WorldWideScience

Sample records for quasi-elastic light scattering

  1. Quasi-elastic laser light scattering study of polyacrylamide hydrogel immersed in water and salt solutions

    Indian Academy of Sciences (India)

    M Sivanantham; B V R Tata

    2010-12-01

    Polyacrylamide (PAAm) hydrogels immersed in water and aqueous NaCl solutions were investigated for their structure and dynamics using static and quasi-elastic laser light scattering (QELS) techniques. Ensemble-averaged electric field correlation function (, ) obtained from the non-ergodic analysis of intensity-autocorrelation function for PAAm gel immersed in water and in 5 M NaCl showed an exponential decay to a plateau with an initial decay followed by saturation at long times. The value of the plateau was found to depend on NaCl concentration and was higher than that of water. Collective diffusion coefficient, , of the polymer network of the hydrogel immersed in water and in different concentrations of NaCl was determined by analysing (, ). The measured diffusion coefficient showed linear decrease with increase in concentration of NaCl. The characteristic network parameters were obtained by analyzing (, ) with harmonically bound Brownian particle model and from static light scattering studies.

  2. Quasi-elastic light scattering of platinum dendrimer-encapsulated nanoparticles.

    Science.gov (United States)

    Wales, Christina H; Berger, Jacob; Blass, Samuel; Crooks, Richard M; Asherie, Neer

    2011-04-05

    Platinum dendrimer-encapsulated nanoparticles (DENs) containing an average 147 atoms were prepared within sixth-generation, hydroxyl-terminated poly(amidoamine) dendrimers (G6-OH). The hydrodynamic radii (R(h)) of the dendrimer/nanoparticle composites (DNCs) were determined by quasi-elastic light scattering (QLS) at high (pH ∼10) and neutral pH for various salt concentrations and identities. At high pH, the size of the DNC (R(h) ∼4 nm) is close to that of the empty dendrimer. At neutral pH, the size of the DNC approximately doubles (R(h) ∼8 nm) whereas that of the empty dendrimer remains unchanged. Changes in ionic strength also alter the size of the DNCs. The increase in size of the DNC is likely due to electrostatic interactions involving the metal nanoparticle.

  3. Quasi-elastic neutron scattering studies of protein dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Rorschach, H.E.

    1993-05-25

    Results that shed new light on the study of protein dynamics were obtained by quasi-elastic neutron scattering. The triple axis instrument H-9 supplied by the cold source was used to perform a detailed study of the quasi-elastic spectrum and the Debye-Waller factor for trypsin in powder form, in solution, and in crystals. A preliminary study of myoglobin crystals was also done. A new way to view the results of quasi-elastic scattering experiments is sketched, and the data on trypsin are presented and analyze according to this new picture.

  4. Effects of Citral on Aspergillus flavus Spores by Quasi-elastic Light Scattering and Multiplex Microanalysis Techniques

    Institute of Scientific and Technical Information of China (English)

    Man LUO; Li-Ke JIANG; Yao-Xiong HUANG; Ming XIAO; Bo LI; Guo-Lin ZOU

    2004-01-01

    Citral refined from Litsea cubeba oil has been found to have a strong influence on fungi,especially Aspergillus flavus. Multiplex microanalysis and quasi-elastic light scattering techniques were applied to study the effects of citral on Aspergillus flavus spores from the levels of membrane, organelle and intracellular macromolecule. It was found that citral injured the wall and the membrane of A. flavus spore,resulting in decrease of its elasticity. After entering the cell, citral not only influenced the genetic expression of mitochondrion reduplication and its morphology, but also changed the aggregation of protein-like macromolecules. As a result, cells, organelles and macromolecules lost their normal structures and functions,eventually leading to the loss of germination ability of A. flavus spores. Since Litsea cubeba oil as food additive and antifungal agent is safe and less poisonous, it is important to elucidate the inhibitory mechanisms of Litsea cubeba oil on the germination ability ofA. flavus spore.

  5. Motility analysis of circularly swimming bull spermatozoa by quasi-elastic light scattering and cinematography.

    Science.gov (United States)

    Craig, T; Hallett, F R; Nickel, B

    1982-04-01

    The Rayleigh-Gans-Debye approximation is used to predict the electric field autocorrelation functions of light scattered from circularly swimming bull spermatozoa. Using parameters determined from cinematography and modeling the cells as coated ellipsoids of semiaxes a = 0.5 micrometers, b = 2.3 micrometers, and c = 9.0 micrometers, we were able to obtain model spectra that mimic the data exactly. A coat is found to be a necessary attribute of the particle. It is also clear that these model functions at 15 degrees may be represented by the relatively simple function used before by Hallett et al. (1978) to fit data from circularly swimming cells, thus giving some physical meaning to these functional shapes. Because of this agreement the half-widths of experimental functions can now be interpreted in terms of an oscillatory frequency for the movement of the circularly swimming cell. The cinematographic results show a trend to chaotic behavior as the temperature of the sample is increased, with concomitant decrease in overall efficiency. This is manifested by a decrease in oscillatory frequency and translational speed.

  6. Quasi-elastic nuclear scattering at high energies

    Science.gov (United States)

    Cucinotta, Francis A.; Townsend, Lawrence W.; Wilson, John W.

    1992-01-01

    The quasi-elastic scattering of two nuclei is considered in the high-energy optical model. Energy loss and momentum transfer spectra for projectile ions are evaluated in terms of an inelastic multiple-scattering series corresponding to multiple knockout of target nucleons. The leading-order correction to the coherent projectile approximation is evaluated. Calculations are compared with experiments.

  7. Mapping from quasi-elastic scattering to fusion reactions

    CERN Document Server

    Hagino, K

    2014-01-01

    The fusion barrier distribution has provided a nice representation for the channel coupling effects on heavy-ion fusion reactions at energies around the Coulomb barrier. Here we discuss how one can extract the same representation using the so called sum-of-differences (SOD) method with quasi-elastic scattering cross sections. In contrast to the conventional quasi-elastic barrier distribution, the SOD barrier distribution has an advantage in that it can be applied both to non-symmetric and symmetric systems. It is also the case that the correspondence to the fusion barrier distribution is much better than the quasi-elastic barrier distribution. We demonstrate its usefulness by studying $^{16}$O+$^{144}$Sm, $^{58}$Ni+$^{58}$Ni, and $^{12}$C+$^{12}$C systems.

  8. Quasi-Elastic Scattering in MINERvA

    CERN Document Server

    McFarland, Kevin S

    2011-01-01

    Determination of the quasi-elastic scattering cross-section over a broad range of neutrino energies, nuclear targets and Q^2 is a primary goal of the MINERvA experiment. We present preliminary comparisons of data and simulation in a sample rich in anti-{\

  9. Quasi-elastic Charm Production In Neutrino-nucleon Scattering

    CERN Document Server

    Bischofberger, M

    2005-01-01

    A study of quasi elastic charm production in charged current neutrino-nucleon scattering is presented. A sample of about 1.3 million interactions recorded with the NOMAD detector in the CERN SPS wide band neutrino beam has been searched for quasi elastically produced charmed baryons ( L+c,Sc and S*c ). The search has been performed in two exclusive decay channels of the L+c, both including a L . Also, the semi-inclusive decay channels L+c,Sc,S *c→L+X have been studied. Kinematic selection criteria have been chosen in order to obtain samples enriched with quasi elastic charm events. Signal efficiencies and background expectations have been estimated by Monte Carlo simulations. The observed number of events in each searched channel has been found to agree with the background expectation from charged and neutral current reactions and an upper limit for the cross section has been derived. For the quasi elastic charm production cross section averaged over the neutrino energy spectrum (&lan...

  10. Hard diffraction from quasi-elastic dipole scattering

    CERN Document Server

    Bialas, A

    1996-01-01

    The contribution to diffraction dissociation of virtual photons due to quasi-elastic scattering of the q-\\bar q component is calculated in the framework of the QCD dipole picture. Both longitudinal and transverse components of the cross-section are given. It is shown that, at fixed mass of the diffractively produced system, quantum mechanical interference plays an important r\\^ ole. Phenomenological consequences are discussed.

  11. Recent Measurements of Neutrino-Nucleus Quasi-Elastic Scattering

    CERN Document Server

    Wascko, M O

    2011-01-01

    We present recent measurements of neutrino charged current quasi-elastic (CC QE) scattering, nu_mu + p -> mu- + n. Measurements of CC QE on carbon near 1 GeV by MiniBooNE and SciBooNE, as well as measurements on iron at 3 GeV by MINOS, disagree with current interaction models, while measurements at higher energies on carbon by NOMAD show excellent agreement with those same models.

  12. Quasi-elastic neutron scattering studies of protein dynamics. Progress report, November 1, 1992--May 25, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Rorschach, H.E.

    1993-05-25

    Results that shed new light on the study of protein dynamics were obtained by quasi-elastic neutron scattering. The triple axis instrument H-9 supplied by the cold source was used to perform a detailed study of the quasi-elastic spectrum and the Debye-Waller factor for trypsin in powder form, in solution, and in crystals. A preliminary study of myoglobin crystals was also done. A new way to view the results of quasi-elastic scattering experiments is sketched, and the data on trypsin are presented and analyze according to this new picture.

  13. Neutron Angular Scatter Effects in 3DHZETRN: Quasi-Elastic

    Science.gov (United States)

    Wilson, John W.; Werneth, Charles M.; Slaba, Tony C.; Badavi, Francis F.; Reddell, Brandon D.; Bahadori, Amir A.

    2017-01-01

    The current 3DHZETRN code has a detailed three dimensional (3D) treatment of neutron transport based on a forward/isotropic assumption and has been compared to Monte Carlo (MC) simulation codes in various geometries. In most cases, it has been found that 3DHZETRN agrees with the MC codes to the extent they agree with each other. However, a recent study of neutron leakage from finite geometries revealed that further improvements to the 3DHZETRN formalism are needed. In the present report, angular scattering corrections to the neutron fluence are provided in an attempt to improve fluence estimates from a uniform sphere. It is found that further developments in the nuclear production models are required to fully evaluate the impact of transport model updates. A model for the quasi-elastic neutron production spectra is therefore developed and implemented into 3DHZETRN.

  14. Measurement of Muon Neutrino Quasi-Elastic Scattering on Carbon

    CERN Document Server

    Aguilar-Arevalo, A A; Brice, S J; Brown, B C; Bugel, L; Cao, J; Coney, L; Conrad, J M; Cox, D C; Curioni, A; Djurcic, Z; Finley, D A; Fleming, B T; Ford, R; García, F G; Garvey, G T; Green, C; Green, J A; Hart, T L; Hawker, E; Imlay, R; Johnson, R A; Kasper, P; Katori, T; Kobilarcik, T; Kourbanis, I; Koutsoliotas, S; Laird, E M; Link, J M; Liu, Y; Liu, Y; Louis, W C; Mahn, K B M; Marsh, W; Martin, P S; McGregor, G; Metcalf, W; Meyers, P D; Mills, F; Mills, G B; Monroe, J; Moore, C D; Nelson, R H; Nienaber, P; Ouedraogo, S; Patterson, R B; Perevalov, D; Polly, C C; Prebys, E; Raaf, Jennifer L; Ray, H; Roe, B P; Russell, A D; Sandberg, V; Schirato, R; Schmitz, D; Shaevitz, M H; Shoemaker, F C; Smith, D; Sorel, M; Spentzouris, P; Stancu, I; Stefanski, R J; Sung, M; Tanaka, H A; Tayloe, R; Tzanov, M; Vande Water, R; Wascko, M O; White, D H; Wilking, M J; Yang, H J; Zeller, G P; Zimmerman, E D

    2007-01-01

    Low energy (200quasi-elastic (CCQE) neutrino interactions to predict signal samples. Using a high-statistics sample of muon neutrino CCQE events, MiniBooNE finds that a simple Fermi gas model, with appropriate adjustments, accurately characterizes the CCQE events observed in a carbon-based detector. The extracted parameters include an effective axial mass, M_A = 1.23 +/- 0.20 GeV, used to describe the four-momentum dependence of the axial-vector form factor of the nucleon and a Pauli-suppression parameter, kappa = 1.019 +/- 0.011.

  15. Quasi-elastic neutron scattering study of the mobility of methane in microporous silica

    NARCIS (Netherlands)

    Benes, Nieck E.; Jobic, Herve; Verweij, Henk

    2001-01-01

    The dynamics of translation and rotation of methane in microporous bulk silica have been studied with quasi-elastic neutron scattering. At T=200 K the self-diffusion coefficient of translation is DS=1.1×10−8 m2 s−1 with an estimated activation energy of 4 kJ mol−1. Any variation of DS with occupanc

  16. Quasi-elastic neutron scattering studies of protein dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Rorschach, H.E.

    1991-03-20

    The techniques of X-ray and neutron scattering that have been so successfully applied to the study of the structure of biological macromolecules have in recent years been also used for the study of the thermal motion of these molecules. The diffraction of X-rays has been widely used to investigate the high-frequency motion of the heavy-atom residues of proteins. In these studies, the mean-square thermal amplitudes can be determined from the intensities of the sharp structural lines obtained from single crystals of the hydrated proteins. Similar information can be obtained on lighter atoms from the study of the neutron scattering from single crystals. The results of these measurements are coupled closely to the rapidly developing field of theoretical molecular dynamics which is now being applied to study the dynamics of large biological molecules. This report discusses research in this area.

  17. Measurement of Muon Antineutrino Quasi-Elastic Scattering on a Hydrocarbon Target at E_{\

    CERN Document Server

    Fields, L; Aliaga, L; Altinok, O; Bodek, A; Boehnlein, D; Bradford, R; Brooks, W K; Budd, H; Butkevich, A; Caicedo, D A M; Castromonte, C M; Christy, M E; da Motta, H; Damiani, D S; Danko, I; Datta, M; Day, M; DeMaat, R; Devan, J; Diaz, G A; Dytman, S A; Eberly, B; Edmondson, D A; Felix, J; Fitzpatrick, T; Fiorentini, G A; Gago, A M; Gallagher, H; Gobbi, B; Gran, R; Harris, D A; Higuera, A; Howley, I J; Hurtado, K; Jerkins, M; Kafka, T; Kanter, M O; Keppel, C; Kordosky, M; Krajeski, A H; Kulagin, S A; Le, T; Leister, A G; Maggi, G; Maher, E; Manly, S; Mann, W A; Marshall, C M; McFarland, K S; McGivern, C L; McGowan, A M; Mislivec, A; Morfin, J G; Mousseau, J; Naples, D; Nelson, J K; Niculescu, G; Niculescu, I; Ochoa, N; O'Connor, C D; Osta, J; Palomino, J L; Paolone, V; Park, J; Patrick, C E; Perdue, G N; Pena, C; Rakotondravohitra, L; Ransome, R D; Ray, H; Ren, L; Rodrigues, P A; Sassin, K E; Schellman, H; Schmitz, D W; Schneider, R M; Schulte, E C; Sedita, P; Simon, C; Snider, F D; Snyder, M C; Sobczyk, J T; Salinas, C J Solano; Tagg, N; Tan, W; Tice, B G; Tzanakos, G; Velasquez, J P; Walding, J; Walton, T; Wolcott, J; Wolthuis, B A; Zavala, G; Zhang, D; Ziemer, B P

    2013-01-01

    We have isolated muon anti-neutrino charged-current quasi-elastic interactions occurring in the segmented scintillator tracking region of the MINERvA detector running in the NuMI neutrino beam at Fermilab. We measure the flux-averaged differential cross-section, d{\\sigma}/dQ^2, and compare to several theoretical models of quasi-elastic scattering. Good agreement is obtained with a model where the nucleon axial mass, M_A, is set to 0.99 GeV/c^2 but the nucleon vector form factors are modified to account for the observed enhancement, relative to the free nucleon case, of the cross-section for the exchange of transversely polarized photons in electron-nucleus scattering. Our data at higher Q^2 favor this interpretation over an alternative in which the axial mass is increased.

  18. A quasi-elastic neutron scattering and neutron spin-echo study of hydrogen bonded system

    Energy Technology Data Exchange (ETDEWEB)

    Branca, C.; Faraone, A.; Magazu, S.; Maisano, G.; Mangione, A

    2004-07-15

    This work reports neutron spin echo results on aqueous solutions of trehalose, a naturally occurring disaccharide of glucose, showing an extraordinary bioprotective effectiveness against dehydration and freezing. We collected data using the SPAN spectrometer (BENSC, Berlin) on trehalose aqueous solutions at different temperature values. The obtained findings are compared with quasi-elastic neutron scattering results in order to furnish new results on the dynamics of the trehalose/water system on the nano and picoseconds scale.

  19. Mobility of hydrogen in microporous silica studied with quasi-elastic neutron scattering

    NARCIS (Netherlands)

    Benes, Nieck E.; Jobic, Herve; Reat, Valerie; Bouwmeester, Henny J.M.; Verweij, Henk

    2003-01-01

    The mobility of H2 in microporous amorphous silica is studied using quasi-elastic neutron scattering. At T=90 K the self-diffusion coefficient is approximately Ds=1.2×10−8 m2 s−1 for low degrees of occupancy (<20%) and decreases slightly to Ds=0.95×10−8 m2 s−1 for an occupancy of 31%. A rough esti

  20. Quasi-elastic electron-deuteron scattering and the electric form factor of the neutron

    Energy Technology Data Exchange (ETDEWEB)

    Arenhoevel, H.; Kim, Y.E. (Mainz Univ. (Germany, F.R.). Inst. fuer Kernphysik); Craver, B.A. (Purdue Univ., Lafayette, IN (USA). Dept. of Physics); Fabian, W. (State Univ. of New York, Stony Brook (USA). Dept. of Physics); Saylor, D.P. (Worcester Polytechnic Inst., MA (USA). Dept. of Physics)

    1978-09-02

    The possibility of extracting accurately the neutron electric form factor from electron-neutron coincidence measurements in quasi-elastic electron-deuteron scattering is investigated for squared three-momentum transfers q/sup 2/<=30 fm/sup -2/ using the Reid soft-core, Hamada-Johnston and Bryan-Gersten potentials. It is found that contributions of the electric form factor of the neutron to the quasi-elastic cross section can be as large as 5.4% at q/sup 2/ approximately equal to 1 fm/sup -2/ (approximately 3% at q/sup 2/ approximately equal to 10 approximately 20 fm/sup 2/). Potential model dependence and corrections due to meson exchange currents and isobar configurations are found to be small (< or approximately 1%).

  1. Cross section measurements for quasi-elastic neutrino-nucleus scattering with the MINOS near detector

    Energy Technology Data Exchange (ETDEWEB)

    Dorman, Mark Edward [Univ. College London, Bloomsbury (United Kingdom)

    2008-04-01

    The Main Injector Neutrino Oscillation Search (MINOS) is a long baseline neutrino oscillation experiment based at the Fermi National Accelerator Laboratory (FNAL) in Chicago, Illinois. MINOS measures neutrino interactions in two large iron-scintillator tracking/sampling calorimeters; the Near Detector on-site at FNAL and the Far Detector located in the Soudan mine in northern Minnesota. The Near Detector has recorded a large number of neutrino interactions and this high statistics dataset can be used to make precision measurements of neutrino interaction cross sections. The cross section for charged-current quasi-elastic scattering has been measured by a number of previous experiments and these measurements disagree by up to 30%. A method to select a quasi-elastic enriched sample of neutrino interactions in the MINOS Near Detector is presented and a procedure to fit the kinematic distributions of this sample and extract the quasi-elastic cross section is introduced. The accuracy and robustness of the fitting procedure is studied using mock data and finally results from fits to the MINOS Near Detector data are presented.

  2. Surface Diffuseness Anomaly in 16O+208pb Quasi-elastic Scattering at Backward Angle

    Institute of Scientific and Technical Information of China (English)

    JIA Hui-Ming; XU Xin-Xing; BAI Chun-Lin; YU Ning; LIN Cheng-Jian; ZHANG Huan-Qiao; LIU Zu-Hua; YANG Feng; JIA Fei; ZHANG Chun-Lei; AN Guang-Peng; WU Zhen-Dong

    2008-01-01

    @@ The quasi-elastic scattering excitation function of the doubly magic 16O+208pb system at a backward angle is measured at sub-barrier energies with high precision. The diffuseness parameters extracted from both the single-channel and the coupled-channels calculations give almost the same value α = 0.76±0.04 fm. The results show that the coupling effect is negligible for the spherical system. The obtained value is smaller than the extracted value from the fusion excitation function, but larger than the value of α = 0.63 fm, which is from the systematic analysis of elastic scattering data.

  3. Extraction of structure functions for lepton-nucleus scattering in the quasi-elastic region

    Science.gov (United States)

    Kim, K. S.; Kim, Hungchong; Cheoun, Myung-Ki; So, W. Y.

    2016-12-01

    Within the framework of a relativistic single-particle model, we calculate inclusive electron-nucleus scattering by electromagnetic current, and neutrino-nucleus scattering by neutral and charged current in the quasi-elastic region. The longitudinal, the transverse, and the transverse-interference structure functions are extracted from the theoretical cross section by using the Rosenbluth separation method at fixed momentum transfer and scattering angle and then compared with each other from the viewpoint of these current interactions. The position of peak for the electron scattering shifts to higher energy transfer than that for the neutrino scattering. The axial and pseudoscalar terms turn out to play an important role in the neutrino-nucleus scattering.

  4. Analysis of the Quasi-Elastic Scattering of Neutrons in Hydrogenous Liquids

    Energy Technology Data Exchange (ETDEWEB)

    Porohit, S.N. [Nuclear Science and Engineering Dept., Rensselaer Polytechnique Inst., Troy, NY (United States)

    1966-11-15

    A critical discussion of the quasi-elastic scattering of neutrons by incoherent (hydrogenous) liquids is presented. Using the line shape expression a comparative discussion of several phenomenological models has been carried out. Extension of the Singwi-Sjoelander zero phonon expression, for the jump-diffusion model, so as to include the one phonon expression has also been given. For a delayed diffusion model a complete treatment of S(K, {omega}) is presented. Along the lines of the macroscopic diffusion cooling, a microscopic diffusion cooling effect in fluids is speculated.

  5. Chiral symmetry, constituent quarks and quasi-elastic electron-nucleus scattering

    Science.gov (United States)

    Henley, E. M.; Krein, G.

    1989-11-01

    The effects of chiral symmetry breaking are examined for quasi-elastic electron scattering on nuclei. Nucleons are assumed to be composed of constituent quarks with masses that depend on density. This density dependence is determined on the basis of the Nambu-Jona-Lasinio model. It is found that the effects of chiral symmetry breaking are in the right direction and the right order of magnitude to explain the discrepancies between theory and experiment. On leave from Departamento de Fisica, Universidade Federal de Santa Maria, 97100 Santa Maria, R.S., Brazil.

  6. Tensor Analyzing Powers for Quasi-Elastic Electron Scattering from Deuterium

    CERN Document Server

    Zhou, Z L; Ferro-Luzzi, M; Passchier, E; Alarcon, R; Anghinolfi, M; Arenhövel, H; Van Bommel, R; Botto, T; Van den Brand, J F J; Bulten, H J; Choi, S; Comfort, J; Dolfini, S M; Ent, R; Gaulard, C; Higinbotham, D W; De Jager, C W; Konstantinov, E S; Lang, J; Leidemann, W; De Lange, D J; Miller, M A; Lenko, D N; Papadakis, N H; Passchier, I; Poolman, H R; Popov, S G; Rachek, Igor A; Ripani, M; Six, E; Steijger, J J M; Taiuti, M; Unal, O; Vodinas, N P; De Vries, H

    1999-01-01

    We report on a first measurement of tensor analyzing powers in quasi-elastic electron-deuteron scattering at an average three-momentum transfer of 1.7 fm$^{-1}$. Data sensitive to the spin-dependent nucleon density in the deuteron were obtained for missing momenta up to 150 MeV/$c$ with a tensor polarized $^2$H target internal to an electron storage ring. The data are well described by a calculation that includes the effects of final-state interaction, meson-exchange and isobar currents, and leading-order relativistic contributions.

  7. Short Range Correlations in Nuclei at Large xbj through Inclusive Quasi-Elastic Electron Scattering

    Energy Technology Data Exchange (ETDEWEB)

    Ye, Zhihong [Univ. of Virginia, Charlottesville, VA (United States)

    2013-12-01

    The experiment, E08-014, in Hall-A at Jefferson Lab aims to study the short-range correlations (SRC) which are necessary to explain the nuclear strength absent in the mean field theory. The cross sections for 2H, 3He, 4He, 12C, 40Ca and 48Ca, were measured via inclusive quasi-elastic electron scattering from these nuclei in a Q2 range between 0.8 and 2.8 (GeV/c)2 for x>1. The cross section ratios of heavy nuclei to 2H were extracted to study two-nucleon SRC for 1

  8. Inverse freezing in {alpha}-cyclodextrin solutions probed by quasi elastic neutron scattering

    Energy Technology Data Exchange (ETDEWEB)

    Plazanet, M. [LENS, University of Florence, Via Nello Carrara 1, I-50019 Sesto-Fiorentino (Italy); INFM-CRS-Soft Matter (CNR), c/o Univ. la Sapienza, Piaz. A. Moro 2, I-00185 Roma (Italy); Institut Laue-Langevin, B.P. 156X, 38042 Grenoble Cx (France); Johnson, M.R. [Institut Laue-Langevin, B.P. 156X, 38042 Grenoble Cx (France); Schweins, R. [Institut Laue-Langevin, B.P. 156X, 38042 Grenoble Cx (France); Trommsdorff, H.P. [Institut Laue-Langevin, B.P. 156X, 38042 Grenoble Cx (France); Laboratoire de Spectrometrie Physique, Universite J. Fourier Grenoble - CNRS (UMR 5588), BP 87, 38402 St. Martin d' Heres Cx (France)], E-mail: trommsdorff@ill.fr

    2006-12-11

    Solutions of {alpha}-cyclodextrin, 4-methylpyridine and water undergo a reversible liquid-solid phase transition on heating ('inverse freezing'). In this paper quasi elastic neutron scattering (QENS) measurements are reported, from which the diffusive dynamics of different components in the liquid and solid phases is determined. Results imply that, in solution, {alpha}-cyclodextrin is contained in a solvation shell of 4-methylpyridine molecules, while in the crystal phase, the majority of the cell contents are immobilized on the nanosecond timescale. This information will be important in evaluating the entropy of the system in its different phases and in understanding the unusual phase transition.

  9. A study of quasi-elastic muon neutrino and antineutrino scattering in the NOMAD experiment

    Science.gov (United States)

    Lyubushkin, V.; Popov, B.; Kim, J. J.; Camilleri, L.; Levy, J.-M.; Mezzetto, M.; Naumov, D.; Alekhin, S.; Astier, P.; Autiero, D.; Baldisseri, A.; Baldo-Ceolin, M.; Banner, M.; Bassompierre, G.; Benslama, K.; Besson, N.; Bird, I.; Blumenfeld, B.; Bobisut, F.; Bouchez, J.; Boyd, S.; Bueno, A.; Bunyatov, S.; Cardini, A.; Cattaneo, P. W.; Cavasinni, V.; Cervera-Villanueva, A.; Challis, R.; Chukanov, A.; Collazuol, G.; Conforto, G.; Conta, C.; Contalbrigo, M.; Cousins, R.; Daniels, D.; Degaudenzi, H.; Del Prete, T.; de Santo, A.; Dignan, T.; di Lella, L.; Do Couto E Silva, E.; Dumarchez, J.; Ellis, M.; Feldman, G. J.; Ferrari, R.; Ferrère, D.; Flaminio, V.; Fraternali, M.; Gaillard, J.-M.; Gangler, E.; Geiser, A.; Geppert, D.; Gibin, D.; Gninenko, S.; Godley, A.; Gomez-Cadenas, J.-J.; Gosset, J.; Gößling, C.; Gouanère, M.; Grant, A.; Graziani, G.; Guglielmi, A.; Hagner, C.; Hernando, J.; Hubbard, D.; Hurst, P.; Hyett, N.; Iacopini, E.; Joseph, C.; Juget, F.; Kent, N.; Kirsanov, M.; Klimov, O.; Kokkonen, J.; Kovzelev, A.; Krasnoperov, A.; Kulagin, S.; Kustov, D.; Lacaprara, S.; Lachaud, C.; Lakić, B.; Lanza, A.; La Rotonda, L.; Laveder, M.; Letessier-Selvon, A.; Ling, J.; Linssen, L.; Ljubičić, A.; Long, J.; Lupi, A.; Marchionni, A.; Martelli, F.; Méchain, X.; Mendiburu, J.-P.; Meyer, J.-P.; Mishra, S. R.; Moorhead, G. F.; Nédélec, P.; Nefedov, Yu.; Nguyen-Mau, C.; Orestano, D.; Pastore, F.; Peak, L. S.; Pennacchio, E.; Pessard, H.; Petti, R.; Placci, A.; Polesello, G.; Pollmann, D.; Polyarush, A.; Poulsen, C.; Rebuffi, L.; Rico, J.; Riemann, P.; Roda, C.; Rubbia, A.; Salvatore, F.; Samoylov, O.; Schahmaneche, K.; Schmidt, B.; Schmidt, T.; Sconza, A.; Seaton, M.; Sevior, M.; Sillou, D.; Soler, F. J. P.; Sozzi, G.; Steele, D.; Stiegler, U.; Stipčević, M.; Stolarczyk, Th.; Tareb-Reyes, M.; Taylor, G. N.; Tereshchenko, V.; Toropin, A.; Touchard, A.-M.; Tovey, S. N.; Tran, M.-T.; Tsesmelis, E.; Ulrichs, J.; Vacavant, L.; Valdata-Nappi, M.; Valuev, V.; Vannucci, F.; Varvell, K. E.; Veltri, M.; Vercesi, V.; Vidal-Sitjes, G.; Vieira, J.-M.; Vinogradova, T.; Weber, F. V.; Weisse, T.; Wilson, F. F.; Winton, L. J.; Wu, Q.; Yabsley, B. D.; Zaccone, H.; Zuber, K.; Zuccon, P.

    2009-10-01

    We have studied the muon neutrino and antineutrino quasi-elastic (QEL) scattering reactions ( ν μ n→ μ - p and bar{ν }_{μ}ptoμ+n ) using a set of experimental data collected by the NOMAD Collaboration. We have performed measurements of the cross-section of these processes on a nuclear target (mainly carbon) normalizing it to the total ν μ ( bar{ν}_{μ} ) charged-current cross section. The results for the flux-averaged QEL cross sections in the (anti)neutrino energy interval 3-100 GeV are < σ_{qel}rangle_{ν_{μ}}=(0.92±0.02(stat)±0.06(syst))×10^{-38} cm2 and <σ_{qel}rangle_{bar{ν}_{μ}}=(0.81±0.05(stat)±0.09(syst))×10^{-38} cm2 for neutrino and antineutrino, respectively. The axial mass parameter M A was extracted from the measured quasi-elastic neutrino cross section. The corresponding result is M A =1.05±0.02(stat)±0.06(syst) GeV. It is consistent with the axial mass values recalculated from the antineutrino cross section and extracted from the pure Q 2 shape analysis of the high purity sample of ν μ quasi-elastic 2-track events, but has smaller systematic error and should be quoted as the main result of this work. Our measured M A is found to be in good agreement with the world average value obtained in previous deuterium filled bubble chamber experiments. The NOMAD measurement of M A is lower than those recently published by K2K and MiniBooNE Collaborations. However, within the large errors quoted by these experiments on M A , these results are compatible with the more precise NOMAD value.

  10. Anharmonic behavior in the multisubunit protein apoferritin as revealed by quasi-elastic neutron scattering.

    Science.gov (United States)

    Telling, Mark T F; Neylon, Cameron; Kilcoyne, Susan H; Arrighi, Valeria

    2008-09-04

    Quasi-elastic neutron scattering (QENS) has been used to study the deviation from Debye-law harmonic behavior in lyophilized and hydrated apoferritin, a naturally occurring, multisubunit protein. Whereas analysis of the measured mean squared displacement (msd) parameter reveals a hydration-dependent inflection above 240 K, characteristic of diffusive motion, a hydration-independent inflection is observed at 100 K. The mechanism responsible for this low-temperature anharmonic response is further investigated, via analysis of the elastic incoherent neutron scattering intensity, by applying models developed to describe side-group motion in glassy polymers. Our results suggest that the deviation from harmonic behavior is due to the onset of methyl group rotations which exhibit a broad distribution of activated processes ( E a,ave = 12.2 kJ.mol (-1), sigma = 5.0 kJ x mol (-1)). Our results are likened to those reported for other proteins.

  11. mQfit, a new program for analyzing quasi-elastic neutron scattering data

    Directory of Open Access Journals (Sweden)

    Martinez Nicolas

    2015-01-01

    Full Text Available Analysis of Quasi-elastic Neutron Scattering (QENS data of complex systems such as biological or soft matter samples in a comprehensive and explicit way often requires great efforts. Most popular software only allows to fit spectra originating from one single instrument and does not permit to extract parameters from a model that is fitted simultaneously to data taken at different instrumental resolutions. We present here a new program, mQfit (multiple QENS dataset fitting, that enables to fit QENS data taken at different spectrometers (with typical resolutions between 0.01 and 0.1 meV and momentum transfer ranges. This allows drastically reducing the number of fitting parameters. The routine is implemented with a user friendly Graphical User's Interface (GUI, and freely available. As an example, we will present results obtained on E. coli bacterial pellets, and compare them to values published in the literature.

  12. Quasi-elastic neutron scattering study of dynamics in condensed matter

    Indian Academy of Sciences (India)

    S Mitra; R Mukhopadhyay

    2004-07-01

    Quasi-elastic neutron scattering (QENS) technique, known to study stochastic motions has been successfully used to elucidate the molecular motions and physical properties related to them, in a variety of systems. QENS is a unique technique that provides information on the time-scale of the motion as well as the geometry of the motions. In this paper, results of some of the systems studied using the facility available at Dhruva, Trombay and other mega-facilities are discussed. Emphasis is given on the results obtained from three different systems studied using QENS, namely, (1) alkyl chain motions in monolayer protected metal clusters, (2) molecular motions of propane in Na-Y zeolitic systems and (3) the study of reorientational motions of liquid crystal in O. series in different mesophases.

  13. Eikonal analysis of Coulomb distortion in quasi-elastic electron scattering

    CERN Document Server

    Tjon, J A

    2008-01-01

    An eikonal expansion is used to provide systematic corrections to the eikonal approximation through order $1/k^2$, where $k$ is the wave number. Electron wave functions are obtained for the Dirac equation with a Coulomb potential. They are used to investigate distorted-wave matrix elements for quasi-elastic electron scattering from a nucleus. A form of effective-momentum approximation is obtained using trajectory-dependent eikonal phases and focusing factors. Fixing the Coulomb distortion effects at the center of the nucleus, the often-used ema approximation is recovered. Comparisons of these approximations are made with full calculations using the electron eikonal wave functions. The ema results are found to agree well with the full calculations.

  14. A study of quasi-elastic muon neutrino and antineutrino scattering in the NOMAD experiment

    Energy Technology Data Exchange (ETDEWEB)

    Lyubushkin, V.; Bunyatov, S.; Chukanov, A.; Klimov, O.; Kustov, D.; Nefedov, Yu.; Samoylov, O.; Tereshchenko, V. [JINR, Dubna (Russian Federation); Popov, B. [JINR, Dubna (Russian Federation); LPNHE, Univ. of Paris VI and VII, Paris (France); Kim, J.J.; Godley, A.; Ling, J.; Mishra, S.R.; Petti, R.; Seaton, M.; Wu, Q. [Univ. of South Carolina, Columbia, SC (United States); Camilleri, L.; Autiero, D.; Di Lella, L.; Couto e Silva, E. do; Ferrere, D.; Grant, A.; Kokkonen, J.; Linssen, L.; Placci, A.; Stiegler, U.; Tsesmelis, E.; Vidal-Sitjes, G.; Wilson, F.F. [CERN, Geneva (Switzerland); Levy, J.M.; Astier, P.; Banner, M.; Dumarchez, J.; Lachaud, C.; Letessier-Selvon, A.; Schahmaneche, K.; Touchard, A.M.; Vannucci, F. [LPNHE, Univ. of Paris VI and VII, Paris (France); Mezzetto, M.; Baldo-Ceolin, M.; Bobisut, F.; Collazuol, G.; Contalbrigo, M.; Gibin, D.; Guglielmi, A.; Lacaprara, S.; Laveder, M.; Rebuffi, L.; Sconza, A.; Zuccon, P. [Univ. of Padova (Italy); INFN, Padova (Italy); Naumov, D. [JINR, Dubna (Russian Federation); Univ. of Florence (Italy); INFN, Florence (Italy); Alekhin, S. [Inst. for High Energy Physics, Protvino, Moscow Region (Russian Federation); Baldisseri, A.; Besson, N.; Bouchez, J.; Gosset, J.; Hagner, C.; Mechain, X.; Meyer, J.P.; Stolarczyk, T.; Zaccone, H. [DAPNIA, Saclay (France); Bassompierre, G.; Gaillard, J.M.; Gouanere, M.; Mendiburu, J.P.; Nedelec, P.; Pessard, H.; Sillou, D. [LAPP, Annecy (France); Benslama, K.; Degaudenzi, H.; Joseph, C.; Juget, F.; Nguyen-Mau, C.; Sozzi, G.; Tareb-Reyes, M.; Tran, M.T.; Vacavant, L.; Vieira, J.M. [Univ. of Lausanne, Lausanne (Switzerland); Bird, I. [CERN, Geneva (Switzerland); Univ. of Lausanne (Switzerland); Blumenfeld, B.; Long, J. [Johns Hopkins Univ., Baltimore, MD (United States); Boyd, S.; Ellis, M.; Peak, L.S.; Ulrichs, J.; Varvell, K.E.; Yabsley, B.D. [Univ. of Sydney (Australia); Bueno, A. [Harvard Univ., Cambridge, MA (United States); ETH Zurich (Switzerland)] [and others

    2009-10-15

    We have studied the muon neutrino and antineutrino quasi-elastic (QEL) scattering reactions ({nu}{sub {mu}}n {yields}{mu}{sup -}p and anti {nu}{sub {mu}}p{yields}{mu}{sup +}n) using a set of experimental data collected by the NOMAD Collaboration. We have performed measurements of the cross-section of these processes on a nuclear target (mainly carbon) normalizing it to the total {nu}{sub {mu}}(anti {nu}{sub {mu}}) charged-current cross section. The results for the flux-averaged QEL cross sections in the (anti)neutrino energy interval 3-100 GeV are left angle {sigma}{sub qel} right angle {sub {nu}}{sub {mu}}=(0.92{+-}0.02(stat){+-}0.06(syst)) x 10{sup -38} cm{sup 2} and left angle {sigma}{sub qel} right angle {sub anti} {sub {nu}{sub {mu}}}{sub =}(0.81{+-}0.05(stat){+-}0.09(syst)) x 10{sup -38} cm{sup 2} for neutrino and antineutrino, respectively. The axial mass parameter M{sub A} was extracted from the measured quasi-elastic neutrino cross section. The corresponding result is M{sub A}=1.05{+-}0.02(stat){+-}0.06(syst) GeV. It is consistent with the axial mass values recalculated from the antineutrino cross section and extracted from the pure Q{sup 2} shape analysis of the high purity sample of {nu}{sub {mu}} quasi-elastic 2-track events, but has smaller systematic error and should be quoted as the main result of this work. Our measured M{sub A} is found to be in good agreement with the world average value obtained in previous deuterium filled bubble chamber experiments. The NOMAD measurement of M{sub A} is lower than those recently published by K2K and MiniBooNE Collaborations. However, within the large errors quoted by these experiments on M{sub A}, these results are compatible with the more precise NOMAD value. (orig.)

  15. Quasi-Elastic Scattering of 16C from 12C at 47.5 MeV/Nucleon

    Institute of Scientific and Technical Information of China (English)

    FAN Feng-Ying; ZHENG Tao; YE Yan-Lin; JIANG Dong-Xing; HUA Hui; LI Zhi-Huan; GE Yu-Cheng; LI Xiang-Qing; LOU Jian-Ling; SHI Fan; LV Lin-Hui; CAO Zhong-Xin; NIE Peng-Xuan; LI Qi-Te; SONG Yu-Shou; LU Fei; XU Hu-Shan; HU Zheng-Guo; WANG Meng; ZHANG Xue-Ying; LI Chen; CHEN Ruo-Fu; TANG Bin; XU Zhi-Guo; YUE Ke; ZHANG Ya-Peng; ZANG Yong-Dong; ZHANG Xue-Heng; YAO Xiang-Wu; CHEN Jin-Da; TU Xiao-Lin; ZHANG Jie; WU Da-Peng; BAI Zhen

    2009-01-01

    Differential cross sections for the quasi-elastic scattering of 16C at 47.5 MeV/nucleon from 12C target are measured.Coupled-channels calculations are carried out and the optical potential parameters are obtained by fitting the experimental angular distribution.

  16. Quasi-elastic neutron scattering studies of the slow dynamics of supercooled and glassy aspirin

    Science.gov (United States)

    Zhang, Yang; Tyagi, Madhusudan; Mamontov, Eugene; Chen, Sow-Hsin

    2012-02-01

    Aspirin, also known as acetylsalicylic acid (ASA), is not only a wonderful drug, but also a good glass former. Therefore, it serves as an important molecular system to study the near-arrest and arrested phenomena. In this paper, a high-resolution quasi-elastic neutron scattering (QENS) technique is used to investigate the slow dynamics of supercooled liquid and glassy aspirin from 410 down to 350 K. The measured QENS spectra can be analyzed with a stretched exponential model. We find that (i) the stretched exponent β(Q) is independent of the wavevector transfer Q in the measured Q range and (ii) the structural relaxation time τ(Q) follows a power-law dependence on Q. Consequently, the Q-independent structural relaxation time τ0 can be extracted for each temperature to characterize the slow dynamics of aspirin. The temperature dependence of τ0 can be fitted with the mode-coupling power law, the Vogel-Fulcher-Tammann equation and a universal equation for fragile glass forming liquids recently proposed by Tokuyama in the measured temperature range. The calculated dynamic response function χT(Q, t) using the experimentally determined self-intermediate scattering function of the hydrogen atoms of aspirin shows direct evidence of the enhanced dynamic fluctuations as the aspirin is increasingly supercooled, in agreement with the fixed-time mean squared displacement langx2rang and the non-Gaussian parameter α2 extracted from the elastic scattering.

  17. The contribution of small angle and quasi-elastic scattering to the physics of liquid water

    Science.gov (United States)

    Teixeira, José

    2017-05-01

    Many properties of liquid water at low temperature show anomalous behaviour. For example, density, isothermal compressibility, heat capacity pass by maxima or minima and transport properties show a super-Arrhenius behaviour. Extrapolations performed beyond the homogeneous nucleation temperature are at the origin of models that predict critical points, liquid-liquid transitions or dynamic cross-overs in the large domain of temperature and pressure not accessible to experiments because of ice nucleation. A careful analysis of existing data can be used to test some of these models. Small angle X-ray or neutron scattering data are incompatible with models where two liquids or heterogeneities are present. Quasi-elastic neutron scattering, taking advantage and combining both coherent and incoherent scattering show that two relaxation times are present in liquid water and that one of them, related to hydrogen bond dynamics, has an Arrhenian behaviour, suggesting that the associated dynamics of the bonds, similar to the β relaxation of polymers, determines the glass transition temperature of water.

  18. Quasi-Elastic Neutron Scattering Studies of the Slow Dynamics of Supercooled and Glassy Aspirin

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yang [ORNL; Tyagi, M. [NCNR and University of Maryland; Mamontov, Eugene [ORNL; Chen, Sow-hsin H [ORNL

    2011-01-01

    Aspirin, also known as acetylsalicylic acid (ASA), is not only a wonderful drug, but also a good glass former. Therefore, it serves as an important molecular system to study the near-arrest and arrested phenomena. In this paper, a high-resolution quasi-elastic neutron scattering (QENS) technique is used to investigate the slow dynamics of supercooled liquid and glassy aspirin from 410 K down to 350 K. The measured QENS spectra can be analyzed with a stretched exponential model. We find that (i) the stretched exponent (Q) is independent of the wave vector transfer Q in the measured Q-range, and (ii) the structural relaxation time (Q) follows a power law dependence on Q. Consequently, the Q-independent structural relaxation time 0 can be extracted for each temperature to characterize the slow dynamics of aspirin. The temperature dependence of 0 can be fitted with the mode coupling power law, the Vogel-Fulcher-Tammann equation and a universal equation for fragile glass forming liquids recently proposed by M. Tokuyama in the measured temperature range. The calculated dynamic response function T(Q,t) using the experimentally determined self-intermediate scattering function of the hydrogen atoms of aspirin shows a direct evidence of the enhanced dynamic fluctuations as the aspirin is increasingly supercooled, in agreement with the fixed-time mean squared displacement x2 and non-Gaussian parameter 2 extracted from the elastic scattering.

  19. Quasi-elastic neutron scattering study on water and polymer dynamics in thermo/pressure sensitive polymer solutions.

    Science.gov (United States)

    Osaka, Noboru; Shibayama, Mitsuhiro; Kikuchi, Tatsuya; Yamamuro, Osamu

    2009-10-01

    Dynamics of water and poly(N-isopropylacrylamide) (PNIPA) in concentrated aqueous solutions, where the majority of water molecules are attached to polymer chains, has been investigated with use of incoherent quasi-elastic neutron scattering (QENS) and dynamic light scattering (DLS) measurements as functions of temperature, T, and hydrostatic pressure, P. It was observed by QENS that the self-diffusion coefficient, D(water), of water in PNIPA/H(2)O solutions increased by P at temperatures below the lower critical solution temperature (LCST) of PNIPA aqueous solutions. However, above the LCST, D(water) decreased by P, as is often reported in non-hydrogen bonding solutions. In isobaric heating runs, therefore, the jump in D(water) at LCST decreased with increasing pressure. On the other hand, the mean-square displacement, , of the local vibrational motion of PNIPA in PNIPA/D(2)O solutions, where the incoherent scattering signal of PNIPA was predominantly observed, was reduced due to the aggregation behavior of PNIPA by pressurizing, which was also confirmed by using DLS. The jump in at the LCST became gradual by pressurizing, which was consistent with the changes of the dynamics of water obtained in PNIPA/H(2)O solutions.

  20. Study of the Quasi-Elastic Scattering in the NOvA Detector Prototype

    Energy Technology Data Exchange (ETDEWEB)

    Betancourt, Minerba [Univ. of Minnesota, Minneapolis, MN (United States)

    2013-06-01

    NOvA is a 810 km long base-line neutrino oscillation experiment with two detectors (far 14 KTon and near detector 300 Ton) currently being installed in the NUMI o -axis neutrino beam produced at Fermilab. A 222 Ton prototype NOvA detector (NDOS) was built and operated in the neutrino beam for over a year to understand the response of the detector and its construction. The goal of this thesis is to study the muon neutrino interaction data collected in this test, specifically the identification of quasi-elastic charged-current interactions and measure the behavior of the quasi-elastic muon neutrino cross section.

  1. Quasi-elastic scattering of 6He, 7Be, and 8B nuclei by 12C nuclei

    CERN Document Server

    Kovalchuk, V I

    2016-01-01

    The observed cross sections of quasi-elastic scattering of 6He, 7Be, and 8B nuclei by 12C nuclei are described within the framework of the diffraction nuclear model and the model of nucleus-nucleus scattering in the high-energy approximation with a double folding potential, for intermediate energies of the incident particles. The calculations make use of realistic distributions of nucleon densities and take account of the Coulomb interaction and inelastic scattering with excitation of low-lying collective states of the target.

  2. Anti-Neutrino Charged Current Quasi-Elastic Scattering in MINER$\

    Energy Technology Data Exchange (ETDEWEB)

    Chvojka, Jesse John [Univ. of Rochester, NY (United States)

    2012-01-01

    The phenomenon of neutrino oscillation is becoming increasingly understood with results from accelerator-based and reactor-based experiments, but unanswered questions remain. The proper ordering of the neutrino mass eigenstates that compose the neutrino avor eigenstates is not completely known. We have yet to detect CP violation in neutrino mixing, which if present could help explain the asymmetry between matter and anti-matter in the universe. We also have not resolved whether sterile neutrinos, which do not interact in any Standard Model interaction, exist. Accelerator-based experiments appear to be the most promising candidates for resolving these questions; however, the ability of present and future experiments to provide answers is likely to be limited by systematic errors. A significant source of this systematic error comes from limitations in our knowledge of neutrino-nucleus interactions. Errors on cross-sections for such interactions are large, existing data is sometimes contradictory, and knowledge of nuclear effects is incomplete. One type of neutrino interaction of particular interest is charged current quasi-elastic (CCQE) scattering, which yields a final state consisting of a charged lepton and nucleon. This process, which is the dominant interaction near energies of 1 GeV, is of great utility to neutrino oscillation experiments since the incoming neutrino energy and the square of the momentum transferred to the final state nucleon, Q2, can be reconstructed using the final state lepton kinematics. To address the uncertainty in our knowledge of neutrino interactions, many experiments have begun making dedicated measurements. In particular, the MINER A experiment is studying neutrino-nucleus interactions in the few GeV region. MINERvA is a fine-grained, high precision, high statistics neutrino scattering experiment that will greatly improve our understanding of neutrino cross-sections and nuclear effects that affect the final state particles

  3. Recent Advances and Open Questions in Neutrino-induced Quasi-elastic Scattering and Single Photon Production

    Energy Technology Data Exchange (ETDEWEB)

    Garvey, G. T. [Los Alamos; Harris, D. A. [Fermilab; Tanaka, H. A. [British Columbia U.; Tayloe, R. [Indiana U.; Zeller, G. P. [Fermilab

    2015-06-15

    The study of neutrino–nucleus interactions has recently seen rapid development with a new generation of accelerator-based neutrino experiments employing medium and heavy nuclear targets for the study of neutrino oscillations. A few unexpected results in the study of quasi-elastic scattering and single photon production have spurred a revisiting of the underlying nuclear physics and connections to electron–nucleus scattering. A thorough understanding and resolution of these issues is essential for future progress in the study of neutrino oscillations.

  4. Important influence of single neutron stripping coupling on near-barrier 8Li + 90Zr quasi-elastic scattering

    Science.gov (United States)

    Pakou, A.; Keeley, N.; Pierroutsakou, D.; Mazzocco, M.; Acosta, L.; Aslanoglou, X.; Boiano, A.; Boiano, C.; Carbone, D.; Cavallaro, M.; Grebosz, J.; La Commara, M.; Manea, C.; Marquinez-Duran, G.; Martel, I.; Parascandolo, C.; Rusek, K.; Sánchez-Benítez, A. M.; Sgouros, O.; Signorini, C.; Soramel, F.; Soukeras, V.; Stiliaris, E.; Strano, E.; Torresi, D.; Trzcińska, A.; Watanabe, Y. X.; Yamaguchi, H.

    2015-07-01

    Quasi-elastic scattering data were obtained for the radioactive nucleus 8Li on a 90Zr target at the near-barrier energy of 18.5MeV over the angular range to 80°. They were analyzed within the coupled channels and coupled reaction channels frameworks pointing to a strong coupling effect for single neutron stripping, in contrast to 6, 7 Li + 90 Zr elastic scattering at similar energies, a non-trivial result linked to detailed differences in the structure of these Li isotopes.

  5. Results for quasi-elastic anti-neutrino scattering on scintillator from the MINERvA experiment

    Science.gov (United States)

    Schellman, Heidi; Minerva Collaboration

    2016-09-01

    We present a new preliminary measurement of the charge-current quasi-elastic scattering cross section for anti-neutrinos on scintillator (CH) over the energy range 1.5-10 GeV. The data were taken with the MINERvA detector in the NuMI beamline at Fermilab and cover the energy range of interest for the proposed DUNE long-baseline neutrino oscillation experiment and of JLAB elastic scattering experiments. Of particular interest to the nuclear community are possible signatures for short range correlations and/or meson exchange currents in these data. We present comparisons to a range of nuclear models.

  6. Effect of coupling in the 28Si+154Sm reaction studied by quasi-elastic scattering

    Science.gov (United States)

    Kaur, Gurpreet; Behera, B. R.; Jhingan, A.; Nayak, B. K.; Dubey, R.; Sharma, Priya; Thakur, Meenu; Mahajan, Ruchi; Saneesh, N.; Banerjee, Tathagata; Khushboo, Kumar, A.; Mandal, S.; Saxena, A.; Sugathan, P.; Rowley, N.

    2016-09-01

    The study of the coupling to collective states of the 28Si projectile and 154Sm target in fusion mechanism is reported. Understanding such couplings is important as they influence the barrier height and the formation probability of the compound nuclei, which in turn may be related to the synthesis of superheavy elements in heavier systems. In the present work, before performing the coupled-channel calculations, we wish to obtain an experimental signature of coupling to projectile and target excitation through barrier distribution (BD) study. To this end, the BDs of the 28Si+154Sm and 16O+154Sm systems have been compared using existing fusion data, scaled to compensate for the differences between the nominal Coulomb barriers and the respective coupling strengths. However, the large error bars on the high-energy side of the fusion BD prevent any definite identification of such signatures. We have, therefore, performed a quasi-elastic (QE) scattering experiment for the heavier 28Si+154Sm system and compared its results with existing QE data for the 16O projectile. Since QE BDs are precise at higher energies, the comparison has shown that the BD of 28Si+154Sm is similar to that of 16O+154Sm to a large extent except for a peaklike structure on the higher energy side. The similarity shows that the 154Sm deformation plays a major role in the fusion mechanism of 28Si+154Sm system. The peaklike structure is attributed to 28Si excitation. In contrast with previous studies, it is found that a coupled-channel calculation with vibrational coupling to the first 2+ state of 28Si reproduces this structure rather well. However, an almost identical result is found with the rotational coupling scheme if one considers the large positive hexadecapole deformation of the projectile. A value around that given by Möller and Nix (β4≈0.25 ) leads to a strong cancellation in the re-orientation term that couples the 2+ state back to itself, making that state look vibrational in this

  7. Measurement of quasi-elastic 12C(p,2p) scattering at high momentum transfer

    Science.gov (United States)

    Mardor, Y.; Aclander, J.; Alster, J.; Barton, D.; Bunce, G.; Carroll, A.; Christensen, N.; Courant, H.; Durrant, S.; Gushue, S.; Heppelmann, S.; Kosonovsky, E.; Mardor, I.; Marshak, M.; Makdisi, Y.; Minor, E. D.; Navon, I.; Nicholson, H.; Piasetzky, E.; Roser, T.; Russell, J.; Sutton, C. S.; Tanaka, M.; White, C.; Wu, J.-Y.

    1998-10-01

    We measured the high-momentum transfer [Q2=4.8 and 6.2 (GeV/c)2] quasi-elastic 12C(p,2p) reaction at θcm~=90 deg for 6 and 7.5 GeV/c incident protons. The momentum components of both outgoing protons and the missing energy and momentum of the proton in the nucleus were measured. We verified the validity of the quasi-elastic picture for ground state momenta up to about 0.5 GeV/c. Transverse and longitudinal momentum distributions of the target proton were measured. They have the same shape with a large momentum tail which is not consistent with independent particle models. We observed that the transverse distribution gets wider as the longitudinal component increases in the beam direction.

  8. Solvent Dynamics in Solutions of PNIPAM in Water/Methanol Mixtures-A Quasi-Elastic Neutron Scattering Study.

    Science.gov (United States)

    Kyriakos, Konstantinos; Philipp, Martine; Silvi, Luca; Lohstroh, Wiebke; Petry, Winfried; Müller-Buschbaum, Peter; Papadakis, Christine M

    2016-05-26

    The solvent dynamics of concentrated solutions of poly(N-isopropylacrylamide) (PNIPAM, 25 wt %) in water/methanol mixtures (85:15 v/v) are measured with the aim of shedding light onto the cononsolvency effect. Quasi-elastic neutron scattering (QENS) with contrast variation has been carried out at temperatures below and above the cloud point by using in the first set of experiments the mixture H2O:d-MeOD (d-MeOD denotes fully deuterated methanol) as a solvent and in the second set of experiments the mixture D2O:MeOH (MeOH denotes methanol). As a reference, bulk H2O, bulk MeOH and the mixtures H2O:d-MeOD and D2O:MeOH (both 85:15 v/v) have been investigated as well. In the PNIPAM solution in H2O:d-MeOD, two water populations are identified, namely strongly and less strongly arrested water. At the cloud point, the former is partially released from PNIPAM. The diffusion coefficient of the latter one is similar to the one in the water/methanol mixture, and its residence time decreases at the cloud point. The PNIPAM solution in D2O:MeOH reveals similar dynamics to the one in H2O:d-MeOD which may reflect that the dynamics of MeOH near the PNIPAM chain is similar to the one of H2O. The similarity may, however, partially be due to H/D exchange between D2O and MeOH. In both PNIPAM solutions, the mean-square displacement of the PNIPAM chain decreases gradually above the cloud point.

  9. Quasi-Elastic Neutron Scattering (QENS) Studies of Hydrogen Dynamics for Nano-Confined NaAlH4

    Science.gov (United States)

    Dobbins, Tabbetha; Narasegowda, Shathabish; Brown, Craig; Tyagi, Madhusudan; Jenkins, Timothy

    The hydrogen dynamics of nano-confined sodium alanate (NaAlH4) has been studied using quasi-elastic neutron scattering (QENS). Results indicate thermodynamic destabilization is responsible for reduced desorption temperatures of NaAlH4 upon confinement within the nanopores of a metal organic framework (MOF). Both the bulk (microscale) NaAlH4 and the nanoconfined NaAlH4 data were fitted to re-orientation models which yielded corresponding percent mobile hydrogen and jump lengths. The jump lengths calculated from the nano-NaAlH4 were ~2.5 Å, and in conformity with those jump lengths determined for bulk NaAlH4 of ~2.3 Å. As much as 18 % of the hydrogen atoms were estimated to be mobile in the nano-NaAlH4 sample even at relatively low temperatures of 350 K. In contrast, bulk NaAlH4 shows less than 7 % mobile H-atoms even at higher temperatures of ~450 K. The activation energy for the long range is 3.1meV. Quasi-Elastic Neutron Scattering (QENS) Studies of Hydrogen Dynamics for Nano-Confined NaAlH4.

  10. Beam-target double spin asymmetry in quasi-elastic electron scattering off the deuteron with CLAS

    CERN Document Server

    Mayer, Michael

    2016-01-01

    Quasi-elastic electron scattering on the deuteron is a benchmark reaction to test our understanding of deuteron structure and the properties and interactions of the two nucleons bound in the deuteron. The experimental data presented here can be used to test state-of-the-art models of the deuteron and the two-nucleon interaction in the final state after two-body breakup of the deuteron. Focusing on polarization degrees of freedom, we gain information on spin-momentum correlations in the deuteron ground state (due to the D-state admixture) and on the limits of the Impulse Approximation (IA) picture as it applies to measurements of spin-dependent observables like spin structure functions for bound nucleons. We measured the beam-target double spin asymmetry for quasi-elastic electron scattering off the deuteron at several beam energies using the CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Accelerator Facility. The deuterons were polarized along (or opposite to) the beam direction. ...

  11. Measurement of Muon Neutrino Quasi-Elastic Scattering on a Hydrocarbon Target at E_{\

    CERN Document Server

    Fiorentini, G A; Rodrigues, P A; Aliaga, L; Altinok, O; Bodek, A; Boehnlein, D; Bradford, R; Brooks, W K; Budd, H; Butkevich, A; Caicedo, D A M; Castromonte, C M; Christy, M E; Chvojka, J; da Motta, H; Damiani, D S; Danko, I; Datta, M; Day, M; DeMaat, R; Devan, J; Diaz, G A; Dytman, S A; Eberly, B; Edmondson, D A; Felix, J; Fields, L; Fitzpatrick, T; Gago, A M; Gallagher, H; Gobbi, B; Gran, R; Harris, D A; Higuera, A; Howley, I J; Hurtado, K; Jerkins, M; Kafka, T; Kanter, M O; Keppel, C; Kordosky, M; Krajeski, A H; Kulagin, S A; Le, T; Leister, A G; Maggi, G; Maher, E; Manly, S; Mann, W A; Marshall, C M; McFarland, K S; McGivern, C L; McGowan, A M; Mislivec, A; Morfin, J G; Mousseau, J; Naples, D; Nelson, J K; Niculescu, G; Niculescu, I; Ochoa, N; O'Connor, C D; Osta, J; Palomino, J L; Paolone, V; Park, J; Patrick, C E; Perdue, G N; Pena, C; Rakotondravohitra, L; Ransome, R D; Ray, H; Ren, L; Sassin, K E; Schellman, H; Schneider, R M; Schulte, E C; Sedita, P; Simon, C; Snider, F D; Snyder, M C; Sobczyk, J T; Salinas, C J Solano; Tagg, N; Tan, W; Tice, B G; Tzanakos, G; Velasquez, J P; Walding, J; Walton, T; Wolcott, J; Wolthuis, B A; Zavala, G; Zhang, D; Ziemer, B P

    2013-01-01

    We report a study of muon neutrino charged-current quasi-elastic events in the segmented scintillator inner tracker of the MINERvA experiment running in the NuMI neutrino beam at Fermilab. The events were selected by requiring a {\\mu}^- and low calorimetric recoil energy separated from the interaction vertex. We measure the flux-averaged differential cross-section, d{\\sigma}/dQ^2, and study the low energy particle content of the final state. Deviations are found between the measured d{\\sigma}/dQ^2 and the expectations of a model of independent nucleons in a relativistic Fermi gas. We also observe an excess of energy near the vertex consistent with multiple protons in the final state.

  12. Static and quasi-elastic small angle neutron scattering on biocompatible ionic ferrofluids: magnetic and hydrodynamic interactions

    CERN Document Server

    Gazeau, F; Dubois, E; Perzynski, R

    2003-01-01

    We investigate the structure and dynamics of ionic magnetic fluids (MFs), based on ferrite nanoparticles, dispersed at pH approx 7 either in H sub 2 O or in D sub 2 O. Polarized and non-polarized static small angle neutron scattering (SANS) experiments in zero magnetic field allow us to study both the magnetic and the nuclear contributions to the neutron scattering. The magnetic interparticle attraction is probed separately from the global thermodynamic repulsion and compares well to direct magnetic susceptibility measurements. The magnetic interparticle correlation is in these fluid samples independent of the probed spatial scale. In contrast, a spatial dependence of the interparticle correlation is evidenced at large PHI by the nuclear structure factor. A model of magnetic interaction quantitatively explains the under-field anisotropy of the SANS nuclear contribution. In a quasi-elastic neutron spin-echo experiment, we probe the Brownian dynamics of translation of the nanoparticles in the range 1.3 sup<=...

  13. Quasi-elastic scattering of a secondary sup 6 He beam on a sup 9 Be target at 25 MeV/nucleon

    CERN Document Server

    Chen Tao; Li Zhi Huan; Jiang Dong Xing; Hua Hui; Li Xiang Qing; Wang Quan Jin; Ge Yuch Eng; Pang Dan Yang; Di Zhenyu; Jin Ge; Xiao Guo Qing; Guo Zhong Yan; Xiao Zhi Gang; Wang Hong Wei; Zhang Bao Guo; Wu He Yu; Li Jia Xing; Sun Zhi Yu; Zhan Wen Long

    2002-01-01

    The quasi-elastic scattering of a secondary sup 6 He beam (25 MeV/n) on a sup 9 Be target has been measured for the first time with the application of a sophisticated tracking detector system. The angular distribution is reported. A phenomenological optical potential is obtained by fitting the experimental data, which encourages more accurate experimental measurements

  14. Quasi-elastic Scattering of a Secondary 6He Beam on a 9Be Target at 25MeV/Nucleon

    Institute of Scientific and Technical Information of China (English)

    陈陶; 叶沿林; 李智焕; 江栋兴; 华辉; 李湘庆; 王全进; 葛榆成; 庞丹阳; 狄振宇; 靳根明; 肖国青; 郭忠言; 肖志刚; 王宏伟; 张保国; 吴和宇; 李家兴; 孙志宇; 詹文龙

    2002-01-01

    The quasi-elastic scattering of a secondary 6He beam (25 MeV/n) on a 9Be target has been measured for the firsttime with the application of a sophisticated tracking detector system. The angular distribution is reported. Aphenomenological optical potential is obtained by fitting the experimental data, which encourages more accurateexperimental measurements.

  15. Measurement of the Antineutrino Double-Differential Charged-Current Quasi-Elastic Scattering Cross Section at MINERvA

    Energy Technology Data Exchange (ETDEWEB)

    Patrick, Cheryl [Northwestern U.

    2016-01-01

    Next-generation neutrino oscillation experiments, such as DUNE and Hyper-Kamiokande, hope to measure charge-parity (CP) violation in the lepton sector. In order to do this, they must dramatically reduce their current levels of uncertainty, particularly those due to neutrino-nucleus interaction models. As CP violation is a measure of the difference between the oscillation properties of neutrinos and antineutrinos, data about how the less-studied antineutrinos interact is especially valuable. We present the MINERvA experiment's first double-differential scattering cross sections for antineutrinos on scintillator, in the few-GeV range relevant to experiments such as DUNE and NOvA. We also present total antineutrino-scintillator quasi-elastic cross sections as a function of energy, which we compare to measurements from previous experiments. As well as being useful to help reduce oscillation experiments' uncertainty, our data can also be used to study the prevalence of various cor relation and final-state interaction effects within the nucleus. We compare to models produced by different model generators, and are able to draw first conclusions about the predictions of these models.

  16. Diffusive properties of water in Artemia cysts as determined from quasi-elastic neutron scattering spectra. [Artemia shrimp

    Energy Technology Data Exchange (ETDEWEB)

    Trantham, E.C.; Rorschach, H.E.; Clegg, J.S.; Hazlewood, C.F.; Nicklow, R.M.; Wakabayashi, N.

    1984-05-01

    Results have been obtained on the quasi-elastic spectra of neutrons scattered from pure water, 20% agarose gel (hydration four grams H/sub 2/O per gram of dry solid) and cysts of the brine shrimp Artemia for hydrations between 0.10 and 1.2 grams H/sub 2/O per gram of dry solids. The spectra were interpreted using a two-component model that included contributions from the covalently bonded protons and the hydration water, and a mobile water fraction. The mobile fraction was described by a jump-diffusion correlation function for the translation motion and a simple diffusive orientational correlation function. The results for the line widths ..gamma..(Q/sup 2/) for pure water were in good agreement with previous measurements. The agarose results were consistent with NMR measurements that show a slightly reduced translational diffusion for the mobile water fraction. The Artemia results show that the translational diffusion coefficient of the mobile water fraction was greatly reduced from that of pure water. The line width was determined mainly by the rotational motion, which was also substantially reduced from the pure water value as determined from dielectric relaxation studies. The translational and rotational diffusion parameters were consistent with the NMR measurements of diffusion and relaxation. Values for the hydration fraction and the mean square thermal displacement as determined from the Q-dependence of line areas were also obtained.

  17. Quasi-elastic neutron scattering studies of protein dynamics. Final report, November 1, 1991--March 31, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Huang, H.W.

    1995-04-10

    Proteins are formed from long polymer chains of amino acids that have been cross linked into a complex three dimensional structure. The structure is not unique, since there are many conformation substates of nearly equal energy, separated by small energy barriers, that are obtained by slight shifts in positions of various segments of the molecule. Transitions among these conformations substates are of a diffusive nature, and they can lead to substantial changes in the shape of the molecule. These changes in shape are important for the biological reactions in the cell. Such diffusive motion is inaccessible to the diffraction methods or to the computer simulations, since it occurs on a long time scale. It is accessible to incoherent quasi-elastic neutron scattering (QNS) studies, which permit a direct determination of the properties of the diffusive motion of the protons in the molecules. The authors have used the IQNS method to study the motions of the side chains in trypsin, a protein of beta-sheet structures and myoglobin, a protein of {alpha}-helical structures, at various D{sub 2}O hydration levels.

  18. Dynamics of iodine anions in KI and LiI aqueous solutions studied by 127I nuclear resonant quasi-elastic scattering

    Science.gov (United States)

    Haruki, Rie; Koshimizu, Masanori; Nishikido, Fumihiko; Masuda, Ryo; Kobayashi, Yasuhiro; Seto, Makoto; Yoda, Yoshitaka; Kishimoto, Shunji

    2016-12-01

    The dynamics of iodine ions in potassium iodide (KI) and lithium iodide (LiI) aqueous solutions have been studied through 127I nuclear resonant quasi-elastic scattering (NRQES). A newly developed Si (12 2 2) double crystal monochromator for 127I 57.6 keV excitation is used. Broadening due to a diffusive motion is measured in the energy spectra of the NRQES from the solutions.

  19. Coherent Dynamics of meta-Toluidine Investigated by QuasiElastic Neutron Scattering

    Energy Technology Data Exchange (ETDEWEB)

    Faraone, Antonio [National Institute of Standards and Technology (NIST); Hong, Kunlun [ORNL; Kneller, Larry [National Institute of Standards and Technology (NIST), Gaithersburg, MD; Ohl, Michael E [ORNL; Copley, John R. D. [National Institute of Standards and Technology (NIST), Gaithersburg, MD

    2012-01-01

    The coherent dynamics of a typical fragile glass former, meta-toluidine, was investigated at the molecular level using quasielastic neutron scattering, with time-of-flight and neutron spin echo spectrometers. It is well known that the static structure factor of meta-toluidine shows a prepeak originating from clustering of the molecules through hydrogen bonding between the amine groups. The dynamics of meta-toluidine was measured for several values of the wavevector transfer Q, which is equivalent to an inverse length scale, in a range encompassing the prepeak and the structure factor peak. Data were collected in the temperature range corresponding to the liquid and supercooled states, down to the glass transition. At least two dynamical processes were identified. This paper focuses on the slowest relaxation process in the system, the {alpha}-relaxation, which was found to scale with the macroscopic shear viscosity at all the investigated Q values. No evidence of 'de Gennes' narrowing associated with the prepeak was observed, in contrast with what happens at the Q value corresponding to the interparticle distance. Moreover, using partially deuterated samples, the dynamics of the clusters was found to be correlated to the single-particle dynamics of the meta-toluidine molecules.

  20. Translational and rotational dynamics of water contained in aged Portland cement pastes studied by quasi-elastic neutron scattering.

    Science.gov (United States)

    Li, Hua; Zhang, Li-Li; Yi, Zhou; Fratini, Emiliano; Baglioni, Piero; Chen, Sow-Hsin

    2015-08-15

    Cement is a widely used construction material in the world. The quality and durability of aged cement pastes have a strong relationship with the water contained in it. The translational and rotational dynamics of water in ordinary Portland cement (OPC) pastes cured for 7, 14 and 30days were studied by analyzing Quasi-elastic Neutron Scattering (QENS) data. The effect of a new super-plasticizer (SP) additive was also studied by comparing the samples with and without the additive. By fitting the QENS spectra with the Jump-diffusion and Rotation-diffusion Model (JRM), six important parameters including the bound water index (BWI), the self-diffusion coefficient, D(t), the average residence time, τ0, the rotational diffusion constant, D(r), the rotational residence time, τ(r), and the mean squared displacement (MSD), 〈u(2)〉, were obtained. From these parameters, we can quantitatively follow the evolution of the bound water fraction (BWI). We can clearly see the different time ranges for the translational and rotational dynamics of water contained in the OPC pastes by τ0 and τ(r). From the MSD values compared with those of molecular dynamics simulation, we can distinguish between immobile water (mainly bound water) and mobile water, which includes confined water and ultraconfined water. Furthermore, by the fitted parameters' values and their change of slopes with increasing setting time for cement pastes with and without additive SP, it becomes clear that the effect of additive SP is to make the mobile water more confined and induce a more uniform the aging process during the evolution of the OPC pastes.

  1. Important influence of single neutron stripping coupling on near-barrier {sup 8}Li + {sup 90}Zr quasi-elastic scattering

    Energy Technology Data Exchange (ETDEWEB)

    Pakou, A.; Aslanoglou, X.; Sgouros, O.; Soukeras, V. [The University of Ioannina, Department of Physics and HINP, Ioannina (Greece); Keeley, N. [National Centre for Nuclear Research, Otwock (Poland); Pierroutsakou, D.; Boiano, A.; Parascandolo, C. [INFN, Napoli (Italy); Mazzocco, M.; Soramel, F.; Strano, E.; Torresi, D. [Universita di Padova, Dipartimento di Fisica e Astronomia, Padova (Italy); INFN, Padova (Italy); Acosta, L. [Universidad Nacional Autonoma de Mexico, Instituto de Fisica, Mexico (Mexico); INFN, Catania (Italy); Boiano, C. [INFN, Milano (Italy); Carbone, D.; Cavallaro, M. [INFN Laboratori Nazionali del Sud, Catania (Italy); Grebosz, J. [The Henryk Niewodniczanski Institute of Nuclear Physics (IFJ PAN), Krakow (Poland); La Commara, M. [INFN, Napoli (Italy); Universita di Napoli ' ' Federico II' ' , Dipartimento di Scienze Fisiche, Napoli (Italy); Manea, C. [INFN, Padova (Italy); Marquinez-Duran, G.; Martel, I. [Universidad de Huelva, Departamento de Fisica Aplicada, Huelva (Spain); Rusek, K.; Trzcinska, A. [University of Warsaw, Heavy Ion Laboratory, Warsaw (Poland); Sanchez-Benitez, A.M. [Centro de Fisica Nuclear da Universidade de Lisboa, Lisboa (Portugal); Signorini, C. [LNL, INFN, Legnaro (Italy); Stiliaris, E. [University of Athens, Institute of Accelerating Systems and Applications and Department of Physics, Athens (Greece); Watanabe, Y.X. [High Energy Accelerator Research Organization (KEK), Institute of Particle and Nuclear Studies (IPNS), Ibaraki (Japan); Yamaguchi, H. [University of Tokyo, RIKEN campus, Center for Nuclear Study (CNS), Saitama (Japan)

    2015-07-15

    Quasi-elastic scattering data were obtained for the radioactive nucleus {sup 8}Li on a {sup 90}Zr target at the near-barrier energy of 18.5 MeV over the angular range θ{sub lab} = 15 {sup circle} to 80 . They were analyzed within the coupled channels and coupled reaction channels frameworks pointing to a strong coupling effect for single neutron stripping, in contrast to {sup 6,} {sup 7}Li + {sup 90}Zr elastic scattering at similar energies, a non-trivial result linked to detailed differences in the structure of these Li isotopes. (orig.)

  2. A new apparatus design for high temperature (up to 950 °C) quasi-elastic neutron scattering in a controlled gaseous environment

    Energy Technology Data Exchange (ETDEWEB)

    Al-Wahish, Amal [Department of Physics and Astronomy, The University of Tennessee, Knoxville, Tennessee 37996-1200 (United States); Armitage, D.; Hill, B.; Mills, R.; Santodonato, L.; Herwig, K. W. [Instrument and Source Design Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37861-6475 (United States); Al-Binni, U. [Department of Physics, Astronomy and Geology, Berry College, Mount Berry, Georgia 30149 (United States); Jalarvo, N. [Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science (JCNS), Outstation at Spallation Neutron Source (SNS), and Chemical and Engineering Materials Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6473 (United States); Mandrus, D. [Department of Physics and Astronomy, The University of Tennessee, Knoxville, Tennessee 37996-1200 (United States); Department of Materials Science and Engineering, The University of Tennessee, Knoxville, Tennessee 37996-1200 (United States); Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6100 (United States)

    2015-09-15

    A design for a sample cell system suitable for high temperature Quasi-Elastic Neutron Scattering (QENS) experiments is presented. The apparatus was developed at the Spallation Neutron Source in Oak Ridge National Lab where it is currently in use. The design provides a special sample cell environment under controlled humid or dry gas flow over a wide range of temperature up to 950 °C. Using such a cell, chemical, dynamical, and physical changes can be studied in situ under various operating conditions. While the cell combined with portable automated gas environment system is especially useful for in situ studies of microscopic dynamics under operational conditions that are similar to those of solid oxide fuel cells, it can additionally be used to study a wide variety of materials, such as high temperature proton conductors. The cell can also be used in many different neutron experiments when a suitable sample holder material is selected. The sample cell system has recently been used to reveal fast dynamic processes in quasi-elastic neutron scattering experiments, which standard probes (such as electrochemical impedance spectroscopy) could not detect. In this work, we outline the design of the sample cell system and present results demonstrating its abilities in high temperature QENS experiments.

  3. Measurement of the Target-Normal Single-Spin Asymmetry in Quasi-Elastic Scattering from the Reaction $^3$He$^\\uparrow(e,e^\\prime)$

    CERN Document Server

    Zhang, Y -W; Mihovilovič, M; Jin, G; Allada, K; Anderson, B; Annand, J R M; Averett, T; Boeglin, W; Bradshaw, P; Camsonne, A; Canan, M; Cates, G D; Chen, C; Chen, J P; Chudakov, E; De Leo, R; Deng, X; Deur, A; Dutta, C; Fassi, L El; Flay, D; Frullani, S; Garibaldi, F; Gao, H; Gilad, S; Gilman, R; Glamazdin, O; Golge, S; Gomez, J; Hansen, O; Higinbotham, D W; Holmstrom, T; Huang, J; Ibrahim, H; de Jager, C W; Jensen, E; Jiang, X; John, J St; Jones, M; Kang, H; Katich, J; Khanal, H P; King, P; Korsch, W; LeRose, J; Lindgren, R; Lu, H -J; Luo, W; Markowitz, P; Meziane, M; Michaels, R; Moffit, B; Monaghan, P; Muangma, N; Nanda, S; Norum, B E; Pan, K; Parno, D; Piasetzky, E; Posik, M; Punjabi, V; Puckett, A J R; Qian, X; Qiang, Y; Qiu, X; Riordan, S; Ron, G; Saha, A; Sawatzky, B; Schiavilla, R; Schoenrock, B; Shabestari, M; Shahinyan, A; Širca, S; Subedi, R; Sulkosky, V; Tobias, W A; Tireman, W; Urciuoli, G M; Wang, D; Wang, K; Wang, Y; Watson, J; Wojtsekhowski, B; Ye, Y; Ye, Z; Zhan, X; Zhang, Y; Zheng, X; Zhao, B; Zhu, L

    2015-01-01

    We report the first measurement of the target single-spin asymmetry, $A_y$, in quasi-elastic scattering from the inclusive reaction $^3$He$^{\\uparrow}(e,e^\\prime)$ on a $^3$He gas target polarized normal to the lepton scattering plane. Assuming time-reversal invariance, this asymmetry is strictly zero for one-photon exchange. A non-zero $A_y$ can arise from the interference between the one- and two-photon exchange processes which is sensitive to the details of the sub-structure of the nucleon. An experiment recently completed at Jefferson Lab yielded asymmetries with high statistical precision at $Q^{2}=$ 0.13, 0.46 and 0.97 GeV$^{2}$. These measurements demonstrate, for the first time, that the $^3$He asymmetry is clearly non-zero and negative with a statistical significance of (8-10)$\\sigma$. Using measured proton-to-$^{3}$He cross-section ratios and the effective polarization approximation, neutron asymmetries of $-$(1-3)% were obtained. The neutron asymmetry at high $Q^2$ is related to moments of the Gene...

  4. Hydrogen motions and the -relaxation in glass-forming polymers: Molecular dynamics simulation and quasi-elastic neutron scattering results

    Indian Academy of Sciences (India)

    J Colmenero; A Arbe; F Alvarez; A Narros; D Richter; M Monkenbush; B Farago

    2004-07-01

    The combination of molecular dynamics simulations and neutron scattering measurements on three different glass-forming polymers (polyisoprene, poly(vinyl ethylene) and polybutadiene) has allowed to establish the existence of a crossover from Gaussian to non-Gaussian behavior for the incoherent scattering function in the -relaxation regime. The deviation from Gaussian behavior observed can be reproduced assuming the existence of a distribution of discrete jump lengths underlying the sublinear diffusion of the atomic motions during the structural relaxation.

  5. Force field based molecular dynamics simulations in highly conducting compounds of poly(aniline). A comparison with quasi-elastic neutron scattering measurements

    Energy Technology Data Exchange (ETDEWEB)

    Sniechowski, M. [Laboratoire de Spectrometrie Physique, UMR5588 (CNRS-UJF), Universite J. Fourier, Grenoble I, Domaine Universitaire, B.P. 87, 38402 St. Martin d' Heres, Cedex (France); Faculty of Physics and Nuclear Techniques, AGH University of Science and Technology, Al. Mickiewicza 30, 30-059 Cracow (Poland); Djurado, D. [Laboratoire de Physique des Metaux Synthetiques, CEA Grenoble, DRFMC/SI3M/SPrAM, UMR 5819 (CEA/CNRS/UJF), 17 Rue des Martyrs, 38054 Grenoble, Cedex 9 (France)], E-mail: djurado@drfmc.ceng.cea.fr; Bee, M. [Laboratoire de Spectrometrie Physique, UMR5588 (CNRS-UJF), Universite J. Fourier, Grenoble I, Domaine Universitaire, B.P. 87, 38402 St. Martin d' Heres, Cedex (France); Institut Laue Langevin, 6 rue Jules Horovitz, B.P. 156, 38042 Grenoble, Cedex 9 (France); Gonzalez, M.A. [Institut Laue Langevin, 6 rue Jules Horovitz, B.P. 156, 38042 Grenoble, Cedex 9 (France); Johnson, M.R. [Institut Laue Langevin, 6 rue Jules Horovitz, B.P. 156, 38042 Grenoble, Cedex 9 (France); Rannou, P. [Laboratoire de Physique des Metaux Synthetiques, CEA Grenoble, DRFMC/SI3M/SPrAM, UMR 5819 (CEA/CNRS/UJF), 17 Rue des Martyrs, 38054 Grenoble, Cedex 9 (France); Dufour, B. [Laboratoire de Physique des Metaux Synthetiques, CEA Grenoble, DRFMC/SI3M/SPrAM, UMR 5819 (CEA/CNRS/UJF), 17 Rue des Martyrs, 38054 Grenoble, Cedex 9 (France); Luzny, W. [Faculty of Physics and Nuclear Techniques, AGH University of Science and Technology, Al. Mickiewicza 30, 30-059 Cracow (Poland)

    2005-10-31

    Dynamics of counter-ions in poly(aniline) doped with di-(2-butoxyethoxyethyl)ester of 4-sulfophthalic acid have been simulated using force field based molecular dynamics involving a semi-empirical charge equilibration procedure and charge rescaling based on DFT calculations. Due to particular relaxational and structural characteristics of such 'plastdoped' poly(anilines), these simulations have proved to be a very effective tool for reproducing the main structural and dynamic features of the material. The experiment/simulation comparison for dynamics is very good in the 10{sup -10}-10{sup -13} s time range. In particular, mean square displacements extracted from the molecular dynamics simulations for atoms in the counter-ions are in good agreement with the analytical model used to analyse the quasi-elastic neutron scattering data. The use of a larger simulation box and longer simulation time give good agreement in the extended time domain and reveal a dynamical heterogeneity between the counter-ions that was not foreseen in the analytical model.

  6. Studying neutrino oscillations using quasi-elastic events in MINOS

    Energy Technology Data Exchange (ETDEWEB)

    Kumaratunga, Sujeewa Terasita [Univ. of Minnesota, Minneapolis, MN (United States)

    2008-02-01

    MINOS (Main Injector Neutrino Oscillation Search), is a long baseline neutrino experiment designed to search for neutrino oscillations using two detectors at Fermi National Accelerator Laboratory, IL (Near Detector) and Soudan, MN (Far Detector). It will study vμ → vτ oscillations and make a measurement on the oscillation parameters, Δm$2\\atop{23}$ and sin223, via a vμ beam made at Fermilab. Charge current neutrino interactions in the MINOS detectors are of three types: quasi-elastic scattering (QEL), resonance scattering (RES) and deep inelastic scattering (DIS). Of these, quasi-elastic scattering leaves the cleanest signal with just one μ and one proton in the final state, thus rendering the reconstruction of the neutrino energy more accurate. This thesis will outline a method to separate QEL events from the others in the two detectors and perform a calculation of Δm$2\\atop{23}$ and sin223 using those events. The period under consideration was May 2005 to February 2006. The number of observed quasi-elastic events with energies below 10 GeV was 29, where the expected number was 60 ± 3. A fit to the energy distribution of these events gives Δm$2\\atop{23}$ = 2.91$+0.49\\atop{-0.53}$(stat)$+0.08\\atop{-0.09}$(sys) x 10-3 eV2 and sin223 = 0.990-0.180(stat)-0.030(sys).

  7. Quasi-elastic cross sections for 1GeV proton incident on {sup 4}He and {sup 12}C

    Energy Technology Data Exchange (ETDEWEB)

    Nishimura, M.; Nakamoto, T.; Shigyo, N. [Kyushu Univ., Fukuoka (Japan). Faculty of Engineering] [and others

    1997-03-01

    The experiment of p-n quasi-elastic scattering cross sections was carried out for 1GeV protons on {sup 4}He and {sup 12}C. The coincident measurement was made at c.m. angles of {+-} 90deg. The experiment was simulated by the use of HETC (High Energy Transport Code). It was examined to apply the p-n quasi-elastic scattering cross sections to neutron flux measurement. (author)

  8. Dynamics of water and ions in clays of type montmorillonite by microscopic simulation and quasi-elastic neutron scattering; Dynamique de l'eau et des ions dans des argiles de type montmorillonite par simulation microscopique et diffusion quasi-elastique des neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Malikova, N

    2005-09-15

    Montmorillonite clays in low hydration states, with Na{sup +} and Cs{sup +} compensating counter ions, are investigated by a combination of microscopic simulation and quasi-elastic neutron scattering to obtain information on the local structure and dynamics of water and ions in the interlayer. At first predictions of simulation into the dynamics of water and ions at elevate temperatures are shown (0 deg C 80 deg C, pertinent for the radioactive waste disposal scenario) Marked difference is observed between the modes of diffusion of the Na{sup +} and C{sup +} counter ions. In water dynamics, a significant step towards bulk water behaviour is seen on transition from the mono- to bilayer states. Secondly, a detailed comparison between simulation and quasi-elastic neutron scattering (Neutron Spin Echo and Time-of-Flight) regarding ambient temperature water dynamics is presented. Overall, the approaches are found to be in good agreement with each other and limitations of each of the methods are clearly shown. (author)

  9. Parallel heterodyne detection of dynamic light scattering spectra from gold nanoparticles diffusing in viscous fluids

    CERN Document Server

    Atlan, Michael; Gross, Michel; Coppey-Moisan, Maite; 10.1364/OL.35.000787

    2010-01-01

    We developed a microscope intended to probe, using a parallel heterodyne receiver, the fluctuation spectrum of light quasi-elastically scattered by gold nanoparticles diffusing in viscous fluids. The cutoff frequencies of the recorded spectra scale up linearly with those expected from single scattering formalism in a wide range of dynamic viscosities (1 to 15 times water viscosity at room temperature). Our scheme enables ensemble-averaged optical fluctuations measurements over multispeckle recordings in low light, at temporal frequencies up to 10 kHz, with a 12 Hz framerate array detector.

  10. Quasi-elastic events and nuclear effects with the K2K Sci-Fi detector

    Energy Technology Data Exchange (ETDEWEB)

    Walter, Christopher W. E-mail: walter@budoe.bu.edu

    2002-11-01

    The near detector complex of the K2K long-baseline neutrino experiment contains a scintillating fiber tracking detector. It is capable of detecting not only the muon but also the outgoing proton in neutrino-nucleon scattering. This allows for the enhancement of quasi-elastic interactions in the data sample. However, a proper modeling of the nuclear re-interactions of the proton is necessary to achieve reliable results.

  11. Measurement of the quasi-elastic axial vector mass in neutrino-oxygen interactions

    CERN Document Server

    Gran, R; Bóna, M; Boutigny, D; Couderc, F; Karyotakis, Yu; Lees, J P; Poireau, V; Tisserand, V; Zghiche, A; Graugès-Pous, E; Palano, A; Pappagallo, M; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Battaglia, M; Brown, D N; Button-Shafer, J; Cahn, R N; Charles, E; Day, C T; Gill, M S; Groysman, Y; Jacobsen, R G; Kadyk, J A; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lynch, G; Mir, L M; Oddone, P J; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, M T; Wenzel, W A; Barrett, M; Ford, K E; Harrison, T J; Hart, A J; Hawkes, C M; Morgan, S E; Watson, A T; Goetzen, K; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Peters, K; Schröder, T; Steinke, M; Boyd, J T; Burke, J P; Cottingham, W N; Walker, D; Çuhadar-Dönszelmann, T; Fulsom, B G; Hearty, C; Knecht, N S; Mattison, T S; McKenna, J A; Khan, A; Kyberd, P; Saleem, M; Teodorescu, L; Blinov, V E; Bukin, A D; Druzhinin, V P; Golubev, V B; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Todyshev, Yu K; Best, D S; Bondioli, M; Bruinsma, M; Chao, M; Curry, S; Eschrich, I; Kirkby, D; Lankford, A J; Lund, P; Mandelkern, M A; Mommsen, R K; Röthel, W; Stoker, D P; Abachi, S; Buchanan, C; Foulkes, S D; Gary, J W; Long, O; Shen, B C; Wang, K; Zhang, L; Hadavand, H K; Hill, E J; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Cunha, A; Dahmes, B; Hong, T M; Kovalskyi, D; Richman, J D; Beck, T W; Eisner, A M; Flacco, C J; Heusch, C A; Kroseberg, J; Lockman, W S; Nesom, G; Schalk, T; Schumm, B A; Seiden, A; Spradlin, P; Williams, D C; Wilson, M G; Albert, J; Chen, E; Dvoretskii, A; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Ryd, A; Samuel, A; Andreassen, R; Mancinelli, G; Meadows, B T; Sokoloff, M D; Blanc, F; Bloom, P C; Chen, S; Ford, W T; Hirschauer, J F; Kreisel, A; Nauenberg, U; Olivas, A; Ruddick, W O; Smith, J G; Ulmer, K A; Wagner, S R; Zhang, J; Chen, A; Eckhart, E A; Soffer, A; Toki, W H; Wilson, R J; Winklmeier, F; Zeng, Q; Altenburg, D D; Feltresi, E; Hauke, A; Jasper, H; Spaan, B; Brandt, T; Klose, V; Lacker, H M; Mader, W F; Nogowski, R; Petzold, A; Schubert, J; Schubert, K R; Schwierz, R; Sundermann, J E; Volk, A; Bernard, D; Bonneaud, G R; Grenier, P; Latour, E; Thiebaux, C; Verderi, M; Bard, D J; Clark, P J; Gradl, W; Muheim, F; Playfer, S; Robertson, A I; Xie, Y; Andreotti, M; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Petrella, A; Piemontese, L; Prencipe, E; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; De Sangro, R; Finocchiaro, G; Pacetti, S; Patteri, P; Peruzzi, I M; Piccolo, M; Rama, M; Zallo, A; Buzzo, A; Capra, R; Contri, R; Lo Vetere, M; Macri, M M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Brandenburg, G; Chaisanguanthum, K S; Morii, M; Wu, J; Dubitzky, R S; Marks, J; Schenk, S; Uwer, U; Bhimji, W; Bowerman, D A; Dauncey, P D; Egede, U; Flack, R L; Gaillard, J R; Nash, J A; Nikolich, M B; Panduro-Vazquez, W; Chai, X; Charles, M J; Mallik, U; Meyer, N T; Ziegler, V; Cochran, J; Crawley, H B; Dong, L; Eyges, V; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Gritsan, A V; Fritsch, M; Schott, G; Arnaud, N; Davier, M; Grosdidier, G; Höcker, A; Le Diberder, F R; Lepeltier, V; Lutz, A M; Oyanguren, A; Pruvot, S; Rodier, S; Roudeau, P; Schune, M H; Stocchi, A; Wang, W F; Wormser, G; Cheng, C H; Lange, D J; Wright, D M; Chavez, C A; Forster, I J; Fry, J R; Gabathuler, E; Gamet, R; George, K A; Hutchcroft, D E; Payne, D J; Schofield, K C; Touramanis, C; Bevan, A J; Di Lodovico, F; Menges, W; Sacco, R; Brown, C L; Cowan, G; Flächer, H U; Hopkins, D A; Jackson, P S; McMahon, T R; Ricciardi, S; Salvatore, F; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Chia, Y M; Edgar, C L; Kelly, M P; Lafferty, G D; Naisbit, M T; Williams, J C; Yi, J I; Chen, C; Hulsbergen, W D; Jawahery, A; Lae, C K; Roberts, D A; Simi, G; Blaylock, G; Dallapiccola, C; Hertzbach, S S; Li, X; Moore, T B; Saremi, S; Stängle, H; Willocq, S Y; Cowan, R; Koeneke, K; Sciolla, G; Sekula, S J; Spitznagel, M; Taylor, F; Yamamoto, R K; Kim, H; Patel, P M; Potter, C T; Robertson, S H; Lazzaro, A; Lombardo, V; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Reidy, J; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Simard, M; Taras, P; Viaud, F B; Nicholson, H; Cavallo, N; De Nardo, Gallieno; Del Re, D; Fabozzi, F; Gatto, C; Lista, L; Monorchio, D; Piccolo, D; Sciacca, C; Baak, M; Bulten, H; Raven, G; Snoek, H L; Jessop, C P; LoSecco, J M; Allmendinger, T; Benelli, G; Gan, K K; Honscheid, K; Hufnagel, D; Jackson, P D; Kagan, H; Kass, R; Pulliam, T; Rahimi, A M; Ter-Antonian, R; Wong, Q K; Blount, N L; Brau, J E; Frey, R; Igonkina, O; Lu, M; Rahmat, R; Sinev, N B; Strom, D; Strube, J; Torrence, E; Galeazzi, F; Gaz, A; Margoni, M; Morandin, M; Pompili, A; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Voci, C; Benayoun, M; Chauveau, J; David, P; Del Buono, L; La Vaissière, C de; Hamon, O; Hartfiel, B L; John, M J J; Leruste, P; Malcles, J; Ocariz, J; Roos, L; Therin, G; Behera, P K; Gladney, L; Panetta, J; Biasini, M; Covarelli, R; Pioppi, M; Angelini, C; Batignani, G; Bettarini, S; Bucci, F; Calderini, G; Carpinelli, M; Cenci, R; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Mazur, M A; Morganti, M; Neri, N; Paoloni, E; Rizzo, G; Walsh, J; Haire, M; Judd, D; Wagoner, D E; Biesiada, J; Danielson, N; Elmer, P; Lau, Y P; Lü, C; Olsen, J; Smith, A J S; Telnov, A V; Bellini, F; Cavoto, G; D'Orazio, A; Di Marco, E; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Li Gioi, L; Mazzoni, M A; Morganti, S; Piredda, G; Polci, F; Safai-Tehrani, F; Voena, C; Ebert, M; Schröder, H; Waldi, R; Adye, T; De Groot, N; Franek, B; Olaiya, E O; Wilson, F F; Emery, S; Gaidot, A; Ganzhur, S F; Hamel de Monchenault, G; Kozanecki, Witold; Legendre, M; Mayer, B; Vasseur, G; Yéche, C; Zito, M; Park, W; Purohit, M V; Weidemann, A W; Wilson, J R; Allen, M T; Aston, D; Bartoldus, R; Bechtle, P; Berger, N; Boyarski, A M; Claus, R; Coleman, J P; Convery, M R; Cristinziani, M; Dingfelder, J C; Dong, D; Dorfan, J; Dubois-Felsmann, G P; Dujmic, D; Dunwoodie, W M; Field, R C; Glanzman, T; Gowdy, S J; Graham, M T; Halyo, V; Hast, C; Hrynóva, T; Innes, W R; Kelsey, M H; Kim, P; Kocian, M L; Leith, D W G S; Li, S; Libby, J; Luitz, S; Lüth, V; Lynch, H L; MacFarlane, D B; Marsiske, H; Messner, R; Müller, D R; O'Grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Snyder, A; Stelzer, J; Su, D; Sullivan, M K; Suzuki, K; Swain, S K; Thompson, J M; Vavra, J; Van Bakel, N; Weaver, M; Weinstein, A J R; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Yi, K; Young, C C; Burchat, P R; Edwards, A J; Majewski, S A; Petersen, B A; Roat, C; Wilden, L; Ahmed, S; Alam, M S; Bula, R; Ernst, J A; Jain, V; Pan, B; Saeed, M A; Wappler, F R; Zain, S B; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Ritchie, J L; Satpathy, A; Schilling, C J; Schwitters, R F; Izen, J M; Kitayama, I; Lou, X C; Ye, S; Bianchi, F; Gallo, F; Gamba, D; Bomben, M; Bosisio, L; Cartaro, C; Cossutti, F; Della Ricca, G; Dittongo, S; Grancagnolo, S; Lanceri, L; Vitale, L; Azzolini, V; Martínez-Vidal, F; Banerjee, Sw; Bhuyan, B; Brown, C M; Fortin, D; Hamano, K; Kowalewski, R V; Nugent, I M; Roney, J M; Sobie, R J; Back, J J; Harrison, P F; Latham, T E; Mohanty, G B; Band, H R; Chen, X; Cheng, B; Dasu, S; Datta, M; Eichenbaum, A M; Flood, K T; Hollar, J J; Johnson, J R; Kutter, P E; Li, H; Liu, R; Mellado, B; Mihályi, A; Mohapatra, A K; Pan, Y; Pierini, M; Prepost, R; Tan, P; Wu, S L; Yu, Z; Neal, H; Back, B B

    2006-01-01

    The weak nucleon axial-vector form factor for quasi-elastic interactions is determined using neutrino interaction data from the K2K Scintillating Fiber detector in the neutrino beam at KEK. More than 12,000 events are analyzed, of which half are charged-current quasi-elastic interactions nu-mu n to mu- p occurring primarily in oxygen nuclei. We use a relativistic Fermi gas model for oxygen and assume the form factor is approximately a dipole with one parameter, the axial vector mass M_A, and fit to the shape of the distribution of the square of the momentum transfer from the nucleon to the nucleus. Our best fit result for M_A = 1.20 \\pm 0.12 GeV. Furthermore, this analysis includes updated vector form factors from recent electron scattering experiments and a discussion of the effects of the nucleon momentum on the shape of the fitted distributions.

  12. Inelastic Light Scattering Processes

    Science.gov (United States)

    Fouche, Daniel G.; Chang, Richard K.

    1973-01-01

    Five different inelastic light scattering processes will be denoted by, ordinary Raman scattering (ORS), resonance Raman scattering (RRS), off-resonance fluorescence (ORF), resonance fluorescence (RF), and broad fluorescence (BF). A distinction between fluorescence (including ORF and RF) and Raman scattering (including ORS and RRS) will be made in terms of the number of intermediate molecular states which contribute significantly to the scattered amplitude, and not in terms of excited state lifetimes or virtual versus real processes. The theory of these processes will be reviewed, including the effects of pressure, laser wavelength, and laser spectral distribution on the scattered intensity. The application of these processes to the remote sensing of atmospheric pollutants will be discussed briefly. It will be pointed out that the poor sensitivity of the ORS technique cannot be increased by going toward resonance without also compromising the advantages it has over the RF technique. Experimental results on inelastic light scattering from I(sub 2) vapor will be presented. As a single longitudinal mode 5145 A argon-ion laser line was tuned away from an I(sub 2) absorption line, the scattering was observed to change from RF to ORF. The basis, of the distinction is the different pressure dependence of the scattered intensity. Nearly three orders of magnitude enhancement of the scattered intensity was measured in going from ORF to RF. Forty-seven overtones were observed and their relative intensities measured. The ORF cross section of I(sub 2) compared to the ORS cross section of N2 was found to be 3 x 10(exp 6), with I(sub 2) at its room temperature vapor pressure.

  13. Scattering Of Light Nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Quaglioni, S; Navratil, P; Roth, R

    2009-12-15

    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.

  14. Light scattering reviews 8 radiative transfer and light scattering

    CERN Document Server

    Kokhanovsky, Alexander A

    2013-01-01

    Light scattering review (vol 8) is aimed at the presentation of recent advances in radiative transfer and light scattering optics. The topics to be covered include: scattering of light by irregularly shaped particles suspended in atmosphere (dust, ice crystals), light scattering by particles much larger as compared the wavelength of incident radiation, atmospheric radiative forcing, astrophysical radiative transfer, radiative transfer and optical imaging in biological media, radiative transfer of polarized light, numerical aspects of radiative transfer.

  15. Weak Quasi-elastic Production of Hyperons

    CERN Document Server

    Singh, S K

    2006-01-01

    The quasielastic weak production of $\\Lambda$ and $\\Sigma$ hyperons from nucleons and nuclei induced by antineutrinos is studied in the energy region of some ongoing neutrino oscillation experiments in the intermediate energy region. The hyperon nucleon transition form factors determined from neutrino nucleon scattering and an analysis of high precision data on semileptonic decays of neutron and hyperons using SU(3) symmetry have been used. The nuclear effects due to Fermi motion and final state interaction effects due to hyperon nucleon scattering have also been studied. The numerical results for differential and total cross sections have been presented.

  16. Quasi-Elastic Electron-Deuteron Scattering and Calculation of Neutron Electromagnetic Form Factors at Q2 = 1.75 to 4.00 (GeV/c)2

    Institute of Scientific and Technical Information of China (English)

    N. Ghahramany; M. Vaez zadeh Asadi; G.R. Boroun

    2003-01-01

    Electric and Magnetic form factors of neutron are calculated via electron-deuteron scattering at 1.511 ~5.507 GeV energy using SLAC group data. Our results show that the neutron electric form factor is not equal to zero;rather it has a small value, indicating that in spite of the fact that total charge is almost neutral, there is a nonuniformcharge distribution within the neutron, and that magnetic form factor follows the dipole fit.

  17. Spectrum of recoil nucleons in quasi-elastic neutrino-nucleus interactions

    Energy Technology Data Exchange (ETDEWEB)

    Juszczak, C.; Nowak, J.A.; Sobczyk, J.T. [Wroclaw University, Institute of Theoretical Physics, Wroclaw (Poland)

    2005-02-01

    We have analyzed the consequences of introducing the local density approximation combined with an effective nuclear momentum-dependent potential into the CC quasi-elastic neutrino-nucleus scattering. We note that the distribution of recoil nucleons momenta becomes smooth for low momentum values and the sharp threshold is removed. Our results may be relevant for Sci-Fi detector analysis of K2K experiments. The total amount of observed recoil protons is reduced because some of them remain bound inside the nucleus. We compare theoretical predictions for a probability of such events with the results given by NUX+FLUKA MC simulations. (orig.)

  18. Light-by-light scattering in UPC at the LHC

    CERN Document Server

    Klusek-Gawenda, Mariola; Szczurek, Antoni

    2016-01-01

    We discuss diphoton semi(exclusive) production in ultraperipheral $PbPb$ collisions at energy of $\\sqrt{s_{NN}}=$ 5.5 TeV (LHC). The nuclear calculations are based on equivalent photon approximation in the impact parameter space. The cross sections for elementary $\\gamma \\gamma \\to \\gamma \\gamma$ subprocess are calculated including two different mechanisms: box diagrams with leptons and quarks in the loops and a VDM-Regge contribution with virtual intermediate hadronic excitations of the photons. We got relatively high cross sections in $PbPb$ collisions ($306$ nb). This opens a possibility to study the $\\gamma \\gamma \\to \\gamma \\gamma$ (quasi)elastic scattering at the LHC. We find that the cross section for elastic $\\gamma\\gamma$ scattering could be measured in the lead-lead collisions for the diphoton invariant mass $W_{\\gamma\\gamma} \\approx 15-20$ GeV.

  19. Light scattering by small particles

    CERN Document Server

    Hulst, H C van de

    1981-01-01

    ""A must for researchers using the techniques of light scattering."" ? S. C. Snowdon, Journal of the Franklin InstituteThe measurement of light scattering of independent, homogeneous particles has many useful applications in physical chemistry, meteorology and astronomy. There is, however, a sizeable gap between the abstract formulae related to electromagnetic-wave-scattering phenomena, and the computation of reliable figures and curves. Dr. van de Hulst's book enables researchers to bridge that gap. The product of twelve years of work, it is an exhaustive study of light-scattering properties

  20. The Transverse Asymmetry A{sub T}, from Quasi-elastic {sup 3}{ovr He}({rvec e}, e{prime}) Process and the Neutron Magnetic Form Factor

    Energy Technology Data Exchange (ETDEWEB)

    Wang Xu; Dipangkar Dutta; Feng Xiong; Brian Anderson; Leonard Auerbach; Todd Averett; William Bertozzi; Tim Black; John Calarco; Lawrence Cardman; Gordon Cates; Zhengwei Chai; Jian-ping Chen; Seonho Choi; Eugene Chudakov; Steve Churchwell; G.S. Corrado; C. Crawford; Daniel Dale; Alexandre Deur; Pibero Djawotho; Bradley Filippone; John Finn; Haiyan Gao; Ronald Gilman; Oleksandr Glamazdin; Charles Glashausser; Walter Gloeckle; J. Golak; Javier Gomez; Viktor Gorbenko; Jens-ole Hansen; F. Hersman; Douglas Higinbotham; Richard Holmes; Calvin Howell; Emlyn Hughes; Thomas Humensky; Sebastien Incerti; Cornelis De Jager; John Jensen; Xiaodong Jiang; C.E. Jones; Mark Jones; R. Kahl; H. Kamada; A. Kievsky; Ioannis Kominis; Wolfgang Korsch; Kevin Kramer; Gerfried Kumbartzki; Michael Kuss; Enkeleida Lakuriqi; Meihua Liang; Nilanga Liyanage; John Lerose; Sergey Malov; Demetrius Margaziotis; J.W. Martin; Kathy Mccormick; Robert Mckeown; Kevin Mcilhany; Zein-eddine Meziani; Robert Michaels; G.W. Miller; Joseph Mitchell; Sirish Nanda; E. Pace; Tina Pavlin; Gerassimos Petratos; Roman Pomatsalyuk; D. Pripstein; David Prout; Ronald Ransome; Yves Roblin; Marat Rvachev; Arunava Saha; G. Salme; Michael Schnee; Taeksu Shin; Karl Slifer; Paul Souder; Steffen Strauch; Riad Suleiman; Mark Sutter; Bryan Tipton; Luminita Todor; Michele Viviani; Branislav Vlahovic; J. Watson; Claude Williamson; H. Witala; Bogdan Wojtsekhowski; Jen-chuan Yeh; Piotr Zolnierczuk

    2000-10-01

    We have measured the transverse asymmetry from inclusive scattering of longitudinally polarized electrons from polarized {sup 3}He nuclei at quasi-elastic kinematics in Hall A at Jefferson Lab with high statistical and systematic precision. The neutron magnetic form factor was extracted based on Faddeev calculations with an experimental uncertainty of less than 2%.

  1. The Transverse Asymmetry $A_{T'}$ from Quasi-elastic $^{3}\\vec{He}(\\vec{e},e')$ Process and the Neutron Magnetic Form Factor

    CERN Document Server

    Xu, W; Xiong, F; Anderson, B; Auberbach, L; Averett, T; Bertozzi, W; Black, T; Calarco, J R; Cardman, L S; Cates, G D; Chai, Z W; Chen, J P; Choi, S; Chudakov, E A; Churchwell, S; Corrado, G S; Crawford, C; Dale, D; Deur, A; Djawotho, P; Filippone, B W; Finn, J M; Gao, H; Gilman, R; Glamazdin, A V; Glashausser, C; Glöckle, W; Golak, J; Gómez, J; Gorbenko, V G; Hansen, J O; Hersman, F W; Higinbotham, D W; Holmes, R; Howell, C R; Hughes, E; Humensky, B; Incerti, S; De Jager, C W; Jensen, J S; Jiang, X; Jones, C E; Jones, M; Kahl, R; Kamada, H; Kievsky, A; Kominis, I; Korsch, W; Krämer, K; Kumbartzki, G J; Kuss, M W; Lakuriqi, E; Liang, M; Liyanage, N K; Le Rose, J J; Malov, S Y; Margaziotis, D J; Martin, J W; McCormick, K; McKeown, R D; McIlhany, K; Meziani, Z E; Michaels, R; Miller, G W; Mitchell, J; Nanda, S; Pace, E; Pavlin, T; Petratos, G G; Pomatsalyuk, R I; Pripstein, D A; Prout, D L; Ransome, R D; Roblin, Y; Rvachev, M M; Saha, A; Salmè, G; Schnee, M; Shin, T; Slifer, K J; Souder, P A; Strauch, S; Suleiman, R; Sutter, M F; Tipton, B; Todor, L; Viviani, M; Vlahovic, B; Watson, J; Williamson, C F; Witala, H; Wojtsekhowski, B B; Yeh, J

    2000-01-01

    We have measured the transverse asymmetry from inclusive scattering of longitudinally polarized electrons from polarized 3He nuclei at quasi-elastic kinematics in Hall A at Jefferson Lab with high statistical and systematic precision. The neutron magnetic form factor was extracted based on Faddeev calculations with an experimental uncertainty of less than 2 %.

  2. Light scattering reviews 9 light scattering and radiative transfer

    CERN Document Server

    Kokhanovsky, Alexander A

    2014-01-01

    This book details modern methods of the radiative transfer theory. It presents recent advances in light scattering (measurements and theory) and highlights the newest developments in remote sensing of aerosol and cloud properties.

  3. Scattering of light by crystals

    CERN Document Server

    Hayes, William

    2012-01-01

    This authoritative graduate-level text describes inelastic light scattering by crystals and its use in the investigation of solid-state excitation, with experimental techniques common to all types of excitation. 1978 edition.

  4. Broadband light scattering spectroscopy utilizing an ultra-narrowband holographic notch filter

    Science.gov (United States)

    Fujii, Yasuhiro; Katayama, Daisuke; Koreeda, Akitoshi

    2016-10-01

    The broadband spectroscopic analysis over Brillouin, quasi-elastic, and Raman regions arising from the same position of the sample has been achieved by employing an ultra-narrowband holographic notch filter (HNF) and an optical isolator. Recently, HNFs are often employed to reject strong elastic scattering in low-frequency Raman experiments. Meanwhile, the rejected spectral component agrees with the frequency range that can be observed by a triple-pass tandem Fabry-Pérot interferometer. Thus the broadband spectroscopy can be accomplished by introducing the rejected light to the interferometer. This system, in combination with the local symmetry analysis by polarization-direction-resolved Raman spectroscopy, is particularly advantageous for the investigation of spatially inhomogeneous systems.

  5. Light Scattering in Solid IX

    CERN Document Server

    Cardona, Manuel

    2007-01-01

    This is the ninth volume of a well-established series in which expert practitioners discuss topical aspects of light scattering in solids. It reviews recent developments concerning mainly semiconductor nanostructures and inelastic x-ray scattering, including both coherent time-domain and spontaneous scattering studies. In the past few years, light scattering has become one of the most important research and characterization methods for studying carbon nanotubes and semiconducting quantum dots, and a crucial tool for exploring the coupled exciton--photon system in semiconductor cavities. Among the novel techniques discussed in this volume are pump--probe ultrafast measurements and those which use synchrotron radiation as light source. The book addresses improvements in the intensity, beam quality and time synchronization of modern synchrotron sources, which made it possible to measure the phonon dispersion in very small samples and to determine electronic energy bands as well as enabling real-time observations...

  6. Light repolarization by scattering media

    CERN Document Server

    Sorrentini, Jacques; Soriano, Gabriel; Amra, Claude

    2011-01-01

    The polarization of a coherent depolarized incident light beam passing through a disordered medium is investigated. The local polarization of the scattered far field and the probability density function are calculated and show an excellent agreement with experiment. It is demonstrated that complex media may confer high degree of polarization (0.75 DOP average) to the incident unpolarized light.

  7. Laser light scattering basic principles and practice

    CERN Document Server

    Chu, Benjamin

    1994-01-01

    Geared toward upper-level undergraduate and graduate students, this text introduces the interdisciplinary area of laser light scattering, focusing chiefly on theoretical concepts of quasielastic laser scattering.

  8. Green's function Monte Carlo calculations of the electromagnetic and neutral-weak response functions in the quasi-elastic sector

    CERN Document Server

    Lovato, Alessandro

    2016-01-01

    A quantitative understanding of neutrino-nucleus interactions is demanded to achieve precise measurement of neutrino oscillations, and hence the determination of their masses. In addition, next generation detectors will be able to detect supernovae neutrinos, which are likely to shed some light on the open questions on the dynamics of core collapse. In this context, it is crucial to account for two-body meson-exchange currents along within realistic models of nuclear dynamics. We summarize our progresses towards the construction of a consistent framework, based on the Green's function Monte Carlo method, that can be exploited to accurately describe neutrino interactions with atomic nuclei in the quasi-elastic sector.

  9. Light dark matter in neutrino beams: production modelling and scattering signatures at MiniBooNE, T2K and SHiP

    CERN Document Server

    deNiverville, Patrick; Pospelov, Maxim; Ritz, Adam

    2016-01-01

    We analyze the prospects for detection of light sub-GeV dark matter produced in experiments designed to study the properties of neutrinos, such as MiniBooNE, T2K, SHiP, DUNE etc. We present an improved production model, when dark matter couples to hadronic states via a dark photon or baryonic vector mediator, incorporating bremsstrahlung of the dark vector. In addition to elastic scattering, we also study signatures of light dark matter undergoing deep inelastic or quasi-elastic NC$\\pi^0$-like scattering in the detector producing neutral pions, which for certain experiments may provide the best sensitivity. An extensive appendix provides documentation for a publicly available simulation tool {\\tt BdNMC} that can be applied to determine the hidden sector dark matter production and scattering rate at a range of proton fixed target experiments.

  10. A sub-GeV charged-current quasi-elastic $\

    Energy Technology Data Exchange (ETDEWEB)

    Walding, Joseph James [Imperial College, London (United Kingdom)

    2009-12-01

    Neutrino-nucleus charged-current quasi-elastic scattering is the signal interaction used by many neutrino oscillation experiments. For muon disappearance studies the signal mode is νμn → μp. Modern oscillation experiments, such as T2K, produce neutrino beams with peak beam energies of order a few-GeV. It is therefore vitally important to have accurate measurements of the charged-current quasi-elastic crosssection for future neutrino oscillation experiments. Neutrino-nucleus cross-sections in the few-GeV region are not well understood, with the main uncertainties coming from understanding of the neutrino beam flux and the final state interactions within nuclei. SciBooNE is a sub-GeV neutrino-nucleus cross-section experiment based at Fermilab, Batavia, USA, with the goal to measure neutrino cross-sections with precision of order 5%. SciBooNE took data from June 2007 until August 2008, in total 0.99×1020 and 1.53×1020 protons on target were collected in neutrino and anti-neutrino mode, respectively. In this thesis a νμ charged-current quasi-elastic (CCQE) cross-section contained within the SciBar sub-detector is presented. A method to tag muons in SciBar was developed and three samples were isolated. An excess in backwards tracks in the one-track sample is observed. A Poisson maximum likelihood is used to extract the CCQE cross-section. The fit was applied using a basic fit parameter model, successfully used to obtain the cross-section in the SciBar-MRD matched CCQE analysis. This method was found to be insufficient in describing the data for the SciBarcontained CCQE analysis. By adding two migration parameters the cross-section was calculated to be 1.004 ± 0.031 (stat)+0.101 -0.150(sys) × 10-38 cm2/neutron, excluding backwards tracks with a χ2 = 203.8/76 d.o.f. and 1.083 ± 0.030(stat)+0.115 -0.177(sys) × 10-38 cm2

  11. Light Scattering in Exoplanet Transits

    Science.gov (United States)

    Robinson, Tyler D.; Fortney, Jonathan J.

    2016-10-01

    Transit spectroscopy is currently the leading technique for studying exoplanet atmospheric composition, and has led to the detection of molecular species, clouds, and/or hazes for numerous worlds outside the Solar System. The field of exoplanet transit spectroscopy will be revolutionized with the anticipated launch of NASA's James Webb Space Telescope (JWST) in 2018. Over the course of the design five year mission for JWST, the observatory is expected to provide in-depth observations of many tens of transiting exoplanets, including some worlds in the poorly understood 2-4 Earth-mass regime. As the quality of transit spectrum observations continues to improve, so should models of exoplanet transits. Thus, certain processes initially thought to be of second-order importance should be revisited and possibly added to modeling tools. For example, atmospheric refraction, which was commonly omitted from early transit spectrum models, has recently been shown to be of critical importance in some terrestrial exoplanet transits. Beyond refraction, another process that has seen little study with regards to exoplanet transits is light multiple scattering. In most cases, scattering opacity in exoplanet transits has been treated as equivalent to absorption opacity. However, this equivalence cannot always hold, such as in the case of a strongly forward scattering, weakly absorbing aerosol. In this presentation, we outline a theory of exoplanet transit spectroscopy that spans the geometric limit (used in most modern models) to a fully multiple scattering approach. We discuss a new technique for improving model efficiency that effectively separates photon paths, which tend to vary slowly in wavelength, from photon absorption, which can vary rapidly in wavelength. Using this newly developed approach, we explore situations where cloud or haze scattering may be important to JWST observations of gas giants, and comment on the conditions necessary for scattering to become a major

  12. Light scattering near phase transitions

    CERN Document Server

    Cummins, HZ

    1983-01-01

    Since the development of the laser in the early 1960's, light scattering has played an increasingly crucial role in the investigation of many types of phase transitions and the published work in this field is now widely dispersed in a large number of books and journals.A comprehensive overview of contemporary theoretical and experimental research in this field is presented here. The reviews are written by authors who have actively contributed to the developments that have taken place in both Eastern and Western countries.

  13. Scattering theory of stochastic electromagnetic light waves.

    Science.gov (United States)

    Wang, Tao; Zhao, Daomu

    2010-07-15

    We generalize scattering theory to stochastic electromagnetic light waves. It is shown that when a stochastic electromagnetic light wave is scattered from a medium, the properties of the scattered field can be characterized by a 3 x 3 cross-spectral density matrix. An example of scattering of a spatially coherent electromagnetic light wave from a deterministic medium is discussed. Some interesting phenomena emerge, including the changes of the spectral degree of coherence and of the spectral degree of polarization of the scattered field.

  14. Incoherent subharmonic light scattering in isotropic media.

    Science.gov (United States)

    Feng, D H; Xu, Z Z; Feng, X L; Jia, T Q; Li, X X; Liu, J S

    2005-02-01

    Incoherent subharmonic light scattering in isotropic media is a new kind of nonlinear light scattering, which involves single input photon and multiple output photons of equal frequency. We investigate theoretically the dependence of the subharmonic scattering intensity on the hyperpolarizability of molecules and the incident intensity using nonlinear optics theory similar to that used for Hyper-Rayleigh scattering and degenerate optical parametric oscillators. It is derived that the subharmonic scattering intensities grow exponentially or superexponentially with the hyperpolarizability of molecules and the incident intensity.

  15. The Amsterdam-Granada Light Scattering Database

    NARCIS (Netherlands)

    Muñoz, O.; Moreno, F.; Guirado, D.; Dabrowska, D.D.; Volten, H.; Hovenier, J.W.

    2012-01-01

    The Amsterdam Light Scattering Database proved to be a very successful way of promoting the use of the data obtained with the Amsterdam Light Scattering apparatus at optical wavelengths. Many different research groups around the world made use of the experimental data. After the closing down of the

  16. Precursor of pion condensation: The softening of the quasi-elastic peak

    Science.gov (United States)

    Alberico, W. M.; Ericson, M.; Molinari, A.

    1980-05-01

    The phase transition of pion condensation is heralded in the disordered phase by an increase in the life time of the fluctuations for the staggered magnetization. This precursor phenomenon entails, in ordinary nuclei, a showing down of the nuclear quasi-elastic response when observed with spin-sensitive probes. Permanent address: Istituto di Fisica Teorica dell'Università di Torino, Turin, Italy.

  17. Correlated model for quasi-elastic responses in finite nuclear systems

    CERN Document Server

    Có, G; Co', Giampaolo; Lallena, Antonio M.

    2001-01-01

    A model to calculate nuclear responses considering short-range correlation effects is presented. The model is applied to the study of electromagnetic responses induced by one-body operators. We calculate one- and two-nucleon emission responses and cross sections of the 16O and 40Ca nuclei in the quasi-elastic region, and we compare them with experimental data.

  18. Inclusive nucleon emission induced by quasi-elastic neutrino-nucleus interactions

    Energy Technology Data Exchange (ETDEWEB)

    Nieves, J. [Departamento de Fisica Moderna, Universidad de Granada, E-18071, Granada (Spain); Valverde, M. [Departamento de Fisica Moderna, Universidad de Granada, E-18071, Granada (Spain); Vicente-Vacas, M.J. [Departamento de Fisica Teorica and IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, Aptdo. 22085, E-46017 Valencia (Spain)

    2006-05-15

    A previous model on inclusive charged-current quasi-elastic nuclear reactions [J. Nieves, J.E. Amaro and M. Valverde, Phys. Rev. C 70 (2004) 055503] is extended to include neutral- and charged-current nucleon emission reactions. The problem of outgoing nucleon propagation is treated by means of a Monte Carlo simulation.

  19. Light scattering on chlorella vulgaris cells

    Science.gov (United States)

    Krol, Tadeusz; Zielinski, Andrzej; Witkowski, Konrad

    1992-12-01

    Laboratory measurements of light scattering on the axenic cultures of unicellular alga Chlorella vulgaris monoculture confirm the thesis of multi-level light scattering by the cell i.e., both by outer cell membrane and the internal structure of the cell, as well as by its molecular structures. In the measurements, the technique of dynamic light scattering and analysis by the regulation method was used, indicate that the light scattering phenomenon is affected by particles of sizes corresponding either to overall dimensions of the cell or to the dimensions of its internal structures. A correlation was found between the suggested sizes and the stage of physiological evolution of the culture. The measurements of 10 functions constituting the elements of the scattering matrix for an alive Chlorella vulgaris culture and cultures with internal cell structures modified by chemical and mechanical agents evidence that the internal structures of cells play an important role in the interaction of phytoplankton and light.

  20. Broadband light-scattering spectroscopy on fractal and non-fractal relaxors

    Science.gov (United States)

    Koreeda, Akitoshi; Ogawa, Tomohiro; Katayama, Daisuke; Fujii, Yasuhiro; Tachibana, Makoto

    2016-10-01

    We show the quasi-elastic light scattering (QELS) spectra of two groups of relaxors: the first group includes relaxors that exhibit glasslike low-temperature thermal conductivity and heat capacity, namely, Pb(Mg1/3Nb2/3)O3 (PMN), (1 - x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-xPT), Pb(Zr1/3Nb2/3)O3 (PZN), and (Na1/2Bi1/2)TiO3 (NBT). The other group consists of relaxors exhibiting a normal (crystal) temperature dependence of the thermal conductivity and heat capacity, namely, K1- x Li x TaO3 (KLT) and KTa1- x Nb x O3 (KTN). The crystals of the first group yielded self-similar (power-law) QELS spectra, indicating the existence of fractal networks/clusters of polar nanoregions, while those of the second group did not show any self-similarity in the QELS spectra. These results imply that the glasslike low-temperature thermal conductivity and heat capacity in relaxors can be attributed to the vibrational modes specific to fractal networks/clusters formed by polar nanoregions.

  1. Radiofrequency encoded angular-resolved light scattering

    DEFF Research Database (Denmark)

    Buckley, Brandon W.; Akbari, Najva; Diebold, Eric D.

    2015-01-01

    The sensitive, specific, and label-free classification of microscopic cells and organisms is one of the outstanding problems in biology. Today, instruments such as the flow cytometer use a combination of light scatter measurements at two distinct angles to infer the size and internal complexity...... of cells at rates of more than 10,000 per second. However, by examining the entire angular light scattering spectrum it is possible to classify cells with higher resolution and specificity. Current approaches to performing these angular spectrum measurements all have significant throughput limitations...... Encoded Angular-resolved Light Scattering (REALS), this technique multiplexes angular light scattering in the radiofrequency domain, such that a single photodetector captures the entire scattering spectrum from a particle over approximately 100 discrete incident angles on a single shot basis. As a proof...

  2. Resonance Light Scattering Imaging Determination of Heparin

    Institute of Scientific and Technical Information of China (English)

    Hong Ping GUO; Cheng Zhi HUANG; Jian LING

    2006-01-01

    A laser-induced resonance light scattering (RLS) imaging method to determine heparin is described based on the high light scattering emission power of the aggregation species of heparin with α, β, γ, δtetra(4-trimethylaminoniumphenyl)prophyrin (TAPP) in solution. By imaging the light scattering signals of the aggregation species, we proposed the method to determine the heparin with a detection range of 0.02 - 0.6 μg/mL and the detection limit (3 σ) of 1.3 ng/mL.

  3. Transparent alumina: A light scattering model

    NARCIS (Netherlands)

    Apetz, R.; Van Bruggen, P.B.

    2003-01-01

    A model based on Rayleigh-Gans-Debye light scattering theory has been developed to describe the light transmission properties of fine-grained, fully dense polycrystalline ceramics consisting of birefringent crystals. This model extends light transmission models based on geometrical optics, which are

  4. Investigating Static and Dynamic Light Scattering

    CERN Document Server

    Sun, Yong

    2011-01-01

    A new size, static radii $R_{s}$, can be measured accurately using Static Light Scattering (SLS) technique when the Rayleigh-Gans-Debye approximation is valid for dilute homogenous spherical particles in dispersion. The method proposed in this work not only can measures the particle size distribution and average molar mass accurately but also enables us to explore Dynamic Light Scattering (DLS) technique further. Detailed investigation of the normalized time auto-correlation function of the scattered light intensity $g^{2)}(\\tau)$ shows that the measurements of DLS can be expected accurately and the static and hydrodynamic radii of nanoparticles are different. Only at some special conditions, the Z-average hydrodynamic radius can be measured accurately at a given scattering angle. The fact that the values of average hydrodynamic radius measured at different scattering angles are consistent or the values of polydispersity index are small does not mean the particle size distribution is narrow or monodisperse.

  5. New evaluation of thermal neutron scattering libraries for light and heavy water

    Directory of Open Access Journals (Sweden)

    Marquez Damian Jose Ignacio

    2017-01-01

    Full Text Available In order to improve the design and safety of thermal nuclear reactors and for verification of criticality safety conditions on systems with significant amount of fissile materials and water, it is necessary to perform high-precision neutron transport calculations and estimate uncertainties of the results. These calculations are based on neutron interaction data distributed in evaluated nuclear data libraries. To improve the evaluations of thermal scattering sub-libraries, we developed a set of thermal neutron scattering cross sections (scattering kernels for hydrogen bound in light water, and deuterium and oxygen bound in heavy water, in the ENDF-6 format from room temperature up to the critical temperatures of molecular liquids. The new evaluations were generated and processable with NJOY99 and also with NJOY-2012 with minor modifications (updates, and with the new version of NJOY-2016. The new TSL libraries are based on molecular dynamics simulations with GROMACS and recent experimental data, and result in an improvement of the calculation of single neutron scattering quantities. In this work, we discuss the importance of taking into account self-diffusion in liquids to accurately describe the neutron scattering at low neutron energies (quasi-elastic peak problem. To improve modeling of heavy water, it is important to take into account temperature-dependent static structure factors and apply Sköld approximation to the coherent inelastic components of the scattering matrix. The usage of the new set of scattering matrices and cross-sections improves the calculation of thermal critical systems moderated and/or reflected with light/heavy water obtained from the International Criticality Safety Benchmark Evaluation Project (ICSBEP handbook. For example, the use of the new thermal scattering library for heavy water, combined with the ROSFOND-2010 evaluation of the cross sections for deuterium, results in an improvement of the C/E ratio in 48 out of

  6. Multiple light scattering in porous gallium phosphide

    OpenAIRE

    Bret, Boris Paul Jean

    2005-01-01

    This thesis presents an experimental study on multiple light scattering, with the necessary introductions: theoretical background and sample preparation. The emphasis is put on the effects of the multiple scattering of waves, i.e., where interference effects exist and are significant, in the search for Anderson localization. In ensemble-averaged random media, there exists a cone of light, superimposed on the diffuse background, in the exact backscattering direction, due to the constructive in...

  7. An Evaluation of the Scattering Law for Light and Heavy Water in ENDF-6 Format, Based on Experimental Data and Molecular Dynamics

    Science.gov (United States)

    Márquez Damián, J. I.; Granada, J. R.; Malaspina, D. C.

    2014-04-01

    In this work we present an evaluation in ENDF-6 format of the scattering law for light and heavy water computed using the LEAPR module of NJOY99. The models used in this evaluation are based on experimental data on light water dynamics measured by Novikov, partial structure factors obtained by Soper, and molecular dynamics calculations performed with GROMACS using a reparameterized version of the flexible SPC model by Toukan and Rahman. The models use the Egelstaff-Schofield diffusion equation for translational motion, and a continuous spectrum calculated from the velocity autocorrelation function computed with GROMACS. The scattering law for H in H2O is computed using the incoherent approximation, and the scattering law D and O in D2O are computed using the Sköld approximation for coherent scattering. The calculations show significant improvement over ENDF/B-VI and ENDF/B-VII when compared with measurements of the total cross section, differential scattering experiments and quasi-elastic neutron scattering experiments (QENS).

  8. Light-by-light scattering in ultraperipheral PbPb collisions at the Large Hadron Collider

    CERN Document Server

    Klusek-Gawenda, Mariola; Szczurek, Antoni

    2016-01-01

    We calculate cross sections for diphoton production in (semi)exclusive $PbPb$ collisions, relevant for the LHC. The calculation is based on equivalent photon approximation in the impact parameter space. The cross sections for elementary $\\gamma \\gamma \\to \\gamma \\gamma$ subprocess are calculated including two different mechanisms. We take into account box diagrams with leptons and quarks in the loops. In addition, we consider a vector-meson dominance (VDM-Regge) contribution with virtual intermediate hadronic (vector-like) excitations of the photons. We get much higher cross sections in $PbPb$ collisions than in earlier calculation from the literature. This opens a possibility to study the $\\gamma \\gamma \\to \\gamma \\gamma$ (quasi)elastic scattering at the LHC. We present many interesting differential distributions which could be measured by the ALICE, CMS or ATLAS Collaborations at the LHC. We study whether a separation or identification of different components (boxes, VDM-Regge) is possible. We find that the...

  9. Light scattering of interacting gold nanorods

    Energy Technology Data Exchange (ETDEWEB)

    McGuirt, Baxter; Kielbasa, Jerry; Park, Jung-Ho; Zhang, Junping; Peterson, Eric; Williams, Richard; Carroll, David [Center for Nanotechnology and Molecular Materials and Department of Physics, Wake Forest University, Winston-Salem, NC (United States); Sisco, Patrick; Murphy, Catherine; Adams, Richard D. [Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC (United States)

    2009-12-15

    The optical field intensity of light scattering from nanorods of gold has been imaged at distances that are intermediate between the near-field and far-field regimes using a near-field scanning optical microscope (NSOM). For scattering from isolated nanorods the Fraunhofer diffractive behaviour is modified slightly by the dipolar nature of metal nanoantannae as would be expected at these imaging distances. However, when the nanorods are brought into close proximity, interactions between the nanorods alter the scattering behaviour substantially creating large field intensities between the structures. By sampling the field with the near-field microscope tip scanned at different heights, detailed maps of the scattering profile can be generated. The NSOM image of far-field scattered light from an isolated gold nanorod. The nanorod was imaged at a distance of roughly 8 {mu}m above the support substrate using a scanning near-field microscope operated at constant height mode. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  10. The Whiteness of Things and Light Scattering

    Science.gov (United States)

    Gratton, L. M.; Lopez-Arias, T.; Calza, G.; Oss, S.

    2009-01-01

    We discuss some simple experiments dealing with intriguing properties of light and its interaction with matter. In particular, we show how to emphasize that light reflection, refraction and scattering can provide a proper, physical description of human perception of the "colour" white. These experiments can be used in the classroom with an enquiry…

  11. Circularly symmetric light scattering from nanoplasmonic spirals.

    Science.gov (United States)

    Trevino, Jacob; Cao, Hui; Dal Negro, Luca

    2011-05-11

    In this paper, we combine experimental dark-field imaging, scattering, and fluorescence spectroscopy with rigorous electrodynamics calculations in order to investigate light scattering from planar arrays of Au nanoparticles arranged in aperiodic spirals with diffuse, circularly symmetric Fourier space. In particular, by studying the three main types of Vogel's spirals fabricated by electron-beam lithography on quartz substrates, we demonstrate polarization-insensitive planar light diffraction in the visible spectral range. Moreover, by combining dark-field imaging with analytical multiparticle calculations in the framework of the generalized Mie theory, we show that plasmonic spirals support distinctive structural resonances with circular symmetry carrying orbital angular momentum. The engineering of light scattering phenomena in deterministic structures with circular Fourier space provides a novel strategy for the realization of optical devices that fully leverage on enhanced, polarization-insensitive light-matter coupling over planar surfaces, such as thin-film plasmonic solar cells, plasmonic polarization devices, and optical biosensors.

  12. Scattered light mapping of protoplanetary disks

    Science.gov (United States)

    Stolker, T.; Dominik, C.; Min, M.; Garufi, A.; Mulders, G. D.; Avenhaus, H.

    2016-12-01

    Context. High-contrast scattered light observations have revealed the surface morphology of several dozen protoplanetary disks at optical and near-infrared wavelengths. Inclined disks offer the opportunity to measure part of the phase function of the dust grains that reside in the disk surface which is essential for our understanding of protoplanetary dust properties and the early stages of planet formation. Aims: We aim to construct a method which takes into account how the flaring shape of the scattering surface of an optically thick protoplanetary disk projects onto the image plane of the observer. This allows us to map physical quantities (e.g., scattering radius and scattering angle) onto scattered light images and retrieve stellar irradiation corrected images (r2-scaled) and dust phase functions. Methods: The scattered light mapping method projects a power law shaped disk surface onto the detector plane after which the observed scattered light image is interpolated backward onto the disk surface. We apply the method on archival polarized intensity images of the protoplanetary disk around HD 100546 that were obtained with VLT/SPHERE in the R' band and VLT/NACO in the H and Ks bands. Results: The brightest side of the r2-scaled R' band polarized intensity image of HD 100546 changes from the far to the near side of the disk when a flaring instead of a geometrically flat disk surface is used for the r2-scaling. The decrease in polarized surface brightness in the scattering angle range of 40°-70° is likely a result of the dust phase function and degree of polarization which peak in different scattering angle regimes. The derived phase functions show part of a forward scattering peak, which indicates that large, aggregate dust grains dominate the scattering opacity in the disk surface. Conclusions: Projection effects of a protoplanetary disk surface need to be taken into account to correctly interpret scattered light images. Applying the correct scaling for the

  13. Light Scattering Reviews, Vol 6 Light Scattering and Remote Sensing of Atmosphere and Surface

    CERN Document Server

    Kokhanovsky, Alexander A

    2012-01-01

    This is the next volume in series of Light Scattering Reviews. Volumes 1-5 have already been printed by Springer. The volume is composed of several papers ( usually, 10) of leading researchers in the respective field. The main focus of this book is light scattering, radiative transfer and optics of snow.

  14. Total, inelastic and (quasi-)elastic cross sections of high energy pA and gamma-A reactions with the dipole formalism

    CERN Document Server

    Gustafson, Gosta; Ster, Andras; Corgo, Tamas

    2015-01-01

    In order to understand the initial partonic state in proton-nucleus and electron-nucleus collisions, we investigate the total, inelastic, and (quasi-)elastic cross sections in pA and gamma-A collisions, as these observables are insensitive to possible collective effects in the final state interactions. We used as a tool the DIPSY dipole model, which is based on BFKL dynamics including non-leading effects, saturation, and colour interference, which we have extended to describe collisions of protons and virtual photons with nuclei. We present results for collisions with O, Cu, and Pb nuclei, and reproduce preliminary data on the pPb inelastic cross section at LHC by CMS and LHCb. The large NN cross section results in pA scattering that scales approximately with the area. The results are compared with conventional Glauber model calculations, and we note that the more subtle dynamical effects are more easily studied in the ratios between the total, inelastic and (quasi-)elastic cross sections. The smaller photon ...

  15. Heavy-ion fusion and scattering with Skyrme energy density functional

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In our recent studies,an empirical barrier distribution was proposed for a unified description of the fusion cross sections of light and medium-heavy fusion systems,the capture cross sections of the reactions leading to superheavy nuclei,and the large-angle quasi-elastic scattering cross sections based on the Skyrme energy-density functional approach.In this paper,we first give a brief review of these results.Then,by examining the barrier distributions in detail,we find that the fusion cross sections depend more strongly on the shape of the left side of the barrier distribution while the quasi-elastic scattering cross sections depend more strongly on the right side.Furthermore,by combining these studies and the HIVAP calculations for the survival probability,the formation probability of the compound nucleus is deduced from the measured evaporation residue cross sections for "cold" and "hot" fusion reactions.

  16. High-Energy Compton Scattering Light Sources

    CERN Document Server

    Hartemann, Fred V; Barty, C; Crane, John; Gibson, David J; Hartouni, E P; Tremaine, Aaron M

    2005-01-01

    No monochromatic, high-brightness, tunable light sources currently exist above 100 keV. Important applications that would benefit from such new hard x-ray sources include: nuclear resonance fluorescence spectroscopy, time-resolved positron annihilation spectroscopy, and MeV flash radiography. The peak brightness of Compton scattering light sources is derived for head-on collisions and found to scale with the electron beam brightness and the drive laser pulse energy. This gamma 2

  17. Light-like Scattering in Quantum Gravity

    CERN Document Server

    Bjerrum-Bohr, N E J; Holstein, Barry R; Plante, Ludovic; Vanhove, Pierre

    2016-01-01

    We consider scattering in quantum gravity and derive long-range classical and quantum contributions to the scattering of light-like bosons and fermions (spin-0, spin-1/2, spin-1) from an external massive scalar field, such as the Sun or a black hole. This is achieved by treating general relativity as an effective field theory and identifying the non-analytic pieces of the one-loop gravitational scattering amplitude. It is emphasized throughout the paper how modern amplitude techniques, involving spinor-helicity variables, unitarity, and squaring relations in gravity enable much simplified computations. We directly verify, as predicted by general relativity, that all classical effects in our computation are universal (in the context of matter type and statistics). Using an eikonal procedure we confirm the post-Newtonian general relativity correction for light-like bending around large stellar objects. We also comment on treating effects from quantum hbar dependent terms using the same eikonal method.

  18. Light-like scattering in quantum gravity

    Energy Technology Data Exchange (ETDEWEB)

    Bjerrum-Bohr, N.E.J. [Niels Bohr International Academy & Discovery Center, Niels Bohr Institute,University of Copenhagen, Blegdamsvej 17, Copenhagen Ø, DK-2100 (Denmark); Donoghue, John F. [Department of Physics-LGRT, University of Massachusetts,Amherst, MA, 01003 (United States); Holstein, Barry R. [Department of Physics-LGRT, University of Massachusetts,Amherst, MA, 01003 (United States); Kavli Institute for Theoretical Physics, University of California,Santa Barbara, CA, 93016 (United States); Planté, Ludovic; Vanhove, Pierre [CEA, DSM, Institut de Physique Théorique, IPhT, CNRS MPPU, URA2306,Saclay, Gif-sur-Yvette, F-91191 (France)

    2016-11-21

    We consider scattering in quantum gravity and derive long-range classical and quantum contributions to the scattering of light-like bosons and fermions (spin-0, spin-(1/2), spin-1) from an external massive scalar field, such as the Sun or a black hole. This is achieved by treating general relativity as an effective field theory and identifying the non-analytic pieces of the one-loop gravitational scattering amplitude. It is emphasized throughout the paper how modern amplitude techniques, involving spinor-helicity variables, unitarity, and squaring relations in gravity enable much simplified computations. We directly verify, as predicted by general relativity, that all classical effects in our computation are universal (in the context of matter type and statistics). Using an eikonal procedure we confirm the post-Newtonian general relativity correction for light-like bending around large stellar objects. We also comment on treating effects from quantum ℏ dependent terms using the same eikonal method.

  19. Light-like scattering in quantum gravity

    Science.gov (United States)

    Bjerrum-Bohr, N. E. J.; Donoghue, John F.; Holstein, Barry R.; Planté, Ludovic; Vanhove, Pierre

    2016-11-01

    We consider scattering in quantum gravity and derive long-range classical and quantum contributions to the scattering of light-like bosons and fermions (spin-0, spin- 1/2 , spin-1) from an external massive scalar field, such as the Sun or a black hole. This is achieved by treating general relativity as an effective field theory and identifying the non-analytic pieces of the one-loop gravitational scattering amplitude. It is emphasized throughout the paper how modern amplitude techniques, involving spinor-helicity variables, unitarity, and squaring relations in gravity enable much simplified computations. We directly verify, as predicted by general relativity, that all classical effects in our computation are universal (in the context of matter type and statistics). Using an eikonal procedure we confirm the post-Newtonian general relativity correction for light-like bending around large stellar objects. We also comment on treating effects from quantum ℏ dependent terms using the same eikonal method.

  20. Protoplanetary disks and exoplanets in scattered light

    NARCIS (Netherlands)

    Stolker, T.

    2017-01-01

    High-contrast imaging facilitates the direct detection of protoplanetary disks in scattered light and self-luminous exoplanets on long-period orbits. The combined power of extreme adaptive optics and differential imaging techniques delivers high spatial resolution images of disk morphologies down to

  1. Scattered light mapping of protoplanetary disks

    CERN Document Server

    Stolker, T; Min, M; Garufi, A; Mulders, G D; Avenhaus, H

    2016-01-01

    High-contrast scattered light observations have revealed the surface morphology of several dozens of protoplanetary disks at optical and near-infrared wavelengths. Inclined disks offer the opportunity to measure part of the phase function of the dust grains that reside in the disk surface which is essential for our understanding of protoplanetary dust properties and the early stages of planet formation. We aim to construct a method which takes into account how the flaring shape of the scattering surface of an (optically thick) protoplanetary disk projects onto the image plane of the observer. This allows us to map physical quantities (scattering radius and scattering angle) onto scattered light images and retrieve stellar irradiation corrected (r^2-scaled) images and dust phase functions. We apply the method on archival polarized intensity images of the protoplanetary disk around HD 100546 that were obtained with VLT/SPHERE in R'-band and VLT/NACO in H- and Ks-band. The brightest side of the r^2-scaled R'-ban...

  2. Light scattering studies of an electrorheological fluid

    Energy Technology Data Exchange (ETDEWEB)

    Martin, J.E.; Odinek, J.

    1993-08-01

    We report real-time, two-dimensional light scattering studies of the evolution of structure in an electrorheological fluid in the quiescent state and under shear. We find that when an electric field is applied to the quiescent fluid, particles chain along the electric field lines and cause strong light scattering lobes to appear at a finite scattering wavevector q orthogonal to the field lines. These lobes then brighten as they move to q=O, indicating the existence of an unstable concentration fluctuation that signifies the segregation of chains into columns. In fact, the observed power law growth kinetics of the characteristic length, as well as the form of the structure factor, are qualitatively similar to two-dimensional spinodal decomposition in a system with a conserved order parameter. When the sample is subjected to shear, we find that the scattering pattern approaches a steady state, with lobes that are rotated in the direction of fluid vorticity. The angle of rotation is found to increase as the cube root of the shear rate, in agreement with a theoretical prediction of the steady state structure of fragmenting particle chains.

  3. Cooperativity in light scattering by cold atoms

    CERN Document Server

    Bienaime, Tom; Piovella, Nicola; Kaiser, Robin

    2012-01-01

    A cloud of cold N two-level atoms driven by a resonant laser beam shows cooperative effects both in the scattered radiation field and in the radiation pressure force acting on the cloud center-of-mass. The induced dipoles synchronize and the scattered light presents superradiant and/or subradiant features. We present a quantum description of the process in terms of a master equation for the atomic density matrix in the scalar, Born-Markov approximations, reduced to the single-excitation limit. From a perturbative approach for weak incident field, we derive from the master equation the effective Hamiltonian, valid in the linear regime. We discuss the validity of the driven timed Dicke ansatz and of a partial wave expansion for different optical thicknesses and we give analytical expressions for the scattered intensity and the radiation pressure force on the center of mass. We also derive an expression for collective suppression of the atomic excitation and the scattered light by these correlated dipoles.

  4. Zeno: Critical Fluid Light Scattering Experiment

    Science.gov (United States)

    Gammon, Robert W.; Shaumeyer, J. N.; Briggs, Matthew E.; Boukari, Hacene; Gent, David A.; Wilkinson, R. Allen

    1996-01-01

    The Zeno (Critical Fluid Light Scattering) experiment is the culmination of a long history of critical fluid light scattering in liquid-vapor systems. The major limitation to making accurate measurements closer to the critical point was the density stratification which occurs in these extremely compressible fluids. Zeno was to determine the critical density fluctuation decay rates at a pair of supplementary angles in the temperature range 100 mK to 100 (mu)K from T(sub c) in a sample of xenon accurately loaded to the critical density. This paper gives some highlights from operating the instrument on two flights March, 1994 on STS-62 and February, 1996 on STS-75. More detail of the experiment Science Requirements, the personnel, apparatus, and results are displayed on the Web homepage at http://www.zeno.umd.edu.

  5. Light scattering measurement of sodium polyacrylate products

    Science.gov (United States)

    Lama, Nisha; Norwood, David; Boone, Steven; Massie-Boyer, Valerie

    2015-03-01

    In the presentation, we will describe the use of a multi-detector HPLC incorporating the DAWN EOS multi-angle laser light scattering (MALLS) detector to measure the properties such as molecular weight, RMS radius, contour and persistence length and polydispersity of sodium polyacrylate products. The samples of sodium polyacrylate are used in various industries as thickening agents, coating dispersants, artificial snow, laundry detergent and disposable diapers. Data and results obtained from the experiment will be presented.

  6. Characterization of Acryl amide Resins Using Static Light Scattering

    Science.gov (United States)

    Libi, Sumit; Norwood, David

    2012-02-01

    Our research is based on the use of light scattering technique for the characterization of known and unknown particles within a liquid. The research focused specifically on the detection of resin polymer that may be present in the given samples using static light scattering. The sample was delivered into a high performance liquid chromatography system with static light scattering, refractive index and viscosity detectors. Static Light scattering measures the intensity of the light scattered as the function of scattering angle and polymer sample concentration. Based on these results the molecular weight and radius of gyration of the given sample can be calculated.

  7. Theory of diffusive light scattering cancellation cloaking

    CERN Document Server

    Farhat, Mohamed; Guenneau, Sebastien; Bagci, Hakan; Salama, Khaled Nabil; Alu, Andrea

    2016-01-01

    We report on a new concept of cloaking objects in diffusive light regime using the paradigm of the scattering cancellation and mantle cloaking techniques. We show numerically that an object can be made completely invisible to diffusive photon density waves, by tailoring the diffusivity constant of the spherical shell enclosing the object. This means that photons' flow outside the object and the cloak made of these spherical shells behaves as if the object were not present. Diffusive light invisibility may open new vistas in hiding hot spots in infrared thermography or tissue imaging.

  8. Model of Light Scattering in Cavitation Area

    Directory of Open Access Journals (Sweden)

    S. P. Skvortsov

    2015-01-01

    Full Text Available The offered work presents analysis of extinction mechanisms and justification of light scattering model in ultrasonic cavitation area to justify a control method of ultrasonic cavitation through its optical sounding by low-intensity laser radiation and through photo-detector record of last radiation.The analysis of the extinction mechanisms has shown that the most essential mechanism causing a change of the transmission coefficient with time is dispersion on pulsating cavitation bubbles. Other extinction mechanisms lead to the time-constant reduction of last radiation intensity and can be taken into consideration by normalizing a recorded transmission coefficient for a previously measured liquid transmission coefficient when there is no cavitation.The feature of light scattering on the cavitation bubbles is primary dispersion in a forward direction that is connected with great values of bubbles radius from units to hundreds of micrometers. In case of single bubbles, dispersion can be described by Mi's theory, and, as to the cavitation area, it is reasonable to use the theory of V. Tversky for multiple light scattering. Thus, dispersion section, according to the paradox of extinction, can be considered to be equal to doubled geometrical section of a bubble. With increasing bubble radius the transmission coefficient monotonically decreases. So, the law of bubble pulsations and the model of light scattering define the law of changing transmission coefficient.Therefore, the cavitation area with its optical sounding acts as a peculiar opto-acoustic modulator. Thus, the demodulated signal of a photo-detector comprises information on pulsations of bubbles.The paper examines the influence of cavitation area thickness and bubbles concentration on the transmission coefficient. It shows a type of transmission coefficient dependence on the radius of cavitation bubbles.The optical sounding method is attractive because it allows us to obtain data on the

  9. Measurements Of Scattered Light From Asbestos Particulate

    Science.gov (United States)

    Riis, P.; Ballik, E. A.

    1987-09-01

    Light-scattering techniques are potentially very important for the low-level detection and identification of particulate species such as asbestos in aerosol and liquid suspensions. Low-level detection is essential because asbestos is a known carcinogen, even at very-low exposure levels. At present, most asbestos particulate monitoring is used on optical microscopy. If detailed analysis is required, then electron microscopy is employed. Both of these methods are labour intensive. Furthermore, the optical microscopy method is not very reliable. Although the light-scattering techniques described here have general applicability, the emphasis is on asbestos measurements. Ordinary measurements of Mie scattering from asbestos suspensions can provide only limited information on asbestos content. owever, a more sophisticated technique can be employed which relies on the fact that asbestos particulate is fibrous rather than spherical in shape, and that the fibres align in a strong magnetic field (approximately 0.5 T). Particulate other than asbestos is generally non-fibrous in shape. Measurements have been carried out on liquid suspensions of asbestos contained in a small cell placed between the poles of a rotating magnet. The aligned fibres, which rotate about their centre of mass as they follow the field, are illuminated using a laser source. The Mie-scattering intensity is measured as a function of rotation angle, and the resulting data is then analysed with the aid of a microcomputer. Intensity maxima and minima provide reliable information on asbestos concentration, even in the presence of strong scattering from other particulate. In addition, the angular location of the intensity peaks provides information on the type of asbestos present. Each type has a characteristic alignment behaviour in a strong magnetic field. Using relatively-simple equipment, chrysotile asbestos (the most commonly-used type) has been detected at levels below 30 ng/l.

  10. Quasi-elastic neutron scattering studies on dynamics of water confined in nanoporous copper rubeanate hydrates.

    Science.gov (United States)

    Yamada, Takeshi; Yonamine, Ryo; Yamada, Teppei; Kitagawa, Hiroshi; Tyagi, Madhusudan; Nagao, Michihiro; Yamamuro, Osamu

    2011-11-24

    We have investigated the mechanism of the first order transition and proton conductivity in copper rubeanate hydrates from microscopic and dynamical points of view. Three different types of neutron spectrometer-time-of-flight, backscattering, and neutron spin echo-were used to cover a wide dynamic range (1 ps to 100 ns). We found that the water molecules adsorbed in the pore are divided into "free water" having diffusion coefficients similar to those of bulk water at room temperature and "condensed water" which is about 10 times slower than bulk water owing to the interaction with the pore wall. The hydrogen atoms in the pore wall exhibited no relaxation within the measured time scales. The free water has, in the framework of the jump-diffusion model, smaller activation energy, longer residence time, and longer jump distance than bulk water. The neutron spin echo measurement revealed that the first order transition is a kind of liquid-liquid transition at which the free water is condensed on the pore surface in the low temperature phase. On cooling the condensed water, the relaxation time starts to deviate from the VFT equation around 200 K as previously observed in the water confined in nanoporous silicates. The free water plays an important role as the proton carrier but the proton conductivity is mainly governed by the number of protons provided into the adsorbed water from the pore wall.

  11. Quasi-elastic scattering, RPA, 2p2h and neutrino--energy reconstruction

    CERN Document Server

    Nieves, J; Sanchez, F; Vacas, M J Vicente

    2013-01-01

    We discuss some nuclear effects, RPA correlations and 2p2h (multinucleon) mechanisms, on charged-current neutrino-nucleus reactions that do not produce a pion in the final state. We study a wide range of neutrino energies, from few hundreds of MeV up to 10 GeV. We also examine the influence of 2p2h mechanisms on the neutrino energy reconstruction.

  12. Search for neutrino oscillations in the MINOS experiment by using quasi-elastic interactions

    Energy Technology Data Exchange (ETDEWEB)

    Piteira, Rodolphe [Univ. Pierre et Marie Curie, Paris (France)

    2005-09-29

    The enthusiasm of the scientific community for studying oscillations of neutrinos is equaled only by the mass of their detectors. The MINOS experiment determines and compares the near spectrum of muonic neutrinos from the NUMI beam to the far one, in order to measure two oscillation parameters: Δm$2\\atop{23}$ and sin2 (2θ23). The spectra are obtained by analyzing the charged current interactions which difficulty lies in identifying the interactions products (e.g. muons). An alternative method identifying the traces of muons, bent by the magnetic field of the detectors, and determining their energies is presented in this manuscript. The sensitivity of the detectors is optimal for the quasi-elastic interactions, for which a selection method is proposed, to study their oscillation. Even though it reduces the statistics, such a study introduces fewer systematic errors, constituting the ideal method on the long range.

  13. ATLAS Event Display: Light-by-Light Scattering

    CERN Multimedia

    ATLAS Collaboration

    2017-01-01

    An event display of light-by-light scattering in ultra-peripheral lead+lead collisions at 5.02 TeV with the ATLAS detector at the LHC. The event 461251458 from run 287931 recorded on 13 December 2015 at 09:51:07 is shown. Two back-to-back photons with an invariant mass of 24 GeV with no additional activity in the detector are presented. All calorimeter cells with E>500 MeV are shown.

  14. Industrial Particle Size Measurement Using Light Scattering

    Science.gov (United States)

    Muly, E. C.; Frock, H. N.

    1980-12-01

    The precise knowledge of particle size and particle size distribution is fundamental to the control of a wide variety of industrial processes. Processing steps as diverse as crystallization, grinding, emulsification, and atomization, produce particles in the size range .1 to 1000 micrometers in diameter. While the object of some processes may be the production of particles of specified sizes, e.g., abrasives and glass beads, other processes may require particle size control for process efficiency, e.g., crystallization, and still others for control of final product quality, e.g., minerals, cement, and ceramics. In many processes more than one of these reasons may be important. A line of instruments has been developed using light scattering to measure various parameters of particulate distributions. These instruments employ laser illumination of a flowing stream of particles, producing Fraunhofer diffraction patterns which are processed both optically and electronically with unique, proprietary techniques. Various parameters of the particle size distribution are measured. The measurement is both rapid and precise. This paper will cover the importance of particle size measurements in various processes, different types of measurement methods, and the application of light scattering technology to size determinations in wet slurries and dry powders. A number of specific applications will be discussed encompassing minerals grinding, Portland cement, and rolling mill emulsions. Some references will be made to energy savings through automation.

  15. Fourier transform light scattering angular spectroscopy using digital inline holography.

    Science.gov (United States)

    Kim, Kyoohyun; Park, YongKeun

    2012-10-01

    A simple and practical method for measuring the angle-resolved light scattering (ARLS) from individual objects is reported. Employing the principle of inline holography and a Fourier transform light scattering technique, both the static and dynamic scattering patterns from individual micrometer-sized objects can be effectively and quantitatively obtained. First, the light scattering measurements were performed on individual polystyrene beads, from which the refractive index and diameter of each bead were retrieved. Also, the measurements of the static and dynamic light scattering from intact human red blood cells are demonstrated. Using the present method, an existing microscope can be directly transformed into a precise instrument for ARLS measurements.

  16. Extinction and Scattering of Light by Magnetic Colloidal Nanoparticles

    Directory of Open Access Journals (Sweden)

    C.V. Yerin

    2015-12-01

    Full Text Available The peculiarities of scattering and extinction of light by colloids with different concentrations of magnetite nanoparticles are investigated. The light absorption effect on spectral dependencies of optical density of magnetic colloid are observed. According to dynamic light scattering experiments, particle size distributions for samples with different concentration of nanoparticles are defined.

  17. A novel full-angle scanning light scattering profiler to quantitatively evaluate forward and backward light scattering from intraocular lenses

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Bennett N., E-mail: bennett.walker@fda.hhs.gov [Optical Therapeutics and Medical Nanophotonics Laboratory, Office of Science and Engineering Laboratories, U.S. Food and Drug Administration, Silver Spring, Maryland 20993 (United States); Office of Device Evaluation, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, Maryland 20993 (United States); James, Robert H.; Ilev, Ilko K. [Optical Therapeutics and Medical Nanophotonics Laboratory, Office of Science and Engineering Laboratories, U.S. Food and Drug Administration, Silver Spring, Maryland 20993 (United States); Calogero, Don [Office of Device Evaluation, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, Maryland 20993 (United States)

    2015-09-15

    Glare, glistenings, optical defects, dysphotopsia, and poor image quality are a few of the known deficiencies of intraocular lenses (IOLs). All of these optical phenomena are related to light scatter. However, the specific direction that light scatters makes a critical difference between debilitating glare and a slightly noticeable decrease in image quality. Consequently, quantifying the magnitude and direction of scattered light is essential to appropriately evaluate the safety and efficacy of IOLs. In this study, we introduce a full-angle scanning light scattering profiler (SLSP) as a novel approach capable of quantitatively evaluating the light scattering from IOLs with a nearly 360° view. The SLSP method can simulate in situ conditions by controlling the parameters of the light source including angle of incidence. This testing strategy will provide a more effective nonclinical approach for the evaluation of IOL light scatter.

  18. Measurement of Dynamic Light Scattering Intensity in Gels

    CERN Document Server

    Rochas, Cyrille

    2015-01-01

    In the scientific literature little attention has been given to the use of dynamic light scattering (DLS) as a tool for extracting the thermodynamic information contained in the absolute intensity of light scattered by gels. In this article we show that DLS yields reliable measurements of the intensity of light scattered by the thermodynamic fluctuations, not only in aqueous polymer solutions, but also in hydrogels. In hydrogels, light scattered by osmotic fluctuations is heterodyned by that from static or slowly varying inhomogeneities. The two components are separable owing to their different time scales, giving good experimental agreement with macroscopic measurements of the osmotic pressure. DLS measurements in gels are, however, tributary to depolarised light scattering from the network as well as to multiple light scattering. The paper examines these effects, as well as the instrumental corrections required to determine the osmotic modulus. For guest polymers trapped in a hydrogel the measured intensity...

  19. How to distinguish elastically scattered light from Stokes shifted light for solid-state lighting?

    NARCIS (Netherlands)

    Meretska, M. L.; Lagendijk, A.; Thyrrestrup, H.; Mosk, A. P.; IJzerman, W. L.; Vos, W.L.

    2016-01-01

    We have studied the transport of light through phosphor diff user plates that are used in commercial solid-state lighting modules (Fortimo). These polymer plates contain YAG:Ce+3 phosphor particles that both elastically scatter and Stokes shift light in the visible wavelength range (400-700 nm). We

  20. Miniature instrumentation for laser light scattering experiments

    Science.gov (United States)

    Brown, Robert G. W.

    1989-01-01

    Traditional optical systems for photon correlation spectroscopy and laser anemometry have relied upon physically large and fairly expensive lasers, bulk-optics such as lenses of a few inches diameter, large mechanical mounts and carefully selected, fragile and bulky photon counting photomultiplier detectors. In some cases, experimental fluid dynamics at a desired position in a flow, perhaps deep inside complex machinery, is physically impossible or very difficult. Similar problems exist with photon correlation spectroscopy, e.g., remote and heterodyne experiments. Various optical and electro optical components were investigated and characterized with the aim of replacing existing photon correlation laser spectroscopy and anemometry techniques in miniaturized form, and with significant cost reduction. Very recently, a range of miniature, modular light scattering systems were constructed from little solid state optical and electro optical components, and experimentally verified measurement performance comparable to standard lab photon correlation spectroscopy and laser anemometry equipment.

  1. The Measurement of Neutrino Induced Quasi-Elastic Cross Section In NOMAD

    CERN Document Server

    Kim, Jae Jun

    2010-01-01

    NOMAD (Neutrino Oscillation MAgnetic Detector) was a short baseline neutrino experiment conducted at CERN (the European Laboratory for Particle physics) West Area Neutrino Facility (WANF) with a neutrino beam provided by the super proton synchrotron (SPS) accelerator. In this dissertation, we present a measurement of muon-neutrino induced quasi-elastic cross section and its axial-mass off an isoscalar target in the NOMAD detector. The incident neutrino energy in NOMAD experiment spans from 2.5 to 300 GeV. The measurement of cross-section is conducted in two seperate kinematic-based topology, two-track and one-track topologies, where a proton is not properly reconstructed. The QEL cross-section as a function of the incoming neutrino energy is consistent for the two different topologies, and within errors , constant as a function of the neutrino energy. We determine the energy-averaged cross-section. From the shape-comparisons of kinematics of QEL-like events, the parameter of QEL axial mass is estimated. It i...

  2. Measurement of the Charged-Current Quasi-Elastic Cross-Section for Electron Neutrinos on a Hydrocarbon Target

    Energy Technology Data Exchange (ETDEWEB)

    Wolcott, Jeremy [Univ. of Rochester, NY (United States)

    2016-01-01

    Appearance-type neutrino oscillation experiments, which observe the transition from muon neutrinos to electron neutrinos, promise to help answer some of the fundamental questions surrounding physics in the post-Standard-Model era. Because they wish to observe the interactions of electron neutrinos in their detectors, and because the power of current results is typically limited by their systematic uncertainties, these experiments require precise estimates of the cross-section for electron neutrino interactions. Of particular interest is the charged-current quasi-elastic (CCQE) process, which gures signi cantly in the composition of the reactions observed at the far detector. However, no experimental measurements of this crosssection currently exist for electron neutrinos; instead, current experiments typically work from the abundance of muon neutrino CCQE cross-section data and apply corrections from theoretical arguments to obtain a prediction for electron neutrinos. Veri cation of these predictions is challenging due to the di culty of constructing an electron neutrino beam, but the advent of modern high-intensity muon neutrino beams|together with the percent-level electron neutrino impurity inherent in these beams| nally presents the opportunity to make such a measurement. We report herein the rst-ever measurement of a cross-section for an exclusive state in electron neutrino scattering, which was made using the MINER A detector in the NuMI neutrino beam at Fermilab. We present the electron neutrino CCQE di erential cross-sections, which are averaged over neutrinos of energies 1-10 GeV (with mean energy of about 3 GeV), in terms of various kinematic variables: nal-state electron angle, nal-state electron energy, and the square of the fourmomentum transferred to the nucleus by the neutrino , Q2. We also provide a total cross-section vs. neutrino energy. While our measurement of this process is found to be in agreement with the predictions of the GENIE

  3. Measurement of the $M_A^{QE}$ parameter using multiple quasi-elastic dominated sub-samples in the minos near detector

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, Nathan Samuel [Indiana Univ., Bloomington, IN (United States)

    2011-12-05

    The Main Injector Neutrino Oscillation Search (MINOS) is a two detector, long baseline neutrino oscillation experiment. The MINOS near detector is an ironscintillator tracking/sampling calorimeter and has recorded the world’s largest data set of neutrino interactions in the 0-5 GeV region. This high statistics data set is used to make precision measurements of neutrino interaction cross-sections on iron. The Q2 dependence in charged current quasi-elastic (CCQE) scattering probes the axial and vector structure (form factor) of the nucleon/nuclear target, and nuclear effects in neutrino scattering. Presented here is a study of the MINOS Data that will introduce a method that improves the existing MINOS CCQE analysis. This analysis uses an additional CCQE dominated sub-sample from a different kinematic region to reduce correlations between fit parameters in the existing MINOS CCQE analysis. The measured value of the axial-vector mass is MQE A = 1.312+0.037 -0.038(fit)+0.123 -0.265(syst.) GeV.

  4. Scattering of light by charged colloidal particles in salt solutions

    NARCIS (Netherlands)

    Vrij, A.; Overbeek, J.Th.G.

    1962-01-01

    In the interpretation of light scattering by colloidal electrolytes in salt solutions the interaction between the colloidal particles and the low molecular weight ions has to be taken into account. When fluctuation theory is applied for the derivation of a light-scattering equation, nonelectroneutra

  5. Utility of light scatter in the morphological analysis of sperm

    Science.gov (United States)

    We were able to differentiate the morphologically diverse sperm nuclei of four animal species by using an Ortho flow cytometer to detect the forward light scatter from a red (helium-neon) laser. Cytograms depicting the axial light loss and forward red scatter signals revealed uni...

  6. Light scattering by neutrophils: Model, simulation, and experiment

    NARCIS (Netherlands)

    Orlova, D.Y.; Yurkin, M.A.; Hoekstra, A.G.; Maltsev, V.P.

    2008-01-01

    We studied the elastic light-scattering properties of human blood neutrophils, both experimentally and theoretically. The experimental study was performed with a scanning flow cytometer measuring the light-scattering patterns (LSPs) of individual cells over an angular range of 5-60 deg. We determine

  7. Light scattering by marine heterotrophic bacteria

    Science.gov (United States)

    Ulloa, Osvaldo; Sathyendranath, Shubha; Platt, Trevor; Quinones, Renato A.

    1992-01-01

    Mie theory is applied to estimate scattering by polydispersions of marine heterotrophic bacteria, and a simple expression is derived for the bacterial scattering coefficient. The error incurred in deriving bacterial optical properties by use of the van de Hulst approximations is computed. The scattering properties of natural bacterial assemblages in three marine environments, Georges Bank, Northeast Channel, and Sargasso Sea, are assessed by applying Mie theory to field data on bacterial size and abundance. Results are used to examine the potential contribution of bacteria to the scattering properties of seawater. The utility of using pigment data to predict the magnitude of scattering by bacteria is discussed.

  8. Improved algorithm of light scattering by a coated sphere

    Institute of Scientific and Technical Information of China (English)

    Lei Liu; Huarui Wang; Bin Yu; Yamin Xu; Jianqi Shen

    2007-01-01

    An efficient numerical algorithm for computing the light scattering by a coated sphere is proposed. The calculation of relevant functions by different recurrence algorithms is discussed. The new algorithm avoids the numerical difficulties, which give rise to significant errors encountered in practice by prior methods. Exemplifying results such as extinction efficiency, scattering efficiency, light scattering intensity as well as calculation speed are provided. The results show that this algorithm is efficient, fast, numerically stable and accurate.

  9. Scattering of light by a system of anisotropic particles.

    Science.gov (United States)

    Du, Xinyue; Zhao, Daomu

    2010-05-15

    The cross-spectral density function of the scattered field that is produced by scattering of a coherent plane light wave incident on a collection of different types of anisotropic particles is derived. We show the phenomena of interference of the fields scattered by each of the particles in the system. Numerical results indicate that the information about the shape, the distance, and the relative orientation of the particles may be obtained from far-zone measurements of the scattered field.

  10. Macrovoids formation and light scattering of PMMA

    Indian Academy of Sciences (India)

    Zhi Hong Chen; Z C Chang; C B Lin

    2007-08-01

    After desorption of PMMA with saturated methanol and ethanol and then desorption by distilled water, the macrovoids are formed because of the phase inversion. The macrovoids on the surface of the specimens are larger and more numerous than those in the bulk. The macrovoids are likely to be closed-type, if the hydrolysis temperature is lower. On the other hand, if the hydrolysis temperature is higher, the macrovoids are likely to be open-type. Due to the formation of macrovoids, smaller than visible wavelengths, the light will disperse, and therefore, reduces the transmittance of the specimens. The transmittance is decreased when the hydrolysis temperature and hydrolysis time are increased. Furthermore, it is much clearer when ethanol is used as solvent than methanol. The scattered intensity of the specimens after hydrolysis is inversely proportional to the visible wavelength with an exponent, , in the range 0.04–2.83 for methanol and 0.02–0.21 for ethanol.

  11. Light scattering of thin azobenzene side-chain polyester layers

    DEFF Research Database (Denmark)

    Kerekes, Á.; Lörincz, E.; Ramanujam, P.S.

    2002-01-01

    characteristics than the liquid crystalline polyester. The amorphous samples have negligible polarization part orthogonal to the incident beam. the liquid crystalline samples have relative high orthogonal polarization part in light scattering, The light scattering results can be used to give a lower limit...... for the domain size in thin liquid crystalline polyester layers being responsible for the dominant light scattering. The characteristic domain Sizes obtained from the Fourier transformation of polarization microscopic Pictures confirm these values.......Light scattering properties of liquid crystalline and amorphous azobenzene side-chain polyester layers used for optical data storage were examined by means of transmissive scatterometry. Comparative experiments show that the amorphous polyester has significantly lower light scattering...

  12. Study of erythrocyte membrane fluctuation using light scattering analysis

    Science.gov (United States)

    Lee, Hoyoon; Lee, Sangyun; Park, YongKeun; Shin, Sehyun

    2016-03-01

    It is commonly known that alteration of erythrocyte deformability lead to serious microcirculatory diseases such as retinopathy, nephropathy, etc. Various methods and technologies have been developed to diagnose such membrane properties of erythrocytes. In this study, we developed an innovative method to measure hemorheological characteristics of the erythrocyte membrane using a light scattering analysis with simplified optic setting and multi-cell analysis as well. Light scattering intensity through multiple erythrocytes and its power density spectrum were obtained. The results of light scattering analyses were compared in healthy control and artificially hardened sample which was treated with glutaraldehyde. These results were further compared with conventional assays to measure deformable property in hemorheology. We found that light scattering information would reflect the disturbance of membrane fluctuation in artificially damaged erythrocytes. Therefore, measuring fluctuation of erythrocyte membrane using light scattering signal could facilitate simple and precise diagnose of pathological state on erythrocyte as well as related complications.

  13. Positron Production in Multiphoton Light-by-Light Scattering

    Energy Technology Data Exchange (ETDEWEB)

    Koffas, Thomas

    2003-07-28

    We present the results of an experimental study on e{sup +}e{sup -} pair production during the collision of a low emittance 46.6 GeV electron beam with terawatt laser pulses from a Nd:glass laser at 527 nm wavelength and with linear polarization. The experiment was conducted at the Final Focus Test Beam facility in the Stanford Linear Accelerator Center. Results with a 49.1 GeV electron beam are also included. A signal of 106 {+-} 14 positrons for the 46.6 GeV electron beam case and of 22 {+-} 10 positrons for the 49.1 GcV case above background, has been detected. We interpret the positrons as the products of a two-step process during which laser photons are backscattered to high energy gamma photons that absorb in their turn several laser photons in order to produce a e{sup +}e{sup -} pair. The data compare well with the existing theoretical models. This is the first observation in the laboratory of inelastic Light-by-Light scattering with only real photons. Alternatively, the data are interpreted as a manifestation of the spontaneous breakdown of the vacuum under the influence of an intense external alternating electric field.

  14. Multiangle static and dynamic light scattering in the intermediate scattering angle range

    CERN Document Server

    Tamborini, Elisa

    2012-01-01

    We describe a light scattering apparatus based on a novel optical scheme covering the scattering angle range $0.5\\dg \\le \\theta \\le 25\\dg$, an intermediate regime at the frontier between wide angle and small angle setups that is difficult to access by existing instruments. Our apparatus uses standard, readily available optomechanical components. Thanks to the use of a charge-coupled device detector, both static and dynamic light scattering can be performed simultaneously at several scattering angles. We demonstrate the capabilities of our apparatus by measuring the scattering profile of a variety of samples and the Brownian dynamics of a dilute colloidal suspension.

  15. Dynamics in γ-Fe2O3 nanoparticles studied by time-of-flight polarized neutron scattering

    DEFF Research Database (Denmark)

    Kuhn, L.T.; Lefmann, K.; Klausen, S.N.;

    2004-01-01

    The inelastic neutron-scattering signal from magnetic nanoparticles contains information on magnetic dynamics like superparamagnetic relaxation and collective magnetic excitations. Often another, very broad quasi-elastic component is observed in addition. We have studied this quasi-elastic neutro...... of disordered surface spins and vibrations of individual nanoparticles. (C) 2004 Elsevier B.V. All rights reserved....

  16. Light scattering in Baltic crude oil - seawater emulsion

    Directory of Open Access Journals (Sweden)

    Adam Stelmaszewski

    2009-09-01

    Full Text Available The paper discusses the scattering of radiation by a Baltic crude oil - seawater emulsion. The scattering spectrum calculated using the Mie solution in the spectral range from 380 nm to 730 nm is compared with the measured spectrum of light scattered through a right angle. Spectra in the wavelength range from 210 nm to 730 nm were measured using a spectrofluorimeter for fresh and stored samples of the Baltic crude oil emulsion. Scattering increases with wavelength in the UV range and then decreases slightly with the wavelength of visible light. The result of the calculation is similar to the measured spectra. Both the calculated and measured spectra display numerous relative extremes throughout the spectral area. Light scattering in the emulsion decreases during storage as the oil concentration in the medium diminishes. The results also demonstrate that the single scattering model describes the phenomenon correctly.

  17. Effects of cellular fine structure on scattered light pattern.

    Science.gov (United States)

    Liu, Caigen; Capjack, Clarence E

    2006-06-01

    Biological cells are complex in both morphological and biochemical structure. The effects of cellular fine structure on light scattered from cells are studied by employing a three-dimensional code named AETHER which solves the full set of Maxwell equations by using the finite-difference time-domain method. It is shown that changes in cellular fine structure can cause significant changes in the scattered light pattern over particular scattering angles. These changes potentially provide the possibility for distinguishability of cellular intrastructures. The effects that features of different intrastructure have on scattered light are discussed from the viewpoint of diagnosing cellular fine structure. Finally, we discuss scattered light patterns for lymphocyte-like cells and basophil-like cells.

  18. Origin of light scattering variations of a latent flaw through light scattering measurement with applied stress effect

    Science.gov (United States)

    Sakata, Yoshitaro; Terasaki, Nao; Sakai, Kazufumi; Nonaka, Kazuhiro

    2016-11-01

    The stress-induced light scattering method (SILSM) was proposed for inspecting surface to detect polishing induced latent flaws. In this study, in order to clarify the mechanism of the light scattering intensity variation of latent flaws using SILSM, we have investigated stress effect of light scattering intensities using polarized light system and calculated the reflectance and the retardation using Jones matrix. As the results, we evaluated the change in the birefringence around a tip of a latent flaw between before and after stress were applied.

  19. Absorption and scattering of light by small particles

    CERN Document Server

    Bohren, Craig F

    1983-01-01

    Absorption and Scattering of Light by Small Particles. Treating absorption and scattering in equal measure, this self-contained, interdisciplinary study examines and illustrates how small particles absorb and scatter light. The authors emphasize that any discussion of the optical behavior of small particles is inseparable from a full understanding of the optical behavior of the parent material-bulk matter. To divorce one concept from the other is to render any study on scattering theory seriously incomplete. Special features and important topics covered in this book include:. * Classical theor

  20. Light scattering by nonspherical particles theory, measurements, and applications

    CERN Document Server

    Mishchenko, Michael I; Travis, Larry D

    1999-01-01

    There is hardly a field of science or engineering that does not have some interest in light scattering by small particles. For example, this subject is important to climatology because the energy budget for the Earth's atmosphere is strongly affected by scattering of solar radiation by cloud and aerosol particles, and the whole discipline of remote sensing relies largely on analyzing the parameters of radiation scattered by aerosols, clouds, and precipitation. The scattering of light by spherical particles can be easily computed using the conventional Mie theory. However, most small solid part

  1. Correlating the morphological and light scattering properties of biological cells

    Science.gov (United States)

    Moran, Marina

    The scattered light pattern from a biological cell is greatly influenced by the internal structure and optical properties of the cell. This research project examines the relationships between the morphological and scattering properties of biological cells through numerical simulations. The mains goals are: (1) to develop a procedure to analytically model biological cells, (2) to quantitatively study the effects of a range of cell characteristics on the features of the light scattering patterns, and (3) to classify cells based on the features of their light scattering patterns. A procedure to create an analytical cell model was developed which extracted structural information from the confocal microscopic images of cells and allowed for the alteration of the cell structure in a controlled and systematic way. The influence of cell surface roughness, nuclear size, and mitochondrial volume density, spatial distribution, size and shape on the light scattering patterns was studied through numerical simulations of light scattering using the Discrete Dipole Approximation. It was found that the light scattering intensity in the scattering angle range of 25° to 45° responded to changes in the surface fluctuation of the cell and the range of 90° to 110° was well suited for characterization of mitochondrial density and nuclear size. A comparison of light scattering pattern analysis methods revealed that the angular distribution of the scattered light and Gabor filters were most helpful in differentiating between the cell characteristics. In addition, a measured increase in the Gabor energy of the light scattering patterns in response to an increase in the complexity of the cell models suggested that a complex nuclear structure and mitochondria should be included when modeling biological cells for light scattering simulations. Analysis of the scattering pattern features with Gabor filters resulted in discrimination of the cell models according to cell surface roughness

  2. Light scattering by particles in water theoretical and experimental foundations

    CERN Document Server

    Jonasz, Miroslaw

    2007-01-01

    Light scattering-based methods are used to characterize small particles suspended in water in a wide range of disciplines ranging from oceanography, through medicine, to industry. The scope and accuracy of these methods steadily increases with the progress in light scattering research. This book focuses on the theoretical and experimental foundations of the study and modeling of light scattering by particles in water and critically evaluates the key constraints of light scattering models. It begins with a brief review of the relevant theoretical fundamentals of the interaction of light with condensed matter, followed by an extended discussion of the basic optical properties of pure water and seawater and the physical principles that explain them. The book continues with a discussion of key optical features of the pure water/seawater and the most common components of natural waters. In order to clarify and put in focus some of the basic physical principles and most important features of the experimental data o...

  3. Measurements and interpretations of light scattering from intact biological cells

    Science.gov (United States)

    Wilson, Jeremy D.

    Visible light interacts with biological cells primarily through elastic scattering. The details of how cells scatter light depend on their morphology and their substructures. In this thesis we first present a series of experiments and models to discern the specific contributions of certain sub-cellular constituents to whole-cell scattering. Exploiting the findings of those studies, we report on experiments within model systems of cell death that demonstrate the potential of light scattering measurements as a tool in modern biology. Instrumentation capable of exploiting the findings of this thesis from a biology-relevant microscopy platform is designed and developed. A Mie theory based interpretation of light scattering signals originating from a collection of particles with a broad size distribution is developed. Upon applying this model to scattering data from intact cells, we find that it robustly extracts the size scale of dominant light scattering particles, suggests that scattering measurements are sensitive primarily to mitochondrial and lysosomal morphology, and unites conflicting results in the literature. Using this model as a basis, we present a collection of studies in which we use various strategies of photodynamic therapy (PDT) as a biophysical tool to perturb mitochondria and lysosomes, and observe the effects of these perturbations on whole-cell scattering. Through these experiments, we are able to discern the individual contributions of mitochondria and lysosomes to whole-cell light scattering, and demonstrate that mitochondria are responsible for roughly 80% of the scattering signal. Results of experiments aimed at demonstrating the potential role that light scattering measurements have to play in future studies of cell death biology are presented. We first show that mitochondrial-PDT-induced morphology changes measured with light scattering map into the cell killing efficacy of the therapy. We next demonstrate that mitochondrial

  4. Interactive directional subsurface scattering and transport of emergent light

    DEFF Research Database (Denmark)

    Dal Corso, Alessandro; Frisvad, Jeppe Revall; Mosegaard, Jesper;

    2016-01-01

    -based analytical models for subsurface scattering but also directional models. In addition, our method enables easy extraction of virtual point lights for transporting emergent light to the rest of the scene. Our method requires neither preprocessing nor texture parameterization of the translucent objects...... is the first to include interactive transport of emergent light from deformable translucent objects....

  5. Light scattering from exoplanet oceans and atmospheres

    CERN Document Server

    Zugger, Michael E; Williams, Darren M; Kane, Timothy J; Philbrick, C Russell

    2010-01-01

    Orbital variation in polarized and unpolarized reflected starlight from exoplanets could eventually be used to detect liquid water on planet surfaces. Exoplanets with rough surfaces, or those dominated by atmospheric Rayleigh scattering, should reach peak brightness in full phase, orbital longitude (OL) = 180 degrees, whereas ocean-covered planets with transparent atmospheres should reach peak brightness in crescent phase near OL = 30 degrees. Application of Fresnel theory to a planet with no atmosphere covered by a calm ocean predicts a peak polarization fraction of 1 at OL = 74 degrees; however, our model shows that clouds, wind-driven waves, aerosols, absorption, and Rayleigh scattering in the atmosphere and within the water column, dilute the polarization fraction and shift the peak to other OLs. Observing at longer wavelengths reduces the obfuscation of the water polarization signature by Rayleigh scattering but does not mitigate the other effects. Planets with thick Rayleigh scattering atmospheres reach...

  6. Light Scattering by Optically Soft Particles Theory and Applications

    CERN Document Server

    Sharma, Subodh K

    2006-01-01

    The present monograph deals with a particular class of approximation methods in the context of light scattering by small particles. This class of approximations has been termed as eikonal or soft particle approximations. The eikonal approximation was studied extensively in the potential scattering and then adopted in optical scattering problems. In this context, the eikonal and other soft particle approximations pertain to scatterers whose relative refractive index compared to surrounding medium is close to unity. The study of these approximations is very important because soft particles occur abundantly in nature. For example, the particles that occur in ocean optics, biomedical optics, atmospheric optics and in many industrial applications can be classified as soft particles. This book was written in recognition of the long-standing and current interest in the field of scattering approximations for soft particles. It should prove to be a useful addition for researchers in the field of light scattering.

  7. Modelling of classical ghost images obtained using scattered light

    Science.gov (United States)

    Crosby, S.; Castelletto, S.; Aruldoss, C.; Scholten, R. E.; Roberts, A.

    2007-08-01

    The images obtained in ghost imaging with pseudo-thermal light sources are highly dependent on the spatial coherence properties of the incident light. Pseudo-thermal light is often created by reducing the coherence length of a coherent source by passing it through a turbid mixture of scattering spheres. We describe a model for simulating ghost images obtained with such partially coherent light, using a wave-transport model to calculate the influence of the scattering on initially coherent light. The model is able to predict important properties of the pseudo-thermal source, such as the coherence length and the amplitude of the residual unscattered component of the light which influence the resolution and visibility of the final ghost image. We show that the residual ballistic component introduces an additional background in the reconstructed image, and the spatial resolution obtainable depends on the size of the scattering spheres.

  8. Selective scattering polymer dispersed liquid crystal film for light enhancement of organic light emitting diode.

    Science.gov (United States)

    Jiang, Jinghua; McGraw, Greg; Ma, Ruiqing; Brown, Julie; Yang, Deng-Ke

    2017-02-20

    We developed a novel light enhancing film for an organic light emitting diode (OLED) based on polymer dispersed liquid crystal (PDLC). In the film, the liquid crystal droplets are unidirectionally aligned along the film normal direction and exhibit selective scattering. The film scatters light emitted only in directions with large incident angles but not light emitted in directions with small incident angles. When the light is scattered, it changes propagation direction and exits the OLED. The PDLC film reduces the total internal reflection and thus can significantly increase the light efficiency of the OLED.

  9. Surface magnetism studied by polarized light emission after He+ scattering

    NARCIS (Netherlands)

    Manske, J; Dirska, M; Lubinski, G; Schleberger, M; Narmann, A; Hoekstra, R

    1997-01-01

    Surface magnetism is studied by means of an ion beam of low energy (2-15 keV) scattered off the surface under grazing incidence conditions. During the scattering, a small fraction of the ions is neutralized into excited states which decay subsequently by light emission. The circular polarization of

  10. Light scattering from polymer solutions and nanoparticle dispersions

    CERN Document Server

    Schärtl, Wolfgang; Janca, Josef

    2007-01-01

    Light scattering is a very powerful method to characterize the structure of polymers and nanoparticles in solution. Recent technical developments have strongly enhanced the possible applications of this technique, overcoming previous limitations like sample turbidity or insufficient experimental time scales. However, despite their importance, these new developments have not yet been presented in a comprehensive form. In addition, and maybe even more important to the broad audience, there lacks a simple-to-read textbook for students and non-experts interested in the basic principles and fundamental techniques of light scattering. As part of the Springer Laboratory series, this book tries not only to provide such a simple-to-read and illustrative textbook about the seemingly very complicated topic of light scattering from polymers and nanoparticles in dilute solution, but also intends to cover some of the newest technical developments in experimental light scattering.

  11. Light scattering by neutrophils: model, simulation, and experiment.

    Science.gov (United States)

    Orlova, Darya Yu; Yurkin, Maxim A; Hoekstra, Alfons G; Maltsev, Valeri P

    2008-01-01

    We studied the elastic light-scattering properties of human blood neutrophils, both experimentally and theoretically. The experimental study was performed with a scanning flow cytometer measuring the light-scattering patterns (LSPs) of individual cells over an angular range of 5-60 deg. We determined the absolute differential light-scattering cross sections of neutrophils. We also proposed an optical model for a neutrophil as a sphere filled by small spheres and prolate spheroids that correspond to granules and segmented nucleus, respectively. This model was used in simulations of LSPs using the discrete dipole approximation and different compositions of internal organelles. A comparison of experimentally measured and simulated LSPs gives a good qualitative agreement in LSP shape and quantitative agreement in overall magnitude of the differential light-scattering cross section.

  12. Light projectile scattering off the Color Glass Condensate

    CERN Document Server

    Fukushima, Kenji

    2007-01-01

    We systematically compute the expectation value of Wilson lines in the McLerran-Venugopalan model, which provides useful formulae for evaluation of the scattering aimplitude in the collision of a light projectile and a heavy target.

  13. Analytic expression for in-field scattered light distribution

    Science.gov (United States)

    Peterson, Gary L.

    2004-01-01

    Light that is scattered from lenses and mirrors in an optical system produces a halo of stray light around bright objects within the field of view. The angular distribution of scattered light from any one component is usually described by the Harvey model. This paper presents analytic expressions for the scattered irradiance at a focal plane from optical components that scatter light in accordance with the Harvey model. It is found that the irradiance is independent of the location of an optical element within the system, provided the element is not located at or near an intermediate image plane. It is also found that the irradiance has little or no dependence on the size of the element.

  14. Efficient light propagation for multiple anisotropic volume scattering

    Energy Technology Data Exchange (ETDEWEB)

    Max, N. [Lawrence Livermore National Lab., CA (United States)]|[California Univ., Davis, CA (United States)

    1993-12-01

    Realistic rendering of participating media like clouds requires multiple anisotropic light scattering. This paper presents a propagation approximation for light scattered into M direction bins, which reduces the ``ray effect`` problem in the traditional ``discrete ordinates`` method. For a volume of n{sup 3} elements, it takes O(M n{sup 3} log n + M{sup 2} n{sup 3}) time and O(M n{sup 3}) space.

  15. Synthesis of aerogel tiles with high light scattering length

    CERN Document Server

    Danilyuk, A F; Okunev, A G; Onuchin, A P; Shaurman, S A

    1999-01-01

    The possibility of aerogel tiles production for RICH detectors is described. Monolithic blocks of silica aerogel were synthesized by two-step sol-gel processing of tetraethoxysilane Si(OEt) sub 4 followed by high temperature supercritical drying with organic solvent. The important characteristic of aerogel is the light scattering length. In the wide range of refraction indexes the light scattering length exceeds 4 cm at 400 nm.

  16. Evaluation of advanced light scattering technology for microgravity experiments

    Science.gov (United States)

    Fredericks, W. J.; Rosenblum, W. M.

    1990-01-01

    The capabilities of modern light scattering equipment and the uses it might have in studying processes in microgravity are evaluated. Emphasis is on the resolution of polydisperse systems. This choice was made since a major use of light scattering was expected to be the study of crystal growth of macromolecules in low gravity environments. An evaluation of a modern photon correlation spectrometer and a Mie spectrometer is presented.

  17. Light-by-light scattering in ultraperipheral Pb-Pb collisions at energies available at the CERN Large Hadron Collider

    Science.gov (United States)

    Kłusek-Gawenda, Mariola; Lebiedowicz, Piotr; Szczurek, Antoni

    2016-04-01

    We calculate cross sections for diphoton production in (semi)exclusive PbPb collisions, relevant for the CERN Large Hadron Collider (LHC). The calculation is based on the equivalent photon approximation in the impact parameter space. The cross sections for the elementary γ γ →γ γ subprocess are calculated including two different mechanisms. We take into account box diagrams with leptons and quarks in the loops. In addition, we consider a vector-meson dominance (VDM-Regge) contribution with virtual intermediate hadronic (vector-like) excitations of the photons. We get measurable cross sections in PbPb collisions. This opens a possibility to study the γ γ →γ γ (quasi)elastic scattering at the LHC. We present many interesting differential distributions which could be measured by the ALICE, CMS, or ATLAS Collaborations at the LHC. We study whether a separation or identification of different components (boxes, VDM-Regge) is possible. We find that the cross section for elastic γ γ scattering could be measured in the heavy-ion collisions for subprocess energies smaller than Wγ γ≈15 -20 GeV.

  18. Visible light scatter as quantitative information source on milk constituents

    DEFF Research Database (Denmark)

    Melentieva, Anastasiya; Kucheryavskiy, Sergey; Bogomolov, Andrey

    2012-01-01

    -time monitoring of processes and products. Optical analysis is generally performed in near and middle infrared (NIR and MIR) regions and relies on the component absorbance and Beer’s Law. The light scatter effect is therefore considered as a disturbance to be avoided during the measurement or eliminated...... at the data analysis stage. The region of visible (Vis) light (400-800 nm) is economically attractive, because it offers a range of inexpensive light sources, optics and detectors. At present, however, it is commonly considered useless, because of the light scatter by fat globules (1-10 μm) and protein...

  19. Polysaccharide characterization by hollow-fiber flow field-flow fractionation with on-line multi-angle static light scattering and differential refractometry.

    Science.gov (United States)

    Pitkänen, Leena; Striegel, André M

    2015-02-06

    Accurate characterization of the molar mass and size of polysaccharides is an ongoing challenge, oftentimes due to architectural diversity but also to the broad molar mass (M) range over which a single polysaccharide can exist and to the ultra-high M of many polysaccharides. Because of the latter, many of these biomacromolecules experience on-column, flow-induced degradation during analysis by size-exclusion and, even, hydrodynamic chromatography (SEC and HDC, respectively). The necessity for gentler fractionation methods has, to date, been addressed employing asymmetric flow field-flow fractionation (AF4). Here, we introduce the coupling of hollow-fiber flow field-flow fractionation (HF5) to multi-angle static light scattering (MALS) and differential refractometry (DRI) detection for the analysis of polysaccharides. In HF5, less stresses are placed on the macromolecules during separation than in SEC or HDC, and HF5 can offer a higher sensitivity, with less propensity for system overloading and analyte aggregation, than generally found in AF4. The coupling to MALS and DRI affords the determination of absolute, calibration-curve-independent molar mass averages and dispersities. Results from the present HF5/MALS/DRI experiments with dextrans, pullulans, and larch arabinogalactan were augmented with hydrodynamic radius (RH) measurements from off-line quasi-elastic light scattering (QELS) and by RH distribution calculations and fractogram simulations obtained via a finite element analysis implementation of field-flow fractionation theory by commercially available software. As part of this study, we have investigated analyte recovery in HF5 and also possible reasons for discrepancies between calculated and simulated results vis-à-vis experimentally determined data.

  20. Application of light scattering to coatings a user's guide

    CERN Document Server

    Diebold, Michael P

    2014-01-01

    The book begins with the fundamentals of light scattering, first by individual particles, then by small groups of particles, and finally by the trillions of particles present in a real-life paint film. From there, Dr. Diebold focuses on application of these fundamentals to paint formulation. The scope includes both theory and practice with an emphasis on application (from both performance and cost standpoints). The book gives a clear understanding of light scattering principles and application of these principles to paint formulation (with a focus on TiO2 - the strongest scattering material a

  1. Backward elastic light scattering of malaria infected red blood cells

    Science.gov (United States)

    Lee, Seungjun; Lu, Wei

    2011-08-01

    We investigated the backward light scattering pattern of healthy and malaria (Plasmodium falciparum) parasitized red blood cells. The spectrum could clearly distinguish between predominant ring stage infected blood cells and healthy blood cells. Further, we found that infected samples mixed with different stages of P. falciparum showed different signals, suggesting that even variance in parasite stages could also be detected by the spectrum. These results together with the backward scattering technique suggest the potential of non-invasive diagnosis of malaria through light scattering of blood cells near the surface of human body, such as using eyes or skin surface.

  2. Scaling in light scattering by sharp conical metal tips

    CERN Document Server

    Pors, Anders; Bozhevolnyi, Sergey I

    2016-01-01

    Using the electrostatic approximation, we analyze electromagnetic fields scattered by sharp conical metal tips, which are illuminated with light polarized along the tip axis. We establish scaling relations for the scattered field amplitude and phase, whose validity is verified with numerical simulations. Analytic expressions for the wavelength, at which the scattered field near the tip changes its direction, and field decay near the tip extremity are obtained, relating these characteristics to the cone angle and metal permittivity. The results obtained have important implications to various tip-enhanced phenomena, ranging from Raman and scattering near-field imaging to photoemission spectroscopy and nano-optical trapping.

  3. How to distinguish elastically scattered light from Stokes shifted light for solid-state lighting?

    CERN Document Server

    Meretska, M; Thyrrestrup, H; Mosk, A P; IJzerman, W L; Vos, W L

    2015-01-01

    We have studied the transport of light through phosphor diffuser plates that are used in commercial solid-state lighting modules (Fortimo). These polymer plates contain $\\mathrm{YAG:Ce}^{+3}$ phosphor particles that elastically scatter light and Stokes shifts it in the visible wavelength range (400-700 nm). We excite the phosphor with a narrowband light source, and measure spectra of the outgoing light. The Stokes shifted light is separated from the elastically scattered light in the measured spectra and using this technique we isolate the elastic transmission of the plates. This result allows us to extract the transport mean free path $l_{\\mathrm{tr}}$ over the full wavelength range by employing diffusion theory. Simultaneously, we determine the absorption mean free path $l_{\\mathrm{abs}}$ in the wavelength range 400 to 530 nm where $\\mathrm{YAG:Ce}^{+3}$ absorbs. The diffuse absorption $\\mu_{\\mathrm{a}} =\\frac{1}{l_{\\mathrm{abs}}}$ spectrum is qualitative similar to the absorption coefficient of $\\mathrm{YA...

  4. Neutrino-nucleus quasi-elastic and 2p2h interactions up to 10 GeV

    CERN Document Server

    Gran, R; Sanchez, F; Vacas, M J Vicente

    2013-01-01

    We extend to 10 GeV results from a microscopic calculation of charged-current neutrino-nucleus reactions that do not produce a pion in the final state. For the class of events coming from neutrino interactions with two nucleons producing two holes (2p2h), limiting the calculation to three-momentum transfers less than 1.2 GeV produces a two dimensional distribution in momentum and energy transfer that is roughly constant as a function of energy. The cross section for 2p2h interactions scales with the number of nucleons for isoscalar nuclei, similar to the quasi-elastic (QE) cross section. When limited to momentum transfers below 1.2 GeV, the cross section is 26% of the QE cross section at 3 GeV, but 14% if we neglect a Delta1232 resonance absorption component. The same quantities are 33% and 17% for anti-neutrinos. For the quasi-elastic interactions, the full nuclear model with long range correlations produces an even larger, but approximately constant distortion of the shape of the four-momentum transfer at a...

  5. Focusing coherent light through a nonlinear scattering medium

    CERN Document Server

    Frostig, Hadas; Derevyanko, Stanislav; Silberberg, Yaron

    2016-01-01

    Wavefront shaping is a powerful technique that can be used to focus light through scattering media, with the limitation that the obtained focus contains a small fraction of the total power. The method is based on the assumption that the field at the output is a linear superposition of the modes traveling through different paths in the medium. However, when the scattering medium also exhibits nonlinearity, as may occur in multiphoton microscopy, this assumption is violated and the applicability of wavefront shaping becomes unclear. Here we show that using adaptive optimization of the wavefront light can still be controlled and focused through a nonlinear scattering medium, and that the focused fraction of power can be significantly enhanced in the presence of moderate positive nonlinearity. Our results suggest that the use of short pulses for focusing through scattering media with a mild self-focusing response might be favorable to the use of continuous-wave light.

  6. Multiple scattering of polarized light: influence of absorption.

    Science.gov (United States)

    Hohmann, A; Voit, F; Schäfer, J; Kienle, A

    2014-06-07

    This work continues previous research about multiple scattering of polarized light propagation in turbid media, putting emphasis on the imaginary part of the scatterers' complex refractive index. The whole angle-dependent Müller matrix is evaluated by comparing results of a polarization sensitive radiative transfer solution to Maxwell theory. Turbid media of defined scatterer concentrations are modelled in three dimensions by sphere ensembles kept inside a cubic or spherical simulation volume. This study addresses the impact of absorption on polarization characteristics for selected media from low to high absorption. Besides that, effects caused by multiple and dependent scattering are shown for increasing volume concentration. In this context some unique properties associated with multiple scattering and absorption are pointed out. Further, scattering results in two dimensions are compared for examples of infinite parallel cylinders of high absorption and perpendicularly incident plane waves.

  7. Light-induced scattering of light in NBS:Ce crystals

    Science.gov (United States)

    Voronov, V. V.; Dorosh, I. R.; Kuzminov, Iu. S.; Tkachenko, N. V.

    1980-11-01

    An experiment is described in which light-induced scattering of laser light was observed in Ce-doped (Sr/x/Ba/1-x/)/1-y/(Nb2O6)/y/ crystals with x = 0.61 and y = 0.4993. It is shown that the observed effect results from the holographic amplification of light scattered by crystal defects and that the observed asymmetry of the scattering is associated with the diffusion mechanism of hologram recording in crystals. A theoretical model of the scattering process is constructed for the diffusion recording mechanism.

  8. Quantum noise memory effect of multiple scattered light

    CERN Document Server

    Lodahl, P

    2005-01-01

    We investigate frequency correlations in multiple scattered light that are present in the quantum fluctuations. The memory effect for quantum and classical noise is compared, and found to have markedly different frequency scaling, which was confirmed in a recent experiment. Furthermore, novel mesoscopic correlations are predicted that depend on the photon statistics of the incoming light.

  9. Quantum noise frequency correlations of multiply scattered light

    DEFF Research Database (Denmark)

    Lodahl, Peter

    2006-01-01

    Frequency correlations in multiply scattered light that are present in quantum fluctuations are investigated. The speckle correlations for quantum and classical noise are compared and are found to depend markedly differently on optical frequency, which was confirmed in a recent experiment....... Furthermore, novel mesoscopic correlations are predicted that depend on the photon statistics of the incoming light....

  10. Light scattering characteristicof TiO2 nanocrystalline porous films

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    TiO2 nanocrystalline porous films consisting of binary particles mixture (mean diameters of 12 and 100 nm) are capable of increasing the light absorption due to the possession of large specific surface area and light scattering property. The simultaneous reduction of the film thickness leads to a decrease of the recombination loss during electron transport and an increase of the photocurrent efficiency.

  11. Light scattering in optical CT scanning of Presage dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Y; Adamovics, J; Cheeseborough, J C; Chao, K S; Wuu, C S, E-mail: yx2010@columbia.ed

    2010-11-01

    The intensity of the scattered light from the Presage dosimeters was measured using a Thorlabs PM100D optical power meter (Thorlabs Inc, Newton, NJ) with an optical sensor of 1 mm diameter sensitive area. Five Presage dosimeters were made as cylinders of 15.2 cm, 10 cm, 4 cm diameters and irradiated with 6 MV photons using a Varian Clinac 2100EX. Each dosimeter was put into the scanning tank of an OCTOPUS' optical CT scanner (MGS Research Inc, Madison, CT) filled with a refractive index matching liquid. A laser diode was positioned at one side of the water tank to generate a stationary laser beam of 0.8 mm width. On the other side of the tank, an in-house manufactured positioning system was used to move the optical sensor in the direction perpendicular to the outgoing laser beam from the dosimeters at an increment of 1 mm. The amount of scattered photons was found to be more than 1% of the primary light signal within 2 mm from the laser beam but decreases sharply with increasing off-axis distance. The intensity of the scattered light increases with increasing light attenuations and/or absorptions in the dosimeters. The scattered light at the same off-axis distance was weaker for dosimeters of larger diameters and for larger detector-to-dosimeter distances. Methods for minimizing the effect of the light scattering in different types of optical CT scanners are discussed.

  12. Comparative Study of Light Scattering from Hepatoma Cells and Hepatocytes

    Science.gov (United States)

    Lin, Xiaogang; Wang, Rongrong; Guo, Yongcai; Gao, Chao; Guo, Xiaoen

    2012-11-01

    Primary liver cancer is one of the highest mortality malignant tumors in the world. China is a high occurrence area of primary liver cancer. Diagnosis of liver cancer, especially early diagnosis, is essential for improving patients' survival. Light scattering and measuring method is an emerging technology developed in recent decades, which has attracted a large number of biomedical researchers due to its advantages, such as fast, simple, high accuracy, good repeatability, and non-destructive. The hypothesis of this project is that there may be some different light scattering information between hepatoma cells and hepatocyte. Combined with the advantages of the dynamic light scattering method and the biological cytology, an experimental scheme to measure the light scattering information of cells was formulated. Hepatoma cells and hepatic cells were irradiated by a semiconductor laser (532 nm). And the Brookhaven BI-200SM wide-angle light scattering device and temperature control apparatus were adopted. The light scattering information of hepatoma cells and hepatic cells in vitro within the 15°C to 30°C temperature range was processed by a BI-9000AT digital autocorrelator. The following points were found: (a) the scattering intensities of human hepatic cells and hepatoma cells are nearly not affected by the temperature factor, and the former is always greater than the latter and (b) the relaxation time of hepatoma cells is longer than that of hepatic cells, and both the relaxation time are shortened with increasing temperature from 15°C to 25°C. It can be concluded that hepatoma cells could absorb more incident light than hepatic cells. The reason may be that there exists more protein and nucleic acid in cancerous cells than normal cells. Furthermore, based on the length relaxation time, a conclusion can be inferred that the Brownian movement of cancer cells is greater.

  13. Using light scattering to determine the stoichiometry of protein complexes.

    Science.gov (United States)

    Mogridge, Jeremy

    2015-01-01

    The stoichiometry of a protein complex can be calculated from an accurate measurement of the complex's molecular weight. Multiangle laser light scattering in combination with size exclusion chromatography and interferometric refractometry provides a powerful means for determining the molecular weights of proteins and protein complexes. In contrast to conventional size exclusion chromatography and analytical centrifugation, measurements do not rely on the use of molecular weight standards and are not affected by the shape of the proteins. The technique is based on the direct relationship between the amount of light scattered by a protein in solution, and the product of its concentration and molecular weight. A typical experimental configuration includes a size exclusion column to fractionate the sample, a light scattering detector to measure scattered light, and an interferometric refractometer to measure protein concentration. The determination of the molecular weight of an anthrax toxin complex will be used to illustrate how multiangle laser light scattering can be used to determine the stoichiometry of protein complexes.

  14. Light fields in complex media: Mesoscopic scattering meets wave control

    Science.gov (United States)

    Rotter, Stefan; Gigan, Sylvain

    2017-01-01

    The newly emerging field of wave front shaping in complex media has recently seen enormous progress. The driving force behind these advances has been the experimental accessibility of the information stored in the scattering matrix of a disordered medium, which can nowadays routinely be exploited to focus light as well as to image or to transmit information even across highly turbid scattering samples. An overview of these new techniques, their experimental implementations, and the underlying theoretical concepts following from mesoscopic scattering theory is provided. In particular, the intimate connections between quantum transport phenomena and the scattering of light fields in disordered media, which can both be described by the same theoretical concepts, are highlighted. Particular emphasis is put on how these topics relate to application-oriented research fields such as optical imaging, sensing, and communication.

  15. LASER BIOLOGY AND MEDICINE: Light scattering study of rheumatoid arthritis

    Science.gov (United States)

    Beuthan, J.; Netz, U.; Minet, O.; Klose, Annerose D.; Hielscher, A. H.; Scheel, A.; Henniger, J.; Müller, G.

    2002-11-01

    The distribution of light scattered by finger joints is studied in the near-IR region. It is shown that variations in the optical parameters of the tissue (scattering coefficient μs, absorption coefficient μa, and anisotropy factor g) depend on the presence of the rheumatoid arthritis (RA). At the first stage, the distribution of scattered light was measured in diaphanoscopic experiments. The convolution of a Gaussian error function with the scattering phase function proved to be a good approximation of the data obtained. Then, a new method was developed for the reconstruction of distribution of optical parameters in the finger cross section. Model tests of the quality of this reconstruction method show good results.

  16. Experimental study of quasi-elastic neutrino interactions on Ar with a liquid Ar TPC exposed to the WANF neutrino beam

    CERN Document Server

    Curioni, A

    2006-01-01

    We present results from the first exposure of a liquid Ar time projection chamber to a neutrino beam. The data have been collected in 1997 with a 50 liter ICARUS-like chamber located between the CHORUS and NOMAD experiment at the CERN West Area Neutrino Facility. We focus on the analysis of quasi-elastic interactions; despite the limited size of the detector, nuclear effects beyond Fermi motion and Pauli blocking have been observed as perturbations to the pure quasi-elastic kinematics.

  17. Inelastic light scattering in low dimensional semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Watt, M

    1988-12-01

    Raman scattering is a powerful technique with which to study the lattice vibrations of semiconductors. Investigations of the phonons of GalnAs-InP heterostructures have shown that although the phonons in GalnAs quantum wells resembled those of bulk GalnAs, they were screened by free carriers. Raman scattering and photoluminescence techniques were employed to estimate the plasma density at which plasmon-phonon coupling became significant. Triple crystal x-ray diffraction measurements complemented the Raman scattering data and provided information on the GalnAs alloy composition and state of strain. It was found that although nominally lattice-matched to the underlying InP, the epitaxially-grown layers were tetragonally distorted in the direction of growth. Assessment of sample damage produced by reactive-ion-etching (RIE) was undertaken as a prerequisite to the study of phonons in fabricated nanostructures. Structural damage to the crystal showed up as a relaxation of the crystalline selection rules allowing the observation of a symmetry-forbidden phonon. The intensity of this phonon correlated well with depth profiling of the damage. Optimised RIE conditions were found to produce negligible crystalline damage. The study of GaAs cylinders (with diameters of less than 100 nanometers) revealed an additional feature in the optical phonon region of their Raman spectra. This feature was identified as a surface phonon of the quantum cylinders. The experimentally-observed frequencies of the surface phonon peaks showed good agreement with calculated frequencies based on vibrations in small, geometrically-regular crystals. The main contribution of this work is the study of the surface phonons of the GaAs quantum cylinders. This is the first time that surface phonons have been observed in small fabricated samples: all previous work has involved specially-prepared crystalline powders or else comparatively large slab geometries. The conclusion that can be drawn from this work

  18. Scattering of non-separable states of light

    CERN Document Server

    Reddy, Chithrabhanu P Salla Gangi; Singh, R P

    2015-01-01

    We experimentally show that the non-separability of polarization and orbital angular momentum present in a light beam remains preserved under scattering through a random medium like rotating ground glass. We verify this by measuring the degree of polarization and observing the intensity distribution of the beam when projected to different polarization states, before as well as after the scattering. We extend our study to the non-maximally non-separable states also.

  19. Resonance light scattering determination of metallothioneins using levofloxacin-palladium complex as a light scattering probe

    Science.gov (United States)

    Xue, Jin-Hua; Qian, Qiu-Mei; Wang, Yong-Sheng; Meng, Xia-Ling; Liu, Lu

    2013-02-01

    A novel method of resonance light scattering (RLS) was developed for the analysis of trace metallothioneins (MTs) in human urine. In a CH3COOH-CH3COONa buffer solution of pH 4.5, the formation of a complex between levofloxacin (LEV)-Pd and MTs led to enhance the RLS intensity of the system, and the enhanced RLS intensity at 468 nm was proportional to the concentration of MTs in the range of 0.059-22.4 μg mL-1. The linear regression equation was ΔI = 127.5 ρ (μg mL-1)-88.02 with a correlation coefficient of 0.9992, and the detection limit of 17.8 ng mL-1. The relative standard deviation and the average recovery were 3.8-5.4% (n = 11) and 92.15%, respectively. The proposed method is convenient, reliable and sensitive, and has been used successfully for the determination of trace MTs in human urine samples.

  20. A Theory of Exoplanet Transits with Light Scattering

    Science.gov (United States)

    Robinson, Tyler D.

    2017-02-01

    Exoplanet transit spectroscopy enables the characterization of distant worlds, and will yield key results for NASA's James Webb Space Telescope. However, transit spectra models are often simplified, omitting potentially important processes like refraction and multiple scattering. While the former process has seen recent development, the effects of light multiple scattering on exoplanet transit spectra have received little attention. Here, we develop a detailed theory of exoplanet transit spectroscopy that extends to the full refracting and multiple scattering case. We explore the importance of scattering for planet-wide cloud layers, where the relevant parameters are the slant scattering optical depth, the scattering asymmetry parameter, and the angular size of the host star. The latter determines the size of the “target” for a photon that is back-mapped from an observer. We provide results that straightforwardly indicate the potential importance of multiple scattering for transit spectra. When the orbital distance is smaller than 10–20 times the stellar radius, multiple scattering effects for aerosols with asymmetry parameters larger than 0.8–0.9 can become significant. We provide examples of the impacts of cloud/haze multiple scattering on transit spectra of a hot Jupiter-like exoplanet. For cases with a forward and conservatively scattering cloud/haze, differences due to multiple scattering effects can exceed 200 ppm, but shrink to zero at wavelength ranges corresponding to strong gas absorption or when the slant optical depth of the cloud exceeds several tens. We conclude with a discussion of types of aerosols for which multiple scattering in transit spectra may be important.

  1. Light scattering from macromolecular systems: Molecular crystals and polymers

    Science.gov (United States)

    Bernstein, E. R.

    1981-11-01

    The research objectives were to: (1) characterize phase transitions theoretically and experimentally in molecular crystal systems; (2) use the above understanding gained by light scattering studies and theoretical interpretation to apply to the more complex system of lyotropic liquid crystals; and (3) then apply knowledge gained on the model systems of increasing complexity to polymer liquid crystals and solid polymers as observed by laser light scattering techniques. Systems experimentally and theoretically discussed are: trioxane, triazine, benzil, and chloranil. Studies of lyotropic liquid crystals (sodium decyl sulfate, sodium sulfate, decanol, water) have progressed. The major findings are: a number of phase transitions occur between 20 and 60 C; these transitions evidence strong critical behavior and long correlation times for fluctuations; and liquid crystals can be studied by light scattering. Spectra of solid powders, ribbons, and liquid crystals of PBT and solid PBO were obtained.

  2. Light losses from scattering in luminescent solar concentrator waveguides.

    Science.gov (United States)

    Breukers, Robert D; Smith, Gerald J; Stirrat, Hedley L; Swanson, Adam J; Smith, Trevor A; Ghiggino, Kenneth P; Raymond, Sebastiampillai G; Winch, Nicola M; Clarke, David J; Kay, Andrew J

    2017-04-01

    The reductions in the transmission of emission originating from a fluorophore dissolved in a polymer matrix due to light scattering were compared in two forms of planar waveguides used as luminescent solar concentrators: a thin film of poly(methylmethacrylate) (PMMA) spin-coated on a glass plate and a solid PMMA plate of the same dimensions. The losses attributable to light scattering encountered in the waveguide consisting of the thin film of polymer coated on a glass plate were not detectable within experimental uncertainty, whereas the losses in the solid polymer plate were significant. The losses in the solid plate are interpreted as arising from light-scattering centers comprising minute bubbles of vapor/gas, incomplete polymerization or water clusters that are introduced during or after the thermally induced polymerization process.

  3. Insulin association in neutral solutions studied by light scattering

    DEFF Research Database (Denmark)

    Hvidt, S.

    1991-01-01

    Molecular weights and weight distributions of sulfated, Zn-free, and 2Zn insulins have been measured at pH 7.3 as a function of concentration from 0.1 to 2 mg/ml by use of a combination of light scattering, refractometry, and size-exclusion chromatography. Results show that sulfated insulin is mo...... absence. An average hydrodynamic radius of 5.6 nm, close to the crystallographic size of the insulin hexamer, was determined from dynamic light scattering of 2Zn insulin solutions....

  4. Nonspherical nanoparticles characterization by partially depolarized dynamic light scattering

    Science.gov (United States)

    Levin, Alexander D.; Shmytkova, Ekaterina A.

    2015-06-01

    The realization of improved depolarized dynamic light scattering method is presented. This technique supports measurement of non-spherical nanoparticals dimensions in liquids. The relations between translational and rotational diffusion coefficients and autocorrelation function of scattered light with polarized and depolarized components in various proportions are derived. Thus measurement of very weak cross-polarized component can be avoided. This improvement permits to reduce measurement time, to improve signal to noise ratio and results precision. The technique was applied for sizing of gold nanorods and multiwalled carbon nanotubes in liquids.

  5. Dynamic light scattering with applications to chemistry, biology, and physics

    CERN Document Server

    Berne, Bruce J

    2000-01-01

    Lasers play an increasingly important role in a variety of detection techniques, making inelastic light scattering a tool of growing value in the investigation of dynamic and structural problems in chemistry, biology, and physics. Until the initial publication of this work, however, no monograph treated the principles behind current developments in the field.This volume presents a comprehensive introduction to the principles underlying laser light scattering, focusing on the time dependence of fluctuations in fluid systems; it also serves as an introduction to the theory of time correlation f

  6. Effect of pyrophosphate on the light scatter in KDP crystal

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Pyrophosphate doped potassium dihydrogen phosphate (KDP) crystal was grown from aqueous solution by the temperature lowering method. Light scatter in KDP crystal was detected with the ultramicroscopic method. The light scatter in KDP crystal was aggravated when pyrophosphate was doped into the growth solution, which was distributed ununiformly in prism and pyramidal sectors of KDP crystal. Different effects of pyrophosphate on prism and pyramidal sectors of KDP crystal can explain this case. The transmission in this crystal was measured, showing that pyrophosphate affects the transmission evidently.

  7. Muon spectra of Quasi-Elastic and 1-pion production events at the KEK LBL neutrino oscillation experiment

    CERN Document Server

    Yu, J Y; Roy, D P; Schienbein, I; Yu, Ji--Young

    2003-01-01

    We present predictions for the flux averaged muon energy spectra of quasi-elastic (QE) and 1-pion production events for the K2K long-baseline experiment. Using the general kinematical considerations we show that the muon energy spectra closely follow the neutrino energy spectrum with downward shift of the energy scale by 0.15 GeV (QE) and 0.4 GeV (1-pion production). These predictions seem to agree with the observed muon energy spectra in the K2K nearby detector. We also show the spectral distortion of these muon energy spectra due to the neutrino oscillation for the SK detector. Comparison of the predicted spectral distortions with the observed muon spectra of the 1-Ring and 2-Ring muon events in the SK detector will help to determine the oscillation parameters. The results will be applicable to other LBL experiments as well.

  8. Uncontained νμ charged-current quasi-elastic events at the NOvA far detector

    Science.gov (United States)

    Sepulveda-Quiroz, Jose; NOvA Collaboration

    2017-01-01

    NOvA is a long-baseline neutrino oscillation experiment that uses an upgraded neutrino beam from Fermilab and two highly active, segmented, liquid scintillator off-axis detectors that offer a remarkable capability in event identification. In its first and second analysis results, NOvA has used only events with an interaction vertex and all secondary particles fully contained in the detectors. I will present studies of the potential sensitivity improvement of the sin2 2θ23 and Δm322 neutrino oscillation parameters from the νμ-disappearance measurement when including uncontained events in the sample. In particular, this study focuses on incorporating νμ charged current quasi-elastic interactions of the type νμ + n -> μ + p where the muon is uncontained but the proton is contained.

  9. Compton scattering of twisted light: angular distribution and polarization of scattered photons

    CERN Document Server

    Stock, S; Fritzsche, S; Seipt, D

    2015-01-01

    Compton scattering of twisted photons is investigated within a non-relativistic framework using first-order perturbation theory. We formulate the problem in the density matrix theory, which enables one to gain new insights into scattering processes of twisted particles by exploiting the symmetries of the system. In particular, we analyze how the angular distribution and polarization of the scattered photons are affected by the parameters of the initial beam such as the opening angle and the projection of orbital angular momentum. We present analytical and numerical results for the angular distribution and the polarization of Compton scattered photons for initially twisted light and compare them with the standard case of plane-wave light.

  10. An empirical correction for moderate multiple scattering in super-heterodyne light scattering

    Science.gov (United States)

    Botin, Denis; Mapa, Ludmila Marotta; Schweinfurth, Holger; Sieber, Bastian; Wittenberg, Christopher; Palberg, Thomas

    2017-05-01

    Frequency domain super-heterodyne laser light scattering is utilized in a low angle integral measurement configuration to determine flow and diffusion in charged sphere suspensions showing moderate to strong multiple scattering. We introduce an empirical correction to subtract the multiple scattering background and isolate the singly scattered light. We demonstrate the excellent feasibility of this simple approach for turbid suspensions of transmittance T ≥ 0.4. We study the particle concentration dependence of the electro-kinetic mobility in low salt aqueous suspension over an extended concentration regime and observe a maximum at intermediate concentrations. We further use our scheme for measurements of the self-diffusion coefficients in the fluid samples in the absence or presence of shear, as well as in polycrystalline samples during crystallization and coarsening. We discuss the scope and limits of our approach as well as possible future applications.

  11. Inelastic light scattering in low dimensional semiconductors

    CERN Document Server

    Watt, M

    1988-01-01

    frequencies of the surface phonon peaks showed good agreement with calculated frequencies based on vibrations in small, geometrically-regular crystals. The main contribution of this work is the study of the surface phonons of the GaAs quantum cylinders. This is the first time that surface phonons have been observed in small fabricated samples: all previous work has involved specially-prepared crystalline powders or else comparatively large slab geometries. The conclusion that can be drawn from this work is that the cylinders are not only well-defined (as observed from the SEM micrographs) but they are also crystalline. The implication is that such structures can now be fabricated at a sufficiently high level to allow progress in prototype devices such as the quantum dot laser. Raman scattering is a powerful technique with which to study the lattice vibrations of semiconductors. Investigations of the phonons of GalnAs-InP heterostructures have shown that although the phonons in GalnAs quantum wells resembled t...

  12. Light-by-light scattering sum rules in light of new data

    CERN Document Server

    Danilkin, Igor

    2016-01-01

    We evaluate the light-quark meson contributions to three exact light-by-light scattering sum rules in light of new data by the Belle Collaboration, which recently has extracted the transition form factors of the tensor meson $f_2(1270)$ as well as of the scalar meson $f_0(980)$. We confirm a previous finding that the $\\eta, \\eta^\\prime$ and helicity-2 $f_2(1270)$ contributions saturate one of these sum rules up to photon virtualities up to around 1 GeV$^2$. At larger virtualities, our sum rule analysis shows an important contribution of the $f_2(1565)$ meson and provides a first empirical extraction of its helicity-2 transition form factor. Two further sum rules allow us to predict the helicity-0 and helicity-1 transition form factors of the $f_2(1270)$ meson. Furthermore, our analysis also provides an update for the scalar and tensor meson hadronic light-by-light contributions to the muon's anomalous magnetic moment.

  13. The impact of dust particle morphological details on light scattering

    Science.gov (United States)

    Kemppinen, Osku; Nousiainen, Timo; Lindqvist, Hannakaisa; Jeong, Gi Young

    2016-04-01

    We investigate the impact of dust particle surface roughness and internal structure on light scattering. Starting from digital representation of realistically shaped dust particles, we vary the particle morphology, and perform light scattering simulations to both the original and the modified particles. By mapping the changes in morphology to the changes in scattering, we will get information of how strongly and in which way a particular change affects scattering. All investigations have been done with complex, irregular particle shapes. For surface roughness studies we have kept the particle total volume virtually constant during the roughening process, and the roughness element size small enough to keep the overall shape relatively unchanged. For internal structure studies, the size and the external shape are kept constant. These safety measures help ensure that the effects seen are in fact due to the feature studied. The work is notable for model development, because some models can not include surface roughness, for example. In that case, the people who use such models have to adjust for the fact that the results are inaccurate, and by knowing how surface roughness typically changes the scattering results, the adjustment can be made. As a corollary, if it is shown that a particular feature does not change scattering results in any noticeable way, the model developers can confidently ignore or simplify it.

  14. Development of bacterial colony phenotyping instrument using reflected scatter light

    Science.gov (United States)

    Doh, Iyll-Joon

    Bacterial rapid detection using optical scattering technology (BARDOT) involves in differentiating elastic scattering pattern of bacterial colony. This elastic light scatter technology has shown promising label-free classification rate. However, there is limited success in certain circumstances where either a growth media or a colony has higher opacity. This situation is due to the physical principles of the current BARDOT which mainly relies on optical patterns generated by transmitted signals. Incoming light is obstructed and cannot be transmitted through the dense bacterial colonies, such as Lactobacillus, Yeast, mold and soil bacteria. Moreover, a blood agar, widely used in clinical field, is an example of an opaque media that does not allow light to be transmitted through. Therefore, in this research, a newly designed reflection type scatterometer is presented. The reflection type scatterometer measures the elastic scattering pattern generated by reflected signal. A theoretical model to study the optical pattern characteristic with respect to bacterial colony morphology is presented. Both theoretical and experiment results show good agreement that the size of backward scattering pattern has positive correlation to colony aspect ratio, a colony elevation to diameter ratio. Four pathogenic bacteria on blood agar, Escherichia coli K12, Listeria innocua, Salmonella Typhimurium, and Staphylococcus aureus, are tested and measured with proposed instrument. The measured patterns are analyzed with a classification software, and high classification rate can be achieved.

  15. Tunable scattering cancellation of light using anisotropic cylindrical cavities

    CERN Document Server

    Díaz-Aviñó, Carlos; Zapata-Rodríguez, Carlos J

    2016-01-01

    Engineered core-shell cylinders are good candidates for applications in invisibility and cloaking.In particular, hyperbolic nanotubes demonstrate tunable ultra-low scattering cross section in the visible spectral range. In this work we investigate the limits of validity of the condition for invisibility, which was shown to rely on reaching an epsilon near zero in one of the components of the effective permittivity tensor of the anisotropic metamaterial cavity. For incident light polarized perpendicularly to the scatterer axis, critical deviations are found in low-birefringent arrangements and also with high-index cores. We demonstrate that the ability of anisotropic metallodielectric nanocavities to dramatically reduce the scattered light is associated with a multiple Fano-resonance phenomenon. We extensively explore such resonant effect to identify tunable windows of invisibility.

  16. Light scattering artefacts in a funnel phantom using optical CT

    Energy Technology Data Exchange (ETDEWEB)

    Bosi, Stephen G [Department of Radiation Oncology, Prince of Wales Hospital, Sydney (Australia); Brown, Saxby; Baldock, Clive [Institute of Medical Physics, School of Physics, University of Sydney Australia (Australia); Sarabipour, Sarvenaz [Department of Nuclear Medicine and Radiobiology, University of Sherbrooke (Canada); De Deene, Yves [Radiotherapy Department, Ghent University Hospital (Belgium)], E-mail: c.baldock@physics.usyd.edu.au

    2009-05-01

    A gelatin phantom containing a funnel-shaped region of high opacity (or optical density OD) was used to examine light-scattering induced artefacts in a cone-beam optical CT scanner used for gel dosimetry. To correctly simulate polymer gel dosimeters, the opacity was introduced by adding a colloidal scatterer to the gelatin. In line profiles of OD taken from 3-D reconstructions of the funnel, those profiles with a long pathlength through high OD regions exhibited a 'dishing' artefact, while those of short pathlength exhibited the opposite effect - 'doming'. These phenomena are accounted for by a model that includes the effect of stray, scattered light.

  17. Hybrid graphene nematic liquid crystal light scattering device

    Science.gov (United States)

    Qasim, M. M.; Khan, A. A.; Kostanyan, A.; Kidambi, P. R.; Cabrero-Vilatela, A.; Braeuninger-Weimer, P.; Gardiner, D. J.; Hofmann, S.; Wilkinson, T. D.

    2015-08-01

    A hybrid graphene nematic liquid crystal (LC) light scattering device is presented. This device exploits the inherent poly-crystallinity of chemical vapour deposited (CVD) graphene films to induce directional anchoring and formation of LC multi-domains. This thereby enables efficient light scattering without the need for crossed polarisers or separate alignment layers/additives. The hybrid LC device exhibits switching thresholds at very low electric fields (crossed polarisers or separate alignment layers/additives. The hybrid LC device exhibits switching thresholds at very low electric fields (< 1 V μm-1) and repeatable, hysteresis free characteristics. This exploitation of LC alignment effects on CVD graphene films enables a new generation of highly efficient nematic LC scattering displays as well as many other possible applications. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr04094a

  18. Half a century of light scatter metrology and counting

    Science.gov (United States)

    Stover, John C.

    2014-09-01

    Back in the early days Bill Wolf once said something like: "The guy with the lowest scatter measurement is closest to the right answer." He was often right then - but not anymore. Everything has changed. Today measurements are limited by Rayleigh scatter from the air - not the instrument. We have both written and physical standards and everybody spells BRDF the same way. In the time it takes to give this talk, over 100,000 silicon wafers will be inspected around the world using a few thousand scatterometers - average price about one million dollars each. The way the world illuminates everything from homes to football fields is changing with the advent of high brightness LED's and these lighting systems are designed using a combination of scatter metrology and analysis techniques - many of which were started at The Optical Sciences Center. This paper reviews two major highlights in half a century of scatter metrology progress.

  19. Optical Characterization of Optofluidic Waveguides Using Scattered Light Imaging.

    Science.gov (United States)

    Jenkins, Micah H; Phillips, Brian S; Zhao, Yue; Holmes, Matthew R; Schmidt, Holger; Hawkins, Aaron R

    2011-08-01

    The use of scattered light images is shown to be an attractive method for the characterization of optofluidic waveguides. The method is shown to be capable of measuring waveguide propagation losses and transmissions between solid and liquid-core structures. Measurement uncertainties are considered and characterized and were typically less than 15%.

  20. HeNe-laser light scattering by human dental enamel

    NARCIS (Netherlands)

    Zijp, [No Value; tenBosch, JJ; Groenhuis, RAJ

    1995-01-01

    Knowledge of the optical properties of tooth enamel and an understanding of the origin of these properties are necessary for the development of new optical methods for caries diagnosis and the measurement of tooth color. We measured the scattering intensity functions for HeNe-laser light of 80- to 1

  1. Light scattering of PMMA latex particles in benzene: structural effects

    NARCIS (Netherlands)

    Nieuwenhuis, E.A.; Vrij, A.

    1979-01-01

    Intra- and interparticle structural effects were studied in polymethylmethacrylate (PMMA) latex dispersions in a nonpolar solvent with the technique of light scattering. The required transparency of the dispersions was attained by a close matching of the refractive index of PMMA and solvent, for whi

  2. Light scattering by photonic crystals with a dirac spectrum

    NARCIS (Netherlands)

    Sepkhanov, Ruslan

    2009-01-01

    In this thesis we consider several effects of a Dirac spectrum in photonic crystals on the scattering and propagation of light. We calculate the effect of a Dirac point (a conical singularity in the band structure) on the transmission of radiation through a photonic crystal. We find that the transmi

  3. Multiple scattering of polarized light in a turbid medium

    NARCIS (Netherlands)

    Gorodnichev, E. E.; Kuzovlev, A. I.; Rogozkin, D. B.

    2007-01-01

    It is shown that multiple scattering of polarized light in a turbid medium can be represented as independent propagation of three basic modes: intensity and linearly and circularly polarized modes. Weak interaction between the basic modes can be described by perturbation theory and gives rise to "ov

  4. Light scattering by photonic crystals with a dirac spectrum

    NARCIS (Netherlands)

    Sepkhanov, Ruslan

    2009-01-01

    In this thesis we consider several effects of a Dirac spectrum in photonic crystals on the scattering and propagation of light. We calculate the effect of a Dirac point (a conical singularity in the band structure) on the transmission of radiation through a photonic crystal. We find that the

  5. Quantum correlations induced by multiple scattering of quadrature squeezed light

    DEFF Research Database (Denmark)

    Lodahl, Peter

    2006-01-01

    Propagating quadrature squeezed light through a multiple scattering random medium is found to induce pronounced spatial quantum correlations that have no classical analogue. The correlations are revealed in the number of photons transported through the sample that can be measured from the intensity...

  6. Using Light Scattering to Track, Characterize and Manipulate Colloids

    NARCIS (Netherlands)

    van Oostrum, P.D.J.

    2011-01-01

    A new technique is developed to analyze in-line Digital Holographic Microscopy images, making it possible to characterize, and track colloidal particles in three dimensions at unprecedented accuracy. We took digital snapshots of the interference pattern between the light scattered by micrometer

  7. Derivation of capture and reaction cross sections from experimental quasi-elastic and elastic backscattering probabilities

    CERN Document Server

    Sargsyan, V V; Antonenko, N V; Gomes, P R S

    2013-01-01

    The direct measurement of the reaction or capture (fusion) cross section is a difficult task since it would require the measurement of individual cross sections of many reaction channels, and most of them could be reached only by specific experiments. This would require different experimental set-ups not always available at the same laboratory and, consequently, such direct measurements would demand a large amount of beam time and would take probably some years to be reached. Because of that, the measurements of elastic scattering angular distributions that cover full angular ranges and optical model analysis have been used for the determination of reaction cross sections. This traditional method consists in deriving the parameters of the complex optical potentials which fit the experimental elastic scattering angular distributions and then of deriving the reaction cross sections predicted by these potentials. Even so, both the experimental part and the analysis of this latter method are not so simple. In the...

  8. Scattering optical elements: stand-alone optical elements exploiting multiple light scattering

    CERN Document Server

    Park, Jongchan; Park, Chunghyun; Lee, KyeoReh; Lee, Heon; Cho, Yong-Hoon; Park, YongKeun

    2016-01-01

    Optical design and fabrication techniques are crucial for making optical elements. From conventional lenses to diffractive optical elements, and to recent metasurfaces, various types of optical elements have been proposed to manipulate light where optical materials are fabricated into desired structures. Here, we propose a scattering optical element (SOE) which exploits multiple light scattering and wavefront shaping. Instead of fabricating optical materials, the SOE consists of a disordered medium and a photopolymer-based wavefront recorder, with shapes the wavefront of impinging light on demand. With the proposed stand-alone SOEs, we experimentally demonstrate control of various properties of light, including intensity, polarisation, spectral frequency and near field. Due to the tremendous freedom brought about by disordered media, the proposed approach will provide unexplored routes to manipulate arbitrary optical fields in stand-alone optical elements.

  9. Light extraction enhancement from organic light-emitting diodes with randomly scattered surface fixture

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Dong-Ying; Shi, Xiao-Bo; Gao, Chun-Hong; Cai, Shi-Duan; Jin, Yue; Liao, Liang-Sheng, E-mail: lsliao@suda.edu.cn

    2014-09-30

    Graphical abstract: - Highlights: • A combination of scattering layer and roughened substrate is used for light extraction from OLEDs. • The scattering layer is readily achieved by spin-coating the TiO{sub 2} sol. • The enhancement relying scattering depends on the size of TiO{sub 2} nano particles. • With the light extraction techniques the uniform emission is achieved. - Abstract: A combination of a scattering medium layer and a roughened substrate was proposed to enhance the light extraction efficiency of organic light-emitting diodes (OLEDs). Comparing with a reference OLED without any scattering layer, 65% improvement in the forward emission has been achieved with a scattering layer formed on an intentionally roughened external substrate surface of the OLED by spin-coating a sol–gel fabricated matrix containing well dispersed titania (TiO{sub 2}) particles. Such a combination method not only demonstrated efficient extraction of the light trapped in the glass substrate but also achieved homogenous emission from the OLED panel. The proposed technique, convenient and inexpensive, is believed to be suitable for the large area OLED production in lighting applications.

  10. Light scattering by optically anisotropic scatterers: T-matrix theory for radial and uniform anisotropies.

    Science.gov (United States)

    Kiselev, A D; Reshetnyak, V Yu; Sluckin, T J

    2002-05-01

    We extend the T-matrix approach to light scattering by spherical particles to some simple cases in which the scatterers are optically anisotropic. Specifically, we consider cases in which the spherical particles include radially and uniformly anisotropic layers. We find that in both cases the T-matrix theory can be formulated using a modified T-matrix ansatz with suitably defined modes. In a uniformly anisotropic medium we derive these modes by relating the wave packet representation and expansions of electromagnetic field over spherical harmonics. The resulting wave functions are deformed spherical harmonics that represent solutions of the Maxwell equations. We present preliminary results of numerical calculations of the scattering by spherical droplets. We concentrate on cases in which the scattering is due only to the local optical anisotropy within the scatterer. For radial anisotropy we find that nonmonotonic dependence of the scattering cross section on the degree of anisotropy can occur in a regime to which both the Rayleigh and semiclassical theories are inapplicable. For uniform anisotropy the cross section is strongly dependent on the angle between the incident light and the optical axis, and for larger droplets this dependence is nonmonotonic.

  11. Disordered Cellulose-Based Nanostructures for Enhanced Light Scattering

    Science.gov (United States)

    2017-01-01

    Cellulose is the most abundant biopolymer on Earth. Cellulose fibers, such as the one extracted form cotton or woodpulp, have been used by humankind for hundreds of years to make textiles and paper. Here we show how, by engineering light–matter interaction, we can optimize light scattering using exclusively cellulose nanocrystals. The produced material is sustainable, biocompatible, and when compared to ordinary microfiber-based paper, it shows enhanced scattering strength (×4), yielding a transport mean free path as low as 3.5 μm in the visible light range. The experimental results are in a good agreement with the theoretical predictions obtained with a diffusive model for light propagation. PMID:28191920

  12. Functional Imaging of Tissue Morphology with Polarized Light Scattering Spectroscopy

    Science.gov (United States)

    Backman, Vadim

    2001-03-01

    We report a new imaging technique to study the morphology of living epithelial cells in vivo. The method is based on light scattering spectroscopy with polarized light (PLSS) and makes it possible to distinguish between single backscattering from epithelial cell nuclei and multiply scattered light. The spectrum of the single backscattering component is further analyzed to provide quantitative histological information about the epithelial cells such as the size distribution, refractive index, and chromatin content of the cell nuclei. The measurement of cell nuclear morphology is crucial for detection and diagnosis of cancerous and precancerous conditions in many human tissues. The method was successfully applied to image precancerous regions of several tissues. Clinical studies in five organs (esophagus, colon, bladder, oral cavity, and uterine cervix) showed the generality and efficacy of the technique.

  13. Shape-dependent light scattering properties of subwavelength silicon nanoblocks.

    Science.gov (United States)

    Ee, Ho-Seok; Kang, Ju-Hyung; Brongersma, Mark L; Seo, Min-Kyo

    2015-03-11

    We explore the shape-dependent light scattering properties of silicon (Si) nanoblocks and their physical origin. These high-refractive-index nanostructures are easily fabricated using planar fabrication technologies and support strong, leaky-mode resonances that enable light manipulation beyond the optical diffraction limit. Dark-field microscopy and a numerical modal analysis show that the nanoblocks can be viewed as truncated Si waveguides, and the waveguide dispersion strongly controls the resonant properties. This explains why the lowest-order transverse magnetic (TM01) mode resonance can be widely tuned over the entire visible wavelength range depending on the nanoblock length, whereas the wavelength-scale TM11 mode resonance does not change greatly. For sufficiently short lengths, the TM01 and TM11 modes can be made to spectrally overlap, and a substantial scattering efficiency, which is defined as the ratio of the scattering cross section to the physical cross section of the nanoblock, of ∼9.95, approaching the theoretical lowest-order single-channel scattering limit, is achievable. Control over the subwavelength-scale leaky-mode resonance allows Si nanoblocks to generate vivid structural color, manipulate forward and backward scattering, and act as excellent photonic artificial atoms for metasurfaces.

  14. Aerosol light scattering measurements as a function of relative humidity.

    Science.gov (United States)

    Day, D E; Malm, W C; Kreidenweis, S M

    2000-05-01

    The hygroscopic nature of atmospheric fine aerosol was investigated at a rural site in the Great Smoky Mountains National Park during July and August 1995. Passing the sample aerosol through an inlet, which housed an array of Perma Pure diffusion dryers, controlled the sample aerosol's relative humidity (RH). After conditioning the aerosol sample in the inlet, the light scattering coefficient and the aerosol size distribution were simultaneously measured. During this study, the conditioned aerosol's humidity ranged between 5% < RH < 95%. Aerosol response curves were produced using the ratio bspw/bspd; where bspw is the scattering coefficient measured at some RH greater than 20% and bspd is the scattering coefficient of the "dry" aerosol. For this work, any sample RH values below 15% were considered dry. Results of this investigation showed that the light scattering ratio increased continuously and smoothly over the entire range of relative humidity. The magnitude of the ratio at a particular RH value, however, varied considerably in time, particularly for RH values greater than approximately 60%. Curves of the scattering coefficient ratios as a function of RH were generated for each day and compared to the average 12-hour chemical composition of the aerosol. This comparison showed that for any particular RH value the ratio was highest during time periods of high sulfate concentrations and lowest during time periods of high soil or high organic carbon concentrations.

  15. Light scattering by fractal dust aggregates: I. Angular dependence of scattering

    CERN Document Server

    Tazaki, Ryo; Okuzumi, Satoshi; Kataoka, Akimasa; Nomura, Hideko

    2016-01-01

    In protoplanetary disks, micron-sized dust grains coagulate to form highly porous dust aggregates. Because the optical properties of these aggregates are not completely understood, it is important to investigate how porous dust aggregates scatter light. In this study, the light scattering properties of porous dust aggregates were calculated using a rigorous method, the T-matrix method, and the results were then compared with those obtained using the Rayleigh-Gans-Debye (RGD) theory and Mie theory with the effective medium approximation (EMT). The RGD theory is applicable to moderately large aggregates made of nearly transparent monomers. This study considered two types of porous dust aggregates, ballistic cluster-cluster agglomerates (BCCAs) and ballistic particle-cluster agglomerates (BPCAs). First, the angular dependence of the scattered intensity was shown to reflect the hierarchical structure of dust aggregates; the large-scale structure of the aggregates is responsible for the intensity at small scatteri...

  16. Evaluation of Influence of Multiple Scattering Effect in Light-Scattering-Based Applications

    Institute of Scientific and Technical Information of China (English)

    XU Sheng-Hua; SUN Zhi-Wei

    2007-01-01

    The extinction cross sections of a system containing two particles are calculated by the T-matrix method, and the results are compared with those of two single particles with single-scattering approximation. The necessity of the correction of the refractive indices of water and polystyrene for different incident wavelengths is particularly addressed in the calculation. By this means, the volume fractions allowed for certain accuracy requirements of single-scattering approximation in the light scattering experiment can be evaluated. The volume fractions calculated with corrected refractive indices are compared with those obtained with fixed refractive indices which have been rather commonly used, showing that fixed refractive indices may cause significant error in evaluating multiple scattering effect. The results also give a simple criterion for selecting the incident wavelength and particle size to avoid the 'blind zone' in the turbidity measurement, where the turbidity change is insensitive to aggregation of two particles.

  17. Using neural networks for dynamic light scattering time series processing

    Science.gov (United States)

    Chicea, Dan

    2017-04-01

    A basic experiment to record dynamic light scattering (DLS) time series was assembled using basic components. The DLS time series processing using the Lorentzian function fit was considered as reference. A Neural Network was designed and trained using simulated frequency spectra for spherical particles in the range 0–350 nm, assumed to be scattering centers, and the neural network design and training procedure are described in detail. The neural network output accuracy was tested both on simulated and on experimental time series. The match with the DLS results, considered as reference, was good serving as a proof of concept for using neural networks in fast DLS time series processing.

  18. Geometrical optics approximation of light scattering by large air bubbles

    Institute of Scientific and Technical Information of China (English)

    Haitao Yu; Jianqi Shen; Yuehuan Wei

    2008-01-01

    For large spherical bubbles in water,geometrical optics approximation is considered a better method for calculating light scattering patterns.In this paper,the basic theory of geometrical optics approximation is clarified.The change of phase for bubbles is calculated when total reflection occurs,which is different from particles with relative refractive indices larger than 1.Verification of the method was achieved by assuming a spherical particle and comparing present results to Mie scattering and Debye calculation.Agreement with the Mie theory was excellent in all directions when the dimensionless size parameter is larger than 50.Limitations of the geometrical optics approximation are also discussed.

  19. Free-form thin lens design with light scattering surfaces for practical LED down light illumination

    Science.gov (United States)

    Lin, Raychiy J.; Sun, Ching-Cherng

    2016-05-01

    The free-form optical quasilens surface technology was utilized to develop and design a solid transparent plastic optical lens for the LED down light with the narrow angular light distribution requirement in the LED lighting applications. In order to successfully complete the mission, the precise mid-field angular distribution model of the LED light source was established and built. And also the optical scattering surface property of the Harvey BSDF scattering model was designed, measured, and established. Then, the optical simulation for the entire optical system was performed to develop and design this solid transparent plastic optical lens system. Finally, the goals of 40 deg angular light distribution pattern defined at full width half maximum with glare reduced in the areas of interest and the optical performance of nearly 82% light energy transmission optics were achieved for the LED down light illumination.

  20. Light scattering from impurity enhanced liquid layers in polycrystalline ice

    Science.gov (United States)

    Thomson, E. S.; Wettlaufer, J. S.; Wilen, L. A.

    2009-12-01

    Impurity enhanced grain boundary premelting underlies a wide range of geophysical phenomena throughout the cryosphere. In particular, it is known that when water droplets freeze in the atmosphere they are highly polycrystalline and impurities are rejected into grain boundaries. The predicted character and sensitivity of grain boundaries to impurities close to the melting point precludes the use of standard techniques for imaging the interface. Unlike their larger more macroscopic relatives such as veins (3 grain intersections) and nodes (4 grain intersections), grain boundaries do not submit to optical microscopy. However, using an experimental light scattering method grain boundary changes can be measured as a function of thermodynamic variables. Accurate analysis of the light scattering data generated using this method requires a full theory of light propagation through the grain boundary layer straddled by ice crystals. Here we present a theory for light scattering from such a boundary, experimental data using NaCl as a dopant, and dicsuss atmospheric implications from the troposphere to the stratosphere.

  1. Simulations of light-light scattering in quantum vacuum

    Science.gov (United States)

    Carneiro, Pedro; Grismayer, Thomas; Silva, LuíS.; Fonseca, Ricardo

    2016-10-01

    Facilities such as the Extreme Light Infrastructure (ELI) or the VULCAN 20 PW project, as well as the Petta-Watt SLAC project, coupled with the x-ray LCLSII source will allow to perform the first experiments on the probing of quantum vacuum. In our work, we developed a numerical method to self-consistently solve the nonlinear system of Maxwell's equations including quantum corrections of vacuum polarization. The robustness of our algorithm allied to the ability to integrate this tool within a particle-in-cell (PIC) method, represents an important milestone in modeling future planned experiments to prove the existence of the quantum vacuum. Such experiments aim to measure the induced ellipticity on a x-ray pulse after probing a strong optical pump due to the quantum vacuum fluctuations. We present simulation results of both the ellipticity induced and polarization rotation, using realistic laser parameters of the Petta-Watt SLAC project, and the x-ray LCLSII source, whilst taking into account all finite-size multi-dimensional effects. We show how the ellipticity induced varies as a function of the distance to the axis of the beam, proving the importance of taking into account finite-size effects. This work serves as an important tool to complement existing efforts within the community to probe the effects of the quantum vacuum, in the strong field regime, for the first time.

  2. Light scattering from acoustic vibrational modes in confined structures

    Science.gov (United States)

    Bandhu, Rudra Shyam

    The acoustic vibrational modes and their light scattering intensities in confined structures such as supported films, double layer free-standing membrane and sub-micron sized wires on a free-standing membrane have been studied using Brillouin Light Scattering (BLS). Standing wave type acoustic phonons were recently observed in supported thin films of silicon oxy-nitride. We build upon this finding to study the acoustic modes in thin zinc selenide (ZnSe) films on gallium arsenide (GaAs). The surprising behaviour of the Brillouin intensities of the standing wave modes in ZnSe are explained in terms of interference of the elasto-optic scattering amplitudes from the film and substrate. Numerical calculations of the scattering cross-section, which takes into account ripple and elasto-optic scattering mechanism, agrees well with the experimental data. Light scattering studies of standing wave type modes in free-standing polymethyl methacrylate (PMMA) layer on Si3N4 were carried out. In these bilayer structures PMMA is much softer than Si3N 4, a property that leads to confinement of low frequency modes associated with the PMMA layer to within its boundaries. In addition, the flexural and the dilatational modes from the Si3N4 layer are observed and are found to hybridize with the standing wave modes from the PMMA layer. Our study of phonon modes in PMMA wires supported on a free-standing Si3N4 membrane extends our work on free-standing double layer membranes. In recent years there is much interest in the study of phonon modes in nano-scale structures such as wires or dots. Although much theoretical work has been carried out in this direction, no experiments exist that explore the dispersion of the phonon modes in such structures. Brillouin Light scattering is ideally suited for studying phonons in such reduced dimensions and our work represents the first effort in this direction. The spectra reveal modes which are quantized both along the width, as well along the thickness

  3. Angularly-resolved elastic light scattering of micro-particles

    Science.gov (United States)

    Aptowicz, Kevin B.

    From microbiology to astrophysics, the scientific community has long embraced elastic light scattering from small particles as a diagnostic tool. Elastic light scattering has an extremely large scattering cross-section, allowing for single particle interrogation. This is critical in applications where trace amounts of suspect particles are to be detected in a diverse background of natural aerosols. By angularly-resolving the elastically scattered light, features can be detected in these patterns that are sensitive to a particle's morphology (shape, size, internal structure, and composition). An apparatus to collect LA TAOS (Large-Angle Two-dimensional Angular Optical Scattering) patterns from single particles in-situ and in real-time was designed and constructed. The setup utilizes a cross-beam trigger system to minimize the effects of the aberration coma stemming from the main collection optic, an ellipsoidal mirror. LA TAOS patterns of ambient aerosols were collected and analyzed. Approximately 15% of the ambient aerosol had a sphere-like shape. The refractive index of these spheres was estimated by curve-fitting to Lorenz-Mie theory. In addition, the island features prevalent in the LA TAOS pattern were analyzed. Metrics generated from these were used to get partial discrimination between clusters of Bacillus subtilis spores (a simulant for anthrax) and aerosol particles found in the ambient atmosphere. A novel experimental setup for collecting simultaneously LA TAOS patterns at two wavelengths in the mid-infrared was also implemented. With this setup, the relative strength of single-particle absorption could be discerned at the two illuminating wavelengths.

  4. Supercontinuum Light Sources for Hyperspectral Subsurface Laser Scattering

    DEFF Research Database (Denmark)

    Nielsen, Otto Højager Attermann; Dahl, Anders Lindbjerg; Larsen, Rasmus;

    2011-01-01

    A materials structural and chemical composition influences its optical scattering properties. In this paper we investigate the use of subsurface laser scattering (SLS) for inferring structural and chemical information of food products. We have constructed a computer vision system based on a super......A materials structural and chemical composition influences its optical scattering properties. In this paper we investigate the use of subsurface laser scattering (SLS) for inferring structural and chemical information of food products. We have constructed a computer vision system based...... on a supercontinuum laser light source and an Acousto- Optic Tunable Filter (AOTF) to provide a collimated light source, which can be tuned to any wavelength in the range from 480 to 900 nm. We present the newly developed hyperspectral vision system together with a proof-of-principle study of its ability...... to discriminate between dairy products with either similar chemical or structural composition. The combined vision system is a new way for industrial food inspection allowing non-intrusive online process inspection of parameters that is hard with existing technology....

  5. Quasielastic Light Scattering and Structure of Nanodroplets Mixed with Polycaprolactone

    Directory of Open Access Journals (Sweden)

    Soheil Sharifi

    2014-01-01

    Full Text Available The interaction of polycaprolactone (PCL with droplets of a microemulsion is studied with quasielastic light scattering and small angle X-ray scattering At constant droplet size we vary the PCL concentration and there is clear evidence for an increasing attractive interaction of the droplets from structural investigations with small-angle X-ray scattering (SAXS. The collective diffusion coefficient (Dc of the droplets is monitored with quasielastic light scattering (QELS. We mainly focus on the variation of the dynamic behavior as a function of the PCL concentration and length scale (M.W. = 5000 and 10000 in microemulsion. With increasing PCL concentration and length scale the dynamics of the system slow down. A hard sphere model with depletion potential can fit well the SAXS experiment of microemulsion mixed with PCL. The results show with increase of PCL on microemulsion the size of droplets is constant at 83Å but the size ratio of polymer to droplets is changing.

  6. Light-scattering and dispersion behavior of multiwalled carbon nanotubes

    Science.gov (United States)

    Saltiel, Craig; Manickavasagam, Siva; Pinar Mengüc, M.; Andrews, Rodney

    2005-08-01

    Elliptically polarized light-scattering measurements were performed to investigate the dispersion behavior of multiwalled carbon nanotubes (MWNT). Xylene- and pyridine-derived MWNT powders were dispersed in water and ethanol in separate optic cells and allowed to sit undisturbed over a two-week time period after probe sonication. Continuous light-scattering measurements taken between scattering angles of 10-170 deg and repeated over several days showed that the nanotubes formed fractal-like networks. The pyridine-derived MWNTs showed greater dispersion variation over time, tending to aggregate and clump much faster than the xylene-derived tubes. The water suspensions appeared much more stable than the ethanol suspensions, which transformed into nonfractal morphology after a few hours. We relate the dispersion stability to size and fringe patterns on the outer surface of the nanotubes. Measured values of fractal dimension were distinctly lower than those in previous studies of single-walled carbon nanotubes. Profiles of both diagonal and off-diagonal scattering matrix elements are presented.

  7. Application of a scattered-light radiometric power meter.

    Science.gov (United States)

    Caron, James N; DiComo, Gregory P; Ting, Antonio C; Fischer, Richard P

    2011-04-01

    The power measurement of high-power continuous-wave laser beams typically calls for the use of water-cooled thermopile power meters. Large thermopile meters have slow response times that can prove insufficient to conduct certain tests, such as determining the influence of atmospheric turbulence on transmitted beam power. To achieve faster response times, we calibrated a digital camera to measure the power level as the optical beam is projected onto a white surface. This scattered-light radiometric power meter saves the expense of purchasing a large area power meter and the required water cooling. In addition, the system can report the power distribution, changes in the position, and the spot size of the beam. This paper presents the theory of the scattered-light radiometric power meter and demonstrates its use during a field test at a 2.2 km optical range. © 2011 American Institute of Physics

  8. Dynamic light scattering on bioconjugated laser generated gold nanoparticles.

    Science.gov (United States)

    Zimbone, Massimo; Baeri, Pietro; Calcagno, Lucia; Musumeci, Paolo; Contino, Annalinda; Barcellona, Maria Luisa; Bonaventura, Gabriele

    2014-01-01

    Gold nanoparticles (AuNPs) conjugated to DNA are widely used for biomedical targeting and sensing applications. DNA functionalization is easily reached on laser generated gold nanoparticles because of their unique surface chemistry, not reproducible by other methods. In this context, we present an extensive investigation concerning the attachment of DNA to the surface of laser generated nanoparticles using Dynamic Light Scattering and UV-Vis spectroscopy. The DNA conjugation is highlighted by the increase of the hydrodynamic radius and by the UV-Vis spectra behavior. Our investigation indicates that Dynamic Light Scattering is a suitable analytical tool to evidence, directly and qualitatively, the binding between a DNA molecule and a gold nanoparticle, therefore it is ideal to monitor changes in the conjugation process when experimental conditions are varied.

  9. Dynamic light scattering on bioconjugated laser generated gold nanoparticles.

    Directory of Open Access Journals (Sweden)

    Massimo Zimbone

    Full Text Available Gold nanoparticles (AuNPs conjugated to DNA are widely used for biomedical targeting and sensing applications. DNA functionalization is easily reached on laser generated gold nanoparticles because of their unique surface chemistry, not reproducible by other methods. In this context, we present an extensive investigation concerning the attachment of DNA to the surface of laser generated nanoparticles using Dynamic Light Scattering and UV-Vis spectroscopy. The DNA conjugation is highlighted by the increase of the hydrodynamic radius and by the UV-Vis spectra behavior. Our investigation indicates that Dynamic Light Scattering is a suitable analytical tool to evidence, directly and qualitatively, the binding between a DNA molecule and a gold nanoparticle, therefore it is ideal to monitor changes in the conjugation process when experimental conditions are varied.

  10. Dust Evolution Can Produce Scattered Light Gaps in Protoplanetary Disks

    CERN Document Server

    Birnstiel, Tilman; Pinilla, Paola; Kama, Mihkel

    2015-01-01

    Recent imaging of protoplanetary disks with high resolution and contrast have revealed a striking variety of substructure. Of particular interest are cases where near-infrared scattered light images show evidence for low-intensity annular "gaps". The origins of such structures are still uncertain, but the interaction of the gas disk with planets is a common interpretation. We study the impact that the evolution of the solid material can have on the observable properties of disks in a simple scenario without any gravitational or hydrodynamical disturbances to the gas disk structure. Even with a smooth and continuous gas density profile, we find that the scattered light emission produced by small dust grains can exhibit ring-like depressions similar to those presented in recent observations. The physical mechanisms responsible for these features rely on the inefficient fragmentation of dust particles. The occurrence and position of the proposed "gap" features depend most strongly on the dust-to-gas ratio, the f...

  11. Parhelic-like circle from light scattering in Plateau borders

    Energy Technology Data Exchange (ETDEWEB)

    Tufaile, A., E-mail: tufaile@usp.br; Tufaile, A.P.B.

    2015-03-06

    We are reporting a new simple optical element to generate halos. We have observed interesting patterns of light scattering in Plateau borders in foams. In analogy to the atmospheric phenomena known as parhelic circle, sun dogs, and sun pillars, we have named the features of the patterns observed as parlaseric circle, laser dogs, and laser pillars. The triangular symmetry of the Plateau borders is analogous to the hexagonal symmetry of ice crystals which produce these atmospheric phenomena. Working with one Plateau border at a time, we have observed wave optics phenomena that are not perceived in the atmospheric phenomena, such as diffraction and interference. - Highlights: • We obtained halo formation from light scattering in a Plateau border using an experiment. • We explained halo formation using geometrical theory of diffraction. • An optical element based on a Plateau border is proposed. • We compared some aspects of the parhelic circle with the parlaseric circle.

  12. Extending Kubelka-Munk's Theory with Lateral Light Scattering

    OpenAIRE

    Mourad, Safer; Emmel, Patrick; Simon, Klaus; Hersch, Roger David

    2001-01-01

    Due to its simplicity, the theory of KUBELKA-MUNK [1] has found a wide acceptance for modeling the optical properties of light scattering materials. However, the concept is not explicitly adapted to predict halftone prints on paper. In this respect, a recent improvement was given by BERG. Our approach is an extension of BERG'S model in order to reduce the gap between the mathematical description of the paper's point spread function and the experimental results of simple reflectance measurements.

  13. Dynamic Light Scattering Based Microelectrophoresis: Main Prospects and Limitations

    OpenAIRE

    Uskoković, Vuk

    2012-01-01

    Microelectrophoresis based on the dynamic light scattering (DLS) effect has been a major tool for assessing and controlling the conditions for stability of colloidal systems. However, both the DLS methods for characterization of the hydrodynamic size of dispersed submicron particles and the theory behind the electrokinetic phenomena are associated with fundamental and practical approximations that limit their sensitivity and information output. Some of these fundamental limitations, including...

  14. Visible light scatter as quantitative information source on milk constituents

    DEFF Research Database (Denmark)

    Melentieva, Anastasiya; Kucheryavskiy, Sergey; Bogomolov, Andrey

    2012-01-01

    VISIBLE LIGHT SCATTER AS A QUANTITATIVE INFORMATION SOURCE ON MILK CONSTITUENTS A. Melenteva 1, S. Kucheryavski 2, A. Bogomolov 1,31Samara State Technical University, Molodogvardeyskaya Street 244, 443100 Samara, Russia. 2Aalborg University, campus Esbjerg, Niels Bohrs vej 8, 6700 Esbjerg, Denmar...... research area are presented and discussed. References: [1] A. Bogomolov, S. Dietrich, B. Boldrini, R.W. Kessler, Food Chemistry (2012), doi:10.1016/j.foodchem.2012.02.077....

  15. Chahine algorithm to invert light scattering spectroscopy of epithelial dysplasia

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    To perceive the epithelial dysplasia from the light scattering spectroscopy (LSS) is an inverse problem, which can be transformed into the inversion of the size distribution of epithelial-cell nuclei. Based on the simulation of single polarized LSS for epithelial-cell nuclei, Chahine algorithm is adopted to retrieve the size distribution. Numerical results show that Chahine algorithm has high inversion precision for both single-peaked and bimodal models, which implies the potential to increase diagnostic resolution of LSS.

  16. Light scattering measurements supporting helical structures for chromatin in solution.

    Science.gov (United States)

    Campbell, A M; Cotter, R I; Pardon, J F

    1978-05-01

    Laser light scattering measurements have been made on a series of polynucleosomes containing from 50 to 150 nucleosomes. Radii of gyration have been determined as a function of polynucleosome length for different ionic strength solutions. The results suggest that at low ionic strength the chromatin adopts a loosely helical structure rather than a random coil. The helix becomes more regular on increasing the ionic strength, the dimension resembling those proposed by Finch and Klug for their solenoid model.

  17. Light scattering studies of an electrorheological fluid in oscillatory shear

    Energy Technology Data Exchange (ETDEWEB)

    Martin, J.E.; Odinek, J.

    1995-12-31

    We have conducted a real time, two-dimensional light scattering study of the nonlinear dynamics of field-induced structures in an electrorheological fluid subjected to oscillatory shear. We have developed a kinetic chain model of the observed dynamics by considering the response of a fragmenting/aggregating particle chain to the prevailing hydrodynamic and electrostatic forces. This structural theory is then used to describe the nonlinear rheology of ER fluids.

  18. Ultraviolet refractometry using field-based light scattering spectroscopy

    OpenAIRE

    2009-01-01

    Accurate refractive index measurement in the deep ultraviolet (UV) range is important for the separate quantification of biomolecules such as proteins and DNA in biology. This task is demanding and has not been fully exploited so far. Here we report a new method of measuring refractive index using field-based light scattering spectroscopy, which is applicable to any wavelength range and suitable for both solutions and homogenous objects with well-defined shape such as microspheres. The angula...

  19. Computational analysis of light scattering from collagen fiber networks

    Science.gov (United States)

    Arifler, Dizem; Pavlova, Ina; Gillenwater, Ann; Richards-Kortum, Rebecca

    2007-07-01

    Neoplastic progression in epithelial tissues is accompanied by structural and morphological changes in the stromal collagen matrix. We used the Finite-Difference Time-Domain (FDTD) method, a popular computational technique for full-vector solution of complex problems in electromagnetics, to establish a relationship between structural properties of collagen fiber networks and light scattering, and to analyze how neoplastic changes alter stromal scattering properties. To create realistic collagen network models, we acquired optical sections from the stroma of fresh normal and neoplastic oral cavity biopsies using fluorescence confocal microscopy. These optical sections were then processed to construct three-dimensional collagen networks of different sizes as FDTD model input. Image analysis revealed that volume fraction of collagen fibers in the stroma decreases with neoplastic progression, and statistical texture features computed suggest that fibers tend to be more disconnected in neoplastic stroma. The FDTD modeling results showed that neoplastic fiber networks have smaller scattering cross-sections compared to normal networks of the same size, whereas high-angle scattering probabilities tend to be higher for neoplastic networks. Characterization of stromal scattering is expected to provide a basis to better interpret spectroscopic optical signals and to develop more reliable computational models to describe photon propagation in epithelial tissues.

  20. High energy light scattering in the generalized eikonal approximation.

    Science.gov (United States)

    Chen, T W

    1989-10-01

    The generalized eikonal approximation method is applied to the study of light scattering by a dielectric medium. In this method, the propagation of light inside the medium is assumed to be rectilinear, as in the usual eikonal method, but with a parameterized propagator which is used to include the edge effect and ray optics behavior at the limit of very short wavelengths. The resulting formulas for the intensity and extinction efficiency factor are compared numerically and shown to agree excellently with the exact results for a homogeneous dielectric sphere.

  1. Subdiffraction scattered light imaging of gold nanoparticles using structured illumination.

    Science.gov (United States)

    Chang, Bo-Jui; Lin, Shiuan Huei; Chou, Li-Jun; Chiang, Su-Yu

    2011-12-15

    A reflective light-scattering (RLS) microscope with structured illumination (SI) provides subdiffraction resolution and improves the image quality of gold nanoparticles in biological systems. The three-dimensional (3D)-structured pattern is rapidly and precisely controlled with a spatial light modulator and scrambled at the conjugate image plane to increase spatial incoherence. The reconstructed SI-RLS image of 100 nm gold nanoparticles reveals lateral and axial resolutions of approximately 117 and 428 nm. We present a high-resolution image of gold nanoparticles inside a HeLa cell, with improved contrast.

  2. Metamaterials. Invisibility cloaking in a diffusive light scattering medium.

    Science.gov (United States)

    Schittny, Robert; Kadic, Muamer; Bückmann, Tiemo; Wegener, Martin

    2014-07-25

    In vacuum, air, and other surroundings that support ballistic light propagation according to Maxwell's equations, invisibility cloaks that are macroscopic, three-dimensional, broadband, passive, and that work for all directions and polarizations of light are not consistent with the laws of physics. We show that the situation is different for surroundings leading to multiple light scattering, according to Fick's diffusion equation. We have fabricated cylindrical and spherical invisibility cloaks made of thin shells of polydimethylsiloxane doped with melamine-resin microparticles. The shells surround a diffusively reflecting hollow core, in which arbitrary objects can be hidden. We find good cloaking performance in a water-based diffusive surrounding throughout the entire visible spectrum and for all illumination conditions and incident polarizations of light. Copyright © 2014, American Association for the Advancement of Science.

  3. Propagation of coherent polarized light in turbid highly scattering medium.

    Science.gov (United States)

    Doronin, Alexander; Macdonald, Callum; Meglinski, Igor

    2014-02-01

    Within the framework of further development of unified Monte Carlo code for the needs of biomedical optics and biophotonics, we present an approach for modeling of coherent polarized light propagation in highly scattering turbid media, such as biological tissues. The temporal coherence of light, linear and circular polarization, interference, and the helicity flip of circularly polarized light due to reflection at the medium boundary and/or backscattering events are taken into account. To achieve higher accuracy in the results and to speed up the modeling, the implementation of the code utilizes parallel computing on NVIDIA graphics processing units using Compute Unified Device Architecture. The results of the simulation of coherent linearly and circularly polarized light are presented in comparison with the results of known theoretical studies and the results of alternative modelings.

  4. Photovoltaic structures having a light scattering interface layer and methods of making the same

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xiangxin; Compaan, Alvin D.; Paudel, Naba Raj

    2015-10-13

    Photovoltaic (PV) cell structures having an integral light scattering interface layer configured to diffuse or scatter light prior to entering a semiconductor material and methods of making the same are described.

  5. Determination of reversible protein equilibrium association coefficients using light scattering

    Science.gov (United States)

    Larkin, Michael

    2009-03-01

    The characterization in solution of reversible protein associations as well as associations between proteins and small molecules is essential in many areas of science. Understanding cellular function or developing and formulating pharmaceuticals or other biologically active materials often requires quantitation of such associations. Most pharmaceuticals have functionality due solely to association with molecules within the body, and the discovery and accurate characterization of these associations is a key element for pharmaceutical development. Unfortunately, most methods used to measure associations of proteins require either immobilizing the protein on a surface (e.g. surface plasmon resonance), which potentially alters the protein characteristics, or require considerable time and effort and large quantities of sample (e.g. analytical ultracentrifugation, isothermal titration calorimetry). Light scattering based measurements of reversible association coefficients require much less sample and may be performed much more rapidly than other free solution techniques. In this talk I describe how static and dynamic light scattering may each independently be used to measure equilibrium association coefficients between proteins in free solution, and may also be used to observe and quantitate the association of small molecules with them. I present background theory for both static and dynamic light scattering measurements of equilibrium associations, and examples of measurements made of both model systems and of systems with commercial relevance in the pharmaceutical industry.

  6. Light scattering studies of solids and atomic vapors

    Energy Technology Data Exchange (ETDEWEB)

    Chiang, T.C.

    1978-09-01

    The general technique of light scattering and luminescence was used to study the properties of a number of material systems. First, multi-phonon resonant Raman scattering up to four phonons in GaSe and one- and two-phonon resonant Raman scattering in the mixed GaS/sub x/Se/sub 1-x/ crystals with x < or = 0.23 were investigated. Second, the observation of one-phonon resonant Raman scattering in HfS/sub 2/ is reported. The result is used to determine the position of the direct gap of HfS/sub 2/. Third, the first observation of the ..pi..-polarized one-magnon luminescence sideband of the /sup 4/T/sub lg/ (/sup 4/G) ..-->.. /sup 6/A/sub lg/(/sup 6/S) excitonic transition in antiferromagnetic MnF/sub 2/ is presented. An effective temperature of the crystal is deduced from the simultaneously observed anti-Stokes sideband emission. Multi-magnon (< or = 7) excitonic luminescence sidebands were also observed in MnF/sub 2/, KMnF/sub 2/, and RbMnF/sub 3/ using pulsed excitation and detection. A simple model based on two-ion local exchange is proposed to explain the results qualitatively. Fourth, the first observation of two-magnon resonant Raman scattering in MnF/sub 2/ around the magnon sidebands is reported. A simple theoretical description explains the experimental observations. Fifth, a detailed theory of exciton-exciton interaction in MnF/sub 2/ is developed to explain and to predict the experimental results on two-exciton absorption, high level excitation, and exciton--exciton scattering. Sixth, Brillouin scattering was used to obtain the five independent elastic constants of the layered compound GaSe. The results show clear elastic anisotropy of the crystal. Resonant Brillouin scattering near the absorption edge was also studied, but no resonant enhancement was found. Seventh, two-photon parametric scattering in sodium vapor was studied. Phase matching angles and scattering cross sections are calculated for a given set of experimental conditions.

  7. Using Quasi-Elastic Events to Measure Neutrino Oscillations with MINOS Detectors in the NuMI Neutrino Beam

    Energy Technology Data Exchange (ETDEWEB)

    Watabe, Masaki [Texas A & M Univ., College Station, TX (United States)

    2010-05-01

    MINOS (Main Injector Neutrino Oscillation Search) experiment has been designed to search for a change in the avor composition of a beam of muon neutrinos as they travel between the Near Detector at Fermi National Accelerator Laboratory and the Far Detector in the Soudan mine in Minnesota, 735 km from the target. The MINOS oscillation analysis is mainly performed with the charged current (CC) events and sensitive to constrain high- Δm2 values. However, the quasi-elastic (QEL) charged current interaction is dominant in the energy region important to access low- m2 values. For further improvement, the QEL oscillation analysis is performed in this dissertation. A data sample based on a total of 2.50 x 1020 POT is used for this analysis. In summary, 55 QEL-like events are observed at the Far detector while 87.06 ± 13.17 (syst:) events are expected with null oscillation hypothesis. These data are consistent with disappearance via oscillation with m2 = 2:10 0.37 (stat:) ± 0.24 (syst:) eV2 and the maximal mixing angle.

  8. Theory of quasi-elastic secondary emission from a quantum dot in the regime of vibrational resonance.

    Science.gov (United States)

    Rukhlenko, Ivan D; Fedorov, Anatoly V; Baymuratov, Anvar S; Premaratne, Malin

    2011-08-01

    We develop a low-temperature theory of quasi-elastic secondary emission from a semiconductor quantum dot, the electronic subsystem of which is resonant with the confined longitudinal-optical (LO) phonon modes. Our theory employs a generalized model for renormalization of the quantum dot's energy spectrum, which is induced by the polar electron-phonon interaction. The model takes into account the degeneration of electronic states and allows for several LO-phonon modes to be involved in the vibrational resonance. We give solutions to three fundamental problems of energy-spectrum renormalization--arising if one, two, or three LO-phonon modes resonantly couple a pair of electronic states--and discuss the most general problem of this kind that admits an analytical solution. With these results, we solve the generalized master equation for the reduced density matrix, in order to derive an expression for the differential cross section of secondary emission from a single quantum dot. The obtained expression is then analyzed to establish the basics of optical spectroscopy for measuring fundamental parameters of the quantum dot's polaron-like states.

  9. Light organization of small particles by multiple scattering

    Science.gov (United States)

    Hang, Zhi Hong

    Optical manipulation is of broad interest in physics, chemistry, and biology. In the literature, most of the studies are focused on the optical trapping on a single object. In this thesis, we investigated the light-induced interaction of a collection of particles. The light-induced interaction between small particles was studied by a hierarchy of methods including the dipole theory, the multiple scattering and Maxwell stress tensor formalism, and the finite-difference-time-domain method. We showed that the multiple scattering between small particles could induce a binding mechanism to stabilize optically organized structures, but at the same time induced an intrinsic unbinding mechanism. The stability of optically organized structure was studied and a concept of "optical density" was introduced to gauge the destabilizing effect. We found that light-induced forces could bind dielectric spheres into extended structures through two mechanisms, each with its own length scale which could be adjusted by the configuration of the external light source. By manipulating the commensurability of the two length scales, these two mechanisms cooperated to bind a large number of spheres. When the two length scales became incommensurate for some particular incident angle, the competition between the two mechanisms led to modulated structures and other complex phenomena such as re-entrant stability. We searched for the possibility for stabilizing larger clusters. For this purpose, we found that circularly polarized light bound dielectric spheres into large-scale two-dimensional hexagonal lattice and multiple scattering also induced a rotation of optically bound structures. We searched for configurations that could induce optical trapping by field enhancement. Enhanced transmission on perforated metallic film system was studied. Surface modes bound on multi perforated perfect metal plate system were analytical solved and related to different high transmittance modes. Near

  10. Spectroscopy of diffuse light in dust clouds. Scattered light and the solar neighbourhood radiation field

    CERN Document Server

    Lehtinen, K

    2012-01-01

    The optical surface brightness of dark nebulae is mainly due to scattering of integrated starlight by classical dust grains. It contains information on the impinging interstellar radiation field, cloud structure, and grain scattering properties. We have obtained spectra of the scattered light from 3500 to 9000 Angstrom in two globules, the Thumbprint Nebula and DC303.8-14.2. We use observations of the scattered light to study the impinging integrated starlight spectrum as well as the scattered H-alpha and other line emissions from all over the sky. We search also for the presence of other than scattered light in the two globules. We obtained long-slit spectra encompassing the whole globule plus adjacent sky in a one-slit setting, thus enabling efficient elimination of airglow and other foreground sky components. We calculated synthetic integrated starlight spectra for the solar neighbourhood using HIPPARCOS-based stellar distributions and the spectral library of Pickles. Spectra are presented separately for t...

  11. Efficient Light Extraction from Organic Light-Emitting Diodes Using Plasmonic Scattering Layers

    Energy Technology Data Exchange (ETDEWEB)

    Rothberg, Lewis

    2012-11-30

    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.

  12. Light scattering and light transmittance in intraocular lenses explanted because of optic opacification.

    Science.gov (United States)

    Michelson, Jennifer; Werner, Liliana; Ollerton, Andrew; Leishman, Lisa; Bodnar, Zachary

    2012-08-01

    To assess light scattering and light transmittance in intraocular lenses (IOLs) explanted because of optic opacification. John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. Experimental study. Poly(methyl methacrylate) (PMMA) IOLs with snowflake degeneration, hydrophilic acrylic IOLs with different calcification patterns, and 1 calcified silicone IOL explanted from an eye with asteroid hyalosis were studied with gross and light microscopy. Light scattering was measured with an EAS-1000 Scheimpflug camera. Light transmittance was measured with a Lambda 35 UV/Vis spectrophotometer (single-beam configuration with RSA-PE-20 integrating sphere). Analyses were performed at room temperature in the hydrated state and compared with controls. The study evaluated 8 PMMA IOLs, 22 hydrophilic acrylic IOLs, and 1 silicone IOL. Light scattering was as follows: 208 to 223 computer-compatible tapes (CCTs) for PMMA IOLs with snowflake degeneration (control = 9 CCTs); 90 to 227 CCTs for calcified hydrophilic acrylic IOLs (controls = 12 to 23 CCTs); 223 CCTs for the calcified silicone IOL (control = 5 CCTs). The mean light transmittance in the visible light spectrum was 81.08% to 97.10% for PMMA IOLs (control = 98.80%); 78.94% to 97.32% for hydrophilic acrylic IOLs (controls = 97.32% to 98.66%); 94.68% for the silicone IOL (control = 97.74%). Intraocular lens opacification led to very high levels of light scattering and a potential for decreased light transmittance, which play a role in the development of symptoms such as glare and halos, decreased contrast sensitivity, and eventually decreased visual acuity. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2012 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  13. LIGHT SOURCE: TW Laser system for Thomson scattering X-ray light source at Tsinghua University

    Science.gov (United States)

    Yan, Li-Xm; Du, Ying-Chao; Du, Qiang; Li, Ren-Kai; Hua, Jian-Fei; Huang, Wen-Hui; Tang, Chuan-Xiang

    2009-06-01

    A TW (Tera Watt) laser system based on Ti:sapphire mainly for the Tsinghua Thomson scattering X-ray light source (TTX) is being built. Both UV (ultraviolet) laser pulse for driving the photocathode radio-frequency (RF) gun and the IR (infrared) laser pulse as the electron-beam-scattered-light are provided by the system. Efforts have also been made in laser pulse shaping and laser beam transport to optimize the high-brightness electron beam production by the photocathode RF gun.

  14. Discovery of polarized light scattered by dust around Alpha Orionis

    Science.gov (United States)

    Mcmillan, R. S.; Tapia, S.

    1978-01-01

    Following the suggestion by Jura and Jacoby (1976), linearly polarized blue continuum starlight scattered by the dust shell around the M2 Iab star Alpha Orionis (Betelgeuse) has been discovered. The polarization has been traced in the NE, NW, SE, and SW directions and has positive (tangential) orientation. Some asymmetry of the optical depth in the shell exists 15 and 30 arcsec from the star. In the NE direction the polarization was measured as far as 90 arcsec (17,000 AU) from the star. The dependence of the average intensity of the scattered light from the nebula on angular distance from the star is more consistent with an inverse-square density law than with inverse 1.5 or inverse-cube laws. Assuming that the density is proportional to the inverse square of distance from the star, the scattering optical depth in blue light along a radius of 0.03 arcsec is no more than 0.15 + or - 0.05. Future observations of the wavelength dependence of polarization will allow a determination of grain size.

  15. Inelastic light scattering spectroscopy of semiconductor nitride nanocolumns

    Energy Technology Data Exchange (ETDEWEB)

    Calleja, J.M.; Lazic, S.; Sanchez-Paramo, J. [Departamento de Fisica de Materiales, Universidad Autonoma de Madrid, 28049 Madrid (Spain); Agullo-Rueda, F. [Materials Science Institute of Madrid, CSIC, 28049 Madrid (Spain); Cerutti, L.; Ristic, J.; Fernandez-Garrido, S.; Sanchez-Garcia, M.A.; Grandal, J.; Calleja, E. [ISOM and Departamento de Ingenieria Electronica, ETSIT, Universidad Politecnica de Madrid, Ciudad Universitaria, 28040 Madrid (Spain); Trampert, A.; Jahn, U. [Paul-Drude-Institut fuer Festkoerperelektronik, Hausvogteiplatz 5-7, 10117 Berlin (Germany)

    2007-08-15

    A review of inelastic light scattering measurements on group III-nitride nanocolumns grown by molecular beam epitaxy is presented. The nanocolumns are hexagonal, high quality single crystals with diameters in the range of 20 to 100 nm, with no traces of extended defects. GaN nanocolumns grown on bare Si substrates with both (111) and (100) orientation display narrow phonon peaks, indicating the absence of strain inhomogeneities. This opens the possibility of efficient integration of the nanocolumns as optoelectronic devices with the complementary metal oxide semiconductor technology. Measurements of the E{sub 2} phonon frequency on AlGaN nanocolumns indicate a linear dependence of the Al concentration on the Al relative flux, up to 60%. The E{sub 2} peak width increases with Al content due to phonon damping by alloy scattering. Inelastic light scattering measurements in InN nanocolumns display a coupled LO phonon-plasmon mode together with uncoupled phonons. The coupled mode is not observed in a reference compact sample. The origin of the coupled mode is attributed to spontaneous accumulation of electrons at the lateral surfaces of the nanocolumns. The presence of free electrons in the nanocolumns is confirmed by infrared reflectance measurements. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  16. Ultraviolet refractometry using field-based light scattering spectroscopy

    Science.gov (United States)

    Fu, Dan; Choi, Wonshik; Sung, Yongjin; Oh, Seungeun; Yaqoob, Zahid; Park, YongKeun; Dasari, Ramachandra R.; Feld, Michael S.

    2010-01-01

    Accurate refractive index measurement in the deep ultraviolet (UV) range is important for the separate quantification of biomolecules such as proteins and DNA in biology. This task is demanding and has not been fully exploited so far. Here we report a new method of measuring refractive index using field-based light scattering spectroscopy, which is applicable to any wavelength range and suitable for both solutions and homogenous objects with well-defined shape such as microspheres. The angular scattering distribution of single microspheres immersed in homogeneous media is measured over the wavelength range 260 to 315 nm using quantitative phase microscopy. By least square fitting the observed scattering distribution with Mie scattering theory, the refractive index of either the sphere or the immersion medium can be determined provided that one is known a priori. Using this method, we have measured the refractive index dispersion of SiO2 spheres and bovine serum albumin (BSA) solutions in the deep UV region. Specific refractive index increments of BSA are also extracted. Typical accuracy of the present refractive index technique is ≤0.003. The precision of refractive index measurements is ≤0.002 and that of specific refractive index increment determination is ≤0.01 mL/g. PMID:20372622

  17. The muon g-2: Dyson-Schwinger status on hadronic light-by-light scattering

    Energy Technology Data Exchange (ETDEWEB)

    Eichmann, Gernot; Fischer, Christian S.; Heupel, Walter; Williams, Richard [Institut für Theoretische Physik, Justus-Liebig–Universität Giessen, 35392 Giessen (Germany)

    2016-01-22

    We give a status report on the hadronic light-by-light scattering contribution to the muon’s anomalous magnetic moment from the Dyson-Schwinger approach. We discuss novel, model-independent properties of the light-by-light amplitude: we give its covariant decomposition in view of electromagnetic gauge invariance and Bose symmetry, and we identify the relevant kinematic regions that are probed under the integral. The decomposition of the amplitude at the quark level and the importance of its various diagrams are discussed and related to model approaches.

  18. Stray-light suppression with high-collection efficiency in laser light-scattering experiments

    Science.gov (United States)

    Deilamian, K.; Gillaspy, J. D.; Kelleher, D. E.

    1992-01-01

    An optical system is described for collecting a large fraction of fluorescent light emitted isotropically from a cylindrical interaction region. While maintaining an overall detection efficiency of 9 percent, the system rejects, by more than 12 orders of magnitude, incident laser light along a single axis that intersects the interaction region. Such a system is useful for a wide variety of light-scattering experiments in which high-collection efficiency is desirable, but in which light from an incident laser beam must be rejected without resorting to spectral filters.

  19. Neutron and light scattering studies of polymers adsorbed on laponite

    CERN Document Server

    Nelson, A R J

    2002-01-01

    The adsorption of poly(ethylene oxide) (PEO) and various poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (Pluronic) copolymers onto the synthetic clay Laponite, was investigated using Small Angle Neutron Scattering (SANS) and Dynamic Light Scattering (DLS). The Laponite particles are anisotropic, with a relatively high aspect ratio; but are the same order of magnitude in size as the polymer radius of gyration. Consequently, the particles present a radically different adsorption geometry compared to a locally planar interface, that is assumed by the majority of adsorption studies. The PEO homo-polymer formed thin layers, with the layer thickness being much smaller on the face than on the edge of the particle. Furthermore, the face thickness remained constant with increasing molecular weight, unlike the edge thickness, which grew with a small power law dependence on the molecular weight. Although the hydrodynamic thicknesses (DLS) were larger than those observed with SANS, the layer thicknesses ...

  20. Light dark matter scattering in outer neutron star crusts

    CERN Document Server

    Cermeño, Marina; Silk, Joseph

    2016-01-01

    We calculate for the first time the phonon excitation rate in the outer crust of a neutron star due to scattering from light dark matter (LDM) particles gravitationally boosted into the star. We consider dark matter particles in the sub-GeV mass range scattering off a periodic array of nuclei through an effective scalar-vector interaction with nucleons. We find that LDM effects cause a modification of the net number of phonons in the lattice as compared to the standard thermal result. In addition, we estimate the contribution of LDM to the ion-ion thermal conductivity in the outer crust and find that it can be significantly enhanced at large densities. Our results imply that for magnetized neutron stars the LDM-enhanced global conductivity in the outer crust will tend to reduce the anisotropic heat conduction between perpendicular and parallel directions to the magnetic field.

  1. Light dark matter scattering in outer neutron star crusts

    Science.gov (United States)

    Cermeño, Marina; Pérez-García, M. Ángeles; Silk, Joseph

    2016-09-01

    We calculate for the first time the phonon excitation rate in the outer crust of a neutron star due to scattering from light dark matter (LDM) particles gravitationally boosted into the star. We consider dark matter particles in the sub-GeV mass range scattering off a periodic array of nuclei through an effective scalar-vector interaction with nucleons. We find that LDM effects cause a modification of the net number of phonons in the lattice as compared to the standard thermal result. In addition, we estimate the contribution of LDM to the ion-ion thermal conductivity in the outer crust and find that it can be significantly enhanced at large densities. Our results imply that for magnetized neutron stars the LDM-enhanced global conductivity in the outer crust will tend to reduce the anisotropic heat conduction between perpendicular and parallel directions to the magnetic field.

  2. A Light Scattering Layer for Internal Light Extraction of Organic Light-Emitting Diodes Based on Silver Nanowires.

    Science.gov (United States)

    Lee, Keunsoo; Shin, Jin-Wook; Park, Jun-Hwan; Lee, Jonghee; Joo, Chul Woong; Lee, Jeong-Ik; Cho, Doo-Hee; Lim, Jong Tae; Oh, Min-Cheol; Ju, Byeong-Kwon; Moon, Jaehyun

    2016-07-13

    We propose and fabricate a random light scattering layer for light extraction in organic light-emitting diodes (OLEDs) with silver nanodots, which were obtained by melting silver nanowires. The OLED with the light scattering layer as an internal light extraction structure was enhanced by 49.1% for the integrated external quantum efficiency (EQE). When a wrinkle structure is simultaneously used for an external light extraction structure, the total enhancement of the integrated EQE was 65.3%. The EQE is maximized to 65.3% at a current level of 2.0 mA/cm(2). By applying an internal light scattering layer and wrinkle structure to an OLED, the variance in the emission spectra was negligible over a broad viewing angle. Power mode analyses with finite difference time domain (FDTD) simulations revealed that the use of a scattering layer effectively reduced the waveguiding mode while introducing non-negligible absorption. Our method offers an effective yet simple approach to achieve both efficiency enhancement and spectral stability for a wide range of OLED applications.

  3. Mandel'shtam-Brillouin scattering of laser light as a remote sensing tool.

    Science.gov (United States)

    Daniels, A.

    1972-01-01

    The mathematical relations regarding the intensity of scattered light are derived. The nature of density inhomogeneities in air is discussed together with scattering due to moving isothermal pressure fluctuations, the spectral distribution of scattering from static isobaric density fluctuations, and applications of Mandel'shtam-Brillouin (M-B) scattering to atmospheric sensing. It is concluded that M-B scattering of laser light from the atmosphere has an outstanding potential for remote atmospheric sensing.

  4. Population of collective modes in light scattering by many atoms

    Science.gov (United States)

    Guerin, William; Kaiser, Robin

    2017-05-01

    The interaction of light with an atomic sample containing a large number of particles gives rise to many collective (or cooperative) effects, such as multiple scattering, superradiance, and subradiance, even if the atomic density is low and the incident optical intensity weak (linear optics regime). Tracing over the degrees of freedom of the light field, the system can be well described by an effective atomic Hamiltonian, which contains the light-mediated dipole-dipole interaction between atoms. This long-range interaction is at the origin of the various collective effects, or of collective excitation modes of the system. Even though an analysis of the eigenvalues and eigenfunctions of these collective modes does allow distinguishing superradiant modes, for instance, from other collective modes, this is not sufficient to understand the dynamics of a driven system, as not all collective modes are significantly populated. Here, we study how the excitation parameters, i.e., the driving field, determines the population of the collective modes. We investigate in particular the role of the laser detuning from the atomic transition, and demonstrate a simple relation between the detuning and the steady-state population of the modes. This relation allows understanding several properties of cooperative scattering, such as why superradiance and subradiance become independent of the detuning at large enough detuning without vanishing, and why superradiance, but not subradiance, is suppressed near resonance. We also show that the spatial properties of the collective modes allow distinguishing diffusive modes, responsible for radiation trapping, from subradiant modes.

  5. Dynamic light scattering in veterinary medicine: refinement of diagnostic criteria

    Science.gov (United States)

    Dubin, Stephen; Zietz, Stanley; Gabriel, Karl L.; Gabriel, David; DellaVecchia, Michael A.; Ansari, Rafat R.

    2001-05-01

    In dynamic light scattering (DLS), the structure or material of interest, suspended in a fluid, is illuminated by a beam of laser light and the scattered light is interpreted in terms of diffusion coefficient, particle size or its distribution. DLS has shown clear promise as a non-invasive, objective and precise diagnostic modality for investigation of lens opacity (cataract) and other medical and toxicological problems. The clinical potential of LDS has been demonstrated in several species both in vivo and in vitro. In many clinical cases, discernment between normal and diseased patients is possible by simple inspection of the particle size distribution. However a more rigorous and sensitive classification scheme is needed, particularly for evaluation of therapy and estimation of tissue injury. The data supplied by DLS investigation is inherently multivariate and its most efficient interpretation requires a multivariate approach which includes the variability among specimens as well as any correlation among the variables (e.g. across the particle size distribution). We present a brief review of DLS methodology, illustrative data and our efforts toward a diagnostic classification scheme. In particular we will describe application of the Mahalanobis distance and related statistical methods to DLS data.

  6. Enhanced Light Scattering of Secondary Organic Aerosols by Multiphase Reactions.

    Science.gov (United States)

    Li, Kun; Li, Junling; Liggio, John; Wang, Weigang; Ge, Maofa; Liu, Qifan; Guo, Yucong; Tong, Shengrui; Li, Jiangjun; Peng, Chao; Jing, Bo; Wang, Dong; Fu, Pingqing

    2017-02-07

    Secondary organic aerosol (SOA) plays a pivotal role in visibility and radiative forcing, both of which are intrinsically linked to the refractive index (RI). While previous studies have focused on the RI of SOA from traditional formation processes, the effect of multiphase reactions on the RI has not been considered. Here, we investigate the effects of multiphase processes on the RI and light-extinction of m-xylene-derived SOA, a common type of anthropogenic SOA. We find that multiphase reactions in the presence of liquid water lead to the formation of oligomers from intermediate products such as glyoxal and methylglyoxal, resulting in a large enhancement in the RI and light-scattering of this SOA. These reactions will result in increases in light-scattering efficiency and direct radiative forcing of approximately 20%-90%. These findings improve our understanding of SOA optical properties and have significant implications for evaluating the impacts of SOA on the rapid formation of regional haze, global radiative balance, and climate change.

  7. Light-by-light scattering in the Lamb shift and the bound electron g factor

    Science.gov (United States)

    Czarnecki, Andrzej; Szafron, Robert

    2016-12-01

    We compute an O ( α2(Zα ) 6) contribution to the hydrogen-atom Lamb shift arising from light-by-light scattering. Analogous diagrams, with one atomic electric field insertion replaced by an external magnetic field, contribute to the gyromagnetic factor of the bound electron at O ( α2(Zα ) 4) . We also calculate the contribution to the gyromagnetic factor from the muon magnetic loop.

  8. On calculating disconnected-type hadronic light-by-light scattering diagrams from lattice QCD

    CERN Document Server

    Hayakawa, M; Christ, N H; Izubuchi, T; Jin, L C; Lehner, C

    2015-01-01

    For reliable comparison of the standard model prediction to the muon g-2 with its experimental value, the hadronic light-by-light scattering (HLbL) contribution must be calculated by lattice QCD simulation. HLbL contribution has many types of disconnected-type diagrams. Here, we start with recalling the point that must be taken care of in every method to calculate them by lattice QCD, and present one concrete method called nonperturbative QED method.

  9. Light-by-light scattering in the Lamb shift and the bound electron g factor

    CERN Document Server

    Czarnecki, Andrzej

    2016-01-01

    We compute an $\\mathcal{O}\\left(\\alpha^2(Z\\alpha)^6\\right)$ contribution to the hydrogen-atom Lamb shift arising from the light-by-light scattering. Analogous diagrams, with one atomic electric field insertion replaced by an external magnetic field, contribute to the gyromagnetic factor of the bound electron at $\\mathcal{O}\\left(\\alpha^2(Z\\alpha)^4\\right)$. We also calculate the contribution to the gyromagnetic factor from the muon magnetic loop.

  10. The effects of density-dependent form factors for (e, e'p) reaction in quasi-elastic region

    Energy Technology Data Exchange (ETDEWEB)

    Kim, K.S. [Korea Aerospace University, School of Liberal Arts and Science, Goyang (Korea, Republic of); Cheoun, Myung-Ki [Soongsil University, Department of Physics, Seoul (Korea, Republic of); Kim, Hungchong [Kookmin University, Department of General Education, Seoul (Korea, Republic of); So, W.Y. [Kangwon National University at Dogye, Department of Radiological Science, Samcheok (Korea, Republic of)

    2016-04-15

    Within the framework of a relativistic single particle model, the effects of density-dependent electromagnetic form factors on the exclusive (e, e'p) reaction are investigated in the quasi-elastic region. The density-dependent electromagnetic form factors are generated from a quark-meson coupling model and used to calculate the cross sections in two different densities, either at the normal density of ρ{sub 0} ∝ 0.15 fm{sup -3} or at the lower density, 0.5ρ{sub 0}. Then these cross sections are analyzed in the two different kinematics: One is that the momentum of the outgoing nucleon is along the momentum transfer. The other is that the angle between the momentum of the outgoing nucleon and the momentum transfer is varied at fixed magnitude of the momentum of the outgoing nucleon. Our theoretical differential reduced cross sections are compared with the NIKHEF data for the {sup 208}Pb(e, e'p) reaction, which is related to the probability that a bound nucleon from a given orbit can be knocked-out of the nucleus. The effects of the density-dependent form factors increase the differential cross sections for both knocked-out proton and neutron by an amount of a few percent. Moreover they are shown to be almost the same within only a few percent, i.e., nearly independent of the shell location of knockout nucleons. These results are quite consistent with the characteristics of double magic nuclei which have relatively sharp smearing in the density distribution. (orig.)

  11. Ultrafast image-based dynamic light scattering for nanoparticle sizing

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Wu; Zhang, Jie; Liu, Lili; Cai, Xiaoshu, E-mail: usst-caixs@163.com [Institute of Particle and Two-Phase Flow Measurement, Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering, University of Shanghai for Science and Technology, 516 Jungong Road, Shanghai 200093 (China)

    2015-11-15

    An ultrafast sizing method for nanoparticles is proposed, called as UIDLS (Ultrafast Image-based Dynamic Light Scattering). This method makes use of the intensity fluctuation of scattered light from nanoparticles in Brownian motion, which is similar to the conventional DLS method. The difference in the experimental system is that the scattered light by nanoparticles is received by an image sensor instead of a photomultiplier tube. A novel data processing algorithm is proposed to directly get correlation coefficient between two images at a certain time interval (from microseconds to milliseconds) by employing a two-dimensional image correlation algorithm. This coefficient has been proved to be a monotonic function of the particle diameter. Samples of standard latex particles (79/100/352/482/948 nm) were measured for validation of the proposed method. The measurement accuracy of higher than 90% was found with standard deviations less than 3%. A sample of nanosilver particle with nominal size of 20 ± 2 nm and a sample of polymethyl methacrylate emulsion with unknown size were also tested using UIDLS method. The measured results were 23.2 ± 3.0 nm and 246.1 ± 6.3 nm, respectively, which is substantially consistent with the transmission electron microscope results. Since the time for acquisition of two successive images has been reduced to less than 1 ms and the data processing time in about 10 ms, the total measuring time can be dramatically reduced from hundreds seconds to tens of milliseconds, which provides the potential for real-time and in situ nanoparticle sizing.

  12. Scaling up Echo-State Networks with multiple light scattering

    CERN Document Server

    Dong, Jonathan; Krzakala, Florent; Wainrib, Gilles

    2016-01-01

    Echo-State Networks and Reservoir Computing have been studied for more than a decade. As they provide an elegant yet powerful alternative to traditional computing, researchers have tried to implement them using physical systems, in particular non-linear optical elements, achieving high bandwidth and low power consumption. Here we present a completely different optical implementation of Echo-State Networks using light-scattering materials. As a proof of concept, binary networks have been successfully trained to perform non-linear operations on time series and memory of such networks has been evaluated. This new method is fast, power efficient and easily scalable to very large networks.

  13. Multiple scattering of light in three-dimensional photonic quasicrystals.

    Science.gov (United States)

    Ledermann, Alexandra; Wiersma, Diederik S; Wegener, Martin; von Freymann, Georg

    2009-02-01

    Recent experiments on three-dimensional icosahedral dielectric photonic quasicrystals have shown several unexpected features: transmitted femtosecond pulses developed a trailing "diffusive" exponential tail and the sum of (zeroth-order) transmittance and reflectance was well below unity. These experimental findings have previously been ascribed to sample imperfections. Here, we analyze these findings by using 3D periodic approximants of the ideal photonic quasicrystals. We show that the experimental observations can be explained in terms of multiple scattering of light within these structures, i.e., in terms of intrinsic rather than purely extrinsic quasicrystal properties.

  14. Wide-field imaging through scattering media by scattered light fluorescence microscopy

    Science.gov (United States)

    Zhou, Yulan; Li, Xun

    2017-08-01

    To obtain images through scattering media, scattered light fluorescence (SLF) microscopy that utilizes the optical memory effect has been developed. However, the small field of view (FOV) of SLF microscopy limits its application. In this paper, we have introduced a re-modulation method to achieve wide-field imaging through scattering media by SLF microscopy. In the re-modulation method, to raster scan the focus across the object plane, the incident wavefront is re-modulated via a spatial light modulator (SLM) in the updated phase compensation calculated using the optimized iterative algorithm. Compared with the conventional optical memory effect method, the re-modulation method can greatly increase the FOV of a SLF microscope. With the phase compensation theoretically calculated, the process of updating the phase compensation of a high speed SLM is fast. The re-modulation method does not increase the imaging time. The re-modulation method is, therefore, expected to make SLF microscopy have much wider applications in biology, medicine and physiology.

  15. HD100546 multi-epoch scattered light observations

    Energy Technology Data Exchange (ETDEWEB)

    Avenhaus, Henning; Quanz, Sascha P.; Meyer, Michael R. [ETH Zurich, Institute for Astronomy, Wolfgang-Pauli-Strasse 27, 8093 Zurich (Switzerland); Brittain, Sean D. [Department of Physics and Astronomy, 118 Kinard Laboratory, Clemson University, Clemson, SC 29634 (United States); Carr, John S. [Naval Research Laboratory, Code 7211, Washington, DC 20375 (United States); Najita, Joan R., E-mail: havenhaus@astro.phys.ethz.ch [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States)

    2014-07-20

    We present H, K{sub s}, and L' filter polarimetric differential imaging (PDI) data for the transitional disk around HD100546 obtained in 2013, together with an improved re-reduction of previously published 2006 data. We reveal the disk in polarized scattered light in all three filters, achieving an inner working angle of ∼0.''1. Additional, short-exposure observations in the H and K{sub s} filters probe the surroundings of the star down to ∼0.''03 (∼3 AU). HD100546 is fascinating because of its variety of sub-structures possibly related to forming planets in the disk, and PDI is currently the best technique for imaging them in the near-IR. For the first time ever, we detect a disk in L-band PDI data, and we constrain the outer radius of the inner hole to 14 ± 2 AU and its eccentricity to <0.133. A dark lane is detected between ∼0.''2-0.''6 AU in the front side of the disk, which is likely an effect of the scattering angle and the scattering function of the grains. We find a spiral arm in the northeast that has no obvious connection to spiral arms seen before by other authors further out in the disk, but winds are in the same direction (clockwise). The two bright scattering peaks along the semi-major axis are asymmetric, with the southeastern one being significantly brighter. This could be related to the inner companion candidate that is close to the brighter side of the disk at the time of the observations. The scattering color is close to gray between the H and K{sub s} filters ([H]–[K{sub s}] = 0.19 ± 0.11), but the scattering in the L' filter is significantly weaker ([H]–[L'] = –1.08 ± 0.35, [K{sub s}]–[L'] = –1.27 ± 0.35). We measure the position angle of the disk to be 138° ± 3°, consistent with previous observations, and we derive the dust scattering function in the H and K{sub s} filters between ∼35° and ∼130° at two different radii (30-50 and 80-110 AU) and show that

  16. Coherence effects in scattering order expansion of light by atomic clouds

    CERN Document Server

    Rouabah, Mohamed-Taha; Bachelard, Romain; Courteille, Philippe W; Kaiser, Robin; Piovella, Nicola

    2014-01-01

    We interpret cooperative scattering by a collection of cold atoms as a multiple scattering process. Starting from microscopic equations describing the response of $N$ atoms to a probe light beam, we represent the total scattered field as an infinite series of multiple scattering events. As an application of the method, we obtain analytical expressions of the coherent intensity in the double scattering approximation for Gaussian density profiles. In particular, we quantify the contributions of coherent backward and forward scattering.

  17. Coherence effects in scattering order expansion of light by atomic clouds.

    Science.gov (United States)

    Rouabah, Mohamed-Taha; Samoylova, Marina; Bachelard, Romain; Courteille, Philippe W; Kaiser, Robin; Piovella, Nicola

    2014-05-01

    We interpret cooperative scattering by a collection of cold atoms as a multiple-scattering process. Starting from microscopic equations describing the response of N atoms to a probe light beam, we represent the total scattered field as an infinite series of multiple-scattering events. As an application of the method, we obtain analytical expressions of the coherent intensity in the double-scattering approximation for Gaussian density profiles. In particular, we quantify the contributions of coherent backward and forward scattering.

  18. HD100546 Multi-Epoch Scattered-Light Observations

    CERN Document Server

    Avenhaus, Henning; Meyer, Michael R; Brittain, Sean D; Carr, John S; Najita, Joan R

    2014-01-01

    We present H, Ks and L filter polarimetric differential imaging (PDI) data for the transitional disk around HD100546 obtained in 2013, together with an improved re-reduction of previously published 2006 data. We reveal the disk in polarized scattered light in all three filters, achieving an inner working angle of 0.1 arcsec. Additional, short-exposure observations in the H and Ks filter probe the surrounding of the star down to about 0.03 (about 3 AU). HD100546 is fascinating because of its variety of sub-structures possibly related to forming planets in the disk, and PDI is currently the best technique to image them in the near-IR. Our key results are: (1) For the first time ever, we detect a disk in L-band PDI data. (2) We constrain the outer radius of the inner hole to 14pm2 AU and its eccentricity to < 0.133. (3) We detect a dark lane in the front side of the disk, which is likely an effect of the scattering angle and the scattering function of the grains. (4) We find a spiral arm in the northeast whic...

  19. Discrimination of airborne material particles from light scattering (TAOS) patterns

    Science.gov (United States)

    Crosta, Giovanni F.; Pan, Yong-Le; Videen, Gorden; Aptowicz, Kevin B.; Chang, Richard K.

    2013-05-01

    Two-dimensional angle-resolved optical scattering (TAOS) is an experimental method which collects the intensity pattern of monochromatic light scattered by a single, micron-sized airborne particle. In general, the interpretation of these patterns and the retrieval of the particle refractive index, shape or size alone, are difficult problems. The solution proposed herewith relies on a learning machine (LM): rather than identifying airborne particles from their scattering patterns, TAOS patterns themselves are classified. The LM consists of two interacting modules: a feature extraction module and a linear classifier. Feature extraction relies on spectrum enhancement, which includes the discrete cosine Fourier transform and non-linear operations. Linear classification relies on multivariate statistical analysis. Interaction enables supervised training of the LM. The application described in this article aims at discriminating the TAOS patterns of single bacterial spores (Bacillus subtilis) from patterns of atmospheric aerosol and diesel soot particles. The latter are known to interfere with the detection of bacterial spores. Classification has been applied to a data set with more than 3000 TAOS patterns from various materials. Some classification experiments are described, where the size of training sets has been varied as well as many other parameters which control the classifier. By assuming all training and recognition patterns to come from the respective reference materials only, the most satisfactory classification result corresponds to ≍ 20% false negatives from Bacillus subtilis particles and <= 11% false positives from environmental and diesel particles.

  20. The Spectrum of the Diffuse Galactic Light I: The Milky Way in Scattered Light

    CERN Document Server

    Brandt, Timothy D

    2011-01-01

    We measure the optical spectrum of the Diffuse Galactic Light--the local Milky Way in reflection--using 92,000 blank-sky spectra from the Sloan Digital Sky Survey. We correlate the SDSS optical flux density in regions of blank sky against 100 \\mu{}m intensity independently measured by the COBE and IRAS satellites, which provides a measure of the dust column density times the intensity of illuminating starlight. The spectrum of scattered light is very blue and shows a clear 4000 \\AA{} break and broad Mg b absorption. This is consistent with scattered starlight, and the continuum of the diffuse galactic light is well-reproduced by a simple radiative transfer model of the Galaxy. We also detect line emission in H\\alpha, H\\beta, [N II], and [S II], consistent with scattered light from the local interstellar medium. The strength of [N II] and [S II], combined with upper limits on [O III] and [He I], indicate a relatively soft ionizing spectrum. We find that our measurements of the diffuse galactic light can constr...

  1. Fining of Red Wine Monitored by Multiple Light Scattering.

    Science.gov (United States)

    Ferrentino, Giovanna; Ramezani, Mohsen; Morozova, Ksenia; Hafner, Daniela; Pedri, Ulrich; Pixner, Konrad; Scampicchio, Matteo

    2017-07-12

    This work describes a new approach based on multiple light scattering to study red wine clarification processes. The whole spectral signal (1933 backscattering points along the length of each sample vial) were fitted by a multivariate kinetic model that was built with a three-step mechanism, implying (1) adsorption of wine colloids to fining agents, (2) aggregation into larger particles, and (3) sedimentation. Each step is characterized by a reaction rate constant. According to the first reaction, the results showed that gelatin was the most efficient fining agent, concerning the main objective, which was the clarification of the wine, and consequently the increase in its limpidity. Such a trend was also discussed in relation to the results achieved by nephelometry, total phenols, ζ-potential, color, sensory, and electronic nose analyses. Also, higher concentrations of the fining agent (from 5 to 30 g/100 L) or higher temperatures (from 10 to 20 °C) sped up the process. Finally, the advantage of using the whole spectral signal vs classical univariate approaches was demonstrated by comparing the uncertainty associated with the rate constants of the proposed kinetic model. Overall, multiple light scattering technique showed a great potential for studying fining processes compared to classical univariate approaches.

  2. Flow speed measurement using two-point collective light scattering

    Energy Technology Data Exchange (ETDEWEB)

    Heinemeier, N.P

    1998-09-01

    Measurements of turbulence in plasmas and fluids using the technique of collective light scattering have always been plagued by very poor spatial resolution. In 1994, a novel two-point collective light scattering system for the measurement of transport in a fusion plasma was proposed. This diagnostic method was design for a great improvement of the spatial resolution, without sacrificing accuracy in the velocity measurement. The system was installed at the W7-AS steallartor in Garching, Germany, in 1996, and has been operating since. This master thesis is an investigation of the possible application of this new method to the measurement of flow speeds in normal fluids, in particular air, although the results presented in this work have significance for the plasma measurements as well. The main goal of the project was the experimental verification of previous theoretical predictions. However, the theoretical considerations presented in the thesis show that the method can only be hoped to work for flows that are almost laminar and shearless, which makes it of very small practical interest. Furthermore, this result also implies that the diagnostic at W7-AS cannot be expected to give the results originally hoped for. (au) 1 tab., 51 ills., 29 refs.

  3. Lysozyme Aggregation and Fibrillation Monitored by Dynamic Light Scattering

    Science.gov (United States)

    Nemzer, Louis; Flanders, Bret; Schmit, Jeremy; Sorensen, Christopher

    2012-02-01

    The aggregation of amyloidogenic proteins provides a rich phase space with significant biomedical implications, including a link with several age-related diseases. We employed dynamic light scattering to monitor the aggregation of lysozyme, a model protein, from a monomeric state until the formation of micron-sized fibrils. For an aqueous lysozyme solution buffered at pH 2, the auto-correlation function of the scattered light intensity was found to be well-fit by a single exponential function with decay time τ = 1/(2Dq^2) = 0.25 ms, which corresponds to a mean hydrodynamic radius (RH) of 2.2 nm, very likely generated by monomers. Ethanol (4% v/v final concentration) induced a partial unfolding, to RH = 4.6 nm. The subsequent addition of 70 mM KCl was found to shrink the size back to RH = 2.5 nm, as expected when a denatured protein refolds due to partial screening of the intramolecular repulsion. However, further aggregation was not observed. At pH 4, using a low-salt acetate buffer, more ethanol (10% v/v) was required to initiate unfolding, but once it occurred, larger aggregates formed. These results are consistent with the model that partial unfolding, which exposes beta-motif secondary structure, is a prerequisite for aggregation and fibrillation, but the aggregation fate depends on the protein charge state (pH) and screening (salt concentration).

  4. Scattered H-alpha light from Galactic dust clouds

    CERN Document Server

    Mattila, K; Lehtinen, K

    2006-01-01

    Bright emission nebulae, or HII regions, around hot stars are readily seen in H-alpha light. However, the all-pervasive faint H-alpha emission has only recently been detected and mapped over the whole sky. Mostly the H-alpha emission observed along a line of sight is produced by ionised gas in situ. There are, however, cases where all or most of the H-alpha radiation is due to scattering by electrons or dust particles which are illuminated by an H-alpha emitting source off the line of sight. Here we demonstrate that diffuse, translucent and dark dust clouds at high galactic latitudes are in many cases observed to have an excess of diffuse H-alpha surface brightness, i.e. they are brighter than the surrounding sky. We show that the majority of this excess surface brightness can be understood as light scattered off the interstellar dust grains. The source of incident photons is the general Galactic H-alpha background radiation impinging on the dust clouds from all over the sky.

  5. THEORETICAL-MODEL FOR THE SCATTERING OF LIGHT BY DENTIN AND COMPARISON WITH MEASUREMENTS

    NARCIS (Netherlands)

    ZIJP, [No Value; TENBOSCH, JJ

    1993-01-01

    A theoretical model of the scattering of light by dentin is presented. The model that results is a superposition of several scattering contributions, i.e., scattering by mineral crystals, collagen fibrils, and dentinal tubules. These tubules are oriented so that they cause an asymmetrical scattering

  6. Modeling diffuse reflectance measurements of light scattered by layered tissues

    Science.gov (United States)

    Rohde, Shelley B.

    In this dissertation, we first present a model for the diffuse reflectance due to a continuous beam incident normally on a half space composed of a uniform scattering and absorbing medium. This model is the result of an asymptotic analysis of the radiative transport equation for strong scattering, weak absorption and a defined beam width. Through comparison with the diffuse reflectance computed using the numerical solution of the radiative transport equation, we show that this diffuse reflectance model gives results that are accurate for small source-detector separation distances. We then present an explicit model for the diffuse reflectance due to a collimated beam of light incident normally on layered tissues. This model is derived using the corrected diffusion approximation applied to a layered medium, and it takes the form of a convolution with an explicit kernel and the incident beam profile. This model corrects the standard diffusion approximation over all source-detector separation distances provided the beam is sufficiently wide compared to the scattering mean-free path. We validate this model through comparison with Monte Carlo simulations. Then we use this model to estimate the optical properties of an epithelial layer from Monte Carlo simulation data. Using measurements at small source-detector separations and this model, we are able to estimate the absorption coefficient, scattering coefficient and anisotropy factor of epithelial tissues efficiently with reasonable accuracy. Finally, we present an extension of the corrected diffusion approximation for an obliquely incident beam. This model is formed through a Fourier Series representation in the azimuthal angle which allows us to exhibit the break in axisymmetry when combined with the previous analysis. We validate this model with Monte Carlo simulations. This model can also be written in the form of a convolution of an explicit kernel with the incident beam profile. Additionally, it can be used to

  7. A Precision Measurement of the Transverse Asymmetry AT from Quasi-elastic 3He(e,e') process, and the Neutron Magnetic Form Factor GNM at low Q2

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Wang [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2002-06-01

    Electromagnetic form factors are fundamental quantities in describing the underlying electromagnetic structure of nucleons. While proton electromagnetic form factors have been determined with good precision, neutron form factors are known poorly, largely due to the lack of free neutron targets. Jefferson Lab Hall A experiment E95-001, a ''precise measurement of the transverse asymmetry AT' from the quasielastic 3He(e, e') process,'' was therefore designed to determine precisely the neutron magnetic form factor, G$n\\atop{M}$ at low momentum transfer values and was successfully completed in Spring 1999. High precision AT'data in the quasi-elastic region at Q2 values of 0.1 to 0.6 (GeV/c)2 were obtained using a high-pressure spin-exchange optically-pumped polarized 3He gas target with an average polarization of 30%, a longitudinally polarized e- beam, and two High Resolution Spectrometers: HRSe and HRSh. HRSe was employed to detect scattered electrons from the quasi-elastic kinematic region, and HRSh was employed as a elastic polarimetry to monitor the product of the beam and target polarizations. The extraction of form factors is usually model-dependent. Significant constraints on theoretical calculations are provided bu additional high precision quasi-elastic asymmetry data at Q2 values of 0.1 and 0.2 (GeV/c)2 in 3He breakup region, where effects of final state interactions (FSI) and meson exchange currents (MEC) are expected to be large [71]. G$n\\atop{M}$ is extracted from a non-relativistic Faddeev calculation which includes both FSI and MEC at Q2 values of 0.1 and 0.2 (GeV/c)2. The uncertainties of G$n\\atop{M}$ at these Q2 values are comparable to those of recent experiments with deuterium targets [58]. At the higher Q2 values from this experiment, G$n\\atop{M}$ is extracted

  8. Polyelectrolyte Conformation, Interactions and Hydrodynamics as Studied by Light Scattering.

    Science.gov (United States)

    Ghosh, Snehasish

    Polyelectrolyte conformation, interactions and hydrodynamics show a marked dependence on the ionic strength (C_{rm s}) of the medium, the concentration (C_{rm p}) of the polymer itself and their charge density (xi). The apparent electrostatic persistence length obtained from static light scattering varied approximately as the inverse square root of C _{rm s} for highly pure, high molecular weight hyaluronate (HA) as well as for variably ionized acrylamide/sodium acrylate copolymers (NaPAA), and linearly with xi. The experimental values of persistence length and second virial coefficient (A_2) are compared to predictions from theories based on the Debye-Huckel approximation for the Poisson-Boltzmann equation and on excluded-volume. Although the mean square radius of gyration () depended strongly on C _{rm s}. decreasing with increasing C_{rm s} for both HA and NaPAA indicating clear evidence of polyion expansion, dynamic light scattering values of the translational diffusion coefficient (D) remains constant when extrapolated to infinite polymer concentration for both the polymers. The behavior of D is compared to predictions from coupled mode theory in the linear limit. The effects of NaOH on the conformations, interactions, diffusion and hydrolysis rates of HA are characterized in detail using static, dynamic and time-dependent light scattering supplemented by size exclusion chromatography (SEC). For the HA , A_2 and the hydrolysis rates all resemble superposing titration curves, while the D remains independent of both the concentration of NaOH, and the contraction of . The indication is that the interactions, conformations and the hydrolysis rates are all controlled by the titration of the HA hydroxyl groups by the NaOH to yield -O ^-, which (i) destroys single strand hydrogen bonds, leading to de-stiffening and contraction of the HA coil and a large decrease in intermolecular interaction, and (ii) slowly depolymerizes HA. The experimental results of HA

  9. A schlieren method for ultra-low angle light scattering measurements

    CERN Document Server

    Brogioli, D; Giglio, M; Giglio, Marzio

    2003-01-01

    We describe a self calibrating optical technique that allows to perform absolute measurements of scattering cross sections for the light scattered at extremely small angles. Very good performances are obtained by using a very simple optical layout similar to that used for the schlieren method, a technique traditionally used for mapping local refraction index changes. The scattered intensity distribution is recovered by a statistical analysis of the random interference of the light scattered in a half-plane of the scattering wave vectors and the main transmitted beam. High quality data can be obtained by proper statistical accumulation of scattered intensity frames, and the static stray light contributions can be eliminated rigorously. The potentialities of the method are tested in a scattering experiment from non equilibrium fluctuations during a free diffusion experiment. Contributions of light scattered from length scales as long as Lambda=1 mm can be accurately determined.

  10. Measurement of the νμ Charged Current π+ to Quasi-Elastic Cross Section Ratio on Mineral Oil in a 0.8 GeV Neutrino Beam

    Energy Technology Data Exchange (ETDEWEB)

    Linden, Steven K. [Yale Univ., New Haven, CT (United States)

    2011-01-01

    Charged current single pion production (CCπ+) and charged current quasi-elastic scattering (CCQE) are the most abundant interaction types for neutrinos at energies around 1 GeV, a region of great interest to oscillation experiments. The cross-sections for these processes, however, are not well understood in this energy range. This dissertation presents a measurement of the ratio of CCπ+ to CCQE cross-sections for muon neutrinos on mineral oil (CH2) in the MiniBooNE experiment. The measurement is presented here both with and without corrections for hadronic re-interactions in the target nucleus and is given as a function of neutrino energy in the range 0.4 GeV < Eν < 2.4 GeV. With more than 46,000 CCπ+ events collected in MiniBooNE, and with a fractional uncertainty of roughly 11% in the region of highest statistics, this measurement represents a dramatic improvement in statistics and precision over previous CCπ+ and CCQE measurements.

  11. Extraction of the Neutron Magnetic Form Factor from Quasi-Elastic 3He(pol)(e(pol),e') at Q^2 = 0.1 - 0.6 (GeV/c)^2

    CERN Document Server

    Anderson, B; Averett, T; Bertozzi, W; Black, T; Calarco, J; Cardman, L; Cates, G D; Chai, Z W; Chen, J P; Seonho Choi; Chudakov, E; Churchwell, S; Corrado, G S; Crawford, C; Dale, D; Deur, A; Djawotho, P; Dutta, D; Finn, J M; Gao, H; Gilman, R; Glamazdin, A V; Glashausser, C; Glöckle, W; Golak, J; Gómez, J; Gorbenko, V G; Hansen, J O; Hersman, F W; Higinbotham, D W; Holmes, R; Howell, C R; Hughes, E; Humensky, B; Incerti, S; De Jager, C W; Jensen, J S; Jiang, X; Jones, C E; Jones, M; Kahl, R; Kamada, H; Kievsky, fA; Kominis, I; Korsch, W; Krämer, K; Kumbartzki, G; Kuss, M; Lakuriqi, E; Liang, M; Liyanage, N; Le Rose, J; Malov, S; Margaziotis, D J; Martin, J W; McCormick, K; McKeown, R D; McIlhany, K; Meziani, Z E; Michaels, R; Miller, G W; Mitchell, J; Nanda, S; Pace, E; Pavlin, T; Petratos, G G; Pomatsalyuk, R I; Pripstein, D; Prout, D; Ransome, R D; Roblin, Y; Rvachev, M; Saha, A; Salmè, G; Schnee, M; Seely, J; Shin, T; Slifer, K J; Souder, P A; Strauch, S; Suleiman, R; Sutter, M; Tipton, B; Todor, L; Viviani, M; Vlahovic, B; Watson, J; Williamson, C F; Witala, H; Wojtsekhowski, B; Xiong, F; Xu, W; Yeh, J

    2006-01-01

    We have measured the spin-dependent transverse asymmetry, A_T', in quasi-elastic inclusive electron scattering from polarized 3He with high precision at Q^2 = 0.1 to 0.6 (GeV/c)^2. The neutron magnetic form factor, GMn, was extracted at Q^2 = 0.1 and 0.2 (GeV/c)^2 using a non-relativistic Faddeev calculation that includes both final-state interactions (FSI) and meson-exchange currents (MEC). In addition, GMn was extracted at Q^2 = 0.3 to 0.6 (GeV/c)^2 using a Plane Wave Impulse Approximation calculation. The accuracy of the modeling of FSI and MEC effects was tested and confirmed with a precision measurement of the spin-dependent asymmetry in the breakup threshold region of the 3He(pol)(e(pol),e') reaction. The total relative uncertainty of the extracted GMn data is approximately 3%. Close agreement was found with other recent high-precision GMn data in this Q^2 range.

  12. Simplifying the calculation of light scattering properties for black carbon fractal aggregates

    Science.gov (United States)

    Smith, A. J. A.; Grainger, R. G.

    2014-02-01

    Black carbon fractal aggregates have complicated shapes that make the calculation of their optical properties particularly computationally expensive. Here, a method is presented to estimate fractal aggregate light scattering properties by optimising simplified models to full light scattering calculations. It is found that there are no possible spherical models (at any size or refractive index) that well represent the light scattering in the visible, or near-thermal infrared. As such, parameterisations of the light scattering as a function of the number of aggregate particles is presented as the most pragmatic choice for modelling distributions of black carbon when the large computational overheads of rigorous scattering calculations cannot be justified. This parameterisation can be analytically integrated to provide light scattering properties for log-normal distributions of black carbon fractal aggregates and return extinction cross-sections with 0.1% accuracy for typical black carbon size distributions. Scattering cross-sections and the asymmetry parameter can be obtained to within 3%.

  13. Simplifying the calculation of light scattering properties for black carbon fractal aggregates

    Directory of Open Access Journals (Sweden)

    A. J. A. Smith

    2014-08-01

    Full Text Available Black carbon fractal aggregates have complicated shapes that make the calculation of their optical properties particularly computationally expensive. Here, a method is presented to estimate fractal aggregate light scattering properties by optimising simplified models to full light scattering calculations. It is found that there are no possible spherical models (at any size or refractive index that well represent the light scattering in the visible or near-thermal infrared. As such, parameterisations of the light scattering as a function of the number of aggregate particles is presented as the most pragmatic choice for modelling distributions of black carbon when the large computational overheads of rigorous scattering calculations cannot be justified. This parameterisation can be analytically integrated to provide light scattering properties for lognormal distributions of black carbon fractal aggregates and return extinction cross sections with 0.1% accuracy for typical black carbon size distributions. Scattering cross sections and the asymmetry parameter can be obtained to within 3%.

  14. Resonance Scattering Spectral Determination of HAS with a New Scattering Enhanced Reagent of K3[Fe(CN)6

    Institute of Scientific and Technical Information of China (English)

    JIANG,Zhi-Liang(蒋治良); PENG,Zhong-Li(彭忠利); LIU,Shao-Pu(刘绍璞)

    2002-01-01

    A new resonance scattering spectral (RSS) method for the determination of human serum album (HSA) has been proposed with the resonance scattering enhanced reagent of K3[Fe(CN)6]. In the medium of HCl (2,0× 10-3 mol/L), HSA may combine with [Fe(CN)6]3- by intermolecular forces (mainly by electrostatic force) to form {[Fe (CN)6]3n-HSAm+ }k nanoparticle of the ion-association complexes of HSAm+-[Fe(CN)6]3n-. There is a strongest resonance scattering intensity at 351 nm, owing to the existence of the resonance scattering of the nanoparticle, [Fe(CN)6]3- molecular absorption and the non-distribution of the emission intensity of Xe lamp in the range of 200-1000 nm. In addition, two resonance scattering peaks at 470 and 700 nm were observed. Tne HSA concentration in the range of 0-12 μg/mL is lhear to the resonance scattering intensity at 351 mn. The determination limit of this method is 0.1 μg/mL HSA, about ten-fold lower than that of Coomassie brilliant blue protein assay. This method has been used for the determination of HSA in human serum ami synthetic samples with satisfactory results. The mechanism of enhanced resonance scattering light, the TEM of the particle, the concepts of quasi-elastic absorption and tm-elastic absorption were also discussed.

  15. The Effects of Scattered Light from Optical Components on Visual Function

    Science.gov (United States)

    2016-02-01

    measures light scatter in the human eye (intraocular scatter) over a region from ~5° - 10° from the optical axis, or at an average scatter angle of...contrast sensitivity were measured in twelve subjects without and with eight different optical materials (OM) positioned in front of their right eye ... measure light scatter with and without an optical component in front of the eye and then calculating the difference, may provide data to derive a measure

  16. Light scattering by planetary-regolith analog samples: computational results

    Science.gov (United States)

    Väisänen, Timo; Markkanen, Johannes; Hadamcik, Edith; Levasseur-Regourd, Anny-Chantal; Lasue, Jeremie; Blum, Jürgen; Penttilä, Antti; Muinonen, Karri

    2017-04-01

    We compute light scattering by a planetary-regolith analog surface. The corresponding experimental work is from Hadamcik et al. [1] with the PROGRA2-surf [2] device measuring the polarization of dust particles. The analog samples are low density (volume fraction 0.15 ± 0.03) agglomerates produced by random ballistic deposition of almost equisized silica spheres (refractive index n=1.5 and diameter 1.45 ± 0.06 µm). Computations are carried out with the recently developed codes entitled Radiative Transfer with Reciprocal Transactions (R2T2) and Radiative Transfer Coherent Backscattering with incoherent interactions (RT-CB-ic). Both codes incorporate the so-called incoherent treatment which enhances the applicability of the radiative transfer as shown by Muinonen et al. [3]. As a preliminary result, we have computed scattering from a large spherical medium with the RT-CB-ic using equal-sized particles with diameters of 1.45 microns. The preliminary results have shown that the qualitative characteristics are similar for the computed and measured intensity and polarization curves but that there are still deviations between the characteristics. We plan to remove the deviations by incorporating a size distribution of particles (1.45 ± 0.02 microns) and detailed information about the volume density profile within the analog surface. Acknowledgments: We acknowledge the ERC Advanced Grant no. 320773 entitled Scattering and Absorption of Electromagnetic Waves in Particulate Media (SAEMPL). Computational resources were provided by CSC - IT Centre for Science Ltd, Finland. References: [1] Hadamcik E. et al. (2007), JQSRT, 106, 74-89 [2] Levasseur-Regourd A.C. et al. (2015), Polarimetry of stars and planetary systems, CUP, 61-80 [3] Muinonen K. et al. (2016), extended abstract for EMTS.

  17. Detection of circular polarization in light scattered from photosynthetic microbes

    CERN Document Server

    Sparks, William B; Germer, Thomas A; Chen, Feng; DasSarma, Shiladitya; DasSarma, Priya; Robb, Frank T; Manset, Nadine; Kolokolova, Ludmilla; Reid, Neill; Macchetto, F Duccio; Martin, William; 10.1073/pnas.0810215106

    2009-01-01

    The identification of a universal biosignature that could be sensed remotely is critical to the prospects for success in the search for life elsewhere in the universe. A candidate universal biosignature is homochirality, which is likely to be a generic property of all biochemical life. Due to the optical activity of chiral molecules, it has been hypothesized that this unique characteristic may provide a suitable remote sensing probe using circular polarization spectroscopy. Here, we report the detection of circular polarization in light scattered by photosynthetic microbes. We show that the circular polarization appears to arise from circular dichroism of the strong electronic transitions of photosynthetic absorption bands. We conclude that circular polarization spectroscopy could provide a powerful remote sensing technique for generic life searches.

  18. Brillouin light scattering studies of 2D magnonic crystals

    Science.gov (United States)

    Tacchi, S.; Gubbiotti, G.; Madami, M.; Carlotti, G.

    2017-02-01

    Magnonic crystals, materials with periodic modulation of their magnetic properties, represent the magnetic counterpart of photonic, phononic and plasmonic crystals, and have been largely investigated in recent years because of the possibility of using spin waves as a new means for carrying and processing information over a very large frequency bandwidth. Here, we review recent Brillouin light scattering studies of 2D magnonic crystals consisting of single- and bi-component arrays of interacting magnetic dots or antidot lattices. In particular, we discuss the principal properties of the magnonic band diagram of such systems, with emphasis given to its dependence on both magnetic and the geometrical parameters. Thanks to the possibility of tailoring their band structure by means of several degrees of freedom, planar magnonic crystals offer a good opportunity to design an innovative class of nanoscale microwave devices.

  19. Remnant lipoprotein size distribution profiling via dynamic light scattering analysis.

    Science.gov (United States)

    Chandra, Richa; Mellis, Birgit; Garza, Kyana; Hameed, Samee A; Jurica, James M; Hernandez, Ana V; Nguyen, Mia N; Mittal, Chandra K

    2016-11-01

    Remnant lipoproteins (RLP) are a metabolically derived subpopulation of triglyceride-rich lipoproteins (TRL) in human blood that are involved in the metabolism of dietary fats or triglycerides. RLP, the smaller and denser variants of TRL particles, are strongly correlated with cardiovascular disease (CVD) and were listed as an emerging atherogenic risk factor by the AHA in 2001. Varying analytical techniques used in clinical studies in the size determination of RLP contribute to conflicting hypotheses in regard to whether larger or smaller RLP particles contribute to CVD progression, though multiple pathways may exist. We demonstrated a unique combinatorial bioanalytical approach involving the preparative immunoseparation of RLP, and dynamic light scattering for size distribution analysis. This is a new facile and robust methodology for the size distribution analysis of RLP that in conjunction with clinical studies may reveal the mechanisms by which RLP cause CVD progression. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. LIGHT SCATTERING OF POLYSACCHARIDE FROM LACQUER IN AQUEOUS SOLUTION

    Institute of Scientific and Technical Information of China (English)

    ZHANG Lina; DU Yumin; KUMANOTANI JU

    1989-01-01

    The polysaccharide having weight-average molecular weight Mw= 1. 09 × 105 , isolated from the sap of lac trees ( Vietnam ), was separated into 12 fractions by aqueous-phase preparative gel permeation chromatography. The molecular weights and molecular weight distributions of the fractions were measured in aqueous 0.08M KCl/0.01 M NaAc and 0.4M KCl/0.05M NaAc at pH = 7.6 by light scattering, viscometry and gel permeation chromatography. The Mark-Houwink equation in aqueous 0.08M KCl/0.01M NaAc at30 ℃ was found to be [ η] = 2.28 ×10-2 M0.52w ( cm3/g ), which indicated the polysaccharide chain in the aqueous solution to be a spherical random coil.

  1. Elastic scattering, fusion, and breakup of light exotic nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Kolata, J.J. [University of Notre Dame, Physics Department, Notre Dame, IN (United States); Guimaraes, V. [Universidade de Sao Paulo, Instituto de Fisica, Sao Paulo, SP (Brazil); Aguilera, E.F. [Instituto Nacional de Investigaciones Nucleares, Departamento de Aceleradores, Mexico, Distrito Federal (Mexico)

    2016-05-15

    The present status of fusion reactions involving light (A< 20) radioactive projectiles at energies around the Coulomb barrier (E<10 MeV per nucleon) is reviewed, emphasizing measurements made within the last decade. Data on elastic scattering (providing total reaction cross section information) and breakup channels for the involved systems, demonstrating the relationship between these and the fusion channel, are also reviewed. Similarities and differences in the behavior of fusion and total reaction cross section data concerning halo nuclei, weakly-bound but less exotic projectiles, and strongly-bound systems are discussed. One difference in the behavior of fusion excitation functions near the Coulomb barrier seems to emerge between neutron-halo and proton-halo systems. The role of charge has been investigated by comparing the fusion excitation functions, properly scaled, for different neutron- and proton-rich systems. Possible physical explanations for the observed differences are also reviewed. (orig.)

  2. 2D Static Light Scattering for Dairy Based Applications

    DEFF Research Database (Denmark)

    Skytte, Jacob Lercke

    Throughout this thesis we investigate a recently introduced optical technique denoted 2D static light scattering (2DSLS). The technique is remote sensing, non-invasive, highly flexible, and appears to be well suited for in-line process control. Moreover, the output signal contains contributions......, this specific process control can be highly beneficial. To provide suitable reference measures on the actual microstructure, we investigate how to quantify micrographs of yogurts objectively. We provide a comparative study, that includes a broad range of different image texture descriptors....... from several different optical phenomena, which can be utilised to provide information on chemical composition and underlying microstructure of an investigated sample. The main goal of this thesis is to provide an exploratory study of the 2DSLS technique in relation to dairy based applications...

  3. Multifractal analysis of light scattering-intensity fluctuations

    Science.gov (United States)

    Shayeganfar, F.; Jabbari-Farouji, S.; Movahed, M. Sadegh; Jafari, G. R.; Tabar, M. Reza Rahimi

    2009-12-01

    We provide a simple interpretation of non-Gaussian nature of the light scattering-intensity fluctuations from an aging colloidal suspension of Laponite using the multiplicative cascade model, Markovian method, and volatility correlations. The cascade model and Markovian method enable us to reproduce most of recent empirical findings: long-range volatility correlations and non-Gaussian statistics of intensity fluctuations. We provide evidence that the intensity increments Δx(τ)=I(t+τ)-I(t) , upon different delay time scales τ , can be described as a Markovian process evolving in τ . Thus, the τ dependence of the probability density function p(Δx,τ) on the delay time scale τ can be described by a Fokker-Planck equation. We also demonstrate how drift and diffusion coefficients in the Fokker-Planck equation can be estimated directly from the data.

  4. Evaluation of urine culture screening by light-scatter photometry

    Energy Technology Data Exchange (ETDEWEB)

    Hale, D.C.; Thrupp, L.D.; Matsen, J.M.

    1981-08-01

    Urine screening for bacteriuria by light-scatter photometry (Autobac) was evaluated for accuracy and compared with a colony count by the calibrated loop method. Incubation time, inoculum size, precision, and interference of particulate matter were evaluated in an effort to standardize the screening procedure. Results showed that urines could be accurately screened for Enterobacteriaceae by inoculating a single Autobac cuvette chamber with 0.1 or 0.2 ml of urine and determining the voltage change after four hours. A change of greater than or equal to 0.2 units indicates significant bacteriuria. Decreased accuracy was noted for urines having greater than 10(5) cfu/ml of Pseudomonas species or gram-positive cocci, possibly because these organisms grow more slowly.

  5. Manipulating scattering of ultracold atoms with light-induced dissipation

    CERN Document Server

    Lemeshko, Mikhail

    2013-01-01

    Recently it has been shown that pairs of atoms can form metastable bonds due to non-conservative forces induced by dissipation [Lemeshko&Weimer, Nature Comm. 4, 2230 (2013)]. Here we study the dynamics of interaction-induced coherent population trapping - the process responsible for the formation of dissipatively bound molecules. We derive the effective dissipative potentials induced between ultracold atoms by laser light, and study the time evolution of the scattering states. We demonstrate that binding occurs on short timescales of ~10 microseconds, even if the initial kinetic energy of the atoms significantly exceeds the depth of the dissipative potential. Dissipatively-bound molecules with preordained bond lengths and vibrational wavefunctions can be created and detected in current experiments with ultracold atoms.

  6. Scattering of light by Gaussian-correlated quasi-homogeneous anisotropic media.

    Science.gov (United States)

    Du, Xinyue; Zhao, Daomu

    2010-02-01

    We investigate the case when light is scattered by Gaussian-correlated, quasi-homogeneous, anisotropic media. The analytical expression for the cross-spectral density function of the scattered field that is produced by scattering of a polychromatic plane wave incident upon a Gaussian-correlated, quasi-homogeneous, anisotropic medium is derived by use of a tensor method. Numerical examples are given to illustrate the normalized spectral density and the spectral degree of coherence of the field scattered by the anisotropic scatterer in contrast with that scattered by the isotropic scatterer.

  7. Coulomb distortion effects in deep-inelastic electron scattering

    Science.gov (United States)

    Co', Giampaolo; Heisenberg, Jochen

    1987-11-01

    The effects of the Coulomb distortion of the electron wave functions in the description of the electron scattering processes in the quasi-elastic region are discussed. A method to extract longitudinal and transverse response functions considering these effects is presented. While the transverse response function is remarkably affected by the Coulomb distortion, the values of the longitudinal response function are practically unchanged.

  8. Impact of non-standard interactions on neutrino-nucleon scattering

    CERN Document Server

    Papoulias, D K

    2016-01-01

    Non-standard neutrino-nucleon interaction is formulated and explored within the energy range of quasi-elastic scattering. In particular, the study focuses on the neutral-current elastic (anti-) neutrino scattering off nucleons described by the exotic reactions $\

  9. Light collection from scattering media in a silicon photonics integrated circuit

    OpenAIRE

    2011-01-01

    We present a silicon photonics integrated circuit to efficiently couple scattered light into a single mode waveguide. By modulating the phase of N light-capturing elements, the collection efficiency can be increased by a factor N.

  10. Focusing light through scattering media by full-polarization digital optical phase conjugation.

    Science.gov (United States)

    Shen, Yuecheng; Liu, Yan; Ma, Cheng; Wang, Lihong V

    2016-03-15

    Digital optical phase conjugation (DOPC) is an emerging technique for focusing light through or within scattering media such as biological tissue. Since DOPC systems are based on time reversal, they benefit from collecting as much information about the scattered light as possible. However, existing DOPC techniques record and subsequently phase-conjugate the scattered light in only a single-polarization state, limited by the operating principle of spatial light modulators. Here, we develop the first, to the best of our knowledge, full-polarization DOPC system that records and phase-conjugates scattered light along two orthogonal polarizations. When focusing light through thick scattering media, such as 2 mm and 4 mm-thick chicken breast tissue, our full-polarization DOPC system on average doubles the focal peak-to-background ratio achieved by single-polarization DOPC systems and improves the phase-conjugation fidelity.

  11. Study of the nanobubble phase of aqueous NaCl solutions by dynamic light scattering

    Energy Technology Data Exchange (ETDEWEB)

    Bunkin, N F; Shkirin, A V [A M Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation); Burkhanov, I S; Chaikov, L L [P N Lebedev Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation); Lomkova, A K [N.E. Bauman Moscow State Technical University, Moscow (Russian Federation)

    2014-11-30

    Aqueous NaCl solutions with different concentrations have been investigated by dynamic scattering of laser radiation. It is experimentally shown that these solutions contain scattering particles with a wide size distribution in a range of ∼10 – 100 nm. The experimental results indirectly confirm the existence of quasi-stable gas nanobubbles in the bulk of aqueous ionic solutions. (light scattering)

  12. Light scattering change precedes loss of cerebral adenosine triphosphate in a rat global ischemic brain model.

    Science.gov (United States)

    Kawauchi, Satoko; Sato, Shunichi; Ooigawa, Hidetoshi; Nawashiro, Hiroshi; Ishihara, Miya; Kikuchi, Makoto

    2009-08-14

    Measurement of intrinsic optical signals (IOSs) is an attractive technique for monitoring tissue viability in brains since it enables noninvasive, real-time monitoring of morphological characteristics as well as physiological and biochemical characteristics of tissue. We previously showed that light scattering signals reflecting cellular morphological characteristics were closely related to the IOSs associated with the redox states of cytochrome c oxidase in the mitochondrial respiratory chain. In the present study, we examined the relationship between light scattering and energy metabolism. Light scattering signals were transcranially measured in rat brains after oxygen and glucose deprivation, and the results were compared with concentrations of cerebral adenosine triphosphate (ATP) measured by luciferin-luciferase bioluminescence assay. Electrophysiological signal was also recorded simultaneously. After starting saline infusion, EEG activity ceased at 108+/-17s, even after which both the light scattering signal and ATP concentration remained at initial levels. However, light scattering started to change in three phases at 236+/-15s and then cerebral ATP concentration started to decrease at about 260s. ATP concentration significantly decreased during the triphasic scattering change, indicating that the start of scattering change preceded the loss of cerebral ATP. The mean time difference between the start of triphasic scattering change and the onset of ATP loss was about 24s in the present model. DC potential measurement showed that the triphasic scattering change was associated with anoxic depolarization. These findings suggest that light scattering signal can be used as an indicator of loss of tissue viability in brains.

  13. Measurement of double-polarization asymmetries in the quasi-elastic $^3\\vec{\\mathrm{He}}(\\vec{\\mathrm{e}},\\mathrm{e}'\\mathrm{d})$ process

    CERN Document Server

    Mihovilovič, M; Long, E; Zhang, Y -W; Allada, K; Anderson, B; Annand, J R M; Averett, T; Boeglin, W; Bradshaw, P; Camsonne, A; Canan, M; Cates, G D; Chen, C; Chen, J P; Chudakov, E; De Leo, R; Deng, X; Deltuva, A; Deur, A; Dutta, C; Fassi, L El; Flay, D; Frullani, S; Garibaldi, F; Gao, H; Gilad, S; Gilman, R; Glamazdin, O; Golak, J; Golge, S; Gomez, J; Hansen, O; Higinbotham, D W; Holmstrom, T; Huang, J; Ibrahim, H; de Jager, C W; Jensen, E; Jiang, X; Jones, M; Kang, H; Katich, J; Khanal, H P; Kievsky, A; King, P; Korsch, W; LeRose, J; Lindgren, R; Lu, H -J; Luo, W; Marcucci, L; Markowitz, P; Meziane, M; Michaels, R; Moffit, B; Monaghan, P; Muangma, N; Nanda, S; Norum, B E; Pan, K; Parno, D; Piasetzky, E; Posik, M; Punjabi, V; Puckett, A J R; Qian, X; Qiang, Y; Qui, X; Riordan, S; Saha, A; Sauer, P U; Sawatzky, B; Schiavilla, R; Shabestari, M; Shahinyan, A; Shoenrock, B; Širca, S; Skibiński, R; John, J St; Subedi, R; Sulkosky, V; Tobias, W A; Tireman, W; Urciuoli, G M; Viviani, M; Wang, D; Wang, K; Wang, Y; Watson, J; Wojtsekhowski, B; Witała, H; Ye, Z; Zhan, X; Zhang, Y; Zheng, X; Zhao, B; Zhu, L

    2014-01-01

    We present a precise measurement of double-polarization asymmetries in the $^3\\vec{\\mathrm{He}}(\\vec{\\mathrm{e}},\\mathrm{e}'\\mathrm{d})$ reaction. This particular process is a uniquely sensitive probe of hadron dynamics in $^3\\mathrm{He}$ and the structure of the underlying electromagnetic currents. The measurements have been performed in and around quasi-elastic kinematics at $Q^2 = 0.25\\,(\\mathrm{GeV}/c)^2$ for missing momenta up to $270\\,\\mathrm{MeV}/c$. The asymmetries are in fair agreement with the state-of-the-art calculations in terms of their functional dependencies on $p_\\mathrm{m}$ and $\\omega$, but are systematically offset. Beyond the region of the quasi-elastic peak, the discrepancies become even more pronounced. Thus, our measurements have been able to reveal deficiencies in the most sophisticated calculations of the three-body nuclear system, and indicate that further refinement in the treatment of their two- and/or three-body dynamics is required.

  14. Polarized synchronous light scattering characterization of the interaction of proteins with sodium dodecyl sulfonate

    Institute of Scientific and Technical Information of China (English)

    ZHAO XiaoHui; HUANG ChengZhi

    2007-01-01

    In acid buffer solution, proteins with positive charge can react with anion surfactant and result in a great enhancement of synchronous light scattering (SLS) signals. In this contribution, the correlative experiment was made to compare the interaction of human serum albumin (HAS) and immunoglobulin G (IgG) with sodium dodecyl sulfonate (SDS). Based on the measurements of the polarization light scattering signals, a new method of scattering polarization was constituted to distinguish these two interaction systems with molecular weight difference (HAS 66 kDa; IgG 150 kDa). The results were consistent with the data measured by dynamic light scattering (DLS) technique.

  15. Analytical techniques for addressing forward and inverse problems of light scattering by irregularly shaped particles.

    Science.gov (United States)

    Li, Xu; Chen, Zhigang; Gong, Jianmin; Taflove, Allen; Backman, Vadim

    2004-06-01

    Understanding light scattering by nonspherical particles is crucial in modeling the transport of light in realistic structures such as biological tissues. We report the application of novel analytical approaches based on modified Wentzel-Kramers-Brillouin and equiphase-sphere methods that facilitate accurate characterization of light scattering by a wide range of irregularly shaped dielectric particles. We also demonstrate that these approaches have the potential to address the inverse-scattering problem by means of a spectral analysis of the total scattering cross section of arbitrarily shaped particles.

  16. Spatio-Temporal Imaging of Light Transport in Highly Scattering Media under White Light Illumination

    CERN Document Server

    Badon, Amaury; Lerosey, Geoffroy; Boccara, Albert C; Fink, Mathias; Aubry, Alexandre

    2016-01-01

    Imaging the propagation of light in time and space is crucial in optics, notably for the study of complex media. We here demonstrate the passive measurement of time-dependent Green's functions between every point at the surface of a strongly scattering medium by means of low coherence interferometry. The experimental access to this Green's matrix is essential since it contains all the information about the complex trajectories of light within the medium. In particular, the spatio-temporal spreading of the diffusive halo can be locally investigated in the vicinity of each point then acting as a virtual source. On the one hand, this approach allows a quantitative imaging of the diffusion constant in the scattering medium with a spatial resolution of the order of a few transport mean free paths. On the other hand, our approach is able to reveal and quantify the anisotropy of light diffusion, which can be of great interest for optical characterization purposes. This study opens important perspectives both in opti...

  17. Optical evaluation of Fricke xylenol orange gel by light scattered at 90 degrees

    Energy Technology Data Exchange (ETDEWEB)

    Svoboda, J; Alwan, R; Guermeur, F; Makovicka, L; Bailly, Y [IRMA/ENISYS/FEMTO-ST UMR 6174 CNRS, Universite de Franche-Comte, Pole Universitaire, BP 71427, 25211 Montbeliard Cedex (France); Spevacek, V; Cechak, T [Department of Dosimetry and Application of Ionizing Radiation, FNSPE, Czech Technical University in Prague, Brehova 7, Praha 1, 115 19 (Czech Republic); Martin, E [Department of Radiotherapy, CH Belfort-Montbeliard, 25209 Montbeliard (France)], E-mail: svobojir@kmlinux.fjfi.cvut.cz

    2009-05-01

    This communication presents optical method for evaluation of Fricke xylenol gel (FXG) using light scattered at 90 degrees to initial direction. Although Fricke gel is predominantly absorbing, gelatine matrix scatters enough light which could be collected and related to dose delivered to gel. Initials experiments were oriented to determination applicability of this approach.

  18. A rotational diffusion coefficient of the 70s ribosome determined by depolarized laser light scattering

    NARCIS (Netherlands)

    Bruining, J.; Fijnaut, H.M.

    We have obtained a rotational diffusion coefficient of the 70S ribosome isolated from Escherichia-coli (MRE-600), from the depolarized light scattering spectrum measured by photon correlation spectroscopy. The intensity correlation function of depolarized scattered light contains contributions due

  19. A rotational diffusion coefficient of the 70s ribosome determined by depolarized laser light scattering

    NARCIS (Netherlands)

    Bruining, J.; Fijnaut, H.M.

    1975-01-01

    We have obtained a rotational diffusion coefficient of the 70S ribosome isolated from Escherichia-coli (MRE-600), from the depolarized light scattering spectrum measured by photon correlation spectroscopy. The intensity correlation function of depolarized scattered light contains contributions due t

  20. Measurements of strong correlations in the transport of light through strongly scattering materials

    NARCIS (Netherlands)

    Akbulut, D.

    2013-01-01

    In this thesis, we study light transport through multiple scattering random photonic materials. Light incident on such materials undergoes many scattering events before exiting the material. The relation between the incident and the transmitted fields is determined by the optical transmission matrix

  1. Measurements of strong correlations in the transport of light through strongly scattering materials

    NARCIS (Netherlands)

    Akbulut, D.

    2013-01-01

    In this thesis, we study light transport through multiple scattering random photonic materials. Light incident on such materials undergoes many scattering events before exiting the material. The relation between the incident and the transmitted fields is determined by the optical transmission matrix

  2. Light-scattering polarization measurements as a new parameter in flow cytometry

    NARCIS (Netherlands)

    Grooth, de B.G.; Terstappen, L.W.M.M.; Puppels, G.J.; Greve, J.

    1987-01-01

    Polarization measurement of orthogonal light scattering is introduced as a new optical parameter in flow cytometry. In the experimental setup, the electrical field of the incident laser beam is polarized in the direction of the sample flow. The intensity of the orthogonal light scattering polarized

  3. The effect of scattered light sensor orientation on roughness measurement of curved polished surfaces

    DEFF Research Database (Denmark)

    Pilny, Lukas; Bissacco, Giuliano; De Chiffre, Leonardo

    The effect of angular orientation of a scattered light sensor with respect to main curvature and surface lay on roughness measurements is evaluated. A commercial scattered light sensor OS 500-32 from Optosurf GmbH was used. The investigation was performed on polished cylindrical surfaces with cro...

  4. Characterization of dental composite curing kinetics using dynamic light scattering

    Science.gov (United States)

    Wells-Gray, Elaine M.; Kirkpatrick, Sean J.; Sakaguchi, Ron L.

    2009-02-01

    Polymer resin composites are a class of widely used restorative dental materials that undergo a complex polymerization curing process that has been the subject of substantial research. This study uses speckle correlation methods based on dynamic light scattering as a tool to monitor the rate and extent of dental composite polymerization during and after photo-curing. Thin disc-shaped samples (composite consisting of 50:50 BisGMA/TEGDMA resin, quartz silica filler particles, and camphorquinone as photo-initiator. A 633 nm HeNe laser beam was used to probe the top surface of the sample via a backscattered speckle pattern, while the bottom surface was illuminated with a halogen curing lamp (peak wavelength=470nm) to initiate the polymerization reaction. The speckle patterns were recorded with a CCD camera, and stored as a 'speckle cube' for post processing. Correlation values of the intensity fluctuation were calculated on a pixel-by-pixel basis for pairs of subsequent speckle images and then ensemble averaged. Results show a sharp decrease in correlation at the onset of curing, indicating a large amount of double bond conversion and movement within the composite. Correlation values then quickly increase, eventually reaching a plateau near unity, indicating cessation of molecular rearrangement. The kinetic behavior demonstrated by our correlation curves are in good agreement with curing data found in the literature, and demonstrate the usefulness of this technique for monitoring dental composite curing.

  5. Physiological and pathological clinical conditions and light scattering in brain

    Science.gov (United States)

    Kurata, Tsuyoshi; Iwata, Sachiko; Tsuda, Kennosuke; Kinoshita, Masahiro; Saikusa, Mamoru; Hara, Naoko; Oda, Motoki; Ohmae, Etsuko; Araki, Yuko; Sugioka, Takashi; Takashima, Sachio; Iwata, Osuke

    2016-08-01

    MRI of preterm infants at term commonly reveals subtle brain lesions such as diffuse white matter injury, which are linked with later cognitive impairments. The timing and mechanism of such injury remains unclear. The reduced scattering coefficient of near-infrared light (μs’) has been shown to correlate linearly with gestational age in neonates. To identify clinical variables associated with brain μs’, 60 preterm and full-term infants were studied within 7 days of birth. Dependence of μs’ obtained from the frontal head on clinical variables was assessed. In the univariate analysis, smaller μs’ was associated with antenatal glucocorticoid, emergency Caesarean section, requirement for mechanical ventilation, smaller gestational age, smaller body sizes, low 1- and 5-minute Apgar scores, higher cord blood pH and PO2, and higher blood HCO3‑ at the time of study. Multivariate analysis revealed that smaller gestational age, requirement for mechanical ventilation, and higher HCO3‑ at the time of study were correlated with smaller μs’. Brain μs’ depended on variables associated with physiological maturation and pathological conditions of the brain. Further longitudinal studies may help identify pathological events and clinical conditions responsible for subtle brain injury and subsequent cognitive impairments following preterm birth.

  6. Light scattering studies of irradiated {kappa}- and {iota}-carrageenan

    Energy Technology Data Exchange (ETDEWEB)

    Abad, L.V. [Neutron Science Laboratory, Institute for Solid State Physics, University of Tokyo, 106-1 Shirakata, Tokai, Ibaraki 319-1106 (Japan) and Philippine Nuclear Research Institute, Commonwealth Ave., Diliman, Quezon City (Philippines)]. E-mail: lvabad@pnri.dost.gov.ph; Nasimova, I.R. [Neutron Science Laboratory, Institute for Solid State Physics, University of Tokyo, 106-1 Shirakata, Tokai, Ibaraki 319-1106 (Japan); Physics Department, Moscow State University, Moscow 119992 (Russian Federation); Aranilla, C.T. [Philippine Nuclear Research Institute, Commonwealth Ave., Diliman, Quezon City (Philippines); Shibayama, M. [Neutron Science Laboratory, Institute for Solid State Physics, University of Tokyo, 106-1 Shirakata, Tokai, Ibaraki 319-1106 (Japan)]. E-mail: sibayama@issp.u-tokyo.ac.jp

    2005-05-01

    The relationships between the molecular weight (Mw) and the characteristic decay time distribution function G({gamma}) of irradiated kappa ({kappa}-) and iota ({iota}-) carrageenan were studied by static and dynamic light scattering (DLS). Mw and the characteristic decay time ({gamma}{sup -1}) are both steep decreasing exponential function with radiation dose. The dynamic behavior of irradiated {iota}-carrageenan was compared to irradiated {kappa}-carrageenan by DLS. The intensity correlation function of both carrageenans shifted towards shorter relaxation times with increasing radiation dose. Irradiated {iota}-carrageenan like {kappa}-carrageenan exhibits power law behavior at 0-50 kGy (at 0.05-0.1M KCl) indicating similar gelation behaviors. The temperature at which transition from coil to helix takes place (conformational transition temperature) decreases with increasing irradiation dose. A new faster relaxation mode appears at around 0.1-1 ms for both carrageenans between 100 and 150 kGy. Maximum peak height for this mode is at 100 kGy which corresponds to the optimum biological activity of {kappa}- and {iota}-carrageenan.

  7. Scattering of electromagnetic light waves from a deterministic anisotropic medium

    Science.gov (United States)

    Li, Jia; Chang, Liping; Wu, Pinghui

    2015-11-01

    Based on the weak scattering theory of electromagnetic waves, analytical expressions are derived for the spectral densities and degrees of polarization of an electromagnetic plane wave scattered from a deterministic anisotropic medium. It is shown that the normalized spectral densities of scattered field is highly dependent of changes of the scattering angle and degrees of polarization of incident plane waves. The degrees of polarization of scattered field are also subjective to variations of these parameters. In addition, the anisotropic effective radii of the dielectric susceptibility can lead essential influences on both spectral densities and degrees of polarization of scattered field. They are highly dependent of the effective radii of the medium. The obtained results may be applicable to determine anisotropic parameters of medium by quantitatively measuring statistics of a far-zone scattered field.

  8. The influence of the nuclear medium on inclusive electron and neutrino scattering off nuclei

    CERN Document Server

    Buss, O; Alvarez-Ruso, L; Mosel, U

    2007-01-01

    We present a model for inclusive electron and neutrino scattering off nuclei paying special attention to the influence of in-medium effects on the quasi-elastic scattering and pion-production mechanisms. Our results for electron scattering off Oxygen are compared to experimental data at beam energies ranging from 0.7-1.5 GeV. The good description of electron scattering serves as a benchmark for neutrino scattering.

  9. Modulation of light-enhancement to symbiotic algae by light-scattering in corals and evolutionary trends in bleaching.

    Directory of Open Access Journals (Sweden)

    Luisa A Marcelino

    Full Text Available Calcium carbonate skeletons of scleractinian corals amplify light availability to their algal symbionts by diffuse scattering, optimizing photosynthetic energy acquisition. However, the mechanism of scattering and its role in coral evolution and dissolution of algal symbioses during "bleaching" events are largely unknown. Here we show that differences in skeletal fractal architecture at nano/micro-lengthscales within 96 coral taxa result in an 8-fold variation in light-scattering and considerably alter the algal light environment. We identified a continuum of properties that fall between two extremes: (1 corals with low skeletal fractality that are efficient at transporting and redistributing light throughout the colony with low scatter but are at higher risk of bleaching and (2 corals with high skeletal fractality that are inefficient at transporting and redistributing light with high scatter and are at lower risk of bleaching. While levels of excess light derived from the coral skeleton is similar in both groups, the low-scatter corals have a higher rate of light-amplification increase when symbiont concentration is reduced during bleaching, thus creating a positive feedback-loop between symbiont concentration and light-amplification that exposes the remaining symbionts to increasingly higher light intensities. By placing our findings in an evolutionary framework, in conjunction with a novel empirical index of coral bleaching susceptibility, we find significant correlations between bleaching susceptibility and light-scattering despite rich homoplasy in both characters; suggesting that the cost of enhancing light-amplification to the algae is revealed in decreased resilience of the partnership to stress.

  10. Recursion relations and scattering amplitudes in the light-front formalism

    CERN Document Server

    Cruz-Santiago, Christian A

    2013-01-01

    The fragmentation functions and scattering amplitudes are investigated in the framework of light-front perturbation theory. It is demonstrated that, the factorization property of the fragmentation functions implies the recursion relations for the off-shell scattering amplitudes which are light-front analogs of the Berends-Giele relations. These recursion relations on the light-front can be solved exactly by induction and it is shown that the expressions for the off-shell light-front amplitudes are represented as a linear combinations of the on-shell amplitudes. By putting external particles on-shell we recover the scattering amplitudes previously derived in the literature.

  11. Towards a data-driven analysis of hadronic light-by-light scattering

    CERN Document Server

    Colangelo, Gilberto; Kubis, Bastian; Procura, Massimiliano; Stoffer, Peter

    2014-01-01

    The hadronic light-by-light contribution to the anomalous magnetic moment of the muon was recently analyzed in the framework of dispersion theory, providing a systematic formalism where all input quantities are expressed in terms of on-shell form factors and scattering amplitudes that are in principle accessible in experiment. We briefly review the main ideas behind this framework and discuss the various experimental ingredients needed for the evaluation of one- and two-pion intermediate states. In particular, we identify processes that in the absence of data for doubly-virtual pion-photon interactions can help constrain parameters in the dispersive reconstruction of the relevant input quantities, the pion transition form factor and the helicity partial waves for $\\gamma^*\\gamma^*\\to\\pi\\pi$.

  12. arXiv Light-by-Light Scattering Constraint on Born-Infeld Theory

    CERN Document Server

    Ellis, John; You, Tevong

    2017-06-27

    The recent measurement by ATLAS of light-by-light scattering in LHC Pb-Pb collisions is the first direct evidence for this basic process. We find that it excludes a range of the mass scale of a nonlinear Born-Infeld extension of QED that is ≲100  GeV, a much stronger constraint than those derived previously. In the case of a Born-Infeld extension of the standard model in which the U(1)Y hypercharge gauge symmetry is realized nonlinearly, the limit on the corresponding mass reach is ∼90  GeV, which, in turn, imposes a lower limit of ≳11  TeV on the magnetic monopole mass in such a U(1)Y Born-Infeld theory.

  13. Light Conversion and Scattering in UV Protective Textiles

    Directory of Open Access Journals (Sweden)

    Grancarić Ana Marija

    2014-12-01

    Full Text Available The primary cause of skin cancer is believed to be a long exposure to solar ultraviolet radiation (UV-R crossed with the amount of skin pigmentation in the population. It is believed that in childhood and adolescence 80% of UV-R gets absorbed, whilst in the remaining 20% gets absorbed later in the lifetime. This suggests that proper and early photoprotection may reduce the risk of subsequent occurrence of skin cancer. Textile and clothing are the most suitable interface between environment and human body. It can show UV protection, but in most cases it does not provide full sun screening properties. UV protection ability highly depends on large number of factors such as type of fibre, fabric surface and construction, type and concentration of dyestuff, fluorescent whitening agent (FWA, UV-B protective agents, as well as nanoparticles, if applied. Based on electronically excited state by energy of UV-R (usually 340-370 nm, the molecules of FWAs show the phenomenon of fluorescence giving to white textiles high whiteness of outstanding brightness by reemitting the energy at the blue region (typically 420-470 nm of the spectrum. By absorbing UV-A radiation, optical brightened fabrics transform this radiation into blue fluorescence, which leads to better UV protection. Natural zeolites are rock-forming, microporous silicate minerals. Applied as nanoparticles to textile surface, it scatters the UV-R resulting in lower UV-A and UV-B transmission. If applied with other UV absorbing agents, e.g. FWAs, synergistic effect occurs. Silicones are inert, synthetic compounds with a variety of forms and uses. It provides a unique soft touch, is very resistant to washing and improves the property of fabric to protect against UV radiation. Therefore, the UV protective properties of cotton fabric achieved by light conversion and scattering was researched in this paper. For that purpose, the stilbene-derived FWAs were applied on cotton fabric in wide concentration

  14. Ultraslow-light effects in symmetric and asymmetric waveguide structures with moon-like scatterers

    Science.gov (United States)

    Wan, Yong; Ge, Xiao-Hui; Xu, Sheng; Guo, Yue; Yuan, Feng

    2017-02-01

    Ultraslow-light effects in two-dimensional hexagonal-lattice coupled waveguide with moon-like scatterers were theoretically studied using the plane-wave expansion method. For symmetric structures, simulations showed that slow light with high group index can be achieved by shifting the scatterers and adjusting the radius of moon-like scatterers. The maximum group index was over 8:0 × 104. For asymmetric structures, simulations showed that slow light with flat band and high group index can be obtained by shifting the scatterers, adjusting the radius of moon-like scatterers, and rotating the scatterers. The maximum group index was over 5:7 × 105 with a "saddle-like" relationship between the frequency and group index.

  15. Light transmittance of 1-piece hydrophobic acrylic intraocular lenses with surface light scattering removed from cadaver eyes.

    Science.gov (United States)

    Werner, Liliana; Morris, Caleb; Liu, Erica; Stallings, Shannon; Floyd, Anne; Ollerton, Andrew; Leishman, Lisa; Bodnar, Zachary

    2014-01-01

    To assess the potential effect of surface light scattering on light transmittance of 1-piece hydrophobic acrylic intraocular lenses (IOLs) with or without a blue-light filter. John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. Experimental study. Intraocular lenses were obtained from human cadavers (49 IOLs total; 36 with blue-light filter) and from finished-goods inventory (controls). The IOLs were removed from cadaver eyes and the power and model matched to unused controls. After surface proteins were removed, the IOLs were hydrated for 24 hours at room temperature. Surface light scattering was measured with a Scheimpflug camera (EAS-1000 Anterior Segment Analysis System). Light transmittance was measured with a Lambda 35 UV/Vis spectrophotometer (single-beam configuration; RSA-PE-20 integrating sphere). Hydrated scatter values ranged from 4.8 to 202.5 computer-compatible tape (CCT) units for explanted IOLs with blue-light filter and 1.5 to 11.8 CCT units for controls; values ranged from 6.0 to 137.5 CCT units for explanted IOLs without a blue-light filter and 3.5 to 9.6 CCT units for controls. In both groups, there was a tendency toward increasing scatter values with increasing postoperative time. No differences in light transmittance were observed between explanted IOLs and controls in both groups (IOLs with blue-light filter: P=.407; IOL with no blue-light filter: P=.487; both paired t test). Although surface light scattering of explanted IOLs was significantly higher than that of controls and appeared to increase with time, no effect was observed on light transmittance of 1-piece hydrophobic acrylic IOLs with or without a blue-light filter. Copyright © 2013 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  16. Polarized light imaging specifies the anisotropy of light scattering in the superficial layer of a tissue

    Science.gov (United States)

    Jacques, Steven L.; Roussel, Stéphane; Samatham, Ravikant

    2016-01-01

    Abstract. This report describes how optical images acquired using linearly polarized light can specify the anisotropy of scattering (g) and the ratio of reduced scattering [μs′=μs(1−g)] to absorption (μa), i.e., N′=μs′/μa. A camera acquired copolarized (HH) and crosspolarized (HV) reflectance images of a tissue (skin), which yielded images based on the intensity (I=HH+HV) and difference (Q=HH−HV) of reflectance images. Monte Carlo simulations generated an analysis grid (or lookup table), which mapped Q and I into a grid of g versus N′, i.e., g(Q,I) and N′(Q,I). The anisotropy g is interesting because it is sensitive to the submicrometer structure of biological tissues. Hence, polarized light imaging can monitor shifts in the submicrometer (50 to 1000 nm) structure of tissues. The Q values for forearm skin on two subjects (one Caucasian, one pigmented) were in the range of 0.046±0.007 (24), which is the mean±SD for 24 measurements on 8 skin sites×3 visible wavelengths, 470, 524, and 625 nm, which indicated g values of 0.67±0.07 (24). PMID:27165546

  17. Positronium energy levels at order $m \\alpha^7$: light-by-light scattering in the two-photon-annihilation channel

    CERN Document Server

    Adkins, Gregory S; Salinger, M D; Wang, Ruihan; Fell, Richard N

    2014-01-01

    Recent and ongoing experimental work on the positronium spectrum motivates new efforts to calculate positronium energy levels at the level of three loop corrections. We have obtained results for one set of such corrections involving light-by-light scattering of the photons produced in a two-photon virtual annihilation process. Our result is an energy shift $1.58377(8) m \\alpha^7/\\pi^3$ for the n=1 singlet state, correcting the ground state hyperfine splitting by -6.95 kHz. We also obtained a new and more precise result for the light-by-light scattering correction to the real decay of parapositronium into two photons.

  18. Polarization control of multiply-scattered light through random media by wavefront shaping

    CERN Document Server

    Guan, Yefeng; Small, Eran; Zhou, Jianying; Silberberg, Yaron

    2015-01-01

    We show that the polarization state of coherent light propagating through an optically thick multiple-scattering medium, can be controlled by wavefront shaping, i.e. by controlling only the spatial phase of the incoming field with a spatial light modulator. Any polarization state of light at any spatial position behind the scattering medium can be attained with this technique. Thus, transforming the random medium to an arbitrary optical polarization component becomes possible.

  19. Spectral polarimetric light-scattering by particulate media: 1. Theory of spectral Vector Radiative Transfer

    Science.gov (United States)

    Ceolato, Romain; Riviere, Nicolas

    2016-07-01

    Spectral polarimetric light-scattering by particulate media has recently attracted growing interests for various applications due to the production of directional broadband light sources. Here the spectral polarimetric light-scattering signatures of particulate media are simulated using a numerical model based on the spectral Vector Radiative Transfer Equation (VRTE). A microphysical analysis is conducted to understand the dependence of the light-scattering signatures upon the microphysical parameters of particles. We reveal that depolarization from multiple scattering results in remarkable spectral and directional features, which are simulated by our model over a wide spectral range from visible to near-infrared. We propose to use these features to improve the inversion of the scattering problem in the fields of remote sensing, astrophysics, material science, or biomedical.

  20. Enhancing light transmission through a random medium with inhomogeneous scattering and loss

    CERN Document Server

    Sarma, Raktim; Cao, Hui

    2016-01-01

    We enhanced the total transmission of light through a disordered waveguide with spatially inhomogeneous scattering and loss by shaping the incident wavefront of a laser beam. Using an on-chip tapered lead, we were able to access all input modes in the waveguide with a spatial light modulator. The adaptive wavefront shaping resulted in selective coupling of input light to high transmission channels, which bypassed the regions of higher scattering and loss in the waveguide. The spatial inhomogeneity of scattering and loss led to redirecting of energy flux to optical paths with less scattering and loss to maximize total energy transported through the system. This work demonstrated the power of wavefront shaping in coherent control of light transport in inhomogeneous scattering media, which are common in real applications.

  1. New scheme of the Discrete Sources Method for light scattering analysis of a particle breaking interface

    Science.gov (United States)

    Eremin, Yuri; Wriedt, Thomas

    2014-12-01

    The Discrete Sources Method (DSM) has been modified to analyze polarized light scattering by an axial symmetric penetrable nanoparticle partially embedded into a substrate. The new numerical scheme of the DSM enables to consider scattering from such substrate defects as flat particles, mounds, pits and voids. A detailed description of the numerical scheme is provided. The developed computer model has been employed to investigate scattering from a shallow particle and pit. Simulation results corresponding to the Differential Scattering Cross-Section and the integral response for P/S polarized light are presented.

  2. Influence of surface light scattering in hydrophobic acrylic intraocular lenses on laser beam transmittance.

    Science.gov (United States)

    Shiraya, Tomoyasu; Kato, Satoshi; Minami, Keiichiro; Miyata, Kazunori

    2017-02-01

    The aim of this study was to experimentally examine the changes in the transmittances of photocoagulation lasers when surface light scattering increases in AcrySof intraocular lenses (IOLs). SA60AT IOLs (Alcon) were acceleratingly aging for 0, 3, 5, and 10 years to simulate surface light scattering, and the surface light-scattering intensities of both IOL surfaces were measured using a Scheimpflug photographer. The powers of laser beams that passed from a laser photocoagulator through the aged IOLs were measured at 532, 577, and 647 nm. Changes in the laser power and transmittance with the years of aging and the intensities of surface light scattering were examined. Although the intensity of surface light scattering increased with the years of aging, the laser power did not change with the years of aging (P > 0.30, Kruskal-Wallis test). There were no significant changes in the laser transmittance with the years of aging or the laser wavelength (P > 0.30 and 0.57, respectively). The intensity of surface light scattering revealed no significant association with the laser transmittance at any wavelength (P > 0.37, liner regression). The increases in the surface light scattering of the AcrySof IOLs would not influence retinal photocoagulation treatments for up to 10 years after implantation.

  3. Laboratory measurements of single light scattering by ensembles of randomly oriented small irregular particles in air. A review

    NARCIS (Netherlands)

    Muñoz, O.; Hovenier, J.W.

    2011-01-01

    In this paper we present an overview of light scattering experiments devoted to measure one or more elements of the scattering matrix as functions of the scattering angle of ensembles of randomly oriented small irregular particles in air. A summary of the most important findings in light scattering

  4. Critical behavior of 2,6-dimethylpyridine-water: Measurements of specific heat, dynamic light scattering, and shear viscosity

    DEFF Research Database (Denmark)

    Mirzaev, S. Z.; Behrends, R.; Heimburg, Thomas Rainer

    2006-01-01

    2,6-dimethylpyridine-water, specific heat, dynamic light scattering, shear viscosity Udgivelsesdato: 14 April......2,6-dimethylpyridine-water, specific heat, dynamic light scattering, shear viscosity Udgivelsesdato: 14 April...

  5. Light scattering changes follow evoked potentials from hippocampal Schaeffer collateral stimulation

    DEFF Research Database (Denmark)

    Rector, D M; Poe, G R; Kristensen, Morten Pilgaard

    1997-01-01

    -coupled device camera to detect scattered light changes, was lowered to the contralateral dorsal hippocampal surface. Light at 660 +/- 10 (SE) nm illuminated the tissue through optic fibers surrounding the optic probe. An attached bipolar electrode recorded evoked right hippocampal commissural potentials......We assessed relationships of evoked electrical and light scattering changes from cat dorsal hippocampus following Schaeffer collateral stimulation. Under anesthesia, eight stimulating electrodes were placed in the left hippocampal CA field and an optic probe, coupled to a photodiode or a charge...... a complex population synaptic potential that lasted 100-200 ms depending on stimulus intensity and electrode position. Light scattering changes peaked 20 ms after stimuli and occurred simultaneously with population spikes. A long-lasting light scattering component peaked 100-500 ms after the stimulus...

  6. Determination of thorium (IV) using isophthalaldehyde-tetrapyrrole as probe by resonance light scattering, second-order scattering and frequency-doubling scattering spectra.

    Science.gov (United States)

    Wang, Jiao; Xue, Jinhua; Xiao, Xilin; Xu, Li; Jiang, Min; Peng, Pengcheng; Liao, Lifu

    2017-12-05

    The coordination reaction of thorium (IV) with a ditopic bidentate ligand to form supramolecular polymer was studied by resonance light scattering (RLS) spectra, second-order scattering (SOS) spectra and frequency-doubling scattering (FDS) spectra, respectively. The ditopic bidentate ligand is isophthalaldehyde-tetrapyrrole (IPTP). It was synthesized through a condensation reaction of isophthalaldehyde with pyrrole. The formation of supramolecular polymer results in remarkable intensity enhancements of the three light scattering signals. The maximum scattering wavelengths of RLS, FDS and SOS were 290, 568 and 340nm, respectively. The reaction was used to establish new light scattering methods for the determination of thorium (IV) by using IPTP as probe. Under optimum conditions, the intensity enhancements of RLS, SOS and FDS were directly proportional to the concentration of thorium (IV) in the ranges of 0.01 to 1.2μgmL(-1), 0.05 to 1.2μgmL(-1) and 0.05 to 1.2μgmL(-1), respectively. The detection limits were 0.003μgmL(-1), 0.012μgmL(-1) and 0.021μgmL(-1), respectively. The methods were suitable for analyzing thorium (IV) in actual samples. The results show acceptable recoveries and precision compared with a reference method. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Equivalence theorem for the spectral density of light waves on weak scattering.

    Science.gov (United States)

    Wang, Tao; Ji, Xiaoling; Zhao, Daomu

    2014-07-01

    The Equivalence theorem for the spectral density of light waves on weak scattering is discussed. It is shown that when a spatially coherent plane light wave is scattered from two entirely different media, the far-zone spectral density may have identical distribution provided the low-frequency antidiagonal spatial Fourier components of the correlation function of the media are the same. An example of light waves on scattering from a Gaussian Schell model medium is discussed, and the condition on which two different media may produce identical spectral densities is presented.

  8. ARTICLES: Photoinduced light scattering in cerium-doped barium strontium niobate crystals

    Science.gov (United States)

    Voronov, Valerii V.; Dorosh, I. R.; Kuz'minov, Yu S.; Tkachenko, N. V.

    1980-11-01

    Photoinduced light scattering was observed in cerium-doped (SrxBa1-x)1-y(Nb2O6)y crystals having the composition x = 0.61, y = 0.4993. It was found that this effect is due to holographic amplification of light scattered by crystal defects. An analysis is made of static and dynamic characteristics of self-amplification of scattered light in the crystals. A theoretical model of the process is constructed assuming that the hologram recording process is of the diffusion type. Theoretical results are compared with the experiment.

  9. Photoinduced light scattering in cerium-doped barium strontium niobate crystals

    Science.gov (United States)

    Voronov, V. V.; Dorosh, I. R.; Kuz'minov, Yu. S.; Tkachenko, N. V.

    Photoinduced light scattering was observed in cerium-doped (Srx Ba1-x)1-y(Nb2O6)y crystals having the composition x = 0.61, y = 0.4993. It was found that this effect is due to holographic amplification of light scattered by crystal defects. An analysis is made of static and dynamic characteristics of self-amplification of scattered light in the crystals. A theoretical model of the process is constructed assuming that the hologram recording process is of the diffusion type. Theoretical results are compared with the experiment.

  10. Ribosome formation from subunits studied by stopped-flow and Rayleigh light scattering.

    Science.gov (United States)

    Antoun, Ayman; Pavlov, Michael Y.; Tenson, Tanel; Ehrenberg M, M åNs

    2004-01-01

    Light scattering and standard stopped-flow techniques were used to monitor rapid association of ribosomal subunits during initiation of eubacterial protein synthesis. The effects of the initiation factors IF1, IF2, IF3 and buffer conditions on subunit association were studied along with the role of GTP in this process. The part of light scattering theory that is essential for kinetic measurements is high-lighted in the main text and a more general treatment of Rayleigh scattering from macromolecules is given in an appendix.

  11. Ribosome formation from subunits studied by stopped-flow and Rayleigh light scattering

    Directory of Open Access Journals (Sweden)

    Antoun Ayman

    2004-01-01

    Full Text Available Light scattering and standard stopped-flow techniques were used to monitor rapid association of ribosomal subunits during initiation of eubacterial protein synthesis. The effects of the initiation factors IF1, IF2, IF3 and buffer conditions on subunit association were studied along with the role of GTP in this process. The part of light scattering theory that is essential for kinetic measurements is high-lighted in the main text and a more general treatment of Rayleigh scattering from macromolecules is given in an appendix.

  12. Analysis of Light Scattering by Nanoobjects on a Plane Surface via Discrete Sources Method

    Science.gov (United States)

    Eremina, Elena; Eremin, Yuri; Wriedt, Thomas

    2012-12-01

    In the last years light scattering by nanostructures is of interest in different areas of science and technology. Analysis of light scattered by nanostructures is an effective tool for a better understanding of their properties. In this work the Discrete Sources Method (DSM) is applied to model light scattering by nanoparticles on a surface. One of attractive features of the DSM is an ability to account for all the features of the modeled system, such as complex refractive index with frequency dispersion of particles and a substrate, scattering interaction of particle and an interface. To demonstrate the variety of possible applications for the DSM, we concentrated on two practical applications. First is light scattering by a nanorod on a surface, which requires the use of a general 3D version of the DSM. The second case discussed in this chapter is light scattering by a nanoshell, which allows the accounting for the axial symmetry of the problem and essential reduction of calculation time. In both cases light scattering characteristics and their dependence on nanostructure characteristics like size, symmetry, incident angle, particle orientation, refractive index and wavelength are analyzed and discussed.

  13. Polarized light scattering as a probe for changes in chromosome structure

    Energy Technology Data Exchange (ETDEWEB)

    Shapiro, Daniel Benjamin [Univ. of California, Berkeley, CA (United States)

    1993-10-01

    Measurements and calculations of polarized light scattering are applied to chromosomes. Calculations of the Mueller matrix, which completely describes how the polarization state of light is altered upon scattering, are developed for helical structures related to that of chromosomes. Measurements of the Mueller matrix are presented for octopus sperm heads, and dinoflagellates. Comparisons of theory and experiment are made. A working theory of polarized light scattering from helices is developed. The use of the first Born approximation vs the coupled dipole approximation are investigated. A comparison of continuous, calculated in this work, and discrete models is also discussed. By comparing light scattering measurements with theoretical predictions the average orientation of DNA in an octopus sperm head is determined. Calculations are made for the Mueller matrix of DNA plectonemic helices at UV, visible and X-ray wavelengths. Finally evidence is presented that the chromosomes of dinoflagellates are responsible for observed differential scattering of circularly-polarized light. This differential scattering is found to vary in a manner that is possibly correlated to the cell cycle of the dinoflagellates. It is concluded that by properly choosing the wavelength probe polarized light scattering can provide a useful tool to study chromosome structure.

  14. Scattering of Sculpted Light in Intact Brain Tissue, with implications for Optogenetics

    Science.gov (United States)

    Favre-Bulle, Itia A.; Preece, Daryl; Nieminen, Timo A.; Heap, Lucy A.; Scott, Ethan K.; Rubinsztein-Dunlop, Halina

    2015-06-01

    Optogenetics uses light to control and observe the activity of neurons, often using a focused laser beam. As brain tissue is a scattering medium, beams are distorted and spread with propagation through neural tissue, and the beam’s degradation has important implications in optogenetic experiments. To address this, we present an analysis of scattering and loss of intensity of focused laser beams at different depths within the brains of zebrafish larvae. Our experimental set-up uses a 488 nm laser and a spatial light modulator to focus a diffraction-limited spot of light within the brain. We use a combination of experimental measurements of back-scattered light in live larvae and computational modelling of the scattering to determine the spatial distribution of light. Modelling is performed using the Monte Carlo method, supported by generalised Lorenz-Mie theory in the single-scattering approximation. Scattering in areas rich in cell bodies is compared to that of regions of neuropil to identify the distinct and dramatic contributions that cell nuclei make to scattering. We demonstrate the feasibility of illuminating individual neurons, even in nucleus-rich areas, at depths beyond 100 μm using a spatial light modulator in combination with a standard laser and microscope optics.

  15. Optimum Forward Light Scattering by Spherical and Spheroidal Dielectric Nanoparticles with High Refractive Index

    CERN Document Server

    Luk`yanchuk, Boris S; Paniagua-Dominguez, Ramon; Kuznetsov, Arseniy I

    2014-01-01

    High-refractive index dielectric nanoparticles may exhibit strong directional forward light scattering at visible and near-infrared wavelengths due to interference of simultaneously excited electric and magnetic dipole resonances. For a spherical high-index dielectric, the so-called first Kerker's condition can be realized, at which the backward scattering practically vanishes for some combination of refractive index and particle size. However, Kerker's condition for spherical particles is only possible at the tail of the scattering resonances, when the particle scatters light weakly. Here we demonstrate that significantly higher forward scattering can be realized if spheroidal particles are considered instead. For each value of refractive index exists an optimum shape of the particle, which produces minimum backscattering efficiency together with maximum forward scattering. This effect is achieved due to the overlapping of magnetic and electric dipole resonances of the spheroidal particle at the resonance fr...

  16. Light scattering by a spherical particle with multiple densely packed inclusions

    Institute of Scientific and Technical Information of China (English)

    Sun Xian-Ming; Wang Hai-Hua; Liu Wan-Qiang; Shen Ji

    2009-01-01

    This paper calculates light scattering by a spherical water particle containing densely packed inclusions at a visible wavelength 0.55 μm by a combination of ray-tracing and Monte Carlo techniques. While the individual reflection and refraction events at the outer boundary of a sphere particle are considered by a ray-tracing program, the Monte Carlo routine simulates internal scattering processes. The main advantage of this method is that the shape of the particle can be arbitrary, and multiple scattering can be considered in the internal scattering processes. A dense-medium light-scattering theory based on the introduction of the static structure factor is used to calculate the phase function and asymmetry parameters for densely packed inclusions. Numerical results of the single scattering characteristics for a sphere containing multiple densely packed inclusions are given.

  17. Density of states governs light scattering in photonic crystals

    CERN Document Server

    García, P D; Froufe-Pérez, Luis S; López, C

    2008-01-01

    We describe a smooth transition from (fully ordered) photonic crystal to (fully disordered) photonic glass that enables us to make an accurate measurement of the scattering mean free path in nanostructured media and, in turn, establishes the dominant role of the density of states. We have found one order of magnitude chromatic variation in the scattering mean free path in photonic crystals for just $\\sim 3%$ shift around the band-gap ($\\sim 27$ nm in wavelength).

  18. Validation of in-line surface characterization by light scattering in Robot Assisted Polishing

    DEFF Research Database (Denmark)

    Pilny, Lukas; Bissacco, Giuliano; De Chiffre, Leonardo

    2014-01-01

    The suitability of a commercial scattered light sensor for in-line characterization of fine surfaces in the roughness range Sa 1 – 30 nm generated by the Robot Assisted Polishing (RAP) was investigated and validated. A number of surfaces were generated and directly measured with the scattered lig...

  19. Dynamics of spontaneous radiation of atoms scattered by a resonance standing light wave

    NARCIS (Netherlands)

    Fedorov, MV; Efremov, MA; Yakovlev, VP; Schleich, WP

    2003-01-01

    The scattering of atoms by a resonance standing light wave is considered under conditions when the lower of two resonance levels is metastable, while the upper level rapidly decays due to mainly spontaneous radiative transitions to the nonresonance levels of an atom. The diffraction scattering regim

  20. Formation of liquid inclusion induced light scatter in KDP (DKDP) crystals

    Institute of Scientific and Technical Information of China (English)

    孙洵; 孙大亮; 许心光; 王正平; 付有君; 王圣来; 曾红; 李毅平; 于锡玲; 高樟寿

    2001-01-01

    We describe in this paper the formation of liquid inclusion induced light scatter in potassium dihydrogen phosphate (KDP) crystal and deuterated potassium dihydrogen phosphate (DKDP) crystals. The measurement has been done with an atomic force microscope (AFM). The mechanism of formation of liquid inclusion scatter has been proposed and the effect of super-saturation discussed.

  1. Comparison of particle size of cracking catalyst determined by laser light scattering and dry sieve methods

    Energy Technology Data Exchange (ETDEWEB)

    Dishman, K.L.; Doolin, P.K.; Hoffman, J.F. (Ashland Petroleum Co., Ashland, KY (United States))

    1993-07-01

    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.

  2. Light scattering reviews 7 radiative transfer and optical properties of atmosphere and underlying surface

    CERN Document Server

    Kokhanovsky, Alexander A

    2014-01-01

    This book describes modern advances in radiative transfer and light scattering. Coverage includes fast radiative transfer techniques, use of polarization in remote sensing and recent developments in remote sensing of snow properties from space observations.

  3. Light Scattering and Thermal Emission by Primitive Dust Particles in Planetary Systems

    CERN Document Server

    Kimura, Hiroshi; Li, Aigen; Lebreton, Jérémy

    2016-01-01

    This review focuses on numerical approaches to deducing the light-scattering and thermal-emission properties of primitive dust particles in planetary systems from astronomical observations. The particles are agglomerates of small grains with sizes comparable to visible wavelength and compositions being mainly magnesium-rich silicates, iron-bearing metals, and organic refractory materials in pristine phases. These unique characteristics of primitive dust particles reflect their formation and evolution around main-sequence stars of essentially solar composition. The development of light-scattering theories has been offering powerful tools to make a thorough investigation of light scattering and thermal emission by primitive dust agglomerates in such a circumstellar environment. In particular, the discrete dipole approximation, the T-matrix method, and effective medium approximations are the most popular techniques for practical use in astronomy. Numerical simulations of light scattering and thermal emission by ...

  4. Neutron and photon (light) scattering on solitons in the quasi-one-dimensional magnetics

    CERN Document Server

    Abdulloev, K O

    1999-01-01

    The general expression we have found earlier for the dynamics form-factor is used to analyse experiments on the neutron and photon (light) scattering by the gas of solitons in quasi-one-dimensional magnetics (Authors)

  5. Polarized and depolarized light-scattering studies on Brownian diffusional and critical fluid systems: theory and experiment

    Energy Technology Data Exchange (ETDEWEB)

    Sorensen, C.M.

    1976-01-01

    An effort to expand light-scattering autocorrelation techniques to Brownian diffusional and critical fluid systems in which multiple scattering effects are important, and to understand the observed similarity of the Rayleigh linewidth of light scattered from these two seemingly different systems is discussed. A formalism was developed to find the light field multiply scattered from a suspension of Brownian diffusing particles. For the field doubly scattered from a system of noninteracting Brownian particles, the intensity and correlation time were much less dependent on the scattering angle than for the singly scattered component. The polarized and depolarized correlation times of light scattered from Brownian particle systems were measured. The double-scattering formalism was extended to light scattered from critical fluid systems. In the region k xi greater than 5 the doubly and singly scattered correlation times were nearly equal. The dynamic droplet model of critical phenomena was developed which gives the proper, experimentally verified, forms for the intensity and linewidth of light scattered from a critical fluid. To test the dynamic droplet model and the mode theories Rayleigh linewidth predictions, light-scattering measurements were performed on the critical fluid system methanol and cyclohexane. The data agreed with both the dynamic droplet and decoupled mode theory predictions. The depolarized scattered spectra from a critical fluid were measured, and qualitative agreement with the double-scattering theory was found. 57 figures, 5 tables.

  6. The scatter of light of different colour in the atmosphere.

    NARCIS (Netherlands)

    Schreuder, D.A.

    1976-01-01

    It is often claimed (Devaux) that yellow light is superior to white light for vehicle headlamps. This claim is supported by evidence of a physical, physiological and psychological nature. In most cases, it appears that the advantages of yellow light are small, and can usually be neglected particul

  7. Simplifying the calculation of light scattering properties for black carbon fractal aggregates

    Directory of Open Access Journals (Sweden)

    A. J. A. Smith

    2014-02-01

    Full Text Available Black carbon fractal aggregates have complicated shapes that make the calculation of their optical properties particularly computationally expensive. Here, a method is presented to estimate fractal aggregate light scattering properties by optimising simplified models to full light scattering calculations. It is found that there are no possible spherical models (at any size or refractive index that well represent the light scattering in the visible, or near-thermal infrared. As such, parameterisations of the light scattering as a function of the number of aggregate particles is presented as the most pragmatic choice for modelling distributions of black carbon when the large computational overheads of rigorous scattering calculations cannot be justified. This parameterisation can be analytically integrated to provide light scattering properties for log-normal distributions of black carbon fractal aggregates and return extinction cross-sections with 0.1% accuracy for typical black carbon size distributions. Scattering cross-sections and the asymmetry parameter can be obtained to within 3%.

  8. Optical Imaging of Cells with Gold Nanoparticle Clusters as Light Scattering Contrast Agents

    DEFF Research Database (Denmark)

    Tanev, Stoyan

    2011-01-01

    developments in advanced cytometry research by pointing out potential new research directions. A brief description of the FDTD method focusing on the features associated with its application to modeling of light scattering and OPCM cell imaging experiments is provided. The examples include light scattering...... from OPCM imaging of single biological cells in conditions of controlled refractive index matching (RIM) and labeling by diffused and clustered gold NPs. The chapter concludes with a discussion and suggestions for future research....

  9. T-matrix computations of light scattering by red blood cells

    OpenAIRE

    Nilsson, Annika M. K.; Alsholm, Peter; Karlsson, Anders; Andersson-Engels, Stefan

    1998-01-01

    The electromagnetic far field, as well as near field, originating from light interaction with a red blood cell (RBC) volume equivalent spheroid, were analyzed utilizing T-matrix theory. This method is a powerful tool which enables the influence of cell shape on the angular distribution of scattered light to be studied. General observations were that the three-dimensional shape, as well as optical thickness apparent to the incident field, affect the forward scattering. The ba...

  10. Detecting quantum coherence of Bose gases in optical lattices by scattering light intensity in cavity.

    Science.gov (United States)

    Zhou, Xiaoji; Xu, Xu; Yin, Lan; Liu, W M; Chen, Xuzong

    2010-07-19

    We propose a new method of detecting quantum coherence of a Bose gas trapped in a one-dimensional optical lattice by measuring the light intensity from Raman scattering in cavity. After pump and displacement process, the intensity or amplitude of scattering light is different for different quantum states of a Bose gas, such as superfluid and Mott-Insulator states. This method can also be useful to detect quantum states of atoms with two components in an optical lattice.

  11. Anomalous Light Scattering by Topological PT-symmetric Particle Arrays

    Science.gov (United States)

    Ling, C. W.; Choi, Ka Hei; Mok, T. C.; Zhang, Zhao-Qing; Fung, Kin Hung

    2016-12-01

    Robust topological edge modes may evolve into complex-frequency modes when a physical system becomes non-Hermitian. We show that, while having negligible forward optical extinction cross section, a conjugate pair of such complex topological edge modes in a non-Hermitian -symmetric system can give rise to an anomalous sideway scattering when they are simultaneously excited by a plane wave. We propose a realization of such scattering state in a linear array of subwavelength resonators coated with gain media. The prediction is based on an analytical two-band model and verified by rigorous numerical simulation using multiple-multipole scattering theory. The result suggests an extreme situation where leakage of classical information is unnoticeable to the transmitter and the receiver when such a -symmetric unit is inserted into the communication channel.

  12. Inelastic electron and light scattering from the elementary electronic excitations in quantum wells: Zero magnetic field

    Directory of Open Access Journals (Sweden)

    Manvir S. Kushwaha

    2012-09-01

    Full Text Available The most fundamental approach to an understanding of electronic, optical, and transport phenomena which the condensed matter physics (of conventional as well as nonconventional systems offers is generally founded on two experiments: the inelastic electron scattering and the inelastic light scattering. This work embarks on providing a systematic framework for the theory of inelastic electron scattering and of inelastic light scattering from the electronic excitations in GaAs/Ga1−xAlxAs quantum wells. To this end, we start with the Kubo's correlation function to derive the generalized nonlocal, dynamic dielectric function, and the inverse dielectric function within the framework of Bohm-Pines’ random-phase approximation. This is followed by a thorough development of the theory of inelastic electron scattering and of inelastic light scattering. The methodological part is then subjected to the analytical diagnoses which allow us to sense the subtlety of the analytical results and the importance of their applications. The general analytical results, which know no bounds regarding, e.g., the subband occupancy, are then specified so as to make them applicable to practicality. After trying and testing the eigenfunctions, we compute the density of states, the Fermi energy, the full excitation spectrum made up of intrasubband and intersubband – single-particle and collective (plasmon – excitations, the loss functions for all the principal geometries envisioned for the inelastic electron scattering, and the Raman intensity, which provides a measure of the real transitions induced by the (laser probe, for the inelastic light scattering. It is found that the dominant contribution to both the loss peaks and the Raman peaks comes from the collective (plasmon excitations. As to the single-particle peaks, the analysis indicates a long-lasting lack of quantitative comparison between theory and experiments. It is inferred that the inelastic electron

  13. Interplay between radiation pressure force and scattered light intensity in the cooperative scattering by cold atoms

    CERN Document Server

    Bienaime, Tom; Chabe, Julien; Rouabah, Mohamed-Taha; Bellando, Louis; Courteille, Philippe W; Piovella, Nicola; Kaiser, Robin

    2013-01-01

    The interplay between the superradiant emission of a cloud of cold two-level atoms and the radiation pressure force is discussed. Using a microscopic model of coupled atomic dipoles driven by an external laser, the radiation field and the average radiation pressure force are derived. A relation between the far-field scattered intensity and the force is derived, using the optical theorem. Finally, the scaling of the sample scattering cross section with the parameters of the system is studied.

  14. Monte Carlo simulation of light scattering from size distributed homogenous and coated spherical particles

    Science.gov (United States)

    Gogoi, Ankur

    Light scattering is a subject of intensive research at the present time in diverse fields of research namely, physics, astronomy, meteorology, biology, nanotechnology, etc. Observation and theoretical calculation of the absorption and scattering properties of particles, whose size ranges from micrometer to nanometer, are not only essential to deduce their physical properties but also capable of giving useful information for better understanding of radiation transfer through a medium containing such scatterer. In addition to such experimental and theoretical studies on light scattering by particulate matter several other groups have been extensively using Monte Carlo (MC) method to simulate light (photon) propagation in scattering media. Importantly such methods of simulating light scattering properties of artificial particles are proving to be a very useful tool in verifying the experimental observations with real samples as well as providing new clues to improve the accuracy of the existing theoretical models. In this contribution we report a MC method developed by implementing Mie theory to simulate the light scattering pattern from size distributed homogenous and coated spherical particles in single scattering regime. The computer program was written in ANSI C-language. The accuracy, efficiency and reliability of the MC method were validated by comparing the results generated by using the MC method with other benchmark theoretical results and experimental results with standard samples. Notably the MC method reported here is found to be stable even for very large spherical particles (size parameters > 1000) with large values of real (= 10) and imaginary part (= 10) of the refractive index. The promising field of application of the reported MC method will be in simulating the light (or electromagnetic) scattering properties of different types of planetary and interplanetary dust particles.

  15. Neutron-scattering studies of a polymer electrolyte, PPO-LiClO4

    DEFF Research Database (Denmark)

    Carlsson, P.; Mattsson, B.; Swenson, J.

    1998-01-01

    The structure and dynamics of a prototype polymer electrolyte, PPO-LiClO4, have been investigated using neutron diffraction (ND) and quasi-elastic neutron scattering (QENS). For comparison, corresponding studies of pure PPO have also been performed. The diffraction data reveal large structural ch...

  16. Physical characterization of hematopoietic stem cells using multidirectional label-free light scatterings.

    Science.gov (United States)

    Shahin, Hesam; Gupta, Manisha; Janowska-Wieczorek, Anna; Rozmus, Wojciech; Tsui, Ying Y

    2016-12-12

    An experimental setup capable of measuring simultaneous 2D scattered light angular distribution from two directions to study cell morphology without the use of bio-labels was developed. Experiments with hematopoietic stem cells (CD34+ cells) show good agreement with detailed numerical simulations of light scattering. Numerical simulations and computer models of cells are used to identify physical features of cells with the largest scattering cross sections. This allows for determination of size, geometry of the nucleus and distribution of mitochondria in hematopoietic stem cells by means of our label-free method.

  17. Imaging in scattering media via the second-order correlation of light field

    CERN Document Server

    Gong, Wenlin; Shen, Xia; Han, Shensheng

    2009-01-01

    Imaging with the second-order correlation of two light fields is a method to image an object by two-photon interference involving a joint detection of two photons at distant space-time points. We demonstrate for the first time that an image with high quality can still be obtained in the scattering media by applying the second-order correlation of illuminating light field. The scattering effect on the visibility of images is analyzed both theoretically and experimentally. Potential applications and the methods to further improve the visibility of the images in scattering media are also discussed.

  18. Double scattering of light from biophotonic nanostructures with short-range order

    CERN Document Server

    Noh, Heeso; Saranathan, Vinodkumar; Prum, Richard O; Mochrie, Simon G J; Dufresne, Eric R; Cao, Hui

    2009-01-01

    We investigate the physical mechanism for color production by isotropic nanostructures with short-range order in bird feather barbs. While the primary peak in optical scattering spectra results from constructive interference of singly-scattered light, many species exhibit secondary peaks with distinct characteristic. Our experimental and numerical studies show that these secondary peaks result from double scattering of light by the correlated structures. Without an analog in periodic or random structures, such a phenomenon is unique for short-range ordered structures, and has been widely used by nature for non-iridescent structural coloration.

  19. Experimental demonstration of singular-optical colouring of regularly scattered white light

    DEFF Research Database (Denmark)

    Angelsky, O.V.; Hanson, Steen Grüner; Maksimyak, P.P.

    2008-01-01

    Experimental interference modelling of the effects of colouring of a beam traversing a light-scattering medium is presented. It is shown that the result of colouring of the beam at the output of the medium depends on the magnitudes of the phase delays of the singly forward scattered partial signals....... The colouring mechanism has for the first time experimentally been illustrated for a forward propagating beam through a light-scattering medium. This is showed in video-fragments of the interferograms recorded within the zero interference fringe with a gradual change of the path difference of the interfering...

  20. Optimal control of light propagation through multiple-scattering media in the presence of noise

    CERN Document Server

    Yilmaz, Hasan; Mosk, Allard P

    2013-01-01

    We study the control of coherent light propagation through multiple-scattering media in the presence of measurement noise. In our experiments, we use a two-step optimization procedure to find the optimal incident wavefront. We conclude that the degree of optimal control of coherent light propagation through a multiple-scattering medium is only determined by the number of photoelectrons detected per single speckle spot. The prediction of our model agrees well with the experimental results. Our results offer opportunities for imaging applications through scattering media such as biological tissue in the shot noise limit.

  1. Observation of spatial quantum correlations induced by multiple scattering of nonclassical light.

    Science.gov (United States)

    Smolka, S; Huck, A; Andersen, U L; Lagendijk, A; Lodahl, P

    2009-05-15

    We present the experimental realization of spatial quantum correlations of photons that are induced by multiple scattering of squeezed light. The quantum correlation relates photons propagating along two different light paths through the random medium and is infinite in range. Both positive and negative spatial quantum correlations are observed when varying the quantum state incident to the multiple scattering medium, and the strength of the correlations is controlled by the number of photons. The experimental results are in excellent agreement with recent theoretical proposals by implementing the full quantum model of multiple scattering.

  2. Microchip Flow Cytometer with Integrated Polymer Optical Elements for Measurement of Scattered Light

    DEFF Research Database (Denmark)

    Wang, Zhenyu; El-Ali, Jamil; Perch-Nielsen, Ivan Ryberg

    2004-01-01

    channels to form a complete microchip flow cytometer. All the optical elements, the microfluidic system, and the fiber-to-waveguide couplers were defined in one layer of polymer (SU-8, negative photoresist) by standard photolithography. With only one single mask procedure, all the fabrication and packaging...... processes can be finished in one day. Polystyrene beads were measured in the microchip flow cytometer, and three signals (forward scattering, large angle scattering and extinction) were measured simultaneously for each bead. The average intensities of the forward Scattered light and the incident light...

  3. Auto-correlation Properties of Scattering Light in Ultrasound-modulated Random Media

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiqin; XING Da; LIU Ying; MA Shining

    2001-01-01

    In this paper, the auto-correlation properties of scattering light in random media modulated by ultrasound were studied. The expression of temporal auto-correlation function of scattering light amplitude in the ultrasound-modulated media was presented. The results show that the auto-correlation function is modulated as the ultrasound is introduced into the media and the modulation amplitude decays with correlation time. The influences of ultrasound amplitude, Brownian diffusion coefficient, scattering and absorption coefficients on auto-correlation function were discussed. The auto-correlation imaging of an object hidden in random media was also studied by the use of Monte Carlo simulations.

  4. Spectrum of an electromagnetic light wave on scattering from an anisotropic semisoft boundary medium.

    Science.gov (United States)

    Wang, Tao; Jiang, Zhenfei; Ji, Xiaoling; Zhao, Daomu

    2016-04-01

    Spectral shifts and spectral switches of a polychromatic electromagnetic light wave on scattering from an anisotropic semisoft boundary medium are discussed. It is shown that both the property of the incident field and the character of the scattering medium play roles in the change of the spectrum of the far-zone scattered field. It is also shown that the distribution of the far-zone scattered spectrum, including the magnitude of the spectral shift and the direction at which the spectral switch occurs, is rotationally nonsymmetric.

  5. Surface light scattering: integrated technology and signal processing

    DEFF Research Database (Denmark)

    Lading, L.; Dam-Hansen, C.; Rasmussen, E.

    1997-01-01

    The miniaturization of surface-scattering instruments for measuring viscoelastic properties is investigated. The concepts are based on the use of holographic optical elements and integrated optics. Compact forms of optics that provide the necessary spatial and angular selections are devised. Four...

  6. Quantum Interference and Entanglement Induced by Multiple Scattering of Light

    DEFF Research Database (Denmark)

    Ott, Johan Raunkjær; Mortensen, Asger; Lodahl, Peter

    2010-01-01

    We report on the effects of quantum interference induced by the transmission of an arbitrary number of optical quantum states through a multiple-scattering medium. We identify the role of quantum interference on the photon correlations and the degree of continuous variable entanglement between tw...

  7. Spherically symmetric inhomogeneous bianisotropic media: Wave propagation and light scattering

    DEFF Research Database (Denmark)

    Novitsky, Andrey; Shalin, Alexander S.; Lavrinenko, Andrei

    2017-01-01

    We develop a technique for finding closed-form expressions for electromagnetic fields in radially inhomogeneous bianisotropic media, both the solutions of the Maxwell equations and material tensors being defined by the set of auxiliary two-dimensional matrices. The approach is applied to determine...... the scattering cross-sections by spherical particles, the fields inside which correspond to the Airy-exponential waves....

  8. Light Scattering of Rough Orthogonal Anisotropic Surfaces with Secondary Most Probable Slope Distributions

    Institute of Scientific and Technical Information of China (English)

    LI Hai-Xia; CHENG Chuan-Fu

    2011-01-01

    @@ We study the light scattering of an orthogonal anisotropic rough surface with secondary most probable slope distribution It is found that the scattered intensity profiles have obvious secondary maxima, and in the direction perpendicular to the plane of incidence, the secondary maxima are oriented in a curve on the observation plane,which is called the orientation curve.By numerical calculation of the scattering wave fields with the height data of the sample, it is validated that the secondary maxima are induced by the side face element, which constitutes the prismoid structure of the anisotropic surface.We derive the equation of the quadratic orientation curve.Experimentally, we construct the system for light scattering measurement using a CCD.The scattered intensity profiles are extracted from the images at different angles of incidence along the orientation curves.The experimental results conform to the theory.

  9. Effects of multiple scattering on light pulses reflected by turbid atmospheres

    Science.gov (United States)

    Weinman, J. A.

    1976-01-01

    Multiple scattering contributions to lidar returns from turbid atmospheres are derived by means of an analytical theory. It is assumed that scattering takes place mainly at small angles except for one event that scatters the light backward. The phase functions are approximated by the sum of Gaussian functions of the scattering angle in both the forward and backward directions. The three-dimensional radiative transfer equation is transformed to a one-dimensional problem by means of Fourier transforms. Neumann solutions to the transformed equation of radiative transfer are then found. A number of examples are presented for cloud, fog and haze models. The results are found to be in satisfactory agreement with results obtained from the Monte Carlo analysis of Kunkel (1974) and the theory of light pulses doubly scattered by turbid atmospheres which was developed by Eloranta (1972).

  10. The measurement and modelling of light scattering by phytoplankton cells at narrow forward angles

    Science.gov (United States)

    MacCallum, Iain; Cunningham, Alex; McKee, David

    2004-07-01

    A procedure has been devised for measuring the angular dependence of light scattering from suspensions of phytoplankton cells at forward angles from 0.25° to 8°. The cells were illuminated with a spatially-filtered laser beam and the angular distribution of scattered light measured by tracking a photodetector across the Fourier plane of a collecting lens using a stepper-motor driven stage. The procedure was calibrated by measuring scattering from latex bead suspensions with known size distributions. It was then used to examine the scattering from cultures of the unicellular algae Isochrysis galbana (4 µm × 5 µm), Dunaliella primolecta (6 µm × 7 µm) and Rhinomonas reticulata (5 µm × 11 µm). The results were compared with the predictions of Mie theory. Excellent agreement was obtained for spherical particles. A suitable choice of spherical-equivalent scattering parameters was required to enable reasonable agreement within the first diffraction lobe for ellipsoidal particles.

  11. Statistical-thermodynamic model for light scattering from eye lens protein mixtures

    Science.gov (United States)

    Bell, Michael M.; Ross, David S.; Bautista, Maurino P.; Shahmohamad, Hossein; Langner, Andreas; Hamilton, John F.; Lahnovych, Carrie N.; Thurston, George M.

    2017-02-01

    We model light-scattering cross sections of concentrated aqueous mixtures of the bovine eye lens proteins γB- and α-crystallin by adapting a statistical-thermodynamic model of mixtures of spheres with short-range attractions. The model reproduces measured static light scattering cross sections, or Rayleigh ratios, of γB-α mixtures from dilute concentrations where light scattering intensity depends on molecular weights and virial coefficients, to realistically high concentration protein mixtures like those of the lens. The model relates γB-γB and γB-α attraction strengths and the γB-α size ratio to the free energy curvatures that set light scattering efficiency in tandem with protein refractive index increments. The model includes (i) hard-sphere α-α interactions, which create short-range order and transparency at high protein concentrations, (ii) short-range attractive plus hard-core γ-γ interactions, which produce intense light scattering and liquid-liquid phase separation in aqueous γ-crystallin solutions, and (iii) short-range attractive plus hard-core γ-α interactions, which strongly influence highly non-additive light scattering and phase separation in concentrated γ-α mixtures. The model reveals a new lens transparency mechanism, that prominent equilibrium composition fluctuations can be perpendicular to the refractive index gradient. The model reproduces the concave-up dependence of the Rayleigh ratio on α/γ composition at high concentrations, its concave-down nature at intermediate concentrations, non-monotonic dependence of light scattering on γ-α attraction strength, and more intricate, temperature-dependent features. We analytically compute the mixed virial series for light scattering efficiency through third order for the sticky-sphere mixture, and find that the full model represents the available light scattering data at concentrations several times those where the second and third mixed virial contributions fail. The model

  12. Stray light analysis for the Thomson scattering diagnostic of the ETE Tokamak

    Science.gov (United States)

    Berni, L. A.; Albuquerque, B. F. C.

    2010-12-01

    Thomson scattering is a well-established diagnostic for measuring local electron temperature and density in fusion plasma, but this technique is particularly difficult to implement due to stray light that can easily mask the scattered signal from plasma. To mitigate this problem in the multipoint Thomson scattering system implemented at the ETE (Experimento Tokamak Esférico) a detailed stray light analysis was performed. The diagnostic system was simulated in ZEMAX software and scattering profiles of the mechanical parts were measured in the laboratory in order to have near realistic results. From simulation, it was possible to identify the main points that contribute to the stray signals and changes in the dump were implemented reducing the stray light signals up to 60 times.

  13. Sub-Nyquist sampling boosts targeted light transport through opaque scattering media

    CERN Document Server

    Shen, Yuecheng; Ma, Cheng; Wang, Lihong V

    2016-01-01

    Optical time-reversal techniques are being actively developed to focus light through or inside opaque scattering media. When applied to biological tissue, these techniques promise to revolutionize biophotonics by enabling deep-tissue non-invasive optical imaging, optogenetics, optical tweezers and photodynamic therapy. In all previous optical time-reversal experiments, the scattered light field was well-sampled during wavefront measurement and wavefront reconstruction, following the Nyquist sampling criterion. Here, we overturn this conventional practice by demonstrating that even when the scattered field is under-sampled, light can still be focused through or inside opaque media. Even more surprisingly, we show both theoretically and experimentally that the focus achieved by under-sampling is usually about one order of magnitude brighter than that achieved by conventional well-sampling conditions. Moreover, sub-Nyquist sampling improves the signal-to-noise ratio and the collection efficiency of the scattered...

  14. Label-free identification of individual bacteria using Fourier transform light scattering

    CERN Document Server

    Jo, YoungJu; Kim, Min-hyeok; Park, HyunJoo; Kang, Suk-Jo; Park, YongKeun

    2015-01-01

    Rapid identification of bacterial species is crucial in medicine and food hygiene. In order to achieve rapid and label-free identification of bacterial species at the single bacterium level, we propose and experimentally demonstrate an optical method based on Fourier transform light scattering (FTLS) measurements and statistical classification. For individual rod-shaped bacteria belonging to four bacterial species (Listeria monocytogenes, Escherichia coli, Lactobacillus casei, and Bacillus subtilis), two-dimensional angle-resolved light scattering maps are precisely measured using FTLS technique. The scattering maps are then systematically analyzed, employing statistical classification in order to extract the unique fingerprint patterns for each species, so that a new unidentified bacterium can be identified by a single light scattering measurement. The single-bacterial and label-free nature of our method suggests wide applicability for rapid point-of-care bacterial diagnosis.

  15. Stray light analysis for the Thomson scattering diagnostic of the ETE Tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Berni, L. A. [Instituto Nacional de Pesquisas Espaciais (INPE), Laboratorio Associado de Sensores e Materiais (LAS), 12.227-010 Sao Jose dos Campos, SP (Brazil); Albuquerque, B. F. C. [Instituto Nacional de Pesquisas Espaciais (INPE), Engenharia e Tecnologia Espaciais, Divisao de Eletronica Aeroespacial, 12.227-010 Sao Jose dos Campos, SP (Brazil)

    2010-12-15

    Thomson scattering is a well-established diagnostic for measuring local electron temperature and density in fusion plasma, but this technique is particularly difficult to implement due to stray light that can easily mask the scattered signal from plasma. To mitigate this problem in the multipoint Thomson scattering system implemented at the ETE (Experimento Tokamak Esferico) a detailed stray light analysis was performed. The diagnostic system was simulated in ZEMAX software and scattering profiles of the mechanical parts were measured in the laboratory in order to have near realistic results. From simulation, it was possible to identify the main points that contribute to the stray signals and changes in the dump were implemented reducing the stray light signals up to 60 times.

  16. Distinguishing Structure Change of Cells Based on Analysis of Light Scattering Patterns

    Institute of Scientific and Technical Information of China (English)

    JIN Yong-Long; YANG Fang; WANG Meng; ZHANG Yu; GU Ning

    2008-01-01

    We develop a new method to distinguish structural change of cells based on light scattering and Fourier spectra analysis. The light scattering detection system is composed of a laser source, an optical microscope, a CCD with high resolution and low distortion. After the scattering patterns of cells are recorded by the CCD, the Fourier spectra are obtained by the intensity distribution of scattered light. In the experiment, the change of cell structure is designed by sonication treatment. It is found that different typical peaks can be shown in the Fourier spectra of MCF7 cells with and without sonication treatment, which indicates that this method can be used to distinguish the structural change of cells.

  17. Fluid description of the cooperative scattering of light by spherical atomic clouds

    CERN Document Server

    Piovella, N; Courteille, Ph W

    2013-01-01

    When a cold atomic gas is illuminated by a quasi-resonant laser beam, light-induced dipole-dipole correlations make the scattering of light a cooperative process. Once a fluid description is adopted for the atoms, many scattering properties are captured by the definition of a complex refractive index. The solution of the scattering problem is here presented for spherical atomic clouds of arbitrary density profiles, such as parabolic densities characteristic of ultra-cold clouds. A new solution for clouds with infinite boundaries is derived, that is particularly useful for the Gaussian densities of thermal atomic clouds. The presence of Mie resonances, a signature of the cloud acting as a cavity for the light, is discussed. These resonances leave their fingerprint in various observables such as the scattered intensity or in the radiation pressure force, and can be observed by tuning the frequency of the incident laser field or the atom number.

  18. Elastic scattering and total reaction cross sections with low-energy light radioactive ion beams.

    Directory of Open Access Journals (Sweden)

    Guimarães Valdir

    2011-10-01

    Full Text Available Elastic scattering experiments have being performed with low-energy radioactive ion beams produced by the RIBRAS facility in Sao Paulo, Brazil. Here I present the results for elastic scattering of 6He on several targets and light beams on 12C target. Special emphasis is given to the analysis of experiments were angular distributions for the elastic scattering of beryllium isotopes projectiles, 7Be, 9Be and 10Be, on a light target 12C were obtained. These elastic scattering angular distributions have been analysed in terms of optical model using the double-folding Sao Paulo potential. From this analysis, the total reaction cross section were also deduced and compared to the total reaction cross sections for many other light projectiles on 12C target. The comparison was made in terms of Universal Function reduction method.

  19. Redshift and blueshift in the spectra of lights coherently and diffusely scattered from random rough interfaces.

    Science.gov (United States)

    Dashtdar, Masoomeh; Tavassoly, M Taghi

    2009-10-01

    We show theoretically and experimentally that the spectrum of coherently scattered light from a randomly rough interface in reflection and transmission is redshifted with a shrinkage in spectral width. In reflection mode the amounts of the redshift and the shrinkage depend on interface roughness, incident angle, and the spectral width of the illuminating light. In transmission mode they also depend on the refractive indices of the surrounding media. The redshift and width shrinkage increase with decrease of the coherently scattered light intensity. This study shows that the spectrum of the diffusely scattered light is blueshifted in the specular direction and in directions with small scattering angles only in situations with appreciable intensity of the coherently scattered light. With decrease of the latter intensity the blueshift reduces and turns into redshift. Also, the redshift and blueshift decay with increase of the scattering angle. An experimental investigation has been carried out, on sheet glasses with different roughness on one side, in reflection and transmission modes. The experimental results and theoretical predictions are quite consistent.

  20. Polarized light-scattering profile-advanced characterization of nonspherical particles with scanning flow cytometry.

    Science.gov (United States)

    Strokotov, Dmitry I; Moskalensky, Alexander E; Nekrasov, Vyacheslav M; Maltsev, Valeri P

    2011-07-01

    We instrumentally, theoretically, and experimentally demonstrate a new approach for characterization of nonspherical individual particles from light scattering. Unlike the original optical scheme of the scanning flow cytometer that measures an angle-resolved scattering corresponding in general to S₁₁ element of the light-scattering matrix, the modernized instrument allows us to measure the polarized light-scattering profile of individual particles simultaneously. Theoretically, the polarized profile is expressed by the combination of a few light-scattering matrix elements. This approach supports us with additional independent data to characterize a particle with a complex shape and an internal structure. Applicability of the new method was demonstrated from analysis of polymer bispheres. The bisphere characteristics, sizes, and refractive indices of each sphere composing the bisphere were successfully retrieved from the solution of the inverse light-scattering problem. The solution provides determination of the Eulerian angles, which describe the orientation of the bispheres relative to the direction of the incident laser beam and detecting polarizer of the optical system. Both the ordinary and polarized profiles show a perfect agreement with T-matrix simulation resulting to 50-nm precision for sizing of bispheres. Copyright © 2011 International Society for Advancement of Cytometry.

  1. Nonequivalence of second virial coefficients from sedimentation equilibrium and static light scattering studies of protein solutions.

    Science.gov (United States)

    Winzor, Donald J; Deszczynski, Marcin; Harding, Stephen E; Wills, Peter R

    2007-06-01

    Experimental data for ovalbumin and lysozyme are presented to highlight the nonequivalence of second virial coefficients obtained for proteins by sedimentation equilibrium and light scattering. Theoretical considerations confirm that the quantity deduced from sedimentation equilibrium distributions is B(22), the osmotic second virial coefficient describing thermodynamic nonideality arising solely from protein self-interaction. On the other hand, the virial coefficient determined by light scattering is shown to reflect the combined contributions of protein-protein and protein-buffer interactions to thermodynamic nonideality of the protein solution. Misidentification of the light scattering parameter as B(22) accounts for published reports of negative osmotic second virial coefficients as indicators of conditions conducive to protein crystal growth. Finally, textbook assertions about the equivalence of second virial coefficients obtained by sedimentation equilibrium and light scattering reflect the restriction of consideration to single-solute systems. Although sedimentation equilibrium distributions for buffered protein solutions are, indeed, amenable to interpretation in such terms, the same situation does not apply to light scattering measurements because buffer constituents cannot be regarded as part of the solvent: instead they must be treated as non-scattering cosolutes.

  2. The propagation dynamics of ultraviolet light filament with Rayleigh scattering in air

    Institute of Scientific and Technical Information of China (English)

    Zhang Hua

    2005-01-01

    In this paper we present for the first time the effects of Rayleigh scattering on the long distance propagation of ultraviolet (UV) light filament in air based on the stationary analysis. The simulation results show that the effects of Rayleigh scattering on the propagation of UV laser filaments may not be ignored. These influences are slightly dependent on the laser wavelength. We also compare the UV filament propagations at different input powers in the presence and the absence of the Rayleigh scattering and discuss the mechanisms of power loss and beam defocusing.In the absence of Rayleigh scattering, the filament propagation is determined by the oscillating behaviour of the beam size. In the presence of the scattering, the propagation lengths of filament are close to each other at different initial powers and determined by the Rayleigh scattering.

  3. Quantifying light scattering with single-mode fiber -optic confocal microscopy

    Directory of Open Access Journals (Sweden)

    Haidekker Mark A

    2009-11-01

    Full Text Available Abstract Background Confocal microscopy has become an important option for examining tissues in vivo as a diagnostic tool and a quality control tool for tissue-engineered constructs. Collagen is one of the primary determinants of biomechanical stability. Since collagen is also the primary scattering element in skin and other soft tissues, we hypothesized that laser-optical imaging methods, particularly confocal scattered-light scanning, would allow us to quantify scattering intensity and determine collagen content in biological layers. Methods We built a fully automated confocal scattered-light scanner to examine how light scatters in Intralipid, a common tissue phantom, and three-dimensional collagen gels. Intralipid with 0.5%, 1.0%, 1.5%, and 2.0% concentration was filled between precisely spaced glass coverslips. Collagen gels at collagen concentrations from 0.30 mg/mL to 3.30 mg/mL were prepared, and all samples underwent A-mode scanning with multiple averaged scans. In Intralipid samples, light reflected from the upper fluid-glass interface was measured. In collagen gels, average scattering intensity inside the actual gel was measured. In both cases, intensity was correlated with concentration. Results By measuring light attenuation at interface reflections of various thicknesses using our device, we were able to determine that the scattering coefficient at 660 nm of Intralipid at increasing concentrations in water to be 39 cm-1 for each percent increase of Intralipid. We were also able to measure the amount of scattering of various concentrations of collagen in gels directly using backscattered light. The results show a highly linear relationship with an increase of 8.2 arbitrary units in backscattering intensity for every 1 mg increase of collagen within a 1 mL gel volume. Conclusion The confocal scattered-light scanner allows to accurately quantify scattering in Intralipid and collagen gels. Furthermore, a linear relationship between

  4. Impact of polishing on the light scattering at aerogel surface

    Energy Technology Data Exchange (ETDEWEB)

    Barnyakov, A.Yu. [Budker Institute of Nuclear Physics SB RAS, Novosibirsk (Russian Federation); Novosibirsk State University, Novosibirsk (Russian Federation); Barnyakov, M.Yu. [Budker Institute of Nuclear Physics SB RAS, Novosibirsk (Russian Federation); Novosibirsk State University, Novosibirsk (Russian Federation); Novosibirsk State Technical University, Novosibirsk (Russian Federation); Bobrovnikov, V.S.; Buzykaev, A.R. [Budker Institute of Nuclear Physics SB RAS, Novosibirsk (Russian Federation); Novosibirsk State University, Novosibirsk (Russian Federation); Danilyuk, A.F. [Novosibirsk State University, Novosibirsk (Russian Federation); Boreskov Institute of Catalysis SB RAS, Novosibirsk (Russian Federation); Katcin, A.A. [Budker Institute of Nuclear Physics SB RAS, Novosibirsk (Russian Federation); Novosibirsk State Technical University, Novosibirsk (Russian Federation); Kononov, S.A. [Budker Institute of Nuclear Physics SB RAS, Novosibirsk (Russian Federation); Novosibirsk State University, Novosibirsk (Russian Federation); Kirilenko, P.S. [Novosibirsk State University, Novosibirsk (Russian Federation); Kravchenko, E.A., E-mail: E.A.Kravchenko@inp.nsk.su [Budker Institute of Nuclear Physics SB RAS, Novosibirsk (Russian Federation); Novosibirsk State University, Novosibirsk (Russian Federation); Kuyanov, I.A. [Budker Institute of Nuclear Physics SB RAS, Novosibirsk (Russian Federation); Novosibirsk State University, Novosibirsk (Russian Federation); Onuchin, A.P.; Ovtin, I.V. [Budker Institute of Nuclear Physics SB RAS, Novosibirsk (Russian Federation); Novosibirsk State University, Novosibirsk (Russian Federation); Novosibirsk State Technical University, Novosibirsk (Russian Federation); Predein, A.Yu.; Protsenko, R.S. [Boreskov Institute of Catalysis SB RAS, Novosibirsk (Russian Federation)

    2016-07-11

    Particle identification power of modern aerogel RICH detectors strongly depends on optical quality of radiators. It was shown that wavelength dependence of aerogel tile transparency after polishing cannot be described by the standard Hunt formula. The Hunt formula has been modified to describe scattering in a thin layer of silica dust on the surface of aerogel tile. Several procedures of polishing of aerogel tile have been tested. The best result has been achieved while using natural silk tissue. The resulting block has optical smooth surfaces. The measured decrease of aerogel transparency due to surface scattering is about few percent. This result could be used for production of radiators for the Focusing Aerogel RICH detectors.

  5. Temporal Quantum Correlations in Inelastic Light Scattering from Water

    Science.gov (United States)

    Kasperczyk, Mark; de Aguiar Júnior, Filomeno S.; Rabelo, Cassiano; Saraiva, Andre; Santos, Marcelo F.; Novotny, Lukas; Jorio, Ado

    2016-12-01

    Water is one of the most prevalent chemicals on our planet, an integral part of both our environment and our existence as a species. Yet it is also rich in anomalous behaviors. Here we reveal that water is a novel—yet ubiquitous—source for quantum correlated photon pairs at ambient conditions. The photon pairs are produced through Raman scattering, and the correlations arise from the shared quantum of a vibrational mode between the Stokes and anti-Stokes scattering events. We confirm the nonclassical nature of the produced photon pairs by showing that the cross-correlation and autocorrelations of the signals violate a Cauchy-Schwarz inequality by over 5 orders of magnitude. The unprecedented degree of violating the inequality in pure water, as well as the well-defined polarization properties of the photon pairs, points to its usefulness in quantum information.

  6. Resonant chirality in light scattered from magnetodielectric particles

    CERN Document Server

    Nieto-Vesperinas, Manuel

    2016-01-01

    We show that the total heliciity of the field scattered by a magnetodielectric particle, bi-isotropic or not, is enhanced not only because of the resonant polarizabilities, but also due to the interference between the left and right circularly polarized components of the incident wave, which in absence of incident helicity does not necessarily require the particle to be chiral. This latter effect goes beyond standard dichroism and may be considered a generalization of this phenomenon.

  7. Maximizing the information transfer in a quantum-limited light-scattering system

    DEFF Research Database (Denmark)

    Lading, Lars; Jørgensen, Thomas Martini

    1990-01-01

    A quantum-limited light-scattering system is considered. The spatial configuration that maximizes a given figure of merit is investigated, assuming that the emitted light has Poisson photon statistics. A specific system for measuring the velocity of a small particle is considered as an example...

  8. Observation of spatial quantum correlations induced by multiple scattering of nonclassical light

    DEFF Research Database (Denmark)

    Smolka, Stephan; Huck, Alexander; Andersen, Ulrik Lund;

    2009-01-01

    We present the experimental realization of spatial quantum correlations of photons that are induced by multiple scattering of squeezed light. The quantum correlation relates photons propagating along two different light paths through the random medium and is infinite in range. Both positive...

  9. Photopolymerization-Induced Two-Beam Coupling and Light-Induced Scattering in Polymethyl Methacrylate

    Institute of Scientific and Technical Information of China (English)

    LI Wei; GAO Feng; TANG Bai-Quan; Christian Pruner; ZHANG Xin-Zheng; SHI Yan-Li; XU Jing-Jun; QIAO Hai-Jun; WU Qiang; Romano A. Rupp; LOU Ci-Bo; WANG Zhen-Hua

    2008-01-01

    @@ Light amplification due to two-beam coupling is realized in doped polymethyl methacrylate (PMMA) glasses. A coupling gain as large as 14 cm-1 is obtained. The dynamic behaviour of absorption and light-induced scattering due to the process of photopolymerization are also studied. The results show that the amplification and its dynamic process enable possible applications of PMMA in optical devices.

  10. Angular scattering of light by a homogeneous spherical particle in a zeroth-order Bessel beam and its relationship to plane wave scattering.

    Science.gov (United States)

    Preston, Thomas C; Reid, Jonathan P

    2015-06-01

    The angular scattering of light from a homogeneous spherical particle in a zeroth-order Bessel beam is calculated using a generalized Lorenz-Mie theory. We investigate the dependence of the angular scattering on the semi-apex angle of the Bessel beam and discuss the major features of the resulting scattering plots. We also compare Bessel beam scattering to plane wave scattering and provide criterion for when the difference between the two cases can be considered negligible. Finally, we discuss a method for characterizing spherical particles using angular light scattering. This work is useful to researchers who are interested in characterizing particles trapped in optical beams using angular dependent light scattering measurements.

  11. Mid-infrared (λ = 8.4-9.9 μm) light scattering from porcine tissue

    Science.gov (United States)

    Liakat, Sabbir; Michel, Anna P. M.; Bors, Kevin A.; Gmachl, Claire F.

    2012-08-01

    Back-scattering of mid-infrared light from porcine skin is studied versus wavelength and angle for a Quantum Cascade laser and a broadband infrared light source. Scattering is detected over 30° away from the specular angle for both sources, and modulation patterns with angle are seen when using the laser. A nonlinear increase in scattered light intensity versus input power indicates that directional scattering from within the skin is dominant. Collagen fibers in the dermis layer, over 200 μm deep into the skin, are conducive to such scattering. We conclude that mid-infrared light penetrates deep enough for potential glucose detection in dermal interstitial fluid.

  12. Accurate optical simulation of nano-particle based internal scattering layers for light outcoupling from organic light emitting diodes

    Science.gov (United States)

    Egel, Amos; Gomard, Guillaume; Kettlitz, Siegfried W.; Lemmer, Uli

    2017-02-01

    We present a numerical strategy for the accurate simulation of light extraction from organic light emitting diodes (OLEDs) comprising an internal nano-particle based scattering layer. On the one hand, the light emission and propagation through the OLED thin film system (including the scattering layer) is treated by means of rigorous wave optics calculations using the T-matrix formalism. On the other hand, the propagation through the substrate is modeled in a ray optics approach. The results from the wave optics calculations enter in terms of the initial substrate radiation pattern and the bidirectional reflectivity distribution of the OLED stack with scattering layer. In order to correct for the truncation error due to a finite number of particles in the simulations, we extrapolate the results to infinitely extended scattering layers. As an application example, we estimate the optimal particle filling fraction for an internal scattering layer in a realistic OLED geometry. The presented treatment is designed to emerge from electromagnetic theory with as few additional assumptions as possible. It could thus serve as a baseline to validate faster but approximate simulation approaches.

  13. Skeletal light-scattering accelerates bleaching response in reef-building corals.

    Science.gov (United States)

    Swain, Timothy D; DuBois, Emily; Gomes, Andrew; Stoyneva, Valentina P; Radosevich, Andrew J; Henss, Jillian; Wagner, Michelle E; Derbas, Justin; Grooms, Hannah W; Velazquez, Elizabeth M; Traub, Joshua; Kennedy, Brian J; Grigorescu, Arabela A; Westneat, Mark W; Sanborn, Kevin; Levine, Shoshana; Schick, Mark; Parsons, George; Biggs, Brendan C; Rogers, Jeremy D; Backman, Vadim; Marcelino, Luisa A

    2016-03-21

    At the forefront of ecosystems adversely affected by climate change, coral reefs are sensitive to anomalously high temperatures which disassociate (bleaching) photosynthetic symbionts (Symbiodinium) from coral hosts and cause increasingly frequent and severe mass mortality events. Susceptibility to bleaching and mortality is variable among corals, and is determined by unknown proportions of environmental history and the synergy of Symbiodinium- and coral-specific properties. Symbiodinium live within host tissues overlaying the coral skeleton, which increases light availability through multiple light-scattering, forming one of the most efficient biological collectors of solar radiation. Light-transport in the upper ~200 μm layer of corals skeletons (measured as 'microscopic' reduced-scattering coefficient, μ'(S,m)), has been identified as a determinant of excess light increase during bleaching and is therefore a potential determinant of the differential rate and severity of bleaching response among coral species. Here we experimentally demonstrate (in ten coral species) that, under thermal stress alone or combined thermal and light stress, low-μ'(S,m) corals bleach at higher rate and severity than high-μ'(S,m) corals and the Symbiodinium associated with low-μ'(S,m) corals experience twice the decrease in photochemical efficiency. We further modelled the light absorbed by Symbiodinium due to skeletal-scattering and show that the estimated skeleton-dependent light absorbed by Symbiodinium (per unit of photosynthetic pigment) and the temporal rate of increase in absorbed light during bleaching are several fold higher in low-μ'(S,m) corals. While symbionts associated with low-[Formula: see text] corals receive less total light from the skeleton, they experience a higher rate of light increase once bleaching is initiated and absorbing bodies are lost; further precipitating the bleaching response. Because microscopic skeletal light-scattering is a robust predictor

  14. Enhancing Localized Evaporation through Separated Light Absorbing Centers and Scattering Centers.

    Science.gov (United States)

    Zhao, Dengwu; Duan, Haoze; Yu, Shengtao; Zhang, Yao; He, Jiaqing; Quan, Xiaojun; Tao, Peng; Shang, Wen; Wu, Jianbo; Song, Chengyi; Deng, Tao

    2015-11-26

    This report investigates the enhancement of localized evaporation via separated light absorbing particles (plasmonic absorbers) and scattering particles (polystyrene nanoparticles). Evaporation has been considered as one of the most important phase-change processes in modern industries. To improve the efficiency of evaporation, one of the most feasible methods is to localize heat at the top water layer rather than heating the bulk water. In this work, the mixture of purely light absorptive plasmonic nanostructures such as gold nanoparticles and purely scattering particles (polystyrene nanoparticles) are employed to confine the incident light at the top of the solution and convert light to heat. Different concentrations of both the light absorbing centers and the light scattering centers were evaluated and the evaporation performance can be largely enhanced with the balance between absorbing centers and scattering centers. The findings in this study not only provide a new way to improve evaporation efficiency in plasmonic particle-based solution, but also shed lights on the design of new solar-driven localized evaporation systems.

  15. Simulations of the Light Scattering Properties of Metal/Oxide Core/Shell Nanospheres

    Directory of Open Access Journals (Sweden)

    F. Ruffino

    2014-01-01

    Full Text Available Given the importance of the optical properties of metal/dielectric core/shell nanoparticles, in this work we focus our attention on the light scattering properties, within the Mie framework, of some specific categories of these noteworthy nanostructures. In particular, we report theoretical results of angle-dependent light scattering intensity and scattering efficiency for Ag/Ag2O, Al/Al2O2, Cu/Cu2O, Pd/PdO, and Ti/TiO2 core/shell nanoparticles as a function of the core radius/shell thickness ratio and on a relative comparison. The results highlight the light scattering characteristics of these systems as a function of the radius/shell thickness ratio, helping in the choice of the more suitable materials and sizes for specific applications (i.e., dynamic light scattering for biological and molecular recognition, increasing light trapping in thin-film silicon, organic solar cells for achieving a higher photocurrent.

  16. Measurement of Concentration Distribution of Hydrogen Gas Flow by Measuring the Intensity of Raman Scattering Light

    Science.gov (United States)

    Asahi, Ippei; Ninomiya, Hideki

    An experimental study to visualize and measure the concentration distribution of hydrogen gas flow using the Raman scattering was performed. A Nd:YAG laser of wavelength at 355 nm was used, and the beam pattern was transformed into a rectangle and a sheet beam was formed. The Raman scattered light was observed at a right angle with respect to the laser beam axis using a gated ICCD camera and an interference filter. Shadowgraph images were obtained at the same condition. The Raman scattering light image from atmospheric nitrogen was first acquired and the function of Raman scattering light acquisition and the background light suppression was confirmed. Next, images of the Raman scattering light image and shadowgraph of hydrogen gas discharged from a nozzle into the atmosphere were acquired. The two obtained Raman images were compared and the spatial concentration distribution of the flow of the hydrogen gas at different flow rates was calculated. This method is effective for visualizing the gas flow and measuring the concentration distribution of the Raman active molecules, such as hydrogen gas.

  17. Optical fibre probes in the measurement of scattered light: Application for sensing turbidity

    Indian Academy of Sciences (India)

    M R Sheno

    2014-01-01

    Optical fibre probes or optrodes often form the heart of multimode fibre-based measurements and sensors. An optrode usually comprises a bundle of multimode fibres, out of which one or more fibres are used for irradiating the sample, and the remaining fibres are used to collect the light reflected/scattered/fluoresced from the sample containing the measurand(s). The so-collected light carries the characteristic signature of the measurand. Here we present our work on the design and realization of optrodes for the measurement of scattered light from liquid samples. Optical properties of a solution are usually characterized by the parameters absorption coefficient $_a$, scattering coefficient $_s$, and anisotropy factor . We have developed a simple method to determine $_a$, $_s$, and , of a turbid medium, and a Monte–Carlo model was used to simulate the light scattering from the turbid medium. As an application, we describe the development of a turbidity sensor that has been designed and realized by employing an optrode in conjunction with a concave mirror. The estimation of turbidity is done on the basis of total interaction, by considering scattering and absorption of light from the sample solution. Details of the experiments and results are presented here.

  18. Study of the (e,e'p) quasi-elastic reaction in complex nuclei: theory and experiment

    Energy Technology Data Exchange (ETDEWEB)

    Herraiz, Joaquin Lopez [Complutense Univ. of Madrid (Spain)

    2010-03-01

    Experimental coincidence cross section and transverse-longitudinal asymmetry ATL have been obtained for the quasielastic (e,e'p) reaction in 16O, 12C, and {sup 208}Pb in constant q-ω kinematics in the missing momentum range -350 < pmiss < 350 MeV/c. In these experiments, performed in experimental Hall A of the Thomas Jefferson National Accelerator Facility (JLAB), the beam energy and the momentum and angle of the scattered electrons were kept fixed, while the angle between the proton momentum and the momentum transfer q was varied in order to map out the missing momentum distribution. The experimental cross section and ATL asymmetry have been compared with Monte Carlo simulations based on Distorted Wave Impulse Approximation (DWIA) calculations with both relativistic and non-relativistic spinor structure. The spectroscopic factors obtained for both models are in agreement with previous experimental values, while ATL measurements favor the relativistic DWIA calculation. This thesis describes the details of the experimental setup, the calibration of the spectrometers, the techniques used in the data analysis to derive the final cross sections and the ATL, the ingredients of the theoretical calculations employed and the comparison of the results with the simulations based on these theoretical models.

  19. Inclusive inelastic electron scattering from nuclei

    CERN Document Server

    Fomin, Nadia

    2007-01-01

    Inclusive electron scattering from nuclei at large x and $Q^2$ is the result of a reaction mechanism that includes both quasi--elastic scattering from nucleons and deep inelastic scattering from the quark constituents of the nucleons. Data in this regime can be used to study a wide variety of topics, including the extraction of nuclear momentum distributions, the influence of final state interactions and the approach to $y$-scaling, the strength of nucleon-nucleon correlations, and the approach to $x$- scaling, to name a few. Selected results from the recent experiment E02-019 at the Thomas Jefferson National Accelerator Facility will be shown and their relevance discussed.

  20. Meaurement of the target single-spin asymmetry in quasi-elastic region from the reaction {sup 3}He{up_arrow}(e,e')

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yawei [Rutgers

    2013-10-01

    A measurement of the inclusive target single-spin asymmetry has been performed using the quasi-elastic {sup 3}He{up_arrow}(e,e') reaction with a vertically polarized {sup 3}He target at Q{sup 2} values of 0.13, 0.46 and 0.97 GeV{sup 2}. This asymmetry vanishes under the one photon exchange assumption. But the interference between two-photon exchange and one-photon exchange gives rise to an imaginary amplitude, so that a non-zero A{sub y} is allowed. The experiment, conducted in Hall A of Jefferson Laboratory in 2009, used two independent spectrometers to simultaneously measure the target single-spin asymmetry. Using the effective polarization approximation, the neutron single-spin asymmetries were extracted from the measured {sup 3}He asymmetries. The measurement is to establish a non-vanishing A{sub y}. Non-zero asymmetries were observed at all Q{sup 2} points, and the overall precision is an order of magnitude improved over the existing proton data. The data provide new constraints on Generalized Parton Distribution (GPD) models and new information on the dynamics of the two-photon exchange process.

  1. Controlling light in scattering media noninvasively using the photo-acoustic transmission-matrix

    CERN Document Server

    Chaigne, T; Boccara, A C; Fink, M; Bossy, E; Gigan, S

    2013-01-01

    Optical wavefront-shaping has emerged as a powerful tool to manipulate light in strongly scattering media. It enables diffraction-limited focusing and imaging at depths where conventional microscopy techniques fail. However, while most wavefront-shaping works to-date exploited direct access to the target or implanted probes, the challenge is to apply it non-invasively inside complex samples. Ultrasonic-tagging techniques have been recently demonstrated but these require a sequential point-by- point acquisition, a major drawback for imaging applications. Here, we introduce a novel approach to non-invasively measure the optical transmission-matrix inside a scattering medium, exploiting the photo-acoustic effect. Our approach allows for the first time to simultaneously discriminate, localize, and selectively focus light on multiple targets inside a scattering sample, as well as to recover and exploit the scattering medium properties. Combining the powerful approach of the transmission-matrix with the advantages ...

  2. Scattering of light halo nuclei on heavy target at energies around the Coulomb barrier

    Directory of Open Access Journals (Sweden)

    Tengblad O.

    2014-03-01

    Full Text Available We report here on experiments performed at TRIUMF to study the scattering of the light halo nuclei 11Li on lead at energies below and around the Coulomb barrier. The the elastic and break-up differential cross section are interpreted in the framework of Continuum-Discretized Coupled-Channel calculations. The departure from Rutherford scattering at energies below the barrier is well beyond the behavior of normal nuclei.

  3. Angular intensity of nonequilibrium interfacial dynamic light scattering: Succinonitrile and naphthalene

    Science.gov (United States)

    Williams, L. M.; Cummins, H. Z.; Ladeira, L. O.; Mesquita, O. N.

    1992-03-01

    We have investigated the phenomenon of intense dynamic light scattering at the nonequilibrium crystal-melt interface in succinonitrile and naphthalene, in order to resolve the ongoing controversy over its origin. Of the several models that have been proposed to explain this phenomenon, the microbubble model of H. Z. Cummins et al. [Solid State Commun. 60, 857 (1986)] and the mesophase model proposed by J. Bilgram and co-workers [P. Boni, J. H. Bilgram, and W. Kanzig, Phys. Rev. A 28, 2953 (1983)] are the only two still considered to be consistent with most of the experimental observations. In these experiments the angular dependence of the scattered light was investigated. In the mesophase model the angular dependence of the scattered light is described by the Ornstein-Zernike form I(q)=I0(1+q2ξ2)-1, whereas light scattered by bubbles can be modeled by the Mie scattering theory. The data for both materials were found to be incompatible with the Ornstein-Zernike form, but could be reasonably well fit by the Mie theory. The behavior of the onset of scattering was also investigated, and it was found that the product R0t0v2g was a constant, where R0 is the onset radius, t0 the onset time, and vg the crystal growth velocity. This result is consistent with the analysis of Mesquita et al. [Phys. Rev. B 38, 1550 (1988)], in which the onset of the scattering was modeled by considering the rate of buildup of dissolved gas at the advancing crystal-melt interface. The time taken for the disappearance of the scattering after growth was terminated was also investigated. Lastly, the gases dissolved in our samples of succinonitrile were identified by mass spectroscopy and found to have a composition similar to air.

  4. Scattering of light halo nuclei on heavy target at energies around the Coulomb barrier

    OpenAIRE

    Tengblad O.; Borge M.J.G.; Cubero M.; Nacher E.; Pesudo V.; Perea A.; Gomez-Camacho J.; Moro A. M.; Fernandez-Garcia J.P.; Alvarez M.A.G.; Rodriguez-Gallardo M.; Lay J. A.; Martel I.; Acosta L.; Sanchez-Benitez A.M.

    2014-01-01

    INPC 2013 – International Nuclear Physics Conference We report here on experiments performed at TRIUMF to study the scattering of the light halo nuclei 11Li on lead at energies below and around the Coulomb barrier. The the elastic and break-up differential cross section are interpreted in the framework of Continuum-Discretized Coupled-Channel calculations. The departure from Rutherford scattering at energies below the barrier is well beyond the behavior of normal nuclei Consejo Interins...

  5. Characterization of the angular memory effect of scattered light in biological tissues

    CERN Document Server

    Schott, Sam; Léger, Jean-Francois; Bourdieu, Laurent; Gigan, Sylvain

    2015-01-01

    High resolution optical microscopy is essential in neuroscience but suffers from scattering in biological tissues. It therefore grants access to superficial layers only. Recently developed techniques use scattered photons for imaging by exploiting angular correlations in transmitted light and could potentially increase imaging depths. But those correlations (`angular memory effect') are of very short range and, in theory, only present behind and not inside scattering media. From measurements on neural tissues and complementary simulations, we find that strong forward scattering in biological tissues can enhance the memory effect range (and thus the possible field-of-view) by more than an order of magnitude compared to isotropic scattering for $\\sim$1\\,mm thick tissue layers.

  6. Characterization of the angular memory effect of scattered light in biological tissues

    Science.gov (United States)

    Schott, Sam; Bertolotti, Jacopo; Léger, Jean-Francois; Bourdieu, Laurent; Gigan, Sylvain

    2015-05-01

    High resolution optical microscopy is essential in neuroscience but suffers from scattering in biological tissues. It therefore grants access to superficial layers only. Recently developed techniques use scattered photons for imaging by exploiting angular correlations in transmitted light and could potentially increase imaging depths. But those correlations (`angular memory effect') are of very short range and, in theory, only present behind and not inside scattering media. From measurements on neural tissues and complementary simulations, we find that strong forward scattering in biological tissues can enhance the memory effect range (and thus the possible field-of-view) by more than an order of magnitude compared to isotropic scattering for $\\sim$1\\,mm thick tissue layers.

  7. Characterization of the angular memory effect of scattered light in biological tissues.

    Science.gov (United States)

    Schott, Sam; Bertolotti, Jacopo; Léger, Jean-Francois; Bourdieu, Laurent; Gigan, Sylvain

    2015-05-18

    High resolution optical microscopy is essential in neuroscience but suffers from scattering in biological tissues and therefore grants access to superficial brain layers only. Recently developed techniques use scattered photons for imaging by exploiting angular correlations in transmitted light and could potentially increase imaging depths. But those correlations ('angular memory effect') are of a very short range and should theoretically be only present behind and not inside scattering media. From measurements on neural tissues and complementary simulations, we find that strong forward scattering in biological tissues can enhance the memory effect range and thus the possible field-of-view by more than an order of magnitude compared to isotropic scattering for ∼1 mm thick tissue layers.

  8. Focusing light inside dynamic scattering media with millisecond digital optical phase conjugation.

    Science.gov (United States)

    Liu, Yan; Ma, Cheng; Shen, Yuecheng; Shi, Junhui; Wang, Lihong V

    2017-02-01

    Wavefront shaping based on digital optical phase conjugation (DOPC) focuses light through or inside scattering media, but the low speed of DOPC prevents it from being applied to thick, living biological tissue. Although a fast DOPC approach was recently developed, the reported single-shot wavefront measurement method does not work when the goal is to focus light inside, instead of through, highly scattering media. Here, using a ferroelectric liquid crystal based spatial light modulator, we develop a simpler but faster DOPC system that focuses light not only through, but also inside scattering media. By controlling 2.6 × 10(5) optical degrees of freedom, our system focused light through 3 mm thick moving chicken tissue, with a system latency of 3.0 ms. Using ultrasound-guided DOPC, along with a binary wavefront measurement method, our system focused light inside a scattering medium comprising moving tissue with a latency of 6.0 ms, which is one to two orders of magnitude shorter than those of previous digital wavefront shaping systems. Since the demonstrated speed approaches tissue decorrelation rates, this work is an important step toward in vivo deep-tissue non-invasive optical imaging, manipulation, and therapy.

  9. A new dump system design for stray light reduction of Thomson scattering diagnostic system on EAST

    Science.gov (United States)

    Xiao, Shumei; Zang, Qing; Han, Xiaofeng; Wang, Tengfei; Yu, Jin; Zhao, Junyu

    2016-07-01

    Thomson scattering (TS) diagnostic is an important diagnostic for measuring electron temperature and density during plasma discharge. However, the measurement of Thomson scattering signal is disturbed by the stray light easily. The stray light sources in the Experimental Advanced Superconducting Tokamak (EAST) TS diagnostic system were analyzed by a simulation model of the diagnostic system, and simulation results show that the dump system is the primary stray light source. Based on the optics theory and the simulation analysis, a novel dump system including an improved beam trap was proposed and installed. The measurement results indicate that the new dump system can reduce more than 60% of the stray light for the diagnostic system, and the influence of stray light on the error of measured density decreases.

  10. Atmospheric corrosion mapping of copper surfaces from diffuse light scattering measurements by an optoelectronic sensor system

    Institute of Scientific and Technical Information of China (English)

    Marimuthu PAULVANNA NAYAKI; Arunachalam P. KABILAN

    2009-01-01

    A novel light scattering technique for mapping metal surface corrosion is presented and its results on copper exposed to atmosphere are reported. The front end of the instrument is made up of a sensor module comprising a thin beam light emitting diode (LED) illuminating a small spot on the metal surface, and a matched pair of photodetectors, one for capturing the reflected light and the other for sampling the scattered light. The analog photocurrent signals are digitized and processed online by a personal computer (PC) to determine the corrosion factor defined in terms of the two current values. By scanning the sample surface using the light beam and by computing the corrosion factor values simultaneously, a three dimensional graph and a two dimensional contour map are generated in the PC using Matlab tools. The values of the corrosion factor measured in different durations of exposure to atmosphere, which obey a bilogarithmic law, testify to the validity of our mathematical model.

  11. A new dump system design for stray light reduction of Thomson scattering diagnostic system on EAST.

    Science.gov (United States)

    Xiao, Shumei; Zang, Qing; Han, Xiaofeng; Wang, Tengfei; Yu, Jin; Zhao, Junyu

    2016-07-01

    Thomson scattering (TS) diagnostic is an important diagnostic for measuring electron temperature and density during plasma discharge. However, the measurement of Thomson scattering signal is disturbed by the stray light easily. The stray light sources in the Experimental Advanced Superconducting Tokamak (EAST) TS diagnostic system were analyzed by a simulation model of the diagnostic system, and simulation results show that the dump system is the primary stray light source. Based on the optics theory and the simulation analysis, a novel dump system including an improved beam trap was proposed and installed. The measurement results indicate that the new dump system can reduce more than 60% of the stray light for the diagnostic system, and the influence of stray light on the error of measured density decreases.

  12. Inelastic light scattering by low-lying excitations of electrons in low-dimensional semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Pellegrini, V. [NEST CNR-INFM and Scuola Normale Superiore, Pisa (Italy); Pinczuk, A. [Department of Physics, Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027 (United States); Bell Laboratories, Lucent Technologies, Murray Hill, New Jersey (United States)

    2006-11-15

    The low-dimensional electron systems that reside in artificial semiconductor heterostructures of great perfection are a contemporary materials base for explorations of collective phenomena. Studies of low-lying elementary excitations by inelastic light scattering offer insights on properties such energetics, interactions and spin magnetization. We review here recent light scattering results obtained from two-dimensional (2D) quantum fluids in semiconductor heterostructures under extreme conditions of low temperature and large magnetic field, where the quantum Hall phases are archetypes of novel behaviors. We also consider recent light scattering experiments that have probed the excitation spectra of few-electron states in semiconductor quantum dots. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  13. Applications of Optical Sensors to the Detection of Light Scattered from Gelling Systems

    Science.gov (United States)

    Bulone, Donatella; Manno, Mauro; San Biagio, Pier Luigi; Martorana, Vincenzo

    Visible light, scattered within an angle of few degrees, (Small Angle Light Scattering, SALS) yields information on the spatial correlations and dynamical properties on the scale of the micrometers. In this way a quick and non-invasive characterization of a variety of samples is feasible. Lately the SALS instruments have been built around multielement optical sensors (CCD, CMOS), allowing the simultaneous measurement of the complete structure factor even during fast kinetics. An assessment of some sensor matrices of different technology will be presented. The omolecular assemblies produced by polysaccharides or proteins can be functional or dysfunctional, their properties being either desirable or detrimental. Anyhow, their morphology often depends, in a very delicate way, on the presence of cosolutes, on the thermal history, on the biopolymer concentration etc. We present some applications of low angle dynamic and static light scattering to the study of gelling systems (agarose, pectin, insulin).

  14. Development of 3D control of a tiny dew droplet by scattered laser light

    Science.gov (United States)

    Matsumoto, Shigeaki

    2009-06-01

    In order to study dropwise condensation on a metal plate, the method for controlling a tiny dew droplet deposited on a copper plate has been developed by using scattered laser light. The method employed the proportional control combined with shifting movement by an integrator to control the intensity of the scattered laser light constantly. Also, the control simulation of the method has been developed to confirm the usefulness of the method and the simulated three-dimensional shape of controlled dew droplet was obtained with the control action. A tiny thin dew droplet, of which the diameter was of handreds micrometers and the mass was about 10-7 g, was controlled in the atmosphere at room temperature for 60 minutes at the preset level of the intensity of scattered laser light and the three-dimensional shape of the controlled dew droplet was shown from the interference fringes.

  15. Determination of liquid-liquid critical point composition using 90∘ laser light scattering

    Science.gov (United States)

    Williamson, J. Charles; Brown, Allison M.; Helvie, Elise N.; Dean, Kevin M.

    2016-04-01

    Despite over a century of characterization efforts, liquid-liquid critical point compositions are difficult to identify with good accuracy. Reported values vary up to 10% for even well-studied systems. Here, a technique is presented for high-precision determination of the critical composition of a partially miscible binary liquid system. Ninety-degree laser light-scattering intensities from single-phase samples are analyzed using an equation derived from nonclassical power laws and the pseudospinodal approximation. Results are reported for four liquid-liquid systems (aniline + hexane, isobutyric acid + water, methanol + cyclohexane, and methanol + carbon disulfide). Compared to other methods, the 90∘ light-scattering approach has a strong dependence on composition near the critical point, is less affected by temperature fluctuations, and is insensitive to the presence of trace impurities in the samples. Critical compositions found with 90∘ light scattering are precise to the parts-per-thousand level and show long-term reproducibility.

  16. Determination of liquid-liquid critical point composition using 90^{∘} laser light scattering.

    Science.gov (United States)

    Williamson, J Charles; Brown, Allison M; Helvie, Elise N; Dean, Kevin M

    2016-04-01

    Despite over a century of characterization efforts, liquid-liquid critical point compositions are difficult to identify with good accuracy. Reported values vary up to 10% for even well-studied systems. Here, a technique is presented for high-precision determination of the critical composition of a partially miscible binary liquid system. Ninety-degree laser light-scattering intensities from single-phase samples are analyzed using an equation derived from nonclassical power laws and the pseudospinodal approximation. Results are reported for four liquid-liquid systems (aniline + hexane, isobutyric acid + water, methanol + cyclohexane, and methanol + carbon disulfide). Compared to other methods, the 90^{∘} light-scattering approach has a strong dependence on composition near the critical point, is less affected by temperature fluctuations, and is insensitive to the presence of trace impurities in the samples. Critical compositions found with 90^{∘} light scattering are precise to the parts-per-thousand level and show long-term reproducibility.

  17. Beam-splitting code for light scattering by ice crystal particles within geometric-optics approximation

    Science.gov (United States)

    Konoshonkin, Alexander V.; Kustova, Natalia V.; Borovoi, Anatoli G.

    2015-10-01

    The open-source beam-splitting code is described which implements the geometric-optics approximation to light scattering by convex faceted particles. This code is written in C++ as a library which can be easy applied to a particular light scattering problem. The code uses only standard components, that makes it to be a cross-platform solution and provides its compatibility to popular Integrated Development Environments (IDE's). The included example of solving the light scattering by a randomly oriented ice crystal is written using Qt 5.1, consequently it is a cross-platform solution, too. Both physical and computational aspects of the beam-splitting algorithm are discussed. Computational speed of the beam-splitting code is obviously higher compared to the conventional ray-tracing codes. A comparison of the phase matrix as computed by our code with the ray-tracing code by A. Macke shows excellent agreement.

  18. Theoretical models for near forward light scattering by a Plasmodium falciparum infected red blood cell

    Science.gov (United States)

    Sharma, S. K.

    2012-12-01

    A number of experimental elastic light scattering studies have been performed in the past few years with the aim of developing automated in vivo tools for differentiating a healthy red blood cell from a Plasmodium falciparum infected cell. This paper examines some theoretical aspects of the problem. An attempt has been made to simulate the scattering patterns of healthy as well as infected individual red blood cells. Two models, namely, a homogeneous sphere model and a coated sphere model have been considered. The scattering patterns predicted by these models are examined. A possible method for discriminating infected red blood cells from healthy ones has been suggested.

  19. [Multiple scattering of visible and infrared light by sea fog over wind driving rough sea surface].

    Science.gov (United States)

    Sun, Xian-Ming; Wang, Hai-Hua; Lei, Cheng-Xin; Shen, Jin

    2013-08-01

    The present paper is concerned with computing the multiple scattering characteristics of a sea fog-sea surface couple system within this context. The single scattering characteristics of sea fog were studied by Mie theory, and the multiple scattering of sunlight by single sea fog layer was studied by radiative transfer theory. The reflection function of a statistically rough ocean surface was obtained using the standard Kirchhoff formulation, with shadowing effects taken into account. The reflection properties of the combined sea fog and ocean surface were obtained employing the adding method, and the results indicated that the reflected light intensity of sea fog increased with the sea background.

  20. Analytic height correlation function of rough surfaces derived from light scattering

    CERN Document Server

    Zamani, M; Fazeli, S M; Downer, M C; Jafari, G R

    2015-01-01

    We obtain an analytic expression for the height correlation function of a rough surface based on the inverse wave scattering method of Kirchhoff theory. The expression directly relates the height correlation function to diffuse scattered intensity. We test the solution by measuring the angular distribution of light scattered from rough silicon surfaces, solving for the height correlation functions, and comparing them to functions derived from AFM measurements. The results show good agreement. The advantages of this method are its accurate analytical equation for the height correlation function and the simplicity of the experimental setup required to measure it.

  1. Thermally induced light-scattering effects as responsible for the degradation of cholesteric liquid crystal lasers.

    Science.gov (United States)

    Etxebarria, J; Ortega, J; Folcia, C L; Sanz-Enguita, G; Aramburu, I

    2015-04-01

    We have studied the degradation process of the laser emission in a cholesteric liquid crystal laser. We have found that there exists a negative correlation between the laser efficiency and the amount of light scattered by the liquid-crystal sample in the illuminated area. The growth of scattering is attributed to the appearance of small imperfections generated in the sample as a result of certain thermal processes that involve the dye molecules. The scattering implies an increase of the coefficient of distributed losses, which is the main response of the rise of the laser threshold.

  2. Temporal intensity correlation of light scattered by a hot atomic vapor

    CERN Document Server

    Dussaux, A; Guerin, W; Alibart, O; Tanzilli, S; Vakili, F; Kaiser, R

    2016-01-01

    We present temporal intensity correlation measurements of light scattered by a hot atomic vapor. Clear evidence of photon bunching is shown at very short time-scales (ns) imposed by the Doppler broadening of the hot vapor. Moreover, we demonstrate that some relevant information about the scattering process, such as the ratio of single to multiple scattering, can be deduced from the measured intensity correlation function. These measurements confirm the interest of temporal intensity correlation measurements to access non-trivial spectral features, with potential applications in astrophysics.

  3. Theoretical Models of Light Scattering Applied in Sizing Particles in Coal Water Slurry

    Institute of Scientific and Technical Information of China (English)

    王仁哲; 张荣曾; 徐志强

    2004-01-01

    Advantges and disadvantage of Mie scattering model and Fraunhofer diffraction model are discussed. The result shows that 1) the Fraunhofer diffraction model is simple in design and fast in operation, which is quite suitable for on-line control and 2) the intensity and energy distribution of diffracted light of both the Mie scattering model and the Fraunhofer theoretical model are compared and researched. Feasibility of using the Fraunhofer diffraction model to replace the Mie scattering model in measuring particles in coal water slurry is demonstrated.

  4. Neutron scattering treatise on materials science and technology

    CERN Document Server

    Kostorz, G

    1979-01-01

    Treatise on Materials Science and Technology, Volume 15: Neutron Scattering shows how neutron scattering methods can be used to obtain important information on materials. The book discusses the general principles of neutron scattering; the techniques used in neutron crystallography; and the applications of nuclear and magnetic scattering. The text also describes the measurement of phonons, their role in phase transformations, and their behavior in the presence of crystal defects; and quasi-elastic scattering, with its special merits in the study of microscopic dynamical phenomena in solids and

  5. Optical characteristics of LGP depending on the scattering pattern orientation for flat-type LED lighting

    Science.gov (United States)

    Park, Sohee; Shin, Yongjin; Oh, Kwanghwan; Bang, Taehwan

    2016-04-01

    In flat-type light-emitting-diode (LED) lighting systems, a planar light is formed using a luminance source positioned on the side of the system and light guide panel (LGP) or reflecting plates. Thus, such systems are favorable for their thinness, which allows a relatively small number of LEDs to be used. However, the application of a high-power LED light to a large-area lighting system yields Lambertian luminaires; therefore, a point or a discomfort glare is produced, which generally causes degradation of the luminance efficiency and uniformity. In this study, we solved the problems of luminance non-uniformity and inefficiency by adjusting the orientation of an applied LGP scattered pattern and removing the remaining glare. Through computer simulation, optical characteristics that increase the efficiency even in the case of low-output LEDs were found. Specifically, a scattered pattern vertically oriented relative to the direction of the incident light improves the luminance uniformity at the side of the system, while a scattered pattern oriented parallel to the direction of the incident light plays the role of a waveguide. We implemented a flat-type LED lighting system by fabricating a large-area LGP based on the computer-simulation results and using an extremely sensitive laser. The optical characteristics observed using the laser-processed LGP were identical to those obtained in the computer simulation. Therefore, for large-area flat-type LED lighting systems, we confirmed that adjusting the orientation of the LGP scattered pattern can increase the luminance efficiency and uniformity.

  6. Li-ion conduction in the LiBH4:LiI system from Density Functional Theory calculations and Quasi-Elastic Neutron Scattering

    DEFF Research Database (Denmark)

    Myrdal, Jon Steinar Gardarsson; Blanchard, Didier; Sveinbjörnsson, Dadi Þorsteinn

    2013-01-01

    defect sites, giving rise to high defect mobility. QENS results at 380 K show long-range diffusion of Li+, with jump lengths of one unit cell and jump rates in agreement with those obtained from DFT, and the application of the bias potential increases the diffusion constant by a factor of 2. At 300 K......The hexagonal high-temperature polymorph of LiBH4 is stabilized by solid solution with LiI to exhibit superionic Li+ ionic conductivity at room temperature. Herein, the mechanisms for the Li+ diffusion are investigated for the first time by density functional theory (DFT) calculations coupled......, the QENS data reveal jump events of shorter length (2 Å), which could correspond to a jump process of Li+ interstitials to an intermediate lattice site, in agreement with DFT calculations....

  7. Light scattering by subwavelength Cu2O particles

    Science.gov (United States)

    Ullah, Kaleem; Liu, Xuefeng; Yadav, N. P.; Habib, Muhammad; Song, Li; García-Cámara, Braulio

    2017-03-01

    Novel metamaterials with new capabilities to manipulate light may be used by considering basic building blocks with new optical properties. This is the case with resonant magneto-dielectric particles. In this work, the resonant response of a high-dielectric Cu2O subwavelength particle is analyzed, both analytically and experimentally. The emergence of electric and magnetic resonances and their interferential effects, producing directional behaviors, can be used in a new generation of metamaterials, as well as new integrated optical devices.

  8. Mathematical methods for restricted domain ternary liquid mixture free energy determination using light scattering.

    Science.gov (United States)

    Wahle, Chris W; Ross, David S; Thurston, George M

    2013-09-28

    We extend methods of solution of a light scattering partial differential equation for the free energy of mixing to apply to connected, isotropic ternary liquid composition domains that do not touch all three binary axes. To do so we mathematically analyze the problem of inferring needed Dirichlet boundary data, and solving for the free energy, with use of hypothetical static light scattering measurements that correspond to dielectric composition gradient vectors that have distinct directions. The physical idea behind the technique is that contrasting absorption properties of mixture components can result in such distinctly directed dielectric composition gradient vectors, due to their differing wavelength dependences of dielectric response. At suitably chosen wavelengths, contrasting light scattering efficiency patterns in the ternary composition triangle can then correspond to the same underlying free energy, and enlarge the scope of available information about the free energy, as shown here. We show how to use distinctly directed dielectric gradients to measure the free energy on both straight lines and curves within the ternary composition triangle, so as to provide needed Dirichlet conditions for light scattering partial differential equation solution. With use of Monte Carlo simulations of noisy light scattering data, we provide estimates of the overall system measurement time and sample spacing needed to determine the free energy to a desired degree of accuracy, for various angles between the assumed dielectric gradient vectors, and indicate how the measurement time depends on instrumental throughput parameters. The present analysis methods provide a way to use static light scattering to measure, directly, mixing free energies of many systems that contain such restricted liquid domains, including aqueous solutions of biological macromolecules, micellar mixtures and microemulsions, and many small molecule systems that are important in separation technology.

  9. Blood cell counting and classification by nonflowing laser light scattering method

    Science.gov (United States)

    Yang, Ye; Zhang, Zhenxi; Yang, Xinhui; Jiang, Dazong; Yeo, Joon Hock

    1999-11-01

    A new non-flowing laser light scattering method for counting and classifying blood cells is presented. A linear charge- coupled device with 1024 elements is used to detect the scattered light intensity distribution of the blood cells. A pinhole plate is combined with the CCD to compete the focusing of the measurement system. An isotropic sphere is used to simulate the blood cell. Mie theory is used to describe the scattering of blood cells. In order to inverse the size distribution of blood cells from their scattered light intensity distribution, Powell method combined with precision punishment method is used as a dependent model method for measurement red blood cells and blood plates. Non-negative constraint least square method combined with Powell method and precision punishment method is used as an independent model for measuring white blood cells. The size distributions of white blood cells and red blood cells, and the mean diameter of red blood cells are measured by this method. White blood cells can be divided into three classes: lymphocytes, middle-sized cells and neutrocytes according to their sizes. And the number of blood cells in unit volume can also be measured by the linear dependence of blood cells concentration on scattered light intensity.

  10. Detection of internal structure by scattered light intensity: Application to kidney cell sorting

    Science.gov (United States)

    Goolsby, C. L.; Kunze, M. E.

    1985-01-01

    Scattered light measurements in flow cytometry were sucessfully used to distinguish cells on the basis of differing morphology and internal structure. Differences in scattered light patterns due to changes in internal structure would be expected to occur at large scattering angles. Practically, the results of these calculations suggest that in experimental situations an array of detectors would be useful. Although in general the detection of the scattered light intensity at several intervals within the 10 to 60 region would be sufficient, there are many examples where increased sensitivity could be acheived at other angles. The ability to measure at many different angular intervals would allow the experimenter to empirically select the optimum intervals for the varying conditions of cell size, N/C ratio, granule size and internal structure from sample to sample. The feasibility of making scattered light measurements at many different intervals in flow cytometry was demonstrated. The implementation of simplified versions of these techniques in conjunction with independant measurements of cell size could potentially improve the usefulness of flow cytometry in the study of the internal structure of cells.

  11. Laboratory light scattering from regolith surface and simulation of data by Hapke model

    CERN Document Server

    Deb, S

    2015-01-01

    The small atmosphereless objects of our solar system, such as asteroids, the moon are covered by layer of dust particles known as regolith, formed by meteoritic impact. The light scattering studies of such dust layer by laboratory experiment and numerical simulation are two important tools to investigate their physical properties. In the present work, the light scattered from a layer of dust particles, containing 0.3{\\mu}m Al2O3 at wavelength 632.8 nm is analysed. This work has been performed by using a light scattering instrument 'ellipsometer', at the Department of Physics, Assam Universiy, Silchar, India. Through this experiment, we generated in laboratory the photometric and polarimetric phase curves of light scattered from such a layer. In order to numerically simulate this data, we used Hapke's model combined with Mie's single particle scattering properties. The perpendicular and parallel components of single particle albedo and the phase function were derived from Mie theory. By using the Hapke's model...

  12. Theory on the scattering of light and surface plasmon polaritons by arrays of holes and dimples in a metal film

    OpenAIRE

    de Leon-Perez, F.; Brucoli, G.; Garcia-Vidal, F.J.; Martin-Moreno, L

    2008-01-01

    The scattering of light and surface plasmon polaritons (SPPs) by finite arrays of either holes or dimples in a metal film is treated theoretically. A modal expansion formalism, capable of handling real metals with up to thousands of indentations, is presented. Computations based on this method demonstrate that a single hole scatters a significant fraction of incoming light into SPPs. It is also observed that holes and dimples scatter SPPs into light with similar efficiencies, provided the dep...

  13. Enhanced light scattering in Si nanostructures produced by pulsed laser irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Sberna, P. M.; Scapellato, G. G.; Boninelli, S.; Miritello, M.; Crupi, I.; Bruno, E.; Privitera, V.; Simone, F.; Mirabella, S. [MATIS IMM-CNR and Dipartimento di Fisica e Astronomia, Università di Catania, via S. Sofia 64, 95123 Catania (Italy); Piluso, N. [IMM-CNR, VIII strada 5, 95121 Catania (Italy)

    2013-11-25

    An innovative method for Si nanostructures (NS) fabrication is proposed, through nanosecond laser irradiation (λ = 532 nm) of thin Si film (120 nm) on quartz. Varying the laser energy fluences (425–1130 mJ/cm{sup 2}) distinct morphologies of Si NS appear, going from interconnected structures to isolated clusters. Film breaking occurs through a laser-induced dewetting process. Raman scattering is enhanced in all the obtained Si NS, with the largest enhancement in interconnected Si structures, pointing out an increased trapping of light due to multiple scattering. The reported method is fast, scalable and cheap, and can be applied for light management in photovoltaics.

  14. Scattered light diagnostics of overdense plasma cavity in solid targets irradiated by an ultraintense laser pulse.

    Science.gov (United States)

    Andreev, A A; Zhidkov, A G; Uesaka, M; Kinoshita, K; Platonov, K Yu

    2002-09-01

    The light scattered backward from a target illuminated by ultraintense laser pulses carries important information about the nonlinear laser-plasma interaction. We analyze the usefulness of this information by plasma corona analysis with the help of an analytical model we developed, and particle-in-cell simulation. The spectrum of scattered light is shown to be shifted, to be broadened, and to be modulated, in comparison with the initial laser spectrum, and the spectral shift is an indicator of laser pulse contrast ratio.

  15. Higher order multipolar polarizabilities of carbon tetrafluoride from isotropic and anisotropic light scattering experiments

    Science.gov (United States)

    El-Kader, M. S. A.; Bancewicz, T.; Maroulis, G.

    2010-12-01

    The higher order dipole-quadrupole and dipole-octopole polarizabilities of carbon tetrafluoride has been determined from isotropic and anisotropic collision-induced light scattering (CILS) experiments of CF 4 and from anisotropic light scattering of its mixture with argon gas. The CILS spectra are analyzed by using the new updated and different intermolecular potentials. Our final estimates for these properties are ∣ A∣ = (1.051 ± 0.073) Å 4 and ∣ E∣ = (1.235 ± 0.282) Å 5 which are in excellent agreement with the ab initio theoretical values.

  16. Dipole-octopole polarizability of sulfur hexafluoride from isotropic and anisotropic light scattering experiments

    Science.gov (United States)

    El-Kader, M. S. A.; Bancewicz, T.

    2013-05-01

    The higher order dipole-octopole polarizability E of sulfur hexafluoride has been determined from isotropic and anisotropic collision-induced light scattering (CILS) experiments of pure SF6 gas and from anisotropic light scattering of its mixture with inert gases. The CILS spectra are analyzed by using the new updated and different intermolecular potentials. Our final estimates for this property is |E| = 96.405 ± 12.045 a.u. which is in excellent agreement with the ab initio theoretical value.

  17. TW Laser system for Thomson scattering X-ray light source at Tsinghua University

    Institute of Scientific and Technical Information of China (English)

    YAN Li-Xin; DU Ying-Chao; DU Qiang; LI Ren-Kai; HUA Jian-Fei; HUANG Wen-Hui; TANG Chuan-Xiang

    2009-01-01

    A TW(Tera Watt)laser system based on Ti:sapphire mainly for the Tsinghua Thomson scattering X-ray light source(TTX)is being built.Both UV(ultraviolet)laser pulse for driving the photocathode radiofrequency(RF)gun and the IR(infrared)laser pulse as the electron-beam-scattered-light are provided by the system.Efforts have also been made in laser pulse shaping and laser beam transport to optimize the high-brightness electron beam production by the photocathode RF gun.

  18. The impact of organic coatings on light scattering by sodium chloride particles

    Science.gov (United States)

    Li, Yan; Ezell, Michael J.; Finlayson-Pitts, Barbara J.

    2011-08-01

    Light scattering by airborne particles plays a major role in visibility degradation and climate change. The composition and structure of particles in air can be complex, so that predictions of light scattering a priori have significant uncertainties. We report here studies of light scattering by NaCl, a model for airborne salt particles from the ocean and alkaline lakes, with and without an organic coating formed from the low volatility products of the reaction of α-pinene with ozone at room temperature at 1 atm in air. Light scattering at 450, 550 and 700 nm was measured using an integrating nephelometer on particles whose size distribution was independently determined using a scanning mobility particle sizer (SMPS). For comparison, polystyrene latex spheres (PSL) of a known size and dioctylphthalate (DOP) particles generated with a narrow size distribution were also studied. The measured values were compared to those calculated using Mie theory. Although excellent agreement between experiment and theory was found for the PSL and DOP particles, there were large discrepancies for a polydisperse NaCl sample. These were traced to errors in the size distribution measurements. Despite the use of 85Kr neutralizers, the Boltzmann charge equilibrium distribution assumption used to derive particle size distributions from SMPS data was shown not to be valid, leading to an overestimate of the concentration of larger particles and their contribution to light scattering. Correcting for this, the combination of experiments and theory show that as salt takes up low volatility organics in the atmosphere and the geometric mean diameter increases, the effect on light scattering may be reasonably approximated from the change in size distribution under conditions where the organic coating is small relative to the core size. However, for a given particle diameter, light scattering decreases as the relative contribution of the organic component increases. Thus, light scattering by

  19. Electron scattering disintegration processes on light nuclei in covariant approach

    Science.gov (United States)

    Kuznietsov, P. E.; Kasatkin, Yu. A.; Klepikov, V. F.

    2016-07-01

    We provide general analysis of electro-break up process of compound scalar system. We use covariant approach with conserved EM current, which gives the ability to include strong interaction into QED. Therefore, we receive the ability to describe disintegration processes on nonlocal matter fields applying standard Feynman rules of QED. Inclusion of phase exponent into wave function receives a physical sense while we deal with the dominance of strong interaction in the process. We apply Green's function (GF) formalism to describe disintegration processes. Generalized gauge invariant electro-break up process amplitude is considered. One is a sum of traditional pole series and the regular part. We explore the deposits of regular part of amplitude, and its physical sense. A transition from virtual to real photon considered in photon point limit. The general analysis for electro-break up process of component scalar system is given. Precisely conserved nuclear electromagnetic currents at arbitrary square of transited momentum are received. The only undefined quantity in theory is vertex function. Therefore, we have the opportunity to describe electron scattering processes taking into account minimal necessary set of parameters.

  20. Electron scattering disintegration processes on light nuclei in covariant approach

    Directory of Open Access Journals (Sweden)

    Kuznietsov P.E.

    2016-01-01

    Full Text Available We provide general analysis of electro-break up process of compound scalar system. We use covariant approach with conserved EM current, which gives the ability to include strong interaction into QED. Therefore, we receive the ability to describe disintegration processes on nonlocal matter fields applying standard Feynman rules of QED. Inclusion of phase exponent into wave function receives a physical sense while we deal with the dominance of strong interaction in the process. We apply Green’s function (GF formalism to describe disintegration processes. Generalized gauge invariant electro-break up process amplitude is considered. One is a sum of traditional pole series and the regular part. We explore the deposits of regular part of amplitude, and its physical sense. A transition from virtual to real photon considered in photon point limit. The general analysis for electro-break up process of component scalar system is given. Precisely conserved nuclear electromagnetic currents at arbitrary square of transited momentum are received. The only undefined quantity in theory is vertex function. Therefore, we have the opportunity to describe electron scattering processes taking into account minimal necessary set of parameters.

  1. Specular, diffuse, and polarized light scattered by two wheat canopies

    Science.gov (United States)

    Vanderbilt, V. C.; Grant, L.; Biehl, L. L.; Robinson, B. F.

    1985-01-01

    Using polarization measurements, the reflectance factor of two wheat canopies is divided into components due to specularly and diffusely reflected light. The data show that two key angles may be predicted, the angle of the polarizer for minimum flux and the angle of incidence of sunlight specularly reflected by a leaf to a sensor. The results show that specular reflection is a key aspect to radiation transfer by two canopies. Results suggest that the advent of heading in wheat may be remotely sensed from polarization measurements of the canopy reflectance.

  2. Scattered-Light Echoes from the Historical Galactic Supernovae Cassiopeia A and Tycho (SN 1572)

    Energy Technology Data Exchange (ETDEWEB)

    Rest, A; Welch, D L; Suntzeff, N B; Oaster, L; Lanning, H; Olsen, K; Smith, R C; Becker, A C; Bergmann, M; Challis, P; Clocchiatti, A; Cook, K H; Damke, G; Garg, A; Huber, M E; Matheson, T; Minniti, D; Prieto, J L; Wood-Vasey, W M

    2008-05-06

    We report the discovery of an extensive system of scattered light echo arclets associated with the recent supernovae in the local neighborhood of the Milky Way: Tycho (SN 1572) and Cassiopeia A. Existing work suggests that the Tycho SN was a thermonuclear explosion while the Cas A supernova was a core collapse explosion. Precise classifications according to modern nomenclature require spectra of the outburst light. In the case of ancient SNe, this can only be done with spectroscopy of their light echo, where the discovery of the light echoes from the outburst light is the first step. Adjacent light echo positions suggest that Cas A and Tycho may share common scattering dust structures. If so, it is possible to measure precise distances between historical Galactic supernovae. On-going surveys that alert on the development of bright scattered-light echo features have the potential to reveal detailed spectroscopic information for many recent Galactic supernovae, both directly visible and obscured by dust in the Galactic plane.

  3. Controlling stimulated Raman scattering by two-color light in inertial confinement fusion

    Science.gov (United States)

    Liu, Z. J.; Chen, Y. H.; Zheng, C. Y.; Cao, L. H.; Li, B.; Xiang, J.; Hao, L.; Lan, K.

    2017-08-01

    A method is proposed to control the stimulated Raman scattering in the inertial confinement fusion by using auxiliary 2ω light to suppress the stimulated Raman scattering of the 3ω light. In this scheme, inverse bremsstrahlung absorption and parametric instabilities in the 2ω light increase the electron temperature and the plasma-density fluctuation, thus preventing the development of Raman scattering of the 3ω light. This scheme is successfully demonstrated by both one-dimensional kinetic simulations and two-dimensional radiative hydrodynamic simulations. The one-dimensional Vlasov results show that the time-averaged transmissivity of the 3ω light increases from 0.75 to 0.95 under certain conditions. Results obtained using the particle-in-cell method with Monte Carlo collisions show that the electron temperature is greatly increased with the increasing intensity of the 2ω light. The two-dimensional radiative hydrodynamic simulation results show that the electron temperature increases from 3.2 keV to 3.5 keV, and the time-averaged backscattering level decreases from 0.28 to 0.1 in the presence of the auxiliary 2ω light.

  4. Light scattering of nanocrystalline TiO2 film used in dye-sensitized solar cells

    Institute of Scientific and Technical Information of China (English)

    Xiong Bi-Tao; Zhou Bao-Xue; Bai Jing; Zheng Qing; Liu Yan-Biao; Cai Wei-Min; Cai Jun

    2008-01-01

    This paper studies the light scattering and adsorption of nanocrystalline TiO2 porous films used in dye-sensitized solar cells composed of anatase and/or rutile particles by using an optical four-flux radiative transfer model.These light properties are difficult to measure directly on the functioning solar cells and they can not be calculated easily from the first-principle computational or quantitative theoretical evaluations.These simulation results indicate that the light scattering of 1-25 nm TiO2 panicles is negligible,but it is effective in the range of 80 and 180 nm.A suitable mixture of small particles(10 nm radius),which are resulted in a large effective surface,and of larger particles(150 nm radius),which are effective light scatterers,have the potential to enhance solar absorption significantly.The rutile crystals have a larger refractive index and thus the light harvest of the mixtures of such larger rutile and relatively small anatase particles is improved in comparison with that of pure anatase films.The light absorption of the 10μm double-layered films is also examined.A maximal light absorption of double-layered film is gotten when the thickness of the first layer of 10 nm-sized anatase particles is comparable to that of the second larger rutile layer.

  5. Laboratory measurements of light scattering properties of a carbonaceous interstellar dust analogue (soot particles)

    Science.gov (United States)

    Gogoi, Ankur; Choudhury, Amarjyoti; Ahmed, Gazi A.; Kashyap Boruah, Goutam

    2012-07-01

    Dust particles are present everywhere in the solar system, cometary comae and tail, interstellar dust clouds, asteroidal atmospheres and aerosols of other planetary atmospheres. The in situ sampling of the cometary dust composition conducted by CIDA (Cometary and Interstellar Dust Analyzer) and observed interstellar extinction and polarization revealed the presence of amorphous carbon, graphite, silicate, graphite, carbonates, metal oxide grains, ice particles and nanodiamonds in the interstellar medium. These particles act as the heterogeneous media to scatter solar or steller light. Observations and simulations of the light scattered by dust particles in cometary comae, interplanetary space and planetary regolith (or analogous terrestrial dust aggregates) is necessary to deduce the physical properties of their constituent particles and may lead to a better understanding of the formation of solar system. Notably the measurement of the volume scattering function (VSF) and degree of linear polarization (DLP) can be used to estimate parameters like size, porosity and roughness of the dust particles. In this contribution we report the design and fabrication of a laser based laboratory light scattering instrument that uses an array of 16 static Si photodetectors and can be operated at three different incident wavelengths (543.5 nm, 594.5 nm and 632.8 nm). The accuracy and the reliability of the setup were verified by conducting light scattering measurements on spherical water droplets and comparing the results with theoretical Mie calculations. The results of the measurements of the VSF and DLP of carbonaceous soot particles (agglomerates) that were sprayed in front of the laser beam by using an aerosol sprayer are presented. The experimental results were further analyzed by comparing with theoretically generated T-matrix and DDA (Discrete Dipole Approximation) plots with estimated parameters to yield more fruitful conclusions. Significant variations of the light

  6. Enhanced light harvesting of dye-sensitized solar cells with TiO2 microspheres as light scattering layer

    Science.gov (United States)

    Guan, Yingli; Song, Lixin; Zhou, Yangyang; Yin, Xin; Xie, Xueyao; Xiong, Jie

    2017-03-01

    Two kinds of TiO2 microspheres (TMS) with average diameter of 1500 nm but different surface were fabricated by solvothermal method from different Ti source. The effect of TMS on the light harvesting and photovoltaic performance of dye-sensitized solar cells (DSSCs)was investigated. The UV-Vis diffusion reflectance spectra and absorption spectra of N719 dye in detached solutions proved that the TMS showed dual functions of light scattering and dye-adsorption which was an important functional material in DSSCs. The results showed that the TMS made from titanium(IV) isopropoxide with rough surface (TMSR) exhibited better photovoltaic performance than that of TMS made from tetrabutyl titanate with smooth surface (TMSS). To further improve the photovoltaic performance, the double-layered DSSCs made of P25 as an underlayer and TMS as a light-scattering layer (P25-TMS) were fabricated. The photovoltaic performance of double-layered DSSCs was higher than that of the single-layered DSSCs with similar thickness. Especially, the DSSCs made of P25 as an underlayer and the TMSR as a light-scattering layer (P25-TMSR) had a highest power conversion efficiency of 7.62%. This was higher than that of single-layered TMSR-based cell (5.54%), P25-based cell (5.75%), and double-layered P25-TMSS-based cell (6.78%) with similar thickness. This was mainly attributed to the large specific surface area, superior light scattering ability, and fast electron transport of TMSR.

  7. Robust sensor for turbidity measurement from light scattering and absorbing liquids.

    Science.gov (United States)

    Kontturi, Ville; Turunen, Petri; Uozumi, Jun; Peiponen, Kai-Erik

    2009-12-01

    Internationally standardized turbidity measurements for probing solid particles in liquid are problematic in the case of simultaneous light scattering and absorption. A method and a sensor to determine the turbidity in the presence of light absorption are presented. The developed sensor makes use of the total internal reflection of a laser beam at the liquid-prism interface, and the turbidity is assessed using the concept of laser speckle pattern. Using average filtering in speckle data analyzing the observed dynamic speckle pattern, which is due to light scattering from particles and the static speckle due to stray light of the sensor, can be separated from each other. Good correlation between the standard deviation of dynamic speckle and turbidity value for nonabsorbing and for absorbing liquids was observed. The sensor is suggested, for instance, for the measurement of ill-behaved as well as small-volume turbid liquids in both medicine and process industry.

  8. A randomly nano-structured scattering layer for transparent organic light emitting diodes.

    Science.gov (United States)

    Huh, Jin Woo; Shin, Jin-Wook; Cho, Doo-Hee; Moon, Jaehyun; Joo, Chul Woong; Park, Seung Koo; Hwang, Joohyun; Cho, Nam Sung; Lee, Jonghee; Han, Jun-Han; Chu, Hye Yong; Lee, Jeong-Ik

    2014-09-21

    A random scattering layer (RSL) consisting of a random nano-structure (RNS) and a high refractive index planarization layer (HRI PL) is suggested and demonstrated as an efficient internal light-extracting layer for transparent organic light emitting diodes (TOLEDs). By introducing the RSL, a remarkable enhancement of 40% and 46% in external quantum efficiency (EQE) and luminous efficacy (LE) was achieved without causing deterioration in the transmittance. Additionally, with the use of the RSL, the viewing angle dependency of EL spectra was reduced to a marginal degree. The results were interpreted as the stronger influence of the scattering effect over the microcavity. The RSL can be applied widely in TOLEDs as an effective light-extracting layer for extracting the waveguide mode of confined light at the indium tin oxide (ITO)/OLED stack without introducing spectral changes in TOLEDs.

  9. Near-field light scattering by parallel glass fibers

    Science.gov (United States)

    Benincasa, Daniel S.; Tsuei, Tak-Goa; Barber, Peter W.

    1987-09-01

    Single glass fibers whose radius-to-wavelength ratio is large, for example, r/λ=100, strongly focus normally incident laser light to give greatly enhanced intensities both within and in the near field of the fiber, even when the fiber is not at resonance. Calculated results show that the enhancement is dependent on the radius-to-wavelength ratio and on the fiber index of refraction. Even greater enhancements are observed for spherical particles. The near-field intensity for a single fiber is greatly modified when a second fiber is moved into its near field. Calculations of the near-field intensities for two coupled fibers provide insight into the coupling mechanism, especially the dependence of the coupling on the fiber separation and on the orientation of the two fibers relative to the incident wave.

  10. Computer simulation of light scattering from dynamic inhomogeneities in live tissue

    Science.gov (United States)

    Priezzhev, Alexander V.; Fedoseev, Victor V.; Kudinov, Dmitry V.

    1999-03-01

    We describe the results of the study of light propagation and scattering in a model biological tissue comprising moving particles simulating blood perfusion. The study was performed by means of Monte Carlo simulation. The obtained dependencies of the total intensity and of the Doppler spectra of the backscattered light on the model parameters are analyzed. The CW and ultra-short pulse modes of sample probing and time gating of the detected signal are considered.

  11. Correlation between light scattering signal and tissue reversibility in rat brain exposed to hypoxia

    Science.gov (United States)

    Kawauchi, Satoko; Sato, Shunichi; Uozumi, Yoichi; Nawashiro, Hiroshi; Ishihara, Miya; Kikuchi, Makoto

    2010-02-01

    Light scattering signal is a potential indicator of tissue viability in brain because cellular and subcellular structural integrity should be associated with cell viability in brain tissue. We previously performed multiwavelength diffuse reflectance measurement for a rat global ischemic brain model and observed a unique triphasic change in light scattering at a certain time after oxygen and glucose deprivation. This triphasic scattering change (TSC) was shown to precede cerebral ATP exhaustion, suggesting that loss of brain tissue viability can be predicted by detecting scattering signal. In the present study, we examined correlation between light scattering signal and tissue reversibility in rat brain in vivo. We performed transcranial diffuse reflectance measurement for rat brain; under spontaneous respiration, hypoxia was induced for the rat by nitrogen gas inhalation and reoxygenation was started at various time points. We observed a TSC, which started at 140 +/- 15 s after starting nitrogen gas inhalation (mean +/- SD, n=8). When reoxygenation was started before the TSC, all rats survived (n=7), while no rats survived when reoxygenation was started after the TSC (n=8). When reoxygenation was started during the TSC, rats survived probabilistically (n=31). Disability of motor function was not observed for the survived rats. These results indicate that TSC can be used as an indicator of loss of tissue reversibility in brains, providing useful information on the critical time zone for treatment to rescue the brain.

  12. Flow cytometry of human embryonic kidney cells: A light scattering approach

    Science.gov (United States)

    Kunze, M. E.; Goolsby, C. L.; Todd, P. W.; Morrison, D. R.; Lewis, M. L.

    1985-01-01

    The mammalian kidney contains cells that transport water, convert vitamin D to active forms, synthesize hormones such a renin and erythropoietin, and produce enzymes such as urokinase, a plasminogen activator. Several of these functions are maintained by human embryonic kidney cells (HEK) cultivated in vitro. Biochemical study of these functions in their individual cell types in vitro requires purified populations of cells. Light-scattering activated cell sorting (LACS) was explored as a means of achieving such purifications. It was found that HEK cells at the first 1 to 5 passages in culture were heterogeneous with respect to 2-parameter light scattering intensity distribution, in which combined measurements included forward angle scattering (2.5 to 19 deg), 90 deg scattering, and time-of-flight size measurements. Size was measured at a resolution of 0.15 microns/channel in 256 channels using pulse-height independent pulse-width measurements. Two-parameter distributions combining these measurements were obtained for HEK cell subpopulations that had been purified by microgravity electrophoresis and subsequently propagated in culture. These distributions contained at least 3 subpopulations in all purified fractions, and results of experiments with prepurified cultured HEK cells indicated that subpopulations of living cells that were high in plasminogen-activator activity also contained the highest per cent of cells with high 90 deg light scatter intensity.

  13. Characterization of highly scattering media by measurement of diffusely backscattered polarized light

    Energy Technology Data Exchange (ETDEWEB)

    Hielscher, A.H.; Mourant, J.R.; Bigio, I.J.

    2000-01-04

    An apparatus and method for recording spatially dependent intensity patterns of polarized light that is diffusely backscattered from highly scattering media are described. These intensity patterns can be used to differentiate different turbid media, such as polystyrene-sphere and biological-cell suspensions. Polarized light from a He-Ne laser ({lambda} = 543 nm) is focused onto the surface of the scattering medium, and a surface area of approximately 4 x 4 cm centered on the light input point is imaged through polarization analysis optics onto a CCD camera. A variety of intensity patterns may be observed by varying the polarization state of the incident laser light and changing the analyzer configuration to detect different polarization components of the backscattered light. Experimental results for polystyrene-sphere and intralipid suspensions demonstrate that the radial and azimuthal variations of the observed pattern depend on the concentration, size, and anisotropy factor, g, of the particles constituting the scattering medium. Measurements performed on biological cell suspensions show that intensity patterns can be used to differentiate between suspensions of cancerous and non-cancerous cells. Introduction of the Mueller-matrix for diffusely backscattered light, permits the selection of a subset of measurements which comprehensively describes the optical properties of backscattering media.

  14. Characterization of highly scattering media by measurement of diffusely backscattered polarized light

    Energy Technology Data Exchange (ETDEWEB)

    Hielscher, Andreas H. (Brooklyn, NY); Mourant, Judith R. (Los Alamos, NM); Bigio, Irving J. (Los Alamos, NM)

    2000-01-01

    An apparatus and method for recording spatially dependent intensity patterns of polarized light that is diffusely backscattered from highly scattering media are described. These intensity patterns can be used to differentiate different turbid media, such as polystyrene-sphere and biological-cell suspensions. Polarized light from a He-Ne laser (.lambda.=543 nm) is focused onto the surface of the scattering medium, and a surface area of approximately 4.times.4 cm centered on the light input point is imaged through polarization analysis optics onto a CCD camera. A variety of intensity patterns may be observed by varying the polarization state of the incident laser light and changing the analyzer configuration to detect different polarization components of the backscattered light. Experimental results for polystyrene-sphere and Intralipid suspensions demonstrate that the radial and azimuthal variations of the observed pattern depend on the concentration, size, and anisotropy factor, g, of the particles constituting the scattering medium. Measurements performed on biological cell suspensions show that intensity patterns can be used to differentiate between suspensions of cancerous and non-cancerous cells. Introduction of the Mueller-matrix for diffusely backscattered light, permits the selection of a subset of measurements which comprehensively describes the optical properties of backscattering media.

  15. Inversion of particle size distribution from light-scattering data using a modified regularization algorithm

    Institute of Scientific and Technical Information of China (English)

    Yanmin Wang; Guobiao Liang; Zhidong Pan

    2010-01-01

    A modified regularization algorithm with a more proper operator was proposed for the inversion of partide size distribution(PSD)from light-scattering data in a laser particle sizer based on the Mie scattering principle.The Generalized Cross-Validation(GCV)method and the L-curve method were used for determining the regularization parameter.The Successive Over-Relaxation(SOR)iterative method was used to increase the exactness and stability of the converged result.The simulated results based on the modified algorithm are in a good agreement with the experimental data measured for nine standard particulate samples,their mixtures as well as three natural particulate materials with irregular shapes,indicating that this modified regularization method is not only feasible but also effective for the simulation of PSD from corresponding light-scattering data.

  16. Multiple scattering of light in cold atomic clouds with a magnetic field

    CERN Document Server

    Sigwarth, Olivier; Delande, Dominique; Miniatura, Christian

    2013-01-01

    Starting from a microscopic theory for atomic scatterers, we describe the scattering of light by a single atom and study the coherent propagation of light in a cold atomic cloud in the presence of a magnetic field B in the mesoscopic regime. Non-pertubative expressions in B are given for the magneto-optical effects and optical anisotropy. We then consider the multiple scattering regime and address the fate of the coherent backscattering (CBS) effect. We show that, for atoms with nonzero spin in their ground state, the CBS interference contrast can be increased compared to its value when B=0, a result at variance with classical samples. We validate our theoretical results by a quantitative comparison with experimental data.

  17. A high-power spatial filter for Thomson scattering stray light reduction

    Science.gov (United States)

    Levesque, J. P.; Litzner, K. D.; Mauel, M. E.; Maurer, D. A.; Navratil, G. A.; Pedersen, T. S.

    2011-03-01

    The Thomson scattering diagnostic on the High Beta Tokamak-Extended Pulse (HBT-EP) is routinely used to measure electron temperature and density during plasma discharges. Avalanche photodiodes in a five-channel interference filter polychromator measure scattered light from a 6 ns, 800 mJ, 1064 nm Nd:YAG laser pulse. A low cost, high-power spatial filter was designed, tested, and added to the laser beamline in order to reduce stray laser light to levels which are acceptable for accurate Rayleigh calibration. A detailed analysis of the spatial filter design and performance is given. The spatial filter can be easily implemented in an existing Thomson scattering system without the need to disturb the vacuum chamber or significantly change the beamline. Although apertures in the spatial filter suffer substantial damage from the focused beam, with proper design they can last long enough to permit absolute calibration.

  18. Differing self-similarity in light scattering spectra: A potential tool for pre-cancer detection

    CERN Document Server

    Ghosh, Sayantan; Purwar, Harsh; Jagtap, Jaidip; Pradhan, Asima; Ghosh, Nirmalya; Panigrahi, Prasanta K

    2011-01-01

    The fluctuations in the elastic light scattering spectra of normal and dysplastic human cervical tissues analyzed through wavelet transform based techniques reveal clear signatures of self-similar behavior in the spectral fluctuations. Significant differences in the power law behavior ascertained through the scaling exponent was observed in these tissues. The strong dependence of the elastic light scattering on the size distribution of the scatterers manifests in the angular variation of the scaling exponent. Interestingly, the spectral fluctuations in both these tissues showed multi-fractality (non-stationarity in fluctuations), the degree of multi-fractality being marginally higher in the case of dysplastic tissues. These findings using the multi-resolution analysis capability of the discrete wavelet transform can contribute to the recent surge in the exploration for non-invasive optical tools for pre-cancer detection.

  19. Control of light scattering by nanoparticles with optically-induced magnetic responses

    CERN Document Server

    Liu, Wei; Kivshar, Yuri S

    2013-01-01

    Conventional approaches to control and shape the scattering patterns of light generated by different nanostructures are mostly based on engineering of their electric response due to the fact that most metallic nanostructures support electric resonances in the optical frequency range. Recently, fuelled by the fast development in the fields of metamaterials and plasmonics, artificial optically-induced magnetic responses have been demonstrated for various nanostructures. This kind of response can be employed to provide an extra degree of freedom for the efficient control and shaping of the scattering patterns of nanoparticles and nanoantennas. Here we review the recent progress in this research direction of nanoparticle scattering shaping and control through the interference of both electric and optically-induced magnetic responses. We discuss the magnetic resonances supported by various structures in different spectral regimes, and then summarize the original results on the scattering shaping involving both ele...

  20. High-speed scattering medium characterization with application to focusing light through turbid media.

    Science.gov (United States)

    Conkey, Donald B; Caravaca-Aguirre, Antonio M; Piestun, Rafael

    2012-01-16

    We introduce a phase-control holographic technique to characterize scattering media with the purpose of focusing light through it. The system generates computer-generated holograms implemented via a deformable mirror device (DMD) based on micro-electro-mechanical technology. The DMD can be updated at high data rates, enabling high speed wavefront measurements using the transmission matrix method. The transmission matrix of a scattering material determines the hologram required for focusing through the scatterer. We demonstrate this technique measuring a transmission matrix with 256 input modes and a single output mode in 33.8 ms and creating a focus with a signal to background ratio of 160. We also demonstrate focusing through a temporally dynamic, strongly scattering sample with short speckle decorrelation times.