Ward, Gregory; Mistrick, Ph.D., Richard; Lee, Eleanor; McNeil, Andrew; Jonsson, Ph.D., Jacob
2011-01-21T23:59:59.000Z
We describe two methods which rely on bidirectional scattering distribution functions (BSDFs) to model the daylighting performance of complex fenestration systems (CFS), enabling greater flexibility and accuracy in evaluating arbitrary assemblies of glazing, shading, and other optically-complex coplanar window systems. Two tools within Radiance enable a) efficient annual performance evaluations of CFS, and b) accurate renderings of CFS despite the loss of spatial resolution associated with low-resolution BSDF datasets for inhomogeneous systems. Validation, accuracy, and limitations of the methods are discussed.
METHODOLOGY. TIME DISTRIBUTION OF MOSSBAUER SCATTERED RADIATION
Paris-Sud XI, Université de
METHODOLOGY. TIME DISTRIBUTION OF MOSSBAUER SCATTERED RADIATION H. DROST, K. PALOW and G. WEYER distribution en temps du rayonnement reemis par un absorbant Mossbauer. Des effets d'interference dus a l la reponse de 1'absorbant. Les mesures ont et6 realisees avec le rayonnement Mossbauer a 14.4 keV du
Symanzik, Jürgen
, distributed computing environment Martin Schneider Philipps-Universit¨at Marburg Dept. of Mathemathics
Ward, Gregory
2011-01-01T23:59:59.000Z
761-81. Tregenza PR. 1983. Daylight coefficients. Lighting773. Reinhart CF. 2001. Daylight availability and manualA visualization of an incident daylight matrix (cumulative
Ward, Gregory
2011-01-01T23:59:59.000Z
D and a set of sky patch luminances, we can compute thewindow s = sky vector, assigning luminance values to patchessky condition, we could quickly compute the outgoing luminance
Bidirectional waveguide coupling with plasmonic Fano nanoantennas
Guo, Rui; Decker, Manuel, E-mail: manuel.decker@anu.edu.au; Staude, Isabelle; Neshev, Dragomir N.; Kivshar, Yuri S. [Nonlinear Physics Centre and Centre for Ultrahigh Bandwidth Devices for Optical Systems (CUDOS), Research School of Physics and Engineering, The Australian National University, Canberra ACT 0200 (Australia)
2014-08-04T23:59:59.000Z
We introduce the concept of a bidirectional, compact single-element Fano nanoantenna that allows for directional coupling of light in opposite directions of a high-index dielectric waveguide for two different operation wavelengths. We utilize a Fano resonance to tailor the radiation phases of a gold nanodisk and a nanoslit that is inscribed into the nanodisk to realize bidirectional scattering. We show that this Fano nanoantenna operates as a bidirectional waveguide coupler at telecommunication wavelengths and, thus, is ideally suitable for integrated wavelength-selective light demultiplexing.
Proton Angular Distribution for 90 Mev Neutron-proton Scattering
Hadley, James
2010-01-01T23:59:59.000Z
3, 1947 The angular distribution of the recoil protons inneutron -proton scattering at 90 Mev has been measured forNO. W ..7405-Eng 48 PROTON .ANGULAR DISTRIBUTION FOR 90 lWEV
Distributions of off-diagonal scattering matrix elements: Exact results
Nock, A., E-mail: a.nock@qmul.ac.uk; Kumar, S., E-mail: skumar.physics@gmail.com; Sommers, H.-J., E-mail: h.j.sommers@uni-due.de; Guhr, T., E-mail: thomas.guhr@uni-due.de
2014-03-15T23:59:59.000Z
Scattering is a ubiquitous phenomenon which is observed in a variety of physical systems which span a wide range of length scales. The scattering matrix is the key quantity which provides a complete description of the scattering process. The universal features of scattering in chaotic systems is most generally modeled by the Heidelberg approach which introduces stochasticity to the scattering matrix at the level of the Hamiltonian describing the scattering center. The statistics of the scattering matrix is obtained by averaging over the ensemble of random Hamiltonians of appropriate symmetry. We derive exact results for the distributions of the real and imaginary parts of the off-diagonal scattering matrix elements applicable to orthogonally-invariant and unitarily-invariant Hamiltonians, thereby solving a long standing problem. -- Highlights: •Scattering problem in complex or chaotic systems. •Heidelberg approach to model the chaotic nature of the scattering center. •A novel route to the nonlinear sigma model based on the characteristic function. •Exact results for the distributions of off-diagonal scattering-matrix elements. •Universal aspects of the scattering-matrix fluctuations.
Stokes, Eleanor (Eleanor Catherine)
2008-01-01T23:59:59.000Z
The effective use of complex fenestration systems (CFS) in buildings requires a detailed knowledge of their optical spectral and directional properties. Bidirectional scattering functions (BSDFs), either in transmission ...
Jedek, Christoph
2012-01-01T23:59:59.000Z
of the slats, blind thickness, and rise. MS Thesis, Bochumblind representation, according to DIN EN 13363-2 (2005, p. 17) MS Thesis,
Jedek, Christoph
2012-01-01T23:59:59.000Z
J.A. , Beckman, W.A. (1991). Solar engineering of thermalA new method for predicting the solar heat gain of complexfenestration systems. ASHRAE Solar Heat Gain Project 548-RP
Generalized Parton Distributions from Deeply Virtual Compton Scattering at HERMES
M. Guidal; H. Moutarde
2009-12-04T23:59:59.000Z
The HERMES collaboration has recently published a set of (correlated) beam charge, beam spin and target spin relative asymmetries for the Deeply Virtual Compton Scattering process. This reaction allows in principle to access the Generalized Parton Distributions of the nucleon. We have fitted, in the QCD leading-order and leading-twist handbag approximation, but in a model independent way, this set of data and we report our results for the extracted Compton Form Factors. In particular, we are able to extract constrains on the $H$ GPD.
Generalized Parton Distributions from Deep Virtual Compton Scattering at CLAS
M. Guidal
2010-03-01T23:59:59.000Z
We have analyzed the beam spin asymmetry and the longitudinally polarized target spin asymmetry of the Deep Virtual Compton Scattering process, recently measured by the Jefferson Lab CLAS collaboration. Our aim is to extract information about the Generalized Parton Distributions of the proton. By fitting these data, in a largely model-independent procedure, we are able to extract numerical values for the two Compton Form Factors $H_{Im}$ and $\\tilde{H}_{Im}$ with uncertainties, in average, of the order of 30%.
Proton Angular Distribution for 90 Mev Neutron-proton Scattering
Hadley, James
2010-01-01T23:59:59.000Z
recoil protons in neutron -proton scattering at 90 Mev hasFOR 90 lWEV NEUTRON-PROTON SCATTERING James Hadley, Cecil E.
Deeply virtual Compton scattering and generalized parton distributions
S. Fazio; R. Fiore; L. L. Jenkovszky
2008-12-16T23:59:59.000Z
We present a comparison of a recently proposed model, which describes the Deeply Virtual Compton Scattering amplitude, to the HERA data.
Alkhazov, G. D.; Sarantsev, V. V., E-mail: saran@pnpi.spb.ru [Petersburg Nuclear Physics Institute NRC KI (Russian Federation)
2012-12-15T23:59:59.000Z
In order to clear up the sensitivity of the nucleus-nucleus scattering to the nuclear matter distributions in exotic halo nuclei, we have calculated differential cross sections for elastic scattering of the {sup 6}He and {sup 11}Li nuclei on several nuclear targets at the energy of 0.8 GeV/nucleon with different assumed nuclear density distributions in {sup 6}He and {sup 11}Li.
Bidirectional buck boost converter
Esser, A.A.M.
1998-03-31T23:59:59.000Z
A bidirectional buck boost converter and method of operating the same allows regulation of power flow between first and second voltage sources in which the voltage level at each source is subject to change and power flow is independent of relative voltage levels. In one embodiment, the converter is designed for hard switching while another embodiment implements soft switching of the switching devices. In both embodiments, first and second switching devices are serially coupled between a relatively positive terminal and a relatively negative terminal of a first voltage source with third and fourth switching devices serially coupled between a relatively positive terminal and a relatively negative terminal of a second voltage source. A free-wheeling diode is coupled, respectively, in parallel opposition with respective ones of the switching devices. An inductor is coupled between a junction of the first and second switching devices and a junction of the third and fourth switching devices. Gating pulses supplied by a gating circuit selectively enable operation of the switching devices for transferring power between the voltage sources. In the second embodiment, each switching device is shunted by a capacitor and the switching devices are operated when voltage across the device is substantially zero. 20 figs.
Bidirectional buck boost converter
Esser, Albert Andreas Maria (Niskayuna, NY)
1998-03-31T23:59:59.000Z
A bidirectional buck boost converter and method of operating the same allows regulation of power flow between first and second voltage sources in which the voltage level at each source is subject to change and power flow is independent of relative voltage levels. In one embodiment, the converter is designed for hard switching while another embodiment implements soft switching of the switching devices. In both embodiments, first and second switching devices are serially coupled between a relatively positive terminal and a relatively negative terminal of a first voltage source with third and fourth switching devices serially coupled between a relatively positive terminal and a relatively negative terminal of a second voltage source. A free-wheeling diode is coupled, respectively, in parallel opposition with respective ones of the switching devices. An inductor is coupled between a junction of the first and second switching devices and a junction of the third and fourth switching devices. Gating pulses supplied by a gating circuit selectively enable operation of the switching devices for transferring power between the voltage sources. In the second embodiment, each switching device is shunted by a capacitor and the switching devices are operated when voltage across the device is substantially zero.
Directional Stand-off Detection of Fast Neutrons and Gammas Using Angular Scattering Distributions
Vanier P. e.; Dioszegi, I.; Salwen, C.; Forman, L.
2009-10-25T23:59:59.000Z
We have investigated the response of a DoubleScatter Neutron Spectrometer (DSNS) for sources at long distances (gr than 200 meters). We find that an alternative method for analyzing double scatter data avoids some uncertainties introduced by amplitude measurements in plastic scintillators.Time of flight is used to discriminate between gamma and neutron events, and the kinematic distributions of scattering angles are assumed to apply. Non-relativistic neutrons are most likely to scatter at 45°, while gammas with energies greater than 2 MeV are most likely to be forward scattered. The distribution of scattering angles of fission neutrons arriving from a distant point source generates a 45° cone, which can be back-projected to give the source direction. At the same time, the distribution of Compton-scattered gammas has a maximum in the forward direction, and can be made narrower by selecting events that deposit minimal energy in the first scattering event. We have further determined that the shape of spontaneous fission neutron spectra at ranges gr than 110 m is still significantly different from thecosmic ray background.
Energy distribution of Compton-scattered gamma rays
Moreland, Richard Wayne
1966-01-01T23:59:59.000Z
JJ 0 O 100 ~ ~ ~ IL ~ ~ ~ ~ ~ 180 200. 220 240 260 280 300 $20 $40L Qypma Re@ gner8y, t, 'kelp, Figure 14. Plot of experimental Compton spectrum from CHf-scatterer, from which background in Fig. 15 has been subtracted. Statistical error...
J. Mol. Biol. (1975) 91, 101-120 A Neutron Scattering Study of the Distribution of Protein
J. Mol. Biol. (1975) 91, 101-120 A Neutron Scattering Study of the Distribution of Protein and RNA coli have been measured by neutron scattering experiments on the intact subunit. In addition the radius, 1972; Lutter et al., 1972), and neutron scattering (Engelman & Moore, 1972; Moore et al., 1974
Generalized Parton Distributions and Deeply Virtual Compton Scattering
Boër, Marie
2014-01-01T23:59:59.000Z
We present a method which allows to extract theoretical informations out of a limited set of experimental data and observables, forming up in general an under- constrained system. It has been applied to the field of nucleon structure, in the domain of Generalized Parton Distributions (GPDs). We take advantage of this review to remove a couple of approximations that we used in our previous works and update our results using the latest data published.
Generalized parton distributions and rapidity gap survival in exclusive diffractive pp scattering
Leonid Frankfurt; Charles Hyde-Wright; Mark Strikman; Christian Weiss
2007-03-01T23:59:59.000Z
We propose a new approach to the problem of rapidity gap survival (RGS) in the production of high-mass systems (H = dijet, heavy quarkonium, Higgs boson) in double-gap exclusive diffractive pp scattering, pp-->p + (gap) + H + (gap) + p. It is based on the idea that hard and soft interactions proceed over widely different time- and distance scales and are thus approximately independent. The high-mass system is produced in a hard scattering process with exchange of two gluons between the protons. Its amplitude is calculable in terms of the gluon generalized parton distributions (GPDs) in the protons, which can be measured in J= production in exclusive ep scattering. The hard scattering process is modified by soft spectator interactions, which we calculate in a model-independent way in terms of the pp elastic scattering amplitude. Contributions from inelastic intermediate states are suppressed. A simple geometric picture of the interplay of hard and soft interactions in diffraction is obtained. The onset of the black-disk limit in pp scattering at TeV energies strongly suppresses diffraction at small impact parameters and is the main factor in determining the RGS probability. Correlations between hard and soft interactions (e.g. due to scattering from the long-range pion field of the proton, or due to possible short-range transverse correlations between partons) further decrease the RGS probability. We also investigate the dependence of the diffractive cross section on the transverse momenta of the final-state protons (''diffraction pattern''). By measuring this dependence one can perform detailed tests of the interplay of hard and soft interactions, and even extract information about the gluon GPD in the proton. Such studies appear to be feasible with the planned forward detectors at the LHC.
Gary R. Goldstein; J. Osvaldo Gonzalez Hernandez; Simonetta Liuti
2011-02-16T23:59:59.000Z
We present a physically motivated parametrization of the chiral-even generalized parton distributions in the non-singlet sector obtained from a global analysis using a set of available experimental data. Our analysis is valid in the kinematical region of intermediate Bjorken $x$ and for $Q^2$ in the multi-GeV region which is accessible at present and currently planned facilities. Relevant data included in our fit are from the nucleon elastic form factors measurements, from deep inelastic scattering experiments. Additional information provided by lattice calculations of the higher moments of generalized parton distributions, is also considered. Recently extracted observables from Deeply Virtual Compton Scattering on the nucleon are reproduced by our fit.
Leading neutron energy and pT distributions in deep inelastic scattering and photoproduction at HERA
ZEUS Collaboration; S. Chekanov
2007-03-09T23:59:59.000Z
The production of energetic neutrons in $ep$ collisions has been studied with the ZEUS detector at HERA. The neutron energy and $p_T^2$ distributions were measured with a forward neutron calorimeter and tracker in a $40 \\pb^{-1}$ sample of inclusive deep inelastic scattering (DIS) data and a $6 \\pb^{-1}$ sample of photoproduction data. The neutron yield in photoproduction is suppressed relative to DIS for the lower neutron energies and the neutrons have a steeper $p_T^2$ distribution, consistent with the expectation from absorption models. The distributions are compared to HERA measurements of leading protons. The neutron energy and transverse-momentum distributions in DIS are compared to Monte Carlo simulations and to the predictions of particle exchange models. Models of pion exchange incorporating absorption and additional secondary meson exchanges give a good description of the data.
Koh, Wonshill
2013-02-22T23:59:59.000Z
The light propagation in highly scattering turbid media composed of the particles with different size distribution is studied using a Monte Carlo simulation model implemented in Standard C. Monte Carlo method has been widely utilized to study...
S. Terashima; H. Sakaguchi; H. Takeda; T. Ishikawa; M. Itoh; T. Kawabata; T. Murakami; M. Uchida; Y. Yasuda; M. Yosoi; J. Zenihiro; H. P. Yoshida; T. Noro; T. Ishida; S. Asaji; T. Yonemura
2008-02-02T23:59:59.000Z
Cross sections and analyzing powers for proton elastic scattering from $^{116,118,120,122,124}$Sn at 295 MeV have been measured for a momentum transfer of up to about 3.5 fm$^{-1}$ to deduce systematic changes of the neutron density distribution. We tuned the relativistic Love-Franey interaction to explain the proton elastic scattering of a nucleus whose density distribution is well known. Then, we applied this interaction to deduce the neutron density distributions of tin isotopes. The result of our analysis shows the clear systematic behavior of a gradual increase in the neutron skin thickness of tin isotopes with mass number.
Ion distributions at charged aqueous surfaces: Synchrotron X-ray scattering studies
Bu, Wei
2009-08-15T23:59:59.000Z
Surface sensitive synchrotron X-ray scattering studies were performed to obtain the distribution of monovalent ions next to a highly charged interface at room temperature. To control surface charge density, lipids, dihexadecyl hydrogen-phosphate (DHDP) and dimysteroyl phosphatidic acid (DMPA), were spread as monolayer materials at the air/water interface, containing CsI at various concentrations. Five decades in bulk concentrations (CsI) are investigated, demonstrating that the interfacial distribution is strongly dependent on bulk concentration. We show that this is due to the strong binding constant of hydronium H3O+ to the phosphate group, leading to proton-transfer back to the phosphate group and to a reduced surface charge. Using anomalous reflectivity off and at the L3 Cs+ resonance, we provide spatial counterion (Cs+) distributions next to the negatively charged interfaces. The experimental ion distributions are in excellent agreement with a renormalized surface charge Poisson-Boltzmann theory for monovalent ions without fitting parameters or additional assumptions. Energy Scans at four fixed momentum transfers under specular reflectivity conditions near the Cs+ L3 resonance were conducted on 10-3 M CsI with DHDP monolayer materials on the surface. The energy scans exhibit a periodic dependence on photon momentum transfer. The ion distributions obtained from the analysis are in excellent agreement with those obtained from anomalous reflectivity measurements, providing further confirmation to the validity of the renormalized surface charge Poisson-Boltzmann theory for monovalent ions. Moreover, the dispersion corrections f0 and f00 for Cs+ around L3 resonance, revealing the local environment of a Cs+ ion in the solution at the interface, were extracted simultaneously with output of ion distributions.
Control of Parallel-Connected Bidirectional AC-DC Converters in Stationary Frame for Microgrid
Teodorescu, Remus
Sistemes Automàtica i Informàtica Industrial Universitat Politècnica de Catalunya Abstract. In this paper, parallel-connected bidirectional converters for AC and DC hybrid microgrid application energy sources [3-6]. A hybrid microgrid can be made up of distributed renewable source, AC and DC common
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Gorelik, Tatiana E.; Billinge, Simon J. L.; Schmidt, Martin U.; Kolb, Ute
2015-04-01T23:59:59.000Z
This paper shows for the first time that pair-distribution function analyses can be carried out on organic and organo-metallic compounds from powder electron diffraction data. Different experimental setups are demonstrated, including selected area electron diffraction (SAED) and nanodiffraction in transmission electron microscopy (TEM) or nanodiffraction in scanning transmission electron microscopy (STEM) modes. The methods were demonstrated on organo-metallic complexes (chlorinated and unchlorinated copper-phthalocyanine) and on purely organic compounds (quinacridone). The PDF curves from powder electron diffraction data, called ePDF, are in good agreement with PDF curves determined from X-ray powder data demonstrating that the problems of obtaining kinematical scattering datamore »and avoiding beam-damage of the sample are possible to resolve.« less
Prokudin, Alexey; Anselmino, Mauro; Boglione, Mariaelena; Melis, Stefano; Gonzalez, J. O.
2014-10-01T23:59:59.000Z
The unpolarised transverse momentum dependent distribution and fragmentation functions (TMDs) are extracted from HERMES and COMPASS experimental measurements of semi- inclusive deep inelastic scattering multiplicities for charged hadron production. A simple factorised functional form of the TMDs is adopted, with a Gaussian dependence on the intrinsic transverse momentum, which turns out to be quite adequate in shape.
Spatial Orientation and Distribution of Reservoir Fractures from Scattered Seismic Energy
Vetri, Laura
2006-01-01T23:59:59.000Z
We present the details of a new method for determining the reflection and scattering characteristics of seismic
Systems and methods for bi-directional energy delivery with galvanic isolation
Kajouke, Lateef A.
2013-06-18T23:59:59.000Z
Systems and methods are provided for bi-directional energy delivery. A charging system comprises a first bi-directional conversion module, a second bi-directional conversion module, and an isolation module coupled between the first bi-directional conversion module and the second bi-directional conversion module. The isolation module provides galvanic isolation between the first bi-directional conversion module and the second bi-directional conversion module.
Sunny, E. E.; Martin, W. R. [University of Michigan, 2355 Bonisteel Boulevard, Ann Arbor MI 48109 (United States)
2013-07-01T23:59:59.000Z
Current Monte Carlo codes use one of three models to model neutron scattering in the epithermal energy range: (1) the asymptotic scattering model, (2) the free gas scattering model, or (3) the S({alpha},{beta}) model, depending on the neutron energy and the specific Monte Carlo code. The free gas scattering model assumes the scattering cross section is constant over the neutron energy range, which is usually a good approximation for light nuclei, but not for heavy nuclei where the scattering cross section may have several resonances in the epithermal region. Several researchers in the field have shown that using the free gas scattering model in the vicinity of the resonances in the lower epithermal range can under-predict resonance absorption due to the up-scattering phenomenon. Existing methods all involve performing the collision analysis in the center-of-mass frame, followed by a conversion back to the laboratory frame. In this paper, we will present a new sampling methodology that (1) accounts for the energy-dependent scattering cross sections in the collision analysis and (2) acts in the laboratory frame, avoiding the conversion to the center-of-mass frame. The energy dependence of the scattering cross section was modeled with even-ordered polynomials to approximate the scattering cross section in Blackshaw's equations for the moments of the differential scattering PDFs. These moments were used to sample the outgoing neutron speed and angle in the laboratory frame on-the-fly during the random walk of the neutron. Results for criticality studies on fuel pin and fuel assembly calculations using these methods showed very close comparison to results using the reference Doppler-broadened rejection correction (DBRC) scheme. (authors)
Bailey-Kellogg, Chris
SCATTERING DATA Paritosh A. Kavathekar Department of Computer Science, Dartmouth College, Hanover, NH 03755 of Computer Science, Dartmouth College, Hanover, NH 0375 Email: devin@cs.dartmouth.edu Abstract: Scattering of neutrons and x-rays from molecules in solution offers alternative approaches to the studying of a wide
A model for motor-mediated bidirectional transport along an antipolar microtubule bundle
Congping Lin; Peter Ashwin; Gero Steinberg
2012-11-21T23:59:59.000Z
Long-distance bidirectional transport of organelles depends on the motor proteins kinesin and dynein. Using quantitative data obtained from a fungal model system, we previously developed ASEP-models of bidirectional motion of motors along unipolar microtubules (MTs) near the cell ends of the elongated hyphal cells (herein referred as "unipolar section"). However, recent quantitative live cell imaging in this system has demonstrated that long-range motility of motors and their endosomal cargo mainly occurs along extended antipolar microtubule bundles within the central part of the cell (herein referred to as "bipolar section"). Dynein and kinesin-3 motors coordinate their activity to move early endosomes (EEs) in a bidirectional fashion, with dynein mediating retrograde motility along the unipolar section near the cell poles, whereas kinesin-3 is responsible for bidirectional motions along the antipolar section. Here we extend our modelling approach to simulate bidirectional motility along an antipolar microtubule bundle. In our model, cargos (particles) change direction on each MT with a turning rate $\\Omega$ and the MTs are linked to each other at the minus ends where particles can hop between MTs with a rate $q_1$ (obstacle-induced switching rate) or $q_2$ (end-induced switching rate). By numerical simulations and mean-field approximations, we investigate the distribution of particles along the MTs for different overall densities $\\Theta$. We find that even if $\\Theta$ is low, the system can exhibit shocks in the density profiles near plus and minus ends caused by queueing of particles. We also discuss how the switching rates $q_{1,2}$ influence the type of motor that dominates the active transport in the bundle.
Spatial Orientation And Distribution Of Reservoir Fractures From Scattered Seismic Energy
Vetri, Laura
2005-01-01T23:59:59.000Z
We present the details of a new method for determining the reflection and scattering characteristics of seismic energy from subsurface fractured formations. The method is based upon observations we have made from 3D finite ...
Spatial Orientation And Distribution Of Reservoir Fractures From Scattered Seismic Energy
Vetri, Laura
2004-01-01T23:59:59.000Z
Expanded details and additional results are presented using a new method (Willis et al, 2003) for determining the reflection and scattering characteristics of seismic energy from subsurface fractured formations. The method ...
Airapetian, A; Akopov, Z; Andrus, A; Aschenauer, E C; Augustyniak, W; Avakian, R; Avetisian, A; Avetissian, E; Belostotskii, S; Bianchi, N; Blok, H P; Bttcher, H; Bonomo, C; Borisov, A; Brüll, A; Bryzgalov, V; Burns, J; Capiluppi, M; Capitani, G P; Cisbani, E; Ciullo, G; Contalbrigo, M; Dalpiaz, P F; Deconinck, W; De Leo, R; Demey, M; De Nardo, L; De Sanctis, E; Diefenthaler, M; Di Nezza, P; Dreschler, J; Düren, M; Ehrenfried, M; Elalaoui-Moulay, A; Elbakian, G; Ellinghaus, F; Elschenbroich, U; Fabbri, R; Fantoni, A; Felawka, L; Frullani, S; Funel, A; Gabbert, D; Gapienko, G; Gapienko, V; Garibaldi, F; Gavrilov, G; Karibian, V; Giordano, F; Gliske, S; Gregor, I M; Guler, H; Hadjidakis, C; Hasch, D; Hasegawa, T; Hesselink, W H A; Hill, G; Hillenbrand, A; Hoek, M; Holler, Y; Hommez, B; Hristova, I; Iarygin, G; Imazu, Y; Ivanilov, A; Izotov, A; Jackson, H E; Jgoun, A; Joosten, S; Kaiser, R; Keri, T; Kinney, E; Kiselev, A; Kobayashi, T; Kopytin, M; Korotkov, V; Kozlov, V; Kravchenko, P; Krivokhizhin, V G; Lagamba, L; Lamb, R; Lapikas, L; Lehmann, I; Lenisa, P; Liebing, P; Linden-Levy, L A; Lopez Ruiz, A; Lorenzon, W; Lu, S; Lu, X R; Ma, B Q; Mahon, D; Maiheu, B; Makins, N C R; Manfr, L; Mao, Y; Marianski, B; Marukyan, H; Mexner, V; Miller, C A; Miyachi, Y; Muccifora, V; Murray, M; Mussgiller, A; Nagaitsev, A; Nappi, E; Naryshkin, Yu; Nass, A; Negodaev, M; Nowak, W D; Osborne, A; Pappalardo, L L; Perez-Benito, R; Pickert, N; Raithel, M; Reggiani, D; Reimer, P E; Reischl, A; Reolon, A R; Riedl, C; Rith, K; Rock, S E; Rosner, G; Rostomyan, A; Rubacek, L; Rubin, J; Ryckbosch, D; Salomatin, Y; Sanjiev, I; Schäfer, A; Schnell, G; Schüler, K P; Seitz, B; Shearer, C; Shibata, T A; Shutov, V; Stancari, M; Statera, M; Steffens, E; Steijger, J J M; Stenzel, H; Stewart, J; Stinzing, F; Streit, J; Tait, P; Taroian, S; Tchuiko, B; Terkulov, A; Trzcinski, A; Tytgat, M; Vandenbroucke, A; Van der Nat, P B; van der Steenhoven, G; Van Haarlem, Y; van Hulse, C; Varanda, M; Veretennikov, D; Vikhrov, V; Vilardi, I; Vogel, C; Wang, S; Yaschenko, S; Ye, H; Ye, Y; Ye, Z; Yen, S; Yu, W; Zeiler, D; Zihlmann, B; Zupranski, P
2008-01-01T23:59:59.000Z
The momentum and helicity density distributions of the strange quark sea in the nucleon are obtained in leading order from charged-kaon production in deep-inelastic scattering on the deuteron. The distributions are extracted from spin-averaged K+/- multiplicities, and from K+/- and inclusive double-spin asymmetries for scattering of polarized positrons by a polarized deuterium target. The shape of the momentum distribution is softer than that of the average of the ubar and dbar quarks. In the region of measurement, the helicity distribution is zero within experimental uncertainties.
Secure Computation in a Bidirectional Relay
Kashyap, Navin; Thangaraj, Andrew
2012-01-01T23:59:59.000Z
Bidirectional relaying, where a relay helps two user nodes to exchange equal length binary messages, has been an active area of recent research. A popular strategy involves a modified Gaussian MAC, where the relay decodes the XOR of the two messages using the naturally-occurring sum of symbols simultaneously transmitted by user nodes. In this work, we consider the Gaussian MAC in bidirectional relaying with an additional secrecy constraint for protection against a honest but curious relay. The constraint is that, while the relay should decode the XOR, it should be fully ignorant of the individual messages of the users. We exploit the symbol addition that occurs in a Gaussian MAC to design explicit strategies that achieve perfect independence between the received symbols and individual transmitted messages. Our results actually hold for a more general scenario where the messages at the two user nodes come from a finite Abelian group, and the relay must decode the sum within the group of the two messages. We pr...
HERMES Collaboration; A. Airapetian; N. Akopov; Z. Akopov; E. C. Aschenauer; W. Augustyniak; R. Avakian; A. Avetissian; E. Avetisyan; S. Belostotski; H. P. Blok; A. Borissov; J. Bowles; V. Bryzgalov; J. Burns; M. Capiluppi; G. P. Capitani; G. Ciullo; M. Contalbrigo; P. F. Dalpiaz; W. Deconinck; R. De Leo; L. De Nardo; E. De Sanctis; M. Diefenthaler; P. Di Nezza; M. Düren; G. Elbakian; F. Ellinghaus; A. Fantoni; L. Felawka; S. Frullani; G. Gapienko; V. Gapienko; F. Garibaldi; G. Gavrilov; V. Gharibyan; F. Giordano; S. Gliske; M. Golembiovskaya; C. Hadjidakis; M. Hartig; D. Hasch; A. Hillenbrand; M. Hoek; Y. Holler; I. Hristova; Y. Imazu; A. Ivanilov; H. E. Jackson; H. S. Jo; S. Joosten; R. Kaiser; G. Karyan; T. Keri; E. Kinney; A. Kisselev; V. Korotkov; V. Kozlov; P. Kravchenko; V. G. Krivokhijine; L. Lagamba; L. Lapikás; I. Lehmann; P. Lenisa; A. López Ruiz; W. Lorenzon; B. -Q. Ma; D. Mahon; N. C. R. Makins; S. I. Manaenkov; L. Manfré; Y. Mao; B. Marianski; A. Martinez de la Ossa; H. Marukyan; C. A. Miller; Y. Miyachi; A. Movsisyan; M. Murray; E. Nappi; Y. Naryshkin; A. Nass; M. Negodaev; W. -D. Nowak; L. L. Pappalardo; R. Perez-Benito; A. Petrosyan; M. Raithel; P. E. Reimer; A. R. Reolon; C. Riedl; K. Rith; G. Rosner; A. Rostomyan; J. Rubin; D. Ryckbosch; Y. Salomatin; F. Sanftl; A. Schäfer; G. Schnell; K. P. Schüler; B. Seitz; T. -A. Shibata; M. Stancari; M. Statera; J. J. M. Steijger; J. Stewart; F. Stinzing; A. Terkulov; R. Truty; A. Trzcinski; M. Tytgat; A. Vandenbroucke; Y. Van Haarlem; C. Van Hulse; D. Veretennikov; V. Vikhrov; I. Vilardi; S. Wang; S. Yaschenko; Z. Ye; S. Yen; W. Yu; V. Zagrebelnyy; D. Zeiler; B. Zihlmann; P. Zupranski
2013-01-18T23:59:59.000Z
The azimuthal cos{\\phi} and cos2{\\phi} modulations of the distribution of hadrons produced in unpolarized semi-inclusive deep-inelastic scattering of electrons and positrons off hydrogen and deuterium targets have been measured in the HERMES experiment. For the first time these modulations were determined in a four-dimensional kinematic space for positively and negatively charged pions and kaons separately, as well as for unidentified hadrons. These azimuthal dependences are sensitive to the transverse motion and polarization of the quarks within the nucleon via, e.g., the Cahn, Boer-Mulders and Collins effects.
Airapetian, A; Akopov, Z; Aschenauer, E C; Augustyniak, W; Avakian, R; Avetissian, A; Avetisyan, E; Belostotski, S; Blok, H P; Borissov, A; Bowles, J; Bryzgalov, V; Burns, J; Capiluppi, M; Capitani, G P; Ciullo, G; Contalbrigo, M; Dalpiaz, P F; Deconinck, W; De Leo, R; De Nardo, L; De Sanctis, E; Diefenthaler, M; Di Nezza, P; Düren, M; Elbakian, G; Ellinghaus, F; Fantoni, A; Felawka, L; Frullani, S; Gapienko, G; Gapienko, V; Garibaldi, F; Gavrilov, G; Gharibyan, V; Giordano, F; Gliske, S; Golembiovskaya, M; Hadjidakis, C; Hartig, M; Hasch, D; Hillenbrand, A; Hoek, M; Holler, Y; Hristova, I; Imazu, Y; Ivanilov, A; Jackson, H E; Jo, H S; Joosten, S; Kaiser, R; Karyan, G; Keri, T; Kinney, E; Kisselev, A; Korotkov, V; Kozlov, V; Kravchenko, P; Krivokhijine, V G; Lagamba, L; Lapikás, L; Lehmann, I; Lenisa, P; Ruiz, A López; Lorenzon, W; Ma, B -Q; Mahon, D; Makins, N C R; Manaenkov, S I; Manfré, L; Mao, Y; Marianski, B; de la Ossa, A Martinez; Marukyan, H; Miller, C A; Miyachi, Y; Movsisyan, A; Murray, M; Nappi, E; Naryshkin, Y; Nass, A; Negodaev, M; Nowak, W -D; Pappalardo, L L; Perez-Benito, R; Petrosyan, A; Raithel, M; Reimer, P E; Reolon, A R; Riedl, C; Rith, K; Rosner, G; Rostomyan, A; Rubin, J; Ryckbosch, D; Salomatin, Y; Sanftl, F; Schäfer, A; Schnell, G; Schüler, K P; Seitz, B; Shibata, T -A; Stancari, M; Statera, M; Steijger, J J M; Stewart, J; Stinzing, F; Terkulov, A; Truty, R; Trzcinski, A; Tytgat, M; Vandenbroucke, A; Van Haarlem, Y; Van Hulse, C; Veretennikov, D; Vikhrov, V; Vilardi, I; Wang, S; Yaschenko, S; Ye, Z; Yen, S; Yu, W; Zagrebelnyy, V; Zeiler, D; Zihlmann, B; Zupranski, P
2012-01-01T23:59:59.000Z
The azimuthal cos{\\phi} and cos2{\\phi} modulations of the distribution of hadrons produced in unpolarized semi-inclusive deep-inelastic scattering of electrons and positrons off hydrogen and deuterium targets have been measured in the HERMES experiment. For the first time these modulations were determined in a four-dimensional kinematic space for positively and negatively charged pions and kaons separately, as well as for unidentified hadrons. These azimuthal dependences are sensitive to the transverse motion and polarization of the quarks within the nucleon via, e.g., the Cahn, Boer-Mulders and Collins effects.
Seipt, D
2013-01-01T23:59:59.000Z
Non-linear Compton scattering in ultra-short intense laser pulses is discussed with the focus on angular distributions of the emitted photon energy. This is an observable which is accessible easily experimentally. Asymmetries of the azimuthal distributions are predicted for both linear and circular polarization. We present a systematic survey of the influence of the laser intensity, the carrier envelope phase and the laser polarization on the emission spectra for single-cycle and few-cycle laser pulses. For linear polarization, the dominant direction of the emission changes from a perpendicular pattern with respect to the laser polarization at low-intensity to a dominantly parallel emission for high-intensity laser pulses.
D. Seipt; B. Kampfer
2013-05-16T23:59:59.000Z
Non-linear Compton scattering in ultra-short intense laser pulses is discussed with the focus on angular distributions of the emitted photon energy. This is an observable which is accessible easily experimentally. Asymmetries of the azimuthal distributions are predicted for both linear and circular polarization. We present a systematic survey of the influence of the laser intensity, the carrier envelope phase and the laser polarization on the emission spectra for single-cycle and few-cycle laser pulses. For linear polarization, the dominant direction of the emission changes from a perpendicular pattern with respect to the laser polarization at low-intensity to a dominantly parallel emission for high-intensity laser pulses.
The full weak charge density distribution of 48Ca from parity violating electron scattering
Lin, Z
2015-01-01T23:59:59.000Z
Background: The ground state neutron density of a medium mass nucleus contains fundamental nuclear structure information and is at present relatively poorly known. Purpose: We explore if parity violating elastic electron scattering can provide a feasible and model independent way to determine not just the neutron radius but the full radial shape of the neutron density $\\rho_n(r)$ and the weak charge density $\\rho_W(r)$ of a nucleus. Methods: We expand the weak charge density of $^{48}$Ca in a model independent Fourier Bessel series and calculate the statistical errors in the individual coefficients that might be obtainable in a model parity violating electron scattering experiment. Results: We find that it is feasible to determine roughly six Fourier Bessel coefficients of the weak charge density of 48Ca within a reasonable amount of beam time. However, it would likely be much harder to determine the full weak density of a significantly heavier nucleus such as 208Pb. Conclusions: Parity violating elastic elec...
Imaging with Scattered Neutrons
H. Ballhausen; H. Abele; R. Gaehler; M. Trapp; A. Van Overberghe
2006-10-30T23:59:59.000Z
We describe a novel experimental technique for neutron imaging with scattered neutrons. These scattered neutrons are of interest for condensed matter physics, because they permit to reveal the local distribution of incoherent and coherent scattering within a sample. In contrast to standard attenuation based imaging, scattered neutron imaging distinguishes between the scattering cross section and the total attenuation cross section including absorption. First successful low-noise millimeter-resolution images by scattered neutron radiography and tomography are presented.
38 CHAPTER 1. ASSEMBLY MANUAL BiDirectional Motor
38 CHAPTER 1. ASSEMBLY MANUAL BiDirectional Motor and Infrared Beacon UniDirectional Motor, LED, Incandescent Lamp Sensor, Polarized Sensor, Nonpolarized Figure 1.26: Standard Connector Plug Configurations
Neutrino-nucleus coherent scattering as a probe of neutron density distributions
Kelly Patton; Jonathan Engel; Gail C. McLaughlin; Nicolas Schunck
2012-07-03T23:59:59.000Z
Neutrino-nucleus coherent elastic scattering provides a theoretically appealing way to measure the neutron part of nuclear form factors. Using an expansion of form factors into moments, we show that neutrinos from stopped pions can probe not only the second moment of the form factor (the neutron radius) but also the fourth moment. Using simple Monte Carlo techniques for argon, germanium, and xenon detectors of 3.5 tonnes, 1.5 tonnes, and 300 kg, respectively, we show that the neutron radii can be found with an uncertainty of a few percent when near a neutrino flux of $3\\times10^{7}$ neutrinos/cm$^{2}$/s. If the normalization of the neutrino flux is known independently, one can determine the moments accurately enough to discriminate among the predictions of various nuclear energy functionals.
Kassianov, Evgueni I.; Barnard, James C.; Pekour, Mikhail S.; Berg, Larry K.; Shilling, John E.; Flynn, Connor J.; Mei, Fan; Jefferson, Anne
2014-10-01T23:59:59.000Z
We propose here a novel approach for retrieving in parallel the effective density and real refractive index of weakly absorbing aerosol from optical and size distribution measurements. Here we define “weakly absorbing” as aerosol single-scattering albedos that exceed 0.95 at 0.5 um.The required optical measurements are the scattering coefficient and the hemispheric backscatter fraction, obtained in this work from an integrating nephelometer. The required size spectra come from a Scanning Mobility Particle Sizer and an Aerodynamic Particle Sizer. The performance of this approach is first evaluated using a sensitivity study with synthetically generated but measurement-related inputs. The sensitivity study reveals that the proposed approach is robust to random noise; additionally the uncertainties of the retrieval are almost linearly proportional to the measurement errors, and these uncertainties are smaller for the real refractive index than for the effective density. Next, actual measurements are used to evaluate our approach. These measurements include the optical, microphysical, and chemical properties of weakly absorbing aerosol which are representative of a variety of coastal summertime conditions observed during the Two-Column Aerosol Project (TCAP; http://campaign.arm.gov/tcap/). The evaluation includes calculating the root mean square error (RMSE) between the aerosol characteristics retrieved by our approach, and the same quantities calculated using the conventional volume mixing rule for chemical constituents. For dry conditions (defined in this work as relative humidity less than 55%) and sub-micron particles, a very good (RMSE~3%) and reasonable (RMSE~28%) agreement is obtained for the retrieved real refractive index (1.49±0.02) and effective density (1.68±0.21), respectively. Our approach permits discrimination between the retrieved aerosol characteristics of sub-micron and sub-10micron particles. The evaluation results also reveal that the retrieved density and refractive index tend to decrease with an increase of the relative humidity.
-inclusive Deep-inelastic Scattering A. Airapetian,30 N. Akopov,30 Z. Akopov,30 M. Amarian,6, 30 V.V. Ammosov,22 A
Engel, Jonathan
2012-01-01T23:59:59.000Z
PHYSICAL REVIEW C 86, 024612 (2012) Neutrino-nucleus coherent scattering as a probe of neutron manuscript received 25 July 2012; published 30 August 2012) Neutrino-nucleus coherent elastic scattering provides a theoretically appealing way to measure the neutron part of nuclear form factors. Using
A Bidirectional Deposition Model of Wax Crayons Dave Rudolf
Mould, David
A Bidirectional Deposition Model of Wax Crayons Dave Rudolf dave.rudolf@usask.ca David Mould mould present a physically-inspired model of wax crayons, which synthesizes drawings from collections of user that evolves as it interacts with the paper. The amount of wax deposition is computed based on the crayon
Onar, Omer C [ORNL
2012-01-01T23:59:59.000Z
Plug-in hybrid electric vehicles (PHEVs) will play a vital role in future sustainable transportation systems due to their potential in terms of energy security, decreased environmental impact, improved fuel economy, and better performance. Moreover, new regulations have been established to improve the collective gas mileage, cut greenhouse gas emissions, and reduce dependence on foreign oil. This paper primarily focuses on two major thrust areas of PHEVs. First, it introduces a grid-friendly bidirectional alternating current/direct current ac/dc dc/ac rectifier/inverter for facilitating vehicle-to-grid (V2G) integration of PHEVs. Second, it presents an integrated bidirectional noninverted buck boost converter that interfaces the energy storage device of the PHEV to the dc link in both grid-connected and driving modes. The proposed bidirectional converter has minimal grid-level disruptions in terms of power factor and total harmonic distortion, with less switching noise. The integrated bidirectional dc/dc converter assists the grid interface converter to track the charge/discharge power of the PHEV battery. In addition, while driving, the dc/dc converter provides a regulated dc link voltage to the motor drive and captures the braking energy during regenerative braking.
USING THE X-RAY DUST SCATTERING HALO OF CYGNUS X-1 TO DETERMINE DISTANCE AND DUST DISTRIBUTIONS
Xiang, Jingen
We present a detailed study of the X-ray dust scattering halo of the black hole candidate Cygnus X-1 based on two Chandra High Energy Transmission Gratings Spectrometer observations. Using 18 different dust models, including ...
Baptiste Guegan
2012-11-01T23:59:59.000Z
The exclusive leptoproduction of a real photon is considered to be the "cleanest" way to access the Generalized Parton Distribution (GPD). This process is called Deeply Virtual Compton Scattering (DVCS) lN {yields} lN{gamma} , and is sensitive to all the four GPDs. Measuring the DVCS cross section is one of the main goals of this thesis. In this thesis, we present the work performed to extract on a wide phase-space the DVCS cross-section from the JLab data at a beam energy of 6 GeV.
Bi-Directional DC-DC Converter for PHEV Applications
Abas Goodarzi
2011-01-31T23:59:59.000Z
Plug-In Hybrid Electric Vehicles (PHEV) require high power density energy storage system (ESS) for hybrid operation and high energy density ESS for Electric Vehicle (EV) mode range. However, ESS technologies to maximize power density and energy density simultaneously are not commercially feasible. The use of bi-directional DC-DC converter allows use of multiple energy storage, and the flexible DC-link voltages can enhance the system efficiency and reduce component sizing. This will improve fuel consumption, increase the EV mode range, reduce the total weight, reduce battery initial and life cycle cost, and provide flexibility in system design.
An Electrothermally-Actuated, Dual-Mode Micromirror for Large Bi-Directional Scanning
Bowers, John
An Electrothermally-Actuated, Dual-Mode Micromirror for Large Bi-Directional Scanning Ankur Jain-crystal-silicon (SCS)-based micromirror that can perform large bi-directional scans and can also generate large piston scan angle) at its resonance of 2.4 kHz. A maximum vertical piston motion of 200 µm is also achieved
Rainer Jakob
2000-10-16T23:59:59.000Z
We present the handbag contribution to Wide Angle Compton Scattering (WACS) at moderately large momentum transfer obtained with a proton distribution amplitude close to the asymptotic form. In comparison it is found to be significantly larger than results from the hard scattering (pQCD) approach.
Active Flow Control on Bidirectional Rotors for Tidal MHK Applications
Shiu, Henry [Research Engineer; van Dam, Cornelis P. [Professor
2013-08-22T23:59:59.000Z
A marine and hydrokinetic (MHK) tidal turbine extracts energy from tidal currents, providing clean, sustainable electricity generation. In general, all MHK conversion technologies are confronted with significant operational hurdles, resulting in both increased capital and operations and maintenance (O&M) costs. To counter these high costs while maintaining reliability, MHK turbine designs can be simplified. Prior study found that a tidal turbine could be cost-effectively simplified by removing blade pitch and rotor/nacelle yaw. Its rotor would run in one direction during ebb and then reverse direction when the current switched to flood. We dubbed such a turbine a bidirectional rotor tidal turbine (BRTT). The bidirectional hydrofoils of a BRTT are less efficient than conventional hydrofoils and capture less energy, but the elimination of the pitch and yaw systems were estimated to reduce levelized cost of energy by 7.8%-9.6%. In this study, we investigated two mechanisms for recapturing some of the performance shortfall of the BRTT. First, we developed a novel set of hydrofoils, designated the yy series, for BRTT application. Second, we investigated the use of active flow control via microtabs. Microtabs are small deployable/retractable tabs, typically located near the leading or trailing edge of an air/hydrofoil with height on the order of the boundary layer thickness (1% - 2% of chord). They deploy approximately perpendicularly to the foil surface and, like gurney flaps and plain flaps, globally affect the aerodynamics of the airfoil. By strategically placing microtabs and selectively deploying them based on the direction of the inflow, performance of a BRTT rotor can be improved while retaining bidirectional operation. The yy foils were computationally designed and analyzed. They exhibited better performance than the baseline bidirectional foil, the ellipse. For example, the yyb07cn-180 had 14.7% higher (l/d)max than an ellipse of equal thickness. The yyb07cn family also had higher c{sub p,min} than equivalently thick ellipses, indicating less susceptibility to cavitation. Microtabs applied on yy foils demonstrated improved energy capture. A series of variable speed and constant speed rotors were developed with the yyb07cn family of hydrofoils. The constant speed yyb07cn rotor (yy-B02-Rcs,opt) captured 0.45% more energy than the equivalent rotor with ellipses (e-B02-Rcs,opt). With microtabs deployed (yy?t-B02-Rcs,opt), the energy capture increase over the rotor with ellipses was 1.05%. Note, however, that microtabs must be applied judiciously to bidirectional foils. On the 18% thick ellipse, performance decreased with the addition of microtabs. Details of hydrofoil performance, microtab sizing and positioning, rotor configurations, and revenue impacts are presented herein.
Chevron beam dump for ITER edge Thomson scattering system
Yatsuka, E.; Hatae, T.; Bassan, M.; Itami, K. [Japan Atomic Energy Agency, 801-1 Mukoyama, Naka, Ibaraki 311-0193 (Japan)] [Japan Atomic Energy Agency, 801-1 Mukoyama, Naka, Ibaraki 311-0193 (Japan); Vayakis, G. [ITER Organization, 13115 St Paul Lez Durance Cedex (France)] [ITER Organization, 13115 St Paul Lez Durance Cedex (France)
2013-10-15T23:59:59.000Z
This paper contains the design of the beam dump for the ITER edge Thomson scattering system and mainly concerns its lifetime under the harsh thermal and electromagnetic loads as well as tight space allocation. The lifetime was estimated from the multi-pulse laser-induced damage threshold. In order to extend its lifetime, the structure of the beam dump was optimized. A number of bent sheets aligned parallel in the beam dump form a shape called a chevron which enables it to avoid the concentration of the incident laser pulse energy. The chevron beam dump is expected to withstand thermal loads due to nuclear heating, radiation from the plasma, and numerous incident laser pulses throughout the entire ITER project with a reasonable margin for the peak factor of the beam profile. Structural analysis was also carried out in case of electromagnetic loads during a disruption. Moreover, detailed issues for more accurate assessments of the beam dump's lifetime are clarified. Variation of the bi-directional reflection distribution function (BRDF) due to erosion by or contamination of neutral particles derived from the plasma is one of the most critical issues that needs to be resolved. In this paper, the BRDF was assumed, and the total amount of stray light and the absorbed laser energy profile on the beam dump were evaluated.
M. Guidal
2010-05-26T23:59:59.000Z
We have analyzed the longitudinally polarized proton target asymmetry data of the Deep Virtual Compton process recently published by the HERMES collaboration in terms of Generalized Parton Distributions. We have fitted these new data in a largely model-independent fashion and the procedure results in numerical constraints on the $\\tilde{H}_\\mathrm{Im}$ Compton Form Factor. We present its $t-$ and $\\xi-$ dependencies. We also find improvement on the determination of two other Compton Form Factors, $H_\\mathrm{Re}$ and $H_\\mathrm{Im}$.
A validation of a ray-tracing tool used to generate bi-directional scattering
and daylighting technologies. Keywords: Daylighting; Solar Heat Gain; Complex fenestration systems; Bi in Solar Energy 98 (2013): 404-414 DOI: 10.1016/j.solener.2013.09.032 #12;DISCLAIMER This document, product, or process disclosed, or represents that its use would not infringe privately owned rights
acid bi-directionally modulates: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
stated in English as "A reservoir contains a liquid, called water, of mass 0.001 kg and heat capacity 4 VanLehn, Kurt 37 A Language for Bi-Directional Tree Transformations...
Bidirectional controlled teleportation by using 5-qubit states: A generalized view
Chitra Shukla; Anindita Banerjee; Anirban Pathak
2013-03-22T23:59:59.000Z
Recently bidirectional controlled perfect teleportation using 5-qubit states are reported in (Int. J. Theor. Phys. (2013) DOI 10.1007/s10773-013-1484-8 and ibid, (2013) DOI 10.1007/s10773-012-1208-5). In this paper we have shown that there exists a class of 5-qubit quantum states that can be used for bidirectional controlled teleportation. Two out of the three reported cases are the special cases of the proposed class of 5-qubit quantum states and one of them is not strictly a case of controlled bidirectional quantum teleportation. Further, we have shown that one can in principle, construct infinitely many 5-qubit quantum states for this purpose. We have also shown that the idea can be extended to bidirectional controlled probabilistic teleportation. Some potential applications of the proposed scheme and its modified versions are also discussed in relation with the implementation of quantum remote control and quantum cryptography.
Dryzek, Jerzy [Institute of Nuclear Physics PAN, ul. Radzikowskiego 152, 31-342 Kraków (Poland) [Institute of Nuclear Physics PAN, ul. Radzikowskiego 152, 31-342 Kraków (Poland); Institute of Physics, Opole University, ul. Oleska 48, 45-052 Opole (Poland); Siemek, Krzysztof [Institute of Nuclear Physics PAN, ul. Radzikowskiego 152, 31-342 Kraków (Poland)] [Institute of Nuclear Physics PAN, ul. Radzikowskiego 152, 31-342 Kraków (Poland)
2013-08-21T23:59:59.000Z
The spatial distribution of positrons emitted from radioactive isotopes into stacks or layered samples is a subject of the presented report. It was found that Monte Carlo (MC) simulations using GEANT4 code are not able to describe correctly the experimental data of the positron fractions in stacks. The mathematical model was proposed for calculations of the implantation profile or positron fractions in separated layers or foils being components of a stack. The model takes into account only two processes, i.e., the positron absorption and backscattering at interfaces. The mathematical formulas were applied in the computer program called LYS-1 (layers profile analysis). The theoretical predictions of the model were in the good agreement with the results of the MC simulations for the semi infinite sample. The experimental verifications of the model were performed on the symmetrical and non-symmetrical stacks of different foils. The good agreement between the experimental and calculated fractions of positrons in components of a stack was achieved. Also the experimental implantation profile obtained using the depth scanning of positron implantation technique is very well described by the theoretical profile obtained within the proposed model. The LYS-1 program allows us also to calculate the fraction of positrons which annihilate in the source, which can be useful in the positron spectroscopy.
Modeling scattered intensity from microspheres in evanescent field
Shah, Suhani Kiran
2008-10-10T23:59:59.000Z
of the total scattered light intensity on microsphere size accounts for the scattered intensity distribution in a polydisperse microsphere sample. Understanding this variation in the scattered light with microsphere size will allow improved characterization...
in Deep-Inelastic Scattering on the Deuteron A. Airapetian,16 N. Akopov,27 Z. Akopov,27 A. Andrus,15 E
On Benefits of Network Coding in Bidirected Networks and Hyper-networks
Li, Zongpeng
. It was shown that network coding helps increase the throughput and reduce the cost of data transmission to study the coding advantage in two types of parameterized networks, with richer modeling power. The firstOn Benefits of Network Coding in Bidirected Networks and Hyper-networks Xunrui Yin, Xin Wang, Jin
ON THE BIDIRECTIONALITY OF THE JWKB CONNECTION FORMULA AT A LINEAR TURNING POINT
Silverstone, Harris J.
ON THE BIDIRECTIONALITY OF THE JWKB CONNECTION FORMULA AT A LINEAR TURNING POINT Hujun SHENa1) connection formula is demonstrated by a simple numerical example constructed from a linear potential and a box. Keywords: JWKB; Connection formula; Borel sum; Asymptotic expansion; Tunneling; Jeffreys
Multiple Access and Two-way Channels with Energy Harvesting and Bi-directional
Yener, Aylin
Multiple Access and Two-way Channels with Energy Harvesting and Bi-directional Energy Cooperation@ee.psu.edu Abstract--This paper considers the multiple access and two- way channels with energy harvesting, and optimal policies were found using a two-dimensional water-filling algorithm. In this paper, the bi
A SingleQuery BiDirectional Probabilistic Roadmap Planner with Lazy Collision Checking
LaValle, Steven M.
1 A SingleQuery BiDirectional Probabilistic Roadmap Planner with Lazy Collision Checking Gildardo probabilistic roadmap (PRM) planner that is: singlequery --it does not precompute a roadmap, but uses the two the robot's free space by concurrently building a roadmap made of two trees rooted at the query
Reactive Power Operation Analysis of a Single-Phase EV/PHEV Bidirectional Battery Charger
Tolbert, Leon M.
of the electric grid by supplying ancillary services such as reactive power compensation, voltage regulation, charger, electric vehicle, EV, PHEV, reactive power, V2G. I. INTRODUCTION According to the internationalReactive Power Operation Analysis of a Single-Phase EV/PHEV Bidirectional Battery Charger Mithat C
Variable mode bi-directional and uni-directional computer communication system
Cornett, Frank N.; Jenkins, Philip N.; Bowman, Terrance L.; Placek, Joseph M.; Thorson, Gregory M.
2004-12-14T23:59:59.000Z
A variable communication systems comprising a plurality of transceivers and a control circuit connected to the transceivers to configure the transceivers to operate in a bi-directional mode and a uni-directional mode at different times using different transfer methods to transfer data.
Predictive Simulation of Bidirectional Glenn Shunt Using a Hybrid Blood Vessel Model
Leow, Wee Kheng
Predictive Simulation of Bidirectional Glenn Shunt Using a Hybrid Blood Vessel Model Hao Li1 to model the deformation of blood vessels. The hybrid blood vessel model consists of a reference Cosserat rod and a surface mesh. The reference Cosserat rod models the blood vessel's global bending
Texas at Austin. University of
Measuring Molecular Motor Forces In Vivo: Implications for Tug-of-War Models of Bidirectional, The University of Texas at Austin, Austin, Texas ABSTRACT Molecular motor proteins use the energy released from the force motors generate amounts to directly probing their function. We report on optical trapping
Bidirectional Seismic Behavior of Controlled Rocking Four-Legged Bridge Steel Truss Piers
Bruneau, Michel
Bidirectional Seismic Behavior of Controlled Rocking Four-Legged Bridge Steel Truss Piers Michael rocking bridge steel truss piers to three components of seismic excitation are presented in this paper. The controlled rocking approach for seismic protection allows a pier to uplift from its base, limiting the force
Consistency of MODIS surface bidirectional reflectance distribution function and albedo retrievals
Liang, Shunlin
as historical global albedos from advanced very high resolution radiometer (AVHRR) and Earth Radiation Budget albedos and the Clouds and Earth's Radiant Energy System (CERES) top-of-the-atmosphere albedos as well observations, and a high bias of 0.016 and a low bias of 0.034 compared to those of the latter albedos
Scattering Summary/Review Spring 2009 Compton Lecture Series
Scattering Summary/Review Spring 2009 Compton Lecture Series: From Quantum Mechanics to the String distributed range of impact parameters. This beam is scattered into a distribution of angles. The number of particles scattered into a given angular range depends on the shape of the potential hill. This is what
Examination of a PHEV Bi-Directional Charger System for V2G Reactive Power Compensation
Kisacikoglu, Mithat C [ORNL] [ORNL; Ozpineci, Burak [ORNL] [ORNL; Tolbert, Leon M [ORNL] [ORNL
2010-01-01T23:59:59.000Z
Plug-in hybrid electric vehicles (PHEVs) potentially have the capability to fulfill the energy storage needs of the electric grid by supplying ancillary services such as reactive power compensation. However, in order to allow bidirectional power transfer, the PHEV battery charger should be designed to manage such capability. While many different battery chargers have been available since the inception of the first electric vehicles (EVs), an on-board, conductive charger with bidirectional power transferring capability have recently drawn attention due to their inherent advantages in charging accessibility, ease of use and efficiency. In this study, a reactive power compensation case study using the inverter dc-link capacitor is given when a PHEV battery is under charging operation. Finally, the impact of providing these services on the batteries is also explained.
Tug-of-war as a cooperative mechanism for bidirectional cargo transport by molecular motors
Melanie J. I. Müller; Stefan Klumpp; Reinhard Lipowsky
2008-07-03T23:59:59.000Z
Intracellular transport is based on molecular motors that pull cargos along cytoskeletal filaments. One motor species always moves in one direction, e.g. conventional kinesin moves to the microtubule plus end, while cytoplasmic dynein moves to the microtubule minus end. However, many cellular cargos are observed to move bidirectionally, involving both plus-end and minus-end directed motors. The presumably simplest mechanism for such bidirectional transport is provided by a tug-of-war between the two motor species. This mechanism is studied theoretically using the load-dependent transport properties of individual motors as measured in single-molecule experiments. In contrast to previous expectations, such a tug-of-war is found to be highly cooperative and to exhibit seven different motility regimes depending on the precise values of the single motor parameters. The sensitivity of the transport process to small parameter changes can be used by the cell to regulate its cargo traffic.
Controlled bidirectional remote state preparation in noisy environment: A generalized view
Vishal Sharma; Chitra Shukla; Subhashish Banerjee; Anirban Pathak
2014-09-02T23:59:59.000Z
It is shown that a realistic, controlled bidirectional remote state preparation is possible using a large class of entangled quantum states having a particular structure. Existing protocols of probabilistic, deterministic and joint remote state preparation are generalized to obtain the corresponding protocols of controlled bidirectional remote state preparation (CBRSP). A general way of incorporating the effects of two well known noise processes, the amplitude-damping and phase-damping noise, on the probabilistic CBRSP process is studied in detail by considering that noise only affects the travel qubits of the quantum channel used for the probabilistic CBRSP process. Also indicated is how to account for the effect of these noise channels on deterministic and joint remote state CBRSP protocols.
Scattering of radiation in collisionless dusty plasmas
Tolias, P.; Ratynskaia, S. [Space and Plasma Physics, Royal Institute of Technology, Stockholm SE-100 44 (Sweden)
2013-04-15T23:59:59.000Z
Scattering of electromagnetic waves in collisionless dusty plasmas is studied in the framework of a multi-component kinetic model. The investigation focuses on the spectral distribution of the scattered radiation. Pronounced dust signatures are identified in the coherent spectrum due to scattering from the shielding cloud around the dust grains, dust acoustic waves, and dust-ion acoustic waves. The magnitude and shape of the scattered signal near these spectral regions are determined with the aid of analytical expressions and its dependence on the dust parameters is investigated. The use of radiation scattering as a potential diagnostic tool for dust detection is discussed.
Nuanmeesri, Sumitra; Meesad, Payung
2010-01-01T23:59:59.000Z
Genealogical information is the best histories resources for culture study and cultural heritage. The genealogical research generally presents family information and depict tree diagram. This paper presents Parent Bidirectional Breadth Algorithm (PBBA) to find consanguine relationship between two persons. In addition, the paper utilizes rules based system in order to identify consanguine relationship. The study reveals that PBBA is fast to solve the genealogical information search problem and the Rule Based Relationship provides more benefits in blood relationship identification.
Anirban Pathak
2014-11-24T23:59:59.000Z
Recently, Hassanpour and Houshmand have proposed a protocol of controlled deterministic secure quantum communication (Quant. Info. Process, DOI 10.1007/s11128-014-0866-z (2014)). The authors compared the efficiency of their protocol with that of two other existing protocols and claimed that their protocol is efficient. Here, we have shown that the efficiency of Hassanpour Houshmand (HH) protocol is not high, and there exist several approaches through which more efficient protocols for the same task can be designed. To establish this point, we have proposed an efficient protocol of controlled deterministic secure quantum communication which is based on permutation of particles (PoP) technique and is considerably efficient compared to HH protocol. We have also generalized this protocol into its bidirectional counterpart. Interestingly, bipartite entanglement (Bell state) is sufficient for the realization of the proposed protocols, but HH protocol and other existing protocols require at least tripartite entanglement. Further, we have shown that it is possible to construct a large number of efficient protocols of unidirectional and bidirectional controlled deterministic secure quantum communication by using various alternative approaches and different quantum states. These alternative protocols can be realized by modifying the existing protocols of quantum secure direct communication and deterministic secure quantum communication. We have also shown that it is possible to design completely orthogonal-state-based protocols for unidirectional and bidirectional controlled deterministic secure quantum communication.
On the Capacity of a Wireless Backhaul for the Distribution Level of the Smart Grid
Namboodiri, Vinod
, Advanced Metering Infrastructure (AMI), Communications, Smart Meter, Capacity. I. INTRODUCTION THE need1 On the Capacity of a Wireless Backhaul for the Distribution Level of the Smart Grid Babak Karimi distribution. The advanced metering infrastructure (AMI) is one such application scenario where bidirectional
Neutron scattering and models: Titanium
Smith, A.B.
1997-07-01T23:59:59.000Z
Differential neutron elastic-scattering cross sections of elemental titanium were measured from 4.5 {r_arrow} 10.0 MeV in incident energy increments of {approx} 0.5 MeV. At each energy the measurements were made at forty or more scattering angles distributed between {approx} 17 and 160{degree}. Concurrently, differential neutron inelastic-scattering cross sections were measured for observed excitations of 0.975 {+-} 0.034, 1.497 {+-} 0.033, 2.322 {+-} 0.058, 3.252 {+-} 0.043, 3.700 {+-} 0.093, 4.317 {+-} 0.075 and 4.795 {+-} 0.100 MeV. All of the observed inelastically-scattered neutron groups were composites of contributions from several isotopes and/or levels. The experimental results were used to develop energy-average optical, statistical and coupled-channels models.
Electromagnetic scattering and induction models for spheroidal geometries
Barrowes, Benjamin E., 1973-
2004-01-01T23:59:59.000Z
Electromagnetic scattering from a medium containing randomly distributed discrete dielectric spheroidal inclusions is studied. Also, the broadband magnetoquasistatic solution for the induced magnetic field from a conducting ...
System and method for bidirectional flow and controlling fluid flow in a conduit
Ortiz, M.G.
1999-03-23T23:59:59.000Z
A system for measuring bidirectional flow, including backflow, of fluid in a conduit is disclosed. The system utilizes a structural mechanism to create a pressure differential in the conduit. Pressure sensors are positioned upstream from the mechanism, at the mechanism, and downstream from the mechanism. Data from the pressure sensors are transmitted to a microprocessor or computer, and pressure differential detected between the pressure sensors is then used to calculate the backflow. Control signals may then be generated by the microprocessor or computer to shut off valves located in the conduit, upon the occurrence of backflow, or to control flow, total material dispersed, etc. in the conduit. 3 figs.
System and method for bidirectional flow and controlling fluid flow in a conduit
Ortiz, Marcos German (Idaho Falls, ID)
1999-01-01T23:59:59.000Z
A system for measuring bidirectional flow, including backflow, of fluid in a conduit. The system utilizes a structural mechanism to create a pressure differential in the conduit. Pressure sensors are positioned upstream from the mechanism, at the mechanism, and downstream from the mechanism. Data from the pressure sensors are transmitted to a microprocessor or computer, and pressure differential detected between the pressure sensors is then used to calculate the backflow. Control signals may then be generated by the microprocessor or computer to shut off valves located in the conduit, upon the occurrence of backflow, or to control flow, total material dispersed, etc. in the conduit.
Scattering apodizer for laser beams
Summers, M.A.; Hagen, W.F.; Boyd, R.D.
1984-01-01T23:59:59.000Z
A method is disclosed for apodizing a laser beam to smooth out the production of diffraction peaks due to optical discontinuities in the path of the laser beam, such method comprising introduction of a pattern of scattering elements for reducing the peak intensity in the region of such optical discontinuities, such pattern having smoothly tapering boundaries in which the distribution density of the scattering elements is tapered gradually to produce small gradients in the distribution density, such pattern of scattering elements being effective to reduce and smooth out the diffraction effects which would otherwise be produced. The apodizer pattern may be produced by selectively blasting a surface of a transparent member with fine abrasive particles to produce a multitude of minute pits. In one embodiment, a scattering apodizer pattern is employed to overcome diffraction patterns in a multiple element crystal array for harmonic conversion of a laser beam. The interstices and the supporting grid between the crystal elements are obscured by the gradually tapered apodizer pattern of scattering elements.
Scattering apodizer for laser beams
Summers, Mark A. (Livermore, CA); Hagen, Wilhelm F. (Livermore, CA); Boyd, Robert D. (Livermore, CA)
1985-01-01T23:59:59.000Z
A method is disclosed for apodizing a laser beam to smooth out the production of diffraction peaks due to optical discontinuities in the path of the laser beam, such method comprising introduction of a pattern of scattering elements for reducing the peak intensity in the region of such optical discontinuities, such pattern having smoothly tapering boundaries in which the distribution density of the scattering elements is tapered gradually to produce small gradients in the distribution density, such pattern of scattering elements being effective to reduce and smooth out the diffraction effects which would otherwise be produced. The apodizer pattern may be produced by selectively blasting a surface of a transparent member with fine abrasive particles to produce a multitude of minute pits. In one embodiment, a scattering apodizer pattern is employed to overcome diffraction patterns in a multiple element crystal array for harmonic conversion of a laser beam. The interstices and the supporting grid between the crystal elements are obscured by the gradually tapered apodizer pattern of scattering elements.
Virtual Compton Scattering off the nucleon
P. A. M. Guichon; M. Vanderhaeghen
1998-06-08T23:59:59.000Z
We review the recent developments of virtual Compton scattering. We focus on the kinematical regimes which look the most promising. The threshold regime gives access to the generalized polarizabilities of the proton. The hard scattering regime allows tests of perturbative QCD predictions and of the valence quark wave function. The Bjorken regime is closely related to deep inelastic scattering. It gives access to the off-forward parton distributions which generalize the ordinary parton distributions and may shed a new light on the spin problem. For each regime we discuss the experimental perspectives and the role of the Bethe-Heitler background.
Locke, D. R.; Chupas, P. J.; Chapman, K. W.; Pugmire, R. J.; Winans, R. E.; Univ. of Utah
2008-01-01T23:59:59.000Z
The compression behavior of a silicate-rich oil shale from the Green River formation in the pressure range 0.0-2.4 GPa was studied using in situ high pressure X-ray pair distribution function (PDF) measurements for the sample contained within a Paris-Edinburgh cell. The real-space local structural information in the PDF, G(r), was used to evaluate the compressibility of the oil shale. Specifically, the pressure-induced reduction in the medium- to long-range atom distances (6-20 {angstrom}) yielded an average sample compressibility corresponding to a bulk modulus of ca. 61-67 GPa. A structural model consisting of a three phase mixture of the principal crystalline oil shale components (quartz, albite and Illite) provided a good fit to the ambient pressure PDF data (R 30.7%). Indeed the features in the PDF beyond 6 {angstrom}, were similarly well fit by a single phase model of the highest symmetry, highly crystalline quartz component.
Simões, Marcelo Godoy
variations, the converter regulates this extra power flow from or to the energy storage element. Furthermore regulates the energy flow between the fuel cell generator, an energy storage device, and the load. Fig. 2 a three-winding transformer and bidirectional high-frequency switching bridges. Full H-bridges are shown
Tolbert, Leon M.
, electric vehicle, EV, PHEV, reactive power, V2G. I. NOMENCLATURE Vde (t) instantaneous dc link voltage, [VEffects of V2G Reactive Power Compensation on the Component Selection in an EV or PHEV Bidirectional Charger Mithat C. Kisacikoglu1 , Burak Ozpineci2 , and Leon M. Tolbert1 ,2 I Dept. of Electrical
of phenomena charac- terizing the solar transition region. Using simultaneously obtained SUMER obser- vations the wider frame-work of the upper solar atmosphere is still uncertain. These dynamic events were #12;rst counterparts to bi-directional jets were presented by Dere (1994), Moses & Cook (1994) and Teriaca, Madjarska
Second-order diffraction forces on an array of vertical cylinders in bichromatic bidirectional waves
Vazquez, J.H. [Lamar Univ., Beaumont, TX (United States). Dept. of Civil Engineering; Williams, A.N. [Univ. of Houston, TX (United States). Dept. of Civil and Environmental Engineering
1995-02-01T23:59:59.000Z
A complete second-order solution is presented for the hydrodynamic forces due to the action of bichromatic, bidirectional waves on an array of bottom-mounted, surface-piercing cylinders of arbitrary cross section in water of uniform finite depth. Based on the constant structural cross section, the first-order problem is solved utilizing a two-dimensional Green function approach, while an assisting radiation potential approach is used to obtain the hydrodynamic loads due to the second-order potential. Results are presented which illustrate the influence of wave directionality on the second-order sum and difference frequency hydrodynamic forces on a two-cylinder array. It is found that wave directionality may have a significant influence on the second-order hydrodynamic forces on these arrays and that the assumption of unidirectional waves does not always lead to conservative estimates of the second-order loading.
Propulsion system for a motor vehicle using a bidirectional energy converter
Tamor, Michael Alan (Toledo, OH); Gale, Allan Roy (Livonia, MI)
1999-01-01T23:59:59.000Z
A motor vehicle propulsion system includes an electrical energy source and a traction motor coupled to receive electrical energy from the electrical energy source. The system also has a first bus provided electrical energy by the electrical energy source and a second bus of relatively lower voltage than the first bus. In addition, the system includes an electrically-driven source of reaction gas for the electrical energy source, the source of reaction gas coupled to receive electrical energy from the first bus. Also, the system has an electrical storage device coupled to the second bus for storing electrical energy at the lower voltage. The system also includes a bidirectional energy converter coupled to convert electrical energy from the first bus to the second bus and from the second bus to the first bus.
Transversity Parton Distribution
Alexei Prokudin
2013-04-01T23:59:59.000Z
Transversity distribution is one of the three fundamental parton distributions that completely describe polarized spin 1/2 nucleon. Its chiral odd nature prevented for many years its experimental exploration, however presently we have obtained great deal of information about this distribution. This includes experimental data from Semi Inclusive Deep Inelastic Scattering, knowledge of scale dependence and phenomenological extractions. I will discuss main features of this distribution and indicate the future improvements of our knowledge.
Coulomb scattering in plasma revised
S. Gordienko; D. V. Fisher; J. Meyer-ter-Vehn
2003-05-13T23:59:59.000Z
A closed expression for the momentum evolution of a test particle in weakly-coupled plasma is derived, starting from quantum many particle theory. The particle scatters from charge fluctuations in the plasma rather than in a sequence of independent binary collisions. Contrary to general belief, Bohr's (rather than Bethe's) Coulomb logarithm is the relevant one in most plasma applications. A power-law tail in the distribution function is confirmed by molecular dynamics simulation.
Observation of cooperative Mie scattering from an ultracold atomic cloud
Bender, H.; Stehle, C.; Slama, S.; Zimmermann, C. [Physikalisches Institut, Eberhardt-Karls-Universitaet Tuebingen, D-72076 Tuebingen (Germany); Kaiser, R. [Institut Non Lineaire de Nice, CNRS, Universite de Nice Sophia-Antipolis, F-06560 Valbonne (France); Piovella, N. [Dipartimento di Fisica, Universita Degli Studi di Milano, Via Celoria 16, I-20133 Milano (Italy); Courteille, Ph. W. [Physikalisches Institut, Eberhardt-Karls-Universitaet Tuebingen, D-72076 Tuebingen (Germany); Institut Non Lineaire de Nice, CNRS, Universite de Nice Sophia-Antipolis, F-06560 Valbonne (France); Instituto de Fisica de Sao Carlos, Universidade de Sao Paulo, 13560-970 Sao Carlos, SP (Brazil)
2010-07-15T23:59:59.000Z
Scattering of light at a distribution of scatterers is an intrinsically cooperative process, which means that the scattering rate and the angular distribution of the scattered light are essentially governed by bulk properties of the distribution, such as its size, shape, and density, although local disorder and density fluctuations may have an important impact on the cooperativity. Via measurements of the radiation pressure force exerted by a far-detuned laser beam on a very small and dense cloud of ultracold atoms, we are able to identify the respective roles of superradiant acceleration of the scattering rate and of Mie scattering in the cooperative process. They lead, respectively, to a suppression or an enhancement of the radiation pressure force. We observe a maximum in the radiation pressure force as a function of the phase shift induced in the incident laser beam by the cloud's refractive index. The maximum marks the borderline of the validity of the Rayleigh-Debye-Gans approximation from a regime, where Mie scattering is more complex. Our observations thus help to clarify the intricate relationship between Rayleigh scattering of light at a coarse-grained ensemble of individual scatterers and Mie scattering at the bulk density distribution.
Cheng, Mingyu
Biochemical and mechanical signals enabling cardiac regeneration can be elucidated using in vitro tissue-engineering models. We hypothesized that insulin-like growth factor-I (IGF) and slow, bi-directional perfusion could ...
Stephen, James D.
1965-01-01T23:59:59.000Z
This report corrects an error discovered in the code used in the study "Fuel Cycle Analysis in a Thorium Fueled Reactor Using Bidirectional Fuel Movement," MIT-2073-1, MITNE-51. The results of the correction show considerable ...
Hadronic ?Z box corrections in Møller scattering
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Hall, Nathan L. [Adelaide U.; Blunden, Peter G. [Manitoba U.; Melnitchouk, Wally [JLAB; Thomas, Anthony W. [Adelaide U.; Young, Ross D. [Adelaide U.
2014-04-01T23:59:59.000Z
The possibility of measuring the parity-violating asymmetry in Moller scattering with sufficient accuracy to determine sin2?W to 0.1% offers a complementary path to the discovery of new physics to that followed at high energy colliders. We present a new calculation of the ?Z box contribution to parity-violating electron-proton scattering, which constitutes an important uncertainty in computing the background to this process. We show that while the ?Z correction grows rapidly with energy, it can be relatively well constrained by data from parity-violating inelastic scattering and parton distribution functions.
Circular polarization memory in polydisperse scattering media
Macdonald, Callum M; Meglinski, Igor
2015-01-01T23:59:59.000Z
We investigate the survival of circularly polarized light in random scattering media. The surprising persistence of this form of polarization has a known dependence on the size and refractive index of scattering particles, however a general description regarding polydisperse media is lacking. Through analysis of Mie theory, we present a means of calculating the magnitude of circular polarization memory in complex media, with total generality in the distribution of particle sizes and refractive indices. Quantification of this memory effect enables an alternate pathway towards recovering particle size distribution, based on measurements of diffusing circularly polarized light.
Heavy quarks in deeply virtual Compton scattering
Jens D. Noritzsch
2003-12-11T23:59:59.000Z
A detailed study of the heavy quark h=c,b,... contributions to deeply virtual Compton scattering is performed at both the amplitude and the cross section level, and their phenomenological relevance is discussed. For this purpose I calculate the lowest order off-forward photon-gluon scattering amplitude with a massive quark loop and the corresponding hard scattering coefficients. In a first numerical analysis these fixed order perturbation theory results are compared with the conventional intrinsic "massless" parton approach considering generalized parton distributions for the heavy quarks. The differences between these two prescriptions can be quite significant, especially at small skewedness where the massless approach largely overestimates the deeply virtual Compton scattering cross section.
A system for differential neutron scattering experiments in the energy range from 0.5 to 20 MeV
Danon, Yaron
A system for differential neutron scattering experiments in the energy range from 0.5 to 20 MeV F 2010 Accepted 15 April 2010 Available online 27 May 2010 Keywords: Scattering Neutron Benchmark dependent scattered neutron distributions. Scattering measurements were performed on carbon and molybdenum
Kahn, Joseph M.
Abstract A 16 mm3 autonomous solar-powered sensor node with bi- directional optical communication, a 2.6 mm2 SOI solar cell array, and a micromachined four-quadrant corner-cube retroreflector (CCR- idly deployed by unmanned aerial vehicles (UAV), tracking the movements of birds, small animals
Some Aspects of Deeply Virtual Compton Scattering
Elena Kuchina
2004-05-10T23:59:59.000Z
We consider different aspects of the virtual Compton amplitude in QCD on two examples: small-x physics accessible in the Regge regime and twist-3 approximation in the description of DVCS through the general parton distributions. Using this model, we give an estimate for the cross section of deeply virtual Compton scattering for the kinematics of CEBAF at Jefferson Lab.
E. Borie
2013-02-05T23:59:59.000Z
A recent proposal to measure the proton form factor by means of muon-proton scattering will use muons which are not ultrarelativistic (and also not nonrelativistic). The usual equations describing the scattering cross section use the approximation that the scattered lepton (usually an electron) is ultrarelativistic, with v/c approximately equal to 1. Here the cross section is calculated for all values of the energy. It agrees with the standard result in the appropriate limit.
Environment scattering in GADRAS.
Thoreson, Gregory G.; Mitchell, Dean James; Theisen, Lisa Anne; Harding, Lee T.
2013-09-01T23:59:59.000Z
Radiation transport calculations were performed to compute the angular tallies for scattered gamma-rays as a function of distance, height, and environment. Green's Functions were then used to encapsulate the results a reusable transformation function. The calculations represent the transport of photons throughout scattering surfaces that surround sources and detectors, such as the ground and walls. Utilization of these calculations in GADRAS (Gamma Detector Response and Analysis Software) enables accurate computation of environmental scattering for a variety of environments and source configurations. This capability, which agrees well with numerous experimental benchmark measurements, is now deployed with GADRAS Version 18.2 as the basis for the computation of scattered radiation.
Lujan Neutron Scattering Center
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
the inadvertent spread of Technetium 99 by employees and contractors at the Lujan Neutron Scattering Center August 27, 2012-The Laboratory is investigating the inadvertent...
Turner, Steven Richard
2006-12-26T23:59:59.000Z
A method and apparatus for measuring current, and particularly bi-directional current, in a field-effect transistor (FET) using drain-to-source voltage measurements. The drain-to-source voltage of the FET is measured and amplified. This signal is then compensated for variations in the temperature of the FET, which affects the impedance of the FET when it is switched on. The output is a signal representative of the direction of the flow of current through the field-effect transistor and the level of the current through the field-effect transistor. Preferably, the measurement only occurs when the FET is switched on.
Estimate of the scatter component in SPECT
Ivanovic, M.; Weber, D.A. [Univ. of California, Sacramento, CA (United States); Loncaric, S. [Univ. of Zagreb (Croatia)
1996-12-31T23:59:59.000Z
Analytical expressions that describe the dependence of slopes and amplitudes of the scatter distribution functions (SDF) on source depth and media density are used to estimate a scatter component in SPECT projection data. Since the ratio of detected scattered to total photons (S/T), SDF amplitude and slope depend strongly on line source length (SL) used to obtain SDFs, we compared estimated scattered components using SDFs, obtained for lengths of 2-21 cm. At 10 cm source depth, S/T changes from 0.19 to 0.36 when SL changes from 2 to 21 cm. Scatter amplitude`s dependence on source depth (d) in water was described by 6.38e{sup -0.186d} for a 2 cm and 16.15e{sup -0.129d} for a 21 cm SL. Slope was described by 0.292d{sup -0.601} for a cm SL and by 0.396d{sup -0.82} for a 21 cm SL. The estimated scatter components are compared with simulated SPECT projection data obtained with Monte Carlo modeling of six hot spheres placed in a cylindrical water filled phantom. The comparison of estimated with simulated total counts/projection shows very good agreement when approaching SDF for a point source (the % difference varied from 2 to 13% for 2 cm SL). Significant overestimate is seen when source length increases.
New methods for measuring spectral bi-directional transmission and reflection using digital cameras
Gayeski, Nicholas (Nicholas Thomas)
2007-01-01T23:59:59.000Z
Advanced fenestration systems are increasingly being used to distribute solar radiation purposefully in buildings. Distribution of visible light and near infrared radiation can be optimized to enhance daylighting and reduce ...
A Practical Framework for Sharing and Rendering Real-World Bidirectional
-world materials has been hindered by a lack of standards for sharing and interpreting measured data. This paper.We also present an advanced interpolation method to reduce measured data into these standard scattering off surfaces is critical to realism for computer graphics and physically-based rendering. While
Hurd, A.J.
1989-01-01T23:59:59.000Z
The realization that structures in Nature often can be described by Mandelbrot's ''fractals'' has led to a revolution in many areas of physics. The interaction of waves with fractal systems has, understandably, become intensely studied since scattering is the method of choice to probe delicate fractal structures such as chainlike particle aggregates. Not all of these waves are electromagnetic: neutron scattering, for example, is an important complementary tool to structural studies by x-ray and light scattering. Since the phenomenology of small-angle neutron scattering (SANS), as it is applied to fractal systems, is identical to that of small-angle x-ray scattering (SAXS), it falls within the scope of this Working Paper. 9 refs.
Quantum Electric Field Fluctuations and Potential Scattering
Huang, Haiyun
2015-01-01T23:59:59.000Z
Some physical effects of time averaged quantum electric field fluctuations are discussed. The one loop radiative correction to potential scattering are approximately derived from simple arguments which invoke vacuum electric field fluctuations. For both above barrier scattering and quantum tunneling, this effect increases the transmission probability. It is argued that the shape of the potential determines a sampling function for the time averaging of the quantum electric field operator. We also suggest that there is a nonperturbative enhancement of the transmission probability which can be inferred from the probability distribution for time averaged electric field fluctuations.
Janos Polonyi; Karima Zazoua
2012-03-11T23:59:59.000Z
The cross section of elastic electron-proton scattering taking place in an electron gas is calculated within the Closed Time Path method. It is found to be the sum of two terms, one being the expression in the vacuum except that it involves dressing due to the electron gas. The other term is due to the scattering particles-electron gas entanglement. This term dominates the usual one when the exchange energy is in the vicinity of the Fermi energy. Furthermore it makes the trajectories of the colliding particles more consistent and the collision more irreversible, rendering the scattering more classical in this regime.
Scattering Solar Thermal Concentrators
Broader source: Energy.gov [DOE]
"This fact sheet describes a scattering solar thermal concentrators project awarded under the DOE's 2012 SunShot Concentrating Solar Power R&D award program. The team, led by the Pennsylvania State University, is working to demonstrate a new, scattering-based approach to concentrating sunlight that aims to improve the overall performance and reliability of the collector field. The research team aims to show that scattering solar thermal collectors are capable of achieving optical performance equal to state-of-the-art parabolic trough systems, but with the added benefits of immunity to wind-load tracking error, more efficient land use, and utilization of stationary receivers."
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Compton Scattering of Picosecond Electron and CO2 beams T. Hirose (TMU) @BNL user meeting, Jan. 31, 2002 JapanUS cooperation in high energy physics (Supported by JSPS from 1998)...
Genov, Roman
and Roman Genov Abstract--Two low-noise bidirectional current acquisition cir- cuits for interfacing-capacitor transimpedance amplifier (TIA). The second design is a current conveyer (CC) with regulated-cascode current with electrochemical amperometric biosensor arrays are presented. The first design is a switched
Azimuthal asymmetry in lepton-proton scattering at high energies
Chay, J.; Ellis, S.D.; Stirling, W.J. (Department of Physics, FM-15, University of Washington, Seattle, Washington 98195 (United States))
1992-01-01T23:59:59.000Z
We consider the azimuthal angular dependence of the distribution of final-state hadrons in high-energy lepton-proton scattering. The distribution displays an azimuthal asymmetry due to both perturbative and nonperturbative effects. At the large momentum transfers attainable, for example, at the DESY {ital ep} collider HERA we expect the perturbative effects to dominate and constitute a clear test of QCD.
Nonlinear X-ray Compton Scattering
Fuchs, Matthias; Chen, Jian; Ghimire, Shambhu; Shwartz, Sharon; Kozina, Michael; Jiang, Mason; Henighan, Thomas; Bray, Crystal; Ndabashimiye, Georges; Bucksbaum, P H; Feng, Yiping; Herrmann, Sven; Carini, Gabriella; Pines, Jack; Hart, Philip; Kenney, Christopher; Guillet, Serge; Boutet, Sebastien; Williams, Garth; Messerschmidt, Marc; Seibert, Marvin; Moeller, Stefan; Hastings, Jerome B; Reis, David A
2015-01-01T23:59:59.000Z
X-ray scattering is a weak linear probe of matter. It is primarily sensitive to the position of electrons and their momentum distribution. Elastic X-ray scattering forms the basis of atomic structural determination while inelastic Compton scattering is often used as a spectroscopic probe of both single-particle excitations and collective modes. X-ray free-electron lasers (XFELs) are unique tools for studying matter on its natural time and length scales due to their bright and coherent ultrashort pulses. However, in the focus of an XFEL the assumption of a weak linear probe breaks down, and nonlinear light-matter interactions can become ubiquitous. The field can be sufficiently high that even non-resonant multiphoton interactions at hard X-rays wavelengths become relevant. Here we report the observation of one of the most fundamental nonlinear X-ray-matter interactions, the simultaneous Compton scattering of two identical photons producing a single photon at nearly twice the photon energy. We measure scattered...
Fracture Properties From Seismic Scattering
Burns, Daniel R.
2007-01-01T23:59:59.000Z
Fractures scatter seismic energy and this energy can be analyzed to provide information about fracture
Spin effects in deeply virtual Compton scattering
A. V. Belitsky; A. Kirchner; D. Müller
2001-06-21T23:59:59.000Z
We consider the azimuthal angle dependence in the cross section of the hard leptoproduction of a photon on a nucleon target. We show that this dependence allows to define observables that isolate the twist-two and twist-three sectors in the deeply virtual Compton scattering amplitude. All twist-two and twist-three Compton form factors can be extracted from measurements of the charge odd part of the polarized cross section and give access to all generalized parton distributions.
Deeply virtual Compton scattering off nuclei
Voutier, Eric
2009-01-01T23:59:59.000Z
Deeply virtual Compton scattering (DVCS) is the golden exclusive channel for the study of the partonic structure of hadrons, within the universal framework of generalized parton distributions (GPDs). This paper presents the aim and general ideas of the DVCS experimental program off nuclei at the Jefferson Laboratory. The benefits of the study of the coherent and incoherent channels to the understanding of the EMC (European Muon Collaboration) effect are discussed, along with the case of nuclear targets to access neutron GPDs.
None
2012-01-30T23:59:59.000Z
Solar ADEPT Project: PV inverters convert DC power generated by modules into usable AC power. IPC’s initial 30kW 94lb. PV inverter reduces the weight of comparable 30kW PV inverters by 90%—reducing the cost of materials, manufacturing, shipping, and installation. With ARPA-E support, new bi-directional silicon power switches will be developed, commercialized, and utilized in IPC’s next-generation PV inverter. With these components, IPC will produce 100kW inverters that weight less than 100lb., reducing the weight of conventional 3,000lb. 100kW inverters by more than 95%. The new power switches will cut IPC’s $/W manufacturing cost in half, as well as further reduce indirect shipping and installation costs.
Anisotropic Elastic Resonance Scattering model for the Neutron Transport equation
Mohamed Ouisloumen; Abderrafi M. Ougouag; Shadi Z. Ghrayeb
2014-11-24T23:59:59.000Z
The resonance scattering transfer cross-section has been reformulated to account for anisotropic scattering in the center-of-mass of the neutron-nucleus system. The main innovation over previous implementations is the relaxation of the ubiquitous assumption of isotropic scattering in the center-of-mass and the actual effective use of scattering angle distributions from evaluated nuclear data files in the computation of the angular moments of the resonant scattering kernels. The formulas for the high order anisotropic moments in the laboratory system are also derived. A multi-group numerical formulation is derived and implemented into a module incorporated within the NJOY nuclear data processing code. An ultra-fine energy mesh cross section library was generated using these new theoretical models and then was used for fuel assembly calculations with the PARAGON lattice physics code. The results obtained indicate a strong effect of this new model on reactivity, multi-group fluxes and isotopic inventory during depletion.
M. -Th. Huett; A. I. L'vov; A. I. Milstein; M. Schumacher
1999-05-13T23:59:59.000Z
The concept of Compton scattering by even-even nuclei from giant-resonance to nucleon-resonance energies and the status of experimental and theoretical researches in this field are outlined. Nuclear Compton scattering in the giant-resonance energy-region provides information on the dynamical properties of the in-medium mass of the nucleon. The electromagnetic polarizabilities of the nucleon in the nuclear medium can be extracted from nuclear Compton scattering data obtained in the quasi-deuteron energy-region. Recent results are presented for two-body effects due to the mesonic seagull amplitude and due to the excitation of nucleon internal degrees of freedom accompanied by meson exchanges. Due to these studies the in-medium electromagnetic polarizabilities are by now well understood, whereas the understanding of nuclear Compton scattering in the Delta-resonance range is only at the beginning. Phenomenological methods how to include retardation effects in the scattering amplitude are discussed and compared with model predictions.
Scattering and Attenuation of Seismic Waves in the Lithosphere / 1 ch11Text.doc 12/30/99 6:41 PM
Running title: Scattering and Attenuation Chapter 11. Scattering and Attenuation of Seismic Waves loss due to distributed heterogeneities. The most prominent evidence for the existence of small and scattering loss due to distributed heterogeneities. As a model of attenuation, we introduce an approach
Thermal Diffuse Scattering of Low-Energy Electrons from Xe
KESMODEL, LL; WETTE, FWD; Allen, Roland E.
1973-01-01T23:59:59.000Z
reciprocal lattice rods. The results are presented in the form of both contour curves and intensity profiles. Several interesting features are apparent, including (i) anisotropies about the reciprocal lattice rods, (ii) differences in intensity... at reciprocal lat- tice points, the TDS is distributed throughout all of reciprocal space. In the case of scattering from a surface, the Bragg scattering is concen- trated at "reciprocal lattice rods" associated with the two-dimensional reciprocal lattice...
Quaglioni, S; Navratil, P; Roth, R
2009-12-15T23:59:59.000Z
The exact treatment of nuclei starting from the constituent nucleons and the fundamental interactions among them has been a long-standing goal in nuclear physics. Above all nuclear scattering and reactions, which require the solution of the many-body quantum-mechanical problem in the continuum, represent an extraordinary theoretical as well as computational challenge for ab initio approaches.We present a new ab initio many-body approach which derives from the combination of the ab initio no-core shell model with the resonating-group method [4]. By complementing a microscopic cluster technique with the use of realistic interactions, and a microscopic and consistent description of the nucleon clusters, this approach is capable of describing simultaneously both bound and scattering states in light nuclei. We will discuss applications to neutron and proton scattering on sand light p-shell nuclei using realistic nucleon-nucleon potentials, and outline the progress toward the treatment of more complex reactions.
SU-E-I-07: An Improved Technique for Scatter Correction in PET
Lin, S; Wang, Y; Lue, K; Lin, H; Chuang, K [Chuang, National Tsing Hua University, Hsichu, Taiwan (China)
2014-06-01T23:59:59.000Z
Purpose: In positron emission tomography (PET), the single scatter simulation (SSS) algorithm is widely used for scatter estimation in clinical scans. However, bias usually occurs at the essential steps of scaling the computed SSS distribution to real scatter amounts by employing the scatter-only projection tail. The bias can be amplified when the scatter-only projection tail is too small, resulting in incorrect scatter correction. To this end, we propose a novel scatter calibration technique to accurately estimate the amount of scatter using pre-determined scatter fraction (SF) function instead of the employment of scatter-only tail information. Methods: As the SF depends on the radioactivity distribution and the attenuating material of the patient, an accurate theoretical relation cannot be devised. Instead, we constructed an empirical transformation function between SFs and average attenuation coefficients based on a serious of phantom studies with different sizes and materials. From the average attenuation coefficient, the predicted SFs were calculated using empirical transformation function. Hence, real scatter amount can be obtained by scaling the SSS distribution with the predicted SFs. The simulation was conducted using the SimSET. The Siemens Biograph™ 6 PET scanner was modeled in this study. The Software for Tomographic Image Reconstruction (STIR) was employed to estimate the scatter and reconstruct images. The EEC phantom was adopted to evaluate the performance of our proposed technique. Results: The scatter-corrected image of our method demonstrated improved image contrast over that of SSS. For our technique and SSS of the reconstructed images, the normalized standard deviation were 0.053 and 0.182, respectively; the root mean squared errors were 11.852 and 13.767, respectively. Conclusion: We have proposed an alternative method to calibrate SSS (C-SSS) to the absolute scatter amounts using SF. This method can avoid the bias caused by the insufficient tail information and therefore improve the accuracy of scatter estimation.
Manson, Joseph R.
Helium atom scattering from isolated CO molecules on copper(001) A. P. Graham, F. Hofmann, and J. P 1996 Angular distributions have been measured for helium atoms scattering from isolated CO molecules with difficulties. Helium atom scattering HAS , on the other hand, can, at least for simple systems, also detect
Manson, Joseph R.
Helium atom scattering from isolated CO molecules on copper(001) A. P. Graham, F. Hofmann, and J. P 1996! Angular distributions have been measured for helium atoms scattering from isolated CO molecules with difficulties. Helium atom scattering ~HAS!, on the other hand, can, at least for simple systems, also detect
What Does a Scattering Pattern Tell US?
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Scattering Space sample light image Image Space lens Angular Space Q 4p sin(q) l Fourier Transform Scattering Pattern Fourier Transform Phase Problem Scattering Pattern...
Neutron Scattering Tutorials | Neutron Science | ORNL
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Neutron Scattering Tutorials SHARE Neutron Scattering Tutorials The following lectures were presented at the 2011 and 2010 National School on Neutron & X-Ray Scattering. This...
Scattering for dummies? Tommy Angelini
is elastic: |k|=|k'| #12;Kinematic Scattering Large R, scattered wave looks like plane wave. #12;2 ( ) ( )I A#q q Kinematic Scattering Many scatterers, add up waves at R. All waves have kR and $t... factor outV Electrons ~1's Ã? 100's keV Okay, not really... we'll treat them the same... neutrons too #12;Kinematic
General introduction to Compton scattering
D. Drechsel
1996-07-12T23:59:59.000Z
Real and virtual Compton scattering has been and will be an important tool to study the structure of hadronic systems. We summarize the status of real Compton scattering and give an outlook at the new theoretical and experimental developments in the field of virtual Compton scattering.
Probing Nanoscale Surface Enhanced Raman Scattering Fluctuation...
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Nanoscale Surface Enhanced Raman Scattering Fluctuation Dynamics using Correalted AFM and Confocal Ultramicroscopy. Probing Nanoscale Surface Enhanced Raman Scattering Fluctuation...
Generalized parton distributions in nuclei
Vadim Guzey
2009-12-01T23:59:59.000Z
Generalized parton distributions (GPDs) of nuclei describe the distribution of quarks and gluons in nuclei probed in hard exclusive reactions, such as e.g. deeply virtual Compton scattering (DVCS). Nuclear GPDs and nuclear DVCS allow us to study new aspects of many traditional nuclear effects (nuclear shadowing, EMC effect, medium modifications of the bound nucleons) as well as to access novel nuclear effects. In my talk, I review recent theoretical progress in the area of nuclear GPDs.
Learning from the Scatter in Type Ia Supernovae
Scott Dodelson; Alberto Vallinotto
2005-11-02T23:59:59.000Z
Type Ia Supernovae are standard candles so their mean apparent magnitude has been exploited to learn about the redshift-distance relationship. Besides intrinsic scatter in this standard candle, additional source of scatter is caused by gravitational magnification by large scale structure. Here we probe the dependence of this dispersion on cosmological parameters and show that information about the amplitude of clustering, \\sigma_8, is contained in the scatter. In principle, it will be possible to constrain \\sigma_8 to within 5% with observations of 2000 Type Ia Supernovae. However, extracting this information requires subtlety as the distribution of magnifications is far from Gaussian. If one incorrectly assumes a Gaussian distribution, the estimate of the clustering amplitude will be biased three-\\sigma away from the true value.
Deeply Virtual Compton Scattering off the neutron
M. Mazouz; A. Camsonne; C. Muñoz Camacho; for the Jefferson Lab Hall A collaboration
2007-12-12T23:59:59.000Z
The present experiment exploits the interference between the Deeply Virtual Compton Scattering (DVCS) and the Bethe-Heitler processes to extract the imaginary part of DVCS amplitudes on the neutron and on the deuteron from the helicity-dependent D$({\\vec e},e'\\gamma)X$ cross section measured at $Q^2$=1.9 GeV$^2$ and $x_B$=0.36. We extract a linear combination of generalized parton distributions (GPDs) particularly sensitive to $E_q$, the least constrained GPD. A model dependent constraint on the contribution of the up and down quarks to the nucleon spin is deduced.
Elastic and diffractive scattering at D0
Edwards, Tamsin; /Manchester U.
2004-04-01T23:59:59.000Z
The first search for diffractively produced Z bosons in the muon decay channel is presented, using a data set collected by the D0 detector at the Fermilab Tevatron at {radical}s = 1.96 TeV between April and September 2003, corresponding to an integrated luminosity of approximately 110 pb{sup -1}. The first dN/d|t| distribution for proton-antiproton elastic scattering at this c.o.m. energy is also presented, using data collected by the D0 Forward Proton Detector between January and May 2002. The measured slope is reproduced by theoretical predictions.
A New Polyethylene Scattering Law Determined Using Inelastic Neutron Scattering
Lavelle, Christopher M [ORNL; Liu, C [Oak Ridge National Laboratory (ORNL); Stone, Matthew B [ORNL
2013-01-01T23:59:59.000Z
Monte Carlo neutron transport codes such as MCNP rely on accurate data for nuclear physics cross-sections to produce accurate results. At low energy, this takes the form of scattering laws based on the dynamic structure factor, S (Q, E). High density polyethylene (HDPE) is frequently employed as a neutron moderator at both high and low temperatures, however the only cross-sections available are for T =300 K, and the evaluation has not been updated in quite some time. In this paper we describe inelastic neutron scattering measurements on HDPE at 5 and 300 K which are used to improve the scattering law for HDPE. We describe the experimental methods, review some of the past HDPE scattering laws, and compare computations using these models to the measured S (Q, E). The total cross-section is compared to available data, and the treatment of the carbon secondary scatterer as a free gas is assessed. We also discuss the use of the measurement itself as a scattering law via the 1 phonon approximation. We show that a scattering law computed using a more detailed model for the Generalized Density of States (GDOS) compares more favorably to this experiment, suggesting that inelastic neutron scattering can play an important role in both the development and validation of new scattering laws for Monte Carlo work.
Using bi-directional communications in a market-based resource allocation system
Chassin, David P; Pratt, Robert G
2014-04-01T23:59:59.000Z
Disclosed herein are representative embodiments of methods, apparatus, and systems for distributing a resource (such as electricity) using a resource allocation system. In one exemplary embodiment, a plurality of requests for electricity are received from a plurality of end-use consumers. The requests indicate a requested quantity of electricity and a consumer-requested index value indicative of a maximum price a respective end-use consumer will pay for the requested quantity of electricity. A plurality of offers for supplying electricity are received from a plurality of resource suppliers. The offers indicate an offered quantity of electricity and a supplier-requested index value indicative of a minimum price for which a respective supplier will produce the offered quantity of electricity. A dispatched index value is computed at which electricity is to be supplied based at least in part on the consumer-requested index values and the supplier-requested index values.
O'Neill, S M
2010-01-01T23:59:59.000Z
We report on a series of three-dimensional magnetohydrodynamic simulations of active galactic nucleus (AGN) jet propagation in realistic models of magnetized galaxy clusters. We are primarily interested in the details of energy transfer between jets and the intracluster medium (ICM) to help clarify what role such flows could have in the reheating of cluster cores. Our simulated jets feature a range of intermittency behaviors, including intermittent jets that periodically switch on and off and one model jet that shuts down completely, naturally creating a relic plume. The ICM into which these jets propagate incorporates tangled magnetic field geometries and density substructure designed to mimic some likely features of real galaxy clusters. We find that our jets are characteristically at least 60% efficient at transferring thermal energy to the ICM. Irreversible heat energy is not uniformly distributed, however, instead residing preferentially in regions very near the jet/cocoon boundaries. While intermittency...
The Compton Effect--Compton Scattering and Gamma Ray Spectroscopy
Dai, Pengcheng
The Compton Effect-- Compton Scattering and Gamma Ray Spectroscopy by Dr. James E. Parks Department and procedures for measuring gamma-ray energy distributions, (7) to learn about photomultipliers the interactions of high energy, electromagnetic photon radiation with materials in general. Gamma rays are high
Electron, Photon, and Positron Scattering Dynamics of Complex Molecular Targets
Carey, Ralph
2012-07-16T23:59:59.000Z
from ground state Cl2 and Pt in the 1S and 3D states in the multichannel configuration-interaction (MCCI) approximation originally developed for photoionization for scattering up to 10 eV. Photoionization cross sections and angular distributions...
MILOU : a Monte-Carlo for Deeply Virtual Compton Scattering
E. Perez; L. Schoeffel; L. Favart
2004-11-30T23:59:59.000Z
In this note, we present a new generator for Deeply Virtual Compton Scattering processes. This generator is based on formalism of Generalized Partons Distributions evolved at Next Leading Order (NLO). In the following we give a brief description of this formalism and we explain the main features of the generator for the elastic reactions, as well as for proton dissociation.
Scattering Techniques and Geometries
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's PossibleRadiationImplementingnpitcheResearch Briefs TheSanket A.LittleFY13Scarboro girlsScattering
Timelike Compton Scattering off the Proton: beam and/or target spin asymmetries
Marie Boër; Michel Guidal
2014-12-05T23:59:59.000Z
We present a sample of results of our work to be published soon on Timelike Compton scattering off the proton, in the framework of the Generalized Parton Distributions formalism.
Timelike Compton Scattering off the Proton: beam and/or target spin asymmetries
Boër, Marie
2014-01-01T23:59:59.000Z
We present a sample of results of our work to be published soon on Timelike Compton scattering off the proton, in the framework of the Generalized Parton Distributions formalism.
Proton-proton multiplicity distributions at LHC and the Pomeron intercept
A. Capella; E. G. Ferreiro
2013-01-15T23:59:59.000Z
We compute the proton-proton multiplicity distributions at LHC energies in the framework of a multiple scattering model assuming a Poisson distribution for each inelastic collision. Multiple scattering is essential to broaden the multiplicity distribution. We obtain approximate KNO scaling for small pseudo-rapidity intervals ($|\\eta | < 0.5$) and sizable KNO scaling violations for larger ones, in agreement with experiment.
Weak Deeply Virtual Compton Scattering
A. Psaker; W. Melnitchouk; A. V. Radyushkin
2006-12-21T23:59:59.000Z
We extend the analysis of the deeply virtual Compton scattering process to the weak interaction sector in the generalized Bjorken limit. The virtual Compton scattering amplitudes for the weak neutral and charged currents are calculated at the leading twist within the framework of the nonlocal light-cone expansion via coordinate space QCD string operators. Using a simple model, we estimate cross sections for neutrino scattering off the nucleon, relevant for future high intensity neutrino beam facilities.
Weak Deeply Virtual Compton Scattering
Ales Psaker; Wolodymyr Melnitchouk; Anatoly Radyushkin
2007-03-01T23:59:59.000Z
We extend the analysis of the deeply virtual Compton scattering process to the weak interaction sector in the generalized Bjorken limit. The virtual Compton scattering amplitudes for the weak neutral and charged currents are calculated at the leading twist within the framework of the nonlocal light-cone expansion via coordinate space QCD string operators. Using a simple model, we estimate cross sections for neutrino scattering off the nucleon, relevant for future high intensity neutrino beam facilities.
Dynamical Outcomes of Planet-Planet Scattering
Sourav Chatterjee; Eric B. Ford; Soko Matsumura; Frederic A. Rasio
2008-05-15T23:59:59.000Z
Observations in the past decade have revealed extrasolar planets with a wide range of orbital semimajor axes and eccentricities. Based on the present understanding of planet formation via core accretion and oligarchic growth, we expect that giant planets often form in closely packed configurations. While the protoplanets are embedded in a protoplanetary gas disk, dissipation can prevent eccentricity growth and suppress instabilities from becoming manifest. However, once the disk dissipates, eccentricities can grow rapidly, leading to close encounters between planets. Strong planet--planet gravitational scattering could produce both high eccentricities and, after tidal circularization, very short-period planets, as observed in the exoplanet population. We present new results for this scenario based on extensive dynamical integrations of systems containing three giant planets, both with and without residual gas disks. We assign the initial planetary masses and orbits in a realistic manner following the core accretion model of planet formation. We show that, with realistic initial conditions, planet--planet scattering can reproduce quite well the observed eccentricity distribution. Our results also make testable predictions for the orbital inclinations of short-period giant planets formed via strong planet scattering followed by tidal circularization.
D. Choudhury; D. R. Phillips; A. Nogga
2006-11-09T23:59:59.000Z
We present first calculations for Compton scattering on $^3$He. The objective of the calculation is an extraction of the neutron polarizabilities.
Advances in total scattering analysis
Proffen, Thomas E [Los Alamos National Laboratory; Kim, Hyunjeong [Los Alamos National Laboratory
2008-01-01T23:59:59.000Z
In recent years the analysis of the total scattering pattern has become an invaluable tool to study disordered crystalline and nanocrystalline materials. Traditional crystallographic structure determination is based on Bragg intensities and yields the long range average atomic structure. By including diffuse scattering into the analysis, the local and medium range atomic structure can be unravelled. Here we give an overview of recent experimental advances, using X-rays as well as neutron scattering as well as current trends in modelling of total scattering data.
Compton and double Compton scattering processes at colliding electron-photon beams
A. N. Ilyichev; E. A. Kuraev; V. Bytev; Yu. P. Peresun'ko
2005-01-21T23:59:59.000Z
Radiative corrections (RC) to the Compton scattering cross section are calculated in the leading and next-to leading logarithmic approximation to the case of colliding high energy photon-electron beams. RC to the double Compton scattering cross section in the same experimental set-up are calculated in the leading logarithmic approximation. We consider the case when no pairs are created in the final state. We show that the differential cross section can be written in the form of the Drell-Yan process cross-section. Numerical values of the $K$-factor and the leading order distribution on the scattered electron energy fraction and scattering angle are presented.
Mean motion resonances from planet-planet scattering
Sean N. Raymond; Rory Barnes; Philip J. Armitage; Noel Gorelick
2008-09-19T23:59:59.000Z
Planet-planet scattering is the leading mechanism to explain the large eccentricities of the observed exoplanet population. However, scattering has not been considered important to the production of pairs of planets in mean motion resonances (MMRs). We present results from a large number of numerical simulations of dynamical instabilities in 3-planet systems. We show that MMRs arise naturally in about five percent of cases. The most common resonances we populate are the 2:1 and 3:1 MMRs, although a wide variety of MMRs can occur, including high-order MMRs (up to eleventh order). MMRs are generated preferentially in systems with uneven mass distributions: the smallest planet is typically ejected after a series of close encounters, leaving the remaining, more massive planets in resonance. The distribution of resonant planets is consistent with the phase-space density of resonant orbits, meaning that planets are randomly thrown into MMRs rather than being slowly pulled into them. It may be possible to distinguish between MMRs created by scattering vs. convergent migration in a gaseous disk by considering planetary mass ratios: resonant pairs of planets beyond ~1 AU with more massive outer planets are likely to have formed by scattering. In addition, scattering may be responsible for pairs of planets in high-order MMRs (3:1 and higher) that are not easily populated by migration. The frequency of MMRs from scattering is comparable to the expected survival rate of MMRs in turbulent disks. Thus, planet-planet scattering is likely to be a major contributor to the population of resonant planets.
Accardi, Alberto [JLAB; Owens, Jeff F. [Florida State U.
2013-07-01T23:59:59.000Z
Three new sets of next-to-leading order parton distribution functions (PDFs) are presented, determined by global fits to a wide variety of data for hard scattering processes. The analysis includes target mass and higher twist corrections needed for the description of deep-inelastic scattering data at large x and low Q^2, and nuclear corrections for deuterium targets. The PDF sets correspond to three different models for the nuclear effects, and provide a more realistic uncertainty range for the d quark PDF compared with previous fits. Applications to weak boson production at colliders are also discussed.
Kegel, Gunter H.R.; Egan, James J
2007-04-18T23:59:59.000Z
This project covers four principal areas of research: Elastic and inelastic neutron scattering studies in odd-A terbium, thulium and other highly deformed nuclei near A=160 with special regard to interband transitions and to the investigation of the direct-interaction versus the compound-nucleus excitation process in these nuclei. Examination of new, fast photomultiplier tubes suitable for use in a miniaturized neutron-time-of-flight spectrometer. Measurement of certain inelastic cross sections of 238U. Determination of the multiplicity of prompt fission gamma rays in even-A fissile actinides. Energies and mean lives of fission isomers produced by fast fission of even-Z, even-A actinides. Study of the mean life of 7Be in different host matrices and its possible astro-physical significance.
Elastic scattering of Beryllium isotopes near the Coulomb barrier
Di Pietro, A.; Figuera, P. [INFN-Laboratori Nazionali del Sud, Catania (Italy); Amorini, F.; Fisichella, M.; Lattuada, M.; Musumarra, A.; Pellegriti, M. G.; Randisi, G.; Rizzo, F.; Santonocito, D.; Scalia, G.; Scuderi, V.; Strano, E.; Torresi, D. [Dipartimento di Fisica ed Astronomia Universita di Catania, Catania (Italy); INFN-Laboratori Nazionali del Sud, Catania (Italy); Papa, M. [INFN-Sezione di Catania, Catania (Italy); Acosta, L.; Martel, I.; Perez-Bernal, F. [Departamento de Fisica Aplicada Universidad de Huelva, Huelva (Spain); Borge, M. J. G.; Tengblad, O. [Instituto de Estructura de la Materia CSIC, Madrid (Spain)
2011-10-28T23:59:59.000Z
In this contribution, results of experiments performed with the three Beryllium isotopes {sup 9,10,11}Be on a medium mass {sup 64}Zn target, at a center of mass energy of {approx_equal}1.4 the Coulomb barrier, will be discussed. Elastic scattering angular distributions have been measured for the {sup 9,10}Be reactions. In the {sup 11}Be case the quasielastic scattering angular distribution was obtained. In the halo nucleus case, the angular distribution exhibit a non-Fresnel-type pattern with a strong damping of the Coulomb-nuclear interference peak. Moreover, it is found that the total reaction cross-section for the halo nucleus induced collision is more than double the ones extracted in the collisions induced by the non-halo Beryllium isotopes. A large contribution to the total-reaction cross-section in the {sup 11}Be case could be attributed to transfer and/or break-up events.
randomly and equally likely a point in that interval), the uniform distribution ... Roughly speaking, this means that from any distribution we can create the uniform.
Infrared limit in external field scattering
Andrzej Herdegen
2012-05-17T23:59:59.000Z
Scattering of electrons/positrons by external classical electromagnetic wave packet is considered in infrared limit. In this limit the scattering operator exists and produces physical effects, although the scattering cross-section is trivial.
What Does a Scattering Pattern Tell US?
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Reciprocal Space Apurva Mehta 7 th X-ray Scattering School Scattering Physics Sample Space Scattering Space sample light image Image Space lens Can we create the image without a...
LIGHT SCATTERING STUDIES OF SILICA AEROGELS
Hunt, A.J.
2010-01-01T23:59:59.000Z
van de Hulst, H.C. , Light Scattering by Small Particles,A New Polarization-Modulated Light Scattering Instrument,"and interpretation of light scattering effects in aerogels.
Requirements, possible alternatives & international NEUTRON SCATTERING
Dimeo, Robert M.
Requirements, possible alternatives & international NEUTRON SCATTERING DETECTORS for Rob Dimeo NIST neutron scattering instruments are the most demanding require background low #12;#12;The Helium-3 Supply Crisis Alternative Techniques to Helium-3 based Detectors for Neutron Scattering Applications
Electron Scattering with Polarized Targets at TESLA
The TESLA-N Study Group; :; M. Anselmino; E. C. Aschenauer; S. Belostotski; W. Bialowons; J. Bluemlein; V. Braun; R. Brinkmann; M. Dueren; F. Ellinghaus; K. Goeke; St. Goertz; A. Gute; J. Harmsen; D. v. Harrach; R. Jakob; E. M. Kabuss; R. Kaiser; V. Korotkov; P. Kroll; E. Leader; B. Lehmann-Dronke; L. Mankiewicz; A. Meier; W. Meyer; N. Meyners; D. Mueller; P. J. Mulders; W. -D. Nowak; L. Niedermeier; K. Oganessyan; P. V. Pobilitsa; M. V. Polyakov; G. Reicherz; K. Rith; D. Ryckbosch; A. Schaefer; K. Sinram; G. v. d. Steenhoven; E. Steffens; J. Steijger; C. Weiss
2000-11-24T23:59:59.000Z
Measurements of polarized electron-nucleon scattering can be realized at the TESLA linear collider facility with projected luminosities that are about two orders of magnitude higher than those expected of other experiments at comparable energies. Longitudinally polarized electrons, accelerated as a small fraction of the total current in the e+ arm of TESLA, can be directed onto a solid state target that may be either longitudinally or transversely polarized. A large variety of polarized parton distribution and fragmentation functions can be determined with unprecedented accuracy, many of them for the first time. A main goal of the experiment is the precise measurement of the x- and Q^2-dependence of the experimentally totally unknown quark transversity distributions that will complete the information on the nucleon's quark spin structure as relevant for high energy processes. Comparing their Q^2-evolution to that of the corresponding helicity distributions constitutes an important precision test of the predictive power of QCD in the spin sector. Measuring transversity distributions and tensor charges allows access to the hitherto unmeasured chirally odd operators in QCD which are of great importance to understand the role of chiral symmetry. The possibilities of using unpolarized targets and of experiments with a real photon beam turn TESLA-N into a versatile next-generation facility at the intersection of particle and nuclear physics.
Elastic meson production and Compton scattering
M. Diehl
2001-09-13T23:59:59.000Z
I discuss recent progress in the theory of exclusive meson production and Compton scattering, focusing on hard-scattering factorization and on the dipole formalism.
Real Compton Scattering from the Proton
Alan M. Nathan
1999-08-31T23:59:59.000Z
Real Compton Scattering on the proton in the hard scattering regime is investigated. Recent theoretical developments are reviewed. Plans for new experimental studies at Jefferson Laboratory are presented.
What Does a Scattering Pattern Tell US?
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
* Good when there is need to remove inelastic scattering signal: e.g., fluorescence, compton scattering - Energy Insensitive detectors: E resol > 1000 eV * photomultiplier,...
Search for: "neutron scattering" | DOE PAGES
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neutron scattering" Find + Advanced Search Advanced Search All Fields: "neutron scattering" Title: Full Text: Bibliographic Data: Creator Author: Name Name ORCID Search...
11th LANSCE School on Neutron Scattering
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
11th LANSCE School on Neutron Scattering LANSCE 11th LANSCE School on Neutron Scattering Home Abstract Lecturers Lecturer Abstracts Hands-On Experiments Free Day About the...
Dipanwita Ghanti; Debashish Chowdhury
2015-01-09T23:59:59.000Z
A microtubule (MT) is a hollow tube of approximately 25 nm diameter. The two ends of the tube are dissimilar and are designated as `plus' and `minus' ends. Motivated by the collective push and pull exerted by a bundle of MTs during chromosome segregation in a living cell, we have developed here a much simplified theoretical model of a bundle of parallel dynamic MTs. The plus-end of all the MTs in the bundle are permanently attached to a movable `wall' by a device whose detailed structure is not treated explicitly in our model. The only requirement is that the device allows polymerization and depolymerization of each MT at the plus-end. In spite of the absence of external force and direct lateral interactions between the MTs, the group of polymerizing MTs attached to the wall create a load force against the group of depolymerizing MTs and vice-versa; the load against a group is shared equally by the members of that group. Such indirect interactions among the MTs gives rise to the rich variety of possible states of collective dynamics that we have identified by computer simulations of the model in different parameter regimes. The bi-directional motion of the cargo, caused by the load-dependence of the polymerization kinetics, is a "proof-of-principle" that the bi-directional motion of chromosomes before cell division does not necessarily need active participation of motor proteins.
The scattering of muons in low Z materials
D. Attwood; P. Bell; S. Bull; T. McMahon; J. Wilson; R. Fernow; P. Gruber; A. Jamdagni; K. Long; E. McKigney; P. Savage; M. Curtis-Rouse; T. R. Edgecock; M. Ellis; J. Lidbury; W. J. Murray; P. Norton; K. Peach; K. Ishida; Y. Matsuda; K. Nagamine; S. Nakamura; G. M. Marshall; S. Benveniste; D. Cline; Y. Fukui; K. Lee; Y. Pischalnikov; S. Holmes; A. Bogacz
2005-12-03T23:59:59.000Z
This paper presents the measurement of the scattering of 172 MeV/c muons in assorted materials, including liquid hydrogen, motivated by the need to understand ionization cooling for muon acceleration. Data are compared with predictions from the Geant 4 simulation code and this simulation is used to deconvolute detector effects. The scattering distributions obtained are compared with the Moliere theory of multiple scattering and, in the case of liquid hydrogen, with ELMS. With the exception of ELMS, none of the models are found to provide a good description of the data. The results suggest that ionization cooling will work better than would be predicted by Geant 4.7.0p01.
The scattering of muons in low Z materials
MuScat Collaboration; D. Attwood; P. Bell; S. Bull; T. McMahon; J. Wilson; R. Fernow; P. Gruber; A. Jamdagni; K. Long; E. McKigney; P. Savage; M. Curtis-Rouse; T. R. Edgecock; M. Ellis; J. Lidbury; W. J. Murray; P. Norton; K. Peach; K. Ishida; Y. Matsuda; K. Nagamine; S. Nakamura; G. M. Marshall; S. Benveniste; D. Cline; Y. Fukui; K. Lee; Y. Pischalnikov; S. Holmes; A. Bogacz
2005-12-02T23:59:59.000Z
This paper presents the measurement of the scattering of 172 MeV/c muons in assorted materials, including liquid hydrogen, motivated by the need to understand ionisation cooling for muon acceleration. Data are compared with predictions from the Geant 4 simulation code and this simulation is used to deconvolute detector effects. The scattering distributions obtained are compared with the Moliere theory of multiple scattering and, in the case of liquid hydrogen, with ELMS. With the exception of ELMS, none of the models are found to provide a good description of the data. The results suggest that ionisation cooling will work better than would be predicted by Geant 4.7.0p01.
Small angle neutron scattering from high impact polystyrene
Pringle, O.A.
1981-01-01T23:59:59.000Z
High impact polystyrene (HIPS) is a toughened plastic composed of a polystyrene matrix containing a few percent rubber in the form of dispersed 0.1 to 10 micron diameter rubber particles. Some commercial formulations of HIPS include the addition of a few percent mineral oil, which improves the toughness of the plastic. Little is known about the mechanism by which the mineral oil helps toughen the plastic. It is hypothesized that the oil is distributed only in the rubber particles, but whether this hypothesis is correct was not known prior to this work. The size of the rubber particles in HIPS and their neutron scattering length density contrast with the polystyrene matrix cause HIPS samples to scatter neutrons at small angles. The variation of this small angle neutron scattering (SANS) signal with mineral oil content has been used to determine the location of the oil in HIPS. The SANS spectrometer at the University of Missouri Research Reactor Facility (MURR) was used to study plastic samples similar in composition to commercial HIPS. The MURR SANS spectrometer is used to study the small angle scattering of a vertical beam of 4.75 A neutrons from solid and liquid samples. The scattered neutrons are detected in a 54 x 60 cm/sup 2/ position sensitive detector designed and built at MURR. A series of plastic samples of varying rubber and oil content and different rubber domain sizes and shapes were examined on the MURR SANS spectrometer. Analysis of the scattering patterns showed that the mineral oil is about eight to ten times more likely to be found in the rubber particles than in the polystyrene matrix. This result confirmed the hypothesis that the mineral oil is distributed primarily in the rubber particles.
Scattering theory with path integrals
Rosenfelder, R. [Particle Theory Group, Paul Scherrer Institute, CH-5232 Villigen PSI (Switzerland)] [Particle Theory Group, Paul Scherrer Institute, CH-5232 Villigen PSI (Switzerland)
2014-03-15T23:59:59.000Z
Starting from well-known expressions for the T-matrix and its derivative in standard nonrelativistic potential scattering, I rederive recent path-integral formulations due to Efimov and Barbashov et al. Some new relations follow immediately.
Aspects of Nucleon Compton Scattering
V. Bernard; N. Kaiser; Ulf-G. Meißner; A. Schmidt
1993-11-24T23:59:59.000Z
We consider the spin-averaged nucleon forward Compton scattering amplitude in heavy baryon chiral perturbation theory including all terms to order ${\\cal O} (q^4)$. The chiral prediction for the spin-averaged forward Compton scattering amplitude is in good agreement with the data for photon energies $\\omega \\le 110$ MeV. We also evaluate the nucleon electric and magnetic Compton polarizabilities to this order and discuss the uncertainties of the various counter terms entering the chiral expansion of these quantities.
Distribution of particles which produces a desired radiation pattern
A. G. Ramm
2005-07-01T23:59:59.000Z
A method is given for calculation of a distribution of small particles, embedded in a medium, so that the resulting medium would have a desired radiation pattern for the plane wave scattering by this medium.
Nonlinear Thomson scattering of an ultrashort laser pulse
Golovinski, P. A., E-mail: golovinski@bk.ru; Mikhin, E. A. [Voronezh State Architectural-Building University (Russian Federation)
2011-10-15T23:59:59.000Z
The nonlinear scattering of an ultrashort laser pulse by free electrons is considered. The pulse is described in the 'Mexican hat' wavelet basis. The equation of motion for a charged particle in the field of a plane electromagnetic wave has an exact solution allowing, together with the instant spectrum approximation, the calculation of the intensity of nonlinear Thomson scattering for a high-intensity laser pulse. The spectral distribution of scattered radiation for the entire pulse duration is found by integrating with respect to time. The maximum of the emission spectrum of a free electron calculated in 10{sup 19}-10{sup 21} W/cm{sup 2} fields lies in the UV spectral region between 3 and 12 eV. A part of the continuous spectrum achieves high photon energies. One percent of the scattered energy for the field intensity 10{sup 20} W/cm{sup 2} is concentrated in the range h{omega} > 2.7 Multiplication-Sign 10{sup 2} eV, for a field intensity of 10{sup 21} W/cm{sup 2} in the range h{Omega} > 7.9 Multiplication-Sign 10{sup 2} eV, and for an intensity of 10{sup 22} W/cm{sup 2} in the range h{Omega} > 2.45 Multiplication-Sign 10{sup 5} eV. These results allow us to estimate nonlinear scattering as a source of hard X-rays.
Light and Color in Nature -Scattering Effects -
Assarsson, Ulf
1 Seminar WS 2003/04 Light and Color in Nature - Scattering Effects - Marcus Magnor WS03/04: Light and Color in Nature Scattering Overview · Last Lecture Interference · Today Light scattering: water rendering #12;2 WS03/04: Light and Color in Nature Scattering List of Topics · Rainbow Stephan
RisR1125(EN) Neutron Scattering
RisøR1125(EN) Neutron Scattering Studies of Modulated Magnetic Structures Steen Aagaard Sørensen investigations of the magnetic systems DyFe4Al8 and MnSi by neutron scattering and in the former case also by X and the correlations between the scattering entities of the sample. The theoretical framework of neutron scattering
Bidirectional coherent classical communication
Aram W. Harrow; Debbie W. Leung
2005-05-12T23:59:59.000Z
A unitary interaction coupling two parties enables quantum communication in both the forward and backward directions. Each communication capacity can be thought of as a tradeoff between the achievable rates of specific types of forward and backward communication. Our first result shows that for any bipartite unitary gate, coherent classical communication is no more difficult than classical communication -- they have the same achievable rate regions. Previously this result was known only for the unidirectional capacities (i.e., the boundaries of the tradeoff). We then relate the tradeoff curve for two-way coherent communication to the tradeoff for two-way quantum communication and the tradeoff for coherent communiation in one direction and quantum communication in the other.
Stimulated Brillouin scattering in solid aerosols
Chitanvis, S.M.
1988-08-01T23:59:59.000Z
We estimate the differential scattering cross-section due to SBS in a glass bead which is much larger than the wavelength of a high energy laser beam which irradiates it. We consider three possible scenarios: neither the incident nor the Stokes wavelength is on a Mie resonance; only the Stokes wavelength is on resonance; and the incident wavelength and the Stokes wavelength are on a Mie resonance. For the first two cases, we find that the SBS scattering cross-section is extremely small compared to the geometric/Mie cross-section. It follows as a corollary that SBS in a glass bead will be insufficient to shatter it in these two cases. In the last case, it is quite possible that due to the buildup of high fields on-resonance within the spherical bead, the bead might be shattered. The chance of such an event occurring in a polydisperse distribution of spherical beads is generally not expected to be very high. 3 figs.
Unitary constraints on Deeply Virtual Compton Scattering
J.M. Laget
2007-11-01T23:59:59.000Z
At moderately low momentum transfer ($-t$ up to 1 GeV$^2$) the coupling to the vector meson production channels gives the dominant contribution to real Compton and deeply virtual Compton scattering (DVCS). Starting from a Regge Pole approach that successfully describes vector meson production, the singular part of the corresponding box diagrams (where the intermediate vector meson-baryon pair propagates on-shell) is evaluated without any further assumptions (unitarity). Such a treatment explains not only the unexpectedly large DVCS unpolarized cross section that has been recently measured at Jefferson Laboratory (JLab), but also all the beam spin and charge asymmetries that has been measured at JLab and Hermes, without explicit need of Generalized Parton Distributions (GPD). The issue of the relationship between the two approaches is addressed.
Radiation damage studies using small-angle neutron scattering
Albertini, G.; Rustichelli, F. [INFM, Ancona (Italy); Carsughi, F. [INFM, Ancona (Italy). Ist. di Scienze Fisiche; [KFA, Juelich (Germany). Inst. fuer Festkoerperforschung; Coppola, R. [ENEA-Casaccia, Roma (Italy); Stefanon, M. [ENEA, Bologna (Italy)
1996-12-31T23:59:59.000Z
This contribution reviews a number of small-angle neutron scattering (SANS) studies of irradiated metals and steels of relevance to fission and fusion technology. Information obtainable by SANS measurements is recalled with special reference to the determination of the size distribution function of the microstructural inhomogeneities. The selected examples concern studies of the main kinds of radiation defects: voids, precipitates, He-bubbles. Some recent results obtained on structural materials for the first-wall of fusion reactors are also presented.
Integrated, Automated Distributed Generation Technologies Demonstration
Jensen, Kevin
2014-09-30T23:59:59.000Z
The purpose of the NETL Project was to develop a diverse combination of distributed renewable generation technologies and controls and demonstrate how the renewable generation could help manage substation peak demand at the ATK Promontory plant site. The Promontory plant site is located in the northwestern Utah desert approximately 25 miles west of Brigham City, Utah. The plant encompasses 20,000 acres and has over 500 buildings. The ATK Promontory plant primarily manufactures solid propellant rocket motors for both commercial and government launch systems. The original project objectives focused on distributed generation; a 100 kW (kilowatt) wind turbine, a 100 kW new technology waste heat generation unit, a 500 kW energy storage system, and an intelligent system-wide automation system to monitor and control the renewable energy devices then release the stored energy during the peak demand time. The original goal was to reduce peak demand from the electrical utility company, Rocky Mountain Power (RMP), by 3.4%. For a period of time we also sought to integrate our energy storage requirements with a flywheel storage system (500 kW) proposed for the Promontory/RMP Substation. Ultimately the flywheel storage system could not meet our project timetable, so the storage requirement was switched to a battery storage system (300 kW.) A secondary objective was to design/install a bi-directional customer/utility gateway application for real-time visibility and communications between RMP, and ATK. This objective was not achieved because of technical issues with RMP, ATK Information Technology Department’s stringent requirements based on being a rocket motor manufacturing facility, and budget constraints. Of the original objectives, the following were achieved: • Installation of a 100 kW wind turbine. • Installation of a 300 kW battery storage system. • Integrated control system installed to offset electrical demand by releasing stored energy from renewable sources during peak hours of the day. Control system also monitors the wind turbine and battery storage system health, power output, and issues critical alarms. Of the original objectives, the following were not achieved: • 100 kW new technology waste heat generation unit. • Bi-directional customer/utility gateway for real time visibility and communications between RMP and ATK. • 3.4% reduction in peak demand. 1.7% reduction in peak demand was realized instead.
Scattering of magnetosonic waves in a relativistic and an-isotropic magnetised plasma
Joachim Moortgat; Jan Kuijpers
2006-02-14T23:59:59.000Z
Gravitational waves (GW) propagating through a magnetised plasma excite low-frequency magnetohydrodynamic (MHD) waves. In this paper we investigate whether these waves can produce observable radio emission at higher frequencies by scattering on an an-isotropic intrinsically relativistic distribution of electrons and positrons in the force-free wind surrounding a double neutron star binary merger. The relativistic particle distribution is assumed to be strictly along the magnetic field lines, while the magneto-plasma streams out at a relativistic speed from the neutron stars. In the case of Compton scattering of an incident MHD wave transverse to the magnetic field, we find that the probability of scattering to both a transverse x-mode and a quasi-transverse Langmuir-o mode is suppressed when the scattered frequency is below the local relativistic gyro-frequency, i.e. when the magnetic field is very strong.
Antognini, Joseph M O
2015-01-01T23:59:59.000Z
Dynamical scattering of binaries and triple systems of stars, planets, and compact objects may produce highly inclined triple systems subject to Kozai-Lidov (KL) oscillations, potentially leading to collisions, mergers, Type Ia supernovae, and other phenomena. We present the results of more than 400 million gravitational scattering experiments of binary-binary, triple-single, and triple-binary scattering. We compute the cross sections for all possible outcomes and explore their dependencies on incoming velocity, mass, semi-major axis, and eccentricity, including analytic fits and discussion of the velocity dependence. For the production of new triple systems by scattering we find that compact triples are preferred, with ratios of outer to inner semi-major axes of ~few--100, flat or quasi-thermal eccentricity distributions, and flat distributions in cosine of the mutual inclination. Dynamically formed triples are thus subject to strong KL oscillations, the "eccentric Kozai mechanism," and non-secular effects. ...
Mechanical property scatter in CFCCs
Steen, M.; Filiou, C.
2000-01-01T23:59:59.000Z
The tensile response of continuous fiber reinforced ceramic matrix composites (CFCCs) is not expected to show the large variation in strength properties commonly observed for monolithic ceramics. Results of recent investigations on a number of two-dimensional reinforced CFCCs have nevertheless revealed a considerable scatter in the initial elastic modulus, in the first matrix cracking stress and in the failure stress. One school of thought considers that the observed variability is caused by experimental factors. Elaborate testing programs have been set up to clarify the origins of this scatter by investigation of the effects of control mode, loading rate, specimen shape, etc. Another school explains the scatter by the presence of (axial) residual stresses in the fibers and in the matrix. Although plausible, this hypothesis is difficult to verify because experimental determination of the residual stress state in CFCCs is not straightforward. In addition, with the available methods it is impractical to determine the residual stresses in every test specimen. This approach is indeed required for establishing the relationship between the magnitude of the residual stresses and the experimentally observed scatter. At IAM a method has been developed and validated which allows to quantify the axial residual stress state in individual CFCC specimens by subjecting them to intermittent unloading-reloading cycles. The method as well as the derived relationship between residual stress state and scatter in mechanical response will be presented.
Microscopic Description of Deeply Virtual Compton Scattering off Spin-0 Nuclei
S. Liuti; S. K. Taneja
2005-05-13T23:59:59.000Z
We evaluate within a microscopic calculation the contributions of both coherent and incoherent deeply virtual Compton scattering from a spin-0 nucleus. The coherent contribution is obtained when the target nucleus recoils as a whole, whereas for incoherent scattering break-up configurations for the final nucleus into a an outgoing nucleon and an $A-1$ system are considered. The two processes encode different characteristics of generalized parton distributions.
Francine Luppé; Jean-Marc Conoir; Andrew N. Norris
2011-10-06T23:59:59.000Z
The dispersion relation is derived for the coherent waves in fluid or elastic media supporting viscous and thermal effects and containing randomly distributed spherical scatterers. The formula obtained is the generalization of Lloyd and Berry's [Proc. Phys. Soc. Lond. 91, 678-688, 1067], the latter being limited to fluid host media, and it is the three-dimensional counterpart of that derived by Conoir and Norris [Wave Motion 47, 183-197, 2010] for cylindrical scatterers in an elastic host medium.
Scattering of {sup 8}He on {sup 208}Pb at 22 MeV
Marquinez-Duran, G.; Sanchez-Benitez, A. M.; Martel, I.; Berjillos, R.; Duenas, J. A.; Parkar, V. V. [Depto. de Fisica Aplicada, Universidad de Huelva, 21071 Huelva (Spain); Acosta, L. [Depto. de Fisica Aplicada, Universidad de Huelva, 21071 Huelva, Spain and Laboratori Nazionali del Sud, INFN, Via Santa Sofia 62, 95123, Catania (Italy); Rusek, K. [Heavy Ion Laboratory, University of Warsaw (Poland); Alvarez, M. A. G.; Gomez-Camacho, J. [Centro Nacional de Aceleradores, 41092, Sevilla, Spain and Depto. de Fisica Atomica, Molecular y Nuclear, Universidad de Sevilla, 41080 Sevilla (Spain); Borge, M. J. G.; Cruz, C.; Cubero, M.; Pesudo, V.; Tengblad, O. [Instituto de Estructura de la Materia, CSIC, 28006 Madrid (Spain); Chbihi, A. [GANIL, CEA and IN2P3-CNRS, B.P. 5027, 14076 Caen cedex (France); Fernandez-Garcia, J. P.; Moro, A. M. [Depto. de Fisica Atomica, Molecular y Nuclear, Universidad de Sevilla, 41080 Sevilla (Spain); Fernandez-Martinez, B.; Labrador, J. A. [Centro Nacional de Aceleradores, 41092, Sevilla (Spain); and others
2013-06-10T23:59:59.000Z
The skin nucleus {sup 8}He is investigated by measuring the angular distribution of the elasticly scattered {sup 8}He and the {sup 6,4}He fragments produced in the collision with a {sup 208}Pb target at 22 MeV, just above the Coulomb barrier. The experiment was carried out at SPIRAL/GANIL in 2010. Here we present preliminary results for the elastic scattering.
Woodley, Christa M.; Wagner, Katie A.; Bryson, Amanda J.
2012-11-09T23:59:59.000Z
The purpose of this report is to assess the performance of bi-directional knotless tissue-closure devices for use in tagging juvenile salmon. This study is part of an ongoing effort at Pacific Northwest National Laboratory (PNNL) to reduce unwanted effects of tags and tagging procedures on the survival and behavior of juvenile salmonids, by assessing and refining suturing techniques, suture materials, and tag burdens. The objective of this study was to compare the performance of the knotless (barbed) suture, using three different suture patterns (treatments: 6-point, Wide “N”, Wide “N” Knot), to the current method of suturing (MonocrylTM monofilament, discontinuous sutures with a 2×2×2×2 knot) used in monitoring and research programs with a novel antiseptic barrier on the wound (“Second Skin”).
Asymptotic Completeness for Compton Scattering
J. Froehlich; M. Griesemer; B. Schlein
2003-07-26T23:59:59.000Z
Scattering in a model of a massive quantum-mechanical particle, an ``electron'', interacting with massless, relativistic bosons, ``photons'', is studied. The interaction term in the Hamiltonian of our model describes emission and absorption of ``photons'' by the ``electron''; but ``electron-positron'' pair production is suppressed. An ultraviolet cutoff and an (arbitrarily small, but fixed) infrared cutoff are imposed on the interaction term. In a range of energies where the propagation speed of the dressed ``electron'' is strictly smaller than the speed of light, unitarity of the scattering matrix is proven, provided the coupling constant is small enough; (asymptotic completeness of Compton scattering). The proof combines a construction of dressed one--electron states with propagation estimates for the ``electron'' and the ``photons''.
Compton Scattering and Generalized Polarizabilities
Stefan Scherer
2004-10-14T23:59:59.000Z
In recent years, real and virtual Compton scattering off the nucleon have attracted considerable interest from both the experimental and theoretical sides. Real Compton scattering gives access to the so-called electromagnetic polarizabilities containing the structure information beyond the global properties of the nucleon such as its charge, mass, and magnetic moment. These polarizabilities have an intuitive interpretation in terms of induced dipole moments and thus characterize the response of the constituents of the nucleon to a soft external stimulus. The virtual Compton scattering reaction $e^-p\\to e^-p\\gamma$ allows one to map out the {\\em local} response to external fields and can be described in terms of generalized electromagnetic polarizabilities. A simple classical interpretation in terms of the induced electric and magnetic polarization densities is proposed. We will discuss experimental results for the polarizabilities of the proton and compare them with theoretical predictions.
Compton Scattering on Light Nuclei
Deepshikha Shukla
2009-12-22T23:59:59.000Z
Compton scattering on light nuclei ($A=2,3$) has emerged as an effective avenue to search for signatures of neutron polarizabilities, both spin--independent and spin--dependent ones. In this discussion I will focus on the theoretical aspect of Compton scattering on light nuclei; giving first a brief overview and therafter concentrating on our Compton scattering calculations based on Chiral effective theory at energies of the order of pion mass. These elastic $\\gamma$d and $\\gamma$He-3 calculations include nucleons, pions as the basic degrees of freedom. I will also discuss $\\gamma$d results where the $\\Delta$-isobar has been included explicitly. Our results on unpolarized and polarization observables suggest that a combination of experiments and further theoretical efforts will provide an extraction of the neutron polarizabilities.
D. Patel; U. Garg; M. Itoh; H. Akimune; G. P. A. Berg; M. Fujiwara; M. N. Harakeh; C. Iwamoto; T. Kawabata; K. Kawase; J. T. Matta; T. Murakami; A. Okamoto; T. Sako; K. W. Schlax; K. Takahashi; M. White; M. Yosoi
2014-06-26T23:59:59.000Z
The excitation of the isoscalar giant monopole resonance (ISGMR) in $^{116}$Sn and $^{208}$Pb has been investigated using small-angle (including $0^\\circ$) inelastic scattering of 100 MeV/u deuteron and multipole-decomposition analysis (MDA). The extracted strength distributions agree well with those from inelastic scattering of 100 MeV/u $\\alpha$ particles. These measurements establish deuteron inelastic scattering at E$_d \\sim$ 100 MeV/u as a suitable probe for extraction of the ISGMR strength with MDA, making feasible the investigation of this resonance in radioactive isotopes in inverse kinematics.
Pion Compton scattering and bremsstrahlung
Göran Fäldt; Ulla Tengblad
2008-02-08T23:59:59.000Z
The pion-polarizability functions are structure functions of pion-Compton scattering. They can be assessed in high-energy pion-nucleus bremsstrahlung reactions, $\\pi^- +A\\to\\pi^- +\\gamma +A$. We present numerical expectations for pion-nucleus bremsstrahlung cross sections in the Coulomb region, i.e. the small-angle region where the nuclear scattering is dominated by the Coulomb interaction. We investigate the prospects of measuring the polarizability functions for pion-Compton c.m. energies from threshold up to 1 GeV. A meson-exchange model is used for the pion-Compton amplitude.
o r est la coordonne du neutron s celle du nuclon optique. La formule (1) conduit une distribution
Boyer, Edmond
. Szteinsznaider and myself. We have measured the angular distribution of the inelastic scattered neutrons on 56Fe neu- trons the number of neutrons scattered at 30° is the same as at 150° with 20 % approximation. To conclude, we have not detected any direct interaction in the inelastic scattering of neutrons at low energy
Danon, Yaron
Quasi-Differential Neutron Scattering Measurements of 238 U A.M. Daskalakis, R.M. Bahran, E between evaluations through the energy-angle distribution of neutrons from scattering and fission of 238 U using the Rensselaer Polytechnic Institute (RPI) neutron scattering system. Differential neutron
Strong coupling effects in near-barrier heavy-ion elastic scattering
N. Keeley; K. W. Kemper; K. Rusek
2014-09-25T23:59:59.000Z
Accurate elastic scattering angular distribution data measured at bombarding energies just above the Coulomb barrier have shapes that can markedly differ from or be the same as the expected classical Fresnel scattering pattern depending on the structure of the projectile, the target or both. Examples are given such as 18O + 184W and 16O + 148,152Sm where the expected rise above Rutherford scattering due to Coulomb-nuclear interference is damped by coupling to the target excited states, and the extreme case of 11Li scattering, where coupling to the 9Li + n + n continuum leads to an elastic scattering shape that cannot be reproduced by any standard optical model parameter set. The recent availability of high quality 6He, 11Li and 11Be data provides further examples of the influence that coupling effects can have on elastic scattering. Conditions for strong projectile-target coupling effects are presented with special emphasis on the importance of the beam-target charge combination being large enough to bring about the strong coupling effects. Several measurements are proposed that can lead to further understanding of strong coupling effects by both inelastic excitation and nucleon transfer on near-barrier elastic scattering. A final note on the anomalous nature of 8B elastic scattering is presented as it possesses a more or less normal Fresnel scattering shape whereas one would a priori not expect this due to the very low breakup threshold of 8B. The special nature of 11Li is presented as it is predicted that no matter how far above the Coulomb barrier the elastic scattering is measured, its shape will not appear as Fresnel like whereas the elastic scattering of all other loosely bound nuclei studied to date should eventually do so as the incident energy is increased, making both 8B and 11Li truly "exotic".
ANL/APS/TB-20 Bremsstrahlung Scattering Calculations for the...
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at rest and in flight, Moliere multiple scattering, Moller and Bhabha scattering, Compton scattering, pair production, photoelectric effect and the continuous energy loss...
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Intrabeam scattering in the HEB
Larson, D.J.
1994-03-01T23:59:59.000Z
A study of Intrabeam Scattering (IBS) in the High Energy Booster (HEB) is presented. Piwinski`s formulas for IBS are presented and evaluated for the HEB. A computer code written to evaluate Piwinski`s formulas is discussed. The result of the study is that IBS should not be a problem for the HEB, although the safety factor is not enormous.
Electromagnetic Scattering by Nonspherical Particles
by the classical Lorenz-Mie theory and must be determined using ad- vanced theoretical and experimental techniques patterns and stress the need for a statistical approach in model- ing scattering and absorption as if the particles were perfect spheres. However, it is becoming increasingly obvious that this approach can cause
Scattering resonances as viscosity limits
Maciej Zworski
2015-05-04T23:59:59.000Z
Using the method of complex scaling we show that scattering resonances of $ - \\Delta + V $, $ V \\in L^\\infty_{\\rm{c}} ( \\mathbb R^n ) $, are limits of eigenvalues of $ - \\Delta + V - i \\epsilon x^2 $ as $ \\epsilon \\to 0+ $. That justifies a method proposed in computational chemistry and reflects a general principle for resonances in other settings.
6, 81258154, 2006 Multiple scattering
Boyer, Edmond
ACPD 6, 81258154, 2006 Multiple scattering effects for Cloudsat A. Battaglia et al. Title Page A. Battaglia1 , M. O. Ajewole2 , and C. Simmer3 1 Meteorological Institute, University of Bonn, Bonn: 28 August 2006 Correspondence to: A. Battaglia (batta@uni-bonn.de) 8125 #12;ACPD 6, 81258154, 2006
Gamma-ray burst polarization via Compton scattering process
Chang, Zhe; Lin, Hai-Nan [Institute of High Energy Physics, Chinese Academy of Sciences, 100049 Beijing (China); Jiang, Yunguo, E-mail: linhn@ihep.ac.cn [School of Space Science and Physics, Shandong University at Weihai, 264209 Weihai (China)
2014-03-01T23:59:59.000Z
Synchrotron radiation and Compton scattering are widely accepted as the most likely emission mechanisms of some astrophysical phenomena, such as gamma-ray bursts (GRBs) and active galactic nuclei. The measurement of the polarization of photons provides a useful tool to distinguish different emission mechanisms and structures of the emission region. Based on the differential cross section of a polarized photon scattered by an unpolarized electron of any initial momentum, we derive an analytical formula of polarization for beamed photons scattered by isotropic electrons with a power-law distribution. Numerical calculations are carried out in four special cases: electrons at rest, Thomson limit, head-on collision, and monochromatic electrons. It is found that the maximum polarization can be as high as 100% for low energy photons, if the electrons are at rest. Although polarization is highly suppressed due to the isotropic electrons, a maximum value of ?10%-20% can still be achieved. The Compton scattering process can be used to explain the polarization of GRB 041219A and GRB 100826A.
Penetration and scattering of lower hybrid waves by density fluctuations
Horton, W. [Institute for Fusion Studies, University of Texas at Austin (United States); Goniche, M.; Peysson, Y.; Decker, J.; Ekedahl, A.; Litaudon, X. [CEA, IRFM, F-13108 St-Paul-Lez-Durance (France)
2014-02-12T23:59:59.000Z
Lower Hybrid [LH] ray propagation in toroidal plasma is controlled by a combination of the azimuthal spectrum launched from the antenna, the poloidal variation of the magnetic field, and the scattering of the waves by the density fluctuations. The width of the poloidal and radial RF wave spectrum increases rapidly as the rays penetrate into higher density and scatter from the turbulence. The electron temperature gradient [ETG] spectrum is particularly effective in scattering the LH waves due to its comparable wavelengths and parallel phase velocities. ETG turbulence is also driven by the radial gradient of the electron current density giving rise to an anomalous viscosity spreading the LH-driven plasma currents. The scattered LH spectrum is derived from a Fokker-Planck equation for the distribution of the ray trajectories with a diffusivity proportional to the fluctuations. The LH ray diffusivity is large giving transport in the poloidal and radial wavenumber spectrum in one - or a few passes - of the rays through the core plasma.
Scattering of very light charged particles
J C Taylor
1993-06-07T23:59:59.000Z
I advance arguments against the view that the Lee-Nauenberg-Kinoshita theorem is relevant in practice to the scattering of charged particles as their mass tends to zero. I also discuss the case of massive coloured particle scattering.
Coherent scattering from a free gas
Sanders, Scott N.
We investigate decoherence in atom interferometry due to scattering from a background gas and show that the supposition that residual coherence is due to near-forward scattering is incorrect. In fact, the coherent part is ...
GPDs, form factors and Compton scattering
P. Kroll
2002-07-09T23:59:59.000Z
The basic theoretical ideas of the handbag factorization and its application to wide-angle scattering reactions are reviewed. With regard to the present experimental program carried out at JLab, wide-angle Compton scattering is discussed in some detail.
Electromagnetic Scattering by Spheres of Topological Insulators
Ge, Lixin; Zi, Jian
2015-01-01T23:59:59.000Z
The electromagnetic scattering properties of topological insulator (TI) spheres are systematically studied in this paper. Unconventional backward scattering caused by the topological magneto-electric (TME) effect of TIs are found in both Rayleigh and Mie scattering regimes. This enhanced backward scattering can be achieved by introducing an impedance-matched background which can suppress the bulk scattering. For the cross-polarized scattering coefficients, interesting antiresonances are found in the Mie scattering regime, wherein the cross-polarized electromagnetic fields induced by the TME effect are trapped inside TI spheres. In the Rayleigh limit, the quantized TME effect of TIs can be determined by measuring the electric-field components of scattered waves in the far field.
10th LANSCE School on Neutron Scattering
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10th LANSCE School on Neutron Scattering LANSCE 10th LANSCE School on Neutron Scattering Home Abstract Lecturers Hands-On Experiments Free Day About the School Sponsors FAQ's...
From hard exclusive meson electroproduction to deeply virtual Compton scattering
Peter Kroll; Hervé Moutarde; Franck Sabatié
2013-04-23T23:59:59.000Z
We systematically evaluate observables for hard exclusive electroproduction of real photons and compare them to experiment using a set of Generalized Parton Distributions (GPDs) whose parameters are constrained by Deeply Virtual Meson Production data, nucleon form factors and parton distributions. The Deeply Virtual Compton Scattering amplitudes are calculated to leading-twist accuracy and leading order in QCD perturbation theory while the leptonic tensor is treated exactly, without any approximation. This study constitutes a check of the universality of the GPDs. We summarize all relevant details on the parametrizations of the GPDs and describe its use in the handbag approach of the aforementioned hard scattering processes. We observe a good agreement between predictions and measurements of deeply virtual Compton scattering on a wide kinematic range, including most data from H1, ZEUS, HERMES, Hall A and CLAS collaborations for unpolarized and polarized targets when available. We also give predictions relevant for future experiments at COMPASS and JLab after the 12 GeV upgrade.
Crystal defect studies using x-ray diffuse scattering
Larson, B.C.
1980-01-01T23:59:59.000Z
Microscopic lattice defects such as point (single atom) defects, dislocation loops, and solute precipitates are characterized by local electronic density changes at the defect sites and by distortions of the lattice structure surrounding the defects. The effect of these interruptions of the crystal lattice on the scattering of x-rays is considered in this paper, and examples are presented of the use of the diffuse scattering to study the defects. X-ray studies of self-interstitials in electron irradiated aluminum and copper are discussed in terms of the identification of the interstitial configuration. Methods for detecting the onset of point defect aggregation into dislocation loops are considered and new techniques for the determination of separate size distributions for vacancy loops and interstitial loops are presented. Direct comparisons of dislocation loop measurements by x-rays with existing electron microscopy studies of dislocation loops indicate agreement for larger size loops, but x-ray measurements report higher concentrations in the smaller loop range. Methods for distinguishing between loops and three-dimensional precipitates are discussed and possibilities for detailed studies considered. A comparison of dislocation loop size distributions obtained from integral diffuse scattering measurements with those from TEM show a discrepancy in the smaller sizes similar to that described above.
Radiative transfer with scattering from closely-spaced spheres
Drolen, B.L.
1986-01-01T23:59:59.000Z
Many heat-transfer applications including fluidized and packed beds, microsphere insulations, and reactor fuel pellets require the analysis of radiative transfer in packed-sphere systems. The radiative properties of surface deposits such as paint and soot layers, and of aerosols such as soot, may be determined by treating them as a collection of spheres. These properties are important for predicting heat transfer in furnaces and flames and for assessing atmospheric attenuation in nuclear-winter scenarios. For many applications when the particle size is larger than the wavelength, or when the volume fraction is small, scattering from individual spheres in the medium is independent of the influence of neighboring particles. Therefore the extinction characteristics of these systems are based on the properties of the discrete particles. This approach is shown to be in good agreement with published experimental data for a packed bed of spheres. When dependent scattering is important, effects caused by the proximity of the neighboring particles must be included. This model examines interference between the scattered waves from each of the particles in the medium. The particle centers correlate via a distribution function which represents the distribution of neighboring particles about a central particle.
Imaging the proton via hard exclusive production in diffractive pp scattering
Charles Hyde; Leonid Frankfurt; Mark Strikman; Christian Weiss
2007-05-21T23:59:59.000Z
We discuss the prospects for probing Generalized Parton Distributions (GPDs) via exclusive production of a high-mass system (H = heavy quarkonium, di-photon, di-jet, Higgs boson) in diffractive pp scattering, pp -> p + H + p. In such processes the interplay of hard and soft interactions gives rise to a diffraction pattern in the final-state proton transverse momenta, which is sensitive to the transverse spatial distribution of partons in the colliding protons. We comment on the plans for diffractive pp measurements at RHIC and LHC. Such studies could complement future measurements of GPDs in hard exclusive ep scattering (JLab, COMPASS, EIC).
Neutron Scattering Studies of Correlated Electron Systems
Boothroyd, Andrew
Neutron Scattering Studies of Correlated Electron Systems Lucy Helme Thesis submitted submitted for the Degree of Doctor of Philosophy, Trinity Term 2006 This thesis presents neutron scatteringO2, through inelastic neutron scattering studies of the crystal field transitions above and below
Measurements of the Thermal Neutron Scattering Kernel
Danon, Yaron
Measurements of the Thermal Neutron Scattering Kernel Li (Emily) Liu, Yaron Danon, Bjorn Becker and discussions Problems and Future study Questions #12;3 M. Mattes and J. Keinert, Thermal Neutron Scattering experimental data used was from 1973-1974! M. Mattes and J. Keinert, Thermal Neutron Scattering Data
Alvarez, Nadir
include the Iberian Peninsula in the west and the Italo-Balkanic region in the east (e.g. Thorpe, 1984 such as the Caucasus, southern Urals and western Asia (Cooper et al., 1995; Bilton et al., 1998; Nesbo et al., 1999 to north-western Turkey and a Near East clade distributed from Georgia to Romania; the two clades separated
Initial Parton Distribution just after Heavy Ion Collisions
Ghi R. Shin; Kang S. Lee
2006-12-08T23:59:59.000Z
We study the initial distribution of a parton system which is formed just after relativistic heavy ion collision by the elastic scattering among the constituent partons in details and analyze the baryon and strangeness contents of the primary parton system. We present the rapidity and energy distributions of the system.
Chen, Yangjun
Distributed DBMS Outline Introduction What is a distributed DBMS Problems Current state-of-affairs Background Distributed DBMS Architecture Distributed Database Design Semantic Data Control Distributed Query Processing Distributed Transaction Management Parallel Database Systems Distributed Object DBMS
Hadron dynamics in high-energy pion-nucleus scattering
Johnson, M.B.
1992-12-31T23:59:59.000Z
It is argued that pion-nucleus scattering at high energy (above 300 MeV) is likely to be easier to interpret than it has been at lower energies where the {Delta}{sub 33} resonance dominates. We establish this by examining the relative importance of various dynamic ingredients of scattering theory for high-energy pions and comparing different versions of the theory: a ``model-exact`` microscopic optical model and an eikonal approximation. For nuclei as heavy as Ca, the eikonal theory is an excellent approximation to the full theory for the angular distribution out to the position of the second minimum in the cross section. The prospects for using high-energy pions to examine modifications of nucleons and baryon resonances in nuclei, nuclear structure, exchange currents, short-range correlations, and to characterize pion propagation are discussed.
Hadron dynamics in high-energy pion-nucleus scattering
Johnson, M.B.
1992-01-01T23:59:59.000Z
It is argued that pion-nucleus scattering at high energy (above 300 MeV) is likely to be easier to interpret than it has been at lower energies where the [Delta][sub 33] resonance dominates. We establish this by examining the relative importance of various dynamic ingredients of scattering theory for high-energy pions and comparing different versions of the theory: a model-exact'' microscopic optical model and an eikonal approximation. For nuclei as heavy as Ca, the eikonal theory is an excellent approximation to the full theory for the angular distribution out to the position of the second minimum in the cross section. The prospects for using high-energy pions to examine modifications of nucleons and baryon resonances in nuclei, nuclear structure, exchange currents, short-range correlations, and to characterize pion propagation are discussed.
Coexistence of high-bit-rate quantum key distribution and data on optical fiber
K. A. Patel; J. F. Dynes; I. Choi; A. W. Sharpe; A. R. Dixon; Z. L. Yuan; R. V. Penty; A. J. Shields
2012-11-30T23:59:59.000Z
Quantum key distribution (QKD) uniquely allows distribution of cryptographic keys with security verified by quantum mechanical limits. Both protocol execution and subsequent applications require the assistance of classical data communication channels. While using separate fibers is one option, it is economically more viable if data and quantum signals are simultaneously transmitted through a single fiber. However, noise-photon contamination arising from the intense data signal has severely restricted both the QKD distances and secure key rates. Here, we exploit a novel temporal-filtering effect for noise-photon rejection. This allows high-bit-rate QKD over fibers up to 90 km in length and populated with error-free bidirectional Gb/s data communications. With high-bit rate and range sufficient for important information infrastructures, such as smart cities and 10 Gbit Ethernet, QKD is a significant step closer towards wide-scale deployment in fiber networks.
User
NORMAL DlSTRlBUTION TABLE. Entries represent the area under the standardized normal distribution from -w to z, Pr(Z
Characterization of scatter in digital mammography from physical measurements
Leon, Stephanie M., E-mail: Stephanie.Leon@uth.tmc.edu; Wagner, Louis K. [Department of Diagnostic and Interventional Imaging, University of Texas Medical School at Houston, Houston, Texas 77030 (United States)] [Department of Diagnostic and Interventional Imaging, University of Texas Medical School at Houston, Houston, Texas 77030 (United States); Brateman, Libby F. [Department of Radiology, University of Florida, Gainesville, Florida 32610 (United States)] [Department of Radiology, University of Florida, Gainesville, Florida 32610 (United States)
2014-06-15T23:59:59.000Z
Purpose: That scattered radiation negatively impacts the quality of medical radiographic imaging is well known. In mammography, even slight amounts of scatter reduce the high contrast required for subtle soft-tissue imaging. In current clinical mammography, image contrast is partially improved by use of an antiscatter grid. This form of scatter rejection comes with a sizeable dose penalty related to the concomitant elimination of valuable primary radiation. Digital mammography allows the use of image processing as a method of scatter correction that might avoid effects that negatively impact primary radiation, while potentially providing more contrast improvement than is currently possible with a grid. For this approach to be feasible, a detailed characterization of the scatter is needed. Previous research has modeled scatter as a constant background that serves as a DC bias across the imaging surface. The goal of this study was to provide a more substantive data set for characterizing the spatially-variant features of scatter radiation at the image detector of modern mammography units. Methods: This data set was acquired from a model of the radiation beam as a matrix of very narrow rays or pencil beams. As each pencil beam penetrates tissue, the pencil widens in a predictable manner due to the production of scatter. The resultant spreading of the pencil beam at the detector surface can be characterized by two parameters: mean radial extent (MRE) and scatter fraction (SF). The SF and MRE were calculated from measurements obtained using the beam stop method. Two digital mammography units were utilized, and the SF and MRE were found as functions of target, filter, tube potential, phantom thickness, and presence or absence of a grid. These values were then used to generate general equations allowing the SF and MRE to be calculated for any combination of the above parameters. Results: With a grid, the SF ranged from a minimum of about 0.05 to a maximum of about 0.16, and the MRE ranged from about 3 to 13 mm. Without a grid, the SF ranged from a minimum of 0.25 to a maximum of 0.52, and the MRE ranged from about 20 to 45 mm. The SF with a grid demonstrated a mild dependence on target/filter combination and kV, whereas the SF without a grid was independent of these factors. The MRE demonstrated a complex relationship as a function of kV, with notable difference among target/filter combinations. The primary source of change in both the SF and MRE was phantom thickness. Conclusions: Because breast tissue varies spatially in physical density and elemental content, the effective thickness of breast tissue varies spatially across the imaging field, resulting in a spatially-variant scatter distribution in the imaging field. The data generated in this study can be used to characterize the scatter contribution on a point-by-point basis, for a variety of different techniques.
Origins of Eccentric Extrasolar Planets: Testing the Planet-Planet Scattering Model
Eric B. Ford; Frederic A. Rasio
2008-06-06T23:59:59.000Z
(Abridged) In planetary systems with two or more giant planets, dynamical instabilities can lead to collisions or ejections through strong planet--planet scattering. Previous studies for simple initial configurations with two equal-mass planets revealed some discrepancies between the results of numerical simulations and the observed orbital elements of extrasolar planets. Here, we show that simulations with two unequal mass planets starting on nearly circular orbits predict a reduced frequency of collisions and a broader range of final eccentricities. The two-planet scattering model can easily reproduce the observed eccentricities with a plausible distribution of planet mass ratios. Further, the two-planet scattering model predicts a maximum eccentricity of about 0.8, independent of the distribution of planet mass ratios, provided that both planets are initially place on nearly circular orbits. This compares favorably with current observations and will be tested by future planet discoveries. The combination of planet--planet scattering and tidal circularization may be able to explain the existence of some giant planets with very short period orbits. Orbital migration due to planet scattering could play an important role in explaining the increased rate of giant planets with very short period orbits. We also re-examine and discuss various possible correlations between eccentricities and other properties of observed extrasolar planets. We demonstrate that the observed distribution of planet masses, orbital periods, and eccentricities can provide constraints for models of planet formation and evolution.
Dishman, K.L.; Doolin, P.K.; Hoffman, J.F. (Ashland Petroleum Co., Ashland, KY (United States))
1993-07-01T23:59:59.000Z
A method of interconversion of dry sieve and laser light scattering particle size values has been developed for cracking catalysts. Values obtained by light scattering techniques were consistently larger than those obtained by dry sieve analysis. The differences were primarily due to lack of sphericity of the particles. The particle size distribution determined by light scattering techniques was based on an average particle diameter. Conversely, the sieve measured the smallest diameter of the particle which can pass through the opening. Microscopic examination of commercial cracking catalysts confirmed their nonuniformity. The sphericity of the catalyst particles decreased as particle size increased. Therefore, the divergence between the laser light scattering and dry sieving value became greater as the catalyst particle size increased.
Update of MRST parton distributions.
Thorne, Robert S; Martin, A D; Stirling, W James; Roberts, R G
knowledge of the partonic structure of the proton is an essential ingredient in the analysis of hard scattering data from pp or p¯p or ep high energy collisions. Much at- tention has recently been devoted to obtaining reliable uncertainties on the parton... photons than dnV (x) quarks. To a rough approximation, the photon distribution should be ?(x,Q2) = ? j e2j ? 2pi ln(Q2/m2q) ? 1 x dy y P?q(y) qj( x y ,Q2). So there is more photon momentum in the proton than in the neutron due to high-x up quarks radiating...
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AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del Sol HomeFacebook Twitter Principal InvestigatorsSave Energy onofCNMS, SNS
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AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del Sol HomeFacebook Twitter Principal InvestigatorsSave Energy onofCNMS, SNSScattering
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AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItemResearch > TheNuclearHomeland andEffectsScanning/Transmission Electron
LED lamp or bulb with remote phosphor and diffuser configuration with enhanced scattering properties
Tong, Tao; Le Toquin, Ronan; Keller, Bernd; Tarsa, Eric; Youmans, Mark; Lowes, Theodore; Medendorp, Jr., Nicholas W; Van De Ven, Antony; Negley, Gerald
2014-11-11T23:59:59.000Z
An LED lamp or bulb is disclosed that comprises a light source, a heat sink structure and an optical cavity. The optical cavity comprises a phosphor carrier having a conversions material and arranged over an opening to the cavity. The phosphor carrier comprises a thermally conductive transparent material and is thermally coupled to the heat sink structure. An LED based light source is mounted in the optical cavity remote to the phosphor carrier with light from the light source passing through the phosphor carrier. A diffuser dome is included that is mounted over the optical cavity, with light from the optical cavity passing through the diffuser dome. The properties of the diffuser, such as geometry, scattering properties of the scattering layer, surface roughness or smoothness, and spatial distribution of the scattering layer properties may be used to control various lamp properties such as color uniformity and light intensity distribution as a function of viewing angle.
Near-barrier quasielastic scattering as a sensitive tool to derive nuclear matter diffuseness
Crema, E.; Simoes, R. F.; Barioni, A. [Departamento de Fisica Nuclear, Instituto de Fisica da Universidade de Sao Paulo, Travessa R da Rua do Matao, 187, 05508-090, Sao Paulo, Sao Paulo (Brazil); Otomar, D. R.; Monteiro, D. S.; Lubian, J.; Gomes, P. R. S. [Instituto de Fisica, Universidade Federal Fluminense, Avenida Litoranea s/n, Gragoata, Niteroi, Rio de Janeiro, 24210-340 (Brazil); Ono, L. K. [Physics Department, University of Central Florida, 4000 Central Florida Boulevard, Orlando, Florida 32816 (United States); Shorto, J. M. B. [Instituto de Pesquisas Energeticas e Nucleares, IPEN/CNEN, Avenida Lineu Prestes, 2242, 05508-000, Sao Paulo, Sao Paulo (Brazil)
2011-08-15T23:59:59.000Z
Quasielastic excitation functions for the {sup 16,18}O + {sup 60}Ni systems were measured at energies near and below the Coulomb barrier, at the backward angle {theta}{sub LAB} = 161 deg. The corresponding quasielastic barrier distributions were derived. The data were compared with predictions from coupled channel calculations using a double-folding potential as a bare potential. For the {sup 16}O-induced scattering, good agreement was obtained for the barrier distribution by using the projectile default nuclear matter diffuseness obtained from the Sao Paulo potential systematic, that is, 0.56 fm. However, for the {sup 18}O-induced scattering, good agreement was obtained only when the projectile nuclear matter diffuseness was changed to 0.62 fm. Therefore, in this paper we show how near-barrier quasielastic scattering can be used as a sensitive tool to derive nuclear matter diffuseness.
Measurements of transverse momentum in semi-inclusive deep-inelastic scattering at CLAS
K.A. Griffioen
2012-12-01T23:59:59.000Z
With mounting experimental evidence that only a small fraction of the proton's spin comes from the spins of its quarks and gluons, the quest for orbital angular momentum has begun. The parton distributions relevant to this depend on transverse quark momenta. Recent CLAS semi-inclusive deep-inelastic scattering measurements probe these new transverse-momentum-dependent parton distributions using longitudinally polarized beams and targets and detecting {pi}{sup +},{pi}{sup -} and {pi}{sup 0} in the final state.
Electron scattering in helium for Monte Carlo simulations
Khrabrov, Alexander V.; Kaganovich, Igor D. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)
2012-09-15T23:59:59.000Z
An analytical approximation for differential cross-section of electron scattering on helium atoms is introduced. It is intended for Monte Carlo simulations, which, instead of angular distributions based on experimental data (or on first-principle calculations), usually rely on approximations that are accurate yet numerically efficient. The approximation is based on the screened-Coulomb differential cross-section with energy-dependent screening. For helium, a two-pole approximation of the screening parameter is found to be highly accurate over a wide range of energies.
DISTRIBUTED DATABASES INTRODUCTION
Liu, Chengfei
D DISTRIBUTED DATABASES INTRODUCTION The development of network and data communication tech- nology distributed database management. Naturally, the decen- tralized approach reflects the distributed aspects in the definition of a distributed database exist. First, a distributed database is distributed
Nuclear Effects in Deep Inelastic Scattering of Charged-Current Neutrino off Nuclear
Duan ChunGui; Li GuangLie; Shen PengNian
2006-04-18T23:59:59.000Z
Nuclear effect in the neutrino-nucleus charged-Current inelastic scattering process is studied by analyzing the CCFR and NuTeV data. Structure functions $F_2(x,Q^2)$ and $xF_3(x,Q^2)$ as well as differential cross sections are calculated by using CTEQ parton distribution functions and EKRS and HKN nuclear parton distribution functions, and compared with the CCFR and NuTeV data. It is found that the corrections of nuclear effect to the differential cross section for the charged-current anti-neutrino scattering on nucleus are negligible, the EMC effect exists in the neutrino structure function $F_2(x,Q^2)$ in the large $x$ region, the shadowing and anti-shadowing effect occurs in the distribution functions of valence quarks in the small and medium $x$ region,respectively. It is also found that shadowing effects on $F_2(x,Q^2)$ in the small $x$ region in the neutrino-nucleus and the charged-lepton-nucleus deep inelastic scattering processes are different. It is clear that the neutrino-nucleus deep inelastic scattering data should further be employed in restricting nuclear parton distributions.
Parameterised Electromagnetic Scattering Solutions for a Range of Incident Wave Angles
Peraire, Jaime
reduction in the computational costs. Reduced--order approximations operate in two stages. In an initial off of these computations are stored. In an online stage, specified outputs of interest are computed at low cost for new in determining the scattering width distribution for a new design. Computational methods can provide assistance
Implementation of a parallel conjugate gradient method for simulation of elastic light scattering
1 Implementation of a parallel conjugate gradient method for simulation of elastic light scattering solved with (preconditioned) conjugate gradient methods. For realistic problems the size of the matrix gradient method for this type of problems, with emphasis on coarse grain distributed memory implementations
Premixed turbulent flame front structure investigation by Rayleigh scattering in the thin
Gülder, Ömer L.
in propane flames. The probability density function of curvature showed a Gaussian-like distribution at allair and propaneair stabilized on a bunsen type burner were studied using planar Rayleigh scattering and particle flames, and from 0.7 to stoichiometric for propane flames. The non-dimensional turbulence rms velocity, u
Compton Scattering on the Proton
O. Scholten; S. Kondratyuk
2002-03-28T23:59:59.000Z
A microscopic coupled-channels model for Compton and pion scattering off the nucleon is introduced which is applicable at the lowest energies (polarizabilities) as well as at GeV energies. To introduce the model first the conventional K-matrix approach is discussed to extend this in a following chapter to the "Dressed K-Matrix" model. The latter approach restores causality, or analyticity, of the amplitude to a large extent. In particular, crossing symmetry, gauge invariance and unitarity are satisfied. The extent of violation of analyticity (causality) is used as an expansion parameter.
Completeness for sparse potential scattering
Shen, Zhongwei, E-mail: zzs0004@auburn.edu [Department of Mathematics and Statistics, Auburn University, Auburn, Alabama 36849 (United States)] [Department of Mathematics and Statistics, Auburn University, Auburn, Alabama 36849 (United States)
2014-01-15T23:59:59.000Z
The present paper is devoted to the scattering theory of a class of continuum Schrödinger operators with deterministic sparse potentials. We first establish the limiting absorption principle for both modified free resolvents and modified perturbed resolvents. This actually is a weak form of the classical limiting absorption principle. We then prove the existence and completeness of local wave operators, which, in particular, imply the existence of wave operators. Under additional assumptions on the sparse potential, we prove the completeness of wave operators. In the context of continuum Schrödinger operators with sparse potentials, this paper gives the first proof of the completeness of wave operators.
Intravalley Multiple Scattering of Quasiparticles in Graphene
J. Y. Vaishnav; Justin Q. Anderson; Jamie D. Walls
2011-05-28T23:59:59.000Z
We develop a theoretical description of intravalley scattering of quasiparticles in graphene from multiple short-range scatterers of size much greater than the carbon-carbon bond length. Our theory provides a method to rapidly calculate the Green's function in graphene for arbitrary configurations of scatterers. We demonstrate that non-collinear multiple scattering trajectories generate pseudospin rotations that alter quasiparticle interference, resulting in significant modifications to the shape, intensity, and pattern of the interference fringes in the local density of states (LDOS). We illustrate these effects via theoretical calculations of the LDOS for a variety of scattering configurations in single layer graphene. A clear understanding of impurity scattering in graphene is a step towards exploiting graphene's unique properties to build future devices.
Small Angle X-Ray Scattering Detector
Hessler, Jan P.
2004-06-15T23:59:59.000Z
A detector for time-resolved small-angle x-ray scattering includes a nearly constant diameter, evacuated linear tube having an end plate detector with a first fluorescent screen and concentric rings of first fiber optic bundles for low angle scattering detection and an annular detector having a second fluorescent screen and second fiber optic bundles concentrically disposed about the tube for higher angle scattering detection. With the scattering source, i.e., the specimen under investigation, located outside of the evacuated tube on the tube's longitudinal axis, scattered x-rays are detected by the fiber optic bundles, to each of which is coupled a respective photodetector, to provide a measurement resolution, i.e., dq/q, where q is the momentum transferred from an incident x-ray to an x-ray scattering specimen, of 2% over two (2) orders of magnitude in reciprocal space, i.e., qmax/qmin approx=lO0.
Badran, R. I.; Masri, Dana Al [Physics Department, Faculty of Sciences, The Hashemite University, Zarqa (Jordan)
2013-12-16T23:59:59.000Z
The diffractive features of angular distribution have been investigated by analyzing the experimental data for a set of elastic scattering processes of {sup 7}Li by different target nuclei at different laboratory energies. Both Frahn-Venter and McIntyre models are used to analyze experimental data of angular distribution for elastic scattering processes. The theoretical models can reasonably reproduce the general pattern of the data. Some geometrical parameters for colliding nuclei have been obtained from the elastic scattering processes. It is found that interpretation of the diffractive features of the data is model-independent. The values of extracted parameters, from adopted models, are found comparable to each other and to those of others. The total reaction cross section is correlated to the incident laboratory energy for each scattering and values of total reaction cross section are found comparable with those of others.
Compton scattering off elementary spin 3/2 particles
E. G. Delgado-Acosta; M. Napsuciale
2009-08-22T23:59:59.000Z
We calculate Compton scattering off an elementary spin 3/2 particle in a recently proposed framework for the description of elementary high spin fields based on the projection onto eigen-subspaces of the Casimir operators of the Poincare group. We also calculate this process in the conventional Rarita-Schwinger formalism. Both formalisms yield the correct Thomson limit but the predictions for the angular distribution and total cross section differ beyond this point. We point out that the average squared amplitudes in the forward direction for Compton scattering off targets with spin s = 0, 1/2, 1 are energy-independent and have the common value 4e^4. As a consequence, in the rest frame of the particle the differential cross section for Compton scattering in the forward direction is energy independent and coincides with the classical squared radius. We show that these properties are also satisfied by a spin 3/2 target in the Poincare projector formalism but not by the Rarita-Schwinger spin 3/2 particle.
Transition representations of quantum evolution with application to scattering resonances
Strauss, Y. [Einstein Institute of Mathematics, Hebrew University of Jerusalem, Jerusalem 91904 (Israel)
2011-03-15T23:59:59.000Z
A Lyapunov operator is a self-adjoint quantum observable whose expectation value varies monotonically as time increases and may serve as a marker for the flow of time in a quantum system. In this paper it is shown that the existence of a certain type of Lyapunov operator leads to representations of the quantum dynamics, termed transition representations, in which an evolving quantum state {psi}(t) is decomposed into a sum {psi}(t) ={psi}{sup b}(t) +{psi}{sup f}(t) of a backward asymptotic component and a forward asymptotic component such that the evolution process is represented as a transition from {psi}{sup b}(t) to {psi}{sup f}(t). When applied to the evolution of scattering resonances, such transition representations separate the process of decay of a scattering resonance from the evolution of outgoing waves corresponding to the probability 'released' by the resonance and carried away to spatial infinity. This separation property clearly exhibits the spatial probability distribution profile of a resonance. Moreover, it leads to the definition of exact resonance states as elements of the physical Hilbert space corresponding to the scattering problem. These resonance states evolve naturally according to a semigroup law of evolution.
None
2010-10-01T23:59:59.000Z
ADEPT Project: HRL Laboratories is using gallium nitride (GaN) semiconductors to create battery chargers for electric vehicles (EVs) that are more compact and efficient than traditional EV chargers. Reducing the size and weight of the battery charger is important because it would help improve the overall performance of the EV. GaN semiconductors process electricity faster than the silicon semiconductors used in most conventional EV battery chargers. These high-speed semiconductors can be paired with lighter-weight electrical circuit components, which helps decrease the overall weight of the EV battery charger. HRL Laboratories is combining the performance advantages of GaN semiconductors with an innovative, interactive battery-to-grid energy distribution design. This design would support 2-way power flow, enabling EV battery chargers to not only draw energy from the power grid, but also store and feed energy back into it.
Phillips, J.L.; Gosling, J.T.; McComas, D.J.; Bame, S.J.; Feldman, W.C.
1991-01-01T23:59:59.000Z
The solar wind electron heat flux is carried primarily by superthermal halo'' electrons with energies at 1 AU of {approximately}80 eV and greater. These halo electrons typically are beamed antisunward along the IMF, indicating effective magnetic connection to the Sun only in one direction. However, ISEE-3 electron observations at 1 AU show that counterstreaming halo beams, suggesting closed magnetic structures, prevail within CMEs. These structures might be magnetic tongues,'' tied to the Sun at both ends, magnetically detached plasmoids, or perhaps complex flux rope structures. We present the results of analysis of ISEE-3 electron observations within 39 CMEs. Parameters analyzed include: the asymmetry between the counterstreaming beams, control by the IMF orientation, and the variation of the electron distributions as a particular CME convects past the spacecraft. We find that some CMEs contain nearly symmetric electron beams, while others are strongly asymmetric, and that beam propagating most nearly antisunward is generally dominant. The more nearly radial the IMF the greater is the symmetry between outward and inward beams. Trends observed as CMEs propagate past the spacecraft probably result primarily from the compression of the leading edge. We present examples of a previously unreported strahl-on-strahl'' distribution, suggesting continued magnetic connection to the corona, in which a narrow antisunward beam is superimposed on a broader beam. Preliminary results show that such spectra are present in a substantial fraction of the observed CMEs. Taken as a whole, our results appear to favor a tongue or flux rope scenario rather than a detached plasmoid.
INVERSE SCATTERING OF SEISMIC DATA WITH THE ...
1910-61-22T23:59:59.000Z
We discuss the inverse scattering of seismic reflection data making use of the generalized Radon transform. Through an extension, the relevant transform attains ...
Coupled-channel scattering on a torus
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Guo, Peng [JLAB; Dudek, Jozef Jon [Old Dominion U., JLAB; Edwards, Robert G. [JLAB; Szczepaniak, Adam Pawel [Indiana U.
2013-07-01T23:59:59.000Z
Based on the Hamiltonian formalism approach, a generalized Luscher's formula for two particle scattering in both the elastic and coupled-channel cases in moving frames is derived from a relativistic Lippmann-Schwinger equation. Some strategies for extracting scattering amplitudes for a coupled-channel system from the discrete finite-volume spectrum are discussed and illustrated with a toy model of two-channel resonant scattering. This formalism will, in the near future, be used to extract information about hadron scattering from lattice QCD computations.
INVERSE SCATTERING PROBLEMS WITH MULTI-FREQUENCIES ...
2015-01-25T23:59:59.000Z
as location, geometry, or material property, from knowledge of the scattered field ... areas such as radar and sonar (e.g., stealth aircraft design and submarine ...
Fast methods for inverse wave scattering problems
Lee, Jung Hoon, Ph. D. Massachusetts Institute of Technology
2008-01-01T23:59:59.000Z
Inverse wave scattering problems arise in many applications including computerized/diffraction tomography, seismology, diffraction/holographic grating design, object identification from radar singals, and semiconductor ...
Recent Studies on Inverse Medium Scattering Problems
2007-06-28T23:59:59.000Z
Numerical examples are presented to illustrate the efficiency and robustness of the ... Energy estimates for the scattered field are established, which provide ...
Multiple-scattering series for color transparency
Greenberg, W.R.; Miller, G.A. (Department of Physics, FM-15, University of Washington, Seattle, Washington 98195 (United States))
1993-03-01T23:59:59.000Z
Cold transparency (CT) depends on the formation of a wave packet of small spatial extent. It is useful to interpret experimental searches for CT with a multiple-scattering series based on wave-packet--nucleon scattering instead of the standard one using nucleon-nucleon scattering. We develop several new techniques which are valid for differing ranges of energy. These techniques are applied to verify some early approximations, study new forms of the wave-packet--nucleon interaction, examine effects of treating wave packets of nonzero size, and predict the production of [ital N][sup *]'s in electron scattering experiments.
Lee, Wu-Jung
2013-01-01T23:59:59.000Z
The interpretation of echoes collected by active remote-sensing systems, such as sonar and radar, is often ambiguous due to the complexities in the scattering processes involving the scatterers, the environment, and the ...
Losses and Impact Distribution and Impacts of Annosus Root Disease in Forests of the
Standiford, Richard B.
expanding root disease centers, in groups of various sizes, and as scattered individuals. Distribution impacts on resource and ecosystem values for a single site. Insofar as possible, the net effect in progressively expanding disease centers, in tree groups of various sizes, and in scattered individuals. One
Fiedler, M.; Frank, H.; Gomer, T.; Hausmann, M.; Pfeilsticker, K.; Platt, U.
1993-05-21T23:59:59.000Z
This paper reports on observations of a minihole ozone depletion event near Kiruna, Sweden on February 6, 1990 in groundbased differential optical absorption spectroscopic measurements. The paper presents a general discussion of the method of zenith scattered sunlight spectroscopy, measurement results for total column ozone, and corrections for interference from polar stratospheric clouds in measurements of such trace gases. Mie scattering can greatly affect the intensity distribution of sunlight scattered at zenith angles, resulting in significant errors in the airmass factor for ozone. When corrections for this scattering are taken into account, no ozone depletion was observed.
Key distributionKey distribution Key distribution, symmetric encryption
Fisher, Michael
COMP 522 Key distributionKey distribution COMP 522 Key distribution, symmetric encryption From in a secure way and must keep the key secure" · Important issue: how to distribute secret keys? COMP 522 Key distribution, manual delivery For two parties A and B: · A key could be created by A and delivered physically
Longitudinal target-spin asymmetries for deeply virtual Compton scattering
Seder, E; Pisano, S; Niccolai, S
2014-01-01T23:59:59.000Z
A measurement of the electroproduction of photons off protons in the deeply inelastic regime was performed at Jefferson Lab using a nearly 6-GeV electron beam, a longitudinally polarized proton target and the CEBAF Large Acceptance Spectrometer. Target-spin asymmetries for $ep\\to e'p'\\gamma$ events, which arise from the interference of the deeply virtual Compton scattering and the Bethe-Heitler processes, were extracted over the widest kinematics in $Q^2$, $x_B$, $t$ and $\\phi$, for 166 four-dimensional bins. In the framework of Generalized Parton Distributions (GPDs), at leading twist the $t$ dependence of these asymmetries provides insight on the spatial distribution of the axial charge of the proton, which appears to be concentrated in its center. These results also bring important and necessary constraints for the existing parametrizations of chiral-even GPDs.
Longitudinal Target-Spin Asymmetries for Deeply Virtual Compton Scattering
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Seder, E.; Biselli, A; Pisano, S; Niccolai, S; Smith, G D.; Joo, K; Adhikari, K; Amaryan, M J.; Anderson, M D.; Anefalos Pereira, S; et al
2015-01-01T23:59:59.000Z
A measurement of the electroproduction of photons off protons in the deeply inelastic regime was performed at Jefferson Lab using a nearly 6-GeV electron beam, a longitudinally polarized proton target and the CEBAF Large Acceptance Spectrometer. Target-spin asymmetries for ep-->e'p'y events, which arise from the interference of the deeply virtual Compton scattering and the Bethe-Heitler processes, were extracted over the widest kinematics in Q2, xB, t and phi, for 166 four-dimensional bins. In the framework of Generalized Parton Distributions (GPDs), at leading twist the t dependence of these asymmetries provides insight on the spatial distribution of the axial charge ofmore »the proton, which appears to be concentrated in its center. These results also bring important and necessary constraints for the existing parametrizations of chiral-even GPDs.« less
Longitudinal target-spin asymmetries for deeply virtual Compton scattering
E. Seder; A. Biselli; S. Pisano; S. Niccolai; the CLAS Collaboration
2014-10-24T23:59:59.000Z
A measurement of the electroproduction of photons off protons in the deeply inelastic regime was performed at Jefferson Lab using a nearly 6-GeV electron beam, a longitudinally polarized proton target and the CEBAF Large Acceptance Spectrometer. Target-spin asymmetries for $ep\\to e'p'\\gamma$ events, which arise from the interference of the deeply virtual Compton scattering and the Bethe-Heitler processes, were extracted over the widest kinematics in $Q^2$, $x_B$, $t$ and $\\phi$, for 166 four-dimensional bins. In the framework of Generalized Parton Distributions (GPDs), at leading twist the $t$ dependence of these asymmetries provides insight on the spatial distribution of the axial charge of the proton, which appears to be concentrated in its center. These results also bring important and necessary constraints for the existing parametrizations of chiral-even GPDs.
Longitudinal Target-Spin Asymmetries for Deeply Virtual Compton Scattering
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Seder, E.; Biselli, A; Pisano, S; Niccolai, S; Smith, G D.; Joo, K; Adhikari, K; Amaryan, M J.; Anderson, M D.; Anefalos Pereira, S; Avakian, H; Battaglieri, M; Bedlinskiy, I; Bono, J; Boiarinov, S; Bosted, P; Briscoe, W; Brock, J; Brooks, W K.; Bueltmann, S; Burkert, V D.; Carman, D S.; Carlin, C; Celentano, A; Chandavar, S; Charles, G; Colaneri, L; Cole, P L.; Contalbrigo, M; Crabb, D; Crede, V; D'Angelo, A; Dashyan, N; De Vita, R; De Sanctis, E; Deur, A; Djalali, C; Doughty, D; Dupre, R; El Fassi, L; Elouadrhiri, L; Eugenio, P; Fedotov, G; Fegan, S; Filippi, A; Fleming, J A.; Fradi, A; Garillon, B; Garcon, M; Gevorgyan, N; Ghandilyan, Y; Giovanetti, K L.; Girod, F X.; Goetz, J T.; Gohn, W; Gothe, R W.; Griffioen, K A.; Guegan, B; Guidal, M; Guo, L; Hafidi, K; Hakobyan, H; Hanretty, C; Harrison, N; Hattawy, M; Hirlinger Saylor, N; Holtrop, M; Hughes, S M.; Ilieva, Y; Ireland, D G.; Ishkhanov, B S.; Isupov, E L.; Jo, H S.; Joosten, S; Keith, C D.; Keller, D; Khachatryan, G; Khandaker, M; Kim, A; Kim, W; Klein, A; Klein, F J.; Koirala, S; Kubarovsky, V; Kuhn, S E.; Lenisa, P; Livingston, K; Lu, H Y.; MacGregor, I J.D.; Markov, N; Mayer, M; McKinnon, B; Meekins, D G.; Mineeva, T; Mirazita, M; Mokeev, V; Montgomery, R; Moody, C I.; Moutarde, H; Movsisyan, A; Munoz Camacho, C; Nadel-Turonski, P; Niculescu, I; Osipenko, M; Ostrovidov, A I.; Paolone, M; Pappalardo, L L.; Park, K; Park, S; Pasyuk, E; Peng, P; Phelps, W; Pogorelko, O; Price, J W.; Prok, Y; Protopopescu, D; Puckett, A J.R.; Ripani, M; Rizzo, A; Rosner, G; Rossi, P; Roy, P; Sabatie, F; Salgado, C; Schott, D; Schumacher, R A.; Senderovich, I; Simonyan, A; Skorodumina, I; Sokhan, D; Sparveris, N; Stepanyan, S; Stoler, P; Strakovsky, I I.; Strauch, S; Sytnik, V; Taiuti, M; Tang, W; Tian, Y; Ungaro, M; Voskanyan, H; Voutier, E; Walford, N K.; Watts, D P.; Wei, X; Weinstein, L B.; Wood, M H.; Zachariou, N; Zana, L; Zhang, J; Zonta, I
2015-01-01T23:59:59.000Z
A measurement of the electroproduction of photons off protons in the deeply inelastic regime was performed at Jefferson Lab using a nearly 6-GeV electron beam, a longitudinally polarized proton target and the CEBAF Large Acceptance Spectrometer. Target-spin asymmetries for ep-->e'p'y events, which arise from the interference of the deeply virtual Compton scattering and the Bethe-Heitler processes, were extracted over the widest kinematics in Q2, xB, t and phi, for 166 four-dimensional bins. In the framework of Generalized Parton Distributions (GPDs), at leading twist the t dependence of these asymmetries provides insight on the spatial distribution of the axial charge of the proton, which appears to be concentrated in its center. These results also bring important and necessary constraints for the existing parametrizations of chiral-even GPDs.
Inclusive Electron Scattering From Nuclei at x >1 and High Q^2
John Arrington
1998-06-02T23:59:59.000Z
CEBAF experiment e89-008 measured inclusive electron scattering from nuclei in a Q{sup 2} range between 0.8 and 7.3 (GeV/c){sup 2} for x{sub Bjorken} approximately greater than 1. The cross sections for scattering from D C, Fe, and Au were measured. The C, Fe, and Au data have been analyzed in terms of F(y) to examine y-scaling of the quasielastic scattering, and to study the momentum distribution of the nucleons in the nucleus. The data have also been analyzed in terms of the structure function vW{sub 2} to examine scaling of the inelastic scattering in x and xi and to study the momentum distribution of the quarks. In the regions where quasielastic scattering dominates the cross section (low Q{sup 2} or large negative values of y), the data are shown to exhibit y-scaling. However, the y-scaling breaks down once the inelastic contributions become large. The data do not exhibit x-scaling, except at the lowest values of x, while the structure function does appear to scale in the Nachtmann variable, xi.
Influence of the Environment Fluctuations on Incoherent Neutron Scattering Functions
D. J. Bicout
2001-04-09T23:59:59.000Z
In extending the conventional dynamic models, we consider a simple model to account for the environment fluctuations of particle atoms in a protein system and derive the elastic incoherent structure factor (EISF) and the incoherent scattering correlation function C(Q,t) for both the jump dynamics between sites with fluctuating site interspacing and for the diffusion inside a fluctuating sphere. We find that the EISF of the system (or the normalized elastic intensity) is equal to that in the absence of fluctuations averaged over the distribution of site interspacing or sphere radius a. The scattering correlation function is $C(Q,t)=\\sum_{n} \\psi(t)$, where the average is taken over the Q-dependent effective distribution of relaxation rates \\lambda_n(a) and \\psi(t) is the correlation function of the length a. When \\psi(t)=1, the relaxation of C(Q,t) is exponential for the jump dynamics between sites (since \\lambda_n(a) is independent of a) while it is nonexponential for diffusion inside a sphere.
A Rgularized Boltzmann Scattering Operator for Highly Forward Peaked Scattering
Anil K. Prinja
2005-04-13T23:59:59.000Z
Extremely short collision mean free paths and near-singular elastic and inelastic differential cross sections (DCS) make analog Monte Carlo and deterministic computational approaches impractical for charged particle transport. The widely used alternative, the condensed history method, while efficient, also suffers from several limitations arising from the use of precomputed infinite medium distributions for sampling particle directions and energies.
Giant Planet Migration through the Action of Disk Torques and Planet Scattering
Althea V. Moorhead; Fred C. Adams
2005-05-11T23:59:59.000Z
This paper presents a parametric study of giant planet migration through the combined action of disk torques and planet-planet scattering. The torques exerted on planets during Type II migration in circumstellar disks readily decrease the semi-major axes, whereas scattering between planets increases the orbital eccentricities. This paper presents a parametric exploration of the possible parameter space for this migration scenario using two (initial) planetary mass distributions and a range of values for the time scale of eccentricity damping (due to the disk). For each class of systems, many realizations of the simulations are performed in order to determine the distributions of the resulting orbital elements of the surviving planets; this paper presents the results of 8500 numerical experiments. Our goal is to study the physics of this particular migration mechanism and to test it against observations of extrasolar planets. The action of disk torques and planet-planet scattering results in a distribution of final orbital elements that fills the a-e plane, in rough agreement with the orbital elements of observed extrasolar planets. In addition to specifying the orbital elements, we characterize this migration mechanism by finding the percentages of ejected and accreted planets, the number of collisions, the dependence of outcomes on planetary masses, the time spent in 2:1 and 3:1 resonances, and the effects of the planetary IMF. We also determine the distribution of inclination angles of surviving planets and the distribution of ejection speeds for exiled planets.
Compton Scattering on Black Body Photons
Lowell S. Brown; Ronald S. Steinke
1996-09-27T23:59:59.000Z
We examine Compton scattering of electrons on black body photons in the case where the electrons are highly relativistic, but the center of mass energy is small in comparison with the electron mass. We derive the partial lifetime of electrons in the LEP accelerator due to this form of scattering in the vacuum beam pipe and compare it with previous results.
Relativistic Wave Equations and Compton Scattering
B. A. Robson; S. H. Sutanto
2006-05-25T23:59:59.000Z
The recently proposed eight-component relativistic wave equation is applied to the scattering of a photon from a free electron (Compton scattering). It is found that in spite of the considerable difference in the structure of this equation and that of Dirac the cross section is given by the Klein-Nishina formula.
A Deeply Virtual Compton Scattering Amplitude
M. Capua; S. Fazio; R. Fiore; L. Jenkovszky; F. Paccanoni
2006-07-07T23:59:59.000Z
A factorized Regge-pole model for deeply virtual Compton scattering is suggested. The use of an effective logarithmic Regge-Pomeron trajectory provides for the description of both ``soft'' (small $|t|$) and ``hard'' (large $|t|$) dynamics. The model contains explicitly the photoproduction and the DIS limits and fits the existing HERA data on deeply virtual Compton scattering.
QCD Sum Rules and Virtual Compton Scattering
A. V. Radyushkin
1996-09-19T23:59:59.000Z
In this talk I report on recent progress in a few areas closely related to the virtual Compton scattering studies. In particular, I discuss the quark-hadron duality estimate of the $\\gamma^* p \\to \\Delta^+$ transition, QCD sum rule calculation of the $\\gamma \\gamma^* \\to \\pi^0$ form factor, and application of perturbative QCD to deeply virtual Compton scattering at small $t$.
Introduction to Dynamic Distributed
Roma "La Sapienza", Università di
Introduction to Dynamic Distributed SystemsSystems #12;Outline Introduction Churn Building Applications in Dynamic Distributed Systems RegistersRegisters Eventual Leader election Connectivity in Dynamic Distributed Systems #12;Dynamic Distributed Systems: Context & Motivations Advent of Complex Distributed
136 3. Scattering The Compton scattering of an x-ray is incoherent because there are de-
136 3. Scattering The Compton scattering of an x-ray is incoherent because there are de- grees of freedom in each scattering event associated with the atomic electron. Compton scattering provides of an atom are the ones that can participate in Compton scattering because they can be- come unbound from
Temperature Dependent Neutron Scattering Sections for Polyethylene
Roger E. Hill; C. -Y. Liu
2003-09-05T23:59:59.000Z
This note presents neutron scattering cross sections for polyethylene at 296 K, 77 K and 4 K derived from a new scattering kernel for neutron scattering off of hydrogen in polyethylene. The kernel was developed in ENDF-6 format as a set of S(alpha,beta) tables using the LEAPR module of the NJOY94 code package. The polyethylene density of states (from 0 to sub eV) adopted to derive the new kernel is presented. We compare our calculated room temperature total scattering cross sections and double differential cross sections at 232 meV at various angles with the available experimental data (at room temperature), and then extrapolate the calculations to lower temperatures (77K and 4K). The new temperature dependent scattering kernel gives a good quantitative fit to the available room temperature data and has a temperature dependence that is qualitatively consistent with thermodynamics.
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AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville Power AdministrationField Campaign:INEA : Papers SubfoldersU.S. RefiningDistributed EnergyUntapped
Ultrasound scattering and the study of vortex correlations in disordered flows
Denis Boyer; Fernando Lund
1999-12-14T23:59:59.000Z
In an idealized way, some turbulent flows can be pictured by assemblies of many vortices characterized by a set of particle distribution functions. Ultrasound provide an useful, nonintrusive, tool to study the spatial structure of vorticity in flows. This is analogous to the use of elastic neutron scattering to determine liquid structure. We express the dispersion relation, as well as the scattering cross section, of sound waves propagating in a ``liquid'' of identical vortices as a function of vortex pair correlation functions. In two dimensions, formal analogies with ionic liquids are pointed out.
The Beam-Charge Azimuthal Asymmetry and Deeply Virtual Compton Scattering
Airapetian, A; Akopov, Z; Amarian, M; Andrus, A; Aschenauer, E C; Augustyniak, W; Avakian, R; Avetisian, A; Avetissian, E; Bailey, P; Balin, D; Beckmann, M; Belostotskii, S; Bianchi, N; Blok, H P; Böttcher, Helmut B; Borisov, A; Borysenko, A; Bouwhuis, M; Brüll, A; Bryzgalov, V; Capiluppi, M; Capitani, G P; Chen, T; Ciullo, G; Contalbrigo, M; Dalpiaz, P F; Deconinck, W; De Leo, R; Demey, M; De Nardo, L; De Sanctis, E; Devitsin, E; Di Nezza, P; Dreschler, J; Düren, M; Ehrenfried, M; Elalaoui-Moulay, A; Elbakian, G; Ellinghaus, F; Elschenbroich, U; Fabbri, R; Fantoni, A; Felawka, L; Frullani, S; Funel, A; Gapienko, G; Gapienko, V; Garibaldi, F; Garrow, K; Gaskell, D; Gavrilov, G; Karibian, V; Grebenyuk, O; Gregor, I M; Hadjidakis, C; Hafidi, K; Hartig, M; Hasch, D; Hesselink, W H A; Hillenbrand, A; Hoek, M; Holler, Y; Hommez, B; Hristova, I; Iarygin, G; Ivanilov, A; Izotov, A; Jackson, H E; Jgoun, A; Kaiser, R; Kinney, E; Kiselev, A; Kobayashi, T; Kopytin, M; Korotkov, V; Kozlov, V; Krauss, B; Krivokhizhin, V G; Lagamba, L; Lapikas, L; Laziev, A; Lenisa, P; Liebing, P; Linden-Levy, L A; Lorenzon, W; Lü, H; Lü, J; Lu, S; Ma, B Q; Maiheu, B; Makins, N C R; Mao, Y; Marianski, B; Marukyan, H; Masoli, F; Mexner, V; Meyners, N; Michler, T; Miklukho, O; Miller, C A; Miyachi, Y; Muccifora, V; Murray, M; Nagaitsev, A; Nappi, E; Naryshkin, Yu; Negodaev, M; Nowak, Wolf-Dieter; Oganessyan, K; Ohsuga, H; Osborne, A; Pickert, N; Potterveld, D H; Raithel, M; Reggiani, D; Reimer, P E; Reischl, A; Reolon, A R; Riedl, C; Rith, K; Rosner, G; Rostomyan, A; Rubacek, L; Rubin, J; Ryckbosch, D; Salomatin, Y; Sanjiev, I; Savin, I; Schäfer, A; Schnell, G; Schüler, K P; Seele, J; Seidl, R; Seitz, B; Shanidze, R; Shearer, C; Shibata, T A; Shutov, V; Sinram, K; Sommer, W; Stancari, M; Statera, M; Steffens, E; Steijger, J J M; Stenzel, H; Stewart, J; Stinzing, F; Tait, P; Tanaka, H; Taroian, S P; Tchuiko, B; Terkulov, A R; Trzcinski, A; Tytgat, M; Vandenbroucke, A; Van der Nat, P B; van der Steenhoven, G; Van Haarlem, Y; Vikhrov, V; Vincter, M G; Vogel, C; Volmer, J; Wang, S; Wendland, J; Ye, Y; Ye, Z; Yen, S; Zihlmann, B
2007-01-01T23:59:59.000Z
The first observation of an azimuthal cross--section asymmetry with respect to the charge of the incoming lepton beam is reported from a study of hard exclusive electroproduction of real photons. The data have been accumulated by the HERMES experiment at DESY, in which the HERA 27.6 GeV electron or positron beam scattered off an unpolarized hydrogen gas target. The observed asymmetry is attributed to the interference between the Bethe--Heitler process and the Deeply Virtual Compton Scattering (DVCS) process. The interference term is sensitive to DVCS amplitudes, which provide the most direct access to Generalized Parton Distributions.
UNIVERSITY OF CALIFORNIA Inelastic Neutron Scattering Study of the
Lawrence, Jon
UNIVERSITY OF CALIFORNIA IRVINE Inelastic Neutron Scattering Study of the Intermediate Valence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2 Inelastic Neutron Scattering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2.a Neutron Scattering Instruments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2.b
Fully portable, highly flexible dilution refrigerator systems for neutron scattering
Boyer, Edmond
775 Fully portable, highly flexible dilution refrigerator systems for neutron scattering P. A systems developed specifically for neutron scattering environ- ments. The refrigerators are completely relatively recently however, the lowest temperatures available in almost all neutron scattering laboratories
Production of $c \\bar c$ pairs at LHC: $k_t$-factorization and double-parton scattering
Antoni Szczurek
2012-06-01T23:59:59.000Z
We discuss charm production at LHC. The production of single $c \\bar c$ pairs is calculated in the $k_t$-factorization approach. We use several unintegrated gluon distributions from the literature. Differential distributions for several charmed mesons are presented and compared to recent results of the ALICE and LHCb collaborations. Some missing strength can be observed. Furthermore we discuss production of two $c \\bar c$ pairs within a simple formalism of double-parton scattering (DPS). Surprisingly large cross sections, comparable to single-parton scattering (SPS) contribution to $c \\bar c$ production, are predicted for LHC energies.
angle light scattering: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Biological tissues tend Kim, Arnold D. 11 Static light scattering and small-angle neutron scattering study on aggregated recombinant gelatin in aqueous solution University...
acoustic wave scattering: Topics by E-print Network
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of scatterers Physics Websites Summary: experimentally and theoretically, the ballistic propagation of ultrasonic wave pulses through a random strongly scattering materials;...
Jefferson Lab experiment works to clarify Real Compton Scattering...
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Real Compton Scattering experiment spokespeople The Real Compton Scattering experiment spokespeople take a short break for a photo. From left is Bogdan Wojtsekhowski, JLab staff...
2012 LANSCE Neutron Scattering School | Los Alamos National Laboratory
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2 LANSCE Neutron Scattering School LANSCE 2012 LANSCE Neutron Scattering School Home About the School Hands-On Experiments Quick Links Application - Closed Schedule Poster...
Application of Neutron Imaging and Scattering to Fluid Flow and...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Application of Neutron Imaging and Scattering to Fluid Flow and Fracture in EGS Environments Application of Neutron Imaging and Scattering to Fluid Flow and Fracture in EGS...
11th LANSCE School on Neutron Scattering | Lecturers
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Laboratory Rex Hjelm Rex P. Hjelm is the Instrument Scientist for the small-angle neutron scattering instrument, LQD, at the Lujan Neutron Scattering Center of LANSCE at...
International Conference on Neutron Scattering 2005 Darling Harbour. Sydney. Australia
International Conference on Neutron Scattering 2005 Darling Harbour. Sydney. Australia 27 November, Hillerød, Denmark Combined application of small-angle neutron scattering and oscillatory shear
11th LANSCE School on Neutron Scattering | About the School
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
students calculate results About the LANSCE School on Neutron Scattering The annual Los Alamos Neutron Science Center (LANSCE) School on Neutron Scattering is 9- to 10-day school...
2012 LANSCE Neutron Scattering School | Los Alamos National Laboratory
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
1 LANSCE Neutron Scattering School LANSCE 2011 LANSCE Neutron Scattering School Home NSS 2011 About the School Lecturers Hands-On Experiments Quick Links Application Schedule...
High Energy Scattering Amplitudes of Superstring Theory
Chuan-Tsung Chan; Jen-Chi Lee; Yi Yang
2005-11-18T23:59:59.000Z
We use three different methods to calculate the proportionality constants among high-energy scattering amplitudes of different string states with polarizations on the scattering plane. These are the decoupling of high-energy zero-norm states (HZNS), the Virasoro constraints and the saddle-point calculation. These calculations are performed at arbitrary but fixed mass level for the NS sector of 10D open superstring. All three methods give the consistent results, which generalize the previous works on the high-energy 26D open bosonic string theory. In addition, we discover new leading order high-energy scattering amplitudes, which are still proportional to the previous ones, with polarizations orthogonal to the scattering plane. These scattering amplitudes are of subleading order in energy for the case of 26D open bosonic string theory. The existence of these new high-energy scattering amplitudes is due to the worldsheet fermion exchange in the correlation functions and is, presumably, related to the high-energy massive spacetime fermionic scattering amplitudes in the R-sector of the theory.
Parton distribution function uncertainties & nuclear corrections for the LHC
Schienbein, I; Keppel, C; Morfín, J G; Olness, Fredrick I; Owens, J F
2008-01-01T23:59:59.000Z
We study nuclear effects of charged current deep inelastic neutrino-iron scattering in the framework of a chi^2 analysis of parton distribution functions (PDFs). We extract a set of iron PDFs which are used to compute x_Bj-dependent and Q^2-dependent nuclear correction factors for iron structure functions which are required in global analyses of free nucleon PDFs. We compare our results with nuclear correction factors from neutrino-nucleus scattering models and correction factors for charged lepton-iron scattering. We find that, except for very high x_Bj, our correction factors differ in both shape and magnitude from the correction factors of the models and charged-lepton scattering.
Valence quark distributions of the proton from maximum entropy approach
Rong Wang; Xurong Chen
2014-10-14T23:59:59.000Z
We present an attempt of maximum entropy principle to determine valence quark distributions in the proton at very low resolution scale $Q_0^2$. The initial three valence quark distributions are obtained with limited dynamical information from quark model and QCD theory. Valence quark distributions from this method are compared to the lepton deep inelastic scattering data, and the widely used CT10 and MSTW08 data sets. The obtained valence quark distributions are consistent with experimental observations and the latest global fits of PDFs. Maximum entropy method is expected to be particularly useful in the case where relatively little information from QCD calculation is given.
Valence quark distributions of the proton from maximum entropy approach
Wang, Rong
2014-01-01T23:59:59.000Z
We present an attempt of maximum entropy principle to determine valence quark distributions in the proton at very low resolution scale $Q_0^2$. The initial three valence quark distributions are obtained with limited dynamical information from quark model and QCD theory. Valence quark distributions from this method are compared to the lepton deep inelastic scattering data, and the widely used CT10 and MSTW08 data sets. The obtained valence quark distributions are consistent with experimental observations and the latest global fits of PDFs. Maximum entropy method is expected to be particularly useful in the case where relatively little information from QCD calculation is given.
CMB Cold Spot from Inflationary Feature Scattering
Wang, Yi
2015-01-01T23:59:59.000Z
We propose a "feature-scattering" mechanism to explain the cosmic microwave background cold spot seen from {\\it WMAP} and {\\it Planck} maps. If there are hidden features in the potential of multi-field inflation, the inflationary trajectory can be scattered by such features. The scattering is controlled by the amount of isocurvature fluctuations, and thus can be considered as a mechanism to convert isocurvature fluctuations into curvature fluctuations. This mechanism predicts localized cold spots (instead of hot ones) on the CMB. In addition, it may also bridge a connection between the cold spot and a dip on the CMB power spectrum at $\\ell \\sim 20$.
Diffraction Patterns in Deeply Virtual Compton Scattering
Asmita Mukherjee
2006-11-30T23:59:59.000Z
We report on a calculation to show that the Fourier transform of the Deeply Virtual Compton Scattering (DVCS) amplitude with respect to the skewness variable \\zeta at fixed invariant momentum transfer squared t gives results that are analogous to the diffractive scattering of a wave in optics. As a specific example, we utilize the quantum fluctuations of a fermion state at one loop in QED to obtain the behavior of the DVCS amplitude for electron-photon scattering. We then simulate the wavefunctions for a hadron by differentiating the above LFWFs with respect to M^2 and study the corresponding DVCS amplitudes in light-front longitudinal space.
Attosecond neutron Compton scattering from protons
C. Aris Chatzidimitriou-Dreismann
2007-02-01T23:59:59.000Z
The effect of "anomalous" scattering of neutrons and electrons from protons in the electron-volt energy-transfer range is considered, and related experimental results are mentioned. A recent independent confirmation of this effect with a new data analysis procedure is presented. Due to the very short characteristic scattering time, there is no well defined separation of time scales of electronic and protonic motions. An outline of a proposed theoretical interpretation is presented, which is based on the fact that scattering protons represent \\textit{open} quantum systems, thus being subject to decoherence.
Nuclear effects in deep inelastic scattering
O. Benhar; V.R. Pandharipande; I. Sick
1998-03-01T23:59:59.000Z
The authors extend the approach used to treat quasi-elastic inclusive electron-nucleus scattering to the deep inelastic region. They provide a general approach to describe lepton scattering from an off-shell nucleon, and calculate the ratio of inclusive deep inelastic scattering cross sections to the deuteron for nuclear matter and helium (EMC-effect). They find that the consistent inclusion of the binding effects, in particular the ones arising from the short-range nucleon-nucleon interaction, allows to describe the data in the region of x > 0.15 where binding fully accounts for the deviation of the cross section ratios from one.
Gordon Chalmers; Olaf Lechtenfeld; Bernd Niemeyer
2000-09-08T23:59:59.000Z
We calculate the genus-one three- and four-point amplitudes in the 2+2 dimensional closed N=(2,2) worldsheet supersymmetric string within the RNS formulation. Vertex operators are redefined with the incorporation of spinor helicity techniques, and the quantum scattering is shown to be manifestly gauge and Lorentz invariant after normalizing the string states. The continuous spin structure summation over the monodromies of the worldsheet fermions is carried out explicitly, and the field-theory limit is extracted. The amplitude in this limit is shown to be the maximally helicity violating amplitude in pure gravity evaluated in a two-dimensional setting, which vanishes, unlike the four-dimensional result. The vanishing of the genus-one N=2 closed string amplitude is related to the absence of one-loop divergences in dimensionally regulated IIB supergravity. Comparisons and contrasts between self-dual field theory and the N=2 string theory are made at the quantum level; they have different S-matrices. Finally, we point to further relations with self-dual field theory and two-dimensional models.
Richard Beyer; Markus Franke; Hans Joachim Schöpe; Eckhard Bartsch; Thomas Palberg
2014-12-02T23:59:59.000Z
Hard spheres are a well recognized model system of statistical physics and soft condensed matter. Their crystallization behaviour has been intensively studied at the structural length scale by Bragg light scattering and/or high resolution microscopy. We here present an improved light scattering apparatus capable to perform simultaneous measurements in the Bragg scattering regime and in the small angle regime. We give an account of its construction and demonstrate its performance for several examples of hard sphere and attractive hard sphere suspensions. Comparison of small angle to Bragg data allows a calibration of the sequence of events in time. We show how important complementary information can be gained from the small angle studies e.g. on the immediate environment of the growing crystals or the global scale crystallite distribution. We further demonstrate that processes occurring on larger length scales have a significant influence on the crystallization kinetics and the final micro-structure.
Deuteron scattering on {sup 6}Li at an energy of 25 MeV
Burtebayev, N. [National Nuclear Center of the Republic of Kazakhstan, Institute of Nuclear Physics (Kazakhstan); Artemov, S. V. [Uzbek Academy of Sciences, Institute of Nuclear Physics (Uzbekistan); Duisebayev, B. A.; Kerimkulov, Zh. K. [National Nuclear Center of the Republic of Kazakhstan, Institute of Nuclear Physics (Kazakhstan); Kuranov, S. B. [Uzbek Academy of Sciences, Institute of Nuclear Physics (Uzbekistan); Sakuta, S. B., E-mail: sakuta@dni.polyn.kiae.s [Russian Research Center Kurchatov Institute (Russian Federation)
2010-05-15T23:59:59.000Z
At an energy of 25 MeV and in the angular range 7{sup o}-175{sup o} in the laboratory frame, angular distributions were measured for elastic deuteron scattering on {sup 6}Li nuclei and for the respective inelastic-scattering processes accompanied by the transitions to the ground state (1+) of the {sup 6}Li nucleus and to its excited state at E{sub x} = 2.186 MeV (J{sup {pi}} = 3{sup +}). The resulting data were analyzed on the basis of the optical model of the nucleus and the coupled-reaction-channel method with allowance for the mechanism of alpha-particle-cluster exchange. It is shown that only upon including, in the analysis, channel coupling and the exchange mechanism can the experimental cross sections for elastic and inelastic scattering be reproduced over the entire range of angles.
Cross sections for electron scattering by propane in the low- and intermediate-energy ranges
Souza, G. L. C. de; Lee, M.-T.; Sanches, I. P.; Rawat, P.; Iga, I.; Santos, A. S. dos; Machado, L. E.; Sugohara, R. T.; Brescansin, L. M.; Homem, M. G. P.; Lucchese, R. R. [Departamento de Quimica, UFSCar, 13565-905 Sao Carlos, SP (Brazil); Departamento de Fisica, UFSCar, 13565-905 Sao Carlos, SP (Brazil); Instituto de Fisica 'Gleb Wataghin', UNICAMP, 13083-970 Campinas, SP (Brazil); Departamento de Fisica, UFSC, 88010-970 Florianopolis, SC (Brazil); Department of Chemistry, Texas A and M University, College Station, Texas 7784-3255 (United States)
2010-07-15T23:59:59.000Z
We present a joint theoretical-experimental study on electron scattering by propane (C{sub 3}H{sub 8}) in the low- and intermediate-energy ranges. Calculated elastic differential, integral, and momentum transfer as well as total (elastic + inelastic) and total absorption cross sections are reported for impact energies ranging from 2 to 500 eV. Also, experimental absolute elastic cross sections are reported in the 40- to 500-eV energy range. A complex optical potential is used to represent the electron-molecule interaction dynamics. A theoretical method based on the single-center-expansion close-coupling framework and corrected by the Pade approximant is used to solve the scattering equations. The experimental angular distributions of the scattered electrons are converted to absolute cross sections using the relative flow technique. The comparison of our calculated with our measured results, as well as with other experimental and theoretical data available in the literature, is encouraging.
Efficient Light Extraction from Organic Light-Emitting Diodes Using Plasmonic Scattering Layers
Rothberg, Lewis
2012-11-30T23:59:59.000Z
Our project addressed the DOE MYPP 2020 goal to improve light extraction from organic light-emitting diodes (OLEDs) to 75% (Core task 6.3). As noted in the 2010 MYPP, “the greatest opportunity for improvement is in the extraction of light from [OLED] panels”. There are many approaches to avoiding waveguiding limitations intrinsic to the planar OLED structure including use of textured substrates, microcavity designs and incorporating scattering layers into the device structure. We have chosen to pursue scattering layers since it addresses the largest source of loss which is waveguiding in the OLED itself. Scattering layers also have the potential to be relatively robust to color, polarization and angular distributions. We note that this can be combined with textured or microlens decorated substrates to achieve additional enhancement.
Airapetian, A; Akopov, Z; Aschenauer, E C; Augustyniak, W; Avakian, R; Avetissian, A; Avetisyan, E; Belostotski, S; Bianchi, N; Blok, H P; Borissov, A; Bowles, J; Brodski, I; Bryzgalov, V; Burns, J; Capiluppi, M; Capitani, G P; Cisbani, E; Ciullo, G; Contalbrigo, M; Dalpiaz, P F; Deconinck, W; De Leo, R; De Nardo, L; De Sanctis, E; Diefenthaler, M; Di Nezza, P; Dueren, M; Ehrenfried, M; Elbakian, G; Ellinghaus, F; Fantoni, A; Felawka, L; Frullani, S; Gabbert, D; Gapienko, G; Gapienko, V; Garibaldi, F; Gavrilov, G; Gharibyan, V; Giordano, F; Gliske, S; Golembiovskaya, M; Hadjidakis, C; Hartig, M; Hasch, D; Hill, G; Hillenbrand, A; Hoek, M; Holler, Y; Hristova, I; Imazu, Y; Ivanilov, A; Jackson, H E; Jgoun, A; Jo, H S; Joosten, S; Kaiser, R; Karyan, G; Keri, T; Kinney, E; Kisselev, A; Kobayashi, N; Korotkov, V; Kozlov, V; Krauss, B; Kravchenko, P; Krivokhijine, V G; Lagamba, L; Lamb, R; Lapikas, L; Lehmann, I; Lenisa, P; Linden-Levy, L A; Ruiz, A Lopez; Lorenzon, W; Lu, X -G; Lu, X -R; Ma, B -Q; Mahon, D; Makins, N C R; Manaenkov, S I; Manfre, L; Mao, Y; Marianski, B; de la Ossa, A Martinez; Marukyan, H; Miller, C A; Movsisyan, A; Muccifora, V; Murray, M; Mueller, D; Mussgiller, A; Nappi, E; Naryshkin, Y; Nass, A; Negodaev, M; Nowak, W -D; Pappalardo, L L; Perez-Benito, R; Pickert, N; Raithel, M; Reimer, P E; Reolon, A R; Riedl, C; Rith, K; Rosner, G; Rostomyan, A; Rubin, J; Ryckbosch, D; Salomatin, Y; Sanftl, F; Schaefer, A; Schnell, G; Schueler, K P; Seitz, B; Shibata, T -A; Shutov, V; Stancari, M; Statera, M; Steffens, E; Steijger, J J M; Stenzel, H; Stewart, J; Stinzing, F; Taroian, S; Terkulov, A; Trzcinski, A; Tytgat, M; Vandenbroucke, A; Van der Nat, P B; Van Haarlem, Y; Van Hulse, C; Veretennikov, D; Vikhrov, V; Vilardi, I; Vogel, C; Wang, S; Yaschenko, S; Ye, Z; Yen, S; Yu, W; Zeiler, D; Zihlmann, B; Zupranski, P
2010-01-01T23:59:59.000Z
Azimuthal asymmetries in exclusive electroproduction of a real photon from a longitudinally polarized deuterium target are measured with respect to target polarization alone and with respect to target polarization combined with beam helicity and/or beam charge. The asymmetries appear in the distribution of the real photons in the azimuthal angle $\\phi$ around the virtual photon direction, relative to the lepton scattering plane. The asymmetries arise from the deeply virtual Compton scattering process and its interference with the Bethe-Heitler process. The results for the beam-charge and beam-helicity asymmetries from a tensor polarized deuterium target with vanishing vector polarization are shown to be compatible with those from an unpolarized deuterium target, which is expected for incoherent scattering dominant at larger momentum transfer. Furthermore, the results for the single target-spin asymmetry and for the double-spin asymmetry are found to be compatible with the corresponding asymmetries previously ...
BIOISIS: Biological Macromolecules by Small Angle X-ray Scattering (SAXS)
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
Tainer, John (Scripps Research Institute); Hura, Greg (LBNL); Rambo, Robert P. (LBNL)
BIOISIS is an open access database dedicated to the study of biological macromolecules by small angle X-ray scattering (SAXS). BIOISIS aims to become the complete source for the deposition, distribution and maintenance of small angle X-ray scattering data and technologies. The database is designed around the concept of an ôexperimentö and relates a specific experiment to a set of genes, organisms, computational models and experimental data. As of May 2012, BIOSIS contains 7,118 genes covering four different organisms. Forty-two modeled structures are available. Clicking on a structures reveals scattering curves, experimental conditions, and experimental values. The data are collected at Beamline 12.3.1 of the Advanced Light Source (ALS).[Copied with editing from http://www.bioisis.net/about
Thulasidasan, Sunil [Los Alamos National Laboratory; Kasiviswanathan, Shiva [Los Alamos National Laboratory; Eidenbenz, Stephan [Los Alamos National Laboratory; Romero, Philip [Los Alamos National Laboratory
2010-01-01T23:59:59.000Z
We re-examine the problem of load balancing in conservatively synchronized parallel, discrete-event simulations executed on high-performance computing clusters, focusing on simulations where computational and messaging load tend to be spatially clustered. Such domains are frequently characterized by the presence of geographic 'hot-spots' - regions that generate significantly more simulation events than others. Examples of such domains include simulation of urban regions, transportation networks and networks where interaction between entities is often constrained by physical proximity. Noting that in conservatively synchronized parallel simulations, the speed of execution of the simulation is determined by the slowest (i.e most heavily loaded) simulation process, we study different partitioning strategies in achieving equitable processor-load distribution in domains with spatially clustered load. In particular, we study the effectiveness of partitioning via spatial scattering to achieve optimal load balance. In this partitioning technique, nearby entities are explicitly assigned to different processors, thereby scattering the load across the cluster. This is motivated by two observations, namely, (i) since load is spatially clustered, spatial scattering should, intuitively, spread the load across the compute cluster, and (ii) in parallel simulations, equitable distribution of CPU load is a greater determinant of execution speed than message passing overhead. Through large-scale simulation experiments - both of abstracted and real simulation models - we observe that scatter partitioning, even with its greatly increased messaging overhead, significantly outperforms more conventional spatial partitioning techniques that seek to reduce messaging overhead. Further, even if hot-spots change over the course of the simulation, if the underlying feature of spatial clustering is retained, load continues to be balanced with spatial scattering leading us to the observation that spatial scattering can often obviate the need for dynamic load balancing.
Saccomandi, Paola; Schena, Emiliano; Silvestri, Sergio [Faculty of Biomedical Engineering, University Campus Bio-Medico, Via Alvaro del Portillo, 21, 00128 Rome (Italy)
2011-02-15T23:59:59.000Z
An optoelectronic target-type volumetric air flow-rate transducer for bidirectional measurements is presented. The sensor is composed of a T-shaped target and two nominally identical LED-photodiode couples which are operated in differential mode. The sensitive surfaces of the photodiodes are differentially shadowed by the deflection of the target, which in turn depends on the gas flow-rate. The principle of operation is described in mathematical terms and the design parameters have been optimized in order to obtain the highest sensitivity along with minimal pressure drop and reduced dimensions. The sensor is placed in a 20 mm diameter hose and was tested with air flow-rate in the typical temperature range of mechanical ventilation between 20 and 40 deg. C. The theoretical model was validated through experiments carried out in the volumetric flow range from -7.0 to +7.0 l min{sup -1}. The nonlinear behavior allows sensitivities equal to 0.6 V l{sup -1} min for flow rates ranging from -2.0 to +2.0 l min{sup -1}, equal to 2.0 V l{sup -1} min for flow rates ranging from -3.0 to -2.0 l min{sup -1} and from +2.0 to +3.0 l min{sup -1}, up to 5.7 V l{sup -1} min at higher flow rates ranging from -7.0 to -3.0 l min{sup -1} and from +3.0 to +7.0 l min{sup -1}. The linear range extends from 3.0 to 7.0 l min{sup -1} with constant sensitivity equal to 5.7 V l{sup -1} min. The sensor is able to detect a flow-rate equal to 1.0 l min{sup -1} with a sensitivity of about 400 mV l{sup -1} min. The differential nature of the output minimizes the influence of the LEDs' power supply variations and allows to obtain a repeatability in the order of 3% of full scale output. The small pressure drop produced by the sensor placed in-line the fluid stream, of about 2.4 Pa at 7 l min{sup -1}, corresponds to a negligible fluid dynamic resistance lower than 0.34 Pa l{sup -1} min.
Stimulated Raman scattering in large plasmas
Phillion, D.W.; Banner, D.L.
1980-11-06T23:59:59.000Z
Stimulated Raman scattering is of concern to laser fusion since it can create a hot electron environment which can increase the difficulty of achieving high final fuel densities. In earlier experiments with one micron laser light, the energy measured in Raman-scattered light has been insignificant. But these experiments were done with, at most, about 100 joules of laser energy. The Raman instability has a high threshold which also requires a large plasma to be irradiated with a large diameter spot. Only with a long interaction length can the Raman-scattered light wave convectively grow to a large amplitude, and only in recent long pulse, high energy experiments (4000 joules in 2 ns) at the Shiva laser facility have we observed as much as several percent of the laser light to be Raman-scattered. We find that the Raman instability has a much lower intensity threshold for longer laser pulselength and larger laser spot size on a solid target.
QED radiative corrections to virtual Compton scattering
M. Vanderhaeghen; J. M. Friedrich; D. Lhuillier; D. Marchand; L. Van Hoorebeke; J. Van de Wiele
2000-01-12T23:59:59.000Z
The QED radiative corrections to virtual Compton scattering (reaction $e p \\to e p \\gamma$) are calculated to first order in $\\alpha_{em} \\equiv e^2 / 4 \\pi$. A detailed study is presented for the one-loop virtual corrections and for the first order soft-photon emission contributions. Furthermore, a full numerical calculation is given for the radiative tail, corresponding with photon emission processes, where the photon energy is not very small compared with the lepton momenta. We compare our results with existing works on elastic electron-proton scattering, and show for the $e p \\to e p \\gamma$ reaction how the observables are modified due to these first order QED radiative corrections. We show results for both unpolarized and polarized observables of the virtual Compton scattering in the low energy region (where one is sensitive to the generalized polarizabilities of the nucleon), as well as for the deeply virtual Compton scattering.
Compton Scattering in the ALS Booster
Robin, David
2008-01-01T23:59:59.000Z
pulses by colliding short laser pulses with highly focusedAs a result of the laser pulses short duration and the elec-ton side scattering of a short visible laser beam by a well-
Scattering Properties of Oriented Hexagonal Ice Crystals
Zhang, Feng
2010-01-14T23:59:59.000Z
To interpret the data from spaceborn lidar measurements, one must have a basic understanding of the backscattering of oriented ice particles. The conventional raytracing method is not applicable to the scattering of light by oriented particles...
Conformal Bootstrap, Universality and Gravitational Scattering
Steven Jackson; Lauren McGough; Herman Verlinde
2014-12-23T23:59:59.000Z
We use the conformal bootstrap equations to study the non-perturbative gravitational scattering between infalling and outgoing particles in the vicinity of a black hole horizon in AdS. We focus on irrational 2D CFTs with large $c$ and only Virasoro symmetry. The scattering process is described by the matrix element of two light operators (particles) between two heavy states (BTZ black holes). We find that the operator algebra in this regime is (i) universal and identical to that of Liouville CFT, and (ii) takes the form of an exchange algebra, specified by an R-matrix that exactly matches with the scattering amplitude of 2+1 gravity. The R-matrix is given by a quantum 6j-symbol and the scattering phase by the volume of a hyperbolic tetrahedron. We comment on the relevance of our results to scrambling and the holographic reconstruction of the bulk physics near black hole horizons.
INELASTIC LIGHT SCATTERING STUDIES OF BOROCARBIDE SUPERCONDUCTORS
Yang, In-Sang
INELASTIC LIGHT SCATTERING STUDIES OF BOROCARBIDE SUPERCONDUCTORS INSANG YANG Department In recent years of studies in ``unconventional'' superconductivity, researchers have concentrated on exotic behavior of the heavy fermion and cuprate su perconductors. However, even superconductors that are thought
What Does a Scattering Pattern Tell US?
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
amplitude e iwt Phase difference Phase difference S e i (ri Q) A(DK) fi A(Q) Fourier Transform ( ri ) DK Q 4p sin(q) l Lensless Imaging Sample Space Scattering Space...
Fully relativistic form factor for Thomson scattering
Palastro, J. P.; Ross, J. S.; Pollock, B.; Divol, L.; Froula, D. H.; Glenzer, S. H. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States)
2010-03-15T23:59:59.000Z
We derive a fully relativistic form factor for Thomson scattering in unmagnetized plasmas valid to all orders in the normalized electron velocity, beta->=v->/c. The form factor is compared to a previously derived expression where the lowest order electron velocity, beta->, corrections are included [J. Sheffield, Plasma Scattering of Electromagnetic Radiation (Academic Press, New York, 1975)]. The beta-> expansion approach is sufficient for electrostatic waves with small phase velocities such as ion-acoustic waves, but for electron-plasma waves the phase velocities can be near luminal. At high phase velocities, the electron motion acquires relativistic corrections including effective electron mass, relative motion of the electrons and electromagnetic wave, and polarization rotation. These relativistic corrections alter the scattered emission of thermal plasma waves, which manifest as changes in both the peak power and width of the observed Thomson-scattered spectra.
Neutron-deuteron breakup and quasielastic scattering
Ohlson, Alice Elisabeth
2009-01-01T23:59:59.000Z
Quasielastic scattering and deuteron breakup in the 200 MeV region is studied by impinging a pulsed neutron beam on a deuterium target at the Weapons Neutron Research facility at the Los Alamos Neutron Science Center. The ...
W. J. Henney
1994-03-11T23:59:59.000Z
A general theoretical framework is developed for interpreting spectropolarimetric observations of optically thin emission line scattering from small dust particles. Spatially integrated and spatially resolved line profiles of both scattered intensity and polarization are calculated analytically from a variety of simple kinematic models. These calculations will provide a foundation for further studies of emission line scattering from dust and electrons in such diverse astrophysical environments as Herbig-Haro objects, symbiotic stars, starburst galaxies and active galactic nuclei.
Can one extract the pi-neutron scattering length from pi-deuteron scattering?
A. Nogga; C. Hanhart
2005-11-02T23:59:59.000Z
We give a prove of evidence that the original power counting by Weinberg can be applied to estimate the contributions of the operators contributing to the pi-deuteron scattering length. As a consequence, pi-deuteron observables can be used to extract neutron amplitudes--in case of pi-deuteron scattering this means that the pi-neutron scattering length can be extracted with high accuracy. This result is at variance with recent claims. We discuss the origin of this difference.
Onar, Omer C [ORNL] [ORNL
2011-01-01T23:59:59.000Z
This study presents a bi-directional multi-level power electronic interface for the grid interactions of plug-in hybrid electric vehicles (PHEVs) as well as a novel bi-directional power electronic converter for the combined operation of battery/ultracapacitor hybrid energy storage systems (ESS). The grid interface converter enables beneficial vehicle-to-grid (V2G) interactions in a high power quality and grid friendly manner; i.e, the grid interface converter ensures that all power delivered to/from grid has unity power factor and almost zero current harmonics. The power electronic converter that provides the combined operation of battery/ultra-capacitor system reduces the size and cost of the conventional ESS hybridization topologies while reducing the stress on the battery, prolonging the battery lifetime, and increasing the overall vehicle performance and efficiency. The combination of hybrid ESS is provided through an integrated magnetic structure that reduces the size and cost of the inductors of the ESS converters. Simulation and experimental results are included as prove of the concept presenting the different operation modes of the proposed converters.
Light-scattering studies of silica aerogels
Hunt, A.J.
1983-02-01T23:59:59.000Z
Due to its combination of transparency and low thermal conductivity, aerogel holds considerable promise for use as insulating window materials for residential and commercial applications. This paper reports on the preliminary investigation of the optical and scattering properties of silica aerogels. It briefly describes the properties of aerogels important for window glazing applications. The optical properties are then described, followed by a discussion of the scattering measurements and their interpretation.
QCD Sum Rules and Compton Scattering
Claudio Coriano'; Anatoly Radyushkin; George Sterman
1993-01-26T23:59:59.000Z
We extend QCD sum rule analysis to moderate energy fixed angle Compton scattering. In this kinematic region there is a strong similarity to the sum rule treatment of electromagnetic form factors, although the four-point amplitude requires a modification of the Borel transform. To illustrate our method, we derive the sum rules for helicity amplitudes in pion Compton scattering and estimate their large-$t$ behavior in the local duality approximation.
Parity Violation in gamma proton Compton Scattering
Paulo F. Bedaque; Martin J. Savage
1999-10-19T23:59:59.000Z
A measurement of parity-violating spin-dependent gamma proton Compton scattering will provide a theoretically clean determination of the parity-violating pion-nucleon coupling constant $h_{\\pi NN}^{(1)}$. We calculate the leading parity-violating amplitude arising from one-loop pion graphs in chiral perturbation theory. An asymmetry of ~5 10^{-8} is estimated for Compton scattering of 100 MeV photons.
Scattering by coupled resonating elements in air
Anton Krynkin; Olga Umnova; Alvin Y. B. Chong; Shahram Taherzadeh; Keith Attenborough
2011-01-12T23:59:59.000Z
Scattering by (a) a single composite scatterer consisting of a concentric arrangement of an outer N-slit rigid cylinder and an inner cylinder which is either rigid or in the form of a thin elastic shell and (b) by a finite periodic array of these scatterers in air has been investigated analytically and through laboratory experiments. The composite scatterer forms a system of coupled resonators and gives rise to multiple low frequency resonances. The corresponding analytical model employs polar angle dependent boundary conditions on the surface of the N-slit cylinder. The solution inside the slits assumes plane waves. It is shown also that in the low-frequency range the N-slit rigid cylinder can be replaced by an equivalent fluid layer. Further approximations suggest a simple square root dependence of the resonant frequencies on the number of slits and this is confirmed by data. The observed resonant phenomena are associated with Helmholtz-like behaviour of the resonator for which the radius and width of the openings are much smaller than the wavelength. The problem of scattering by a finite periodic array of such coupled resonators in air is solved using multiple scattering techniques. The resulting model predicts band-gap effects resulting from the resonances of the individual composite scatterers below the first Bragg frequency . Predictions and data confirm that use of coupled resonators results in substantial insertion loss peaks related to the resonances within the concentric configuration. In addition, for both scattering problems experimental data, predictions of the analytical approach and predictions of the equivalent fluid layer approximations are compared in the low-frequency interval.
Symmetry Algebra of IIB Superstring Scattering
Gordon Chalmers
2005-10-26T23:59:59.000Z
The graviton scattering in IIB superstring theory is examined in the context of S-duality and symmetry. There is an algebra that generates all of the terms in the four-point function to any order in derivatives. A map from the algebra to the scattering is given; it suggests the correctness of the full four-point function with the S-duality. The higher point functions are expected to follow a similar pattern.
Variation of Entanglement Entropy in Scattering Process
I. Y. Park; Shigenori Seki; Sang-Jin Sin
2015-01-09T23:59:59.000Z
In a scattering process, the final state is determined by an initial state and an S-matrix. We focus on two-particle scattering processes and consider the entanglement between these particles. For two types initial states; i.e., an unentangled state and an entangled one, we calculate perturbatively the change of entanglement entropy from the initial state to the final one. Then we show a few examples in a field theory and in quantum mechanics.
Combinatorial Design of Key Distribution Mechanisms for Wireless Sensor Networks
Bystroff, Chris
Combinatorial Design of Key Distribution Mechanisms for Wireless Sensor Networks Seyit A. CÂ¸amtepe1 of the most challenging security issues in wireless sensor networks where sensor nodes are randomly scattered-chain sizes. 1 Introduction and Problem Definition In this work, we consider a sensor network in which sensor
Combinatorial Design of Key Distribution Mechanisms for Wireless Sensor Networks
Bystroff, Chris
Combinatorial Design of Key Distribution Mechanisms for Wireless Sensor Networks Seyit A. Câ?º amtepe of the most challenging security issues in wireless sensor networks where sensor nodes are randomly scatteredÂchain sizes. 1 Introduction and Problem Definition In this work, we consider a sensor network in which sensor
Distributed DBMS I Introduction
Chen, Yangjun
Distributed DBMS Outline I Introduction I Background I Distributed DBMS Architecture I Distributed Data server approach Parallel architectures Parallel DBMS techniques Parallel execution models Parallel Database Systems Distributed Object DBMS Database Interoperability Concluding Remarks #12
Distributed Theorem Proving for Distributed Hybrid Systems
Platzer, André
system with a varying number of arbitrarily many cars. 1 Introduction Hybrid systems with joint discrete a multi-agent system, e.g., distributed car control systems. Such systems form distributed hybrid systemsDistributed Theorem Proving for Distributed Hybrid Systems David W. Renshaw, Sarah M. Loos
Ps-atom scattering at low energies
Fabrikant, I I
2015-01-01T23:59:59.000Z
A pseudopotential for positronium-atom interaction, based on electron-atom and positron-atom phase shifts, is constructed, and the phase shifts for Ps-Kr and Ps-Ar scattering are calculated. This approach allows us to extend the Ps-atom cross sections, obtained previously in the impulse approximation [Phys. Rev. Lett. 112, 243201 (2014)], to energies below the Ps ionization threshold. Although experimental data are not available in this low-energy region, our results describe well the tendency of the measured cross sections to drop with decreasing velocity at $v<1$ a.u. Our results show that the effect of the Ps-atom van der Waals interaction is weak compared to the polarization interaction in electron-atom and positron-atom scattering. As a result, the Ps scattering length for both Ar and Kr is positive, and the Ramsauer-Townsend minimum is not observed for Ps scattering from these targets. This makes Ps scattering quite different from electron scattering in the low-energy region, in contrast to the inter...
Study on generating of thermal neutron scattering cross sections for LiH
Wang, L.; Jiang, X.; Zhao, Z.; Chen, L. [Northwest Institute of Nuclear Technology, Xi'an 710024 (China)
2013-07-01T23:59:59.000Z
LiH is designated as a promising moderator and shielding material because of its low density, high melting point and large fraction of H atoms. However, lack of the thermal neutron cross sections of LiH makes numerical calculation deviate from experimental data to some extent. As a result, it is necessary to study LiH thermal kernel effect. The phonon property of LiH has been investigated by first-principles calculations using the plane-wave pseudo potential method with CASTEP code. The scattering law and the thermal neutron scattering cross sections for Li and H have been generated using this distribution. The results have been compared with zirconium hydride data. The GASKET and NJOY/LEAPR codes have been used in the calculation of scattering law, whose results have been compared with the reference; the discrepancy mainly comes from phonon spectrums and its expansion. LEAPR had the capability to compute scattering through larger energy and momentum transfers than GASKET did. By studying LiH phonon spectrum and constructing the model of LiH thermal kernel and scattering matrix, the ACE format LiH thermal neutron cross sections for MCNP software could be made and used for reactor Neutronics calculation. (authors)
Neutron and X-ray Scattering Study of Magnetic Manganites
Boothroyd, Andrew
Neutron and X-ray Scattering Study of Magnetic Manganites Graeme Eoin Johnstone A Thesis submitted are performed using a variety of neutron scattering and x-ray scattering techniques. The electronic ground for analysing the results of the polarised neutron scattering experiment. There are a large number of people who
Neutron scattering at high pressure D. B. McWhan
Paris-Sud XI, Université de
715 Neutron scattering at high pressure D. B. McWhan Room 1D-234, Murray Hill, New Jersey 07974, U scattering at steady-state and pulsed sources are reviewed. The pressure cells available at most neutron 10 GPa have been made. For elastic scattering, a comparison is made between neutron scattering and X
Magnetic response of energy levels of superconducting nanoparticles with spin-orbit scattering
Nesterov, Konstantin N
2015-01-01T23:59:59.000Z
Discrete energy levels of ultrasmall metallic grains are extracted in single-electron-tunneling-spectroscopy experiments. We study the response of these energy levels to an external magnetic field in the presence of both spin-orbit scattering and pairing correlations. In particular, we investigate $g$-factors and level curvatures that parametrize, respectively, the linear and quadratic terms in the magnetic-field dependence of the many-particle energy levels of the grain. Both of these quantities exhibit level-to-level fluctuations in the presence of spin-orbit scattering. We show that the distribution of $g$-factors is not affected by the pairing interaction and that the distribution of level curvatures is sensitive to pairing correlations even in the smallest grains in which the pairing gap is smaller than the mean single-particle level spacing. We propose the level curvature in a magnetic field as a tool to probe pairing correlations in tunneling spectroscopy experiments.
Producing a compound Nucleus via Inelastic Scattering: The 90Zr(alpha,alpha')90Zr* Case
Escher, J E; Dietrich, F S
2008-05-23T23:59:59.000Z
In a Surrogate reaction a compound nucleus is produced via a direct reaction (pickup, stripping, or inelastic scattering). For a proper application of the Surrogate approach it is necessary to predict the resulting angular momentum and parity distribution in the compound nucleus. A model for determining these distributions is developed for the case of inelastic alpha scattering off a spherical nucleus. The focus is on obtaining a first, simple description of the direct-reaction process that produces the compound nucleus and on providing the basis for a more complete treatment of the problem. The approximations employed in the present description are discussed and the extensions required for a more rigorous treatment of the problem are outlined. To illustrate the formalism, an application to {sup 90}Zr({alpha},{alpha}{prime}){sup 90}Zr* is presented.
Anirban Pathak; Jaromir Krepelka; Jan Perina
2012-10-14T23:59:59.000Z
A completely quantum description of Raman process is used to investigate the nonclassical properties of the modes in the stimulated, spontaneous and partially spontaneous Raman process. Both coherent scattering (where all the initial modes are coherent) and chaotic scattering (where initial phonon mode is chaotic and all the other modes are coherent) are studied. Nonclassical character of Raman process is observed by means of intermodal entanglement, single mode and intermodal squeezing of vacuum fluctuations, sub-shot noise and wave variances. Joint photon-phonon number and integrated-intensity distributions are then used to illustrate the observed nonclassicalities. Conditional and difference number distributions are also provided to illustrate the nonclassical character. The mutual relation between the obtained nonclassicalities and their variations dependent on phases, rescalled time and ratio of coupling constants are also reported.
Effective Spectral Function for Quasielastic Scattering on Nuclei from Deuterium to Lead
A. Bodek; M. E. Christy; B. Coopersmith
2014-09-30T23:59:59.000Z
Spectral functions do not fully describe quasielastic electron and neutrino scattering from nuclei because they only model the initial state. Final state interactions distort the shape of the differential cross section at the peak and increase the cross section at the tails of the distribution. We show that the kinematic distributions predicted by the $\\psi'$ superscaling formalism can be well described with a modified {\\it {effective spectral function}} (ESF). By construction, models using ESF in combination with the transverse enhancement contribution correctly predict electron QE scattering data. Our values for the binding energy parameter $\\Delta$ are smaller than $\\overline{\\epsilon}$ extracted within the Fermi gas model from pre 1971 data by Moniz, probably because these early cross sections were not corrected for coulomb effects.
Investigation of quasielastic muon-neutrino scattering on nuclei at E{sub v} < 1 GeV
Agababyan, N. M. [Joint Institute for Nuclear Research (Russian Federation); Ammosov, V. V. [Institute for High Energy Physics (Russian Federation); Atayan, M.; Grigoryan, N.; Gulkanyan, H. [Yerevan Physics Institute (Armenia); Ivanilov, A. A. [Institute for High Energy Physics (Russian Federation)], E-mail: ivanilov@ihep.ru; Karamyan, Zh. [Yerevan Physics Institute (Armenia); Korotkov, B. A. [Institute for High Energy Physics (Russian Federation)
2007-10-15T23:59:59.000Z
Quasielastic muon-neutrino scattering on nuclei of propane-Freon mixture at energies in the range E{sub v} < 1 GeV is studied. The multiplicity, momentum, and emission-angle distributions of final protons are measured along with the dependence of the mean values for these distributions on the neutrino energy in the range 0.2 < E{sub v} < 1 GeV.
Infrared Safety in Factorized Hard Scattering Cross-Sections
Andrew Hornig; Christopher Lee; Grigory Ovanesyan
2009-05-13T23:59:59.000Z
The rules of soft-collinear effective theory can be used naively to write hard scattering cross-sections as convolutions of separate hard, jet, and soft functions. One condition required to guarantee the validity of such a factorization is the infrared safety of these functions in perturbation theory. Using e+e- angularity distributions as an example, we propose and illustrate an intuitive method to test this infrared safety at one loop. We look for regions of integration in the sum of Feynman diagrams contributing to the jet and soft functions where the integrals become infrared divergent. Our analysis is independent of an explicit infrared regulator, clarifies how to distinguish infrared and ultraviolet singularities in pure dimensional regularization, and demonstrates the necessity of taking zero-bins into account to obtain infrared-safe jet functions.
A passive FPAA based RF scatter meteor detector
Popowicz, Adam; Bernacki, Krzysztof; Fietkiewicz, Karol
2015-01-01T23:59:59.000Z
In the article we present a hardware meteor detector. The detection principle is based on the electromagnetic wave reflection from the ionized meteor trail in the atmosphere. The detector uses the ANADIGM field programmable analogue array (FPAA), which is an attractive alternative for a typically used detecting equipment - a PC computer with dedicated software. We implement an analog signal path using most of available FPAA resources to obtain precise audio signal detection. Our new detector was verified in collaboration with the Polish Fireball Network - the organization which monitors meteor activity in Poland. When compared with currently used signal processing PC software employing real radio meteor scatter signals, our low-cost detector proved to be more precise and reliable. Due to its cost and efficiency superiority over the current solution, the presented module is going to be implemented in the planned distributed detectors system.
Single and double polarization observables in timelike Compton scattering off proton
Boër, Marie; Vanderhaeghen, Marc
2015-01-01T23:59:59.000Z
We study the exclusive photoproduction of a lepton pair off the proton with the aim of studying the proton quark structure via the Generalized Parton Distributions (GPD) formalism. After deriving the amplitudes of the processes contributing to the $\\gamma P\\to P' e^+e^-$, the Timelike Compton Scattering and the Bethe-Heitler process, we calculate all unpolarized, single- and double- beam-target spin observables in the valence region in terms of GPDs.
Elastic scattering and total reaction cross section of {sup 6}He+{sup 120}Sn
Faria, P. N. de; Lichtenthaeler, R.; Pires, K. C. C.; Lepine-Szily, A.; Guimaraes, V.; Mendes, D. R. Jr.; Barioni, A.; Morcelle, V.; Morais, M. C.; Camargo, O. Jr.; Alcantara Nunez, J. [Instituto de Fisica-Universidade de Sao Paulo, C. P. 66318, 05389-970 Sao Paulo, SP (Brazil); Moro, A. M. [Departamento de FAMN, Universidad de Sevilla, Apartado 1065, E-41080 Sevilla (Spain); Arazi, A. [Laboratorio Tandar, Comision Nacional de Energia Atomica, Av. del Libertador 8250, 1429 Buenos Aires (Argentina); Rodriguez-Gallardo, M. [Departamento de FAMN, Universidad de Sevilla, Apartado 1065, E-41080 Sevilla (Spain); Instituto de Estructura de la Materia, CSIC, Serrano 123, E-28006 Madrid (Spain); Assuncao, M. [Universidade Federal de Sao Paulo, Campus Diadema, 09941-510 Sao Paulo, SP (Brazil)
2010-04-15T23:59:59.000Z
The elastic scattering of {sup 6}He on {sup 120}Sn has been measured at four energies above the Coulomb barrier using the {sup 6}He beam produced at the RIBRAS (Radioactive Ion Beams in Brasil) facility. The elastic angular distributions have been analyzed with the optical model and three- and four-body continuum-discretized coupled-channels calculations. The total reaction cross sections have been derived and compared with other systems of similar masses.
Foroutan, G. R.; Robinson, P. A.; Sobhanian, S.; Moslehi-Fard, M.; Li, B.; Cairns, I. H. [School of Physics, University of Sydney, NSW 2006, Sydney (Australia); Research Institute for Astronomy and Astrophysics of Maragha, P.O. Box 55134-441 Maragha (Iran, Islamic Republic of) and Physics Department, Faculty of Science, Sahand University of Technology, 51335-1996 Tabriz (Iran); School of Physics, University of Sydney, NSW 2006, Sydney (Australia); Research Institute for Astronomy and Astrophysics of Maragha, P.O. Box 55134-441 Maragha (Iran, Islamic Republic of) and Faculty of Physics, Tabriz University, Tabriz 51664 (Iran); Faculty of Physics, Tabriz University, Tabriz 51664 (Iran, Islamic Republic of); School of Physics, University of Sydney, NSW 2006, Sydney (Australia)
2007-01-15T23:59:59.000Z
Gas-dynamic theory is generalized to incorporate the effects of beam-driven Langmuir waves scattering off ambient density fluctuations, and the consequent effects on the propagation of a cloud of hot electrons in an inhomogeneous plasma. Assuming Langmuir scattering as the limit of nonlinear three-wave interactions with fluctuations that are weak, low-frequency, long-wavelength ion-sound waves, the net effect of scattering is equivalent to effective damping of the Langmuir waves. Under the assumption of self-similarity in the evolution of the beam and Langmuir wave distribution functions, gas-dynamic theory shows that the effects of Langmuir scattering on the beam distribution are equivalent to a perturbation in the injection profile of the beam. Analytical expressions are obtained for the height of the plateau of the beam distribution function, wave spectral number density, total wave and particle energy density, and the beam number density. The main results of gas-dynamic theory are then compared with simulation results from numerical solutions of quasilinear equations. The relaxation of the beam in velocity space is retarded in the presence of density fluctuations and the magnitude of the upper velocity boundary is less than that in the absence of fluctuations. There are four different regimes for the height of the plateau, corresponding to different stages of relaxation of the beam in velocity space. Moreover, Langmuir scattering results in transfer of electrons from moderate velocity to low velocity; this effect produces an enhancement in the beam number density at small distances near the injection site and a corresponding decrease at large distances. There are sharp decreases in the profiles of the beam and total wave energy densities, which are related to dissipation of energy at large phase velocities. Due to a slower velocity space diffusion of the beam distribution in the presence of scattering effects, the spatial width of the beam is reduced while its mean velocity of propagation increases slightly.
Manson, Joseph R.
Gas-surface scattering with multiple collisions in the physisorption potential well Guoqing Fan The problem of gas-surface collisions is developed in terms of a theoretical formalism that allows calcula gas distributions are considered, a monoenergetic incident beam and an equilibrium gas appropriate
Boley, Aaron C.; Payne, Matthew J.; Ford, Eric B. [Department of Astronomy, University of Florida, 211 Bryant Space Science Center, P.O. Box 112055, Gainesville, FL 32611 (United States)
2012-07-20T23:59:59.000Z
The chance that a planetary system will interact with another member of its host star's nascent cluster would be greatly increased if gas giant planets form in situ on wide orbits. In this paper, we explore the outcomes of planet-planet scattering for a distribution of multi-planet systems that all have one of the planets on an initial orbit of 100 AU. The scattering experiments are run with and without stellar flybys. We convolve the outcomes with distributions for protoplanetary disk and stellar cluster sizes to generalize the results where possible. We find that the frequencies of large mutual inclinations and high eccentricities are sensitive to the number of planets in a system, but not strongly to stellar flybys. However, flybys do play a role in changing the low and moderate portions of the mutual inclination distributions, and erase dynamically cold initial conditions on average. Wide-orbit planets can be mixed throughout the planetary system, and in some cases, can potentially become hot Jupiters, which we demonstrate using scattering experiments that include a tidal damping model. If planets form in situ on wide orbits, then there will be discernible differences in the proper-motion distributions of a sample of wide-orbit planets compared with a pure scattering formation mechanism. Stellar flybys can enhance the frequency of ejections in planetary systems, but autoionization is likely to remain the dominant source of free-floating planets.
Simulation and Application of Light Scattering Properties for Scatterers with Large Aspect Ratios
Sun, Bingqiang
2014-12-02T23:59:59.000Z
scatterers with one dimension periodicity, a semi-analytical solution instead of the iterative technique has been obtained by extending the application of the MBIT method to infinite number of sub-units. The semi-analytical solution of a scatterer with 1-D...
Simulation and Application of Light Scattering Properties for Scatterers with Large Aspect Ratios
Sun, Bingqiang
2014-12-02T23:59:59.000Z
For scatterers with axial or N-fold rotational symmetry, the T-matrix is one of the most efficient techniques to obtain the scattering properties. Extended boundary condition method (EBCM) and invariant imbedding T-matrix method (II-TM...
Bipolar pulse coding for enhanced performance in Brillouin distributed optical fiber sensors
Thévenaz, Jacques
Bipolar pulse coding for enhanced performance in Brillouin distributed optical fiber sensors-sideband suppressed-carrier (SSB-SC) modulation in Brillouin optical time-domain analysis (BOTDA) sensors. The SSB conventional unipolar sequences. Keywords: Stimulated Brillouin scattering, distributed optical fiber sensor
Modeling and evaluating the performance of Brillouin distributed optical fiber sensors
Dalang, Robert C.
Modeling and evaluating the performance of Brillouin distributed optical fiber sensors Marcelo A analysis of the key factors impacting on the performance of Brillouin distributed optical fiber sensors of America OCIS codes: (060.2310) Fiber optics; (060.2370) Fiber optics sensors; (290.5900) Scattering
Thévenaz, Jacques
Double-pulse Brillouin distributed optical fiber sensors: analytical model and experimental-pulse Brillouin optical time-domain analysis (DP-BOTDA) sensors. The proposed model is a tool that provides a full. Keywords: Stimulated Brillouin scattering, distributed optical fiber sensor, temperature sensing, strain
Hard quark-quark scattering with exclusive reactions
Barton, D.S.; Bunce, G.M.; Carroll, A.S.; Makdisi, Y.I.; Baller, B.; Blazey, G.C.; Courant, H.; Heller, K.J.; Heppelmann, S.; Marshak, M.L.
1984-07-19T23:59:59.000Z
We have begun a program designed to study hard quark-quark scattering with exclusive reactions, focusing on quasi-elastic two-body reactions with all possible quark flavor exchanges. Examples are ..pi../sup -/p ..-->.. ..pi../sup -/p, rho/sup -/p, ..pi../sup +/..delta../sup -/, K/sup +/..sigma../sup -/, or K..lambda... Of the two-body exclusives, only elastic scattering had been measured at such large t previous to our experiment. By comparing the relative importance of different final states, the energy dependence of the production ratios of these states, the prominence of resonances such as rho/sup -/ over background in this region, and measuring polarizations where accessible, we have collected a large body of data on hard scattering in a completely new domain. Previously, essential all short distance QCD tests have been for inclusive processes. We have taken data with both negative and positive incident beam at 10 GeV/c on a hydrogen target and will present the first results, for ..pi../sup -/p ..-->.. ..pi../sup -/p and rho/sup -/p at THETA/sub cm/ = 90/sup 0/, -t = 9 GeV/sup 2//c/sup 2/. The apparatus consists of a magnetic spectrometer, with Cerenkov particle identification, which selects stable charged particles (protons in this case) at high momentum near 90/sup 0/ in the center-of-mass. A large aperture array of PWCs observes the recoil particle or charged decay products. Cross sections are extremely low, approximately a 1 nb/(GeV/c)/sup 2/ for elastic scattering. We will report on a sample of more than 1000 ..pi../sup -/p elastic events, and on rho/sup -/p, where the rho/sup -/ decay distribution was observed. We find a surprisingly large rho/sup -/p cross section in this large momentum transfer region, with rho/sup -/p about half the elastic cross section, and a striking spin alignment of the rho/sup -/.
Inclusion of Scatter in HADES: Final Report
Aufderheide, M B
2010-12-20T23:59:59.000Z
Covert nuclear attack is one of the foremost threats facing the United States and is a primary focus of the War on Terror. The Domestic Nuclear Detection Office (DNDO), within the Department of Homeland Security (DHS), is chartered to develop, and improve domestic systems to detect and interdict smuggling for the illicit use of a nuclear explosive device, fissile material or radiologica1 material. The CAARS (Cargo Advanced Automated Radiography System) program is a major part of the DHS effort to enhance US security by harnessing cutting-edge technologies to detect radiological and nuclear threats at points of entry to the United States. DNDO has selected vendors to develop complete radiographic systems. It is crucial that the initial design and testing concepts for the systems be validated and compared prior to the substantial efforts to build and deploy prototypes and subsequent large-scale production. An important aspect of these systems is the scatter which interferes with imaging. Monte Carlo codes, such as MCNP (X-5 Monte Carlo Team, 2005 Revision) allow scatter to be calculatied, but these calculations are very time consuming. It would be useful to have a fast scatter estimation algorithm in a fast ray tracing code. We have been extending the HADES ray-tracing radiographic simulation code to model vendor systems in a flexible and quick fashion and to use this tool to study a variety of questions involving system performance and the comparative value of surrogates. To enable this work, HADES has been linked to the BRL-CAD library (BRL-CAD Open Source Project, 2010), in order to enable the inclusion of complex CAD geometries in simulations, scanner geometries have been implemented in HADES, and the novel detector responses have been included in HADES. A major extension of HADES which has been required by this effort is the inclusion of scatter in these radiographic simulations. Ray tracing codes generally do not easily allow the inclusion of scatter, because these codes define a source and a grid of detector pixels and only compute the attenuation along rays between these points. Scatter is an extremely complex set of processes which can involve rays which change directions many times between the source and detector. Scatter from outside the field of view of the imaging system, as well as within the field of view, can have an important role in image formation. In this report, we will describe how we implemented a treatment of scatter in HADES. We begin with a discussion of how we define scatter in Section 2, followed by a description of how single Compton scatter is now included in HADES in Section 3. In Section 4 we report a set of verification tests against MCNP and tests of how the technique scales with image size, number of scatters allowed and number of processors used in the calculations. In Section 5, we describe how we plan to extend this approach to other forms of scatter and conclude in Section 6. It should be emphasized that the purpose of this report is to show that a form of scatter has been implemented in HADES and has been verified against MCNP. Validation, the process of comparing simulation and experiment, is a future task.
Measurement of the Neutron Radius of 208Pb Through Parity-Violation in Electron Scattering
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Abrahamyan, Sergey; Albataineh, Hisham; Aniol, Konrad; Armstrong, David; Armstrong, Whitney; Averett, Todd; Babineau, Benjamin; Barbieri, A; Bellini, Vincenzo; Beminiwattha, Rakitha; Benesch, Jay; Benmokhtar, Fatiha; Bierlarski, Trevor; Boeglin, Werner; Camsonne, Alexandre; Canan, Mustafa; Carter, Philip; Cates, Gordon; Chen, Chunhua; Chen, Jian-Ping; Hen, O; Cusanno, Francesco; Dalton, Mark; De Leo, Raffaele; De Jager, Cornelis; Deconinck, Wouter; Decowski, Piotr; Deng, Xiaoyan; Deur, Alexandre; Dutta, Dipangkar; Etile, Asenath; Flay, David; Franklin, Gregg; Friend, Megan; Frullani, Salvatore; Fuchey, Eric; Garibaldi, Franco; Gasser, Estelle; Gilman, Ronald; Guisa, Antonio; Glamazdin, Oleksandr; Gomez, Javier; Grames, Joseph; Gu, Chao; Hansen, Jens-Ole; Hansknecht, John; Higinbotham, Douglas; Holmes, Richard; Holmstrom, Timothy; Horowitz, Charles; Hoskins, Joshua; Huang, Jin; Hyde, Charles; Itard, Florian; Jen, Chun-Min; Jensen, Eric; Jin, Ge; Johnston, Sereres; Kelleher, Aidan; Kliakhandler, Konstantin; King, Paul; Kowalski, Stanley; Kumar, Krishna; Leacock, John; Leckey, John; Lee, Jeong Han; LeRose, John; Lindgren, Richard; Liyanage, Nilanga; Lubinsky, Nicholas; Mammei, Juliette; Mammoliti, Francesco; Margaziotis, Demetrius; Markowitz, Pete; McCreary, Amber; McNulty, Dustin; Mercado, Luis; Meziani, Zein-Eddine; Michaels, Robert; Mihovilovic, Miha; Muangma, Navaphon; Munoz Camacho, Carlos; Nanda, Sirish; Nelyubin, Vladimir; Nuruzzaman,; Oh, Yongseok; Palmer, Alvin; Parno, Diana; Paschke, Kent; Phillips, Sarah; Poelker, Benard; Pomatsalyuk, Roman; Posik, Matthew; Puckett, Andrew; Quinn, Brian; Rakhman, A; Reimer, Paul; Riordan, Seamus; Rogan, Patrick; Ron, Guy; Russo, Guiseppe; Saenboonruang, Kiadtisak; Saha, Arunava; Sawatzky, Bradley; Shahinyan, Albert; Silwal, Rupesh; Sirca, Simon; Slifer, Karl; Solvignon-Slifer, Patricia; Souder, Paul; Leda Sperduto, Maria; Subedi, Ramesh; Suleiman, Riad; Sulkosky, Vincent; Sutera, Concetta; Tobias, William; Troth, Wolfgang; Urciuoli, Guido; Buddhini Waidyawansa, Dinayadura; Wang, Diancheng; Wexler, Jonathan; Wilson, Richard; Wojtsekhowski, Bogdan; Yan, Xinhu; Yao, Huan; Ye, Yunxiu; Ye, Zhiohong; Yim, Vireak; Zana, Lorenzo; Zhan, Xiaohui; Zhang, Jixie; Zhang, Y; Zheng, Xiaochao; Zhu, Pengjia
2012-03-15T23:59:59.000Z
We report the first measurement of the parity-violating asymmetry APV in the elastic scattering of polarized electrons from 208Pb. APV is sensitive to the radius of the neutron distribution (Rn). The result APV = 0.656 ± 0.060 (stat) ± 0.013 (syst) corresponds to a difference between the radii of the neutron and proton distributions Rn-Rp = 0.33-0.18+0.16 fm and provides the first electroweak observation of the neutron skin which is expected in a heavy, neutron-rich nucleus.
Parton distribution function for quarks in an s-channel approach
F. Hautmann; D. E. Soper
2007-02-07T23:59:59.000Z
We use an s-channel picture of hard hadronic collisions to investigate the parton distribution function for quarks at small momentum fraction x, which corresponds to very high energy scattering. We study the renormalized quark distribution at one loop in this approach. In the high-energy picture, the quark distribution function is expressed in terms of a Wilson-line correlator that represents the cross section for a color dipole to scatter from the proton. We model this Wilson-line correlator in a saturation model. We relate this representation of the quark distribution function to the corresponding representation of the structure function F_T(x,Q^2) for deeply inelastic scattering.
Investigation of multiple scattering effects in aerosols. Final report, Sep 1978 - Dec 1979
Deepak, A.
1980-05-01T23:59:59.000Z
The results are presented of investigations on the various aspects of multiple scattering effects on visible and infrared laser beams transversing dense fog oil aerosols contained in a chamber (4' x 4' x 9'). The report briefly describes: (1) the experimental details and measurements (2) analytical representation of the aerosol size distribution data by two analytical models (the regularized power law distribution and the inverse modified gamma distribution) (3) retrieval of aerosol size distributions from multispectral optical depth measurements by two methods (the two and three parameter fast table search methods and the nonlinear least squares method) (4) modeling of the effects of aerosol microphysical (coagulation and evaporation) and dynamical processes (gravitational settling) on the temporal behavior of aerosol size distribution, and hence on the extinction of four laser beams with wavelengths 0.44, 0.6328, 1.15, and 3.39 micrometers and (5) the exact and approximate formulations for four methods for computing the effects of multiple scattering on the transmittance of laser beams in dense aerosols, all of which are based on the solution of the radiative transfer equation under the small angle approximation.
BUILDING A NETWORK FOR NEUTRON SCATTERING EDUCATION
Pynn, Roger [ORNL; Baker, Shenda Mary [ORNL; Louca, Despo A [ORNL; McGreevy, Robert L [ORNL; Ekkebus, Allen E [ORNL; Kszos, Lynn A [ORNL; Anderson, Ian S [ORNL
2008-10-01T23:59:59.000Z
In a concerted effort supported by the National Science Foundation, the Department of Commerce, and the Department of Energy, the United States is rebuilding its leadership in neutron scattering capability through a significant investment in U.S. neutron scattering user facilities and related instrumentation. These unique facilities provide opportunities in neutron scattering to a broad community of researchers from academic institutions, federal laboratories, and industry. However, neutron scattering is often considered to be a tool for 'experts only' and in order for the U.S. research community to take full advantage of these new and powerful tools, a comprehensive education and outreach program must be developed. The workshop described below is the first step in developing a national program that takes full advantage of modern education methods and leverages the existing educational capacity at universities and national facilities. During March 27-28, 2008, a workshop entitled 'Building a Network for Neutron Scattering Education' was held in Washington, D.C. The goal of the workshop was to define and design a roadmap for a comprehensive neutron scattering education program in the United States. Successful implementation of the roadmap will maximize the national intellectual capital in neutron sciences and will increase the sophistication of research questions addressed by neutron scattering at the nation's forefront facilities. (See Appendix A for the list of attendees, Appendix B for the workshop agenda, Appendix C for a list of references. Appendix D contains the results of a survey given at the workshop; Appendix E contains summaries of the contributed talks.) The workshop brought together U.S. academicians, representatives from neutron sources, scientists who have developed nontraditional educational programs, educational specialists, and managers from government agencies to create a national structure for providing ongoing neutron scattering education. A concerted effort was made to involve representatives from historically black colleges and universities (HBCUs) and minority educational institutions (MEIs). The roadmap contained herein provides the path to a national infrastructure for education of students, faculty, and professional researchers who wish to make use of national neutron scattering facilities but do not have (or do not believe they have) the educational background to do so. Education of other stakeholders, including the public, students in kindergarten through twelfth grade (K-12), and policy makers is also included. The opening sessions of the workshop provided the current status of neutron scattering education in North America, Europe, and Australia. National neutron sources have individually developed outreach and advertising programs aimed at increasing awareness among researchers of the potential applications of neutron scattering. However, because their principal mission is to carry out scientific research, their outreach efforts are necessarily self-limiting. The opening session was designed to build awareness that the individual programs need to be coupled with, and integrated into, a broader education program that addresses the complete range of experience, from the student to the experienced researcher, and the wide range of scientific disciplines covered by neutron scattering. Such a program must also take full advantage of existing educational programs and expertise at universities and expand them using modern distance learning capabilities, recognizing that the landscape of education is changing.
Scattering and; Delay, Scale, and Sum Migration
Lehman, S K
2011-07-06T23:59:59.000Z
How do we see? What is the mechanism? Consider standing in an open field on a clear sunny day. In the field are a yellow dog and a blue ball. From a wave-based remote sensing point of view the sun is a source of radiation. It is a broadband electromagnetic source which, for the purposes of this introduction, only the visible spectrum is considered (approximately 390 to 750 nanometers or 400 to 769 TeraHertz). The source emits an incident field into the known background environment which, for this example, is free space. The incident field propagates until it strikes an object or target, either the yellow dog or the blue ball. The interaction of the incident field with an object results in a scattered field. The scattered field arises from a mis-match between the background refractive index, considered to be unity, and the scattering object refractive index ('yellow' for the case of the dog, and 'blue' for the ball). This is also known as an impedance mis-match. The scattering objects are referred to as secondary sources of radiation, that radiation being the scattered field which propagates until it is measured by the two receivers known as 'eyes'. The eyes focus the measured scattered field to form images which are processed by the 'wetware' of the brain for detection, identification, and localization. When time series representations of the measured scattered field are available, the image forming focusing process can be mathematically modeled by delayed, scaled, and summed migration. This concept of optical propagation, scattering, and focusing have one-to-one equivalents in the acoustic realm. This document is intended to present the basic concepts of scalar scattering and migration used in wide band wave-based remote sensing and imaging. The terms beamforming and (delayed, scaled, and summed) migration are used interchangeably but are to be distinguished from the narrow band (frequency domain) beamforming to determine the direction of arrival of a signal, and seismic migration in which wide band time series are shifted but not to form images per se. Section 3 presents a mostly graphically-based motivation and summary of delay, scale, and sum beamforming. The model for incident field propagation in free space is derived in Section 4 under specific assumptions. General object scattering is derived in Section 5 and simplified under the Born approximation in Section 6. The model of this section serves as the basis in the derivation of time-domain migration. The Foldy-Lax, full point scatterer scattering, method is derived in Section 7. With the previous forward models in hand, delay, scale, and sum beamforming is derived in Section 8. Finally, proof-of-principle experiments are present in Section 9.
Massive superstring scatterings in the Regge regime
He Song; Lee, Jen-Chi; Takahashi, Keijiro; Yang Yi [Institute of High Energy Physics, Chinese Academic of Sciences, Beijing (China); Department of Electrophysics, National Chiao-Tung University and Physics Division, National Center for Theoretical Sciences, Hsinchu, Taiwan (China); Department of Electrophysics, National Chiao-Tung University, Hsinchu, Taiwan (China); Department of Electrophysics, National Chiao-Tung University and Physics Division, National Center for Theoretical Sciences, Hsinchu, Taiwan (China)
2011-03-15T23:59:59.000Z
We calculate four classes of high-energy massive string scattering amplitudes of fermionic string theory at arbitrary mass levels in the Regge regime (RR). We show that all four leading order amplitudes in the RR can be expressed in terms of the Kummer function of the second kind. Based on the summation algorithm of a set of extended signed Stirling number identities, we show that all four ratios calculated previously by the method of decoupling of zero-norm states among scattering amplitudes in the Gross regime can be extracted from this Kummer function in the RR. Finally, we conjecture and give evidence that the existence of these four Gross regime ratios in the RR persists to subleading orders in the Regge expansion of all high-energy fermionic string scattering amplitudes.
Alternating current response of carbon nanotubes with randomly distributed impurities
Hirai, Daisuke; Watanabe, Satoshi [Department of Materials Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656 (Japan); Yamamoto, Takahiro [Department of Electrical Engineering and Department of Liberal Arts (Physics), Tokyo University of Science, 6-3-1 Niijuku, Katsushika, Tokyo 125-8585 (Japan)
2014-10-27T23:59:59.000Z
The increasing need for nanodevices has necessitated a better understanding of the electronic transport behavior of nanomaterials. We therefore theoretically examine the AC transport properties of metallic carbon nanotubes with randomly distributed impurities. We find that the long-range impurity scattering increases the emittance, but does not affect the DC conductance. The estimated dwell time of electrons increases with the potential amplitudes. That is, multiple scattering by the impurities increases the kinetic inductance in proportion to the dwell time, which eventually increases the emittance. We believe that our findings can contribute significantly to nanodevice development.
The oxygen abundance distribution in M101
L. S. Pilyugin
2001-05-07T23:59:59.000Z
The well-observed spiral galaxy M101 was considered. The radial distributions of oxygen abundances determined in three different ways (with the classic Te - method, with the R23 - method, and with the P -- method) were compared. It was found that the parameters (the central oxygen abundance and the gradient) of the radial O/H(P) abundance distribution are close to those of the O/H(Te) abundance distribution. The parameters of the O/H(R23) abundance distribution differ significantly from those of the O/H(Te) abundance distribution: the central O/H(R23) oxygen abundance is higher by around 0.4dex and the gradient is steeper by a factor of around 1.5 as compared to those values in the O/H(Te) abundance distribution. The dispersion in O/H(P) abundance at fixed radius is rather small, around 0.08 dex, and is equal to that in O/H(Te) abundance. The dispersion in O/H(R23) abundance at fixed radius is appreciably larger, around 0.16 dex, compared to that in O/H(Te) abundance. It has been shown that the extra dispersion in O/H(R23) abundances is an artifact and reflects scatter in excitation parameter P at fixed radius.
Neutron scattering measurements at intermediate energies
N. Olsson; J. Blomgren; E. Ramstrom
The study of elastic neutron scattering at intermediate energies is essential for the understanding of the isovector term in the nucleon-nucleus interaction, as well as for the development of macroscopic and microscopic optical potentials at these energies. The techniques used for neutron scattering measurements is presented in this paper, as well as the di culties encountered. The few facilities that have been used are reviewed, and a newly installed setup for such measurements in Uppsala is described. Finally, the normalization problem is speci cally addressed. 1
Fitzpatrick, A.Liam; /Boston U.; Kaplan, Jared; /SLAC
2012-02-14T23:59:59.000Z
We show that suitably regulated multi-trace primary states in large N CFTs behave like 'in' and 'out' scattering states in the flat-space limit of AdS. Their transition matrix elements approach the exact scattering amplitudes for the bulk theory, providing a natural CFT definition of the flat space S-Matrix. We study corrections resulting from the AdS curvature and particle propagation far from the center of AdS, and show that AdS simply provides an IR regulator that disappears in the flat space limit.
Radiation from SU(3) monopole scattering
Patrick Irwin
2000-04-07T23:59:59.000Z
The energy radiated during the scattering of SU(3) monopoles is estimated as a function of their asymptotic velocity v. In a typical scattering process the total energy radiated is of order v^3 as opposed to v^5 for SU(2) monopoles. For charge (1,1) monopoles the dipole radiation produced is estimated for all geodesics on the moduli space. For charge (2,1) monopoles the dipole radiation is estimated for the axially symmetric geodesic. The power radiated appears to diverge in the massless limit. The implications of this for the case of non-Abelian unbroken symmetry are discussed.
Real Compton Scattering via Color Dipoles
B. Z. Kopeliovich; Ivan Schmidt; M. Siddikov
2009-08-24T23:59:59.000Z
We study photoabsorption reaction and real Compton scattering (RCS) within the color dipole model. We rely on a photon wave function derived in the instanton vacuum model, and on the energy dependent phenomenological elastic dipole amplitude. Data for the photoabsorption cross section at high energies agree with our parameter free calculations. We also provide predictions for the differential RCS cross section. Although no data for small angle Compton scattering are available so far, this process can be measured in ultra-peripheral hadronic and nuclear collisions at the LHC.
Alpha resonant scattering for astrophysical reaction studies
Yamaguchi, H.; Kahl, D.; Nakao, T. [Center for Nuclear Study (CNS), University of Tokyo, RIKEN campus, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Wakabayashi, Y.; Kubano, S. [The Institute of Physical and Chemical Research (RIKEN), 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Hashimoto, T. [Research Center for Nuclear Physics (RCNP), Osaka University, 10-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan); Hayakawa, S. [Istituto Nazionale Fisica Nucleare - Laboratori Nazionali del Sud (INFN-LNS), Via S. Sofia 62, 95125 Catania (Italy); Kawabata, T. [Department of Physics, Kyoto University, Kita-Shirakawa, Kyoto 606-8502 (Japan); Iwasa, N. [Department of Physics, Tohoku University, Aoba, Sendai, Miyagi 980-8578 (Japan); Teranishi, T. [Department of Physics, Kyushu University, 6-10-1 Hakozaki, Fukuoka 812-8581 (Japan); Kwon, Y. K. [Institute for Basic Science, 70, Yuseong-daero 1689-gil, Yuseong-gu, Daejeon 305-811 (Korea, Republic of); Binh, D. N. [30 MeV Cyclotron Center, Tran Hung Dao Hospital, Hoan Kiem District, Hanoi (Viet Nam); Khiem, L. H.; Duy, N. G. [Institute of Physics, Vietnam Academy of Science and Technology, 18 Hong Quoc Viet, Nghia do, Hanoi (Viet Nam)
2014-05-02T23:59:59.000Z
Several alpha-induced astrophysical reactions have been studied at CRIB (CNS Radioactive Ion Beam separator), which is a low-energy RI beam separator at Center for Nuclear Study (CNS) of the University of Tokyo. One of the methods to study them is the ? resonant scattering using the thick-target method in inverse kinematics. Among the recent studies at CRIB, the measurement of {sup 7}Be+? resonant scattering is discussed. Based on the result of the experiment, we evaluated the contributions of high-lying resonances for the {sup 7}Be(?,?) reaction, and proposed a new cluster band in {sup 11}C.
DEEPLY INELASTIC SCATTERING OFF NUCLEI AT RHIC.
VENUGOPALAN, R.
2001-09-14T23:59:59.000Z
In this talk, we discussed the physics case for an eA collider. We emphasized the novel physics that might be studied at small x. The interesting physics at intermediate x's has been discussed elsewhere [3]. Plans for an electron-ion collider include, as a major part of the program, the possibility of doing polarized electron-polarized proton/light ion scattering. A discussion of the combined case for high energy electron nucleus and polarized electron-polarized proton scattering will be published separately [66].
[Inelastic electron scattering from surfaces]. [Progress report
Not Available
1993-10-01T23:59:59.000Z
This program uses ab-initio and multiple scattering to study surface dynamical processes; high-resolution electron-energy loss spectroscopy is used in particular. Off-specular excitation cross sections are much larger if electron energies are in the LEED range (50--300 eV). The analyses have been extended to surfaces of ordered alloys. Phonon eigenvectors and eigenfrequencies were used as inputs to electron-energy-loss multiple scattering cross section calculations. Work on low-energy electron and positron holography is mentioned.
Quantum-entanglement-initiated super Raman scattering
Agarwal, G. S. [Department of Physics, Oklahoma State University, Stillwater, Oklahoma 74078 (United States)
2011-02-15T23:59:59.000Z
It has now been possible to prepare a chain of ions in an entangled state and thus the question arises: How will the optical properties of a chain of entangled ions differ from say a chain of independent particles? We investigate nonlinear optical processes in such chains. Since light scattering is quite a versatile technique to probe matter, we explicitly demonstrate the possibility of entanglement-produced super Raman scattering. Our results suggest the possibility of similar enhancement factors in other nonlinear processes like four-wave mixing.
Geometric phases in a scattering process
H. D. Liu; X. X. Yi
2011-03-19T23:59:59.000Z
The study of geometric phase in quantum mechanics has so far be confined to discrete (or continuous) spectra and trace preserving evolutions. Consider only the transmission channel, a scattering process with internal degrees of freedom is neither a discrete spectrum problem nor a trace preserving process. We explore the geometric phase in a scattering process taking only the transmission process into account. We find that the geometric phase can be calculated by the some method as in an unitary evolution. The interference visibility depends on the transmission amplitude. The dependence of the geometric phase on the barrier strength and the spin-spin coupling constant is also presented and discussed.
Extrasolar Planet Eccentricities from Scattering in the Presence of Residual Gas Disks
Nickolas Moeckel; Sean N. Raymond; Philip J. Armitage
2008-07-25T23:59:59.000Z
Gravitational scattering between massive planets has been invoked to explain the eccentricity distribution of extrasolar planets. For scattering to occur, the planets must either form in -- or migrate into -- an unstable configuration. In either case, it is likely that a residual gas disk, with a mass comparable to that of the planets, will be present when scattering occurs. Using explicit hydrodynamic simulations, we study the impact of gas disks on the outcome of two-planet scattering. We assume a specific model in which the planets are driven toward instability by gravitational torques from an outer low mass disk. We find that the accretion of mass and angular momentum that occurs when a scattered planet impacts the disk can strongly influence the subsequent dynamics by reducing the number of close encounters. The eccentricity of the innermost surviving planet at the epoch when the system becomes Hill stable is not substantially altered from the gas-free case, but the outer planet is circularized by its interaction with the disk. The signature of scattering initiated by gas disk migration is thus a high fraction of low eccentricity planets at larger radii accompanying known eccentric planets. Subsequent secular evolution of the two planets in the presence of damping can further damp both eccentricities, and tends to push systems away from apsidal alignment and toward anti-alignment. We note that the late burst of accretion when the outer planet impacts the disk is in principle observable, probably via detection of a strong near-IR excess in systems with otherwise weak disk and stellar accretion signatures.
Pretzelosity distribution function
H. Avakian; A. V. Efremov; P. Schweitzer; F. Yuan
2008-08-28T23:59:59.000Z
The 'pretzelosity' distribution is discussed. Theoretical properties, model results, and perspectives to access experimental information on this leading twist, transverse momentum dependent parton distribution function are reviewed. Its relation to helicity and transversity distributions is highlighted.
Learning poisson binomial distributions
Daskalakis, Constantinos
We consider a basic problem in unsupervised learning: learning an unknown Poisson Binomial Distribution. A Poisson Binomial Distribution (PBD) over {0,1,...,n} is the distribution of a sum of n independent Bernoulli random ...
Hara, Yousuke, E-mail: y-hara@nirs.go.jp; Furukawa, Takuji; Inaniwa, Taku; Mizushima, Kota; Shirai, Toshiyuki; Noda, Koji [Medical Physics Research Group, Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan)] [Medical Physics Research Group, Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan)
2014-02-15T23:59:59.000Z
Purpose: It is essential to consider large-angle scattered particles in dose calculation models for therapeutic carbon-ion beams. However, it is difficult to measure the small dose contribution from large-angle scattered particles. In this paper, the authors present a novel method to derive the parameters describing large-angle scattered particles from the measured results. Methods: The authors developed a new parallel-plate ionization chamber consisting of concentric electrodes. Since the sensitive volume of each channel is increased linearly with this type, it is possible to efficiently and easily detect small contributions from the large-angle scattered particles. The parameters describing the large-angle scattered particles were derived from pencil beam dose distribution in water measured with the new ionization chamber. To evaluate the validity of this method, the correction for the field-size dependence of the doses, “predicted-dose scaling factor,” was calculated with the new parameters. Results: The predicted-dose scaling factor calculated with the new parameters was compared with the existing one. The difference between the new correction factor and the existing one was 1.3%. For target volumes of different sizes, the calculated dose distribution with the new parameters was in good agreement with the measured one. Conclusions: Parameters describing the large-angle scattered particles can be efficiently and rapidly determined using the new ionization chamber. The authors confirmed that the field-size dependence of the doses could be compensated for by the new parameters. This method makes it possible to easily derive the parameters describing the large-angle scattered particles, while maintaining the dose calculation accuracy.
Angular distributions of neutron-nucleus collisions
Mukhopadhyay, Tapan; Lahiri, Joydev; Basu, D. N. [Variable Energy Cyclotron Centre, 1/AF Bidhan Nagar, Kolkata 700 064 (India)
2011-06-15T23:59:59.000Z
We derive the total and the differential cross sections with respect to angle for neutron-induced reactions from an analytical model having a simple functional form to demonstrate the quantitative agreement with the measured cross sections. The energy dependence of the neutron-nucleus interaction cross sections are estimated successfully for energies ranging from 5 to 600 MeV. In this work, the effect of the imaginary part of the nuclear potential is treated more appropriately compared to our earlier work. The angular distributions for neutron scattering also agree reasonably well with the experimental data at forward angles.
About Industrial Distributed Energy
Broader source: Energy.gov [DOE]
The Advanced Manufacturing Office's (AMO's) Industrial Distributed Energy activities build on the success of predecessor DOE programs on distributed energy and combined heat and power (CHP) while...
Simulation of a D-T Neutron Source for Neutron Scattering Experiments
Lou, T.P.; Ludewigt, B.A.; Vujic, J.L.; Leung, K.-N.
2003-01-01T23:59:59.000Z
T Neutron Source for Neutron Scattering Experiments T.P. Louor cold neutrons for neutron scattering experiments. Thisto simulate a neutron scattering setup and to estimate
Deeply virtual Compton Scattering cross section measured with CLAS
Guegan, Baptistse [Institut de Physique Nucleaire, Orsay
2014-09-01T23:59:59.000Z
The Generalized Parton Distributions (GPDs) provide a new description of nucleon structure in terms of its elementary constituents, the quarks and the gluons. Including and extending the information provided by the form factors and the parton distribution functions, they describe the correlation between the transverse position and the longitudinal momentum fraction of the partons in the nucleon. Deeply Virtual Compton Scattering (DVCS), the electroproduction of a real photon on a single quark in the nucleon eN --> e'N'g, is the exclusive process most directly interpretable in terms of GPDs. A dedicated experiment to study DVCS with the CLAS detector at Jefferson Lab has been carried out using a 5.9-GeV polarized electron beam and an unpolarized hydrogen target, allowing us to collect DVCS events in the widest kinematic range ever explored in the valence region : 1.0 < Q2 < 4.6 GeV2, 0.1 < xB < 0.58 and 0.09 < -t < 2.0 GeV2. In this paper, we show preliminary results of unpolarized cross sections and of polarized cross section differences for the DVCS channel.
Quasielastic Scattering at MiniBooNE Energies
Alvarez-Ruso, L. [Departamento de Fisica, Universidad de Murcia (Spain); Departamento de Fisica, Centro de Fisica Computacional, Universidade de Coimbra (Portugal); Buss, O.; Leitner, T.; Mosel, U. [Institut fuer Theoretische Physik, Universitaet Giessen (Germany)
2009-11-25T23:59:59.000Z
We present our description of neutrino induced charged current quasielastic scattering (CCQE) in nuclei at energies relevant for the MiniBooNE experiment. In our framework, the nucleons, with initial momentum distributions according to the Local Fermi Gas model, move in a density- and momentum-dependent mean field potential. The broadening of the outgoing nucleons due to nucleon-nucleon interactions is taken into account by spectral functions. Long range (RPA) correlations renormalizing the electroweak strength in the medium are also incorporated. The background from resonance excitation events that do not lead to pions in the final state is also predicted by propagating the outgoing hadrons with the Giessen semiclassical BUU model in coupled channels (GiBUU). We achieve a good description of the shape of the CCQE Q{sup 2} distribution extracted from data by MiniBooNE, thanks to the inclusion of RPA correlations, but underestimate the integrated cross section when the standard value of M{sub A} = 1 GeV is used. Possible reasons for this mismatch are discussed.
Scattering theory of electrical Markus Bttiker
Paris-Sud 11, Université de
symmetry H-invariant if momenta and magnetic field are reversed 13 but is an even function incident current density density of states independent of material !! 6 Landauer formula #12;Drift state scattering matrix current conservation S is a unitray matrix In the absence of a magnetic field
RADIATION FIELDS, SCATTERING AND ... - Purdue University
2006-12-26T23:59:59.000Z
We define the forward and backward radiation fields on an asymptotically hyperbolic man- ... There is a history of interest in scattering theory for this class of manifolds, ...... and lower order terms as in in (4.10). ...... We first re-examine (
Compton scattering and polarizabilities of the nucleon
M. Gorchtein; D. Drechsel; B. Pasquini; M. Vanderhaeghen
1999-11-19T23:59:59.000Z
Fixed-$t$ subtracted dispersion relations are presented for Compton scattering off the nucleon at energies $E_\\gamma \\leq 500$ MeV, as a formalism to extract the nucleon polarizabilities from the data with a minimum of model dependence. The scalar polarizabilities difference $\\alpha - \\beta$ and the backward spin polarizability $\\gamma_\\pi$ enter directly as fit parameters in this formalism.
Colour dipoles and deeply virtual Compton scattering
R. Sandapen
2002-07-01T23:59:59.000Z
I report on an analysis of Deeply Virtual Compton Scattering (DVCS) within the dipole model, done in collaboration with M. McDermott and G. Shaw. The two models considered here are distinct in their structure and implications. They both agree with the available cross-section data on DVCS from HERA. Predictions for various asymmetries are also given.
Pion Compton Scattering in Perturbative QCD
E. Maina; R. Torasso
1993-09-23T23:59:59.000Z
Pion Compton scattering is studied in perturbative QCD for real and space--like initial photons. Different methods for the convolution of the hard amplitude with the pion wave--functions, which have in the past led to conflicting results, are compared.
The Kinematic Algebras from the Scattering Equations
Monteiro, Ricardo
2013-01-01T23:59:59.000Z
We study kinematic algebras associated to the recently proposed scattering equations, which arise in the description of the scattering of massless particles. In particular, we describe the role that these algebras play in the BCJ duality between colour and kinematics in gauge theory, and its relation to gravity. We find that the scattering equations are a consistency condition for a self-dual-type vertex which is associated to each solution of those equations. We also identify an extension of the anti-self-dual vertex, such that the two vertices are not conjugate in general. Both vertices correspond to the structure constants of Lie algebras. We give a prescription for the use of the generators of these Lie algebras in trivalent graphs that leads to a natural set of BCJ numerators. In particular, we write BCJ numerators for each contribution to the amplitude associated to a solution of the scattering equations. This leads to a decomposition of the determinant of a certain kinematic matrix, which appears natur...
Geometry of Scattering at Planckian Energies
Renata Kallosh
1991-11-05T23:59:59.000Z
We present an alternative derivation and geometrical formulation of Verlinde topological field theory, which may describe scattering at center of mass energies comparable or larger than the Planck energy. A consistent trunckation of 3+1 dimensional Einstein action is performed using the standard geometrical objects, like tetrads and spin connections. The resulting topological invariant is given in terms of differential forms.
A modified variational approach to scattering
Parnell, Gregory Elliott
1978-01-01T23:59:59.000Z
, 11'-99 -C. ', i493 Q I; 49". , 0 ;Q594 -0. 105&34 1CSoc TABLE III. phase shiftstl for single'. p-wave electron scattering from H calculated by the modi- fied variational method (with second basis function peak at 1/2). H is the number of basis...
Fiber optic probe for light scattering measurements
Nave, Stanley E. (Evans, GA); Livingston, Ronald R. (Aiken, SC); Prather, William S. (Augusta, GA)
1995-01-01T23:59:59.000Z
A fiber optic probe and a method for using the probe for light scattering analyses of a sample. The probe includes a probe body with an inlet for admitting a sample into an interior sample chamber, a first optical fiber for transmitting light from a source into the chamber, and a second optical fiber for transmitting light to a detector such as a spectrophotometer. The interior surface of the probe carries a coating that substantially prevents non-scattered light from reaching the second fiber. The probe is placed in a region where the presence and concentration of an analyte of interest are to be detected, and a sample is admitted into the chamber. Exciting light is transmitted into the sample chamber by the first fiber, where the light interacts with the sample to produce Raman-scattered light. At least some of the Raman-scattered light is received by the second fiber and transmitted to the detector for analysis. Two Raman spectra are measured, at different pressures. The first spectrum is subtracted from the second to remove background effects, and the resulting sample Raman spectrum is compared to a set of stored library spectra to determine the presence and concentration of the analyte.
Fiber optic probe for light scattering measurements
Nave, S.E.; Livingston, R.R.; Prather, W.S.
1993-01-01T23:59:59.000Z
This invention is comprised of a fiber optic probe and a method for using the probe for light scattering analyses of a sample. The probe includes a probe body with an inlet for admitting a sample into an interior sample chamber, a first optical fiber for transmitting light from a source into the chamber, and a second optical fiber for transmitting light to a detector such as a spectrophotometer. The interior surface of the probe carries a coating that substantially prevents non-scattered light from reaching the second fiber. The probe is placed in a region where the presence and concentration of an analyte of interest are to be detected, and a sample is admitted into the chamber. Exciting light is transmitted into the sample chamber by the first fiber, where the light interacts with the sample to produce Raman-scattered light. At least some of the Raman- scattered light is received by the second fiber and transmitted to the detector for analysis. Two Raman spectra are measured, at different pressures. The first spectrum is subtracted from the second to remove background effects, and the resulting sample Raman spectrum is compared to a set of stored library spectra to determine the presence and concentration of the analyte.
Rutherford Scattering MIT Department of Physics
Seager, Sara
of the scattering angle, the alpha particle energy, and the nuclear charge. You will then measure the intensity atomic weight, but to its atomic number, determined by its position in the periodic table. Since the mass in any atom is associated with the positive charge. The central problem was to figure out how
SCATTERING BY CRACKS BENEATH FLUIDSOLID INTERFACES
Craster, Richard
parameters relevant for watermetal and waterrock combinations are taken and far field scattering patterns the fluid. For line source excitation surface waves are generated that impinge upon defects near the surface with distance along the interface from its source of excitation. The light fluid loading limit is important f
Photophoresis and the scattering of electromagnetic radiation
Ipser, J.R.
1985-09-01T23:59:59.000Z
Electron-microscope photographs of soot lend support to the picture in which a soot particle is modeled as a collection of chains of small carbon spheres. The soot particle itself is typically considerably larger than the small carbon spheres making up the chains. Thus the soot particles might have a size approx.0.1 - 1 ..mu..m while the small carbon spheres might have a size approx.0.03 ..mu..m in typical situations. Further, measurements of the density of soot yield values much less than that of normal carbon, indicating that an individual soot particle has a rather small filling factor, i.e., the fraction of the volume of the particle tht is occupied by chains. If a soot particle is taken to be a sphere partially filled with carbon chains, what are its scattering and absorption properties. Several workers have adopted the view that the net scattering and absorption properties can be determined simply by summing the cross-sections for the individual small carbon spheres. We feel that such a procedure cannot be valid in general because it neglects coherence effects among the various randomly located scatterers within the soot particle. It appears that in a first rough approximation the scattering and absorption properties of soot can be determined by estimating the effective dielectric constant of a soot sphere.
Inelastic neutron scattering in valence fluctuation compounds
Jon M Lawrence
2011-02-15T23:59:59.000Z
The valence fluctuation compounds are rare earth intermetallics where hybridization of the nearly-localized 4f electrons with the conduction electrons leads to incorporation of the 4f's into the itinerant states. This hybridization slows down the conduction electrons and hence gives them a heavy effective mass, justifying application of the term 'heavy Fermion' (HF) to these materials. During the project period, we grew large single crystals of several such compounds and measured their properties using both standard thermodynamic probes and state-of-the-art inelastic neutron scattering. We obtained three main results. For the intermediate valence compounds CePd{sub 3} and YbAl{sub 3}, we showed that the scattering of neutrons by the fluctuations of the 4f magnetic moment does not have the momentum dependence expected for the itinerant heavy mass state; rather, the scattering is more typical of a localized spin fluctuation. We believe that incoherent scattering localizes the excitation. For the heavy Fermion compound Ce(Ni{sub 0.935}Pd{sub 0.065}){sub 2}Ge{sub 2}, which sits at a T = 0 critical point for transformation into an antiferromagnetic (AF) phase, we showed that the scattering from the AF fluctuations does not exhibit any of the divergences that are expected at a phase transition. We speculate that alloy disorder profoundly suppresses the growth of the fluctuating AF regions, leading to short range clusters rather than regions of infinite size. Finally, we explored the applicability of key concepts used to describe the behavior of rare earth heavy Fermions to uranium based HF compounds where the 5f electrons are itinerant as opposed to localized. We found that scaling laws relating the spin fluctuation energy measured in neutron scattering to the low temperature specific heat and susceptibility are valid for the uranium compounds, once corrections are made for AF fluctuations; however, the degeneracy of the high temperature moment is smaller than expected for rare-earth-like Hund's rule behavior, essentially because the orbital moment is suppressed for itinerant 5f electrons. We also found that the standard local-moment-based theory of the temperature dependence of the specific heat, susceptibility and neutron scattering fails badly for URu{sub 2}Zn{sub 20} and UCo{sub 2}Zn{sub 20}, even though the theory is phenomenally successful for the closely related rare earth compound YbFe{sub 2}Zn{sub 20}. Both these results highlight the distinction between the itineracy of the 5f's and the localization of the 4f's. It is our hope that these results are sufficiently significant as to stimulate deeper investigation of these compounds.
G. Morlino; P. Blasi; M. Vietri
2007-01-08T23:59:59.000Z
A mathematical approach to investigate particle acceleration at shock waves moving at arbitrary speed in a medium with arbitrary scattering properties was first discussed in (Vietri 2003) and (Blasi & Vietri 2005}. We use this method and somewhat extend it in order to include the effect of a large scale magnetic field in the upstream plasma, with arbitrary orientation with respect to the direction of motion of the shock. We also use this approach to investigate the effects of anisotropic scattering on spectra and anisotropies of the distribution function of the accelerated particles.
Accurate and Approximate Calculations of Raman Scattering in the Atmosphere of Neptune
Sromovsky, Lawrence
2015-01-01T23:59:59.000Z
Raman scattering by H$_2$ in Neptune's atmosphere has significant effects on its reflectivity for $\\lambda 0.5 $\\mu$m, producing baseline decreases of $\\sim$ 20% in a clear atmosphere and $\\sim$ 10% in a hazy atmosphere. Here we present the first radiation transfer algorithm that includes both polarization and Raman scattering and facilitates computation of spatially resolved spectra. New calculations show that Cochran and Trafton's (1978, Astrophys. J. 219, 756-762) suggestion that light reflected in the deep CH$_4$ bands is mainly Raman scattered is not valid for current estimates of the CH$_4$vertical distribution, which implies only a 4% Raman contribution. Comparisons with IUE, HST, and groundbased observations confirm that high altitude haze absorption is reducing Neptune's geometric albedo by $\\sim$6% in the 0.22-0.26 $\\mu$m range and by $\\sim$13% in the 0.35-0.45 $\\mu$m range. We used accurate calculations to evaluate several approximations of Raman scattering. The Karkoschka (1994, Icarus 111, ...
The HERMES Collaboration; A. Airapetian; N. Akopov; Z. Akopov; E. C. Aschenauer; W. Augustyniak; R. Avakian; A. Avetissian; E. Avetisyan; S. Belostotski; N. Bianchi; H. P. Blok; A. Borissov; J. Bowles; I. Brodski; V. Bryzgalov; J. Burns; M. Capiluppi; G. P. Capitani; E. Cisbani; G. Ciullo; M. Contalbrigo; P. F. Dalpiaz; W. Deconinck; R. De Leo; L. De Nardo; E. De Sanctis; M. Diefenthaler; P. Di Nezza; M. Dueren; M. Ehrenfried; G. Elbakian; F. Ellinghaus; A. Fantoni; L. Felawka; S. Frullani; D. Gabbert; G. Gapienko; V. Gapienko; F. Garibaldi; G. Gavrilov; V. Gharibyan; F. Giordano; S. Gliske; M. Golembiovskaya; C. Hadjidakis; M. Hartig; D. Hasch; G. Hill; A. Hillenbrand; M. Hoek; Y. Holler; I. Hristova; Y. Imazu; A. Ivanilov; H. E. Jackson; A. Jgoun; H. S. Jo; S. Joosten; R. Kaiser; G. Karyan; T. Keri; E. Kinney; A. Kisselev; N. Kobayashi; V. Korotkov; V. Kozlov; B. Krauss; P. Kravchenko; V. G. Krivokhijine; L. Lagamba; R. Lamb; L. Lapikas; I. Lehmann; P. Lenisa; L. A. Linden-Levy; A. Lopez Ruiz; W. Lorenzon; X. -G. Lu; X. -R. Lu; B. -Q. Ma; D. Mahon; N. C. R. Makins; S. I. Manaenkov; L. Manfre; Y. Mao; B. Marianski; A. Martinez de la Ossa; H. Marukyan; C. A. Miller; A. Movsisyan; V. Muccifora; M. Murray; D. Mueller; A. Mussgiller; E. Nappi; Y. Naryshkin; A. Nass; M. Negodaev; W. -D. Nowak; L. L. Pappalardo; R. Perez-Benito; N. Pickert; M. Raithel; P. E. Reimer; A. R. Reolon; C. Riedl; K. Rith; G. Rosner; A. Rostomyan; J. Rubin; D. Ryckbosch; Y. Salomatin; F. Sanftl; A. Schaefer; G. Schnell; K. P. Schueler; B. Seitz; T. -A. Shibata; V. Shutov; M. Stancari; M. Statera; E. Steffens; J. J. M. Steijger; H. Stenzel; J. Stewart; F. Stinzing; S. Taroian; A. Terkulov; A. Trzcinski; M. Tytgat; A. Vandenbroucke; P. B. Van der Nat; Y. Van Haarlem; C. Van Hulse; D. Veretennikov; V. Vikhrov; I. Vilardi; C. Vogel; S. Wang; S. Yaschenko; Z. Ye; S. Yen; W. Yu; D. Zeiler; B. Zihlmann; P. Zupranski
2011-05-02T23:59:59.000Z
Azimuthal asymmetries in exclusive electroproduction of a real photon from a longitudinally polarized deuterium target are measured with respect to target polarization alone and with respect to target polarization combined with beam helicity and/or beam charge. The asymmetries appear in the distribution of the real photons in the azimuthal angle $\\phi$ around the virtual photon direction, relative to the lepton scattering plane. The asymmetries arise from the deeply virtual Compton scattering process and its interference with the Bethe-Heitler process. The results for the beam-charge and beam-helicity asymmetries from a tensor polarized deuterium target with vanishing vector polarization are shown to be compatible with those from an unpolarized deuterium target, which is expected for incoherent scattering dominant at larger momentum transfer. Furthermore, the results for the single target-spin asymmetry and for the double-spin asymmetry are found to be compatible with the corresponding asymmetries previously measured on a hydrogen target. For coherent scattering on the deuteron at small momentum transfer to the target, these findings imply that the tensor contribution to the cross section is small. Furthermore, the tensor asymmetry is found to be compatible with zero.
Quark Structure of the Nucleon and Angular Asymmetry of Proton-Neutron Hard Elastic Scattering
Carlos G. Granados; Misak M. Sargsian
2009-07-29T23:59:59.000Z
We investigate an asymmetry in the angular distribution of hard elastic proton-neutron scattering with respect to 90deg center of mass scattering angle. We demonstrate that the magnitude of the angular asymmetry is related to the helicity-isospin symmetry of the quark wave function of the nucleon. Our estimate of the asymmetry within the quark-interchange model of hard scattering demonstrates that the quark wave function of a nucleon based on the exact SU(6) symmetry predicts an angular asymmetry opposite to that of experimental observations. On the other hand the quark wave function based on the diquark picture of the nucleon produces an asymmetry consistent with the data. Comparison with the data allowed us to extract the relative sign and the magnitude of the vector and scalar diquark components of the quark wave function of the nucleon. These two quantities are essential in constraining QCD models of a nucleon. Overall, our conclusion is that the angular asymmetry of a hard elastic scattering of baryons provides a new venue in probing quark-gluon structure of baryons and should be considered as an important observable in constraining the theoretical models.
Off-Shell Scattering Amplitudes for WW Scattering and the Role of the Photon Pole
J. Bartels; F. Schwennsen
2005-06-06T23:59:59.000Z
We derive analytic expressions for high energy $2 \\to 2$ off-shell scattering amplitudes of weak vector bosons. They are obtained from six fermion final states in processes of the type $e^+ e^- \\to \\bar\
Inverse scattering J-matrix approach to nucleon-nucleus scattering and the shell model
A. M. Shirokov; A. I. Mazur; J. P. Vary; E. A. Mazur
2008-10-06T23:59:59.000Z
The $J$-matrix inverse scattering approach can be used as an alternative to a conventional $R$-matrix in analyzing scattering phase shifts and extracting resonance energies and widths from experimental data. A great advantage of the $J$-matrix is that it provides eigenstates directly related to the ones obtained in the shell model in a given model space and with a given value of the oscillator spacing $\\hbar\\Omega$. This relationship is of a particular interest in the cases when a many-body system does not have a resonant state or the resonance is broad and its energy can differ significantly from the shell model eigenstate. We discuss the $J$-matrix inverse scattering technique, extend it for the case of charged colliding particles and apply it to the analysis of $n\\alpha$ and $p\\alpha$ scattering. The results are compared with the No-core Shell Model calculations of $^5$He and $^5$Li.
Scattered neutron tomography based on a neutron transport problem
Scipolo, Vittorio
2005-11-01T23:59:59.000Z
scattering objects because it does not adequately account for the scattering component of the neutron beam intensity exiting the sample. We proposed a new method of computed tomography which employs an inverse problem analysis of both the transmitted...
A study of neutron-deuteron scattering in configuration space
V. M. Suslov; M. A. Braun; I. Filikhin; B. Vlahovic
2006-10-09T23:59:59.000Z
A new computational method for solving the configuration-space Faddeev equations for the breakup scattering problem has been applied to nd scattering both below and above the two-body threshold.
Wavelet Analysis of Two Dimensional Quantum Scattering A thesis presented
Heller, Eric
Wavelet Analysis of Two Dimensional Quantum Scattering A thesis presented by Jonathan Dillwyn the local nature of the scattering. We present an alternative discretization based on the discrete wavelet
Anisotropic light scattering of individual sickle red blood cells
Kim, Youngchan
We present the anisotropic light scattering of individual red blood cells (RBCs) from a patient with sickle cell disease (SCD). To measure light scattering spectra along two independent axes of elongated-shaped sickle RBCs ...
Scattered neutron tomography based on a neutron transport problem
Scipolo, Vittorio
2005-11-01T23:59:59.000Z
scattering objects because it does not adequately account for the scattering component of the neutron beam intensity exiting the sample. We proposed a new method of computed tomography which employs an inverse problem analysis of both the transmitted...
Raman scattering from defects in GaN: The question of vibrational or electronic scattering mechanism
Nabben, Reinhard
Raman scattering from defects in GaN: The question of vibrational or electronic scattering on defects in GaN, which appear in the Raman spectra as sharp and intense lines in the low-energy region from into the GaN material. S0163-1829 98 00344-0 I. INTRODUCTION Low-temperature Raman spectra of GaN films grown
Particle sizing by dynamic light scattering: non-linear cumulant analysis
Alastair G. Mailer; Paul S. Clegg; Peter N. Pusey
2015-04-24T23:59:59.000Z
We revisit the method of cumulants for analysing dynamic light scattering data in particle sizing applications. Here the data, in the form of the time correlation function of scattered light, is written as a series involving the first few cumulants (or moments) of the distribution of particle diffusion constants. Frisken (2001 Applied Optics 40, 4087) has pointed out that, despite greater computational complexity, a non-linear, iterative, analysis of the data has advantages over the linear least-squares analysis used originally. In order to explore further the potential and limitations of cumulant methods we analyse, by both linear and non-linear methods, computer-generated data with realistic `noise', where the parameters of the distribution can be set explicitly. We find that, with modern computers, non-linear analysis is straightforward and robust. The mean and variance of the distribution of diffusion constants can be obtained quite accurately for distributions of width (standard deviation/mean) up to about 0.6, but there appears to be little prospect of obtaining meaningful higher moments.
Introduction to Distributed Systems
Pous, Damien
1 Introduction to Distributed Systems Fabienne Boyer, LIG, fabienne.boyer@inria.fr Sources: Cours d'Olivier Gruber, Sacha Krakowiak, Sara Bouchenak, UJF Fabienne Boyer, Distributed Programming 2 Objectives Study conceptual and practical aspects of distributed systems l Client-server model l Distributed protocols l
Distributed Paging Yair Bartal
Bartal, Yair
. We survey distributed data management problems including distributed paging, file allocation fantastically on an annual basis. This survey deals with distributed data management problems. Such probÂ lems in distributed data management is the deÂ sign of a dynamic allocation of file copies in a network in order
Nolte, R; Plompen, A; Röttger, S
2014-01-01T23:59:59.000Z
The angular distribution of neutron-deuteron scattering was investigated using the proportional counter P2 simultaneously as scattering target and detector for the recoil deuterons. The measurements were carried out using monoenergetic neutrons in the energy range from 150 keV to 500 keV. Various techniques were employed to reduce distortions of the experimental pulse-height distribution by photon-induced events. The experimental data were compared with realistic simulations which were carried out using different evaluated data sets. This comparison allows to conclude on inconsistencies in the evaluations.
2D Static Light Scattering for Dairy Based Applications
2D Static Light Scattering for Dairy Based Applications Jacob Lercke Skytte Kongens Lyngby 2014 Ph information on the microstructure. The second paper makes a direction comparison between the light scattering a recently introduced light scattering tech- nique. The system setup of the technique is highly flexible
Fractal dimension in dissipative chaotic scattering Jess M. Seoane,1,
Rey Juan Carlos, Universidad
Fractal dimension in dissipative chaotic scattering JesÃºs M. Seoane,1, * Miguel A. F. SanjuÃ¡n,1 on chaotic scattering is relevant to situations of physical interest. We inves- tigate how the fractal is thus the fractal dimension of the set of singularities. For nonhyperbolic scattering, it has been known
Small Angle X-ray Scattering (SAXS) Laboratory Learning Experiences
Meagher, Mary
.A. & Svergun D.I. (1987). Structure Analysis by Small-Angle X-Ray and Neutron Scattering. NY: Plenum PressSmall Angle X-ray Scattering (SAXS) Laboratory Learning Experiences o - Use of small angle X-ray scattering instrumentation o - Programs that you will use SAXS (BRUKER AXS) PRIMUS (Konarev, Volkov, Koch
Diffractive and deeply virtual Compton scattering in holographic QCD
Alexander Stoffers; Ismail Zahed
2012-10-13T23:59:59.000Z
We further analyze the holographic dipole-dipole scattering amplitude developed in arXiv:1202.0831, 1205.3223. Gribov diffusion at strong coupling yields the scattering amplitude in a confining background. We compare the holographic result for the differential cross section to proton-proton and deeply virtual Compton scattering data.
INTRA BEAM SCATTERING IN LINEAR ACCELERATORS, ESPECIALLY ERLS
Hoffstaetter, Georg
are called Touschek particles. Touschek scattering in a linear acceler- ator is interesting because. In this paper we describe two ways of simu- lating particle loss by these scattering affects, both imple- mented complete propagation of scattered particle. For the example of the ERL x-ray facility that Cornell plans
Disorder scattering in graphene nanoribbons F. Libisch1
Florian, Libisch
Disorder scattering in graphene nanoribbons F. Libisch1 , S. Rotter1 , J. Burgd¨orfer1 1 Institute investigate transport through bulk-disordered graphene nanoribbons and nanoconstrictions. Employing a modular transforming the scattered wave we disentangle inter-valley scattering between the two Dirac cones of graphene
Raman Scattering through a quantum-critical point
Freericks, Jim
spectral weight with underdoping. J. G. Naeini et al., PRB 1999 J. K. Freericks, Georgetown University, Raman scattering talk, 2001 M. Opel et al., PRB 2000 //( >> 0) k() qp scattering talk, 2001 #12;Experimental data for Kondo insulators · Nyhus et al, PRB 95 Raman scattering on Fe
Automatically Identifying Scatter in Fluorescence Data using Robust Techniques.
(PARAFAC) to fluorescence excitation-emission data (EEM). The scatter does not contain any relevant handle first and second order Rayleigh scatter as well as Raman scatter in various types of EEM data of such a measurement is an excitation-emission matrix (EEM). When several samples (I) are mea- sured the data can
Neutron Scattering Society of America Purpose and New Initiatives
Pennycook, Steve
1 Neutron Scattering Society of America (NSSA) Purpose and New Initiatives www.neutronscattering.org SNS/ANL School on Neutron and X-Ray Scattering June 2010 Visit us now on Facebook #12;2 What and provide a focal point for the neutron scattering community in the USA To identify the needs
Fourteenth National School on Neutron and X-ray Scattering
Pennycook, Steve
Fourteenth National School on Neutron and X-ray Scattering August 12 - 25, 2012 at Argonne National of the National School on Neutron and X-ray Scattering is to educate graduate students on the utilization of major Ridge National Laboratory's Neutron Scattering Science Division. Scientific Directors: Jonathan C. Lang
The Neutron Scattering Society www.neutronscattering.org
Chen, Sow-Hsin
The Neutron Scattering Society of America www.neutronscattering.org Press Release, February 4, 2008 The Neutron Scattering Society of America is pleased to announce the 2008 recipients of its 3 major prizes. The Neutron Scattering Society of America (NSSA) established the Clifford G. Shull Prize in Neutron Science
Nitrogen Contamination in Elastic Neutron Scattering Songxue Chi,ab
Lynn, Jeffrey W.
Nitrogen Contamination in Elastic Neutron Scattering Songxue Chi,ab Jeffrey W. Lynn,a* Ying Chen a neutron scattering measurement is a contribution to the background, especially in inelastic measurements of having N2 in the sample environment system during elastic neutron scattering measurements on a single
Tenth National School on Neutron and X-ray Scattering
Pennycook, Steve
Tenth National School on Neutron and X-ray Scattering September 24 - October 11, 2008 at Argonne of the National School on Neutron and X-ray Scattering is to educate graduate students on the utilization of major National Laboratory's Neutron Scattering Science Division. Scientific Directors: Jonathan C. Lang, Suzanne
Neutron Scattering Society of America Purpose and New Initiatives
1 Neutron Scattering Society of America (NSSA) Purpose and New Initiatives www.neutronscattering.org SNS/ANL School on Neutron and X-Ray Scattering June 2011 Visit us now on Facebook #12;2 What and provide a focal point for the neutron scattering community in the USA To identify the needs
National School on Neutron and X-ray Scattering
15th National School on Neutron and X-ray Scattering August 10 - 24, 2013 at Argonne National of the National School on Neutron and X-ray Scattering is to educate graduate students on the utilization of major Ridge National Laboratory's Neutron Scattering Science Division. Scientific Directors: Jonathan C. Lang
TUTORIAL / ARTICLE DIDACTIQUE Neutron scattering study of the classical
Ryan, Dominic
TUTORIAL / ARTICLE DIDACTIQUE Neutron scattering study of the classical antiferromagnet MnF2: a perfect hands-on neutron scattering teaching course1 Z. Yamani, Z. Tun, and D.H. Ryan Abstract: We present of neutron scattering concepts. The nature of antiferromagnetism and the magnetic Hamiltonian in this classi
Thirteenth National School on Neutron and X-ray Scattering
Thirteenth National School on Neutron and X-ray Scattering June 11 June 25, 2011 at Argonne of the National School on Neutron and X-ray Scattering is to educate graduate students on the utilization of major National Laboratory's Neutron Scattering Science Division. Scientific Directors: Jonathan C. Lang, Suzanne
LANSCE School on Neutron Scattering: Materials at the Mesoscale
1 11th LANSCE School on Neutron Scattering: Materials at the Mesoscale Lujan Center Los Alamos. Please name the applicant for admission to the 11th LANSCE School on Neutron Scattering: Last, First LANSCE School on Neutron Scattering including: drive and motivation, ability to work with others
The Neutron Scattering Society www.neutronscattering.org
Homes, Christopher C.
The Neutron Scattering Society of America www.neutronscattering.org Press Release February 11, 2008 The Neutron Scattering Society of America is pleased to announce the election as Fellows of the Society of in application of neutron scattering to studies of surfaces and crystal field excitations as well as his
Sixteenth National School on Neutron and X-ray Scattering
Pennycook, Steve
Sixteenth National School on Neutron and X-ray Scattering June 14-28, 2014 at Argonne National of the National School on Neutron and X-ray Scattering is to educate graduate students on the utilization of major's Neutron Scattering Science Division. Scientific Directors: Suzanne G.E. te Velthuis, Esen Ercan Alp
Neutron scattering in magnetic fields (*) W. C. Koehler
Boyer, Edmond
691 Neutron scattering in magnetic fields (*) W. C. Koehler Solid State Division, Oak Ridge. Abstract 2014 The use of magnetic fields in neutron scattering experimentation is reviewed briefly. Two of the scattering sample ; in the second the field acts on the neutron itself. Several examples are discussed
Twelfth National School on Neutron and X-ray Scattering
Pennycook, Steve
Twelfth National School on Neutron and X-ray Scattering June 12 June 26, 2010 at Argonne National of the National School on Neutron and X-ray Scattering is to educate graduate students on the utilization of major National Laboratory's Neutron Scattering Science Division. Scientific Directors: Jonathan C. Lang, Suzanne
National School on Neutron and X-ray Scattering
Pennycook, Steve
National School on Neutron and X-ray Scattering May 30 June 13, 2009 at Argonne National of the National School on Neutron and X-ray Scattering is to educate graduate students on the utilization of major National Laboratory's Neutron Scattering Science Division. Scientific Directors: Jonathan C. Lang, Suzanne
A Java-based Science Portal for Neutron Scattering Experiments
Vazhkudai, Sudharshan
A Java-based Science Portal for Neutron Scattering Experiments Sudharshan S. Vazhkudai James A scattering facility recently commissioned by the US Department of Energy (DOE). The neutron beam produced (SNS) [14] is a large-scale leading- edge neutron scattering facility that hopes to fundamen- tally
ORNL Neutron Scattering School May 30 -June 5, 2009
Pennycook, Steve
ORNL Neutron Scattering School May 30 - June 5, 2009 Oak Ridge National Laboratory Oak Ridge, 2009, for the first week of the Neutron Xray Scattering School. Please be certain to bring photo for Neutron Scattering Users · Radiological Worker Training for HFIR and SNS Users In addition
ccsd00002835, Light scattering from cold rolled aluminum surfaces
ccsd00002835, version 2 14 Sep 2004 Light scattering from cold rolled aluminum surfaces Damien Camille Soula , 31400 Toulouse, France We present experimental light scattering measurements from aluminum scattering measurements of an s-polarized electromagnetic wave (632.8 nanometers) from a rough aluminum alloy
Boyer, Edmond
,, or on the differencep, -p, bet- ween the neutron and proton distributions. These experiments include scattering NEUTRON DISTRIBUTIONS R. C. BARRETT University of Surrey, Guildford, Surrey, U. K. RBsumB. -Un rappel des calculs de distributions de densite de neutrons B partir du modtile a particules independantes, du modtile
Local Two-Photon Couplings and the J=0 Fixed Pole in Real and Virtual Compton Scattering
Stanley J. Brodsky; Felipe J. Llanes-Estrada; Adam P. Szczepaniak
2008-12-02T23:59:59.000Z
The local coupling of two photons to the fundamental quark currents of a hadron gives an energy-independent contribution to the Compton amplitude proportional to the charge squared of the struck quark, a contribution which has no analog in hadron scattering reactions. We show that this local contribution has a real phase and is universal, giving the same contribution for real or virtual Compton scattering for any photon virtuality and skewness at fixed momentum transfer squared t. The t-dependence of this J=0 fixed Regge pole is parameterized by a yet unmeasured even charge-conjugation form factor of the target nucleon. The t=0 limit gives an important constraint on the dependence of the nucleon mass on the quark mass through the Weisberger relation. We discuss how this 1/x form factor can be extracted from high energy deeply virtual Compton scattering and examine predictions given by models of the H generalized parton distribution.
Adams, T.; /Florida State U.; Batra, P.; /Columbia U.; Bugel, Leonard G.; /Columbia U.; Camilleri, Leslie Loris; /Columbia U.; Conrad, Janet Marie; /MIT; de Gouvea, A.; /Northwestern U.; Fisher, Peter H.; /MIT; Formaggio, Joseph Angelo; /MIT; Jenkins, J.; /Northwestern U.; Karagiorgi, Georgia S.; /MIT; Kobilarcik, T.R.; /Fermilab /Texas U.
2009-06-01T23:59:59.000Z
We extend the physics case for a new high-energy, ultra-high statistics neutrino scattering experiment, NuSOnG (Neutrino Scattering On Glass) to address a variety of issues including precision QCD measurements, extraction of structure functions, and the derived Parton Distribution Functions (PDFs). This experiment uses a Tevatron-based neutrino beam to obtain a sample of Deep Inelastic Scattering (DIS) events which is over two orders of magnitude larger than past samples. We outline an innovative method for fitting the structure functions using a parameterized energy shift which yields reduced systematic uncertainties. High statistics measurements, in combination with improved systematics, will enable NuSOnG to perform discerning tests of fundamental Standard Model parameters as we search for deviations which may hint of 'Beyond the Standard Model' physics.
Scattering of electromagnetic waves by many thin cylinders: theory and computational modeling
Ramm, A G
2015-01-01T23:59:59.000Z
Electromagnetic (EM) wave scattering by many parallel infinite cylinders is studied asymptotically as a tends to 0, where a is the radius of the cylinders. It is assumed that the centres of the cylinders are distributed so that their numbers is determined by some positive function N(x). The function N(x) >= 0 is a given continuous function. An equation for the self-consistent (limiting) field is derived as a tends to 0. The cylinders are assumed perfectly conducting. Formula for the effective refraction coefficient of the new medium, obtained by embedding many thin cylinders into a given region, is derived. The numerical results presented demonstrate the validity of the proposed approach and its efficiency for solving the many-body scattering problems, as well as the possibility to create media with negative refraction coefficients.
Simulations of gamma quanta scattering in a single module of the J-PET detector
Szyma?ski, K; Bednarski, T; Bia?as, P; Czerwi?ski, E; Giergiel, K; Kap?on, ?; Kochanowski, A; Korcyl, G; Kowal, J; Kowalski, P; Kozik, T; Krzemie?, W; Molenda, M; Moskal, I; Nied?wiecki, Sz; Pa?ka, M; Pawlik, M; Raczy?ski, L; Rudy, Z; Salabura, P; Sharma, N G; Silarski, M; S?omski, A; Smyrski, J; Strzelecki, A; Witkowski, P; Wi?licki, W; Zieli?ski, M; Zo?, N
2013-01-01T23:59:59.000Z
This article describes simulations of scattering of annihilation gamma quanta in a strip of plastic scintillator. Such strips constitute basic detection modules in a newly proposed Positron Emission Tomography which utilizes plastic scintillators instead of inorganic crystals. An algorithm simulating chain of Compton scatterings was elaborated and series of simulations have been conducted for the scintillator strip with the cross section of 5 mm x 19 mm. Obtained results indicate that secondary interactions occur only in the case of about 8% of events and out of them only 25$\\%$ take place in the distance larger than 0.5 cm from the primary interaction. It was also established that light signals produced at primary and secondary interactions overlap with the delay which distribution is characterized by FWHM of about 40 ps.
Analysis of the DENZ04 low-energy $\\pi^\\pm p$ elastic-scattering data
Matsinos, Evangelos
2012-01-01T23:59:59.000Z
This paper presents the results of an analysis of the DENZ04 low-energy $\\pi^\\pm p$ differential cross sections. We first analysed separately the $\\pi^+ p$ and the $\\pi^- p$ elastic-scattering measurements on the basis of standard low-energy expansions of the s- and p-wave $K$-matrix elements. After the removal of the outliers (eleven degrees of freedom in the initial database), we subjected the truncated $\\pi^\\pm p$ elastic-scattering databases into a common optimisation scheme using the ETH model; the optimisation failed to produce reasonable values for the model parameters. The phase-shift solution, extracted from the model fit to the data, is very odd. The problems we have encountered in the analysis of the DENZ04 data are due to the shape of the angular distributions of their $\\pi^+ p$ differential cross sections.
Selective coupling of optical energy into the fundamental diffusion mode of a scattering medium
Ojambati, Oluwafemi S; Lagendijk, Ad; Mosk, Allard P; Vos, Willem L
2015-01-01T23:59:59.000Z
We demonstrate experimentally that optical wavefront shaping selectively couples light into the fundamental diffusion mode of a scattering medium. The total energy density inside a scattering medium of zinc oxide (ZnO) nanoparticles was probed by measuring the emitted fluorescent power of spheres that were randomly positioned inside the medium. The fluorescent power of an optimized incident wave front is observed to be enhanced compared to a non-optimized incident front. The observed enhancement increases with sample thickness. Based on diffusion theory, we derive a model wherein the distribution of energy density of wavefront-shaped light is described by the fundamental diffusion mode. The agreement between our model and the data is striking not in the least since there are no adjustable parameters. Enhanced total energy density is crucial to increase the efficiency of white LEDs, solar cells, and of random lasers, as well as to realize controlled illumination in biomedical optics.
Neutron-Proton Scattering in the Context of the $d^*$(2380) Resonance
P. Adlarson; W. Augustyniak; W. Bardan; M. Bashkanov; F. S. Bergmann; M. Ber?owski; H. Bhatt; M. Büscher; H. Calén; I. Ciepa?; H. Clement; D. Coderre; E. Czerwi?ski; K. Demmich; E. Doroshkevich; R. Engels; A. Erven; W. Erven; W. Eyrich; P. Fedorets; K. Föhl; K. Fransson; F. Goldenbaum; P. Goslawski; A. Goswami; K. Grigoryev; C. --O. Gullström; F. Hauenstein; L. Heijkenskjöld; V. Hejny; M. Hodana; B. Höistad; N. Hüsken; A. Jany; B. R. Jany; L. Jarczyk; T. Johansson; B. Kamys; G. Kemmerling; F. A. Khan; A. Khoukaz; D. A. Kirillov; S. Kistryn; H. Kleines; B. K?os; M. Krapp; W. Krzemie?; P. Kulessa; A. Kup??; K. Lalwani; D. Lersch; B. Lorentz; A. Magiera; R. Maier; P. Marciniewski; B. Maria?ski; M. Mikirtychiants; H. --P. Morsch; P. Moskal; H. Ohm; I. Ozerianska; E. Perez del Rio; N. M. Piskunov; P. Podkopa?; D. Prasuhn; A. Pricking; D. Pszczel; K. Pysz; A. Pyszniak; C. F. Redmer; J. Ritman; A. Roy; Z. Rudy; S. Sawant; S. Schadmand; T. Sefzick; V. Serdyuk; R. Siudak; T. Skorodko; M. Skurzok; J. Smyrski; V. Sopov; R. Stassen; J. Stepaniak; E. Stephan; G. Sterzenbach; H. Stockhorst; H. Ströher; A. Szczurek; A. Täschner; A. Trzci?ski; R. Varma; G. J. Wagner; M. Wolke; A. Wro?ska; P. Wüstner; P. Wurm; A. Yamamoto; L. Yurev; J. Zabierowski; M. J. Zieli?ski; A. Zink; J. Z?oma?czuk; P. {?}upra?ski; M. {?}urek; R. L. Workman; W. J. Briscoe; I. I. Strakovsky
2014-08-21T23:59:59.000Z
New data on quasifree polarized neutron-proton scattering, in the region of the recently observed $d^*$ resonance structure, have been obtained by exclusive and kinematically complete high-statistics measurements with WASA at COSY. This paper details the determination of the beam polarization, checks of the quasifree character of the scattering process, on all obtained $A_y$ angular distributions and on the new partial-wave analysis, which includes the new data producing a resonance pole in the $^3D_3$-$^3G_3$ coupled partial waves at ($2380\\pm10 - i40\\pm5$) MeV -- in accordance with the $d^*$ dibaryon resonance hypothesis. The effect of the new partial-wave solution on the description of total and differential cross section data as well as specific combinations of spin-correlation and spin-transfer observables available from COSY-ANKE measurements at $T_d$ = 2.27 GeV is discussed.
Deep Inelastic Electron Scattering Off the Helium and Tritium Mirror Nuclei
Holt, Roy J. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Petratos, Gerassimos G. [Department of Physics, Kent State University, Kent, OH 44242 (United States)
2011-09-21T23:59:59.000Z
We discuss a possible measurement of the ratio of nucleon structure functions, F{sub 2}{sup n}/F{sub 2}{sup p}, and the ratio of up to down quark distributions, u/d, at large Bjorken x, by performing deep inelastic electron scattering from the {sup 3}H and {sup 3}He mirror nuclei with the 11 GeV upgraded beam of Jefferson Lab. The measurement is expected to be almost free of nuclear effects, which introduce a significant uncertainty in the extraction of these two ratios from deep inelastic scattering off the proton and deuteron. The results are expected to test perturbative and non-perturbative mechanisms of spin-flavor symmetry breaking in the nucleon, and constrain the structure function parametrizations needed for the interpretation of high energy collider and neutrino oscillations data. The precision of the expected data can also test models of the nuclear EMC effect and provide valuable input for its full explanation.
Suppression of Quantum Scattering in Strongly Confined Systems
Kim, J. I. [Departamento de Pesquisas, Altanova, R. Silva Teles 712, CEP 03026-000, Bras, Sa(tilde sign)o Paulo, SP, Brasil (Brazil); Melezhik, V. S. [Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, Dubna, Moscow Region 141980 (Russian Federation); Schmelcher, P. [Physikalisches Institut, Universitaet Heidelberg, Philosophenweg 12, 69120 Heidelberg (Germany); Theoretische Chemie, Institut fuer Physikalische Chemie, Universitaet Heidelberg, Im Neuenheimer Feld 229, 69120 Heidelberg (Germany)
2006-11-10T23:59:59.000Z
We demonstrate that scattering of particles strongly interacting in three dimensions (3D) can be suppressed at low energies in a quasi-one-dimensional (1D) confinement. The underlying mechanism is the interference of the s- and p-wave scattering contributions with large s- and p-wave 3D scattering lengths being a necessary prerequisite. This low-dimensional quantum scattering effect might be useful in 'interacting' quasi-1D ultracold atomic gases, guided atom interferometry, and impurity scattering in strongly confined quantum wire-based electronic devices.
Inelastic Scatterings of Entangled Mossbauer Gammas
Yao Cheng; Zhongming Wang
2006-10-12T23:59:59.000Z
We report the observation of the temperature-dependent inelastic scattering of three entangled Mossbauer gammas in the time-resolved Mossbauer spectroscopy. Recently, the long-lived E3 Mossbauer transition of rhodium generated by bremsstrahlung irradiation has been reported. Two kinds of X-rays with the fast decay are attributed to the tri-photon effect. They are tri-photon pile-up of rhodium K X-rays and the high-Z impurity K X-rays. Energy of the particular K emission is higher than the sum energy of two Mossbauer gammas. This letter reports new discoveries by cooling down the sample using liquid nitrogen, namely the collective anomalous emission of entangled Mossbauer gammas. The enhancement of inelastic scatterings at low temperature such as rhodium K satellites is attributed to this entanglement.
Inelastic Scatterings of Entangled Mossbauer Gammas
Cheng, Y; Cheng, Yao; Wang, Zhongming
2006-01-01T23:59:59.000Z
We report the observation of the temperature-dependent inelastic scattering of three entangled Mossbauer gammas in the time-resolved Mossbauer spectroscopy. Recently, the long-lived E3 Mossbauer transition of rhodium generated by bremsstrahlung irradiation has been reported. Two kinds of x rays with the fast decay are attributed to the tri-photon effect. They are tri-photon pile-up of rhodium K x rays and the high-Z impurity K x rays. Energy of the particular K emission is greater than the sum energy of two Mossbauer gammas. This letter reports new discoveries by cooling down the sample using liquid nitrogen, namely the collective anomalous emission of entangled Mossbauer gammas. The enhancement of inelastic scatterings at low temperature such as rhodium K satellites is attributed to this entanglement.
Optical theorem and elastic nucleon scattering
Milos V. Lokajicek; Vojtech Kundrat
2009-06-22T23:59:59.000Z
In the theoretical analysis of high-energy elastic nucleon scattering one starts commonly from the description based on the validity of optical theorem, which allows to derive the value of total cross section directly from the experimentally measured t-dependence of elastic differential cross section. It may be shown, however, that this theorem has been derived on the basis of one assumption that might be regarded perhaps as acceptable for long-range (e.g., Coulomb) forces but must be denoted as quite unacceptable for finite-range hadron forces. Consequently, the conclusions leading to the increase of total cross section with energy at higher collision energies must be newly analyzed. The necessity of new analysis concerns also the derivation of elastic scattering t-dependence at very low transverse momenta from measured data.
Multiple Scattering Measurements in the MICE Experiment
Carlisle, T.; Cobb, J.; /Oxford U.; Neuffer, D.; /Fermilab
2012-05-01T23:59:59.000Z
The international Muon Ionization Cooling Experiment (MICE), under construction at RAL, will test a prototype cooling channel for a future Neutrino Factory or Muon Collider. The cooling channel aims to achieve, using liquid hydrogen absorbers, a 10% reduction in transverse emittance. The change in 4D emittance will be determined with an accuracy of 1% by measuring muons individually. Step IV of MICE will make the first precise emittance-reduction measurements of the experiment. Simulation studies using G4MICE, based on GEANT4, find a significant difference in multiple scattering in low Z materials, compared with the standard expression quoted by the Particle Data Group. Direct measurement of multiple scattering using the scintillating-fibre trackers is found to be possible, but requires the measurement resolution to be unfolded from the data.
Scattering theory of topological insulators and superconductors
I. C. Fulga; F. Hassler; A. R. Akhmerov
2013-01-10T23:59:59.000Z
The topological invariant of a topological insulator (or superconductor) is given by the number of symmetry-protected edge states present at the Fermi level. Despite this fact, established expressions for the topological invariant require knowledge of all states below the Fermi energy. Here, we propose a way to calculate the topological invariant employing solely its scattering matrix at the Fermi level without knowledge of the full spectrum. Since the approach based on scattering matrices requires much less information than the Hamiltonian-based approaches (surface versus bulk), it is numerically more efficient. In particular, is better-suited for studying disordered systems. Moreover, it directly connects the topological invariant to transport properties potentially providing a new way to probe topological phases.
Pumping angular momentum by driven chaotic scattering
T. Dittrich; F. L. Dubeibe
2008-04-29T23:59:59.000Z
Chaotic scattering with an internal degree of freedom and the possibility to generate directed transport of angular momentum is studied in a specific model, a magnetic dipole moving in a periodically modulated magnetic field confined to a compact region in space. We show that this system is an irregular scatterer in large parts of its parameter space. If in addition all spatio-temporal symmetries are broken, directed transport of mass as well as angular momentum occurs. The sensitive parameter dependence of the corresponding currents includes frequent sign reversals. Zeros of either quantity entail the exclusive occurrence of the other and thus give rise in particular to angular-momentum separation without mass transport as a classical analogue of spin-polarized currents.
Ab initio alpha-alpha scattering
Serdar Elhatisari; Dean Lee; Gautam Rupak; Evgeny Epelbaum; Hermann Krebs; Timo A. Lähde; Thomas Luu; Ulf-G. Meißner
2015-06-11T23:59:59.000Z
Processes involving alpha particles and alpha-like nuclei comprise a major part of stellar nucleosynthesis and hypothesized mechanisms for thermonuclear supernovae. In an effort towards understanding alpha processes from first principles, we describe in this letter the first ab initio calculation of alpha-alpha scattering. We use lattice effective field theory to describe the low-energy interactions of nucleons and apply a technique called the adiabatic projection method to reduce the eight-body system to an effective two-cluster system. We find good agreement between lattice results and experimental phase shifts for S-wave and D-wave scattering. The computational scaling with particle number suggests that alpha processes involving heavier nuclei are also within reach in the near future.
Ab initio alpha-alpha scattering
Elhatisari, Serdar; Rupak, Gautam; Epelbaum, Evgeny; Krebs, Hermann; Lähde, Timo A; Luu, Thomas; Meißner, Ulf-G
2015-01-01T23:59:59.000Z
Processes involving alpha particles and alpha-like nuclei comprise a major part of stellar nucleosynthesis and hypothesized mechanisms for thermonuclear supernovae. In an effort towards understanding alpha processes from first principles, we describe in this letter the first ab initio calculation of alpha-alpha scattering. We use lattice effective field theory to describe the low-energy interactions of nucleons and apply a technique called the adiabatic projection method to reduce the eight-body system to an effective two-cluster system. We find good agreement between lattice results and experimental phase shifts for S-wave and D-wave scattering. The computational scaling with particle number suggests that alpha processes involving heavier nuclei are also within reach in the near future.
Recent results from COMPASS muon scattering measurements
Capozza, Luigi [Irfu/SPhN - CEA Saclay, 91190 Gif-sur-Yvette (France); Collaboration: COMPASS Collaboration
2012-10-23T23:59:59.000Z
A sample of recent results in muon scattering measurements from the COMPASS experiment at CERN will be reviewed. These include high energy processes with longitudinally polarised proton and deuteron targets. High energy polarised measurements provide important constraints for studying the nucleon spin structure and thus permit to test the applicability of the theoretical framework of factorisation theorems and perturbative QCD. Specifically, latest results on longitudinal quark polarisation, quark helicity densities and gluon polarisation will be reviewed.
Scattering off the Color Glass Condensate
Heikki Mäntysaari
2015-06-24T23:59:59.000Z
In this thesis the Color Glass Condensate (CGC) framework, which describes quantum chromodynamics (QCD) at high energy, is applied to various scattering processes. Higher order corrections to the CGC evolution equations, known as the BK and JIMWLK equations, are also considered. It is shown that the leading order CGC calculations describe the experimental data from electron-proton deep inelastic scattering (DIS), proton-proton and proton-nucleus collisions. The initial condition for the BK evolution equation is obtained by performing a fit to deep inelastic scattering data. The fit result is used as an input to calculations of single particle spectra and nuclear suppression in proton-proton and proton-nucleus collisions, which are shown to be in agreement with RHIC and LHC measurements. In particular, the importance of a proper description of the nuclear geometry consistently with the DIS data fits is emphasized, as it results in a nuclear suppression factor $R_{pA}$ which is consistent with the available experimental data. In addition to single particle production, the correlations between two hadrons at forward rapidity are computed. The RHIC measurements are shown to be naturally explainable in the CGC framework, and the previous CGC calculations are improved by including the so called inelastic and double parton scattering contributions. This improvement is shown to be required in order to get results compatible with the experimentally measured correlations. Exclusive vector meson production, which can be a powerful tool to study the gluonic structure of nuclei at small Bjorken-$x$, is also considered. The cross sections are calculated within the CGC framework in the context of a future electron-ion collider. In particular, the cross section for incoherent diffractive vector meson production is derived and a centrality estimator for this process is proposed.
Thompson Scattering in an Expanding Universe
James L. Anderson
1997-09-14T23:59:59.000Z
The Thompson cross section for scattering of electromagnetic waves by a free electron in an expanding universe is derived here. The equations of motion of the electron are obtained using the Einstein-Infeld-Hoffmann (EIH) surface integral method. These integrals are evaluated approximately by perturbing off an Einstein-deSitter cosmological field. It is found that the Thompson cross section varies with time as the inverse square of the cosmic scale factor R(t).
Harmonic polylogarithms for massive Bhabha scattering
M. Czakon; J. Gluza; T. Riemann
2005-08-19T23:59:59.000Z
One- and two-dimensional harmonic polylogarithms, HPLs and GPLs, appear in calculations of multi-loop integrals. We discuss them in the context of analytical solutions for two-loop master integrals in the case of massive Bhabha scattering in QED. For the GPLs we discuss analytical representations, conformal transformations, and also their transformations corresponding to relations between master integrals in the s- and t-channel.
Thomson scattering for core plasma on DEMO
Mukhin, E. E.; Kurskiev, G. S.; Tolstyakov, S. Yu.; Bukreev, I. M.; Chernakov, P. V.; Kochergin, M. M.; Koval, A. N.; Litvinov, A. E.; Masyukevich, S. V.; Razdobarin, A. G.; Semenov, V. V. [Ioffe Physical Technical Institute, 26 Polytechnicheskaya St., St. Petersburg (Russian Federation); Kukushkin, A. B.; Sdvizhenskii, P. A. [NRC Kurchatov Institute, 1, Akademika Kurchatova pl., Moscow, 123182 (Russian Federation); Andrew, P. [ITER Organization, Route de Vinon sur Verdon, 13115 St Paul Lez Durance (France)
2014-08-21T23:59:59.000Z
This paper describes the challenges of Thomson scattering implementation for core plasma on DEMO and evaluates the capability to measure extremely high electron temperature range 0.5-40keV. A number of solutions to be developed for ITER diagnostics are suggested in consideration of their realization for DEMO. New approaches suggested for DEMO may also be of interest to ITER and currently operating magnetic confinement devices.
Management of a large distributed control system development project
Gurd, D. P. (David P.)
2002-01-01T23:59:59.000Z
Building an accelerator at six geographically dispersed sites is quite mad, but politically expedient. The Spallation Neutron Source (SNS), currently under construction in Oak Ridge, Tennessee, combines a pulsed 1 Gev H{sup -} superconducting linac with a compressor ring to deliver 2 MW of beam power to a liquid mercury target for neutron production [1]. Accelerator components, target and experimental (neutron-scattering) instruments are being developed collaboratively by Lawrence Berkeley (Ion Source and Front End), Los Alamos (Linac), Thomas Jefferson (Cryosystems), Brookhaven (Compressor Ring), Oak Ridge (Target and Conventional Facilities) and Argonne (Neutron Scattering Instruments) National Laboratories. Similarly, a team distributed among all of the participating laboratories is developing the EPICS-based control system. this paper discusses the management model and strategies being used to address the unusual issues of organization, communication, standardization, integration and hand-off inherent in this widely-distributed project.
ANALYSIS OF DISTRIBUTION FEEDER LOSSES DUE TO ADDITION OF DISTRIBUTED PHOTOVOLTAIC GENERATORS
Tuffner, Francis K.; Singh, Ruchi
2011-08-09T23:59:59.000Z
Distributed generators (DG) are small scale power supplying sources owned by customers or utilities and scattered throughout the power system distribution network. Distributed generation can be both renewable and non-renewable. Addition of distributed generation is primarily to increase feeder capacity and to provide peak load reduction. However, this addition comes with several impacts on the distribution feeder. Several studies have shown that addition of DG leads to reduction of feeder loss. However, most of these studies have considered lumped load and distributed load models to analyze the effects on system losses, where the dynamic variation of load due to seasonal changes is ignored. It is very important for utilities to minimize the losses under all scenarios to decrease revenue losses, promote efficient asset utilization, and therefore, increase feeder capacity. This paper will investigate an IEEE 13-node feeder populated with photovoltaic generators on detailed residential houses with water heater, Heating Ventilation and Air conditioning (HVAC) units, lights, and other plug and convenience loads. An analysis of losses for different power system components, such as transformers, underground and overhead lines, and triplex lines, will be performed. The analysis will utilize different seasons and different solar penetration levels (15%, 30%).
Scattering off the Color Glass Condensate
Mäntysaari, Heikki
2015-01-01T23:59:59.000Z
In this thesis the Color Glass Condensate (CGC) framework, which describes quantum chromodynamics (QCD) at high energy, is applied to various scattering processes. Higher order corrections to the CGC evolution equations, known as the BK and JIMWLK equations, are also considered. It is shown that the leading order CGC calculations describe the experimental data from electron-proton deep inelastic scattering (DIS), proton-proton and proton-nucleus collisions. The initial condition for the BK evolution equation is obtained by performing a fit to deep inelastic scattering data. The fit result is used as an input to calculations of single particle spectra and nuclear suppression in proton-proton and proton-nucleus collisions, which are shown to be in agreement with RHIC and LHC measurements. In particular, the importance of a proper description of the nuclear geometry consistently with the DIS data fits is emphasized, as it results in a nuclear suppression factor $R_{pA}$ which is consistent with the available exp...
Modeling light scattering from diesel soot particles
Hull, Patricia; Shepherd, Ian; Hunt, Arlon
2002-07-16T23:59:59.000Z
The Mie model is widely used to analyze light scattering from particulate aerosols. The Diesel Particle Scatterometer (DPS), for example, determines the size and optical properties of diesel exhaust particles that are characterized by measuring three angle-dependent elements of the Mueller scattering matrix. These elements are then fitted using Mie calculations with a Levenburg-Marquardt optimization program. This approach has achieved good fits for most experimental data. However, in many cases, the predicted real and imaginary parts of the index of refraction were less than that for solid carbon. To understand this result and explain the experimental data, we present an assessment of the Mie model by use of a light scattering model based on the coupled dipole approximation. The results indicate that the Mie calculation can be used to determine the largest dimension of irregularly shaped particles at sizes characteristic of Diesel soot and, for particles of known refractive index, tables can be constructed to determine the average porosity of the particles from the predicted index of refraction.
Scattering properties of dark atoms and molecules
James M. Cline; Zuowei Liu; Guy D. Moore; Wei Xue
2014-01-15T23:59:59.000Z
There has been renewed interest in the possibility that dark matter exists in the form of atoms, analogous to those of the visible world. An important input for understanding the cosmological consequences of dark atoms is their self-scattering. Making use of results from atomic physics for the potentials between hydrogen atoms, we compute the low-energy elastic scattering cross sections for dark atoms. We find an intricate dependence upon the ratio of the dark proton to electron mass, allowing for the possibility to "design" low-energy features in the cross section. Dependences upon other parameters, namely the gauge coupling and reduced mass, scale out of the problem by using atomic units. We derive constraints on the parameter space of dark atoms by demanding that their scattering cross section does not exceed bounds from dark matter halo shapes. We discuss the formation of molecular dark hydrogen in the universe, and determine the analogous constraints on the model when the dark matter is predominantly in molecular form.
Scattering properties of dark atoms and molecules
Cline, James M; Moore, Guy; Xue, Wei
2013-01-01T23:59:59.000Z
There has been renewed interest in the possibility that dark matter exists in the form of atoms, analogous to those of the visible world. An important input for understanding the cosmological consequences of dark atoms is their self-scattering. Making use of results from atomic physics for the potentials between hydrogen atoms, we compute the low-energy elastic scattering cross sections for dark atoms. We find an intricate dependence upon the ratio of the dark proton to electron mass, allowing for the possibility to "design" low-energy features in the cross section. Dependences upon other parameters, namely the gauge coupling and reduced mass, scale out of the problem by using atomic units. We derive constraints on the parameter space of dark atoms by demanding that their scattering cross section does not exceed bounds from dark matter halo shapes. We discuss the formation of molecular dark hydrogen in the universe, and determine the analogous constraints on the model when the dark matter is predominantly in ...
Scattering Theory for Open Quantum Systems
J. Behrndt; M. M. Malamud; H. Neidhardt
2006-10-31T23:59:59.000Z
Quantum systems which interact with their environment are often modeled by maximal dissipative operators or so-called Pseudo-Hamiltonians. In this paper the scattering theory for such open systems is considered. First it is assumed that a single maximal dissipative operator $A_D$ in a Hilbert space $\\sH$ is used to describe an open quantum system. In this case the minimal self-adjoint dilation $\\widetilde K$ of $A_D$ can be regarded as the Hamiltonian of a closed system which contains the open system $\\{A_D,\\sH\\}$, but since $\\widetilde K$ is necessarily not semibounded from below, this model is difficult to interpret from a physical point of view. In the second part of the paper an open quantum system is modeled with a family $\\{A(\\mu)\\}$ of maximal dissipative operators depending on energy $\\mu$, and it is shown that the open system can be embedded into a closed system where the Hamiltonian is semibounded. Surprisingly it turns out that the corresponding scattering matrix can be completely recovered from scattering matrices of single Pseudo-Hamiltonians as in the first part of the paper. The general results are applied to a class of Sturm-Liouville operators arising in dissipative and quantum transmitting Schr\\"{o}dinger-Poisson systems.
Elastic scattering of Dirac fermions on Schwarzschild black holes
Ion I. Cotaescu; Cosmin Crucean; Ciprian A. Sporea
2015-02-11T23:59:59.000Z
Approximative analytic solutions of the Dirac equation in the Schwarzschild geometry are used for building the partial wave analysis of Dirac fermions scattered by black holes. The analytic expressions of the differential cross section and induced polarization degree are derived in terms of scattering angle, mass of the black hole, energy and mass of the fermion. We perform a graphical study of differential cross section analysing the forward/backward scattering (known also as glory scattering) and the polarization degree as functions of scattering angle. The graphical analysis shows the presence of oscillations in scattering intensity around forward/backward directions, phenomena known as spiral scattering. The energy dependence of the differential cross section is also established by using analytical and graphical methods.
Stone, Kevin H.
2014-07-14T23:59:59.000Z
Some polymer properties, such as conductivity, are very sensitive to short- and intermediate-range orientational and positional ordering of anisotropic molecular functional groups, and yet means to characterize orientational order in disordered systems are very limited. We demonstrate that resonant scattering at the carbon K-edge is uniquely sensitive to short-range orientation correlations in polymers through depolarized scattering at high momentum transfers, using atactic polystyrene as a well-characterized test system. Depolarized scattering is found to coexist with unpolarized fluorescence, and to exhibit pronounced anisotropy. We also quantify the spatially averaged optical anisotropy from low-angle reflectivity measurements, finding anisotropy consistent with prior visible, x-ray absorption, and theoretical studies. The average anisotropy is much smaller than that in the depolarized scattering and the two have different character. Both measurements exhibit clear spectral signatures from the phenyl rings and the polyethylene-like backbone. Discussion focuses on analysis considerations and prospects for using this depolarized scattering for studies of disorder in soft condensed matter.
V. P. Levashev
2008-12-22T23:59:59.000Z
We have studied the relations between the neutron-triton scattering lengths and effective ranges and the corresponding quantities for the p --$^{3}$He scattering in the framework of the potential model with an effective nucleon-nucleus interaction in the form of a $\\delta $-shell potential. It is shown that the Coulomb renormalization of the pure nuclear scattering lengths does not change the relation well established for the n + $^{3}$H system between the lengths: $A^{1} scattering lengths which give preference to set I of the phase analysis performed by E.A. George et al. (2003), which corresponds to the inequality $A^{1}_{nc} scattering lengths.
Boothroyd, Andrew
Concepts of Neutron ScatteringConcepts of Neutron Scattering 66thth PSI Summer School on Condensed Andrew Boothroyd University of Oxford Basic features of neutron scattering Neutron diffraction Neutron on the lattice * * * #12;ScatteringScattering ``nuts and boltsnuts and bolts'' Neutrons, photons, electrons
Victor G. Zubko; Ari Laor
1999-09-21T23:59:59.000Z
Spectropolarimetry from the near IR to the far UV of light scattered by dust provides a valuable diagnostic of the dust composition, grain size distribution and spatial distribution. To facilitate the use of this diagnostic, we present detailed calculations of the intensity and polarization spectral signature of light scattered by optically thin and optically thick dust in various geometries. The polarized light radiative transfer calculations are carried out using the adding-doubling method for a plane-parallel slab, and are extended to an optically thick sphere by integrating over its surface. The calculations are for the Mathis, Rumple & Nordsieck Galactic dust model, and cover the range from 1 $\\mu m$ to 500 \\AA. We find that the wavelength dependence of the scattered light intensity provides a sensitive probe of the optical depth of the scattering medium, while the polarization wavelength dependence provides a probe of the grain scattering properties, which is practically independent of optical depth. We provide a detailed set of predictions, including polarization maps, which can be used to probe the properties of dust through imaging spectropolarimetry in the near IR to far UV of various Galactic and extragalactic objects. In a following paper we use the codes developed here to provide predictions for the dependence of the intensity and polarization on grain size distribution and composition.
Love, Steven P.; Davis, A. B. (Anthony B.); Rohde, C. A. (Charles A.); Tellier, L. L. (Larry L.); Ho, Cheng,
2002-01-01T23:59:59.000Z
At most optical wavelengths, laser light in a cloud lidar experiment is not absorbed but merely scattered out of the beam, eventually escaping the cloud via multiple scattering. There is much information available in this light scattered far from the input beam, information ignored by traditional 'on-beam' lidar. Monitoring these off-beam returns in a fully space- and time-resolved manner is the essence of our unique instrument, Wide Angle Imaging Lidar (WAIL). In effect, WAIL produces wide-field (60-degree full-angle) 'movies' of the scattering process and records the cloud's radiative Green functions. A direct data product of WAIL is the distribution of photon path lengths resulting from multiple scattering in the cloud. Following insights from diffusion theory, we can use the measured Green functions to infer the physical thickness and optical depth of the cloud layer, and, from there, estimate the volume-averaged liquid water content. WAIL is notable in that it is applicable to optically thick clouds, a regime in which traditional lidar is reduced to ceilometry. Here we present recent WAIL data oti various clouds and discuss the extension of WAIL to full diurnal monitoring by means of an ultra-narrow magneto-optic atomic line filter for daytime measurements.
2012-03-14T23:59:59.000Z
Index Terms—Basis pursuit, distributed optimization, sensor networks, augmented ... and image denoising and restoration [1], [2], compression, fitting and ...
Progress in the Neural Network Determination of Polarized Parton Distributions
J. Rojo; G. Ridolfi; R. D. Ball; V. Bertone; F. Cerutti; L. Del Debbio; S. Forte; A. Guffanti; J. I. Latorre; M. Ubiali
2010-07-02T23:59:59.000Z
We review recent progress towards a determination of a set of polarized parton distributions from a global set of deep-inelastic scattering data based on the NNPDF methodology, in analogy with the unpolarized case. This method is designed to provide a faithful and statistically sound representation of parton distributions and their uncertainties. We show how the FastKernel method provides a fast and accurate method for solving the polarized DGLAP equations. We discuss the polarized PDF parametrizations and the physical constraints which can be imposed. Preliminary results suggest that the uncertainty on polarized PDFs, most notably the gluon, has been underestimated in previous studies.
Limitations for heterodyne detection of Brillouin scattered light
Allemeier, R.T.; Wagner, J.W.; Telschow, K.L.
1995-01-01T23:59:59.000Z
One means by which elastic properties of a material may be determined is measuring sound wave velocities in the material, from which elastic moduli of interest can be computed. Velocity can be measured by conventional piezoelectric transduction techniques, by applying laser ultrasonics, or by using Brillouin-scattering methods. Brillouin-scattering techniques for determining the sound wave velocity are particularly attractive since they are completely noninvasive. Only a probe beam of light is required since the thermal energy in the material provides the elastic motion. Heterodyne methods for detection of Brillouin-scattered light are considered one possible means to increase the speed of the scattered light frequency detection. Results of experiments with simulated Brillouin scattering suggest that heterodyne detection of the Brillouin-scattered light is feasible. Experiments to detect Brillouin-scattered light, with water as the scattering medium, were designed and interpreted using the results of the simulated scattering experiments. Overall, results showed that it is difficult to narrow the linewidth for Brillouin scattering to an acceptable level. The results given indicate that heterodyne detection of the Brillouin components requires detection bandwidths that are quite small, perhaps 10 Hz or lower. These small bandwidths can be routinely achieved using lock-in amplifier techniques.
FRIB cryogenic distribution system
Ganni, V.; Dixon, K.; Laverdure, N.; Knudsen, P.; Arenius, D. [Thomas Jefferson National Accelerator Facility (JLab), Newport News, VA 23606 (United States); Barrios, M.; Jones, S.; Johnson, M.; Casagrande, F. [Facility for Rare Isotope Beams (FRIB), Michigan State University, East Lansing, MI 48824 (United States)
2014-01-29T23:59:59.000Z
The Michigan State University Facility for Rare Isotope Beams (MSU-FRIB) helium distribution system has been revised to include bayonet/warm valve type disconnects between each cryomodule and the transfer line distribution system, similar to the Thomas Jefferson National Accelerator Facility (JLab) and the Spallation Neutron Source (SNS) cryogenic distribution systems. The heat loads at various temperature levels and some of the features in the design of the distribution system are outlined. The present status, the plans for fabrication, and the procurement approach for the helium distribution system are also included.
FRIB cryogenic distribution system
Ganni, Venkatarao [JLAB; Dixon, Kelly D. [JLAB; Laverdure, Nathaniel A. [JLAB; Knudsen, Peter N. [JLAB; Arenius, Dana M. [JLAB; Barrios, Matthew N. [Michigan State; Jones, S. [Michigan State; Johnson, M. [Michigan State; Casagrande, Fabio [Michigan State
2014-01-01T23:59:59.000Z
The Michigan State University Facility for Rare Isotope Beams (MSU-FRIB) helium distribution system has been revised to include bayonet/warm valve type disconnects between each cryomodule and the transfer line distribution system, similar to the Thomas Jefferson National Accelerator Facility (JLab) and the Spallation Neutron Source (SNS) cryogenic distribution systems. The heat loads at various temperature levels and some of the features in the design of the distribution system are outlined. The present status, the plans for fabrication, and the procurement approach for the helium distribution system are also included.
Obtaining information on short-range correlations from inclusive electron scattering
Claudio Ciofi degli Atti; Chiara Benedetta Mezzetti
2009-05-19T23:59:59.000Z
In view of recent data from the Thomas Jefferson National Accelerator Facility (JLab) on inclusive electron scattering off nuclei at high momentum transfer (Q^2 > 1 GeV^2) and their current analysis, it is shown that, if the scaling variable is properly chosen, the analysis in terms of scaling functions can provide useful information on Short Range Correlations (SRC). This is demonstrated by introducing a new relativistic scaling variable that incorporates the momentum dependence of the excitation energy of the (A-1)system, with the resulting scaling function being closely related to the longitudinal momentum distributions.
Deeply virtual Compton scattering on longitudinally polarized protons and neutrons at CLAS
Silvia Niccolai; for the CLAS Collaboration
2012-07-13T23:59:59.000Z
This paper focuses on a measurement of deeply virtual Compton scattering (DVCS) performed at Jefferson Lab using a nearly-6-GeV polarized electron beam, two longitudinally polarized (via DNP) solid targets of protons (NH3) and deuterons (ND3) and the CEBAF Large Acceptance Spectrometer. Here, preliminary results for target-spin asymmetries and double (beam-target) asymmetries for proton DVCS, as well as a very preliminary extraction of beam-spin asymmetry for neutron DVCS, are presented and linked to Generalized Parton Distributions.
Deeply virtual Compton scattering on longitudinally polarized protons and neutrons at CLAS
Silvia Niccolai
2012-04-01T23:59:59.000Z
This paper focuses on a measurement of deeply virtual Compton scattering (DVCS) performed at Jefferson Lab using a nearly-6-GeV polarized electron beam, two longitudinally polarized (via DNP) solid targets of protons (NH{sub 3}) and deuterons (ND{sub 3}) and the CEBAF Large Acceptance Spectrometer. Here, preliminary results for target-spin asymmetries and double (beam-target) asymmetries for proton DVCS, as well as a very preliminary extraction of beam-spin asymmetry for neutron DVCS, are presented and linked to Generalized Parton Distributions.
Running of the QED coupling in small-angle Bhabha scattering at LEP
G. Abbiendi
2005-05-18T23:59:59.000Z
Using the OPAL detector at LEP, the running of the effective QED coupling alpha(t) is measured for space-like momentum transfer, 2 \\leq -t \\leq 6 GeV^2, from the angular distribution of small-angle Bhabha scattering. This is currently the most significant direct observation of the running of the QED coupling in a single experiment and the first clear evidence of the hadronic contribution to the running in the space-like region. Our result is in good agreement with standard evaluations of alpha(t), based on data in the time-like region.
book review: Species distribution models for species distribution modellers
Dormann, Carsten F
2012-01-01T23:59:59.000Z
Mapping species distributions: spa? tial inference and news and update book review Species distribution models for species distribution modellers Ecological niches and
Neutron Scattering Experiment Automation with Python
Zolnierczuk, Piotr A [ORNL] [ORNL; Riedel, Richard A [ORNL] [ORNL
2010-01-01T23:59:59.000Z
The Spallation Neutron Source (SNS) at Oak Ridge National Laboratory currently holds the Guinness World Record as the world most powerful pulsed spallation neutron source. Neutrons scattered off atomic nuclei in a sample yield important information about the position, motions, and magnetic properties of atoms in materials. A neutron scattering experiment usually involves sample environment control (temperature, pressure, etc.), mechanical alignment (slits, sample and detector position), magnetic field controllers, neutron velocity selection (choppers) and neutron detectors. The SNS Data Acquisition System (DAS) consists of real-time sub-system (detector read-out with custom electronics, chopper interface), data preprocessing (soft real-time) and a cluster of control and ancillary PCs. The real-time system runs FPGA firmware and programs running on PCs (C++, LabView) typically perform one task such as motor control and communicate via TCP/IP networks. PyDas is a set of Python modules that are used to integrate various components of the SNS DAS system. It enables customized automation of neutron scattering experiments in a rapid and flexible manner. It provides wxPython GUIs for routine experiments as well as IPython command line scripting. Matplotlib and numpy are used for data presentation and simple analysis. We will present an overview of SNS Data Acquisition System and PyDas architectures and implementation along with the examples of use. We will also discuss plans for future development as well as the challenges that have to be met while maintaining PyDas for 20+ different scientific instruments.
Electromagnetic scattering and absorption by aerosol agglomerates
Chen, Hsingyi.
1989-01-01T23:59:59.000Z
Calculation of scattering and absorption by smoke aerosols is required in many applications, including characterization of atmospheric aerosols, prediction of climatic impact of smoke, evaluation of smoke effectiveness in obscuration, calculation of heat transfer from flames, and evaluation of various scenarios of nuclear winter. In this dissertation two procedures were developed to accurately make these calculations utilizing realistic models of smoke agglomerates including oriented chains and fractal geometries. First the Iterative Extended Boundary Condition Method (IEBCM) was utilized to calculate the electromagnetic (EM) scattering and absorption of elongated aerosol particles. The computation efficiency and capability of IEBCM were improved by implementing the sectioning and the segmentation procedures. The sectioning procedure resulted in improving the computational efficiency and the segmentation method made it possible to make calculations for particles with aspect ratios as high as 250. The other procedure employed the Volume Integral Equation Formulation (VIEF) to compute the EM scattering and absorption by agglomerates of complex geometries. The validity of the procedure was checked first by comparing the obtained results with those obtained from the Mie solution for a spherical object and with the IEBCM for nonspherical objects. The comparison between results showed excellent agreement and hence validated the accuracy of the VIEF. The VIEF solution was then used to make calculations for five types of fractal agglomerates of smoke aerosol particles with fractal dimensions in the range from 1.7 to 1.9. The results obtained were compared with those based on the fractal theory recently published by Berry and Percival, and some differences were observed.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Zhao, Y X; Wang, Y; Allada, K; Aniol, K; Annand, J R; Averett, T; Benmokhtar, F; Bertozzi, W; Bradshaw, P C; Bosted, P; Camsonne, A; Canan, M; Cates, G D; Chen, C; Chen, J -P; Chen, W; Chirapatpimol, K; Chudakov, E; Cisbani, E; Cornejo, J C; Cusanno, F; Dalton, M M; Deconinck, W; de Jager, C W; De Leo, R; Deng, X; Deur, A; Ding, H; Dolph, P A; Dutta, C; Dutta, D; El Fassi, L; Frullani, S; Gao, H; Garibaldi, F; Gaskell, D; Gilad, S; Gilman, R; Glamazdin, O; Golge, S; Guo, L; Hamilton, D; Hansen, O; Higinbotham, D W; Holmstrom, T; Huang, J; Huang, M; Ibrahim, H F; Iodice, M; Jiang, X; Jin, G; Jones, M K; Katich, J; Kelleher, A; Kim, W; Kolarkar, A; Korsch, W; LeRose, J J; Li, X; Li, Y; Lindgren, R; Liyanage, N; Long, E; Lu, H -J; Margaziotis, D J; Markowitz, P; Marrone, S; McNulty, D; Meziani, Z -E; Michaels, R; Moffit, B; Munoz Camacho, C; Nanda, S; Narayan, A; Nelyubin, V; Norum, B; Oh, Y; Osipenko, M; Parno, D; Peng, J -C; Phillips, S K; Posik, M; Puckett, A J; Qian, X; Qiang, Y; Rakhman, A; Ransome, R; Riordan, S; Saha, A; Sawatzky, B; Schulte, E; Shahinyan, A; Shabestari, M H; Sirca, S; Stepanyan, S; Subedi, R; Sulkosky, V; Tang, L -G; Tobias, A; Urciuoli, G M; Vilardi, I; Wang, K; Wojtsekhowski, B; Yan, X; Yao, H; Ye, Y; Ye, Z; Yuan, L; Zhan, X; Zhang, Y; Zhang, Y -W; Zhao, B; Zheng, X; Zhu, L; Zhu, X; Zong, X
2014-11-01T23:59:59.000Z
We report the first measurement of target single spin asymmetries of charged kaons produced in semi-inclusive deep inelastic scattering of electrons off a transversely polarized 3He target. Both the Collins and Sivers moments, which are related to the nucleon transversity and Sivers distributions, respectively, are extracted over the kinematic range of 0.1
Kucheyev, S O; Toth, M; Baumann, T F; Hamza, A V; Ilavsky, J; Knowles, W R; Thiel, B L; Tileli, V; van Buuren, T; Wang, Y M; Willey, T M
2006-06-05T23:59:59.000Z
We use low-vacuum scanning electron microscopy to image directly the ligament and pore size and shape distributions of representative aerogels over a wide range of length scales ({approx} 10{sup 0}-10{sup 5} nm). The images are used for unambiguous, real-space interpretation of small-angle scattering data for these complex nanoporous systems.
Zhao, Y X; Wang, Y; Allada, K; Aniol, K; Annand, J R; Averett, T; Benmokhtar, F; Bertozzi, W; Bradshaw, P C; Bosted, P; Camsonne, A; Canan, M; Cates, G D; Chen, C; Chen, J -P; Chen, W; Chirapatpimol, K; Chudakov, E; Cisbani, E; Cornejo, J C; Cusanno, F; Dalton, M M; Deconinck, W; de Jager, C W; De Leo, R; Deng, X; Deur, A; Ding, H; Dolph, P A; Dutta, C; Dutta, D; El Fassi, L; Frullani, S; Gao, H; Garibaldi, F; Gaskell, D; Gilad, S; Gilman, R; Glamazdin, O; Golge, S; Guo, L; Hamilton, D; Hansen, O; Higinbotham, D W; Holmstrom, T; Huang, J; Huang, M; Ibrahim, H F; Iodice, M; Jiang, X; Jin, G; Jones, M K; Katich, J; Kelleher, A; Kim, W; Kolarkar, A; Korsch, W; LeRose, J J; Li, X; Li, Y; Lindgren, R; Liyanage, N; Long, E; Lu, H -J; Margaziotis, D J; Markowitz, P; Marrone, S; McNulty, D; Meziani, Z -E; Michaels, R; Moffit, B; Munoz Camacho, C; Nanda, S; Narayan, A; Nelyubin, V; Norum, B; Oh, Y; Osipenko, M; Parno, D; Peng, J -C; Phillips, S K; Posik, M; Puckett, A J; Qian, X; Qiang, Y; Rakhman, A; Ransome, R; Riordan, S; Saha, A; Sawatzky, B; Schulte, E; Shahinyan, A; Shabestari, M H; Sirca, S; Stepanyan, S; Subedi, R; Sulkosky, V; Tang, L -G; Tobias, A; Urciuoli, G M; Vilardi, I; Wang, K; Wojtsekhowski, B; Yan, X; Yao, H; Ye, Y; Ye, Z; Yuan, L; Zhan, X; Zhang, Y; Zhang, Y -W; Zhao, B; Zheng, X; Zhu, L; Zhu, X; Zong, X
2014-11-01T23:59:59.000Z
We report the first measurement of target single spin asymmetries of charged kaons produced in semi-inclusive deep inelastic scattering of electrons off a transversely polarized 3He target. Both the Collins and Sivers moments, which are related to the nucleon transversity and Sivers distributions, respectively, are extracted over the kinematic range of 0.1
Fano resonances in scattering: an alternative perspective
Lukas Schwarz; Holger Cartarius; Günter Wunner; Walter Dieter Heiss; Jörg Main
2015-06-24T23:59:59.000Z
In a previous paper it has been shown that the interference of the first and second order pole of the Green's function at an exceptional point, as well as the interference of the first order poles in the vicinity of the exceptional point, gives rise to asymmetric scattering cross section profiles. In the present paper we demonstrate that these line profiles are indeed well described by the Beutler-Fano formula, and thus are genuine Fano resonances. Also further away from the exceptional points excellent agreement can be found by introducing energy dependent Fano parameters.
Positron scattering from neon and argon
Jones, A. C. L.; Makochekanwa, C.; Caradonna, P.; Slaughter, D. S.; Machacek, J. R.; McEachran, R. P.; Sullivan, J. P.; Buckman, S. J.; Stauffer, A. D.; Bray, I.; Fursa, D. V. [ARC Centre for Antimatter-Matter Studies, Research School of Physics and Engineering, Australian National University, Canberra 0200 Australia (Australia); Department of Physics, York University, Toronto (Canada); ARC Centre for Antimatter-Matter Studies, Curtin University of Technology, G.P.O. Box U1987, Perth, Western Australia 6845 (Australia)
2011-03-15T23:59:59.000Z
High-resolution measurements of positron interactions with Ne and Ar are presented, as well as theoretical treatments. The data extend over a range of 0.3 to 60 eV and comprise measurements of the grand total, positonium formation, and grand total minus positronium formation cross sections. Theoretical treatments of scattering from Ne and Ar are performed under the relativistic optical potential approach, as well as calculations using the convergent close-coupling method. Comparisons of the present measurements and theories are made with previous theoretical and experimental work.
Transient Rayleigh scattering from single semiconductor nanowires
Montazeri, Mohammad; Jackson, Howard E.; Smith, Leigh M. [Department of Physics, University of Cincinnati, Cincinnati, OH 45221-0011 (United States); Yarrison-Rice, Jan M. [Department of Physics, Miami University, Oxford, OH 45056 (United States); Kang, Jung-Hyun; Gao, Qiang; Tan, Hark Hoe; Jagadish, Chennupati [Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 0200 (Australia)
2013-12-04T23:59:59.000Z
Transient Rayleigh scattering spectroscopy is a new pump-probe technique to study the dynamics and cooling of photo-excited carriers in single semiconductor nanowires. By studying the evolution of the transient Rayleigh spectrum in time after excitation, one can measure the time evolution of the density and temperature of photo-excited electron-hole plasma (EHP) as they equilibrate with lattice. This provides detailed information of dynamics and cooling of carriers including linear and bimolecular recombination properties, carrier transport characteristics, and the energy-loss rate of hot electron-hole plasma through the emission of LO and acoustic phonons.
Deeply Virtual Compton Scattering at HERA II
Laurent Schoeffel
2007-05-22T23:59:59.000Z
A new measurement is presented of elastic deeply virtual Compton scattering (DVCS) based on data taken by the H1 detector during the complete HERA II period. The data are well described by QCD based calculations. For the first time, a beam charge asymmetry is obtained in a colliding mode, using data recorded in $e^-p$ and $e^+p$. A significant non zero value is measured, related to the interference of QCD and QED processes, namely the DVCS and Bethe-Heitler reactions.
Total Cross Sections for Neutron Scattering
C. R. Chinn; Ch. Elster; R. M. Thaler; S. P. Weppner
1994-10-19T23:59:59.000Z
Measurements of neutron total cross-sections are both extensive and extremely accurate. Although they place a strong constraint on theoretically constructed models, there are relatively few comparisons of predictions with experiment. The total cross-sections for neutron scattering from $^{16}$O and $^{40}$Ca are calculated as a function of energy from $50-700$~MeV laboratory energy with a microscopic first order optical potential derived within the framework of the Watson expansion. Although these results are already in qualitative agreement with the data, the inclusion of medium corrections to the propagator is essential to correctly predict the energy dependence given by the experiment.
Fano resonances in scattering: an alternative perspective
Schwarz, Lukas; Wunner, Günter; Heiss, Walter Dieter; Main, Jörg
2015-01-01T23:59:59.000Z
In a previous paper it has been shown that the interference of the first and second order pole of the Green's function at an exceptional point, as well as the interference of the first order poles in the vicinity of the exceptional point, gives rise to asymmetric scattering cross section profiles. In the present paper we demonstrate that these line profiles are indeed well described by the Beutler-Fano formula, and thus are genuine Fano resonances. Also further away from the exceptional points excellent agreement can be found by introducing energy dependent Fano parameters.
Quadratic electroweak corrections for polarized Moller scattering
A. Aleksejevs, S. Barkanova, Y. Kolomensky, E. Kuraev, V. Zykunov
2012-01-01T23:59:59.000Z
The paper discusses the two-loop (NNLO) electroweak radiative corrections to the parity violating electron-electron scattering asymmetry induced by squaring one-loop diagrams. The calculations are relevant for the ultra-precise 11 GeV MOLLER experiment planned at Jefferson Laboratory and experiments at high-energy future electron colliders. The imaginary parts of the amplitudes are taken into consideration consistently in both the infrared-finite and divergent terms. The size of the obtained partial correction is significant, which indicates a need for a complete study of the two-loop electroweak radiative corrections in order to meet the precision goals of future experiments.