yeast prion protein, and is shown to produce excellent orientation and to maintain hydration and order at the molecular level.

McDonald, M.; Kendall, A.; Tanaka, M.; Weissman, J.S.; Stubbs, G.

2009-05-26T23:59:59.000Z

352

A framework for 3-D coherent diffraction imaging by focused beam x-ray Bragg ptychography.  

Science Conference Proceedings (OSTI)

We present the framework for convergent beam Bragg ptychography, and, using simulations, we demonstrate that nanocrystals can be ptychographically reconstructed from highly convergent x-ray Bragg diffraction. The ptychographic iterative engine is extended to three dimensions and shown to successfully reconstruct a simulated nanocrystal using overlapping raster scans with a defocused curved beam, the diameter of which matches the crystal size. This object reconstruction strategy can serve as the basis for coherent diffraction imaging experiments at coherent scanning nanoprobe x-ray sources.

Hruszkewycz, S. O.; Holt, M. V.; Tripathi, A.; Maser, J.; Fuoss, P. H. (Center for Nanoscale Materials); ( MSD); (Univ. of California at San Diego)

2011-06-15T23:59:59.000Z

353

Electrochemical and in situ neutron diffraction investigations of La-Ni-Al-H alloys  

DOE Green Energy (OSTI)

Li/metal hydride batteries are a strong contender to replace Ni/Cd batteries. Since the role of alloying components is not yet understood, a combination of electrochemical and neutron diffraction techniques has been designed to investigate metal hydrides. In this work, several Al-substituted LaNi{sub 5} alloys were investigated for their specific capacity (measured by mAh/La and symbolized by x in LaNi{sub 5-y}Al{sub y}H{sub x}), impedance, and cycling stability. Neutron diffraction was used to study the electrochemically induced phase transformation and structure change during charge/discharge.

Peng, W. [Illinois Institute of Technology (United States); Redey, L.; Vissers, D.R.; Myles, K.M.; Carpenter, J.; Richardson; Burr, G. [Argonne National Lab., IL (United States)

1996-05-01T23:59:59.000Z

354

Low energy electron and positron diffraction from surfaces. What you learn. How they differ  

Science Conference Proceedings (OSTI)

An overview of similarities and differences between low-energy (30 Ev to 250 Ev) electron and positron diffraction as probes of material surfaces is given. LEPD may offer greater surface sensitivity, and also better spatial resolution for polyatomic materials. (AIP)

Lessor, D.L. (Pacific Northwest Laboratory, Richland, Washington 99352 (United States)); Canter, K.F. (Brandeis University, Waltham, Massachusetts 02254 (United States)); Duke, C.B. (Xerox Webster Research Center, Webster, New York 14580 (United States))

1994-06-15T23:59:59.000Z

355

Positron-diffraction experiments with a brightness-enhanced slow positron beam  

Science Conference Proceedings (OSTI)

The construction of a high brightness slow positron beam has enabled us to extend Low Energy Positron Diffraction (LEPD) measurements well beyond the previously accessible range of energies. Details of the design and construction of this beam, which utilizes two stages of reflection remoderation for a 500-fold increase in brightness-per-volt, are presented, with emphasis on the positron optics. The positron beam is maintained in an ultra-high vacuum environment. This, together with the inclusion of facilities for display LEED and Auger Electron Spectroscopy, make the apparatus well suited for surface studies. Two sets of experiments performed with this new apparatus are described. Measurements of the specularly diffracted intensity from Cu(001) and Cu(111) single crystals show large peaks in the previously inaccessible 10-30 volt range. These peaks are well displaced from the kinematic Bragg positions and may be influenced by the emergence of non-specular diffraction beams, but the sharp series of features characteristic of beam threshold effects has not been observed. In the second set of experiments neutral positronium atom production is measured as a function of incident positron energy. The observed positronium production is correlated to the intensity vs. energy spectrum for diffracted positrons, suggesting that positronium formation is an important channel for elastically scattered positrons. The angular distribution of positronium formed changes with incident beam energy and may contain information on the details of the potential in the surface region.

Lippel, P.H.

1988-01-01T23:59:59.000Z

356

Orientation Determination in Single Particle X-ray Coherent Diffraction Imaging Experiments  

E-Print Network (OSTI)

Single particle diffraction imaging experiments at free-electron lasers (FEL) have a great potential for structure determination of reproducible biological specimens that can not be crystallized. One of the challenges in processing the data from such an experiment is to determine correct orientation of each diffraction pattern from samples randomly injected in the FEL beam. We propose an algorithm (see also O. Yefanov et al., Photon Science - HASYLAB Annual Report 2010) that can solve this problem and can be applied to samples from tens of nanometers to microns in size, measured with sub-nanometer resolution in the presence of noise. This is achieved by the simultaneous analysis of a large number of diffraction patterns corresponding to different orientations of the particles. The algorithms efficiency is demonstrated for two biological samples, an artificial protein structure without any symmetry and a virus with icosahedral symmetry. Both structures are few tens of nanometers in size and consist of more than 100 000 non-hydrogen atoms. More than 10 000 diffraction patterns with Poisson noise were simulated and analyzed for each structure. Our simulations indicate the possibility to achieve resolution of about 3.3 {\\AA} at 3 {\\AA} wavelength and incoming flux of 10^{12} photons per pulse focused to 100\\times 100 nm^2.

O. M. Yefanov; I. A. Vartanyants

2013-02-22T23:59:59.000Z

357

Plasmonic Nanolasers Without Cavity, Threshold and Diffraction Limit using Stopped Light  

E-Print Network (OSTI)

We present a plasmonic waveguide where light pulses are stopped at well-accessed complex-frequency zero-group-velocity points. Introducing gain at such points results in cavity-free, "thresholdless" nanolasers beating the diffraction limit via a novel, stopped-light mode-locking mechanism.

Tsakmakidis, Kosmas L; Pickering, Tim W; Hess, Ortwin

2013-01-01T23:59:59.000Z

358

In situ X-ray diffraction study of thin film Ir/Si solid state reactions  

Science Conference Proceedings (OSTI)

The solid state reaction between a thin (30nm) Ir film and different Si substrates (p-type Si(100), n- and p-type Si(111), silicon on insulator (SOI) and polycrystalline Si) was studied using a combination of in situ X-ray diffraction (XRD), in situ ... Keywords: Ir, NiSi, Si, XRD

W. Knaepen; J. Demeulemeester; D. Deduytsche; J. L. Jordan-Sweet; A. Vantomme; R. L. Van Meirhaeghe; C. Detavernier; C. Lavoie

2010-03-01T23:59:59.000Z

359

High spatial resolution X-ray and gamma ray imaging system using diffraction crystals  

DOE Patents (OSTI)

A method and a device for high spatial resolution imaging of a plurality of sources of x-ray and gamma-ray radiation are provided. The device comprises a plurality of arrays, with each array comprising a plurality of elements comprising a first collimator, a diffracting crystal, a second collimator, and a detector.

Smither, Robert K. (Hinsdale, IL)

2011-05-17T23:59:59.000Z

360

Three-dimensional imaging of dislocations by X-ray diffraction laminography  

Science Conference Proceedings (OSTI)

Synchrotron radiation laminography with X-ray diffraction contrast enables three-dimensional imaging of dislocations in monocrystalline wafers. We outline the principle of the technique, the required experimental conditions, and the reconstruction procedure. The feasibility and the potential of the method are demonstrated by three-dimensional imaging of dislocation loops in an indent-damaged and annealed silicon wafer.

Haenschke, D. [Karlsruhe Institute of Technology (KIT), Laboratory for Applications of Synchrotron Radiation (LAS), 76128 Karlsruhe (Germany); Helfen, L. [Karlsruhe Institute of Technology (KIT), Institute for Photon Science and Synchrotron Radiation (IPS/ANKA), 76344 Eggenstein (Germany); European Synchrotron Radiation Facility (ESRF), BP220, 38043 Grenoble (France); Altapova, V. [Karlsruhe Institute of Technology (KIT), Laboratory for Applications of Synchrotron Radiation (LAS), 76128 Karlsruhe (Germany); National Research Tomsk Polytechnic University, 634050 Tomsk (Russian Federation); Danilewsky, A. [University Freiburg, Kristallographie, Institut fuer Geowissenschaften, 79104 Freiburg (Germany); Baumbach, T. [Karlsruhe Institute of Technology (KIT), Laboratory for Applications of Synchrotron Radiation (LAS), 76128 Karlsruhe (Germany); Karlsruhe Institute of Technology (KIT), Institute for Photon Science and Synchrotron Radiation (IPS/ANKA), 76344 Eggenstein (Germany)

2012-12-10T23:59:59.000Z

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


361

Beam Size Measurement by Optical Diffraction Radiation and Laser System for Compton Polarimeter  

SciTech Connect

Beam diagnostics is an essential constituent of any accelerator, so that it is named as "organs of sense" or "eyes of the accelerator." Beam diagnostics is a rich field. A great variety of physical effects or physical principles are made use of in this field. Some devices are based on electro-magnetic influence by moving charges, such as faraday cups, beam transformers, pick-ups; Some are related to Coulomb interaction of charged particles with matter, such as scintillators, viewing screens, ionization chambers; Nuclear or elementary particle physics interactions happen in some other devices, like beam loss monitors, polarimeters, luminosity monitors; Some measure photons emitted by moving charges, such as transition radiation, synchrotron radiation monitors and diffraction radiation-which is the topic of the first part of this thesis; Also, some make use of interaction of particles with photons, such as laser wire and Compton polarimeters-which is the second part of my thesis. Diagnostics let us perceive what properties a beam has and how it behaves in a machine, give us guideline for commissioning, controlling the machine and indispensable parameters vital to physics experiments. In the next two decades, the research highlight will be colliders (TESLA, CLIC, JLC) and fourth-generation light sources (TESLA FEL, LCLS, Spring 8 FEL) based on linear accelerator. These machines require a new generation of accelerator with smaller beam, better stability and greater efficiency. Compared with those existing linear accelerators, the performance of next generation linear accelerator will be doubled in all aspects, such as 10 times smaller horizontal beam size, more than 10 times smaller vertical beam size and a few or more times higher peak power. Furthermore, some special positions in the accelerator have even more stringent requirements, such as the interaction point of colliders and wigglor of free electron lasers. Higher performance of these accelerators increases the difficulty of diagnostics. For most cases, intercepting measurements are no longer acceptable, and nonintercepting method like synchrotron radiation monitor can not be applied to linear accelerators. The development of accelerator technology asks for simutanous diagnostics innovations, to expand the performance of diagnostic tools to meet the requirements of the next generation accelerators. Diffraction radiation and inverse Compton scattering are two of the most promising techniques, their nonintercepting nature avoids perturbance to the beam and damage to the instrumentation. This thesis is divided into two parts, beam size measurement by optical diffraction radiation and Laser system for Compton polarimeter. Diffraction radiation, produced by the interaction between the electric field of charged particles and the target, is related to transition radiation. Even though the theory of diffraction radiation has been discussed since 1960s, there are only a few experimental studies in recent years. The successful beam size measurement by optical diffraction radiation at CEBAF machine is a milestone: First of all, we have successfully demonstrated diffraction radiation as an effective nonintercepting diagnostics; Secondly, the simple linear relationship between the diffraction radiation image size and the actual beam size improves the reliability of ODR measurements; And, we measured the polarized components of diffraction radiation for the first time and I analyzed the contribution from edge radiation to diffraction radiation.

Chuyu Liu

2012-12-31T23:59:59.000Z

362

Anomalous earth stress measurements during a six-year sequence of pumping tests at Fenton Hill, New Mexico  

DOE Green Energy (OSTI)

Since 1982, the Los Alamos National Laboratory has been conducting fracturing and flow-through tests on a deep region of jointed Precambrian rock underlying the western flank of the Valles Caldera, in the Jemez Mountains of north-central New Mexico. These experiments have been conducted as part of the Laboratory's Hot Dry Rock (HDR) Geothermal Energy Project, at our Fenton Hill Test Facility, 30 km west of Los Alamos. During this time, the overall project goal has been to experimentally study (and model) the development and performance of a commercial-sized HDR reservoir -- created hydraulically by multiply-fracturing a very large region of hot crystalline rock. One of the primary objectives of this extensive series of fracturing tests has been to study how hard ''competent'' rock dilates and shears during the continuing injection of water under pressure. In association with these tests, a number of seemingly anomalous results have been observed which, if taken separately, would have been fairly easy to ignore or explain anyway. However, in concert, these disparate results have started to form a picture of rock deformation which is quite different from our previously accepted concepts of hydraulic fracturing, and the interpretation of the resulting stress measurements. Key to this better understanding is the realization that almost all bodies of deep crystalline rock are already flawed by one or more sets of joints or planes of weakness, and that it is the interaction between these joints and the existing stress field determines the nature of the pressure-induced deformation. 16 refs., 8 figs., 2 tabs.

Brown, D.W.

1988-01-01T23:59:59.000Z

363

ON THE X-RAY OUTBURSTS OF TRANSIENT ANOMALOUS X-RAY PULSARS AND SOFT GAMMA-RAY REPEATERS  

SciTech Connect

We show that the X-ray outburst light curves of four transient anomalous X-ray pulsars (AXPs) and soft gamma-ray repeaters (SGRs), namely, XTE J1810-197, SGR 0501+4516, SGR 1627-41, and CXOU J164710.2-455216, can be produced by the fallback disk model that was also applied to the outburst light curves of persistent AXPs and SGRs in our earlier work. The model solves the diffusion equation for the relaxation of a disk that has been pushed back by a soft gamma-ray burst. The sets of main disk parameters used for these transient sources are very similar to each other and to those employed in our earlier models of persistent AXPs and SGRs. There is a characteristic difference between the X-ray outburst light curves of transient and persistent sources. This can be explained by the differences in the disk surface density profiles of the transient and persistent sources in quiescence indicated by their quiescent X-ray luminosities. Our results imply that a viscous disk instability operating at a critical temperature in the range of {approx}1300-2800 K is a common property of all fallback disks around AXPs and SGRs. The effect of the instability is more pronounced and starts earlier for the sources with lower quiescent luminosities, which leads to the observable differences in the X-ray enhancement light curves of transient and persistent sources. A single active disk model with the same basic disk parameters can account for the enhancement phases of both transient and persistent AXPs and SGRs. We also present a detailed parameter study to show the effects of disk parameters on the evolution of the X-ray luminosity of AXPs and SGRs in the X-ray enhancement phases.

Cal Latin-Small-Letter-Dotless-I skan, Sirin; Ertan, Uenal [Sabanc Latin-Small-Letter-Dotless-I University, Orhanl Latin-Small-Letter-Dotless-I -Tuzla, Istanbul, 34956 (Turkey)

2012-10-20T23:59:59.000Z

364

ANOMALOUS ANISOTROPIC CROSS-CORRELATIONS BETWEEN WMAP CMB MAPS AND SDSS GALAXY DISTRIBUTION AND IMPLICATIONS ON THE DARK FLOW SCENARIO  

SciTech Connect

We search for the dark flow induced diffuse kinetic Sunyaev-Zel'dovich (kSZ) effect through CMB-galaxy cross-correlation. Such angular correlation is anisotropic, with a unique cos ({theta}{sub DF}) angular dependence, and hence can be distinguished from other components. Here, {theta}{sub DF} is the angle between the opposite dark flow direction and the direction of the sky where the correlation is measured. We analyze the KIAS-VAGC galaxy catalog of SDSS-DR7 and the WMAP seven-year temperature maps, applying an unbiased optimal weighting scheme to eliminate any statistically isotropic components and to enhance the dark flow detection signal. Non-zero weighted cross-correlations are detected at 3.5 {sigma} for the redshift bin z < 0.1 and at 3 {sigma} for the bin 0.1 < z < 0.2, implying the existence of statistically anisotropic components in CMB. However, further analysis does not support the dark flow explanation. The observed directional dependence deviates from the {proportional_to}cos {theta}{sub DF} relation expected, and hence cannot be explained by the presence of a single dark flow, and if the observed cross-correlation is generated by the dark flow induced kSZ effect, the velocity would be too high ({approx}> 6000 km s{sup -1}). We report this work as the first attempt to search for dark flow through weighted CMB-galaxy cross-correlation and to draw the attention on the sources of the detected anomalous CMB-galaxy cross-correlation.

Li Zhigang; Chen Xuelei [Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Science, Beijing 100012 (China); Zhang Pengjie, E-mail: zgli@bao.ac.cn, E-mail: pjzhang@shao.ac.cn, E-mail: xuelei@cosmology.bao.ac.cn [Key Laboratory for Research in Galaxies and Cosmology, Shang Astronomical Observatory, Nandan Road 80, Shanghai 200030 (China)

2012-10-20T23:59:59.000Z

365

neutron diffraction  

Science Conference Proceedings (OSTI)

... Page 7. PBR (NG1) at the NCNR one of a handful globally buried magnetism nuclear contrast wide variety of science also Asterix at LANL

2011-11-14T23:59:59.000Z

366

Anomalous Chemical Expansion Behavior of Pr[subscript 0.2]Ce[subscript 0.8]O[subscript 2-?] Thin Films Grown by Pulsed Laser Deposition  

E-Print Network (OSTI)

The chemomechanical and electrical properties of (Pr,Ce)O[subscript 2-?] thin films were studied between 30 and 875C in air by in situ X-ray diffraction and complex impedance spectroscopy measurements. Reduction/oxidation ...

Kuru, Y.

367

Microstructural evolution in adiabatic shear bands of copper at high strain rates: Electron backscatter diffraction characterization  

SciTech Connect

The microstructural evolution of adiabatic shear bands in annealed copper with different large strains at high strain rates has been investigated by electron backscatter diffraction. The results show that mechanical twinning can occur with minimal contribution to shear localization under dynamic loading. Elongated ultrafine grains with widths of 100-300 nm are observed during the evolution of the adiabatic shear bands. A rotational dynamic recrystallization mechanism is proposed to explain the formation of the elongated ultrafine grains. - Highlights: Black-Right-Pointing-Pointer The microstructural evolution of ASB is studied by electron backscatter diffraction. Black-Right-Pointing-Pointer Twinning can occur in ASB while the contribution to shear localization is slight. Black-Right-Pointing-Pointer Elongated ultrafine grains are observed during the evolution process of ASB. Black-Right-Pointing-Pointer A possible mechanism is proposed to explain the microstructure evolution of ASB.

Tang Lin [School of Materials Science and Engineering, Central South University, Changsha 410083 (China); Chen Zhiyong, E-mail: czysh@netease.com [School of Materials Science and Engineering, Central South University, Changsha 410083 (China); Zhan Congkun; Yang Xuyue; Liu Chuming [School of Materials Science and Engineering, Central South University, Changsha 410083 (China); Cai Hongnian [School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China)

2012-02-15T23:59:59.000Z

368

High-Energy X-ray Diffraction Study of Internal Stresses in Metal Matrix  

NLE Websites -- All DOE Office Websites (Extended Search)

High-Energy X-ray Diffraction Study of Internal Stresses in Metal Matrix High-Energy X-ray Diffraction Study of Internal Stresses in Metal Matrix Composites Metal matrix composites (MMCs) comprise an intriguing new class of materials coming to prominence in the aerospace, electronics, and automotive industries. Internal stresses play an important role in the behavior and successful application of MMCs and multi-phase alloys. These stresses form during processing and service due to transformation or thermal expansion mismatch, as well as elastic and plastic mismatch during deformation. In order to develop a deeper understanding of the thermo-mechanical behavior of these materials, it is of key interest to examine the development of mean stresses in the phases of the composite as a function of time upon changes of temperature and/or external load.

369

Reciprocal space mapping by spot profile analyzing low energy electron diffraction  

SciTech Connect

We present an experimental approach for the recording of two-dimensional reciprocal space maps using spot profile analyzing low energy electron diffraction (SPA-LEED). A specialized alignment procedure eliminates the shifting of LEED patterns on the screen which is commonly observed upon variation of the electron energy. After the alignment, a set of one-dimensional sections through the diffraction pattern is recorded at different energies. A freely available software tool is used to assemble the sections into a reciprocal space map. The necessary modifications of the Burr-Brown computer interface of the two Leybold and Omicron type SPA-LEED instruments are discussed and step-by-step instructions are given to adapt the SPA 4.1d software to the changed hardware. Au induced faceting of 4 deg. vicinal Si(001) is used as an example to demonstrate the technique.

Meyer zu Heringdorf, Frank-J.; Horn-von Hoegen, Michael [Institut fuer Experimentelle Physik, Universitaet Duisburg-Essen, 45117 Essen (Germany)

2005-08-15T23:59:59.000Z

370

In-Situ Studies of Intercritically Austempered Ductile Iron Using Neutron Diffraction  

Science Conference Proceedings (OSTI)

Intercritically austempered ductile irons hold promise for applications requiring fatigue durability, excellent castability, low production energy requirements, reduced greenhouse gas emissions and excellent machinability. In the present study, four different ductile iron alloys, containing manganese and nickel as the primary austenite-stabilizing elements, were heat treated to obtain different quantities of austenite in the final microstructure. This paper reports the microstructures and phases present in these alloys. Further, lattice strains and diffraction elastic constants in various crystallographic directions and the transformation characteristics of the austenite as a function of applied stress were determined using in-situ loading with neutron diffraction at the second generation Neutron Residual Stress Facility (NRSF2) at the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory (ORNL).

Druschitz, Alan [University of Alabama, Birmingham; Aristizabal, Ricardo [University of Alabama, Birmingham; Druschitz, Edward [University of Alabama, Birmingham; Hubbard, Camden R [ORNL; Watkins, Thomas R [ORNL; Walker, Larry R [ORNL; Ostrander, M [Rex Heat Treat, Anniston, AL

2012-01-01T23:59:59.000Z

371

Method for improving x-ray diffraction determinations of residual stress in nickel-base alloys  

DOE Patents (OSTI)

A process for improving the technique of measuring residual stress by x-ray diffraction in pieces of nickel-base alloys is discussed. Part of a predetermined area of the surface of a nickel-base alloy is covered with a dispersion. This exposes the covered and uncovered portions of the surface of the alloy to x-rays by way of an x-ray diffractometry apparatus, making x-ray diffraction determinations of the exposed surface, and measuring the residual stress in the alloy based on these determinations. The dispersion is opaque to x-rays and serves a dual purpose, since it masks off unsatisfactory signals such that only a small portion of the surface is measured, and it supplies an internal standard by providing diffractogram peaks comparable to the peaks of the nickel alloy so that the alloy peaks can be very accurately located regardless of any sources of error external to the sample. 2 figs.

Berman, R.M.; Cohen, I.

1988-04-26T23:59:59.000Z

372

The electrochemical reactions of pure In with Li and Na: anomalous electrolyte decomposition, benefits of FEC additive, phase transitions and electrode performance  

SciTech Connect

Indium thin films are evaluated as an anode material for Li-ion and Na-ion batteries (theoretical capacities of 1012 mAh g-1 for Li and 467 mAh g-1 for Na). The native surface oxides are responsible for the anomalous electrolyte decomposition during the first cycle while oxidized In species are found to be responsible for the electrolyte decomposition during the subsequent cycles. The presence of 5wt% FEC electrolyte additive suppresses the occurrence of the anomalous electrolyte decomposition during the first cycle but is not sufficient to prevent the decomposition upon further cycling from 0 to 2 V. Prevention of the anomalous decomposition can be achieved by restricting the charge cut-off, for instance at 1.1 V, or by using larger amounts of FEC. The In films show moderately good capacity retention with storage capacities when cycled with Li (950 mAh g-1) but significantly less when cycled with Na (125 mAh g-1). XRD data reveal that several known Li-In phases (i.e LiIn, Li3In2, LiIn2 and Li13In3) form during the electrochemical reaction. In contrast, the reaction with Na is severely limited. The largest amount of inserted Na is evidenced for cells short-circuited 40 hrs at 65C, for which the XRD data show the coexistence of NaIn, In, and an unknown phase. During cycling, mechanical degradation due to repeated expansion/shrinkage, evidenced by SEM, coupled with SEI formation is the primary source of the capacity fade. Finally, we show that the In thin films exhibit very high rate capability for both Li (100 C) and Na (30 C).

Hawks, Samantha A [ORNL] [ORNL; Baggetto, Loic [ORNL] [ORNL; Bridges, Craig A [ORNL] [ORNL; Veith, Gabriel M [ORNL] [ORNL

2014-01-01T23:59:59.000Z

373

X-ray diffraction study of residual stress in model weldments. Final report  

Science Conference Proceedings (OSTI)

Residual stress in a model weldment in nickel plate was characterized using x-ray diffraction techniques. The stress was mapped in 2 mm divisions up to the boundary of the weld pool. Results were in generally good agreement with the stress levels previously predicted for this system by finite element studies at LLNL. Recommendations are made that would permit 1 mm/sup 2/ spatial resolution maps of residual stress in stainless steel weldments.

Stroud, R.D.; Shackelford, J.F.

1980-11-01T23:59:59.000Z

374

Quantitative determination of mineral composition by powder x-ray diffraction  

DOE Patents (OSTI)

An external standard intensity ratio method is used for quantitatively determining mineralogic compositions of samples by x-ray diffraction. The method uses ratios of x-ray intensity peaks from a single run. Constants are previously determined for each mineral which is to be quantitatively measured. Ratios of the highest intensity peak of each mineral to be quantified in the sample and the highest intensity peak of a reference mineral contained in the sample are used to calculate sample composition.

Pawloski, G.A.

1984-08-10T23:59:59.000Z

375

Microstructure Characterization of Magnetic-Pulse-Welded AA 6061-T6 by Electron Backscattered Diffraction  

Science Conference Proceedings (OSTI)

The grain boundary crystallographic misorientations of magnetic-pulse-welded (MPW) aluminum alloy (AA) 6061-T6 in linear and tubular configurations were examined using the electron backscattered diffraction (EBSD) technique. A refined structure of heavily deformed grains with higher grain boundary angles was observed in linear welds. Significant spalling was observed away from the joints, in the interior of tubular welds. The results show the complex interaction of shock waves with the materials during this impact welding process.

Zhang, Yuan [Ohio State University; Babu, Suresh [Ohio State University; Zhang, P [Edison Welding Institute; Kenik, Edward A [ORNL; Daehn, Glenn [Ohio State University

2008-01-01T23:59:59.000Z

376

Elimination of higher-order diffraction using zigzag transmission grating in soft x-ray region  

Science Conference Proceedings (OSTI)

We present a realization of the sinusoidal transmission function using a series of zigzag-profiled strips where the transmission takes on the binary values 0 and 1 in a two-dimensional distribution. A zigzag transmission grating of 1000 line/mm has been fabricated and demonstrated on the soft x-ray beam of synchrotron radiation. The axial single-order diffraction indicates that the zigzag transmission grating is adequate for spectroscopic application.

Zang, H. P.; Wang, C. K. [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang, Sichuan 621900 (China); Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065 (China); Gao, Y. L.; Zhou, W. M.; Kuang, L. Y.; Wei, L.; Fan, W.; Zhang, W. H.; Zhao, Z. Q.; Cao, L. F.; Gu, Y. Q.; Zhang, B. H. [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang, Sichuan 621900 (China); Jiang, G. [Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065 (China); Zhu, X. L.; Xie, C. Q. [Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029 (China); Zhao, Y. D.; Cui, M. Q. [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)

2012-03-12T23:59:59.000Z

377

Quantitative determination of mineral composition by powder X-ray diffraction  

DOE Patents (OSTI)

An external standard intensity ratio method is used for quantitatively determining mineralogic compositions of samples by x-ray diffraction. The method uses ratios of x-ray intensity peaks from a single run. Constants are previously determined for each mineral which is to be quantitatively measured. Ratios of the highest intensity peak of each mineral to be quantified in the sample and the highest intensity peak of a reference mineral contained in the sample are used to calculate sample composition.

Pawloski, Gayle A. (Livermore, CA)

1986-01-01T23:59:59.000Z

378

Surface x-ray speckles : coherent surface diffraction from Au(0 01).  

Science Conference Proceedings (OSTI)

We present coherent speckled x-ray diffraction patterns obtained from a monolayer of surface atoms. We measured both the specular anti-Bragg reflection and the off-specular hexagonal reconstruction peak for the Au(001) surface reconstruction. We observed fluctuations of the speckle patterns even when the integrated intensity appears static. By autocorrelating the speckle patterns, we were able to identify two qualitatively different surface dynamic behaviors of the hex reconstruction depending on the sample temperature.

Pierce, M. S.; Chang, K. C.; Hennessy, D.; Komanicky, V.; Sprung, M.; Sandy, A.; You, H.; Safarik Univ.; HASYLAB

2009-10-16T23:59:59.000Z

379

Search for anomalous Wtb couplings in single top quark production in p(p)over-bar collisions at root s=1.96 TeV  

SciTech Connect

We present new direct constraints on a general Wtb interaction using data corresponding to an integrated luminosity of 5.4 fb{sup -1} collected by the D0 detector at the Tevatron p{bar p} collider. The standard model provides a purely left-handed vector coupling at the Wtb vertex, while the most general, lowest dimension Lagrangian allows right-handed vector and left- or right-handed tensor couplings as well. We obtain precise limits on these anomalous couplings by comparing the data to the expectations from different assumptions on the Wtb coupling.

Abazov V. M.; Abazov V. M.; Abbott B.; Acharya B. S.; Adams M.; Adams T.; Alexeev G. D.; Alkhazov G.; Alton A.; Alverson G.; Alves G. A.; Aoki M.; Askew A.; Asman B.; Atkins S.; Atramentov O.; Augsten K.; Avila C.; BackusMayes J.; Badaud F.; Bagby L.; Baldin B.; Bandurin D. V.; Banerjee S.; Barberis E.; Baringer P.; Barreto J.; Bartlett J. F.; Bassler U.; Bazterra V.; Bean A.; Begalli M.; Belanger-Champagne C.; Bellantoni L.; Beni S. B.; Bernardi G.; Bernhard R.; Bertram I.; Besancon M.; Beuselinck R.; Bezzubov V. A.; Bhat P. C.; Bhatnagar V.; Blazey G.; Blessing S.; Bloom K.; Boehnlein A.; Boline D.; Boos E. E.; Borissov G.; Bose T.; Brandt A.; Brandt O.; Brock R.; Brooijmans G.; Bross A.; Brown D.; Brown J.; Bu X. B.; Buehler M.; Buescher V.; Bunichev V.; Burdin S.; Burnett T. H.; Buszello C. P.; Calpas B.; Camacho-Perez E.; Carrasco-Lizarraga M. A.; Casey B. C. K.; Castilla-Valdez H.; Chakrabarti S.; Chakraborty D.; Chan K. M.; Chandra A.; Chapon E.; Chen G.; Chevalier-Thery S.; Cho D. K.; Cho S. W.; Choi S.; Choudhary B.; Cihangir S.; Claes D.; Clutter J.; Cooke M.; Cooper W. E.; Corcoran M.; Couderc F.; Cousinou M. -C.; Croc A.; Cutts D.; Das A.; Davies G.; De K.; de Jong S. J.; De La Cruz-Burelo E.; Deliot F.; Demina R.; Denisov D.; Denisov S. P.; Desai S.; Deterre C.; DeVaughan K.; Diehl H. T.; Diesburg M.; Ding P. F.; Dominguez A.; Dorland T.; Dubey A.; Dudko L. V.; Duggan D.; Duperrin A.; Dutt S.; Dyshkant A.; Eads M.; Edmunds D.; Ellison J.; Elvira V. D.; Enari Y.; Evans H.; Evdokimov A.; Evdokimov V. N.; Facini G.; Ferbel T.; Fiedler F.; Filthaut F.; Fisher W.; Fisk H. E.; Fortner M.; Fox H.; Fuess S.; Garcia-Bellido A.; Garcia-Guerra G. A.; Gavrilov V.; Gay P.; Geng W.; Gerbaudo D.; Gerber C. E.; Gershtein Y.; Ginther G.; Golovanov G.; Goussiou A.; Grannis P. D.; Greder S.; Greenlee H.; Greenwood Z. D.; Gregores E. M.; Grenier G.; Gris Ph.; Grivaz J. -F.; Grohsjean A.; Gruenendahl S.; Gruenewald M. W.; Guillemin T.; Gutierrez G.; Gutierrez P.; Haas A.; Hagopian S.; Haley J.; Han L.; Harder K.; Harel A.; Hauptman J. M.; Hays J.; Head T.; Hebbeker T.; Hedin D.; Hegab H.; Heinson A. P.; Heintz U.; Hensel C.; Heredia-De La Cruz I.; Herner K.; Hesketh G.; Hildreth M. D.; Hirosky R.; Hoang T.; Hobbs J. D.; Hoeneisen B.; Hohlfeld M.; Hubacek Z.; Hynek V.; Iashvili I.; Ilchenko Y.; Illingworth R.; Ito A. S.; Jabeen S.; Jaffre M.; Jamin D.; Jayasinghe A.; Jesik R.; Johns K.; Johnson M.; Jonckheere A.; Jonsson P.; Joshi J.; Jung A. W.; Juste A.; Kaadze K.; Kajfasz E.; Karmanov D.; Kasper P. A.; Katsanos I.; Kehoe R.; Kermiche S.; Khalatyan N.; Khanov A.; Kharchilava A.; Kharzheev Y. N.; Kohli J. M.; Kozelov A. V.; Kraus J.; Kulikov S.; Kumar A.; Kupco A.; Kurca T.; Kuzmin V. A.; Kvita J.; Lammers S.; Landsberg G.; Lebrun P.; Lee H. S.; Lee S. W.; Lee W. M.; Lellouch J.; Li L.; Li Q. Z.; Lietti S. M.; Lim J. K.; Lincoln D.; Linnemann J.; Lipaev V. V.; Lipton R.; Liu Y.; Lobodenko A.; Lokajicek M.; de Sa R. Lopes; Lubatti H. J.; Luna-Garcia R.; Lyon A. L.; Maciel A. K. A.; Mackin D.; Madar R.; Magana-Villalba R.; Malik S.; Malyshev V. L.; Maravin Y.; Martinez-Ortega J.; McCarthy R.; McGivern C. L.; Meijer M. M.; Melnitchouk A.; Menezes D.; Mercadante P. G.; Merkin M.; Meyer A.; Meyer J.; et al.

2012-02-14T23:59:59.000Z

380

CP violating anomalous top-quark coupling in p$\\bar{p}$ collision at $\\sqrt{s}=1.96$ TeV  

SciTech Connect

We conduct the first study of the T-odd correlations in tt events produced in p{bar p} collision at the Fermilab Tevatron collider that can be used to search for CP violation. We select events which have lepton+jets final states to identify t{bar t} events and measure counting asymmetries of several physics observables. Based on the result, we search the top quark anomalous couplings at the production vertex at the Tevatron. In addition, Geant4 development, photon identification, the discrimination of a single photon and a photon doublet from {pi}{sup 0} decay are discussed in this thesis.

Lee, Sehwook; /Iowa State U.

2011-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "multiple-wavelength anomalous diffraction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
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381

Improving the diffraction of full-length human selenomethionyl metavinculin crystals by streak-seeding  

Science Conference Proceedings (OSTI)

Metavinculin is an alternatively spliced isoform of vinculin that has a 68-residue insert in its tail domain (1134 total residues) and is exclusively expressed in cardiac and smooth muscle tissue, where it plays important roles in myocyte adhesion complexes. Mutations in the metavinculin-specific insert are associated with dilated cardiomyopathy (DCM) in man. Crystals of a DCM-associated mutant of full-length selenomethionine-labeled metavinculin grown by hanging-drop vapor diffusion diffracted poorly and were highly sensitive to radiation, preventing the collection of a complete X-ray diffraction data set at the highest possible resolution. Streak-seeding markedly improved the stability, crystal-growth rate and diffraction quality of DCM-associated mutant metavinculin crystals, allowing complete data collection to 3.9 {angstrom} resolution. These crystals belonged to space group P4{sub 3}2{sub 1}2, with two molecules in the asymmetric unit and unit-cell parameters a = b = 170, c = 211 {angstrom}, {alpha} = {beta} = {gamma} = 90{sup o}.

Rangarajan, Erumbi S.; Izard, Tina (Scripps)

2012-06-28T23:59:59.000Z

382

A laboratory based system for Laue micro x-ray diffraction  

SciTech Connect

A laboratory diffraction system capable of illuminating individual grains in a polycrystalline matrix is described. Using a microfocus x-ray source equipped with a tungsten anode and prefigured monocapillary optic, a micro-x-ray diffraction system with a 10 mum beam was developed. The beam profile generated by the ellipsoidal capillary was determined using the"knife edge" approach. Measurement of the capillary performance, indicated a beam divergence of 14 mrad and a useable energy bandpass from 5.5 to 19 keV. Utilizing the polychromatic nature of the incident x-ray beam and application of the Laue indexing software package X-Ray Micro-Diffraction Analysis Software, the orientation and deviatoric strain of single grains in a polycrystalline material can be studied. To highlight the system potential the grain orientation and strain distribution of individual grains in a polycrystalline magnesium alloy (Mg 0.2 wt percent Nd) was mapped before and after tensile loading. A basal (0002) orientation was identified in the as-rolled annealed alloy; after tensile loading some grains were observed to undergo an orientation change of 30 degrees with respect to (0002). The applied uniaxial load was measured as an increase in the deviatoric tensile strain parallel to the load axis (37 References).

Advanced Light Source; Tamura, Nobumichi; Lynch, P.A.; Stevenson, A.W.; Liang, D.; Parry, D.; Wilkins, S.; Tamura, N.

2007-02-28T23:59:59.000Z

383

The catalytic mechanism of an aspartic proteinase explored with neutron and X-ray diffraction  

DOE Green Energy (OSTI)

Hydrogen atoms play key roles in enzyme mechanism, but as this study shows, even high-quality X-ray data to a resolution of 1 {angstrom} cannot directly visualize them. Neutron diffraction, however, can locate deuterium atoms even at resolutions around 2 {angstrom}. Both neutron and X-ray diffraction data have been used to investigate the transition state of the aspartic proteinase endothiapepsin. The different techniques reveal a different part of the story, revealing the clearest picture yet of the catalytic mechanism by which the enzyme operates. Room temperature neutron and X-ray diffraction data were used in a newly developed joint refinement software package to visualize deuterium atoms within the active site of the enzyme when a gem-diol transition state analogue inhibitor is bound at the active site. These data were also used to estimate their individual occupancy, while analysis of the differences between the bond lengths of the catalytic aspartates was performed using atomic resolution X-ray data. The two methods are in agreement on the protonation state of the active site with a transition state analogue inhibitor bound confirming the catalytic mechanism at which the enzyme operates.

Kovalevsky, Andrey [Los Alamos National Laboratory (LANL); Erskine, Peter T. [University of Southampton, England; Cooper, Jon [University of Southampton, England

2008-01-01T23:59:59.000Z

384

Low-energy electron and positron diffraction measurements and analysis on Cu(100)  

Science Conference Proceedings (OSTI)

The results of an experimental study and quantitative analysis of the intensity versus energy (I-V) curves are reported for low-energy electron diffraction and low-energy positron diffraction (LEPD) with a brightness-enhanced electrostatically focused positron beam. In a close comparative study, the incident electrons and positrons scattered at a large incident polar angle (thetagreater than or equal to50/sup 0/) with respect to the surface normal off clean Cu(100) and the I-V spectra from six and seven diffraction beams were taken with electrons and positrons, respectively. The analysis of the experimental data from the electron studies indicates first- and second-layer relaxation that is consistent with earlier results. Use of the structure derived from the electron studies, analysis of the I-V curves from the LEPD studies suggests that the attenuation for positrons is greater than the value for electrons over the energy range 50--400 eV, possibly as a result of the enhanced electron-image cloud surrounding the positron. The real part of the inner potential is 0 eV for positrons compared with 11 eV for electrons, in rough agreement with predictions. Further, the best agreement between experiment and calculation for LEPD I-V curve analysis tends to favor the potential formed by changing of the sign of the Coulomb term (relative to electrons), eliminating the exchange, and retaining the correlation term.

Mayer, R.; Zhang, C.; Lynn, K.G.; Frieze, W.E.; Jona, F.; Marcus, P.M.

1987-03-01T23:59:59.000Z

385

Discriminating between Z Prime -boson effects and effects of anomalous gauge couplings in the double production of W{sup {+-}} bosons at a linear collider  

Science Conference Proceedings (OSTI)

The potential of the International Linear electron-positron Collider (ILC) for seeking, in the annihilation production of W{sup {+-}}-boson pairs, signals induced by new neutral gauge bosons predicted by models belonging to various classes and featuring an extended gauge sector is studied. Limits that will be obtained at ILC for the parameters and masses of Z Prime bosons are compared with present-day and future data from the Large Hadron Collider (LHC). The possibility of discriminating between the effects of Z-Z Prime mixing and signals induced by anomalous gauge couplings (AGC) is demonstrated within theoretically motivated trilinear gauge models involving several free anomalous parameters. It is found that the sensitivity of ILC to the effects of Z-Z Prime mixing in the process e{sup +}e{sup -} {yields} W{sup +}W{sup -} and its ability to discriminate between these two new-physics scenarios, Z Prime and AGC, become substantially higher upon employing polarized initial (e{sup +}e{sup -}) and final (W{sup {+-}}) states.

Andreev, Vasili V., E-mail: quarks@gsu.by [Francisk Skorina Gomel State University (Belarus); Pankov, A. A., E-mail: pankov@ictp.it [Abdus Salam ICTP International Centre for Theoretical Physics (Italy)

2013-06-15T23:59:59.000Z

386

The ion acoustic decay instability, and anomalous laser light absorption for the OMEGA upgrade, large scale hot plasma application to a critical surface diagnostic, and instability at the quarter critical density. Final report  

SciTech Connect

It is shown that laser light can be anomalously absorbed with a moderate intensity laster (I{lambda}{sup 2}{approx}10{sup 14} W/cm{sup 2}-{mu}m{sup 2}) in a large scale, laser produced plasma. The heating regime, which is characterized by a relatively weak instability in a large region, is different from the regime studied previously, which is characterized by a strong instability in a narrow region. The two dimensional geometrical effect (lateral heating) has an important consequence on the anomalous electron heating. The characteristics of the IADI, and the anomalous absorption of the laser light were studied in a large scale, hot plasma applicable to OMEGA upgrade plasma. These results are important for the diagnostic application of the IADI.

Mizuno, K.; DeGroot, J.S.; Seka, W. [and others

1996-11-01T23:59:59.000Z

387

Low energy positron diffraction from Cu(111): Importance of surface loss processes at large angles of incidence  

Science Conference Proceedings (OSTI)

Intensities of positrons specularly diffracted from Cu(111) were measured at the Brandeis positron beam facility and analyzed in the energy range 8eV40{degree}. 30 refs., 5 figs., 1 tab.

Lessor, D.L. (Pacific Northwest Lab., Richland, WA (USA)); Duke, C.B. (Xerox Corp., Webster, NY (USA). Webster Research Center); Lippel, P.H.; Brandes, G.R.; Canter, K.F.; Horsky, T.N. (Brandeis Univ., Waltham, MA (USA). Dept. of Physics)

1990-10-01T23:59:59.000Z

388

Quantitative Analysis of Mt. St. Helens Ash by X-Ray Diffraction and X-Ray Fluorescence Spectrometry  

Science Conference Proceedings (OSTI)

A quantitative study by x-ray diffraction, optical polarizing microscopy, and x-ray fluorescence spectrometry of fallout and ambient ash from three Mt. St. Helens eruptions has revealed a consistent picture of the mineralogical and elemental ...

Briant L. Davis; L. Ronald Johnson; Dana T. Griffen; William Revell Phillips; Robert K. Stevens; David Maughan

1981-08-01T23:59:59.000Z

389

Improved Normalization of the Size Distribution of Atmospheric Particles Retrieved from Aureole Measurements Using the Diffraction Approximation  

Science Conference Proceedings (OSTI)

This paper describes an improvement in the diffraction approximation used to retrieve the size distribution of atmospheric particles from solar aureole radiance measurements. Normalization using total optical thickness based on measurement of the ...

J. G. DeVore

2011-08-01T23:59:59.000Z

390

Neutron diffraction of alpha, beta and gamma cyclodextrins: hydrogen bonding patterns  

DOE Green Energy (OSTI)

Cyclodextrins (CD's) have proved useful as model systems. They are torus-shaped molecules composed of six (..cap alpha..), seven (..beta..) or eight (..gamma..) (1 to 4) linked glucoses. In order to understand the hydrogen bonding in these enzyme models, neutron diffraction data were collected to unambiguously determine the hydrogen atom positions, which could not be done from x-ray diffraction data alone. ..cap alpha..-CD has been shown to have two different structures with well-defined hydrogen bonds, one tense and the other relaxed. An induced-fit-like mechanism for ..cap alpha..-CD complex formation has been proposed. Circular and infinite chain hydrogen bond networks have also been observed, which are energetically favored due to the cooperative effect. ..beta..-CD with a disordered water structure possesses an unusual flip-flop hydrogen bonding system of the type O-H . . . H-O representing an equilibrium between two states: O-H . . . O and O . . . H-O. ..gamma..-CD has now been studied at room temperature by neutron diffraction and also possesses the flip-flop hydrogen bond. Data have been collected to 0.62 A resolution at the ORNL reactor (HFIR). 235 atoms have been refined to R=0.077 for 4816 observed reflections (I > sigma) and R=0.099 for all 5864 reflections. Low temperature neutron data will be collected. This study demonstrates that hydrogen bonds are operative in disordered systems and display dynamics even in the solid state. 17 references, 1 figure, 2 tables.

Hingerty, B.; Betzel, C.; Saenger, W.

1984-01-01T23:59:59.000Z

391

Real-time X-ray Diffraction Measurements of Shocked Polycrystalline Tin and Aluminum  

SciTech Connect

A new, fast, single-pulse x-ray diffraction (XRD) diagnostic for determining phase transitions in shocked polycrystalline materials has been developed. The diagnostic consists of a 37-stage Marx bank high-voltage pulse generator coupled to a needle-and-washer electron beam diode via coaxial cable, producing line and bremsstrahlung x-ray emission in a 35-ns pulse. The characteristic K? lines from the selected anodes of silver and molybdenum are used to produce the diffraction patterns, with thin foil filters employed to remove the characteristic K? line emission. The x-ray beam passes through a pinhole collimator and is incident on the sample with an approximately 3-mm by 6-mm spot and 1 full-width-half-maximum (FWHM) angular divergence in a Bragg-reflecting geometry. For the experiments described in this report, the angle between the incident beam and the sample surface was 8.5. A Debye-Scherrer diffraction image was produced on a phosphor located 76 mm from the polycrystalline sample surface. The phosphor image was coupled to a charge-coupled device (CCD) camera through a coherent fiberoptic bundle. Dynamic single-pulse XRD experiments were conducted with thin foil samples of tin, shock loaded with a 1-mm vitreous carbon back window. Detasheet high explosive with a 2-mm-thick aluminum buffer was used to shock the sample. Analysis of the dynamic shock-loaded tin XRD images revealed a phase transformation of the tin beta phase into an amorphous or liquid state. Identical experiments with shock-loaded aluminum indicated compression of the face-centered-cubic (fcc) aluminum lattice with no phase transformation.

Dane V. Morgan, Don Macy, Gerald Stevens

2008-11-22T23:59:59.000Z

392

NEUTRON AND SYNCHROTRON X-RAY FIBER DIFFRACTION STUDIES OF CELLULOSE POLYMORPHS.  

DOE Green Energy (OSTI)

Although the crystalline nature of cellulose has been one of most studied structural problems in polymer science there remain many open questions. Cellulose is a polymer formed by (1-4)-linked {beta}-D-glucosyl residues that are alternately rotated by 180o along the polymer axis to form flat ribbon-like chains. Each glucosyl unit bears three hydroxyl groups, one an hydroxymethyl group. It has been long recognized that these hydroxyl groups and their ability to bond via hydrogen bonding not only play a major role in directing how the crystal structure of cellulose forms but also in governing important physical properties of cellulose materials. Through the development of new techniques we have been able to prepare fiber samples of cellulose with exceptionally high order. The quality of these samples is allowing us to exploit the unique properties of synchrotron X-ray and neutron sources in order to collect diffraction data to near atomic resolution. Synchrotron X-rays are used to provide accurate crystallographic parameters for C and O atoms. However, because of the relatively weak scattering power of H atoms for X-rays, neutrons are used to determine H atom parameters. We have developed methods for replacing labile H atoms with D, without any loss in crystalline perfection. Deuterated fibers can diffract neutrons with intensities that are substantially different from the intensities diffracted from hydrogenated fibers. These differences, along with the phases calculated from the C and O positions determined in our X-ray studies, are used to calculate Fourier difference syntheses in which density associated with labile hydrogen atoms is imaged. The unprecedented high resolution of these data is revealing new information on cellulose structure and hydrogen bonding.

Los Alamos National Laboratory

2001-01-01T23:59:59.000Z

393

TOTAL DIFFRACTION AND THERMAL DIFFUSE SCATTERING FROM A MULTI-BOUNCE CHANNEL-CUT SINGLE CRYSTAL  

SciTech Connect

We studied Bragg diffraction and Thermal Diffuse Scattering (TDS) from a Si(111) channel-cut triple-bounce crystal using the time-of-flight technique at a pulsed neutron source. Cadmium shielding restricted the detector s direct view of the first bounce surface. The channel-cut crystal dramatically suppresses TDS in the vicinity of the (111), (333) and (444) Bragg reflections; however, TDS appears and increases with the decrease of wavelength in the range of the (555), (777) and (888) orders where cadmium becomes transparent and the single-bounce reflections and TDS contaminate the triple-bounce (555), (777) and (888) reflections.

Carpenter, John M [ORNL; Agamalian, Michael [ORNL

2010-01-01T23:59:59.000Z

394

Overview of Nonintercepting Beam-Size Monitoring with Optical Diffraction Radiation  

SciTech Connect

The initial demonstrations over the last several years of the use of optical diffraction radiation (ODR) as nonintercepting electron-beam-parameter monitors are reviewed. Developments in both far-field imaging and near-field imaging are addressed for ODR generated by a metal plane with a slit aperture, a single metal plane, and two-plane interferences. Polarization effects and sensitivities to beam size, divergence, and position will be discussed as well as a proposed path towards monitoring 10-micron beam sizes at 25 GeV.

Lumpkin, Alex H. [Fermilab, Batavia IL 60510 (United States)

2010-11-04T23:59:59.000Z

395

Method and apparatus for reducing diffraction-induced damage in high power laser amplifier systems  

DOE Patents (OSTI)

Self-focusing damage caused by diffraction in laser amplifier systems may be minimized by appropriately tailoring the input optical beam profile by passing the beam through an aperture having a uniform high optical transmission within a particular radius r.sub.o and a transmission which drops gradually to a low value at greater radii. Apertures having the desired transmission characteristics may readily be manufactured by exposing high resolution photographic films and plates to a diffuse, disk-shaped light source and mask arrangement.

Campillo, Anthony J. (Los Alamos, NM); Newnam, Brian E. (Los Alamos, NM); Shapiro, Stanley L. (Los Alamos, NM); Terrell, Jr., N. James (Los Alamos, NM)

1976-01-01T23:59:59.000Z

396

Experimental demonstration of high quality MeV ultrafast electron diffraction  

SciTech Connect

The simulation optimization and an experimental demonstration of improved performances of mega-electron-volt ultrafast electron diffraction (MeV UED) are reported in this paper. Using ultrashort high quality electron pulses from an S-band photocathode rf gun and a polycrystalline aluminum foil as the sample, we experimentally demonstrated an improved spatial resolution of MeV UED, in which the Debye-Scherrer rings of the (111) and (200) planes were clearly resolved. This result showed that MeV UED is capable to achieve an atomic level spatial resolution and a -100 fs temporal resolution simultaneously, and will be a unique tool for ultrafast structural dynamics studies.

Li, R.; Tang, C., Du, Y., Huang, W., Du, Q., Shi, J., Yan, L., Wang, X.

2009-08-18T23:59:59.000Z

397

Integration of diffractive lenses with addressable vertical-cavity laser arrays  

Science Conference Proceedings (OSTI)

An optical interconnection system is being developed to provide vertical, digital data channels for stacked multichip modules. A key component of the system is an array of individually addressable vertical-cavity surface-emitting lasers with diffractive lenses integrated into the substrate to control beam divergence and direction. The lenses were fabricated by direct-write e-beam lithography and reactive ion beam etching into the GaAs substrate. Preliminary device performance data and the design and fabrication issues are discussed.

Warren, M.E.; Du, T.C.; Wendt, J.R.; Vawter, G.A.; Carson, R.F.; Lear, K.L.; Kilcoyne, S.P.; Schneider, R.P.; Zolper, J.C.

1995-04-01T23:59:59.000Z

398

Phase and amplitude retrieval of objects embedded in a sinusoidal background from its diffraction pattern  

SciTech Connect

Efforts of phase and amplitude retrieval from diffraction patterns have almost exclusively been applied for nonperiodic objects. We investigated the quality of retrieval of nonperiodic objects embedded in a sinusoidal background, using the approach of iterative hybrid input-output with oversampling. Two strategies were employed; one by filtering in the frequency domain prior to phase retrieval, and the other by filtering the phase or amplitude image after retrieval. Results obtained indicate better outcomes with the latter approach provided detector noise is not excessive.

Wu, Chu; Ng, Tuck Wah; Neild, Adrian

2010-04-01T23:59:59.000Z

399

Diffraction spectral filter for use in extreme-UV lithography condenser  

Science Conference Proceedings (OSTI)

A condenser system for generating a beam of radiation includes a source of radiation light that generates a continuous spectrum of radiation light; a condenser comprising one or more first optical elements for collecting radiation from the source of radiation light and for generating a beam of radiation; and a diffractive spectral filter for separating first radiation light having a particular wavelength from the continuous spectrum of radiation light. Cooling devices can be employed to remove heat generated. The condenser system can be used with a ringfield camera in projection lithography.

Sweatt, William C. (Albuquerque, NM); Tichenor, Daniel A. (Castro Valley, CA); Bernardez, Luis J. (Livermore, CA)

2002-01-01T23:59:59.000Z

400

High resolution x-ray and gamma ray imaging using diffraction lenses with mechanically bent crystals  

DOE Patents (OSTI)

A method for high spatial resolution imaging of a plurality of sources of x-ray and gamma-ray radiation is provided. High quality mechanically bent diffracting crystals of 0.1 mm radial width are used for focusing the radiation and directing the radiation to an array of detectors which is used for analyzing their addition to collect data as to the location of the source of radiation. A computer is used for converting the data to an image. The invention also provides for the use of a multi-component high resolution detector array and for narrow source and detector apertures.

Smither, Robert K. (Hinsdale, IL)

2008-12-23T23:59:59.000Z

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


401

THE CRYSTAL STRUCTURE OF THORIUM AND ZIRCONIUM DIHYDRIDES BY X-RAY AND NEUTRON DIFFRACTION  

DOE Green Energy (OSTI)

Thorium forms a tetragonal lower hydride of composition ThH{sub 2}. The hydrides ThH{sub 2}, ThD{sub 2} and ZrD{sub 2} have been studied by neutron diffraction in order that hydrogen positions could be determined. The hydrides are isomorphous, and have a deformed fluorite structure. Metal-hydrogen distances in thorium hydride are unusually large, as in UH{sub 3}. Thorium and zirconium scattering amplitudes and a revised scattering amplitude for deuterium are reported.

Rundle, R.E.; Shull, C.G.; Wollan, E.O.

1951-04-20T23:59:59.000Z

402

Measurement of the electrostrictive coefficients of modified lead magnesium niobate using neutron powder diffraction  

Science Conference Proceedings (OSTI)

Neutron powder diffraction measurements and a constitutive model were used to determine the bulk longitudinal and transverse electrostrictive coefficients (Q{sub ijkl}) for polycrystalline samples of the subject material. Effective single-crystal Q{sub ijkl} were calculated from the powder neutron diffraction data. The resulting values of the three independent Q{sub ijkl}, as determined from the cubic symmetry of the underlying lattice, are Q{sub 3333}=2.1{times}10{sup {minus}2}m{sup 4}/C{sup 2}, Q{sub 3322}={minus}0.87{times}10{sup {minus}2}m{sup 4}/C{sup 2}, and Q{sub 3232}=1.2{times}10{sup {minus}2}m{sup 4}/C{sup 2}. Using these effective single-crystal values, a random ensemble average was used to predict the electromechanical performance of the polycrystalline material. Predicted values of bulk Q{sub 3333}=1.86{times}10{sup {minus}2}m{sup 4}/C{sup 2} and Q{sub 3322}={minus}0.78{times}10{sup {minus}2}m{sup 4}/C{sup 2} are 89{percent} and 87{percent}, respectively, of the effective single-crystal values for Q{sub 3333} and Q{sub 3322}, while measured values of polycrystalline specimens are only {approximately}70{percent} of the single-crystal values. {copyright} {ital 1998 American Institute of Physics.}

Misture, S.T.; Pilgrim, S.M. [New York State College of Ceramics at Alfred University, Alfred, New York 14802 (United States); Hicks, J.C.; Blue, C.T. [Materials, Sensors, and Systems Branch, Code D364, NCCOSC/RDTE Division, San Diego, California 92152-6147 (United States); Payzant, E.A.; Hubbard, C.R. [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

1998-03-01T23:59:59.000Z

403

IMAGING SPECTROSCOPY USING AIA DIFFRACTION PATTERNS IN CONJUNCTION WITH RHESSI AND EVE OBSERVATIONS  

SciTech Connect

Extreme-ultraviolet (EUV) spectroscopy is a very powerful tool that can be used for probing the dynamic response of the solar corona and chromosphere during solar flares. Here we present a unique application of observations from the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory using the artifacts of diffraction and dispersion. Using these techniques we can achieve imaging spectroscopy at the resolution of AIA (0.''6 plate scale) and at the revolutionary cadence of the instrument (nominally 12 s) for the brightest (saturated) pixels during solar flares. Analyzing the dispersion and diffraction effects that are observed as a result of the support grids used for the instrument's front filters, we can achieve up to 0.5 A spectral resolution across the EUV, optically thin passbands. Here we describe the technique used and present the first result of its application-the emission measure distribution for a single pixel at the top of a flaring loop. We analyze the AIA dispersion spectrum in conjunction with Extreme Ultraviolet Variability Experiment observations and spectroscopic and imaging results from the Reuven Ramaty High Energy Solar Spectroscopic Imager.

Raftery, Claire L. [Space Sciences Lab, UC Berkeley, 7 Gauss Way, Berkeley, CA 94720-7450 (United States); Krucker, Saem [Institute of 4D Technologies, School of Engineering, University of Applied Sciences, North Western Switzerland, 5210 Windisch (Switzerland); Lin, Robert P., E-mail: claire@ssl.berkeley.edu [Physics Department, University of California, Berkeley, CA 94720-7450 (United States)

2011-12-20T23:59:59.000Z

404

Cage occupancies in the high pressure structure H methane hydrate: A neutron diffraction study  

SciTech Connect

A neutron diffraction study was performed on the CD{sub 4}: D{sub 2}O structure H clathrate hydrate to refine its CD{sub 4} fractional cage occupancies. Samples of ice VII and hexagonal (sH) methane hydrate were produced in a Paris-Edinburgh press and in situ neutron diffraction data collected. The data were analyzed with the Rietveld method and yielded average cage occupancies of 3.1 CD{sub 4} molecules in the large 20-hedron (5{sup 12}6{sup 8}) cages of the hydrate unit cell. Each of the pentagonal dodecahedron (5{sup 12}) and 12-hedron (4{sup 3}5{sup 6}6{sup 3}) cages in the sH unit cell are occupied with on average 0.89 and 0.90 CD{sub 4} molecules, respectively. This experiment avoided the co-formation of Ice VI and sH hydrate, this mixture is more difficult to analyze due to the proclivity of ice VI to form highly textured crystals, and overlapping Bragg peaks of the two phases. These results provide essential information for the refinement of intermolecular potential parameters for the water methane hydrophobic interaction in clathrate hydrates and related dense structures.

Tulk, Christopher A [ORNL; Klug, Dennis D [National Research Council of Canada; Moreira Dos Santos, Antonio F [ORNL; Karotsis, Georgios [ORNL; Guthrie, Malcolm [Carnegie Institution of Washington; Molaison, Jamie J [ORNL; Pradhan, Neelam [ORNL

2012-01-01T23:59:59.000Z

405

Dynamic in-situ X-ray Diffraction of Catalyzed Alanates  

DOE Green Energy (OSTI)

The discovery that hydrogen can be reversible absorbed and desorbed from NaAlH{sub 4} by the addition of catalysts has created an entirely new prospect for lightweight hydrogen storage. NaAlH{sub 4} releases hydrogen through the following set of decomposition reactions: NaAlH{sub 4} {r_arrow} 1/3({alpha}-Na{sub 3}AlH{sub 6}) + 2/3Al + H{sub 2} {r_arrow} NaH + Al + 3/2H{sub 2}. These decomposition reactions as well as the reverse recombination reactions were directly observed using time-resolved in-situ x-ray powder diffraction. These measurements were performed under conditions similar to those found in PEM fuel cell operations (hydrogen absorption: 50--70 C, 10--15 bar Hz, hydrogen resorption: 80--110 C, 5--100 mbar H{sub 2}). Catalyst doping was found to dramatically improve kinetics under these conditions. In this study, the alanate was doped with a catalyst by dry ball-milling NaAlH{sub 4} with 2 mol.% solid TiCl{sub 3}. X-ray diffraction clearly showed that TiCl{sub 3} reacts with NaAlH{sub 4} to form NaCl during the doping process. Partial desorption of NaAlH{sub 4} was even observed to occur during the catalyst doping process.

Gross, K.J.; Sandrock, G.; Thomas, G.J.

2000-11-01T23:59:59.000Z

406

High-Resolution Infrared and Electron-Diffraction Studies of Trimethylenecyclopropane ([3]-Radialene)  

SciTech Connect

Combined high-resolution spectroscopic, electron-diffraction, and quantum theoretical methods are particularly advantageous for small molecules of high symmetry and can yield accurate structures that reveal subtle effects of electron delocalization on molecular bonds. The smallest of the radialene compounds, trimethylenecyclopropane, [3]-radialene, has been synthesized and examined in the gas phase by these methods. The first high-resolution infrared spectra have been obtained for this molecule of D3h symmetry, leading to an accurate B0 rotational constant value of 0.1378629(8) cm-1, within 0.5% of the value obtained from electronic structure calculations (density functional theory (DFT) B3LYP/cc-pVTZ). This result is employed in an analysis of electron-diffraction data to obtain the rz bond lengths (in ): C-H = 1.072 (17), C-C = 1.437 (4), and C=C = 1.330 (4). The analysis does not lead to an accurate value of the HCH angle; however, from comparisons of theoretical and experimental angles for similar compounds, the theoretical prediction of 117.5? is believed to be reliable to within 2?. The effect of electron delocalization in radialene is to reduce the single C-C bond length by 0.07 compared to that in cyclopropane.

Wright, Corey R.; Holmes, Joshua; Nibler, Joseph W.; Hedberg, Kenneth; White, James D.; Hedberg, Lise; Weber, Alfons; Blake, Thomas A.

2013-05-16T23:59:59.000Z

407

NEUTRON DIFFRACTION STUDY OF A NON-STOICHIOMETRIC Ni-Mn-Ga MSM ALLOY  

SciTech Connect

The structure and chemical order of a Heusler alloy of non-stoichiometric composition Ni-Mn-Ga were studied using constant-wavelength (1.538 ) neutron diffraction at 363K and the diffraction pattern was refined using the FullProf software. At this temperature the structure is austenite (cubic) with Fm-3m space group and lattice constant of a = 5.83913(4) [ ]. The chemical order is of critical importance in these alloys, as Mn becomes antiferromagnetic when the atoms are closer than the radius of the 3d shell. In the studied alloy the refinement of the site occupancy showed that the 4b (Ga site) contained as much as 22% Mn; that significantly alters the distances between the Mn atoms in the crystal and, as a result, also the exchange energy between some of the Mn atoms. Based on the refinement, the composition was determined to be Ni1.91Mn1.29Ga0.8

Ari-Gur, Pnina [Western Michigan University; Garlea, Vasile O [ORNL

2013-01-01T23:59:59.000Z

408

Structure of molten Al and eutectic Al-Si alloy studied by neutron diffraction  

Science Conference Proceedings (OSTI)

The structure of molten eutectic Al87.8Si12.2 alloy has been studied by neutron diffraction during a temperature cycle. For comparison measurements were performed on pure molten Al. The measurements show that the alloy after heating above the liquidus contains particles of two kinds, aluminum-rich and silicon-rich. The silicon-rich particles are partly dissolved after a further heating. Earlier published data obtained by the ?-ray absorption technique of the density of the molten eutectic AlSi alloy had demonstrated the existence of two temperatures above the liquidus temperature: A dissolution temperature Td, at which the microstructure of the melt inherited from the ingot starts to dissolve and a branching temperature, Tb, at which the melt reaches a fully mixed state. The highest temperature that was possible to reach during the neutron experiments lies between Td and Tb. The obtained results support these conclusions that molten alloys after melting are inhomogeneous up to a temperature well above the liquidus. Moreover, the difference in shape between the static structure factors measured by neutron and X-ray diffraction on molten aluminum is observed and is found to be more accentuated and to extend to larger wavevectors than in earlier works.

Dahlborg, U. [University of Rouen; Kramer, Matthew J. [Ames Laboratory; Besser, M. [Ames Laboratory; Morris, J. R. [Oak Ridge National Laboratory; Calvo-Dahlborg, M. [University of Rouen

2012-11-24T23:59:59.000Z

409

Search for Anomalous Kinematics of Top Dilepton Events in Proton - Anti-proton Collisions at s**(1/2) = 1.96-TeV  

SciTech Connect

The author presents a search for anomalous kinematics of t{bar t} dilepton events in p{bar p} collisions at {radical}s = 1.96 TeV using 193 pb{sup -1} of data collected with the CDF II detector. They developed a new a priori technique designed to silate the subset in a data sample revealing the largest deviation from Standard Model expectations and to quantify the significance of this departure. In the four-variable space considered, no particular subset shows a significant discrepancy and they find that the probability to obtain a data sample less consistent with the Standard Model than what is observed is 1.0-4.5%.

Ivanov, Andrew Gennadievich; /Rochester U.

2004-12-01T23:59:59.000Z

410

Diffractive Dijet Production in $\\bar{p}p$ Collisions at $\\sqrt{s}=1.96$ TeV  

Science Conference Proceedings (OSTI)

We report on a study of diffractive dijet production in {bar p}p collisions at {radical}s = 1.96 TeV using the CDF II detector at the Fermilab Tevatron {bar p}p collider. A data sample from 310 pb{sup -1} of integrated luminosity collected by triggering on a high transverse energy jet, E{sub T}{sup jet}, in coincidence with a recoil antiproton detected in a Roman pot spectrometer is used to measure the ratio of single-diffractive to inclusive-dijet event rates as a function of x{sup {bar p}} of the interacting parton in the antiproton, the Bjorken-x, x{sub Bj}{sup {bar p}}, and a Q{sup 2} {approx} (E{sub T}{sup jet}){sup 2} in the ranges 10{sup -3} -4 GeV{sup 2}. The t{sub {bar p}} dependence is measured as a function of Q{sup 2} and x{sub Bj}{sup {bar p}} and compared with that of inclusive single diffraction dissociation. We find weak x{sub Bj}{sup bar p}} and Q{sup 2} dependencies in the ratio of single diffractive to inclusive event rates, and no significant Q{sup 2} dependence in the diffractive t{sub {bar p}} distributions.

Aaltonen, T.; /Helsinki Inst. of Phys.; Albrow, M.; /Fermilab; Alvarez Gonzalez, B.; /Oviedo U. /Cantabria Inst. of Phys.; Amerio, S.; /INFN, Padua; Amidei, D.; /Michigan U.; Anastassov, A.; /Northwestern U. /Fermilab; Annovi, A.; /Frascati; Antos, J.; /Comenius U.; Apollinari, G.; /Fermilab; Appel, J.A.; /Fermilab; Arisawa, T.; /Waseda U. /Dubna, JINR

2012-06-01T23:59:59.000Z

411

In situ high-pressure x-ray diffraction study of H[subscript 2]O ice VII  

DOE Green Energy (OSTI)

Ice VII was examined over the entire range of its pressure stability by a suite of x-ray diffraction techniques in order to understand a number of unexplained characteristics of its high-pressure behavior. Axial and radial polycrystalline (diamond anvil cell) x-ray diffraction measurements reveal a splitting of diffraction lines accompanied by changes in sample texture and elastic anisotropy. In situ laser heating of polycrystalline samples resulted in the sharpening of diffraction peaks due to release of nonhydrostatic stresses but did not remove the splitting. Radial diffraction measurements indicate changes in strength of the material at this pressure. Taken together, these observations provide evidence for a transition in ice VII near 14 GPa involving changes in the character of the proton order/disorder. The results are consistent with previous reports of changes in phase boundaries and equation of state at this pressure. The transition can be interpreted as ferroelastic with the appearance of spontaneous strain that vanishes at the hydrogen bond symmetrization transition near 60 GPa.

Somayazulu, M.; Shu, J.; Zha, C.-S.; Goncharov, A.F. (CIW)

2008-06-30T23:59:59.000Z

412

Time-of-flight neutron diffraction study of bovine [gamma]-chymotrypsin at the Protein Crystallography Station  

SciTech Connect

The overarching goal of this research project is to determine, for a subset of proteins, exact hydrogen positions using neutron diffraction, thereby improving H-atom placement in proteins so that they may be better used in various computational methods that are critically dependent upon said placement. In order to be considered applicable for neutron diffraction studies, the protein of choice must be amenable to ultrahigh-resolution X-ray crystallography, be able to form large crystals (1 mm{sup 3} or greater) and have a modestly sized unit cell (no dimension longer than 100 {angstrom}). As such, {gamma}-chymotrypsin is a perfect candidate for neutron diffraction. To understand and probe the role of specific active-site residues and hydrogen-bonding patterns in {gamma}-chymotrypsin, neutron diffraction studies were initiated at the Protein Crystallography Station (PCS) at Los Alamos Neutron Science Center (LANSCE). A large single crystal was subjected to H/D exchange prior to data collection. Time-of-flight neutron diffraction data were collected to 2.0 {angstrom} resolution at the PCS with 85% completeness. Here, the first time-of-flight neutron data collection from {gamma}-chymotrypsin is reported.

Lazar, Louis M.; Fisher, S. Zoe; Moulin, Aaron G.; Kovalevsky, Andrey; Novak, Walter R.P.; Langan, Paul; Petsko, Gregory A.; Ringe, Dagmar (Brandeis); (LANL)

2012-02-06T23:59:59.000Z

413

Design of a triaxial residual stress measurement system using high energy x-ray diffraction  

Science Conference Proceedings (OSTI)

Previous design studies in developing concepts for residual stress measurement in engineering materials have been extended. A pre-prototype energy dispersive x-ray diffraction (EDXRD) system has been fabricated. A 300 kV radiography source is used in conjunction with an intrinsic germanium detector and a MacII/LabVIEW data acquisition system. Specimens up to 25mm equivalent steel thickness (and one meter gross dimensions) can now be evaluated. The pre-prototype system serves as the hard x-ray, bulk stress measurement component of the previously reported hybrid stress measuring system (which would include a traditional multi-angle surface measurement system using soft x-rays). In addition, a detailed study of residual stress analytical equations has been completed and applied to various metallic and ceramic materials. During the grant period, related studies were completed on stress measurement using synchrotron radiation and on a critical review of the residual stress literature. 6 refs., 3 figs.

Shackelford, J.F.; Brown, B.D.; Park, J.S.

1989-01-01T23:59:59.000Z

414

Diffraction coefficients of a semi-infinite planar crack embedded in a transversely-isotropic space  

E-Print Network (OSTI)

We have considered a semi-infinite crack embedded in a transversely isotropic medium and studied two special cases, one, in which the axis of symmetry is normal to the crack face and the wave incidence is arbitrary and another, in which the axis lies in the crack plane normal to the edge and the incident wave vector is also normal to the edge. The problem is of interest in Non-Destructive Evaluation, because austenitic steels that are found in claddings and other welds in the nuclear reactors are often modeled as transversely isotropic. In both of cases, we have expressed the scattered field in a closed form and computed the corresponding diffraction coefficients.

A. Gautesen; V. Zernov; L. Fradkin

2008-02-04T23:59:59.000Z

415

Characterization of nanocrystalline Pd by x-ray diffraction and EXAFS  

DOE Green Energy (OSTI)

Since the fraction of atoms located within a few atomic distances of one or more internal interfaces increases rapidly with decreasing grain size in the nanometer regime, it is expected that the structure of grain boundaries plays an important role in determining and controlling the properties of nanocrystalline materials. A high resolution electron microscopy study of nanocrystalline Pd found no evidence for extended, disordered boundary regions that would differ from boundaries in coarse-grained materials. Recent results from x-ray diffraction, EXAFS and hydriding studies have yielded clear evidence that the boundaries in nanocrystalline Pd are ordered and/or extremely localized in nature. The present paper will summarize and discuss the principal results of these three studies. 12 refs., 4 figs.

Eastman, J.A. (Argonne National Lab., IL (USA)); Fitzsimmons, M.R.; Mueller-Stach, M.; Wallner, G. (Ludwig-Maximilians-Universitaet, Munich (Germany, F.R.)); Elam, W.T. (Naval Research Lab., Washington, DC (USA))

1990-12-01T23:59:59.000Z

416

UNITED STATES ATOMIC ENERGY COMMISSION OAK RIDGE TENNESSEE THE DIFFRACTION OF NEUTRONS BY CRYSTALLINE POWDERS  

NLE Websites -- All DOE Office Websites (Extended Search)

MDDC 869 MDDC 869 UNITED STATES ATOMIC ENERGY COMMISSION OAK RIDGE TENNESSEE THE DIFFRACTION OF NEUTRONS BY CRYSTALLINE POWDERS by E. 0. Wollan C. G. Shull Clinton Laboratories Published for use within the Atomic Energy Commission. Inquiries for additional -copies and any questions regarding reproduction by recipients of this document may be referred to the Documents Distribution Subsection, Publication Section, Technical Information Branch, Atomic Energy Commission, P. 0. Box E, Oak Ridge, Tennessee. Inasmuch as a declassified document may differ materially from the original classified document by reason of deletions necessary to accomplish declassification, this copy does not constitute authority for declassification of classified copies of a similar document which may bear the same title and authors.

417

Mechanism of elastic and inelastic proton scattering on a {sup 15}C nucleus in diffraction theory  

SciTech Connect

The amplitudes for elastic and inelastic proton scattering on the neutron-rich nucleus {sup 15}C (to its J{sup {pi}} = 5/2{sup +} level in the latter case) in inverse kinematics were calculated within Glauber diffraction theory. First- and second-order terms were taken into account in the multiple-scattering operator. The {sup 15}C wave function in the multiparticle shell model was used. This made it possible to calculate not only respective differential cross sections but also the contribution of proton scattering on nucleons occurring in different shells. The differential cross sections for elastic and inelastic scattering were calculated at the energies of 0.2, 0.6, and 1 GeV per nucleon.

Ibraeva, E. T., E-mail: ibr@inp.kz [National Nuclear Center of the Republic of Kazakhstan, Institute of Nuclear Physics (Kazakhstan); Zhusupov, M. A. [Al-Farabi Kazakh National University (Kazakhstan); Imambekov, O. [National Nuclear Center of the Republic of Kazakhstan, Institute of Nuclear Physics (Kazakhstan)

2012-11-15T23:59:59.000Z

418

Residual stress determination in an overlay dissimilar welded pipe by neutron diffraction  

Science Conference Proceedings (OSTI)

Residual stresses were determined through the thickness of a dissimilar weld overlay pipe using neutron diffraction. The specimen has a complex joining structure consisting of a ferritic steel (SA508), austenitic steel (F316L), Ni-based consumable (Alloy 182), and overlay of Ni-base superalloy (Alloy 52M). It simulates pressurized nozzle components, which have been a critical issue under the severe crack condition of nuclear power reactors. Two neutron diffractometers with different spatial resolutions have been utilized on the identical specimen for comparison. The macroscopic 'stress-free' lattice spacing (d{sub o}) was also obtained from both using a 2-mm width comb-like coupon. The results show significant changes in residual stresses from tension (300-400 MPa) to compression (-600 MPa) through the thickness of the dissimilar weld overlay pipe specimen.

Woo, Wan Chuck [ORNL; Em, Vyacheslav [Korea Atomic Energy Research Institute; Hubbard, Camden R [ORNL; Lee, Ho-Jin [Korea Atomic Energy Research Institute; Park, Kwang Soo [Doosan Heavy Industries & Construction

2011-01-01T23:59:59.000Z

419

Infrared Imaging of Temperature Distribution in a High Temperature X-Ray Diffraction Furnace  

Science Conference Proceedings (OSTI)

High Temperature X-ray Diffraction (HTXRD) is a very powerful tool for studies of reaction kinetics, phase transformations, and lattice thermal expansion of advanced materials. Accurate temperature measurement is a critical part of the technique. Traditionally, thermocouples, thermistors, and optical pyrometers have been used for temperature control and measurement and temperature could only be measured at a single point. Infrared imaging was utilized in this study to characterize the thermal gradients resulting from various sample and furnace configurations in a commercial strip heater furnace. Furnace configurations include a metallic strip heater, with and without a secondary surround heater, or a surround heater alone. Sample configurations include low and high thermal conductivity powders and solids. The IR imaging results have been used to calibrate sample temperatures in the HTXRD furnace.

Payzant, E.A.; Wang, H.

1999-04-05T23:59:59.000Z

420

At-wavelength interferometry of high-NA diffraction-limited EUV optics  

SciTech Connect

Recent advances in all-reflective diffraction-limited optical systems designed for extreme ultraviolet (EUV) lithography have pushed numerical aperture (NA) values from 0.1 to 0.3, providing Rayleigh resolutions of 27-nm. Worldwide, several high-NA EUV optics are being deployed to serve in the development of advanced lithographic techniques required for EUV lithography, including the creation and testing of new, high-resolution photoresists. One such system is installed on an undulator beamline at Lawrence Berkeley National Laboratory's Advanced Light Source. Sub{angstrom}-accuracy optical testing and alignment techniques, developed for use with the previous generations of EUV lithographic optical systems, are being extended for use at high NA. Considerations for interferometer design and use are discussed.

Goldberg, Kenneth A.; Naulleau, Patrick; Rekawa, Senajith; Denham, Paul; Liddle, J. Alexander; Anderson, Erik; Jackson, Keith; Bokor, Jeffrey; Attwood, David

2003-08-01T23:59:59.000Z

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421

Coherent hard x-ray diffractive imaging of nonisolated objects confined by an aperture  

Science Conference Proceedings (OSTI)

Coherent hard x-ray imaging of nonisolated weak phase objects is demonstrated by confining x-ray beam in a region of a few micrometers in cross section using a micrometer-sized aperture. Two major obstacles in the hard x-ray coherent diffraction imaging, isolating samples and obtaining central speckles, are addressed by using the aperture. The usefulness of the proposed method is illustrated by reconstructing the exit wave field of a nanoscale trench structure fabricated on silicon which serves as a weak phase object. The quantitative phase information of the exit wave field was used to reconstruct the depth profile of the trench structure. The scanning capability of this method was also briefly discussed.

Kim, Sunam; Kim, Chan; Lee, Suyong; Marathe, Shashidhara; Noh, D. Y.; Kang, H. C.; Kim, S. S.; Sandy, A.; Narayanan, S. [Department of Materials Science and Engineering and Nanobio Materials and Electronics, Graduate Program of Photonics and Applied Physics, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of); Department of Advanced Materials Engineering and BK21 Education Center of Mould Technology for Advanced Materials and Parts, Chosun University, Gwangju 501-759 (Korea, Republic of); Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

2010-04-15T23:59:59.000Z

422

High quality single shot diffraction patterns using ultrashort megaelectron volt electron beams from a radio frequency photoinjector  

SciTech Connect

Single shot diffraction patterns using a 250-fs-long electron beam have been obtained at the UCLA Pegasus laboratory. High quality images with spatial resolution sufficient to distinguish closely spaced peaks in the Debye-Scherrer ring pattern have been recorded by scattering the 1.6 pC 3.5 MeV electron beam generated in the rf photoinjector off a 100-nm-thick Au foil. Dark current and high emittance particles are removed from the beam before sending it onto the diffraction target using a 1 mm diameter collimating hole. These results open the door to the study of irreversible phase transformations by single shot MeV electron diffraction.

Musumeci, P.; Moody, J. T.; Scoby, C. M.; Gutierrez, M. S. [Department of Physics and Astronomy, UCLA, Los Angeles, California 90095 (United States); Bender, H. A.; Wilcox, N. S. [National Security Technologies, LLC, Los Alamos Operations, Los Alamos, New Mexico 87544 (United States)

2010-01-15T23:59:59.000Z

423

High Quality Single Shot Diffraction Patterns Using Ultrashort Megaelectron Volt Electron Beams from a Radio Frequency Photoinjector  

SciTech Connect

Single shot diffraction patterns using a 250 fs long electron beam have been obtained at the UCLA Pegasus laboratory. High quality images with spatial resolution sufficient to distinguish closely spaced peaks in the Debye-Scherrer ring pattern have been recorded by scattering the 1.6 pC 3.5 MeV electron beam generated in the RF photoinjector off a 100 nm thick Au foil. Dark current and high emittance particles are removed from the beam before sending it onto the diffraction target using a 1 mm diameter collimating hole. These results open the door to the study of irreversible phase transformations by single shot MeV electron diffraction

P. Musumeci, J. T. Moody, C. M. Scoby, M. S. Gutierrez, H. A. Bender, N. S. Wilcox

2010-01-01T23:59:59.000Z

424

Electron diffraction study of 1M illites with interstratified trans- and cis-vacant 2 : 1 layers  

SciTech Connect

Illites from the volcanogenic Zn-Au-Ag sulfide deposit Galkinskoe (Northern Urals) have been investigated using oblique-texture electron diffraction patterns in combination with the simulation of diffraction effects. Along with single-phase tv/cv1M illites, the structures of which are formed by statistically interstratified dioctahedral 2: 1 layers with vacant trans- or cis-octahedra, illites in the form of a mixture of two interstratified tv/cv1M phases, with the dominance of tv- or cv layers, are identified. It is shown that in the latter case the diffraction pattern can also be interpreted within the single-phase tv/cv model, provided that the tv- and cv layers are distributed with some tendency to segregate. The structural features indicating the preference of the two-phase model are analyzed.

Zhukhlistov, A. P., E-mail: anzhu@igem.ru; Vikent'ev, I. V.; Rusinova, O. V. [Russian Academy of Sciences, Institute of Geology of Ore Deposits, Petrography, Mineralogy, and Geochemistry (Russian Federation)

2012-03-15T23:59:59.000Z

425

Soft X-Ray Microscopy at HZB: Zone Plate Development and Imaging Using the Third Order of Diffraction  

Science Conference Proceedings (OSTI)

The Helmholtz-Zentrum Berlin (HZB) operates a transmission x-ray microscope (TXM) in the soft x-ray photon energy range with an energy resolution up to E/{Delta}E = 10{sup 4}. An approach to achieve ultrahigh spatial resolution with conventional, standard zone plate optics is to employ higher orders of diffraction of the zone plate objective. In this paper, we demonstrate that 11-nm lines and spaces of a multilayer test structure are clearly resolved by the x-ray microscope using the third order of diffraction of a zone plate objective with 20-nm outermost zone width. The disadvantage of high-order imaging is an about one order of magnitude lower diffraction efficiency of the used zone plates employed in the third order compared to the first order of diffraction. In addition, the measured background signal in the TXM images is no longer negligible. Therefore, we worked on the fabrication of zone plates with sub-20-nm outermost zone width to increase the spatial resolution in the first order of diffraction. A new high-resolution 100-keV e-beam lithography system from VISTEC, which was recently installed at the Helmholtz-Zentrum Berlin, makes these developments possible. Initial results on zone plates with an outermost zone width down to 15 nm exposed with the new e-beam system are presented. Furthermore, the contrast transfer function of the transmission x-ray microscope operating in partial coherence mode is measured by using the first and third diffraction order of the zone plate objective.

Rehbein, S.; Guttmann, P.; Werner, S.; Schneider, G. [Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH, Wilhelm-Conrad-Roentgen-Campus, BESSY II, Albert-Einstein-Str. 15, 12489 Berlin (Germany)

2011-09-09T23:59:59.000Z

426

Fixture for supporting and aligning a sample to be analyzed in an x-ray diffraction apparatus  

DOE Patents (OSTI)

A fixture is provided for supporting and aligning small samples of material on a goniometer for x-ray diffraction analysis. A sample-containing capillary is accurately positioned for rotation in the x-ray beam by selectively adjusting the fixture to position the capillary relative to the x and y axes thereof to prevent wobble and position the sample along the z axis or the axis of rotation. By employing the subject fixture relatively small samples of materials can be analyzed in an x-ray diffraction apparatus previously limited to the analysis of much larger samples.

Green, L.A.; Heck, J.L. Jr.

1985-04-23T23:59:59.000Z

427

Thermal expansion and decomposition of jarosite: a high-temperature neutron diffraction study  

DOE Green Energy (OSTI)

The structure of deuterated jarosite, KFe{sub 3}(SO{sub 4}){sub 2}(OD){sub 6}, was investigated using time-of-flight neutron diffraction up to its dehydroxylation temperature. Rietveld analysis reveals that with increasing temperature, its c dimension expands at a rate {approx}10 times greater than that for a. This anisotropy of thermal expansion is due to rapid increase in the thickness of the (001) sheet of [Fe(O,OH){sub 6}] octahedra and [SO{sub 4}] tetrahedra with increasing temperature. Fitting of the measured cell volumes yields a coefficient of thermal expansion, a = a{sub 0} + a{sub 1} T, where a{sub 0} = 1.01 x 10{sup -4} K{sup -1} and a{sub 1} = -1.15 x 10{sup -7} K{sup -2}. On heating, the hydrogen bonds, O1{hor_ellipsis}D-O3, through which the (001) octahedral-tetrahedral sheets are held together, become weakened, as reflected by an increase in the D{hor_ellipsis}O1 distance and a concomitant decrease in the O3-D distance with increasing temperature. On further heating to 575 K, jarosite starts to decompose into nanocrystalline yavapaiite and hematite (as well as water vapor), a direct result of the breaking of the hydrogen bonds that hold the jarosite structure together.

Xu, Hongwu [Los Alamos National Laboratory; Zhao, Yusheng [Los Alamos National Laboratory; Vogel, Sven C [Los Alamos National Laboratory; Hickmott, Donald D [Los Alamos National Laboratory; Daemen, Luke L [Los Alamos National Laboratory; Hartl, Monika A [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

428

Convergent-beam electron diffraction studies of domains in Rhombohedral phase of lead zirconate titanate ceramics  

SciTech Connect

Lead zirconate titanate Pb(Zr{sub x}Ti{sub 1-x})O{sub 3} (PZT) ceramics are ferroelectrics formed as solid solutions between PbTiO{sub 3} and PbZrO{sub 3}. Among the different phases in the ferroelectric state, the primary ones are the Ti{sup +} rich tetragonal (T) phase and the Zr{sup +4} rich rhombohedral (R) phase and the phase boundary between them (x {approx} 0.53). A net polarization for the piezoelectric activity is obtained under an applied field whereby the polarization vectors of individual grains reorient and this process is called poling. The boundary composition is of great technological importance owing to the high piezo eletric activity. It is suggested, that the excellent piezo electric property is due to the coexistence of both the T and R phases which favours easy poling. Domain types in the R phase of PZT ceramic have been identified using the CBED method. However, the fringe contrast at the domain boundaries indicate that the domain walls are inclined. The orientation relation of domain walls is being studied by conventional microscopy contrast and diffraction techniques. 4 refs., 4 figs.

Dass, M.L.A.; Thomas, G.

1987-07-01T23:59:59.000Z

429

Diffraction at a time grating in above-threshold ionization: The influence of the Coulomb potential  

SciTech Connect

We analyze the photoelectron emission spectrum in atomic above-threshold ionization by a linearly polarized short-laser pulse. Direct electrons can be characterized by both intracycle and intercycle interferences. The former results from the coherent superposition of two different electron trajectories released in the same optical cycle, whereas the latter is the consequence of the superposition of multiple trajectories released in different cycles. In the present article, a semiclassical analytical expression for the complete (both intracycle and intercycle) interference pattern is derived. We show that the recently proposed semiclassical description in terms of a diffraction process at a time grating remains qualitatively unchanged in the presence of the long-range Coulomb potential. The latter causes only a phase shift of the intracycle interference pattern. We verify the predictions of the semiclassical model by comparison with full three-dimensional (3D) time-dependent Schroedinger equation (TDSE) solutions. One key finding is that the subcycle interference structures originating from trajectories launched within a time interval of less than 1 femtosecond should be experimentally observable also in low-resolution spectra for longer multicycle pulses.

Arbo, Diego G. [Institute for Astronomy and Space Physics, IAFE (CONICET-UBA), CC 67, Suc. 28 (1428) Buenos Aires (Argentina); Department of Physics, FCEN, University of Buenos Aires (Argentina); Ishikawa, Kenichi L. [Photon Science Center, Graduate School of Engineering, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-8656 (Japan); Schiessl, Klaus; Persson, Emil; Burgdoerfer, Joachim [Institute for Theoretical Physics, Vienna University of Technology, Wiedner Hauptstrasse 8-10/136, A-1040 Vienna (Austria)

2010-10-15T23:59:59.000Z

430

Diffraction Considerations for Planar Detectors in the Few-Mode Limit  

E-Print Network (OSTI)

Filled arrays of bolometers are currently being employed for use in astronomy from the far-infrared through millimeter parts of the electromagnetic spectrum. Because of the large range of wavelengths for which such detectors are applicable, the number of modes supported by a pixel will vary according to the specific application of a given available technology. We study the dependence of image fidelity and induced polarization on the size of the pixel by employing a formalism in which diffraction due to the pixel boundary is treated by propagating the second-order statistical correlations of the radiation field through a model optical system. We construct polarized beam pattern images of square pixels for various ratios of p/\\lambda where p is the pixel size and \\lambda is the wavelength of the radiation under consideration. For the limit in which few modes are supported by the pixel (p/\\lambda1), the geometric limit is approached as expected. This technique gives a quantitative approach to optimize the imaging properties of arrays of planar detectors in the few-mode limit.

David T. Chuss; Edward J. Wollack; S. Harvey Moseley; Stafford Withington; George Saklatvala

2007-02-28T23:59:59.000Z

431

Phase analysis of metallic plutonium-containing fuel alloys using neutron diffraction  

Science Conference Proceedings (OSTI)

Pulsed neutron powder diffraction studies at IPNS have expanded our understanding of the phases present in Integral Fast Reactor (IFR) metal fuel alloys at temperatures in the range of reactor operating conditions. We report results from the binary alloy (U-10 wt % Zr) and ternary alloys (U-8% Pu-10% Zr) and (U-19% Pu-10% Zr). Determining the role and the location of Zr and Pu in these alloys is considered of fundamental importance for maximizing engineering efficiency. Rietveld profile analysis was utilized to study the phase diagrams. Data were collected at temperatures ranging from 25--650{degree}C. Although the expected U/Pu/Zr phases ({alpha}-U, {beta}-U, {gamma}-U, {delta}-U/Zr/Pu, {zeta}-U/Pu) were observed in appropriate temperature ranges, there were some unexpected results. Relative amounts of all phases at each temperature were calculated from Rietveld scale factors and inferences were made as to the location of zirconium and plutonium, i.e. amounts in each phase, from site occupancies and absorption characteristics of the phases present. Finally, we were able to identify ZrO and ZrO{sub 1-x} inclusion phases in the U-Zr alloy present in very small (0.5--1.0%) amounts. 15 refs., 9 figs., 2 tabs.

Mueller, M.H.; Richardson, J.W. Jr.; Strain, R.V.; Hofman, G.L.

1990-01-01T23:59:59.000Z

432

Producing acoustic 'Frozen Waves': Simulated experiments with diffraction/attenuation resistant beams, in lossy media  

E-Print Network (OSTI)

The so-called Localized Waves (LW), and the "Frozen Waves" (FW), have arisen significant attention in the areas of Optics and Ultrasound, because of their surprising energy localization properties. The LWs resist the effects of diffraction for large distances, and possess an interesting self-reconstruction (self-healing) property, after obstacles with size smaller than the antenna's; while the FWs, a sub-class of theirs, offer the possibility of arbitrarily modeling the field longitudinal intensity pattern inside a prefixed interval, for instance 0 < z < L, of the wave propagation axis. More specifically, the FWs are localized fields "at rest", that is, with a static envelope (within which only the carrier wave propagates), and can be endowed moreover with a high transverse localization. In this paper we investigate by simulated experiments, various cases of generation of ultrasonic FW fields, with frequency f_o = 1 MHz in a water-like medium, taking account of the effects of attenuation. We present res...

Prego-Borges, Jose' L; Recami, Erasmo; Tavares-Costa, Eduardo

2013-01-01T23:59:59.000Z

433

Kinetic Analysis of Cation Exchange in Birnessite using Time-resolved Synchrotron X-ray Diffraction  

SciTech Connect

In this study, we applied time-resolved synchrotron X-ray diffraction (TRXRD) to develop kinetic models that test a proposed two-stage reaction pathway for cation exchange in birnessite. These represent the first rate equations calculated for cation exchange in layered manganates. Our previous work has shown that the substitution of K, Cs, and Ba for interlayer Na in synthetic triclinic birnessite induces measurable changes in unit-cell parameters. New kinetic modeling of this crystallographic data supports our previously postulated two-stage reaction pathway for cation exchange, and we can correlate the kinetic steps with changes in crystal structure. In addition, the initial rates of cation exchange, R ({angstrom}{sup 3} min{sup -1}), were determined from changes in unit-cell volume to follow these rate laws: R = 1.75[K{sup +}{sub (aq)}]{sup 0.56}, R = 41.1[Cs{sup +}{sub (aq)}]{sup 1.10}, R = 1.15[Ba{sup 2+}{sub (aq)}]{sup 0.50}. Thus, the exchange rates for Na in triclinic birnessite decreased in the order: Cs >> K > Ba. These results are likely a function of hydration energy differences of the cations and the preference of the solution phase for the more readily hydrated cation.

C Lopano; P Heaney; J Bandstra; J Post; S Brantley

2011-12-31T23:59:59.000Z

434

DEVELOPMENT OF NEXT-GENERATION DETECTORS AND INSTRUMENTATION FOR PHOTOELECTRON SPECTROSCOPY, DIFFRACTION AND HOLOGRAPHY  

SciTech Connect

We have developed a new multichannel detector for use in photoelectron spectroscopy (as well as other types of high-count-rate spectroscopy) that will operate at rates of up to 1 GHz. Such detectors are crucial to the full utilization of the high-brightness radiation generated by third-generation synchrotron radiation sources. In addition, new software and hardware has been developed to permit rapidly and accurately scanning photoelectron spectra that will be accumulated in as little as a 200 micros. A versatile next-generation sample goniometer permitting equally rapid scanning of specimen angles or photon energies for angle-resolved photoemission studies, photoelectron diffraction, and photoelectron holography measurements, and cooling to below 10K has also been designed and constructed. These capabilities have been incorporated into a unique photoelectron spectrometer/diffractometer at the Advanced Light Source of the Lawrence Berkeley National Laboratory; this experimental system includes ultrahigh energy resolution, in situ rotation, variable polarization, and optional spin detection. This overall system is now being used in studies of a variety of problems including magnetic metals and oxides; metal/metal, metal/metal oxide, and metal-oxide/metal-oxide multilayers; and systems exhibiting giant and colossal magnetoresistance.

Charles S. Fadley, Principal Investigator

2005-10-16T23:59:59.000Z

435

Single-site addressing of ultracold atoms beyond the diffraction limit via position dependent adiabatic passage  

E-Print Network (OSTI)

We propose a single-site addressing implementation based on the sub-wavelength localization via adiabatic passage (SLAP) technique. We consider a sample of ultracold neutral atoms loaded into a two-dimensional optical lattice with one atom per site. Each atom is modeled by a three-level \\Lambda-system in interaction with a pump and a Stokes laser pulse. Using a pump field with a node in its spatial profile, the atoms at all sites are transferred from one ground state of the system to the other via stimulated Raman adiabatic passage, except the one at the position of the node that remains in the initial ground state. This technique allows for the preparation, manipulation, and detection of atoms with a spatial resolution better than the diffraction limit, which either relaxes the requirements on the optical setup used or extends the achievable spatial resolution to lattice spacings smaller than accessible to date. In comparison to techniques based on coherent population trapping, SLAP gives a higher addressing resolution and has additional advantages such as robustness against parameter variations, coherence of the transfer process, and the absence of photon induced recoil. Additionally, the advantages of our proposal with respect to adiabatic spin-flip techniques are highlighted. Analytic expressions for the achievable addressing resolution and efficiency are derived and compared to numerical simulations for Rb-87 atoms in state-of-the-art optical lattices.

Daniel Viscor; Juan Luis Rubio; Gerhard Birkl; Jordi Mompart; Vernica Ahufinger

2013-01-08T23:59:59.000Z

436

Trapping the M sub 1 and M sub 2 substrates of bacteriorhodopsin for electron diffraction studies  

DOE Green Energy (OSTI)

Visible and Fourier transform infrared (FTIR) absorption spectroscopies are used to observe protein conformational changes occuring during the bacteriorhodopsin photocycle. Spectroscopic measurements which define the conditions under which bacteriorhodopsin can be isolated and trapped in two distinct substates of the m intermediate of the photocycle, M{sub 1}, and M{sub 2}, are described. A protocol that can be used for high-resolution electron diffraction studies is presented that will trap glucose-embedded purple membrane in the M{sub 1}and M{sub 2} substates at greater than 90% concentration. It was discovered that glucose alone does not provide a fully hydrated environment for bacteriorhodopsin. Equilibration of glucose-embedded samples at high humidity can result in a physical state that is demonstrably closer to the native, fully hydrated state. An extension of the C-T Model of bacteriorhodopsin functionality (Fodor et al., 1988; Mathies et al., 1991) is proposed based on FTIR results and guided by published spectra from resonance Raman and FTIR work. 105 refs.

Perkins, G.A.

1992-05-01T23:59:59.000Z

437

An experimental apparatus for diffraction-limites soft x-ray nanofocusing  

Science Conference Proceedings (OSTI)

Realizing the experimental potential of high-brightness, next generation synchrotron and free-electron laser light sources requires the development of reflecting x-ray optics capable of wavefront preservation and high-resolution nano-focusing. At the Advanced Light Source (ALS) beamline 5.3.1, we are developing broadly applicable, high-accuracy, in situ, at-wavelength wavefront measurement techniques to surpass 100-nrad slope measurement accuracy for diffraction-limited Kirkpatrick-Baez (KB) mirrors. The at-wavelength methodology we are developing relies on a series of wavefront-sensing tests with increasing accuracy and sensitivity, including scanning-slit Hartmann tests, grating-based lateral shearing interferometry, and quantitative knife-edge testing. We describe the original experimental techniques and alignment methodology that have enabled us to optimally set a bendable KB mirror to achieve a focused, FWHM spot size of 150 nm, with 1 nm (1.24 keV) photons at 3.7 mrad numerical aperture. The predictions of wavefront measurement are confirmed by the knife-edge testing.The side-profiled elliptically bent mirror used in these one-dimensional focusing experiments was originally designed for a much different glancing angle and conjugate distances. This work demonstrates that high-accuracy, at-wavelength wavefront-slope feedback can be used to optimize the pitch, roll, and mirror-bending forces in situ, using procedures that are deterministic and repeatable.

Merthe, Daniel; Goldberg, Kenneth; Yashchuk, Valeriy; Yuan, Sheng; McKinney, Wayne; Celestre, Richard; Mochi, Iacopo; Macdougall, James; Morrison, Gregory; Rakawa, Senajith; Anderson, Erik; Smith, Brian; Domning, Edward; Warwick, Tony; Padmore, Howard

2011-10-21T23:59:59.000Z

438

Electron Backscatter Diffraction Analysis of a CZT Growth Tip from a Vertical Gradient Freeze Furnace  

Science Conference Proceedings (OSTI)

Electronic backscatter diffraction (EBSD) was used to characterize the growth-tip region of a 4.2-cm diameter CdZnTe (CZT) boule grown using low-pressure Bridgman method in a vertical gradient freeze furnace. The boule was sectioned and polished and a section taken along the boule longitudinal centerline with an approximate surface area of 1-cm2 was used for optical and scanning electron microscopy. A collage was assembled using EBSD/SEM images to show morphological features, e.g., twin structure, grain structure, and overall crystal growth direction. Severely twinned regions originating from the tip and side walls were observed. The overall growth orientation was close to and directions. In some regions, the (001) poles of the CZT matrix aligned with the growth direction, while twins aligned such that (111) and (112) poles aligned with the growth direction. In some other areas, (112) or (011) poles of the CZT matrix aligned with the growth direction. New relationships between the CZT matrix and large Te polycrystalline particles were revealed: {11 }CZT??{1 00}Te and {001}CZT??{0 1}Te.

Sundaram, S. K.; Henager, Charles H.; Edwards, Danny J.; Schemer-Kohrn, Alan L.; Bliss, Mary; Riley, Brian J.

2011-08-15T23:59:59.000Z

439

The magnetic and crystal structures of Sr2IrO4: A neutron diffraction study  

SciTech Connect

We report a single-crystal neutron diffraction study of the layered Sr2IrO4. This work unambigu- ously determines the magnetic and crystal structures, and reveals that the spin orientation rigidly tracks the staggered rotation of the IrO6 octahedra in Sr2IrO4. The long-range antiferromagnetic order has a canted spin configuration with an ordered moment of 0.208(3) B/Ir site within the basal plane; a detailed examination of the spin canting yields 0.202(3) and 0.049(2) B/site for the a-axis and the b-axis, respectively. It is intriguing that forbidden nuclear reflections of space group I41/acd are also observed in a wide temperature range from 4 K to 600 K, which suggests a reduced crystal structure symmetry. This neutron scattering work provides a direct, well-refined experimen- tal characterization of the magnetic and crystal structures that are crucial to the understanding of the unconventional magnetism existent in this unusual magnetic insulator.

Ye, Feng [ORNL; Chi, Songxue [ORNL; Chakoumakos, Bryan C [ORNL; Fernandez-Baca, Jaime A [ORNL; Qi, Tongfei [University of Kentucky; Cao, Gang [University of Kentucky

2013-01-01T23:59:59.000Z

440

Diffractive Dijet Production in $\\bar{p}p$ Collisions at $\\sqrt{s}=1.96$ TeV  

SciTech Connect

We report on a study of diffractive dijet production in {bar p}p collisions at {radical}s = 1.96 TeV using the CDF II detector at the Fermilab Tevatron {bar p}p collider. A data sample from 310 pb{sup -1} of integrated luminosity collected by triggering on a high transverse energy jet, E{sub T}{sup jet}, in coincidence with a recoil antiproton detected in a Roman pot spectrometer is used to measure the ratio of single-diffractive to inclusive-dijet event rates as a function of x{sup {bar p}} of the interacting parton in the antiproton, the Bjorken-x, x{sub Bj}{sup {bar p}}, and a Q{sup 2} {approx} (E{sub T}{sup jet}){sup 2} in the ranges 10{sup -3} < x{sub Bj}{sup {bar p}} < 10{sup -1} and 10{sup 2} < Q{sup 2} < 10{sup 4} GeV{sup 2}, respectively. Results are presented for the region of {bar p}-momentum-loss fraction 0.03 < {zeta}{sub {bar p}} < 0.09 and a four-momentum transfer squared t{sub {bar p}} > -4 GeV{sup 2}. The t{sub {bar p}} dependence is measured as a function of Q{sup 2} and x{sub Bj}{sup {bar p}} and compared with that of inclusive single diffraction dissociation. We find weak x{sub Bj}{sup bar p}} and Q{sup 2} dependencies in the ratio of single diffractive to inclusive event rates, and no significant Q{sup 2} dependence in the diffractive t{sub {bar p}} distributions.

Aaltonen, T.; /Helsinki Inst. of Phys.; Albrow, M.; /Fermilab; Alvarez Gonzalez, B.; /Oviedo U. /Cantabria Inst. of Phys.; Amerio, S.; /INFN, Padua; Amidei, D.; /Michigan U.; Anastassov, A.; /Northwestern U. /Fermilab; Annovi, A.; /Frascati; Antos, J.; /Comenius U.; Apollinari, G.; /Fermilab; Appel, J.A.; /Fermilab; Arisawa, T.; /Waseda U. /Dubna, JINR

2012-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "multiple-wavelength anomalous diffraction" from the National Library of EnergyBeta (NLEBeta).
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441

Comparative Study Between Measurement and Predictions Using Geometrical Optics and Uniform Theory of Diffraction for Case of Non-Line-of-Sight (NLOS) in Indoor Environment  

Science Conference Proceedings (OSTI)

This paper describes the investigation and comparison of the accuracy of a deterministic model for a WLAN system in the indoor environment. The measurement system consisted of a spectrum analyzer and a log-periodic antenna. Non-line-of-sight (NLOS) propagation ... Keywords: Diffraction, Geometrical optics, Uniform theory of diffraction

E. M. Cheng; Zulkifly Abbas; M. Fareq; K. Y. Lee; K. Y. You; S. F. Khor

2013-08-01T23:59:59.000Z

442

Observation of differences between low-energy electron- and positron-diffraction structural determinations of the cleavage faces of CdSe  

Science Conference Proceedings (OSTI)

Low-energy positron diffraction (LEPD) is used in conjunction with low-energy electron diffraction (LEED) to determine the relaxed atomic geometries of the CdSe cleavage surfaces. The LEPD analyses yield optimal fits at smaller top-layer perpendicular relaxations than LEED for both cleavage faces, and significantly better agreement between theoretical and experimental intensity profiles.

Horsky, T.N.; Brandes, G.R.; Canter, K.F.; Duke, C.B.; Horng, S.F.; Kahn, A.; Lessor, D.L.; Mills A.P. Jr.; Paton, A.; Stevens, K.; and others

1989-04-17T23:59:59.000Z

443

Ruthenium-Platinum Thin Film Analysis Using Grazing Incidence X-ray Diffraction  

DOE Green Energy (OSTI)

Ruthenium (Ru, Z = 44) is a Platinum Group Metal that has a standard hexagonal close packed (HCP) crystalline structure. Platinum (Pt, Z = 78) has a face-centered cubic (FCC) crystalline structure. When these metals are co-sputtered onto a silicon substrate, creating a few nm-thin film, they form an alloy with a combination of HCP and FCC structure. Direct methanol fuel cells rely on an anode catalyst to draw hydrogen from liquid methanol. Highly efficient fuel cells based on polymer electrolyte catalysts, known as proton-exchange membrane fuel cells, have been developed, but require large amounts of a costly platinum catalyst. Thin-film nanostructure bimetallic alloys have been produced to reduce the amount of expensive Platinum needed for catalysis, and also to improve the electrochemical properties of the catalyst. Supported RuPt particles have been shown to have superior activity as anode catalysts for methanol electro-oxidation and demonstrate an improvement in resistance to poisoning in comparison to unalloyed Pt. The percentage of Ruthenium in a RuPt thin film and the process by which the alloy is produced will dictate the crystalline structure, and thus the electrochemical properties of the film. Pure Ruthenium, Pure Platinum, and eight intermediate samples at differing percent composition of Ruthenium were characterized by their X-ray diffraction patterns. The incident beam is from the Stanford Synchrotron Radiation Laboratory beam and operates at approximately a 1.4 Angstrom wavelength. The results show that 0% Ru through 46.17% Ru exhibit a majority FCC structure, 56.07% Ru and 60.61% Ru are mixed phase, and from 67.03% Ru through 100% Ru, the samples exhibit a HCP structure.

Jones, L.

2004-09-03T23:59:59.000Z

444

SCANNING ELECTRON MICROSCOPY AND X-RAY DIFFRACTION ANALYSIS OF TANK 18 SAMPLES  

Science Conference Proceedings (OSTI)

The F-Area Tank Farm (FTF) Performance Assessment (PA) utilizes waste speciation in the waste release model used in the FTF fate and transport modeling. The waste release modeling associated with the residual plutonium in Tank 18 has been identified as a primary contributor to the Tank 18 dose uncertainty. In order to reduce the uncertainty related to plutonium in Tank 18, a better understanding of the plutonium speciation in the Tank 18 waste (including the oxidation state and stoichiometry) is desired. Savannah River National Laboratory (SRNL) utilized Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) to analyze Tank 18 samples to provide information on the speciation of plutonium in the waste material. XRD analysis of the Tank 18 samples did not identify any plutonium mineral phases in the samples. These indicates the crystalline mineral phases of plutonium are below the detection limits of the XRD method or that the plutonium phase(s) lack long range order and are present as amorphous or microcrystalline solids. SEM analysis of the Tank 18 samples did locate particles containing plutonium. The plutonium was found as small particles, usually <1 {micro}m but ranging up to several micrometers in diameter, associated with particles of an iron matrix and at low concentration in other elemental matrices. This suggests the plutonium has an affinity for the iron matrix. Qualitatively, the particles of plutonium found in the SEM analysis do not appear to account for all of the plutonium in the sample based on concentrations determined from the chemical analysis of the Tank 18 samples. This suggests that plutonium is also distributed throughout the solids in low concentrations.

Hay, M.; O'Rourke, P.; Ajo, H.

2012-03-08T23:59:59.000Z

445

Cu isotope fractionation during bornite dissolution: An in situ X-ray diffraction analysis  

Science Conference Proceedings (OSTI)

Low-temperature ore deposits exhibit a large variation in {delta}{sup 65}Cu ({approx}12{per_thousand}), and this range has been attributed, in part, to isotope fractionation during weathering reactions of primary minerals such as chalcocite and chalcopyrite. Here, we examine the fractionation of Cu isotopes during dissolution of another important Cu ore mineral, bornite, using a novel approach that combines time-resolved X-ray diffraction (XRD) and isotope analysis of reaction products. During the initial stages of bornite oxidative dissolution by ferric sulfate ( 20 mol% Cu was leached from the solid, the difference between the Cu isotope composition of the aqueous and mineral phases approached zero, with {Delta}{sub aq - min}{sup 0} values ranging from - 0.21 {+-} 0.61{per_thousand} to 0.92 {+-} 0.25{per_thousand}. XRD analysis allowed us to correlate changes in the atomic structure of bornite with the apparent isotope fractionation as the dissolution reaction progressed. These data revealed that the greatest degree of apparent fractionation is accompanied by a steep contraction in the unit-cell volume, which we identified as a transition from stoichiometric to non-stoichiometric bornite. We propose that the initially high {Delta}{sub aq - min} values result from isotopically heavy Cu ({sup 65}Cu) concentrating within Cu{sup 2+} during dissolution. The decrease in the apparent isotope fractionation as the reaction progresses occurs from the distillation of isotopically heavy Cu ({sup 65}Cu) during dissolution or kinetic isotope effects associated with the depletion of Cu from the surfaces of bornite particles.

Wall, Andrew J.; Mathur, Ryan; Post, Jeffrey E.; Heaney, Peter J. (Juniata); (Smithsonian); (Penn)

2012-10-24T23:59:59.000Z

446

Neutron Diffraction Residual Strain Tensor Measurements Within The Phase IA Weld Mock-up Plate P-5  

SciTech Connect

Oak Ridge National Laboratory (ORNL) has worked with NRC and EPRI to apply neutron and X-ray diffraction methods to characterize the residual stresses in a number of dissimilar metal weld mockups and samples. The design of the Phase IA specimens aimed to enable stress measurements by several methods and computational modeling of the weld residual stresses. The partial groove in the 304L stainless steel plate was filled with weld beads of Alloy 82. A summary of the weld conditions for each plate is provided in Table 1. The plates were constrained along the long edges during and after welding by bolts with spring-loaded washers attached to the 1-inch thick Al backing plate. The purpose was to avoid stress relief due to bending of the welded stainless steel plate. The neutron diffraction method was one of the methods selected by EPRI for non-destructive through thickness strain and stress measurement. Four different plates (P-3 to P-6) were studied by neutron diffraction strain mapping, representing four different welding conditions. Through thickness neutron diffraction strain mappings at NRSF2 for the four plates and associated strain-free d-zero specimens involved measurement along seven lines across the weld and at six to seven depths. The mountings of each plate for neutron diffraction measurements were such that the diffraction vector was parallel to each of the three primary orthogonal directions of the plate: two in-plane directions, longitudinal and transverse, and the direction normal to the plate (shown in left figure within Table 1). From the three orthogonal strains for each location, the residual stresses along the three plate directions were calculated. The principal axes of the strain and stress tensors, however, need not necessarily align with the plate coordinate system. To explore this, plate P-5 was selected for examination of the possibility that the principal axes of strain are not along the sample coordinate system axes. If adequate data could be collected the goal would be to determine the strain tensor's orientation and magnitude of strain along each principle axis direction.

Hubbard, Camden R [ORNL

2011-09-01T23:59:59.000Z

447

Anisotropic polarization, predicted as a result of the diffraction of blackbody radiation at a reflective phase grating with ideal conductivity  

E-Print Network (OSTI)

In the course of analyzing the axiomatic principles that form the basis of statistical physics, the validity of the postulate that all the isoenergetic microstates of a closed system are equally probable was checked. This article reports the results of numerically modelling the interaction of thermodynamically equilibrium blackbody radiation with a reflective phase diffraction grating that possesses ideal conductivity. Cases are found in which anisotropy of the polarization parameters is guaranteed to appear inside a closed volume of initially homogeneous blackbody radiation, resulting in a formal decrease of its Boltzmann entropy as a consequence of deviation from the microcanonical Gibbs distribution. This is apparently caused by the discontinuous character of the change of the phase trajectories of the photons during diffraction, which makes the physical system under consideration nonergodic.

Savukov, Vladimir V

2013-01-01T23:59:59.000Z

448

Influence of diffraction in crystals on the coherence properties of X-ray free-electron laser pulses  

SciTech Connect

The spatial and temporal evolution of the field of random X-ray femtosecond pulses and their coherent properties upon pulse propagation in free space and under dynamical diffraction in perfect crystals in the Bragg and Laue geometries has been analyzed on the basis of the formalism developed in statistical optics. Particular attention is paid to the influence of large pulse propagation distances, which are characteristic of lengthy channels of X-ray free-electron lasers.

Bushuev, V. A., E-mail: vabushuev@yandex.ru [Moscow State University (Russian Federation); Samoylova, L. [European XFEL GmbH (Germany)

2011-09-15T23:59:59.000Z

449

Diffraction analysis of a double-shielded antenna in theFraunhofer and Fresnel regimes: Model predictions  

DOE Green Energy (OSTI)

We analytically investigate the use of a wire mesh ground screen (fence) and a halo of extension panels around a helically fed parabolic reflector in order to estimate the ground contribution to the antenna noise temperature in an experiment aimed at surveying the sky at decimeter wavelengths. We use geometric diffraction theory to model the effect of these screening and blocking shields when scanning in azimu that tilt angles from zenith in the range 0 degrees greater than or equal to Z greater than or equal to 45 degrees. We report estimates based on existing formulas for monofilar axial-mode helical antennas with expected low-level sidelobes in the direction of the halo region. As long as there is no significant coupling between the near-field patterns of both the feed and the diffracting halo, estimates using the Fraunhofer approximation agree with those calculated with the Fresnel approach at a tilt angle Z(eq), which increases with the proximity of the diffracting edge from the near-/far-field boundary of the feed pattern. Our estimates show that for a fence of some IO-dB attenuation and high enough to level out the horizon profile at the prime focus of the antenna, the diffracted components dominate the contribution for tilt angles Z less than or similar to 35 degrees. The fence is the main diffractor when Z greater than or similar to 20 degrees, but for Z greater than or similar to 25 degrees its contribution becomes insensitive to the presence of the halo. On the other hand, if the attenuation is low (<1dB), the increase in ground solid angle with tilt angle makes the contribution due to transmission and ground exposure the dominant one.

Tello, C.; Villela, T.; Wuensche, C.A.; Figueiredo, N.; Torres,S.; Bersanelli, M.; Bensadoun, M.; De Amici, G.; Smoot, G.F.

1999-01-01T23:59:59.000Z

450

Absolute x-ray energy calibration over a wide energy range using a diffraction-based iterative method  

SciTech Connect

In this paper, we report a method of precise and fast absolute x-ray energy calibration over a wide energy range using an iterative x-ray diffraction based method. Although accurate x-ray energy calibration is indispensable for x-ray energy-sensitive scattering and diffraction experiments, there is still a lack of effective methods to precisely calibrate energy over a wide range, especially when normal transmission monitoring is not an option and complicated micro-focusing optics are fixed in place. It is found that by using an iterative algorithm the x-ray energy is only tied to the relative offset of sample-to-detector distance, which can be readily varied with high precision of the order of 10{sup -5}-10{sup -6} spatial resolution using gauge blocks. Even starting with arbitrary initial values of 0.1 A, 0.3 A, and 0.4 A, the iteration process converges to a value within 3.5 eV for 31.122 keV x-rays after three iterations. Different common diffraction standards CeO{sub 2}, Au, and Si show an energy deviation of 14 eV. As an application, the proposed method has been applied to determine the energy-sensitive first sharp diffraction peak of network forming GeO{sub 2} glass at high pressure, exhibiting a distinct behavior in the pressure range of 2-4 GPa. Another application presented is pair distribution function measurement using calibrated high-energy x-rays at 82.273 keV. Unlike the traditional x-ray absorption-based calibration method, the proposed approach does not rely on any edges of specific elements, and is applicable to the hard x-ray region where no appropriate absorption edge is available.

Hong Xinguo; Chen Zhiqiang [Mineral Physics Institute, Stony Brook University, Stony Brook, New York 11794 (United States); Duffy, Thomas S. [Department of Geosciences, Princeton University, Princeton, New Jersey 08544 (United States)

2012-06-15T23:59:59.000Z

451

Radial Diffraction Strength and Elastic Behavior of CaF2 in Low- and High-Pressure Phases  

SciTech Connect

The radial-diffraction lattice behavior of CaF2 was analyzed in its low-pressure (fluorite) and high-pressure phase up to 11.5 GPa using radial x-ray diffraction techniques in the diamond anvil cell. Between 3.5 and 7.1 GPa, fluorite develops a radial-diffraction strength of {approx}0.8 GPa. The corresponding lattice anisotropy of the fluorite phase was measured to be equal to 0.73, in good agreement with previous Brillouin spectroscopy measurements. By 8.8 GPa, CaF2 has undergone a phase transformation to its high-pressure (orthorhombic) phase, with a corresponding volume decrease of 10.4%. By 11.5 GPa, the volume drop between the low-pressure and high-pressure phase has increased to 11.5%. In addition, the high-pressure phase is found to withstand a significantly larger differential stress than the low-pressure fluorite phase, with a large degree of lattice anisotropy. In the maximum stress direction at 8.8 GPa, we observe a time-dependent evolution of the lattice parameters of CaF2, indicating that the high-pressure structure is still undergoing deformation on time scales of hours after the phase boundary has been crossed.

Kavner,A.

2008-01-01T23:59:59.000Z

452

Simulation of the electron diffraction patterns from needle/rod-like precipitates in Al-Mg-Si alloys  

Science Conference Proceedings (OSTI)

The origin of the selected area electron diffraction (SAED) patterns from needle/rod-like metastable precipitates embedded in {alpha}-Al matrix in Al-Mg-Si alloys have been studied via an example of {beta}'' phase. In addition, the SAED pattern from {beta}'' phase has been simulated with significant improvement in comparison with the previous simulations. Three important factors, i.e. the 12 crystallographically equivalent variants of {beta}'' phase in the {alpha}-Al matrix due to the highly symmetric f.c.c. structure of {alpha}-Al, the coherence between {beta}'' phase and the {alpha}-Al matrix, and the double diffractions from the {alpha}-Al matrix and {beta}'' phase, are proved to contribute to the special square-shaped features in the SAED patterns from {beta}'' phase and thus fully taken into account in the simulation. An improved but simplified method for simulating the SAED patterns from needle/rod-like metastable precipitates has been developed. This method is further verified by simulating the SAED pattern from Q phase. The simulated SAED patterns from both {beta}'' and Q phases fit the experimentally determined patterns very well. - Highlights: {yields}An improved method has been developed to simulate the SADPs of Al alloys. {yields}The formation mechanism of SADPs of Al alloys has been systemically studied. {yields}Double diffraction contributes to the formation of the SADPs of Al alloys.

Li Kai [State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China); Song Min, E-mail: Min.Song.Th05@Alum.Dartmouth.ORG [State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China); Du Yong [State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China); Zhang Hong [School of Materials Science and Engineering, Central South University, Changsha 410083 (China)

2011-09-15T23:59:59.000Z

453

MEASUREMENT OF Z + GAMMA PRODUCTION AND SEARCH FOR ANOMALOUS TRIPLE GAUGE COUPLINGS IN PROTON-ANTIPROTON COLLISIONS AT s**(1/2) = 1.96 TEV  

SciTech Connect

The author presents a measurement of p{bar p} {yields} Z{gamma} + X {yields} e{sup +}e{sup -}{gamma} + X production using proton-antiproton collisions data collected at the Collider Detector at Fermilab at a center of mass energy of 1.96 TeV. Z{gamma} production provides a direct test of the triple neutral gauge couplings. A measurement of Z{gamma} production cross section and search for anomalous ZZ{gamma} and Z{gamma}{gamma} couplings are presented. The data presented are from 1.1 fb{sup -1} of p{bar p} integrated luminosity collected at the CDF Detector. Electrons from Z decays are selected with E{sub t} > 20 Gev. Photons (E{sub t} > 7 GeV) are required to be well-separated from the electrons. There are 390 ee{gamma} candidate events found with 1.1 fb{sup -1} of data, compared to the SM prediction of 375.3 {+-} 25.2 events. The Standard Model prediction for the cross section for p{bar p} {yields} e{sup +}e{sup -}{gamma} + X production at {radical}s = 1.96 TeV is 4.5 {+-} 0.4 pb. The measured cross section is 4.7 {+-} 0.6 pb. The cross section and kinematic distributions of the ee{gamma} events are in good agreement with theoretical predictions. Limits on the ZZ{gamma} and Z{gamma}{gamma} couplings are extracted using the photon E{sub t} distribution of ee{gamma} events with m{sub ee{gamma}} > 100 GeV/c{sup 2}. These are the first limits measured using CDF Run II data. These limits provide important test of the interaction of the photon and the Z boson.

Deng, Jianrong; /Duke U.

2008-01-01T23:59:59.000Z

454

Three XMM-Newton observations of the Anomalous X-ray Pulsar 1E 1048.1-5937: long term variations in spectrum and pulsed fraction  

E-Print Network (OSTI)

We report the results of a recent (July 2004) XMM-Newton Target of Opportunity observation of the Anomalous X-ray pulsar 1E 1048.1-5937, together with a detailed re-analysis of previous observations carried out in 2000 and 2003. In July 2004 the source had a 2-10 keV flux of 6.2$\\times10^{-12}$ erg cm$^{-2}$ s$^{-1}$ and a pulsed fraction P$_F$=0.68. The comparison of the three data sets shows the presence of an anti-correlation between flux and pulsed fraction, implying that previous estimates of the source energetics based on the assumption of a large and constant pulsed fraction might be significantly underestimated. The source spectrum is well described by a power law plus blackbody model (kT~0.63 keV, photon index $\\Gamma$~2.7-3.5) or, alternatively, by the sum of two blackbodies of which the hotter is Comptonized by relativistic electrons. In this case the temperatures are kT${_1}$~0.2-0.3 keV and kT${_2}$~0.4-0.5 keV and the emitting area of the cooler component is consistent with the whole neutron star surface. The long term luminosity variation of a factor >~2 is accompanied by relatively small variations in the spectral shape. Phase resolved spectroscopy indicates a harder spectrum in correspondence of the pulse maximum. No spectral features have been detected with 4$\\sigma$ limits on the equivalent width in the range ~10-220 eV, depending on line energy and width.

A. Tiengo; S. Mereghetti; R. Turolla; S. Zane; N. Rea; L. Stella; G. L. Israel

2005-03-17T23:59:59.000Z

455

Search for anomalous WW/WZ {r_arrow} e{nu}jj production at D0; Busqueda de produccion anomala WW/WZ {r_arrow}e{nu}jj en D-Zero  

SciTech Connect

A search for anomalous WW and WZ production in p{anti p} collisions at {radical}s = 1.8 TeV using the D0 detector at Fermilab is presented. With a data sample of p{anti p} {r_arrow} e{nu}jjX events corresponding to an integrated luminosity of 76.5 {+-} 4.1pb{sup {minus}1}. 399 candidate events were identified, from which 387.1 {+-} 39.8 events were estimated to be background. No deviations from the Standard Model were seen, which predicts 16.2 {+-} 2.7 events. The 95% CL limit on the cross section {sigma}(p{anti p} {r_arrow} W{sup +}W{sup {minus}}X) was calculated to be 93.8 pb. Limits on the CP-conserving anomalous WW{sub {gamma}} and WWZ coupling parameters were obtained from a binned likelihood fit to the transverse momentum spectrum of the W boson. Assuming that the WW{sub {gamma}} and WWZ coupling parameters are equal, the 95% CL limits on the CP-conserving couplings are {minus}0.56 < {Delta}{kappa} < 0.75 (with {lambda} = 0) and {minus}0.42 < {lambda} < 0.44 (with {Delta}{kappa} = 0), for a form factor scale {Lambda}{sub FF} = 1.5 TeV. Limits on other assumptions are also reported. These results were combined with the previous D0 WW, WZ {r_arrow} e{nu}jj published results (13.7 {+-} 0.7 pb{sup {minus}1}), and the limits on the anomalous coupling parameters were set to {minus}0.44 < {Delta}{kappa} < 0.60 (with {lambda} = 0) and {minus}0.34 < {lambda} 0.37 (with {Delta}{kappa} = 0), for a form factor scale {Lambda}{sub FF} = 2.0 TeV.

Hernandez, A.S.

1997-02-01T23:59:59.000Z

456

Formation of delta ferrite in 9 wt.% Cr steel investigated by in-situ X-ray diffraction using synchrotron radiation  

E-Print Network (OSTI)

In-situ X-ray diffraction (XRD) measurements using high energy synchrotron radiation were performed to monitor in real time the formation of delta ferrite in a martensitic 9 wt pct chromium steel under simulated weld thermal ...

Mayr, P.

457

Cocoa Butter and Related CompoundsChapter 14 New Method to Study Molecular Interactions in FatsSynchrotron Radiation Microbeam X-ray Diffraction  

Science Conference Proceedings (OSTI)

Cocoa Butter and Related Compounds Chapter 14 New Method to Study Molecular Interactions in FatsSynchrotron Radiation Microbeam X-ray Diffraction Food Science Health Nutrition eChapters Food Science & Technology Health - Nutrition - Bioc

458

Crystallization and Solidification Properties of LipidsChapter 3 Simultaneous Exam Structural/Thermal Behaviors of Fatsby Coupled X-ray Diffraction and Differential Scanning Calorimetry  

Science Conference Proceedings (OSTI)

Crystallization and Solidification Properties of Lipids Chapter 3 Simultaneous Exam Structural/Thermal Behaviors of Fatsby Coupled X-ray Diffraction and Differential Scanning Calorimetry Health Nutrition Biochemistry eChapters Health - N

459

Structure-Function Analysis of Edible FatsChapter 3 Powder X-ray Diffraction of Triglycerides in the Study of Polymorphism  

Science Conference Proceedings (OSTI)

Structure-Function Analysis of Edible Fats Chapter 3 Powder X-ray Diffraction of Triglycerides in the Study of Polymorphism Methods and Analyses eChapters Food Science & Technology Health - Nutrition - Biochemistry Processing Methods - An

460

Anomalous change detection in imagery  

DOE Patents (OSTI)

A distribution-based anomaly detection platform is described that identifies a non-flat background that is sp