Sample records for neutron scattering study

  1. Neutron Scattering Studies of Correlated Electron Systems

    E-Print Network [OSTI]

    Boothroyd, Andrew

    Neutron Scattering Studies of Correlated Electron Systems Lucy Helme Thesis submitted submitted for the Degree of Doctor of Philosophy, Trinity Term 2006 This thesis presents neutron scatteringO2, through inelastic neutron scattering studies of the crystal field transitions above and below

  2. UNIVERSITY OF CALIFORNIA Inelastic Neutron Scattering Study of the

    E-Print Network [OSTI]

    Lawrence, Jon

    UNIVERSITY OF CALIFORNIA IRVINE Inelastic Neutron Scattering Study of the Intermediate Valence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2 Inelastic Neutron Scattering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2.a Neutron Scattering Instruments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2.b

  3. Neutron and X-ray Scattering Study of Magnetic Manganites

    E-Print Network [OSTI]

    Boothroyd, Andrew

    Neutron and X-ray Scattering Study of Magnetic Manganites Graeme Eoin Johnstone A Thesis submitted are performed using a variety of neutron scattering and x-ray scattering techniques. The electronic ground for analysing the results of the polarised neutron scattering experiment. There are a large number of people who

  4. TUTORIAL / ARTICLE DIDACTIQUE Neutron scattering study of the classical

    E-Print Network [OSTI]

    Ryan, Dominic

    TUTORIAL / ARTICLE DIDACTIQUE Neutron scattering study of the classical antiferromagnet MnF2: a perfect hands-on neutron scattering teaching course1 Z. Yamani, Z. Tun, and D.H. Ryan Abstract: We present of neutron scattering concepts. The nature of antiferromagnetism and the magnetic Hamiltonian in this classi

  5. Quasielastic neutron scattering study of water confined in carbon...

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

    Quasielastic neutron scattering study of water confined in carbon nanopores This article has been downloaded from IOPscience. Please scroll down to see the full text article. 2011...

  6. ORNL study uses neutron scattering, supercomputing to demystify...

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

    Morgan McCorkle Communications and Media Relations 865.574.7308 ORNL study uses neutron scattering, supercomputing to demystify forces at play in biofuel production This graphical...

  7. Neutron scattering studies in the actinide region. Progress report, August 1, 1992--July 31, 1993

    SciTech Connect (OSTI)

    Kegel, G.H.R.; Egan, J.J.

    1993-09-01T23:59:59.000Z

    This report discusses the following topics: Prompt fission neutron energy spectra for {sup 235}U and {sup 239}Pu; Two-parameter measurement of nuclear lifetimes; ``Black`` neutron detector; Data reduction techniques for neutron scattering experiments; Inelastic neutron scattering studies in {sup 197}Au; Elastic and inelastic scattering studies in {sup 239}Pu; and neutron induced defects in silicon dioxide MOS structures.

  8. Neutron and X-ray Scattering Studies of Strongly Correlated Electron Systems

    E-Print Network [OSTI]

    Boothroyd, Andrew

    Neutron and X-ray Scattering Studies of Strongly Correlated Electron Systems Russell A. Ewings 2008 #12;Abstract Neutron and X-ray Scattering Studies of Strongly Correlated Electron Systems Russell-ray scattering and neutron scattering experiments on several strongly correlated transition metal oxides

  9. Small-Angle Neutron Scattering Studies of Charged Carboxyl-Terminated Dendrimers in Solutions

    E-Print Network [OSTI]

    Dubin, Paul D.

    Small-Angle Neutron Scattering Studies of Charged Carboxyl-Terminated Dendrimers in Solutions Q. R-angle neutron scattering was used to characterize the solution behavior of charged carboxylic acid terminated- copy,16 small-angle X-ray scattering,17 and small-angle neutron scattering (SANS),18-25 have been used

  10. Radiation damage studies using small-angle neutron scattering

    SciTech Connect (OSTI)

    Albertini, G.; Rustichelli, F. [INFM, Ancona (Italy); Carsughi, F. [INFM, Ancona (Italy). Ist. di Scienze Fisiche; [KFA, Juelich (Germany). Inst. fuer Festkoerperforschung; Coppola, R. [ENEA-Casaccia, Roma (Italy); Stefanon, M. [ENEA, Bologna (Italy)

    1996-12-31T23:59:59.000Z

    This contribution reviews a number of small-angle neutron scattering (SANS) studies of irradiated metals and steels of relevance to fission and fusion technology. Information obtainable by SANS measurements is recalled with special reference to the determination of the size distribution function of the microstructural inhomogeneities. The selected examples concern studies of the main kinds of radiation defects: voids, precipitates, He-bubbles. Some recent results obtained on structural materials for the first-wall of fusion reactors are also presented.

  11. Ris-PhD-7(EN) Neutron scattering studies of two-

    E-Print Network [OSTI]

    Risø-PhD-7(EN) Neutron scattering studies of two- dimensional antiferromagnetic spin fluctuations Denmark January 2005 #12;Neutron scattering studies of two-dimensional antiferromagnetic spin fluctuations Laboratory 4000 Roskilde, Denmark #12;#12;Abstract: In this thesis, neutron scattering techniques are used

  12. A comparison of neutron scattering studies and computer simulations of polymer melts

    E-Print Network [OSTI]

    Utah, University of

    A comparison of neutron scattering studies and computer simulations of polymer melts G.D. Smith a; in ®nal form 22 May 2000 Abstract Neutron scattering and computer simulations are powerful tools in particular. When neutron scattering studies and quan- titative atomistic molecular dynamics simulations

  13. Solid phases of spatially nanoconfined oxygen: A neutron scattering study

    SciTech Connect (OSTI)

    Kojda, Danny [Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, 14109 Berlin (Germany) [Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, 14109 Berlin (Germany); Freie Universität Berlin, 14195 Berlin (Germany); Wallacher, Dirk; Hofmann, Tommy, E-mail: tommy.hofmann@helmholtz-berlin.de [Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, 14109 Berlin (Germany)] [Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, 14109 Berlin (Germany); Baudoin, Simon; Hansen, Thomas [Institut Laue-Langevin, BP 156, 38042 Grenoble Cedex 9 (France)] [Institut Laue-Langevin, BP 156, 38042 Grenoble Cedex 9 (France); Huber, Patrick [Technische Universität Hamburg-Harburg, 21073 Hamburg (Germany)] [Technische Universität Hamburg-Harburg, 21073 Hamburg (Germany)

    2014-01-14T23:59:59.000Z

    We present a comprehensive neutron scattering study on solid oxygen spatially confined in 12 nm wide alumina nanochannels. Elastic scattering experiments reveal a structural phase sequence known from bulk oxygen. With decreasing temperature cubic ?-, orthorhombic ?- and monoclinic ?-phases are unambiguously identified in confinement. Weak antiferromagnetic ordering is observed in the confined monoclinic ?-phase. Rocking scans reveal that oxygen nanocrystals inside the tubular channels do not form an isotropic powder. Rather, they exhibit preferred orientations depending on thermal history and the very mechanisms, which guide the structural transitions.

  14. TTOTT Ris0-R-986(EN) A Neutron Scattering Study of Triblock

    E-Print Network [OSTI]

    TTOTT Ris0-R-986(EN) DK9800004 A Neutron Scattering Study of Triblock Copolymer Micelles Michael C. Gerstenberg Ris0 National Laboratory, Roskilde, Denmark November 1997 #12;Ris0-R-986(EN) A Neutron Scattering, Denmark November 1997 #12;Abstract The thesis describes the neutron scattering experiments performed

  15. Neutron scattering study of unconventional superconductors

    SciTech Connect (OSTI)

    Lee, Seunghun

    2014-06-30T23:59:59.000Z

    My group’s primary activity at the University of Virginia supported by DOE is to study novel electronic, magnetic, and structural phenomena that emerge out of strong interactions between electrons. Some of these phenomena are unconventional superconductivity, exotic states in frustrated magnets, quantum spin liquid states, and magneto-electricity. The outcome of our research funded by the grant advanced microscopic understanding of the emergence of the collective states in the systems.

  16. Imaging with Scattered Neutrons

    E-Print Network [OSTI]

    H. Ballhausen; H. Abele; R. Gaehler; M. Trapp; A. Van Overberghe

    2006-10-30T23:59:59.000Z

    We describe a novel experimental technique for neutron imaging with scattered neutrons. These scattered neutrons are of interest for condensed matter physics, because they permit to reveal the local distribution of incoherent and coherent scattering within a sample. In contrast to standard attenuation based imaging, scattered neutron imaging distinguishes between the scattering cross section and the total attenuation cross section including absorption. First successful low-noise millimeter-resolution images by scattered neutron radiography and tomography are presented.

  17. Neutron Scattering Tutorials | Neutron Science | ORNL

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

    Neutron Scattering Tutorials SHARE Neutron Scattering Tutorials The following lectures were presented at the 2011 and 2010 National School on Neutron & X-Ray Scattering. This...

  18. Neutrons for Catalysis: A Workshop on Neutron Scattering Techniques for Studies in Catalysis

    SciTech Connect (OSTI)

    Overbury, Steven {Steve} H [ORNL; Coates, Leighton [ORNL; Herwig, Kenneth W [ORNL; Kidder, Michelle [ORNL

    2011-10-01T23:59:59.000Z

    This report summarizes the Workshop on Neutron Scattering Techniques for Studies in Catalysis, held at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL) on September 16 and 17, 2010. The goal of the Workshop was to bring experts in heterogeneous catalysis and biocatalysis together with neutron scattering experimenters to identify ways to attack new problems, especially Grand Challenge problems in catalysis, using neutron scattering. The Workshop locale was motivated by the neutron capabilities at ORNL, including the High Flux Isotope Reactor (HFIR) and the new and developing instrumentation at the SNS. Approximately 90 researchers met for 1 1/2 days with oral presentations and breakout sessions. Oral presentations were divided into five topical sessions aimed at a discussion of Grand Challenge problems in catalysis, dynamics studies, structure characterization, biocatalysis, and computational methods. Eleven internationally known invited experts spoke in these sessions. The Workshop was intended both to educate catalyst experts about the methods and possibilities of neutron methods and to educate the neutron community about the methods and scientific challenges in catalysis. Above all, it was intended to inspire new research ideas among the attendees. All attendees were asked to participate in one or more of three breakout sessions to share ideas and propose new experiments that could be performed using the ORNL neutron facilities. The Workshop was expected to lead to proposals for beam time at either the HFIR or the SNS; therefore, it was expected that each breakout session would identify a few experiments or proof-of-principle experiments and a leader who would pursue a proposal after the Workshop. Also, a refereed review article will be submitted to a prominent journal to present research and ideas illustrating the benefits and possibilities of neutron methods for catalysis research.

  19. Small angle neutron scattering study of Linde 80 RPV welds

    SciTech Connect (OSTI)

    Wirth, B.D.; Odette, G.R.; Lucas, G.E. [Univ. of California, Santa Barbara, CA (United States). Dept. of Mechanical and Environmental Engineering; Pavinich, W.A. [Framatome Technologies Inc., Knoxville, TN (United States); Spooner, S.E. [Oak Ridge National Lab., TN (United States). Solid state Div.

    1999-10-01T23:59:59.000Z

    Small angle neutron scattering (SANS) results are presented for Linde 80 welds irradiated, as part of the B and W Owners Group Integrated Surveillance Program, at low fluxes (<10{sup 15} n/m{sup 2}-s) to fluences from 0.29 to 3.5 {times} 10{sup 23} n/m{sup 2} (E > 1 MeV) at irradiation temperatures from 276 to 292 C. The welds all contain about 0.6 Ni (all composition units are in wt.%), 0.009 to 0.18 P and 0.05 to 0.28 Cu. In the welds with significant amounts of copper (>0.2 Cu) the measured defect scattering cross sections were consistent with either: (a) copper rich precipitates (CRPs) alloyed with manganese and nickel; or (b) dominant CRP scattering, plus a weak contribution from so-called matrix defect features. Similar weak scattering was observed in a low copper (0.06 Cu) weld. The identity of matrix defect features cannot be determined from the SANS data alone, but the scattering is consistent with the presence of subnanometer vacancy cluster-solute complexes. The general character of the CRPs, and the trends in their number density, volume fraction and average radius as a function of fluence and irradiation temperature, are very similar to those observed in a wide range of pressure vessel-type steels irradiated in test reactors at intermediate to high flux. The SANS data in the surveillance welds is also in unity with: (a) thermodynamic-kinetic radiation enhanced diffusion models of CRP evolution; (b) mechanical property changes, including predictions of the correlations of the surveillance data base; and (c) an atomic scale, atom probe field ion microscopy study into the nanostructure-chemistry of a CRP.

  20. Salt-Dependent Compaction of Di-and Trinucleosomes Studied by Small-Angle Neutron Scattering

    E-Print Network [OSTI]

    Langowski, Jörg

    Salt-Dependent Compaction of Di- and Trinucleosomes Studied by Small-Angle Neutron Scattering, Germany, and Institut Laue-Langevin Grenoble, F-38042 Grenoble, France ABSTRACT Using small-angle neutron scattering (SANS), we have measured the salt-dependent static structure factor of di- and trinucleosomes from

  1. X-ray and Neutron Scattering Studies of Magnetic Domain Dynamics and Spin Structures /

    E-Print Network [OSTI]

    Chen, San-Wen

    2014-01-01T23:59:59.000Z

    Stanley. X-ray and neutron scattering from rough surfaces.1988. [3] R. Pynn. Neutron scattering by rough surfaces at39] V. F. Sears. Neutron scattering lengths and cross

  2. Eur. J. Biochem. 85, 529-534 (1978) X-Ray and Neutron Small-Angle Scattering Studies

    E-Print Network [OSTI]

    1978-01-01T23:59:59.000Z

    Eur. J. Biochem. 85, 529-534 (1978) X-Ray and Neutron Small-Angle Scattering Studies of the Complex-ray and neutron scattering techniques. In this work, we concentrated mainly on radius of gyration analyses and a neutron scattering experiment is performed in 21-Iz0 solvent. This decrease simply reflects the fact

  3. Small angle neutron scattering study of deuterated sodium dodecylsulfate micellization in dilute poly((2edimethylamino)ethyl methacrylate) solutions

    E-Print Network [OSTI]

    Kofinas, Peter

    Small angle neutron scattering study of deuterated sodium dodecylsulfate micellization in dilute 2010 Keywords: Poly((2edimethylamino)ethyl methacrylate) Micelle Small angle neutron scattering a b angle neutron scattering. We found three transitions of the poly ((2edimethylamino)ethyl methacrylate

  4. J. Mol. Biol. (1975) 91, 101-120 A Neutron Scattering Study of the Distribution of Protein

    E-Print Network [OSTI]

    J. Mol. Biol. (1975) 91, 101-120 A Neutron Scattering Study of the Distribution of Protein and RNA coli have been measured by neutron scattering experiments on the intact subunit. In addition the radius, 1972; Lutter et al., 1972), and neutron scattering (Engelman & Moore, 1972; Moore et al., 1974

  5. The Nature of the Surface Species Formed on Au/TiO2 during the Reaction of H2 and O2: An Inelastic Neutron Scattering Study

    E-Print Network [OSTI]

    Goodman, Wayne

    Neutron Scattering Study Chinta Sivadinarayana, Tushar V. Choudhary, Luke L. Daemen, Juergen Eckert of obvious interest for understanding this process. Vibrational spectroscopy by inelastic neutron scattering

  6. Lujan Neutron Scattering Center

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

    the inadvertent spread of Technetium 99 by employees and contractors at the Lujan Neutron Scattering Center August 27, 2012-The Laboratory is investigating the inadvertent...

  7. RisR1125(EN) Neutron Scattering

    E-Print Network [OSTI]

    Risø­R­1125(EN) Neutron Scattering Studies of Modulated Magnetic Structures Steen Aagaard Sørensen investigations of the magnetic systems DyFe4Al8 and MnSi by neutron scattering and in the former case also by X and the correlations between the scattering entities of the sample. The theoretical framework of neutron scattering

  8. Static light scattering and small-angle neutron scattering study on aggregated recombinant gelatin in aqueous solution

    E-Print Network [OSTI]

    Sutter, Marc

    2006-10-25T23:59:59.000Z

    Static Light Scattering and Small-Angle Neutron Scattering Study on Aggregated Recombinant Gelatin in Aqueous Solution A. Ramzi 1, M. Sutter 2, W.E. Hennink 1, W. Jiskoot 1,2 1 Department of Pharmaceutics, UIPS, Utrecht University, The Netherlands...-angle neutron scattering (SANS) for detecting aggregation of recombinant gelatin in aqueous solution and to obtain structural information about the aggregates. Recombinant Gelatin: RG-15-His 5.6Ser 25.2Pro 1.9Lys 3.7His 34.2Gly 15.5Gln 5.2Glu 11.8Asn 1.2Ala...

  9. Anisotropic Motion and Molecular Dynamics of Cholesterol, Lanosterol, and Ergosterol in Lecithin Bilayers Studied by Quasi-elastic Neutron Scattering

    E-Print Network [OSTI]

    Brown, Michael F.

    Bilayers Studied by Quasi-elastic Neutron Scattering Emil Endress, Helmut Heller,§ He´le`ne CasaltaVised Manuscript ReceiVed June 27, 2002 ABSTRACT: Quasi-elastic neutron scattering (QENS) was employed to study of motion within the bilayer on the molecular dynamics time scale. In a recent quasi-elastic neutron

  10. Neutron-deuteron breakup and quasielastic scattering

    E-Print Network [OSTI]

    Ohlson, Alice Elisabeth

    2009-01-01T23:59:59.000Z

    Quasielastic scattering and deuteron breakup in the 200 MeV region is studied by impinging a pulsed neutron beam on a deuterium target at the Weapons Neutron Research facility at the Los Alamos Neutron Science Center. The ...

  11. Salt-Dependent DNA Superhelix Diameter Studied by Small Angle Neutron Scattering Measurements and Monte Carlo Simulations

    E-Print Network [OSTI]

    Langowski, Jörg

    Salt-Dependent DNA Superhelix Diameter Studied by Small Angle Neutron Scattering Measurements-38042 Grenoble Cedex 9, France ABSTRACT Using small angle neutron scattering we have measured the static the same behavior between 10 and 100 mM salt concentration: An undulation in the scattering curve

  12. Measurements of the Thermal Neutron Scattering Kernel

    E-Print Network [OSTI]

    Danon, Yaron

    Measurements of the Thermal Neutron Scattering Kernel Li (Emily) Liu, Yaron Danon, Bjorn Becker and discussions Problems and Future study Questions #12;3 M. Mattes and J. Keinert, Thermal Neutron Scattering experimental data used was from 1973-1974! M. Mattes and J. Keinert, Thermal Neutron Scattering Data

  13. Neutron Scattering Stiudies

    SciTech Connect (OSTI)

    Kegel, Gunter H.R.; Egan, James J

    2007-04-18T23:59:59.000Z

    This project covers four principal areas of research: Elastic and inelastic neutron scattering studies in odd-A terbium, thulium and other highly deformed nuclei near A=160 with special regard to interband transitions and to the investigation of the direct-interaction versus the compound-nucleus excitation process in these nuclei. Examination of new, fast photomultiplier tubes suitable for use in a miniaturized neutron-time-of-flight spectrometer. Measurement of certain inelastic cross sections of 238U. Determination of the multiplicity of prompt fission gamma rays in even-A fissile actinides. Energies and mean lives of fission isomers produced by fast fission of even-Z, even-A actinides. Study of the mean life of 7Be in different host matrices and its possible astro-physical significance.

  14. Dynamics of water in prussian blue analogues: Neutron scattering study

    SciTech Connect (OSTI)

    Sharma, V. K.; Mitra, S.; Thakur, N.; Yusuf, S. M.; Mukhopadhyay, R., E-mail: mukhop@barc.gov.in [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Juranyi, Fanni [Laboratory for Neutron Scattering, Paul Scherrer Institut, Villigen (Switzerland)

    2014-07-21T23:59:59.000Z

    Dynamics of crystal water in Prussian blue (PB), Fe(III){sub 4}[Fe(II)(CN){sub 6}]{sub 3}.14H{sub 2}O and its analogue Prussian green (PG), ferriferricynaide, Fe(III){sub 4}[Fe(III)(CN){sub 6}]{sub 4}.16H{sub 2}O have been investigated using Quasielastic Neutron Scattering (QENS) technique. PB and its analogue compounds are important materials for their various interesting multifunctional properties. It is known that crystal water plays a crucial role towards the multifunctional properties of Prussian blue analogue compounds. Three structurally distinguishable water molecules: (i) coordinated water molecules at empty nitrogen sites, (ii) non-coordinated water molecules in the spherical cavities, and (iii) at interstitial sites exist in PB. Here spherical cavities are created due to the vacant sites of Fe(CN){sub 6} units. However, PG does not have any such vacant N or Fe(CN){sub 6} units, and only one kind of water molecules, exists only at interstitial sites. QENS experiments have been carried out on both the compounds in the temperature range of 260–360?K to elucidate the dynamical behavior of different kinds of water molecules. Dynamics is found to be much more pronounced in case of PB, compared to PG. A detailed data analysis showed that localized translational diffusion model could describe the observed data for both PB and PG systems. The average diffusion coefficient is found to be much larger in the PB than PG. The obtained domain of dynamics is found to be consistent with the geometry of the structure of the two systems. Combining the data of the two systems, a quantitative estimate of the dynamics, corresponding to the water molecules at different locations is made.

  15. STUDY MAGNETIC EXCITATIONS IN DOPED TRANSITION METAL OXIDES USING INELASTIC NEUTRON SCATTERING

    SciTech Connect (OSTI)

    Dai, Pengcheng

    2014-02-18T23:59:59.000Z

    Understanding the interplay between magnetism and superconductivity continues to be a “hot” topic in modern condensed matter physics. The discovery of high-temperature superconductivity in iron-based materials in 2008 provided an unique opportunity to compare and contrast these materials with traditional high-Tc copper oxide superconductors. Neutron scattering plays an important role in determining the dynamical spin properties in these materials. This proposal is a continuation of previous DOE supported proposal. This report summarizes the final progress we have made over from May 2005 till Aug. 2013. Overall, we continue to carry out extensive neutron scattering experiments on Fe-based materials, focusing on understanding their magnetic properties. In addition, we have established a materials laboratory at UT that has allowed us to grow these superconductors. Because neutron scattering typically demands a large amount of samples, by growing these materials in our own laboratory, we can now pursuit neutron scattering experiments over the entire electronic phase diagram, focusing on regions of interests. The material synthesis laboratory at UT was established entirely with the support of DOE funding. This not only allowed us to carry out neutron scattering experiments, but also permit us to provide samples to other US/International collaborators for studying these materials.

  16. A study of neutron-deuteron scattering in configuration space

    E-Print Network [OSTI]

    V. M. Suslov; M. A. Braun; I. Filikhin; B. Vlahovic

    2006-10-09T23:59:59.000Z

    A new computational method for solving the configuration-space Faddeev equations for the breakup scattering problem has been applied to nd scattering both below and above the two-body threshold.

  17. Effective Long-Range Attraction between Protein Molecules in Solutions Studied by Small Angle Neutron Scattering

    E-Print Network [OSTI]

    Chen, Sow-Hsin

    Neutron Scattering Yun Liu,1 Emiliano Fratini,2 Piero Baglioni,1,2 Wei-Ren Chen,1 and Sow-Hsin Chen1,* 1, Italy (Received 8 February 2005; published 8 September 2005) Small angle neutron scattering intensity neutron and x-ray scattering investigations of proteins suggest the presence of a short-range attractive

  18. Study on generating of thermal neutron scattering cross sections for LiH

    SciTech Connect (OSTI)

    Wang, L.; Jiang, X.; Zhao, Z.; Chen, L. [Northwest Institute of Nuclear Technology, Xi'an 710024 (China)

    2013-07-01T23:59:59.000Z

    LiH is designated as a promising moderator and shielding material because of its low density, high melting point and large fraction of H atoms. However, lack of the thermal neutron cross sections of LiH makes numerical calculation deviate from experimental data to some extent. As a result, it is necessary to study LiH thermal kernel effect. The phonon property of LiH has been investigated by first-principles calculations using the plane-wave pseudo potential method with CASTEP code. The scattering law and the thermal neutron scattering cross sections for Li and H have been generated using this distribution. The results have been compared with zirconium hydride data. The GASKET and NJOY/LEAPR codes have been used in the calculation of scattering law, whose results have been compared with the reference; the discrepancy mainly comes from phonon spectrums and its expansion. LEAPR had the capability to compute scattering through larger energy and momentum transfers than GASKET did. By studying LiH phonon spectrum and constructing the model of LiH thermal kernel and scattering matrix, the ACE format LiH thermal neutron cross sections for MCNP software could be made and used for reactor Neutronics calculation. (authors)

  19. The role of CP violating scatterings in baryogenesis - case study of the neutron portal

    E-Print Network [OSTI]

    Iason Baldes; Nicole F. Bell; Alexander Millar; Kalliopi Petraki; Raymond R. Volkas

    2014-11-28T23:59:59.000Z

    Many baryogenesis scenarios invoke the charge parity (CP) violating out-of-equilibrium decay of a heavy particle in order to explain the baryon asymmetry. Such scenarios will in general also allow CP violating scatterings. We study the effect of these CP violating scatterings on the final asymmetry in a neutron portal scenario. We solve the Boltzmann equations governing the evolution of the baryon number numerically and show that the CP violating scatterings play a dominant role in a significant portion of the parameter space.

  20. Small Angle Neutron Scattering Study of Conformation of Oligo(ethylene glycol)-Grafted Polystyrene in Dilute Solutions: Effect of the Backbone Length

    E-Print Network [OSTI]

    Small Angle Neutron Scattering Study of Conformation of Oligo(ethylene glycol)- Grafted Polystyrene Fengjun Hua,2 Kunlun Hong,2 and Jimmy W. Mays2 1Neutron Scattering Sciences Division, ORNL 2Center

  1. Structure and dynamics of cadmium telluride studied by x-ray and inelastic neutron scattering

    SciTech Connect (OSTI)

    Niedziela, Jennifer L [ORNL; Stone, Matthew B [ORNL

    2014-01-01T23:59:59.000Z

    We present a combined study of density functional theory, x-ray diffraction, and inelastic neutron scattering examining the temperature dependent structure and lattice dynamics of commercially available cadmium telluride. A subtle change in the structure is evinced near 80~K, which manifests also in the measured phonon density of states. There is no change to the long-range ordered structure. The implications of the change in relation to structural defects are discussed.

  2. Structure and dynamics of cadmium telluride studied by x-ray and inelastic neutron scattering

    SciTech Connect (OSTI)

    Niedziela, J. L., E-mail: niedzielajl@ornl.gov [Instrument and Source Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Stone, M. B., E-mail: stonemb@ornl.gov [Quantum Condensed Matter Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

    2014-09-08T23:59:59.000Z

    We present a combined study of density functional theory, x-ray diffraction, and inelastic neutron scattering examining the temperature dependent structure and lattice dynamics of commercially available cadmium telluride. A subtle change in the structure is evinced near 80?K, which manifests also in the measured phonon density of states. There is no change to the long-range ordered structure. The implications of the change in relation to structural defects are discussed.

  3. Inelastic neutron scattering study of hydrogen in d8-THF/D2O ice clathrate Kimberly T. Tait,a

    E-Print Network [OSTI]

    Downs, Robert T.

    Inelastic neutron scattering study of hydrogen in d8-THF/D2O ice clathrate Kimberly T. Tait,a Frans Trouw,b and Yusheng Zhao Manuel Lujan Jr. Neutron Scattering Center, Los Alamos National Laboratory, Los October 2007 In situ neutron inelastic scattering experiments on hydrogen adsorbed into a fully deutrated

  4. Neutron Scattering Studies of Vortex Matter in Type-II Superconductors

    SciTech Connect (OSTI)

    Xinsheng Ling

    2012-02-02T23:59:59.000Z

    The proposed program is an experimental study of the fundamental properties of Abrikosov vortex matter in type-II superconductors. Most superconducting materials used in applications such as MRI are type II and their transport properties are determined by the interplay between random pinning, interaction and thermal fluctuation effects in the vortex state. Given the technological importance of these materials, a fundamental understanding of the vortex matter is necessary. The vortex lines in type-II superconductors also form a useful model system for fundamental studies of a number of important issues in condensed matter physics, such as the presence of a symmetry-breaking phase transition in the presence of random pinning. Recent advances in neutron scattering facilities such as the major upgrade of the NIST cold source and the Spallation Neutron Source are providing unprecedented opportunities in addressing some of the longstanding issues in vortex physics. The core component of the proposed program is to use small angle neutron scattering and Bitter decoration experiments to provide the most stringent test of the Bragg glass theory by measuring the structure factor in both the real and reciprocal spaces. The proposed experiments include a neutron reflectometry experiment to measure the precise Q-dependence of the structure factor of the vortex lattice in the Bragg glass state. A second set of SANS experiments will be on a shear-strained Nb single crystal for testing a recently proposed theory of the stability of Bragg glass. The objective is to artificially create a set of parallel grain boundaries into a Nb single crystal and use SANS to measure the vortex matter diffraction pattern as a function of the changing angle between the applied magnetic field to the grain boundaries. The intrinsic merits of the proposed work are a new fundamental understanding of type-II superconductors on which superconducting technology is based, and a firm understanding of phases and phase transitions in condensed matter systems with random pinning. The broader impact of the program includes the training of future generation of neutron scientists, and further development of neutron scattering and complementary techniques for studies of superconducting materials. The graduate and undergraduate students participating in this project will learn the state-of-the-art neutron scattering techniques, acquire a wide range of materials research experiences, and participate in the frontier research of superconductivity. This should best prepare the students for future careers in academia, industry, or government.

  5. Neutron Scattering Studies of Nanomagnetism and Artificially Structured Materials

    SciTech Connect (OSTI)

    Fitzsimmons, M.R.; Bader, S.D.; Borchers, J.A.; Felcher, G.P.; Furdyna, J.K.; Hoffmann, A.; Kortright, J.B.; Schuller, Ivan K.; Schulthess, T.C.; Sinha, S.K.; Toney, M.F.; Weller, D.; Wolf, S.

    2003-02-01T23:59:59.000Z

    Nanostructured magnetic materials are intensively studied due to their unusual properties and promise for possible applications. The key issues in these materials relate to the connection between their physical properties (transport, magnetism, mechanical, etc.) and their chemical-physical structure. In principle, a detailed knowledge of the chemical and physical structure allows calculation of their physical properties. Theoretical and computational methods are rapidly evolving so that magnetic properties of nanostructured materials might soon be predicted. Success in this endeavor requires detailed quantitative understanding of the magnetic structure and properties.

  6. Hydrogen Species Motion in Piezoelectrics: A Quasi-Elastic Neutron Scattering Study

    SciTech Connect (OSTI)

    Alvine, Kyle J.; Tyagi, Madhu; Brown, Craig; Udovic, Terrence J.; Jenkins, T. J.; Pitman, Stan G.

    2012-03-05T23:59:59.000Z

    Hydrogen is known to damage or degrade piezoelectric materials, at low pressure for ferroelectric random access memory applications, and at high pressure for hydrogen powered vehicle applications. The piezoelectric degradation is in part governed by the motion of hydrogen species within the piezoelectric materials. We present here Quasi-Elastic Neutron Scattering (QENS) measurements of the local hydrogen species motion within lead zirconate titanate (PZT) and barium titanate (BTO) on samples charged by gaseous exposure to high-pressure gaseous hydrogen {approx}17 MPa. Filter Analyzed Neutron Spectroscopy (FANS) studies of the hydrogen enhanced vibrational modes are presented as well. Results are discussed in context of theoretically predicted interstitial hydrogen lattice sites and compared to comparable bulk diffusion studies of hydrogen diffusion in lead zirconate titanate.

  7. Dynamics of a globular protein and its hydration water studied by neutron scattering and MD simulations

    E-Print Network [OSTI]

    Chen, Sow-Hsin

    2010-01-01T23:59:59.000Z

    This review article describes our neutron scattering experiments made in the past four years for the understanding of the single-particle (hydrogen atom) dynamics of a protein and its hydration water and the strong coupling ...

  8. Requirements, possible alternatives & international NEUTRON SCATTERING

    E-Print Network [OSTI]

    Dimeo, Robert M.

    Requirements, possible alternatives & international NEUTRON SCATTERING DETECTORS for Rob Dimeo NIST neutron scattering instruments are the most demanding require background low #12;#12;The Helium-3 Supply Crisis ­ Alternative Techniques to Helium-3 based Detectors for Neutron Scattering Applications

  9. Simulation of a D-T Neutron Source for Neutron Scattering Experiments

    E-Print Network [OSTI]

    Lou, T.P.; Ludewigt, B.A.; Vujic, J.L.; Leung, K.-N.

    2003-01-01T23:59:59.000Z

    T Neutron Source for Neutron Scattering Experiments T.P. Louor cold neutrons for neutron scattering experiments. Thisto simulate a neutron scattering setup and to estimate

  10. Search for: "neutron scattering" | DOE PAGES

    Office of Scientific and Technical Information (OSTI)

    neutron scattering" Find + Advanced Search Advanced Search All Fields: "neutron scattering" Title: Full Text: Bibliographic Data: Creator Author: Name Name ORCID Search...

  11. 11th LANSCE School on Neutron Scattering

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

    11th LANSCE School on Neutron Scattering LANSCE 11th LANSCE School on Neutron Scattering Home Abstract Lecturers Lecturer Abstracts Hands-On Experiments Free Day About the...

  12. X-ray and neutron scattering studies of the Rb?MnF? and Cu?â??õxMgx̳GeO? in an external magnetic field

    E-Print Network [OSTI]

    Christianson, Rebecca J. (Rebecca Jean), 1973-

    2001-01-01T23:59:59.000Z

    This thesis presents results of two scattering studies of low dimensional magnetic materials. The first is a neutron scattering study of Rb2MnF4, a nearly ideal two-dimensional square lattice Heisenberg antiferromagnet ...

  13. The Neutron Scattering Society www.neutronscattering.org

    E-Print Network [OSTI]

    Homes, Christopher C.

    The Neutron Scattering Society of America www.neutronscattering.org Press Release February 11, 2008 The Neutron Scattering Society of America is pleased to announce the election as Fellows of the Society of in application of neutron scattering to studies of surfaces and crystal field excitations as well as his

  14. Z .Reviews in Molecular Biotechnology 74 2000 207 231 X-ray and neutron surface scattering for studying

    E-Print Network [OSTI]

    Kuhl, Tonya L.

    Z .Reviews in Molecular Biotechnology 74 2000 207 231 X-ray and neutron surface scattering,U , Tonya L. Kuhlb , Joyce Y. Wongc , Gregory S. Smitha,1 a Manuel Lujan Jr. Neutron Scattering Center is defined as the Zratio of the number of particles neutrons or .photons elastically and specularly scattered

  15. Neutron scatter camera

    DOE Patents [OSTI]

    Mascarenhas, Nicholas; Marleau, Peter; Brennan, James S.; Krenz, Kevin D.

    2010-06-22T23:59:59.000Z

    An instrument that will directly image the fast fission neutrons from a special nuclear material source has been described. This instrument can improve the signal to background compared to non imaging neutron detection techniques by a factor given by ratio of the angular resolution window to 4.pi.. In addition to being a neutron imager, this instrument will also be an excellent neutron spectrometer, and will be able to differentiate between different types of neutron sources (e.g. fission, alpha-n, cosmic ray, and D-D or D-T fusion). Moreover, the instrument is able to pinpoint the source location.

  16. Neutron scattering and models: Titanium

    SciTech Connect (OSTI)

    Smith, A.B.

    1997-07-01T23:59:59.000Z

    Differential neutron elastic-scattering cross sections of elemental titanium were measured from 4.5 {r_arrow} 10.0 MeV in incident energy increments of {approx} 0.5 MeV. At each energy the measurements were made at forty or more scattering angles distributed between {approx} 17 and 160{degree}. Concurrently, differential neutron inelastic-scattering cross sections were measured for observed excitations of 0.975 {+-} 0.034, 1.497 {+-} 0.033, 2.322 {+-} 0.058, 3.252 {+-} 0.043, 3.700 {+-} 0.093, 4.317 {+-} 0.075 and 4.795 {+-} 0.100 MeV. All of the observed inelastically-scattered neutron groups were composites of contributions from several isotopes and/or levels. The experimental results were used to develop energy-average optical, statistical and coupled-channels models.

  17. Neutron Scattering: Condensed Matter and Magnetic Science, MPA...

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

    Neutron Scattering Neutron Scattering Capability description: Neutron scattering is a powerful probe of structure and collective modes of condensed matter. We are focused on direct...

  18. Instrumentation development for neutron scattering at high pressure 

    E-Print Network [OSTI]

    Fang, Junwei

    2012-11-29T23:59:59.000Z

    Neutron scattering at extremes of pressure is a powerful tool for studying the response of structural and magnetic properties of materials on microscopic level to applied stresses. However, experimental neutron studies ...

  19. 10th LANSCE School on Neutron Scattering

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

    10th LANSCE School on Neutron Scattering LANSCE 10th LANSCE School on Neutron Scattering Home Abstract Lecturers Hands-On Experiments Free Day About the School Sponsors FAQ's...

  20. Soluble Hydrogen-bonding Interpolymer Complexes in Water: A Small-Angle Neutron Scattering Study

    E-Print Network [OSTI]

    Maria Sotiropoulou; Julian Oberdisse; Georgios Staikos

    2006-04-03T23:59:59.000Z

    The hydrogen-bonding interpolymer complexation between poly(acrylic acid) (PAA) and the poly(N,N-dimethylacrylamide) (PDMAM) side chains of the negatively charged graft copolymer poly(acrylic acid-co-2-acrylamido-2-methyl-1-propane sulfonic acid)-graft-poly(N, N dimethylacrylamide) (P(AA-co-AMPSA)-g-PDMAM), containing 48 wt % of PDMAM, and shortly designated as G48, has been studied by small-angle neutron scattering in aqueous solution. Complexation occurs at low pH (pH < 3.75), resulting in the formation of negatively charged colloidal particles, consisting of PAA/PDMAM hydrogen-bonding interpolymer complexes, whose radius is estimated to be around 165 A. As these particles involve more than five graft copolymer chains, they act as stickers between the anionic chains of the graft copolymer backbone. This can explain the characteristic thickening observed in past rheological measurements with these mixtures in the semidilute solution, with decreasing pH. We have also examined the influence of pH and PAA molecular weight on the formation of these nanoparticles.

  1. Neutron and x-ray scattering studies of the metallurgical condition and residual stresses in Weldalite welds

    SciTech Connect (OSTI)

    Spooner, S. [Oak Ridge National Lab., TN (United States); Pardue, E.B.S. [Technology for Energy Corp., Knoxville, TN (United States)

    1995-12-31T23:59:59.000Z

    Weldalite is a lithium-containing aluminum alloy which is being considered for aerospace applications because its favorable strength-to-weight ratio. Successful welding of this alloy depends on the control of the metallurgical condition and residual stresses in the heat affected zone. Neutron and x-ray scattering methods of residual stress measurement were applied to plasma arc welds made in aluminum-lithium alloy test panels as part of an evaluation of materials for use in welded structures. In the course of these studies discrepancies between x-ray and neutron results from the heat affected zone (HAZ) of the weld were found. Texture changes and recovery from the cold work, indicated in peak widths, were found in the HAZ as well. The consideration of x-ray and neutron results leads to the conclusion that there is a change in solute composition which modifies the d-spacings in the HAZ which affects the neutron diffraction determination of residual stresses. The composition changes give the appearance of significant compressive strains in the HAZ. This effect and sharp gradients in the texture give severe anomalies in the neutron measurement of residual stress. The use of combined x-ray and neutron techniques and the solution to the minimizing of the neutron diffraction anomalies are discussed.

  2. Neutron scattering measurements at intermediate energies

    E-Print Network [OSTI]

    N. Olsson; J. Blomgren; E. Ramstrom

    The study of elastic neutron scattering at intermediate energies is essential for the understanding of the isovector term in the nucleon-nucleus interaction, as well as for the development of macroscopic and microscopic optical potentials at these energies. The techniques used for neutron scattering measurements is presented in this paper, as well as the di culties encountered. The few facilities that have been used are reviewed, and a newly installed setup for such measurements in Uppsala is described. Finally, the normalization problem is speci cally addressed. 1

  3. Neutron Interactions: Q-Equation, Elastic Scattering

    E-Print Network [OSTI]

    unknown authors

    Since a neutron has no charge it can easily enter into a nucleus and cause a reaction. Neutrons interact primarily with the nucleus of an atom, except in the special case of magnetic scattering where the interaction involves the neutron spin and the magnetic moment of the atom. Because magnetic scattering is of no interest in this class, we can neglect the interaction between neutrons and electrons and think of atoms and nuclei interchangeably. Neutron reactions can take place at any energy, so one has to pay particular attention to the energy variation of the interaction cross section. In a nuclear reactor neutrons can have energies ranging from 10-3 ev (1 mev) to 10 7 ev (10 Mev). This means our study of neutron interactions, in principle, will have to cover an energy range of 10 ten orders of magnitude. In practice we will limit ourselves to two energy ranges, the slowing down region (ev to Kev) and the thermal region (around 0.025 ev). For a given energy region – thermal, epithermal, resonance, fast – not all the possible reactions are equally important. Which reaction is important depends on the target nucleus and the neutron energy. Generally speaking the important types of interactions, in the order of increasing complexity from the standpoint of theoretical

  4. Neutron Scattering Study on spin dynamics in superconducting (TlRb)2Fe4Se5

    SciTech Connect (OSTI)

    Chi, Songxue [ORNL; Ye, Feng [ORNL; Bao, Wei [Renmin University of China; Fang, Dr. Minghu [Zhejiang University; Wang, H.D. [Zhejiang University; Dong, C.H. [Zhejiang University; Savici, Andrei T [ORNL; Granroth, Garrett E [ORNL; Stone, Matthew B [ORNL; Fishman, Randy Scott [ORNL

    2013-01-01T23:59:59.000Z

    Spin dynamics in superconducting (Tl,Rb)2Fe4Se5 was investigated using the inelastic neutron scattering technique. Spin wave branches that span an energy range from 6.5 to 209 meV are success- fully described by a Heisenberg model whose dominant interactions include only the in-plane nearest (J1 and J0 1) and next nearest neighbor (J2 and J0 2) exchange terms within and between the tetramer spin blocks, respectively. These exchange constants, experimentally determined in this work, would crucially constrain the diverse theoretical viewpoints on magnetism and superconductivity in the Fe-based materials.

  5. Patchy worm-like micelles: solution structure studied by small-angle neutron scattering

    E-Print Network [OSTI]

    S. Rosenfeldt; F. Luedel; C. Schulreich; T. Hellweg; A. Radulescu; J. Schmelz; H. Schmalz; L. Harnau

    2012-09-20T23:59:59.000Z

    Triblock terpolymers exhibit a rich self-organization behavior including the formation of fascinating cylindrical core-shell structures with a phase separated corona. After crystallization-induced self-assembly of polystryrene-(block)-polyethylene-(block)-poly(methyl methacrylate) triblock terpolymers (abbreviated as SEMs = Styrene-Ethylene-Methacrylates) from solution, worm-like core-shell micelles with a patchy corona of polystryrene and poly(methyl methacrylate) were observed by transmission electron microscopy. However, the solution structure is still a matter of debate. Here, we present a method to distinguish in-situ between a Janus-type (two faced) and a patchy (multiple compartments) configuration of the corona. To discriminate between both models the scattering intensity must be determined mainly by one corona compartment. Contrast variation in small-angle neutron scattering enables us to focus on one compartment of the SEMs. The results validate the existence of the patchy structure also in solution.

  6. Neutron Scattering Tutorials | Neutron Science | ORNL

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's Possible for Renewable Energy:Nanowire Solar541,9337, 2011 at3,Neutron Scattering Tutorials SHARE

  7. 11th LANSCE School on Neutron Scattering | About the School

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

    students calculate results About the LANSCE School on Neutron Scattering The annual Los Alamos Neutron Science Center (LANSCE) School on Neutron Scattering is 9- to 10-day school...

  8. Study of slow dynamics in supercooled water by molecular dynamics and quasi-elastic neutron scattering

    E-Print Network [OSTI]

    Liu, Li, Ph. D. Massachusetts Institute of Technology

    2005-01-01T23:59:59.000Z

    The slow dynamics of supercooled water is studied by modelling the spectrum of test particle fluctuations: intermediate scattering function (ISF). The theoretical models are compared with experimental measurements by ...

  9. Refined model of the {Fe9} magnetic molecule from low-temperature inelastic neutron scattering studies

    SciTech Connect (OSTI)

    Engelhardt, Larry [Francis Marion University; Demmel, Franz [Rutherford Appleton Laboratory; Luban, Marshall [Ames Laboratory; Timco, Grigore A [The University of Manchester; Tuna, Floriana [The University of Manchester; Winpenny, Richard E [The University of Manchester

    2014-06-01T23:59:59.000Z

    We present a refined model of the {Fe9} tridiminished icosahedron magnetic molecule system. This molecule was originally modeled as being composed of two ({Fe3} and {Fe6}) clusters, with the Fe3+ ions within each cluster being coupled via exchange interactions, but with no coupling between the clusters. The present inelastic neutron scattering (INS) measurements were used to probe the low-lying energy spectrum of {Fe9}, and these results demonstrate that the previously published model of two uncoupled clusters is incomplete. To achieve agreement between the experiment and theory, we have augmented the model with relatively small exchange coupling between the clusters. A combination of Lanczos matrix diagonalization and quantum Monte Carlo simulations have been used to achieve good agreement between the experimental data and the improved model of the full {Fe9} system despite the complexity of this model (with Hilbert space dimension >107).

  10. Bending elasticity of a curved amphiphilic film decorated anchored copolymers: a small angle neutron scattering study

    E-Print Network [OSTI]

    Jacqueline Appell; Christian Ligoure; Gregoire Porte

    2004-06-30T23:59:59.000Z

    Microemulsion droplets (oil in water stabilized by a surfactant film) are progressively decorated with increasing amounts of poly ethylene- oxide (PEO) chains anchored in the film by the short aliphatic chain grafted at one end of the PEO chain . The evolution of the bending elasticity of the surfactant film with increasing decoration is deduced from the evolution in size and polydispersity of the droplets as reflected by small angle neutron scattering. The optimum curvature radius decreases while the bending rigidity modulus remains practically constant. The experimental results compare well with the predictions of a model developed for the bending properties of a curved film decorated by non-adsorbing polymer chains, which takes into account, the finite curvature of the film and the free diffusion of the chains on the film.

  11. Small angle neutron and X-ray scattering studies of carbons prepared using inorganic templates

    SciTech Connect (OSTI)

    Sandi, G.; Thiyagarajan, P.; Winans, R.E.; Carrado, K.A.

    1997-09-01T23:59:59.000Z

    Small angle neutron (SANS) and X-ray (SAXS) scattering analyses of carbons derived from organic-loaded inorganic template materials, used as anodes in lithium ion cells, have been performed. Two clays were used as templates to load the organic precursors, pillared montmorrillonite (PILC), a layered silicate clay whose sheets have been permanently propped open by sets of thermally stable molecular props, and sepiolite, a natural channeled clay. Five different organic precursors were used to load the PILC: pyrene, styrene, pyrene/trioxane copolymer, ethylene and propylene, whereas only propylene and ethylene were used to load sepiolite. Pyrolysis took place at 700{degrees}C under nitrogen. Values such as hole radius, fractal dimension, cutoff length and density of the final carbons will be compared as a function of the clay and carbon precursors.

  12. Enhanced reaction rates in NDP analysis with neutron scattering

    SciTech Connect (OSTI)

    Downing, R. Gregory, E-mail: gregory.downing@nist.gov [National Institute of Standards and Technology, Chemical Sciences Division, Gaithersburg, Maryland 20899 (United States)

    2014-04-15T23:59:59.000Z

    Neutron depth profiling (NDP) makes accessible quantitative information on a few isotopic concentration profiles ranging from the surface into the sample a few micrometers. Because the candidate analytes for NDP are few, there is little interference encountered. Furthermore, neutrons have no charge so mixed chemical states in the sample are of no direct concern. There are a few nuclides that exhibit large probabilities for neutron scattering. The effect of neutron scattering on NDP measurements has not previously been evaluated as a basis for either enhancing the reaction rates or as a source of measurement error. Hydrogen is a common element exhibiting large neutron scattering probability found in or around sample volumes being analyzed by NDP. A systematic study was conducted to determine the degree of signal change when neutron scattering occurs during analysis. The relative signal perturbation was evaluated for materials of varied neutron scattering probability, concentration, total mass, and geometry. Signal enhancements up to 50% are observed when the hydrogen density is high and in close proximity to the region of analysis with neutron beams of sub thermal energies. Greater signal enhancements for the same neutron number density are reported for thermal neutron beams. Even adhesive tape used to position the sample produces a measureable signal enhancement. Because of the shallow volume, negligible distortion of the NDP measured profile shape is encountered from neutron scattering.

  13. Scattered neutron tomography based on a neutron transport problem 

    E-Print Network [OSTI]

    Scipolo, Vittorio

    2005-11-01T23:59:59.000Z

    scattering objects because it does not adequately account for the scattering component of the neutron beam intensity exiting the sample. We proposed a new method of computed tomography which employs an inverse problem analysis of both the transmitted...

  14. Scattered neutron tomography based on a neutron transport problem

    E-Print Network [OSTI]

    Scipolo, Vittorio

    2005-11-01T23:59:59.000Z

    scattering objects because it does not adequately account for the scattering component of the neutron beam intensity exiting the sample. We proposed a new method of computed tomography which employs an inverse problem analysis of both the transmitted...

  15. Fully portable, highly flexible dilution refrigerator systems for neutron scattering

    E-Print Network [OSTI]

    Boyer, Edmond

    775 Fully portable, highly flexible dilution refrigerator systems for neutron scattering P. A systems developed specifically for neutron scattering environ- ments. The refrigerators are completely relatively recently however, the lowest temperatures available in almost all neutron scattering laboratories

  16. 2012 LANSCE Neutron Scattering School | Los Alamos National Laboratory

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

    2 LANSCE Neutron Scattering School LANSCE 2012 LANSCE Neutron Scattering School Home About the School Hands-On Experiments Quick Links Application - Closed Schedule Poster...

  17. Proton Angular Distribution for 90 Mev Neutron-proton Scattering

    E-Print Network [OSTI]

    Hadley, James

    2010-01-01T23:59:59.000Z

    recoil protons in neutron -proton scattering at 90 Mev hasFOR 90 lWEV NEUTRON-PROTON SCATTERING James Hadley, Cecil E.

  18. Application of Neutron Imaging and Scattering to Fluid Flow and...

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

    Application of Neutron Imaging and Scattering to Fluid Flow and Fracture in EGS Environments Application of Neutron Imaging and Scattering to Fluid Flow and Fracture in EGS...

  19. 11th LANSCE School on Neutron Scattering | Lecturers

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

    Laboratory Rex Hjelm Rex P. Hjelm is the Instrument Scientist for the small-angle neutron scattering instrument, LQD, at the Lujan Neutron Scattering Center of LANSCE at...

  20. International Conference on Neutron Scattering 2005 Darling Harbour. Sydney. Australia

    E-Print Network [OSTI]

    International Conference on Neutron Scattering 2005 Darling Harbour. Sydney. Australia 27 November, Hillerød, Denmark Combined application of small-angle neutron scattering and oscillatory shear

  1. 2012 LANSCE Neutron Scattering School | Los Alamos National Laboratory

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

    1 LANSCE Neutron Scattering School LANSCE 2011 LANSCE Neutron Scattering School Home NSS 2011 About the School Lecturers Hands-On Experiments Quick Links Application Schedule...

  2. Dynamic Properties of Materials: Phonons from Neutron Scattering

    E-Print Network [OSTI]

    Cope, Elizabeth Ruth

    2010-01-01T23:59:59.000Z

    A detailed understanding of fundamental material properties can be obtained through the study of atomic vibrations, performed experimentally with neutron scattering techniques and coupled with the two powerful new computational methodologies I have...

  3. Electron microscopy and small angle neutron scattering study of precipitation in low alloy steel submerged-arc welds

    SciTech Connect (OSTI)

    Williams, T.J. [Rolls-Royce and Associates Ltd., Raynesway (United Kingdom); Phythian, W.J. [AEA Reactors Services, Didcot (United Kingdom)

    1996-12-31T23:59:59.000Z

    In previous studies, submerged-arc welds with a range of compositions were irradiated in test reactors over a range of dose and dose-rates. The effect of irradiation was measured by Charpy V-notch and hardness tests, and an irradiation response model was developed. In this paper the authors report the results of a combined electron microscopy and small angle neutron scattering (SANS) study on material from some of the Charpy specimens. The results have been interpreted in terms of the Russell and Brown modulus hardening model. In general they have confirmed the predictions of the irradiation response model, and shown that the copper precipitation contribution to the observed macroscopic to the observed macroscopic hardening is strongly dependent on nickel, dose and dose-rate.

  4. Adsorption of Supercritical CO2 in Aeroglass Studied by Small--Angle Neutron Scattering and Neutron Transmission Techniques

    SciTech Connect (OSTI)

    Melnichenko, Yuri B [ORNL; Wignall, George D [ORNL; Cole, David R [ORNL; Frielinghaus, H. [Forschungszentrum Julich, Julich, Germany

    2006-01-01T23:59:59.000Z

    Small-angle neutron scattering (SANS) has been used to study the adsorption behavior of supercritical carbon dioxide (CO{sub 2}) in porous Vycor glass and silica aerogels. Measurements were performed along two isotherms (T = 35 and 80 C) as a function of pressure (P) ranging from atmospheric up to 25 MPa, which corresponds to the bulk fluid densities ranging from {rho}CO{sub 2} - 0 to 0.9 g/cm{sup 3}. The intensity of scattering from CO{sub 2}-saturated Vycor porous glass can be described by a two-phase model which suggests that CO{sub 2} does not adsorb on the pore walls and fills the pore space uniformly. In CO{sub 2}-saturated aerogels an adsorbed phase is formed with a density substantially higher that of the bulk fluid, and neutron transmission data were used to monitor the excess adsorption at different pressures. The results indicate that adsorption of CO{sub 2} is significantly stronger in aerogels than in activated carbons, zeolites, and xerogels due to the extremely high porosity and optimum pore size of these materials. SANS data revealed the existence of a compressed adsorbed phase with the average density - 1.07 g/cm{sup 3}, close to the density corresponding to closely packed van der Waals volume of CO{sub 2}. A three-phase model [W. L. Wu, Polymer 23, 1907 (1982)] was used to estimate the volume fraction {phi}{sub 3} of the adsorbed phase as a function of the fluid density, and gave {phi}{sub 3} - 0.78 in the maximum adsorption regime around {rho}CO{sub 2} - 0.374 g/cm{sup 3}. The results presented in this work demonstrate the utility of SANS combined with the transmission measurements to study the adsorption of supercritical fluids in porous materials.

  5. Small-Angle Neutron Scattering study of solubilization of tributyl phosphate in aqueous solutions of L64 Pluronic triblock copolymers

    E-Print Network [OSTI]

    Jeremy Causse; Julian Oberdisse; Jacques Jestin; Serge Lagerge

    2010-12-04T23:59:59.000Z

    We have studied the solubilization behaviour of tributylphosphate (TBP) in aqueous solutions of L64-Pluronics, using light and small angle neutron scattering (SANS). Varying the temperature and the oil-content, the system presents a non trivial phase behaviour. In particular, at 308K, a first solubilization followed by an emulsification failure and a resolubilization is found. We have measured the microstructure by SANS and characterized the microemulsion droplet core-size, corona-thickness, polydispersity, and interactions. It is shown that at low oil content, the system is made of small swollen micelles. After the phase separation, the resolubilization is carried by larger oil droplets decorated by copolymer. From specific surface measurements at large angles, a surprising change in surfactant conformation is found to accompany this morphological evolution which is also supported by previous results obtained from 1H NMR experiments. In independent measurements, our structural modelling is confirmed using contrast-variation SANS.

  6. Micellar structure from comparison of X-ray and neutron small-angle scattering

    E-Print Network [OSTI]

    Boyer, Edmond

    249 Micellar structure from comparison of X-ray and neutron small-angle scattering T. Zemb and P according to the method developed by Hayter and Penfold. Both X-ray and neutron scattering signals, or by a combination of both. It has been shown recent- ly [1, 2] that it is possible in neutron scattering studies

  7. neutron scattering shows magnetic excitation mechanism at work in new materials.

    E-Print Network [OSTI]

    neutron scattering shows magnetic excitation mechanism at work in new materials. In 2008 dai of orNl and the university of tennes- see led early neutron scattering studies of the pnictides. dai ticks off four main things neutron scattering has revealed about superconducting iron com- pounds

  8. A New Polyethylene Scattering Law Determined Using Inelastic Neutron Scattering

    SciTech Connect (OSTI)

    Lavelle, Christopher M [ORNL; Liu, C [Oak Ridge National Laboratory (ORNL); Stone, Matthew B [ORNL

    2013-01-01T23:59:59.000Z

    Monte Carlo neutron transport codes such as MCNP rely on accurate data for nuclear physics cross-sections to produce accurate results. At low energy, this takes the form of scattering laws based on the dynamic structure factor, S (Q, E). High density polyethylene (HDPE) is frequently employed as a neutron moderator at both high and low temperatures, however the only cross-sections available are for T =300 K, and the evaluation has not been updated in quite some time. In this paper we describe inelastic neutron scattering measurements on HDPE at 5 and 300 K which are used to improve the scattering law for HDPE. We describe the experimental methods, review some of the past HDPE scattering laws, and compare computations using these models to the measured S (Q, E). The total cross-section is compared to available data, and the treatment of the carbon secondary scatterer as a free gas is assessed. We also discuss the use of the measurement itself as a scattering law via the 1 phonon approximation. We show that a scattering law computed using a more detailed model for the Generalized Density of States (GDOS) compares more favorably to this experiment, suggesting that inelastic neutron scattering can play an important role in both the development and validation of new scattering laws for Monte Carlo work.

  9. Nanosecond molecular relaxations in lipid bilayers studied by high energy resolution neutron scattering and in-situ diffraction

    E-Print Network [OSTI]

    Maikel C. Rheinstädter; Tilo Seydel; Tim Salditt

    2006-07-20T23:59:59.000Z

    We report a high energy-resolution neutron backscattering study to investigate slow motions on nanosecond time scales in highly oriented solid supported phospholipid bilayers of the model system DMPC -d54 (deuterated 1,2-dimyristoyl-sn-glycero-3-phoshatidylcholine), hydrated with heavy water. Wave vector resolved quasi-elastic neutron scattering (QENS) is used to determine relaxation times $\\tau$, which can be associated with different molecular components, i.e., the lipid acyl chains and the interstitial water molecules in the different phases of the model membrane system. The inelastic data are complemented both by energy resolved and energy integrated in-situ diffraction. From a combined analysis of the inelastic data in the energy and time domain, the respective character of the relaxation, i.e., the exponent of the exponential decay is also determined. From this analysis we quantify two relaxation processes. We associate the fast relaxation with translational diffusion of lipid and water molecules while the slow process likely stems from collective dynamics.

  10. Neutrons used to study model vascular systems

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

    the endothelial cells and the supporting substrate. In what may be the first use of neutron scattering to study complex bio-medical systems under dynamic conditions, Los...

  11. Neutron and X-ray Scattering Techniques have proved so successful in condensed matter studies that a wide variety of sample environments have been developed in consquence. Many

    E-Print Network [OSTI]

    Boyer, Edmond

    Foreword Neutron and X-ray Scattering Techniques have proved so successful in condensed matter whose function is to develop and optimise the techniques appropriate to neutron scattering. Since other neutron and X-ray research centres have similar technical support groups, it was felt timely to unité

  12. BUILDING A NETWORK FOR NEUTRON SCATTERING EDUCATION

    SciTech Connect (OSTI)

    Pynn, Roger [ORNL; Baker, Shenda Mary [ORNL; Louca, Despo A [ORNL; McGreevy, Robert L [ORNL; Ekkebus, Allen E [ORNL; Kszos, Lynn A [ORNL; Anderson, Ian S [ORNL

    2008-10-01T23:59:59.000Z

    In a concerted effort supported by the National Science Foundation, the Department of Commerce, and the Department of Energy, the United States is rebuilding its leadership in neutron scattering capability through a significant investment in U.S. neutron scattering user facilities and related instrumentation. These unique facilities provide opportunities in neutron scattering to a broad community of researchers from academic institutions, federal laboratories, and industry. However, neutron scattering is often considered to be a tool for 'experts only' and in order for the U.S. research community to take full advantage of these new and powerful tools, a comprehensive education and outreach program must be developed. The workshop described below is the first step in developing a national program that takes full advantage of modern education methods and leverages the existing educational capacity at universities and national facilities. During March 27-28, 2008, a workshop entitled 'Building a Network for Neutron Scattering Education' was held in Washington, D.C. The goal of the workshop was to define and design a roadmap for a comprehensive neutron scattering education program in the United States. Successful implementation of the roadmap will maximize the national intellectual capital in neutron sciences and will increase the sophistication of research questions addressed by neutron scattering at the nation's forefront facilities. (See Appendix A for the list of attendees, Appendix B for the workshop agenda, Appendix C for a list of references. Appendix D contains the results of a survey given at the workshop; Appendix E contains summaries of the contributed talks.) The workshop brought together U.S. academicians, representatives from neutron sources, scientists who have developed nontraditional educational programs, educational specialists, and managers from government agencies to create a national structure for providing ongoing neutron scattering education. A concerted effort was made to involve representatives from historically black colleges and universities (HBCUs) and minority educational institutions (MEIs). The roadmap contained herein provides the path to a national infrastructure for education of students, faculty, and professional researchers who wish to make use of national neutron scattering facilities but do not have (or do not believe they have) the educational background to do so. Education of other stakeholders, including the public, students in kindergarten through twelfth grade (K-12), and policy makers is also included. The opening sessions of the workshop provided the current status of neutron scattering education in North America, Europe, and Australia. National neutron sources have individually developed outreach and advertising programs aimed at increasing awareness among researchers of the potential applications of neutron scattering. However, because their principal mission is to carry out scientific research, their outreach efforts are necessarily self-limiting. The opening session was designed to build awareness that the individual programs need to be coupled with, and integrated into, a broader education program that addresses the complete range of experience, from the student to the experienced researcher, and the wide range of scientific disciplines covered by neutron scattering. Such a program must also take full advantage of existing educational programs and expertise at universities and expand them using modern distance learning capabilities, recognizing that the landscape of education is changing.

  13. The Neutron Scattering Society www.neutronscattering.org

    E-Print Network [OSTI]

    Chen, Sow-Hsin

    The Neutron Scattering Society of America www.neutronscattering.org Press Release, February 4, 2008 The Neutron Scattering Society of America is pleased to announce the 2008 recipients of its 3 major prizes. The Neutron Scattering Society of America (NSSA) established the Clifford G. Shull Prize in Neutron Science

  14. Neutron scattering at high pressure D. B. McWhan

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    715 Neutron scattering at high pressure D. B. McWhan Room 1D-234, Murray Hill, New Jersey 07974, U scattering at steady-state and pulsed sources are reviewed. The pressure cells available at most neutron 10 GPa have been made. For elastic scattering, a comparison is made between neutron scattering and X

  15. Temperature Dependent Neutron Scattering Sections for Polyethylene

    E-Print Network [OSTI]

    Roger E. Hill; C. -Y. Liu

    2003-09-05T23:59:59.000Z

    This note presents neutron scattering cross sections for polyethylene at 296 K, 77 K and 4 K derived from a new scattering kernel for neutron scattering off of hydrogen in polyethylene. The kernel was developed in ENDF-6 format as a set of S(alpha,beta) tables using the LEAPR module of the NJOY94 code package. The polyethylene density of states (from 0 to sub eV) adopted to derive the new kernel is presented. We compare our calculated room temperature total scattering cross sections and double differential cross sections at 232 meV at various angles with the available experimental data (at room temperature), and then extrapolate the calculations to lower temperatures (77K and 4K). The new temperature dependent scattering kernel gives a good quantitative fit to the available room temperature data and has a temperature dependence that is qualitatively consistent with thermodynamics.

  16. Conformation of Oligo(Ethylene Glycol) grafted Poly(Norbornene) in solutions: A Small Angle Neutron Scattering Study

    SciTech Connect (OSTI)

    Cheng, Gang [ORNL; Melnichenko, Yuri B [ORNL; Hua, Fengjun [ORNL; Hong, Kunlun [ORNL; Wignall, George D [ORNL; Hammouda, B. [National Institute of Standards and Technology (NIST); Mays, Jimmy [ORNL

    2008-01-01T23:59:59.000Z

    The structure of thermo sensitive poly(methoxyoligo(ethylene glycol) norbornenyl esters) homopolymers in dilute solution was investigated by Small Angle Neutron Scattering (SANS). The homopolymers consist of a polynorbornene (PNB) backbone with a degree of polymerization (DP) of 50, and each backbone monomer has a grafted Ethylene Glycol (EG) side chain with an average DP of 6.6. The hydrophobic backbone and hydrophilic side chains interact differently with solvents depending on their polarity, which makes the conformation very sensitive to the solvent quality. The polymer conformation was studied in two solvents, d-toluene and D2O, with the aim of understanding the influence of solvent/polymer interactions on the resulting structures. It was found that in a 0.5 wt. % solution in d-toluene the polymers assume wormlike chains and gradually contract with increasing polymer concentration. In a 0.5 wt. % solution in D2O, the polymers are partially contracted at room temperature and their conformation can be described by the form factor of a rigid cylinder. The volume of the cylinder shows no concentration dependence. Furthermore, the polymers in D2O collapse at higher temperatures due to decreasing solubility of the side chains in water.

  17. The Ramsauer model for the total cross sections of neutron nucleus scattering

    E-Print Network [OSTI]

    R. S. Gowda; S. S. V. Suryanarayana; S. Ganesan

    2005-06-02T23:59:59.000Z

    Theoretical study of systematics of neutron scattering cross sections on various materials for neutron energies up to several hundred MeV are of practical importance. In this paper, we analysed the experimental neutron scattering total cross sections from 20MeV to 550MeV using Ramsauer model for nuclei ranging from Be to Pb.

  18. Concepts of Neutron ScatteringConcepts of Neutron Scattering 66thth PSI Summer School on Condensed Matter ResearchPSI Summer School on Condensed Matter Research

    E-Print Network [OSTI]

    Boothroyd, Andrew

    Concepts of Neutron ScatteringConcepts of Neutron Scattering 66thth PSI Summer School on Condensed Andrew Boothroyd University of Oxford Basic features of neutron scattering Neutron diffraction Neutron on the lattice * * * #12;ScatteringScattering ``nuts and boltsnuts and bolts'' Neutrons, photons, electrons

  19. High-energy magnetic excitations in overdoped La 2 - x Sr x CuO 4 studied by neutron and resonant inelastic x-ray scattering

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

    Wakimoto, S.; Ishii, K.; Kimura, H.; Fujita, M.; Dellea, G.; Kummer, K.; Braicovich, L.; Ghiringhelli, G.; Debeer-Schmitt, L. M.; Granroth, G. E.

    2015-05-01T23:59:59.000Z

    We have performed neutron inelastic scattering and resonant inelastic x-ray scattering (RIXS) at the Cu-L? edge to study high-energy magnetic excitations at energy transfers of more than 100 meV for overdoped La2-xSrxCuO? with x=0.25 (Tc=15 K) and x=0.30 (nonsuperconducting) using identical single-crystal samples for the two techniques. From constant-energy slices of neutron-scattering cross sections, we have identified magnetic excitations up to ~250 meV for x=0.25. Although the width in the momentum direction is large, the peak positions along the (?,?) direction agree with the dispersion relation of the spin wave in the nondoped La?CuO? (LCO), which is consistent with the previous RIXS results of cuprate superconductors. Using RIXS at the Cu-L? edge, we have measured the dispersion relations of the so-called paramagnon mode along both (?,?) and (?,0) directions. Although in both directions the neutron and RIXS data connect with each other and the paramagnon along (?,0) agrees well with the LCO spin-wave dispersion, the paramagnon in the (?,?) direction probed by RIXS appears to be less dispersive and the excitation energy is lower than the spin wave of LCO near (?/2,?/2). Thus, our results indicate consistency between neutron inelastic scattering and RIXS, and elucidate the entire magnetic excitation in the (?,?) direction by the complementary use of two probes. The polarization dependence of the RIXS profiles indicates that appreciable charge excitations exist in the same energy range of magnetic excitations, reflecting the itinerant character of the overdoped sample. A possible anisotropy in the charge excitation intensity might explain the apparent differences in the paramagnon dispersion in the (?,?) direction as detected by the x-ray scattering.

  20. High-energy magnetic excitations in overdoped La 2 - x Sr x CuO 4 studied by neutron and resonant inelastic x-ray scattering

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

    Wakimoto, S.; Ishii, K.; Kimura, H.; Fujita, M.; Dellea, G.; Kummer, K.; Braicovich, L.; Ghiringhelli, G.; Debeer-Schmitt, L. M.; Granroth, G. E.

    2015-05-01T23:59:59.000Z

    We have performed neutron inelastic scattering and resonant inelastic x-ray scattering (RIXS) at the Cu-L? edge to study high-energy magnetic excitations at energy transfers of more than 100 meV for overdoped La2-xSrxCuO? with x=0.25 (Tc=15 K) and x=0.30 (nonsuperconducting) using identical single-crystal samples for the two techniques. From constant-energy slices of neutron-scattering cross sections, we have identified magnetic excitations up to ~250 meV for x=0.25. Although the width in the momentum direction is large, the peak positions along the (?,?) direction agree with the dispersion relation of the spin wave in the nondoped La?CuO? (LCO), which is consistent with themore »previous RIXS results of cuprate superconductors. Using RIXS at the Cu-L? edge, we have measured the dispersion relations of the so-called paramagnon mode along both (?,?) and (?,0) directions. Although in both directions the neutron and RIXS data connect with each other and the paramagnon along (?,0) agrees well with the LCO spin-wave dispersion, the paramagnon in the (?,?) direction probed by RIXS appears to be less dispersive and the excitation energy is lower than the spin wave of LCO near (?/2,?/2). Thus, our results indicate consistency between neutron inelastic scattering and RIXS, and elucidate the entire magnetic excitation in the (?,?) direction by the complementary use of two probes. The polarization dependence of the RIXS profiles indicates that appreciable charge excitations exist in the same energy range of magnetic excitations, reflecting the itinerant character of the overdoped sample. A possible anisotropy in the charge excitation intensity might explain the apparent differences in the paramagnon dispersion in the (?,?) direction as detected by the x-ray scattering.« less

  1. Cold neutron scattering in imperfect deuterium crystals

    E-Print Network [OSTI]

    Andrzej Adamczak

    2010-12-10T23:59:59.000Z

    The differential cross sections for cold neutron scattering in mosaic deuterium crystals have been calculated for various target temperatures. The theoretical results are compared with the recent experimental data for the neutron wavelengths $\\lambda\\approx$~1--9~\\AA. It is shown that the structures of observed Bragg peaks can be explained by the mosaic spread of about $3^{\\circ}$ and contributions from a~limited number of crystal orientations. Such a~crystal structure should be also taken into account in ultracold neutron upscattering due to the coherent phonon annihilation in solid deuterium.

  2. Forward Helion Scattering and Neutron Polarization

    SciTech Connect (OSTI)

    Buttimore, N. H. [Trinity College Dublin (Ireland)

    2009-03-23T23:59:59.000Z

    The elastic scattering of spin half helium-3 nuclei at small angles can show a sufficiently large analyzing power to enable the level of helion polarization to be evaluated. As the helion to a large extent inherits the polarization of its unpaired neutron the asymmetry observed in helion collisions can be transformed into a measurement of the polarization of its constituent neutron. Neutron polarimetry therefore relies upon understanding the spin dependence of the electromagnetic and hadronic interactions in the region of interference where there is an optimal analyzing power.

  3. An effective long-range attraction between protein molecules in solutions studied by small angle neutron scattering

    E-Print Network [OSTI]

    Yun Liu; Emiliano Fratini; Piero Baglioni; Wei-Ren Chen; Sow-Hsin Chen

    2005-08-05T23:59:59.000Z

    Small angle neutron scattering intensity distributions taken from cytochrome C and lysozyme protein solutions show a rising intensity at very small wave vector, Q, which can be interpreted in terms of the presence of a weak long-range attraction between protein molecules. This interaction has a range several times that of the diameter of the protein molecule, much greater than the range of the screened electrostatic repulsion. We show evidence that this long-range attraction is closely related to the type of anion present and ion concentration in the solution.

  4. Attosecond neutron Compton scattering from protons

    E-Print Network [OSTI]

    C. Aris Chatzidimitriou-Dreismann

    2007-02-01T23:59:59.000Z

    The effect of "anomalous" scattering of neutrons and electrons from protons in the electron-volt energy-transfer range is considered, and related experimental results are mentioned. A recent independent confirmation of this effect with a new data analysis procedure is presented. Due to the very short characteristic scattering time, there is no well defined separation of time scales of electronic and protonic motions. An outline of a proposed theoretical interpretation is presented, which is based on the fact that scattering protons represent \\textit{open} quantum systems, thus being subject to decoherence.

  5. Neutron Scattering Society of America Purpose and New Initiatives

    E-Print Network [OSTI]

    Pennycook, Steve

    1 Neutron Scattering Society of America (NSSA) Purpose and New Initiatives www.neutronscattering.org SNS/ANL School on Neutron and X-Ray Scattering June 2010 Visit us now on Facebook #12;2 What and provide a focal point for the neutron scattering community in the USA To identify the needs

  6. Fourteenth National School on Neutron and X-ray Scattering

    E-Print Network [OSTI]

    Pennycook, Steve

    Fourteenth National School on Neutron and X-ray Scattering August 12 - 25, 2012 at Argonne National of the National School on Neutron and X-ray Scattering is to educate graduate students on the utilization of major Ridge National Laboratory's Neutron Scattering Science Division. Scientific Directors: Jonathan C. Lang

  7. Nitrogen Contamination in Elastic Neutron Scattering Songxue Chi,ab

    E-Print Network [OSTI]

    Lynn, Jeffrey W.

    Nitrogen Contamination in Elastic Neutron Scattering Songxue Chi,ab Jeffrey W. Lynn,a* Ying Chen a neutron scattering measurement is a contribution to the background, especially in inelastic measurements of having N2 in the sample environment system during elastic neutron scattering measurements on a single

  8. Tenth National School on Neutron and X-ray Scattering

    E-Print Network [OSTI]

    Pennycook, Steve

    Tenth National School on Neutron and X-ray Scattering September 24 - October 11, 2008 at Argonne of the National School on Neutron and X-ray Scattering is to educate graduate students on the utilization of major National Laboratory's Neutron Scattering Science Division. Scientific Directors: Jonathan C. Lang, Suzanne

  9. Neutron Scattering Society of America Purpose and New Initiatives

    E-Print Network [OSTI]

    1 Neutron Scattering Society of America (NSSA) Purpose and New Initiatives www.neutronscattering.org SNS/ANL School on Neutron and X-Ray Scattering June 2011 Visit us now on Facebook #12;2 What and provide a focal point for the neutron scattering community in the USA To identify the needs

  10. National School on Neutron and X-ray Scattering

    E-Print Network [OSTI]

    15th National School on Neutron and X-ray Scattering August 10 - 24, 2013 at Argonne National of the National School on Neutron and X-ray Scattering is to educate graduate students on the utilization of major Ridge National Laboratory's Neutron Scattering Science Division. Scientific Directors: Jonathan C. Lang

  11. Thirteenth National School on Neutron and X-ray Scattering

    E-Print Network [OSTI]

    Thirteenth National School on Neutron and X-ray Scattering June 11 ­ June 25, 2011 at Argonne of the National School on Neutron and X-ray Scattering is to educate graduate students on the utilization of major National Laboratory's Neutron Scattering Science Division. Scientific Directors: Jonathan C. Lang, Suzanne

  12. LANSCE School on Neutron Scattering: Materials at the Mesoscale

    E-Print Network [OSTI]

    1 11th LANSCE School on Neutron Scattering: Materials at the Mesoscale Lujan Center Los Alamos. Please name the applicant for admission to the 11th LANSCE School on Neutron Scattering: Last, First LANSCE School on Neutron Scattering including: drive and motivation, ability to work with others

  13. Sixteenth National School on Neutron and X-ray Scattering

    E-Print Network [OSTI]

    Pennycook, Steve

    Sixteenth National School on Neutron and X-ray Scattering June 14-28, 2014 at Argonne National of the National School on Neutron and X-ray Scattering is to educate graduate students on the utilization of major's Neutron Scattering Science Division. Scientific Directors: Suzanne G.E. te Velthuis, Esen Ercan Alp

  14. Neutron scattering in magnetic fields (*) W. C. Koehler

    E-Print Network [OSTI]

    Boyer, Edmond

    691 Neutron scattering in magnetic fields (*) W. C. Koehler Solid State Division, Oak Ridge. Abstract 2014 The use of magnetic fields in neutron scattering experimentation is reviewed briefly. Two of the scattering sample ; in the second the field acts on the neutron itself. Several examples are discussed

  15. Twelfth National School on Neutron and X-ray Scattering

    E-Print Network [OSTI]

    Pennycook, Steve

    Twelfth National School on Neutron and X-ray Scattering June 12 ­ June 26, 2010 at Argonne National of the National School on Neutron and X-ray Scattering is to educate graduate students on the utilization of major National Laboratory's Neutron Scattering Science Division. Scientific Directors: Jonathan C. Lang, Suzanne

  16. National School on Neutron and X-ray Scattering

    E-Print Network [OSTI]

    Pennycook, Steve

    National School on Neutron and X-ray Scattering May 30 ­ June 13, 2009 at Argonne National of the National School on Neutron and X-ray Scattering is to educate graduate students on the utilization of major National Laboratory's Neutron Scattering Science Division. Scientific Directors: Jonathan C. Lang, Suzanne

  17. A Java-based Science Portal for Neutron Scattering Experiments

    E-Print Network [OSTI]

    Vazhkudai, Sudharshan

    A Java-based Science Portal for Neutron Scattering Experiments Sudharshan S. Vazhkudai James A scattering facility recently commissioned by the US Department of Energy (DOE). The neutron beam produced (SNS) [14] is a large-scale leading- edge neutron scattering facility that hopes to fundamen- tally

  18. ORNL Neutron Scattering School May 30 -June 5, 2009

    E-Print Network [OSTI]

    Pennycook, Steve

    ORNL Neutron Scattering School May 30 - June 5, 2009 Oak Ridge National Laboratory Oak Ridge, 2009, for the first week of the Neutron Xray Scattering School. Please be certain to bring photo for Neutron Scattering Users · Radiological Worker Training for HFIR and SNS Users In addition

  19. Inelastic scattering of fast neutrons from $^{56}$Fe

    E-Print Network [OSTI]

    Beyer, R; Hannaske, R; Junghans, A R; Massarczyk, R; Anders, M; Bemmerer, D; Ferrari, A; Kögler, T; Röder, M; Schmidt, K; Wagner, A

    2014-01-01T23:59:59.000Z

    Inelastic scattering of fast neutrons from $^{56}$Fe was studied at the photoneutron source nELBE. The neutron energies were determined on the basis of a timeof- flight measurement. Gamma-ray spectra were measured with a high-purity germanium detector. The total scattering cross sections deduced from the present experiment in an energy range from 0.8 to 9.6 MeV agree within 15% with earlier data and with predictions of the statistical-reaction code Talys.

  20. Neutron Scattering Experiment Automation with Python

    SciTech Connect (OSTI)

    Zolnierczuk, Piotr A [ORNL] [ORNL; Riedel, Richard A [ORNL] [ORNL

    2010-01-01T23:59:59.000Z

    The Spallation Neutron Source (SNS) at Oak Ridge National Laboratory currently holds the Guinness World Record as the world most powerful pulsed spallation neutron source. Neutrons scattered off atomic nuclei in a sample yield important information about the position, motions, and magnetic properties of atoms in materials. A neutron scattering experiment usually involves sample environment control (temperature, pressure, etc.), mechanical alignment (slits, sample and detector position), magnetic field controllers, neutron velocity selection (choppers) and neutron detectors. The SNS Data Acquisition System (DAS) consists of real-time sub-system (detector read-out with custom electronics, chopper interface), data preprocessing (soft real-time) and a cluster of control and ancillary PCs. The real-time system runs FPGA firmware and programs running on PCs (C++, LabView) typically perform one task such as motor control and communicate via TCP/IP networks. PyDas is a set of Python modules that are used to integrate various components of the SNS DAS system. It enables customized automation of neutron scattering experiments in a rapid and flexible manner. It provides wxPython GUIs for routine experiments as well as IPython command line scripting. Matplotlib and numpy are used for data presentation and simple analysis. We will present an overview of SNS Data Acquisition System and PyDas architectures and implementation along with the examples of use. We will also discuss plans for future development as well as the challenges that have to be met while maintaining PyDas for 20+ different scientific instruments.

  1. Anharmonic lattice dynamics of Ag2O studied by inelastic neutron scattering and first-principles molecular dynamics simulations

    SciTech Connect (OSTI)

    Lan, Tian [California Institute of Technology, Pasadena] [California Institute of Technology, Pasadena; Li, Chen [ORNL] [ORNL; Niedziela, Jennifer L [ORNL] [ORNL; Smith, Hillary [California Institute of Technology, Pasadena] [California Institute of Technology, Pasadena; Abernathy, Douglas L [ORNL] [ORNL; Rossman, George [California Institute of Technology, Pasadena] [California Institute of Technology, Pasadena; Fultz, B. [California Institute of Technology, Pasadena] [California Institute of Technology, Pasadena

    2014-01-01T23:59:59.000Z

    Inelastic neutron scattering measurements on silver oxide (Ag2O) with the cuprite structure were performed at temperatures from 40 to 400 K, and Fourier transform far-infrared spectra were measured from 100 to 300 K. The measured phonon densities of states and the infrared spectra showed unusually large energy shifts with temperature, and large linewidth broadenings. First principles molecular dynamics (MD) calculations were performed at various temperatures, successfully accounting for the negative thermal expansion (NTE) and local dynamics. Using the Fourier-transformed velocity autocorrelation method, the MD calculations reproduced the large anharmonic effects of Ag2O, and were in excellent agreement with the neutron scattering data. The quasiharmonic approximation (QHA) was less successful in accounting for much of the phonon behavior. The QHA could account for some of the NTE below 250 K, although not at higher temperatures. Strong anharmonic effects were found for both phonons and for the NTE. The lifetime broadenings of Ag2O were explained by anharmonic perturbation theory, which showed rich interactions between the Ag-dominated modes and the O-dominated modes in both up- and down-conversion processes.

  2. Deep Inelastic Scattering of Polarized Electrons by Polarized $^3$He and the Study of the Neutron Spin Structure

    E-Print Network [OSTI]

    The E142 Collaboration; P. L. Anthony et al

    1996-10-14T23:59:59.000Z

    The neutron longitudinal and transverse asymmetries $A^n_1$ and $A^n_2$ have been extracted from deep inelastic scattering of polarized electrons by a polarized $^3$He target at incident energies of 19.42, 22.66 and 25.51 GeV. The measurement allows for the determination of the neutron spin structure functions $g^n_1 (x,Q^2)$ and $g^n_2(x,Q^2)$ over the range $0.03 neutron spin structure function $g^n_1 (x,Q^2)$ is small and negative within the range of our measurement, yielding an integral ${\\int_{0.03}^{0.6} g_1^n(x) dx}= -0.028 \\pm 0.006 (stat) \\pm 0.006 (syst) $. Assuming Regge behavior at low $x$, we extract $\\Gamma_1^n=\\int^1_0 g^n_1(x)dx = -0.031 \\pm 0.006 (stat)\\pm 0.009 (syst) $. Combined with previous proton integral results from SLAC experiment E143, we find $\\Gamma_1^p - \\Gamma_1^n = 0.160 \\pm 0.015$ in agreement with the Bjorken sum rule prediction $\\Gamma^p_1 - \\Gamma ^n_1 = 0.176 \\pm 0.008$ at a $Q^2$ value of 3 (GeV$/c)^2$ evaluated using $\\alpha_s = 0.32\\pm 0.05$.

  3. Optimizing Moderator Dimensions for Neutron Scattering at the Spallation Neutron Source

    SciTech Connect (OSTI)

    Zhao, Jinkui [ORNL; Robertson, Lee [ORNL; Herwig, Kenneth W [ORNL; Gallmeier, Franz X [ORNL; Riemer, Bernie [ORNL

    2013-01-01T23:59:59.000Z

    In this work, we investigate the effect of neutron moderator dimensions on the performance of neutron scattering instruments at the Spallation Neutron Source. In a recent study of the planned second target station at the Spallation Neutron Source (SNS) facility [1,2], we have found that the dimensions of a moderator play a significant role in determining its surface brightness. A smaller moderator may be significantly brighter for a smaller viewing area [4]. One of the immediate implications of this finding is that for modern neutron scattering instrument designs, moderator dimensions and brightness have to be incorporated as an integrated optimization parameter. Here, we establish a strategy of matching neutron scattering instruments with moderators using analytical and Monte Carlo techniques. In order to simplify our treatment, we group the instruments into two broad categories, those with natural collimation and those that use neutron guide systems. We found that the cross-sections of the sample and the neutron guide, respectively, are the deciding factors for choosing the moderator. Beam divergence plays no role as long as it is within the reach of practical constraints. Namely, the required divergence is not too large for the guide or sample to be located close enough to the moderator on an actual spallation source.

  4. Neutron-deuteron breakup reaction as a tool for studying neutron-neutron interactions

    SciTech Connect (OSTI)

    Konobeevski, E. S., E-mail: konobeev@inr.ru; Zuyev, S. V.; Mordovskoy, M. V.; Potashev, S. I.; Sharapov, I. M. [Russian Academy of Sciences, Institute for Nuclear Research (Russian Federation)] [Russian Academy of Sciences, Institute for Nuclear Research (Russian Federation)

    2013-11-15T23:59:59.000Z

    An analysis of the most recent data on the reaction nd {yields} pnn revealed a serious discrepancy between theoretical predictions and cross sections measured for this reaction in various configurations where the role of neutron-neutron interactions is important. In view of this, it seems necessary both to develop theoretical approaches and to obtain new experimental data. For this purpose, a setup for studying the neutron-deuteron breakup reaction was created at the Institute for Nuclear Research on the basis of the neutron beam in the RADEX channel and deuterium targets. This facility makes it possible to perform experiments over a broad region of primary-neutron energies (10-60 MeV) and in various (final-state interaction, quasifree scattering, and spatial-star) configurations. Preliminary results of the respective experiment were obtained for configurations of final-state neutron-neutron interaction and quasifree neutron-neutron scattering.

  5. Neutron-Proton High-Energy Charge Exchange Scattering

    E-Print Network [OSTI]

    Y. Yan; R. Tegen; T. Gutsche; V. E. Lyubovitskij; Amand Faessler

    2002-04-18T23:59:59.000Z

    The high energy proton-neutron charge exchange scattering reaction is studied in an effective hadron model for the energy range of s from 45.9 to 414.61 GeV*GeV. The main features of the observed differential cross section, the forward peak and the scaling behavior over a large energy region, are well reproduced.

  6. In-situ neutron scattering studies of magnetic shape memory alloys under stress, temperature, and magnetic fields

    SciTech Connect (OSTI)

    Brown, Donald W [Los Alamos National Laboratory; Sisneros, Thomas A [Los Alamos National Laboratory; Kabra, Saurabh [ANSTO/AUSTRALIA; Lograsso, Thomas A [AMES LAB; Schlagel, Deborah [AMES LAB

    2010-01-01T23:59:59.000Z

    We have utilized the SMARTS engineering neutron diffractometer to study the crystallographic orientation and phase transformations in the ferromagnetic shape memory alloy Ni 2MnGa under conditions of temperature (200-600K), stress (500MPa), and magnetic field (2T). Neutrons are uniquely suited to probe the crystallographic response of materials to external stimuli because of their high penetration, which allows them to sample the bulk of the material (as opposed to the surface) as well as pass through environmental chambers. A single crystal of Ni{sub 5}MnGa was repeatedly thermally cycled through the Austenitic-Martensitic phase transformation under varying conditions of applied stress, magnetic field or both. In-situ neutron diffraction was used to quantitatively monitor the population of the crystallographic variants in the martensitic phase as a function of the external stimuli during cooling. Neutron diffraction was used to monitor variant selection in the Ferromagnetic Shape Memory Alloy Ni{sub 2}Mn Ga during austenitic to martensitic transformation under varying conditions of externally applied stress and magnetic field. Qualitatively, the results were to be expected in this simple example. The shorter and magnetically soft c-axis of the tetragonal martensitic phase aligned with the compressive stress or magnetic field. However, neutron diffraction proved useful in directly quantifying the selection of the preferred variant by external influence. For instance, by quantifying the variant selection, the neutron diffraction results made apparent that the sample 'remembered' a loading cycle following a 'reset' cycle with no external applied stress. Moreover, the power of in-situ neutron diffraction will become more apparent when applied to more complex, less understood, samples such as polycrystalline samples or composite samples.

  7. Total Cross Sections for Neutron Scattering

    E-Print Network [OSTI]

    C. R. Chinn; Ch. Elster; R. M. Thaler; S. P. Weppner

    1994-10-19T23:59:59.000Z

    Measurements of neutron total cross-sections are both extensive and extremely accurate. Although they place a strong constraint on theoretically constructed models, there are relatively few comparisons of predictions with experiment. The total cross-sections for neutron scattering from $^{16}$O and $^{40}$Ca are calculated as a function of energy from $50-700$~MeV laboratory energy with a microscopic first order optical potential derived within the framework of the Watson expansion. Although these results are already in qualitative agreement with the data, the inclusion of medium corrections to the propagator is essential to correctly predict the energy dependence given by the experiment.

  8. Neutron scattering and extra short range interactions

    E-Print Network [OSTI]

    V. V. Nesvizhevsky; G. Pignol; K. V. Protasov

    2007-11-14T23:59:59.000Z

    The available data on neutron scattering were analyzed to constrain a hypothetical new short-range interaction. We show that these constraints are several orders of magnitude better than those usually cited in the range between 1 pm and 5 nm. This distance range occupies an intermediate space between collider searches for strongly coupled heavy bosons and searches for new weak macroscopic forces. We emphasise the reliability of the neutron constraints in so far as they provide several independent strategies. We have identified the most promising way to improve them.

  9. Small angle neutron scattering from high impact polystyrene

    SciTech Connect (OSTI)

    Pringle, O.A.

    1981-01-01T23:59:59.000Z

    High impact polystyrene (HIPS) is a toughened plastic composed of a polystyrene matrix containing a few percent rubber in the form of dispersed 0.1 to 10 micron diameter rubber particles. Some commercial formulations of HIPS include the addition of a few percent mineral oil, which improves the toughness of the plastic. Little is known about the mechanism by which the mineral oil helps toughen the plastic. It is hypothesized that the oil is distributed only in the rubber particles, but whether this hypothesis is correct was not known prior to this work. The size of the rubber particles in HIPS and their neutron scattering length density contrast with the polystyrene matrix cause HIPS samples to scatter neutrons at small angles. The variation of this small angle neutron scattering (SANS) signal with mineral oil content has been used to determine the location of the oil in HIPS. The SANS spectrometer at the University of Missouri Research Reactor Facility (MURR) was used to study plastic samples similar in composition to commercial HIPS. The MURR SANS spectrometer is used to study the small angle scattering of a vertical beam of 4.75 A neutrons from solid and liquid samples. The scattered neutrons are detected in a 54 x 60 cm/sup 2/ position sensitive detector designed and built at MURR. A series of plastic samples of varying rubber and oil content and different rubber domain sizes and shapes were examined on the MURR SANS spectrometer. Analysis of the scattering patterns showed that the mineral oil is about eight to ten times more likely to be found in the rubber particles than in the polystyrene matrix. This result confirmed the hypothesis that the mineral oil is distributed primarily in the rubber particles.

  10. Optimizing moderator dimensions for neutron scattering at the spallation neutron source

    SciTech Connect (OSTI)

    Zhao, J. K.; Robertson, J. L.; Herwig, Kenneth W.; Gallmeier, Franz X.; Riemer, Bernard W. [Instrument and Source Division, Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)] [Instrument and Source Division, Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

    2013-12-15T23:59:59.000Z

    In this work, we investigate the effect of neutron moderator dimensions on the performance of neutron scattering instruments at the Spallation Neutron Source (SNS). In a recent study of the planned second target station at the SNS facility, we have found that the dimensions of a moderator play a significant role in determining its surface brightness. A smaller moderator may be significantly brighter over a smaller viewing area. One of the immediate implications of this finding is that for modern neutron scattering instrument designs, moderator dimensions and brightness have to be incorporated as an integrated optimization parameter. Here, we establish a strategy of matching neutron scattering instruments with moderators using analytical and Monte Carlo techniques. In order to simplify our treatment, we group the instruments into two broad categories: those with natural collimation and those that use neutron guide systems. For instruments using natural collimation, the optimal moderator selection depends on the size of the moderator, the sample, and the moderator brightness. The desired beam divergence only plays a role in determining the distance between sample and moderator. For instruments using neutron optical systems, the smallest moderator available that is larger than the entrance dimension of the closest optical element will perform the best (assuming, as is the case here that smaller moderators are brighter)

  11. Identification and rejection of scattered neutrons in AGATA

    E-Print Network [OSTI]

    M. ?enyi?it; A. Ataç; S. Akkoyun; A. Ka?ka?; D. Bazzacco; J. Nyberg; F. Recchia; S. Brambilla; F. Camera; F. C. L. Crespi; E. Farnea; A. Giaz; A. Gottardo; R. Kempley; J. Ljungvall; D. Mengoni; C. Michelagnoli; B. Million; M. Palacz; L. Pellegri; S. Riboldi; E. ?ahin; P. A. Söderström; J. J. Valiente Dobon; the AGATA collaboration

    2013-06-12T23:59:59.000Z

    Gamma rays and neutrons, emitted following spontaneous fission of 252Cf, were measured in an AGATA experiment performed at INFN Laboratori Nazionali di Legnaro in Italy. The setup consisted of four AGATA triple cluster detectors (12 36-fold segmented high-purity germanium crystals), placed at a distance of 50 cm from the source, and 16 HELENA BaF2 detectors. The aim of the experiment was to study the interaction of neutrons in the segmented high-purity germanium detectors of AGATA and to investigate the possibility to discriminate neutrons and gamma rays with the gamma-ray tracking technique. The BaF2 detectors were used for a time-of-flight measurement, which gave an independent discrimination of neutrons and gamma rays and which was used to optimise the gamma-ray tracking-based neutron rejection methods. It was found that standard gamma-ray tracking, without any additional neutron rejection features, eliminates effectively most of the interaction points due to recoiling Ge nuclei after elastic scattering of neutrons. Standard tracking rejects also a significant amount of the events due to inelastic scattering of neutrons in the germanium crystals. Further enhancements of the neutron rejection was obtained by setting conditions on the following quantities, which were evaluated for each event by the tracking algorithm: energy of the first and second interaction point, difference in the calculated incoming direction of the gamma ray, figure-of-merit value. The experimental results of tracking with neutron rejection agree rather well with Geant4 simulations.

  12. Inelastic neutron scattering in valence fluctuation compounds

    SciTech Connect (OSTI)

    Jon M Lawrence

    2011-02-15T23:59:59.000Z

    The valence fluctuation compounds are rare earth intermetallics where hybridization of the nearly-localized 4f electrons with the conduction electrons leads to incorporation of the 4f's into the itinerant states. This hybridization slows down the conduction electrons and hence gives them a heavy effective mass, justifying application of the term 'heavy Fermion' (HF) to these materials. During the project period, we grew large single crystals of several such compounds and measured their properties using both standard thermodynamic probes and state-of-the-art inelastic neutron scattering. We obtained three main results. For the intermediate valence compounds CePd{sub 3} and YbAl{sub 3}, we showed that the scattering of neutrons by the fluctuations of the 4f magnetic moment does not have the momentum dependence expected for the itinerant heavy mass state; rather, the scattering is more typical of a localized spin fluctuation. We believe that incoherent scattering localizes the excitation. For the heavy Fermion compound Ce(Ni{sub 0.935}Pd{sub 0.065}){sub 2}Ge{sub 2}, which sits at a T = 0 critical point for transformation into an antiferromagnetic (AF) phase, we showed that the scattering from the AF fluctuations does not exhibit any of the divergences that are expected at a phase transition. We speculate that alloy disorder profoundly suppresses the growth of the fluctuating AF regions, leading to short range clusters rather than regions of infinite size. Finally, we explored the applicability of key concepts used to describe the behavior of rare earth heavy Fermions to uranium based HF compounds where the 5f electrons are itinerant as opposed to localized. We found that scaling laws relating the spin fluctuation energy measured in neutron scattering to the low temperature specific heat and susceptibility are valid for the uranium compounds, once corrections are made for AF fluctuations; however, the degeneracy of the high temperature moment is smaller than expected for rare-earth-like Hund's rule behavior, essentially because the orbital moment is suppressed for itinerant 5f electrons. We also found that the standard local-moment-based theory of the temperature dependence of the specific heat, susceptibility and neutron scattering fails badly for URu{sub 2}Zn{sub 20} and UCo{sub 2}Zn{sub 20}, even though the theory is phenomenally successful for the closely related rare earth compound YbFe{sub 2}Zn{sub 20}. Both these results highlight the distinction between the itineracy of the 5f's and the localization of the 4f's. It is our hope that these results are sufficiently significant as to stimulate deeper investigation of these compounds.

  13. Inelastic neutron scattering, Raman and DFT investigations of...

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

    Inelastic neutron scattering, Raman and DFT investigations of the adsorption of phenanthrenequinone on onion-like carbon Daniela M. Anjos a , Alexander I. Kolesnikov a , Zili Wu a...

  14. 11th LANSCE School on Neutron Scattering | Lecturers

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

    a window into the internal structure of Layer-by-Layer grown films. The dependence of neutron refractive index on nuclear rather than electronic scattering allows one to...

  15. 11th LANSCE School on Neutron Scattering | School Abstract

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

    Materials at the Mesoscale The 11th LANSCE School on Neutron Scattering will focus on science of Materials at the Mesoscale: the influence of surfaces, interfaces, and...

  16. Swollen Micelles Plus Hydrophobically Modified Hydrosoluble Polymers in Aqueous Solutions: Decoration Versus Bridging. a Small Angle Neutron Scattering Study

    E-Print Network [OSTI]

    Mohammed Filali; Raymond Aznar; Mattias Svenson; Gregoire Porte; Jacqueline Appell

    2004-10-12T23:59:59.000Z

    In this paper we examine the effective interactions introduced between the droplets of an oil in water microemulsion upon progressive addition of hydrophobically modified water soluble poly(ethylene oxide)-PEO using essentially small angle neutron scattering. To discuss the relative importance of decoration and bridging of the droplets we compare analogous samples with addition of a PEO grafted at both extremities with hydrophobic C12H 25 chains (PEO-2m) or addition of a PEO grafted at one extremity only with a C12H 25 chain (PEO-m). PEO-m or PEO-2m adsorb onto the droplets via their hydrophobic extremities and the droplets are found to retain their form and size upon addition of up to 40 hydrophobic C12H 25 chains per droplet. When the volume fraction of droplets is less than about 10%, the effective interactions introduced by PEO-m or PEO-2m are found to be very different: PEO-m introduces a repulsive interaction while PEO-2m introduces an effective attractive interaction. This attractive interaction leads to an associative phase separation in the range of low volume fraction when a sufficient amount of PEO-2m is added.

  17. Structural Evolution of Polylactide Molecular Bottlebrushes: Kinetics Study by Size Exclusion Chromatography, Small Angle Neutron Scattering and Simulations

    SciTech Connect (OSTI)

    Pickel, Deanna L [ORNL; Kilbey, II, S Michael [ORNL; Uhrig, David [ORNL; Hong, Kunlun [ORNL; Carrillo, Jan-Michael Y [ORNL; Sumpter, Bobby G [ORNL; Ahn, Suk-Kyun [ORNL; Han, Youngkyu [ORNL; Kim, Dr. Tae-Hwan [Korea Atomic Energy Research Institute; Smith, Gregory Scott [ORNL; Do, Changwoo [ORNL

    2014-01-01T23:59:59.000Z

    Structural evolution from poly(lactide) (PLA) macromonomer to resultant PLA molecular bottlebrush during ring opening metathesis polymerization (ROMP) was investigated for the first time by combining size exclusion chromatography (SEC), small-angle neutron scattering (SANS) and coarse-grained molecular dynamics (CG-MD) simulations. Multiple aliquots were collected at various reaction times during ROMP, and subsequently analyzed by SEC and SANS. The two complementary techniques enable the understanding of systematic changes in conversion, molecular weight and dispersity as well as structural details of PLA molecular bottlebrushes. CG-MD simulation not only predicts the experimental observations, but it also provides further insight into the analysis and interpretation of data obtained in SEC and SANS experiments. We find that PLA molecular bottlebrushes undergo three conformational transitions with increasing conversion (i.e., increasing the backbone length): (1) from an elongated to a globular shape due to longer side chain at lower conversion, (2) from a globular to an elongated shape at intermediate conversion caused by excluded volume of PLA side chain, and (3) the saturation of contour length at higher conversion due to chain transfer reactions.

  18. Deeply Virtual Compton Scattering off the neutron

    E-Print Network [OSTI]

    M. Mazouz; A. Camsonne; C. Muñoz Camacho; for the Jefferson Lab Hall A collaboration

    2007-12-12T23:59:59.000Z

    The present experiment exploits the interference between the Deeply Virtual Compton Scattering (DVCS) and the Bethe-Heitler processes to extract the imaginary part of DVCS amplitudes on the neutron and on the deuteron from the helicity-dependent D$({\\vec e},e'\\gamma)X$ cross section measured at $Q^2$=1.9 GeV$^2$ and $x_B$=0.36. We extract a linear combination of generalized parton distributions (GPDs) particularly sensitive to $E_q$, the least constrained GPD. A model dependent constraint on the contribution of the up and down quarks to the nucleon spin is deduced.

  19. A neutron diffraction study of nano-crystalline graphite oxide

    E-Print Network [OSTI]

    and regions containing oxidized chain-like structures. The neutron scattering pair distribution function is heterogeneous, the total neutron scattering data presented in this paper gives a statistically averagedA neutron diffraction study of nano-crystalline graphite oxide J.A. Johnsona,b,*, C.J. Benmoreb , S

  20. angle scattering studies: Topics by E-print Network

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

    report gives selected examples illustrating the use of specific techni- cal 2 Small-Angle Neutron Scattering Studies of Charged Carboxyl-Terminated Dendrimers in Solutions...

  1. angle neutron scattering: Topics by E-print Network

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

    neutron scattering First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 SANS -Small Angle Neutron Scattering...

  2. Ferroelectric nanoscale domains and the 905 K phase transition in SrSnO{sub 3}: A neutron total-scattering study

    SciTech Connect (OSTI)

    Goodwin, Andrew L.; Redfern, Simon A. T.; Dove, Martin T.; Keen, David A.; Tucker, Matthew G. [Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ (United Kingdom); ISIS Facility, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0QX, United Kingdom and Clarendon Laboratory, Department of Physics, Oxford University, Parks Road, Oxford OX1 3PU (United Kingdom); ISIS Facility, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0QX (United Kingdom)

    2007-11-01T23:59:59.000Z

    The 905 K Pnma-Imma phase transition in SrSnO{sub 3} is studied here using a combination of variable-temperature neutron total scattering together with the reverse Monte Carlo (RMC) refinement method. The real-space RMC configurations obtained are analyzed in terms of bond distance and bond-angle distributions, and a geometric algebra approach is used to quantify the associated octahedral-tilting distributions. What emerges from this analysis is that the transition is displacive in nature, in contrast to the results of a recent average-structure investigation in which an order-disorder model was proposed [E. H. Mountstevens et al., Phys. Rev. B 71, 220102(R) (2005)]. Three-dimensional diffuse scattering patterns calculated from the same RMC configurations reveal the existence of an additional disorder mechanism which persists across the Pnma-Imma transition. The ''reflection conditions'' of this diffuse scattering, together with displacement correlation calculations, point to the existence of ferroelectric nanoscale domains within the configurations, which are found to extend across planar regions of approximately 10-15 A ring in diameter.

  3. SANS -Small Angle Neutron Scattering Tcnica de difrao

    E-Print Network [OSTI]

    Loh, Watson

    SANS - Small Angle Neutron Scattering Técnica de difração informações sobre tamanho e forma de- Neutrons are created in the centre of the target station when the beam of high energy protons collides by evaporating nuclear particles, mainly neutrons, in all directions. Each proton produces approximately 15

  4. Lujan Neutron Scattering Center (Lujan Center) | U.S. DOE Office...

    Office of Science (SC) Website

    Lujan Neutron Scattering Center (Lujan Center) Scientific User Facilities (SUF) Division SUF Home About User Facilities User Facilities Dev X-Ray Light Sources Neutron Scattering...

  5. Neutron Scattering Facilities | U.S. DOE Office of Science (SC...

    Office of Science (SC) Website

    Neutron Scattering Facilities Scientific User Facilities (SUF) Division SUF Home About User Facilities User Facilities Dev X-Ray Light Sources Neutron Scattering Facilities High...

  6. Quasielastic neutron scattering of -NH3 and -BH3 rotational dynamics...

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

    Quasielastic neutron scattering of -NH3 and -BH3 rotational dynamics in orthorhombic ammonia borane. Quasielastic neutron scattering of -NH3 and -BH3 rotational dynamics in...

  7. Investigating Neutron Polarizabilities through Compton Scattering on $^3He$

    E-Print Network [OSTI]

    Deepshikha Choudhury; Andreas Nogga; Daniel R. Phillips

    2007-06-11T23:59:59.000Z

    We examine manifestations of neutron electromagnetic polarizabilities in coherent Compton scattering from the Helium-3 nucleus. We calculate $\\gamma ^3He$ elastic scattering observables using chiral perturbation theory to next-to-leading order (${\\mathcal O}(e^2 Q)$). We find that the unpolarized differential cross section can be used to measure neutron electric and magnetic polarizabilities, while two double-polarization observables are sensitive to different linear combinations of the four neutron spin polarizabilities.

  8. Structural and magnetic properties of transition metal substituted BaFe{sub 2}As{sub 2} compounds studied by x-ray and neutron scattering

    SciTech Connect (OSTI)

    Kim, Min Gyu [Ames Laboratory

    2012-08-28T23:59:59.000Z

    The purpose of my dissertation is to understand the structural and magnetic properties of the newly discovered FeAs-based superconductors and the interconnection between superconductivity, antiferromagnetism, and structure. X-ray and neutron scattering techniques are powerful tools to directly observe the structure and magnetism in this system. I used both xray and neutron scattering techniques on di#11;erent transition substituted BaFe2As2 compounds in order to investigate the substitution dependence of structural and magnetic transitions and try to understand the connections between them.

  9. Dynamic neutron scattering on incoherent systems using efficient resonance spin flip techniques

    SciTech Connect (OSTI)

    Häussler, Wolfgang [Heinz Maier-Leibnitz Zentrum, Technische Universität München, D-85748 Garching, Germany and Physik-Department E21, Technische Universität München, D-85748 Garching (Germany); Kredler, Lukas [Physik-Department E21, Technische Universität München, D-85748 Garching (Germany)

    2014-05-15T23:59:59.000Z

    We have performed numerical ray-tracing Monte-Carlo-simulations of incoherent dynamic neutron scattering experiments. We intend to optimize the efficiency of incoherent measurements depending on the fraction of neutrons scattered without and with spin flip at the sample. In addition to conventional spin echo, we have numerically and experimentally studied oscillating intensity techniques. The results point out the advantages of these different spin echo variants and are an important prerequisite for neutron resonance spin echo instruments like RESEDA (FRM II, Munich), to choose the most efficient technique depending on the scattering vector range and the properties of the sample system under study.

  10. Quantum Monte Carlo calculations of neutron-alpha scattering

    E-Print Network [OSTI]

    Kenneth M. Nollett; Steven C. Pieper; R. B. Wiringa; J. Carlson; G. M. Hale

    2006-12-09T23:59:59.000Z

    We describe a new method to treat low-energy scattering problems in few-nucleon systems, and we apply it to the five-body case of neutron-alpha scattering. The method allows precise calculations of low-lying resonances and their widths. We find that a good three-nucleon interaction is crucial to obtain an accurate description of neutron-alpha scattering.

  11. Structural evolution across the insulator-metal transition in oxygen-deficient BaTiO3-? studied using neutron total scattering and Rietveld analysis

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

    Jeong, I.-K.; Lee, Seunghun; Jeong, Se-Young; Won, C. J.; Hur, N.; Llobet, A.

    2011-08-01T23:59:59.000Z

    Oxygen-deficient BaTiO3-? exhibits an insulator-metal transition with increasing ?. We performed neutron total scattering measurements to study structural evolution across an insulator-metal transition in BaTiO3-?. Despite its significant impact on resistivity, slight oxygen reduction (?=0.09) caused only a small disturbance on the local doublet splitting of Ti-O bond. This finding implies that local polarization is well preserved under marginal electric conduction. In the highly oxygen-deficient metallic state (?=0.25), however, doublet splitting of the Ti-O bond became smeared. The smearing of the local Ti-O doublet is complemented with long-range structural analysis and demonstrates that the metallic conduction in the highly oxygen-reducedmore »BaTiO3-? is due to the appearance of nonferroelectric cubic lattice.« less

  12. Structural evolution across the insulator-metal transition in oxygen-deficient BaTiO3-? studied using neutron total scattering and Rietveld analysis

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

    Jeong, I.-K.; Lee, Seunghun; Jeong, Se-Young; Won, C. J.; Hur, N.; Llobet, A.

    2011-08-01T23:59:59.000Z

    Oxygen-deficient BaTiO3-? exhibits an insulator-metal transition with increasing ?. We performed neutron total scattering measurements to study structural evolution across an insulator-metal transition in BaTiO3-?. Despite its significant impact on resistivity, slight oxygen reduction (?=0.09) caused only a small disturbance on the local doublet splitting of Ti-O bond. This finding implies that local polarization is well preserved under marginal electric conduction. In the highly oxygen-deficient metallic state (?=0.25), however, doublet splitting of the Ti-O bond became smeared. The smearing of the local Ti-O doublet is complemented with long-range structural analysis and demonstrates that the metallic conduction in the highly oxygen-reduced BaTiO3-? is due to the appearance of nonferroelectric cubic lattice.

  13. A high resolution neutron scattering study of Tb2Mo2O7: A geometrically frustrated and disorder-free spin glass

    SciTech Connect (OSTI)

    Ehlers, Georg [ORNL; Gardner, Jason [Indiana University; Qiu, Y. [National Institute of Standards and Technology (NIST); Rule, K [Helmholtz-Zentrum Berlin; Greedan, John E [McMaster University; Stewart, John Ross [ISIS Facility, Rutherford Appleton Laboratory; Fouquet, Peter [Institut Laue-Langevin (ILL); Cornelius, A. L. [University of Nevada, Las Vegas; Adriano, Cris [ORNL; Pagliuso, P G [Instituto de Fisica Gleb Wataghin, Unicamp, Brazil

    2010-01-01T23:59:59.000Z

    Neutron scattering, muon spin relaxation, and de susceptibility studies have been carried out on polycrystalline Tb{sub 2}Ti{sub 2}O{sub 7}, a pyrochlore antiferromagnet in which the Tb{sup 3+} moments reside on a network of corner-sharing tetrahedra. Unlike other geometrically frustrated systems, Tb{sub 2}Ti{sub 2}O{sub 7} remains paramagnetic down to {approx}0.07 K, rather than ordering into a conventional Neel or spin-glass-like state, despite the fact that short-range antiferromagnetic correlations (AFC) develop at {approx}50 K. At the first AFC wave vector, its low-lying, relatively flat magnetic excitation spectrum softens partially below 30 K.

  14. Liquid Argon Cryogenic Detector Calibration by Inelastic Scattering of Neutrons

    E-Print Network [OSTI]

    Sergey Polosatkin; Evgeny Grishnyaev; Alexander Dolgov

    2014-07-10T23:59:59.000Z

    A method for calibration of cryogenic liquid argon detector response to recoils with certain energy -8.2 keV - is proposed. The method utilizes a process of inelastic scattering of monoenergetic neutrons produced by fusion DD neutron generator. Features of kinematics of inelastic scattering cause sufficient (forty times) increase in count rate of useful events relative to traditional scheme exploited elastic scattering with the same recoil energy and compatible energy resolution. The benefits of the proposed scheme of calibration most well implemented with the use of tagged neutron generator as a neutron source that allows to eliminate background originated from casual coincidence of signals on cryogenic detector and additional detector of scattered neutrons.

  15. Determination of the effective parameters of proton-$^{3}$He scattering on the basis of the neutron-triton scattering data

    E-Print Network [OSTI]

    V. P. Levashev

    2008-12-22T23:59:59.000Z

    We have studied the relations between the neutron-triton scattering lengths and effective ranges and the corresponding quantities for the p --$^{3}$He scattering in the framework of the potential model with an effective nucleon-nucleus interaction in the form of a $\\delta $-shell potential. It is shown that the Coulomb renormalization of the pure nuclear scattering lengths does not change the relation well established for the n + $^{3}$H system between the lengths: $A^{1} scattering lengths which give preference to set I of the phase analysis performed by E.A. George et al. (2003), which corresponds to the inequality $A^{1}_{nc} scattering lengths.

  16. NEUTRONS AND 2 D ADSORBED PHASES. NEUTRON SCATTERING FROM 36ArAND 4HeFILMS

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    NEUTRONS AND 2 D ADSORBED PHASES. NEUTRON SCATTERING FROM 36ArAND 4HeFILMS K. CARNEIRO Physics. - The technique of neutron scattering is well established as a unique tool to investigate the details technique to physisorbed phases is quite natural. But on the other hand since neutron scattering, compared

  17. A neutron imaging device for sample alignment in a pulsed neutron scattering instrument

    SciTech Connect (OSTI)

    Grazzi, F.; Scherillo, A.; Zoppi, M. [Consiglio Nazionale delle Ricerche, Istituto dei Sistemi Complessi, via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy)

    2009-09-15T23:59:59.000Z

    A neutron-imaging device for alignment purposes has been tested on the INES beamline at ISIS, the pulsed neutron source of Rutherford Appleton Laboratory (U.K.). Its use, in conjunction with a set of movable jaws, turns out extremely useful for scattering application to complex samples where a precise and well-defined determination of the scattering volume is needed.

  18. A New Measurement of the 1S0 Neutron-Neutron Scattering Length using the Neutron-Proton Scattering Length as a Standard

    E-Print Network [OSTI]

    D. E. Gonzalez Trotter; F. Salinas; Q. Chen; A. S. Crowell; W. Gloeckle; C. R. Howell; C. D. Roper; D. Schmidt; I. Slaus; H. Tang; W. Tornow; R. L. Walter; H. Witala; Z. Zhou

    1999-08-11T23:59:59.000Z

    The present paper reports high-accuracy cross-section data for the 2H(n,nnp) reaction in the neutron-proton (np) and neutron-neutron (nn) final-state-interaction (FSI) regions at an incident mean neutron energy of 13.0 MeV. These data were analyzed with rigorous three-nucleon calculations to determine the 1S0 np and nn scattering lengths, a_np and a_nn. Our results are a_nn = -18.7 +/- 0.6 fm and a_np = -23.5 +/- 0.8 fm. Since our value for a_np obtained from neutron-deuteron (nd) breakup agrees with that from free np scattering, we conclude that our investigation of the nn FSI done simultaneously and under identical conditions gives the correct value for a_nn. Our value for a_nn is in agreement with that obtained in pion-deuteron capture measurements but disagrees with values obtained from earlier nd breakup studies.

  19. 11th LANSCE School on Neutron Scattering | FAQ's

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

    Frequently Asked Questions Who can apply? The LANSCE School on Neutron Scattering is intended primarily for graduate students & post-docs in the topical area of that year's school....

  20. Measurement of Leading Neutron Production in Deep-Inelastic Scattering at HERA

    E-Print Network [OSTI]

    H1 Collaboration

    2010-01-04T23:59:59.000Z

    The production of leading neutrons, where the neutron carries a large fraction x_L of the incoming proton's longitudinal momentum, is studied in deep-inelastic positron-proton scattering at HERA. The data were taken with the H1 detector in the years 2006 and 2007 and correspond to an integrated luminosity of 122 pb^{-1}. The semi-inclusive cross section is measured in the phase space defined by the photon virtuality 6 neutron transverse momentum p_T neutron structure function, F_2^{LN(3)}(Q^2,x,x_L), and the fraction of deep-inelastic scattering events containing a leading neutron are studied as a function of Q^2, x and x_L. Assuming that the pion exchange mechanism dominates leading neutron production, the data provide constraints on the shape of the pion structure function.

  1. Can one extract the pi-neutron scattering length from pi-deuteron scattering?

    E-Print Network [OSTI]

    A. Nogga; C. Hanhart

    2005-11-02T23:59:59.000Z

    We give a prove of evidence that the original power counting by Weinberg can be applied to estimate the contributions of the operators contributing to the pi-deuteron scattering length. As a consequence, pi-deuteron observables can be used to extract neutron amplitudes--in case of pi-deuteron scattering this means that the pi-neutron scattering length can be extracted with high accuracy. This result is at variance with recent claims. We discuss the origin of this difference.

  2. NEUTRON SPECTROSCOPY BY DOUBLE SCATTER AND ASSOCIATED PARTICLE TECHNIQUES.

    SciTech Connect (OSTI)

    DIOSZEGI,I.

    2007-10-28T23:59:59.000Z

    Multiple detectors can provide [1,2] both directional and spectroscopic information. Neutron spectra may be obtained by neutron double scatter (DSNS), or the spontaneous fission associated particle (AP) technique. Spontaneous fission results in the creation of fission fragments and the release of gamma rays and neutrons. As these occur at the same instant, they are correlated in time. Thus gamma ray detection can start a timing sequence relative to a neutron detector where the time difference is dominated by neutron time-of-flight. In this paper we describe these techniques and compare experimental results with Monte Carlo calculations.

  3. The structure of fillers, polymers and their interfaces in polymer composites using neutron scattering methods

    SciTech Connect (OSTI)

    Hjelm, R.P.

    1998-12-01T23:59:59.000Z

    The neutron scattering methods, small-angle neutron scattering and neutron reflectometry, provide information on the structure of polymer composite materials that is not available from other structural probes. The unique capabilities of these methods derive from three factors. First, the length scales probed correspond to polymer conformation, molecular and domain scales and to the characteristic sizes of many fillers. Second, neutrons are able to penetrate relatively thick samples, allowing bulk samples to be measured, and enabling buried interfaces to be studied. This characteristic also allows for the construction of special sample containment needed for studying materials under stress, extremes in pressure and temperature, etc. Third, neutrons readily distinguish between different light elements, and between different isotopes of the same element. The ability to distinguish between hydrogen and deuterium is particularly important in this regard. New ways of exploiting the capabilities of neutrons are opening up with the development of improved sources and instruments in the US and elsewhere. In this talk the author will discuss the basic concepts that give rise to the unique capabilities of neutron scattering, giving several examples of the uses of neutron scattering techniques in the study of polymer composites. The examples will include the morphology of fillers, polymer binders and matrices, interfaces and defect structures.

  4. Electron Scattering From High-Momentum Neutrons in Deuterium

    SciTech Connect (OSTI)

    A.V. Klimenko; S.E. Kuhn

    2005-10-12T23:59:59.000Z

    We report results from an experiment measuring the semi-inclusive reaction D(e,e'p{sub s}) where the proton p{sub s} is moving at a large angle relative to the momentum transfer. If we assume that the proton was a spectator to the reaction taking place on the neutron in deuterium, the initial state of that neutron can be inferred. This method, known as spectator tagging, can be used to study electron scattering from high-momentum (off-shell) neutrons in deuterium. The data were taken with a 5.765 GeV electron beam on a deuterium target in Jefferson Laboratory's Hall B, using the CLAS detector. A reduced cross section was extracted for different values of final-state missing mass W*, backward proton momentum {rvec p}{sub s} and momentum transfer Q{sup 2}. The data are compared to a simple PWIA spectator model. A strong enhancement in the data observed at transverse kinematics is not reproduced by the PWIA model. This enhancement can likely be associated with the contribution of final state interactions (FSI) that were not incorporated into the model. A ''bound neutron structure function'' F{sub 2n}{sup eff} was extracted as a function of W* and the scaling variable x* at extreme backward kinematics, where effects of FSI appear to be smaller. For p{sub s} > 400 MeV/c, where the neutron is far off-shell, the model overestimates the value of F{sub 2n}{sup eff} in the region of x* between 0.25 and 0.6. A modification of the bound neutron structure function is one of possible effects that can cause the observed deviation.

  5. Electron Scattering From High-Momentum Neutrons in Deuterium

    E-Print Network [OSTI]

    A. V. Klimenko; S. E. Kuhn; for the CLAS collaboration

    2005-10-12T23:59:59.000Z

    We report results from an experiment measuring the semi-inclusive reaction $d(e,e'p_s)$ where the proton $p_s$ is moving at a large angle relative to the momentum transfer. If we assume that the proton was a spectator to the reaction taking place on the neutron in deuterium, the initial state of that neutron can be inferred. This method, known as spectator tagging, can be used to study electron scattering from high-momentum (off-shell) neutrons in deuterium. The data were taken with a 5.765 GeV electron beam on a deuterium target in Jefferson Laboratory's Hall B, using the CLAS detector. A reduced cross section was extracted for different values of final-state missing mass $W^{*}$, backward proton momentum $\\vec{p}_{s}$ and momentum transfer $Q^{2}$. The data are compared to a simple PWIA spectator model. A strong enhancement in the data observed at transverse kinematics is not reproduced by the PWIA model. This enhancement can likely be associated with the contribution of final state interactions (FSI) that were not incorporated into the model. A ``bound neutron structure function'' $F_{2n}^{eff}$ was extracted as a function of $W^{*}$ and the scaling variable $x^{*}$ at extreme backward kinematics, where effects of FSI appear to be smaller. For $p_{s}>400$ MeV/c, where the neutron is far off-shell, the model overestimates the value of $F_{2n}^{eff}$ in the region of $x^{*}$ between 0.25 and 0.6. A modification of the bound neutron structure function is one of possible effects that can cause the observed deviation.

  6. Entangling neutrons via successive scattering from a substrate

    E-Print Network [OSTI]

    M. Avellino; S. Bose; A. J. Fisher

    2008-08-18T23:59:59.000Z

    This letter details a simple scheme to entangle two neutrons by successive scattering from a macroscopic sample. In zero magnetic field the entanglement falls as the sample size increases. However, by applying a field and tuning the momentum of the neutrons, one can achieve a substantial degree of entanglement irrespective of the size of the sample.

  7. Neutron-deuteron elastic scattering and three-nucleon force

    E-Print Network [OSTI]

    Chtangeev, Maxim B

    2005-01-01T23:59:59.000Z

    The differential cross section for neutron-deuteron elastic scattering was measured at six angles over the center-of-mass angular range 65? - 1300? and incident neutron energies 140 - 240 MeV at the LANSCE/WNR facility of ...

  8. FAST NEUTRON SOURCE DETECTION AT LONG DISTANCES USING DOUBLE SCATTER SPECTROMETRY.

    SciTech Connect (OSTI)

    FORMAN,L.VANIER,P.WELSH,K.

    2003-08-03T23:59:59.000Z

    Fast neutrons can be detected with relatively high efficiency, >15%, using two planes of hydrogenous scintillator detectors where a scatter in the first plane creates a start pulse and scatter in the second plane is separated by time-of-flight. Indeed, the neutron spectrum of the source can be determined as the sum of energy deposited by pulse height in the first added to the energy of the second found by time-of-flight to the second detector. Gamma rays can also create a double scatter by Compton interaction in the first with detection in the second, but these events occur in a single time window because the scattered photons all travel at the speed of light. Thus, gamma ray events can be separated from neutrons by the time-of-flight differences. We have studied this detection system with a Cf-252 source using Bicron 501A organic scintillators and report on the ability to efficiently detect fast neutrons with high neutron/gamma detection ratios. We have further studied cosmic-ray neutron background detection response that is the dominant background in long range detection. We have found that most of the neutrons are excluded from the time-of-flight window because they are either too high in energy, >10 keV, or too low, < 10 keV. Moreover, if the detection planes are position-sensitive, the angular direction of the source can be determined by the ratio of the energy of scattered protons in the first detector relative to the position and energy of the scattered neutron detected in the second. This ability to locate the source in theta is useful, but more importantly increases the signal to noise relative to cosmic-ray produced neutrons that are relatively isotropic. This technique may be used in large arrays to detect neutrons at ranges up to 0.5 kilometer.

  9. Bulk effects in the coherent inelastic scattering of ultracold neutrons

    E-Print Network [OSTI]

    A. L. Barabanov; S. T. Belyaev

    2005-09-20T23:59:59.000Z

    With the use of theory developed earlier, bulk effects in ultracold neutron coherent inelastic scattering are considered both for solid and liquid target samples related to energy and momentum exchange with phonon and diffusion-like modes. For the neutron in a material trap, differential and integral probabilities for the energy transfer per bounce are presented in a simple analytic form which exhibits the parameter dependence. As an example, the theoretical values for the ultracold neutron loss rate from a storage bottle with Fomblin coated walls and stainless steel walls are evaluated. Possible contribution from incoherent inelastic scattering on hydrogen contamination is discussed.

  10. Small-angle neutron scattering study of magnetic ordering and inhomogeneity across the martensitic phase transformation in Ni50–xCoxMn??Sn?? alloys

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

    Bhatti, Kanwal Preet; El-Khatib, S.; Srivastava, Vijay; James, R. D.; Leighton, C.

    2012-04-01T23:59:59.000Z

    The Heusler-derived multiferroic alloy Ni50–xCoxMn??Sn?? has recently been shown to exhibit, at just above room temperature, a highly reversible martensitic phase transformation with an unusually large magnetization change. In this work the nature of the magnetic ordering above and below this transformation has been studied in detail in the critical composition range x = 6–8 via temperature-dependent (5–600 K) magnetometry and small-angle neutron scattering (SANS). We observe fairly typical paramagnetic to long-range-ordered ferromagnetic phase transitions on cooling to 420–430 K, with the expected critical spin fluctuations, followed by first-order martensitic phase transformations to a nonferromagnetic state below 360–390 K. Themore »static magnetization reveals complex magnetism in this low-temperature nonferromagnetic phase, including a Langevin-like field dependence, distinct spin freezing near 60 K, and significant exchange bias effects, consistent with superparamagnetic blocking of ferromagnetic clusters of nanoscopic dimensions. We demonstrate that these spin clusters, whose existence has been hypothesized in a variety of martensitic alloys exhibiting competition between ferromagnetic and antiferromagnetic exchange interactions, can be directly observed by SANS. The scattering data are consistent with a liquidlike spatial distribution of interacting magnetic clusters with a mean center-to-center spacing of 12 nm. Considering the behavior of the superparmagnetism, cooling-field and temperature-dependent exchange bias, and magnetic SANS, we discuss in detail the physical form and origin of these spin clusters, their intercluster interactions, the nature of the ground-state magnetic ordering in the martensitic phase, and the implications for our understanding of such alloy systems.« less

  11. Small-angle neutron scattering study of magnetic ordering and inhomogeneity across the martensitic phase transformation in Ni50–xCoxMn??Sn?? alloys

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

    Bhatti, Kanwal Preet; El-Khatib, S.; Srivastava, Vijay; James, R. D.; Leighton, C.

    2012-04-01T23:59:59.000Z

    The Heusler-derived multiferroic alloy Ni50–xCoxMn??Sn?? has recently been shown to exhibit, at just above room temperature, a highly reversible martensitic phase transformation with an unusually large magnetization change. In this work the nature of the magnetic ordering above and below this transformation has been studied in detail in the critical composition range x = 6–8 via temperature-dependent (5–600 K) magnetometry and small-angle neutron scattering (SANS). We observe fairly typical paramagnetic to long-range-ordered ferromagnetic phase transitions on cooling to 420–430 K, with the expected critical spin fluctuations, followed by first-order martensitic phase transformations to a nonferromagnetic state below 360–390 K. The static magnetization reveals complex magnetism in this low-temperature nonferromagnetic phase, including a Langevin-like field dependence, distinct spin freezing near 60 K, and significant exchange bias effects, consistent with superparamagnetic blocking of ferromagnetic clusters of nanoscopic dimensions. We demonstrate that these spin clusters, whose existence has been hypothesized in a variety of martensitic alloys exhibiting competition between ferromagnetic and antiferromagnetic exchange interactions, can be directly observed by SANS. The scattering data are consistent with a liquidlike spatial distribution of interacting magnetic clusters with a mean center-to-center spacing of 12 nm. Considering the behavior of the superparmagnetism, cooling-field and temperature-dependent exchange bias, and magnetic SANS, we discuss in detail the physical form and origin of these spin clusters, their intercluster interactions, the nature of the ground-state magnetic ordering in the martensitic phase, and the implications for our understanding of such alloy systems.

  12. Realization of adiabatic Aharonov-Bohm scattering with neutrons

    E-Print Network [OSTI]

    Erik Sjöqvist; Martin Almquist; Ken Mattsson; Zeynep Nilhan Gürkan; Björn Hessmo

    2015-03-08T23:59:59.000Z

    The adiabatic Aharonov-Bohm (AB) effect is a manifestation of the Berry phase acquired when some slow variables take a planar spin around a loop. While the effect has been observed in molecular spectroscopy, direct measurement of the topological phase shift in a scattering experiment has been elusive in the past. Here, we demonstrate an adiabatic AB effect for neutrons that scatter on a long straight current-carrying wire. We propose an experiment to verify the effect and demonstrate its feasibility by explicit simulation of the dynamics of unpolarized very slow neutrons that scatter on the wire under realistic conditions.

  13. Data acquisition system for the neutron scattering instruments at the intense pulsed neutron source

    SciTech Connect (OSTI)

    Crawford, R.K.; Daly, R.T.; Haumann, J.R.; Hitterman, R.L.; Morgan, C.B.; Ostrowski, G.E.; Worlton, T.G.

    1981-01-01T23:59:59.000Z

    The Intense Pulsed Neutron Source (IPNS) at Argonne National Laboratory is a major new user-oriented facility which is now coming on line for basic research in neutron scattering and neutron radiation damage. This paper describes the data-acquisition system which will handle data acquisition and instrument control for the time-of-flight neutron-scattering instruments at IPNS. This discussion covers the scientific and operational requirements for this system, and the system architecture that was chosen to satisfy these requirements. It also provides an overview of the current system implementation including brief descriptions of the hardware and software which have been developed.

  14. Lipid Bilayer Structure Determined by the Simultaneous Analysis of Neutron and X-Ray Scattering Data

    E-Print Network [OSTI]

    Nagle, John F.

    Lipid Bilayer Structure Determined by the Simultaneous Analysis of Neutron and X-Ray Scattering) and dipalmitoylphosphatidylcholine (DPPC) bilayers by simultaneously analyzing x-ray and neutron scattering data. The neutron data electron and neutron scattering density profiles. A key result of the analysis is the molecular surface

  15. Instrumentation for Neutron Scattering at the Missouri University Research Reactor Paul F. Miceli

    E-Print Network [OSTI]

    Montfrooij, Wouter

    Instrumentation for Neutron Scattering at the Missouri University Research Reactor Paul F. Miceli Research Reactor (MURR) provides significant thermal neutron flux, which enables neutron scattering]. There are presently 5 instruments located on the beam port floor that are dedicated to neutron scattering: (1) TRIAX

  16. 2010 American Conference on Neutron Scattering (ACNS 2010)

    SciTech Connect (OSTI)

    Billinge, Simon

    2011-06-17T23:59:59.000Z

    The ACNS provides a focal point for the national neutron user community to strengthen ties within this diverse group, while at the same time promoting neutron research among colleagues in related disciplines identified as “would-be” neutron users. The American Conference on Neutron Scattering thus serves a dual role as a national user meeting and a scientific meeting. As a venue for scientific exchange, the ACNS showcases recent results and provides forums for scientific discussion of neutron research in diverse fields such as hard and soft condensed matter, liquids, biology, magnetism, engineering materials, chemical spectroscopy, crystal structure, and elementary excitations, fundamental physics and development of neutron instrumentation through a combination of invited talks, contributed talks and poster sessions. As a “super-user” meeting, the ACNS fulfills the main objectives of users' meetings previously held periodically at individual national neutron facilities, with the advantage of a larger and more diverse audience. To this end, each of the major national neutron facilities (NIST, LANSCE, HFIR and SNS) have an opportunity to exchange information and update users, and potential users, of their facility. This is also an appropriate forum for users to raise issues that relate to the facilities. For many of the national facilities, this super-user meeting should obviate the need for separate user meetings that tax the time, energy and budgets of facility staff and the users alike, at least in years when the ACNS is held. We rely upon strong participation from the national facilities. The NSSA intends that the American Conference on Neutron Scattering (ACNS) will occur approximately every two years, but not in years that coincide with the International or European Conferences on Neutron Scattering. The ACNS is to be held in association with one of the national neutron centers in a rotating sequence, with the host facility providing local organization and planning assistance. Additional logistical support is being provided this year through a partnership with the conferencing office of the Materials Research Society (MRS). The ACNS, targeting the entire potential neutron North American user community, complements the annual NIST, ANL and LANSCE neutron and scattering schools which give hands-on experience primarily to graduate students who anticipate using neutron scattering in their thesis research. The summer schools are promoted at the ACNS and represent a natural path for students to take after being inspired by the activities of the ACNS.

  17. Test of the consistency of various linearized semiclassical initial value time correlation functions in application to inelastic neutron scattering from liquid para-hydrogen

    E-Print Network [OSTI]

    Liu, Jian

    2008-01-01T23:59:59.000Z

    Theory of Thermal Neutron Scattering. (Dover Publications,S. W. Lovesey, Theory of Neutron Scattering from Condensedwith the inelastic neutron scattering experiment results.

  18. Leading neutron energy and pT distributions in deep inelastic scattering and photoproduction at HERA

    E-Print Network [OSTI]

    ZEUS Collaboration; S. Chekanov

    2007-03-09T23:59:59.000Z

    The production of energetic neutrons in $ep$ collisions has been studied with the ZEUS detector at HERA. The neutron energy and $p_T^2$ distributions were measured with a forward neutron calorimeter and tracker in a $40 \\pb^{-1}$ sample of inclusive deep inelastic scattering (DIS) data and a $6 \\pb^{-1}$ sample of photoproduction data. The neutron yield in photoproduction is suppressed relative to DIS for the lower neutron energies and the neutrons have a steeper $p_T^2$ distribution, consistent with the expectation from absorption models. The distributions are compared to HERA measurements of leading protons. The neutron energy and transverse-momentum distributions in DIS are compared to Monte Carlo simulations and to the predictions of particle exchange models. Models of pion exchange incorporating absorption and additional secondary meson exchanges give a good description of the data.

  19. Quasi-Differential Neutron Scattering in Zirconium from 0.5 to 20 MeV

    E-Print Network [OSTI]

    Danon, Yaron

    Quasi-Differential Neutron Scattering in Zirconium from 0.5 to 20 MeV D. P. Barry,* G. Leinweber, R-3590 Received January 10, 2012 Accepted August 10, 2012 Abstract ­ High-energy-neutron-scattering experiments of the neu- tron scattering cross sections for zirconium. The neutron differential scattering cross

  20. hal-00154048,version1-12Jun2007 The new very small angle neutron scattering

    E-Print Network [OSTI]

    Boyer, Edmond

    hal-00154048,version1-12Jun2007 The new very small angle neutron scattering spectrometer The design and characteristics of the new very small angle neutron scattering spectrometer under construction in order to fill the gap between light scattering and classical small angle neutron scattering (SANS

  1. MAGNETIC NEUTRON SCATTERING. And Recent Developments in the Triple Axis Spectroscopy

    E-Print Network [OSTI]

    Johnson, Peter D.

    Chapter 1 MAGNETIC NEUTRON SCATTERING. And Recent Developments in the Triple Axis Spectroscopy Igor.................................................................................... 2 2. Neutron interaction with matter and scattering cross-section ........ 6 2.1 Basic scattering theory and differential cross-section................ 7 2.2 Neutron interactions and scattering lengths

  2. New measurement of the scattering cross section of slow neutrons on liquid parahydrogen from neutron transmission

    E-Print Network [OSTI]

    K. B. Grammer; R. Alarcon; L. Barrón-Palos; D. Blyth; J. D. Bowman; J. Calarco; C. Crawford; K. Craycraft; D. Evans; N. Fomin; J. Fry; M. Gericke; R. C. Gillis; G. L. Greene; J. Hamblen; C. Hayes; S. Kucuker; R. Mahurin; M. Maldonado-Velázquez; E. Martin; M. McCrea; P. E. Mueller; M. Musgrave; H. Nann; S. I. Penttilä; W. M. Snow; Z. Tang; W. S. Wilburn

    2014-12-12T23:59:59.000Z

    Slow neutron scattering provides quantitative information on the structure and dynamics of materials of interest in physics, chemistry, materials science, biology, geology, and other fields. Liquid hydrogen is a widely-used neutron moderator medium, and an accurate knowledge of its slow neutron cross section is essential for the design and optimization of intense slow neutron sources. In particular the rapid drop of the slow neutron scattering cross section of liquid parahydrogen below 14.5~meV is especially interesting and important. We have measured the total cross section and the scattering cross section for slow neutrons with energies between 0.43~meV and 16.1~meV on liquid hydrogen at 15.6~K using neutron transmission measurements on the hydrogen target of the NPDGamma collaboration at the Spallation Neutron Source at Oak Ridge National Laboratory. At 1~meV this measurement is a factor of 3 below the data from previous work which has been used in the design of liquid hydrogen moderators at slow neutron sources. We describe our measurements, compare them with previous work, and discuss the implications for designing more intense slow neutron sources.

  3. 11th LANSCE School on Neutron Scattering | Hands-On Experiments

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

    of various exemplary neutron experiments in the areas of materials at the mesoscale. They will use several instruments utlizing different neutron scattering and...

  4. The Algebraic Approach to the Phase Problem for Neutron Scattering

    E-Print Network [OSTI]

    A. Cervellino; S. Ciccariello

    2004-01-27T23:59:59.000Z

    The algebraic approach to the phase problem for the case of X-ray scattering from an ideal crystal is extended to the case of the neutron scattering, overcoming the difficulty related to the non-positivity of the scattering density. In this way, it is proven that the atomicity is the crucial assumption while the positiveness of the scattering density only affects the method for searching the basic sets of reflections. We also report the algebraic expression of the determinants of the Karle-Hauptman matrices generated by the basic sets with the most elongated shape along one of the reciprocal crystallographic axes.

  5. Analysis of neutron scattering data: Visualization and parameter estimation

    SciTech Connect (OSTI)

    Beauchamp, J.J.; Fedorov, V.; Hamilton, W.A.; Yethiraj, M.

    1998-09-01T23:59:59.000Z

    Traditionally, small-angle neutron and x-ray scattering (SANS and SAXS) data analysis requires measurements of the signal and corrections due to the empty sample container, detector efficiency and time-dependent background. These corrections are then made on a pixel-by-pixel basis and estimates of relevant parameters (e.g., the radius of gyration) are made using the corrected data. This study was carried out in order to determine whether treatment of the detector efficiency and empty sample cell in a more statistically sound way would significantly reduce the uncertainties in the parameter estimators. Elements of experiment design are shortly discussed in this paper. For instance, we studied the way the time for a measurement should be optimally divided between the counting for signal, background and detector efficiency. In Section 2 we introduce the commonly accepted models for small-angle neutron and x-scattering and confine ourselves to the Guinier and Rayleigh models and their minor generalizations. The traditional approaches of data analysis are discussed only to the extent necessary to allow their comparison with the proposed techniques. Section 3 describes the main stages of the proposed method: visual data exploration, fitting the detector sensitivity function, and fitting a compound model. This model includes three additive terms describing scattering by the sampler, scattering with an empty container and a background noise. We compare a few alternatives for the first term by applying various scatter plots and computing sums of standardized squared residuals. Possible corrections due to smearing effects and randomness of estimated parameters are also shortly discussed. In Section 4 the robustness of the estimators with respect to low and upper bounds imposed on the momentum value is discussed. We show that for the available data set the most accurate and stable estimates are generated by models containing double terms either of Guinier's or Rayleigh's type. The optimal partitioning of the total experimental time between measuring various signals is discussed in Section 5. We applied a straightforward optimization instead of some special experimental techniques because of the numerical simplicity of the corresponding problem. As a criterion of optimality we selected the variance of the gyration radius maximum likelihood estimator. The statistical background of the proposed approach is given in the appendix. The properties of the maximum likelihood estimators and the corresponding iterated estimator together with its possible numerical realization are presented in subsection A.1. In subsection A.2 we prove that the use of a compound model leads to more efficient estimators than a stage-wise analysis of different components entering that model.

  6. Constraints on new interactions from neutron scattering experiments

    E-Print Network [OSTI]

    Yu. N. Pokotilovski

    2006-01-19T23:59:59.000Z

    Constraints for the constants of hypothetical Yukawa-type corrections to the Newtonian gravitational potential are obtained from analysis of neutron scattering experiments. Restrictions are obtained for the interaction range between 10^{-12} and 10^{-7} cm, where Casimir force experiments and atomic force microscopy are not sensitive. Experimental limits are obtained also for non-electromagnetic inverse power law neutron-nucleus potential. Some possibilities are discussed to strengthen these constraints.

  7. Improved di-neutron cluster model for 6He scattering

    E-Print Network [OSTI]

    A. M. Moro; K. Rusek; J. M. Arias; J. Gomez-Camacho; M. Rodriguez-Gallardo

    2007-03-01T23:59:59.000Z

    The structure of the three-body Borromean nucleus 6He is approximated by a two-body di-neutron cluster model. The binding energy of the 2n-\\alpha system is determined to obtain a correct description of the 2n-\\alpha coordinate, as given by a realistic three-body model calculation. The model is applied to describe the break-up effects in elastic scattering of 6He on several targets, for which experimental data exist. We show that an adequate description of the di-neutron-core degree of freedom permits a fairly accurate description of the elastic scattering of 6He on different targets.

  8. SciTech Connect: Neutron Scattering of CeNi at the SNS-ORNL:...

    Office of Scientific and Technical Information (OSTI)

    Conference: Neutron Scattering of CeNi at the SNS-ORNL: A Preliminary Report Citation Details In-Document Search Title: Neutron Scattering of CeNi at the SNS-ORNL: A Preliminary...

  9. Scattered Neutron Tomography Based on A Neutron Transport Inverse Problem

    SciTech Connect (OSTI)

    William Charlton

    2007-07-01T23:59:59.000Z

    Neutron radiography and computed tomography are commonly used techniques to non-destructively examine materials. Tomography refers to the cross-sectional imaging of an object from either transmission or reflection data collected by illuminating the object from many different directions.

  10. Neutron scattering of CeNi at the SNS-ORNL: A preliminary report

    SciTech Connect (OSTI)

    Mirmelstein, A. [Russian Federal Nuclear Center VNIITF, Snezhinsk, Russia; Podlesnyak, Andrey A [ORNL; Kolesnikov, Alexander I [ORNL; Saporov, B. [Oak Ridge National Laboratory (ORNL); Sefat, A.S. [Oak Ridge National Laboratory (ORNL); Tobin, J. G. [Lawrence Livermore National Laboratory (LLNL)

    2014-01-01T23:59:59.000Z

    This is a preliminary report of a neutron scattering experiment used to investigate 4f electron behavior in Ce.

  11. A workshop on enhanced national capability for neutron scattering

    SciTech Connect (OSTI)

    Hurd, Alan J [Los Alamos National Laboratory; Rhyne, James J [Los Alamos National Laboratory; Lewis, Paul S [Los Alamos National Laboratory

    2009-01-01T23:59:59.000Z

    This two-day workshop will engage the international neutron scattering community to vet and improve the Lujan Center Strategic Plan 2007-2013 (SP07). Sponsored by the LANL SC Program Office and the University of California, the workshop will be hosted by LANSCE Professor Sunny Sinha (UCSD). Endorsement by the Spallation Neutron Source will be requested. The discussion will focus on the role that the Lujan Center will play in the national neutron scattering landscape assuming full utilization of beamlines, a refurbished LANSCE, and a 1.4-MW SNS. Because the Lujan Strategic Plan is intended to set the stage for the Signature Facility era at LANSCE, there will be some discussion of the long-pulse spallation source at Los Alamos. Breakout groups will cover several new instrument concepts, upgrades to present instruments, expanded sample environment capabilities, and a look to the future. The workshop is in keeping with a request by BES to update the Lujan strategic plan in coordination with the SNS and the broader neutron community. Workshop invitees will be drawn from the LANSCE User Group and a broad cross section of the US, European, and Pacific Rim neutron scattering research communities.

  12. alamos neutron scattering: Topics by E-print Network

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

    alamos neutron scattering First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Los Alamos National...

  13. Helium in confinement: the filling A Neutron Scattering investigation.

    E-Print Network [OSTI]

    Glyde, Henry R.

    Helium in confinement: the filling parameter. A Neutron Scattering investigation. Francesco Albergamo Institut Laue-Langevin, France Helium in confinement: the filling parameter. ­ p.1/13 #12;outline introduction and motivation Helium in confinement: the filling parameter. ­ p.2/13 #12;outline introduction

  14. Time Reversal Invariance Violation in Neutron Deuteron Scattering

    E-Print Network [OSTI]

    Young-Ho Song; Rimantas Lazauskas; Vladimir Gudkov

    2011-04-15T23:59:59.000Z

    Time reversal invariance violating (TRIV) effects for low energy elastic neutron deuteron scattering are calculated for meson exchange and EFT-type of TRIV potentials in a Distorted Wave Born Approximation, using realistic hadronic strong interaction wave functions, obtained by solving three-body Faddeev equations in configuration space. The relation between TRIV and parity violating observables are discussed.

  15. National School on Neutron and X-ray Scattering August 10-24, 2013

    E-Print Network [OSTI]

    Kemner, Ken

    National School on Neutron and X-ray Scattering August 10-24, 2013 Argonne National Laboratory National Laboratory 3:15 ­ 3:30 Break #12;National School on Neutron and X-ray Scattering August 10 Dinner Week 1 wrap-up Picnic #12;National School on Neutron and X-ray Scattering August 10-24, 2012 Oak

  16. Spin-dependent scattering and absorption of thermal neutrons on dynamically polarized nuclei

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    957 Spin-dependent scattering and absorption of thermal neutrons on dynamically polarized nuclei H neutrons and polarized nuclei have been used to measure spin-dependent scattering lengths and absorption cross sections of slow (S-wave) neutrons on nuclei. In order to obtain those scattering lengths

  17. SPIN-DEPENDENT SCATTERING LENGTHS OF SLOW NEUTRONS WITH NUCLEI BY PSEUDOMAGNETIC MEASUREMENTS

    E-Print Network [OSTI]

    Boyer, Edmond

    L-263 SPIN-DEPENDENT SCATTERING LENGTHS OF SLOW NEUTRONS WITH NUCLEI BY PSEUDOMAGNETIC MEASUREMENTS vu par les noyaux. Abstract. - The spin-dependent scattering length of slow neutrons by the nuclei 23 can be of practical importance in many thermal neutron scattering experiments. A new method, called

  18. Dynamics of Different Hydrogen Classes in -lactoglobulin: A Quasielastic Neutron Scattering Investigation

    E-Print Network [OSTI]

    Tuscia, Università Degli Studi Della

    Dynamics of Different Hydrogen Classes in -lactoglobulin: A Quasielastic Neutron Scattering investigated by means of quasielastic neutron scattering. To discriminate the possibly different dynamical- thods,11-13 molecular dynamics (MD) simulations,14 X-ray crys- tallography,15 and neutron scattering.6

  19. Neutron scattering evidence of a boson peak in protein hydration water Alessandro Paciaroni,1

    E-Print Network [OSTI]

    Tuscia, Università Degli Studi Della

    Neutron scattering evidence of a boson peak in protein hydration water Alessandro Paciaroni,1 Anna Viterbo, Italy Received 24 February 1999 Measurement of the low temperature neutron excess of scattering, has been detected by neutron scattering and Raman spectros- copy in a large variety of glassy systems

  20. Naysaying the Neutron Scattering Society Lawrence Cranberg, Jill Trewhella, and Henry R. Glyde

    E-Print Network [OSTI]

    Glyde, Henry R.

    Naysaying the Neutron Scattering Society Lawrence Cranberg, Jill Trewhella, and Henry R. Glyde, Austin Naysaying the Neutron Scattering Society The news story announcing the estab- lishment of the Neutron Scattering Society of America (June, page 73) raises a number of questions, and further

  1. Small angle neutron scattering on periodically deformed polymers A. R. Rennie

    E-Print Network [OSTI]

    Boyer, Edmond

    765 Small angle neutron scattering on periodically deformed polymers A. R. Rennie Institut für Phys-768 SEPTEMBRE 1984, 1. Introduction. Neutron scattering has proved a useful tool for the investigation of a wide time for a small angle neutron scattering spectrum is several minutes. Obser- vation on rapidly

  2. THE JOURNAL OF CHEMICAL PHYSICS 139, 175101 (2013) Dynamic neutron scattering from conformational dynamics. I. Theory

    E-Print Network [OSTI]

    2013-01-01T23:59:59.000Z

    #12;THE JOURNAL OF CHEMICAL PHYSICS 139, 175101 (2013) Dynamic neutron scattering from, a conformational dynamics theory of dynamical neutron and X-ray scattering is developed, follow- ing our previous spectroscopy (dynamic neutron scattering) probes time correlations on the sub pico- to microsec- ond timescales

  3. PHYSICAL REVIEW B VOLUME 25, NUMBER 7 Neutron scattering from paramagnetic bcc 'He

    E-Print Network [OSTI]

    Glyde, Henry R.

    PHYSICAL REVIEW B VOLUME 25, NUMBER 7 Neutron scattering from paramagnetic bcc 'He 1 APRIL 1982 H is calculated using the self-consistent-phonon (SCP) theory for comparison with proposed neutron scattering excitations or critical scattering will be observable only at very small neutron energy transfers (-0.1 pev

  4. The Neutron Scattering Society of America http:///www.neutronscattering.org

    E-Print Network [OSTI]

    The Neutron Scattering Society of America http:///www.neutronscattering.org Page 8 of 9 Dr. Claire of the Neutron Scattering Society of America (NSSA) with the citation "For pioneering a new methodology and computational chemistry" The Neutron Scattering Society of America (NSSA) established the Prize for Outstanding

  5. High temperature furnaces for small and large angle neutron scattering of disordered materials

    E-Print Network [OSTI]

    Boyer, Edmond

    725 High temperature furnaces for small and large angle neutron scattering of disordered materials and small angle neutron scattering (SANS) experiments respectively. They are vacuum furnaces with a thin maintained in a tantalum box. In a neutron beam, the furnaces produce a very low scattering level (without

  6. ELSEVIER Physica B 213&214 11995J454 458 Neutron scattering from liquid 3He

    E-Print Network [OSTI]

    Glyde, Henry R.

    ELSEVIER Physica B 213&214 11995J454 458 HIYSICA[ Neutron scattering from liquid 3He at large Abstract Neutron inelastic scattering measurements have been made on liquid 3He at 1,4 K for wave vectors to investigate the neutron inelastic scattering from liquid 3He at T = 1.4 K for wave vec- tors between 9 and 20

  7. INELASTIC NEUTRON SCATTERING SELECTION RULES OF 03B1 HgI2 M. SIESKIND

    E-Print Network [OSTI]

    Boyer, Edmond

    899 INELASTIC NEUTRON SCATTERING SELECTION RULES OF 03B1 HgI2 M. SIESKIND Laboratoire de The inelastic neutron scattering selection rules of 03B1 HgI2 in the directions 0394, 03A3 and 039B are derived Abstracts 63.20D Introduction. - Inelastic neutron scattering is a powerful technique for the determination

  8. 2015 LaCNS Neutron Scattering Seed Funding Request for White Papers

    E-Print Network [OSTI]

    pg. 1 2015 LaCNS Neutron Scattering Seed Funding Request for White Papers DEADLINE: January 12, 2015 The Louisiana Consortium for Neutron Scattering (LaCNS), a Department of Energy ­ EPSCo projects involving neutron scattering. These projects can be in any area of Materials Science

  9. ads neutronics study: Topics by E-print Network

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

    radii of elements of relevance to atomic parity-violating expe... Todd, B G 2003-01-01 5 Neutron Scattering Studies of Correlated Electron Systems Materials Science Websites...

  10. Anisotropic Elastic Resonance Scattering model for the Neutron Transport equation

    SciTech Connect (OSTI)

    Mohamed Ouisloumen; Abderrafi M. Ougouag; Shadi Z. Ghrayeb

    2014-11-24T23:59:59.000Z

    The resonance scattering transfer cross-section has been reformulated to account for anisotropic scattering in the center-of-mass of the neutron-nucleus system. The main innovation over previous implementations is the relaxation of the ubiquitous assumption of isotropic scattering in the center-of-mass and the actual effective use of scattering angle distributions from evaluated nuclear data files in the computation of the angular moments of the resonant scattering kernels. The formulas for the high order anisotropic moments in the laboratory system are also derived. A multi-group numerical formulation is derived and implemented into a module incorporated within the NJOY nuclear data processing code. An ultra-fine energy mesh cross section library was generated using these new theoretical models and then was used for fuel assembly calculations with the PARAGON lattice physics code. The results obtained indicate a strong effect of this new model on reactivity, multi-group fluxes and isotopic inventory during depletion.

  11. Neutrino Scattering in a Newly Born Neutron Star

    E-Print Network [OSTI]

    Sanjay Reddy; Madappa Prakash

    1996-10-16T23:59:59.000Z

    We calculate neutrino cross sections from neutral current reactions in the dense matter encountered in the evolution of a newly born neutron star. Effects of composition and of strong interactions in the deleptonization and cooling phases of the evolution are studied. The influence of the possible presence of strangeness-rich hyperons on the neutrino scattering cross sections is explored. Due to the large vector couplings of the Sigma-minus and Cascade-minus, |C_V|~2, these particles, if present in protoneutron star matter, give significant contributions to neutrino scattering. In the deleptonization phase, the presence of strangeness leads to large neutrino energies, which results in large enhancements in the cross sections compared to those in matter with nucleons only. In the cooling phase, in which matter is nearly neutrino free, the response of the Sigma-minus hyperons to thermal neutrinos is the most significant. Neutrinos couple relatively weakly to the Lambda hyperons and, hence, their contributions are significant only at high density.

  12. Dynamic behavior of hydration water in calcium-silicate-hydrate gel: A quasielastic neutron scattering spectroscopy investigation

    E-Print Network [OSTI]

    Li, Hua

    The translational dynamics of hydration water confined in calcium-silicate-hydrate (C-S-H) gel was studied by quasielastic neutron scattering spectroscopy in the temperature range from 280 to 230 K. The stretch exponent ...

  13. Optimizing Neutron Thermal Scattering Effects in very High Temperature Reactors

    SciTech Connect (OSTI)

    Hawari, Ayman; Ougouag, Abderrafi

    2014-07-08T23:59:59.000Z

    This project aims to develop a holistic understanding of the phenomenon of neutron thermalization in the VHTR. Neutron thermaliation is dependent on the type and structure of the moderating material. The fact that the moderator (and reflector) in the VHTR is a solid material will introduce new and interesting considerations that do not apply in other (e.g. light water) reactors. The moderator structure is expected to undergo radiation induced changes as the irradiation (or burnup) history progresses. In this case, the induced changes in structure will have a direct impact on many properties including the neutronic behavior. This can be easily anticipated if one recognizes the dependence of neutron thermalization on the scattering law of the moderator. For the pebble bed reactor, it is anticipated that the moderating behavior can be tailored, e.g. using moderators that consist of composite materials, which could allow improved optimization of the moderator-to-fuel ratio.

  14. Level crossings and zero-field splitting in the {Cr8}-cubane spin-cluster studied using inelastic neutron scattering and magnetization

    SciTech Connect (OSTI)

    Vaknin, D. [Ames Laboratory; Garlea, Vasile O [ORNL; Demmel, F. [ISIS Facility, Rutherford Appleton Laboratory; Mamontov, Eugene [ORNL; Nojiri, H [Institute for Materials Research, Tohoku University, Sendai, Japan; Martin, Catalin [Florida State University; Chiorescu, Irinel [Florida State University; Qiu, Y. [National Institute of Standards and Technology (NIST); Luban, M. [Ames Laboratory; Kogerler, P. [Ames Laboratory; Fielden, J. [Ames Laboratory; Engelhardt, L [Francis Marion University, Florence, South Sarolina; Rainey, C [Francis Marion University, Florence, South Sarolina

    2010-01-01T23:59:59.000Z

    Inelastic neutron scattering (INS) in variable magnetic field and high-field magnetization measurements in the millikelvin temperature range were performed to gain insight into the low-energy magnetic excitation spectrum and the field-induced level crossings in the molecular spin cluster {Cr8}-cubane. These complementary techniques provide consistent estimates of the lowest level-crossing field. The overall features of the experimental data are explained using an isotropic Heisenberg model, based on three distinct exchange interactions linking the eight CrIII paramagnetic centers (spins s = 3/2), that is supplemented with a relatively large molecular magnetic anisotropy term for the lowest S = 1 multiplet. It is noted that the existence of the anisotropy is clearly evident from the magnetic field dependence of the excitations in the INS measurements, while the magnetization measurements are not sensitive to its effects.

  15. 2009 International Conference on Neutron Scattering (ICNS 2009)

    SciTech Connect (OSTI)

    Gopal Rao, PhD; Donna Gillespie

    2010-08-05T23:59:59.000Z

    The ICNS provides a focal point for the worldwide neutron user community to strengthen ties within this diverse group, while at the same time promoting neutron research among colleagues in related disciplines identified as �¢����would-be�¢��� neutron users. The International Conference on Neutron Scattering thus serves a dual role as an international user meeting and a scientific meeting. As a venue for scientific exchange, the ICNS showcases recent results and provides forums for scientific discussion of neutron research in diverse fields such as hard and soft condensed matter, liquids, biology, magnetism, engineering materials, chemical spectroscopy, crystal structure, and elementary excitations, fundamental physics and development of neutron instrumentation through a combination of invited talks, contributed talks and poster sessions. Each of the major national neutron facilities (NIST, LANSCE, ANL, HFIR and SNS), along with their international counterparts, has an opportunity to exchange information with each other and to update users, and potential users, of their facility. This is also an appropriate forum for users to raise issues that relate to the facilities.

  16. RECENT MAGNETIC STRUCTURE STUDIES BY NEUTRON DIFFRACTION(1) By C. G. SHULL,

    E-Print Network [OSTI]

    Boyer, Edmond

    classification by neutron scattering include the determination of the magnitude and quality of an atom of this moment as represented in the form factor for neutron scattering. Within the second classification169 RECENT MAGNETIC STRUCTURE STUDIES BY NEUTRON DIFFRACTION(1) By C. G. SHULL, Massachusetts

  17. A neutron diffraction study of macroscopically entangled proton states in the high temperature

    E-Print Network [OSTI]

    be represented by a state vector. Raman spectroscopy and quasi-elastic neutron scattering suggest that the |C2/m with solid-state NMR and quasi-elastic neutron scattering (QENS) [1]. Semiclassical protons are dimensionlessA neutron diffraction study of macroscopically entangled proton states in the high temperature

  18. Thermal up-scattering of very cold and ultra-cold neutrons in solid deuterium

    E-Print Network [OSTI]

    Kasprzak, M

    2004-01-01T23:59:59.000Z

    The work presented in this thesis forms part of a program at the Paul Scherrer Institute (PSI) to construct a high intensity superthermal ultra-cold neutron (UCN) source based on solid deuterium as UCN production medium. We carried out a set of experiments to gain a better understanding of the properties and the behaviour of solid deuterium as a cold neutron moderator and ultra-cold neutron converter. We present the measurements of the total neutron cross section as obtained by transmission studies with very cold neutrons and ultra-cold neutrons in solid deuterium. The experimental set-up and the methods of data analysis are described and also the procedure of preparing the solid deuterium samples is given. The neutron transmission studies are supported by optical investigation of the crystal and by Raman spectroscopy. We have thus characterised the temperature dependence of the neutron transmission through solid deuterium and we have been able to identify the role that coherent neutron scattering plays for t...

  19. Thermal up-scattering of very cold and ultra-cold neutrons in solid deuterium

    E-Print Network [OSTI]

    Malgorzata Kasprzak

    2004-07-26T23:59:59.000Z

    The work presented in this thesis forms part of a program at the Paul Scherrer Institute (PSI) to construct a high intensity superthermal ultra-cold neutron (UCN) source based on solid deuterium as UCN production medium. We carried out a set of experiments to gain a better understanding of the properties and the behaviour of solid deuterium as a cold neutron moderator and ultra-cold neutron converter. We present the measurements of the total neutron cross section as obtained by transmission studies with very cold neutrons and ultra-cold neutrons in solid deuterium. The experimental set-up and the methods of data analysis are described and also the procedure of preparing the solid deuterium samples is given. The neutron transmission studies are supported by optical investigation of the crystal and by Raman spectroscopy. We have thus characterised the temperature dependence of the neutron transmission through solid deuterium and we have been able to identify the role that coherent neutron scattering plays for the investigated deuterium samples.

  20. Neutron scattering study on cathode LiMn{sub 2}O{sub 4} and solid electrolyte 5(Li{sub 2}O)(P{sub 2}O{sub 5})

    SciTech Connect (OSTI)

    Kartini, E., E-mail: kartini@batan.go.id; Putra, Teguh P., E-mail: kartini@batan.go.id; Jahya, A. K., E-mail: kartini@batan.go.id; Insani, A., E-mail: kartini@batan.go.id [Technology Center for Nuclear Industry Materials, National Nuclear Energy Agency, Serpong 15314 (Indonesia); Adams, S. [Department of Materials Science and Engineering, National University of Singapore, Singapore-117576 (Singapore)

    2014-09-30T23:59:59.000Z

    Neutron scattering is very important technique in order to investigate the energy storage materials such as lithium-ion battery. The unique advantages, neutron can see the light atoms such as Hydrogen, Lithium, and Oxygen, where those elements are negligible by other corresponding X-ray method. On the other hand, the energy storage materials, such as lithium ion battery is very important for the application in the electric vehicles, electronic devices or home appliances. The battery contains electrodes (anode and cathode), and the electrolyte materials. There are many challenging to improve the existing lithium ion battery materials, in order to increase their life time, cyclic ability and also its stability. One of the most scientific challenging is to investigate the crystal structure of both electrode and electrolyte, such as cathodes LiCoO{sub 2}, LiMn{sub 2}O{sub 4} and LiFePO{sub 4}, and solid electrolyte Li{sub 3}PO{sub 4}. Since all those battery materials contain Lithium ions and Oxygen, the used of neutron scattering techniques to study their structure and related properties are very important and indispensable. This article will review some works of investigating electrodes and electrolytes, LiMn{sub 2}O{sub 4} and 5(Li{sub 2}O)(P{sub 2}O{sub 5}), by using a high resolution powder diffraction (HRPD) at the multipurpose research reactor, RSG-Sywabessy of the National Nuclear Energy Agency (BATAN), Indonesia.

  1. Neutron Scattering | U.S. DOE Office of Science (SC)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's Possible for Renewable Energy:Nanowire Solar541,9337, 2011 at3,Neutron Scattering TutorialsNeutron

  2. [49] INTERSUBUNIT MEASUREMENTS BY NEUTRON SCATTERING 629 ribosomal 30 S subparticle in its lateral view. The amount of the particles

    E-Print Network [OSTI]

    [49] INTERSUBUNIT MEASUREMENTS BY NEUTRON SCATTERING 629 ribosomal 30 S subparticle in its lateral Neutron Scattering By PETER B. MOOREand DONALDM. ENGELMAN Several years ago we suggested that neutron.28 " The scattering lengths are taken from G. E. Bacon, "Neutron Scattering." Oxford Univ. Press (Clarendon

  3. Causality bounds for neutron-proton scattering

    E-Print Network [OSTI]

    Serdar Elhatisari; Dean Lee

    2012-07-25T23:59:59.000Z

    We consider the constraints of causality and unitarity for the low-energy interactions of protons and neutrons. We derive a general theorem that non-vanishing partial-wave mixing cannot be reproduced with zero-range interactions without violating causality or unitarity. We define and calculate interaction length scales which we call the causal range and the Cauchy-Schwarz range for all spin channels up to J = 3. For some channels we find that these length scales are as large as 5 fm. We investigate the origin of these large lengths and discuss their significance for the choice of momentum cutoff scales in effective field theory and universality in many-body Fermi systems.

  4. Resonant Cyclotron Scattering and Comptonization in Neutron Star Magnetospheres

    E-Print Network [OSTI]

    Maxim Lyutikov; Fotis P. Gavriil

    2006-02-10T23:59:59.000Z

    Resonant cyclotron scattering of the surface radiation in the magnetospheres of neutron stars may considerably modify the emergent spectra and impede efforts to constraint neutron star properties. Resonant cyclotron scattering by a non-relativistic warm plasma in an inhomogeneous magnetic field has a number of unusual characteristics: (i) in the limit of high resonant optical depth, the cyclotron resonant layer is half opaque, in sharp contrast to the case of non-resonant scattering. (ii) The transmitted flux is on average Compton up-scattered by ~ $1+ 2 beta_T$, where $\\beta_T$ is the typical thermal velocity in units of the velocity of light; the reflected flux has on average the initial frequency. (iii) For both the transmitted and reflected fluxes the dispersion of intensity decreases with increasing optical depth. (iv) The emergent spectrum is appreciably non-Plankian while narrow spectral features produced at the surface may be erased. We derive semi-analytically modification of the surface Plankian emission due to multiple scattering between the resonant layers and apply the model to anomalous X-ray pulsar 1E 1048.1--5937. Our simple model fits just as well as the ``canonical'' magnetar spectra model of a blackbody plus power-law.

  5. Accurate Development of Thermal Neutron Scattering Cross Section Libraries

    SciTech Connect (OSTI)

    Hawari, Ayman; Dunn, Michael

    2014-06-10T23:59:59.000Z

    The objective of this project is to develop a holistic (fundamental and accurate) approach for generating thermal neutron scattering cross section libraries for a collection of important enutron moderators and reflectors. The primary components of this approach are the physcial accuracy and completeness of the generated data libraries. Consequently, for the first time, thermal neutron scattering cross section data libraries will be generated that are based on accurate theoretical models, that are carefully benchmarked against experimental and computational data, and that contain complete covariance information that can be used in propagating the data uncertainties through the various components of the nuclear design and execution process. To achieve this objective, computational and experimental investigations will be performed on a carefully selected subset of materials that play a key role in all stages of the nuclear fuel cycle.

  6. Previously, DC Magnets located at Neutron-Scattering Beamlines were commercially-manufactured superconducting magnets and limited to 17 T. A

    E-Print Network [OSTI]

    Weston, Ken

    Previously, DC Magnets located at Neutron-Scattering Beamlines were commercially, this was the first designed specifically for neutron scattering and the first to include resistive suitable for neutron scattering, diffraction and spectroscopy experiments with the neutron beam passing

  7. Neutron scattering-modern techniques and their scientific impact

    E-Print Network [OSTI]

    J W White; C G Windsor; J W White; C G Windsor

    The sustained interest in the neutron and its use as a probe of the structure and dynamics of condensed matter is examined against the background of neutron availabil-ity. An analysis is made of developments in neutron source brightness, instrument physics and experimental methodology which have been or are likely to be of outstand-ing value in physics, chemistry, biology and materials technology studies. The role of pulsed sources as the next step ahead in neutron source brightness, their need for extensive instrument development to realise this potential and their complementarity with steady-state reactors is analysed using newly available experimental results. This review was received in December 1983.

  8. New High Field Magnet for Neutron Scattering at Hahn-Meitner Institute

    E-Print Network [OSTI]

    M Steiner; D A Tennant; P Smeibidl

    Abstract. The Berlin Neutron Scattering Center BENSC at the Hahn-Meitner-Institute (HMI) is a user facility for the study of structure and dynamics of condensed matter with neutrons and synchrotron radiation with special emphasis on experiments under extreme conditions. Neutron scattering is uniquely suited to study magnetic properties on a microscopic length scale, because neutrons have comparable wavelengths and, due to their magnetic moment, they interact with the atomic magnetic moments. Magnetic interactions and magnetic phenomena depend on thermodynamic parameters like magnetic field, temperature and pressure. At HMI special efforts are being made to offer outstanding sample environments such as very low temperatures or high magnetic fields or combination of both. For the future a dedicated instrument for neutron scattering at extreme fields is under construction, the Extreme Environment Diffractometer ExED. For this instrument the existing superconducting magnets as well as a future hybrid system can be used. The highest fields, above 30 T will be produced by the planned series-connected hybrid magnet system, designed and constructed in collaboration with the National High Magnetic Field Laboratory, Tallahassee, FL. 1.

  9. Nucleon semimagic numbers and low-energy neutron scattering

    E-Print Network [OSTI]

    D. A. Zaikin; I. V. Surkova

    2010-04-09T23:59:59.000Z

    It is shown that experimental values of the cross sections of inelastic low-energy neutron scattering on even-even nuclei together with the description of these cross sections in the framework of the coupled channel optical model may be considered as a reliable method for finding nuclei with a semimagic number (or numbers) of nucleons. Some examples of the application of this method are considered.

  10. Scientific opportunities with advanced facilities for neutron scattering

    SciTech Connect (OSTI)

    Lander, G.H.; Emery, V.J. (eds.)

    1984-01-01T23:59:59.000Z

    The present report documents deliberations of a large group of experts in neutron scattering and fundamental physics on the need for new neutron sources of greater intensity and more sophisticated instrumentation than those currently available. An additional aspect of the Workshop was a comparison between steady-state (reactor) and pulsed (spallation) sources. The main conclusions were: (1) the case for a new higher flux neutron source is extremely strong and such a facility will lead to qualitatively new advances in condensed matter science and fundamental physics; (2) to a large extent the future needs of the scientific community could be met with either a 5 x 10/sup 15/ n cm/sup -2/s/sup -1/ steady state source or a 10/sup 17/ n cm/sup -2/s/sup -1/ peak flux spallation source; and (3) the findings of this Workshop are consistent with the recommendations of the Major Materials Facilities Committee.

  11. Novel Boron-10-based detectors for Neutron Scattering Science

    E-Print Network [OSTI]

    Piscitelli, Francesco

    2015-01-01T23:59:59.000Z

    Nowadays neutron scattering science is increasing its instrumental power. Most of the neutron sources in the world are pushing the development of their technologies to be more performing. The neutron scattering development is also pushed by the European Spallation Source (ESS) in Sweden, a neutron facility which has just started construction. Concerning small area detectors (1m^2), the 3He technology, which is today cutting edge, is reaching fundamental limits in its development. Counting rate capability, spatial resolution and cost-e?ectiveness, are only a few examples of the features that must be improved to ful?fill the new requirements. On the other hand, 3He technology could still satisfy the detector requirements for large area applications (50m^2), however, because of the present 3He shortage that the world is experiencing, this is not practical anymore. The recent detector advances (the Multi-Grid and the Multi-Blade prototypes) developed in the framework of the collaboration between the Institut Laue...

  12. Structure of K-doped polyacetylene and its variations with annealing, studied by neutron diffraction

    E-Print Network [OSTI]

    Boyer, Edmond

    complementary information to X-ray diffraction can be obtained with neutrons. In addition, neutron scatteringL-379 Structure of K-doped polyacetylene and its variations with annealing, studied by neutron~u le 9 janvier 1985, accepte le 21 fevrier 1985) Résumé. 2014 On a étudié par diffraction de neutrons

  13. National School on Neutron and X-ray Scattering June 14-28, 2014

    E-Print Network [OSTI]

    Kemner, Ken

    National School on Neutron and X-ray Scattering June 14-28, 2014 Argonne National Laboratory:00 Dinner Dinner Dinner Dinner Week 1 wrap-up Picnic #12;National School on Neutron and X-ray Scattering Restaurant 9:45 - 10:45 Lecture Interaction of X-rays and Neutrons with Matter Roger Pynn University

  14. Total cross section of neutron-proton scattering at low energies in quark-gluon model

    E-Print Network [OSTI]

    V. A. Abramovsky; N. V. Radchenko

    2011-07-30T23:59:59.000Z

    We show that analysis of nonrelativistic neutron-proton scattering in a framework of relativistic QCD based quark model can give important information about QCD vacuum structure. In this model we describe total cross section of neutron-proton scattering at kinetic energies of projectile neutron from 1 eV up to 1 MeV.

  15. Small angle neutron scattering from single-wall carbon nanotube suspensions: evidence for isolated

    E-Print Network [OSTI]

    Wang, Howard "Hao"

    Small angle neutron scattering from single-wall carbon nanotube suspensions: evidence for isolated online: Abstract We report small angle neutron scattering (SANS) from dilute suspensions of purified University, Houghton, MI 49931, USA e NIST Center for Neutron Research, National Institute of Standards

  16. American Conference on Neutron Scattering M4-C4 (5:15 pm)

    E-Print Network [OSTI]

    Danon, Yaron

    50 American Conference on Neutron Scattering M4-C4 (5:15 pm) aCORN: A New MeasurementBeamlineatSnS.Inthistalk,theprinciple oftheexperiment,andthestatusofongoingR&d willbereviewedanddiscussed. M4-C6 (5:45 pm) Neutron-proton Scattering of the Electron- antineutrino Correlation Coefficient in Neutron Decay M. Leuschner (Indiana University Cyclotron

  17. NEUTRON SCATTERING SHOWS THAT CYTOCHROME b5 PENETRATES DEEPLY INTO THE LIPID BILAYER

    E-Print Network [OSTI]

    NEUTRON SCATTERING SHOWS THAT CYTOCHROME b5 PENETRATES DEEPLY INTO THE LIPID BILAYER E. P. GOGOL to lipid vesicles using neutron small-angle scattering methods. To increase scat- tering contrast between of a highly deuterated phospholipid. Small-angle neutron diffraction patterns were collected in a series of H

  18. Small angle neutron scattering (SANS) under non-equilibrium conditions R. C. Oberthr

    E-Print Network [OSTI]

    Boyer, Edmond

    663 Small angle neutron scattering (SANS) under non-equilibrium conditions R. C. Oberthür Institut with the times obtained from quasi- elastic neutron and light scattering, which yield information about neutrons aux petits angles (DNPA) pour l'étude des systèmes hors d'équi- libre thermodynamique est

  19. Synaptic Arrangement of the Neuroligin/b-Neurexin ComplexRevealedbyX-RayandNeutronScattering

    E-Print Network [OSTI]

    Sandini, Giulio

    Structure Article Synaptic Arrangement of the Neuroligin/b-Neurexin ComplexRevealedbyX-RayandNeutronScattering away from the dimer in- terface. X-ray scattering and neutron contrast variation data show that two that associate with their presynaptic part- ners, the neurexins. Using small-angle X-ray scattering, we

  20. Solvent Entrainment in and Flocculation of Asphaltenic Aggregates Probed by Small-Angle Neutron Scattering

    E-Print Network [OSTI]

    Kilpatrick, Peter K.

    -Angle Neutron Scattering Keith L. Gawrys, George A. Blankenship, and Peter K. Kilpatrick* Department of ChemicalVed September 14, 2005. In Final Form: January 30, 2006 While small-angle neutron scattering (SANS) has proven to the scattering intensity curves were performed using the Guinier approximation, the Ornstein- Zernike (or Zimm

  1. A High Count Rate Neutron Beam Monitor for Neutron Scattering Facilities

    SciTech Connect (OSTI)

    Barnett, Amanda [University of Tennessee, Knoxville (UTK); Crow, Lowell [ORNL; Diawara, Yacouba [ORNL; Hayward, J P [University of Tennessee, Knoxville (UTK); Hayward, Jason P [ORNL; Menhard, Kocsis [European Synchrotron Radiation Facility (ESRF); Sedov, Vladislav N [ORNL; Funk, Loren L [ORNL

    2013-01-01T23:59:59.000Z

    Abstract Beam monitors are an important diagnostic tool in neutron science facilities. Present beam monitors use either ionization chambers in integration mode, which are slow and have no timing information, or pulse counters which can easily be saturated by high beam intensities. At high flux neutron scattering facilities, neutron beam monitors with very low intrinsic efficiency (10-5) are presently selected to keep the counting rate within a feasible range, even when a higher efficiency would improve the counting statistics and yield a better measurement of the incident beam. In this work, we report on a high count rate neutron beam monitor. This beam monitor offers good timing with an intrinsic efficiency of 10-3 and a counting rate capability of over 1,000,000 cps without saturation.

  2. New measurement of the scattering cross section of slow neutrons on liquid parahydrogen from neutron transmission

    E-Print Network [OSTI]

    K. B. Grammer; R. Alarcon; L. Barrón-Palos; D. Blyth; J. D. Bowman; J. Calarco; C. Crawford; K. Craycraft; D. Evans; N. Fomin; J. Fry; M. Gericke; R. C. Gillis; G. L. Greene; J. Hamblen; C. Hayes; S. Kucuker; R. Mahurin; M. Maldonado-Velázquez; E. Martin; M. McCrea; P. E. Mueller; M. Musgrave; H. Nann; S. I. Penttilä; W. M. Snow; Z. Tang; W. S. Wilburn

    2015-04-24T23:59:59.000Z

    Liquid hydrogen is a dense Bose fluid whose equilibrium properties are both calculable from first principles using various theoretical approaches and of interest for the understanding of a wide range of questions in many body physics. Unfortunately, the pair correlation function $g(r)$ inferred from neutron scattering measurements of the differential cross section $d\\sigma \\over d\\Omega$ from different measurements reported in the literature are inconsistent. We have measured the energy dependence of the total cross section and the scattering cross section for slow neutrons with energies between 0.43~meV and 16.1~meV on liquid hydrogen at 15.6~K (which is dominated by the parahydrogen component) using neutron transmission measurements on the hydrogen target of the NPDGamma collaboration at the Spallation Neutron Source at Oak Ridge National Laboratory. The relationship between the neutron transmission measurement we perform and the total cross section is unambiguous, and the energy range accesses length scales where the pair correlation function is rapidly varying. At 1~meV our measurement is a factor of 3 below the data from previous work. We present evidence that these previous measurements of the hydrogen cross section, which assumed that the equilibrium value for the ratio of orthohydrogen and parahydrogen has been reached in the target liquid, were in fact contaminated with an extra non-equilibrium component of orthohydrogen. Liquid parahydrogen is also a widely-used neutron moderator medium, and an accurate knowledge of its slow neutron cross section is essential for the design and optimization of intense slow neutron sources. We describe our measurements and compare them with previous work.

  3. Safety & Security Guidelines Annual U.S. National School on Neutron and X-ray Scattering

    E-Print Network [OSTI]

    Safety & Security Guidelines 15th Annual U.S. National School on Neutron and X-ray Scattering-574-4600. Neutron Sciences User Programs and Outreach Office Oak Ridge National Laboratory #12;

  4. Demonstration of a novel focusing small-angle neutron scattering instrument equipped with axisymmetric mirrors

    E-Print Network [OSTI]

    Liu, Dazhi

    Small-angle neutron scattering (SANS) is the most significant neutron technique in terms of impact on science and engineering. However, the basic design of SANS facilities has not changed since the technique’s inception ...

  5. The bound coherent neutron scattering length of the oxygen isotopes

    SciTech Connect (OSTI)

    Fischer, Henry E [Institut Laue-Langevin (ILL); Simonson, J Michael {Mike} [ORNL; Neuefeind, Joerg C [ORNL; Lemmel, Hartmut [Technical University Vienna; Rauch, Helmut [E141 Atominstitut der Österreichischen Universitäten,; Zeidler, Anita [University of Bath; Salmon, Phil [University of Bath

    2012-01-01T23:59:59.000Z

    The technique of neutron interferometry was used to measure the bound coherent neutron scattering length bcoh of the oxygen isotopes 17O and 18O. From the measured difference in optical path between two water samples, either H2 17O or H2 18O versus H2 natO, where nat denotes the natural isotopic composition, we obtain bcoh , 17O = 5.867(4) fm and bcoh , 18O = 6.009(5) fm, based on the accurately known value of bcoh , natO = 5.805(4) fm which is equal to bcoh , 16O within the experimental uncertainty. Our results for bcoh , 17O and bcoh , 18O differ appreciably from the standard tabulated values of 5.6(5) fm and 5.84(7) fm, respectively. In particular, our measured scattering length contrast of 0.204(3) fm between 18O and natO is nearly a factor of 6 greater than the tabulated value, which renders feasible neutron diffraction experiments using 18O isotope substitution and thereby offers new possibilites for measuring the partial structure factors of oxygen-containing compounds, such as water.

  6. Neutron-3H and Proton-3He Zero Energy Scattering

    E-Print Network [OSTI]

    M. Viviani; S. Rosati; A. Kievsky

    1998-07-23T23:59:59.000Z

    The Kohn variational principle and the (correlated) Hyperspherical Harmonics technique are applied to study the n-3H and p-3He scattering at zero energy. Predictions for the singlet and triplet scattering lengths are obtained for non-relativistic nuclear Hamiltonians including two- and three-body potentials. The calculated n-3H total cross section agrees well with the measured value, while some small discrepancy is found for the coherent scattering length. For the p-3He channel, the calculated scattering lengths are in reasonable agreement with the values extrapolated from the measurements made above 1 MeV.

  7. Precision Measurement of the n-3He Incoherent Scattering Length Using Neutron Interferometry

    E-Print Network [OSTI]

    M. G. Huber; M. Arif; T. C. Black; W. C. Chen; T. R. Gentile; D. S. Hussey; D. Pushin; F. E. Wietfeldt; L. Yang

    2009-05-12T23:59:59.000Z

    We report the first measurement of the low-energy neutron-$^3$He incoherent scattering length using neutron interferometry: $b_i' = (-2.512\\pm 0.012{statistical}\\pm0.014{systematic})$ fm. This is in good agreement with a recent calculation using the AV18+3N potential. The neutron-$^3$He scattering lengths are important for testing and developing nuclear potential models that include three nucleon forces, effective field theories for few-body nuclear systems, and neutron scattering measurements of quantum excitations in liquid helium. This work demonstrates the first use of a polarized nuclear target in a neutron interferometer.

  8. 11th LANSCE School on Neutron Scattering | Free-Day Excursion

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

    for Integrated Nanotechnologies Bandelier Cave dwelling at Bandelier National Monument... - Image courtesy of J. Rhyne (former LANSCE School on Neutron Scattering Co-Director)...

  9. Neutron Scattering Facilities | U.S. DOE Office of Science (SC...

    Office of Science (SC) Website

    Neutron Scattering Facilities User Facilities User Facilities Home User Facilities at a Glance All User Facilities ASCR User Facilities BES User Facilities X-Ray Light Sources...

  10. Lambda-Neutron Scattering Lengths from Radiative K-minus Capture

    E-Print Network [OSTI]

    W. R. Gibbs; S. A. Coon; H. K. Han; B. F. Gibson

    2000-01-02T23:59:59.000Z

    Radiative capture of the K-minus by the deuteron as a reaction for measurement of the Lambda-neutron scattering lengths. The use of spin information to separate the singlet and triplet scattering lengths is treated.

  11. Parallel Computational Modelling of Inelastic Neutron Scattering in Multi-node and Multi-core Architectures 

    E-Print Network [OSTI]

    Garba, M.T.; Gonzales-Velez, H.; Roach, D.L.

    2010-11-26T23:59:59.000Z

    This paper examines the initial parallel implementation of SCATTER, a computationally intensive inelastic neutron scattering routine with polycrystalline averaging capability, for the General Utility Lattice Program (GULP). Of particular importance...

  12. A system for differential neutron scattering experiments in the energy range from 0.5 to 20 MeV

    E-Print Network [OSTI]

    Danon, Yaron

    A system for differential neutron scattering experiments in the energy range from 0.5 to 20 MeV F 2010 Accepted 15 April 2010 Available online 27 May 2010 Keywords: Scattering Neutron Benchmark dependent scattered neutron distributions. Scattering measurements were performed on carbon and molybdenum

  13. Inelastic neutron and low-frequency Raman scattering in a niobium-phosphate glass for Raman gain applications

    E-Print Network [OSTI]

    Schirmacher, Walter

    Inelastic neutron and low-frequency Raman scattering in a niobium-phosphate glass for Raman gain: Raman scattering; Neutron scattering; Raman gain; Boson peak We present measurements of the vibrational, extracted from specific-heat or neutron scattering measurements [7,8]. Only very recently two of the present

  14. For more information: Neutron Scattering Science User Office, neutronusers@ornl.gov or (865) 574-4600.

    E-Print Network [OSTI]

    Pennycook, Steve

    For more information: Neutron Scattering Science User Office, neutronusers@ornl.gov or (865) 574 Cold Neutron Triple-Axis Spectrometer CallforProposals neutrons.ornl.gov Neutron Scattering Science Neutron Source (SNS) will be accepted via the web-based proposal system until 11:59 a.m. EDT, (NOON

  15. Hydrogen Species Motion in Piezoelectrics: A Quasi-Elastic Neutron...

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

    Species Motion in Piezoelectrics: A Quasi-Elastic Neutron Scattering Study. Hydrogen Species Motion in Piezoelectrics: A Quasi-Elastic Neutron Scattering Study. Abstract: Hydrogen...

  16. Comparison of collimation systems for small-angle neutron scattering

    SciTech Connect (OSTI)

    Seeger, P.A.

    1985-01-01T23:59:59.000Z

    It is shown by simple first-order geometric arguments that for a given resolution, the flux on sample in a small-angle scattering instrument is independent of the form of the collimator or of the length of the instrument. Count rate may be increased by increasing the sample size, through the use of multi-aperture systems. In second order, it is shown to be advantageous to place the beam defining elements as close as possible to the source and the sample. The multiple-pinhole system gives maximum flux on small samples but has non-uniform illumination so that intensity increases only about half as fast as sample area. Soller slits and continuous tubes from source to sample were also considered, but neutron scattering and reflection from surfaces generate a large halo. Monte-Carlo simulations confirm these results, with the conclusion that the optimum collimator configuration is the multiple-pinhole system. 4 refs., 4 figs.

  17. Neutrino pair emission due to scattering of electrons off fluxoids in superfluid neutron star cores

    E-Print Network [OSTI]

    A. D. Kaminker; D. G. Yakovlev; P. Haensel

    1997-02-18T23:59:59.000Z

    We study the emission of neutrinos, resulting from the scattering of electrons off magnetic flux tubes (fluxoids) in the neutron star cores with superfluid (superconducting) protons. In the absence of proton superfluidity (T> T_{cp}), this process transforms into the well known electron synchrotron emission of neutrino pairs in a locally uniform magnetic field B, with the neutrino energy loss rate Q proportional to B^2 T^5. For temperatures T not much below T_{cp}, the synchrotron regime (Q \\propto T^5) persists and the emissivity Q can be amplified by several orders of magnitude due to the appearance of the fluxoids and associated enhancement of the field within them. For lower T, the synchrotron regime transforms into the bremsstrahlung regime (Q \\propto T^6) similar to the ordinary neutrino-pair bremsstrahlung of electrons which scatter off atomic nuclei. We calculate Q numerically and represent our results through a suitable analytic fit. In addition, we estimate the emissivities of two other neutrino-production mechanisms which are usually neglected -- neutrino-pair bremsstrahlung processes due to electron-proton and electron-electron collisions. We show that the electron-fluxoid and electron-electron scattering can provide the main neutrino production mechanisms in the neutron star cores with highly superfluid protons and neutrons at T scattering is significant if the initial, locally uniform magnetic field B > 10^{13} G.

  18. Review of the Lujan neutron scattering center: basic energy sciences prereport February 2009

    SciTech Connect (OSTI)

    Hurd, Alan J [Los Alamos National Laboratory; Rhyne, James J [Los Alamos National Laboratory; Lewis, Paul S [Los Alamos National Laboratory

    2009-01-01T23:59:59.000Z

    The Lujan Neutron Scattering Center (Lujan Center) at LANSCE is a designated National User Facility for neutron scattering and nuclear physics studies with pulsed beams of moderated neutrons (cold, thermal, and epithermal). As one of five experimental areas at the Los Alamos Neutron Science Center (LANSCE), the Lujan Center hosts engineers, scientists, and students from around the world. The Lujan Center consists of Experimental Room (ER) 1 (ERl) built by the Laboratory in 1977, ER2 built by the Office of Basic Energy Sciences (BES) in 1989, and the Office Building (622) also built by BES in 1989, along with a chem-bio lab, a shop, and other out-buildings. According to a 1996 Memorandum of Agreement (MOA) between the Defense Programs (DP) Office of the National Nuclear Security Agency (NNSA) and the Office of Science (SC, then the Office of Energy Research), the Lujan Center flight paths were transferred from DP to SC, including those in ERI. That MOA was updated in 2001. Under the MOA, NNSA-DP delivers neutron beam to the windows of the target crypt, outside of which BES becomes the 'landlord.' The leveraging nature of the Lujan Center on the LANSCE accelerator is a substantial annual leverage to the $11 M BES operating fund worth approximately $56 M operating cost of the linear accelerator (LINAC)-in beam delivery.

  19. Neutron observables from inclusive lepton scattering on nuclei

    SciTech Connect (OSTI)

    Rinat, A. S.; Taragin, M. F. [Weizmann Institute of Science, Department of Particle Physics, Rehovot 76100 (Israel)

    2010-07-15T23:59:59.000Z

    We analyze new data from Thomas Jefferson National Accelerator Facility (JLab) for inclusive electron scattering on various targets. Computed and measured total inclusive cross sections in the range 0.3 < or approx. x < or approx. 0.95 show reasonable agreement on a logarithmic scale for all targets. However, closer inspection of the quasielastic components reveals serious discrepancies. European Muon Collaboration (EMC) ratios with conceivably smaller systematic errors fare the same. As a consequence, the new data do not enable the extraction of the magnetic form factor G{sub M}{sup n} and the structure function F{sub 2}{sup n} of the neutron, although the application of exactly the same analysis to older data had been successful. We incorporate in the above analysis older CLAS Collaboration data on F{sub 2}{sup 2H}. Removal of some scattered points from those makes it appear possible to obtain the desired neutron information. We compare our results with others from alternative sources. Special attention is paid to the A=3 isodoublet cross sections and EMC ratios. Present data exist only for {sup 3}He, but the available input in combination with charge symmetry enables computations for {sup 3}H. Their average is the computed isoscalar part and is compared with the empirical modification of {sup 3}He EMC ratios toward a fictitious A=3 isosinglet.

  20. Neutron Polarisabilities from Deuteron Compton Scattering in \\chiEFT

    E-Print Network [OSTI]

    Harald W. Griesshammer

    2007-10-15T23:59:59.000Z

    Chiral Effective Field Theory is for photon energies up to 200 MeV the tool to accurately determine the polarisabilities of the neutron from deuteron Compton scattering. A multipole analysis reveals that dispersive effects from an explicit Delta(1232) prove in particular indispensable to understand the data at 95 MeV measured at SAL. Simple power-counting arguments derived from nuclear phenomenology lead to the correct Thomson limit and gauge invariance. At next-to-leading order, the static scalar dipole polarisabilities are extracted as identical for proton and neutron within the error-bar of available data: \\alpha^n=11.6\\pm1.5_stat\\pm0.6_Baldin, \\beta^n=3.6\\mp1.5_stat\\pm0.6_Baldin for the neutron, in units of 10^-4 fm^3, compared to \\alpha^p=11.0\\pm1.4_stat\\pm0.4_Baldin, \\beta}^p=2.8\\mp1.4_stat\\pm0.4_Baldin for the proton in the same framework. New experiments e.g. at MAXlab (Lund) will improve the statistical error-bar.

  1. ON QUASI-ELASTIC SCATTERING OF SLOW NEUTRONS IN MOLECULAR LIQUIDS

    E-Print Network [OSTI]

    Boyer, Edmond

    L-317 ON QUASI-ELASTIC SCATTERING OF SLOW NEUTRONS IN MOLECULAR LIQUIDS M. UTSURO Research Reactor de neutrons avec élargissement par rotation moléculaire dans le liquide sont étudiés dans le cadre du du benzène liquide. Abstract. 2014 The rotational broadened quasi-elastic scattering spectrum

  2. Proposal for a 30-T Pulsed Magnet Suitable for Neutron Scattering Experiments

    E-Print Network [OSTI]

    Robinson Eyssa Schneider-Muntau; R. A. Robinson (a; Y. M. Eyssa (b; H. J. Schneider-muntau (b; H. J. Boenig (a

    this paper, we describe a conceptual design for a 30-T pulsed magnet that could be used in conjunction with neutron-scattering apparatus, along with the scientific opportunities that such a magnet might open up. Neutron diffraction has long been the technique of choice for determining the arrangements (magnetic structures) of magnetic moments in solids, the spatial extent of the magnetic electrons around their parent ions (form factors) and the full moment-density distribution function in real space. The proposed 30-T magnet would enable one to study such spatial aspects of many field-induced phase transitions for the first time, whether they are driven by competing exchange interactions, single-ion anisotropy, or a more radical change, say from an itinerant to a localised state. Inelastic Neutron Scattering, on the other hand, is the best general-purpose tool for the study of magnetic excitations like spin waves, crystal-field levels and spin fluctuations. These excitations manifest themselves in the imaginary part of the generalised magnetic susceptibility c"(Q,w), which is measured directly in a neutron scattering experiment. A field of 30T acting on a moment of 1 B corresponds to an energy of 1.7 meV, and we should be able to generate splittings or close gaps of this order. The present generation of spectrometers at spallation neutron sources have both sufficient resolution (as good as 10 eV) and sufficient dynamic range (up to 2 eV) to cover the effects that might be induced by such a field.

  3. Evidence for Narrow N*(1685) Resonance in Quasifree Compton Scattering on the Neutron

    E-Print Network [OSTI]

    V. Kuznetsov; M. V. Polyakov; V. Bellini; T. Boiko; S. Chebotarev; H. S. Dho; G. Gervino; F. Ghio; A. Giusa; A. Kim; W. Kim; F. Mammoliti; E. Milman; A. Ni; I. A. Perevalova; C. Randieri; G. Russo; M. L. Sperduto; C. M. Sutera; A. N. Vall

    2011-02-21T23:59:59.000Z

    The first study of quasi-free Compton scattering on the neutron in the energy range of $E_{\\gamma}=0.75 - 1.5$ GeV is presented. The data reveals a narrow peak at $W\\sim 1.685$ GeV. This result, being considered in conjunction with the recent evidence for a narrow structure at $W\\sim 1.68$GeV in the $\\eta$ photoproduction on the neutron, suggests the existence of a new nucleon resonance with unusual properties: the mass $M\\sim 1.685$GeV, the narrow width $\\Gamma \\leq 30$MeV, and the much stronger photoexcitation on the neutron than on the proton.

  4. PHYSICAL REVIEW C 85, 065503 (2012) Quasielastic scattering in the interaction of ultracold neutrons with a liquid wall and application

    E-Print Network [OSTI]

    Steyerl, Albert

    2012-01-01T23:59:59.000Z

    20 June 2012) We develop a theory of ultracold and very cold neutron scattering on viscoelastic-order approach to quasielastic UCN and very cold neutron (VCN) scattering and loss at a liquid wall. This allowed is organized as follows. In Sec. II we describe the basics of neutron quasielastic scattering by thermally

  5. Models to analyze small-angle neutron scattering from unilamellar lipid vesicles Norbert Kucerka* and John F. Nagle

    E-Print Network [OSTI]

    Nagle, John F.

    Models to analyze small-angle neutron scattering from unilamellar lipid vesicles Norbert Kucerka from small-angle neutron scattering of unilamellar vesicles. DOI: 10.1103/PhysRevE.69.051903 PACS discrete diffraction peaks that occur for multilamellar arrays, the scattering of x rays or neutrons from

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

    E-Print Network [OSTI]

    Turro, Nicholas J.

    2012-01-01T23:59:59.000Z

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

  7. Los Alamos National Laboratory | Science and people highlights from the Lujan Neutron Scattering Center at LANSCE CENTER SCIENCE & PEOPLE

    E-Print Network [OSTI]

    Los Alamos National Laboratory | Science and people highlights from the Lujan Neutron Scattering tuning: a new approach for making zero thermal expansion materials 8 Neutron scattering enables- Preferred Orientation beamline at the Los Ala- mos Neutron Scattering Center. In the back- ground

  8. HIV-1 Tat membrane interactions probed using X-ray and neutron scattering, CD spectroscopy and MD simulations

    E-Print Network [OSTI]

    Nagle, John F.

    HIV-1 Tat membrane interactions probed using X-ray and neutron scattering, CD spectroscopy and MD translocation, were provided by wide-angle X-ray scattering (WAXS) and neutron scattering. CD spectroscopy for Neutron Research, 100 Bureau Drive, Stop 6102, Gaithersburg, MD 20899, United States d CHESS, Cornell

  9. Low-frequency Vibrational Anomalies in -Lactoglobulin: Contribution of Different Hydrogen Classes Revealed by Inelastic Neutron Scattering

    E-Print Network [OSTI]

    Tuscia, Università Degli Studi Della

    Revealed by Inelastic Neutron Scattering A. Orecchini, A. Paciaroni, A. R. Bizzarri, and S. Cannistraro -lactoglobulin has been investigated by inelastic neutron scattering, on both dry and D2O-hydrated samples. Both typically accessible energy and momentum transfers, inelastic thermal neutron scattering is probably

  10. What's wrong with the field of bio-neutron scattering? 1) Not enough professional science and not enough professional scientists

    E-Print Network [OSTI]

    Doster, Wolfgang

    What's wrong with the field of bio-neutron scattering? 1) Not enough professional science a paper in this field. Anybody can do it! The most detailed analysis of bio-neutron scattering data up independent moment analysis of the neutron scattering spectrum. Up to today nobody, not even MD people, picked

  11. Neutron scattering Materials research for modern life Almost all of the major changes in our society, the dramatic

    E-Print Network [OSTI]

    Crowther, Paul

    Neutron scattering Materials research for modern life #12;Almost all of the major changes in our scattering experiments, materials are exposed to intense beams of neutrons inside specialised instruments that neutron scattering science contributes to our lives. Because of the collaborative nature of modern

  12. A View of Dynamics Changes in the Molten Globule-native Folding Step by Quasielastic Neutron Scattering

    E-Print Network [OSTI]

    dynamics that occur in the ®nal stages of protein folding, we have used neutron scattering to probe- lastic neutron scattering (IQNS). The IQNS results show length scale dependent, pico-second dynamics neutron scattering; a-lactalbumin*Corresponding author Introduction Proteins can form collapsed, partially

  13. Quasi-differential neutron scattering from 238 U from 0.5 to 20 MeV

    E-Print Network [OSTI]

    Danon, Yaron

    Quasi-differential neutron scattering from 238 U from 0.5 to 20 MeV A.M. Daskalakis a, , R Measurement Neutron scattering Time-of-flight experiment Benchmark a b s t r a c t The Rensselaer Polytechnic scattering sample 30 m from the source. Eight liquid scintillator (EJ-301) proton recoil fast neutron

  14. Test of the consistency of various linearized semiclassical initial value time correlation functions in application to inelastic neutron scattering

    E-Print Network [OSTI]

    Miller, William H.

    functions in application to inelastic neutron scattering from liquid para-hydrogen Jian Liua and William H for inelastic neutron scattering from liquid para-hydrogen at 14 K. Various time correlations functions were neutron scattering experimental data all suggest that the LSC-IVR is indeed a good short

  15. For more information: Neutron Scattering Science User Office, neutronusers@ornl.gov or (865) 574-4600.

    E-Print Network [OSTI]

    Pennycook, Steve

    For more information: Neutron Scattering Science User Office, neutronusers@ornl.gov or (865) 574 Spectrometer (ARCS) CallforProposals neutrons.ornl.gov Neutron Scattering Science - Oak Ridge National Neutron Source (SNS) will be accepted via the web-based proposal system until 11:59 a.m. EST, (NOON

  16. For more information: Neutron Scattering Science User Office, neutronusers@ornl.gov or (865) 574-4600.

    E-Print Network [OSTI]

    For more information: Neutron Scattering Science User Office, neutronusers@ornl.gov or (865) 574Proposals neutrons.ornl.gov Neutron Scattering Science - Oak Ridge National Laboratory Due March 6, 2013 #12; Neutron Source (SNS) will be accepted via the web-based proposal system until 11:59 a.m. EST, (NOON

  17. Review of Indirect Methods Used to Determine the $^1S_0$ Neutron-Neutron Scattering Length

    E-Print Network [OSTI]

    C. R. Howell

    2008-05-08T23:59:59.000Z

    We have determined a value for the $^1S_0$ neutron-neutron scattering length ($a_{nn}$) from high-precision measurements of time-of-flight spectra of neutrons from the $^2H(\\pi^-,n \\gamma)n$ capture reaction. The measurements were done at the Los Alamos Meson Physics Facility by the E1286 collaboration. The high spatial resolution of our gamma-ray detector enabled us to make a detailed assessment of the systematic uncertainties in our techniques. The value obtained in the present work is $a_{nn} = -18$.63 $\\pm $0.10 (statistical) $\\pm$ 0.44 (systematic) $\\pm$ 0.30 (theoretical) fm. This result is consistent with previous determinations of $a_{nn}$ from the $\\pi^-d$ capture reaction. We found that the analysis of the data with calculations that use a relativistic phase-space factor gives a more negative value for $a_{nn}$ by 0.33 fm over the analysis done using a nonrelativistic phase-space factor. Combining the present result with the previous ones from $\\pi^-d$ capture gives: $a_{nn} = - 18$.63 $\\pm$ 0.27 (expt) $\\pm$ 0.30 fm (theory). For the first time the combined statistical and systematic experimental uncertainty in $a_{nn}$ is smaller than the theoretical uncertainty and comparable to the uncertainty in the proton-proton $^1S_0$ scattering length ($a_{pp}$). This average value of $a_{nn}$ when corrected for the magnetic-moment interaction of the two neutrons becomes -18.9 $\\pm$ 0.4 fm which is 1.6 $\\pm$ 0.5 fm different from the recommended value of $a_{pp}$, thereby confirming charge symmetry breaking at the 1% confidence level.

  18. Faddeev calculation for breakup neutron-deuteron scattering at 14.1 MeV lab energy

    E-Print Network [OSTI]

    V M Suslov; I Filikhin; B Vlahovic; M A Braun; I Slaus

    2013-04-03T23:59:59.000Z

    A new computational method for solving the nucleon-deuteron breakup scattering problem has been applied to study the inelastic neutron-deuteron scattering on the basis of the configuration-space Faddeev equations. This method is based on the spline-decomposition in the angular variable and on a generalization of the Numerov method for the hyperradius. The Merkuriev-Gignoux-Laverne approach has been generalized for arbitrary nucleon-nucleon potentials and with an arbitrary number of partial waves. Neutron-deuteron observables at the incident nucleon energy 14.1 MeV have been calculated using the charge-independent AV14 nucleon-nucleon potential. Results have been compared with those of other authors and with experimental neutron-deuteron scattering data.

  19. acp safeguards neutron: Topics by E-print Network

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

    29 Supercool Neutrons (Ultracold Neutrons) Physics Websites Summary: . Korobkina, NCSU Neutron scattering is a valuable tool to study the structure of materials. Because Helium...

  20. Compton Scattering from the Deuteron and Extracted Neutron Polarizabilities

    E-Print Network [OSTI]

    M. Lundin; J. -O. Adler; M. Boland; K. Fissum; T. Glebe; K. Hansen; L. Isaksson; O. Kaltschmidt; M. Karlsson; K. Kossert; M. I. Levchuk; P. Lilja; B. Lindner; A. I. L'vov; B. Nilsson; D. E. Oner; C. Poech; S. Proff; A. Sandell; B. Schröder; M. Schumacher; D. A. Sims

    2003-06-13T23:59:59.000Z

    Differential cross sections for Compton scattering from the deuteron were measured at MAX-lab for incident photon energies of 55 MeV and 66 MeV at nominal laboratory angles of $45^\\circ$, $125^\\circ$, and $135^\\circ$. Tagged photons were scattered from liquid deuterium and detected in three NaI spectrometers. By comparing the data with theoretical calculations in the framework of a one-boson-exchange potential model, the sum and difference of the isospin-averaged nucleon polarizabilities, $\\alpha_N + \\beta_N = 17.4 \\pm 3.7$ and $\\alpha_N - \\beta_N = 6.4 \\pm 2.4$ (in units of $10^{-4}$ fm$^3$), have been determined. By combining the latter with the global-averaged value for $\\alpha_p - \\beta_p$ and using the predictions of the Baldin sum rule for the sum of the nucleon polarizabilities, we have obtained values for the neutron electric and magnetic polarizabilities of $\\alpha_n= 8.8 \\pm 2.4$(total) $\\pm 3.0$(model) and $\\beta_n = 6.5 \\mp 2.4$(total) $\\mp 3.0$(model), respectively.

  1. JOURNAL DE PHYSIQUE Colloque C6, suppldment au no 8, Tome 39, aolit 1978, page C6-1334 RECENT NEUTRON STUDIES OF ELEMENTARY EXCITATIONS IN LIQUID 3 ~ eAND 4 ~ e

    E-Print Network [OSTI]

    Boyer, Edmond

    . INTRODUCTION.- After more than twenty years ofin- tensive study by neutron inelastic scattering (N. I. S, there is the innate attraction of this unique substance. The hope that neutron scattering would help provide-atomic distances are very similar to the wavelengths of thermal neutrons. Although neutron scattering yields

  2. 11th LANSCE School on Neutron Scattering | About the School

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

    Interactions in Extremes Planning and logistic support is provided by: Los Alamos Neutron Science Center New Mexico State University Los Alamos Neutron Science Center New...

  3. 22.101 Applied Nuclear Physics (Fall 2006) Lecture 8 (10/4/06) Neutron-Proton Scattering

    E-Print Network [OSTI]

    unknown authors

    We continue the study of the neutron-proton system by taking up the well-known problem of neutron scattering in hydrogen. The scattering cross section has been carefully measured to be 20.4 barns over a wide energy range. Our intent is to apply the method of phase shifts summarized in the preceding lecture to this problem. We see very quickly that the s-wave approximation (the condition of interaction at low energy) is very well justified in the neutron energy range of 1- 1000 eV. The scattering-state solution, with E> 0, gives us the phase shift or equivalently the scattering length. This calculation yields a cross section of 2.3 barns which is considerably different from the experimental value. The reason for the discrepancy lies in the fact that we have not taken into account the spin-dependent nature of the n-p interaction. The neutron and proton spins can form two distinct spin configurations, the two spins being parallel (triplet state) or anti-parallel (singlet), each giving rise to a scattering length. When this is taken into account, the new estimate is quite close to the experimental value. The conclusion is therefore that n-p interaction is spin-dependent and that the anomalously large value of the hydrogen scattering cross section for neutrons is really due to this aspect of the nuclear force. For the scattering problem our task is to solve the radial wave equation for s-wave for solutions with E> 0. The interior and exterior solutions have the form ur () = Bsin ( Kr ' ) , r < ro (8.1) and ur () = C sin(

  4. Current Status and Future Works of Neutron Scattering Laboratory at BATAN in Serpong

    SciTech Connect (OSTI)

    Ikram, A. [Center of Technology for Nuclear Industrial Materials, National Nuclear Energy Agency of Indonesia (BATAN) Kawasan Puspiptek Serpong, Tangerang 15314 (Indonesia)

    2008-03-17T23:59:59.000Z

    Current status of neutron beam instruments using neutrons produced by the Multi Purpose Research Reactor--30MWth (MPR 30, RSG GA Siwabessy) located in Serpong is presented. Description of the reactor as the neutron source is mentioned briefly. There are six neutron beam tubes coming from the beryllium reflector surrounding half of the reactor core providing neutrons in the experimental hall of the reactor (XHR). Four of them are dedicated to R and D in materials science using neutron scattering techniques. Neutron Radiography Facility (NRF), Triple Axis Spectrometer (TAS) and Residual Stress Measurement (RSM) Diffractometer are installed respectively at beam tubes S2, S4 and S6. The largest neutron beam tube (S5) is exploited to accommodate two neutron guide tubes that transfer the neutrons to a neighbouring building called neutron guide hall (NGH). There are three other neutron beam instruments installed in this building, namely Small Angle Neutron Scattering (SANS) Spectrometer (SMARTer), High Resolution SANS (HRSANS) Spectrometer and High Resolution Powder Diffractometer (HRPD). In the XHR, a Four Circle and Texture Diffractometer (FCD/TD) is attached to one of the neutron guide tubes. These seven instruments were installed to utilize the neutrons for materials science research, and recently the RSM diffractometer has shown its capabilities in identifying different amount of stress left due to different treatments of welding in fuel cladding, while the SANS spectrometer is now gaining capabilities in identifying different sizes and shapes of macromolecules in polymers as well as investigations of magnetic samples. In the mean time, non-destructive tests using the NRF is gathering more confidence from some latest real time measurements eventhough there are still some shortcomings in the components and their alignments. Future works including improvement of each facility and its components, even replacement of some parts are necessary and have to be carried out carefully. A plan for developing a neutron reflectometer at one of the neutron guide in the Neutron Guide Hall is also part of the near future activities.

  5. Your access to the Oak Ridge National Laboratory (ORNL) is approved beginning Sunday, June 20, 2010, for the second week of the Neutron X-ray Scattering School.

    E-Print Network [OSTI]

    Pennycook, Steve

    , for the second week of the Neutron X-ray Scattering School. Please be certain to bring photo identification access to the Target Facility.) · General User Access Training for Neutron Scattering Users, Neutron Scattering Science User Office Oak Ridge National Laboratory ORNL Neutron Scattering School June

  6. Gravitational waves from a test particle scattered by a neutron star: Axial mode case

    E-Print Network [OSTI]

    Kazuhiro Tominaga; Motoyuki Saijo; Kei-ichi Maeda

    1999-09-20T23:59:59.000Z

    Using a metric perturbation method, we study gravitational waves from a test particle scattered by a spherically symmetric relativistic star. We calculate the energy spectrum and the waveform of gravitational waves for axial modes. Since metric perturbations in axial modes do not couple to the matter fluid of the star, emitted waves for a normal neutron star show only one peak in the spectrum, which corresponds to the orbital frequency at the turning point, where the gravitational field is strongest. However, for an ultracompact star (the radius $R \\lesssim 3M$), another type of resonant periodic peak appears in the spectrum. This is just because of an excitation by a scattered particle of axial quasinormal modes, which were found by Chandrasekhar and Ferrari. This excitation comes from the existence of the potential minimum inside of a star. We also find for an ultracompact star many small periodic peaks at the frequency region beyond the maximum of the potential, which would be due to a resonance of two waves reflected by two potential barriers (Regge-Wheeler type and one at the center of the star). Such resonant peaks appear neither for a normal neutron star nor for a Schwarzschild black hole. Consequently, even if we analyze the energy spectrum of gravitational waves only for axial modes, it would be possible to distinguish between an ultracompact star and a normal neutron star (or a Schwarzschild black hole).

  7. Low Resolution Structure and Dynamics of a Colicin-Receptor Complex Determined by Neutron Scattering

    SciTech Connect (OSTI)

    Clifton, Luke A [ORNL; Johnson, Christopher L [ORNL; Solovyova, Alexandra [University of Newcastle upon Tyne; Callow, Phil [Institut Laue-Langevin (ILL); Weiss, Kevin L [ORNL; Ridley, Helen [University of Newcastle upon Tyne; Le Brun, Anton P [ORNL; Kinane, Christian [ISIS Facility, Rutherford Appleton Laboratory; Webster, John [ISIS Facility, Rutherford Appleton Laboratory; Holt, Stephen A [ORNL; Lakey, Jeremy H [ORNL

    2012-01-01T23:59:59.000Z

    Proteins that translocate across cell membranes need to overcome a significant hydrophobic barrier. This is usually accomplished via specialized protein complexes, which provide a polar transmembrane pore. Exceptions to this include bacterial toxins, which insert into and cross the lipid bilayer itself. We are studying the mechanism by which large antibacterial proteins enter Escherichia coli via specific outer membrane proteins. Here we describe the use of neutron scattering to investigate the interaction of colicin N with its outer membrane receptor protein OmpF. The positions of lipids, colicin N, and OmpF were separately resolved within complex structures by the use of selective deuteration. Neutron reflectivity showed, in real time, that OmpF mediates the insertion of colicin N into lipid monolayers. This data were complemented by Brewster Angle Microscopy images, which showed a lateral association of OmpF in the presence of colicin N. Small angle neutron scattering experiments then defined the three-dimensional structure of the colicin N-OmpF complex. This revealed that colicin N unfolds and binds to the OmpF-lipid interface. The implications of this unfolding step for colicin translocation across membranes are discussed.

  8. Multi-Grid Boron-10 detector for large area applications in neutron scattering science

    E-Print Network [OSTI]

    Ken Andersen; Thierry Bigault; Jens Birch; Jean-Claude Buffet; Jonathan Correa; Patrick van Esch; Bruno Guerard; Richard Hall-Wilton; Lars Hultman; Carina Höglund; Jens Jensen; Anton Khaplanov; Oliver Kirstein; Francesco Piscitelli; Christian Vettier

    2012-09-04T23:59:59.000Z

    The present supply of 3He can no longer meet the detector demands of the upcoming ESS facility and continued detector upgrades at current neutron sources. Therefore viable alternative technologies are required to support the development of cutting-edge instrumentation for neutron scattering science. In this context, 10B-based detectors are being developed by collaboration between the ESS, ILL, and Link\\"{o}ping University. This paper reports on progress of this technology and the prospects applying it in modern neutron scattering experiments. The detector is made-up of multiple rectangular gas counter tubes coated with B4C, enriched in 10B. An anode wire reads out each tube, thereby giving position of conversion in one of the lateral co-ordinates as well as in depth of the detector. Position resolution in the remaining co-ordinate is obtained by segmenting the cathode tube itself. Boron carbide films have been produced at Link\\"{o}ping University and a detector built at ILL. The characterization study is presented in this paper, including measurement of efficiency, effects of the fill gas species and pressure, coating thickness variation on efficiency and sensitivity to gamma-rays.

  9. Directional Stand-off Detection of Fast Neutrons and Gammas Using Angular Scattering Distributions

    SciTech Connect (OSTI)

    Vanier P. e.; Dioszegi, I.; Salwen, C.; Forman, L.

    2009-10-25T23:59:59.000Z

    We have investigated the response of a DoubleScatter Neutron Spectrometer (DSNS) for sources at long distances (gr than 200 meters). We find that an alternative method for analyzing double scatter data avoids some uncertainties introduced by amplitude measurements in plastic scintillators.Time of flight is used to discriminate between gamma and neutron events, and the kinematic distributions of scattering angles are assumed to apply. Non-relativistic neutrons are most likely to scatter at 45°, while gammas with energies greater than 2 MeV are most likely to be forward scattered. The distribution of scattering angles of fission neutrons arriving from a distant point source generates a 45° cone, which can be back-projected to give the source direction. At the same time, the distribution of Compton-scattered gammas has a maximum in the forward direction, and can be made narrower by selecting events that deposit minimal energy in the first scattering event. We have further determined that the shape of spontaneous fission neutron spectra at ranges gr than 110 m is still significantly different from thecosmic ray background.

  10. Measurement of the Neutron Radius of [superscript 208]Pb through Parity Violation in Electron Scattering

    E-Print Network [OSTI]

    Deconinck, W.

    We report the first measurement of the parity-violating asymmetry A[subscript PV] in the elastic scattering of polarized electrons from [superscript 208]Pb. A[subscript PV] is sensitive to the radius of the neutron ...

  11. Initial characterization of mudstone nanoporosity with small angle neutron scattering using caprocks from carbon sequestration sites.

    SciTech Connect (OSTI)

    McCray, John (Colorado School of Mines); Navarre-Sitchler, Alexis (Colorado School of Mines); Mouzakis, Katherine (Colorado School of Mines); Heath, Jason E.; Dewers, Thomas A.; Rother, Gernot (Oak Ridge National Laboratory)

    2010-11-01T23:59:59.000Z

    Geological carbon sequestration relies on the principle that CO{sub 2} injected deep into the subsurface is unable to leak to the atmosphere. Structural trapping by a relatively impermeable caprock (often mudstone such as a shale) is the main trapping mechanism that is currently relied on for the first hundreds of years. Many of the pores of the caprock are of micrometer to nanometer scale. However, the distribution, geometry and volume of porosity at these scales are poorly characterized. Differences in pore shape and size can cause variation in capillary properties and fluid transport resulting in fluid pathways with different capillary entry pressures in the same sample. Prediction of pore network properties for distinct geologic environments would result in significant advancement in our ability to model subsurface fluid flow. Specifically, prediction of fluid flow through caprocks of geologic CO{sub 2} sequestration reservoirs is a critical step in evaluating the risk of leakage to overlying aquifers. The micro- and nanoporosity was analyzed in four mudstones using small angle neutron scattering (SANS). These mudstones are caprocks of formations that are currently under study or being used for carbon sequestration projects and include the Marine Tuscaloosa Group, the Lower Tuscaloosa Group, the upper and lower shale members of the Kirtland Formation, and the Pennsylvanian Gothic shale. Total organic carbon varies from <0.3% to 4% by weight. Expandable clay contents range from 10% to {approx}40% in the Gothic shale and Kirtland Formation, respectively. Neutrons effectively scatter from interfaces between materials with differing scattering length density (i.e. minerals and pores). The intensity of scattered neutrons, I(Q), where Q is the scattering vector, gives information about the volume of pores and their arrangement in the sample. The slope of the scattering data when plotted as log I(Q) vs. log Q provides information about the fractality or geometry of the pore network. Results from this study, combined with high-resolution TEM imaging, provide insight into the differences in volume and geometry of porosity between these various mudstones.

  12. Small-angle neutron scattering study of magnetic ordering and inhomogeneity across the martensitic phase transformation in Ni50–xCoxMn??Sn?? alloys

    SciTech Connect (OSTI)

    Bhatti, Kanwal Preet; El-Khatib, S.; Srivastava, Vijay; James, R. D.; Leighton, C.

    2012-04-01T23:59:59.000Z

    The Heusler-derived multiferroic alloy Ni50–xCoxMn??Sn?? has recently been shown to exhibit, at just above room temperature, a highly reversible martensitic phase transformation with an unusually large magnetization change. In this work the nature of the magnetic ordering above and below this transformation has been studied in detail in the critical composition range x = 6–8 via temperature-dependent (5–600 K) magnetometry and small-angle neutron scattering (SANS). We observe fairly typical paramagnetic to long-range-ordered ferromagnetic phase transitions on cooling to 420–430 K, with the expected critical spin fluctuations, followed by first-order martensitic phase transformations to a nonferromagnetic state below 360–390 K. The static magnetization reveals complex magnetism in this low-temperature nonferromagnetic phase, including a Langevin-like field dependence, distinct spin freezing near 60 K, and significant exchange bias effects, consistent with superparamagnetic blocking of ferromagnetic clusters of nanoscopic dimensions. We demonstrate that these spin clusters, whose existence has been hypothesized in a variety of martensitic alloys exhibiting competition between ferromagnetic and antiferromagnetic exchange interactions, can be directly observed by SANS. The scattering data are consistent with a liquidlike spatial distribution of interacting magnetic clusters with a mean center-to-center spacing of 12 nm. Considering the behavior of the superparmagnetism, cooling-field and temperature-dependent exchange bias, and magnetic SANS, we discuss in detail the physical form and origin of these spin clusters, their intercluster interactions, the nature of the ground-state magnetic ordering in the martensitic phase, and the implications for our understanding of such alloy systems.

  13. The new very small angle neutron scattering spectrometer at Laboratoire Leon Brillouin

    E-Print Network [OSTI]

    Sylvain Desert; Vincent Thevenot; Julian Oberdisse; Annie Brulet

    2007-06-12T23:59:59.000Z

    The design and characteristics of the new very small angle neutron scattering spectrometer under construction at the Laboratoire Leon Brillouin is described. Its goal is to extend the range of scattering vectors magnitudes towards 2x10{-4} /A. The unique feature of this new spectrometer is a high resolution two dimensional image plate detector sensitive to neutrons. The wavelength selection is achieved by a double reflection supermirror monochromator and the collimator uses a novel multibeam design.

  14. Coherent neutron scattering and collective dynamics on mesoscale

    SciTech Connect (OSTI)

    Novikov, Vladimir [ORNL; Schweizer, Kenneth S [ORNL; Sokolov, Alexei P [ORNL

    2013-01-01T23:59:59.000Z

    By combining, and modestly extending, a variety of theoretical concepts for the dynamics of liquids in the supercooled regime, we formulate a simple analytic model for the temperature and wavevector dependent collective density fluctuation relaxation time that is measurable using coherent dynamic neutron scattering. Comparison with experiments on the ionic glass-forming liquid Ca K NO3 in the lightly supercooled regime suggests the model captures the key physics in both the local cage and mesoscopic regimes, including the unusual wavevector dependence of the collective structural relaxation time. The model is consistent with the idea that the decoupling between diffusion and viscosity is reflected in a different temperature dependence of the collective relaxation time at intermediate wavevectors and near the main (cage) peak of the static structure factor. More generally, our analysis provides support for the ideas that decoupling information and growing dynamic length scales can be at least qualitatively deduced by analyzing the collective relaxation time as a function of temperature and wavevector, and that there is a strong link between dynamic heterogeneity phenomena at the single and many particle level. Though very simple, the model can be applied to other systems, such as molecular liquids.

  15. 16th National School on Neutron and X-ray Scattering

    ScienceCinema (OSTI)

    Chakoumakos, Bryan; Achilles, Cherie; Cybulskis, Viktor; Gilbert, Ian

    2014-07-23T23:59:59.000Z

    Students talk about their experience at the 16th National School on Neutron and X-ray Scattering, or NXS 2014. Jointly conducted by Oak Ridge and Argonne national laboratories, NXS immerses graduate students in national user facilities to learn in a hands-on environment how to use neutrons and X-rays in their research.

  16. The Manuel Lujan, Jr. Neutron Scattering Center LANSCE experiment reports 1989 run cycle

    SciTech Connect (OSTI)

    Hyer, D.K.; DiStravolo, M.A. (comps.)

    1990-10-01T23:59:59.000Z

    This report contains a listing and description of experiments carried on at the LANSCE neutron scattering facility in the following areas: High Density Powder Diffraction; Neutron Powder Diffractometer, (NPD); Single Crystal Diffractometer, (SCD); Low-Q Diffractometer, (LQD); Surface Profile Analysis Reflectometer, (SPEAR); Filter Difference Spectrometer, (FDS); and Constant-Q Spectrometer.

  17. 16th National School on Neutron and X-ray Scattering

    SciTech Connect (OSTI)

    Chakoumakos, Bryan; Achilles, Cherie; Cybulskis, Viktor; Gilbert, Ian

    2014-07-02T23:59:59.000Z

    Students talk about their experience at the 16th National School on Neutron and X-ray Scattering, or NXS 2014. Jointly conducted by Oak Ridge and Argonne national laboratories, NXS immerses graduate students in national user facilities to learn in a hands-on environment how to use neutrons and X-rays in their research.

  18. Supplementary data for HIV-1 Tat membrane interaction probed using X-ray and neutron scattering, CD, and MD simulations

    E-Print Network [OSTI]

    Nagle, John F.

    1 Supplementary data for HIV-1 Tat membrane interaction probed using X-ray and neutron scattering- spacing are linearly related. Figure S3. Neutron scattering from stacks of DOPC:DOPE (3:1)/Tat, x=0 of Physics, Rensselaer Polytechnic Institute, 110 Eighth Street, Troy, NY 12180, 3 NIST Center for Neutron

  19. Apparatus for the investigation of liquid systems in a shear gradient by small angle neutron scattering (SANS)

    E-Print Network [OSTI]

    Boyer, Edmond

    of small angle neutron scattering from fluids in a constant shear gradient. Typical systems which can angle neutron scattering experiments with liquids have given information about structural pro- perties759 Apparatus for the investigation of liquid systems in a shear gradient by small angle neutron

  20. For more information: Neutron Scattering Science User Office, neutronusers@ornl.gov or (865) 574-4600.

    E-Print Network [OSTI]

    Pennycook, Steve

    For more information: Neutron Scattering Science User Office, neutronusers@ornl.gov or (865) 574.ornl.gov Neutron Scattering Science - Oak Ridge National Laboratory Due February 26, 2014 #12; Neutron Source (SNS) will be accepted via the web-based proposal system until 11:59 a.m. EST, (NOON

  1. Neutron scattering as a probe of liquid crystal polymer-reinforced composite materials

    SciTech Connect (OSTI)

    Hjelm, R.P.; Douglas, E.P.; Benicewicz, B.C.; Langlois, D.A.

    1995-12-31T23:59:59.000Z

    This is the final report of a three-year Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). This research project sought to obtain nanoscale and molecular level information on the mechanism of reinforcement in liquid crystal polymer (LCP)-reinforced composites, to realize molecular-reinforced LCP composites, and to test the validity of the concept of molecular reinforcement. Small-angle neutron scattering was used to study the structures in the ternary phase diagram of LCP with liquid crystal thermosets and solvent on length scales ranging from 1-100 nm. The goal of the scattering measurements is to understand the phase morphology and degree of segregation of the reinforcing and matrix components. This information helps elucidate the physics of self assembly in these systems. This work provides an experimental basis for a microengineering approach to composites of vastly improved properties.

  2. Cold dilute neutron matter on the lattice I: Lattice virial coefficients and large scattering lengths

    E-Print Network [OSTI]

    Dean Lee; Thomas Schaefer

    2005-09-07T23:59:59.000Z

    We study cold dilute neutron matter on the lattice using an effective field theory. We work in the unitary limit in which the scattering length is much larger than the interparticle spacing. In this paper we focus on the equation of state at temperatures above the Fermi temperature and compare lattice simulations to the virial expansion on the lattice and in the continuum. We find that in the unitary limit lattice discretization errors in the second virial coefficient are significantly enhanced. As a consequence the equation of state does not show the universal scaling behavior expected in the unitary limit. We suggest that scaling can be improved by tuning the second virial coefficient rather than the scattering length.

  3. Precision neutron interferometric measurement of the nd coherent neutron scattering length and consequences for models of three-nucleon forces

    E-Print Network [OSTI]

    T. C. Black; P. R. Huffman; D. L. Jacobson; W. M. Snow; K. Schoen; M. Arif; H. Kaiser; S. K. Lamoreaux; S. A. Werner

    2003-05-21T23:59:59.000Z

    We have performed the first high precision measurement of the coherent neutron scattering length of deuterium in a pure sample using neutron interferometry. We find b_nd = (6.665 +/- 0.004) fm in agreement with the world average of previous measurements using different techniques, b_nd = (6.6730 +/- 0.0045) fm. We compare the new world average for the nd coherent scattering length b_nd = (6.669 +/- 0.003) fm to calculations of the doublet and quartet scattering lengths from several modern nucleon-nucleon potential models with three-nucleon force (3NF) additions and show that almost all theories are in serious disagreement with experiment. This comparison is a more stringent test of the models than past comparisons with the less precisely-determined nuclear doublet scattering length of a_nd = (0.65 +/- 0.04) fm.

  4. 2011 U.S. National School on Neutron and X-ray Scattering

    SciTech Connect (OSTI)

    Lang, Jonathan [Argonne National Laboratory (ANL); te Vethuis, Suzanne [Argonne National Laboratory (ANL); Ekkebus, Allen E [ORNL; Chakoumakos, Bryan C [ORNL; Budai, John D [ORNL

    2012-01-01T23:59:59.000Z

    The 13th annual U.S. National School on Neutron and X-ray Scattering was held June 11 to 25, 2011, at both Oak Ridge and Argonne National Laboratories. This school brought together 65 early career graduate students from 56 different universities in the US and provided them with a broad introduction to the techniques available at the major large-scale neutron and synchrotron x-ray facilities. This school is focused primarily on techniques relevant to the physical sciences, but also touches on cross-disciplinary bio-related scattering measurements. During the school, students received lectures by over 30 researchers from academia, industry, and national laboratories and participated in a number of short demonstration experiments at Argonne's Advanced Photon Source (APS) and Oak Ridge's Spallation neutron Source (SNS) and High Flux Isotope Reactor (HFIR) facilities to get hands-on experience in using neutron and synchrotron sources. The first week of this year's school was held at Oak Ridge National Lab, where Lab director Thom Mason welcomed the students and provided a shitorical perspective of the neutron and x-ray facilities both at Oak Ridge and Argonne. The first few days of the school were dedicated to lectures laying out the basics of scattering theory and the differences and complementarity between the neutron and x-ray probes given by Sunil Sinha. Jack Carpenter provided an introduction into how neutrons are generated and detected. After this basic introduction, the students received lectures each morning on specific techniques and conducted demonstration experiments each afternoon on one of 15 different instruments at either the SNS or HFIR. Some of the topics covered during this week of the school included inelastic neutron scattering by Bruce Gaulin, x-ray and neutron reflectivity by Chuck Majkrazak, small-angle scattering by Volker Urban, powder diffraction by Ashfia Huq and diffuse scattering by Gene Ice.

  5. Elastic and inelastic neutron scattering cross sections for fission reactor applications

    SciTech Connect (OSTI)

    Hicks, S. F.; Combs, B.; Downes, L.; Girgis, J.; Kersting, L. J.; Lueck, C. J.; McDonough, P. J.; Schniederjan, J.; Sidwell, L.; Sigillito, A. J. [Department of Physics, University of Dallas, Irving TX 75019 (United States); Chakraborty, A.; Crider, B. P.; Kumar, A.; McEllistrem, M. T.; Peters, E. E.; Prados-Estevz, F. M. [Department of Physics and Astronomy, University of Kentucky, Lexington, KY 40506 (United States); Vanhoy, J. R.; Watts, D. [Department of Physics, United States Naval Academy, Annapolis MD 21402 (United States); Yates, S. W. [Department of Physics and Astronomy, University of Kentucky, Lexington, KY 40506 (United States) and Department of Chemistry, University of Kentucky, Lexington, KY 40506 (United States)

    2013-04-19T23:59:59.000Z

    Nuclear data important for the design and development of the next generation of light-water reactors and future fast reactors include neutron elastic and inelastic scattering cross sections on important structural materials, such as Fe, and on coolant materials, such as Na. These reaction probabilities are needed since neutron reactions impact fuel performance during irradiations and the overall efficiency of reactors. While neutron scattering cross sections from these materials are available for certain incident neutron energies, the fast neutron region, particularly above 2 MeV, has large gaps for which no measurements exist, or the existing uncertainties are large. Measurements have been made at the University of Kentucky Accelerator Laboratory to measure neutron scattering cross sections on both Fe and Na in the region where these gaps occur and to reduce the uncertainties on scattering from the ground state and first excited state of these nuclei. Results from measurements on Fe at incident neutron energies between 2 and 4 MeV will be presented and comparisons will be made to model calculations available from data evaluators.

  6. Measurements of the Total Cross Section for the Scattering of Polarized Neutrons from Polarized $^3$He

    E-Print Network [OSTI]

    C. D. Keith; C. R. Gould; D. G. Haase; M. L. Seely; P. R. Huffman; N. R. Roberson; W. Tornow; W. S. Wilburn

    1996-07-19T23:59:59.000Z

    Measurements of polarized neutron--polarized $^3$He scattering are reported. The target consisted of cryogenically-polarized solid $^3$He, thickness 0.04 atom/b and polarization 40%. The longitudinal and transverse total cross-section differences $\\Delta\\sigma_L$ and $\\Delta\\sigma_T$ were measured for incident neutron energies 2-8 MeV. The results are compared to phase-shift predictions based on four different analyses of n-$^3$He scattering. The best agreement is obtained with a recent R-matrix analysis of A=4 scattering and reaction data, lending strong suport to the $^4$He level scheme obtained in that analysis.

  7. Neutron tube design study for boron neutron capture therapy application

    SciTech Connect (OSTI)

    Verbeke, J.M.; Lee, Y.; Leung, K.N.; Vujic, J.; Williams, M.D.; Wu, L.K.; Zahir, N.

    1999-05-06T23:59:59.000Z

    Radio-frequency (RF) driven ion sources are being developed in Lawrence Berkeley National Laboratory (LBNL) for sealed-accelerator-tube neutron generator application. By using a 5-cm-diameter RF-driven multicusp source H{sup +} yields over 95% have been achieved. These experimental findings will enable one to develop compact neutron generators based on the D-D or D-T fusion reactions. In this new neutron generator, the ion source, the accelerator and the target are all housed in a sealed metal container without external pumping. Recent moderator design simulation studies have shown that 14 MeV neutrons could be moderated to therapeutically useful energy ranges for boron neutron capture therapy (BNCT). The dose near the center of the brain with optimized moderators is about 65% higher than the dose obtained from a typical neutron spectrum produced by the Brookhaven Medical Research Reactor (BMRR), and is comparable to the dose obtained by other accelerator-based neutron sources. With a 120 keV and 1 A deuteron beam, a treatment time of {approx}35 minutes is estimated for BNCT.

  8. associated-particle sealed-tube neutron: Topics by E-print Network

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

    9 Supercool Neutrons (Ultracold Neutrons) Physics Websites Summary: . Korobkina, NCSU Neutron scattering is a valuable tool to study the structure of materials. Because Helium...

  9. am-be isotopic neutron: Topics by E-print Network

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

    of fast neutrons. Earlier studies characteristic gamma photons through inelastic scattering of an external neutron beam. These stable isotopes canNeutron Stimulated...

  10. Adsorption and grafting on colloidal interfaces studied by scattering techniques

    E-Print Network [OSTI]

    Julian Oberdisse

    2007-05-23T23:59:59.000Z

    The adsorption of polymer and surfactant molecules onto colloidal particles or droplets in solution can be characterized non-destructively by scattering techniques. In a first part, the general framework of Dynamic Light Scattering, Small Angle Neutron and X-ray Scattering for the determination of the structure of adsorbed layers, and namely of the density profile, is presented. We then review recent studies of layers of the model polymer poly(ethylene oxide), as homopolymer or part of a block copolymer. In this field, scattering with contrast variation has been shown to be a powerful tool to obtain a detailed description of the layer structure. Adsorption of chemically more complex systems, including polyelectrolytes, polymer complexes, grafted chains and biomacromolecules are also discussed in this review, as well as surfactant adsorption.

  11. Analyzing the Effects of Neutron Polarizabilities in Elastic Compton Scattering off ${}^3He$

    E-Print Network [OSTI]

    Deepshikha Shukla; Andreas Nogga; Daniel R. Phillips

    2008-12-01T23:59:59.000Z

    Motivated by the fact that a polarized ${}^3He$ nucleus behaves as an `effective' neutron target, we examine manifestations of neutron electromagnetic polarizabilities in elastic Compton scattering from the Helium-3 nucleus. We calculate both unpolarized and double-polarization observables using chiral perturbation theory to next-to-leading order (${\\mathcal O}(e^2 Q)$) at energies, $\\omega \\lsim m_{\\pi}$, where $m_{\\pi}$ is the pion mass. Our results show that the unpolarized differential cross section can be used to measure neutron electric and magnetic polarizabilities, while two double-polarization observables are sensitive to different linear combinations of the four neutron spin polarizabilities.

  12. Measurement of the Neutron Radius of 208Pb Through Parity-Violation in Electron Scattering

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

    Abrahamyan, Sergey; Albataineh, Hisham; Aniol, Konrad; Armstrong, David; Armstrong, Whitney; Averett, Todd; Babineau, Benjamin; Barbieri, A; Bellini, Vincenzo; Beminiwattha, Rakitha; Benesch, Jay; Benmokhtar, Fatiha; Bierlarski, Trevor; Boeglin, Werner; Camsonne, Alexandre; Canan, Mustafa; Carter, Philip; Cates, Gordon; Chen, Chunhua; Chen, Jian-Ping; Hen, O; Cusanno, Francesco; Dalton, Mark; De Leo, Raffaele; De Jager, Cornelis; Deconinck, Wouter; Decowski, Piotr; Deng, Xiaoyan; Deur, Alexandre; Dutta, Dipangkar; Etile, Asenath; Flay, David; Franklin, Gregg; Friend, Megan; Frullani, Salvatore; Fuchey, Eric; Garibaldi, Franco; Gasser, Estelle; Gilman, Ronald; Guisa, Antonio; Glamazdin, Oleksandr; Gomez, Javier; Grames, Joseph; Gu, Chao; Hansen, Jens-Ole; Hansknecht, John; Higinbotham, Douglas; Holmes, Richard; Holmstrom, Timothy; Horowitz, Charles; Hoskins, Joshua; Huang, Jin; Hyde, Charles; Itard, Florian; Jen, Chun-Min; Jensen, Eric; Jin, Ge; Johnston, Sereres; Kelleher, Aidan; Kliakhandler, Konstantin; King, Paul; Kowalski, Stanley; Kumar, Krishna; Leacock, John; Leckey, John; Lee, Jeong Han; LeRose, John; Lindgren, Richard; Liyanage, Nilanga; Lubinsky, Nicholas; Mammei, Juliette; Mammoliti, Francesco; Margaziotis, Demetrius; Markowitz, Pete; McCreary, Amber; McNulty, Dustin; Mercado, Luis; Meziani, Zein-Eddine; Michaels, Robert; Mihovilovic, Miha; Muangma, Navaphon; Munoz Camacho, Carlos; Nanda, Sirish; Nelyubin, Vladimir; Nuruzzaman,; Oh, Yongseok; Palmer, Alvin; Parno, Diana; Paschke, Kent; Phillips, Sarah; Poelker, Benard; Pomatsalyuk, Roman; Posik, Matthew; Puckett, Andrew; Quinn, Brian; Rakhman, A; Reimer, Paul; Riordan, Seamus; Rogan, Patrick; Ron, Guy; Russo, Guiseppe; Saenboonruang, Kiadtisak; Saha, Arunava; Sawatzky, Bradley; Shahinyan, Albert; Silwal, Rupesh; Sirca, Simon; Slifer, Karl; Solvignon-Slifer, Patricia; Souder, Paul; Leda Sperduto, Maria; Subedi, Ramesh; Suleiman, Riad; Sulkosky, Vincent; Sutera, Concetta; Tobias, William; Troth, Wolfgang; Urciuoli, Guido; Buddhini Waidyawansa, Dinayadura; Wang, Diancheng; Wexler, Jonathan; Wilson, Richard; Wojtsekhowski, Bogdan; Yan, Xinhu; Yao, Huan; Ye, Yunxiu; Ye, Zhiohong; Yim, Vireak; Zana, Lorenzo; Zhan, Xiaohui; Zhang, Jixie; Zhang, Y; Zheng, Xiaochao; Zhu, Pengjia

    2012-03-15T23:59:59.000Z

    We report the first measurement of the parity-violating asymmetry APV in the elastic scattering of polarized electrons from 208Pb. APV is sensitive to the radius of the neutron distribution (Rn). The result APV = 0.656 ± 0.060 (stat) ± 0.013 (syst) corresponds to a difference between the radii of the neutron and proton distributions Rn-Rp = 0.33-0.18+0.16 fm and provides the first electroweak observation of the neutron skin which is expected in a heavy, neutron-rich nucleus.

  13. Fast, Quantitative, and Nondestructive Evaluation on Hydrided LWR Fuel Cladding by Small Angle Incoherent Neutron Scattering of Hydrogen

    SciTech Connect (OSTI)

    Yan, Yong [ORNL; Qian, Shuo [ORNL; Littrell, Ken [ORNL; Parish, Chad M [ORNL; Plummer, Lee K [ORNL

    2015-01-01T23:59:59.000Z

    A non-destructive neutron scattering method to precisely measure the uptake of hydrogen and the distribution of hydride precipitates in light water reactor (LWR) fuel cladding was developed. Zircaloy-4 cladding used in commercial LWRs was used to produce hydrided specimens. The hydriding apparatus consists of a closed stainless steel vessel that contains Zr alloy specimens and hydrogen gas. Following hydrogen charging, the hydrogen content of the hydrided specimens was measured using the vacuum hot extraction method, by which the samples with desired hydrogen concentration were selected for the neutron study. Optical microscopy shows that our hydriding procedure results in uniform distribution of circumferential hydrides across the wall. Small angle neutron incoherent scattering was performed in the High Flux Isotope Reactor at Oak Ridge National Laboratory. Our study demonstrates that the hydrogen in commercial Zircaloy-4 cladding can be measured very accurately in minutes by this nondestructive method over a wide range of hydrogen concentrations from a very small amount ( 20 ppm) to over 1000 ppm. The hydrogen distribution in a tube sample was obtained by scaling the neutron scattering rate with a factor determined by a calibration process using standard, destructive direct chemical analysis methods on the specimens. This scale factor can be used in future tests with unknown hydrogen concentrations, thus providing a nondestructive method for absolute hydrogen concentration determination.

  14. A neutron diffraction study from 6 to 293 K and a macroscopic-scale quantum theory of the hydrogen bonded dimers in the crystal of benzoic acid

    E-Print Network [OSTI]

    -state-NMR and quasi-elastic neutron scattering are consistent with wave-like, rather than particle-like protons. We is essentially the case for solid-state NMR or quasi-elastic neutron scattering (QENS);6,15 (iii) theoreticalA neutron diffraction study from 6 to 293 K and a macroscopic-scale quantum theory of the hydrogen

  15. Asterix is a reflectometer/diffractometer/grazing-incidence-SANS/SESAME-enabled-SANS spectrometer that is primarily used for experiments or neutron scattering

    E-Print Network [OSTI]

    that is primarily used for experiments or neutron scattering techniques requiring polarized neutron beams detector arm is readily configurable for polarization or energy analysis of the scattered neutron beam be translated in the horizontal and vertical directions. Neutron detector (Spin Echo Scattering Angle

  16. Journal of the Korean Physical Society, Vol. 55, No. 4, October 2009, pp. 13891393 Measurements of the Neutron Scattering Spectrum from 238

    E-Print Network [OSTI]

    Danon, Yaron

    of the Neutron Scattering Spectrum from 238 U and Comparison of the Results with a Calculation at the 36.68-e, in final form 22 July 2009) Neutrons elastically scattered from 238 U were measured in the neutron energy neutrons were measured at 25.5 m from the U sample by using a 6 Li detector, and the scattering direction

  17. Solvent contribution to the stability of a physical gel characterized by quasi-elastic neutron scattering

    E-Print Network [OSTI]

    Sylvie Spagnoli; Isabelle Morfin; Miguel A. Gonzalez; Pierre Carcabal; Marie Plazanet

    2015-02-05T23:59:59.000Z

    The dynamics of a physical gel, namely the Low Molecular Mass Organic Gelator {\\textit Methyl-4,6-O-benzylidene-$\\alpha$ -D-mannopyranoside ($\\alpha$-manno)} in water and toluene are probed by neutron scattering. Using high gelator concentrations, we were able to determine, on a timescale from a few ps to 1 ns, the number of solvent molecules that are immobilised by the rigid network formed by the gelators. We found that only few toluene molecules per gelator participate to the network which is formed by hydrogen bonding between the gelators' sugar moieties. In water, however, the interactions leading to the gel formations are weaker, involving dipolar, hydrophobic or $\\pi-\\pi$ interactions and hydrogen bonds are formed between the gelators and the surrounding water. Therefore, around 10 to 14 water molecules per gelator are immobilised by the presence of the network. This study shows that neutron scattering can give valuable information about the behaviour of solvent confined in a molecular gel.

  18. National School on Neutron and X-ray Scattering Oak Ridge National Laboratory June 12-26, 2010 Oak Ridge, Tennessee

    E-Print Network [OSTI]

    Pennycook, Steve

    National School on Neutron and X-ray Scattering Oak Ridge National Laboratory June 12-26, 2010 Oak:30 Lecture Inelastic Neutron Scattering B. D. Gaulin McMaster University Lecture Magnetic Scattering B. D Break Break Break Break 9:45 - 10:45 Lecture Continued Inelastic Neutron Scattering B. D. Gaulin Mc

  19. Measurement of the elastic scattering cross section of neutrons from argon and neon

    E-Print Network [OSTI]

    S. MacMullin; M. Kidd; R. Henning; W. Tornow; C. R. Howell; M. Brown

    2012-12-12T23:59:59.000Z

    Background: The most significant source of background in direct dark matter searches are neutrons that scatter elastically from nuclei in the detector's sensitive volume. Experimental data for the elastic scattering cross section of neutrons from argon and neon, which are target materials of interest to the dark matter community, were previously unavailable. Purpose: Measure the differential cross section for elastic scattering of neutrons from argon and neon in the energy range relevant to backgrounds from (alpha,n) reactions in direct dark matter searches. Method: Cross-section data were taken at the Triangle Universities Nuclear Laboratory (TUNL) using the neutron time-of-flight technique. These data were fit using the spherical optical model. Results: The differential cross section for elastic scatting of neutrons from neon at 5.0 and 8.0 MeV and argon at 6.0 MeV was measured. Optical-model parameters for the elastic scattering reactions were determined from the best fit to these data. The total elastic scattering cross section for neon was found to differ by 6% at 5.0 MeV and 13% at 8.0 MeV from global optical-model predictions. Compared to a local optical-model for 40Ar, the elastic scattering cross section was found to differ from the data by 8% at 6.0 MeV. Conclusions: These new data are important for improving Monte-Carlo simulations and background estimates for direct dark matter searches and for benchmarking optical models of neutron elastic scattering from these nuclei.

  20. Scaling analysis of bio-molecular dynamics derived from elastic incoherent neutron scattering experiments

    SciTech Connect (OSTI)

    Doster, W. [Physik-Department, Technische Universität München, D-85748 Garching (Germany)] [Physik-Department, Technische Universität München, D-85748 Garching (Germany); Nakagawa, H. [Jülich Centre for Neutron Science, Forschungszentrum Jülich GmbH, Outstation at MLZ, Lichtenbergstraße 1, 85747 Garching (Germany) [Jülich Centre for Neutron Science, Forschungszentrum Jülich GmbH, Outstation at MLZ, Lichtenbergstraße 1, 85747 Garching (Germany); Japan Atomic Energy Agency, Quantum Beam Science Directorate, Tokai, Ibaraki 319-1195 (Japan); Appavou, M. S. [Jülich Centre for Neutron Science, Forschungszentrum Jülich GmbH, Outstation at MLZ, Lichtenbergstraße 1, 85747 Garching (Germany)] [Jülich Centre for Neutron Science, Forschungszentrum Jülich GmbH, Outstation at MLZ, Lichtenbergstraße 1, 85747 Garching (Germany)

    2013-07-28T23:59:59.000Z

    Numerous neutron scattering studies of bio-molecular dynamics employ a qualitative analysis of elastic scattering data and atomic mean square displacements. We provide a new quantitative approach showing that the intensity at zero energy exchange can be a rich source of information of bio-structural fluctuations on a pico- to nano-second time scale. Elastic intensity scans performed either as a function of the temperature (back-scattering) and/or by varying the instrumental resolution (time of flight spectroscopy) yield the activation parameters of molecular motions and the approximate structural correlation function in the time domain. The two methods are unified by a scaling function, which depends on the ratio of correlation time and instrumental resolution time. The elastic scattering concept is illustrated with a dynamic characterization of alanine-dipeptide, protein hydration water, and water-coupled protein motions of lysozyme, per-deuterated c-phycocyanin (CPC) and hydrated myoglobin. The complete elastic scattering function versus temperature, momentum exchange, and instrumental resolution is analyzed instead of focusing on a single cross-over temperature of mean square displacements at the apparent onset temperature of an-harmonic motions. Our method predicts the protein dynamical transition (PDT) at T{sub d} from the collective (?) structural relaxation rates of the solvation shell as input. By contrast, the secondary (?) relaxation enhances the amplitude of fast local motions in the vicinity of the glass temperature T{sub g}. The PDT is specified by step function in the elastic intensity leading from elastic to viscoelastic dynamic behavior at a transition temperature T{sub d}.

  1. Scattering Theory When an x-ray beam (or neutron or light) passes through a material with

    E-Print Network [OSTI]

    Beaucage, Gregory

    Scattering Theory When an x-ray beam (or neutron or light) passes through a material radiation is scattered in directions that differ from that of the incident beam. Scattering arises since x of scattered radiation resulting from this process bears a direct relationship to the structure (the pattern

  2. Microscopic calculation of the spin-dependent neutron scattering lengths on 3He

    E-Print Network [OSTI]

    H. M. Hofmann; G. M. Hale

    2003-04-16T23:59:59.000Z

    We report on the spin.dependent neutron scattering length on 3He from a microscopic calculation of p-3H, n-3He, and d-2H scattering employing the Argonne v18 nucleon-nucleon potential with and without additional three-nucleon force. The results and that of a comprehensive R-matrix analysis are compared to a recent measurement. The overall agreement for the scattering lengths is quite good. The imaginary parts of the scattering lengths are very sensitive to the inclusion of three-nucleon forces, whereas the real parts are almost insensitive.

  3. Finite volume effects in low-energy neutron-deuteron scattering

    E-Print Network [OSTI]

    Alexander Rokash; Evgeny Epelbaum; Hermann Krebs; Dean Lee; Ulf-G. Meißner

    2013-08-15T23:59:59.000Z

    We present a lattice calculation of neutron-deuteron scattering at very low energies and investigate in detail the impact of the topological finite-volume corrections. Our calculations are carried out in the framework of pionless effective field theory at leading order in the low-energy expansion. Using lattice sizes and a lattice spacing comparable to those employed in nuclear lattice simulations, we find that the topological volume corrections must be taken into account in order to obtain correct results for the neutron-proton S-wave scattering lengths.

  4. Note: Versatile sample stick for neutron scattering experiments in high electric fields

    SciTech Connect (OSTI)

    Bartkowiak, M., E-mail: marek.bartkowiak@psi.ch [Laboratory for Developments and Methods, Paul Scherrer Institut, CH-5232 Villigen (Switzerland); White, J. S. [Laboratory for Neutron Scattering, Paul Scherrer Institut, CH-5232 Villigen (Switzerland) [Laboratory for Neutron Scattering, Paul Scherrer Institut, CH-5232 Villigen (Switzerland); Laboratory for Quantum Magnetism, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland); Rønnow, H. M.; Prša, K. [Laboratory for Quantum Magnetism, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland)] [Laboratory for Quantum Magnetism, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland)

    2014-02-15T23:59:59.000Z

    We present a versatile high voltage sample stick that fits into all cryomagnets and standard cryostats at the Swiss Spallation Neutron Source, Paul Scherrer Institut, and which provides a low effort route to neutron scattering experiments that combine electric field with low temperature and magnetic field. The stick allows for voltages up to 5 kV and can be easily adapted for different scattering geometries. We discuss the design consideration and thermal behavior of the stick, and give one example to showcase the abilities of the device.

  5. Exact limiting relation between the structure factors in neutron and x-ray scattering

    E-Print Network [OSTI]

    V. B. Bobrov; S. A. Trigger; S. N. Skovorod'ko

    2010-07-11T23:59:59.000Z

    The ratio of the static matter structure factor measured in experiments on coherent X-ray scattering to the static structure factor measured in experiments on neutron scattering is considered. It is shown theoretically that this ratio in the long-wavelength limit is equal to the nucleus charge at arbitrary thermodynamic parameters of a pure substance (the system of nuclei and electrons, where interaction between particles is pure Coulomb) in a disordered equilibrium state. This result is the exact relation of the quantum statistical mechanics. The experimental verification of this relation can be done in the long wavelength X-ray and neutron experiments.

  6. Meausrement of the Neutron Radius of {sup 208}Pb Through Parity Violation in Electron Scattering

    SciTech Connect (OSTI)

    Saenboonruang, Kiadtisak [Virginia U., JLAB

    2013-05-31T23:59:59.000Z

    In contrast to the nuclear charge densities, which have been accurately measured with electron scattering, the knowledge of neutron densities still lack precision. Previous model-dependent hadron experiments suggest the difference between the neutron radius, R{sub n}, of a heavy nucleus and the proton radius, R{sub p}, to be in the order of several percent. To accurately obtain the difference, R{sub n}-R{sub p}, which is essentially a neutron skin, the Jefferson Lab Lead ({sup 208}Pb) Radius Experiment (PREX) measured the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from {sup 208}Pb at an energy of 1.06 GeV and a scattering angle of 5{degrees}#14;. Since Z{sup 0} boson couples mainly to neutrons, this asymmetry provides a clean measurement of R{sub n} with respect to R{sub p}. PREX was conducted at the Jefferson lab experimental Hall A, from March to June 2010. The experiment collected a final data sample of 2x#2;10{sup 7} helicity-window quadruplets. The measured parity-violating electroweak asymmetry A{sub PV} = 0.656 {+-}#6; 0.060 (stat) {+-}#6; 0.014 (syst) ppm corresponds to a difference between the radii of the neutron and proton distributions, R{sub n}-R{sub p} = 0.33{sup +0.16}{sub -0.18} fm and provides the #12;first electroweak observation of the neutron skin as expected in a heavy, neutron-rich nucleus. The value of the neutron radius of {sup 208}Pb has important implications for models of nuclear structure and their application in atomic physics and astrophysics such as atomic parity non-conservation (PNC) and neutron stars.

  7. PHYSICAL REVIEW C 86, 024612 (2012) Neutrino-nucleus coherent scattering as a probe of neutron density distributions

    E-Print Network [OSTI]

    Engel, Jonathan

    2012-01-01T23:59:59.000Z

    PHYSICAL REVIEW C 86, 024612 (2012) Neutrino-nucleus coherent scattering as a probe of neutron manuscript received 25 July 2012; published 30 August 2012) Neutrino-nucleus coherent elastic scattering provides a theoretically appealing way to measure the neutron part of nuclear form factors. Using

  8. Is there an Ay problem in low-energy neutron-proton scattering?

    E-Print Network [OSTI]

    Franz Gross; Alfred Stadler

    2008-08-21T23:59:59.000Z

    We calculate Ay in neutron-proton scattering for the interactions models WJC-1 and WJC-2 in the Covariant Spectator Theory. We find that the recent 12 MeV measurements performed at TUNL are in better agreement with our results than with the Nijmegen Phase Shift Analysis of 1993, and after reviewing the low-energy data, conclude that there is no Ay problem in low-energy np scattering.

  9. For more information: Neutron Scattering Science User Office, neutronusers@ornl.gov or (865) 574-4600.

    E-Print Network [OSTI]

    For more information: Neutron Scattering Science User Office, neutronusers@ornl.gov or (865) 574 Neutron Source (SNS) will be accepted via the web-based proposal system until 11:59 a.m. EST, (NOON. Information and instructions To learn more about submitting a proposal for beam time, go to http://neutrons

  10. Molecular structures of fluid phase phosphatidylglycerol bilayers as determined by small angle neutron and X-ray scattering

    E-Print Network [OSTI]

    Nagle, John F.

    neutron and X-ray scattering Jianjun Pan a, , Frederick A. Heberle a , Stephanie Tristram-Nagle b Matter Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, TN 378316100 Institute for Neutron Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 378316453, USA e Canadian

  11. Proton Angular Distribution for 90 Mev Neutron-proton Scattering

    E-Print Network [OSTI]

    Hadley, James

    2010-01-01T23:59:59.000Z

    3, 1947 The angular distribution of the recoil protons inneutron -proton scattering at 90 Mev has been measured forNO. W ..7405-Eng 48 PROTON .ANGULAR DISTRIBUTION FOR 90 lWEV

  12. Re-evaluation of Neutron-4He Elastic Scattering Data near 20 MeV

    E-Print Network [OSTI]

    M. Drosg; R. Avalos Ortiz; B. Hoop

    2012-10-02T23:59:59.000Z

    Measured differential elastic scattering cross sections of 17.71-, 20.97-, and 23.72-MeV neutrons from liquid helium-4 were re-evaluated and corrected for sample size and multiple scattering effects by means of a Monte Carlo technique implemented in a more recent code (MCNPX). Results indicate that earlier corrections via a code, MAGGIE-2, overestimated the size of multiple scattering effects by an order of magnitude. The corrected differential cross sections and Legendre coefficients obtained by least-squares fits are given.

  13. Nanoscale structure in AgSbTe2 determined by diffuse elastic neutron scattering

    SciTech Connect (OSTI)

    Specht, Eliot D [ORNL; Ma, Jie [ORNL; Delaire, Olivier A [ORNL; Budai, John D [ORNL; May, Andrew F [ORNL; Karapetrova, Evguenia A. [Argonne National Laboratory (ANL)

    2015-01-01T23:59:59.000Z

    Diffuse elastic neutron scattering measurements confirm that AgSbTe2 has a hierarchical structure, with defects on length scales from nanometers to microns. While scattering from mesoscale structure is consistent with previously-proposed structures in which Ag and Sb order on a NaCl lattice, more diffuse scattering from nanoscale structure suggests a structural rearrangement in which hexagonal layers form a combination of (ABC), (ABA), and (AAB) stacking sequences. The AgCrSe2 structure is the best-fitting model for the local atomic arrangements.

  14. Possible doublet mechanism for a regular component of parity violation in neutron scattering

    E-Print Network [OSTI]

    V. V. Flambaum; V. G. Zelevinsky

    1994-12-19T23:59:59.000Z

    A nucleus with octupole deformation of the mean field reveals rotational doublets with the same angular momentum and opposite parity. Mediated by the Coriolis-type interaction, the doublet structure leads to a strong regular component in the parity violation caused by weak interaction. This can explain sign correlations observed in polarized neutron scattering by $^{232}$Th.

  15. Time-reversal invariance violation measurement using polarized neutron scattering from polarized xenon

    E-Print Network [OSTI]

    Pinghan Chu

    2014-03-06T23:59:59.000Z

    We proposed to use polarized neutrons scattering from a hyperpolarized 131Xe gaseous target in order to measure time-reversal violation effect in baryon processes with nucleons. This article provides a brief introduction, historical review, and possible methods to construct a hyperpolarized 131Xe gaseous target.

  16. National School on Neutron and X-ray Scattering Building 223 Auditorium, Room B002 September 24 -October 11, 2008 Argonne National Laboratory

    E-Print Network [OSTI]

    Pennycook, Steve

    National School on Neutron and X-ray Scattering Building 223 Auditorium, Room B002 September 24 (HFIR) Neutron Scattering Science Division Oak Ridge Laboratory 10:15 - 10:30 Break 9:30 - 9:45 Break 10 School on Neutron and X-ray Scattering Building 8600, Main Lobby September 24 - October 11, 2008 Oak

  17. Week 2 AGENDA: National School on Neutron and X-ray Scattering page 1 of 5 Oak Ridge National Laboratory [9/30/08

    E-Print Network [OSTI]

    Pennycook, Steve

    Week 2 AGENDA: National School on Neutron and X-ray Scattering page 1 of 5 Oak Ridge National Ridge National Laboratory Dean Myles, Director ORNL Neutron Scattering Science Division 1 GROUPS [A,B,C,D,E,F,G,H,I] Iran Thomas Auditorium Lecture Inelastic Neutron Scattering R. Osborn, ANL ALL

  18. Inelastic neutron scattering spectrum of H2@C60 and its temperature dependence decoded using rigorous quantum calculations and a new

    E-Print Network [OSTI]

    Turro, Nicholas J.

    Inelastic neutron scattering spectrum of H2@C60 and its temperature dependence decoded using://jcp.aip.org/about/rights_and_permissions #12;THE JOURNAL OF CHEMICAL PHYSICS 139, 064309 (2013) Inelastic neutron scattering spectrum of H2@C60 quantum cal- culations of the inelastic neutron scattering (INS) spectra of this prototypical endohedral

  19. Large volume high-pressure cell for inelastic neutron scattering W. Wang, D. A. Sokolov, A. D. Huxley, and K. V. Kamenev

    E-Print Network [OSTI]

    Hall, Christopher

    Large volume high-pressure cell for inelastic neutron scattering W. Wang, D. A. Sokolov, A. D for inelastic neutron scattering measurements of quantum fluids and solids Rev. Sci. Instrum. 84, 015101 (2013) TOF-SEMSANS--Time-of-flight spin-echo modulated small-angle neutron scattering J. Appl. Phys. 112

  20. The Lujan Center is a national user facility funded by Basic Energy Sciences of the Department of Energy which o ers capability for basic and applied neutron scattering

    E-Print Network [OSTI]

    of Energy which o ers capability for basic and applied neutron scattering relevant to national security are the domain of the low-Q scattering intrument, LQD. These well-established neutron techniques probe long Matter, Local Structure, and Nanomaterials The Lujan Neutron Scattering Center encompasses a set

  1. JOURNAL DE PHYSIQUE Colloque C4, supplment au n" 4, Tome 40, avril 1979, page C4-142 Magnetic neutron scattering on intermetallic uranium compounds (*)

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    neutron scattering on intermetallic uranium compounds (*) M. Loewenhaupt (f ), S. Horn (**), F. Steglich.- Abstract. -- We report on inelastic neutron scattering experiments performed in the temperature range 5 K quasielastic line. Using thermal neutrons, no inelastic contributions to the magnetic scattering could

  2. Scattering of 64 eV to 3 keV Neutrons from Polyethylene and Graphite and the Coherence Length Problem

    E-Print Network [OSTI]

    Danon, Yaron

    Scattering of 64 eV to 3 keV Neutrons from Polyethylene and Graphite and the Coherence Length 12180, USA (Received 31 August 2005; published 8 February 2006) We measured the neutron scattering by the neutron coherence length. The scattered intensity ratios were found to conform to conventional

  3. Measurement of the structure function of the nearly free neutron using spectator tagging in inelastic $^2$H(e, e'p)X scattering with CLAS

    E-Print Network [OSTI]

    S. Tkachenko; N. Baillie; S. E. Kuhn; J. Zhang; J. Arrington; P. Bosted; S. Bültmann; M. E. Christy; D. Dutta; R. Ent; H. Fenker; K. A. Griffioen; M. Ispiryan; N. Kalantarians; C. E. Keppel; W. Melnitchouk; V. Tvaskis; K. P. Adhikari; M. Aghasyan; M. J. Amaryan; S. Anefalos Pereira; H. Avakian; J. Ball; N. A. Baltzell; M. Battaglieri; I. Bedlinskiy; A. S. Biselli; W. J. Briscoe; W. K. Brooks; V. D. Burkert; D. S. Carman; A. Celentano; S. Chandavar; G. Charles; P. L. Cole; M. Contalbrigo; O. Cortes; V. Crede; A. D'Angelo; N. Dashyan; R. De Vita; E. De Sanctis; A. Deur; C. Djalali; G. E. Dodge; D. Doughty; R. Dupre; H. Egiyan; A. El Alaoui; L. El Fassi; L. Elouadrhiri; P. Eugenio; G. Fedotov; J. A. Fleming; B. Garillon; N. Gevorgyan; Y. Ghandilyan; G. P. Gilfoyle; K. L. Giovanetti; F. X. Girod; J. T. Goetz; E. Golovatch; R. W. Gothe; M. Guidal; L. Guo; K. Hafidi; H. Hakobyan; C. Hanretty; N. Harrison; M. Hattawy; K. Hicks; D. Ho; M. Holtrop; C . E. Hyde; Y. Ilieva; D. G. Ireland; B. S. Ishkhanov; H. S. Jo; D. Keller; M. Khandaker; A. Kim; W. Kim; P. M. King; A. Klein; F. J. Klein; S. Koirala; V. Kubarovsky; S. V. Kuleshov; P. Lenisa; S. Lewis; K. Livingston; H. Lu; M. MacCormick; I. J. D. MacGregor; N. Markov; M. Mayer; B. McKinnon; T. Mineeva; M. Mirazita; V. Mokeev; R. A. Montgomery; H. Moutarde; C. Munoz Camacho; P. Nadel-Turonski; S. Niccolai; G. Niculescu; I. Niculescu; M. Osipenko; L. L. Pappalardo; R. Paremuzyan; K. Park; E. Pasyuk; J. J. Phillips; S. Pisano; O. Pogorelko; S. Pozdniakov; J. W. Price; S. Procureur; D. Protopopescu; A. J . R. Puckett; D. Rimal; M. Ripani; A. Rizzo; G. Rosner; P. Rossi; P. Roy; F. Sabatié; D. Schott; R. A. Schumacher; E. Seder; I. Senderovich; Y. G. Sharabian; A. Simonyan; G. D. Smith; D. I. Sober; D. Sokhan; S. Stepanyan; S. S. Stepanyan; S. Strauch; W. Tang; M. Ungaro; A. V. Vlassov; H. Voskanyan; E. Voutier; N. K. Walford; D. Watts; X. Wei; L. B. Weinstein; M. H. Wood; L. Zana; I. Zonta

    2014-10-03T23:59:59.000Z

    Much less is known about neutron structure than that of the proton due to the absence of free neutron targets. Neutron information is usually extracted from data on nuclear targets such as deuterium, requiring corrections for nuclear binding and nucleon off-shell effects. These corrections are model dependent and have significant uncertainties, especially for large values of the Bjorken scaling variable x. The Barely Off-shell Nucleon Structure (BONuS) experiment at Jefferson Lab measured the inelastic electron deuteron scattering cross section, tagging spectator protons in coincidence with the scattered electrons. This method reduces nuclear binding uncertainties significantly and has allowed for the first time a (nearly) model independent extraction of the neutron structure function. A novel compact radial time projection chamber was built to detect protons with momentum between 70 and 150 MeV/c. For the extraction of the free neutron structure function $F_{2n}$, spectator protons at backward angle and with momenta below 100 MeV/c were selected, ensuring that the scattering took place on a nearly free neutron. The scattered electrons were detected with Jefferson Lab's CLAS spectrometer. The extracted neutron structure function $F_{2n}$ and its ratio to the deuteron structure function $F_{2d}$ are presented in both the resonance and deep inelastic regions. The dependence of the cross section on the spectator proton momentum and angle is investigated, and tests of the spectator mechanism for different kinematics are performed. Our data set can be used to study neutron resonance excitations, test quark hadron duality in the neutron, develop more precise parametrizations of structure functions, as well as investigate binding effects (including possible mechanisms for the nuclear EMC effect) and provide a first glimpse of the asymptotic behavior of d/u as x goes to 1.

  4. Neutron Scattering Science User Office, neutronusers@ornl.gov or (865) 574-4600. Proposals for beam time at Oak Ridge National Laboratory's High Flux Isotope Reactor (HFIR)

    E-Print Network [OSTI]

    Pennycook, Steve

    Neutron Scattering Science User Office, neutronusers@ornl.gov or (865) 574-4600. Proposals for beam Wildgruber, wildgrubercu@ornl.gov. VISION CallforProposals neutrons.ornl.gov Neutron Scattering Science - Oak time at Oak Ridge National Laboratory's High Flux Isotope Reactor (HFIR) and Spallation Neutron Source

  5. Quark-Model Baryon-Baryon Interaction Applied to the Neutron-Deuteron Scattering (II) Polalization Observables of the Elastic Scattering

    E-Print Network [OSTI]

    Kenji Fukukawa; Yoshikazu Fujiwara

    2011-02-15T23:59:59.000Z

    The neutron-deuteron (nd) scattering is solved in the Faddeev formalism, employing the energy-independent version of the quark-model baryon-baryon interaction fss2. The differential cross sections and the spin polarization of the elastic scattering up to the neutron incident energy $E_n=65$ MeV are well reproduced without reinforcing fss2 with the three-body force. The vector analyzing-power of the neutron, $A_y(\\theta)$, in the energy region $E_n$ < 25 MeV is largely improved in comparison with the predictions by the meson-exchange potentials, thus yielding a partial solution of the long-standing $A_y$-puzzle owing to the nonlocality of the short-range repulsion produced by the quark-model baryon-baryon interaction. The large Coulomb effect in the vector and tensor analyzing-powers in $E_n$ < 10 MeV is also analyzed based on the Vincent and Phatak method and recent detailed studies by other authors.

  6. Importance of Compton scattering to radiation spectra of isolated neutron stars

    E-Print Network [OSTI]

    V. Suleimanov; K. Werner

    2006-12-22T23:59:59.000Z

    Model atmospheres of isolated neutron stars with low magnetic field are calculated with Compton scattering taking into account. Models with effective temperatures 1, 3 and 5 MK, with two values of surface gravity log(g)g = 13.9 and 14.3), and different chemical compositions are calculated. Radiation spectra computed with Compton scattering are softer than the computed with Thomson scattering at high energies (E > 5 keV) for hot (T_eff > 1 MK) atmospheres with hydrogen-helium composition. Compton scattering is more significant to hydrogen models with low surface gravity. The emergent spectra of the hottest (T_eff > 3 MK) model atmospheres can be described by diluted blackbody spectra with hardness factors ~ 1.6 - 1.9. Compton scattering is less important for models with solar abundance of heavy elements.

  7. Characterization of irradiation-induced precipitates by small angle x-ray and neutron scattering experiments

    SciTech Connect (OSTI)

    Grosse, M.; Eichhorn, F.; Boehmert, J.; Brauer, G. [Research Center Rossendorf Inc., Dresden (Germany)

    1996-12-31T23:59:59.000Z

    The nature of the irradiation-induced precipitates in the VVER-440-type steel 15Kh2MFA has been investigated by the combination of small angle neutron scattering and anomalous small angle X-ray scattering. Information about the chemical composition of the irradiation-induced precipitates was obtained by the method of contrast variation. ASAXS experiments with variation of the X-ray energy near the energy of the vanadium K-absorption edge prove the content of vanadium within the irradiation-induced precipitates. The scattering density of the precipitates is lower than the scattering density of the iron matrix. The chemical shift of the vanadium-K{sub {alpha}}-absorption-edge and the results of the variation of the contribution of the magnetic scattering in the SANS experiment show, that vanadium does not precipitate in an elementary state. These results can be explained by assuming the precipitates are vanadium carbide.

  8. Comparison of discrete and continuous thermal neutron scattering treatments in MCNP5

    SciTech Connect (OSTI)

    Pavlou, A. T. [Univ. of Michigan, Dept. of Nuclear Engineering and Radiological Sciences, 2355 Bonisteel Boulevard, Ann Arbor, MI 48109 (United States); Brown, F. B. [Los Alamos National Laboratory, Monte Carlo Codes Group, MS A143, PO Box 1663, Los Alamos, NM 87545 (United States); Martin, W. R. [Univ. of Michigan, Dept. of Nuclear Engineering and Radiological Sciences, 2355 Bonisteel Boulevard, Ann Arbor, MI 48109 (United States); Kiedrowski, B. C. [Los Alamos National Laboratory, Monte Carlo Codes Group, MS A143, PO Box 1663, Los Alamos, NM 87545 (United States)

    2012-07-01T23:59:59.000Z

    The standard discrete thermal neutron S({alpha},{beta}) scattering treatment in MCNP5 is compared with a continuous S({alpha},{beta}) scattering treatment using a criticality suite of 119 benchmark cases and ENDF/B-VII.0 nuclear data. In the analysis, six bound isotopes are considered: beryllium metal, graphite, hydrogen in water, hydrogen in polyethylene, beryllium in beryllium oxide and oxygen in beryllium oxide. Overall, there are only small changes in the eigenvalue (k{sub eff}) between discrete and continuous treatments. In the comparison of 64 cases that utilize S({alpha},{beta}) scattering, 62 agreed at the 95% confidence level, and the 2 cases with differences larger than 3 {sigma} agreed within 1 {sigma} when more neutrons were run in the calculations. The results indicate that the changes in eigenvalue between continuous and discrete treatments are random, small, and well within the uncertainty of measured data for reactor criticality experiments. (authors)

  9. INELASTIC LIGHT SCATTERING STUDIES OF BOROCARBIDE SUPERCONDUCTORS

    E-Print Network [OSTI]

    Yang, In-Sang

    INELASTIC LIGHT SCATTERING STUDIES OF BOROCARBIDE SUPERCONDUCTORS IN­SANG YANG Department In recent years of studies in ``unconventional'' superconductivity, researchers have concentrated on exotic behavior of the heavy fermion and cuprate su­ perconductors. However, even superconductors that are thought

  10. Neutron Scattering Investigation of Phonon Scattering Rates in Ag1-xSb1+xTe2+x (x = 0, 0.1, and 0.2)

    SciTech Connect (OSTI)

    Abernathy, Douglas L [ORNL; Budai, John D [ORNL; Delaire, Olivier A [ORNL; Ehlers, Georg [ORNL; Hong, Tao [ORNL; Karapetrova, Evguenia A. [Argonne National Laboratory (ANL); Ma, Jie [ORNL; May, Andrew F [ORNL; McGuire, Michael A [ORNL; Specht, Eliot D [ORNL

    2014-01-01T23:59:59.000Z

    The phonon dispersions and scattering rates of the thermoelectric material AgSbTe$_{2}$ were measured as a function of temperature with inelastic neutron scattering. The results show that phonon scattering rates are large and weakly dependent on temperature. The lattice thermal conductivity was calculated from the measured phonon lifetimes and group velocities, providing good agreement with bulk transport measurements. The measured phonon scattering rates and their temperature dependence are compared with models of phonon scattering by anharmonicity and point defect. We find that these processes cannot account for the large total phonon scattering rates observed, and their lack of temperature dependence. Neutron and synchrotron diffraction measurements on single crystals revealed an extensive nanostructure from cation ordering, which is likely responsible for the strong phonon scattering.

  11. Discrimination of gamma rays due to inelastic neutron scattering in AGATA

    E-Print Network [OSTI]

    A. Ataç; A. Kas¸kas A; S. Akkoyun A; M. S¸enyi?git A; T. Hüyük A; S. O. Kara A; J. Nyberg B

    Possibilities of discriminating neutrons and ? rays in the AGATA ?-ray tracking spectrometer have been investigated with the aim of reducing the background due to inelastic scattering of neutrons in the high-purity germanium crystals. This background may become a serious problem especially in experiments with neutron-rich radioactive ion beams. Simulations using the Geant4 toolkit and a tracking program based on the forward tracking algorithm were carried out by emitting neutrons and ? rays from the center of AGATA. Three different methods were developed and tested in order to find “fingerprints ” of the neutron interaction points in the detectors. In a simulation with simultaneous emission of six neutrons with energies in the range 1-5 MeV and ten ? rays with energies between 150 and 1450 keV, the peak-to-background ratio at a ?-ray energy of 1.0 MeV was improved by a factor of 2.4 after neutron rejection with a reduction of the photopeak efficiency at 1.0 MeV of only a factor of 1.25.

  12. Discrimination of gamma rays due to inelastic neutron scattering in AGATA

    E-Print Network [OSTI]

    A. Ataç; A. Ka?ka?; S. Akkoyun; M. ?enyi?it; T. Hüyük; S. O. Kara; J. Nyberg

    2009-06-10T23:59:59.000Z

    Possibilities of discriminating neutrons and gamma rays in the AGATA gamma-ray tracking spectrometer have been investigated with the aim of reducing the background due to inelastic scattering of neutrons in the high-purity germanium crystals. This background may become a serious problem especially in experiments with neutron-rich radioactive ion beams. Simulations using the Geant4 toolkit and a tracking program based on the forward tracking algorithm were carried out by emitting neutrons and gamma rays from the center of AGATA. Three different methods were developed and tested in order to find 'fingerprints' of the neutron interaction points in the detectors. In a simulation with simultaneous emission of six neutrons with energies in the range 1-5 MeV and ten gamma rays with energies between 150 and 1450 keV, the peak-to-background ratio at a gamma-ray energy of 1.0 MeV was improved by a factor of 2.4 after neutron rejection with a reduction of the photopeak efficiency at 1.0 MeV of only a factor of 1.25.

  13. Importance of Compton scattering for radiation spectra of isolated neutron stars with weak magnetic fields

    E-Print Network [OSTI]

    V. Suleimanov; K. Werner

    2007-02-15T23:59:59.000Z

    Emergent model spectra of neutron star atmospheres are widely used to fit the observed soft X-ray spectra of different types of isolated neutron stars. We investigate the effect of Compton scattering on the emergent spectra of hot (T_eff > 10^6 K) isolated neutron stars with weak magnetic fields. In order to compute model atmospheres in hydrostatic and radiative equilibrium we solve the radiation transfer equation with the Kompaneets operator. We calculate a set of models with effective temperatures in the range 1 - 5 * 10^6 K, with two values of surface gravity (log g = 13.9 and 14.3) and different chemical compositions. Radiation spectra computed with Compton scattering are softer than those computed without Compton scattering at high energies (E > 5 keV) for light elements (H or He) model atmospheres. The Compton effect is more significant in H model atmospheres and models with low surface gravity. The emergent spectra of the hottest (T_eff > 3 * 10^6 K) model atmospheres can be described by diluted blackbody spectra with hardness factors ~ 1.6 - 1.9. Compton scattering is less important in models with solar abundance of heavy elements.

  14. Mantid - Data Analysis and Visualization Package for Neutron Scattering and $\\mu SR$ Experiments

    SciTech Connect (OSTI)

    Arnold, Owen [ISIS Facility, Rutherford Appleton Laboratory (ISIS); Bilheux, Jean-Christophe [ORNL; Borreguero Calvo, Jose M [ORNL; Buts, Alex [ISIS Facility, Rutherford Appleton Laboratory (ISIS); Campbell, Stuart I [ORNL; Doucet, Mathieu [ORNL; Draper, Nicholas J [ORNL; Ferraz Leal, Ricardo F [ORNL; Gigg, Martyn [ISIS Facility, Rutherford Appleton Laboratory (ISIS); Lynch, Vickie E [ORNL; Mikkelson, Dennis J [ORNL; Mikkelson, Ruth L [ORNL; Miller, Ross G [ORNL; Perring, Toby G [ORNL; Peterson, Peter F [ORNL; Ren, Shelly [ORNL; Reuter, Michael A [ORNL; Savici, Andrei T [ORNL; Taylor, Jonathan W [ORNL; Taylor, Russell J [ORNL; Zhou, Wenduo [ORNL; Zikovsky, Janik L [ORNL

    2014-11-01T23:59:59.000Z

    The Mantid framework is a software solution developed for the analysis and visualization of neutron scattering and muon spin measurements. The framework is jointly developed by a large team of software engineers and scientists at the ISIS Neutron and Muon Facility and the Oak Ridge National Laboratory. The objective of the development is to improve software quality, both in terms of performance and ease of use, for the the user community of large scale facilities. The functionality and novel design aspects of the framework are described.

  15. angle light scattering: Topics by E-print Network

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

    Biological tissues tend Kim, Arnold D. 11 Static light scattering and small-angle neutron scattering study on aggregated recombinant gelatin in aqueous solution University...

  16. Influence of the Environment Fluctuations on Incoherent Neutron Scattering Functions

    E-Print Network [OSTI]

    D. J. Bicout

    2001-04-09T23:59:59.000Z

    In extending the conventional dynamic models, we consider a simple model to account for the environment fluctuations of particle atoms in a protein system and derive the elastic incoherent structure factor (EISF) and the incoherent scattering correlation function C(Q,t) for both the jump dynamics between sites with fluctuating site interspacing and for the diffusion inside a fluctuating sphere. We find that the EISF of the system (or the normalized elastic intensity) is equal to that in the absence of fluctuations averaged over the distribution of site interspacing or sphere radius a. The scattering correlation function is $C(Q,t)=\\sum_{n} \\psi(t)$, where the average is taken over the Q-dependent effective distribution of relaxation rates \\lambda_n(a) and \\psi(t) is the correlation function of the length a. When \\psi(t)=1, the relaxation of C(Q,t) is exponential for the jump dynamics between sites (since \\lambda_n(a) is independent of a) while it is nonexponential for diffusion inside a sphere.

  17. Neutron scattering study of underdoped Ba1-xKxFe?As? (x=0.09 and 0.17) self-flux-grown single crystals and the universality of the tricritical point

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

    Rotundu, C. R.; Tian, W.; Rule, K. C.; Forrest, T. R.; Zhao, J.; Zarestky, J. L.; Birgeneau, R. J.

    2012-04-01T23:59:59.000Z

    We present a combination of elastic neutron scattering measurements in zero and 14.5 T and magnetization measurements in zero and 14 T on underdoped superconducting Ba1-xKxFe?As? (x=0.17), and the same measurements in zero field on a nonsuperconducting crystal with x=0.09. The data suggest that the underdoped materials may not be electronic phase separated but rather have slightly inhomogeneous potassium doping. The temperature dependence of the magnetic order parameter below the transition of the sample with x=0.09 is more gradual than that for the case of the undoped BaFe?As?, suggesting that this doping may be in the vicinity of a tricriticalmore »point. We advance therefore the hypothesis that the tricritical point is a common feature of all superconducting 122s. For the x=0.17 sample, while Tc is suppressed from ?17 to ?8 K by a magnetic field of 14 T, the intensity of the magnetic Bragg peaks (1 0 3) at 1.2 K is enhanced by 10%, showing competition of superconductivity and antiferromagnetism. The intensity of the magnetic Bragg peaks (1 0 3) in the (Tc, TN) temperature interval remain practically unchanged in 14.5 T within a 10% statistical error. The present results are discussed in the context of the existing literature.« less

  18. Neutron scattering study of underdoped Ba1-xKxFe?As? (x=0.09 and 0.17) self-flux-grown single crystals and the universality of the tricritical point

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

    Rotundu, C. R.; Tian, W.; Rule, K. C.; Forrest, T. R.; Zhao, J.; Zarestky, J. L.; Birgeneau, R. J.

    2012-04-01T23:59:59.000Z

    We present a combination of elastic neutron scattering measurements in zero and 14.5 T and magnetization measurements in zero and 14 T on underdoped superconducting Ba1-xKxFe?As? (x=0.17), and the same measurements in zero field on a nonsuperconducting crystal with x=0.09. The data suggest that the underdoped materials may not be electronic phase separated but rather have slightly inhomogeneous potassium doping. The temperature dependence of the magnetic order parameter below the transition of the sample with x=0.09 is more gradual than that for the case of the undoped BaFe?As?, suggesting that this doping may be in the vicinity of a tricritical point. We advance therefore the hypothesis that the tricritical point is a common feature of all superconducting 122s. For the x=0.17 sample, while Tc is suppressed from ?17 to ?8 K by a magnetic field of 14 T, the intensity of the magnetic Bragg peaks (1 0 3) at 1.2 K is enhanced by 10%, showing competition of superconductivity and antiferromagnetism. The intensity of the magnetic Bragg peaks (1 0 3) in the (Tc, TN) temperature interval remain practically unchanged in 14.5 T within a 10% statistical error. The present results are discussed in the context of the existing literature.

  19. Neutron scattering study of underdoped Ba1-xKxFe?As? (x=0.09 and 0.17) self-flux-grown single crystals and the universality of the tricritical point

    SciTech Connect (OSTI)

    Rotundu, C. R.; Tian, W.; Rule, K. C.; Forrest, T. R.; Zhao, J.; Zarestky, J. L.; Birgeneau, R. J.

    2012-04-01T23:59:59.000Z

    We present a combination of elastic neutron scattering measurements in zero and 14.5 T and magnetization measurements in zero and 14 T on underdoped superconducting Ba1-xKxFe?As? (x=0.17), and the same measurements in zero field on a nonsuperconducting crystal with x=0.09. The data suggest that the underdoped materials may not be electronic phase separated but rather have slightly inhomogeneous potassium doping. The temperature dependence of the magnetic order parameter below the transition of the sample with x=0.09 is more gradual than that for the case of the undoped BaFe?As?, suggesting that this doping may be in the vicinity of a tricritical point. We advance therefore the hypothesis that the tricritical point is a common feature of all superconducting 122s. For the x=0.17 sample, while Tc is suppressed from ?17 to ?8 K by a magnetic field of 14 T, the intensity of the magnetic Bragg peaks (1 0 3) at 1.2 K is enhanced by 10%, showing competition of superconductivity and antiferromagnetism. The intensity of the magnetic Bragg peaks (1 0 3) in the (Tc, TN) temperature interval remain practically unchanged in 14.5 T within a 10% statistical error. The present results are discussed in the context of the existing literature.

  20. Quantum correlations in bulk properties of solids obtained from neutron scattering

    E-Print Network [OSTI]

    Ben-Qiong Liu; Lian-Ao Wu; Guo-Mo Zeng; Jian-Ming Song; Wei Luo; Yang Lei; Guang-Ai Sun; Bo Chen; Shu-Ming Peng

    2014-07-02T23:59:59.000Z

    We demonstrate that inelastic neutron scattering technique can be used to indirectly detect and measure the macroscopic quantum correlations quantified by both entanglement and discord in a quantum magnetic material, VODPO4 . 1D2O. The amount of quantum correlations is obtained 2 by analyzing the neutron scattering data of magnetic excitations in isolated V4+ spin dimers. Our quantitative analysis shows that the critical temperature of this material can reach as high as Tc = 82.5 K, where quantum entanglement drops to zero. Significantly, quantum discord can even survive at Tc = 300 K and may be used in room temperature quantum devices. Taking into account the spin-orbit (SO) coupling, we also predict theoretically that entanglement can be significantly enhanced and the critical temperature Tc increases with the strength of spin-orbit coupling.

  1. Low-energy neutron-12C analyzing powers: Results from a multichannel algebraic scattering theory

    E-Print Network [OSTI]

    J. P. Svenne; K. Amos; S. Karataglidis; D. van der Knijff; L. Canton; G. Pisent

    2005-10-29T23:59:59.000Z

    Analyzing powers in low-energy neutron scattering from 12C are calculated in an algebraic momentum-space coupled-channel formalism (MCAS). The results are compared with recently obtained experimental data. The channel-coupling potentials have been defined previously to reproduce the total cross section and sub-threshold bound states of the compound system. Without further adjustment, good agreement with data for the analyzing powers is obtained.

  2. Polarized Deep Inelastic Scattering Off the "Neutron" From Gauge/String Duality

    E-Print Network [OSTI]

    Jian-Hua Gao; Zong-Gang Mou

    2010-05-25T23:59:59.000Z

    We investigate deep inelastic scattering off the polarized "neutron" using gauge/string duality. The "neutron" corresponds to a supergravity mode of the neutral dilatino. Through introducing the Pauli interaction term into the action in $\\textrm{AdS}_{5}$ space, we calculate the polarized deep inelastic structure functions of the "neutron" in supergravity approximation at large t' Hooft coupling $\\lambda$ and finite $x$ with $\\lambda^{-1/2}\\ll xneutron" are power suppressed at the same order as the ones of the "proton." Especially, we find the Burkhardt-Cottingham-like sum rule, which is satisfied in the work by Gao and Xiao, is broken due to the Pauli interaction term. We also illustrate how such a Pauli interaction term can arise naturally from higher dimensional fermion-graviton coupling through the usual Kaluza-Klein reduction.

  3. Neutrino-nucleus coherent scattering as a probe of neutron density distributions

    E-Print Network [OSTI]

    Kelly Patton; Jonathan Engel; Gail C. McLaughlin; Nicolas Schunck

    2012-07-03T23:59:59.000Z

    Neutrino-nucleus coherent elastic scattering provides a theoretically appealing way to measure the neutron part of nuclear form factors. Using an expansion of form factors into moments, we show that neutrinos from stopped pions can probe not only the second moment of the form factor (the neutron radius) but also the fourth moment. Using simple Monte Carlo techniques for argon, germanium, and xenon detectors of 3.5 tonnes, 1.5 tonnes, and 300 kg, respectively, we show that the neutron radii can be found with an uncertainty of a few percent when near a neutrino flux of $3\\times10^{7}$ neutrinos/cm$^{2}$/s. If the normalization of the neutrino flux is known independently, one can determine the moments accurately enough to discriminate among the predictions of various nuclear energy functionals.

  4. Measurement of Leading Proton and Neutron Production in Deep Inelastic Scattering at HERA

    E-Print Network [OSTI]

    C. Adloff

    1998-11-09T23:59:59.000Z

    Deep--inelastic scattering events with a leading baryon have been detected by the H1 experiment at HERA using a forward proton spectrometer and a forward neutron calorimeter. Semi--inclusive cross sections have been measured in the kinematic region 2 neutron with energy E' >= 160 GeV. The measurements are used to test production models and factorization hypotheses. A Regge model of leading baryon production which consists of pion, pomeron and secondary reggeon exchanges gives an acceptable description of both semi-inclusive cross sections in the region 0.7 neutron data are used to estimate for the first time the structure function of the pion at small Bjorken--x.

  5. Method for improving the angular resolution of a neutron scatter camera

    DOE Patents [OSTI]

    Mascarenhas, Nicholas; Marleau, Peter; Gerling, Mark; Cooper, Robert Lee; Mrowka, Stanley; Brennan, James S.

    2012-12-25T23:59:59.000Z

    An instrument that will directly image the fast fission neutrons from a special nuclear material source wherein the neutron detection efficiency is increased has been described. Instead of the previous technique that uses a time-of-flight (TOF) between 2 widely spaced fixed planes of neutron detectors to measure scatter neutron kinetic energy, we now use the recoil proton energy deposited in the second of the 2 scatter planes which can now be repositioned either much closer together or further apart. However, by doubling the separation distance between the 2 planes from 20 cm to a distance of 40 cm we improved the angular resolution of the detector from about 12.degree. to about 10.degree.. A further doubling of the separation distance to 80 cm provided an addition improvement in angular resolution of the detector to about 6.degree. without adding additional detectors or ancillary electronics. The distance between planes also may be dynamically changed using a suitable common technique such as a gear- or motor-drive to toggle between the various positions. The angular resolution of this new configuration, therefore, is increased at the expanse of detection sensitivity. However, the diminished sensitivity may be acceptable for those applications where the detector is able to interrogate a particular site for an extended period.

  6. Alpha resonant scattering for astrophysical reaction studies

    SciTech Connect (OSTI)

    Yamaguchi, H.; Kahl, D.; Nakao, T. [Center for Nuclear Study (CNS), University of Tokyo, RIKEN campus, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Wakabayashi, Y.; Kubano, S. [The Institute of Physical and Chemical Research (RIKEN), 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Hashimoto, T. [Research Center for Nuclear Physics (RCNP), Osaka University, 10-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan); Hayakawa, S. [Istituto Nazionale Fisica Nucleare - Laboratori Nazionali del Sud (INFN-LNS), Via S. Sofia 62, 95125 Catania (Italy); Kawabata, T. [Department of Physics, Kyoto University, Kita-Shirakawa, Kyoto 606-8502 (Japan); Iwasa, N. [Department of Physics, Tohoku University, Aoba, Sendai, Miyagi 980-8578 (Japan); Teranishi, T. [Department of Physics, Kyushu University, 6-10-1 Hakozaki, Fukuoka 812-8581 (Japan); Kwon, Y. K. [Institute for Basic Science, 70, Yuseong-daero 1689-gil, Yuseong-gu, Daejeon 305-811 (Korea, Republic of); Binh, D. N. [30 MeV Cyclotron Center, Tran Hung Dao Hospital, Hoan Kiem District, Hanoi (Viet Nam); Khiem, L. H.; Duy, N. G. [Institute of Physics, Vietnam Academy of Science and Technology, 18 Hong Quoc Viet, Nghia do, Hanoi (Viet Nam)

    2014-05-02T23:59:59.000Z

    Several alpha-induced astrophysical reactions have been studied at CRIB (CNS Radioactive Ion Beam separator), which is a low-energy RI beam separator at Center for Nuclear Study (CNS) of the University of Tokyo. One of the methods to study them is the ? resonant scattering using the thick-target method in inverse kinematics. Among the recent studies at CRIB, the measurement of {sup 7}Be+? resonant scattering is discussed. Based on the result of the experiment, we evaluated the contributions of high-lying resonances for the {sup 7}Be(?,?) reaction, and proposed a new cluster band in {sup 11}C.

  7. Cross sections for neutron-deuteron elastic scattering in the energy range 135–250 MeV

    E-Print Network [OSTI]

    Ertan, E.

    We report new measurements of the neutron-deuteron elastic scattering cross section at energies from 135 to 250 MeV and center-of-mass angles from 80[degrees] to 130[degrees]. Cross sections for neutron-proton elastic ...

  8. A Measurement of the neutron electric form factor at very large momentum transfer using polaried electrions scattering from a polarized helium-3 target

    SciTech Connect (OSTI)

    Aidan Kelleher

    2010-10-01T23:59:59.000Z

    Knowledge of the electric and magnetic elastic form factors of the nucleon is essential for an understanding of nucleon structure. Of the form factors, the electric form factor of the neutron has been measured over the smallest range in Q{sup 2} and with the lowest precision. Jefferson Lab experiment 02-013 used a novel new polarized {sup 3}He target to nearly double the range of momentum transfer in which the neutron form factor has been studied and to measure it with much higher precision. Polarized electrons were scattered off this target, and both the scattered electron and neutron were detected. G{sup n}{sub E} was measured to be 0.0242 ± 0.0020(stat) ± 0.0061(sys) and 0.0247 ± 0.0029(stat) ± 0.0031(sys) at Q{sup 2} = 1.7 and 2.5 GeV{sup 2}, respectively.

  9. Quantification of microstructural features in HMX using small angle neutron scattering techniques

    SciTech Connect (OSTI)

    Mang, J.T.; Skidmore, C.B.; Hjelm, R.P.; Howe, P.M.

    1998-12-01T23:59:59.000Z

    Microstructural features in raw powders of High Explosives have been qualitatively observed by many researchers, using polarized light and scanning electron microscopy. Here, the authors present a method for non-destructive quantification of volume fraction and structure of intragranular cracks and crystallization voids in a bulk sample (100--300 mg). By employing Small Angle Neutron Scattering (SANS) in conjunction with the method of contrast variation, they can effectively highlight different structural features of a complex system. The technique of contrast variation relies on immersing the sample in a uniform fluid of known neutron scattering length density. By selectively varying the scattering length density of the immersion fluid, scattering contributions from internal and external structures can be separated. This approach is analogous to varying the index of refraction for immersion oil relative to a sample in polarized light microscopy. SANS experiments on HMX were conducted using loose powders (261 and 10 micron mean particle diameters) and pellets made by uniaxial consolidation (without binder) to 7 and 10 volume percent porosity respectively. Detailed modeling of the SANS data indicate significant alteration of the intragranular void/crack/pore structure, with pressing, of the HMX powders.

  10. Rapidly pulsed TRIGA reactor: an intense source for neutron scattering experiments

    SciTech Connect (OSTI)

    Whittemore, William L. [General Atomics, San Diego, CA (United States)

    1994-07-01T23:59:59.000Z

    The need for ever increasing intensities of thermal neutron beams for neutron scattering experiments has stimulated the development of intense steady state research reactors such as the 53-MW ILL reactor at Grenoble. The source flux at the reactor end of the beam ports is typically 10{sup 15}n/cm{sup 2}.s for its thermal neutron beams. To achieve still higher source fluxes of neutrons, the family of pulsing IBR was developed. In this type of facility the pulse repetition rate is low ({approx}5/sec) typically but the instantaneous peak fluxes are high, ranging up to 5 x 10{sup 15}n/cm{sup 2}.s at the surface of the moderator. Another type of intense neutron source is that exemplified by the proton synchrotron accelerators with their spallation targets. The first of these has been the IPNS at Argonne National laboratory. This neutron source produces 30 pulses per second with an individual peak thermal neutron intensity of 4 x 10{sup 14}n/cm{sup 2}.s from the moderator. An equivalent, alternative intense neutron source can be based on a rapidly pulsed TRIGA reactor. With a pulsed thermal neutron intensity of more than 10{sup 15}n/cm{sup 2}.s occurring 50 times per second at the source end of beam ports, the rapidly pulsed TRIGA reactor combines some of the best features of the pulsed fast reactors such as IBR-2 and the spallation neutron sources but with the safety of a thermal neutron reactor with a large, prompt, negative temperature coefficient of reactivity. The initial concept of the rapidly pulsed TRIGA reactor was developed and initially reported in 1966. Subsequently, the standard fuel format for U-ZrH{sub x} fuel has been developed to include a small diameter fuel particularly well suited for the rapidly pulsed application. This fuel is LEU, satisfying all the requirements for non proliferation, and has a very long core life time. In the proposed application, the peak fuel temperature does not vary more than 1 deg. C from the average peak fuel temperatures during each pulse. Hence long term metallurgical stability is thus assured. With a core lifetime that can be designed for up to 10,000 MWD, operation at an average power of 10 MW (with peak pulsed powers of {approx}50 MW) with an equilibrium core can be conducted for 1000 full power days. (author)

  11. Characterization of porous materials using combined small-angle X-ray and neutron scattering techniques

    SciTech Connect (OSTI)

    Hu, Naiping; Borkar, Neha; Kohls, Doug; Schaefer, Dale W. (UCIN)

    2014-09-24T23:59:59.000Z

    A combination of ultra small angle X-ray scattering (USAXS) and ultra small angle neutron scattering (USANS) is used to characterize porous materials. The analysis methods yield quantitative information, including the mean skeletal chord length, mean pore chord length, skeletal density, and composition. A mixed cellulose ester (MCE) membrane with a manufacturer-labeled pore size of 0.1 {mu}m was used as a model to elucidate the specifics of the method. Four approaches describing four specific scenarios (different known parameters and form of the scattering data) are compared. Pore chords determined using all four approaches are in good agreement with the scanning electron microscopy estimates but are larger than the manufacturer's nominal pore size. Our approach also gives the average chord of the skeletal solid (struts) of the membrane, which is also consistent for all four approaches. Combined data from USAXS and USANS gives the skeletal density and the strut composition.

  12. Nuclear-spectroscopy problems studied with neutrons

    SciTech Connect (OSTI)

    Raman, S.

    1982-01-01T23:59:59.000Z

    Nuclear spectroscopy with neutrons continues to have a major impact on the progress of nuclear science. Neutrons, being uncharged, are particularly useful for the study of low energy reactions. Recent advances in time-of-flight spectroscopy, as well as in the gamma ray spectroscopy following neutron capture, have permitted precision studies of unbound and bound nuclear levels and related phenomena. By going to new energy domains, by using polarized beams and targets, through the invention of new kinds of detectors, and through the general improvement in beam quantity and quality, new features of nuclear structure and reactions have been obtained that are not ony interesting per se but are also grist for old and new theory mills. The above technical advances have opened up new opportunities for further discoveries.

  13. Small angle neutron scattering characterization of the porous structure of carbons prepared using inorganic templates

    SciTech Connect (OSTI)

    Sandi, G.; Thiyagarajan, P.; Carrado, K.A.; Winans, R.E. [Argonne National Lab., IL (United States)] [Argonne National Lab., IL (United States)

    1999-02-01T23:59:59.000Z

    Small angle neutron scattering (SANS) was used for the characterization of the microstructure of carbons derived from organic-loaded inorganic template materials that are used as anodes in lithium ion cells. Pillared clays (PILC), layered silicates whose sheets have been permanently propped open by sets of thermally stable molecular props, were used as a template to load the organic precursors. Five organic precursors, namely pyrene, styrene, pyrene/trioxane copolymer, ethylene, and propylene, were used to load the PILC. Pyrolysis was carried out at 700 C under nitrogen atmosphere. From SANS, information has been derived about the pore radius, mass fractal dimension, and the cutoff length (above which the fractal property breaks down) on each carbon. In general, the pore radius ranges from 4 to 11 {angstrom}, and the mass fractal dimension varies in the range from 2.5 to 2.9. Contrast-match SANS studies of carbons wetted in 84% deuterated toluene indicate that a significant amount of pores in carbon from pyrene are not accessible to the solvent, while most of the porous network of carbon from propylene is accessible.

  14. Proton elastic scattering from tin isotopes at 295 MeV and systematic change of neutron density distributions

    E-Print Network [OSTI]

    S. Terashima; H. Sakaguchi; H. Takeda; T. Ishikawa; M. Itoh; T. Kawabata; T. Murakami; M. Uchida; Y. Yasuda; M. Yosoi; J. Zenihiro; H. P. Yoshida; T. Noro; T. Ishida; S. Asaji; T. Yonemura

    2008-02-02T23:59:59.000Z

    Cross sections and analyzing powers for proton elastic scattering from $^{116,118,120,122,124}$Sn at 295 MeV have been measured for a momentum transfer of up to about 3.5 fm$^{-1}$ to deduce systematic changes of the neutron density distribution. We tuned the relativistic Love-Franey interaction to explain the proton elastic scattering of a nucleus whose density distribution is well known. Then, we applied this interaction to deduce the neutron density distributions of tin isotopes. The result of our analysis shows the clear systematic behavior of a gradual increase in the neutron skin thickness of tin isotopes with mass number.

  15. Cross sections for neutron-deuteron elastic scattering in the energy range 135-250 MeV

    E-Print Network [OSTI]

    E. Ertan; T. Akdogan; M. B. Chtangeev; W. A. Franklin; P. A. M. Gram; M. A. Kovash; J. L. Matthews; M. Yuly

    2012-11-22T23:59:59.000Z

    We report new measurements of the neutron-deuteron elastic scattering cross section at energies from 135 to 250 MeV and center-of-mass angles from $80^\\circ$ to $130^\\circ$. Cross sections for neutron-proton elastic scattering were also measured with the same experimental setup for normalization purposes. Our $nd$ cross section results are compared with predictions based on Faddeev calculations including three-nucleon forces, and with cross sections measured with charged particle and neutron beams at comparable energies.

  16. Structure of spontaneously formed solid-electrolyte interphase on lithiated graphite determined using small-angle neutron scattering

    SciTech Connect (OSTI)

    Sacci, Robert L [ORNL; Banuelos, Jose Leo [ORNL; Veith, Gabriel M [ORNL; Littrell, Ken [ORNL; Cheng, Yongqiang [ORNL; Wildgruber, Christoph U [ORNL; Jones, Lacy L [ORNL; Ramirez-Cuesta, Anibal J [ORNL; Rother, Gernot [ORNL; Dudney, Nancy J [ORNL

    2015-01-01T23:59:59.000Z

    We report the first small-angle neutron scattering of a chemically formed solid-electrolyte interphase from LixC6 reacting with ethylene carbonate/dimethyl carbon solvent. This provides a different and perhaps simpler view of SEI formation than the usual electrochemically-driven reaction. We show that an organic layer coats the graphite particles filling in micro-pores and is polymeric in nature being 1-3 nm thick. We used inelastic neutron scattering to probe the chemistry, and we found that the SEI showed similar inelastic scattering to polyethylene oxide.

  17. A Survey of Students from the National School on Neutron and X-ray Scattering: Communication Habits and Preferences

    SciTech Connect (OSTI)

    Bryant, Rebecca [Bryant Research, LLC

    2010-12-01T23:59:59.000Z

    Oak Ridge National Laboratory (ORNL) offers the scientific community unique access to two types of world-class neutron sources at a single site - the Spallation Neutron Source (SNS) and the High Flux Isotope Reactor (HFIR). The 85-MW HFIR provides one of the highest steady-state neutron fluxes of any research reactor in the world. And the SNS is one of the world's most intense pulse neutron beams. Management of these resources is the responsibility of the Neutron Sciences Directorate (NScD). NScD started conducting the National School on Neutron and X-ray Scattering (NXS) in conjunction with the Advanced Photon Source (APS) at Argonne National Laboratory in 2007. This survey was conducted to determine the most effective ways to reach students with information about what SNS and HFIR offer the scientific community, including content and communication vehicles. The emphasis is on gaining insights into compelling messages and the most effective channels, e.g., Web sites and social media, for communicating with students about neutron science The survey was conducted in two phases using a classic qualitative investigation to confirm language and content followed by a survey designed to quantify issues, assumptions, and working hypotheses. Phase I consisted of a focus group in late June 2010 with students attending NXS. The primary intent of the group was to inform development of an online survey. Phase two consisted of an online survey that was developed and pre-tested in July 2010 and launched on August 9, 2010 and remained in the field until September 9, 2010. The survey achieved an overall response rate of 48% for a total of 157 completions. The objective of this study is to determine the most effective ways to reach students with information about what SNS and HFIR offer the scientific community, including content and communication vehicles. The emphasis is on gaining insights into compelling messages and the most effective channels, e.g., Web sites, social media, for communicating with students about neutron science.

  18. FINAL REPORT: DOE CONTRACT NUMBER FG0205ER64026 Biological Neutron Scattering: A Collaboration with the Oak Ridge Center for Structural Molecular Biology

    SciTech Connect (OSTI)

    Jill Trewhella

    2011-01-12T23:59:59.000Z

    The overarching goal of this project was to promote applications of small-angle scattering in structural molecular biology by providing model examples of cutting edge applications that demonstrate the unique capabilities and potential of the DOE national user facilities at Oak Ridge, especially the newly commissioned BioSANS. The approach taken was three-fold: (1) to engage in high impact collaborative research projects that would benefit from small-angle neutron scattering to both demonstrate the power of the technique while expanding the potential user community; (2) to provide access to scattering facilities established at the University of Utah to as broad a set of researchers as possible to increase the expertise in small-angle scattering generally; and (3) to develop new methods and tools for small-angle scattering. To these ends, three major research collaborations were pursued that resulted in a significant body of published work where neutron scattering and contrast variation played a major role. These major collaborations involved studies of protein complexes involved in (1) bacterial transcription regulation and adaptive response (a DOE/BER priority area); (2) regulation of cardiac muscle; and (3) neuronal disorders. In addition, to broaden the impact of the project, smaller collaborative efforts were supported that used either small-angle X-ray or neutron scattering. Finally, the DOE supported facilities at the University of Utah were made available to researchers on a service basis and a number of independent groups took advantage of this opportunity. In all of this work, there was an emphasis on the training of students and post docs in scattering techniques, and a set of publications (a book chapter, a review, and an encyclopedia article) were produced to guide the non-specialist potential user of scattering techniques in successful applications of the techniques. We also developed a suite of user friendly web-based computational tools currently being accessed world-wide by researchers as an aid in neutron scattering data interpretation. In all, these collaborative projects and resulted in 29 original refereed journal articles published between 2005 and 2010 and engaged groups from at least 14 Universities (10 US, 4 international) and 3 National Laboratories (2 US, 1 international). An important final initiative from this project was to begin a process for international community agreement on a set of standards for the publication of biomolecular small-angle scattering data. This initiative is being championed with the International Union of Crystallography and has engaged a number of Journal Editors and is a very important step in the maturing of this now burgeoning field.

  19. Search for Anomalous Scattering of keV Neutrons from H2O-D2O Mixtures R. Moreh,1,2,* R. C. Block,2

    E-Print Network [OSTI]

    Danon, Yaron

    Search for Anomalous Scattering of keV Neutrons from H2O-D2O Mixtures R. Moreh,1,2,* R. C. Block,2 (Received 20 January 2005; published 12 May 2005) We measured the neutron scattering intensities from pure Linac and the final energy of the scattered neutrons was fixed at 24.3 keV using a 20 cm thick pure iron

  20. Neutron Transmission, Capture, and Scattering Measurements at the Gaerttner LINAC Center Y. Danon, L. Liu, E.J. Blain, A.M. Daskalakis, B.J. McDermott, K. Ramic, C.R. Wendorff

    E-Print Network [OSTI]

    Danon, Yaron

    Neutron Transmission, Capture, and Scattering Measurements at the Gaerttner LINAC Center Y. Danon . As the energy of the neutrons increases to the keV region neutron resonance scattering becomes dominant compared to capture, and scattered neutrons can penetrate the 10 B4C liner of the NaI capture detector and get

  1. Quasi-Differential Neutron Scattering Measurements of 238 A.M. Daskalakis, R.M. Bahran, E.J. Blain, B.J. McDermott, S. Piela, and Y. Danon

    E-Print Network [OSTI]

    Danon, Yaron

    Quasi-Differential Neutron Scattering Measurements of 238 U A.M. Daskalakis, R.M. Bahran, E between evaluations through the energy-angle distribution of neutrons from scattering and fission of 238 U using the Rensselaer Polytechnic Institute (RPI) neutron scattering system. Differential neutron

  2. accelerator-based neutron source: Topics by E-print Network

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

    moderator is in agreement with simulation and the cold neutron flux is sufficient for neutron scattering studies of materials. We describe some possible modifications to the...

  3. accelerator-based neutron sources: Topics by E-print Network

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

    moderator is in agreement with simulation and the cold neutron flux is sufficient for neutron scattering studies of materials. We describe some possible modifications to the...

  4. Digenetic Changes in Macro- to Nano-Scale Porosity in the St. Peter Sandstone:L An (Ultra) Small Angle Neutron Scattering and Backscattered Electron Imagining Analysis

    SciTech Connect (OSTI)

    Anovitz, Lawrence {Larry} M [ORNL; Cole, David [Ohio State University; Rother, Gernot [ORNL; Allard Jr, Lawrence Frederick [ORNL; Jackson, Andrew [NIST Center for Neutron Research (NCRN), Gaithersburg, MD; Littrell, Ken [ORNL

    2013-01-01T23:59:59.000Z

    Small- and Ultra-Small Angle Neutron Scattering (SANS and USANS) provide powerful tools for quantitative analysis of porous rocks, yielding bulk statistical information over a wide range of length scales. This study utilized (U)SANS to characterize shallowly buried quartz arenites from the St. Peter Sandstone. Backscattered electron imaging was also used to extend the data to larger scales. These samples contain significant volumes of large-scale porosity, modified by quartz overgrowths, and neutron scattering results show significant sub-micron porosity. While previous scattering data from sandstones suggest scattering is dominated by surface fractal behavior over many orders of magnitude, careful analysis of our data shows both fractal and pseudo-fractal behavior. The scattering curves are composed of subtle steps, modeled as polydispersed assemblages of pores with log-normal distributions. However, in some samples an additional surface-fractal overprint is present, while in others there is no such structure, and scattering can be explained by summation of non-fractal structures. Combined with our work on other rock-types, these data suggest that microporosity is more prevalent, and may play a much more important role than previously thought in fluid/rock interactions.

  5. Development and application of setup for ac magnetic field in neutron scattering experiments

    SciTech Connect (OSTI)

    Klimko, Sergey [Laboratoire Leon Brillouin, 91191 Gif-sur-Yvette (France); Zhernenkov, Kirill; Toperverg, Boris P.; Zabel, Hartmut [Institut fuer Festkoerperphys IV, Ruhr Universitaet Bochum, D-44780 Bochum (Germany)

    2010-10-15T23:59:59.000Z

    We report on a new setup developed for neutron scattering experiments in periodically alternating magnetic fields at the sample position. The assembly consisting of rf generator, amplifier, wide band transformer, and resonance circuit. It allows to generate homogeneous ac magnetic fields over a volume of a few cm{sup 3} and variable within a wide range of amplitudes and frequencies. The applicability of the device is exemplified by ac polarized neutron reflectometry (PNR): a new method established to probe remagnetization kinetics in soft ferromagnetic films. Test experiments with iron films demonstrate that the ac field within the accessible range of frequencies and amplitudes produces a dramatic effect on the PNR signal. This shows that the relevant ac field parameters generated by the device match well with the scales involved in the remagnetization processes. Other possible applications of the rf unit are briefly discussed.

  6. Neutrino-Pair Emission due to Electron-Phonon Scattering in a Neutron Star Crust

    E-Print Network [OSTI]

    D. G. Yakovlev; A. D. Kaminker

    1996-04-19T23:59:59.000Z

    Neutrino-pair bremsstrahlung radiation is considered due to electron--phonon scattering of degenerate, relativistic electrons in a lattice of spherical atomic nuclei in a neutron star crust. The neutrino energy generation rate is calculated taking into account exact spectrum of phonons, the Debye--Waller factor, and the nuclear form--factor in the density range from $10^7$~g~cm$^{-3}$ to $10^{14}$~g~cm$^{-3}$ at arbitrary nuclear composition for body-centered-cubic and face-centered-cubic Coulomb crystals. The results are fitted by a unified analytic expression. A comparison is given of the neutrino bremsstrahlung energy losses in a neutron star crust composed of ground state and accreted matter, in the solid and liquid phases.

  7. Exploration of deeply virtual Compton scattering on the neutron in the Hall A of Jefferson Laboratory

    SciTech Connect (OSTI)

    Malek Mazouz

    2006-12-08T23:59:59.000Z

    Generalized Parton Distributions (GPDs) are universal functions which provide a comprehensive description of hadron properties in terms of quarks and gluons. Deeply Virtual Compton Scattering (DVCS) is the simplest hard exclusive process involving GPDs. In particular, the DVCS on the neutron is mostly sensitive to E, the less constrained GPD, wich allows to access to the quark angular momentum. The first dedicated DVCS experiment on the neutron ran in the Hall A of Jefferson Lab in fall 2004. The high luminosity of the experiment and the resulting background rate recquired specific devices which are decribed in this document. The analysis methods and the experiment results, leading to preliminary constraints on the GPD E, are presented.

  8. Deep Inelastic Scattering from A=3 Nuclei and the Neutron Structure Function

    SciTech Connect (OSTI)

    I. Afnan; F. Bissey; J. Gomez; A. Katramatou; S. Liuti; W. Melnitchouk; G. Petratos; A.W. Thomas

    2003-03-01T23:59:59.000Z

    We present a comprehensive analysis of deep inelastic scattering from {sup 3}He and {sup 3}H, focusing in particular on the extraction of the free neutron structure function, F{sup n}{sub 2}. Nuclear corrections are shown to cancel to within 1-2% for the isospin-weighted ratio of {sup 3}He to {sup 3}H structure functions, which leads to more than an order of magnitude improvement in the current uncertainty on the neutron to proton ratio F{sup 2n}{sub 2}/F{sup p}{sub 2} at large x. Theoretical uncertainties originating tom the nuclear wave function, including possible non-nucleonic components, are evaluated. Measurement of the {sup 3}He and {sup 3}H structure functions will, in addition, determine the magnitude of the EMC effect in all A [lte] 3 nuclei.

  9. JOURNAL DE PHYSIQUE Colloque C2, suppl&mentau n o3, Tome 40, mars 1979,page C2-666 ?~OSSBAUE%SCATTERING AND NEUTRON SCATTEZINS ON L I Q U I D GLYCEROL

    E-Print Network [OSTI]

    Boyer, Edmond

    the temperature range, a high regolution neutron-scattering experiment was performed. There the q-range extended is obtained from the width and intensity of the quasielastic scattering. The neutron scattering experiment 0.7 A-' up to 3.5 A-' while for neutron scattering q was between 1 0.2 I-' and 2 A

  10. Observation of spin-wave dispersion in Nd-Fe-B magnets using neutron Brillouin scattering

    SciTech Connect (OSTI)

    Ono, K., E-mail: kanta.ono@kek.jp; Inami, N.; Saito, K.; Takeichi, Y.; Kawana, D.; Yokoo, T.; Itoh, S. [Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801 (Japan); Yano, M.; Shoji, T.; Manabe, A.; Kato, A. [Toyota Motor Corporation, Toyota, Aichi 471-8571 (Japan); Kaneko, Y. [Toyota Central R and D Labs. Inc., Aichi 480-1192 (Japan)

    2014-05-07T23:59:59.000Z

    The low-energy spin-wave dispersion in polycrystalline Nd-Fe-B magnets was observed using neutron Brillouin scattering (NBS). Low-energy spin-wave excitations for the lowest acoustic spin-wave mode were clearly observed. From the spin-wave dispersion, we were able to determine the spin-wave stiffness constant D{sub sw} (100.0?±?4.9?meV.Å{sup 2}) and the exchange stiffness constant A (6.6 ± 0.3 pJ/m)

  11. Deeply virtual Compton scattering on longitudinally polarized protons and neutrons at CLAS

    E-Print Network [OSTI]

    Silvia Niccolai; for the CLAS Collaboration

    2012-07-13T23:59:59.000Z

    This paper focuses on a measurement of deeply virtual Compton scattering (DVCS) performed at Jefferson Lab using a nearly-6-GeV polarized electron beam, two longitudinally polarized (via DNP) solid targets of protons (NH3) and deuterons (ND3) and the CEBAF Large Acceptance Spectrometer. Here, preliminary results for target-spin asymmetries and double (beam-target) asymmetries for proton DVCS, as well as a very preliminary extraction of beam-spin asymmetry for neutron DVCS, are presented and linked to Generalized Parton Distributions.

  12. Deeply virtual Compton scattering on longitudinally polarized protons and neutrons at CLAS

    SciTech Connect (OSTI)

    Silvia Niccolai

    2012-04-01T23:59:59.000Z

    This paper focuses on a measurement of deeply virtual Compton scattering (DVCS) performed at Jefferson Lab using a nearly-6-GeV polarized electron beam, two longitudinally polarized (via DNP) solid targets of protons (NH{sub 3}) and deuterons (ND{sub 3}) and the CEBAF Large Acceptance Spectrometer. Here, preliminary results for target-spin asymmetries and double (beam-target) asymmetries for proton DVCS, as well as a very preliminary extraction of beam-spin asymmetry for neutron DVCS, are presented and linked to Generalized Parton Distributions.

  13. Neutron inelastic scattering in natural Pb as a background in neutrinoless

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's Possible for Renewable Energy:Nanowire Solar541,9337, 2011 at3,Neutron Scattering3

  14. Neutron-Proton Scattering in the Context of the $d^*$(2380) Resonance

    E-Print Network [OSTI]

    P. Adlarson; W. Augustyniak; W. Bardan; M. Bashkanov; F. S. Bergmann; M. Ber?owski; H. Bhatt; M. Büscher; H. Calén; I. Ciepa?; H. Clement; D. Coderre; E. Czerwi?ski; K. Demmich; E. Doroshkevich; R. Engels; A. Erven; W. Erven; W. Eyrich; P. Fedorets; K. Föhl; K. Fransson; F. Goldenbaum; P. Goslawski; A. Goswami; K. Grigoryev; C. --O. Gullström; F. Hauenstein; L. Heijkenskjöld; V. Hejny; M. Hodana; B. Höistad; N. Hüsken; A. Jany; B. R. Jany; L. Jarczyk; T. Johansson; B. Kamys; G. Kemmerling; F. A. Khan; A. Khoukaz; D. A. Kirillov; S. Kistryn; H. Kleines; B. K?os; M. Krapp; W. Krzemie?; P. Kulessa; A. Kup??; K. Lalwani; D. Lersch; B. Lorentz; A. Magiera; R. Maier; P. Marciniewski; B. Maria?ski; M. Mikirtychiants; H. --P. Morsch; P. Moskal; H. Ohm; I. Ozerianska; E. Perez del Rio; N. M. Piskunov; P. Podkopa?; D. Prasuhn; A. Pricking; D. Pszczel; K. Pysz; A. Pyszniak; C. F. Redmer; J. Ritman; A. Roy; Z. Rudy; S. Sawant; S. Schadmand; T. Sefzick; V. Serdyuk; R. Siudak; T. Skorodko; M. Skurzok; J. Smyrski; V. Sopov; R. Stassen; J. Stepaniak; E. Stephan; G. Sterzenbach; H. Stockhorst; H. Ströher; A. Szczurek; A. Täschner; A. Trzci?ski; R. Varma; G. J. Wagner; M. Wolke; A. Wro?ska; P. Wüstner; P. Wurm; A. Yamamoto; L. Yurev; J. Zabierowski; M. J. Zieli?ski; A. Zink; J. Z?oma?czuk; P. {?}upra?ski; M. {?}urek; R. L. Workman; W. J. Briscoe; I. I. Strakovsky

    2014-08-21T23:59:59.000Z

    New data on quasifree polarized neutron-proton scattering, in the region of the recently observed $d^*$ resonance structure, have been obtained by exclusive and kinematically complete high-statistics measurements with WASA at COSY. This paper details the determination of the beam polarization, checks of the quasifree character of the scattering process, on all obtained $A_y$ angular distributions and on the new partial-wave analysis, which includes the new data producing a resonance pole in the $^3D_3$-$^3G_3$ coupled partial waves at ($2380\\pm10 - i40\\pm5$) MeV -- in accordance with the $d^*$ dibaryon resonance hypothesis. The effect of the new partial-wave solution on the description of total and differential cross section data as well as specific combinations of spin-correlation and spin-transfer observables available from COSY-ANKE measurements at $T_d$ = 2.27 GeV is discussed.

  15. Quark Structure of the Nucleon and Angular Asymmetry of Proton-Neutron Hard Elastic Scattering

    E-Print Network [OSTI]

    Carlos G. Granados; Misak M. Sargsian

    2009-07-29T23:59:59.000Z

    We investigate an asymmetry in the angular distribution of hard elastic proton-neutron scattering with respect to 90deg center of mass scattering angle. We demonstrate that the magnitude of the angular asymmetry is related to the helicity-isospin symmetry of the quark wave function of the nucleon. Our estimate of the asymmetry within the quark-interchange model of hard scattering demonstrates that the quark wave function of a nucleon based on the exact SU(6) symmetry predicts an angular asymmetry opposite to that of experimental observations. On the other hand the quark wave function based on the diquark picture of the nucleon produces an asymmetry consistent with the data. Comparison with the data allowed us to extract the relative sign and the magnitude of the vector and scalar diquark components of the quark wave function of the nucleon. These two quantities are essential in constraining QCD models of a nucleon. Overall, our conclusion is that the angular asymmetry of a hard elastic scattering of baryons provides a new venue in probing quark-gluon structure of baryons and should be considered as an important observable in constraining the theoretical models.

  16. Precision neutron interferometric measurements of the n-p, n-d, and n-3He zero-energy coherent neutron scattering amplitudes

    E-Print Network [OSTI]

    P. R. Huffman; M. Arif; T. C. Black; D. L. Jacobson; K. Schoen; W. M. Snow; S. A. Werner

    2005-08-12T23:59:59.000Z

    We have performed high precision measurements of the zero-energy neutron scattering amplitudes of gas phase molecular hydrogen, deuterium, and $^{3}$He using neutron interferometry. We find $b_{\\mathit{np}}=(-3.7384 \\pm 0.0020)$ fm\\cite{Schoen03}, $b_{\\mathit{nd}}=(6.6649 \\pm 0.0040)$ fm\\cite{Black03,Schoen03}, and $b_{n^{3}\\textrm{He}} = (5.8572 \\pm 0.0072)$ fm\\cite{Huffman04}. When combined with the previous world data, properly corrected for small multiple scattering, radiative corrections, and local field effects from the theory of neutron optics and combined by the prescriptions of the Particle Data Group, the zero-energy scattering amplitudes are: $b_{\\mathit{np}}=(-3.7389 \\pm 0.0010)$ fm, $b_{\\mathit{nd}}=(6.6683 \\pm 0.0030)$ fm, and $b_{n^{3}\\textrm{He}} = (5.853 \\pm .007)$ fm. The precision of these measurements is now high enough to severely constrain NN few-body models. The n-d and n-$^{3}$He coherent neutron scattering amplitudes are both now in disagreement with the best current theories. The new values can be used as input for precision calculations of few body processes. This precision data is sensitive to small effects such as nuclear three-body forces, charge-symmetry breaking in the strong interaction, and residual electromagnetic effects not yet fully included in current models.

  17. Excess wing in glass-forming glycerol and LiCl-glycerol mixtures detected by neutron scattering

    E-Print Network [OSTI]

    S. Gupta; N. Arend; P. Lunkenheimer; A. Loidl; L. Stingaciu; N. Jalarvo; E. Mamontov; M. Ohl

    2014-03-08T23:59:59.000Z

    The relaxational dynamics in glass-forming glycerol and glycerol mixed with LiCl is in-vestigated using different neutron scattering techniques. The performed neutron spin-echo experiments, which extend up to relatively long relaxation-time scales of the order of 10 ns, should allow for the detection of contributions from the so-called excess wing. This phenomenon, whose microscopic origin is controversially discussed, arises in a variety of glass formers and, until now, was almost exclusively investigated by dielectric spectros-copy and light scattering. Here we show that the relaxational process causing the excess wing also can be detected by neutron scattering, which directly couples to density fluctua-tions.

  18. LIGHT SCATTERING STUDIES OF SILICA AEROGELS

    E-Print Network [OSTI]

    Hunt, A.J.

    2010-01-01T23:59:59.000Z

    van de Hulst, H.C. , Light Scattering by Small Particles,A New Polarization-Modulated Light Scattering Instrument,"and interpretation of light scattering effects in aerogels.

  19. Neutron Scattering Facility for Characterization of CRESST and EURECA Detectors at mK Temperatures

    E-Print Network [OSTI]

    J. -C. Lanfranchi; C. Ciemniak; C. Coppi; F. von Feilitzsch; A. Gütlein; H. Hagn; C. Isaila; J. Jochum; M. Kimmerle; S. Pfister; W. Potzel; W. Rau; S. Roth; K. Rottler; C. Sailer; S. Scholl; I. Usherov; W. Westphal

    2008-10-01T23:59:59.000Z

    CRESST (Cryogenic Rare Event Search with Superconducting Thermometers) is an experiment located at the Gran Sasso underground laboratory and aimed at the direct detection of dark matter in the form of WIMPs. The setup has just completed a one year commissioning run in 2007 and is presently starting a physics run with an increased target mass. Scintillating $\\mathrm{CaWO_4}$ single crystals, operated at temperatures of a few millikelvin, are used as target to detect the tiny nuclear recoil induced by a WIMP. The powerful background identification and rejection of $\\alpha$, e$^{-}$ and $\\gamma$ events is realized via the simultaneous measurement of a phonon and a scintillation signal generated in the $\\mathrm{CaWO_4}$ crystal. However, neutrons could still be misidentified as a WIMP signature. Therefore, a detailed understanding of the individual recoil behaviour in terms of phonon generation and scintillation light emission due to scattering on Ca, O or W nuclei, respectively, is mandatory. The only setup which allows to perform such measurements at the operating temperature of the CRESST detectors has been installed at the Maier-Leibnitz-Accelerator Laboratory in Garching and is presently being commissioned. The design of this neutron scattering facility is such that it can also be used for other target materials, e.g. $\\mathrm{ZnWO_4}$, $\\mathrm{PbWO_4}$ and others as foreseen in the framework of the future multitarget tonne-scale experiment EURECA (European Underground Rare Event Calorimeter Array).

  20. Equilibrium Structure of a Triblock Copolymer System Revealed by Mesoscale Simulation and Neutron Scattering

    SciTech Connect (OSTI)

    Do, Changwoo [ORNL] [ORNL; Chen, Wei-Ren [ORNL] [ORNL; Hong, Kunlun [ORNL] [ORNL; Smith, Gregory Scott [ORNL] [ORNL

    2013-01-01T23:59:59.000Z

    We have performed both mesoscale simulations and neutron scattering experiments on Pluronic L62, a poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) triblock copolymer system in aqueous solution. The influence of simulation variables such PEO/PPO block ratio, interaction parameters, and coarse-graining methods is extensively investigated by covering all permutations of parameters found in the literatures. Upon increasing the polymer weight fraction from 50 wt% to 90 wt%, the equilibrium structure of the isotropic, reverse micellar, bicontinuous, worm-like micelle network, and lamellar phases are respectively predicted from the simulation depending on the choices of simulation parameters. Small angle neutron scattering (SANS) measurements show that the same polymer systems exhibit the spherical micellar, lamellar, and reverse micellar phases with the increase of the copolymer concentration at room temperature. Detailed structural analysis and comparison with simulations suggest that one of the simulation parameter sets can provide reasonable agreement with the experimentally observed structures.

  1. The Manuel Lujan Jr. Neutron Scattering Center (LANSCE) experiment reports 1993 run cycle. Progress report

    SciTech Connect (OSTI)

    Farrer, R.; Longshore, A. [comps.

    1995-06-01T23:59:59.000Z

    This year the Manuel Lujan Jr. Neutron Scattering Center (LANSCE) ran an informal user program because the US Department of Energy planned to close LANSCE in FY1994. As a result, an advisory committee recommended that LANSCE scientists and their collaborators complete work in progress. At LANSCE, neutrons are produced by spallation when a pulsed, 800-MeV proton beam impinges on a tungsten target. The proton pulses are provided by the Clinton P. Anderson Meson Physics Facility (LAMPF) accelerator and a associated Proton Storage Ring (PSR), which can Iter the intensity, time structure, and repetition rate of the pulses. The LAMPF protons of Line D are shared between the LANSCE target and the Weapons Neutron Research (WNR) facility, which results in LANSCE spectrometers being available to external users for unclassified research about 80% of each annual LAMPF run cycle. Measurements of interest to the Los Alamos National Laboratory (LANL) may also be performed and may occupy up to an additional 20% of the available beam time. These experiments are reviewed by an internal program advisory committee. This year, a total of 127 proposals were submitted. The proposed experiments involved 229 scientists, 57 of whom visited LANSCE to participate in measurements. In addition, 3 (nuclear physics) participating research teams, comprising 44 scientists, carried out experiments at LANSCE. Instrument beam time was again oversubscribed, with 552 total days requested an 473 available for allocation.

  2. Neutron Reflectometry Studies of the Adsorbed Structure of the...

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

    Reflectometry Studies of the Adsorbed Structure of the Amelogenin, LRAP. Neutron Reflectometry Studies of the Adsorbed Structure of the Amelogenin, LRAP. Abstract: Amelogenins make...

  3. Neutron Powder Diffraction and Molecular Simulation Study of...

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

    Powder Diffraction and Molecular Simulation Study of the Structural Evolution of Ammonia Borane from 15 to 340 K. Neutron Powder Diffraction and Molecular Simulation Study of the...

  4. Microemulsion nanocomposites: phase diagram, rheology and structure using a combined small angle neutron scattering and reverse Monte Carlo approach

    E-Print Network [OSTI]

    Nicolas Puech; Serge Mora; Ty Phou; Gregoire Porte; Jacques Jestin; Julian Oberdisse

    2010-12-04T23:59:59.000Z

    The effect of silica nanoparticles on transient microemulsion networks made of microemulsion droplets and telechelic copolymer molecules in water is studied, as a function of droplet size and concentration, amount of copolymer, and nanoparticle volume fraction. The phase diagram is found to be affected, and in particular the percolation threshold characterized by rheology is shifted upon addition of nanoparticles, suggesting participation of the particles in the network. This leads to a peculiar reinforcement behaviour of such microemulsion nanocomposites, the silica influencing both the modulus and the relaxation time. The reinforcement is modelled based on nanoparticles connected to the network via droplet adsorption. Contrast-variation Small Angle Neutron Scattering coupled to a reverse Monte Carlo approach is used to analyse the microstructure. The rather surprising intensity curves are shown to be in good agreement with the adsorption of droplets on the nanoparticle surface.

  5. Scattering of particles by neutron stars: Time-evolutions for axial perturbations

    E-Print Network [OSTI]

    V. Ferrari; K. D. Kokkotas

    2000-08-23T23:59:59.000Z

    The excitation of the axial quasi-normal modes of a relativistic star by scattered particles is studied by evolving the time dependent perturbation equations. This work is the first step towards the understanding of more complicated perturbative processes, like the capture or the scattering of particles by rotating stars. In addition, it may serve as a test for the results of the full nonlinear evolution of binary systems.

  6. Response to 'Comment on 'Elastic incoherent neutron scattering operating by varying instrumental energy resolution: Principle, simulations, and experiments of the resolution elastic neutron scattering (RENS)'' [Rev. Sci. Instrum. 83, 107101 (2012)

    SciTech Connect (OSTI)

    Magazu, Salvatore; Migliardo, Federica; Benedetto, Antonio [Dipartimento di Fisica, Universita di Messina, C.da Papardo n Degree-Sign 31, P.O. Box 55, Vill. S. Agata 98166 Messina (Italy)

    2012-10-15T23:59:59.000Z

    Recently [S. Magazu et al., Rev. Sci. Instrum. 82, 105115 (2011)] we have proposed a new method for characterizing, by neutron scattering, the dynamical properties of complex material systems, such as, the ones of interest in the biophysical field. This approach called Resolution Elastic Neutron Scattering, in short RENS, is based on the detection of the elastically scattered neutron intensity as a function of the instrumental energy resolution. By experimental, theoretical, and numerical findings, we have pointed out that an inflection point occurs in the elastic intensity when the system relaxation time approaches the instrumental energy resolution time. This approach, differently from quasi-elastic neutron scattering (QENS), gives the chance to evaluate the system relaxation times without using pre-defined models that can be wrong and/or misleading. Here, we reply to a Comment on the above-mentioned main paper in which Wuttke proposes a different approach to evaluate the above-mentioned inflection point; on this regard, it should be noticed that the existence of the inflection point, which is the main topic of our work, is not questioned and that the approach proposed by Wuttke in the Comment, although valid for a class of dynamical processes, is not applicable when different and distinct processes occur simultaneously at different time scale.

  7. Analysis and simulation of a small-angle neutron scattering instrument on a 1 MW long pulse spallation source

    SciTech Connect (OSTI)

    Olah, G.A.; Hjelm, R.P.; Lujan, M. Jr.

    1996-12-31T23:59:59.000Z

    We studied the design and performance of a small-angle neutron scattering (SANS) instrument for a proposed 1 MW, 60 Hz long pulsed spallation source at the Los Alamos Neutron Science Center (LANSCE). An analysis of the effects of source characteristics and chopper performance combined with instrument simulations using the LANSCE Monte Carlo instrument simulations package shows that the T{sub 0} chopper should be no more than 5 m from the source with the frame overlap and frame definition choppers at 5.6 and greater than 7 m, respectively. The study showed that an optimal pulse structure has an exponential decaying tail with {tau} {approx} 750 {mu}s. The Monte Carlo simulations were used to optimize the LPSS SANS, showing that an optimal length is 18 m. The simulations show that an instrument with variable length is best to match the needs of a given measurement. The performance of the optimized LPSS instrument was found to be comparable with present world standard instruments.

  8. Neutron resonance study of a delayed neutron emitter, /sup 87/Kr

    E-Print Network [OSTI]

    Fogelberg, B; Macklin, R L; Raman, S; Stelson, P H

    1981-01-01T23:59:59.000Z

    The unbound levels in /sup 87/Kr have been studied as neutron resonances up to 400 keV neutron energy at the ORELA linear electron accelerator. The observed p-wave resonances, with I/sup pi /=1/2/sup - / and 3/2/sup -/ can also be populated in the beta -decay of the 3/2 /sup -/ ground state of /sup 87/Br. When comparing the present results with previous studies of beta -delayed neutron spectra, the authors find that almost all observed p-wave resonances can be identified with peaks in the delayed neutron spectra. (0 refs).

  9. New insight into the properties of proton conducting oxides from neutron total scattering

    SciTech Connect (OSTI)

    Proffen, Thomas E [Los Alamos National Laboratory; Kim, Hyunjeong [Los Alamos National Laboratory; Malavasi, Lorenzo [U PAVIA, ITALY; Flor, Giorgio [U PAVIA, ITALY

    2008-01-01T23:59:59.000Z

    In recent years there has been a growing interest in searching for new proton conducting materials that could be successfully used in medium temperature solid oxide fuel cells (SOFC). In particular, proton conducting oxides have been the subject of a massive research activity. Among the most promising oxide the acceptor doped cerates appears to be those most appealing in view of practical applications. A relevant aspect of these materials is the investigation of the local distortion of the structure arising from water incorporation. This kind of study is of great help in defining how the structure changes in order to accommodate the proton which is usually thought to enter the structure in form of hydroxyl group where the oxygen vacancy results from the acceptor doping on the Ce site. Atomistic simulation work confirmed that the preferential location of dopant ions is on the Ce site. To the best of our knowledge the only experimental work addressing the role of dopant and water incorporation on the local structure of V-doped cerates is a X-ray absorption spectroscopy (XAS) work carried out by Longo and coworkers at the Y K-edge. The main conclusion of that work was the observation that Y-doping induces a distortion of the parent BaCe0{sub 3} structure resulting in a significantly distorted Y local environment. However, local structure information derived from XAS study does not provide a direct structural information and depends strongly upon the model used to calcualte theoretical {chi}(k) which is not unique. Moreover, the XAS analysis usually provide significant information only up to the second shell. As a consequence, a more reliable and useful technique to investigate the local arrangement in these proton conducting oxides appears to be the Pair Distribution Function (PDF) analysis derived from total neutron scattering measurements. In the present work we investigated the pure BaCeO{sub 3} and the acceptor doped BaCe{sub 0.90}Y{sub 0.10}O{sub 2.85} compounds. In both cases the samples have been measured at room temperature and after being exposed to dry and wet air (humidification attained through bubbling air in D{sub 2}O). Aim of this work is to look at the effect of Y-doping and water doping on the local structure of the above mentioned samples.

  10. Fast neutron scattering on Gallium target at 14.8 MeV

    E-Print Network [OSTI]

    R. Han; R. Wada; Z. Chen; Y. Nie; X. Liu; S. Zhang; P. Ren; B. Jia; G. Tian; F. Luo; W. Lin; J. Liu; F. Shi; M. Huang; X. Ruan; J. Ren; Z. Zhou; H. Huang; J. Bao; K. Zhang; B. Hu

    2014-11-03T23:59:59.000Z

    Benchmarking of evaluated nuclear data libraries was performed for $\\sim 14.8$ MeV neutrons on Gallium targets. The experiments were performed at China Institute of Atomic Energy(CIAE). Solid samples of natural Gallium (3.2 cm and 6.4 cm thick) were bombarded by $\\sim 14.8$ MeV neutrons and leakage neutron energy spectra were measured at 60$^{\\circ}$ and 120$^{\\circ}$. The measured spectra are rather well reproduced by MCNP-4C simulations with the CENDL-3.1, ENDF/B-VII and JENDL-4.0 evaluated nuclear data libraries, except for the inelastic contributions around $E_{n} = 10-13$ MeV. All three libraries significantly underestimate the inelastic contributions. The inelastic contributions are further studied, using the Talys simulation code and the experimental spectra are reproduced reasonably well in the whole energy range by the Talys calculation, including the inelastic contributions.

  11. Fast neutron scattering on Gallium target at 14.8 MeV

    E-Print Network [OSTI]

    Han, R; Chen, Z; Nie, Y; Liu, X; Zhang, S; Ren, P; Jia, B; Tian, G; Luo, F; Lin, W; Liu, J; Shi, F; Huang, M; Ruan, X; Ren, J; Zhou, Z; Huang, H; Bao, J; Zhang, K; Hu, B

    2014-01-01T23:59:59.000Z

    Benchmarking of evaluated nuclear data libraries was performed for $\\sim 14.8$ MeV neutrons on Gallium targets. The experiments were performed at China Institute of Atomic Energy(CIAE). Solid samples of natural Gallium (3.2 cm and 6.4 cm thick) were bombarded by $\\sim 14.8$ MeV neutrons and leakage neutron energy spectra were measured at 60$^{\\circ}$ and 120$^{\\circ}$. The measured spectra are rather well reproduced by MCNP-4C simulations with the CENDL-3.1, ENDF/B-VII and JENDL-4.0 evaluated nuclear data libraries, except for the inelastic contributions around $E_{n} = 10-13$ MeV. All three libraries significantly underestimate the inelastic contributions. The inelastic contributions are further studied, using the Talys simulation code and the experimental spectra are reproduced reasonably well in the whole energy range by the Talys calculation, including the inelastic contributions.

  12. LANSCE | Lujan Center | Highlights | Neutron Reflectometry (NR...

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

    of the crystallinity of the sample (single crystal, polycrystalline, or amorphous). Neutron scattering is a unique tool to study such nanolayered composites because the...

  13. Atomic dynamics in molten AlCu alloys of different compositions and at different temperatures by cold neutron scattering

    SciTech Connect (OSTI)

    Dahlborg, U. [University of Rouen; Besser, M. [Ames Laboratory; Kramer, Matthew J. [Ames Laboratory; Morris, J. R. [Oak Ridge National Laboratory; Calvo-Dahlborg, M. [University of Rouen

    2013-12-21T23:59:59.000Z

    The atomic motions in molten Al1?xCux (x=0.10, 0.171 and 0.25) around the eutectic composition (x=0.171) were studied by cold neutron inelastic scattering at three different temperatures (973 K, 1173 K and 1373 K). An alloy of eutectic composition containing the 63Cu isotope was also studied. Self-diffusion coefficients for the Cu ions were determined from the width of quasielastic peaks and were found to decrease slightly with increasing Cu concentration. Longitudinal current correlation functions Jl(Q,E) exhibit at all temperatures and at all compositions a shoulder at energies below 10 meV and one main maximum at higher energies. These features can be interpreted in terms of excitations of acoustic and optic nature. The shape of Jl(Q,E) is sensitive to composition, being considerably more structured for larger Cu content. This can be coupled to the existence of a prepeak in the measured zeroth moment of dynamic scattering function indicating an increased chemical ordering with increasing Cu concentration for all temperatures. Indications for an existence of a liquid–liquid phase transition are presented.

  14. National School on Neutron and X-ray Scattering Oak Ridge National Laboratory and Argonne National Laboratory

    E-Print Network [OSTI]

    Pennycook, Steve

    National School on Neutron and X-ray Scattering Oak Ridge National Laboratory and Argonne National Laboratory May 30-June 14, 2009 Air Travel Arrangements The Argonne Division of Educational Programs has made to Argonne - June 8 through and including June 13, 2009 Daily bus transportation will be provided for School

  15. National School on Neutron and X-ray Scattering Argonne National Laboratory and Oak Ridge National Laboratory

    E-Print Network [OSTI]

    Pennycook, Steve

    National School on Neutron and X-ray Scattering Argonne National Laboratory and Oak Ridge National Laboratory June 12-26, 2010 Schedule for Saturday, June 12, 2010 School participants arrive at Argonne and check in at the Argonne Guest House, Building 460. 3:00 PM until 8:00 PM - Registration and informal get

  16. National School on Neutron and X-ray Scattering Oak Ridge National Laboratory and Argonne National Laboratory

    E-Print Network [OSTI]

    National School on Neutron and X-ray Scattering Oak Ridge National Laboratory and Argonne National Laboratory June 11-25, 2011 Air Travel Arrangements The Argonne Division of Educational Programs has made at the Argonne Guest House at approximately 6:00 p.m. (CDT). Dinner will be provided upon arrival to the hotel

  17. Inelastic neutron scattering of a quantum translator-rotator encapsulated in a closed fullerene cage: Isotope effects and translation-rotation coupling in H2@C60 and HD@C60

    E-Print Network [OSTI]

    Turro, Nicholas J.

    Inelastic neutron scattering of a quantum translator-rotator encapsulated in a closed fullerene, New York 10027, USA Received 1 July 2010; published 20 August 2010 We report an inelastic neutron-scattering inelastic neutron scattering INS ,6 and specific heat7 inves- tigations have recently been reported

  18. A neutron transmission study of environmental Gd

    E-Print Network [OSTI]

    Cristiana Oprea; Ioan Alexandru Oprea; Alexandru Mihul

    2014-06-02T23:59:59.000Z

    A new method for the determination of environmental Gd by neutron transmission (NT) experiments is proposed. The NT method is based on the measurements of neutron spectra passing through a target. From the attenuation neutron spectra new data as concentration, width, resonance energies and cross section have been obtained.

  19. A cryogenic high pressure cell for inelastic neutron scattering measurements of quantum fluids and solids

    SciTech Connect (OSTI)

    Carmichael, Justin R [ORNL; Omar Diallo, Souleymane [ORNL

    2013-01-01T23:59:59.000Z

    We present our new development of a high pressure cell for inelastic neutron scattering measurements of helium at ultra-low temperatures. The cell has a large sample volume of ~140 cm3, and a working pressure of ~70 bar, with a relatively thin wall-thickness (1.1 mm) - thanks to the high yield strength aluminum used in the design. Two variants of this cell have been developed; one with permanently joined components using electron-beam welding and explosion welding, methods that have little or no impact on the global heat treatment of the cell, and another with modular and interchangeable components, which include a capacitance pressure gauge, that can be sealed using traditional indium wire technique. The performance of the cell has been tested in recent measurements on superfluid liquid helium near the solidification line.

  20. Small angle neutron scattering analysis of novel carbons for lithium secondary batteries.

    SciTech Connect (OSTI)

    Sandi, G.; Thiyagarajan, P.; Winans, R.; Carrado, K.

    1998-01-14T23:59:59.000Z

    Small angle neutron scattering analyses of carbonaceous materials used as anodes in lithium ion cells have been performed. The carbons have been synthesized using pillared clays (PILCs) as inorganic templates. Pillared clays are layered silicates whose sheets have been permanently propped open by sets of thermally stable molecular props. The calcined PILC was loaded with five different organic precursors and heated at 700 C under nitrogen. When the inorganic pillars were removed by acid treatment, carbon sheets are produced with holes. The fitting of the data in the high q region suggested that the carbon sheets have voids with radii ranging from 4 to 8 {angstrom}. Similar radii were obtained for the PILC and PILC/organic precursor, which suggests that the carbon was well distributed in the clay prior to pyrolysis.

  1. Ultrasound scattering and the study of vortex correlations in disordered flows

    E-Print Network [OSTI]

    Denis Boyer; Fernando Lund

    1999-12-14T23:59:59.000Z

    In an idealized way, some turbulent flows can be pictured by assemblies of many vortices characterized by a set of particle distribution functions. Ultrasound provide an useful, nonintrusive, tool to study the spatial structure of vorticity in flows. This is analogous to the use of elastic neutron scattering to determine liquid structure. We express the dispersion relation, as well as the scattering cross section, of sound waves propagating in a ``liquid'' of identical vortices as a function of vortex pair correlation functions. In two dimensions, formal analogies with ionic liquids are pointed out.

  2. Present status and plans for upgrading the Lujan neutron scattering center

    SciTech Connect (OSTI)

    Rhyne, James J [LANSCE-LC

    2010-01-01T23:59:59.000Z

    The Lujan Center, part of the LANSCE accelerator complex at Los Alamos National Laboratory, operates a comprehensive neutron scattering facility for the U.S. Department of Energy that serves approximately 300 users per year. This paper will discuss the current instruments and status of the facility and also focus on the plans for a major upgrade of the Center including new instruments and enhancements to specific existing instruments. The instrument suite currently includes two reflectometers (one with full polarization), an engineering diffraction machine, a diffractometer specialized to pair-distribution analysis, 2 general purpose powder diffractometers, and 2 inelastic spectrometers. To complement these spectrometers, a full range of pressure, temperature, and magnetic field sample environments is available for users. As part of the planning for a forthcoming enhancement of Lujan Center, a series of workshops have been held over the past year to encourage user input to the design for new instruments as well as major upgrades of existing machines. Many of the planned facilities are designed to take advantage of the Lujan Center 20 Hz pulse repetition rate and cold source moderators, both of which are beneficial for high-resolution instruments using long neutron wavelengths.

  3. A Neutron Reflectivity Study of Polymer-Modified Phospholipid Monolayers at the Solid-Solution Interface: Polyethylene Glycol-Lipids on

    E-Print Network [OSTI]

    Wong, Joyce

    A Neutron Reflectivity Study of Polymer-Modified Phospholipid Monolayers at the Solid,# S. Steinberg,# D. E. Leckband,§ J. N. Israelachvili,# and G. S. Smith* *Manuel Lujan, Jr. Neutron Scattering Center, Los Alamos National Laboratory, Los Alamos, New Mexico 87545; # Department of Chemical

  4. Neutron–proton effective mass splitting in neutron-rich matter at normal density from analyzing nucleon–nucleus scattering data within an isospin dependent optical model

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

    Li, Xiao -Hua; Guo, Wen -Jun; Li, Bao -An; Chen, Lie -Wen; Fattoyev, Farrukh J.; Newton, William G.

    2015-04-01T23:59:59.000Z

    The neutron–proton effective mass splitting in asymmetric nucleonic matter of isospin asymmetry ? and normal density is found to be m*n-p?(m*n – m*p)/m = (0.41 ± 0.15)? from analyzing globally 1088 sets of reaction and angular differential cross sections of proton elastic scattering on 130 targets with beam energies from 0.783 MeV to 200 MeV, and 1161 sets of data of neutron elastic scattering on 104 targets with beam energies from 0.05 MeV to 200 MeV within an isospin dependent non-relativistic optical potential model. It sets a useful reference for testing model predictions on the momentum dependence of the nucleonmore »isovector potential necessary for understanding novel structures and reactions of rare isotopes.« less

  5. A New On-the-Fly Sampling Method for Incoherent Inelastic Thermal Neutron Scattering Data in MCNP6

    SciTech Connect (OSTI)

    Pavlou, Andrew Theodore [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Brown, Forrest B. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Ji, Wei [Rensselaer Polytechnic Inst., Troy, NY (United States)

    2014-09-02T23:59:59.000Z

    At thermal energies, the scattering of neutrons in a system is complicated by the comparable velocities of the neutron and target, resulting in competing upscattering and downscattering events. The neutron wavelength is also similar in size to the target's interatomic spacing making the scattering process a quantum mechanical problem. Because of the complicated nature of scattering at low energies, the thermal data files in ACE format used in continuous-energy Monte Carlo codes are quite large { on the order of megabytes for a single temperature and material. In this paper, a new storage and sampling method is introduced that is orders of magnitude less in size and is used to sample scattering parameters at any temperature on-the-fly. In addition to the reduction in storage, the need to pre-generate thermal scattering data tables at fine temperatures has been eliminated. This is advantageous for multiphysics simulations which may involve temperatures not known in advance. A new module was written for MCNP6 that bypasses the current S(?,?) table lookup in favor of the new format. The new on-the-fly sampling method was tested for graphite for two benchmark problems at ten temperatures: 1) an eigenvalue test with a fuel compact of uranium oxycarbide fuel homogenized into a graphite matrix, 2) a surface current test with a \\broomstick" problem with a monoenergetic point source. The largest eigenvalue difference was 152pcm for T= 1200K. For the temperatures and incident energies chosen for the broomstick problem, the secondary neutron spectrum showed good agreement with the traditional S(?,?) sampling method. These preliminary results show that sampling thermal scattering data on-the-fly is a viable option to eliminate both the storage burden of keeping thermal data at discrete temperatures and the need to know temperatures before simulation runtime.

  6. Neutron Diffraction and Neutron Vibrational Spectroscopy Studies of Hydrogen Adsorption in the Prussian Blue Analogue

    E-Print Network [OSTI]

    The transition to an energy infrastructure based upon hydrogen as an energy carrier is critically dependent uponNeutron Diffraction and Neutron Vibrational Spectroscopy Studies of Hydrogen Adsorption, Berkeley, California 94720-1460 ReceiVed April 13, 2006 The adsorption of molecular hydrogen

  7. Measurement of the Neutron Radius of 208Pb Through Parity-Violation in Electron Scattering

    SciTech Connect (OSTI)

    Abrahamyan, Sergey; Albataineh, Hisham; Aniol, Konrad; Armstrong, David; Armstrong, Whitney; Averett, Todd; Babineau, Benjamin; Barbieri, A; Bellini, Vincenzo; Beminiwattha, Rakitha; Benesch, Jay; Benmokhtar, Fatiha; Bierlarski, Trevor; Boeglin, Werner; Camsonne, Alexandre; Canan, Mustafa; Carter, Philip; Cates, Gordon; Chen, Chunhua; Chen, Jian-Ping; Hen, O; Cusanno, Francesco; Dalton, Mark; De Leo, Raffaele; De Jager, Cornelis; Deconinck, Wouter; Decowski, Piotr; Deng, Xiaoyan; Deur, Alexandre; Dutta, Dipangkar; Etile, Asenath; Flay, David; Franklin, Gregg; Friend, Megan; Frullani, Salvatore; Fuchey, Eric; Garibaldi, Franco; Gasser, Estelle; Gilman, Ronald; Guisa, Antonio; Glamazdin, Oleksandr; Gomez, Javier; Grames, Joseph; Gu, Chao; Hansen, Jens-Ole; Hansknecht, John; Higinbotham, Douglas; Holmes, Richard; Holmstrom, Timothy; Horowitz, Charles; Hoskins, Joshua; Huang, Jin; Hyde, Charles; Itard, Florian; Jen, Chun-Min; Jensen, Eric; Jin, Ge; Johnston, Sereres; Kelleher, Aidan; Kliakhandler, Konstantin; King, Paul; Kowalski, Stanley; Kumar, Krishna; Leacock, John; Leckey, John; Lee, Jeong Han; LeRose, John; Lindgren, Richard; Liyanage, Nilanga; Lubinsky, Nicholas; Mammei, Juliette; Mammoliti, Francesco; Margaziotis, Demetrius; Markowitz, Pete; McCreary, Amber; McNulty, Dustin; Mercado, Luis; Meziani, Zein-Eddine; Michaels, Robert; Mihovilovic, Miha; Muangma, Navaphon; Munoz Camacho, Carlos; Nanda, Sirish; Nelyubin, Vladimir; Nuruzzaman,; Oh, Yongseok; Palmer, Alvin; Parno, Diana; Paschke, Kent; Phillips, Sarah; Poelker, Benard; Pomatsalyuk, Roman; Posik, Matthew; Puckett, Andrew; Quinn, Brian; Rakhman, A; Reimer, Paul; Riordan, Seamus; Rogan, Patrick; Ron, Guy; Russo, Guiseppe; Saenboonruang, Kiadtisak; Saha, Arunava; Sawatzky, Bradley; Shahinyan, Albert; Silwal, Rupesh; Sirca, Simon; Slifer, Karl; Solvignon-Slifer, Patricia; Souder, Paul; Leda Sperduto, Maria; Subedi, Ramesh; Suleiman, Riad; Sulkosky, Vincent; Sutera, Concetta; Tobias, William; Troth, Wolfgang; Urciuoli, Guido; Buddhini Waidyawansa, Dinayadura; Wang, Diancheng; Wexler, Jonathan; Wilson, Richard; Wojtsekhowski, Bogdan; Yan, Xinhu; Yao, Huan; Ye, Yunxiu; Ye, Zhiohong; Yim, Vireak; Zana, Lorenzo; Zhan, Xiaohui; Zhang, Jixie; Zhang, Y; Zheng, Xiaochao; Zhu, Pengjia

    2012-03-15T23:59:59.000Z

    We report the first measurement of the parity-violating asymmetry APV in the elastic scattering of polarized electrons from 208Pb. APV is sensitive to the radius of the neutron distribution (Rn). The result APV = 0.656 ± 0.060 (stat) ± 0.013 (syst) corresponds to a difference between the radii of the neutron and proton distributions Rn-Rp = 0.33-0.18+0.16 fm and provides the first electroweak observation of the neutron skin which is expected in a heavy, neutron-rich nucleus.

  8. Neutron interferometric measurement of the scattering length difference between the triplet and singlet states of n-$^3$He

    E-Print Network [OSTI]

    M. G. Huber; M. Arif; W. C. Chen; T. R. Gentile; D. S. Hussey; T. C. Black; D. A. Pushin; C. B. Shahi; F. E. Wietfeldt; L. Yang

    2014-09-30T23:59:59.000Z

    We report a determination of the n-$^3$He scattering length difference $\\Delta b^{\\prime} = b_{1}^{\\prime}-b_{0}^{\\prime} = $ ($-5.411$ $\\pm$ $0.031$ (statistical) $\\pm$ $0.039$ (systematic)) fm between the triplet and singlet states using a neutron interferometer. This revises our previous result $\\Delta b^{\\prime} = $ (-5.610 $\\pm$ $0.027$ (statistical) $\\pm$ $0.032$ (systematic) fm obtained using the same technique in 2008. This revision is due to a re-analysis of the 2008 experiment that includes a more robust treatment of the phase shift caused by magnetic field gradients near the $^3$He cell. Furthermore, we more than doubled our original data set from 2008 by acquiring six months of additional data in 2013. Both the new data set and a re-analysis of the older data are in good agreement. Scattering lengths of low Z isotopes are valued for use in few-body nuclear effective field theories, provide important tests of modern nuclear potential models and in the case of $^3$He aid in the interpretation of neutron scattering from quantum liquids. The difference $\\Delta b^{\\prime}$ was determined by measuring the relative phase shift between two incident neutron polarizations caused by the spin-dependent interaction with a polarized $^3$He target. The target $^3$He gas was sealed inside a small, flat windowed glass cell that was placed in one beam path of the interferometer. The relaxation of $^3$He polarization was monitored continuously with neutron transmission measurements. The neutron polarization and spin flipper efficiency were determined separately using $^3$He analyzers and two different polarimetry analysis methods. A summary of the measured scattering lengths for n-$^3$He with a comparison to nucleon interaction models is given.

  9. Low frequency scattering excess in supercooled confined water F. Venturini, P. Gallo, and M. A. Riccia)

    E-Print Network [OSTI]

    Tuscia, Università Degli Studi Della

    Received 9 January 2001; accepted 1 March 2001 Inelastic neutron scattering data on water confined in Vycor quasielastic neutron scattering QENS and neutron resonance spin­echo NRSE studies of the slow relaxation regionLow frequency scattering excess in supercooled confined water F. Venturini, P. Gallo, and M. A

  10. Recent Studies on Inverse Medium Scattering Problems

    E-Print Network [OSTI]

    2007-06-28T23:59:59.000Z

    Numerical examples are presented to illustrate the efficiency and robustness of the ... Energy estimates for the scattered field are established, which provide ...

  11. SUPPLEMENTARY MATERIAL Lipid bilayer structure determined by the simultaneous analysis of neutron

    E-Print Network [OSTI]

    Nagle, John F.

    scattering intensities I(q) for both neutrons and x-rays using )()()()( qPqPqIqF TSLC= , (1.) where PLC in structure between oriented and spherical bilayers experimentally using both neutron and x-ray scattering in (2). Our study concluded no difference between the two for x-ray and neutron scattering data

  12. ANOMALOUS DISPERSION OF SLOW NEUTRONS IN CRYSTALS By H. G. SMITH and S. W. PETERSON (1),

    E-Print Network [OSTI]

    Boyer, Edmond

    Studies of anomalous scattering of neutrons from CdI2 single crystals were conti- nued over an energy neutron scattering by nuclei and crystals has been fairly well understood for many years. An incident, and depends on the neutron-nucleus interactions. In general, the scattering amplitude can be expressed

  13. Study on neutron radiation field of carbon ions therapy

    E-Print Network [OSTI]

    Xu, Jun-Kui; Li, Wu-Yuan; Yan, Wei-Wei; Chen, Xi-Meng; Mao, Wang; Pang, Cheng-Guo

    2015-01-01T23:59:59.000Z

    Carbon ions offer significant advantages for deep-seated local tumors therapy due to their physical and biological properties. Secondary particles, especially neutrons caused by heavy ion reactions should be carefully considered in treatment process and radiation protection. For radiation protection purposes, the FLUKA Code was used in order to evaluate the radiation field at deep tumor therapy room of HIRFL in this paper. The neutron energy spectra, neutron dose and energy deposition of carbon ion and neutron in tissue-like media was studied for bombardment of solid water target by 430MeV/u C ions. It is found that the calculated neutron dose have a good agreement with the experimental date, and the secondary neutron dose may not exceed one in a thousand of the carbon ions dose at Bragg peak area in tissue-like media.

  14. Body composition to climate change studies - the many facets of neutron induced prompt gamma-ray analysis

    SciTech Connect (OSTI)

    Mitra,S.

    2008-11-17T23:59:59.000Z

    In-vivo body composition analysis of humans and animals and in-situ analysis of soil using fast neutron inelastic scattering and thermal neutron capture induced prompt-gamma rays have been described. By measuring carbon (C), nitrogen (N) and oxygen (O), protein, fat and water are determined. C determination in soil has become important for understanding below ground carbon sequestration process in the light of climate change studies. Various neutron sources ranging from radio isotopic to compact 14 MeV neutron generators employing the associated particle neutron time-of-flight technique or micro-second pulsing were implemented. Gamma spectroscopy using recently developed digital multi-channel analyzers has also been described.

  15. Measurement of the Wolfenstein parameters for proton-proton and proton-neutron scattering at 500 MeV

    SciTech Connect (OSTI)

    Marshall, J.A.

    1984-07-01T23:59:59.000Z

    Using liquid hydrogen and liquid deuterium targets respectively, forward angle (ten degrees to sixty degrees in the center of Mass) free proton-proton and quasielastic proton-proton and proton-neutron triple scattering data at 500 MeV have been obtained using the high resolution spectrometer at the Los Alamos Meson Physics Facility. The data are in reasonable agreement with recent predictions from phase shift analyses, indicating that the proton-nucleon scattering amplitudes are fairly well determined at 500 MeV. 32 references.

  16. Neutron scattering in molecular liquids: Influence of orientational degrees of freedom and the prepeak in a fragile glass former

    E-Print Network [OSTI]

    Christoph Theis; Rolf Schilling

    1998-08-07T23:59:59.000Z

    The intermediate scattering function S(q,t) for neutron scattering is expanded with respect to a complete set of correlation functions which describe the dynamical correlations in a molecular liquid. For the static ns-structure factor S(q) of a system of diatomic molecules the results of the expansion are compared with the exact results from a MD-imulation and it is shown that the Sears-expansion, which is commonly used to interpret such data, fails in the supercooled regime. The representation for S(q) is used to draw conclusions about the q-dependence and especially the origin of the prepeak.

  17. Parameterization of structures in HE composites using surrogate materials: A small angle neutron scattering investigation

    SciTech Connect (OSTI)

    Mang, J.T.; Hjelm, R.P.; Skidmore, C.B.; Howe, P.M.

    1996-07-01T23:59:59.000Z

    High explosive materials used in the nuclear stockpile are composites of crystalline high explosives (HE) with binder materials, such as Estane. In such materials, there are naturally occurring density fluctuations (defects) due to cracks, internal (in the HE) and external (in the binder) voids and other artifacts of preparation. Changes in such defects due to material aging can affect the response of explosives due to shock, impact and thermal loading. Modeling efforts are attempting to provide quantitative descriptions of explosive response from the lowest ignition thresholds to the development of full blown detonations and explosions, however, adequate descriptions of these processes require accurate measurements of a number of structural parameters of the HE composite. Since different defects are believed to affect explosive sensitivity in different ways it is necessary to quantitatively differentiate between defect types. The authors report here preliminary results of SANS measurements on surrogates for HE materials. The objective of these measurements was to develop methodologies using SANS techniques to parameterize internal void size distributions in a surrogate material, sugar, to simulate an HE used in the stockpile, HMX. Sugar is a natural choice as a surrogate material, as it has the same crystal structure, has similar intragranular voids and has similar mechanical properties as HMX. It is used extensively as a mock material for explosives. Samples were used with two void size distributions: one with a sufficiently small mean particle size that only small occluded voids are present in significant concentrations, and one where the void sizes could be larger. By using methods in small-angle neutron scattering, they were able to isolate the scattering arising from particle-liquid interfaces and internal voids.

  18. Feasibility Study of Neutron Dose for Real Time Image Guided Proton Therapy: A Monte Carlo Study

    E-Print Network [OSTI]

    Kim, Jin Sung; Kim, Daehyun; Shin, EunHyuk; Chung, Kwangzoo; Cho, Sungkoo; Ahn, Sung Hwan; Ju, Sanggyu; Chung, Yoonsun; Jung, Sang Hoon; Han, Youngyih

    2015-01-01T23:59:59.000Z

    Two full rotating gantry with different nozzles (Multipurpose nozzle with MLC, Scanning Dedicated nozzle) with conventional cyclotron system is installed and under commissioning for various proton treatment options at Samsung Medical Center in Korea. The purpose of this study is to investigate neutron dose equivalent per therapeutic dose, H/D, to x-ray imaging equipment under various treatment conditions with monte carlo simulation. At first, we investigated H/D with the various modifications of the beam line devices (Scattering, Scanning, Multi-leaf collimator, Aperture, Compensator) at isocenter, 20, 40, 60 cm distance from isocenter and compared with other research groups. Next, we investigated the neutron dose at x-ray equipments used for real time imaging with various treatment conditions. Our investigation showed the 0.07 ~ 0.19 mSv/Gy at x-ray imaging equipments according to various treatment options and intestingly 50% neutron dose reduction effect of flat panel detector was observed due to multi- lea...

  19. Study of Fuel Cell Water Transport With Neutron Imaging

    E-Print Network [OSTI]

    detector system, constructing computer controlled fuel cell handling mechanism and optimizing dataStudy of Fuel Cell Water Transport With Neutron Imaging David Jacobson (NIST) Paul Huffman (NIST in fully assembled operating fuel cells. Develop a nuclear reactor based state of the art neutron imaging

  20. Neutron Stimulated Emission Computed Tomography of Stable Isotopes

    E-Print Network [OSTI]

    on the development of a new molecular imaging technique using inelastic scattering of fast neutrons. Earlier studies characteristic gamma photons through inelastic scattering of an external neutron beam. These stable isotopes canNeutron Stimulated Emission Computed Tomography of Stable Isotopes Carey E. Floyd Jr.*ab , Calvin

  1. HFIR Experiment Facilities | ORNL Neutron Sciences

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

    Scattering Neutron Scattering Facilities at HFIR The fully instrumented HFIR will eventually include 15 state-of-the-art neutron scattering instruments, seven of which will be...

  2. Measurement Of Neutron Radius In Lead By Parity Violating Scattering Flash ADC DAQ

    SciTech Connect (OSTI)

    Ahmed, Zafar [Christopher Newport Univ., Newport News, VA (United States)

    2012-06-01T23:59:59.000Z

    This dissertation reports the experiment PREx, a parity violation experiment which is designed to measure the neutron radius in {sup 208}Pb. PREx is performed in hall A of Thomas Jefferson National Accelerator Facility from March 19th to June 21st. Longitudionally polarized electrons at energy 1 GeV scattered at and angle of {theta}{sub lab} = 5.8 {degrees} from the Lead target. Beam corrected pairty violaing counting rate asymmetry is (A{sub corr} = 594 ± 50(stat) ± 9(syst))ppb at Q{sup 2} = 0.009068GeV {sup 2}. This dissertation also presents the details of Flash ADC Data Acquisition(FADC DAQ) system for Moller polarimetry in Hall A of Thomas Jefferson National Accelerator Facility. The Moller polarimeter measures the beam polarization to high precision to meet the specification of the PREx(Lead radius experiment). The FADC DAQ is part of the upgrade of Moller polarimetery to reduce the systematic error for PREx. The hardware setup and the results of the FADC DAQ analysis are presented

  3. Status report on the analysis of inelastic neutron scattering from carbon, iron, yttrium and lead at 96 MeV

    E-Print Network [OSTI]

    C. Gustavsson; C. Hellesen; S. Pomp; A. Öhrn; J. Blomgren; U. Tippawan

    2013-03-27T23:59:59.000Z

    This work is part of an effort to provide more experimental data for the (n,n'x) reaction. The experiments were carried out at The Svedberg Laboratory in Uppsala, Sweden, at the quasi-mono-energetic neutron beam of 96 MeV, before the facility was upgraded in 2004. Using an extended data analysis of data primarily intended for measuring elastic neutron scattering only, it was found to be possible to extract information on the inelastic scattering from several nuclei. In the preliminary data analysis, an iterative forward-folding technique was applied, in which a physically reasonable trial spectrum was folded with the response function of the detector system and the output was compared to the experimental data. As a result, double-differential cross sections and angular distributions of inelastic neutron scattering from 12-C, 56-Fe, 89-Y and 208-Pb could be obtained. In this paper, a status update on the efforts to improve the description of the detector response function is given.

  4. Light-scattering studies of silica aerogels

    SciTech Connect (OSTI)

    Hunt, A.J.

    1983-02-01T23:59:59.000Z

    Due to its combination of transparency and low thermal conductivity, aerogel holds considerable promise for use as insulating window materials for residential and commercial applications. This paper reports on the preliminary investigation of the optical and scattering properties of silica aerogels. It briefly describes the properties of aerogels important for window glazing applications. The optical properties are then described, followed by a discussion of the scattering measurements and their interpretation.

  5. Extraction of the Ratio of the Neutron to Proton Structure Functions from Deep Inelastic Scattering

    E-Print Network [OSTI]

    Simonetta Liuti; Franz Gross

    1995-06-05T23:59:59.000Z

    We study the nuclear ($A$) dependence of the European Muon Collaboration (EMC) effect at high values of $x$ ($x \\geq 0.6$). Our approach makes use of conventional nuclear degrees of freedom within the Relativistic Impulse Approximation. By performing a non-relativistic series expansion we demonstrate that relativistic corrections make a substantial contribution to the effect at $x \\gtrsim 0.6$ and show that the ratio of neutron to proton structure functions extracted from a global fit to all nuclei is not inconsistent with values obtained from the deuteron.

  6. Neutrons used to study model vascular systems

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's Possible for Renewable Energy:Nanowire Solar541,9337, 2011 at3,NeutronNeutrons provide newATHENA

  7. Neutrons used to study model vascular systems

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's Possible for Renewable Energy:Nanowire Solar541,9337, 2011 at3,NeutronNeutrons provide

  8. A light scattering study of colloid-polymer mixtures 

    E-Print Network [OSTI]

    Pirie, Angus D

    A detailed light scattering study of non-equilibrium states found in a model colloid-polymer mixture is presented. Conventional light scattering is used to examine the average structure of the phase, over a wide range of wavevectors. For all non...

  9. The Neutron Energy Spectrum Study from the Phase II Solid Methane Moderator at the LENS Neutron Source

    E-Print Network [OSTI]

    Yunchang Shin; W. Mike Snow; Christopher M. Lavelle; David V. Baxter; Xin Tong; Haiyang Yan; Mark Leuschner

    2007-11-19T23:59:59.000Z

    Neutron energy spectrum measurements from a solid methane moderator were performed at the Low Energy Neutron Source (LENS) at Indiana University Cyclotron Facility (IUCF) to verify our neutron scattering model of solid methane. The time-of-flight method was used to measure the energy spectrum of the moderator in the energy range of 0.1$meV\\sim$ 1$eV$. Neutrons were counted with a high efficiency $^{3}{He}$ detector. The solid methane moderator was operated in phase II temperature and the energy spectra were measured at the temperatures of 20K and 4K. We have also tested our newly-developed scattering kernels for phase II solid methane by calculating the neutron spectral intensity expected from the methane moderator at the LENS neutron source using MCNP (Monte Carlo N-particle Transport Code). Within the expected accuracy of our approximate approach, our model predicts both the neutron spectral intensity and the optimal thickness of the moderator at both temperatures. The predictions are compared to the measured energy spectra. The simulations agree with the measurement data at both temperatures.

  10. Sensitivity studies for the weak r process: neutron capture rates

    SciTech Connect (OSTI)

    Surman, R., E-mail: surmanr@union.edu [Department of Physics and Astronomy, Union College, Schenectady, NY 12308 (United States); Mumpower, M. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States)] [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Sinclair, R.; Jones, K. L. [Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996 (United States)] [Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996 (United States); Hix, W. R. [Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996 (United States) [Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996 (United States); Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); McLaughlin, G. C. [Department of Physics, North Carolina State University, Raleigh, NC 27695 (United States)] [Department of Physics, North Carolina State University, Raleigh, NC 27695 (United States)

    2014-04-15T23:59:59.000Z

    Rapid neutron capture nucleosynthesis involves thousands of nuclear species far from stability, whose nuclear properties need to be understood in order to accurately predict nucleosynthetic outcomes. Recently sensitivity studies have provided a deeper understanding of how the r process proceeds and have identified pieces of nuclear data of interest for further experimental or theoretical study. A key result of these studies has been to point out the importance of individual neutron capture rates in setting the final r-process abundance pattern for a ‘main’ (A ? 130 peak and above) r process. Here we examine neutron capture in the context of a ‘weak’ r process that forms primarily the A ? 80 r-process abundance peak. We identify the astrophysical conditions required to produce this peak region through weak r-processing and point out the neutron capture rates that most strongly influence the final abundance pattern.

  11. New Measurement of Compton Scattering from the Deuteron and an Improved Extraction of the Neutron Electromagnetic Polarizabilities

    E-Print Network [OSTI]

    L. S. Myers; J. R. M. Annand; J. Brudvik; G. Feldman; K. G. Fissum; H. W. Grießhammer; K. Hansen; S. S. Henshaw; L. Isaksson; R. Jebali; M. A. Kovash; M. Lundin; J. A. McGovern; D. G. Middleton; A. M. Nathan; D. R. Phillips; B. Schröder; S. C. Stave

    2014-11-13T23:59:59.000Z

    The electromagnetic polarizabilities of the nucleon are fundamental properties that describe its response to external electric and magnetic fields. They can be extracted from Compton-scattering data --- and have been, with good accuracy, in the case of the proton. In contradistinction, information for the neutron requires the use of Compton scattering from nuclear targets. Here we report a new measurement of elastic photon scattering from deuterium using quasimonoenergetic tagged photons at the MAX IV Laboratory in Lund, Sweden. These first new data in more than a decade effectively double the world dataset. Their energy range overlaps with previous experiments and extends it by 20 MeV to higher energies. An analysis using Chiral Effective Field Theory with dynamical \\Delta(1232) degrees of freedom shows the data are consistent with and within the world dataset. After demonstrating that the fit is consistent with the Baldin sum rule, extracting values for the isoscalar nucleon polarizabilities and combining them with a recent result for the proton, we obtain the neutron polarizabilities as \\alpha_n = [11.55 +/- 1.25(stat) +/- 0.2(BSR) +/- 0.8(th)] X 10^{-4} fm^3 and \\beta_n = [3.65 -/+ 1.25(stat) +/- 0.2(BSR) -/+ 0.8(th)] X 10^{-4} fm3, with \\chi^2 = 45.2 for 44 degrees of freedom.

  12. Comments to the problem of experimental determination of the neutron-electron scattering length and its theoretical interpretation

    E-Print Network [OSTI]

    A. B. Popov; T. Yu. Tretyakova

    2008-12-30T23:59:59.000Z

    We discuss the experimental data on the n,e-scattering length bne and the values of mean square charge radius of the neutron obtained from them. It is shown that the accumulated during the last 50 years most significant experimental estimates of the bne are not contradictory and lead to the average value =-0.1178+-0.0037 fm^2. Assuming that all the authors have underestimated the errors of their measurements by a factor of 1.7, the combined fit of all available experimental data would lead to Chi^2~1 per degree of freedom. Different modern theoretical predictions of are considered. They are found to be in a good agreement with the obtained experimental value . However the existing theoretical description of the structure of neutron does not provide a value of with a sufficient accuracy.

  13. Magnetism studies using resonant, coherent, x-ray scattering...

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

    Magnetism studies using resonant, coherent, x-ray scattering Monday, September 10, 2012 - 10:00am SLAC, Bldg. 137, Room 226 Keoki Seu Seminar: With the advent of free electron...

  14. Neutron Scattering Study of Anharmonic Phonon Dynamics in Thermoelectr...

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

    4:10 pm LOCATION: Physics 0003 Understanding the Electroweak Symmetry Breaking: The Higgs Boson and Beyond, Chen Li, Oak Ridge National Laboratory Knowledge on phonon...

  15. ORNL study uses neutron scattering, supercomputing to demystify forces at

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC)Integrated CodesTransparencyDOENurseResourcesThe Value Thescientists generate

  16. Neutron Small Angle Scattering on Liquid Helium in the temperature Range 1.5-4.2 K

    E-Print Network [OSTI]

    Yu. M. Tsipenyuk; R. P. May

    2002-07-11T23:59:59.000Z

    The small angle neutron scattering from liquid helium at saturated vapour pressure in the temperature range from 1.5 to 4.2 K was measured with the instrument D22 of the ILL Grenoble at a wavelength of 4.6 angstrom. The zero angle cross section is monotonically decreasing with decreasing temperature and does not show any singularity at the lambda-point. On the other handd, we observe a change of the slope of the temperature dependence of thw second momentum of the pair correlation function at the lambda-point that reflects the transition of liquid to the superfluid state.

  17. Investigation of coercivity mechanism in hot deformed Nd-Fe-B permanent magnets by small-angle neutron scattering

    SciTech Connect (OSTI)

    Yano, M., E-mail: masao-yano-aa@mail.toyota.co.jp; Manabe, A.; Shoji, T.; Kato, A. [Advanced Material Engineering Division, Toyota Motor Corporation, Susono 410-1193 (Japan); Ono, K. [High Energy Accelerator Research Organization (KEK), Tsukuba 305-0801 (Japan); Harada, M. [Toyota Central R and D Labs, Inc., Aichi 480-1192 (Japan); Kohlbrecher, J. [Laboratory for Neutron Scattering, Paul Scherrer Institut, 5232 Villigen PSI (Switzerland)

    2014-05-07T23:59:59.000Z

    The magnetic reversal behaviors of single domain sized Nd-Fe-B permanent magnets, with and without isolation between the Nd{sub 2}Fe{sub 14}B grains, was clarified using small-angle neutron scattering (SANS). The SANS patterns obtained arose from changes in the magnetic domains and were analyzed using the Teubner–Stray model, a phenomenological correlation length model, to quantify the periodicity and morphology of the magnetic domains. The results indicated that the magnetic reversal evolved with the magnetic domains that had similar sized grains. The grain isolation enabled us to realize the reversals of single domains.

  18. Neutron Scattering of CeNi at the SNS-ORNL: A Preliminary Report | SciTech

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's Possible for Renewable Energy:Nanowire Solar541,9337, 2011 at3,Neutron Scattering Tutorials

  19. Quantum Monte Carlo study of inhomogeneous neutron matter

    E-Print Network [OSTI]

    Stefano Gandolfi

    2012-08-31T23:59:59.000Z

    We present an ab-initio study of neutron drops. We use Quantum Monte Carlo techniques to calculate the energy up to 54 neutrons in different external potentials, and we compare the results with Skyrme forces. We also calculate the rms radii and radial densities, and we find that a re-adjustment of the gradient term in Skyrme is needed in order to reproduce the properties of these systems given by the ab-initio calculation. By using the ab-initio results for neutron drops for close- and open-shell configurations, we suggest how to improve Skyrme forces when dealing with systems with large isospin-asymmetries like neutron-rich nuclei.

  20. Phonon self-energy and origin of anomalous neutron scattering spectra in SnTe and PbTe thermoelectrics

    SciTech Connect (OSTI)

    Li, Chen [ORNL] [ORNL; Ma, Jie [ORNL] [ORNL; May, Andrew F [ORNL] [ORNL; Cao, Huibo [ORNL] [ORNL; Christianson, Andrew D [ORNL] [ORNL; Ehlers, Georg [ORNL] [ORNL; Singh, David J [ORNL] [ORNL; Sales, Brian C [ORNL] [ORNL; Delaire, Olivier A [ORNL] [ORNL

    2014-01-01T23:59:59.000Z

    The anharmonic lattice dynamics of rock-salt thermoelectric compounds SnTe and PbTe are investigated with inelastic neutron scattering (INS) and first-principles calculations. The experiments show that, surprisingly, although SnTe is closer to the ferroelectric instability, phonon spectra in PbTe exhibit a more anharmonic character. This behavior is reproduced in first-principles calculations of the temperature-dependent phonon self-energy. Our simulations reveal how the nesting of phonon dispersions induces prominent features in the self-energy, which account for the measured INS spectra and their temperature dependence. We establish that the phase-space for three-phonon scattering processes, rather than just the proximity to the lattice instability, is the mechanism determining the complex spectrum of the transverse-optical ferroelectric mode.

  1. Some major achievements of the Doster group (Bioneutron Scattering) F. Post, F. Demmel, M. Bachleitner, M. Settles, M. Diehl, R. Gebhardt, A.M. Gaspar, M. S.

    E-Print Network [OSTI]

    Doster, Wolfgang

    , H. Leyser.. Many neutron scattering experiments of proteins, were first performed by the Munich). 1988-1989: First wide temperature-, wide frequency-, wide Q- range inelastic neutron scattering study and the elastic scattering function of alanine peptide and MD simulations (with Smith Kneller) Dynamic neutron

  2. Scattering from fractals

    SciTech Connect (OSTI)

    Hurd, A.J.

    1989-01-01T23:59:59.000Z

    The realization that structures in Nature often can be described by Mandelbrot's ''fractals'' has led to a revolution in many areas of physics. The interaction of waves with fractal systems has, understandably, become intensely studied since scattering is the method of choice to probe delicate fractal structures such as chainlike particle aggregates. Not all of these waves are electromagnetic: neutron scattering, for example, is an important complementary tool to structural studies by x-ray and light scattering. Since the phenomenology of small-angle neutron scattering (SANS), as it is applied to fractal systems, is identical to that of small-angle x-ray scattering (SAXS), it falls within the scope of this Working Paper. 9 refs.

  3. Neutrons used to study model vascular systems

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC)Integrated CodesTransparency VisitSilverNephelineNeural probeNeutrons findKatie

  4. Neutron scattering residual stress measurements on gray cast iron brake discs

    SciTech Connect (OSTI)

    Spooner, S.; Payzant, E.A.; Hubbard, C.R. [and others

    1996-11-01T23:59:59.000Z

    Neutron diffraction was used to investigate the effects of a heat treatment designed to remove internal residual stresses in brake discs. It is believed that residual stresses may change the rate of deformation of the discs during severe braking conditions when the disc temperature is increased significantly. Neutron diffraction was used to map out residual strain distributions in a production disc before and after a stress-relieving heat treatment. Results from these neutron diffraction experiments show that some residual strains were reduced by as much as 400 microstrain by stress relieving. 5 refs., 5 figs., 1 tab.

  5. Neutron inelastic scattering and reactions in natural Pb as a background in neutrinoless double-beta-decay experiments

    E-Print Network [OSTI]

    V. E. Guiseppe; M. Devlin; S. R. Elliott; N. Fotiades; A. Hime; D. -M. Mei; R. O. Nelson; D. V. Perepelitsa

    2009-09-24T23:59:59.000Z

    Inelastic neutron scattering and reactions on Pb isotopes can result in gamma rays near the signature endpoint energy in a number of double-beta decay isotopes. In particular, there are gamma-ray transitions in Pb-206,207,208 that might produce energy deposits at the 76-Ge Q value in Ge detectors used for double-beta decay searches. The levels that produce these gamma rays can be excited by (n,n'gamma) or (n,xngamma) reactions, but the cross sections are small and previously unmeasured. This work uses the pulsed neutron beam at the Los Alamos Neutron Science Center to directly measure reactions of interest to double-beta decay experiments. The cross section on natural Pb to produce the 2041-keV gamma ray from Pb-206 is measured to be 3.6 +/- 0.7 (stat.) +/- 0.3 (syst.) mb at ~9.6 MeV. The cross section on natural Pb to produce the 3062-keV gamma ray from Pb-207 and Pb-208 is measured to be 3.9 +/- 0.8 (stat.) +/- 0.4 (syst.) mb at the same energy. We report cross sections or place upper limits on the cross sections for exciting some other levels in Pb that have transition energies corresponding to Q value in other double-beta decay isotopes.

  6. Measurement of the differential neutron-deuteron scattering cross section in the energy range from 100 keV to 600 keV using a proportional counter

    E-Print Network [OSTI]

    Nolte, R; Plompen, A; Röttger, S

    2014-01-01T23:59:59.000Z

    The angular distribution of neutron-deuteron scattering was investigated using the proportional counter P2 simultaneously as scattering target and detector for the recoil deuterons. The measurements were carried out using monoenergetic neutrons in the energy range from 150 keV to 500 keV. Various techniques were employed to reduce distortions of the experimental pulse-height distribution by photon-induced events. The experimental data were compared with realistic simulations which were carried out using different evaluated data sets. This comparison allows to conclude on inconsistencies in the evaluations.

  7. JOURNAL DE PHYSIQUE Colloque C I, supplPment au no 2-3, Tome 32, FPvrier-Mars 1971,page C 1 -70 NEUTRON DIFFRACTION STUDY OF SHORT RANGE ORDER

    E-Print Network [OSTI]

    Boyer, Edmond

    cross-section for neutron scattering is do -dQ = m~ m~(b, - bd2 i=o ai exp i(K.Ri) (I) where ai = 1 - Pi NEUTRON DIFFRACTION STUDY OF SHORT RANGE ORDER IN r-iMnNi P. WELLS and J. H. SMITH Physics Department un moment magnetique par atome de manganese de 1,5 +. 0,l WB. Une etude par diffraction de neutrons r

  8. A neutron diffraction study of the crystal structure of ferrocene

    E-Print Network [OSTI]

    Takusagawa, Fusao; Koetzle, Thomas F.

    1979-05-01T23:59:59.000Z

    . E. (1968) . Acta Chem. Scand. 22, 2 6 5 3 - 2 6 7 0 . HOLM, C. H. & IBERS, J. A . (1959) . J. Chem. Phys. 30, 885-888. HYAMS, I. J. & RON, A . (1973) . J. Chem. Phys. 59, 3027- 3030. JOHNSON, C . K. (1965) . ORTEP. Report ORNL-3794. Oak Ridge... //(neutron, X = 1-0399 A) = 0-198 * Seiler & Dunitz (1979). 1076 A NEUTRON DIFFRACTION STUDY OF THE STRUCTURE OF FERROCENE according to A20 = 1-76° (1 + 6-90 tan 0) for 20 > 50° and A20 = 4-00° for 29 < 50°. The step size was adjusted to give approximately...

  9. Structure of light neutron-rich nuclei and mechanism of elastic proton scattering

    SciTech Connect (OSTI)

    Ibraeva, E. T., E-mail: ibr@inp.kz [National Nuclear Center of the Republic of Kazakhstan, Institute of Nuclear Physics (Kazakhstan); Zhusupov, M. A. [Al-Farabi Kazakh National University (Kazakhstan); Imambekov, O. [National Nuclear Center of the Republic of Kazakhstan, Institute of Nuclear Physics (Kazakhstan)

    2011-11-15T23:59:59.000Z

    Differential cross sections for elastic p{sup 6}He, p{sup 8}Li, and p{sup 9}Li scattering at two energies of 70 and 700 MeV per nucleon were calculated within the Glauber theory of multiple diffractive scattering. Threeparticle wave functions ({alpha}-n-n for {sup 6}He, {alpha}-t-n for {sup 8}Li, and {sup 7}Li-n-n for {sup 9}Li) were used for realistic potentials of intercluster interactions. The sensitivity of elastic scattering to proton-nucleus interaction and to the structure of nuclei was explored. In particular, the dependence of the differential cross section on the contribution of higher order collisions, on scattering on the core and peripheral nucleons, and on the contribution of small wave-function components and their asymptotic behavior was determined. A comparison with available experimental data and with the results of calculations within different formalisms was performed.

  10. E-Print Network 3.0 - alkali ion scattering Sample Search Results

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

    3 Floppy modes and the Boson peak in crystalline and amorphous silicates: an inelastic neutron scattering study Summary: ion from Li+ to K+ in the alkali disilicate glasses,...

  11. Construction and testing of the instrument for neutron holographic study at the Budapest Research Reactor

    SciTech Connect (OSTI)

    Marko, Marton; Toeroek, Gyula; Cser, Laszlo [Department of Neutron Spectroscopy, Research Institute for Solid State Physics and Optics, P.O.B. 49, H-1525 Budapest (Hungary); Szakal, Alex [Department of Neutron Spectroscopy, Research Institute for Solid State Physics and Optics, P.O.B. 49, H-1525 Budapest (Hungary); Budapest University of Technology and Economics, Muegyetem rakpart 1-3, H-1113 Budapest (Hungary)

    2010-10-15T23:59:59.000Z

    Neutron scattering device dedicated to neutron holography experiments is described. The device is operating at a constant wavelength prepared by a double focusing monochromator. It is equipped by highly efficient shielding, proper collimator, Eulerian cradle, monitor detector, gamma-ray, and neutron detectors as well. Relevant software serves as control for the measurement and data collection. The harmonized application of the components enumerated above makes our device extremely efficient and unparalleled. Two atomic resolution neutron holographic experiments carried out illustrate the efficiency and power of the instrument.

  12. E-Print Network 3.0 - applying advanced neutron Sample Search...

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

    Source FRM II: Overview and Uses for Biological Studies Summary: a recent book on "Neutron Scattering in Biology, Techniques and Appli- cations" 3. INSTRUMENTS...

  13. NSF Students Gain Hands-on Experience in Neutron Sciences at...

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

    at Oak Ridge National Laboratory in April for an intensive course in how to apply neutron scattering to their studies of materials science and biological systems. The...

  14. VOLUME 75, NUMBER 2 P H Y S I C A L R E V I E W L E T T E R S 10 JULY 1995 Phonon and Magnetic Neutron Scattering at 41 meV in YBa2Cu3O7

    E-Print Network [OSTI]

    Aksay, Ilhan A.

    Neutron Scattering at 41 meV in YBa2Cu3O7 Hung Fai Fong, B. Keimer, and P. W. Anderson Department is the generalized magnetic susceptibility whose imaginary part x00 q, v is measur- able by neutron scattering. Below to be of mag- netic origin in polarized neutron scattering experiments by Mook et al. [2]. (We quote the in

  15. Polarized inelastic neutron scattering of the partially ordered Tb2Sn2O7 K. C. Rule,1 G. Ehlers,2 J. R. Stewart,3 A. L. Cornelius,4 P. P. Deen,3 Y. Qiu,5,6 C. R. Wiebe,7,8 J. A. Janik,7 H. D. Zhou,7

    E-Print Network [OSTI]

    Weston, Ken

    Polarized inelastic neutron scattering of the partially ordered Tb2Sn2O7 K. C. Rule,1 G. Ehlers,2 J 17 August 2007; published 21 December 2007 We present inelastic neutron scattering results neutron scattering, susceptibility, and specific heat techniques have shown that below 0.87 K Tb2Sn2O7

  16. Q-dependence of the inelastic neutron scattering cross section for molecular spin clusters with high molecular symmetry

    E-Print Network [OSTI]

    O. Waldmann

    2003-04-21T23:59:59.000Z

    For powder samples of polynuclear metal complexes the dependence of the inelastic neutron scattering intensity on the momentum transfer Q is known to be described by a combination of so called interference terms. They reflect the interplay between the geometrical structure of the compound and the spatial properties of the wave functions involved in the transition. In this work, it is shown that the Q-dependence is strongly interrelated with the molecular symmetry of molecular nanomagnets, and, if the molecular symmetry is high enough, is actually completely determined by it. A general formalism connecting spatial symmetry and interference terms is developed. The arguments are detailed for cyclic spin clusters, as experimentally realized by e.g. the octanuclear molecular wheel Cr8, and the star like tetranuclear cluster Fe4.

  17. Structure of neutron-rich Isotopes {sup 8}Li and {sup 9}Li and allowance for it in elastic scattering

    SciTech Connect (OSTI)

    Ibraeva, E. T., E-mail: ibr@inp.k [National Nuclear Center of the Republic of Kazakhstan, Institute for Nuclear Physics (Kazakhstan); Zhusupov, M. A.; Imambekov, O.; Sagindykov, Sh. Sh. [Al Farabi Kazakh National University (Kazakhstan)

    2008-07-15T23:59:59.000Z

    The differential cross sections for elastic proton scattering on the unstable neutron-rich nuclei {sup 8}Li and {sup 9}Li at E = 700 and 60 MeV per nucleon were considered. The {sup 8}Li nucleus was treated on the basis of the three-body {alpha}-t-n model, while the {sup 9}Li nucleus was considered within the {alpha}-t-n and {sup 7}Li-n-n models. The cross sections in question were calculated within Glauber diffraction theory. A comparison of the results with available experimental data made it possible to draw conclusions on the quality of the wave functions and potential used in the calculations.

  18. Electric dipole response of 208Pb from proton inelastic scattering: constraints on neutron skin thickness and symmetry energy

    E-Print Network [OSTI]

    A. Tamii; P. von Neumann-Cosel; I. Poltoratska

    2013-10-02T23:59:59.000Z

    The electric dipole (E1) response of 208Pb has been precisely determined by measuring Coulomb excitation induced by proton scattering at very forward angles. The electric dipole polarizability, defined as inverse energy-weighted sum rule of the E1 strength, has been extracted as 20.1+-0.6 fm^3. The data can be used to constrain the neutron skin thickness of 208Pb to 0.168(+-0.009)_expt(+-0.013)_theo(+-0.021)_est fm, where the subscript "expt" refers to the experimental uncertainty, "theor" to the theoretical confidence band and "est" to the uncertainty associated with the estimation of the symmetry energy at the saturation density. In addition, a constraint band has been extracted in the plane of the symmetry energy (J) and its slope parameter (L) at the saturation density.

  19. Adsorption and grafting on colloidal interfaces studied by scattering techniques

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 Adsorption and grafting on colloidal interfaces studied by scattering techniques - REVISED) [0] 4 67 14 46 37 12th of October 2006 Abstract The adsorption of polymer and surfactant molecules to be a powerful tool to obtain a detailed description of the layer structure. Adsorption of chemically more

  20. Small-angle neutron scattering reveals the assembly mode and oligomeric architecture of TET, a large, dodecameric aminopeptidase

    SciTech Connect (OSTI)

    Appolaire, Alexandre; Girard, Eric; Colombo, Matteo; Durá, M. Asunción [Université Grenoble Alpes, IBS, 38044 Grenoble (France); CNRS, IBS, 38044 Grenoble (France); CEA, IBS, 38044 Grenoble (France); Moulin, Martine; Härtlein, Michael [Institut Laue–Langevin, 38042 Grenoble CEDEX 9 (France); Franzetti, Bruno [Université Grenoble Alpes, IBS, 38044 Grenoble (France); CNRS, IBS, 38044 Grenoble (France); CEA, IBS, 38044 Grenoble (France); Gabel, Frank, E-mail: frank.gabel@ibs.fr [Université Grenoble Alpes, IBS, 38044 Grenoble (France); CNRS, IBS, 38044 Grenoble (France); CEA, IBS, 38044 Grenoble (France); Institut Laue–Langevin, 38042 Grenoble CEDEX 9 (France)

    2014-11-01T23:59:59.000Z

    The present work illustrates that small-angle neutron scattering, deuteration and contrast variation, combined with in vitro particle reconstruction, constitutes a very efficient approach to determine subunit architectures in large, symmetric protein complexes. In the case of the 468 kDa heterododecameric TET peptidase machine, it was demonstrated that the assembly of the 12 subunits is a highly controlled process and represents a way to optimize the catalytic efficiency of the enzyme. The specific self-association of proteins into oligomeric complexes is a common phenomenon in biological systems to optimize and regulate their function. However, de novo structure determination of these important complexes is often very challenging for atomic-resolution techniques. Furthermore, in the case of homo-oligomeric complexes, or complexes with very similar building blocks, the respective positions of subunits and their assembly pathways are difficult to determine using many structural biology techniques. Here, an elegant and powerful approach based on small-angle neutron scattering is applied, in combination with deuterium labelling and contrast variation, to elucidate the oligomeric organization of the quaternary structure and the assembly pathways of 468 kDa, hetero-oligomeric and symmetric Pyrococcus horikoshii TET2–TET3 aminopeptidase complexes. The results reveal that the topology of the PhTET2 and PhTET3 dimeric building blocks within the complexes is not casual but rather suggests that their quaternary arrangement optimizes the catalytic efficiency towards peptide substrates. This approach bears important potential for the determination of quaternary structures and assembly pathways of large oligomeric and symmetric complexes in biological systems.

  1. Determination of Low-Energy Parameters of Neutron--Proton Scattering on the Basis of Modern Experimental Data from Partial-Wave Analyses

    E-Print Network [OSTI]

    V. A. Babenko; N. M. Petrov

    2007-04-08T23:59:59.000Z

    The triplet and singlet low-energy parameters in the effective-range expansion for neutron--proton scattering are determined by using the latest experimental data on respective phase shifts from the SAID nucleon--nucleon database. The results differ markedly from the analogous parameters obtained on the basis of the phase shifts of the Nijmegen group and contradict the parameter values that are presently used as experimental ones. The values found with the aid of the phase shifts from the SAID nucleon--nucleon database for the total cross section for the scattering of zero-energy neutrons by protons, $\\sigma_{0}=20.426 $b, and the neutron--proton coherent scattering length, $f=-3.755 $fm, agree perfectly with the experimental cross-section values obtained by Houk, $\\sigma_{0}=20.436\\pm 0.023 $b, and experimental scattering-length values obtained by Houk and Wilson, $f=-3.756\\pm 0.009 $fm, but they contradict cross-section values of $\\sigma_{0}=20.491\\pm 0.014 $b according to Dilg and coherent-scattering-length values of $f=-3.7409\\pm 0.0011 $fm according to Koester and Nistler.

  2. Toward a Taxonomy of the Denatured State: Small Angle Scattering Studies of Unfolded Proteins

    SciTech Connect (OSTI)

    Millett, I.S.; Doniach, S.; Plaxco, K.W. (Stanford); (UCSB)

    2005-02-15T23:59:59.000Z

    Despite the critical role the unfolded state plays in defining protein folding kinetics and thermodynamics (Berg et al., 2002; Dunker, 2002; Shortle, 2002; Wright and Dyson, 2002), our understanding of its detailed structure remains rather rudimentary; the heterogeneity of the unfolded ensemble renders difficult or impossible its study by traditional, atomic-level structural methods. Consequently, recent years have seen a significant expansion of small-angle X-ray and neutron scattering (SAXS and SANS, respectively) techniques that provide direct, albeit rotationally and time-averaged, measures of the geometric properties of the unfolded ensemble. These studies have reached a critical mass, allowing us for the first time to define general observations regarding the nature of the geometry - and possibly the chemistry and physics - of unfolded proteins.

  3. Average over energy effect of parity nonconservation in neutron scattering on heavy nuclei

    E-Print Network [OSTI]

    O. P. Sushkov

    1996-03-05T23:59:59.000Z

    Using semiclassical approximation we consider parity nonconservation (PNC) averaged over compound resonances. We demonstrate that the result of the averaging crucially depends on the properties of residual strong nucleon-nucleon interaction. Natural way to elucidate this problem is to investigate experimentally PNC spin rotation with nonmonachromatic neutron beam: $E \\sim \\Delta E \\sim 1MeV$. Value of the effect can reach $\\psi \\sim 10^{-5}-10^{-4}$ per mean free path.

  4. Format requirements of thermal neutron scattering data in a nuclear data format to succeed the ENDF format

    SciTech Connect (OSTI)

    Brown, D. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2014-03-31T23:59:59.000Z

    In November 2012, the Working Party on Evaluation Cooperation Subgroup 38 (WPEC-SG38) began with the task of developing a nuclear data format and supporting infrastructure to replace the now nearly 50 year old ENDF format. The first step in this process is to develop requirements for the new format and infrastructure. In this talk, I will review the status of ENDF's Thermal Scattering Law (TSL) formats as well as support for this data in the GND format (from which the new format is expected to evolve). Finally, I hope to begin a dialog with members of the thermal neutron scattering community so that their data needs can be accurately and easily accommodated by the new format and tools, as captured by the requirements document. During this discussion, we must keep in mind that the new tools and format must; Support what is in existing data files; Support new things we want to put in data files; and Be flexible enough for us to adapt it to future unanticipated challenges.

  5. The Manuel Lujan, Jr. Neutron Scattering Center, LANSCE experiment reports: 1990 Run Cycle

    SciTech Connect (OSTI)

    DiStravolo, M.A. (comp.)

    1991-10-01T23:59:59.000Z

    This year was the third in which LANSCE ran a formal user program. A call for proposals was issued before the scheduled run cycles, and experiment proposals were submitted by scientists from universities, industry, and other research facilities around the world. An external program advisory committee, which LANSCE shares with the Intense Pulsed Neutron Source (IPNS), Argonne National Laboratory examined the proposals and made recommendations. At LANSCE, neutrons are produced by spallation when a pulsed, 800-MeV proton beam impinges on a tungsten target. The proton pulses are provided by the Clinton P. Anderson Meson Physics Facility (LAMPF) accelerator and an associated Proton Storage Ring (PSR), which can alter the intensity, time structure, and repetition rate of the pulses. The LAMPF protons of Line D are shared between the LANSCE target and the Weapons Neutron Research facility, which results in LANSCE spectrometers being available to external users for unclassified research about 80% of each six-month LAMPF run cycle. Measurements of interest to the Los Alamos National Laboratory may also be performed and may occupy up to an additional 20% of the available beam time. These experiments are reviewed by an internal program advisory committee. One hundred thirty-four proposals were submitted for unclassified research and twelve proposals for research of a programmatic nature to the Laboratory. Our definition of beam availability is when the proton current from the PSR exceeds 50% of the planned value. The PSR ran at 65{mu}A current (average) at 20 Hz for most of 1990. All of the scheduled experiments were performed and experiments in support of the LANSCE research program were accomplished during the discretionary periods.

  6. The Manuel Lujan, Jr. Neutron Scattering Center (LANSCE) experiment reports 1992 run cycle. Progress report

    SciTech Connect (OSTI)

    DiStravolo, M.A. [comp.

    1993-09-01T23:59:59.000Z

    This year was the fifth in which LANSCE ran a formal user program. A call for proposals was issued before the scheduled run cycles, and experiment proposals were submitted by scientists from universities, industry, and other research facilities around the world. An external program advisory committee, which LANSCE shares with the Intense Pulsed Neutron Source (IPNS), Argonne National Laboratory, examined the proposals and made recommendations. At LANSCE, neutrons are produced by spallation when a pulsed, 800-MeV proton beam impinges on a tungsten target. The proton pulses are provided by the Clinton P. Anderson Meson Physics Facility (LAMPF) accelerator and an associated Proton Storage Ring (PSR), which can alter the intensity, time structure, and repetition rate of the pulses. The LAMPF protons of Line D are shared between the LANSCE target and the Weapons Neutron Research (WNR) facility, which results in LANSCE spectrometers being available to external users for unclassified research about 80% of each annual LAMPF run cycle. Measurements of interest to the Los Alamos National Laboratory may also be performed and may occupy up to an additional 20% of the available beam time. These experiments are reviewed by an internal program advisory committee. One hundred sixty-seven proposals were submitted for unclassified research and twelve proposals for research of a programmatic interest to the Laboratory; six experiments in support of the LANSCE research program were accomplished during the discretionary periods. Oversubscription for instrument beam time by a factor of three was evident with 839 total days requested and only 371 available for allocation.

  7. Scintillation efficiency of liquid argon in low energy neutron-argon scattering

    E-Print Network [OSTI]

    Creus, W; Amsler, C; Ferella, A D; Rochet, J; Scotto-Lavina, L; Walter, M

    2015-01-01T23:59:59.000Z

    Experiments searching for weak interacting massive particles with noble gases such as liquid argon require very low detection thresholds for nuclear recoils. A determination of the scintillation efficiency is crucial to quantify the response of the detector at low energy. We report the results obtained with a small liquid argon cell using a monoenergetic neutron beam produced by a deuterium-deuterium fusion source. The light yield relative to electrons was measured for six argon recoil energies between 11 and 120 keV at zero electric drift field.

  8. Crystal defect studies using x-ray diffuse scattering

    SciTech Connect (OSTI)

    Larson, B.C.

    1980-01-01T23:59:59.000Z

    Microscopic lattice defects such as point (single atom) defects, dislocation loops, and solute precipitates are characterized by local electronic density changes at the defect sites and by distortions of the lattice structure surrounding the defects. The effect of these interruptions of the crystal lattice on the scattering of x-rays is considered in this paper, and examples are presented of the use of the diffuse scattering to study the defects. X-ray studies of self-interstitials in electron irradiated aluminum and copper are discussed in terms of the identification of the interstitial configuration. Methods for detecting the onset of point defect aggregation into dislocation loops are considered and new techniques for the determination of separate size distributions for vacancy loops and interstitial loops are presented. Direct comparisons of dislocation loop measurements by x-rays with existing electron microscopy studies of dislocation loops indicate agreement for larger size loops, but x-ray measurements report higher concentrations in the smaller loop range. Methods for distinguishing between loops and three-dimensional precipitates are discussed and possibilities for detailed studies considered. A comparison of dislocation loop size distributions obtained from integral diffuse scattering measurements with those from TEM show a discrepancy in the smaller sizes similar to that described above.

  9. Neutron scattering from myelin revisited: bilayer asymmetry and water-exchange kinetics

    SciTech Connect (OSTI)

    Denninger, Andrew R. [Boston College, Chestnut Hill, MA 02467 (United States); Demé, Bruno; Cristiglio, Viviana [Institut Laue–Langevin (ILL), CS 20156, F-38042 Grenoble CEDEX 9 (France); LeDuc, Géraldine [European Synchrotron Radiation Facility (ESRF), CS 40220, F-38043 Grenoble CEDEX 9 (France); Feller, W. Bruce [NOVA Scientific Inc., Sturbridge, MA 01566 (United States); Kirschner, Daniel A., E-mail: kirschnd@bc.edu [Boston College, Chestnut Hill, MA 02467 (United States)

    2014-12-01T23:59:59.000Z

    The structure of internodal myelin in the rodent central and peripheral nervous systems has been determined using neutron diffraction. The kinetics of water exchange in these tissues is also described. Rapid nerve conduction in the central and peripheral nervous systems (CNS and PNS, respectively) of higher vertebrates is brought about by the ensheathment of axons with myelin, a lipid-rich, multilamellar assembly of membranes. The ability of myelin to electrically insulate depends on the regular stacking of these plasma membranes and on the presence of a number of specialized membrane-protein assemblies in the sheath, including the radial component, Schmidt–Lanterman incisures and the axo–glial junctions of the paranodal loops. The disruption of this fine-structure is the basis for many demyelinating neuropathies in the CNS and PNS. Understanding the processes that govern myelin biogenesis, maintenance and destabilization requires knowledge of myelin structure; however, the tight packing of internodal myelin and the complexity of its junctional specializations make myelin a challenging target for comprehensive structural analysis. This paper describes an examination of myelin from the CNS and PNS using neutron diffraction. This investigation revealed the dimensions of the bilayers and aqueous spaces of myelin, asymmetry between the cytoplasmic and extracellular leaflets of the membrane, and the distribution of water and exchangeable hydrogen in internodal multilamellar myelin. It also uncovered differences between CNS and PNS myelin in their water-exchange kinetics.

  10. Precision electroweak studies using parity violation in electron scattering

    SciTech Connect (OSTI)

    Paschke, K. D. [Department of Physics, University of Virginia, Charlottesville, Virginia 22903 (United States)

    2013-11-07T23:59:59.000Z

    The nature of new neutral-current interactions can be revealed at the low-energy precision frontier, where studies of parity-violation in electron scattering will complement the energy-frontier studies at the LHC. Measurements of the parity-violating observable A{sub PV} - the cross-section asymmetry in the scattering of longitudinally polarized electrons from an unpolarized target - are sensitive to possible contact interactions from new physics at multi-TeV mass scales. The 12 GeV upgrade at JLab and a new, high-intensity beam at Mainz offer opportunities for significant improvements in measurements of electron-electron and electron-quark parity-violating interactions.

  11. PHILOSOPHICAL MAGAZINE B, 2002, VOL. 82, NO. 5, 507515 Study of the b relaxation in supercooled conned water

    E-Print Network [OSTI]

    Tuscia, Università Degli Studi Della

    S. Camillo de Lellis, 01100 Viterbo, Italy. Abstract An inelastic neutron scattering experiment). In this study we have performed an inelastic neutron scattering (INS) experiment in order to test the behaviour

  12. The reflection of very cold neutrons from diamond powder nanoparticles

    E-Print Network [OSTI]

    V. V. Nesvizhevsky; E. V. Lychagin; A. Yu. Muzychka; A. V. Strelkov; G. Pignol; K. V. Protasov

    2008-05-17T23:59:59.000Z

    We study possibility of efficient reflection of very cold neutrons (VCN) from powders of nanoparticles. In particular, we measured the scattering of VCN at a powder of diamond nanoparticles as a function of powder sample thickness, neutron velocity and scattering angle. We observed extremely intense scattering of VCN even off thin powder samples. This agrees qualitatively with the model of independent nanoparticles at rest. We show that this intense scattering would allow us to use nanoparticle powders very efficiently as the very first reflectors for neutrons with energies within a complete VCN range up to $10^{-4}$ eV.

  13. A simulation-based study of the neutron backgrounds for NaI dark matter experiments

    E-Print Network [OSTI]

    Jeon, Eunju

    2015-01-01T23:59:59.000Z

    Among the direct search experiments for weakly interacting massive particle (WIMP) dark matter, the DAMA experiment observed an annual modulation signal interpreted as WIMP interactions with a significance of 9.2$\\sigma$. Recently, Jonathan Davis claimed that the DAMA modulation may be interpreted on the basis of the neutron scattering events induced by the muons and neutrinos together. We tried to simulate the neutron backgrounds at the Gran Sasso and Yangyang laboratory with and without the polyethylene shielding to quantify the effects of the ambient neutrons on the direct detection experiments based on the crystals.

  14. Neutrons for Catalysis: A Workshop on Neutron Scattering Techniques for Studies in Catalysis

    E-Print Network [OSTI]

    Pennycook, Steve

    -EM Fischer Tropsch Catalysis on Fe- or Co-catalysts, ,,CTL" Coal to Liquids ­ ,a rough (?) analogy #12;Peter Albers, AQ-EM Carbonaceous Deposits on Catalysts #12;Peter Albers, AQ-EM IINS on Coked Catalysts from Industrial Plants High-temperature and low-temperature cokes deposited on catalysts during

  15. Determination of the properties of nuclear energy levels using resonance-scattered neutron capture gamma rays

    E-Print Network [OSTI]

    McCormick, Russell A

    1968-01-01T23:59:59.000Z

    GETElc&ii!'iV! cbN O. ' '! IE FROPENT1ES OF NUCI. EAIl El(E"". GY I. EYEc S USING GESOlIANCE-SCATTEIIEG NE'll'HGN . APTUPZ GAIIMA RAYS A !iles ls IU!Sb "ebb A. Mc. COFci!1CK SubmitteU to the Graclua!. e Colleoo or" Texas Afoul&! Uniser ity... RUSSELL A. PicCOPMTCK Approved "s to stylo and content I?: (CiInirman oE Coaaaittoe V (Member plead nf Dep, . tmont) P! v. oer) (Member) Ma&, l968 Detemsination of the properties of Nuclear Bnergy Lese is Osi: 6 Resonance-Scattered deut...

  16. HFIR History - ORNL Neutron Sciences

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

    has grown to include materials irradiation, neutron activation, and, most recently, neutron scattering. In 2007, HFIR completed the most dramatic transformation in its...

  17. X-ray scattering studies of structure and dynamics of surfaces and interfaces of polymeric liquids

    E-Print Network [OSTI]

    Jiang, Zhang

    2007-01-01T23:59:59.000Z

    and S. K. Sinha, “Structure and dynamics of thin polymer ?Scattering Studies of Structure and Dynamics of Surfaces andScattering Studies of Structure and Dynamics of Surfaces and

  18. New insights into water bonding during early tricalcium silicate hydration with quasielastic neutron scattering

    SciTech Connect (OSTI)

    Gutberlet, T., E-mail: gutberlet@cbm.bv.tum.de [Centre for Building Materials (CBM), Technische Universität München, Baumbachstraße 7, 81245 Munich (Germany); Hilbig, H.; Beddoe, R.E. [Centre for Building Materials (CBM), Technische Universität München, Baumbachstraße 7, 81245 Munich (Germany)] [Centre for Building Materials (CBM), Technische Universität München, Baumbachstraße 7, 81245 Munich (Germany); Lohstroh, W. [Forschungs-Neutronenquelle Heinz Maier-Leibnitz (FRM II), Technische Universität München, Lichtenbergstraße 1, 85748 Garching (Germany)] [Forschungs-Neutronenquelle Heinz Maier-Leibnitz (FRM II), Technische Universität München, Lichtenbergstraße 1, 85748 Garching (Germany)

    2013-09-15T23:59:59.000Z

    New information on the water bonding during the first 36 h of hydration of tricalcium silicate was obtained using the high neutron flux at the sample position of the time-of-flight spectrometer (TOFTOF), FRM II in Garching, Germany, together with {sup 29}Si NMR and X-ray diffraction measurements. A rapid increase in the amount of constrained water was observed at the beginning of the induction period. This is attributed to the formation of an early C-S-H with a large specific surface area (around 800 m{sup 2}/g). During subsequent hydration, the amount of constrained water, as given by the total surface area of the hydration products, is controlled by (a) the formation of new metastable early C-S-H which increases total surface area and (b) polymerisation processes which reduce total surface area. The relative contribution of these processes varies during hydration.

  19. Determination of Differential Elastic and Inelastic and Double-differential Neutron Scattering Cross Sections of Elemental Titanium at Energies between 7.93 MeV and 14.72 MeV

    E-Print Network [OSTI]

    Schmidt, Dankwart; Xichao, R

    2006-01-01T23:59:59.000Z

    Determination of Differential Elastic and Inelastic and Double-differential Neutron Scattering Cross Sections of Elemental Titanium at Energies between 7.93 MeV and 14.72 MeV

  20. Measurement of Feynman-x Spectra of Photons and Neutrons in the Very Forward Direction in Deep-Inelastic Scattering at HERA

    E-Print Network [OSTI]

    H1 Collaboration

    2014-04-01T23:59:59.000Z

    Measurements of normalised cross sections for the production of photons and neutrons at very small angles with respect to the proton beam direction in deep-inelastic $ep$ scattering at HERA are presented as a function of the Feynman variable $x_F$ and of the centre-of-mass energy of the virtual photon-proton system $W$. The data are taken with the H1 detector in the years 2006 and 2007 and correspond to an integrated luminosity of $131 \\mathrm{pb}^{-1}$. The measurement is restricted to photons and neutrons in the pseudorapidity range $\\eta>7.9$ and covers the range of negative four momentum transfer squared at the positron vertex $6scattering models and of models for hadronic interactions of high energy cosmic rays are compared to the measured cross sections.