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Sample records for neutron scattering gatlinburg

  1. Neutron scattering. Lectures

    International Nuclear Information System (INIS)

    Brueckel, Thomas; Heger, Gernot; Richter, Dieter; Roth, Georg; Zorn, Reiner

    2012-01-01

    The following topics are dealt with: Neutron scattering in contemporary research, neutron sources, symmetry of crystals, diffraction, nanostructures investigated by small-angle neutron scattering, the structure of macromolecules, spin dependent and magnetic scattering, structural analysis, neutron reflectometry, magnetic nanostructures, inelastic scattering, strongly correlated electrons, dynamics of macromolecules, applications of neutron scattering. (HSI)

  2. Neutron scattering. Lectures

    International Nuclear Information System (INIS)

    Brueckel, Thomas; Heger, Gernot; Richter, Dieter; Roth, Georg; Zorn, Reiner

    2013-01-01

    The following topics are dealt with: Neutron sources, symmetry of crystals, nanostructures investigated by small-angle neutron scattering, structure of macromolecules, spin dependent and magnetic scattering, structural analysis, neutron reflectometry, magnetic nanostructures, inelastic neutron scattering, strongly correlated electrons, polymer dynamics, applications of neutron scattering. (HSI)

  3. Neutron scattering. Lectures

    Energy Technology Data Exchange (ETDEWEB)

    Brueckel, Thomas; Heger, Gernot; Richter, Dieter; Roth, Georg; Zorn, Reiner (eds.)

    2010-07-01

    The following topics are dealt with: Neutron sources, neutron properties and elastic scattering, correlation functions measured by scattering experiments, symmetry of crystals, applications of neutron scattering, polarized-neutron scattering and polarization analysis, structural analysis, magnetic and lattice excitation studied by inelastic neutron scattering, macromolecules and self-assembly, dynamics of macromolecules, correlated electrons in complex transition-metal oxides, surfaces, interfaces, and thin films investigated by neutron reflectometry, nanomagnetism. (HSI)

  4. Neutron scattering. Lectures

    International Nuclear Information System (INIS)

    Brueckel, Thomas; Heger, Gernot; Richter, Dieter; Roth, Georg; Zorn, Reiner

    2010-01-01

    The following topics are dealt with: Neutron sources, neutron properties and elastic scattering, correlation functions measured by scattering experiments, symmetry of crystals, applications of neutron scattering, polarized-neutron scattering and polarization analysis, structural analysis, magnetic and lattice excitation studied by inelastic neutron scattering, macromolecules and self-assembly, dynamics of macromolecules, correlated electrons in complex transition-metal oxides, surfaces, interfaces, and thin films investigated by neutron reflectometry, nanomagnetism. (HSI)

  5. Neutron scattering. Lectures

    Energy Technology Data Exchange (ETDEWEB)

    Brueckel, Thomas; Heger, Gernot; Richter, Dieter; Roth, Georg; Zorn, Reiner [eds.

    2010-07-01

    The following topics are dealt with: Neutron sources, symmetry of crystals, diffraction, nanostructures investigated by small-angle neutron scattering, the structure of macromolecules, spin dependent and magnetic scattering, structural analysis, neutron reflectometry, magnetic nanostructures, inelastic scattering, strongly correlated electrons, dynamics of macromolecules, applications of neutron scattering. (HSI)

  6. Neutron scattering. Lectures

    International Nuclear Information System (INIS)

    Brueckel, Thomas; Heger, Gernot; Richter, Dieter; Roth, Georg; Zorn, Reiner

    2010-01-01

    The following topics are dealt with: Neutron sources, symmetry of crystals, diffraction, nanostructures investigated by small-angle neutron scattering, the structure of macromolecules, spin dependent and magnetic scattering, structural analysis, neutron reflectometry, magnetic nanostructures, inelastic scattering, strongly correlated electrons, dynamics of macromolecules, applications of neutron scattering. (HSI)

  7. Calculations of neutron spectra after neutron-neutron scattering

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, B E [Gettysburg College, Box 405, Gettysburg, PA 17325 (United States); Stephenson, S L [Gettysburg College, Box 405, Gettysburg, PA 17325 (United States); Howell, C R [Duke University and Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States); Mitchell, G E [North Carolina State University, Raleigh, NC 27695-8202 (United States); Tornow, W [Duke University and Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States); Furman, W I [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Lychagin, E V [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Muzichka, A Yu [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Nekhaev, G V [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Strelkov, A V [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Sharapov, E I [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Shvetsov, V N [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation)

    2004-09-01

    A direct neutron-neutron scattering length, a{sub nn}, measurement with the goal of 3% accuracy (0.5 fm) is under preparation at the aperiodic pulsed reactor YAGUAR. A direct measurement of a{sub nn} will not only help resolve conflicting results of a{sub nn} by indirect means, but also in comparison to the proton-proton scattering length, a{sub pp}, shed light on the charge-symmetry of the nuclear force. We discuss in detail the analysis of the nn-scattering data in terms of a simple analytical expression. We also discuss calibration measurements using the time-of-flight spectra of neutrons scattered on He and Ar gases and the neutron activation technique. In particular, we calculate the neutron velocity and time-of-flight spectra after scattering neutrons on neutrons and after scattering neutrons on He and Ar atoms for the proposed experimental geometry, using a realistic neutron flux spectrum-Maxwellian plus epithermal tail. The shape of the neutron spectrum after scattering is appreciably different from the initial spectrum, due to collisions between thermal-thermal and thermal-epithermal neutrons. At the same time, the integral over the Maxwellian part of the realistic scattering spectrum differs by only about 6 per cent from that of a pure Maxwellian nn-scattering spectrum.

  8. Neutron Scattering Software

    Science.gov (United States)

    Home Page | Facilities | Reference | Software | Conferences | Announcements | Mailing Lists Neutron Scattering Banner Neutron Scattering Software A new portal for neutron scattering has just been established sets KUPLOT: data plotting and fitting software ILL/TAS: Matlab probrams for analyzing triple axis data

  9. MAGNETIC NEUTRON SCATTERING

    Energy Technology Data Exchange (ETDEWEB)

    ZALIZNYAK,I.A.; LEE,S.H.

    2004-07-30

    Much of our understanding of the atomic-scale magnetic structure and the dynamical properties of solids and liquids was gained from neutron-scattering studies. Elastic and inelastic neutron spectroscopy provided physicists with an unprecedented, detailed access to spin structures, magnetic-excitation spectra, soft-modes and critical dynamics at magnetic-phase transitions, which is unrivaled by other experimental techniques. Because the neutron has no electric charge, it is an ideal weakly interacting and highly penetrating probe of matter's inner structure and dynamics. Unlike techniques using photon electric fields or charged particles (e.g., electrons, muons) that significantly modify the local electronic environment, neutron spectroscopy allows determination of a material's intrinsic, unperturbed physical properties. The method is not sensitive to extraneous charges, electric fields, and the imperfection of surface layers. Because the neutron is a highly penetrating and non-destructive probe, neutron spectroscopy can probe the microscopic properties of bulk materials (not just their surface layers) and study samples embedded in complex environments, such as cryostats, magnets, and pressure cells, which are essential for understanding the physical origins of magnetic phenomena. Neutron scattering is arguably the most powerful and versatile experimental tool for studying the microscopic properties of the magnetic materials. The magnitude of the cross-section of the neutron magnetic scattering is similar to the cross-section of nuclear scattering by short-range nuclear forces, and is large enough to provide measurable scattering by the ordered magnetic structures and electron spin fluctuations. In the half-a-century or so that has passed since neutron beams with sufficient intensity for scattering applications became available with the advent of the nuclear reactors, they have became indispensable tools for studying a variety of important areas of modern

  10. Polarized Neutron Scattering

    OpenAIRE

    Roessli, B.; Böni, P.

    2000-01-01

    The technique of polarized neutron scattering is reviewed with emphasis on applications. Many examples of the usefulness of the method in various fields of physics are given like the determination of spin density maps, measurement of complex magnetic structures with spherical neutron polarimetry, inelastic neutron scattering and separation of coherent and incoherent scattering with help of the generalized XYZ method.

  11. Diffuse scattering of neutrons

    International Nuclear Information System (INIS)

    Novion, C.H. de.

    1981-02-01

    The use of neutron scattering to study atomic disorder in metals and alloys is described. The diffuse elastic scattering of neutrons by a perfect crystal lattice leads to a diffraction spectrum with only Bragg spreads. the existence of disorder in the crystal results in intensity and position modifications to these spreads, and above all, to the appearance of a low intensity scatter between Bragg peaks. The elastic scattering of neutrons is treated in this text, i.e. by measuring the number of scattered neutrons having the same energy as the incident neutrons. Such measurements yield information on the static disorder in the crystal and time average fluctuations in composition and atomic displacements [fr

  12. Scattering with polarized neutrons

    International Nuclear Information System (INIS)

    Schweizer, J.

    2007-01-01

    In the history of neutron scattering, it was shown very soon that the use of polarized neutron beams brings much more information than usual scattering with unpolarized neutrons. We shall develop here the different scattering methods that imply polarized neutrons: 1) polarized beams without polarization analysis, the flipping ratio method; 2) polarized beams with a uniaxial polarization analysis; 3) polarized beams with a spherical polarization analysis. For all these scattering methods, we shall give examples of the physical problems which can been solved by these methods, particularly in the field of magnetism: investigation of complex magnetic structures, investigation of spin or magnetization densities in metals, insulators and molecular compounds, separation of magnetic and nuclear scattering, investigation of magnetic properties of liquids and amorphous materials and even, for non magnetic material, separation between coherent and incoherent scattering. (author)

  13. Introductory theory of neutron scattering

    International Nuclear Information System (INIS)

    Gunn, J.M.F.

    1986-12-01

    The paper comprises a set of six lecture notes which were delivered to the summer school on 'Neutron Scattering at a pulsed source', Rutherford Laboratory, United Kingdom, 1986. The lectures concern the physical principles of neutron scattering. The topics of the lectures include: diffraction, incoherent inelastic scattering, connection with the Schroedinger equation, magnetic scattering, coherent inelastic scattering, and surfaces and neutron optics. (UK)

  14. Single Crystal Diffuse Neutron Scattering

    Directory of Open Access Journals (Sweden)

    Richard Welberry

    2018-01-01

    Full Text Available Diffuse neutron scattering has become a valuable tool for investigating local structure in materials ranging from organic molecular crystals containing only light atoms to piezo-ceramics that frequently contain heavy elements. Although neutron sources will never be able to compete with X-rays in terms of the available flux the special properties of neutrons, viz. the ability to explore inelastic scattering events, the fact that scattering lengths do not vary systematically with atomic number and their ability to scatter from magnetic moments, provides strong motivation for developing neutron diffuse scattering methods. In this paper, we compare three different instruments that have been used by us to collect neutron diffuse scattering data. Two of these are on a spallation source and one on a reactor source.

  15. Neutron scattering and magnetism

    International Nuclear Information System (INIS)

    Mackintosh, A.R.

    1983-01-01

    Those properties of the neutron which make it a unique tool for the study of magnetism are described. The scattering of neutrons by magnetic solids is briefly reviewed, with emphasis on the information on the magnetic structure and dynamics which is inherent in the scattering cross-section. The contribution of neutron scattering to our understanding of magnetic ordering, excitations and phase transitions is illustrated by experimental results on a variety of magnetic crystals. (author)

  16. Gatlinburg conference: barometer of progress in analytical chemistry

    International Nuclear Information System (INIS)

    Shults, W.D.

    1981-01-01

    Much progress has been made in the field of analytical chemistry over the past twenty-five years. The AEC-ERDA-DOE family of laboratories contributed greatly to this progress. It is not surprising then to find a close correlation between program content of past Gatlinburg conferences and developments in analytical methodology. These conferences have proved to be a barometer of technical status

  17. Neutron scattering. Experiment manuals

    Energy Technology Data Exchange (ETDEWEB)

    Brueckel, Thomas; Heger, Gernot; Richter, Dieter; Roth, Georg; Zorn, Reiner (eds.)

    2010-07-01

    The following topics are dealt with: The thermal triple axis spectrometer PUMA, the high-resolution powder diffractometer SPODI, the hot single-crystal diffractometer HEiDi for structure analysis with neutrons, the backscattering spectrometer SPHERES, neutron polarization analysis with tht time-of-flight spectrometer DNS, the neutron spin-echo spectrometer J-NSE, small-angle neutron scattering with the KWS-1 and KWS-2 diffractometers, the very-small-angle neutron scattering diffractrometer with focusing mirror KWS-3, the resonance spin-echo spectrometer RESEDA, the reflectometer TREFF, the time-of-flight spectrometer TOFTOF. (HSI)

  18. Neutron scattering. Experiment manuals

    International Nuclear Information System (INIS)

    Brueckel, Thomas; Heger, Gernot; Richter, Dieter; Roth, Georg; Zorn, Reiner

    2010-01-01

    The following topics are dealt with: The thermal triple axis spectrometer PUMA, the high-resolution powder diffractometer SPODI, the hot single-crystal diffractometer HEiDi for structure analysis with neutrons, the backscattering spectrometer SPHERES, neutron polarization analysis with tht time-of-flight spectrometer DNS, the neutron spin-echo spectrometer J-NSE, small-angle neutron scattering with the KWS-1 and KWS-2 diffractometers, the very-small-angle neutron scattering diffractrometer with focusing mirror KWS-3, the resonance spin-echo spectrometer RESEDA, the reflectometer TREFF, the time-of-flight spectrometer TOFTOF. (HSI)

  19. Neutron scattering. Experiment manuals

    International Nuclear Information System (INIS)

    Brueckel, Thomas; Heger, Gernot; Richter, Dieter; Roth, Georg; Zorn, Reiner

    2014-01-01

    The following topics are dealt with: The thermal triple-axis spectrometer PUMA, the high-resolution powder diffractometer SPODI, the hot-single-crystal diffractometer HEiDi, the three-axis spectrometer PANDA, the backscattering spectrometer SPHERES, the DNS neutron-polarization analysis, the neutron spin-echo spectrometer J-NSE, small-angle neutron scattering at KWS-1 and KWS-2, a very-small-angle neutron scattering diffractometer with focusing mirror, the reflectometer TREFF, the time-of-flight spectrometer TOFTOF. (HSI)

  20. Virtual neutron scattering experiments

    DEFF Research Database (Denmark)

    Overgaard, Julie Hougaard; Bruun, Jesper; May, Michael

    2017-01-01

    . In the last week of the course, students travel to a large-scale neutron scattering facility to perform real neutron scattering experiments. Through student interviews and survey answers, we argue, that the virtual training prepares the students to engage more fruitfully with experiments by letting them focus......We describe how virtual experiments can be utilized in a learning design that prepares students for hands-on experiments at large-scale facilities. We illustrate the design by showing how virtual experiments are used at the Niels Bohr Institute in a master level course on neutron scattering...

  1. Deep inelastic neutron scattering

    International Nuclear Information System (INIS)

    Mayers, J.

    1989-03-01

    The report is based on an invited talk given at a conference on ''Neutron Scattering at ISIS: Recent Highlights in Condensed Matter Research'', which was held in Rome, 1988, and is intended as an introduction to the techniques of Deep Inelastic Neutron Scattering. The subject is discussed under the following topic headings:- the impulse approximation I.A., scaling behaviour, kinematical consequences of energy and momentum conservation, examples of measurements, derivation of the I.A., the I.A. in a harmonic system, and validity of the I.A. in neutron scattering. (U.K.)

  2. Neutron scattering science in Australia

    International Nuclear Information System (INIS)

    Knott, Robert

    1999-01-01

    Neutron scattering science in Australia is making an impact on a number of fields in the scientific and industrial research communities. The unique properties of the neutron are being used to investigate problems in chemistry, materials science, physics, engineering and biology. The reactor HIFAR at the Australian Nuclear Science and Technology Organisation research laboratories is the only neutron source in Australia suitable for neutron scattering science. A suite of instruments provides a wide range of opportunities for the neutron scattering community that extends throughout universities, government and industrial research laboratories. Plans are in progress to replace the present research reactor with a modern multi-purpose research reactor to offer the most advanced neutron scattering facilities. The experimental and analysis equipment associated with a modern research reactor will permit the establishment of a national centre for world class neutron science research focussed on the structure and functioning of materials, industrial irradiations and analyses in support of Australian manufacturing, minerals, petrochemical, pharmaceuticals and information science industries. (author)

  3. Neutron scattering science in Australia

    Energy Technology Data Exchange (ETDEWEB)

    Knott, Robert [Australian Nuclear Science and Technology Organisation, Menai, NSW (Australia)

    1999-10-01

    Neutron scattering science in Australia is making an impact on a number of fields in the scientific and industrial research communities. The unique properties of the neutron are being used to investigate problems in chemistry, materials science, physics, engineering and biology. The reactor HIFAR at the Australian Nuclear Science and Technology Organisation research laboratories is the only neutron source in Australia suitable for neutron scattering science. A suite of instruments provides a wide range of opportunities for the neutron scattering community that extends throughout universities, government and industrial research laboratories. Plans are in progress to replace the present research reactor with a modern multi-purpose research reactor to offer the most advanced neutron scattering facilities. The experimental and analysis equipment associated with a modern research reactor will permit the establishment of a national centre for world class neutron science research focussed on the structure and functioning of materials, industrial irradiations and analyses in support of Australian manufacturing, minerals, petrochemical, pharmaceuticals and information science industries. (author)

  4. Introduction to neutron scattering

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, W E [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1996-11-01

    We give here an introduction to the theoretical principles of neutron scattering. The relationship between scattering- and correlation-functions is particularly emphasized. Within the framework of linear response theory (justified by the weakness of the basic interaction) the relation between fluctuation and dissipation is discussed. This general framework explains the particular power of neutron scattering as an experimental method. (author) 4 figs., 4 refs.

  5. Detection of explosives by neutron scattering

    International Nuclear Information System (INIS)

    Brooks, F.D.; Buffler, A.; Allie, M.S.; Nchodu, M.R.; Bharuth-Ram, K.

    1998-01-01

    For non-intrusive detection of hidden explosives or other contraband such as narcotics a fast neutron scattering analysis (FNSA) technique is proposed. An experimental arrangement uses a collimated, pulsed beam of neutrons directed at the sample. Scattered neutrons are detected by liquid scintillation counters at different scattering angles. A scattering signature is derived from two-parameter data, counts vs pulse height and time-of-flight measured for each element (H, C, N or O) at each of two scattering angles and two neutron energies. The elemental signatures are very distinctive and constitute a good response matrix for unfolding elemental components from the scattering signatures measured for different compounds

  6. Applications of thermal neutron scattering

    International Nuclear Information System (INIS)

    Kostorz, G.

    1978-01-01

    Although in the past neutrons have been used quite frequently in the study of condensed matter, a more recent development has lead to applications of thermal neutron scattering in the investigation of more practical rather than purely academic problems. Physicists, chemists, materials scientists, biologists, and others have recognized and demonstrated that neutron scattering techniques can yield supplementary information which, in many cases, could not be obtained with other methods. The paper illustrates the use of neutron scattering in these areas of applied research. No attempt is made to present all the aspects of neutron scattering which can be found in textbooks. From the vast amount of experimental data, only a few examples are presented for the study of structure and atomic arrangement, ''extended'' structure, and dynamic phenomena in substances of current interest in applied research. (author)

  7. Application of neutron scattering in polymers

    International Nuclear Information System (INIS)

    Han, C.C.

    2003-01-01

    Full text: Neutron scattering offers many opportunities in sciences and technology. This is particularly true in the field of polymer sciences and materials. It is mainly because that the scattering length scales (q -1 ) and scattering contrast (scattering cross-sections) makes neutron a perfect tool for polymer studies. Several examples will be used to illustrate the importance of the small angle neutron scattering and the neutron reflection studies in polymer physics. These include the determination of phase diagram, interaction parameter, and spinodal decomposition kinetics by SANS. In the dynamics area, examples will be given to illustrate the critical temperature shift and mixing of polymer blends under shear flow. Also, the confinement effect on the phase separated structure of polymer blend films will be used to demonstrate the importance of the neutron reflectivity measurement

  8. Neutron scattering studies in the actinide region

    International Nuclear Information System (INIS)

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

    1993-09-01

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

  9. Neutron-proton scattering

    International Nuclear Information System (INIS)

    Doll, P.

    1990-02-01

    Neutron-proton scattering as fundamental interaction process below and above hundred MeV is discussed. Quark model inspired interactions and phenomenological potential models are described. The seminar also indicates the experimental improvements for achieving new precise scattering data. Concluding remarks indicate the relevance of nucleon-nucleon scattering results to finite nuclei. (orig.) [de

  10. Neutron scattering in Australia

    Energy Technology Data Exchange (ETDEWEB)

    Knott, R.B. [Australian Nuclear Science and Technology Organisation, Menai (Australia)

    1994-12-31

    Neutron scattering techniques have been part of the Australian scientific research community for the past three decades. The High Flux Australian Reactor (HIFAR) is a multi-use facility of modest performance that provides the only neutron source in the country suitable for neutron scattering. The limitations of HIFAR have been recognized and recently a Government initiated inquiry sought to evaluate the future needs of a neutron source. In essence, the inquiry suggested that a delay of several years would enable a number of key issues to be resolved, and therefore a more appropriate decision made. In the meantime, use of the present source is being optimized, and where necessary research is being undertaken at major overseas neutron facilities either on a formal or informal basis. Australia has, at present, a formal agreement with the Rutherford Appleton Laboratory (UK) for access to the spallation source ISIS. Various aspects of neutron scattering have been implemented on HIFAR, including investigations of the structure of biological relevant molecules. One aspect of these investigations will be presented. Preliminary results from a study of the interaction of the immunosuppressant drug, cyclosporin-A, with reconstituted membranes suggest that the hydrophobic drug interdigitated with lipid chains.

  11. Neutron scattering in Australia

    International Nuclear Information System (INIS)

    Knott, R.B.

    1994-01-01

    Neutron scattering techniques have been part of the Australian scientific research community for the past three decades. The High Flux Australian Reactor (HIFAR) is a multi-use facility of modest performance that provides the only neutron source in the country suitable for neutron scattering. The limitations of HIFAR have been recognized and recently a Government initiated inquiry sought to evaluate the future needs of a neutron source. In essence, the inquiry suggested that a delay of several years would enable a number of key issues to be resolved, and therefore a more appropriate decision made. In the meantime, use of the present source is being optimized, and where necessary research is being undertaken at major overseas neutron facilities either on a formal or informal basis. Australia has, at present, a formal agreement with the Rutherford Appleton Laboratory (UK) for access to the spallation source ISIS. Various aspects of neutron scattering have been implemented on HIFAR, including investigations of the structure of biological relevant molecules. One aspect of these investigations will be presented. Preliminary results from a study of the interaction of the immunosuppressant drug, cyclosporin-A, with reconstituted membranes suggest that the hydrophobic drug interdigitated with lipid chains

  12. Neutron scattering

    International Nuclear Information System (INIS)

    1991-02-01

    The annual report on hand gives an overview of the research work carried out in the Laboratory for Neutron Scattering (LNS) of the ETH Zuerich in 1990. Using the method of neutron scattering, it is possible to examine in detail the static and dynamic properties of the condensed material. In accordance with the multidisciplined character of the method, the LNS has for years maintained a system of intensive co-operation with numerous institutes in the areas of biology, chemistry, solid-state physics, crystallography and materials research. In 1990 over 100 scientists from more than 40 research groups both at home and abroad took part in the experiments. It was again a pleasure to see the number of graduate students present, who were studying for a doctorate and who could be introduced into the neutron scattering during their stay at the LNS and thus were in the position to touch on central ways of looking at a problem in their dissertation using this modern experimental method of solid-state research. In addition to the numerous and interesting ways of formulating the questions to explain the structure, nowadays the scientific programme increasingly includes particularly topical studies in connection with high temperature-supraconductors and materials research

  13. Dynamically Polarized Sample for Neutron Scattering At the Spallation Neutron Source

    International Nuclear Information System (INIS)

    Pierce, Josh; Zhao, J. K.; Crabb, Don

    2009-01-01

    The recently constructed Spallation Neutron Source at the Oak Ridge National Laboratory is quickly becoming the world's leader in neutron scattering sciences. In addition to the world's most intense pulsed neutron source, we are continuously constructing state of the art neutron scattering instruments as well as sample environments to address today and tomorrow's challenges in materials research. The Dynamically Polarized Sample project at the SNS is aimed at taking maximum advantage of polarized neutron scattering from polarized samples, especially biological samples that are abundant in hydrogen. Polarized neutron scattering will allow us drastically increase the signal to noise ratio in experiments such as neutron protein crystallography. The DPS project is near completion and all key components have been tested. Here we report the current status of the project.

  14. Magnetism and magnetic materials probed with neutron scattering

    International Nuclear Information System (INIS)

    Velthuis, S.G.E. te; Pappas, C.

    2014-01-01

    Neutron scattering techniques are becoming increasingly accessible to a broader range of scientific communities, in part due to the onset of next-generation, high-power spallation sources, high-performance, sophisticated instruments and data analysis tools. These technical advances also advantageously impact research into magnetism and magnetic materials, where neutrons play a major role. In this Current Perspective series, the achievements and future prospects of elastic and inelastic neutron scattering, polarized neutron reflectometry, small angle neutron scattering, and neutron imaging, are highlighted as they apply to research into magnetic frustration, superconductivity and magnetism at the nanoscale. - Highlights: • Introduction to Current Perspective series titled Magnetism and Magnetic Materials probed with Neutron Scattering. • Elastic and inelastic neutron scattering in systems with magnetic frustration and superconductivity. • Small angle neutron scattering and polarized neutron reflectometry in studying magnetism at the nanoscale. • Imaging of magnetic fields and domains

  15. Magnetism and magnetic materials probed with neutron scattering

    Energy Technology Data Exchange (ETDEWEB)

    Velthuis, S.G.E. te, E-mail: tevelthuis@anl.gov [Materials Science Division, Argonne National Laboratory, 9700 S Cass Ave, Argonne, IL 60439 (United States); Pappas, C. [Faculty of Applied Sciences, Delft University of Technology, Mekelweg 15, NL-2629JB Delft (Netherlands)

    2014-01-15

    Neutron scattering techniques are becoming increasingly accessible to a broader range of scientific communities, in part due to the onset of next-generation, high-power spallation sources, high-performance, sophisticated instruments and data analysis tools. These technical advances also advantageously impact research into magnetism and magnetic materials, where neutrons play a major role. In this Current Perspective series, the achievements and future prospects of elastic and inelastic neutron scattering, polarized neutron reflectometry, small angle neutron scattering, and neutron imaging, are highlighted as they apply to research into magnetic frustration, superconductivity and magnetism at the nanoscale. - Highlights: • Introduction to Current Perspective series titled Magnetism and Magnetic Materials probed with Neutron Scattering. • Elastic and inelastic neutron scattering in systems with magnetic frustration and superconductivity. • Small angle neutron scattering and polarized neutron reflectometry in studying magnetism at the nanoscale. • Imaging of magnetic fields and domains.

  16. Huang diffuse scattering of neutrons

    International Nuclear Information System (INIS)

    Burkel, E.; Guerard, B. v.; Metzger, H.; Peisl, J.

    1979-01-01

    Huang diffuse neutron scattering was measured for the first time on niobium with interstitially dissolved deuterium as well as on MgO after neutron irradiation and Li 7 F after γ-irradiation. With Huang diffuse scattering the strength and symmetry of the distortion field around lattice defects can be determined. Our results clearly demonstrate that this method is feasible with neutrons. The present results are compared with X-ray experiments and the advantages of using neutrons is discussed in some detail. (orig.)

  17. Polarimetric neutron scattering

    International Nuclear Information System (INIS)

    Tasset, F.

    2001-01-01

    Polarimetric Neutron Scattering in introduced, both by, explaining methodological issues and the corresponding instrumental developments. After a short overview of neutron spin polarization and the neutron polarization 3d-vector a pictorial approach of the microscopic theory is used to show how a polarized beam interacts with lattice and magnetic Fourier components in a crystal. Examples are given of using Spherical Neutron Polarimetry (SNP) and the corresponding Cryopad polarimeter for the investigation of non-collinear magnetic structures. (R.P.)

  18. La nouvelle vague in polarized neutron scattering

    International Nuclear Information System (INIS)

    Mezei, F.

    1986-01-01

    Polarized neutron research, like many other subjects in neutron scattering developed in the footsteps of Cliff Shull. The classical polarized neutron technique he pioneered was generalized around 1970 to vectorial beam polarizations and this opened up the way to a ''nouvelle vague'' of neutron scattering experiments. In this paper I will first reexamine the old controversy on the question whether the nature of the neutron magnetic moment is that of a microscopic dipole or of an Amperian current loop. The problem is not only of historical interest, but also of relevance to modern applications. This will be followed by a review of the fundamentals on spin coherence effects in neutron beams and scattering, which are the basis of vectorial beam polarization work. As an example of practical importance, paramagnetic scattering will be discussed. The paper concludes with some examples of applications of the vector polarization techniques, such as study of ferromagnetic domains by neutron beam depolarization and Neutron Spin Echo high resolution inelastic spectroscopy. The sample results presented demonstrate the new opportunities this novel approach opened up in neutrons scattering research. (orig.)

  19. Neutron scattering equipments in JAERI. Current status

    International Nuclear Information System (INIS)

    Hamaguchi, Yoshikazu; Minakawa, Nobuaki

    2003-01-01

    24 neutron scattering instruments are installed in the JRR-3M research reactor. Among them JAERI has 12 neutron scattering instruments. Those instruments are HRPD for high-resolution structural analysis, TAS-1 and TAS-2 for elastic and inelastic scattering and for magnetic scattering measurements by the polarized neutron, LTAS for elastic and inelastic scattering measurement at a low energy region, and for neutron device development, PNO for topography and for very small angle scattering measurement in a small Q range, NRG for neutron radiography, RESA for internal strain measurements, SANS for the molecule and semi-macroscopic magnetic structural analysis, BIX-2 and BIX-3 for the biological structural analysis research, and PGA for the research of prompt gamma-ray analysis. The university groups have 12 neutron scattering instruments. Since those instruments were installed at the period when JRR-3M was completed, about 10 years have passed. In order to match the old control systems with the progress of recent computer technologies, and peripheral equipment, numbers of instruments are being renewed. In the neutron guide hall of JRR-3M, the Ni mirror guide tube was replaced by a super mirror guide tube to increase neutron flux. The intensity of 2A flux was increased by a factor of about two. (J.P.N.)

  20. Neutron spin echo scattering angle measurement (SESAME)

    International Nuclear Information System (INIS)

    Pynn, R.; Fitzsimmons, M.R.; Fritzsche, H.; Gierlings, M.; Major, J.; Jason, A.

    2005-01-01

    We describe experiments in which the neutron spin echo technique is used to measure neutron scattering angles. We have implemented the technique, dubbed spin echo scattering angle measurement (SESAME), using thin films of Permalloy electrodeposited on silicon wafers as sources of the magnetic fields within which neutron spins precess. With 30-μm-thick films we resolve neutron scattering angles to about 0.02 deg. with neutrons of 4.66 A wavelength. This allows us to probe correlation lengths up to 200 nm in an application to small angle neutron scattering. We also demonstrate that SESAME can be used to separate specular and diffuse neutron reflection from surfaces at grazing incidence. In both of these cases, SESAME can make measurements at higher neutron intensity than is available with conventional methods because the angular resolution achieved is independent of the divergence of the neutron beam. Finally, we discuss the conditions under which SESAME might be used to probe in-plane structure in thin films and show that the method has advantages for incident neutron angles close to the critical angle because multiple scattering is automatically accounted for

  1. Zeeman splitting of surface-scattered neutrons

    International Nuclear Information System (INIS)

    Felcher, G.P.; Adenwalla, S.; De Haan, V.O.; Van Well, A.A.

    1995-01-01

    If a beam of slow neutrons impinges on a solid at grazing incidence, the neutrons reflected can be used to probe the composition and magnetization of the solid near its surface. In this process, the incident and reflected neutrons generally have identical kinetic energies. Here we report the results of an experiment in which subtle inelastic scattering processes are revealed as relatively large deviations in scattering angle. The neutrons are scattered from a ferromagnetic surface in the presence of a strong ambient magnetic field, and exhibit a small but significant variation in kinetic energy as a function of the reflection angle. This effect is attributable to the Zeeman splitting of the energies of the neutron spin states due to the ambient magnetic field: some neutrons flip their spins upon reflection from the magnetized surface, thereby exchanging kinetic energy for magnetic potential energy. The subtle effects of Zeeman splitting are amplified by the extreme sensitivity of grazing-angle neutron scattering, and might also provide a useful spectroscopic tool if significant practical obstacles (such as low interaction cross-sections) can be overcome. (author)

  2. Neutron scattering lengths of 3He

    International Nuclear Information System (INIS)

    Alfimenkov, V.P.; Akopian, G.G.; Wierzbicki, J.; Govorov, A.M.; Pikelner, L.B.; Sharapov, E.I.

    1976-01-01

    The total neutron scattering cross-section of 3 He has been measured in the neutron energy range from 20 meV to 2 eV. Together with the known value of coherent scattering amplitude it leads to the two sts of n 3 He scattering lengths

  3. Virtual neutron scattering experiments

    DEFF Research Database (Denmark)

    Overgaard, Julie Hougaard; Bruun, Jesper; May, Michael

    2016-01-01

    We describe how virtual experiments can be utilized in a learning design that prepares students for hands-on experiments at large-scale facilities. We illustrate the design by showing how virtual experiments are used at the Niels Bohr Institute in a master level course on neutron scattering....... In the last week of the course, students travel to a large-scale neutron scattering facility to perform real neutron scattering experiments. Through student interviews and survey answers, we argue, that the virtual training prepares the students to engage more fruitfully with experiments by letting them focus...... on physics and data rather than the overwhelming instrumentation. We argue that this is because they can transfer their virtual experimental experience to the real-life situation. However, we also find that learning is still situated in the sense that only knowledge of particular experiments is transferred...

  4. Neutron scattering in Indonesia. Country report

    Energy Technology Data Exchange (ETDEWEB)

    Ikram, Abarrul [Neutron Scattering Laboratory, R and D Center for Materials Science and Technology, National Nuclear Energy Agency, Serpong (Indonesia)

    2000-10-01

    Neutron scattering in Indonesia is still alienated due to some reasons and conditions which are discussed. The reactor and its latest operation mode are also described. The neutron beam facilities which include one diffractometer for residual stress measurement, one diffractometer for single crystal structural determination and texture measurement, one high resolution powder diffractometer, one neutron radiography facility, one triple axis spectrometer, one small angle neutron scattering spectrometer and one high resolution small angle neutron scattering spectrometer were presented briefly together with improvements of neutron intensities at some spectrometers in connection with the setting of main beam shutter position. Special attention is given for four instruments mostly related to this workshop. Their performances and problems faced in the past 9 months are presented as well as the future plan for refurbishment and development. (author)

  5. Thermal-neutron multiple scattering: critical double scattering

    International Nuclear Information System (INIS)

    Holm, W.A.

    1976-01-01

    A quantum mechanical formulation for multiple scattering of thermal-neutrons from macroscopic targets is presented and applied to single and double scattering. Critical nuclear scattering from liquids and critical magnetic scattering from ferromagnets are treated in detail in the quasielastic approximation for target systems slightly above their critical points. Numerical estimates are made of the double scattering contribution to the critical magnetic cross section using relevant parameters from actual experiments performed on various ferromagnets. The effect is to alter the usual Lorentzian line shape dependence on neutron wave vector transfer. Comparison with corresponding deviations in line shape resulting from the use of Fisher's modified form of the Ornstein-Zernike spin correlations within the framework of single scattering theory leads to values for the critical exponent eta of the modified correlations which reproduce the effect of double scattering. In addition, it is shown that by restricting the range of applicability of the multiple scattering theory from the outset to critical scattering, Glauber's high energy approximation can be used to provide a much simpler and more powerful description of multiple scattering effects. When sufficiently close to the critical point, it provides a closed form expression for the differential cross section which includes all orders of scattering and has the same form as the single scattering cross section with a modified exponent for the wave vector transfer

  6. Neutron Scattering Differential Cross Sections for 12C

    Science.gov (United States)

    Byrd, Stephen T.; Hicks, S. F.; Nickel, M. T.; Block, S. G.; Peters, E. E.; Ramirez, A. P. D.; Mukhopadhyay, S.; McEllistrem, M. T.; Yates, S. W.; Vanhoy, J. R.

    2016-09-01

    Because of the prevalence of its use in the nuclear energy industry and for our overall understanding of the interactions of neutrons with matter, accurately determining the effects of fast neutrons scattering from 12C is important. Previously measured 12C inelastic neutron scattering differential cross sections found in the National Nuclear Data Center (NNDC) show significant discrepancies (>30%). Seeking to resolve these discrepancies, neutron inelastic and elastic scattering differential cross sections for 12C were measured at the University of Kentucky Acceleratory Laboratory for incident neutron energies of 5.58, 5.83, and 6.04 MeV. Quasi mono-energetic neutrons were scattered off an enriched 12C target (>99.99%) and detected by a C6D6 liquid scintillation detector. Time-of-flight (TOF) techniques were used to determine scattered neutron energies and allowed for elastic/inelastic scattering distinction. Relative detector efficiencies were determined through direct measurements of neutrons produced by the 2H(d,n) and 3H(p,n) source reactions, and absolute normalization factors were found by comparing 1H scattering measurements to accepted NNDC values. This experimental procedure has been successfully used for prior neutron scattering measurements and seems well-suited to our current objective. Significant challenges were encountered, however, with measuring the neutron detector efficiency over the broad incident neutron energy range required for these measurements. Funding for this research was provided by the National Nuclear Security Administration (NNSA).

  7. Very High Energy Neutron Scattering from Hydrogen

    International Nuclear Information System (INIS)

    Cowley, R A; Stock, C; Bennington, S M; Taylor, J; Gidopoulos, N I

    2010-01-01

    The neutron scattering from hydrogen in polythene has been measured with the direct time-of flight spectrometer, MARI, at the ISIS facility of the Rutherford Appleton Laboratory with incident neutron energies between 0.5 eV and 600 eV. The results of experiments using the spectrometer, VESUVIO, have given intensities from hydrogen containing materials that were about 60% of the intensity expected from hydrogen. Since VESUVIO is the only instrument in the world that routinely operates with incident neutron energies in the eV range we have chosen to measure the scattering from hydrogen at high incident neutron energies with a different type of instrument. The MARI, direct time-of-flight, instrument was chosen for the experiment and we have studied the scattering for several different incident neutron energies. We have learnt how to subtract the gamma ray background, how to calibrate the incident energy and how to convert the spectra to an energy plot . The intensity of the hydrogen scattering was independent of the scattering angle for scattering angles from about 5 degrees up to 70 degrees for at least 3 different incident neutron energies between 20 eV and 100 eV. When the data was put on an absolute scale, by measuring the scattering from 5 metal foils with known thicknesses under the same conditions we found that the absolute intensity of the scattering from the hydrogen was in agreement with that expected to an accuracy of ± 5.0% over a wide range of wave-vector transfers between 1 and 250 A -1 . These measurements show that it is possible to measure the neutron scattering with incident neutron energies up to at least 100 eV with a direct geometry time-of-flight spectrometer and that the results are in agreement with conventional scattering theory.

  8. An empirical formula for scattered neutron components in fast neutron radiography

    International Nuclear Information System (INIS)

    Dou Haifeng; Tang Bin

    2011-01-01

    Scattering neutrons are one of the key factors that may affect the images of fast neutron radiography. In this paper, a mathematical model for scattered neutrons is developed on a cylinder sample, and an empirical formula for scattered neutrons is obtained. According to the results given by Monte Carlo methods, the parameters in the empirical formula are obtained with curve fitting, which confirms the logicality of the empirical formula. The curve-fitted parameters of common materials such as 6 LiD are given. (authors)

  9. Recent development in magnetic neutron scattering studies

    International Nuclear Information System (INIS)

    Endoh, Yasuo

    1993-01-01

    Neutron scattering results contain many new concepts in modern magnetism. We review here the most recent neutron magnetic scattering studies from so called '214' copper oxide lamellar materials, because a number of important developments in magnetism are condensed in this novel subject. We show that neutron scattering has played crucial role in our understanding of modern magnetism. (author)

  10. Scattering of fast neutrons from elemental molybdenum

    International Nuclear Information System (INIS)

    Smith, A.B.; Guenther, P.T.

    1982-11-01

    Differential broad-resolution neutron-scattering cross sections of elemental molybdenum were measured at 10 to 20 scattering angles distributed between 20 and 160 degrees and at incident-neutron energy intervals of approx. = 50 to 200 keV from 1.5 to 4.0 MeV. Elastically-scattered neutrons were fully resolved from inelastic events. Lumped-level inelastic-neutron-scattering cross sections were determined corresponding to observed excitation energies of; 789 +- 23, 195 +- 23, 1500 +- 34, 1617 +- 12, 1787, 1874, 1991, 2063 +- 24, 2296, 2569 and 2802 keV. An optical-statistical model was deduced from the measured elastic-scattering results. The experimental values were compared with the respective quantities given in ENDF/B-V

  11. DISCUS, Neutron Single to Double Scattering Ratio in Inelastic Scattering Experiment by Monte-Carlo

    International Nuclear Information System (INIS)

    Johnson, M.W.

    1993-01-01

    1 - Description of problem or function: DISCUS calculates the ratio of once-scattered to twice-scattered neutrons detected in an inelastic neutron scattering experiment. DISCUS also calculates the flux of once-scattered neutrons that would have been observed if there were no absorption in the sample and if, once scattered, the neutron would emerge without further re-scattering or absorption. Three types of sample geometry are used: an infinite flat plate, a finite flat plate or a finite length cylinder. (The infinite flat plate is included for comparison with other multiple scattering programs.) The program may be used for any sample for which the scattering law is of the form S(/Q/, omega). 2 - Method of solution: Monte Carlo with importance sampling is used. Neutrons are 'forced' both into useful angular trajectories, and useful energy bins. Biasing of the collision point according to the point of entry of the neutron into the sample is also utilised. The first and second order scattered neutron fluxes are calculated in independent histories. For twice-scattered neutron histories a square distribution in Q-omega space is used to sample the neutron coming from the first scattering event, whilst biasing is used for the second scattering event. (A square distribution is used so as to obtain reasonable inelastic-inelastic statistics.) 3 - Restrictions on the complexity of the problem: Unlimited number of detectors. Max. size of (Q, omega) matrix is 39*149. Max. number of points in momentum space for the scattering cross section is 199

  12. Neutron scattering treatise on materials science and technology

    CERN Document Server

    Kostorz, G

    1979-01-01

    Treatise on Materials Science and Technology, Volume 15: Neutron Scattering shows how neutron scattering methods can be used to obtain important information on materials. The book discusses the general principles of neutron scattering; the techniques used in neutron crystallography; and the applications of nuclear and magnetic scattering. The text also describes the measurement of phonons, their role in phase transformations, and their behavior in the presence of crystal defects; and quasi-elastic scattering, with its special merits in the study of microscopic dynamical phenomena in solids and

  13. Neutron Brillouin scattering in dense fluids

    Energy Technology Data Exchange (ETDEWEB)

    Verkerk, P [Technische Univ. Delft (Netherlands); FINGO Collaboration

    1997-04-01

    Thermal neutron scattering is a typical microscopic probe for investigating dynamics and structure in condensed matter. In contrast, light (Brillouin) scattering with its three orders of magnitude larger wavelength is a typical macroscopic probe. In a series of experiments using the improved small-angle facility of IN5 a significant step forward is made towards reducing the gap between the two. For the first time the transition from the conventional single line in the neutron spectrum scattered by a fluid to the Rayleigh-Brillouin triplet known from light-scattering experiments is clearly and unambiguously observed in the raw neutron data without applying any corrections. Results of these experiments are presented. (author).

  14. German neutron scattering conference. Programme and abstracts

    Energy Technology Data Exchange (ETDEWEB)

    Brueckel, Thomas (ed.)

    2012-07-01

    The German Neutron Scattering Conference 2012 - Deutsche Neutronenstreutagung DN 2012 offers a forum for the presentation and critical discussion of recent results obtained with neutron scattering and complementary techniques. The meeting is organized on behalf of the German Committee for Research with Neutrons - Komitee Forschung mit Neutronen KFN - by the Juelich Centre for Neutron Science JCNS of Forschungszentrum Juelich GmbH. In between the large European and international neutron scattering conferences ECNS (2011 in Prague) and ICNS (2013 in Edinburgh), it offers the vibrant German and international neutron community an opportunity to debate topical issues in a stimulating atmosphere. Originating from ''BMBF Verbundtreffen'' - meetings for projects funded by the German Federal Ministry of Education and Research - this conference series has a strong tradition of providing a forum for the discussion of collaborative research projects and future developments in the field of research with neutrons in general. Neutron scattering, by its very nature, is used as a powerful probe in many different disciplines and areas, from particle and condensed matter physics through to chemistry, biology, materials sciences, engineering sciences, right up to geology and cultural heritage; the German Neutron Scattering Conference thus provides a unique chance for exploring interdisciplinary research opportunities. It also serves as a showcase for recent method and instrument developments and to inform users of new advances at neutron facilities.

  15. German neutron scattering conference. Programme and abstracts

    International Nuclear Information System (INIS)

    Brueckel, Thomas

    2012-01-01

    The German Neutron Scattering Conference 2012 - Deutsche Neutronenstreutagung DN 2012 offers a forum for the presentation and critical discussion of recent results obtained with neutron scattering and complementary techniques. The meeting is organized on behalf of the German Committee for Research with Neutrons - Komitee Forschung mit Neutronen KFN - by the Juelich Centre for Neutron Science JCNS of Forschungszentrum Juelich GmbH. In between the large European and international neutron scattering conferences ECNS (2011 in Prague) and ICNS (2013 in Edinburgh), it offers the vibrant German and international neutron community an opportunity to debate topical issues in a stimulating atmosphere. Originating from ''BMBF Verbundtreffen'' - meetings for projects funded by the German Federal Ministry of Education and Research - this conference series has a strong tradition of providing a forum for the discussion of collaborative research projects and future developments in the field of research with neutrons in general. Neutron scattering, by its very nature, is used as a powerful probe in many different disciplines and areas, from particle and condensed matter physics through to chemistry, biology, materials sciences, engineering sciences, right up to geology and cultural heritage; the German Neutron Scattering Conference thus provides a unique chance for exploring interdisciplinary research opportunities. It also serves as a showcase for recent method and instrument developments and to inform users of new advances at neutron facilities.

  16. Evaluation of room-scattered neutrons at the JNC Tokai neutron reference field

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Tadayoshi; Tsujimura, Norio [Japan Nuclear Cycle Development Inst., Tokai, Ibaraki (Japan). Tokai Works; Oyanagi, Katsumi [Japan Radiation Engineering Co., Ltd., Hitachi, Ibaraki (Japan)

    2002-09-01

    Neutron reference fields for calibrating neutron-measuring devices in JNC Tokai Works are produced by using radionuclide neutron sources, {sup 241}Am-Be and {sup 252}Cf sources. The reference field for calibration includes scattered neutrons from the material surrounding sources, wall, floor and ceiling of the irradiation room. It is, therefore, necessary to evaluate the scattered neutrons contribution and their energy spectra at reference points. Spectral measurements were performed with a set of Bonner multi-sphere spectrometers and the reference fields were characterized in terms of spectral composition and the fractions of room-scattered neutrons. In addition, two techniques stated in ISO 10647, the shadow-cone method and the polynomial fit method, for correcting the contributions from the room-scattered neutrons to the readings of neutron survey instruments were compared. It was found that the two methods gave an equivalent result within a deviation of 3.3% at a source-to-detector distance from 50cm to 500cm. (author)

  17. Evaluation of room-scattered neutrons at the JNC Tokai neutron reference field

    International Nuclear Information System (INIS)

    Yoshida, Tadayoshi; Tsujimura, Norio

    2002-01-01

    Neutron reference fields for calibrating neutron-measuring devices in JNC Tokai Works are produced by using radionuclide neutron sources, 241 Am-Be and 252 Cf sources. The reference field for calibration includes scattered neutrons from the material surrounding sources, wall, floor and ceiling of the irradiation room. It is, therefore, necessary to evaluate the scattered neutrons contribution and their energy spectra at reference points. Spectral measurements were performed with a set of Bonner multi-sphere spectrometers and the reference fields were characterized in terms of spectral composition and the fractions of room-scattered neutrons. In addition, two techniques stated in ISO 10647, the shadow-cone method and the polynomial fit method, for correcting the contributions from the room-scattered neutrons to the readings of neutron survey instruments were compared. It was found that the two methods gave an equivalent result within a deviation of 3.3% at a source-to-detector distance from 50cm to 500cm. (author)

  18. Techniques in high pressure neutron scattering

    CERN Document Server

    Klotz, Stefan

    2013-01-01

    Drawing on the author's practical work from the last 20 years, Techniques in High Pressure Neutron Scattering is one of the first books to gather recent methods that allow neutron scattering well beyond 10 GPa. The author shows how neutron scattering has to be adapted to the pressure range and type of measurement.Suitable for both newcomers and experienced high pressure scientists and engineers, the book describes various solutions spanning two to three orders of magnitude in pressure that have emerged in the past three decades. Many engineering concepts are illustrated through examples of rea

  19. Neutron scattering studies of solid electrolytes

    International Nuclear Information System (INIS)

    Shapiro, S.M.

    1976-01-01

    The role which neutron scattering can play in determining the nature of the disorder and the conducting mechanism in the solid electrolytes is discussed. First, some of the general formalism for elastic and inelastic neutron scattering is reviewed, and the quantities which can be measured are pointed out. Then the application of neutron scattering to the studies of three different problems is examined; the anion disorder in the fluorite system, the dynamical behavior in beta-alumina, and the cation diffusion in αAgI are discussed. 8 figures

  20. Material classification by fast neutron scattering

    Energy Technology Data Exchange (ETDEWEB)

    Buffler, A. E-mail: abuffler@physci.uct.ac.za; Brooks, F.D. E-mail: brooks@physci.uct.ac.za; Allie, M.S.; Bharuth-Ram, K.; Nchodu, M.R

    2001-02-01

    The scattering of a beam of fast monoenergetic neutrons is used to determine elemental compositions of bulk samples (0.2-0.8 kg) of materials composed from one or more of the elements H, C, N, O, Al, S, Fe and Pb. Scattered neutrons are detected by liquid scintillators placed at forward and at backward angles. Different elements are identified by their characteristic scattering signatures derived either from a combination of time-of-flight and pulse height measurements, or from pulse height measurements alone. Scattering signatures measured for multi-element samples are analysed to determine atom fractions for H, C, N, O and other elements in the sample. Atom fractions determined from scattering signatures are insensitive to neutron interactions in material surrounding the scattering sample, provided the amount of material is not excessive. The atom fraction data are used to classify scattering material into categories including 'explosives', 'illicit drugs' and 'other materials' for the purpose of contraband detection.

  1. Some Notes on Neutron Up-Scattering and the Doppler-Broadening of High-Z Scattering Resonances

    Energy Technology Data Exchange (ETDEWEB)

    Parsons, Donald Kent [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-09-28

    When neutrons are scattered by target nuclei at elevated temperatures, it is entirely possible that the neutron will actually gain energy (i.e., up-scatter) from the interaction. This phenomenon is in addition to the more usual case of the neutron losing energy (i.e., down-scatter). Furthermore, the motion of the target nuclei can also cause extended neutron down-scattering, i.e., the neutrons can and do scatter to energies lower than predicted by the simple asymptotic models. In recent years, more attention has been given to temperature-dependent scattering cross sections for materials in neutron multiplying systems. This has led to the inclusion of neutron up-scatter in deterministic codes like Partisn and to free gas scattering models for material temperature effects in Monte Carlo codes like MCNP and cross section processing codes like NJOY. The free gas scattering models have the effect of Doppler Broadening the scattering cross section output spectra in energy and angle. The current state of Doppler-Broadening numerical techniques used at Los Alamos for scattering resonances will be reviewed, and suggestions will be made for further developments. The focus will be on the free gas scattering models currently in use and the development of new models to include high-Z resonance scattering effects. These models change the neutron up-scattering behavior.

  2. BUILDING A NETWORK FOR NEUTRON SCATTERING EDUCATION

    International Nuclear Information System (INIS)

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

    2008-01-01

    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

  3. BUILDING A NETWORK FOR NEUTRON SCATTERING EDUCATION

    Energy Technology Data Exchange (ETDEWEB)

    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

    2008-10-01

    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

  4. Ramsauer effect in triplet neutron-neutron scattering

    International Nuclear Information System (INIS)

    Pupyshev, V.V.; Solovtsova, O.P.

    1995-01-01

    As we show, due to interplay of pure nuclear and magnetic moment interactions, the total cross section of triplet neutron-neutron scattering should possess a non-zero limit at E cm = 0 and a local minimum at ∼ 20 keV. 17 refs., 1 fig

  5. Toward a new polyethylene scattering law determined using inelastic neutron scattering

    International Nuclear Information System (INIS)

    Lavelle, C.M.; Liu, C.-Y.; Stone, M.B.

    2013-01-01

    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 ambient temperatures (∼300K), 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 294 K which are used to improve the scattering law for HDPE. We review some of the past HDPE scattering laws, describe the experimental methods, 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 one 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. -- Highlights: ► Polyethylene at 5 K and 300 K is measured using inelastic neutron scattering (INS). ► Measurements conducted at the Wide Angular-Range Chopper Spectrometer at SNS. ► Several models for Polyethylene are compared to measurements. ► Improvements to existing models for the polyethylene scattering law are suggested. ► INS is shown to be highly valuable tool for scattering law development

  6. Phase transitions and neutron scattering

    International Nuclear Information System (INIS)

    Shirane, G.

    1993-01-01

    A review is given of recent advances in neutron scattering studies of solid state physics. I have selected the study of a structural phase transition as the best example to demonstrate the power of neutron scattering techniques. Since energy analysis is relatively easy, the dynamical aspects of a transition can be elucidated by the neutron probe. I shall discuss in some detail current experiments on the 100 K transition in SrTiO 3 , the crystal which has been the paradigm of neutron studies of phase transitions for many years. This new experiment attempts to clarify the relation between the neutron central peak, observed in energy scans, and the two length scales observed in recent x-ray diffraction studies where only scans in momentum space are possible. (author)

  7. Commercial applications of neutron scattering

    International Nuclear Information System (INIS)

    Hutchings, M.T.

    1993-01-01

    The fact that industry is now willing to pay the full commercial cost for certain neutron scattering experiments aimed at solving its urgent materials - related problems is a true testimony to the usefulness of neutrons as microscopic probes. This paper gives examples of such use of three techniques drawn mainly from our experience at AEA Technology Harwell Laboratory. These are diffraction to measure residual stress, small angle neutron scattering to examine hardening precipitates in ferritic steels brought about by irradiation, and reflectivity to study amorphous diamond layers deposited on silicon. In most cases it is the penetrative power of the neutron which proves to be its best asset for commercial industrial applicaitons. (author)

  8. Inelastic neutron scattering from superconducting rings

    International Nuclear Information System (INIS)

    Agafonov, A.I.

    2010-01-01

    For the first time the differential cross section for the inelastic magnetic neutron scattering by superconducting rings is derived taking account of the interaction of the neutron magnetic moment with the magnetic field generated by the superconducting current. Calculations of the scattering cross section are carried out for cold neutrons and thin film rings from type-II superconductors with the magnetic fields not exceeding the first critical field.

  9. Studies of the dynamic properties of materials using neutron scattering

    International Nuclear Information System (INIS)

    Lovesey, S.W.; Windsor, C.G.

    1985-09-01

    The dynamic properties of materials using the neutron scattering technique is reviewed. The basic properties of both nuclear scattering and magnetic scattering are summarized. The experimental methods used in neutron scattering are described, along with access to neutron sources, and neutron inelastic instruments. Applied materials science using inelastic neutron scattering; rotational tunnelling of a methyl group; molecular diffusion from quasi-elastic scattering; and the diffusion of colloidal particles and poly-nuclear complexes; are also briefly discussed. (U.K.)

  10. Neutron scattering studies in the actinide region

    International Nuclear Information System (INIS)

    Beghian, L.E.; Kegel, G.H.R.

    1991-08-01

    During the report period we have investigated the following areas: Neutron elastic and inelastic scattering measurements on 14 N, 181 Ta, 232 Th, 238 U and 239 Pu; Prompt fission spectra for 232 Th, 235 U, 238 U and 239 Pu; Theoretical studies of neutron scattering; Neutron filters; New detector systems; and Upgrading of neutron target assembly, data acquisition system, and accelerator/beam-line apparatus

  11. Instruments and accessories for neutron scattering research

    International Nuclear Information System (INIS)

    Ishii, Yoshinobu; Morii, Yukio

    2000-04-01

    This report describes neutron scattering instruments and accessories installed by four neutron scattering research groups at the ASRC (Advanced Science Research Center) of the JAERI and the recent topics of neutron scattering research using these instruments. The specifications of nine instruments (HRPD, BIX-I, TAS-1 and PNO in the reactor hall, RESA, BIX-II, TAS-2, LTAS and SANS-J in the guide hall of the JRR-3M) are summarized in this booklet. (author)

  12. Neutrons scattering studies in the actinide region

    International Nuclear Information System (INIS)

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

    1992-09-01

    During the report period were investigated the following areas: prompt fission neutron energy spectra measurements; neutron elastic and inelastic scattering from 239 Pu; neutron scattering in 181 Ta and 197 Au; response of a 235 U fission chamber near reaction thresholds; two-parameter data acquisition system; ''black'' neutron detector; investigation of neutron-induced defects in silicon dioxide; and multiple scattering corrections. Four Ph.D. dissertations and one M.S. thesis were completed during the report period. Publications consisted of three journal articles, four conference papers in proceedings, and eleven abstracts of presentations at scientific meetings. There are currently four Ph.D. and one M.S. candidates working on dissertations directly associated with the project. In addition, three other Ph.D. candidates are working on dissertations involving other aspects of neutron physics in this laboratory

  13. Neutron scattering studies of modulated magnetic structures

    Energy Technology Data Exchange (ETDEWEB)

    Aagaard Soerensen, Steen

    1999-08-01

    This report describes investigations of the magnetic systems DyFe{sub 4}Al{sub 8} and MnSi by neutron scattering and in the former case also by X-ray magnetic resonant scattering. The report is divided into three parts: An introduction to the technique of neutron scattering with special emphasis on the relation between the scattering cross section and the correlations between the scattering entities of the sample. The theoretical framework of neutron scattering experiments using polarized beam technique is outlined. The second part describes neutron and X-ray scattering investigation of the magnetic structures of DyFe{sub 4}Al{sub 8}. The Fe sublattice of the compound order at 180 K in a cycloidal structure in the basal plane of the bct crystal structure. At 25 K the ordering of the Dy sublattice shows up. By the element specific technique of X-ray resonant magnetic scattering, the basal plane cycloidal structure was also found for the Dy sublattice. The work also includes neutron scattering studies of DyFe{sub 4}Al{sub 8} in magnetic fields up to 5 T applied along a <110> direction. The modulated structure at the Dy sublattice is quenched by a field lower than 1 T, whereas modulation is present at the Fe sublattice even when the 5 T field is applied. In the third part of the report, results from three small angle neutron experiments on MnSi are presented. At ambient pressure, a MnSi is known to form a helical spin density wave at temperature below 29 K. The application of 4.5 kbar pressure intended as hydrostatic decreased the Neel temperature to 25 K and changed the orientation of the modulation vector. To understand this reorientation within the current theoretical framework, anisotropic deformation of the sample crystal must be present. The development of magnetic critical scattering with an isotropic distribution of intensity has been studied at a level of detail higher than that of work found in the literature. Finally the potential of a novel polarization

  14. Next generation neutron scattering at Neutron Science Center project in JAERI

    International Nuclear Information System (INIS)

    Yamada, Yasusada; Watanabe, Noboru; Niimura, Nobuo; Morii, Yukio; Katano, Susumu; Aizawa, Kazuya; Suzuki, Jun-ichi; Koizumi, Satoshi; Osakabe, Toyotaka.

    1997-01-01

    Japan Atomic Energy Research Institute (JAERI) has promoted neutron scattering researches by means of research reactors in Tokai Research Establishment, and proposes 'Neutron Science Research Center' to develop the future prospect of the Tokai Research Establishment. The scientific fields which will be expected to progress by the neutron scattering experiments carried out at the proposed facility in the Center are surveyed. (author)

  15. Larmor-precession based neutron scattering instrumentation

    International Nuclear Information System (INIS)

    Ioffe, Alexander

    2009-01-01

    The Larmor precession of the neutron spin in a magnetic field allows the attachment of a Larmor clock to every neutron. Such Larmor labelling opens the possibility for the development of unusual neutron scattering techniques, where the energy (momentum) resolution does not require the initial and final states to be well selected. This principally allows for achievement of very high energy (momentum) resolution that is not feasible at all with conventional neutron scattering techniques, because the required neutron beam monochromatization (collimation) will result in intolerable intensity losses. Such decoupling of resolution and collimation allows, for example, for a significant increase in the luminosity of small-angle scattering or high-resolution diffractometers; the fact that opens new perspectives for their implementation at middle flux neutron sources. Different kinds of Larmor clock-based instrumentation, particularly two alternative NSE techniques using rotating and time-gradient magnetic field arrangements, which can be considered as inexpensive and affordable alternatives to present day NSE techniques, will be discussed and results of simulations and first experiments will be presented. (author)

  16. American Conference on Neutron Scattering 2014

    Energy Technology Data Exchange (ETDEWEB)

    Dillen, J. Ardie [Materials Research Society, Warrendale, PA (United States)

    2014-12-31

    Scientists from the around the world converged in Knoxville, TN to have share ideas, present technical information and contribute to the advancement of neutron scattering. Featuring over 400 oral/poster presentations, ACNS 2014 offered a strong program of plenary, invited and contributed talks and poster sessions covering topics in soft condensed matter, hard condensed matter, biology, chemistry, energy and engineering applications in neutron physics – confirming the great diversity of science that is enabled by neutron scattering.

  17. American Conference on Neutron Scattering 2014

    International Nuclear Information System (INIS)

    Dillen, J. Ardie

    2014-01-01

    Scientists from the around the world converged in Knoxville, TN to have share ideas, present technical information and contribute to the advancement of neutron scattering. Featuring over 400 oral/poster presentations, ACNS 2014 offered a strong program of plenary, invited and contributed talks and poster sessions covering topics in soft condensed matter, hard condensed matter, biology, chemistry, energy and engineering applications in neutron physics - confirming the great diversity of science that is enabled by neutron scattering.

  18. Neutron scattering instruments for the Spallation Neutron Source (SNS)

    International Nuclear Information System (INIS)

    Crawford, R.K.; Fornek, T.; Herwig, K.W.

    1998-01-01

    The Spallation Neutron Source (SNS) is a 1 MW pulsed spallation source for neutron scattering planned for construction at Oak Ridge National Laboratory. This facility is being designed as a 5-laboratory collaboration project. This paper addresses the proposed facility layout, the process for selection and construction of neutron scattering instruments at the SNS, the initial planning done on the basis of a reference set of ten instruments, and the plans for research and development (R and D) to support construction of the first ten instruments and to establish the infrastructure to support later development and construction of additional instruments

  19. Non-destructive diagnostics of irradiated materials using neutron scattering from pulsed neutron sources

    Energy Technology Data Exchange (ETDEWEB)

    Korenev, Sergey E-mail: sergey_korenev@steris.com; Sikolenko, Vadim

    2004-10-01

    The advantage of neutron-scattering studies as compared to the standard X-ray technique is the high penetration of neutrons that allow us to study volume effects. The high resolution of instrumentation on the basis neutron scattering allows measurement of the parameters of lattice structure with high precision. We suggest the use of neutron scattering from pulsed neutron sources for analysis of materials irradiated with pulsed high current electron and ion beams. The results of preliminary tests using this method for Ni foils that have been studied by neutron diffraction at the IBR-2 (Pulsed Fast Reactor at Joint Institute for Nuclear Research) are presented.

  20. Non-destructive diagnostics of irradiated materials using neutron scattering from pulsed neutron sources

    Science.gov (United States)

    Korenev, Sergey; Sikolenko, Vadim

    2004-09-01

    The advantage of neutron-scattering studies as compared to the standard X-ray technique is the high penetration of neutrons that allow us to study volume effects. The high resolution of instrumentation on the basis neutron scattering allows measurement of the parameters of lattice structure with high precision. We suggest the use of neutron scattering from pulsed neutron sources for analysis of materials irradiated with pulsed high current electron and ion beams. The results of preliminary tests using this method for Ni foils that have been studied by neutron diffraction at the IBR-2 (Pulsed Fast Reactor at Joint Institute for Nuclear Research) are presented.

  1. Set of thermal neutron-scattering experiments for the Weapons Neutron Research Facility

    International Nuclear Information System (INIS)

    Brugger, R.M.

    1975-12-01

    Six classes of experiments form the base of a program of thermal neutron scattering at the Weapons Neutron Research (WNR) Facility. Three classes are to determine the average microscopic positions of atoms in materials and three are to determine the microscopic vibrations of these atoms. The first three classes concern (a) powder sample neutron diffraction, (b) small angle scattering, and (c) single crystal Laue diffraction. The second three concern (d) small kappa inelastic scattering, (e) scattering surface phonon measurements, and (f) line widths. An instrument to couple with the WNR pulsed source is briefly outlined for each experiment

  2. Introduction to neutron scattering. Lecture notes of the introductory course

    International Nuclear Information System (INIS)

    Furrer, A.

    1996-01-01

    These proceedings enclose ten papers presented at the 1. European Conference on Neutron scattering (ECNS '96). The aim of the Introductory Course was fourfold: - to learn the basic principles of neutron scattering, - to get introduced into the most important classes of neutron scattering instruments, -to learn concepts and their transformation into neutron scattering experiments in various fields of condensed matter research, - to recognize the limitations of the neutron scattering technique as well as to the complementarity of other methods. figs., tabs., refs

  3. Neutron scattering studies of the heavy Fermion superconductors

    International Nuclear Information System (INIS)

    Goldman, A.I.

    1985-01-01

    Recent neutron scattering measurements of the heavy Fermion superconductors are described. Those materials offer an exciting opportunity for neutron scattering since the f-electrons, which couple directly to magnetic scattering measurements, seem to be the same electrons which form the superconducting state below T/sub c/. In addition, studies of the magnetic fluctuations in these, and other heavy Fermion systems, by inelastic magnetic neutron scattering can provide information about the nature of the low temperature Fermi liquid character of these novel compounds

  4. New Techniques in Neutron Scattering

    DEFF Research Database (Denmark)

    Birk, Jonas Okkels

    potential performance than any existing facility, however in order to use this pulse structure optimally many existing neutron scattering instruments will need to be redesigned. This defense will concentrate on the design and optimization of the inverse time-of-flight cold neutron spectrometer CAMEA......, simulations and prototyping to optimize the instrument and ensure that it will deliver the predicted performance when constructed. During the design a new prismatic analyser concept that can be of interest to many other neutron spectrometers was developed. The design work was compiled into an instrument......Neutron scattering is an important experimental technique in amongst others solid state physics, biophysics, and engineering. This year construction of European Spallation Source (ESS) was commenced in Lund, Sweeden. The facility will use a new long pulsed source principle to obtain higher...

  5. The analysis and correction of neutron scattering effects in neutron imaging

    International Nuclear Information System (INIS)

    Raine, D.A.; Brenizer, J.S.

    1997-01-01

    A method of correcting for the scattering effects present in neutron radiographic and computed tomographic imaging has been developed. Prior work has shown that beam, object, and imaging system geometry factors, such as the L/D ratio and angular divergence, are the primary sources contributing to the degradation of neutron images. With objects smaller than 20--40 mm in width, a parallel beam approximation can be made where the effects from geometry are negligible. Factors which remain important in the image formation process are the pixel size of the imaging system, neutron scattering, the size of the object, the conversion material, and the beam energy spectrum. The Monte Carlo N-Particle transport code, version 4A (MCNP4A), was used to separate and evaluate the effect that each of these parameters has on neutron image data. The simulations were used to develop a correction algorithm which is easy to implement and requires no a priori knowledge of the object. The correction algorithm is based on the determination of the object scatter function (OSF) using available data outside the object to estimate the shape and magnitude of the OSF based on a Gaussian functional form. For objects smaller than 1 mm (0.04 in.) in width, the correction function can be well approximated by a constant function. Errors in the determination and correction of the MCNP simulated neutron scattering component were under 5% and larger errors were only noted in objects which were at the extreme high end of the range of object sizes simulated. The Monte Carlo data also indicated that scattering does not play a significant role in the blurring of neutron radiographic and tomographic images. The effect of neutron scattering on computed tomography is shown to be minimal at best, with the most serious effect resulting when the basic backprojection method is used

  6. Applications of thermal neutron scattering in biology, biochemistry and biophysics

    International Nuclear Information System (INIS)

    Worcester, D.L.

    1977-01-01

    Biological applications of thermal neutron scattering have increased rapidly in recent years. The following categories of biological research with thermal neutron scattering are presently identified: crystallography of biological molecules; neutron small-angle scattering of biological molecules in solution (these studies have already included numerous measurements of proteins, lippoproteins, viruses, ribosomal subunits and chromatin subunit particles); neutron small-angle diffraction and scattering from biological membranes and membrane components; and neutron quasielastic and inelastic scattering studies of the dynamic properties of biological molecules and materials. (author)

  7. Progress report on neutron scattering at JAERI

    Energy Technology Data Exchange (ETDEWEB)

    Morii, Yukio [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-10-01

    In the first half of fiscal year 1997, JRR-3M was operated for 97 days followed by a long term shut down for its annual maintenance. Three days were lost out of 100 scheduled operation days, due to a trouble in irradiation facility. Neutron scattering research activities at the JRR-3M have been extended from that of fiscal year 1996. In the Research Group for Quantum Condensed Matter System, experimental study under high pressures, low temperatures and high fields as well as coupling of these conditions were planned to find new quantum condensed matter systems. And, obtained experimental results were immediately provided to theorists for their investigations. In cooperation with new group, Research Group for Neutron Scattering of Strongly Correlated Electron Systems and Research Group for Neutron Scattering at Ultralow Temperatures were carrying neutron scattering experiments at JRR-3M. Research Group for Neutron Crystallography in Biology had opened a way for investigating biomatter neutron diffraction research with high experimental accuracy by growing a millimeter-class large single crystal. In fiscal year 1997, 39 research projects were conducted by these four groups and other staffs in JAERI, 27 projects collaborated with university researchers and 3 projects collaborated with private enterprises were also conducted as complementary researches. 2117 days of machine times were requested to use 8 neutron scattering instruments this year, which corresponded to 1.51 times larger than those planned at its beginning. (G.K.)

  8. Fast-neutron scattering from elemental cadmium

    International Nuclear Information System (INIS)

    Smith, A.B.; Guenther, P.T.

    1982-07-01

    Neutron differential-elastic-scattering cross sections of elemental cadmium are measured from approx. = 1.5 to 4.0 MeV at incident-neutron energy intervals of 50 to 200 keV and at 10 to 20 scattering angles distributed between approx. = 20 and 160 degrees. Concurrently, lumped-level neutron inelastic-excitation cross sections are measured. The experimental results are used to deduce parameters of an optical-statistical model that is descriptive of the observables and are compared with corresponding quantities given in ENDF/B-V

  9. Slow neutron scattering experiments

    International Nuclear Information System (INIS)

    Moon, R.M.

    1985-01-01

    Neutron scattering is a versatile technique that has been successfully applied to condensed-matter physics, biology, polymer science, chemistry, and materials science. The United States lost its leadership role in this field to Western Europe about 10 years ago. Recently, a modest investment in the United States in new facilities and a positive attitude on the part of the national laboratories toward outside users have resulted in a dramatic increase in the number of US scientists involved in neutron scattering research. Plans are being made for investments in new and improved facilities that could return the leadership role to the United States. 23 references, 4 figures, 3 tables

  10. Current status of neutron scattering in Thailand

    International Nuclear Information System (INIS)

    Ampornrat, Pantip

    1999-01-01

    Thailand's neutron spectrometer has been installed soon after the startup of the reactor. The neutron scattering experiments have been done continuously, although there were some problems involving the neutron intensity and instruments. Development program has been planned for better experimental result. This paper reports the past and present status of neutron scattering equipment and experiments in Thailand. In addition, installation of a HRPD (High Resolution Powder Diffraction) system is included within the scope of the Ongkharak Nuclear Research Center project. (author)

  11. Neutron scattering applications in structural biology: now and the future

    Energy Technology Data Exchange (ETDEWEB)

    Trewhella, J [Los Alamos National Lab., NM (United States)

    1996-05-01

    Neutrons have an important role to play in structural biology. Neutron crystallography, small-angle neutron scattering and inelastic neutron scattering techniques all contribute unique information on biomolecular structures. In particular, solution scattering techniques give critical information on the conformations and dispositions of the components of complex assemblies under a wide variety of relevant conditions. The power of these methods is demonstrated here by studies of protein/DNA complexes, and Ca{sup 2+}-binding proteins complexed with their regulatory targets. In addition, we demonstrate the utility of a new structural approach using neutron resonance scattering. The impact of biological neutron scattering to date has been constrained principally by the available fluxes at neutron sources and the true potential of these approaches will only be realized with the development of new more powerful neutron sources. (author)

  12. Symposium on neutron scattering

    International Nuclear Information System (INIS)

    Lehmann, M.S.; Saenger, W.; Hildebrandt, G.; Dachs, H.

    1984-01-01

    Extended abstracts of the named symposium are presented. The first part of this report contains the abstracts of the lectures, the second those of the posters. Topics discussed on the symposium include neutron diffraction and neutron scattering studies in magnetism, solid state chemistry and physics, materials research. Some papers discussing instruments and methods are included too. (GSCH)

  13. Background determination for the neutron-neutron scattering experiment at the reactor YAGUAR

    Energy Technology Data Exchange (ETDEWEB)

    Muzichka, A.Yu. [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Furman, W.I. [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Lychagin, E.V. [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Krylov, A.R. [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Nekhaev, G.V. [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Sharapov, E.I. [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Shvetsov, V.N. [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Strelkov, A.V. [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Levakov, B.G. [Russian Federal Nuclear Center-All-Russian Research Institute of Technical Physics, PO Box 245, 456770 Snezhinsk (Russian Federation); Lyzhin, A.E. [Russian Federal Nuclear Center-All-Russian Research Institute of Technical Physics, PO Box 245, 456770 Snezhinsk (Russian Federation); Chernukhin, Yu.I. [Russian Federal Nuclear Center-All-Russian Research Institute of Technical Physics, PO Box 245, 456770 Snezhinsk (Russian Federation); Kandiev, Ya.Z. [Russian Federal Nuclear Center-All-Russian Research Institute of Technical Physics, PO Box 245, 456770 Snezhinsk (Russian Federation); Howell, C.R. [Duke University and Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States); Mitchell, G.E. [North Carolina State University, Raleigh, NC 27695-8202 (United States); Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States); Crawford, B.E. [Gettysburg College, Box 405, Gettysburg, PA 17325 (United States); Stephenson, S.L. [Gettysburg College, Box 405, Gettysburg, PA 17325 (United States)]. E-mail: sstephen@gettysburg.edu; Tornow, W. [Duke University and Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States)

    2007-06-01

    The motivation and design is outlined for the experiment to measure the neutron-neutron singlet scattering length directly with thermal neutrons at the pulsed reactor YAGUAR. A statistical accuracy of 3% can be reached, though achieving the goal of an overall accuracy of 3-5% for the nn-scattering length depends on the background level. Possible sources of background are discussed in depth and the results of extensive modeling of the background are presented. Measurements performed at YAGUAR to test these background calculations are described. The experimental results indicate an anticipated background level up to 30% relative to the expected nn effect at the maximal energy burst of the reactor. The conclusion is made that the nn experiment at YAGUAR is feasible to produce the first directly measured value for the neutron-neutron scattering length.

  14. Study of scattering in bi-dimensional neutron radiographic images

    International Nuclear Information System (INIS)

    Oliveira, K.A.M. de; Crispim, V.R.; Silva, F.C.

    2009-01-01

    The effect of neutron scattering frequently causes distortions in neutron radiographic images and, thus, reduces the quality. In this project, a type of filter, comprised of cadmium (a neutron absorber), was used in the form of a grid to correct this effect. This device generated image data in the discrete shadow bands of the absorber, components relative to neutron scattering on the test object and surroundings. Scattering image data processing, together with the original neutron radiographic image, resulted in a corrected image with improved edge delineation and, thus, greater definition in the neutron radiographic image of the test object. The objective of this study is to propose a theoretical/experimental methodology that is capable of eliminating the components relative to neutron scattering in neutron radiographic images, coming from the material that composes the test object and the materials that compose the surrounding area. (author)

  15. Local-field refinement of neutron scattering lengths

    International Nuclear Information System (INIS)

    Sears, V.F.

    1985-01-01

    We examine the way in which local field effects in the neutron refractive index affect the values of coherent scattering lengths determined by various kinds of neutron optical measurements. We find that under typical experimental conditions these effects are negligible for interferometry measurements but that they are significant for gravity refractometry measurements, producing changes in the effective scattering length of as much as two or three standard deviations in some cases. Refined values of the scattering length are obtained for the thirteen elements for which data are presently available. The special role of local field effects in neutron transmission is also discussed. (orig.)

  16. Local-field refinement of neutron scattering lengths

    Energy Technology Data Exchange (ETDEWEB)

    Sears, V F

    1985-06-01

    We examine the way in which local field effects in the neutron refractive index affect the values of coherent scattering lengths determined by various kinds of neutron optical measurements. We find that under typical experimental conditions these effects are negligible for interferometry measurements but that they are significant for gravity refractometry measurements, producing changes in the effective scattering length of as much as two or three standard deviations in some cases. Refined values of the scattering length are obtained for the thirteen elements for which data are presently available. The special role of local field effects in neutron transmission is also discussed.

  17. Current status of neutron scattering in Thailand

    International Nuclear Information System (INIS)

    Kornduangkaeo, Areeratt; Pongkasem, Somchai; Putchar, Suriya; Ampornrat, Pantip; Kajornrith, Varavuth; Sangariyavanich, Archara

    2003-01-01

    The current neutron powder diffractometer at the Thai Research Reactor-1/M1 (TRR-1/M1) has been modified from the obsolete neutron diffractometer which had been used during 1968-1975. The upgraded diffractometer has medium resolution and is appropriate for studying samples with small unit cell dimensions and training university students in the field of neutron scattering. This paper describes the current activities of neutron scattering research in Thailand as well as a new research reactor for enlarging the perspectives of its utilization in the future. (author)

  18. Neutron scattering at the high-flux isotope reactor

    International Nuclear Information System (INIS)

    Cable, J.W. Chakoumakos, B.C.; Dai, P.

    1995-01-01

    The title facilities offer the brightest source of neutrons in the national user program. Neutron scattering experiments probe the structure and dynamics of materials in unique and complementary ways as compared to x-ray scattering methods and provide fundamental data on materials of interest to solid state physicists, chemists, biologists, polymer scientists, colloid scientists, mineralogists, and metallurgists. Instrumentation at the High- Flux Isotope Reactor includes triple-axis spectrometers for inelastic scattering experiments, a single-crystal four diffractometer for crystal structural studies, a high-resolution powder diffractometer for nuclear and magnetic structure studies, a wide-angle diffractometer for dynamic powder studies and measurements of diffuse scattering in crystals, a small-angle neutron scattering (SANS) instrument used primarily to study structure-function relationships in polymers and biological macromolecules, a neutron reflectometer for studies of surface and thin-film structures, and residual stress instrumentation for determining macro- and micro-stresses in structural metals and ceramics. Research highlights of these areas will illustrate the current state of neutron science to study the physical properties of materials

  19. Studies on biological macromolecules by neutron inelastic scattering

    International Nuclear Information System (INIS)

    Fujiwara, Satoru; Nakagawa, Hiroshi

    2013-01-01

    Neutron inelastic scattering techniques, including quasielastic and elastic incoherent neutron scattering, provide unique tools to directly measure the protein dynamics at a picosecond time scale. Since the protein dynamics at this time scale is indispensable to the protein functions, elucidation of the protein dynamics is indispensable for ultimate understanding of the protein functions. There are two complementary directions of the protein dynamics studies: one is to explore the physical basis of the protein dynamics using 'model' proteins, and the other is more biology-oriented. Examples of the studies on the protein dynamics with neutron inelastic scattering are described. The examples of the studies in the former direction include the studies on the dynamical transitions of the proteins, the relationship between the protein dynamics and the hydration water dynamics, and combined analysis of the protein dynamics with molecular dynamics simulation. The examples of the studies in the latter direction include the elastic incoherent and quasielastic neutrons scattering studies of actin. Future prospects of the studies on the protein dynamics with neutron scattering are briefly described. (author)

  20. Fluence-compensated down-scattered neutron imaging using the neutron imaging system at the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Casey, D. T., E-mail: casey21@llnl.gov; Munro, D. H.; Grim, G. P.; Landen, O. L.; Spears, B. K.; Fittinghoff, D. N.; Field, J. E.; Smalyuk, V. A. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Volegov, P. L.; Merrill, F. E. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2016-11-15

    The Neutron Imaging System at the National Ignition Facility is used to observe the primary ∼14 MeV neutrons from the hotspot and down-scattered neutrons (6-12 MeV) from the assembled shell. Due to the strong spatial dependence of the primary neutron fluence through the dense shell, the down-scattered image is convolved with the primary-neutron fluence much like a backlighter profile. Using a characteristic scattering angle assumption, we estimate the primary neutron fluence and compensate the down-scattered image, which reveals information about asymmetry that is otherwise difficult to extract without invoking complicated models.

  1. Polarized neutron inelastic scattering experiments on spin dynamics

    International Nuclear Information System (INIS)

    Kakurai, Kazuhisa

    2016-01-01

    The principles of polarized neutron scattering are introduced and examples of polarized neutron inelastic scattering experiments on spin dynamics investigation are presented. These examples should demonstrate the importance of the polarized neutron utilization for the investigation of non-trivial magnetic ground and excited states in frustrated and low dimensional quantum spin systems. (author)

  2. Lectures on neutron scattering techniques: 1

    International Nuclear Information System (INIS)

    Carlile, C.J.

    1988-08-01

    The lecture on the production of neutrons was presented at a Summer School on neutron scattering, Rome, 1986. A description is given of the production of neutrons by natural radioactive sources, fission, and particle accelerator sources. Modern neutron sources with high intensities are discussed including the ISIS pulsed neutron source at the Rutherford Appleton Laboratory and the High Flux Reactor at the Institut Laue Langevin. (U.K.)

  3. Monte Carlo simulations of neutron scattering instruments

    International Nuclear Information System (INIS)

    Aestrand, Per-Olof; Copenhagen Univ.; Lefmann, K.; Nielsen, K.

    2001-01-01

    A Monte Carlo simulation is an important computational tool used in many areas of science and engineering. The use of Monte Carlo techniques for simulating neutron scattering instruments is discussed. The basic ideas, techniques and approximations are presented. Since the construction of a neutron scattering instrument is very expensive, Monte Carlo software used for design of instruments have to be validated and tested extensively. The McStas software was designed with these aspects in mind and some of the basic principles of the McStas software will be discussed. Finally, some future prospects are discussed for using Monte Carlo simulations in optimizing neutron scattering experiments. (R.P.)

  4. Latest developments of neutron scattering instrumentation at the Juelich Centre for Neutron Science

    International Nuclear Information System (INIS)

    Ioffe, Alexander

    2013-01-01

    Jülich Centre for Neutron Science (JCNS) is operating a number of world-class neutron scattering instruments situated at the most powerful and advanced neutron sources (FRM II, ILL and SNS) and is continuously undertaking significant efforts in the development and upgrades to keep this instrumentation in line with the continuously changing scientific request. These developments are mostly based upon the latest progress in neutron optics and polarized neutron techniques. For example, the low-Q limit of the suite of small angle-scattering instruments has been extended to 4·10 -5 Å -1 by the successful use of focusing optics. A new generation of correction elements for the neutron spin-echo spectrometer has allowed for the use of the full field integral available, thus pushing further the instrument resolution. A significant progress has been achieved in the developments of 3 He neutron spin filters for purposes of the wide-angle polarization analysis for off-specular reflectometry and (grazing incidence) small-angle neutron scattering, e.g. the on-beam polarization of 3 He in large cells is allowing to achieve a high neutron beam polarization without any degradation in time. The wide Q-range polarization analysis using 3 He neutron spin filters has been implemented for small-angle neutron scattering that lead to the reduction up to 100 times of the intrinsic incoherent background from non-deuterated biological molecules. Also the work on wide-angle XYZ magnetic cavities (Magic PASTIS) will be presented. (author)

  5. Some thoughts on the future of neutron scattering

    International Nuclear Information System (INIS)

    Egelstaff, P.A.

    1991-01-01

    Attendance of ICANS meetings believe that neutron scattering has a bright future, but critics of neutron scattering argue that its practitioners are an aging group, that they use a few, very expensive neutron sources and that the interesting science may be done by other techniques. The ICANS committee asked me to comment on the future of neutron scattering in the light of this contrast. Some comments will be made on the age distribution, on the proper distribution of sources, on the convenient availability of neutron instruments and methods, on the expansion into new areas of science, on applications to industry and on the probable impact of synchrotron sources. It is hoped that these comments will lead to an outward looking discussion on the future. (author)

  6. Polarized neutron scattering research: the beginning

    International Nuclear Information System (INIS)

    Mezei, F.

    2005-01-01

    The visionary idea of using neutron scattering for the study of magnetic phenomena in condensed matter was proposed by Bloch in 1936, mere 4 years after the neutron was discovered. It was based on one of the surprises the neutron presented the scientific community with: it is neutral, yet it has a magnetic moment, which latter was then not yet directly observed though. Although the first results proved to be mathematically wrong, due to a non-trivial ambiguity of classical electromagnetism theory, which could only be settled by neutron beam experiments 15 years later, the recognition lead to the advent of a most productive area of modern research, which culminated in the development of the powerful and sophisticated techniques of polarized neutron scattering. This recollection traces the early milestones of the development of the field in strong interaction between theory and experiment

  7. Spectral distortion due to scattered cold neutrons in beryllium filter

    International Nuclear Information System (INIS)

    Sakamoto, Yukio; Inoue, Kazuhiko

    1980-01-01

    Polycrystalline beryllium filters are used to discriminate the cold neutrons from the thermal neutrons with energies above Bragg cut-off energy. The cold neutron scattering cross section is very small, but the remaining cross section is not zero. Then the neutrons scattered once from the filter in the cold neutron energy region have chance of impinging on the outlet of filter. Those neutrons are almost upscattered and develop into thermal neutrons; thus the discriminated cold neutrons include a small spectral distortion due to the thermal neutrons. In the present work we have evaluated the effect on the cold neutron spectrum due to the repeatedly scattered and transmitted neutrons by using a Monte Carlo calculation method. (author)

  8. The hydrogen anomaly problem in neutron Compton scattering

    Science.gov (United States)

    Karlsson, Erik B.

    2018-03-01

    Neutron Compton scattering (also called ‘deep inelastic scattering of neutrons’, DINS) is a method used to study momentum distributions of light atoms in solids and liquids. It has been employed extensively since the start-up of intense pulsed neutron sources about 25 years ago. The information lies primarily in the width and shape of the Compton profile and not in the absolute intensity of the Compton peaks. It was therefore not immediately recognized that the relative intensities of Compton peaks arising from scattering on different isotopes did not always agree with values expected from standard neutron cross-section tables. The discrepancies were particularly large for scattering on protons, a phenomenon that became known as ‘the hydrogen anomaly problem’. The present paper is a review of the discovery, experimental tests to prove or disprove the existence of the hydrogen anomaly and discussions concerning its origin. It covers a twenty-year-long history of experimentation, theoretical treatments and discussions. The problem is of fundamental interest, since it involves quantum phenomena on the subfemtosecond time scale, which are not visible in conventional thermal neutron scattering but are important in Compton scattering where neutrons have two orders of magnitude times higher energy. Different H-containing systems show different cross-section deficiencies and when the scattering processes are followed on the femtosecond time scale the cross-section losses disappear on different characteristic time scales for each H-environment. The last section of this review reproduces results from published papers based on quantum interference in scattering on identical particles (proton or deuteron pairs or clusters), which have given a quantitative theoretical explanation both regarding the H-cross-section reduction and its time dependence. Some new explanations are added and the concluding chapter summarizes the conditions for observing the specific quantum

  9. Neutron scattering and the search for mechanisms of superconductivity

    DEFF Research Database (Denmark)

    Aeppli, G.; Bishop, D.J.; Broholm, C.

    1999-01-01

    Neutron scattering is a direct probe of mass and magnetization density in solids. We start with a brief review of experimental strategies for determining the mechanisms of superconductivity and how neutron scattering contributed towards our understanding of conventional superconductors. The remai......Neutron scattering is a direct probe of mass and magnetization density in solids. We start with a brief review of experimental strategies for determining the mechanisms of superconductivity and how neutron scattering contributed towards our understanding of conventional superconductors....... The remainder of the article gives examples of neutron results with impact on the search for the mechanism of superconductivity in more recently discovered, 'exotic', materials, namely the heavy fermion compounds and the layered cuprates, (C) 1999 Elsevier Science B.V. All rights reserved....

  10. Introduction to the theory of thermal neutron scattering

    CERN Document Server

    Squires, G L

    2012-01-01

    Since the advent of the nuclear reactor, thermal neutron scattering has proved a valuable tool for studying many properties of solids and liquids, and research workers are active in the field at reactor centres and universities throughout the world. This classic text provides the basic quantum theory of thermal neutron scattering and applies the concepts to scattering by crystals, liquids and magnetic systems. Other topics discussed are the relation of the scattering to correlation functions in the scattering system, the dynamical theory of scattering and polarisation analysis. No previous knowledge of the theory of thermal neutron scattering is assumed, but basic knowledge of quantum mechanics and solid state physics is required. The book is intended for experimenters rather than theoreticians, and the discussion is kept as informal as possible. A number of examples, with worked solutions, are included as an aid to the understanding of the text.

  11. The contribution of neutron scattering to molecular biology

    International Nuclear Information System (INIS)

    Stuhrmann, H.B.

    1983-01-01

    About half of the atoms of living cells are hydrogens, and nearly all biological applications of neutron scattering rely on the well-known difference in the scattering lengths of the proton and the deuteron. This introduces us to a wide variety of biological problems, which are related with hydrogen in water, proteins, nucleic acids and lipids. Neutron scattering gives an answer to both structural and dynamical aspects of the system in question. With deuterium labelled samples unambiguous information about molecular structure and motion becomes accessible. The architecture of viruses, cell membranes and gene expressing molecules has become a lot clearer with neutron scattering. (author)

  12. Neutron Scattering from 36Ar and 4He Films

    DEFF Research Database (Denmark)

    Carneiro, K.

    1977-01-01

    Scale factors for neutron diffraction and neutron inelastic scattering are presented for common adsorbates, and the feasibility of experiments is discussed together with the information gained by each type of experiment. Diffraction, coherent inelastic scattering, and incoherent scattering are tr...

  13. Critical magnetic scattering of polarized neutrons on iron

    International Nuclear Information System (INIS)

    Hetzelt, M.

    1975-01-01

    A new spectrometer has been built and tested. The instrument was designed particularly for small angle scattering of polarized neutrons whereby the degree of polarisation of the scattered neutrons can be measured. The use of polarizing neutron pipes as polarizer and analyser allows the performence with a very broad wavelength spectrum (2 A 7 n/cm 2 sec) with good collimation (Δ theta approximately 0.2 0 ). The instrument is applied for the measurement of the critical magnetic scattering of polarized neutrons on an iron single crystal. For this purpose a special oven with an appropriate magnetic field configuration and a high precision in temperature has been constructed. The measured intensity distributions are in good agreement with other experiments. The critical exponent of the correlation range xi results in 0.65 +- 0.06. Angle and temperature dependence of the scattered neutron polarisation could be determined with good precision. The measurements are partly in extreme contradiction to the only hitherto existing experiment of this kind of Drabkin et al, and to assumptions in the theoretical evaluation. This contradiction is shown to be caused by the influence of multiple scattering. (orig./HPOE) [de

  14. New techniques in neutron scattering

    International Nuclear Information System (INIS)

    Hayter, J.B.

    1993-01-01

    New neutron sources being planned, such as the Advanced Neutron Source (ANS) or the European Spallation Source (ESS), will provide an order of magnitude flux increase over what is available today, but neutron scattering will still remain a signal-limited technique. At the same time, the development of new materials, such as polymer and ceramic composites or a variety of complex fluids, will increasingly require neutron-based research. This paper will discuss some of the new techniques which will allow us to make better use of the available neutrons, either through improved instrumentation or through sample manipulation. Discussion will center primarily on unpolarized neutron techniques since polarized neutrons will be the subject of the next paper. (author)

  15. Debye-Waller Factor in Neutron Scattering by Ferromagnetic Metals

    Science.gov (United States)

    Paradezhenko, G. V.; Melnikov, N. B.; Reser, B. I.

    2018-04-01

    We obtain an expression for the neutron scattering cross section in the case of an arbitrary interaction of the neutron with the crystal. We give a concise, simple derivation of the Debye-Waller factor as a function of the scattering vector and the temperature. For ferromagnetic metals above the Curie temperature, we estimate the Debye-Waller factor in the range of scattering vectors characteristic of polarized magnetic neutron scattering experiments. In the example of iron, we compare the results of harmonic and anharmonic approximations.

  16. Neutron total scattering cross sections of elemental antimony

    Energy Technology Data Exchange (ETDEWEB)

    Smith, A.B.; Guenther, P.T.; Whalen, J.F.

    1982-11-01

    Neutron total cross sections are measured from 0.8 to 4.5 MeV with broad resolutions. Differential-neutron-elastic-scattering cross sections are measured from 1.5 to 4.0 MeV at intervals of 50 to 200 keV and at scattering angles distributed between 20 and 160 degrees. Lumped-level neutron-inelastic-scattering cross sections are measured over the same angular and energy range. The exPerimental results are discussed in terms of an optical-statistical model and are compared with respective values given in ENDF/B-V.

  17. Neutron total scattering cross sections of elemental antimony

    International Nuclear Information System (INIS)

    Smith, A.B.; Guenther, P.T.; Whalen, J.F.

    1982-11-01

    Neutron total cross sections are measured from 0.8 to 4.5 MeV with broad resolutions. Differential-neutron-elastic-scattering cross sections are measured from 1.5 to 4.0 MeV at intervals of 50 to 200 keV and at scattering angles distributed between 20 and 160 degrees. Lumped-level neutron-inelastic-scattering cross sections are measured over the same angular and energy range. The exPerimental results are discussed in terms of an optical-statistical model and are compared with respective values given in ENDF/B-V

  18. Inelastic scattering of 275 keV neutrons by silver

    International Nuclear Information System (INIS)

    Litvinsky, L.L.; Zhigalov, Ya.A.; Krivenko, V.G.; Purtov, O.A.; Sabbagh, S.

    1997-01-01

    Neutron total, elastic and inelastic scattering cross-scattering of Ag at the E n = 275 KeV neutron energy were measured by using the filtered neutron beam of the WWR-M reactor in Kiev. The d-neutron strength function S n2 of Ag was determined from the analysis of all available data in the E n ≤ keV energy region on neutron inelastic scattering cross-sections with excitation of the first isomeric levels I π m = 7/2 + , E m ∼ 90 keV of 107,109 Ag: S n2 = (1.03 ± 0.19) · 10 -4 . (author). 10 refs, 3 figs

  19. Neutron Scattering and High Magnetic Fields

    Energy Technology Data Exchange (ETDEWEB)

    Winn, Barry L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Stone, Matthew B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2014-11-01

    The workshop “Neutron Scattering and High Magnetic Fields” was held September 4-5, 2014 at the Oak Ridge National Laboratory (ORNL). The workshop was held in response to a recent report by the National Research Council of the National Academy of Sciences entitled “High Magnetic Field Science and Its Application in the United States: Current Status and Future Directions.”1 This report highlights the fact that neutron scattering measurements carried out in high magnetic fields provide important opportunities for new science. The workshop explored the range of the scientific discoveries that could be enabled with neutron scattering measurements at high fields (25 Tesla or larger), the various technologies that might be utilized to build specialized instruments and sample environment equipment to enable this research at ORNL, and possible routes to funding and constructing these facilities and portable high field sample environments.

  20. Development of temperature related thermal neutron scattering database for MCNP

    International Nuclear Information System (INIS)

    Mei Longwei; Cai Xiangzhou; Jiang Dazhen; Chen Jingen; Guo Wei

    2013-01-01

    Based on ENDF/B-Ⅶ neutron library, the thermal neutron scattering library S(α, β) for molten salt reactor moderators was developed. The temperatures of this library were chose as the characteristic temperature of the molten salt reactor. The cross section of the thermal neutron scattering of ACE format was investigated, and this library was also validated by the benchmarks of ICSBEP. The uncertainties shown in the validation were in reasonable range when compared with the thermal neutron scattering library tmccs which included in the MCNP data library. It was proved that the thermal neutron scattering library processed in this study could be used in the molten salt reactor design. (authors)

  1. Interface detection by neutron scattering

    International Nuclear Information System (INIS)

    De Monchy, A.R.; Kok, C.A.; Dorrepaal, J.

    1979-01-01

    A method and apparatus for detecting an interface of materials having different hydrogen content present in a metal vessel or pipe eg. made of steel, are described. Steel walls of columns, reactors, pipelines etc can be monitored. It is very suitable for detection of liquid water or hydrocarbons present in gas pipelines and also for the detection of a liquid hydrocarbon in a vessel or column. A series of measurements of the hydrogen density of the contents of a vessel or pipe are made using at least one californium-252 neutron source located near the outer side of the pipe. Neutrons are emitted and are scattered by the contents of the pipe. At least one neutron detector is located near the outer side of the metal wall. The detectors have a higher sensitivity for scattered neutrons (from the light hydrogen nuclei present in water or hydrocarbons). A source of 0.1 - 1 micrograms produces enough neutrons for most technical applications so the handling is relatively safe although shielding is advocated. The detectors contain helium-3 at a pressure of about 10 bar. Current pulses from the detector are counted. (U.K.)

  2. Diffuse neutron scattering signatures of rough films

    International Nuclear Information System (INIS)

    Pynn, R.; Lujan, M. Jr.

    1992-01-01

    Patterns of diffuse neutron scattering from thin films are calculated from a perturbation expansion based on the distorted-wave Born approximation. Diffuse fringes can be categorised into three types: those that occur at constant values of the incident or scattered neutron wavevectors, and those for which the neutron wavevector transfer perpendicular to the film is constant. The variation of intensity along these fringes can be used to deduce the spectrum of surface roughness for the film and the degree of correlation between the film's rough surfaces

  3. Elements of slow-neutron scattering basics, techniques, and applications

    CERN Document Server

    Carpenter, J M

    2015-01-01

    Providing a comprehensive and up-to-date introduction to the theory and applications of slow-neutron scattering, this detailed book equips readers with the fundamental principles of neutron studies, including the background and evolving development of neutron sources, facility design, neutron scattering instrumentation and techniques, and applications in materials phenomena. Drawing on the authors' extensive experience in this field, this text explores the implications of slow-neutron research in greater depth and breadth than ever before in an accessible yet rigorous manner suitable for both students and researchers in the fields of physics, biology, and materials engineering. Through pedagogical examples and in-depth discussion, readers will be able to grasp the full scope of the field of neutron scattering, from theoretical background through to practical, scientific applications.

  4. Current status of neutron scattering in Thailand

    International Nuclear Information System (INIS)

    Kornduangkaeo, Areeratt; Pongkasem, Somchai; Putchar, Suriya; Ampornrat, Pantip; Kajornrith, Varavuth; Chamchang, Jipawat

    2006-01-01

    The current neutron powder diffractometer at the Thai Research Reactor-1/Modification 1 (TRR-1/M1) has been modified from the obsolete neutron diffractometer which had been used during 1968-1975. The upgraded diffractometer has medium resolution and is appropriate for studying samples with small unit cell dimensions and training university students in the field of neutron scattering. This paper describes the current activities of neutron scattering research in Thailand, the current status of a new research reactor project at Ongkarak for enlarging the perspectives of its utilization in the future as well as the organizational reformation of the Office of Atomic Energy for Peace (OAEP). (author)

  5. Inelastic neutron scattering and lattice dynamics of minerals

    Indian Academy of Sciences (India)

    We review current research on minerals using inelastic neutron scattering and lattice dynamics calculations. Inelastic neutron scattering studies in combination with first principles and atomistic calculations provide a detailed understanding of the phonon dispersion relations, density of states and their manifestations in ...

  6. Inelastic neutron scattering and lattice dynamics of minerals

    Indian Academy of Sciences (India)

    Abstract. We review current research on minerals using inelastic neutron scattering and lattice dynamics calculations. Inelastic neutron scattering studies in combination with first principles and atomistic calculations provide a detailed understanding of the phonon dispersion relations, density of states and their ...

  7. Advances in neutron scattering spectroscopy

    International Nuclear Information System (INIS)

    White, J.W.

    1977-01-01

    Some aspects of the application of neutron scattering to problems in polymer science, surface chemistry, and adsorption phenomena, as well as molecular biology, are reviewed. In all these areas, very significant work has been carried out using the medium flux reactors at Harwell, Juelich and Risoe, even without the use of advanced multidetector techniques or of a neutron cold source. A general tendency can also be distinguished in that, for each of these new fields, a distinct preference for colder neutrons rather than thermal neutron beams can be seen. (author)

  8. Neutron-neutron quasifree scattering in nd breakup at 10 MeV

    Science.gov (United States)

    Malone, R. C.; Crowe, B.; Crowell, A. S.; Cumberbatch, L. C.; Esterline, J. H.; Fallin, B. A.; Friesen, F. Q. L.; Han, Z.; Howell, C. R.; Markoff, D.; Ticehurst, D.; Tornow, W.; Witała, H.

    2016-03-01

    The neutron-deuteron (nd) breakup reaction provides a rich environment for testing theoretical models of the neutron-neutron (nn) interaction. Current theoretical predictions based on rigorous ab-initio calculations agree well with most experimental data for this system, but there remain a few notable discrepancies. The cross section for nn quasifree (QFS) scattering is one such anomaly. Two recent experiments reported cross sections for this particular nd breakup configuration that exceed theoretical calculations by almost 20% at incident neutron energies of 26 and 25 MeV [1, 2]. The theoretical values can be brought into agreement with these results by increasing the strength of the 1S0 nn potential matrix element by roughly 10%. However, this modification of the nn effective range parameter and/or the 1S0 scattering length causes substantial charge-symmetry breaking in the nucleon-nucleon force and suggests the possibility of a weakly bound di-neutron state [3]. We are conducting new measurements of the cross section for nn QFS in nd breakup. The measurements are performed at incident neutron beam energies below 20 MeV. The neutron beam is produced via the 2H(d, n)3He reaction. The target is a deuterated plastic cylinder. Our measurements utilize time-of-flight techniques with a pulsed neutron beam and detection of the two emitted neutrons in coincidence. A description of our initial measurements at 10 MeV for a single scattering angle will be presented along with preliminary results. Also, plans for measurements at other energies with broad angular coverage will be discussed.

  9. Quasielastic neutron scattering in biology: Theory and applications.

    Science.gov (United States)

    Vural, Derya; Hu, Xiaohu; Lindner, Benjamin; Jain, Nitin; Miao, Yinglong; Cheng, Xiaolin; Liu, Zhuo; Hong, Liang; Smith, Jeremy C

    2017-01-01

    Neutrons scatter quasielastically from stochastic, diffusive processes, such as overdamped vibrations, localized diffusion and transitions between energy minima. In biological systems, such as proteins and membranes, these relaxation processes are of considerable physical interest. We review here recent methodological advances and applications of quasielastic neutron scattering (QENS) in biology, concentrating on the role of molecular dynamics simulation in generating data with which neutron profiles can be unambiguously interpreted. We examine the use of massively-parallel computers in calculating scattering functions, and the application of Markov state modeling. The decomposition of MD-derived neutron dynamic susceptibilities is described, and the use of this in combination with NMR spectroscopy. We discuss dynamics at very long times, including approximations to the infinite time mean-square displacement and nonequilibrium aspects of single-protein dynamics. Finally, we examine how neutron scattering and MD can be combined to provide information on lipid nanodomains. This article is part of a Special Issue entitled "Science for Life" Guest Editor: Dr. Austen Angell, Dr. Salvatore Magazù and Dr. Federica Migliardo. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Neutron elastic scattering at very small angles

    CERN Multimedia

    2002-01-01

    This experiment will measure neutron-proton elastic scattering at very small angles and hence very small four-momentum transfer, |t|. The range of |t| depends on the incident neutron momentum of the events but the geometrical acceptance will cover the angular range 0.025 < $\\Theta_{lab}$ < 1.9 mrad. The higher figure could be extended to 8.4 mrad by changing the geometry of the experiment in a later phase. \\\\ \\\\ The neutron beam will be highly collimated and will be derived from a 400 GeV external proton beam of up to $4 \\times 10^{10}$ protons per pulse in the SPS North Area Hall 1. The hydrogen target will be gaseous, operating at 40 atm. pressure and acts as a multiwire proportional chamber to detect the recoil protons. The forward neutron will be detected and located by interaction in a neutron vertex detector and its energy measured by a conventional steel plate calorimeter. \\\\ \\\\ The experiment will cover the angular region of nucleon-nucleon scattering which is dominated by Coulomb scattering ...

  11. Proposal for the design of a small-angle neutron scattering facility at a pulsed neutron source

    International Nuclear Information System (INIS)

    Kley, W.

    1980-01-01

    The intensity-resolution-background considerations of an optimized small angle neutron scattering facility are reviewed for the special case of a pulsed neutron source. In the present proposal we conclude that for 'true elastic scattering experiments' filters can be used instead of expensive neutron guide tubes since low background conditions can be achieved by a combined action of filters as well as a proper time gating of the twodimensional detector. The impinging neutron beam is monochromatized by phasing a disk chopper to the neutron source pulses and in the scattered beam a second disk chopper is used to eliminate the inelastically scattered neutrons. Therefore, no time of fligh analysis is necessary for the scattered neutron intensity and true-elastic conditions are obtained by simply gating the two-dimensional detector. Considering a 4 m thick shield for the pulsed neutron source and choosing for optimum conditions a detector area element of (2.5 cm) 2 and a sample area of (1.25 cm) 2 , than for a minimum sample-detector-distance of 1.5 m, a maximum neutron source diameter of 6.67 cm is required in order to maintain always the optimum intensity- and resolution requirements

  12. New statistical model of inelastic fast neutron scattering

    International Nuclear Information System (INIS)

    Stancicj, V.

    1975-07-01

    A new statistical model for treating the fast neutron inelastic scattering has been proposed by using the general expressions of the double differential cross section in impuls approximation. The use of the Fermi-Dirac distribution of nucleons makes it possible to derive an analytical expression of the fast neutron inelastic scattering kernel including the angular momenta coupling. The obtained values of the inelastic fast neutron cross section calculated from the derived expression of the scattering kernel are in a good agreement with the experiments. A main advantage of the derived expressions is in their simplicity for the practical calculations

  13. Status of thermal neutron scattering data for graphite

    International Nuclear Information System (INIS)

    Mattes, M.; Keinert, J.

    2005-07-01

    At thermal neutron energies, the binding of the scattering nucleus in a solid, liquid, or gas affects the cross sections and the angular and energy distributions of the scattered neutrons. These effects are described in the thermal sub-library of evaluated files in File 7 of the ENDF-6 format. A re-evaluation of thermal neutron scattering data for carbon bound in graphite has been performed to investigate the impact of models (e.g., generalised frequency distributions) based on different experimental and theoretical data for the generation of scattering law data files S(α,β,T) and coherent elastic scattering data. Two phonon frequency distributions of graphite published in 2002 and 2004 were considered and the results compared with those based on the phonon spectra from Koppel et al. (published in 1968), on which the evaluations of ENDF/B-VI and JEFF-3.1 are based. The new frequency distributions were partly derived from ab initio simulations. Detailed comparisons with measurements of differential and integral neutron cross sections and other relevant data are reported. In addition, thermal MCNP data sets for use in the continuous Monte Carlo codes MCNP and MCNPX were generated from these evaluations for different temperatures. Calculated neutron spectra were found to be in good agreement with the measurements. (author)

  14. Neutron scattering and models: Silver

    International Nuclear Information System (INIS)

    Smith, A.B.

    1996-07-01

    Differential neutron elastic-scattering cross sections of elemental silver were measured from 1.5 → 10 MeV at ∼ 100 keV intervals up to 3 MeV, at ∼ 200 keV intervals from 3 → 4 MeV, and at ∼ 500 keV intervals above 4 MeV. At ≤ 4 MeV the angular range of the measurements was ∼ 20 0 → 160 0 with 10 measured values below 3 MeV and 20 from 3 → 4 MeV at each incident energy. Above 4 MeV ≥ 40 scattering angles were used distributed between ∼ 17 0 and 16 0 All of the measured elastic distributions included some contributions due to inelastic scattering. Below 4 MeV the measurements determined cross sections for ten inelastically-scattered neutron groups corresponding to observed excitations of 328 ± 13, 419 ± 50, 748 ± 25, 908 ± 26, 115 ± 38, 1286 ± 25, 1507 ± 20, 1632 ± 30, 1835 ± 20 and 1944 ± 26 keV. All of these inelastic groups probably were composites of contributions from the two isotopes 107 Ag and 109 Ag. The experimental results were interpreted in terms of the spherical optical model and of rotational and vibrational coupled-channels models, and physical implications are discussed. In particular, the neutron-scattering results are consistent with a ground-state rotational band with a quadrupole deformation Β 2 = 0.20 ± ∼ 10% for both of the naturally-occurring silver isotopes

  15. A Monte Carlo evaluation of analytical multiple scattering corrections for unpolarised neutron scattering and polarisation analysis data

    International Nuclear Information System (INIS)

    Mayers, J.; Cywinski, R.

    1985-03-01

    Some of the approximations commonly used for the analytical estimation of multiple scattering corrections to thermal neutron elastic scattering data from cylindrical and plane slab samples have been tested using a Monte Carlo program. It is shown that the approximations are accurate for a wide range of sample geometries and scattering cross-sections. Neutron polarisation analysis provides the most stringent test of multiple scattering calculations as multiply scattered neutrons may be redistributed not only geometrically but also between the spin flip and non spin flip scattering channels. A very simple analytical technique for correcting for multiple scattering in neutron polarisation analysis has been tested using the Monte Carlo program and has been shown to work remarkably well in most circumstances. (author)

  16. Proceedings of a workshop on methods for neutron scattering instrumentation design

    International Nuclear Information System (INIS)

    Hjelm, R.P.

    1997-09-01

    The future of neutron and x-ray scattering instrument development and international cooperation was the focus of the workshop. The international gathering of about 50 participants representing 15 national facilities, universities and corporations featured oral presentations, posters, discussions and demonstrations. Participants looked at a number of issues concerning neutron scattering instruments and the tools used in instrument design. Objectives included: (1) determining the needs of the neutron scattering community in instrument design computer code and information sharing to aid future instrument development, (2) providing for a means of training scientists in neutron scattering and neutron instrument techniques, and (3) facilitating the involvement of other scientists in determining the characteristics of new instruments that meet future scientific objectives, and (4) fostering international cooperation in meeting these needs. The scope of the meeting included: (1) a review of x-ray scattering instrument design tools, (2) a look at the present status of neutron scattering instrument design tools and models of neutron optical elements, and (3) discussions of the present and future needs of the neutron scattering community. Selected papers were abstracted separately for inclusion to the Energy Science and Technology Database

  17. Proceedings of a workshop on methods for neutron scattering instrumentation design

    Energy Technology Data Exchange (ETDEWEB)

    Hjelm, R.P. [ed.] [Los Alamos National Lab., NM (United States)

    1997-09-01

    The future of neutron and x-ray scattering instrument development and international cooperation was the focus of the workshop. The international gathering of about 50 participants representing 15 national facilities, universities and corporations featured oral presentations, posters, discussions and demonstrations. Participants looked at a number of issues concerning neutron scattering instruments and the tools used in instrument design. Objectives included: (1) determining the needs of the neutron scattering community in instrument design computer code and information sharing to aid future instrument development, (2) providing for a means of training scientists in neutron scattering and neutron instrument techniques, and (3) facilitating the involvement of other scientists in determining the characteristics of new instruments that meet future scientific objectives, and (4) fostering international cooperation in meeting these needs. The scope of the meeting included: (1) a review of x-ray scattering instrument design tools, (2) a look at the present status of neutron scattering instrument design tools and models of neutron optical elements, and (3) discussions of the present and future needs of the neutron scattering community. Selected papers were abstracted separately for inclusion to the Energy Science and Technology Database.

  18. Resonance effects in neutron scattering lengths

    Energy Technology Data Exchange (ETDEWEB)

    Lynn, J.E.

    1989-06-01

    The nature of neutron scattering lengths is described and the nuclear effects giving rise to their variation is discussed. Some examples of the shortcomings of the available nuclear data base, particularly for heavy nuclei, are given. Methods are presented for improving this data base, in particular for obtaining the energy variation of the complex coherent scattering length from long to sub-/angstrom/ wave lengths from the available sources of slow neutron cross section data. Examples of this information are given for several of the rare earth nuclides. Some examples of the effect of resonances in neutron reflection and diffraction are discussed. This report documents a seminar given at Argonne National Laboratory in March 1989. 18 refs., 18 figs.

  19. Resonance effects in neutron scattering lengths

    International Nuclear Information System (INIS)

    Lynn, J.E.

    1989-01-01

    The nature of neutron scattering lengths is described and the nuclear effects giving rise to their variation is discussed. Some examples of the shortcomings of the available nuclear data base, particularly for heavy nuclei, are given. Methods are presented for improving this data base, in particular for obtaining the energy variation of the complex coherent scattering length from long to sub-angstrom wave lengths from the available sources of slow neutron cross section data. Examples of this information are given for several of the rare earth nuclides. Some examples of the effect of resonances in neutron reflection and diffraction are discussed. This report documents a seminar given at Argonne National Laboratory in March 1989. 18 refs., 18 figs

  20. Neutron scattering research at JAERI reactors - past, present and future -

    International Nuclear Information System (INIS)

    Funahashi, Satoru; Morii, Yukio; Minakawa, Nobuaki

    1992-01-01

    It was in 1961 that the first neutron scattering experiment was performed in Japan at JRR-2. The start of JRR-3 in 1964 accelerated the neutron scattering activities in Japan. The research in this field in Japan grew up by using these two research reactors. Among them JRR-2 has played an important role because its neutron flux was about seven times higher than that of the old JRR-3. The completion of the new JRR-3M in 1990 made an epoch to the neutron scattering activities in Japan. The long-waited JRR-3M came up to the expectations of the scientists of Japan. It is a realization of the ideal reactor with tangential beam holes, cold source and neutron guides in a large guide hall. The flux at the neutron scattering instruments is about five times higher than that of JRR-2. Utilization of JRR-3M has just started. Twelve neutron scattering machines are running there. The number will increase up to close twenty in a couple of years. (author)

  1. Neutron detection efficiency determinations for the TUNL neutron-neutron and neutron-proton scattering-length measurements

    International Nuclear Information System (INIS)

    Trotter, D.E. Gonzalez; Meneses, F. Salinas; Tornow, W.; Crowell, A.S.; Howell, C.R.; Schmidt, D.; Walter, R.L.

    2009-01-01

    The methods employed and the results obtained from measurements and calculations of the detection efficiency for the neutron detectors used at Triangle Universities Nuclear Laboratory (TUNL) in the simultaneous determination of the 1 S 0 neutron-neutron and neutron-proton scattering lengths a nn and a np , respectively, are described. Typical values for the detector efficiency were 0.3. Very good agreement between the different experimental methods and between data and calculation has been obtained in the neutron energy range below E n =13MeV.

  2. Neutron spectral modulation as a new thermal neutron scattering technique. Pt. 1

    International Nuclear Information System (INIS)

    Ito, Y.; Nishi, M.; Motoya, K.

    1982-01-01

    A thermal neutron scattering technique is presented based on a new idea of labelling each neutron in its spectral position as well as in time through the scattering process. The method makes possible the simultaneous determination of both the accurate dispersion relation and its broadening by utilizing the resolution cancellation property of zero-crossing points in the cross-correlated time spectrum together with the Fourier transform scheme of the neutron spin echo without resorting to the echoing. The channel Fourier transform applied to the present method also makes possible the determination of the accurate direct energy scan profile of the scattering function with a rather broad incident neutron wavelength distribution. Therefore the intensity sacrifice for attaining high accurarcy is minimized. The technique is used with either a polarized or unpolarized beam at the sample position with no precautions against beam depolarization at the sample for the latter case. Relative time accurarcy of the order of 10 -3 to 10 -4 may be obtained for the general dispersion relation and for the quasi-elastic energy transfers using correspondingly the relative incident neutron wavelength spread of 10 to 1% around an incident neutron energy of a few meV. (orig.)

  3. Small angle neutron scattering

    International Nuclear Information System (INIS)

    Bernardini, G.; Cherubini, G.; Fioravanti, A.; Olivi, A.

    1976-09-01

    A method for the analysis of the data derived from neutron small angle scattering measurements has been accomplished in the case of homogeneous particles, starting from the basic theory without making any assumption on the form of particle size distribution function. The experimental scattering curves are interpreted with the aid the computer by means of a proper routine. The parameters obtained are compared with the corresponding ones derived from observations at the transmission electron microscope

  4. Early history of neutron scattering at Oak Ridge

    International Nuclear Information System (INIS)

    Wilkinson, M.K.

    1985-07-01

    Most of the early development of neutron scattering techniques utilizing reactor neutrons occurred at the Oak Ridge National Laboratory during the years immediately following World War II. C.G. Shull, E.O. Wollan, and their associates systematically established neutron diffraction as a quantitative research tool and then applied this technique to important problems in nuclear physics, chemical crystallography, and magnetism. This article briefly summarizes the very important research at ORNL during this period, which laid the foundation for the establishment of neutron scattering programs throughout the world. 47 refs., 10 figs

  5. Neutron scattering on equilibrium and nonequilibrium phonons, excitons and polaritons

    International Nuclear Information System (INIS)

    Broude, V.L.; Sheka, E.F.

    1978-01-01

    A number of problems of solid-state physics representing interest for neutron spectroscopy of future is considered. The development of the neutron inelastic scattering spectroscopy (neutron spectroscopy of equilibrium phonons) is discussed with application to nuclear dynamics of crystals in the thermodynamic equilibrium. The results of high-flux neutron source experiments on molecular crystals are presented. The advantages of neutron inelastic scattering over optical spectroscopy are discussed. The spectroscopy of quasi-equilibrium and non-equilibrium quasi-particles is discussed. In particular, the neutron scattering on polaritons, excitons in thermal equilibrium and production of light-excitons are considered. The problem of the possibility of such experiments is elucidated

  6. The basic physics of neutron scattering experiments

    International Nuclear Information System (INIS)

    Mezei, F.

    1999-01-01

    The basic physical principles behind the well-established but also developing practice of neutron scattering experiments are presented. A few examples are given either to illustrate the physical principles or to give an idea of the variety, importance or magnitude of various phenomena. The evolution of neutron scattering experimental techniques is investigated from a special aspect: the increasing capability of taking into account more and more important and sometimes decisive finer details by using more and more realistic mathematical models of the evolution of the neutrons from birth do death, eventually passing by the sample and being scattered more than one times. Working with such numerical 'virtual instruments' one will have to go far beyond notions like resolution function, convolution etc, and actually eliminate a large number of approximations currently in use. (K.A.)

  7. Neutron detection efficiency determinations for the TUNL neutron-neutron and neutron-proton scattering-length measurements

    Energy Technology Data Exchange (ETDEWEB)

    Trotter, D.E. Gonzalez [Department of Physics, Duke University and Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States)], E-mail: crowell@tunl.duke.edu; Meneses, F. Salinas [Department of Physics, Duke University and Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States); Tornow, W. [Department of Physics, Duke University and Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States)], E-mail: tornow@tunl.duke.edu; Crowell, A.S.; Howell, C.R. [Department of Physics, Duke University and Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States); Schmidt, D. [Physikalisch-Technische Bundesanstalt, D-38116, Braunschweig (Germany); Walter, R.L. [Department of Physics, Duke University and Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States)

    2009-02-11

    The methods employed and the results obtained from measurements and calculations of the detection efficiency for the neutron detectors used at Triangle Universities Nuclear Laboratory (TUNL) in the simultaneous determination of the {sup 1}S{sub 0} neutron-neutron and neutron-proton scattering lengths a{sub nn} and a{sub np}, respectively, are described. Typical values for the detector efficiency were 0.3. Very good agreement between the different experimental methods and between data and calculation has been obtained in the neutron energy range below E{sub n}=13MeV.

  8. Small angle neutron scattering

    Directory of Open Access Journals (Sweden)

    Cousin Fabrice

    2015-01-01

    Full Text Available Small Angle Neutron Scattering (SANS is a technique that enables to probe the 3-D structure of materials on a typical size range lying from ∼ 1 nm up to ∼ a few 100 nm, the obtained information being statistically averaged on a sample whose volume is ∼ 1 cm3. This very rich technique enables to make a full structural characterization of a given object of nanometric dimensions (radius of gyration, shape, volume or mass, fractal dimension, specific area… through the determination of the form factor as well as the determination of the way objects are organized within in a continuous media, and therefore to describe interactions between them, through the determination of the structure factor. The specific properties of neutrons (possibility of tuning the scattering intensity by using the isotopic substitution, sensitivity to magnetism, negligible absorption, low energy of the incident neutrons make it particularly interesting in the fields of soft matter, biophysics, magnetic materials and metallurgy. In particular, the contrast variation methods allow to extract some informations that cannot be obtained by any other experimental techniques. This course is divided in two parts. The first one is devoted to the description of the principle of SANS: basics (formalism, coherent scattering/incoherent scattering, notion of elementary scatterer, form factor analysis (I(q→0, Guinier regime, intermediate regime, Porod regime, polydisperse system, structure factor analysis (2nd Virial coefficient, integral equations, characterization of aggregates, and contrast variation methods (how to create contrast in an homogeneous system, matching in ternary systems, extrapolation to zero concentration, Zero Averaged Contrast. It is illustrated by some representative examples. The second one describes the experimental aspects of SANS to guide user in its future experiments: description of SANS spectrometer, resolution of the spectrometer, optimization of

  9. Methods of contrast variation by nuclear polarisation in small-angle neutron scattering: Observation of domains of nuclear polarisation by neutron scattering

    International Nuclear Information System (INIS)

    Leymarie, E.

    2002-11-01

    In this thesis we study the theoretical and experimental aspects of Contrast Variation by Nuclear Polarization (CVNP) applied to small-angle neutron scattering. The basics of neutron scattering theory is developed by highlighting the origin of the CVNP method: the strong spin dependence of thermal neutron scattering, especially on protons. We also present the principles of NMR with a special attention on the method of dynamic nuclear polarization by the solid effect which makes it possible to control the proton polarization and therefore the contrast for neutron scattering. We present a theoretical study of the CVNP method called static which supposes that the nuclear polarization is homogeneous in the sample and constant during the experiment. We show that it allows one to obtain partial structure functions of systems with multiple components, by carrying out several acquisitions with different polarizations on a single sample. For this purpose, we tested a simple device to stabilize the nuclear polarization. We describe finally a new application of the CVNP method called dynamic. In a solution of deuterated glycerol-water containing a small concentration of paramagnetic centres, we showed the existence of domains of polarized protons at the onset of dynamic polarization. This reinforces considerably the coherent scattering of paramagnetic centres. We describe the theoretical reasons explaining the appearance of these domains of polarization, as well as the various techniques used to observe them by neutron scattering. (author)

  10. Current status and future development of neutron scattering in CIAE

    International Nuclear Information System (INIS)

    Chen, D.F.; Gou, C.; Ye, C.T.; Guo, L.P.; Sun, K.

    2003-01-01

    Currently, the 15 MW Heavy Water Research Reactor (HWRR) at China Institute of Atomic Energy (CIAE) in Beijing is the only neutron source available for neutron scattering experiments in China. A 60 MW tank-in-pool inverse neutron trap-type research reactor, China Advanced Research Reactor (CARR), now is being built at CIAE to meet the increasing demand of neutron scattering research in China. According to design, the maximum unperturbed thermal neutron flux would be expected to be 8x10 14 n/cm 2 .s in the reflector region. Seven out of nine tangential horizontal beam tubes will be dedicated for neutron scattering experiments. A cold source, a hot source and a 30x60 m 2 guide tube hall will also be constructed. In this paper, a brief introduction of HWRR, the existing neutron scattering facilities and research activities at HWRR, CARR, and the facilities to be built at CARR are presented. (author)

  11. Advantages of neutron scattering for biological structure analysis

    International Nuclear Information System (INIS)

    Schoenborn, B.P.

    1975-01-01

    The advantages and disadvantages of neutron scattering for protein crystallography, scattering from oriented systems, and solution scattering are summarized. Techniques for minimizing the disadvantages are indicated

  12. Neutron Scattering in Biology Techniques and Applications

    CERN Document Server

    Fitter, Jörg; Katsaras, John

    2006-01-01

    The advent of new neutron facilities and the improvement of existing sources and instruments world wide supply the biological community with many new opportunities in the areas of structural biology and biological physics. The present volume offers a clear description of the various neutron-scattering techniques currently being used to answer biologically relevant questions. Their utility is illustrated through examples by some of the leading researchers in the field of neutron scattering. This volume will be a reference for researchers and a step-by-step guide for young scientists entering the field and the advanced graduate student.

  13. 2010 American Conference on Neutron Scattering (ACNS 2010)

    Energy Technology Data Exchange (ETDEWEB)

    Billinge, Simon

    2011-06-17

    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

  14. Low energy neutron scattering for energy dependent cross sections. General considerations

    Energy Technology Data Exchange (ETDEWEB)

    Rothenstein, W; Dagan, R [Technion-Israel Inst. of Tech., Haifa (Israel). Dept. of Mechanical Engineering

    1996-12-01

    We consider in this paper some aspects related to neutron scattering at low energies by nuclei which are subject to thermal agitation. The scattering is determined by a temperature dependent joint scattering kernel, or the corresponding joint probability density, which is a function of two variables, the neutron energy after scattering, and the cosine of the angle of scattering, for a specified energy and direction of motion of the neutron, before the interaction takes place. This joint probability density is easy to calculate, when the nucleus which causes the scattering of the neutron is at rest. It can be expressed by a delta function, since there is a one to one correspondence between the neutron energy change, and the cosine of the scattering angle. If the thermal motion of the target nucleus is taken into account, the calculation is rather more complicated. The delta function relation between the cosine of the angle of scattering and the neutron energy change is now averaged over the spectrum of velocities of the target nucleus, and becomes a joint kernel depending on both these variables. This function has a simple form, if the target nucleus behaves as an ideal gas, which has a scattering cross section independent of energy. An energy dependent scattering cross section complicates the treatment further. An analytic expression is no longer obtained for the ideal gas temperature dependent joint scattering kernel as a function of the neutron energy after the interaction and the cosine of the scattering angle. Instead the kernel is expressed by an inverse Fourier Transform of a complex integrand, which is averaged over the velocity spectrum of the target nucleus. (Abstract Truncated)

  15. Small angle neutron scattering and small angle X-ray scattering ...

    Indian Academy of Sciences (India)

    Abstract. The morphology of carbon nanofoam samples comprising platinum nanopar- ticles dispersed in the matrix was characterized by small angle neutron scattering (SANS) and small angle X-ray scattering (SAXS) techniques. Results show that the structure of pores of carbon matrix exhibits a mass (pore) fractal nature ...

  16. Inelastic neutron scattering for materials science and engineering

    International Nuclear Information System (INIS)

    Shapiro, S.M.

    1995-01-01

    The neutron is the ideal probe for studying the positions and motions of atoms in condensed matter. The main advantage of the neutron in inelastic scattering results from its heavy mass when compared to other particles which are used to probe materials such as the photon (light, x-rays, or γ-rays) or the electron. The author discusses the application of neutron scattering to study a number of different materials related problems, including, hard magnets, shape memory effects, and hydrogen distribution in metals

  17. Fragility of complexity biophysical systems by neutron scattering

    Energy Technology Data Exchange (ETDEWEB)

    Magazu, Salvatore [Dipartimento di Fisica, Universita di Messina, P.O. Box 55, I-98166 Messina (Italy)]. E-mail: smagazu@unime.it; Migliardo, Federica [Dipartimento di Fisica, Universita di Messina, P.O. Box 55, I-98166 Messina (Italy); Bellocco, Ersilia [Dipartimento di Chimica Organica e Biologica, Universita di Messina, I-98166 Messina (Italy); Lagana, Giuseppina [Dipartimento di Chimica Organica e Biologica, Universita di Messina, I-98166 Messina (Italy); Mondelli, Claudia [CNR-INFM OGG and CRS-SOFT, c/o ILL, 6 Jules Horowitz, BP 156, 38042 Grenoble Cedex 9 (France)

    2006-11-15

    Neutron scattering is an exceptional tool to investigate structural and dynamical properties of systems of biophysical interest, such as proteins, enzymes, lipids and sugars. Moreover, elastic neutron scattering enhances the investigation of atomic motions in hydrated proteins in a wide temperature range and on the picosecond timescale. Homologous disaccharides, such as trehalose, maltose and sucrose, are cryptobiotic substances, since they allow to many organisms to undergo in a 'suspended life' state, known as cryptobiosis in extreme environmental conditions. The present paper is aimed to discuss the fragility degree of disaccharides, as evaluated of the temperature dependence of the mean square displacement by elastic neutron scattering, in order to link this feature with their bioprotective functions.

  18. Neutron scattering from 12C in the few-MeV region

    International Nuclear Information System (INIS)

    Smith, A.; Holt, R.; Whalen, J.

    1978-09-01

    Neutron total cross sections of natural carbon are deduced from the observed transmission of approximately monoenergetic neutrons through carbon samples of varying thickness. The measurements extend from approximately equal to 0.1 to 4.5 MeV with resolutions of approximately equal to 2 to 100 keV. Neutron differential-elastic-scattering cross sections of natural carbon are measured from 1.5 to 4.0 MeV at incident-neutron energy intervals of approximately less than 100 keV, over an angular range of approximately equal to 20 to 160 0 and with energy resolutions of 20 to 50 keV. The experimental results are interpreted in terms of a multilevel R-function analysis. Results are compared with the large body of measured and evaluated neutron total and scattering cross sections and scattered neutron polarizations reported in the literature. It is suggested that the observed neutron total and scattering cross sections of carbon are physically consistent and suitable for use as a reference standard in experimental studies of neutron processes. The R-function description should provide a convenient description of neutron total and scattering cross sections of carbon as a function of both angle and energy. 88 references

  19. Magnetic anisotropy and neutron scattering studies of some rare earth metals

    International Nuclear Information System (INIS)

    Day, R.

    1978-08-01

    The thesis is concerned with magnetic anisotropy of dysprosium and alloys of gadolinium: yttrium, and also neutron scattering studies of dysprosium. The experiments are discussed under the topic headings: magnetic anisotropy, rare earths, torque measurements, elastic neutron scattering, inelastic neutron scattering, dysprosium measurements, and results for the gadolinium: yttrium alloys. (U.K.)

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

    OpenAIRE

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

    1999-01-01

    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 agr...

  1. Development of neutron diffuse scattering analysis code by thin film and multilayer film

    International Nuclear Information System (INIS)

    Soyama, Kazuhiko

    2004-01-01

    To research surface structure of thin film and multilayer film by neutron, a neutron diffuse scattering analysis code using DWBA (Distorted-Wave Bron Approximation) principle was developed. Subjects using this code contain the surface and interface properties of solid/solid, solid/liquid, liquid/liquid and gas/liquid, and metal, magnetism and polymer thin film and biomembran. The roughness of surface and interface of substance shows fractal self-similarity and its analytical model is based on DWBA theory by Sinha. The surface and interface properties by diffuse scattering are investigated on the basis of the theoretical model. The calculation values are proved to be agreed with the experimental values. On neutron diffuse scattering by thin film, roughness of surface of thin film, correlation function, neutron propagation by thin film, diffuse scattering by DWBA theory, measurement model, SDIFFF (neutron diffuse scattering analysis program by thin film) and simulation results are explained. On neutron diffuse scattering by multilayer film, roughness of multilayer film, principle of diffuse scattering, measurement method and simulation examples by MDIFF (neutron diffuse scattering analysis program by multilayer film) are explained. (S.Y.)To research surface structure of thin film and multilayer film by neutron, a neutron diffuse scattering analysis code using DWBA (Distorted-Wave Bron Approximation) principle was developed. Subjects using this code contain the surface and interface properties of solid/solid, solid/liquid, liquid/liquid and gas/liquid, and metal, magnetism and polymer thin film and biomembran. The roughness of surface and interface of substance shows fractal self-similarity and its analytical model is based on DWBA theory by Sinha. The surface and interface properties by diffuse scattering are investigated on the basis of the theoretical model. The calculation values are proved to be agreed with the experimental values. On neutron diffuse scattering

  2. Experimental studies of the critical scattering of neutrons for large scattering vectors

    International Nuclear Information System (INIS)

    Ciszewski, R.

    1972-01-01

    The most recent results concerned with the critical scattering of neutrons are reviewed. The emphasis is on the so-called thermal shift, that is the shift of the main maximum in the intensity of critically scattered neutrons with temperature changes. Four theories of this phenomenon are described and their shortcomings are shown. It has been concluded that the situation is involved at present and needs further theoretical and experimental study. (S.B.)

  3. Monte Carlo simulation of fast neutron scattering experiments including DD-breakup neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, D.; Siebert, B.R.L.

    1993-06-01

    The computational simulation of the deuteron breakup in a scattering experiment has been investigated. Experimental breakup spectra measured at 16 deuteron energies and at 7 angles for each energy served as the data base. Analysis of these input data and of the conditions of the scattering experiment made it possible to reduce the input data. The use of one weighted breakup spectrum is sufficient to simulate the scattering spectra at one incident neutron energy. A number of tests were carried out to prove the validity of this result. The simulation of neutron scattering on carbon, including the breakup, was compared with measured spectra. Differences between calculated and measured spectra were for the most part within the experimental uncertainties. Certain significant deviations can be attributed to erroneous scattering cross sections taken from an evaluation and used in the simulation. Scattering on higher-lying states in [sup 12]C can be analyzed by subtracting the simulated breakup-scattering from the experimental spectra. (orig.)

  4. Monte Carlo simulation of fast neutron scattering experiments including DD-breakup neutrons

    International Nuclear Information System (INIS)

    Schmidt, D.; Siebert, B.R.L.

    1993-06-01

    The computational simulation of the deuteron breakup in a scattering experiment has been investigated. Experimental breakup spectra measured at 16 deuteron energies and at 7 angles for each energy served as the data base. Analysis of these input data and of the conditions of the scattering experiment made it possible to reduce the input data. The use of one weighted breakup spectrum is sufficient to simulate the scattering spectra at one incident neutron energy. A number of tests were carried out to prove the validity of this result. The simulation of neutron scattering on carbon, including the breakup, was compared with measured spectra. Differences between calculated and measured spectra were for the most part within the experimental uncertainties. Certain significant deviations can be attributed to erroneous scattering cross sections taken from an evaluation and used in the simulation. Scattering on higher-lying states in 12 C can be analyzed by subtracting the simulated breakup-scattering from the experimental spectra. (orig.)

  5. Diffuse scattering of neutrons and X-rays

    International Nuclear Information System (INIS)

    Novion, C.H. de

    1978-01-01

    Diffuse scattering is used to study defect concentrations of about 10 -4 in the case of X-rays and 10 -3 in the case of neutrons. The foundations of diffuse scattering formalism are given, some experimental devices described and a few applications discussed: study by diffraction on powders of defects in CeOsub(2-x); short-range order study by X-rays on Cusub(0.75) Ausub(0.25); short-range order study by neutrons on Cusub(0.435)Nisub(0.565); short-range order study by electrons TiOx; study of irradiation-induced self-interstitials in Al; study of holes created by neutrons in Al [fr

  6. Neutron Scattering studies of magnetic molecular magnets

    International Nuclear Information System (INIS)

    Chaboussant, G.

    2009-01-01

    This work deals with inelastic neutron scattering studies of magnetic molecular magnets and focuses on their magnetic properties at low temperature and low energies. Several molecular magnets (Mn 12 , V 15 , Ni 12 , Mn 4 , etc.) are reviewed. Inelastic neutron scattering is shown to be a perfectly suited spectroscopy tool to -a) probe magnetic energy levels in such systems and -b) provide key information to understand the quantum tunnel effect of the magnetization in molecular spin clusters. (author)

  7. Neutron scattering facilities at China Institute of Atomic Energy. Present and future situations

    International Nuclear Information System (INIS)

    Ye, C.T.; Gou, C.; Yang, T.H.

    2001-01-01

    The 15 MW Heavy Water Research Reactor (HWRR) at CIAE in Beijing is the only neutron source available for neutron scattering experiments in China at present. So far totally 5 neutron scattering spectrometers are installed at 4 beam tubes. A 60 MW new research reactor, China Advanced Research Reactor (CARR), now is being built at CIAE to meet the increasing demand of neutron scattering research in China. A brief description of HWRR, the presently existing neutron scattering equipments at HWRP, CARR, and the neutron scattering facilities to be installed at CARR are presented. (J.P.N.)

  8. Inelastic scattering of neutrons by laser photons and excitons in crystals

    International Nuclear Information System (INIS)

    Agranovich, V.M.; Lalov, I.J.

    1975-01-01

    The cross section for the neutron scattering by photons sharply increases in crystals. In view of the fact that a propagating photon in a crystal (polariton), being the superposition of transverse photons and Coulomb excitations (optical phonons, excitons, etc.), involves in the motion also a nucleus subsystem, the cross section for the neutron scattering on the photon turns out to be proportional to the cross section for neutron scattering on nuclei and to the strength function of phonons at the polariton frequency. Numerical estimates for the cross section of the noncoherent photon absorption by a neutron in the case of a LiH crystal in the presence of an intense, electromagnetic radiation point to the possibility of an action of neutron fluxes by laser radiation. A similar effect of involvement (superposition) also takes place for excitons. This fact can be used for calculations of the cross section for neutron inelastic scattering by excitons, which is proportional to the scattering of neutron on nuclei cross section. The paper also discussed the effect of laser radiation of neutron-induced nuclear reaction (radiative capture and threshold reactions)

  9. Lectures on magnetism and neutron scattering

    International Nuclear Information System (INIS)

    Gunn, J.M.F.

    1983-12-01

    The paper contains six lectures given to the Neutron Division of the Rutherford Appleton laboratory in 1983. The aim was to explain fundamental physics of neutron scattering and basic magnetism to the non-specialist scientist. The text includes: origin of neutron's magnetic moment and spin-dependent interactions with electrons and nuclei, why are solids magnetic, magnetic anistropy and domain structure, phenomenological spin waves, magnetic phase transitions and electronic excitations in magnets. (U.K.)

  10. LANSCE '90: the Manuel Lujan Jr. Neutron Scattering Center

    International Nuclear Information System (INIS)

    Pynn, Roger

    1991-01-01

    This paper describes progress that has been made at the Manuel Lujan Jr. Neutron Scattering Center (LANSCE) during the past two years. Presently, LANSCE provides a higher peak neutron flux than any other pulsed spallation neutron source. There are seven spectrometers for neutron scattering experiments that are operated for a national user program sponsored by the U.S. Department of Energy. Two more spectrometers are under construction. Plans have been made to raise the number of beam holes available for instrumentation and to improve the efficiency of the target/moderator system. (author)

  11. LANSCE '90: The Manuel Lujan Jr. Neutron Scattering Center

    International Nuclear Information System (INIS)

    Pynn, R.

    1990-01-01

    This paper describes progress that has been made at the Manuel Lujan Jr. Neutron Scattering Center (LANSCE) during the past two years. Presently, LANSCE provides a higher peak neutron flux than any other pulsed spallation neutron source. There are seven spectrometers for neutron scattering experiments that are operated for a national user program sponsored by the US Department of Energy. Two more spectrometers are under construction. Plans have been made to raise the number of beam holes available for instrumentation and to improve the efficiency of the target/moderator system. 9 refs., 4 figs

  12. Steel research using neutron beam techniques. In-situ neutron diffraction, small-angle neutron scattering and residual stress analysis

    International Nuclear Information System (INIS)

    Sueyoshi, Hitoshi; Ishikawa, Nobuyuki; Yamada, Katsumi; Sato, Kaoru; Nakagaito, Tatsuya; Matsuda, Hiroshi; Arakaki, Yu; Tomota, Yo

    2014-01-01

    Recently, the neutron beam techniques have been applied for steel researches and industrial applications. In particular, the neutron diffraction is a powerful non-destructive method that can analyze phase transformation and residual stress inside the steel. The small-angle neutron scattering is also an effective method for the quantitative evaluation of microstructures inside the steel. In this study, in-situ neutron diffraction measurements during tensile test and heat treatment were conducted in order to investigate the deformation and transformation behaviors of TRIP steels. The small-angle neutron scattering measurements of TRIP steels were also conducted. Then, the neutron diffraction analysis was conducted on the high strength steel weld joint in order to investigate the effect of the residual stress distribution on the weld cracking. (author)

  13. Magnetic particles studied with neutron depolarization and small-angle neutron scattering

    International Nuclear Information System (INIS)

    Rosman, R.

    1991-01-01

    Materials containing magnetic single-domain particles, referred to as 'particulate media', have been studied using neutron depolarization (ND) and small-angle neutron scattering (SANS). In a ND experiment the polarization vector of a polarized neutron beam is analyzed after transmission through a magnetic medium. Such an analysis in general yields the correlation length of variations in magnetic induction along the neutron path (denoted 'magnetic correlation length'), mean orientation of these variations and mean magnetic induction. In a SANS experiment, information about nuclear and magnetic inhomogeneities in the medium is derived from the broadening of a generally unpolarized neutron beam due to scattering by these inhomogeneities. Spatial and magnetic microstructure of a variety of particulate media have been studied using ND and/or SANS, by determination of the magnetic or nuclear correlation length in these media in various magnetic states. This thesis deals with the ND theory and its application to particulate media. ND and SANS experiments on a variety of particulate media are discussed. (author). 178 refs., 97 figs., 8 tabs

  14. On the theory of ultracold neutrons scattering by Davydov solitons

    International Nuclear Information System (INIS)

    Brizhik, L.S.

    1984-01-01

    Elastic coherent scattering of ultracold neutrons by Davydov solitons in one-dimensional periodic molecular chains without account of thermal oscillations of chain atoms is studied. It is shown that the expression for the differential cross section of the elastic neutron scattering by Davydov soliton breaks down into two components. One of them corresponds to scattering by a resting soliton, the other is proportional to the soliton velocity and has a sharp maximum in the direction of mirror reflection of neutrons from the chain

  15. US-Japan Cooperative Program on neutron scattering

    International Nuclear Information System (INIS)

    Wilkinson, M.K.; Blume, M.; Stevens, D.K.; Iizumi, M.; Yamada, Y.

    1987-01-01

    The US-Japan Cooperative Program on Neutron Scattering was implemented through arrangements by the United States Department of Energy with the Science and Technology Agency (STA) and the Ministry of Science, Education, and Culture (Monbusho) of Japan. It involves research collaboration in neutron scattering by Japanese scientists with scientists at Oak Ridge National Laboratory (ORNL) and Brookhaven National Laboratory (BNL) and the construction of new neutron scattering equipment at both laboratories with funds provided by the Japanese government. The United States provides neutrons in exchange for the new equipment, and other costs of the program are equally shared by the two countries. The assignments of Japanese scientists to ORNL and BNL vary in length, but they correspond to about two person years annually at each laboratory. An equal number of US scientists also participate in the research program. The main research collaboration is centered around the new equipment provided by the Japanese, but other facilities are utilized when they are needed. The new equipment includes a new type of wide-angle diffractometer and equipment for maintaining extreme sample environments at ORNL and a sophisticated polarized-beam triple-axis spectrometer at BNL. 13 refs., 3 figs

  16. Progress in small angle neutron scattering activities in Malaysia

    International Nuclear Information System (INIS)

    Mohamed, Abudl Aziz Bin

    2000-01-01

    Research activities by use of small angle neutron scattering in Malaysia are briefly reported. Scattered neutron data are displayed in two or three-dimensional isometric view by the data acquisition system. Visual Basic is utilized for data acquisition and MathCad for data processing and analyses. (Y. Kazumata)

  17. Progress in small angle neutron scattering activities in Malaysia

    Energy Technology Data Exchange (ETDEWEB)

    Mohamed, Abudl Aziz Bin [Industrial Technology Division, Malaysian Institute for Nuclear Technology Research (MINT) (Indonesia)

    2000-10-01

    Research activities by use of small angle neutron scattering in Malaysia are briefly reported. Scattered neutron data are displayed in two or three-dimensional isometric view by the data acquisition system. Visual Basic is utilized for data acquisition and MathCad for data processing and analyses. (Y. Kazumata)

  18. Bibliography for thermal neutron scattering

    International Nuclear Information System (INIS)

    Sakamoto, M.; Chihara, J.; Nakahara, Y.; Kadotani, H.; Sekiya, T.

    1976-12-01

    It contains bibliographical references to measurements, calculations, reviews and basic studies on thermal neutron scatterings and dynamical properties of condensed matter. About 2,700 documents up to the end of 1975 are covered. (auth.)

  19. The polarization of MeV neutrons elastically scattered from 4He

    International Nuclear Information System (INIS)

    Bond, J.E.; Firk, F.W.K.

    1976-01-01

    The analyzing power of 4 He for neutron elastic scattering has been measured at four angles between 20 0 and 80 0 (lab) throughout the energy range 1.5-6.0 MeV using a double-scattering method. The intense flux of polarized neutrons was generated via the reactions Pb(γ, n)→ 12 C(n, n(pol.) 12 C, and the magnitude of the polarization of the neutron beam measured absolutely in a separate double-scattering experiment. Neutron energies were determined with a nanosecond time-of-flight spectrometer, and the generalized neutron spin-precession method was used to minimize systematic uncertainties. (Auth.)

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

    International Nuclear Information System (INIS)

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

    1981-01-01

    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

  1. Neutron scattering in soft matter physics and chemistry

    International Nuclear Information System (INIS)

    White, J.W.

    1999-01-01

    Recent experiments area of soft matter science show that self assembly on the micron scale as well as the nanometer scale can be directed chemically. This lecture illustrates how such processes can be studied using the contrast variation available in neutron scattering through isotopic replacement and the techniques of neutron small angle scattering and neutron reflectivity. Related dynamical information at nanometer resolution and on time scales between a nanosecond and a few tenths of a picosecond will become accessible with brighter neutron sources. The examples presented concern the template induced crystallisation of zeolites, the liquid crystal template induced synthesis of mesoporous materials and the structure of thin films at the air water interface. (J.P.N.)

  2. Material science and neutron scattering

    International Nuclear Information System (INIS)

    1983-01-01

    Neutron scattering experiments complete and extend the condensed matter studies made with X and gamma rays. Then story show a permanent evolution of the instrumentation, methods and experimental techniques to improve the result quality. This is more especially important as neutron sources are weaker than photon and electron sources. Progress in this research domain is due, in most part, to discovery and development of materials for the different measurement device components [fr

  3. Inelastic neutron scattering from glass formers

    International Nuclear Information System (INIS)

    Buchenau, U.

    1997-01-01

    Neutron spectra below and above the glass transition temperature show a pronounced difference between strong and fragile glass formers in Angell's fragility scheme. The strong anharmonic increase of the inelastic scattering with increasing temperature in fragile substances is absent in the strongest glass former SiO 2 . That difference is reflected in the temperature dependence of Brillouin sound velocities above the glass transition. Coherent inelastic neutron scattering data indicate a mixture of sound waves and local modes at the low frequency boson peak. A relation between the fragility and the temperature dependence of the transverse hypersound velocity at the glass temperature is derived. (author)

  4. Inelastic magnetic scattering of polarized neutrons by a superconducting ring

    International Nuclear Information System (INIS)

    Agafonov, A. I.

    2011-01-01

    The inelastic scattering of cold neutrons by a ring leads to quantum jumps of a superconducting current which correspond to a decrease in the fluxoid quantum number by one or several units while the change in the ring energy is transferred to the kinetic energy of the scattered neutron. The scattering cross sections of transversely polarized neutrons have been calculated for a thin type-II superconductor ring, the thickness of which is smaller than the field penetration depth but larger than the electron mean free path.

  5. Analytic scattering kernels for neutron thermalization studies

    International Nuclear Information System (INIS)

    Sears, V.F.

    1990-01-01

    Current plans call for the inclusion of a liquid hydrogen or deuterium cold source in the NRU replacement vessel. This report is part of an ongoing study of neutron thermalization in such a cold source. Here, we develop a simple analytical model for the scattering kernel of monatomic and diatomic liquids. We also present the results of extensive numerical calculations based on this model for liquid hydrogen, liquid deuterium, and mixtures of the two. These calculations demonstrate the dependence of the scattering kernel on the incident and scattered-neutron energies, the behavior near rotational thresholds, the dependence on the centre-of-mass pair correlations, the dependence on the ortho concentration, and the dependence on the deuterium concentration in H 2 /D 2 mixtures. The total scattering cross sections are also calculated and compared with available experimental results

  6. Thermal Neutron Capture and Thermal Neutron Burn-up of K isomeric state of 177mLu: a way to the Neutron Super-Elastic Scattering cross section

    International Nuclear Information System (INIS)

    Roig, O.; Belier, G.; Meot, V.; Daugas, J.-M.; Romain, P.; Aupiais, J.; Jutier, Ch.; Le Petit, G.; Letourneau, A.; Marie, F.; Veyssiere, Ch.

    2006-01-01

    Thermal neutron radiative capture and burn-up measurements of the K isomeric state in 177Lu form part of an original method to indirectly obtain the neutron super-elastic scattering cross section at thermal energy. Neutron super-elastic scattering, also called neutron inelastic acceleration, occurs during the neutron collisions with an excited nuclear level. In this reaction, the nucleus could partly transfer its excitation energy to the scattered neutron

  7. Inelastic neutron scattering from synthetic and biological polymers

    International Nuclear Information System (INIS)

    White, J.W.

    1976-01-01

    Neutron elastic and inelastic scattering measurements have provided many unique insights into structure, and by reviewing progress on synthetics, important differences likely to arise in biological systems are identified and a direction for studies of the latter is suggested. By neutron inelastic scattering it is possible to measure the frequency of thermally excited interatomic and intermolecular vibrations in crystals. With perfect organic and inorganic crystals the technique is now classical and has given great insight into the crystal forces responsible for the observed structures as well as the phase transitions they undergo. The study of polymer crystals immediately presents two problems of disorder: (1) Macroscopic disorder arises because the sample is a mixture of amorphous and crystalline fractions, and it may be acute enough to inhibit growth of a single crystal large enough for neutron studies. (2) Microscopic disorder in the packing of polymer chains in the ''crystalline'' regions is indicated by broadening of Bragg peaks. Both types of disorder problem arise in biological systems. The methods by which they were partially overcome to allow neutron measurements with synthetic polymers are described but first a classical example of the determination of interatomic forces by inelastic neutron scattering is given

  8. Neutron scattering study of dilute supercritical solutions

    International Nuclear Information System (INIS)

    Cochran, H.D.; Wignall, G.D.; Shah, V.M.; Londono, J.D.; Bienkowski, P.R.

    1994-01-01

    Dilute solutions in supercritical solvents exhibit interesting microstructures that are related to their dramatic macroscopic behavior. In typical attractive solutions, solutes are believed to be surrounded by clusters of solvent molecules, and solute molecules are believed to congregate in the vicinity of one another. Repulsive solutions, on the other hand, exhibit a local region of reduced solvent density around the solute with solute-solute congregation. Such microstructures influence solubility, partial molar volume, reaction kinetics, and many other properties. We have undertaken to observe these interesting microstructures directly by neutron scattering experiments on dilute noble gas systems including Ar. The three partial structure factors for such systems and the corresponding pair correlation functions can be determined by using the isotope substitution technique. The systems studied are uniquely suited for our objectives because of the large coherent neutron scattering length of the isotope 36 Ar and because of the accurate potential energy functions that are available for use in molecular simulations and theoretical calculations to be compared with the scattering results. We will describe our experiment, the unique apparatus we have built for it, and the neutron scattering results from our initial allocations of beam time. We will also describe planned scattering experiments to follow those with noble gases, including study of long-chain molecules in supercritical solvents. Such studies will involve hydrocarbon mixtures with and without deuteration to provide contrast

  9. New neutron imaging techniques to close the gap to scattering applications

    International Nuclear Information System (INIS)

    Lehmann, Eberhard H.; Peetermans, S.; Trtik, P.; Betz, B.; Grünzweig, C.

    2017-01-01

    Neutron scattering and neutron imaging are activities at the strong neutron sources which have been developed rather independently. However, there are similarities and overlaps in the research topics to which both methods can contribute and thus useful synergies can be found. In particular, the spatial resolution of neutron imaging has improved recently, which - together with the enhancement of the efficiency in data acquisition- can be exploited to narrow the energy band and to implement more sophisticated methods like neutron grating interferometry. This paper provides a report about the current options in neutron imaging and describes how the gap to neutron scattering data can be closed in the future, e.g. by diffractive imaging, the use of polarized neutrons and the dark-field imagining of relevant materials. This overview is focused onto the interaction between neutron imaging and neutron scattering with the aim of synergy. It reflects mainly the authors’ experiences at their PSI facilities without ignoring the activities at the different other labs world-wide. (paper)

  10. New neutron imaging techniques to close the gap to scattering applications

    Science.gov (United States)

    Lehmann, Eberhard H.; Peetermans, S.; Trtik, P.; Betz, B.; Grünzweig, C.

    2017-01-01

    Neutron scattering and neutron imaging are activities at the strong neutron sources which have been developed rather independently. However, there are similarities and overlaps in the research topics to which both methods can contribute and thus useful synergies can be found. In particular, the spatial resolution of neutron imaging has improved recently, which - together with the enhancement of the efficiency in data acquisition- can be exploited to narrow the energy band and to implement more sophisticated methods like neutron grating interferometry. This paper provides a report about the current options in neutron imaging and describes how the gap to neutron scattering data can be closed in the future, e.g. by diffractive imaging, the use of polarized neutrons and the dark-field imagining of relevant materials. This overview is focused onto the interaction between neutron imaging and neutron scattering with the aim of synergy. It reflects mainly the authors’ experiences at their PSI facilities without ignoring the activities at the different other labs world-wide.

  11. Small-angle neutron-scattering experiments

    International Nuclear Information System (INIS)

    Hardy, A.D.; Thomas, M.W.; Rouse, K.D.

    1981-04-01

    A brief introduction to the technique of small-angle neutron scattering is given. The layout and operation of the small-angle scattering spectrometer, mounted on the AERE PLUTO reactor, is also described. Results obtained using the spectrometer are presented for three materials (doped uranium dioxide, Magnox cladding and nitrided steel) of interest to Springfields Nuclear Power Development Laboratories. The results obtained are discussed in relation to other known data for these materials. (author)

  12. Neutron, x-ray scattering and TEM studies of Ni-Ti multilayers

    International Nuclear Information System (INIS)

    Keem, J.E.; Wood, J.; Grupido, N.; Hart, K.; Nutt, S.; Reichel, D.G.; Yelon, W.B.

    1988-01-01

    The authors present an analysis of Ni-Ti multilayer neutron reflectors and supermirrors undertaken to identify the causes of the lower than expected observed scattering power and critical angle enhancement of Ni-Ti supermirrors. Results of these investigations focus attention on cusp formation in the Ni-Ti bilayers as probable cause for the reduced neutron scattering power. Grazing angle x-ray and neutron scattering, wide angle neutron diffraction and analytical cross sectional TEM have been used. The multilayers were produced by magnetron sputtering and ion-beam deposition on float glass substrates and silicon wafers

  13. Small Angle Neutron Scattering From Iron. Vol. 2

    Energy Technology Data Exchange (ETDEWEB)

    Adib, M; Abdel-Kawy, A; Naguib, K; Habib, N; Kilany, M [Reactor and Neutron Physics Dept., Nuclear Research Centre, AEA, Cairo, (Egypt); Wahba, M [Faculty of Engineering, ain Shams University, Cairo, (Egypt); Ashry, A [Faculty of Education, Ain Shams University, Cairo, (Egypt)

    1996-03-01

    The total neutron cross-section measurements have been carried out for iron in both metallic and powder forms in the wavelengths band 0.35 nm to 0.52 nm. The measurements were performed using the TOF spectrometer installed in front of one of the horizontal channels of the ET-RR-1 reactor. The observed behavior for the small-angle neutron scattering cross-section of iron powder was analyzed in terms of its particle diameter, incident neutron wavelength and beam divergence. It was found that for iron particles of diameter 25 {mu}m the small-angle neutron scattering is only due to refraction of neutron wave traversing the particles. A method was established to determine the particle size of iron powders within an accuracy of 8% which is higher than that obtained by mesh analysis. 4 figs., 1 tab.

  14. Monte Carlo simulation of neutron scattering instruments

    International Nuclear Information System (INIS)

    Seeger, P.A.

    1995-01-01

    A library of Monte Carlo subroutines has been developed for the purpose of design of neutron scattering instruments. Using small-angle scattering as an example, the philosophy and structure of the library are described and the programs are used to compare instruments at continuous wave (CW) and long-pulse spallation source (LPSS) neutron facilities. The Monte Carlo results give a count-rate gain of a factor between 2 and 4 using time-of-flight analysis. This is comparable to scaling arguments based on the ratio of wavelength bandwidth to resolution width

  15. The Manuel Lujan Jr. Neutron Scattering Center

    International Nuclear Information System (INIS)

    Goldstone, J.A.

    1994-01-01

    High in the northcentral mountains of Los Alamos, New Mexico, is the Manuel Lujan Jr. Neutron Scattering Center (LANSCE), a pulsed-spallation neutron source located at Los Alamos National Laboratory. 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 a linear accelerator and an associated Proton Storage Ring (PSR), which alters the intensity, time structure, and repetition rate of the pulses. In October 1986, LANSCE was designated a national user facility, with a formal user program initiated in 1988. In July 1989, the LANSCE facility was dedicated as the Manuel Lujan Jr. Neutron Scattering Center in honor of the long-term Congressman from New Mexico. At present, the PSR operates with a proton pulse width of 0.27 μs at 20 Hz and 80 μA, attaining the highest peak neutron flux in the world and close to its goal of 100 μA, which would yield a peak thermal neutron flux of 10 16 n/cm -2 s -1 . This paper discusses the target/moderator/reflector shield system, the LANSCE instruments, the facility improvement projects, and user programs

  16. Studies of molecular dynamics with neutron scattering techniques. Part of a coordinated programme on neutron scattering techniques

    International Nuclear Information System (INIS)

    Vinhas, L.A.

    1980-05-01

    Molecular dynamics was studied in samples of tert-butanol, cyclohexanol and methanol, using neutron inelastic and quasi-elastic techniques. The frequency spectra of cyclohexanol in crystalline phase were interpreted by assigning individual energy peaks to hindered rotation of molecules, lattice vibration, hydrogen bond stretching and ring bending modes. Neutron quasi-elastic scattering measurements permitted the testing of models for molecular diffusion as a function of temperature. The interpretation of neutron incoherent inelastic scattering on methanol indicated the different modes of molecular dynamics in this material; individual inelastic peaks in the spectra could be assigned to vibrations of crystalline lattice, stretching of hydrogen bond and vibrational and torsional modes of CH 3 OH molecule. The results of the experimental work on tertbutanol indicate two distinct modes of motion in this material: individual molecular librations are superposed to a cooperative rotation diffusion which occurs both in solid and in liquid state

  17. Scattering of neutrons and critical phenomena in antiferromagnetic fermi liquid

    International Nuclear Information System (INIS)

    Akhiezer, I.A.; Barannik, E.A.

    1980-01-01

    The scattering of slow neutrons in an antiferromagnetic with collectivized magnetic electrons is considered and it is shown to significantly differ from the neutron scattering in an antiferromagnetic with localized magnetic electrons. The behaviour of scattering cross sections and fluctuation correlators near the Neel point is studied. These magnitudes are shown to increase with the critical index r=-1 [ru

  18. Magnetic Dynamics of Fine Particles Studied by Inelastic Neutron Scattering

    DEFF Research Database (Denmark)

    Hansen, Mikkel Fougt; Bødker, Franz; Mørup, Steen

    2000-01-01

    We give an introduction to inelastic neutron scattering and the dynamic scattering function for magnetic nanoparticles. Differences between ferromagnetic and antiferromagnetic nanoparticles are discussed and we give a review of recent results on ferromagnetic Fe nanoparticles and canted antiferro......We give an introduction to inelastic neutron scattering and the dynamic scattering function for magnetic nanoparticles. Differences between ferromagnetic and antiferromagnetic nanoparticles are discussed and we give a review of recent results on ferromagnetic Fe nanoparticles and canted...

  19. Application of Van Hove theory to fast neutron inelastic scattering

    International Nuclear Information System (INIS)

    Stanicicj, V.

    1974-11-01

    The Vane Hove general theory of the double differential scattering cross section has been used to derive the particular expressions of the inelastic fast neutrons scattering kernel and scattering cross section. Since the considered energies of incoming neutrons being less than 10 MeV, it enables to use the Fermi gas model of nucleons. In this case it was easy to derive an analytical expression for the time-dependent correlation function of the nucleus. Further, by using an impulse approximation and a short-collision time approach, it was possible to derive the analytical expression of the scattering kernel and scattering cross section for the fast neutron inelastic scattering. The obtained expressions have been used for Fe nucleus. It has been shown a surprising agreement with the experiments. The main advantage of this theory is in its simplicity for some practical calculations and for some theoretical investigations of nuclear processes

  20. Extraction of the neutron-neutron scattering length ann from kinematically complete neutron-deuteron breakup experiments

    International Nuclear Information System (INIS)

    Witala, H.; Hueber, D.; Gloeckle, W.; Tornow, W.; Gonzalez Trotter, D.E.

    1996-01-01

    Data for the neutron-neutron final-state-interaction cross section obtained recently in a kinematically complete neutron-deuteron breakup experiment have been reanalyzed using rigorous solutions of the three-nucleon Faddeev equations with realistic nucleon-nucleon interactions. A discrepancy was found with respect to a recent analysis based on the W-matrix approximation to the Paris potential. We also estimate theoretical uncertainties in extracting the neutron-neutron scattering length resulting from the use of different nucleon-nucleon interactions and the possible action of the two pion-exchange three-nucleon force. We find that there exists a certain production angle for the interacting neutron-neutron pair where the uncertainties become minimal. (author)

  1. Inelastic neutron scattering from cerium under pressure

    International Nuclear Information System (INIS)

    Rainford, B.D.; Buras, B.; Lebech, B.

    1976-01-01

    Inelastic neutron scattering from Ce metal at 300K was studied both below and above the first order γ-α phase transition, using a triple axis spectrometer. It was found that (a) there is no indication of any residual magnetic scattering in the collapsed α phase and (b) the energy width of the paramagnetic scattering in the γ-phase increases with pressure. (Auth.)

  2. Activity report on neutron scattering research. V. 1, 1994

    International Nuclear Information System (INIS)

    Fujii, Y.; Oohara, Y.

    1994-09-01

    In April, 1993, the Neutron Scattering Laboratory attached to the Institute for Solid State Physics, University of Tokyo, was newly established in Tokai, Ibaraki Prefecture, to promote nationwide users' programs for utilizing the university-owned neutron instruments installed at the JRR-3M reactor of Japan Atomic Energy Research Institute. This upgraded reactor (20 MW, the cold source is installed) has drastically expanded the number of users and research areas since 1990 when it became operational. Currently 8 and 3 out of 18 new spectrometers in total at the JRR-3M are owned by ISSP and Tohoku University, respectively, while the remaining 7 spectrometers belong to JAERI. In addition, 3 conventional spectrometers in the 30 years old JRR-2 reactor (10 MW) have also supported research activities. This is the first issue of 'Activity report on neutron scattering research', and it is to be published annually. In this report, the brief history of neutron scattering research, the users' programs, the committees, the neutron scattering instruments available at the JRR-3M and the JRR-2M, the activity reports on structures and excitation, magnetism, superconductors, liquid and glass, material science, polymers, biology and instrumentation, and publication list are reported. (K.I.)

  3. Scattering of Neutrons by an Anharmonic Crystal

    Energy Technology Data Exchange (ETDEWEB)

    Hoegberg, T; Bohlin, L; Ebbsjoe, I

    1967-04-15

    Numerical calculations have been performed for the anharmonic effects in neutron scattering. The phonon frequency widths and shifts have been calculated as a function of neutron frequency at different wave numbers and temperatures for a potential with central symmetry and for a face-centered cubic lattice.

  4. Neutron scattering lengths of molten metals determined by gravity refractometry

    Energy Technology Data Exchange (ETDEWEB)

    Reiner, G.; Waschkowski, W.; Koester, L. (Technische Univ. Muenchen, Garching (Germany, F.R.). Fakultaet fuer Physik)

    1990-10-01

    Very accurate values of the coherent neutron scattering lengths of the heavy elements Bi and Pb are important quantities for the investigation of the electric interactions of neutrons with atoms. We performed, therefore, a series of experiments to determine accurate scattering lengths by means of neutron gravity refractometry on liquid mirrors of molten metals. The possible perturbations of the necessary reflection measurements have been discussed in details. After taking into account the uncertainties and corrections associated with observable perturbations we obtained the following values for bound atoms: b(Bi)=8.532{plus minus}0.002 fm, b(Pb)=9.405{plus minus}0.003 fm, b(Tl)=8.776{plus minus}0.005 fm, b(Sn)=6.225{plus minus}0.002 fm and b(Ga)=7.288{plus minus}0.002 fm. These data are corrected for the local field effect occuring in the reflection on liquids. The recently reported results for the neutron's electric polarizability and the neutron-electron scattering length are supported by the Bi- and Pb-scattering length of this work. (orig.).

  5. Neutron scattering lengths of molten metals determined by gravity refractometry

    International Nuclear Information System (INIS)

    Reiner, G.; Waschkowski, W.; Koester, L.

    1990-01-01

    Very accurate values of the coherent neutron scattering lengths of the heavy elements Bi and Pb are important quantities for the investigation of the electric interactions of neutrons with atoms. We performed, therefore, a series of experiments to determine accurate scattering lengths by means of neutron gravity refractometry on liquid mirrors of molten metals. The possible perturbations of the necessary reflection measurements have been discussed in details. After taking into account the uncertainties and corrections associated with observable perturbations we obtained the following values for bound atoms: b(Bi)=8.532±0.002 fm, b(Pb)=9.405±0.003 fm, b(Tl)=8.776±0.005 fm, b(Sn)=6.225±0.002 fm and b(Ga)=7.288±0.002 fm. These data are corrected for the local field effect occuring in the reflection on liquids. The recently reported results for the neutron's electric polarizability and the neutron-electron scattering length are supported by the Bi- and Pb-scattering length of this work. (orig.)

  6. Neutron scattering lengths of molten metals determined by gravity refractometry

    Energy Technology Data Exchange (ETDEWEB)

    Reiner, G; Waschkowski, W; Koester, L [Technische Univ. Muenchen, Garching (Germany, F.R.). Fakultaet fuer Physik

    1990-10-01

    Very accurate values of the coherent neutron scattering lengths of the heavy elements Bi and Pb are important quantities for the investigation of the electric interactions of neutrons with atoms. We performed, therefore, a series of experiments to determine accurate scattering lengths by means of neutron gravity refractometry on liquid mirrors of molten metals. The possible perturbations of the necessary reflection measurements have been discussed in details. After taking into account the uncertainties and corrections associated with observable perturbations we obtained the following values for bound atoms: b(Bi)=8.532{plus minus}0.002 fm, b(Pb)=9.405{plus minus}0.003 fm, b(Tl)=8.776{plus minus}0.005 fm, b(Sn)=6.225{plus minus}0.002 fm and b(Ga)=7.288{plus minus}0.002 fm. These data are corrected for the local field effect occuring in the reflection on liquids. The recently reported results for the neutron's electric polarizability and the neutron-electron scattering length are supported by the Bi- and Pb-scattering length of this work. (orig.).

  7. Theoretical challenges in neutron scattering

    International Nuclear Information System (INIS)

    Lovesey, S.W.

    1985-07-01

    Topics in the interpretation of neutron scattering experiments from paramagnets and quantum fluids are used to illustrate the puissance of the technique in condensed matter research, and to record some fundamental shortcomings in the available theory of many-particle systems. (author)

  8. Study of material science by neutron scattering

    International Nuclear Information System (INIS)

    Kim, H.J.; Yoon, B.K.; Cheon, B.C.; Lee, C.Y.; Kim, C.S.

    1980-01-01

    To develop accurate methods of texture measurement in metallic materials by neutron diffraction, (100),(200),(111) and (310) pole figures have been measured for the oriented silicon steel sheet, and currently study of correction methods for neutron absorption and extinction effects are in progress. For quantitative analysis of texture of polycrystalline material with a cubic structure, a software has been developed to calculate inverse pole figures for arbitrary direction specified in the speciman as well as pole figures for arbitrary chosen crystallographic planes from three experimental pole figures. This work is to be extended for the calculation of three dimensional orientation distribution function and for the evaluation of errors in the quantitative analysis of texture. Work is also for the study of N-H...O hydrogen bond in amino acid by observing molecular motions using neutron inelastic scattering. Measurement of neutron inelastic scattering spectrum of L-Serine is completed at 100 0 K and over the energy transfer range of 20-150 meV. (KAERI INIS Section)

  9. Development of new methods for studying nanostructures using neutron scattering

    International Nuclear Information System (INIS)

    Pynn, Roger

    2016-01-01

    The goal of this project was to develop improved instrumentation for studying the microscopic structures of materials using neutron scattering. Neutron scattering has a number of advantages for studying material structure but suffers from the well-known disadvantage that neutrons' ability to resolve structural details is usually limited by the strength of available neutron sources. We aimed to overcome this disadvantage using a new experimental technique, called Spin Echo Scattering Angle Encoding (SESAME) that makes use of the neutron's magnetism. Our goal was to show that this innovation will allow the country to make better use of the significant investment it has recently made in a new neutron source at Oak Ridge National Laboratory (ORNL) and will lead to increases in scientific knowledge that contribute to the Nation's technological infrastructure and ability to develop advanced materials and technologies. We were successful in demonstrating the technical effectiveness of the new method and established a baseline of knowledge that has allowed ORNL to start a project to implement the method on one of its neutron beam lines.

  10. Symmetry effects in neutron scattering from isotopically enriched Se isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Lachkar, J.; Haouat, G.; McEllistrem, M. T.; Patin, Y.; Sigaud, J.; Cocu, F.

    1975-06-01

    Differential cross sections for neutron elastic and inelastic scattering from {sup 76}Se, {sup 78}Se, {sup 80}Se and {sup 82}Se, have been measured at 8-MeV incident neutron energy and from {sup 76}Se and {sup 82}Se at 6- and 10-MeV incident energies. The differences observed in the elastic scattering cross sections are interpretable as the effects of isospin term in the scattering potentials. A full analysis of the elastic scattering data are presented.

  11. Fast neutron scattering near shell closures: Scandium

    International Nuclear Information System (INIS)

    Smith, A.B.; Guenther, P.T.

    1992-08-01

    Neutron differential elastic- and inelastic-scattering cross sections are measured from ∼ 1.5 to 10 MeV with sufficient detail to define the energy-averaged behavior of the scattering processes. Neutrons corresponding to excitations of 465 ± 23, 737 ± 20, 1017 ± 34, 1251 ± 20, 1432 ± 23 and 1692 ± 25 keV are observed. It is shown that the observables, including the absorption cross section, are reasonably described with a conventional optical-statistical model having energy-dependent geometric parameters. These energy dependencies are alleviated when the model is extended to include the contributions of the dispersion relationship. The model parameters are conventional, with no indication of anomalous behavior of the neutron interaction with 45 Sc, five nucleons from the doubly closed shell at 40 Ca

  12. Long-Lifetime Low-Scatter Neutron Polarization Target

    International Nuclear Information System (INIS)

    Richardson, Jonathan M.

    2004-01-01

    Polarized neutrons scattering is an important technology for characterizing magnetic and other materials. Polarized helium three (P-3He) is a novel technology for creating polarized beams and, perhaps more importantly, for the analysis of polarization in highly divergent scattered beams. Analysis of scattered beams requires specialized targets with complex geometries to ensure accurate results. Special materials and handling procedures are required to give the targets a long useful lifetime. In most cases, the targets must be shielded from stray magnetic fields from nearby equipment. SRL has developed and demonstrated hybrid targets made from glass and aluminum. We have also developed and calibrated a low-field NMR system for measuring polarization lifetimes. We have demonstrated that our low-field system is able to measure NMR signals in the presence of conducting (metallic) cell elements. We have also demonstrated a non-magnetic valve that can be used to seal the cells. We feel that these accomplishments in Phase I are sufficient to ensure a successful Phase II program. The commercial market for this technology is solid. There are over nine neutron scattering centers in the US and Canada and over 22 abroad. Currently, the US plans to build a new $1.4B scattering facility called the Spallation Neutron Source (SNS). The technology developed in this project will allow SRL to supply targets to both existing and future facilities. SRL is also involved with the application of P-3He to medical imaging

  13. Small angle neutron scattering by polymer solutions

    International Nuclear Information System (INIS)

    Farnoux, B.; Jannink, G.

    1980-08-01

    Small angle neutron scattering is an experimental technique introduced since about 10 years for the observation of the polymer conformation in all the concentration range from dilute solution to the melt. After a brief recall of the elementary relations between scattering amplitude, index of refraction and scattered intensity, two concepts related to this last quantity (the contrast and the pair correlation function) are discussed in details

  14. Current status of neutron scattering in Thailand

    International Nuclear Information System (INIS)

    Ampornrat, Pantip

    2000-01-01

    The neutron scattering experiments in Thailand have been done continuously since the start up of the reactor. In 1977, Thai research reactor was modified into TRIGA MARK III core. After that, the neutron spectrometer was installed again under a development program. Installation of upgrading spectrometer was delayed because of some problems involving the neutron intensity and instruments. However, these problems were solved and the setup is almost completed. The paper reports the current status of neutron spectrometer, the problems and plans for the experiments. (author)

  15. Small-angle neutron scattering instrument at MINT

    International Nuclear Information System (INIS)

    Mohd Ali Sufi; Yusof Abdullah; Razali Kassim; Hamid; Shahidan Radiman; Mohammad Deraman; Abdul Ghaffar Ramli

    1996-01-01

    The Small Angle Neutron Scattering (SANS) Instrument has been developed at Malaysian Institute for Nuclear Technology Research (MINT) for studying structural properties of materials on the length scale 1 nm to 100 nm. This is the length scale which is relevant for many topics within soft condensed matter, like polymers, colloids, biological macromolecules, etc. The SANS is a complementary technique to X-ray and electron scattering. However, while these later techniques give information on structures near surface, SANS concerns the structure of the bulk. Samples studied by SANS technique are typically bulk materials of the sizes mm's to cm's, or materials dissolved in a liquid. This paper described the general characteristics of SANS instrument as well as the experimental formulation in neutron scattering. The preliminary results obtained by this instrument are shown

  16. Summary of neutron scattering lengths

    International Nuclear Information System (INIS)

    Koester, L.

    1981-12-01

    All available neutron-nuclei scattering lengths are collected together with their error bars in a uniform way. Bound scattering lengths are given for the elements, the isotopes, and the various spin-states. They are discussed in the sense of their use as basic parameters for many investigations in the field of nuclear and solid state physics. The data bank is available on magnetic tape, too. Recommended values and a map of these data serve for an uncomplicated use of these quantities. (orig.)

  17. Neutron-scattering studies of chromatin

    International Nuclear Information System (INIS)

    Bradbury, E.M.; Baldwin, J.P.; Carpenter, B.G.; Hjelm, R.P.; Hancock, R.; Ibel, K.

    1976-01-01

    It is clear that a knowledge of the basic molecular structure of chromatin is a prerequisite for any progress toward an understanding of chromosome organization. With a two-component system, protein and nucleic acid, neutrons have a particularly powerful application to studies of the spatial arrangements of these components because of the ability, by contrast matching with H 2 O-D 2 O mixtures, to obtain neutron-scattering data on the individual components. With this approach it has been shown that the neutron diffraction of chromatin is consistent with a ''beads on a string'' model in which the bead consists of a protein core with DNA coiled on the outside. However, because chromatin is a gel and gives limited structural data, confirmation of such a model requires extension of the neutron studies by deuteration of specific chromatin components and the isolation of chromatin subunits. Although these studies are not complete, the neutron results so far obtained support the subunit model described above

  18. Introduction of sample environment equipment for neutron scattering experiments

    International Nuclear Information System (INIS)

    Shimojo, Yutaka; Ihata, Yoshiaki; Kaneko, Koji; Takeda, Masayasu

    2013-02-01

    Neutron scattering experiments have been frequently performed under variety of sample conditions, such as various temperatures, pressures, magnetic fields and stresses, and those complex conditions to fully utilize superior properties of neutron. To this aim, a number of sample environment equipment, refrigerators, furnaces, pressure cells, superconducting magnets are equipped in JRR-3 to be used for experiments. In this document, all available sample environment equipment in both JRR-3 reactor and guide halls are summarized. We hope this document would help neutron scattering users to perform effective and excellent experiments. (author)

  19. Status and neutron scattering experiments at KENS

    International Nuclear Information System (INIS)

    Watanabe, N.; Sasaki, H.; Ishikawa, Y.; Endoh, Y.; Inoue, K.

    1983-01-01

    This paper reports present status of the KENS facility, progress in neutron scattering experiments and instrumental developments, and status of the KENS-I' program. A design study of a high intensity rapid-cycle 800 MeV proton synchrotron for proposed new pulsed neutron (KENS-II) and meson source is also descirbed

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

    International Nuclear Information System (INIS)

    Overbury, Steven H.; Coates, Leighton; Herwig, Kenneth W.; Kidder, Michelle

    2011-01-01

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-10-01

    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.

  2. Annual report on neutron scattering studies in JAERI

    International Nuclear Information System (INIS)

    Sato, Masatoshi; Nishi, Masakazu; Fujishita, Hideshi; Iizumi, Masashi

    1982-07-01

    Neutron scattering studies carried out from September 1979 to August 1981 by Division of Physics, JAERI, and universities with JRR-2 and -3 neutron beam facilities are described: 61 summary reports, and a list of publications. (author)

  3. NEUTRON-SCATTERING STUDY OF DCN

    DEFF Research Database (Denmark)

    Mackenzie, Gordon A.; Pawley, G. S.

    1979-01-01

    Phonons in deuterium cyanide have been measured by neutron coherent inelastic scattering. The main subject of study was the transverse acoustic mode in the (110) direction polarised along (110) which is associated with the first-order structural phase transition at 160K. Measurements have shown...

  4. Advances on detectors for low-angle scattering of epithermal neutrons

    International Nuclear Information System (INIS)

    Perelli Cippo, E; Gorini, G; Tardocchi, M; Andreani, C; Pietropaolo, A; Senesi, R; Rhodes, N J; Schoonveld, E M

    2008-01-01

    The Very Low Angle Detector (VLAD) installed at the ISIS spallation neutron source is a novel instrument for epithermal neutron scattering with a range of applications in solid state physics. VLAD extends the kinematical space of the VESUVIO spectrometer to low momentum transfers at neutron energies above 1 eV. Measurements at scattering angles as low as 1° have been made with limitations due to the achievable signal/background ratio. (technical design note)

  5. MCRTOF, Multiple Scattering of Resonance Region Neutron in Time of Flight Experiments

    International Nuclear Information System (INIS)

    Ohkubo, Mako

    1984-01-01

    1 - Description of program or function: Multiple scattering of neutrons in the resonance energy region impinging on a disk with an arbitrary angle. 2 - Method of solution: The Monte Carlo method is employed to simulate the path of an incident neutron in a medium for which macroscopic cross sections are determined by resonance parameters. By tracing a large number of neutrons, probabilities for capture, transmission, front-face scattering, rear-face scattering and side-face scattering are determined and printed out as function of incident neutron energy. Optionally, the distribution of capture locations in the disk can be printed. The incident neutron energy is swept to fit a situation as encountered in time-of-flight experiments. 3 - Restrictions on the complexity of the problem: The cross section file is constructed from input resonance parameters with a single- level Breit-Wigner formula. The following restrictions and simplifications apply: - The maximum number of resonances is five. - Reactions other than capture and scattering are neglected. - The angular scattering distribution in the center-of-mass system is assumed to be uniform. - Chemical binding effects are neglected

  6. Neutron scattering in applied research: possibilities for medium-flux research reactors

    International Nuclear Information System (INIS)

    Reijonen, H.

    1977-01-01

    The possibilities for neutron scattering techniques in applied research are reviewed. The areas covered are magnetism, determination of hydrogen self-diffusion constants and ionic mobility in superionic conductors, liquid crystals, molecular solids, polymers, surface chemistry and catalysts, colloids biology, physical metallurgy and neutron diagnostics. Established applications and new proposals for research projects are presented in various degrees of detail. Small angle scattering techniques, physical metallurgy and biology were identified as having particular potential. Prospective users should be realistically informed of the possibilities of neutron scattering techniques. (author)

  7. 2016 American Conference on Neutron Scattering (ACNS)

    International Nuclear Information System (INIS)

    Woodward, Patrick

    2017-01-01

    The 8th American Conference on Neutron Scattering (ACNS) was held July 10-14, 2016 in Long Beach California, marking the first time the meeting has been held on the west coast. The meeting was coordinated by the Neutron Scattering Society of America (NSSA), and attracted 285 attendees. The meeting was chaired by NSSA vice president Patrick Woodward (the Ohio State University) assisted by NSSA president Stephan Rosenkranz (Argonne National Laboratory) together with the local organizing chair, Brent Fultz (California Institute of Technology). As in past years the Materials Research Society assisted with planning, logistics and operation of the conference. The science program was divided into the following research areas: (a) Sources, Instrumentation, and Software; (b) Hard Condensed Matter; (c) Soft Matter; (d) Biology; (e) Materials Chemistry and Materials for Energy; (f) Engineering and Industrial Applications; and (g) Neutron Physics.

  8. 2016 American Conference on Neutron Scattering (ACNS)

    Energy Technology Data Exchange (ETDEWEB)

    Woodward, Patrick [Materials Research Society, Warrendale, PA (United States)

    2017-02-09

    The 8th American Conference on Neutron Scattering (ACNS) was held July 10-14, 2016 in Long Beach California, marking the first time the meeting has been held on the west coast. The meeting was coordinated by the Neutron Scattering Society of America (NSSA), and attracted 285 attendees. The meeting was chaired by NSSA vice president Patrick Woodward (the Ohio State University) assisted by NSSA president Stephan Rosenkranz (Argonne National Laboratory) together with the local organizing chair, Brent Fultz (California Institute of Technology). As in past years the Materials Research Society assisted with planning, logistics and operation of the conference. The science program was divided into the following research areas: (a) Sources, Instrumentation, and Software; (b) Hard Condensed Matter; (c) Soft Matter; (d) Biology; (e) Materials Chemistry and Materials for Energy; (f) Engineering and Industrial Applications; and (g) Neutron Physics.

  9. Anomalous neutron scattering and feroelectric modes

    International Nuclear Information System (INIS)

    Viswanathan, K.S.

    1977-01-01

    It is suggested that anomalous neutron scattering could prove a powerful experimental tool in studying ferroelectric phase transition, the sublattice displacements of the soft modes as well as their symmetry characteristics. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-10-25

    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.

  11. Analysis of a neutron scattering integral experiment on iron for neutron energies from 1 to 15 MeV

    International Nuclear Information System (INIS)

    Cramer, S.N.; Oblow, E.M.

    1976-11-01

    Monte Carlo calculations were made to analyze the results of an integral experiment with an iron sample to determine the adequacy of neutron scattering cross section data for iron. The experimental results analyzed included energy-dependent NE-213 detector count rates at a scattering angle of 90 deg and pulse-height spectra for scattered neutrons produced in an iron ring pulsed with a 1- to 20-MeV neutron source. The pulse-height data were unfolded to generate secondary neutron spectra at 90 deg as a function of incident neutron energy. Multigroup Monte Carlo calculations using the MORSE code and ENDF/B-IV cross sections were made to analyze all reported results. Discrepancies between calculated and measured responses were found for inelastic scattering reactions in the range from 1 to 4 MeV. These results were related to deficiencies in ENDF/B-IV iron cross section data

  12. Scattering of Neutrons on Fluctuations of the Density of the Thin Films

    Directory of Open Access Journals (Sweden)

    S. G. ABDULVAHABOVA

    2016-11-01

    Full Text Available Abstract. The cross section for scattering neutron  on the density of  fluctuations of the  thin films is obtained in the framework of the quantum theory of multiple scattering  in the quasielastic approximation. Inhomogeneity can be caused by dynamic density fluctuations, and be statistical in nature. Fluctuations in the density of the scattering material cause neutron scattering wave. The probability of a collision between a neutron and an atomic nucleus depends on the number of neutrons and on their velocity. The formulas have been obtained under the assumption that the imaginary part of the optical potential is a local operator. It was determined that the scattering in density fluctuations does not contribute to the attenuation of the coherent neutron wave. In the approximation of a thin target the solution of the equation for the total scattering amplitude is identical to the expression obtained in the usual eikonal approximation and differs significantly, at least functionally, from the solution for the case of a thick target. There have been detailed investigations of the reflection and refraction of neutron waves in matter, and the details of their dispersion law have been studied. The results are  hown  also, that  the total cross section for scattering by the complete target becomes universal and does not depend on cross section for scattering by one nucleus.Keywords: 25.40-Ep

  13. Fast-neutron scattering cross sections of elemental silver

    International Nuclear Information System (INIS)

    Smith, A.B.; Guenther, P.T.

    1982-05-01

    Differential neutron elastic- and inelastic-scattering cross sections of elemental silver are measured from 1.5 to 4.0 MeV at intervals of less than or equal to 200 keV and at 10 to 20 scattering angles distributed between 20 and 160 0 . Inelastically-scattered neutron groups are observed corresponding to the excitation of levels at; 328 +- 13, 419 +- 50, 748 +- 25, 908 +- 26, 1150 +- 38, 1286 +- 25, 1507 +- 20, 1623 +- 30, 1835 +- 20 and 1944 +- 26 keV. The experimental results are used to derive an optical-statistical model that provides a good description of the observed cross sections. The measured values are compared with corresponding quantities given in ENDF/B-V

  14. Ten year's activity in the field of neutron scattering workshop

    International Nuclear Information System (INIS)

    Hamaguchi, Yoshikazu

    2003-01-01

    'Neutron scattering' is in the frame of the 'Utilization of Research Reactor's of the FNCA (Forum for Nuclear Cooperation in Asia) project, which held the workshops from FY 1992. This report is a summary of the results and activities of neutron scattering workshops and sub-workshops since the start in FY 1992. (author)

  15. An inelastic neutron scattering study of hematite nanoparticles

    DEFF Research Database (Denmark)

    Hansen, Mikkel Fougt; Klausen, Stine Nyborg; Lefmann, K

    2003-01-01

    We have studied the magnetic dynamics in nanocrystalline hematite by inelastic neutron scattering at the high-resolution time-of-flight spectrometer IRIS at ISIS. Compared to previous inelastic neutron scattering experiments an improvement of the resolution function is achieved and more detailed...... moment at the antiferromagnetic Bragg reflection. We have studied different weightings of the particle size distribution. The data and their temperature dependence can with good agreement be interpreted on the basis of the Neel-Brown theory for superparamagnetic relaxation and a model for the collective...

  16. TOF-SEMSANS—Time-of-flight spin-echo modulated small-angle neutron scattering

    NARCIS (Netherlands)

    Strobl, M.; Tremsin, A.S.; Hilger, A.; Wieder, F.; Kardjilov, N.; Manke, I.; Bouwman, W.G.; Plomp, J.

    2012-01-01

    We report on measurements of spatial beam modulation of a polarized neutron beam induced by triangular precession regions in time-of-flight mode and the application of this novel technique spin-echo modulated small-angle neutron scattering (SEMSANS) to small-angle neutron scattering in the very

  17. A workshop on enhanced national capability for neutron scattering

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-01-01

    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.

  18. Progress report: determinations of the neutron-neutron scattering length ann from kinematically incomplete neutron-deuteron breakup data revisited

    International Nuclear Information System (INIS)

    Tornow, W.; Braun, R.T.; Witala, H.

    1996-01-01

    We review published analyses of the final-state-interaction enhancement observed in proton energy distributions obtained from kinematically incomplete neutron-deuteron breakup experiments. We compare the results derived from these analyses for the neutron-neutron scattering length, a nn with our results based on a rigorous treatment of the three-nucleon Faddeev equations in conjunction with the use of realistic nucleon-nucleon potentials. Our values for a nn deviate outside the quoted uncertainties from the ones obtained in the previous analyses where simplified nucleon-nucleon interaction models were employed. In contrast to the previous determinations, the present results for a nn are in clear disagreement with the values for a nn based on π - -deuteron capture experiments. Unless inconsistencies in the experimental neutron-deuteron breakup data at low energies can be resolved and the influence of possible three-nucleon-force effects can be reliably determined, we recommend that one not resort to the kinematically incomplete neutron-deuteron breakup reaction as a tool for determining a quantity as important for nuclear and particle physics as is the neutron-neutron scattering length a nn . (author)

  19. Scatterings and reactions by means of polarized neutron beam

    International Nuclear Information System (INIS)

    Koori, N.

    1989-01-01

    A high resolution polarized neutron beam should be prepared for nuclear physics, which will be planned with the new ring cyclotron at RCNP. Studies on scatterings and reactions by means of polarized neutron beams are reviewed briefly. Beam lines for polarized neutrons are summarized. An example of high resolution measurements of neutron induced reactions is described. (author)

  20. Geometry Survey of the Time-of-Flight Neutron-Elastic Scattering (Antonella) Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Oshinowo, Babatunde O. [Fermilab; Izraelevitch, Federico [Buenos Aires U.

    2016-10-17

    The Antonella experiment is a measurement of the ionization efficiency of nuclear recoils in silicon at low energies [1]. It is a neutron elastic scattering experiment motivated by the search for dark matter particles. In this experiment, a proton beam hits a lithium target and neutrons are produced. The neutron shower passes through a collimator that produces a neutron beam. The beam illuminates a silicon detector. With a certain probability, a neutron interacts with a silicon nucleus of the detector producing elastic scattering. After the interaction, a fraction of the neutron energy is transferred to the silicon nucleus which acquires kinetic energy and recoils. This kinetic energy is then dissipated in the detector producing ionization and thermal energy. The ionization produced is measured with the silicon detector electronics. On the other hand, the neutron is scattered out of the beam. A neutron-detector array (made of scintillator bars) registers the neutron arrival time and the scattering angle to reconstruct the kinematics of the neutron-nucleus interaction with the time-of-flight technique [2]. In the reconstruction equations, the energy of the nuclear recoil is a function of the scattering angle with respect to the beam direction, the time-of-flight of the neutron and the geometric distances between components of the setup (neutron-production target, silicon detector, scintillator bars). This paper summarizes the survey of the different components of the experiment that made possible the off-line analysis of the collected data. Measurements were made with the API Radian Laser Tracker and I-360 Probe Wireless. The survey was completed at the University of Notre Dame, Indiana, USA in February 2015.

  1. Neutron-triton scattering lengths for interactions reproducing low-energy trinucleon data

    International Nuclear Information System (INIS)

    Levashev, V.P.

    1981-01-01

    By solving the integral equations for four nucleons the neutron-triton scattering lengths and total cross section are calculated using different S-wave rank-one separable potentials. A number of linear correlations between the neutron-triton scattering lengths and triton binding energy are found. The scattering lengths consistent with low-energy trinucleon data. The results obtained are compared with available experimental data [ru

  2. Neutron-neutron quasifree scattering in nd breakup at 10 MeV

    Directory of Open Access Journals (Sweden)

    Malone R.C.

    2016-01-01

    We are conducting new measurements of the cross section for nn QFS in nd breakup. The measurements are performed at incident neutron beam energies below 20 MeV. The neutron beam is produced via the 2H(d, n3He reaction. The target is a deuterated plastic cylinder. Our measurements utilize time-of-flight techniques with a pulsed neutron beam and detection of the two emitted neutrons in coincidence. A description of our initial measurements at 10 MeV for a single scattering angle will be presented along with preliminary results. Also, plans for measurements at other energies with broad angular coverage will be discussed.

  3. Software for simulation and design of neutron scattering instrumentation

    DEFF Research Database (Denmark)

    Bertelsen, Mads

    designed using the software. The Union components uses a new approach to simulation of samples in McStas. The properties of a sample are split into geometrical and material, simplifying user input, and allowing the construction of complicated geometries such as sample environments. Multiple scattering...... from conventional choices. Simulation of neutron scattering instrumentation is used when designing instrumentation, but also to understand instrumental effects on the measured scattering data. The Monte Carlo ray-tracing package McStas is among the most popular, capable of simulating the path of each...... neutron through the instrument using an easy to learn language. The subject of the defended thesis is contributions to the McStas language in the form of the software package guide_bot and the Union components.The guide_bot package simplifies the process of optimizing neutron guides by writing the Mc...

  4. Small angle neutron scattering (SANS) under non-equilibrium conditions

    International Nuclear Information System (INIS)

    Oberthur, R.C.

    1984-01-01

    The use of small angle neutron scattering (SANS) for the study of systems under non-equilibrium conditions is illustrated by three types of experiments in the field of polymer research: - the relaxation of a system from an initial non-equilibrium state towards equilibrium, - the cyclic or repetitive installation of a series of non-equilibrium states in a system, - the steady non-equilibrium state maintained by a constant dissipation of energy within the system. Characteristic times obtained in these experiments with SANS are compared with the times obtained from quasi-elastic neutron and light scattering, which yield information about the equilibrium dynamics of the system. The limits of SANS applied to non-equilibrium systems for the measurement of relaxation times at different length scales are shown and compared to the limits of quasielastic neutron and light scattering

  5. Multiple scattering and attenuation corrections in Deep Inelastic Neutron Scattering experiments

    International Nuclear Information System (INIS)

    Dawidowski, J; Blostein, J J; Granada, J R

    2006-01-01

    Multiple scattering and attenuation corrections in Deep Inelastic Neutron Scattering experiments are analyzed. The theoretical basis of the method is stated, and a Monte Carlo procedure to perform the calculation is presented. The results are compared with experimental data. The importance of the accuracy in the description of the experimental parameters is tested, and the implications of the present results on the data analysis procedures is examined

  6. PREFACE: Structure and dynamics determined by neutron and x-ray scattering Structure and dynamics determined by neutron and x-ray scattering

    Science.gov (United States)

    Müller-Buschbaum, Peter

    2011-06-01

    Neutron and x-ray scattering have emerged as powerful methods for the determination of structure and dynamics. Driven by emerging new, powerful neutron and synchrotron radiation sources, the continuous development of new instrumentation and novel scattering techniques gives rise to exciting possibilities. For example, in situ observations become possible via a high neutron or x-ray flux at the sample and, as a consequence, morphological transitions with small time constants can be detected. This special issue covers a broad range of different materials from soft to hard condensed matter. Hence, different material classes such as colloids, polymers, alloys, oxides and metals are addressed. The issue is dedicated to the 60th birthday of Professor Winfried Petry, scientific director of the Research Neutron Source Heinz Maier-Leibnitz (FRM-II), Germany, advisor at the physics department for the Bayerische Elite-Akademie, chair person of the Arbeitsgemeinschaft Metall- und Materialphysik of the German Physical Society (DPG) and a member of the professional council of the German Science Foundation (Deutsche Forschungsgemeinschaft, DFG). We would like to acknowledge and thank all contributors for their submissions, which made this special issue possible in the first place. Moreover, we would like to thank the staff at IOP Publishing for helping us with the administrative aspects and for coordinating the refereeing process, and Valeria Lauter for the beautiful cover artwork. Finally, to the readers, we hope that you find this special issue a valuable resource that provides insights into the present possibilities of neutron and x-ray scattering as powerful tools for the investigation of structure and dynamics. Structure and dynamics determined by neutron and x-ray scattering contents In situ studies of mass transport in liquid alloys by means of neutron radiography F Kargl, M Engelhardt, F Yang, H Weis, P Schmakat, B Schillinger, A Griesche and A Meyer Magnetic spin

  7. A high pressure sample facility for neutron scattering

    International Nuclear Information System (INIS)

    Carlile, C.J.; Glossop, B.H.

    1981-06-01

    Commissioning tests involving deformation studies and tests to destruction as well as neutron diffraction measurements of a standard sample have been carried out on the SERC high pressure sample facility for neutron scattering studies. A detailed description of the pressurising equipment is given. (author)

  8. Kartini Research Reactor prospective studies for neutron scattering application

    International Nuclear Information System (INIS)

    Widarto

    1999-01-01

    The Kartini Research Reactor (KRR) is located in Yogyakarta Nuclear Research Center, Yogyakarta - Indonesia. The reactor is operated for 100 kW thermal power used for research, experiments and training of nuclear technology. There are 4 beam ports and 1 column thermal are available at the reactor. Those beam ports have thermal neutron flux around 10 7 n/cm 2 s each other and used for sub critical assembly, neutron radiography studies and Neutron Activation Analysis (NAA). Design of neutron collimator has been done for piercing radial beam port and the calculation result of collimated neutron flux is around 10 9 n/cm 2 s. This paper describes experiment facilities and parameters of the Kartini research reactor, and further more the prospective studies for neutron scattering application. The purpose of this paper is to optimize in utilization of the beam ports facilities and enhance the manpower specialty. The special characteristic of the beam ports and preliminary studies, pre activities regarding with neutron scattering studies for KKR is presented. (author)

  9. VI European Conference on Neutron Scattering (ECNS2015)

    International Nuclear Information System (INIS)

    2016-01-01

    It was a great pleasure for the Materials Science Institute of Aragón (CSIC- University of Zaragoza) to host the VI European Conference on Neutron Scattering (ECNS) from the 30th of August until the 4th of September 2015. The meeting was held in Zaragoza, Spain, a prosperous and well communicated city founded by the Emperor Octavio Augustus over 2000 years ago. Zaragoza, a city where different cultures, Muslims, Jewish, and Christians have left their mark is famous for its landmarks such as the Basilica del Pilar, La Seo Cathedral and the Aljaferfa Palace as well as the local cuisine. The conference is organized every four years as a forum for the European neutron scattering community to discuss recent developments and advances in all branches of science in which neutron scattering is, or eventually could be used. In 2015 the conference gathered more than 650 participants from 31 different countries from around the globe including Japan, United States of America, Taiwan, Republic of Korea, India, Argentina, China and Australia. This volume assembles the proceedings of the ECNS 2015. The main topics in the conference were; Neutron Sources and Facilities, Neutron Instrumentation (Optics, Sample Environment, Detectors and Software), Fundamental Science, Chemistry of Materials, Magnetism, Superconductivity, Functional Materials, Glasses and Liquids, Thin Films and Interfaces, Soft Condensed Matter, Health and Life Sciences, Engineering applications, Cultural Heritage and Archaeometry. Jean-Marie Tarascon, J. Manuel Perez-Mato, Roberto Caciuffo, Paul Schofield, Peter Fierlinger, Helmut Schober and Frank Gabel presented plenary talks. In addition, 33 keynote talks and 222 oral presentations were given during the four parallel sessions as well as 325 poster presentations. The poster sessions, which were held during the lunch and coffee breaks, were well attended and participants had time to visit not only the posters but also the exhibition. The VI European Conference on

  10. The dynamics of physisorbed layers studied by neutron scattering

    International Nuclear Information System (INIS)

    Nielsen, M.; McTague, J.P.

    1978-01-01

    We discuss the neutron scattering technique applied to the study of adsorbed thin films. Despite the fact that neutrons are scattered very weakly by surfaces, recent studies have shown that both structural and dynamical information can be obtained even for submonolayer coverages. Results will be shown for films of Ar, D 2 , H 2 , and O 2 adsorbed on (001) surfaces of graphite and for H 2 molecules adsorbed on activated alumina. (orig.) [de

  11. Thermal neutron scattering cross sections of beryllium and magnesium oxides

    International Nuclear Information System (INIS)

    Al-Qasir, Iyad; Jisrawi, Najeh; Gillette, Victor; Qteish, Abdallah

    2016-01-01

    Highlights: • Neutron thermalization in BeO and MgO was studied using Ab initio lattice dynamics. • The BeO phonon density of states used to generate the current ENDF library has issues. • The BeO cross sections can provide a more accurate ENDF library than the current one. • For MgO an ENDF library is lacking: a new accurate one can be built from our results. • BeO is a better filter than MgO, especially when cooled down to 77 K. - Abstract: Alkaline-earth beryllium and magnesium oxides are fundamental materials in nuclear industry and thermal neutron scattering applications. The calculation of the thermal neutron scattering cross sections requires a detailed knowledge of the lattice dynamics of the scattering medium. The vibrational properties of BeO and MgO are studied using first-principles calculations within the frame work of the density functional perturbation theory. Excellent agreement between the calculated phonon dispersion relations and the experimental data have been obtained. The phonon densities of states are utilized to calculate the scattering laws using the incoherent approximation. For BeO, there are concerns about the accuracy of the phonon density of states used to generate the current ENDF/B-VII.1 libraries. These concerns are identified, and their influences on the scattering law and inelastic scattering cross section are analyzed. For MgO, no up to date thermal neutron scattering cross section ENDF library is available, and our results represent a potential one for use in different applications. Moreover, the BeO and MgO efficiencies as neutron filters at different temperatures are investigated. BeO is found to be a better filter than MgO, especially when cooled down, and cooling MgO below 77 K does not significantly improve the filter’s efficiency.

  12. Nondestructive hydrogen analysis of steam-oxidized Zircaloy-4 by wide-angle neutron scattering

    Science.gov (United States)

    Yan, Yong; Qian, Shuo; Garrison, Ben; Smith, Tyler; Kim, Peter

    2018-04-01

    A nondestructive neutron scattering method to precisely measure the hydrogen content in high-temperature steam-oxidized Zircaloy-4 cladding was developed. Zircaloy-4 cladding was used to produce hydrided specimens with hydrogen content up to ≈500 wppm. 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 concentrations were selected for the neutron study. The hydrided samples were then oxidized in steam up to ≈6.0 wt. % at 1100 °C. Optical microscopy shows that our hydriding procedure results in uniform distribution of circumferential hydrides across the wall thickness, and uniform oxide layers were formed on the sample surfaces by the steam oxidation. Small- and wide-angle neutron scattering were simultaneously performed to provide a quick (less than an hour per sample) measurement of the hydrogen content in various types of hydrided and oxidized Zircaloy-4. Our study demonstrates that the hydrogen in pre-oxidized Zircaloy-4 cladding can be measured very accurately by both small- and wide-angle neutron scattering. For steam-oxidized samples, the small-angle neutron scattering is contaminated with coherent scattering from additional structural features induced by the steam oxidation. However, the scattering intensity of the wide-angle neutron scattering increases proportionally with the hydrogen charged in the samples. The hydrogen content and wide-angle neutron scattering intensity are highly linearly correlated for the oxidized cladding samples examined in this work, and can be used to precisely determine the hydrogen content in steam-oxidized Zircaloy-4 samples. Hydrogen contents determined by neutron scattering of oxidation samples were also found to be consistent with the results of chemical analysis within acceptable margins for error.

  13. The small-angle neutron scattering facility at the SAFARI-1 reactor

    International Nuclear Information System (INIS)

    Hofmeyr, C.; Mayer, R.M.; Tillwick, D.L.

    1979-01-01

    A long-wavelength neutron scattering facility at the SAFARI-1 reactor is described. Neutrons of wavelength between 5 and 15 A can be selected. Features of the facility are the use of microwave guides as neutron conductors, flexible guide-pipe configuration and automatic sequential sample changing. Examples are given of measurements on radiation-induced voids in copper, aluminium, Al-0.4%Si and Al-0.1%In after neutron irradiation and magnetic scattering in US and in 80US-10UC-10UC 2 . (Auth.)

  14. Fast Neutron Elastic and Inelastic Scattering of Vanadium

    Energy Technology Data Exchange (ETDEWEB)

    Holmqvist, B; Johansson, S G; Lodin, G; Wiedling, T

    1969-11-15

    Fast neutron scattering interactions with vanadium were studied using time-of-flight techniques at several energies in the interval 1.5 to 8.1 MeV. The experimental differential elastic scattering cross sections have been fitted to optical model calculations and the inelastic scattering cross sections have been compared with Hauser-Feshbach calculations, corrected for the fluctuation of compound-nuclear level widths.

  15. Multiple small-angle neutron scattering studies of anisotropic materials

    CERN Document Server

    Allen, A J; Long, G G; Ilavsky, J

    2002-01-01

    Building on previous work that considered spherical scatterers and randomly oriented spheroidal scatterers, we describe a multiple small-angle neutron scattering (MSANS) analysis for nonrandomly oriented spheroids. We illustrate this with studies of the multi-component void morphologies found in plasma-spray thermal barrier coatings. (orig.)

  16. Development of new methods for studying nanostructures using neutron scattering

    Energy Technology Data Exchange (ETDEWEB)

    Pynn, Roger [Indiana Univ., Bloomington, IN (United States)

    2016-03-18

    The goal of this project was to develop improved instrumentation for studying the microscopic structures of materials using neutron scattering. Neutron scattering has a number of advantages for studying material structure but suffers from the well-known disadvantage that neutrons’ ability to resolve structural details is usually limited by the strength of available neutron sources. We aimed to overcome this disadvantage using a new experimental technique, called Spin Echo Scattering Angle Encoding (SESAME) that makes use of the neutron’s magnetism. Our goal was to show that this innovation will allow the country to make better use of the significant investment it has recently made in a new neutron source at Oak Ridge National Laboratory (ORNL) and will lead to increases in scientific knowledge that contribute to the Nation’s technological infrastructure and ability to develop advanced materials and technologies. We were successful in demonstrating the technical effectiveness of the new method and established a baseline of knowledge that has allowed ORNL to start a project to implement the method on one of its neutron beam lines.

  17. Proceedings of the workshop on neutron scattering instrumentation for SNQ

    International Nuclear Information System (INIS)

    Scherm, R.; Stiller, H.

    1984-10-01

    These proceedings contain the articles presented at the named workshop. These concern instrumentation for neutron diffraction with special regards to small angle scattering, diffuse scattering, inelastic scattering, high resolution spectroscopy, and special techniques. (HSI)

  18. Dynamic properties of electrons in solids by neutron scattering

    International Nuclear Information System (INIS)

    Lovesey, S.W.

    1980-12-01

    Illustrative cases of the use of neutron scattering in the study of the electronic properties of materials discussed here include scattering by localised electrons, narrow band materials and electron plasmas. (U.K.)

  19. Neutron scattering for the analysis of biological structures. Brookhaven symposia in biology. Number 27

    Energy Technology Data Exchange (ETDEWEB)

    Schoenborn, B P [ed.

    1976-01-01

    Sessions were included on neutron scattering and biological structure analysis, protein crystallography, neutron scattering from oriented systems, solution scattering, preparation of deuterated specimens, inelastic scattering, data analysis, experimental techniques, and instrumentation. Separate entries were made for the individual papers.

  20. A thermal neutron scattering law for yttrium hydride

    Science.gov (United States)

    Zerkle, Michael; Holmes, Jesse

    2017-09-01

    Yttrium hydride (YH2) is of interest as a high temperature moderator material because of its superior ability to retain hydrogen at elevated temperatures. Thermal neutron scattering laws for hydrogen bound in yttrium hydride (H-YH2) and yttrium bound in yttrium hydride (Y-YH2) prepared using the ab initio approach are presented. Density functional theory, incorporating the generalized gradient approximation (GGA) for the exchange-correlation energy, is used to simulate the face-centered cubic structure of YH2 and calculate the interatomic Hellmann-Feynman forces for a 2 × 2 × 2 supercell containing 96 atoms. Lattice dynamics calculations using PHONON are then used to determine the phonon dispersion relations and density of states. The calculated phonon density of states for H and Y in YH2 are used to prepare H-YH2 and Y-YH2 thermal scattering laws using the LEAPR module of NJOY2012. Analysis of the resulting integral and differential scattering cross sections demonstrates adequate resolution of the S(α,β) function. Comparison of experimental lattice constant, heat capacity, inelastic neutron scattering spectra and total scattering cross section measurements to calculated values are used to validate the thermal scattering laws.

  1. Simulation of complete neutron scattering experiments: from model systems to liquid germanium

    International Nuclear Information System (INIS)

    Hugouvieux, V.

    2004-11-01

    In this thesis, both theoretical and experimental studies of liquids are done. Neutron scattering enables structural and dynamical properties of liquids to be investigated. On the theoretical side, molecular dynamics simulations are of great interest since they give positions and velocities of the atoms and the forces acting on each of them. They also enable spatial and temporal correlations to be computed and these quantities are also available from neutron scattering experiments. Consequently, the comparison can be made between results from molecular dynamics simulations and from neutron scattering experiments, in order to improve our understanding of the structure and dynamics of liquids. However, since extracting reliable data from a neutron scattering experiment is difficult, we propose to simulate the experiment as a whole, including both instrument and sample, in order to gain understanding and to evaluate the impact of the different parasitic contributions (absorption, multiple scattering associated with elastic and inelastic scattering, instrument resolution). This approach, in which the sample is described by its structure and dynamics as computed from molecular dynamics simulations, is presented and tested on isotropic model systems. Then liquid germanium is investigated by inelastic neutron scattering and both classical and ab initio molecular dynamics simulations. This enables us to simulate the experiment we performed and to evaluate the influence of the contributions from the instrument and from the sample on the detected signal. (author)

  2. Superfluidity, Bose condensation and neutron scattering in liquid 4He

    International Nuclear Information System (INIS)

    Silver, R.N.

    1997-01-01

    The relation between superfluidity and Bose condensation in 4 He provides lessons that may be valuable in understanding the strongly correlated electron system of high T c superconductivity. Direct observation of a Bose condensate in the superfluid by deep inelastic neutron scattering measurements has been attempted over many years. But the impulse approximation, which relates momentum distributions to neutron scattering structure functions, is broadened by final state effects. Nevertheless, the excellent quantitative agreement between ab initio quantum many body theory and high precision neutron experiments provides confidence in the connection between superfluidity and Bose condensation

  3. A combined neutron scattering and simulation study on bioprotectant systems

    Energy Technology Data Exchange (ETDEWEB)

    Affouard, F. [Laboratoire de Dynamique et Structure des Materiaux Moleculaires UMR 8024, Universite Lille I - 59655 Villeneuve d' Ascq cedex (France); Bordat, P. [Laboratoire de Dynamique et Structure des Materiaux Moleculaires UMR 8024, Universite Lille I - 59655 Villeneuve d' Ascq cedex (France); Descamps, M. [Laboratoire de Dynamique et Structure des Materiaux Moleculaires UMR 8024, Universite Lille I - 59655 Villeneuve d' Ascq cedex (France); Lerbret, A. [Laboratoire de Dynamique et Structure des Materiaux Moleculaires UMR 8024, Universite Lille I - 59655 Villeneuve d' Ascq cedex (France); Magazu, S. [Dipartimento di Fisica and INFM, Universita di Messina, P.O. Box 55, I-98166 Messina (Italy); Migliardo, F. [Laboratoire de Dynamique et Structure des Materiaux Moleculaires UMR 8024, Universite Lille I - 59655 Villeneuve d' Ascq cedex (France); Dipartimento di Fisica and INFM, Universita di Messina, P.O. Box 55, I-98166 Messina (Italy)], E-mail: fmigliardo@unime.it; Ramirez-Cuesta, A.J. [ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot (United Kingdom); Telling, M.F.T. [ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot (United Kingdom)

    2005-10-31

    The present work shows quasi elastic neutron scattering, neutron spin echo and inelastic neutron scattering results on a class of bioprotectant systems, such as homologous disaccharides (i.e., trehalose and sucrose)/water solutions, as a function of temperature. The whole set of findings indicates a noticeable 'kosmotrope' character of the disaccharides, and in particular of trehalose, which is able to strongly modify both the structural and dynamical properties of water. This superior capability of trehalose can be linked to its higher bioprotective effectiveness in respect with the other disaccharides.

  4. The world’s first pelletized cold neutron moderator at a neutron scattering facility

    Energy Technology Data Exchange (ETDEWEB)

    Ananiev, V.; Belyakov, A.; Bulavin, M.; Kulagin, E.; Kulikov, S.; Mukhin, K.; Petukhova, T.; Sirotin, A.; Shabalin, D.; Shabalin, E.; Shirokov, V.; Verhoglyadov, A., E-mail: verhoglyadov_al@mail.ru

    2014-02-01

    In July 10, 2012 cold neutrons were generated for the first time with the unique pelletized cold neutron moderator CM-202 at the IBR-2M reactor. This new moderator system uses small spherical beads of a solid mixture of aromatic hydrocarbons (benzene derivatives) as the moderating material. Aromatic hydrocarbons are known as the most radiation-resistant hydrogenous substances and have properties to moderate slow neutrons effectively. Since the new moderator was put into routine operation in September 2013, the IBR-2 research reactor of the Frank Laboratory of Neutron Physics has consolidated its position among the world’s leading pulsed neutron sources for investigation of matter with neutron scattering methods.

  5. X-ray, neutron, and electron scattering. Report of a materials sciences workshop

    International Nuclear Information System (INIS)

    1977-08-01

    The ERDA Workshop on X-ray, Neutron, and Electron Scattering to assess needs and establish priorities for energy-related basic research on materials. The general goals of the Workshop were: (1) to review various energy technologies where x-ray, neutron, and electron scattering techniques might make significant contributions, (2) to identify present and future materials problems in the energy technologies and translate these problems into requirements for basic research by x-ray, neutron, and electron scattering techniques, (3) to recommend research areas utilizing these three scattering techniques that should be supported by the DPR Materials Sciences Program, and (4) to assign priorities to these research areas

  6. The use of vanadium as a scattering standard for pulsed source neutron spectrometers

    International Nuclear Information System (INIS)

    Mayers, J.

    1983-06-01

    The Gaussian approximation for multiphonon cross-sections has been used in a calculation of the variation of vanadium cross-sections with incident neutron energy. The results show that vanadium behaves as an elastic scatterer to within a few percent on pulsed neutron spectrometers with incident neutron energies up to 1 eV. There is a calculated anisotropy in the scattering of 8%. It is found that the scattering properties of vanadium at 77K and 293K differ by a maximum of 1% except for neutron energies < 15 meV. (author)

  7. Anomalous neutron Compton scattering cross section in zirconium hydride

    International Nuclear Information System (INIS)

    Abdul-Redah, T.; Krzystyniak, M.; Mayers, J.; Chatzidimitriou-Dreismann, C.A.

    2005-01-01

    In the last few years we observed a shortfall of intensity of neutrons scattered from protons in various materials including metal hydrogen systems using neutron Compton scattering (NCS) on the VESUVIO instrument (ISIS, UK). This anomaly has been attributed to the existence of short-lived quantum entangled states of protons in these materials. Here we report on results of very recent NCS measurements on ZrH 2 at room temperature. Also here an anomalous shortfall of scattering intensity due to protons is observed. In contrast to previous experiments on NbH 0.8 , the anomalies found in ZrH 2 are independent of the scattering angle (or momentum transfer). These different results are discussed in the light of recent criticisms and experimental tests related to the data analysis procedure on VESUVIO

  8. The electron-spin--nuclear-spin interaction studied by polarized neutron scattering.

    Science.gov (United States)

    Stuhrmann, Heinrich B

    2007-11-01

    Dynamic nuclear spin polarization (DNP) is mediated by the dipolar interaction of paramagnetic centres with nuclear spins. This process is most likely to occur near paramagnetic centres at an angle close to 45 degrees with respect to the direction of the external magnetic field. The resulting distribution of polarized nuclear spins leads to an anisotropy of the polarized neutron scattering pattern, even with randomly oriented radical molecules. The corresponding cross section of polarized coherent neutron scattering in terms of a multipole expansion is derived for radical molecules in solution. An application using data of time-resolved polarized neutron scattering from an organic chromium(V) molecule is tested.

  9. Quantum entanglement and neutron scattering experiments

    International Nuclear Information System (INIS)

    Cowley, R A

    2003-01-01

    It is shown that quantum entanglement in condensed matter can be observed with scattering experiments if the energy resolution of the experiments enables a clear separation between the elastic scattering and the scattering from the excitations in the system. These conditions are not satisfied in recent deep inelastic neutron scattering experiments from hydrogen-containing systems that have been interpreted as showing the existence of quantum entanglement for short times in, for example, water at room temperature. It is shown that the theory put forward to explain these experiments is inconsistent with the first-moment sum rule for the Van Hove scattering function and we suggest that the theory is incorrect. The experiments were performed using the unique EVS spectrometer at ISIS and suggestions are made about how the data and their interpretation should be re-examined

  10. Polymer research by neutron scattering

    International Nuclear Information System (INIS)

    Richter, D.

    1993-01-01

    Polymer physics aims on an understanding of the macroscopic behavior of polymer systems on the basis of their molecular structure and dynamics. For this purpose neutrons serve as a unique probe, allowing a simultaneous investigation of polymer structure and dynamics on a molecular scale. Furthermore, hydrogen deuterium exchange facilitates molecular labeling and offers the possibility to observe selected chains or chain parts in dense systems. Neutron small angle scattering reveals information on the conformation and possible aggregation of polymer chains. Data on linear and star like molecules are shown as examples. High resolution neutron spin-echospectroscopy observes the molecular dynamics of long chain molecules. Results on the large scale motion of chins in polymer melts are presented. finally, experiments on chain relaxation close to the glass transition are displayed. Three distinctly different relaxation processes are revealed. (author)

  11. Neutron scattering facility for the calibration of the response to nuclear recoils

    International Nuclear Information System (INIS)

    Jochum, J.; Feilitzsch, F. von; Huber, M.; Jagemann, T.; Lachenmaier, T.; Lanfranchi, J.-C.; Potzel, W.; Ruedig, A.; Schnagl, J.; Stark, M.; Wulandari, H.; Chambon, B.; Drain, D.; Gascon, J.; Jesus, M. de; Martineau, O.; Simon, E.; Stern, M.

    2002-01-01

    A possibility to search for elementary particles as dark matter candidates is to detect elastic scattering with cryogenic detectors. For the interpretation of the data one has to determine the detector response to nuclear recoils, the so-called quenching factors. They can differ for the heat-, for the scintillation- and for the ionization-signal and can be measured by scattering of neutrons. The CRESST- and the EDELWEISS-collaborations have set up a neutron scattering facility for cryogenic detectors at the tandem-accelerator of the Munich 'Maier-Leibniz-Labor.' The scattering angle and the time-of-flight of the neutrons are measured by an array of liquid scintillator cells. The pulsed high energy (11 MeV) neutron beam is created by nuclear reaction of a 11 B on a H 2 -gas target. The set-up and the results of first tests are presented

  12. Bibliography for thermal neutron scattering

    International Nuclear Information System (INIS)

    Sakamoto, Masanobu; Chihara, Junzo; Gotoh, Yorio; Kadotani, Hiroyuki; Sekiya, Tamotsu.

    1979-09-01

    Bibliographic references are given for measurements, calculations, reviews and basic studies of thermal neutron scattering and dynamical properties of condensed matter. This is the sixth edition covering 3,326 articles collected up to 1978. The edition being the final issue of the present bibliography series, a forthcoming edition will be published in a new form of bibliography. (author)

  13. Time-of-flight and vector polarization analysis for diffuse neutron scattering

    International Nuclear Information System (INIS)

    Schweika, W.

    2003-01-01

    The potential of pulsed neutron sources for diffuse scattering including time-of-flight (TOF) and polarization analysis is discussed in comparison to the capabilities of the present instrument diffuse neutron scattering at the research center Juelich. We present first results of a new method for full polarization analysis using precessing neutron polarization. A proposal is made for a new type of instrument at pulsed sources, which allows for vector polarization analysis in TOF instruments with multi-detectors

  14. Neutron scattering from polarised proton domains

    CERN Document Server

    Van den Brandt, B; Kohbrecher, J; Konter, J A; Mango, S; Glattli, H; Leymarie, E; Grillo, I; May, R P; Jouve, H; Stuhrmann, H B; Stuhrmann, H B; Zimmer, O

    2002-01-01

    Time-dependent small-angle polarised neutron scattering from domains of polarised protons has been observed at the onset of dynamic nuclear polarisation in a frozen solution of 98% deuterated glycerol-water at 1 K containing a small concentration of paramagnetic centres (EHBA-Cr sup V). Simultaneous NMR measurements show that the observed scattering arises from protons around the Cr sup V -ions which are polarised to approx 10% in a few seconds, much faster than the protons in the bulk. (authors)

  15. The neutron spin-echo spectrometer: a new high resolution technique in neutron scattering

    International Nuclear Information System (INIS)

    Nicholson, L.K.

    1981-01-01

    The neutron spin-echo (NSE) spectrometer provides the highest energy resolution available in neutron scattering experiments. The article describes the principles behind the first NSE spectrometer (at the Institute Laue-Langevin, Grenoble, France) and, as an example of one of its applications, some recent results on polymer chain dynamics are presented. (author)

  16. Spectrometer for neutron inelastic scattering investigations of microsamples

    International Nuclear Information System (INIS)

    Balagurov, A.M.; Kozlenko, D.P.; Platonov, S.L.; Savenko, B.N.; Glazkov, V.P.; Krasnikov, Yu.M.; Naumov, I.V.; Pukhov, A.V.; Somenkov, V.A.; Syrykh, G.F.

    1997-01-01

    A new neutron spectrometer for investigation of inelastic neutron scattering on polycrystal microsamples under high pressure in sapphire and diamond anvils cells is described. The spectrometer is operating at the IBR-2 pulsed reactor in JINR. Parameters and methodical peculiarities of the spectrometer and the examples of experimental studies are given. (author)

  17. Neutron Scattering at HIFAR—Glimpses of the Past

    Directory of Open Access Journals (Sweden)

    Margaret Elcombe

    2017-04-01

    Full Text Available This article attempts to give a description of neutron scattering down under for close on forty-six years. The early years describe the fledgling group buying parts and cobbling instruments together to its emergence as a viable neutron scattering group with up to ten working instruments. The second section covers the consolidation of this group, despite tough higher level management. The Australian Science and Technology Council (ASTEC enquiry in 1985 and the Government decision not to replace the HIgh Flux Australian Reactor (HIFAR, led to major expansion and upgrading of the existing neutron beam facilities during the 1990s. Finally, there were some smooth years of operation while other staff were preparing for the replacement reactor. It has concentrated on the instruments as they were built, modified, replaced with new ones, and upgraded at different times.

  18. Elastic neutron scattering studies at 96 MeV for transmutation.

    Science.gov (United States)

    Osterlund, M; Blomgren, J; Hayashi, M; Mermod, P; Nilsson, L; Pomp, S; Ohrn, A; Prokofiev, A V; Tippawan, U

    2007-01-01

    Elastic neutron scattering from (12)C, (14)N, (16)O, (28)Si, (40)Ca, (56)Fe, (89)Y and (208)Pb has been studied at 96 MeV in the10-70 degrees interval, using the SCANDAL (SCAttered Nucleon Detection AssembLy) facility. The results for (12)C and (208)Pb have recently been published, while the data on the other nuclei are under analysis. The achieved energy resolution, 3.7 MeV, is about an order of magnitude better than for any previous experiment above 65 MeV incident energy. A novel method for normalisation of the absolute scale of the cross section has been used. The estimated normalisation uncertainty, 3%, is unprecedented for a neutron-induced differential cross section measurement on a nuclear target. Elastic neutron scattering is of utmost importance for a vast number of applications. Besides its fundamental importance as a laboratory for tests of isospin dependence in the nucleon-nucleon, and nucleon-nucleus, interaction, knowledge of the optical potentials derived from elastic scattering come into play in virtually every application where a detailed understanding of nuclear processes is important. Applications for these measurements are dose effects due to fast neutrons, including fast neutron therapy, as well as nuclear waste incineration and single event upsets in electronics. The results at light nuclei of medical relevance ((12)C, (14)N and (16)O) are presented separately. In the present contribution, results on the heavier nuclei are presented, among which several are of relevance to shielding of fast neutrons.

  19. A review of neutron scattering correction for the calibration of neutron survey meters using the shadow cone method

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sang In; Kim, Bong Hwan; Kim, Jang Lyul; Lee, Jung Il [Health Physics Team, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-12-15

    The calibration methods of neutron-measuring devices such as the neutron survey meter have advantages and disadvantages. To compare the calibration factors obtained by the shadow cone method and semi-empirical method, 10 neutron survey meters of five different types were used in this study. This experiment was performed at the Korea Atomic Energy Research Institute (KAERI; Daejeon, South Korea), and the calibration neutron fields were constructed using a {sup 252}Californium ({sup 252}Cf) neutron source, which was positioned in the center of the neutron irradiation room. The neutron spectra of the calibration neutron fields were measured by a europium-activated lithium iodide scintillator in combination with KAERI's Bonner sphere system. When the shadow cone method was used, 10 single moderator-based survey meters exhibited a smaller calibration factor by as much as 3.1 - 9.3% than that of the semi-empirical method. This finding indicates that neutron survey meters underestimated the scattered neutrons and attenuated neutrons (i.e., the total scatter corrections). This underestimation of the calibration factor was attributed to the fact that single moderator-based survey meters have an under-ambient dose equivalent response in the thermal or thermal-dominant neutron field. As a result, when the shadow cone method is used for a single moderator-based survey meter, an additional correction and the International Organization for Standardization standard 8529-2 for room-scattered neutrons should be considered.

  20. A review of neutron scattering correction for the calibration of neutron survey meters using the shadow cone method

    International Nuclear Information System (INIS)

    Kim, Sang In; Kim, Bong Hwan; Kim, Jang Lyul; Lee, Jung Il

    2015-01-01

    The calibration methods of neutron-measuring devices such as the neutron survey meter have advantages and disadvantages. To compare the calibration factors obtained by the shadow cone method and semi-empirical method, 10 neutron survey meters of five different types were used in this study. This experiment was performed at the Korea Atomic Energy Research Institute (KAERI; Daejeon, South Korea), and the calibration neutron fields were constructed using a 252 Californium ( 252 Cf) neutron source, which was positioned in the center of the neutron irradiation room. The neutron spectra of the calibration neutron fields were measured by a europium-activated lithium iodide scintillator in combination with KAERI's Bonner sphere system. When the shadow cone method was used, 10 single moderator-based survey meters exhibited a smaller calibration factor by as much as 3.1 - 9.3% than that of the semi-empirical method. This finding indicates that neutron survey meters underestimated the scattered neutrons and attenuated neutrons (i.e., the total scatter corrections). This underestimation of the calibration factor was attributed to the fact that single moderator-based survey meters have an under-ambient dose equivalent response in the thermal or thermal-dominant neutron field. As a result, when the shadow cone method is used for a single moderator-based survey meter, an additional correction and the International Organization for Standardization standard 8529-2 for room-scattered neutrons should be considered

  1. Influence of orientation averaging on the anisotropy of thermal neutrons scattering on water molecules

    International Nuclear Information System (INIS)

    Markovic, M. I.; Radunovic, J. B.

    1976-01-01

    Determination of spatial distribution of neutron flux in water, most frequently used moderator in thermal reactors, demands microscopic scattering kernels dependence on cosine of thermal neutrons scattering angle when solving the Boltzmann equation. Since spatial orientation of water molecules influences this dependence it is necessary to perform orientation averaging or rotation-vibrational intermediate scattering function for water molecules. The calculations described in this paper and the obtained results showed that methods of orientation averaging do not influence the anisotropy of thermal neutrons scattering on water molecules, but do influence the inelastic scattering

  2. Polarized neutron scattering on HYSPEC: the HYbrid SPECtrometer at SNS

    OpenAIRE

    Zaliznyak, Igor A; Savici, Andrei T.; Garlea, V. Ovidiu; Winn, Barry; Filges, Uwe; Schneeloch, John; Tranquada, John M.; Gu, Genda; Wang, Aifeng; Petrovic, Cedomir

    2016-01-01

    We describe some of the first polarized neutron scattering measurements performed at HYSPEC spectrometer at the Spallation Neutron Source, Oak Ridge National Laboratory. We discuss details of the instrument setup and the experimental procedures in the mode with full polarization analysis. Examples of polarized neutron diffraction and polarized inelastic neutron data obtained on single crystal samples are presented.

  3. Corrections on energy spectrum and scattering for fast neutron radiography at NECTAR facility

    International Nuclear Information System (INIS)

    Liu Shuquan; Thomas, Boucherl; Li Hang; Zou Yubin; Lu Yuanrong; Guo Zhiyu

    2013-01-01

    Distortions caused by the neutron spectrum and scattered neutrons are major problems in fast neutron radiography and should be considered for improving the image quality. This paper puts emphasis on the removal of these image distortions and deviations for fast neutron radiography performed at the NECTAR facility of the research reactor FRM-Ⅱ in Technische Universitaet Mounchen (TUM), Germany. The NECTAR energy spectrum is analyzed and established to modify the influence caused by the neutron spectrum, and the Point Scattered Function (PScF) simulated by the Monte-Carlo program MCNPX is used to evaluate scattering effects from the object and improve image quality. Good analysis results prove the sound effects of the above two corrections. (authors)

  4. Corrections on energy spectrum and scatterings for fast neutron radiography at NECTAR facility

    Science.gov (United States)

    Liu, Shu-Quan; Bücherl, Thomas; Li, Hang; Zou, Yu-Bin; Lu, Yuan-Rong; Guo, Zhi-Yu

    2013-11-01

    Distortions caused by the neutron spectrum and scattered neutrons are major problems in fast neutron radiography and should be considered for improving the image quality. This paper puts emphasis on the removal of these image distortions and deviations for fast neutron radiography performed at the NECTAR facility of the research reactor FRM- II in Technische Universität München (TUM), Germany. The NECTAR energy spectrum is analyzed and established to modify the influence caused by the neutron spectrum, and the Point Scattered Function (PScF) simulated by the Monte-Carlo program MCNPX is used to evaluate scattering effects from the object and improve image quality. Good analysis results prove the sound effects of the above two corrections.

  5. A new instrumental set-up for polarized neutron scattering experiments

    International Nuclear Information System (INIS)

    Schmidt, Wolfgang; Ohl, Michael

    2005-01-01

    Neutron scattering with polarization analysis is a powerful tool to determine magnetic structures and excitations. A common setup is to mount the sample at the center of a Helmholtz-type coil which can provide a magnetic field of any direction at the sample position and also a guide field along the neutron flight paths around the sample. Recent experiments showed quite a high demand for measurements at low momentum transfers. For the corresponding low scattering angles air scattering gives rise to a very large background. For this reason we have extended the standard setup to a combination of a large vacuum tank surrounded by electrical coils. The vacuum tank eliminates the air scattering and we can use the polarization analysis down to the lowest accessible momentum transfers. The coils themselves also show some new features: In contrary to the classic (symmetric) coil distribution we use an asymmetric setup which gives the advantage of a larger scattering window. Due to a more sophisticated current distribution this modified coil arrangement needs not to be rotated for different scattering conditions. The whole set-up will soon be available at IN12, a cold neutrons three-axis spectrometer operated by FZ Juelich in collaboration with CEA Grenoble as a CRG-B instrument at the Institut Laue Langevin in Grenoble

  6. Note on neutron scattering and the optical model near A = 208

    International Nuclear Information System (INIS)

    Guenther, P.; Havel, D.; Smith, A.

    1976-09-01

    Elastic neutron scattering cross sections of 206 Pb, 207 Pb, 208 Pb and 209 Bi are measured at incident neutron energy intervals of approx. 25 keV from 0.6 to 1.0 MeV with resolutions of approx. 25 keV. Optical model parameters are obtained from the energy-averaged experimental results for each of the isotopes. The observed elastic-neutron-scattering distributions and derived parameters for the lead isotopes (doubly magic or neutron holes in the closed shell) tend to differ from those of 209 Bi (doubly closed shell plus a proton). These potentials, derived in the approx. spherical region of A approximately 208, are extrapolated for the analysis of total and scattering cross sections of 238 U introducing only a small N-Z/A dependence and the known deformation of 238 U. Good descriptions of 238 U total cross sections are obtained from a few hundred keV to 10.0 MeV and the prediction of measured scattering distributions in the low MeV region are as suitable as frequently reported with other specially developed potentials

  7. Fast-neutron total and scattering cross sections of niobium

    Energy Technology Data Exchange (ETDEWEB)

    Smith, A.B.; Guenther, P.T.; Whalen, J.F.

    1982-07-01

    Neutron total cross sections of niobium were measured from approx. = 0.7 to 4.5 MeV at intervals of less than or equal to 50 keV with broad resolution. Differential-elastic-scattering cross sections were measured from approx. = 1.5 to 4.0 MeV at intervals of 0.1 to 0.2 MeV and at 10 to 20 scattering angles distributed between approx. = 20 and 160 degrees. Inelastically-scattered neutrons, corresponding to the excitation of levels at: 788 +- 23, 982 +- 17, 1088 +- 27, 1335 +- 35, 1504 +- 30, 1697 +- 19, 1971 +- 22, 2176 +- 28, 2456 +- (.), and 2581 +- (.) keV, were observed. An optical-statistical model, giving a good description of the observables, was deduced from the measured differential-elastic-scattering cross sections. The experimental-results were compared with the respective evaluated quantities given in ENDF/B-V.

  8. Fast-neutron total and scattering cross sections of niobium

    International Nuclear Information System (INIS)

    Smith, A.B.; Guenther, P.T.; Whalen, J.F.

    1982-07-01

    Neutron total cross sections of niobium were measured from approx. = 0.7 to 4.5 MeV at intervals of less than or equal to 50 keV with broad resolution. Differential-elastic-scattering cross sections were measured from approx. = 1.5 to 4.0 MeV at intervals of 0.1 to 0.2 MeV and at 10 to 20 scattering angles distributed between approx. = 20 and 160 degrees. Inelastically-scattered neutrons, corresponding to the excitation of levels at: 788 +- 23, 982 +- 17, 1088 +- 27, 1335 +- 35, 1504 +- 30, 1697 +- 19, 1971 +- 22, 2176 +- 28, 2456 +- (.), and 2581 +- (.) keV, were observed. An optical-statistical model, giving a good description of the observables, was deduced from the measured differential-elastic-scattering cross sections. The experimental-results were compared with the respective evaluated quantities given in ENDF/B-V

  9. Investigation of static and dynamic properties of condensed matter by using neutron scattering

    International Nuclear Information System (INIS)

    Davidovic, M.

    1997-01-01

    Possibilities of using neutron scattering for investigating microscopic properties of materials are analyzed. Basic neutron scattering theory is presented and its use in structure and dynamics analyses of condense systems. (author)

  10. The importance of anisotropic scattering in high energy neutron transport problems

    International Nuclear Information System (INIS)

    Prillinger, G.; Mattes, M.

    1984-01-01

    To describe the highly anisotropic scattering of very fast neutrons adequately the transport code ANISN has been improved. Fokker-Planck terms have been introduced into the transport equation which accurately describe the small changes in energy and angle. The new code has been tested for a d(50)-Be neutron source in a deep penetration iron problem. The influence of the forward peaked elastic scattering on the fast neutron spectrum is shown to be significant and can be handled efficiently in the new ANISN version. Since common cross-section libraries are limited by Legendre expansion, or by their upper energy boundary, or exclude elastic scattering above 20 MeV a special library has been created. (Auth.)

  11. Optimising polarised neutron scattering measurements--XYZ and polarimetry analysis

    International Nuclear Information System (INIS)

    Cussen, L.D.; Goossens, D.J.

    2002-01-01

    The analytic optimisation of neutron scattering measurements made using XYZ polarisation analysis and neutron polarimetry techniques is discussed. Expressions for the 'quality factor' and the optimum division of counting time for the XYZ technique are presented. For neutron polarimetry the optimisation is identified as analogous to that for measuring the flipping ratio and reference is made to the results already in the literature

  12. Optimising polarised neutron scattering measurements--XYZ and polarimetry analysis

    CERN Document Server

    Cussen, L D

    2002-01-01

    The analytic optimisation of neutron scattering measurements made using XYZ polarisation analysis and neutron polarimetry techniques is discussed. Expressions for the 'quality factor' and the optimum division of counting time for the XYZ technique are presented. For neutron polarimetry the optimisation is identified as analogous to that for measuring the flipping ratio and reference is made to the results already in the literature.

  13. Interesting results from neutron-scattering

    International Nuclear Information System (INIS)

    Woods, A.D.B.

    Neutron scattering has been a useful tool in the determination of the lattice dynamics of metals, studies of the physics of magnetism in rare-earth systems, observing changes in the structure of DNA bases after ultraviolet irradiation, looking at plastic crystals, following structural phase changes in ferroelectric materials, and studying liquid He. Both low- and high-flux facilities are useful. (LL)

  14. The TUNL neutron-neutron scattering length experiment

    International Nuclear Information System (INIS)

    Trotter, D.E.G.; Tornow, W.; Howell, C.R.

    1995-01-01

    Since an accurate value for the neutron-neutron (nn) scattering length a nn is of fundamental interest, its determination should not rely on one source of experimental information only. Besides the π d capture reaction, the nd breakup reaction has been the classical reaction used for determining a nn . However, none of the published values for a nn obtained from kinematically complete nd → n+n+p breakup data are based on a rigorous treatment of the three-nucleon continuum. In addition, the scale uncertainty associated with the existing nd breakup cross-section data in the region of the nn final-state interaction peak is too large to allow for a meaningful reanalysis. Therefore, a new kinematically complete nd breakup experiment is underway at TUNL at an incident neutron energy of 13 MeV. State-of-the-art three-nucleon continuum calculations will be used to analyze the data. In order to investigate the possible influence of three-nucleon force effects, a nn will be determined from data taken at four production angles of the nn pair between 20.5 degrees and 43 degrees (lab)

  15. Options for a next generation neutron source for neutron scattering based on the projected linac facility at JAERI

    International Nuclear Information System (INIS)

    Mezei, F.; Watanabe, Noboru; Niimura, Nobuo; Morii, Yukio; Aizawa, Kazuya; Suzuki, Jun-ichi.

    1997-03-01

    Japan Atomic Energy Research Institute (JAERI) has a project to construct a high intensity proton accelerator to promote wide basic science using neutrons and nuclear power technologies such as radioactive nuclide transmutation. One of the most important field for utilization of neutron beam is neutron scattering. The energy and the averaged current obtained by the proton accelerator are 1.5 GeV and 4-5.3 mA, respectively and these provide 6-8 MW power. The repetition frequency is 50-60 Hz. Evaluation of options for the use of accelerators for neutron production for neutron scattering research and investigation of the neutron research opportunities offered by sharing the superconducting linac planned at JAERI were discussed. There are two ways of the utilization of proton beams for neutron scattering experiment. One is for long pulse spallation source (LPSS) and the other is for short pulse spallation source (SPSS). Quantitative evaluation of instrument performance with LPSS and SPSS was examined in the intensive discussion, calculations, workshop on this topics with Prof. F. Mezei who stayed at JAERI from October 24 to November 6, 1996. A report of the collaborative workshop will be also published separately. (author)

  16. Spin observables in proton-neutron scattering at intermediate energy

    International Nuclear Information System (INIS)

    Spinka, H.

    1986-05-01

    A summary of np elastic scattering spin measurements at intermediate energy is given. Preliminary results from a LAMPF experiment to measure free neutron-proton elastic scattering spin-spin correlation parameters are presented. A longitudinally polarized proton target was used. These measurements are part of a program to determine the neutron-proton amplitudes in a model independent fashion at 500, 650, and 800 MeV. Some new proton-proton total cross sections in pure helicity states (Δσ/sub L/(pp)) near 3 GeV/c are also given. 37 refs., 2 figs

  17. Polarized neutron scattering on HYSPEC: the HYbrid SPECtrometer at SNS

    Energy Technology Data Exchange (ETDEWEB)

    Zaliznyak, Igor [Brookhaven National Laboratory (BNL); Savici, Andrei T [ORNL; Garlea, Vasile O [ORNL; Winn, Barry L [ORNL; Schneelock, John [Brookhaven National Laboratory (BNL); Tranquada, John M. [Brookhaven National Laboratory (BNL); Gu, G. D. [Brookhaven National Laboratory (BNL); Wang, Aifeng [Brookhaven National Laboratory (BNL); Petrovic, C [Brookhaven National Laboratory (BNL)

    2017-01-01

    We describe some of the first polarized neutron scattering measurements performed at HYSPEC spectrometer at the Spallation Neutron Source, Oak Ridge National Laboratory. We discuss details of the instrument setup and the experimental procedures in the mode with the full polarization analysis. Examples of the polarized neutron diffraction and the polarized inelastic neutron data obtained on single crystal samples are presented.

  18. Incoherent neutron scattering in acetanilide and three deuterated derivatives

    Science.gov (United States)

    Barthes, Mariette; Almairac, Robert; Sauvajol, Jean-Louis; Moret, Jacques; Currat, Roland; Dianoux, José

    1991-03-01

    Incoherent-neutron-scattering measurements of the vibrational density of states of acetanilide and three deuterated derivatives are presented. These data allow one to identify an intense maximum, assigned to the N-H out-of-plane bending mode. The data display the specific behavior of the methyl torsional modes: large isotopic shift and strong low-temperature intensity; confirm our previous inelastic-neutron-scattering studies, indicating no obvious anomalies in the range of frequency of the acoustic phonons. In addition, the data show the existence of thermally activated quasielastic scattering above 100 K, assigned to the random diffusive motion of the methyl protons. These results are discussed in the light of recent theoretical models proposed to explain the anomalous optical properties of this crystal.

  19. Design Principle of A Small Angle Neutron Scattering Spectrometer. Vol. 2

    Energy Technology Data Exchange (ETDEWEB)

    Ashry, A [Dept. of Physics, Faculty of Education, Ain Shams University, Cairo (Egypt)

    1996-03-01

    The design principle of a small angle neutron scattering (SANS) spectrometer is based on producing monochromatic neutron bursts using two phased rotors. The rotors have a number of slots to achieve the highly available intensity of monoenergetic neutrons at the required resolution. The design principle was applied to improve the performance of the pulsed monochromatic double rotor system at ET-RR-1 to operate as SANS spectrometer. It is shown that for rotors having 19 slots each with radius of curvature 96.8 cm, the intensity gain factor is 13. The proposed SANS spectrometer could cover the neutron wavelength range from 2 A{sup {omicron}} up to 6 A{sup {omicron}} through small angles of scattering from 5 x 10{sup -3} rad. to 0.1 rad. i.e, the scattering wavevector transfer between 0.6 A{sup {omicron}-1} and 0.01 A{sup {omicron}-1}. The maximum neutron flux density on the specimen is 5 x 10{sup 5} n cm{sup -2} s{sup -1}. 8 figs.

  20. Resolution effects and analysis of small-angle neutron scattering data

    DEFF Research Database (Denmark)

    Pedersen, J.S.

    1993-01-01

    A discussion of the instrumental smearing effects for small-angle neutron scattering (SANS) data sets is given. It is shown that these effects can be described by a resolution function, which describes the distribution of scattering vectors probed for the nominal values of the scattering vector...

  1. Solution structure of a short dna fragment studied by neutron scattering

    DEFF Research Database (Denmark)

    Lederer, H.; May, R. P.; Kjems, Jørgen

    1986-01-01

    -DNA. The neutron scattering curve is well fitted by that of a rigid rod with a length of 44 nm and a diameter of 2 nm. The result were confirmed by quasi-elastic light scattering and analytical centrifugation. The neutron measurements in H2O and D2O buffer reveal a cross-sectional in homogeneity not detected by X...

  2. Slow neutron scattering in molecular crystals. 5-4

    International Nuclear Information System (INIS)

    Inoue, Kazuhiko

    1976-01-01

    The utilization of incoherent inelastic neutron scattering (INS) as a probe for molecular crystals is reviewed. In particular, some typical examples of the measurement of incoherent inelastic neutron scattering spectra (INSS) in molecular crystals are presented in the first section of this report. The results of measurement are shown for theta-xylene, benzene, polypropylene oxide, deuteride, and formic acid. The second section presents an equation for the incoherent scattering cross section of a crystal by dividing the molecular motion into the outer and inner modes. Phonon expansion is also used for the easy understanding of the relation between the INSS and the dynamic characteristics of molecular crystals. In the third section, the measured results are analyzed on the basis of the theory presented in the previous section. And the difference between the van der Waals bond and the hydrogen bond is shortly discussed. (Aoki, K.)

  3. 7Li neutron-induced elastic scattering cross section measurement using a slowing-down spectrometer

    Directory of Open Access Journals (Sweden)

    Heusch M.

    2010-10-01

    Full Text Available A new integral measurement of the 7Li neutron induced elastic scattering cross section was determined in a wide neutron energy range. The measurement was performed on the LPSC-PEREN experimental facility using a heterogeneous graphite-LiF slowing-down time spectrometer coupled with an intense pulsed neutron generator (GENEPI-2. This method allows the measurement of the integral elastic scattering cross section in a slowing-down neutron spectrum. A Bayesian approach coupled to Monte Carlo calculations was applied to extract naturalC, 19F and 7Li elastic scattering cross sections.

  4. Chemical shift of neutron resonances and some ideas on neutron resonances and scattering theory

    International Nuclear Information System (INIS)

    Ignatovich, V.K.; )

    2002-01-01

    The dependence of positions of neutron resonances in nuclei in condensed matter on chemical environment is considered. A possibility of theoretical description of neutron resonances, different from R-matrix theory is investigated. Some contradictions of standard scattering theory are discussed and a new approach without these contradictions is formulated [ru

  5. Evaluation of new pharmaceuticals using in vivo neutron inelastic scattering and neutron activation analysis

    International Nuclear Information System (INIS)

    Kehayias, J.J.

    2000-01-01

    Nutritional status of patients can be evaluated by monitoring changes in body composition, including depletion of protein and muscle, adipose tissue distribution and changes in hydration status, bone or cell mass. Fast neutron activation (for N and P) and neutron inelastic scattering (for C and O) are used to assess in vivo elements characteristic of specific body compartments. The fast neutrons are produced with a sealed deuterium-tritium (D-T) neutron generator. This method provides the most direct assessment of body composition. Non-bone phosphorus for muscle is measured by the 31 P(n,α) 28 Al reaction, and nitrogen for protein via the (n,2n) fast neutron reaction. Inelastic neutron scattering is used for the measurement of total body carbon and oxygen. Carbon is used to derive body fat, after subtracting carbon contributions due to protein, bone and glycogen. Carbon-to-oxygen (C/O) ratio is used to measure distribution of fat and lean tissue in the body and to monitor small changes of lean mass and its quality. In addition to evaluating the efficacy of new treatments, the system is used to study the mechanisms of lean tissue depletion with aging and to investigate methods for preserving function and quality of life in the elderly. (author)

  6. Current status of neutron scattering research and accelerator technology in Indonesia

    International Nuclear Information System (INIS)

    Ridwan; Ikram, Abarul; Wuryanto

    2001-01-01

    The neutron beam generated from steady state reactor 30 MW RSG-GAS are used mainly for neutron scattering studies and isotope production. There are seven neutron scattering facilities under responsible and operated by Research and Development Center for Materials Science and Technology of National Nuclear Energy Agency (Batan) of Indonesia. In this report, current conditions of the facilities namely, DN1-M, HRPD, FCD/TD, SANS, HRSANS, TAS and NRF and research activities will be described. Also, a part of research activities by using accelerator technology at Batan-Yogyakarta will be reviewed. (author)

  7. Radio-analysis of hydrogenous material using neutron back-scattering technique

    International Nuclear Information System (INIS)

    Holly, Wiam Ahmed Alteghany

    2014-10-01

    In this work, we have explored the possibility of using neutron back-scattering technique in performing radio analysis for samples of hydrogenous materials such as explosives, drugs, crude oil and water, looking for different signals that may be used to discriminate these samples. Monte Carlo simulations were carried out to model the detection system and select the optimal geometry as well. The results were determined in terms of the energy spectra of the back-scattered neutrons.(Author)

  8. Fast-neutron total and scattering cross sections of 103Rh

    International Nuclear Information System (INIS)

    Smith, A.B.; Guenther, P.T.; Whalen, J.F.

    1982-07-01

    Fast-neutron total cross sections of 103 Rh are measured with 30 to 50 keV resolutions from 0.7 to 4.5 MeV. Differential elastic- and inelastic-scattering cross sections are measured from 1.45 to 3.85 MeV. Scattered-neutron groups corresponding to excited levels at 334 +- 13, 536 +- 7, 648 +- 25, 796 +- 20, 864 +- 22, 1120 +- 22, 1279 +- 50, 1481 +- 27, 1683 +- 39, 1840 +- 79, 1991 +- 71 and 2050 (tentative) keV are observed. An optical-statistical model is derived from the elastic-scattering results. The experimental values are compared with comparable quantities given in the ENDF/B-V evaluation

  9. Method for calculating anisotropic neutron transport using scattering kernel without polynomial expansion

    International Nuclear Information System (INIS)

    Takahashi, Akito; Yamamoto, Junji; Ebisuya, Mituo; Sumita, Kenji

    1979-01-01

    A new method for calculating the anisotropic neutron transport is proposed for the angular spectral analysis of D-T fusion reactor neutronics. The method is based on the transport equation with new type of anisotropic scattering kernels formulated by a single function I sub(i) (μ', μ) instead of polynomial expansion, for instance, Legendre polynomials. In the calculation of angular flux spectra by using scattering kernels with the Legendre polynomial expansion, we often observe the oscillation with negative flux. But in principle this oscillation disappears by this new method. In this work, we discussed anisotropic scattering kernels of the elastic scattering and the inelastic scatterings which excite discrete energy levels. The other scatterings were included in isotropic scattering kernels. An approximation method, with use of the first collision source written by the I sub(i) (μ', μ) function, was introduced to attenuate the ''oscillations'' when we are obliged to use the scattering kernels with the Legendre polynomial expansion. Calculated results with this approximation showed remarkable improvement for the analysis of the angular flux spectra in a slab system of lithium metal with the D-T neutron source. (author)

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

    Directory of Open Access Journals (Sweden)

    Marquez Damian Jose Ignacio

    2017-01-01

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

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

    Science.gov (United States)

    Marquez Damian, Jose Ignacio; Granada, Jose Rolando; Cantargi, Florencia; Roubtsov, Danila

    2017-09-01

    In order to improve the design and safety of thermal nuclear reactors and for verification of criticality safety conditions on systems with significant amount of fissile materials and water, it is necessary to perform high-precision neutron transport calculations and estimate uncertainties of the results. These calculations are based on neutron interaction data distributed in evaluated nuclear data libraries. To improve the evaluations of thermal scattering sub-libraries, we developed a set of thermal neutron scattering cross sections (scattering kernels) for hydrogen bound in light water, and deuterium and oxygen bound in heavy water, in the ENDF-6 format from room temperature up to the critical temperatures of molecular liquids. The new evaluations were generated and processable with NJOY99 and also with NJOY-2012 with minor modifications (updates), and with the new version of NJOY-2016. The new TSL libraries are based on molecular dynamics simulations with GROMACS and recent experimental data, and result in an improvement of the calculation of single neutron scattering quantities. In this work, we discuss the importance of taking into account self-diffusion in liquids to accurately describe the neutron scattering at low neutron energies (quasi-elastic peak problem). To improve modeling of heavy water, it is important to take into account temperature-dependent static structure factors and apply Sköld approximation to the coherent inelastic components of the scattering matrix. The usage of the new set of scattering matrices and cross-sections improves the calculation of thermal critical systems moderated and/or reflected with light/heavy water obtained from the International Criticality Safety Benchmark Evaluation Project (ICSBEP) handbook. For example, the use of the new thermal scattering library for heavy water, combined with the ROSFOND-2010 evaluation of the cross sections for deuterium, results in an improvement of the C/E ratio in 48 out of 65

  12. Consequences of inelastic discrete-level neutron-collision mechanics for inelastic continuum scattering

    Energy Technology Data Exchange (ETDEWEB)

    Hoogenboom, J.E. (Technische Hogeschool Delft (Netherlands))

    1983-01-01

    From the collision mechanics of inelastic discrete-level scattering several properties are derived for the secondary-neutron energy distribution (SNED) for inelastic continuum scattering, when conceived as scattering with continuously-distributed inelastic levels. Using assumptions about the level density and neutron cross section the SNED can be calculated and some examples are shown. A formula is derived to calculate from a given inelastic continuum SNED a function, which is proportional to the level density and the neutron cross section. From this relation further conditions follow for the SNED. Representations for the inelastic continuum SNED currently in use do not, in general, satisfy most of the derived conditions.

  13. Consequences of inelastic discrete-level neutron-collision mechanics for inelastic continuum scattering

    International Nuclear Information System (INIS)

    Hoogenboom, J.E.

    1983-01-01

    From the collision mechanics of inelastic discrete-level scattering several properties are derived for the secondary-neutron energy distribution (SNED) for inelastic continuum scattering, when conceived as scattering with continuously-distributed inelastic levels. Using assumptions about the level density and neutron cross section the SNED can be calculated and some examples are shown. A formula is derived to calculate from a given inelastic continuum SNED a function, which is proportional to the level density and the neutron cross section. From this relation further conditions follow for the SNED. Representations for the inelastic continuum SNED currently in use do not, in general, satisfy most of the derived conditions. (author)

  14. Discerning the neutron density distribution of 208Pb from nucleon elastic scattering

    International Nuclear Information System (INIS)

    Karataglidis, S.; Amos, K.; University of Melbourne, VIC; Brown, B.A.; Deb, P.K.

    2001-01-01

    We seek a measure of the neutron density of 208 Pb from analyses of intermediate energy nucleon elastic scattering. The pertinent model for such analyses is based on coordinate space nonlocal optical potentials obtained from model nuclear ground state densities. As a calibration of the use of Skyrme-Hartree-Fock models the elastic scattering from 40 Cawas considered as well. Those potentials give predictions of integral observables and of angular distributions which show sensitivity to the neutron density. When compared with experiment, and correlated with analyses of electron scattering data, the results suggest that 208 Pb has a neutron skin thickness ∼ 0.17 fm

  15. A Workshop on Methods for Neutron Scattering Instrument Design. Introduction and Summary

    International Nuclear Information System (INIS)

    Hjelm, Rex P.

    1996-09-01

    The future of neutron and x-ray scattering instrument development and international cooperation was the focus of the workshop on ''Methods for Neutron Scattering Instrument Design'' September 23-25 at the E.O. Lawrence Berkeley National Laboratory. These proceedings are a collection of a portion of the invited and contributed presentations

  16. Extraction of neutron-neutron scattering length from nn coincidence-geometry nd breakup data

    Directory of Open Access Journals (Sweden)

    E. S. Konobeevski

    2011-03-01

    Full Text Available We report preliminary results of a kinematically complete experiment on measurement of nd breakup reaction yield at neutron beam RADEX of Institute for Nuclear Research (Moscow, Russia. In the experiment two secondary neutrons are detected in geometry of neutron-neutron final-state interaction. Data are obtained at energy of incident neutrons En = 40 - 60 MeV for various divergence angles of two neutrons ΔΘ = 4, 6, 8º. 1S0 neutron-neutron scattering length ann were determined by comparison of the experimental dependence of reaction yield on the relative energy of two secondary neutrons with results of simulation depending on ann. For En = 40 MeV and ΔΘ = 6º (the highest statistics in the experiment the value ann = -17.9 ± 1.0 fm is obtained. The further improving of accuracy of the experiment and more rigorous theoretical analysis will allow one to remove the existing difference in ann values obtained in different experiments.

  17. Small Angle Neutron Scattering instrument at Malaysian TRIGA reactor

    Energy Technology Data Exchange (ETDEWEB)

    Mohd, Shukri; Kassim, Razali; Mahmood, Zal Uyun [Malaysian Inst. for Nuclear Technology Research (MINT), Bangi, Kajang (Malaysia); Radiman, Shahidan

    1998-10-01

    The TRIGA MARK II Research reactor at the Malaysian Institute for Nuclear Research (MINT) was commissioned in July 1982. Since then various works have been performed to utilise the neutrons produced from this steady state reactor. One of the project involved the Small Angle Neutron Scattering (SANS). (author)

  18. Small-Angle Neutron Scattering investigations of ferrofluids with different carrier liquids

    International Nuclear Information System (INIS)

    Balasoiu, M.; Avdeev, M. V.; Hasegan, D.; Ghenescu, V.; Ghenescu, M.; Bica, D.; Vekas, L.

    2004-01-01

    The aim of this paper is to present a method to investigate the properties of magnetic fluids by means of small angle neutron scattering (SANS). Ferrofluids are dispersions of small, single-domain magnetic particles suspended in a fluid carrier. The neutron scattering methods have been largely used the last two decades for the determination of structural properties of magnetic liquids at microscopic level. There can be investigated the structure of the particle, the aggregation phenomena, the magnetic liquid dynamics, particle-surfactant interaction, surfactant liquid-base interaction and structure and magnetic behavior of the samples. SANS is often used in structural studies of ferrofluids exploring two specific features of neutrons, the possibility of wide contrast variation using protonated/deuterated components and high magnetic scattering from ferromagnetics. This method can be effectively used for determination of the structural parameters of ferrofluids at the scale interval of 1-100 nm. In previous SANS experiments with ferrofluids of the same type it was shown that the nuclear scattering is described well by the spherical core-shell model (magnetite core plus surfactant shell) in a wide interval of momentum transfer (0.05 - 5 nm -1 ) and no significant effects of aggregation and interparticle interaction were observed in this interval for the magnetite concentration up to 5 vol. %. Experiments on small angle neutron scattering were carried out on SANS instrument YuMO in function at IBR-2 high pulsed reactor at the Frank Laboratory of Neutron Physics, Joint Institute of Nuclear Research, Dubna, Russia. (authors)

  19. Effects of Hot-Spot Geometry on Backscattering and Down-Scattering Neutron Spectra

    Science.gov (United States)

    Mohamed, Z. L.; Mannion, O. M.; Forrest, C. J.; Knauer, J. P.; Anderson, K. S.; Radha, P. B.

    2017-10-01

    The measured neutron spectrum produced by a fusion experiment plays a key role in inferring observable quantities. One important observable is the areal density of an implosion, which is inferred by measuring the scattering of neutrons. This project seeks to use particle-transport simulations to model the effects of hot-spot geometry on backscattering and down-scattering neutron spectra along different lines of sight. Implosions similar to those conducted at the Laboratory of Laser Energetics are modeled by neutron transport through a DT plasma and a DT ice shell using the particle transport codes MCNP and IRIS. Effects of hot-spot geometry are obtained by ``detecting'' scattered neutrons along different lines of sight. This process is repeated for various hot-spot geometries representing known shape distortions between the hot spot and the shell. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  20. A neutron scattering study of DCN

    International Nuclear Information System (INIS)

    Mackenzie, G.A.; Pawley, G.S.

    1979-01-01

    Phonons in deuterium cyanide have been measured by neutron coherent inelastic scattering. The main subject of study was the transverse acoustic mode in the (110) direction polarised along (110) which is associated with the first-order structural phase transition at 160 K. Measurements have shown that the frequency decreases by about 25% between about 225 and 160 K as the transition temperature is approached. The other acoustic modes observable in the a*b* scattering plane have been measured and show no anomalous temperature dependence. Optic modes were unobservable because of the small size of the single-crystal sample which gave insufficient scattered intensity. Apart from the 'soft' mode, the measured frequencies are in good agreement with lattice dynamics calculations. (author)

  1. Fast-neutron elastic scattering from elemental vanadium

    International Nuclear Information System (INIS)

    Smith, A.B.; Guenther, P.T.; Lawson, R.D.

    1988-03-01

    Differential neutron elastic- and inelastic-scattering cross sections of vanadium were measured from 4.5 to 10 MeV. These results were combined with previous 1.5 to 4.0 MeV data from this laboratory, the 11.1 MeV elastic-scattering results obtained at Ohio University, and the reported neutron total cross sections to energies of ∼20.0 MeV, to form a data base which was interpreted in terms of the spherical optical-statistical model. A fit to the data was achieved by making both the strengths and geometries of the optical-model potential energy dependent. This energy dependence was large below ∼6.0 MeV. Above ∼6.0 MeV the energy dependencies are smaller, and similar to those characteristic of global models. Using the dispersion relationship and the method of moments, the optical-model potential energy deduced from 0.0 to 11.1 MeV neutron-scattering data was extrapolated to higher energies and to the bound-state regime. This extrapolation leads to predicted neutron total cross sections that are within 3% of the experimental values throughout the energy range 0.0 to 20.0 MeV. Furthermore, the values of the volume-integral-per-nucleon of the real potential are in excellent agreement with those needed to reproduce the observed binding energies of particle- and hole-states. The latter gives clear evidence of the Fermi surface anomaly. Using only the 0.0 to 11.1 MeV data, the predicted E < O behavior of the strength and radius of the real shell-model Woods-Saxon potential are somewhat different from those obtained by Mahaux and Sartor in their analysis of nuclei near closed shells. 61 refs., 9 figs., 2 tabs

  2. Neutron scattering studies on frustrated magnets

    International Nuclear Information System (INIS)

    Arima, Taka-hisa

    2013-01-01

    A lot of frustrated magnetic systems exhibit a nontrivial magnetic order, such as long-wavelength modulation, noncollinear, or noncoplanar order. The nontrivial order may pave the way for the novel magnetic function of matter. Neutron studies are necessary to determine the magnetic structures in the frustrated magnetic systems. In particular, spin-polarized neutron scattering is a useful technique for the investigation of the novel physical properties relevant to the nontrivial spin arrangement. Here some neutron studies on a multiferroic perovskite manganese oxide system are demonstrated as a typical case. The frustrated magnetic systems may also a playground of novel types of local magnetic excitations, which behave like particles in contrast to the magnetic waves. It is becoming a good challenge to study such particle-type magnetic excitations relevant to the magnetic frustration. (author)

  3. Neutron Inelastic Scattering Study of Liquid Argon

    Energy Technology Data Exchange (ETDEWEB)

    Skoeld, K; Rowe, J M; Ostrowski, G [Solid State Science Div., Argonne National Laboratory, Argonne, Illinois (US); Randolph, P D [Nuclear Technology Div., Idaho Nuclear Corporation, Idaho Falls, Idaho (US)

    1972-02-15

    The inelastic scattering functions for liquid argon have been measured at 85.2 K. The coherent scattering function was obtained from a measurement on pure A-36 and the incoherent function was derived from the result obtained from the A-36 sample and the result obtained from a mixture of A-36 and A-40 for which the scattering is predominantly incoherent. The data, which are presented as smooth scattering functions at constant values of the wave vector transfer in the range 10 - 44/nm, are corrected for multiple scattering contributions and for resolution effects. Such corrections are shown to be essential in the derivation of reliable scattering functions from neutron scattering data. The incoherent data are compared to recent molecular dynamics results and the mean square displacement as a function of time is derived. The coherent data are compared to molecular dynamics results and also, briefly, to some recent theoretical models

  4. Quasi-free Compton scattering and the polarizabilities of the neutron

    International Nuclear Information System (INIS)

    Kossert, K.; Camen, M.; Wissmann, F.; Schumacher, M.; Seitz, B.; Ahrens, J.; Arends, H.J.; Beck, R.; Caselotti, G.; Jahn, O.; Jennewein, P.; Olmos de Leon, V.; Annand, J.R.M.; McGeorge, J.C.; Rosner, G.; Grabmayr, P.; Natter, A.; Levchuk, M.I.; L'vov, A.I.; Petrun'kin, V.A.; Smend, F.; Thomas, A.; Weihofen, W.; Zapadtka, F.

    2003-01-01

    Differential cross-sections for quasi-free Compton scattering from the proton and neutron bound in the deuteron have been measured using the Glasgow/Mainz photon tagging spectrometer at the Mainz MAMI accelerator together with the Mainz 48cm diameter x 64cm NaI(Tl) photon detector and the Goettingen SENECA recoil detector. The data cover photon energies ranging from 200MeV to 400MeV at θ LAB γ =136.2 . Liquid deuterium and hydrogen targets allowed direct comparison of free and quasi-free scattering from the proton. The neutron detection efficiency of the SENECA detector was measured via the reaction p(γ,π + n). The ''free'' proton Compton scattering cross-sections extracted from the bound proton data are in reasonable agreement with those for the free proton which gives confidence in the method to extract the differential cross-section for free scattering from quasi-free data. Differential cross-sections on the free neutron have been extracted and the difference of the electromagnetic polarizabilities of the neutron has been determined to be α n -β n =9.8±3.6(stat) +2.1 -1.1 (syst)±2.2(model) in units of 10 -4 fm 3 . In combination with the polarizability sum α n +β n =15.2±0.5 deduced from photoabsorption data, the neutron electric and magnetic polarizabilities, α n =12.5±1.8(stat) + 1 .1 -0.6 (syst)±1.1(model) and β n =2.7±1.8(stat) +0.6 -1.1 (syst)±1.1(model) are obtained. The backward spin polarizability of the neutron was determined to be γ (n) π =(58.6±4.0) x 10 -4 fm 4 . (orig.)

  5. Critical scattering of neutrons from terbium

    DEFF Research Database (Denmark)

    Als-Nielsen, Jens Aage; Dietrich, O.W.; Marshall, W.

    1968-01-01

    The inelasticity of the critical scattering of neutrons in terbium has been measured above the Neél temperature at the (0, 0, 2−Q) satellite position. The results show that dynamic slowing down of the fluctuations does occur in a second‐order phase transition in agreement with the general theory...

  6. Research within the coordinated programme on neutron scattering techniques in applied research

    International Nuclear Information System (INIS)

    Satya Murthy, N.S.

    1982-02-01

    This paper reviews developments of neutron scattering studies at Bhabha Atomic Research Centre (BARC) over the past two decades through utilisation of Apsara and Circus reactor facilities. Salient results in neutron crystallography, magnetic diffraction and inelastic neutron scattering will be presented highlighting progressive involvement in more and more complex studies. The growth of non-neutronic activities as a natural outcome of overall necessity and interest of investigators will be indicated. A description of facilities planned at R5 and the nature of studies that are likely to be taken up at R5 will be briefly discussed. (author)

  7. Inelastic neutron scattering from clusters

    International Nuclear Information System (INIS)

    Gudel, H.U.

    1985-01-01

    Magnetic excitations in clusters of paramagnetic ions have non-vanishing cross-sections for inelastic neutron scattering (INS). Exchange splittings can be determined, the temperature dependence of exchange can be studied, intra- and intercluster effects can be separated and magnetic form factors determined. INS provides a more direct access to the molecular properties than bulk techniques. Its application is restricted to complexes with no or few (< 10%) hydrogen atoms

  8. Frozen concentration fluctuations in a poly(N-isopropyl acrylamide) gel studied by neutron spin echo and small-angle neutron scattering

    CERN Document Server

    Koizumi, S; Richter, D; Schwahn, D; Faragó, B; Annaka, M

    2002-01-01

    By employing neutron spin echo and small-angle neutron scattering, we determined the structure factor of the frozen concentration fluctuations on nano-length scales in a swollen poly(N-isopropyl acrylamide) gel. The frozen contribution, showing a plateau at the low scattering wavenumber q (0.02 A sup - sup 1), is intimately related to the abnormal butterfly scattering pattern appearing at low q under deformation. (orig.)

  9. Dynamics of liquid N2 studied by neutron inelastic scattering

    DEFF Research Database (Denmark)

    Pedersen, Karen Schou; Carneiro, Kim; Hansen, Flemming Yssing

    1982-01-01

    Neutron inelastic-scattering data from liquid N2 at wave-vector transfer κ between 0.18 and 2.1 Å-1 and temperatures ranging from T=65-77 K are presented. The data are corrected for the contribution from multiple scattering and incoherent scattering. The resulting dynamic structure factor S (κ,ω)...

  10. Theory of neutron scattering in disordered alloys

    International Nuclear Information System (INIS)

    Yussouff, M.; Mookerjee, A.

    1984-08-01

    A comprehensive theory of thermal neutron scattering in disordered alloys is presented here. We consider in detail the case of substitutional random binary alloy with random changes in mass and force constants; and for all values of the concentration. The cluster CPA formalism in argumented space developed here is free from analytical difficulties for the Green function, performs correct averaging over random atomic scattering lengths and employs a self-consistent medium for the calculations. For easy computation, we describe the graphical representation of the resolvent where the approximation steps can be depicted as closed paths in augmented space. Our results for scattering cross sections, both coherent and incoherent, include new types of terms and these lead to asymmetric line shapes for the coherent scattering. (author)

  11. Investigation of solid solution of hydrogen in α-manganese by neutron diffraction and inelastic neutron scattering

    International Nuclear Information System (INIS)

    Fedotov, V.K.; Antonov, V.E.; Kolesnikov, A.I.; Kornell, K.; Vipf, G.; Grosse, G.; Vagner, F.Eh.; Sikolenko, V.V.; Sumin, V.V.; )

    1997-01-01

    The FCC-lattice of the solid solution α-MnH 0.073 with the mass of 8.45 g is investigated by the neutron diffraction method and the inelastic neutron scattering technique. The neutron diffraction measurements are made by the diffractometer D1B with pyrographite monochromator and the high-resolution Fourier diffractometer HRFD at 300 K. The study of the inelastic incoherent neutron scattering is carried out by means of the inverse geometry spectrometer KDSOG-M at 90 K. The comparative analysis of α-MnH 0.073 and α-Mn spectra is fulfilled for the more correct separation of effects of hydrogen introduction. It is found out that the structure of the solid solution α-MnH 0.073 belongs to the same spatial group I-43m as the structure of α-Mn [ru

  12. Neutron scattering cross sections for 204,206Pb and neutron and proton amplitudes of E2 and E3 excitations

    International Nuclear Information System (INIS)

    Hicks, S.F.; Hanly, J.M.; Hicks, S.E.; Shen, G.R.; McEllistrem, M.T.

    1994-01-01

    Differential elastic and inelastic scattering cross sections have been measured for neutrons incident on 204 Pb and 206 Pb at energies of 2.5, 4.6, and 8.0 MeV and total cross sections in 100-keV steps from 250 keV to 4.0 MeV. Both spherical and coupled-channels analyses have been used to interpret this large set of data, together with other cross sections extending to 8 MeV. Several purposes motivate this work. The first is to establish the dispersion-corrected mean field appropriate for these nuclei. A consistent description of the energy dependent neutron scattering potential includes a dispersion relation connecting the real and imaginary parts of the potential; the resultant potential relates the energy dependent scattering field to one representing bound single particle levels. Dispersion relations using both the single channel and coupled-channels models have been examined; both give very similar results. The second motivation is to deduce neutron and proton excitation strengths of the lowest-energy quadrupole and octupole excitations seen via neutron scattering, and to compare those strengths with similar values derived from electromagnetic exciton, heavy-ion and pion scattering. The role of target neutrons in both collective excitations was found to be enhanced compared to the proton role

  13. New era of neutron scattering research on advanced materials

    International Nuclear Information System (INIS)

    Ikeda, Susumu

    2001-01-01

    The projects of the next generation of pulsed spallation neutron source are planed in USA, Europe and Japan. They are one order of magnitude more powerful than the most powerful existing neutron source, ISIS in UK. They offer the exciting prospects for the future, and will open the new era of neutron scattering research on advanced materials. The Japanese project is named as the 'Joint project' between JAERI and KEK on high-intensity proton accelerators. The details of the neutron science facility in the 'Joint project' and the sciences to be developed are summarized. (author)

  14. Phenylene ring dynamics in bisphenol-A-polysulfone by neutron scattering

    International Nuclear Information System (INIS)

    Arrese-Igor, S.; Arbe, A.; Alegria, A.; Colmenero, J.; Frick, B.

    2004-01-01

    We have investigated the dynamics of phenylene rings in a glassy polysulfone (bisphenol-A-polysulfone) by means of quasielastic neutron scattering. Nowadays it is well known that these molecular motions are directly connected with the mechanical properties of engineering thermoplastics in general. The particular system investigated by us has the advantage that by selective deuteration of the methyl groups, the neutron scattering measured is dominated by the incoherent contribution from the protons in the phenylene rings. In this way, the dynamics of such molecular groups can be experimentally isolated. Two different types of neutron spectrometers: time of flight and backscattering, were used in order to cover a wide dynamic range, which extends from microscopic (10 -13 s) to mesoscopic (10 -9 s) times. Moreover, neutron diffraction experiments with polarization analysis were also carried out in order to characterize the structural features of the sample investigated. Fast oscillations of increasing amplitude with temperature and π-flips are identified for phenylene rings motions. Due to the structural disorder characteristic of the amorphous state, both molecular motions display a broad distribution of relaxation times, which spreads over several orders of magnitude. Based on the results obtained, we propose a model for phenylene rings dynamics, which combines the two kinds of molecular motions identified. This model nicely describes the neutron scattering results in the whole dynamic range investigated

  15. The lineshape of inelastic neutron scattering in the relaxor ferroelectrics

    International Nuclear Information System (INIS)

    Ivanov, M.A.; Kozlovski, M.; Piesiewicz, T.; Stephanovich, V.A.; Weron, A.; Wymyslowski, A.

    2005-01-01

    The possibilities of theoretical and experimental investigations of relaxor ferroelectrics by inelastic neutron scattering method are considered. The simple model to description of the peculiarities of inelastic neutron scattering lineshapes in ferroelectric relaxors is suggested. The essence of this model is to consider the interaction of the phonon subsystem of relaxor ferroelectrics with the ensemble of defects and impurities. The modification of the Latin Hypercube Sampling (LHS) method is presented. The optimization of planning of experiment by the modified LHS method is considered [ru

  16. Small-angle neutron scattering of short-segment block polymers

    International Nuclear Information System (INIS)

    Cooper, S.L.; Miller, J.A.; Homan, J.G.

    1988-01-01

    Small-angle neutron scattering has been used to investigate the chain conformation of the hard and soft segments in short-segment polyether-polyester and polyether-polyurethane materials. The method of phase-contrast matching was used to eliminate the coherent neutron scattering due to the two-phase microstructure in these materials. The partial deutero-labelling necessary for this technique also provides a neutron scattering contrast between labelled and unlabelled segments. The structure factor for each segment type is determined from the coherent scattering from such deuterolabelled materials. In all of the materials examined, the poly(tetramethylene oxide) (PTMO) soft segment was found to be in a slightly extended conformation relative to bulk PTMO at room temperature. Upon heating, the PTMO segments contracted to a more relaxed conformation. In one polyether-polyurethane sample, the radius of gyration of the PTMO segment increased again at high temperatures, indicating phase mixing. The hardsegment radii of gyration in the polyether-polyester materials were found to increase with temperature, indicating a transition from a chain-folded conformation at room temperature to a more extended conformation at higher temperatures. The radius of gyration of the whole polyether-polyester chain first decreased then increased with temperature, indicative of the combined effects of the component hard- and soft-segment chain conformation changes. The hard-segment radius of gyration in a polyether-polyurethane was observed to decrease with temperature. (orig.)

  17. Anomalous neutron scattering in nuclear-polarized media

    International Nuclear Information System (INIS)

    Bashkin, E.P.

    1989-01-01

    A novel inelastic scattering exchange mechanism involving spin flip is considered for slow neutrons moving through a nuclear-polarized medium. The scattering is accompanied by the emission or absorption of thermal fluctuations of the transverse magnetization of the medium. The main role in the fluctuations is played by weakly decaying Larmor precession of the nuclear spins in an external magnetic field. Under 'giant opalescence' conditions the effect is enormous and the respective cross sections exceed significantly those for ordinary elastic scattering. Thus, for 29 Si and 3 He in typical experimental conditions the cross sections for the inelastic processes are of the order of 10 5 -10 6 barn

  18. Early Years of Neutron Scattering and Its Manpower Development in Indonesia

    International Nuclear Information System (INIS)

    Marsongkohadi

    2008-01-01

    In this paper I shall give a short history of the development of neutron scattering at the Research Centre for Nuclear Techniques (PPTN), in Bandung, and the early development of a more advanced facilities at the Neutron Scattering Laboratory (NSL BATAN), Centre of Technology for Nuclear Industrial Materials, in Serpong. The first research reactor in Indonesia was the TRIGA MARK II in Bandung, which became operational in 1965, with a power of 250 KW, upgraded to 1 MW in 1971, and to 2 MW in 2000. The neutron scattering activities was started in 1967, with the design and construction of the first powder diffractometer, and put in operation in 1970. It was followed by the second instrument, the filter detector spectrometer built in 1975 in collaboration with the Bhabha Atomic Research Centre (BARC), India. A powder diffractometer for magnetic studies was built in 1980, and finally, a modification of the filter detector spectrometer to measure textures was made in 1986. A brief description of the design and construction of the instruments, and a highlight of some research topics will be presented. Early developments of neutron scattering activities at the 30 MW, RSG-GAS reactor in Serpong in choosing suitable research program, which will be mainly centred around materials testing/characterization, and materials/condensed matter researches has been agreed. Instrument planning and layout which were appropriate to carry out the program had been decided. Manpower development for the neutron scattering laboratory is a severe problem. The efforts to overcome this problem has been solved. International Cooperation through workshops and on the job trainings also support the supply of qualified manpower

  19. One-neutron and two-neutron transfer in the scattering

    International Nuclear Information System (INIS)

    Reisdorf, W.N.; Lau, P.H.; Vandenbosch, R.

    1975-01-01

    Angular distributions have been measured for one- and two-neutron transfer reactions induced by 18 O beams on 16 O targets at laboratory bombarding energies of 42 and 52 MeV. The reactions populating the ground and first excited states of 17 O and 18 O are analyzed in terms of single step finite range plus recoil DWBA theory taking into account antisymmetrization effects. Special attention is paid to an internally consistent description of the observed absolute magnitudes of all the reactions and to the theoretically expected interferences between various backward-forward scattering mechanisms. The importance of neutron transfer in accounting for different absorbing properties of the 16 O- 18 O systems as compared to the 16 O- 16 O system is shown. (13 figures, 2 tables)

  20. Small-angle neutron scattering in materials science

    International Nuclear Information System (INIS)

    Fratzl, P.

    1999-01-01

    Small-angle scattering (SAS) in an ideal tool for studying the structure of materials in the mesoscopic size range between 1 and about 100 nanometers. The basic principles of the method are reviewed, with particular emphasis on data evaluation and interpretation for isotropic as well as oriented or single-crystalline materials. Examples include metal alloys, composites and porous materials. The last section gives a comparison between the use of neutrons and (synchrotron) x-rays for small-angle scattering in materials physics. (author)

  1. Structure analysis of liquids and disordered materials using pulsed neutron diffraction and total scattering

    International Nuclear Information System (INIS)

    Suzuya, Kentaro

    2011-01-01

    Neutron diffraction·total scattering at pulsed neutron source is a powerful method to analyze the complex structure of disordered materials: liquids, glasses, amorphous materials and disordered crystals. The basic idea of the structure of disordered materials, the fundamental diffraction theory for disordered materials, and structure analysis of disordered materials using pulsed neutron diffraction·total scattering technique (TOF method) are described in detail. In addition, the precise information of the world highest class J-PARC MLF spallation neutron source and typical J-PARC neutron total scattering instrument NOVA are also given. Recent structural modelling methods of disordered materials such like reverse Monte Carlo (RMC) simulation method is briefly described using an example of the analysis of a typical disordered material silica glass. (author)

  2. Effect of fractional parameter on neutron transport in finite disturbed reactors with quadratic scattering

    International Nuclear Information System (INIS)

    Sallah, M.; Margeanu, C. A.

    2016-01-01

    The space-fractional neutron transport equation is used to describe the neutrons transport in finite disturbed reactors. It is approximated using the Pomraning-Eddington technique to yield two space-fractional differential equations, in terms of neutron density and net neutron flux. These resultant equations are coupled into a fractional diffusion-like equation for the neutron density whose solution is obtained by using Laplace transformation method. The solution is represented in terms of the Mittag-Leffler function and its different orders. The scattering is considered as quadratic scattering to offer a more realistic, compact representation of the system, and to increase the accuracy of the estimated neutronic parameters. The results are presented graphically to illustrate the fractional parameter effect in addition to the effect of radiative-transfer properties on the physical parameters of interest (reflection coefficient, transmission coefficient, neutron energy, and net neutron flux). The neutron transport problem in finite disturbed reactor with quadratic scattering is considered in investigating the shielding effectiveness, by using MAVRIC shielding module from SCALE6 programs package. The fractional parameter can be used to adjust the analysed data on neutron energy and flux, both for the theoretical model and the neutron transport application. (authors)

  3. Neutron scattering science at the Australian Nuclear Science and Technology Organisation (ANSTO)

    International Nuclear Information System (INIS)

    Knott, Robert

    2000-01-01

    Neutron scattering science at ANSTO is integrated into a number of fields in the Australian scientific and industrial research communities. The unique properties of the neutron are being used to investigate problems in chemistry, materials science, physics, engineering and biology. The reactor HIFAR at the Australian Nuclear Science and Technology Organisation research laboratories is the only neutron source in Australia suitable for neutron scattering science. A suite of instruments provides a range of opportunities for the neutron scattering community that extends throughout universities, government and industrial research laboratories. Plans to replace the present research reactor with a modern multi-purpose research reactor are well advanced. The experimental and analysis equipment associated with a modern research reactor will permit the establishment of a national centre for world class neutron science research focussed on the structure and functioning of materials, industrial irradiations and analyses in support of Australian manufacturing, minerals, petrochemical, pharmaceuticals and information science industries. A brief overview will be presented of all the instruments presently available at ANSTO with emphasis on the SANS instrument. This will be followed by a description of the replacement research reactor and its instruments. (author)

  4. Neutron scattering science at the Australian Nuclear Science and Technology Organisation (ANSTO)

    Energy Technology Data Exchange (ETDEWEB)

    Knott, Robert [Australian Nuclear Science and Technology Organisation (Australia)

    2000-10-01

    Neutron scattering science at ANSTO is integrated into a number of fields in the Australian scientific and industrial research communities. The unique properties of the neutron are being used to investigate problems in chemistry, materials science, physics, engineering and biology. The reactor HIFAR at the Australian Nuclear Science and Technology Organisation research laboratories is the only neutron source in Australia suitable for neutron scattering science. A suite of instruments provides a range of opportunities for the neutron scattering community that extends throughout universities, government and industrial research laboratories. Plans to replace the present research reactor with a modern multi-purpose research reactor are well advanced. The experimental and analysis equipment associated with a modern research reactor will permit the establishment of a national centre for world class neutron science research focussed on the structure and functioning of materials, industrial irradiations and analyses in support of Australian manufacturing, minerals, petrochemical, pharmaceuticals and information science industries. A brief overview will be presented of all the instruments presently available at ANSTO with emphasis on the SANS instrument. This will be followed by a description of the replacement research reactor and its instruments. (author)

  5. Random pulsing of neutron source for inelastic neutron scattering gamma ray spectroscopy

    International Nuclear Information System (INIS)

    Hertzog, R.C.

    1981-01-01

    Method and apparatus are described for use in the detection of inelastic neutron scattering gamma ray spectroscopy. Data acquisition efficiency is enhanced by operating a neutron generator such that a resulting output burst of fast neutrons is maintained for as long as practicably possible until a gamma ray is detected. Upon the detection of a gamma ray the generator burst output is terminated. Pulsing of the generator may be accomplished either by controlling the burst period relative to the burst interval to achieve a constant duty cycle for the operation of the generator or by maintaining the burst period constant and controlling the burst interval such that the resulting mean burst interval corresponds to a burst time interval which reduces contributions to the detected radiation of radiation occasioned by other than the fast neutrons

  6. Spin dynamics above the Curie temperature studied by neutron scattering

    International Nuclear Information System (INIS)

    Steinsvoll, O.; Riste, T.

    1986-01-01

    Neutron scattering can in principle give information about magnetic fluctuations over the entire atomic space and time domain. The weakness of the neutron-matter interaction renders this information undistorted by the neutron probe, but at the same time puts intensity limitations on the method. A considerable number of studies on the magnetism of 3d metals have been performed at some of the larger reactor laboratories. In the regions of overlap the experimental results from the different laboratories are consistent, but the interpretations are along different lines. Among the controversial issues are itinerancy versus localization, the degree of order above T C . In our talk we shall give an introduction to the neutron scattering method, including some of the sophisticated polarized beam methods. In the rest of the talk we shall review recent experimental results and some of the theoretical models used in their interpretation. (orig.)

  7. Modern quantum magnetism by means of neutron scattering

    International Nuclear Information System (INIS)

    Grenier, B.; Ziman, T.

    2007-01-01

    We review a selection of recent applications of neutron scattering to the field of quantum magnetism. We focus on systems where, because of quantum fluctuations enhanced by frustration and low dimension, there is no long range magnetic order in the ground state. We select two examples that we treat in more depth to show how neutron studies, in conjunction with the results of other experimental techniques, can give new insights. The first is the case of the spin ladder NaV 2 O 5 , where the origin of the spin gap at low temperature is now understood in detail. Apparent contradictions between quantitative measures of the charge order from neutron inelastic scattering, resonant X-ray scattering and NMR have been resolved giving interesting insights into the correlations. The second case is that of spin dimer system Cs 3 Cr 2 X 9 (X = Br, Cl), undergoing transitions to field induced transverse magnetic order. The Br compound is attractive as the critical fields are sufficiently low that a complete study, in different field directions, is possible. In addition, it is noteworthy in that the magnon that softens and condenses is incommensurable with the lattice. The common description in terms of Bose-Einstein condensation must be extended to include a continuous degeneracy and single ion anisotropy, and conclusions can be drawn by comparison with the Cl compound. (authors)

  8. Some applications of polarized inelastic neutron scattering

    Indian Academy of Sciences (India)

    A brief account of applications of polarized inelastic neutron scattering in condensed matter research is given. ... the itinerant antiferromagnet chromium we demonstrate that the dynamics of the longitudinal and transverse excitations are very different, resolving a long standing puzzle concerning the slope of their dispersion.

  9. Neutron scattering (progress report) January - December 1991

    International Nuclear Information System (INIS)

    Buehrer, W.; Fischer, P.; Furrer, A.

    1992-02-01

    Progress made by the Laboratory for Neutron Scattering of the Swiss Federal Institute of Technology during the year 1991 in the fields of high-T c superconductors, materials science, magnetism, structural research, lattice dynamics, phase transitions, instrumental and support activities is reported. figs., tabs., refs

  10. Report on inelastic neutron scattering for the Australian Replacement Research Reactor

    International Nuclear Information System (INIS)

    Cussen, L.

    2001-01-01

    The Replacement Reactor Project includes a sub project, the Neutron Beam Instrument project, to construct a suite of eight leading edge neutron scattering instruments to be ready at reactor start up in 2005. Amongst these will be an inelastic scattering instrument and this workshop explored the options that would best serve the future needs of the Australian neutron scattering community.Considering the dynamic range of each of these instruments and the ability to address the needs of the widest group of problems, the workshop endorsed the recommendation of the Beam Facilities Consultative Group to build a thermal neutron three-axis spectrometer, which offers the project the best opportunity and flexibility in terms of the available wave-vector and energy range. It was also recommend that priority consideration be given to developing cold neutron three-axis and time-of-flight spectrometers, perhaps in collaboration with outside organisations, after completion of the initial project. thermal neutron three axis spectrometer. The workshop recommended that such an instrument should be built at the reactor face on a thermal beam, using a double-focussing monochromator and analyser. Polarisation analysis should be available as an option and that the instrument perform at or close to world's best level. Recommendations were received on sample environment requirements and low temperature, high temperature and strong magnetic fields are seen as necessary

  11. The microstructure of neutron-irradiated Fe-Cr alloys: A small-angle neutron scattering study

    International Nuclear Information System (INIS)

    Heintze, C.; Bergner, F.; Ulbricht, A.; Eckerlebe, H.

    2009-01-01

    Ferritic-martensitic chromium steels are candidate materials for future applications in both Gen-IV fission and fusion technology. Experimental investigation of neutron-irradiated Fe-Cr model alloys is important in order to gain a better understanding of the interplay of chromium content and irradiation behaviour. Small-angle neutron scattering (SANS) is particularly well suited to unfold the size distribution of non-planar irradiation-induced nanoscale features such as defect-solute clusters, nanovoids and α'- particles. This size distribution represents a statistically reliable average over a macroscopic volume. Assumptions on the dominant type of features can be checked against the ratio of magnetic and nuclear scattering. The materials investigated in this work are commercial-purity Fe-Cr alloys of nominal compositions Fe-2.5Cr, Fe-5Cr, Fe- 9Cr and Fe-12.5Cr (at %). Neutron irradiation was performed in the reactor BR2 at Mol (Belgium) at a temperature of 300 deg. C and neutron flux of 9 x 10 13 cm -2 s -1 (E > 1 MeV) [Matijasevic, JNM 377 (2008) 147]. The neutron exposures expressed in units of displacements per atom correspond to 0.6 and 1.5 dpa. A wavelength of 0.58 nm and three detector-sample distances of 1, 4 and 16 m were used in the SANS experiments carried out at the SANS-2 facility of GKSS Geesthacht (Germany). The samples were placed in a saturation magnetic field in order to separate magnetic and nuclear contributions. The scattering curves obtained for the unirradiated conditions of the four Fe-Cr alloys were taken as reference. We have found that the volume fraction of scatterers slightly increases with neutron exposure (Fe-9Cr) or exhibits a saturation-like behaviour (Fe-2.5Cr, Fe-5Cr and Fe-12.5Cr) and that the volume fraction at 1.5 dpa is an increasing function of the chromium level with a slight increase up to 9 at%Cr and a steep increase between 9 and 12.5 at%Cr. The radii of irradiation-induced scatterers are essentially less than 8 nm and

  12. X-ray and neutron scattering investigations of YCo3-H

    International Nuclear Information System (INIS)

    Benham, M.J.; Bennington, S.M.; Ross, D.K.; Noreus, D.; Yamaguchi, M.

    1989-01-01

    Various structural studies of YCo 3 H(D) x in the β-phase (0 2 . Neutron diffraction and inelastic neutron scattering were also used in tandem, and hydrogen occupation of a single (36i) tetrahedral site was inferred for the entire concentration range. (orig.)

  13. Elastic Neutron Scattering at 96 MeV from {sup 12}C and {sup 208}Pb

    Energy Technology Data Exchange (ETDEWEB)

    Klug, J.; Blomgren, J.; Atac, A. [and others

    2003-04-01

    A facility for detection of scattered neutrons in the energy interval 50-130 MeV, SCANDAL (SCAttered Nucleon Detection AssembLy), has recently been installed at the 20-180 MeV neutron beam line of the The Svedberg Laboratory, Uppsala. Elastic neutron scattering from {sup 12}C and {sup 208}Pb has been studied at 96 MeV in the 10-70 deg interval. The achieved energy resolution, 3.7 MeV, is about an order of magnitude better than for any previous experiment above 65 MeV incident energy. The present experiment represents the highest neutron energy where the ground state has been resolved from the first excited state in neutron scattering. A novel method for normalization of the absolute scale of the cross section has been used. The estimated uncertainty, 3 %, is unprecedented for a neutron-induced differential cross section measurement on a nuclear target. The results are compared with modern optical model predictions, based on phenomenology or microscopic nuclear theory.

  14. Scattering of 14.2 MeV polarized neutrons from 12C

    International Nuclear Information System (INIS)

    Casparis, R.; Leemann, B.Th.; Preiswerk, M.; Rudin, H.; Wagner, R.; Zupranski, P.

    1976-01-01

    Polarized 14.2 MeV neutrons with a polarization of approximately 50% were produced in the 3 H(d(pol),n(pol)) 4 He reaction using vector polarized deuterons from an 'atomic beam' source of polarized ions. The angular distributions of the analyzing power in the elastic and inelastic (Q = -4.43 MeV) scattering of neutrons from carbon have been measured at ten angles in the range from 22 0 to 152 0 c.m. A time-of-flight technique was used to separate elastically and inelastically scattered neutrons. The results have been compared with theoretical calculations obtained with the DWBA and the coupled channels method. (Auth.)

  15. Interpretation of the quasi-elastic neutron scattering on PAA by rotational diffusion models

    International Nuclear Information System (INIS)

    Bata, L.; Vizi, J.; Kugler, S.

    1974-10-01

    First the most important data determined by other methods for para azoxy anisolon (PAA) are collected. This molecule makes a rotational oscillational motion around the mean molecular direction. The details of this motion can be determined by inelastic neutron scattering. Quasielastic neutron scattering measurements were carried out without orienting magnetic field on a time-of-flight facility with neutron beam of 4.26 meV. For the interpretation of the results two models, the spherical rotation diffusion model and the circular random walk model are investigated. The comparison shows that the circular random walk model (with N=8 sites, d=4A diameter and K=10 10 s -1 rate constant) fits very well with the quasi-elastic neutron scattering, while the spherical rotational diffusion model seems to be incorrect. (Sz.N.Z.)

  16. Applications of neutron scattering in molecular biological research

    International Nuclear Information System (INIS)

    Nierhaus, K.H.

    1984-01-01

    The study of the molecular structure of biological materials by neutron scattering is described. As example the results of the study of the components of a ribosome of Escherichia coli are presented. (HSI) [de

  17. Quasielastic neutron scattering facility at Dhruva reactor

    International Nuclear Information System (INIS)

    Mukhopadhyay, R.; Mitra, S.; Paranjpe, S.K.; Dasannacharya, B.A.

    2001-01-01

    Quasi-elastic neutron scattering is a powerful experimental tool for studying the various dynamical motions in solids and liquids. In this paper, we have described the salient features of the quasi-elastic neutron spectrometer in operation at Dhruva reactor at Trombay, India. The design criteria have been such as to maximise the throughput by various means like closer approach to the source, focusing a larger beam on to a sample, and Multi-Angle Reflecting X-tal mode of energy analysis. Some results of molecular motions from recently studied systems using this spectrometer are also reported

  18. Theoretical study of the slow neutron coherent scattering by nemanic liquid crystals

    International Nuclear Information System (INIS)

    Sugakov, V.I.; Shiyanovskij, S.V.

    1982-01-01

    An exact expression is obtained for neutron coherent quasielastic scattering cross section in nematic liquid crystals. Expressions are analyzed or big and small values of scattering wave vector. In the first case scattering is occured on the separate molecules and the account of the molecule form noncylindricity is to be essential. In the second case an intermolecular correlations contribute greatly to cross sections. A connection is found for pair correlation function with fluctuation for density, dipole moment and order parameters. The performed cross section analysis allow to determine the significant microscopic parameters of the nematic liquid crystal from the experimental data of slow neutron scattering

  19. Inelastic neutron scattering cross-section measurements on 7Li and 63,65Cu

    Science.gov (United States)

    Nyman, Markus; Belloni, Francesca; Ichinkhorloo, Dagvadorj; Pirovano, Elisa; Plompen, Arjan; Rouki, Chariklia

    2017-09-01

    The γ-ray production cross section for the 477.6-keV transition in 7Li following inelastic neutron scattering has been measured from the reaction threshold up to 18 MeV. This cross section is interesting as a possible standard for other inelastic scattering measurements. The experiment was conducted at the Geel Electron LINear Accelerator (GELINA) pulsed white neutron source with the Gamma Array for Inelastic Neutron Scattering (GAINS) spectrometer. Previous measurements of this cross section are reviewed and compared with our results. Recently, this cross section has also been calculated using the continuum discretized coupled-channels (CDCC) method. Experiments for studying neutrinoless double-β decay (2β0ν) or other very rare processes require greatly reducing the background radiation level (both intrinsic and external). Copper is a common shielding and structural material, used extensively in experiments such as COBRA, CUORE, EXO, GERDA, and MAJORANA. Understanding the background contribution arising from neutron interactions in Cu is important when searching for very weak experimental signals. Neutron inelastic scattering on natCu was investigated with GAINS. The results are compared with previous experimental data and evaluated nuclear data libraries.

  20. Inelastic neutron scattering cross-section measurements on 7Li and 63,65Cu

    Directory of Open Access Journals (Sweden)

    Nyman Markus

    2017-01-01

    Full Text Available The γ-ray production cross section for the 477.6-keV transition in 7Li following inelastic neutron scattering has been measured from the reaction threshold up to 18 MeV. This cross section is interesting as a possible standard for other inelastic scattering measurements. The experiment was conducted at the Geel Electron LINear Accelerator (GELINA pulsed white neutron source with the Gamma Array for Inelastic Neutron Scattering (GAINS spectrometer. Previous measurements of this cross section are reviewed and compared with our results. Recently, this cross section has also been calculated using the continuum discretized coupled-channels (CDCC method. Experiments for studying neutrinoless double-β decay (2β0ν or other very rare processes require greatly reducing the background radiation level (both intrinsic and external. Copper is a common shielding and structural material, used extensively in experiments such as COBRA, CUORE, EXO, GERDA, and MAJORANA. Understanding the background contribution arising from neutron interactions in Cu is important when searching for very weak experimental signals. Neutron inelastic scattering on natCu was investigated with GAINS. The results are compared with previous experimental data and evaluated nuclear data libraries.

  1. High count problems in elemental analysis using pulsed neutron inelastic scattering

    Energy Technology Data Exchange (ETDEWEB)

    Vartsky, D; Wielopolski, L; Ellis, K J; Cohn, S H [Brookhaven National Lab., Upton, NY (USA). Medical Dept.

    1983-03-01

    Elemental analysis by neutron inelastic scattering using a miniature intense pulsed neutron source ('Zetatron') was evaluated. The particular problems associated with detector pulse-pile-up during the neutron burst and the limited ability of the analyzer to process on average more than one detector pulse per neutron burst were examined. The severity of these problems is described and a solution using a multiple ADC system is proposed.

  2. Preparation of a bent crystal and its use in neutron scattering

    International Nuclear Information System (INIS)

    Kraxenberger, H.

    1980-01-01

    The aim of this thesis was the construction of a horizontally bendable neutron monochromator e.g. analyzator, the application to different measuring problem in neutron scattering, and the development of an exact theory. (HSI) [de

  3. Neutron scattering on molten transition metals and on Fe-C melts

    International Nuclear Information System (INIS)

    Weber, M.

    1978-01-01

    In order to find out whether short-range order phenomena can be detected in iron-carbon melts, neutron scattering experiments were carried out in molten iron-carbon alloys. The method of isotope substitution, where the natural alloying iron was substituted by a 57 Fe-enriched isotope mixture, helped to increase the ratio between the scattering length of the carbon atoms and that of the iron atoms. The mean coherent scattering length for the isotope mixture which is required for further evaluation of the measurements, was determined in an experiment by measuring the limiting angle for total reflection of neutrons on evaporated films. From this determination of the scattering length, a value for the so far unknown scattering length of the 58 Fe isotope was obtained. The small angle scattering in corrected intensity curves of molten Fe-C alloys was investigated in detail. Scattering experiments in unalloyed Fe, Co, and Ni in the range of small scattering vectors proved that this small-angle scattering effect, which was observed here for the first time, is of magnetic origin. It is caused by short-range spin correlations fluctuating with space and time. [de

  4. Incoherent neutron-scattering determination of hydrogen content : Theory and modeling

    NARCIS (Netherlands)

    Perego, R.C.; Blaauw, M.

    2005-01-01

    Hydrogen concentrations of 0 up to 350?mg/kg in a titanium alloy have been determined at National Institute of Standards and Technology (NIST) with neutron incoherent scattering (NIS) and with cold neutron prompt gamma activation analysis. The latter is a well-established technique, while the former

  5. Neutron-Proton Scattering Experiments at ANKE-COSY

    Science.gov (United States)

    Kacharava, A.; Chiladze, D.; Chiladze, B.; Keshelashvili, I.; Lomidze, N.; Macharashvili, G.; McHedlishvili, D.; Nioradze, M.; Rathmann, F.; Ströher, H.; Wilkin, C.

    2010-04-01

    The nucleon-nucleon interaction (NN) is fundamental for the whole of nuclear physics and hence to the composition of matter as we know it. It has been demonstrated that stored, polarised beams and polarised internal targets are experimental tools of choice to probe spin effects in NN-scattering experiments. While the EDDA experiment has dramatically improved the proton-proton date base, information on spin observables in neutron-proton scattering is very incomplete above 800 MeV, resulting in large uncertainties in isoscalar n p phase shifts. Experiments at COSY, using a polarised deuteron beam or target, can lead to significant improvements in the situation through the study of quasi-free reactions on the neutron in the deuteron. Such a measurements has already been started at ANKE by using polarised deuterons on an unpolarised target to study the dp → ppn deuteron charge-exchange reaction and the full program with a polarised storage cell target just has been conducted. At low excitation energies of the final pp system, the spin observables are directly related to the spin- dependent parts of the neutron-proton charge-exchange amplitudes. Our measurement of the deuteron-proton spin correlations will allow us to determine the relative phases of these amplitudes in addition to their overall magnitudes.

  6. Quantum effects in deep inelastic neutron scattering

    International Nuclear Information System (INIS)

    Mayers, J.

    1989-07-01

    In the Impulse Approximation (IA), which is used to interpret deep inelastic neutron scattering (DINS) measurements, it is assumed both that the target system can be treated as a gas of free atoms and that the struck atom recoils freely after the collision with the neutron. Departures from the IA are generally attributed to final state effects (FSE), which are due to the inaccuracy of the latter assumption. However it is shown that even when FSE are neglected, significant departures from the IA occur at low temperatures due to inaccuracies in the former assumption. These are referred to as initial state effects (ISE) and are due to the quantum nature of the initial state. Comparison with experimental data and exactly soluble models shows that ISE largely account for observed asymmetries and peak shifts in the neutron scattering function S(q,ω), compared with the IA prediction. It is shown that when FSE are neglected, ISE can also be neglected when either the momentum transfer or the temperature is high. Finally it is shown that FSE should be negligible at high momentum transfers in systems other than quantum fluids and that therefore in this regime the IA is reached in such systems. (author)

  7. Probing fine magnetic particles with neutron scattering

    International Nuclear Information System (INIS)

    Pynn, R.

    1991-01-01

    Because thermal neutrons are scattered both by nuclei and by unpaired electrons, they provide an ideal probe for studying the atomic and magnetic structures of fine-grained magnetic materials, including nanocrystalline solids, thin epitaxial layers, and colloidal suspensions of magnetic particles, known as ferrofluids. Diffraction, surface reflection, and small angle neutron scattering (SANS) are the techniques used. With the exception of surface reflection, these methods are described in this article. The combination of SANS with refractive-index matching and neutron polarisation analysis is particularly powerful because it allows the magnetic and atomic structures to be determined independently. This technique has been used to study both dilute and concentrated ferrofluid suspensions of relatively monodisperse cobalt particles, subjected to a series of applied magnetic fields. The size of the cobalt particle core and the surrounding surfactant layer were determined. The measured interparticle structure factor agrees well with a recent theory that allows correlations in binary mixtures of magnetic particles to be calculated in the case of complete magnetic alignment. When one of the species in such a binary mixture is a nonmagnetic, cyclindrical macromolecule, application of a magnetic field leads to some degree of alignment of the nonmagnetic species. This result has been demonstrated with tobacco mosaic virus suspended in a water-based ferrofluid

  8. New generation of cryogen free advanced superconducting magnets for neutron scattering experiments

    International Nuclear Information System (INIS)

    Kirichek, O; Adroja, D T; Manuel, P; Bewley, R I; Brown, J; Kouzmenko, G; Wotherspoon, R

    2012-01-01

    Recent advances in superconducting technology and cryocooler refrigeration have resulted in a new generation of advanced superconducting magnets for neutron beam applications. These magnets have outstanding parameters such as high homogeneity and stability at highest magnetic fields possible, a reasonably small stray field, low neutron scattering background and larger exposure to neutron detectors. At the same time the pulse tube refrigeration technology provides a complete re-condensing regime which allows to minimise the requirements for cryogens without introducing additional noise and mechanical vibrations. The magnets can be used with dilution refrigerator insert which expands the temperature range from 20mK to 300K. Here we are going to present design, test results and the operational data of the 14T magnet for neutron diffraction and the 9T wide angle chopper magnet for neutron spectroscopy developed by Oxford Instruments in collaboration with ISIS neutron source. First scientific results obtained from the neutron scattering experiments with these magnets are also going to be discussed.

  9. Some neutron scattering studies on magnetic and molecular phase transitions

    International Nuclear Information System (INIS)

    Bevaart, L.

    1978-01-01

    In this thesis neutron-scattering investigations on two different systems are described. The first study is concerned with the magnetic ordering phenomena in pseudo two-dimensional (d = 2), two-component antiferromagnets K 2 Mnsub(1-x)Msub(x)F 4 (M = Fe, Co), as a function of the composition x and temperature T. For one of the samples in this series, K 2 Musub(0.978)Fesub(0.022)F 4 , the influence of an external magnetic field on the ordering characteristics was studied in addition. The second study deals with the rotational motions of the NH 4 + groups in NH 4 ZnF 3 in relation with the structural phase transition at Tsub(c) = 115.1 K. The experimental techniques were chosen according to the requirements of each of these two subjects. The former study was carried out by observing the elastic magnetic neutron scattering with a double-axis diffractometer, whereas for the latter study time-of-flight (TOF) techniques were applied to observe the inelastic and quasi-elastic incoherent neutron scattering by the protons of the rotating NH 4 + groups. (Auth.)

  10. Neutron scattering cross sections of uranium-238

    International Nuclear Information System (INIS)

    Beghian, L.E.; Kegel, G.H.R.; Marcella, T.V.; Barnes, B.K.; Couchell, G.P.; Egan, J.J.; Mittler, A.; Pullen, D.J.; Schier, W.A.

    1979-01-01

    The University of Lowell high-resolution time-of-flight spectrometer was used to measure angular distributions and 90-deg excitation functions for neutrons scattered from 238 U in the energy range from 0.9 to 3.1 MeV. This study was limited to the elastic and the first two inelastic groups, corresponding to states of 238 U at 45 keV (2 + ) and 148 keV (4 + ). Angular distributions were measured at primary neutron energies of 1.1, 1.9, 2.5, and 3.1 MeV for the same three neutron groups. Whereas the elastic data are in fair agreement with the evaluation in the ENDF/B-IV file, there is substantial disagreement between the inelastic measurements and the evaluated cross sections. 12 figures

  11. SCANDAL -- A facility for elastic neutron scattering studies in the 50--130 MeV range

    International Nuclear Information System (INIS)

    Klug, J.; Blomgren, J.; Atac, A.; Bergenwall, B.; Dangtip, S.; Elmgren, K.; Johansson, C.; Olsson, N.; Prokofiev, A.V.; Rahm, J.; Oberstedt, A.; Tovesson, F.; Eudes, Ph.; Haddad, F.; Kerveno, M.; Kirchner, T.; Lebrun, C.; Stuttge, L.; Slypen, I.; Michel, R.; Neumann, S.; Herpers, U.

    2001-01-01

    A facility for detection of scattered neutrons in the energy interval 50--130 MeV, SCANDAL (SCAttered Nucleon Detection AssembLy), has recently been installed at the 20--180 MeV neutron beam facility of the The Svedberg Laboratory, Uppsala. It is primarily intended for studies of elastic neutron scattering, but can be used for the (n,p) and (n,d) reaction experiments as well. The performance of the spectrometer is illustrated in measurements of the (n,p) and (n,n) reactions on 1 H and 12 C. In addition, the neutron beam facility is described in some detail

  12. SCANDAL--a facility for elastic neutron scattering studies in the 50-130 MeV range

    CERN Document Server

    Klug, J; Atac, A; Bergenwall, B; Dangtip, S; Elmgren, K; Johansson, C; Olsson, N; Pomp, S; Prokofiev, A V; Rahm, J; Tippawan, U; Jonsson, O; Nilsson, L; Renberg, P U; Nadel-Turonski, P; Ringbom, A; Oberstedt, A; Tovesson, F; Blideanu, V; Le Brun, C; Lecolley, J F; Lecolley, F R; Louvel, M; Marie, N; Schweitzer, C; Varignon, C; Eudes, P; Haddad, F; Kerveno, M; Kirchner, T; Lebrun, C; Stuttgé, L; Slypen, I; Smirnov, A N; Michel, R; Neumann, S; Herpers, U

    2002-01-01

    A facility for detection of scattered neutrons in the energy interval 50-130 MeV, SCAttered Nucleon Detection AssembLy (SCANDAL), has recently been installed at the 20-180 MeV neutron beam facility of The Svedberg Laboratory, Uppsala. It is primarily intended for studies of elastic neutron scattering, but can be used for (n,p) and (n,d) reaction experiments as well. The performance of the spectrometer is illustrated in measurements of the (n,p) and (n,n) reactions on sup 1 H and sup 1 sup 2 C. In addition, the neutron beam facility is described in some detail.

  13. Earth formation pulsed neutron porosity logging system utilizing epithermal neutron and inelastic scattering gamma ray detectors

    International Nuclear Information System (INIS)

    Smith, H.D. Jr.; Smith, M.P.; Schultz, W.E.

    1978-01-01

    An improved pulsed neutron porosity logging system is provided in the present invention. A logging tool provided with a 14 MeV pulsed neutron source, an epithermal neutron detector and an inelastic scattering gamma ray detector is moved through a borehole. The detection of inelastic gamma rays provides a measure of the fast neutron population in the vicinity of the detector. repetitive bursts of neutrons irradiate the earth formation and, during the busts, inelastic gamma rays representative of the fast neutron population is sampled. During the interval between bursts the epithermal neutron population is sampled along with background gamma radiation due to lingering thermal neutrons. the fast and epithermal neutron population measurements are combined to provide a measurement of formation porosity

  14. Inelastic scattering of neutrons

    International Nuclear Information System (INIS)

    Sal'nikov, O.A.

    1984-06-01

    The paper reviews the main problems concerning the mechanism of the inelastic scatterings of neutrons by nuclei, concentrating on the different models which calculate the angular distributions. In the region of overlapping levels, both the compound nucleus mechanism and the preequilibrium Griffin (exciton) model are discussed, and their contribution relative to that of a direct mechanism is considered. The parametrization of the level density and of the nuclear moment of inertia are also discussed. The excitation functions of discrete levels are also presented, and the importance of elucidating their five structure (for practical calculations, such as for shielding) is pointed out

  15. Neutron scattering. Annual progress report 1997

    International Nuclear Information System (INIS)

    Allenspach, P.; Boeni, B.; Fischer, P.; Furrer, A.

    1998-02-01

    The present progress report describes the scientific and technical activities obtained by LNS staff members in 1997. It also includes the work performed by external groups at our CRG instruments D1A and IN3 at the ILL Grenoble. Due to the outstanding properties of neutrons and x-rays the research work covered many areas of science and materials research. The highlight of the year 1997 was certainly the production of neutrons at the new spallation neutron source SINQ. From July to November, SINQ was operating for typically two days/week and allowed the commissioning of four instruments at the neutron guide system: - the triple-axis spectrometer Druechal, - the powder diffractometer DMC, - the double-axis diffractometer TOPSI, the polarised triple-axis spectrometer TASP. These instruments are now fully operational and have already been used for condensed matter studies, partly in cooperation with external groups. Five further instruments are in an advanced state, and their commissioning is expected to occur between June and October 1998: - the high-resolution powder diffractometer HRPT, - the single-crystal diffractometer TriCS, - the time-of-flight spectrometer FOCUS, - the reflectometer AMOR, - the neutron optical bench NOB. Together with the small angle neutron scattering facility SANS operated by the spallation source department, all these instruments will be made available to external user groups in the future. (author) figs., tabs., refs

  16. Characterization of the γ background in epithermal neutron scattering measurements at pulsed neutron sources

    International Nuclear Information System (INIS)

    Pietropaolo, A.; Tardocchi, M.; Schooneveld, E.M.; Senesi, R.

    2006-01-01

    This paper reports the characterization of the different components of the γ background in epithermal neutron scattering experiments at pulsed neutron sources. The measurements were performed on the VESUVIO spectrometer at ISIS spallation neutron source. These measurements, carried out with a high purity germanium detector, aim to provide detailed information for the investigation of the effect of the γ energy discrimination on the signal-to-background ratio. It is shown that the γ background is produced by different sources that can be identified with their relative time structure and relative weight

  17. The neutron-deuteron elastic scattering angular distribution at 95 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Mermod, Philippe

    2004-04-01

    The neutron-deuteron elastic scattering differential cross section has been measured at 95 MeV incident neutron energy, with the Medley setup at TSL in Uppsala. The neutron-proton differential cross section has also been measured for normalization purposes. The data are compared with theoretical calculations to investigate the role of three-nucleon force effects.

  18. Proposal for the Simultaneous Measurement of the Neutron-Neutron and Neutron-Proton Quasi-Free Scattering Cross Section via the Neutron-Deuteron Breakup Reaction at E n = 19 MeV

    Science.gov (United States)

    Tornow, W.; Howell, C. R.; Crowell, A. S.

    2013-12-01

    In order to confirm or refute the present discrepancy between data and calculation for the neutron-neutron quasi-free scattering cross section in the neutron-deuteron breakup reaction, we describe a new experimental approach currently being pursued at TUNL.

  19. Spin-Echo Small-Angle Neutron Scattering Development

    NARCIS (Netherlands)

    Uca, O.

    2003-01-01

    Spin-Echo Small-Angle Neutron Scattering (SESANS) instrument is a novel SANS technique which enables one to characterize distances from a few nanometers up to the micron range. The most striking difference between normal SANS and SESANS is that in SESANS one gets information in real space, whereas

  20. Neutron scattering studies of mixed-valence semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Mignot, J M [Laboratoire Leon Brillouin (LLB) - Centre d` Etudes de Saclay, 91 - Gif-sur-Yvette (France); Alekseev, P A [Kurchatov Institute, Moscow (Russian Federation)

    1994-12-31

    Neutron scattering experiments on the mixed-valence (MV) compounds SmB{sub 6} are reported. The inelastic magnetic response of SmB{sub 6} at T = 2 K, measured on a double-isotope single crystal,displays a strongly damped peak at 35 meV corresponding to the inter multiplet transition of Sm{sup 2+}. At lower energies ( h.{omega} {approx_equal} 14 meV), a narrow magnetic excitation is observed, with remarkable scattering-vector and temperature dependences of its intensity. This novel feature is discussed in terms of recent theoretical works describing the formation of an anisotropic local bound state in semiconducting MV materials. If the average samarium valence is decreased by substituting La for Sm, a peak is found to appear at high energies. The elastic magnetic form factor of SmB{sub 6} was determined using polarised neutrons and no significant difference is observed in its Q-dependence with respect to that of pure divalent samarium. This surprising behaviour is constant with previous measurements on the gold (high-pressure) phase of SmS. The above results are compared to those already reported for other MV materials. In particular existing information for TmSe is supplemented by recent inelastic scattering measurements carried out on a large stoichiometric single crystal. (author). 44 refs., 7 figs.

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

    CERN Document Server

    Aaron, F.D.; Alimujiang, K.; Andreev, V.; Antunovic, B.; Backovic, S.; Baghdasaryan, A.; Barrelet, E.; Bartel, W.; Begzsuren, K.; Belousov, A.; Bizot, J.C.; Boudry, V.; Bozovic-Jelisavcic, I.; Bracinik, J.; Brandt, G.; Brinkmann, M.; Brisson, V.; Bruncko, D.; Bunyatyan, A.; Buschhorn, G.; Bystritskaya, L.; Campbell, A.J.; Cantun Avila, K.B.; Cerny, K.; Cerny, V.; Chekelian, V.; Cholewa, A.; Contreras, J.G.; Coughlan, J.A.; Cozzika, G.; Cvach, J.; Dainton, J.B.; Daum, K.; Deak, M.; Delcourt, B.; Delvax, J.; De Wolf, E.A.; Diaconu, C.; Dodonov, V.; Dossanov, A.; Dubak, A.; Eckerlin, G.; Efremenko, V.; Egli, S.; Eliseev, A.; Elsen, E.; Falkiewicz, A.; Favart, L.; Fedotov, A.; Felst, R.; Feltesse, J.; Ferencei, J.; Fischer, D.-J.; Fleischer, M.; Fomenko, A.; Gabathuler, E.; Gayler, J.; Ghazaryan, Samvel; Glazov, A.; Glushkov, I.; Goerlich, L.; Gogitidze, N.; Gouzevitch, M.; Grab, C.; Greenshaw, T.; Grell, B.R.; Grindhammer, G.; Habib, S.; Haidt, D.; Helebrant, C.; Henderson, R.C.W.; Hennekemper, E.; Henschel, H.; Herbst, M.; Herrera, G.; Hildebrandt, M.; Hiller, K.H.; Hoffmann, D.; Horisberger, R.; Hreus, T.; Jacquet, M.; Janssen, X.; Jonsson, L.; Jung, Andreas Werner; Jung, H.; Kapichine, M.; Katzy, J.; Kenyon, I.R.; Kiesling, C.; Klein, M.; Kleinwort, C.; Kluge, T.; Knutsson, A.; Kogler, R.; Kostka, P.; Kraemer, M.; Krastev, K.; Kretzschmar, J.; Kropivnitskaya, A.; Kruger, K.; Kutak, K.; Landon, M.P.J.; Lange, W.; Lastovicka-Medin, G.; Laycock, P.; Lebedev, A.; Lendermann, V.; Levonian, S.; Li, G.; Lipka, K.; Liptaj, A.; List, B.; List, J.; Loktionova, N.; Lopez-Fernandez, R.; Lubimov, V.; Lytkin, L.; Makankine, A.; Malinovski, E.; Marage, P.; Marti, Ll.; Martyn, H.-U.; Maxfield, S.J.; Mehta, A.; Meyer, A.B.; Meyer, H.; Meyer, H.; Meyer, J.; Mikocki, S.; Milcewicz-Mika, I.; Moreau, F.; Morozov, A.; Morris, J.V.; Mozer, Matthias Ulrich; Mudrinic, M.; Muller, K.; Murin, P.; Naumann, Th.; Newman, P.R.; Niebuhr, C.; Nikiforov, A.; Nikitin, D.; Nowak, G.; Nowak, K.; Olsson, J.E.; Osman, S.; Ozerov, D.; Pahl, P; Palichik, V.; Panagoulias, I.; Pandurovic, M.; Papadopoulou, Th.; Pascaud, C.; Patel, G.D.; Pejchal, O.; Perez, E.; Petrukhin, A.; Picuric, I.; Piec, S.; Pitzl, D.; Placakyte, R.; Pokorny, B.; Polifka, R.; Povh, B.; Radescu, V.; Rahmat, A.J.; Raicevic, N.; Raspiareza, A.; Ravdandorj, T.; Reimer, P.; Rizvi, E.; Robmann, P.; Roland, B.; Roosen, R.; Rostovtsev, A.; Rotaru, M.; Ruiz Tabasco, J.E.; Rusakov, S.; Salek, D.; Sankey, D.P.C.; Sauter, M.; Sauvan, E.; Schmitt, S.; Schoeffel, L.; Schoning, A.; Schultz-Coulon, H.-C.; Sefkow, F.; Shaw-West, R.N.; Shtarkov, L.N.; Shushkevich, S.; Sloan, T.; Smiljanic, Ivan; Soloviev, Y.; Sopicki, P.; South, D.; Spaskov, V.; Specka, Arnd E.; Staykova, Z.; Steder, M.; Stella, B.; Stoicea, G.; Straumann, U.; Sunar, D.; Sykora, T.; Tchoulakov, V.; Thompson, G.; Thompson, P.D.; Toll, T.; Tomasz, F.; Tran, T.H.; Traynor, D.; Trinh, T.N.; Truol, P.; Tsakov, I.; Tseepeldorj, B.; Turnau, J.; Urban, K.; Valkarova, A.; Vallee, C.; Van Mechelen, P.; Vargas Trevino, A.; Vazdik, Y.; Vinokurova, S.; Volchinski, V.; von den Driesch, M.; Wegener, D.; Wissing, Ch.; Wunsch, E.; Zacek, J.; Zalesak, J.; Zhang, Z.; Zhokin, A.; Zimmermann, T.; Zohrabyan, H.; Zomer, F.

    2010-01-01

    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 < Q^2 < 100 GeV^2, Bjorken scaling variable 1.5x10^{-4} < x < 3x10^{-2}, longitudinal momentum fraction 0.32 < x_L < 0.95 and neutron transverse momentum p_T < 0.2 GeV. The leading 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.

  2. High pressure sample container for thermal neutron spectroscopy and diffraction on strongly scattering fluids

    International Nuclear Information System (INIS)

    Verkerk, P.; Pruisken, A.M.M.

    1979-01-01

    A description is presented of the construction and performance of a container for thermal neutron scattering on a fluid sample with about 1.5 cm -1 macroscopic cross section (neglecting absorption). The maximum pressure is about 900 bar. The container is made of 5052 aluminium capillary with inner diameter 0.75 mm and wall thickness 0.25 mm; it covers a neutron beam with a cross section of 9 X 2.5 cm 2 . The container has been successfully used in neutron diffraction and time-of-flight experiments on argon-36 at 120 K and several pressures up to 850 bar. It is shown that during these measurements the temperature gradient over the sample as well as the error in the absolute temperature were both less than 0.05 K. Subtraction of the Bragg peaks due to container scattering in diffraction experiments may be dfficult, but seems feasible because of the small amount of aluminium in the neutron beam. Correction for container scattering and multiple scattering in time-of-flight experiments may be difficult only in the case of coherently scattering samples and small scattering angles. (Auth.)

  3. Neutron scattering studies in the actinide region. Progress report, August 1, 1991--July 31, 1994

    International Nuclear Information System (INIS)

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

    1994-09-01

    During the period August 1, 1991 to July 31, 1994 the authors report progress on the following: (a) prompt fission neutron energy spectra for 235 U and 239 Pu; (b) two-parameter measurement of nuclear lifetimes; (c) 'black' neutron detector; (d) data reduction techniques for neutron scattering experiments; (e) elastic and inelastic neutron scattering studies in 197 Au; (f) elastic and inelastic neutron scattering studies in 239 Pu; (g) neutron induced defects in silicon dioxide MOS structures; (h) response of a 235 U fission chamber near reaction thresholds; (i) efficiency calibration of a liquid scintillation detector using the WNR facility at LAMPF; (j) prompt fission neutron energy spectrum measurements below the incident neutron energy; (k) multi-parameter data acquisition system; (l) accelerator improvements; (m) non-DOE supported research. Eight Ph.D. dissertations and two M.S. theses were completed during the report period. Publications consisted of 6 journal articles, 10 conference proceedings, and 19 abstracts of presentations at scientific meetings. One invited talk was given

  4. Investigation of collective excitations in fluid neon by coherent neutron scattering at small scattering vectors

    International Nuclear Information System (INIS)

    Bell, H.G.

    1976-07-01

    The energy spectra of Ne studied under different temperatures and pressures with the aid of inelastic, coherent neutron scattering can be described by a scattering law derived from the basic hydrodynamic equations. The Brillouin lines found with very small momentum transfer 0.06 A -1 -1 are interpreted as collective, adiabatic pressure fluctuations. (orig./WL) [de

  5. Neutron scattering study of magnetic and crystalline electirc field interactions in RCrO3

    International Nuclear Information System (INIS)

    Shamir, N.

    1978-05-01

    Magnetic and crystalline electric field interactions in the compounds RCrO 3 (R-rare earth) , were studied by neutron scattering. Elastic neutron scattering was utilized in the study of the temperature dependence of the Cr 3+ and Ho 3+ magnetic reflections in Lu CrO 3 and HoCrO 3 , respectively. Analysis of this temperature dependence yielde constant canting angles for the Cr 3+ and Ho 3+ magnetic moments. Molecular magnetic field constants and crystalline electric field splitting were also calculated from the temperature dependence of the Ho 3+ magnetic reflection. These parameters were obtained directly by inelastic neutron scattering measurement. Inelastic neutron scattering measurements of crystlline electric field transitions of R 3+ (R=Pr, Nd, Tb, Ho, Er, Tm, Yb) in RCrO 3 , formed the basis for the calculation of the common crystalline electirc field parameters of the heavy R 3+ ions. (author)

  6. The use of neutron scattering to determine the functional structure of glycoside hydrolase.

    Science.gov (United States)

    Nakamura, Akihiko; Ishida, Takuya; Samejima, Masahiro; Igarashi, Kiyohiko

    2016-10-01

    Neutron diffraction provides different information from X-ray diffraction, because neutrons are scattered by atomic nuclei, whereas X-rays are scattered by electrons. One of the key advantages of neutron crystallography is the ability to visualize hydrogen and deuterium atoms, making it possible to observe the protonation state of amino acid residues, hydrogen bonds, networks of water molecules and proton relay pathways in enzymes. But, because of technical difficulties, less than 100 enzyme structures have been evaluated by neutron crystallography to date. In this review, we discuss the advantages and disadvantages of neutron crystallography as a tool to investigate the functional structure of glycoside hydrolases, with some examples. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Small-angle neutron scattering technique in liquid crystal studies

    International Nuclear Information System (INIS)

    Shahidan Radiman

    2005-01-01

    The following topics discussed: general principles of SAS (Small-angle Neutron Scattering), liquid crystals, nanoparticle templating on liquid crystals, examples of SAS results, prospects of this studies

  8. Thermal neutron inelastic scattering and it's application to the material science

    International Nuclear Information System (INIS)

    Li Zhuqi

    1986-01-01

    A brief description of the elementary scattering theory of the interaction between the thermal neutrons and the condensed matter is given and the characteristics related to the experimental method of the thermal neutrons inelastic scattering is described. Expressions of the phonons dispersion, density of the phonon state and the self-diffusion coefficient at the some conditions are also introduced. Some examples of describing diagram of the phonon dispersion, density of the phonons state and selfdiffusion coefficient measured by different authors are given

  9. Neutron scattering. Lectures of the JCNS laboratory course held at Forschungszentrum Juelich and the research reactor FRM II of TU Munich

    International Nuclear Information System (INIS)

    Brueckel, T.; Heger, G.; Richter, D.; Zorn, R.

    2007-01-01

    The following topics are dealt with: Fourier transform, basic assumptions of quantum mechanics and the Born approximation, symmtery in crystals, neutron sources, neutron elastic scattering and properties, polarized neutron scattering, correlation functions measured by scattering experiments, grazing incidence neutron scattering, neutron diffractometers, small-angle scattewring inelastic crystal spectrometers, time-of-flight spectrometers using NSE, structure determination, inelastic neutron scattering with phonon and magnon excitations, structure of complex fluids and macromolecules, polymer dynamics, magnetism. (HSI)

  10. Estimation of scattering contribution in the calibration of neutron devices with radionuclide sources in rooms of different sizes

    Directory of Open Access Journals (Sweden)

    Khabaz Rahim

    2015-01-01

    Full Text Available Calibrations of neutron devices used in area monitoring are often performed by radionuclide neutron sources. Device readings increase due to neutrons scattered by the surroundings and the air. The influence of said scattering effects have been investigated in this paper by performing Monte Carlo simulations for ten different radionuclide neutron sources inside several sizes of concrete wall spherical rooms (Rsp = 200 to 1500 cm. In order to obtain the parameters that relate the additional contribution from scattered neutrons, calculations using a polynomial fit model were evaluated. Obtained results show that the contribution of scattering is roughly independent of the geometric shape of the calibration room. The parameter that relates the room-return scattering has been fitted in terms of the spherical room radius, so as to reasonably accurately estimate the scattering value for each radionuclide neutron source in any geometry of the calibration room.

  11. Significance of collective motions in biopolymers and neutron scattering

    Energy Technology Data Exchange (ETDEWEB)

    Go, Nobuhiro [Kyoto Univ. (Japan)

    1996-05-01

    Importance of collective variable description of conformational dynamics of biopolymers and the vital role that neutron inelastic scattering phenomena would play in its experimental determination are discussed. (author)

  12. The 7th Japan-Taiwan joint meeting on neutron and X-ray scattering. Proceedings

    International Nuclear Information System (INIS)

    2016-03-01

    The 7th Japan-Taiwan joint meeting on neutron and X-ray scattering in Kumatori is held bilaterally in Japan and Taiwan. This meeting provides the recent outstanding results in the fields of fundamental polymer and biological sciences and their applications as well. In the fields of the X-ray and/or neutron scattering, the methodological progress expands the research fields and gives us new scientific insights. This meeting invites the researchers developing new methodologies, such as dynamics measurement utilizing nuclear Bragg resonance, subunit-kinetics measurement with deuteration-assisted small-angle neutron scattering and so on. (J.P.N.)

  13. 2009 International Conference on Neutron Scattering (ICNS 2009)

    Energy Technology Data Exchange (ETDEWEB)

    Gopal Rao, PhD; Gillespie, Donna

    2010-08-05

    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.

  14. Measurements of prompt fission neutron spectra and double-differential neutron inelastic-scattering cross sections for 238U and 232Th

    International Nuclear Information System (INIS)

    Baba, Mamoru; Itoh, Nobuo; Maeda, Kazuto; Hirakawa, Naohiro; Wakabayashi, Hidetaka.

    1989-10-01

    This report presents the summary of experimental studies of prompt fission neutron spectra and double-differential neutron inelastic-scattering cross sections of 238 U and 232 Th. The experiments were performed at Tohoku University Fast Neutron Laboratory employing a time-of-flight technique and Dynamitron accelerator as the pulsed neutron generator. From the experiments, we obtained the following data for both nuclei; 1. prompt fission neutron spectrum for 2 MeV neutrons, 2. double-differential neutron inelastic-scattering cross sections for 1.2, 2.0, 4.2, 6.1 and 14.1 MeV incident neutrons. Both in experiments and data processing, cares were taken to obtain reliable data by avoiding systematic uncertainty. The experimental data were compared with those by other experiments, evaluations and model calculations. Through the data comparison, some fundamental problems were found in the experiments by previous authors and the evaluations. The present data will provide useful data base for refinement of the evaluated data and theoretical models. (author)

  15. To semi-centenary anniversary of discovering the Schwinger scattering and starting the first works on neutron polarizability

    International Nuclear Information System (INIS)

    Alexandrov, Yu.A.

    2006-01-01

    The theory of neutron Schwinger scattering was proposed and developed by Schwinger in 1948, but despite multiple efforts, the experimental discovery of this phenomenon was made eight years later. Currently, Schwinger scattering should be accounted for in many precise neutron experiments, for example, while studying the electromagnetic interaction of neutrons with nuclei. By means of Schwinger scattering it is possible to measure the degree of polarization of the initial beam even at particle energies of 1 GeV order. The concept of neutron polarizability was introduced as additional natural phenomenon indicating the nucleon space structure after the first Hofstadter's experiments (1953-1954). The neutron polarizability was detected in a small-angle neutron scattering experiment in 1957. However, the serious contradiction between the results obtained in megaelectronvolt and kiloelectronvolt neutron energy ranges was explained only in 2001. It is also shown that existent small-angle neutron experiments at megaelectronvolt energy by heavy nuclei do not confirm the idea of (n+3)-dimensional gravity

  16. Scattering of fast neutrons from 103Rh

    International Nuclear Information System (INIS)

    Barnard, E.; Reitmann, D.

    1978-01-01

    The scattering of fast neutrons from 103 Rh was studied by means of (n, n), (n, n') and (n, n'γ) measurements at neutron energies up to 2 MeV. More than fifty unknown γ-transitions were identified and a level scheme established which includes fifteen unreported excited states. Branching ratios, spins and parities for these levels were deduced, as well as the effective activation cross sections for the 103 Rh(n, n')sup(103m)Rh reaction. The results are compared with existing data and with calculations based on the optical and statistical models. (Auth.)

  17. Monte Carlo simulation of neutron scattering instruments

    International Nuclear Information System (INIS)

    Seeger, P.A.; Daemen, L.L.; Hjelm, R.P. Jr.

    1998-01-01

    A code package consisting of the Monte Carlo Library MCLIB, the executing code MC RUN, the web application MC Web, and various ancillary codes is proposed as an open standard for simulation of neutron scattering instruments. The architecture of the package includes structures to define surfaces, regions, and optical elements contained in regions. A particle is defined by its vector position and velocity, its time of flight, its mass and charge, and a polarization vector. The MC RUN code handles neutron transport and bookkeeping, while the action on the neutron within any region is computed using algorithms that may be deterministic, probabilistic, or a combination. Complete versatility is possible because the existing library may be supplemented by any procedures a user is able to code. Some examples are shown

  18. Small angle neutron scattering from hydrated cement pastes

    International Nuclear Information System (INIS)

    Sabine, T.M.; Bertram, W.K.; Aldridge, L.P.

    1996-01-01

    Small angle neutron scattering (SANS) was used to study the microstructure of hydrating cement made with, and without silica fume. Some significant differences were found between the SANS spectra of pastes made from OPC (ordinary Portland cement) and DSP (made with silica fume and superplasticiser). The SANS spectra are interpreted in terms of scattering from simple particles. Particle growth was monitored during hydration and it was found that the growth correlated with the heat of hydration of the cement

  19. Neutron scattering studies on the high Tc superconductor YBa2Cu306+x

    International Nuclear Information System (INIS)

    Jurgens, M.J.G.M.

    1990-01-01

    The aim of the work described in this thesis is to clarify some of the magnetic aspects of high T c superconductors across the phase diagram as a function of doping and temperature, for which YBa 2 Cu 3 o 6+x has been chosen. Mainly the neutron scattering technique has been employed, which supplies a very powerful tool for this kind of research, for it directly shows the microscopic phenomena of the magnetism involved. First an introduction to the neutron scattering technique is given and a description of the spectrometers employed (ch. 2). The determination of the crystal structure of YBa 2 Cu 3 o 6+x is described, and the single crystals which were used during all the experiments on the magnetic properties as described in this thesis, are characterized (ch. 3). Ch. 4 deals with the phase diagram of the insulating antiferromagnetic phase in YBa 2 Cu 3 o 6+x , as obtained with neutron scattering. The inelastic scattering experiments on the magnetic excitations in this system are presented in ch. 5. In ch. 6 the total susceptibility, measure with a AQUID, is discussed. The local magnetizations, as determined with a polarized neutron scattering technique are the subject of ch. 7. (author). 254 refs.; 77 figs.; 25 tabs

  20. Scattering and depolarization of polarized neutrons in ferrofluids

    International Nuclear Information System (INIS)

    Balasoiu, M.; Dokukin, E.B.; Kozhevnikov, S.V.; Nikitenko, Y.V.

    1999-01-01

    On the SPN - 1 polarized neutron spectrometer at IBR -2 high - flux pulsed rector there were carried out preliminary measurements on transmission and polarization of a neutron beam passing through a magnetic colloidal system of Fe 3 O 4 particles in transformer oil and dodecane carriers. It was found that in the ferrofluids with magnetite particles exist, dependent on the particle volume concentration and the magnitude of the external magnetic field, effects of depolarization and nuclear - magnetic small angle scattering. (author)

  1. Investigation of high-energy inelastic neutron scattering from liquid water confined in silica xerogel

    International Nuclear Information System (INIS)

    Perelli-Cippo, E.; Andreani, C.; Casalboni, M.; Dire, S.; Fernandez-Canoto, D.; Gorini, G.; Imberti, S.; Pietropaolo, A.; Prosposito, P.; Schutzmann, S.; Senesi, R.; Tardocchi, M.

    2006-01-01

    High-energy inelastic neutron scattering (HINS) employing epithermal neutrons is a new technique under development at the VESUVIO spectrometer at ISIS, aiming to access the high-energy and low wave-vector transfer region in neutron scattering experiments at eV energies. New neutron detectors have been developed for HINS based on the resonant detector (RD). These make use of the detection of prompt gammas after neutron absorption in an analyzer foil. The RD is used in the very low angle detector (VLAD) bank, which will extend the explored kinematical region to momentum transfer -1 , whilst still keeping energy transfer >300 meV. The final VLAD will cover the scattering range 1-5 o and will be installed by the end of 2005. The results obtained with prototype VLAD detectors on polycrystalline ice and liquid water in silica xerogels provide a demonstration of the feasibility of the measurements under realistic conditions

  2. Life at extreme conditions: Neutron scattering studies of biological

    Indian Academy of Sciences (India)

    Extremophile bacteria; molecular adaptation; halophile; water dynamics; protein dynamics. ... Results of neutron scattering measurements on the dynamics of proteins ... The experiments were performed on a halophilic protein, and membrane ...

  3. Collective Excitations in Liquid Hydrogen Observed by Coherent Neutron Scattering

    DEFF Research Database (Denmark)

    da Costa Carneiro, Kim; Nielsen, M.; McTague, J. P.

    1973-01-01

    Coherent scattering of neutrons by liquid parahydrogen shows the existence of well-defined collective excitations in this liquid. Qualitative similarity with the scattering from liquid helium is found. Furthermore, in the range of observed wave vectors, 0.7 Å-1 ≤κ≤3.1 Å-1, extending from the firs...

  4. Studies of Water by Scattering of Slow Neutrons

    International Nuclear Information System (INIS)

    Skoeld, K.; Pilcher, E.; Larsson, K.E.

    1964-01-01

    The quasielastic scattering peak in light water at room temperature has been studied with neutrons of energy ∼ 5x10 -3 eV. The width and shape of the peak has been determined by the time-of-flight technique at two scattering angles. If it is assumed that the broad inelastic spectrum is due to scattering by a monoatomic gas of mass 18, it is found that the quasielastic scattering is in good agreement with the predictions by the continuous diffusion model. Inelastic spectra were recorded up to 13x10 -3 eV. Indications of two discrete energy transfers (8 and 14x10 -4 eV) are observed in the 90 deg run. The results are discussed and compared with earlier observations

  5. Optical model calculation of neutron-nucleus scattering cross sections

    International Nuclear Information System (INIS)

    Smith, M.E.; Camarda, H.S.

    1980-01-01

    A program to calculate the total, elastic, reaction, and differential cross section of a neutron interacting with a nucleus is described. The interaction between the neutron and the nucleus is represented by a spherically symmetric complex potential that includes spin-orbit coupling. This optical model problem is solved numerically, and is treated with the partial-wave formalism of scattering theory. The necessary scattering theory required to solve this problem is briefly stated. Then, the numerical methods used to integrate the Schroedinger equation, calculate derivatives, etc., are described, and the results of various programming tests performed are presented. Finally, the program is discussed from a user's point of view, and it is pointed out how and where the program (OPTICAL) can be changed to satisfy particular needs

  6. Measurement of leading neutron production in deep-inelastic scattering at HERA

    International Nuclear Information System (INIS)

    Aaron, F.D.; Alexa, C.; Rotaru, M.; Stoicea, G.; Andreev, V.; Belousov, A.; Eliseev, A.; Fomenko, A.; Gogitidze, N.; Lebedev, A.; Loktionova, N.; Malinovski, E.; Rusakov, S.; Shtarkov, L.N.; Soloviev, Y.; Vazdik, Y.; Antunovic, B.; Bartel, W.; Brandt, G.; Campbell, A.J.; Cholewa, A.; Deak, M.; Eckerlin, G.; Elsen, E.; Felst, R.; Fischer, D.J.; Fleischer, M.; Gayler, J.; Ghazaryan, S.; Glazov, A.; Gouzevitch, M.; Grell, B.R.; Haidt, D.; Helebrant, C.; Jung, H.; Katzy, J.; Kleinwort, C.; Knutsson, A.; Kraemer, M.; Krastev, K.; Kutak, K.; Levonian, S.; Lipka, K.; List, J.; Marti, L.; Meyer, A.B.; Meyer, H.; Meyer, J.; Niebuhr, C.; Nikiforov, A.; Olsson, J.E.; Pahl, P.; Panagoulias, I.; Papadopoulou, T.; Pitzl, D.; Placakyte, R.; Schmitt, S.; Sefkow, F.; Staykova, Z.; Steder, M.; Sunar, D.; Vargas Trevino, A.; Vinokurova, S.; Driesch, M. von den; Wissing, C.; Wuensch, E.; Backovic, S.; Dubak, A.; Lastovicka-Medin, G.; Picuric, I.; Raicevic, N.; Baghdasaryan, A.; Volchinski, V.; Zohrabyan, H.; Barrelet, E.; Begzsuren, K.; Ravdandorj, T.; Tseepeldorj, B.; Bizot, J.C.; Brisson, V.; Delcourt, B.; Jacquet, M.; Li, G.; Pascaud, C.; Tran, T.H.; Zhang, Z.; Zomer, F.; Boudry, V.; Moreau, F.; Specka, A.; Bozovic-Jelisavcic, I.; Mudrinic, M.; Pandurovic, M.; Smiljanic, I.; Bracinik, J.; Kenyon, I.R.; Newman, P.R.; Shaw-West, R.N.; Thompson, P.D.; Brinkmann, M.; Habib, S.; List, B.; Toll, T.; Bruncko, D.; Cerny, V.; Ferencei, J.; Murin, P.; Tomasz, F.; Bunyatyan, A.; Buschhorn, G.; Chekelian, V.; Dossanov, A.; Grindhammer, G.; Kiesling, C.; Kogler, R.; Liptaj, A.; Raspiareza, A.; Shushkevich, S.; Bystritskaya, L.; Efremenko, V.; Fedotov, A.; Kropivnitskaya, A.; Lubimov, V.; Ozerov, D.; Petrukhin, A.; Rostovtsev, A.; Zhokin, A.; Cantun Avila, K.B.; Contreras, J.G.; Ruiz Tabasco, J.E.; Cerny, K.; Pejchal, O.; Pokorny, B.; Polifka, R.; Salek, D.; Valkarova, A.; Zacek, J.; Coughlan, J.A.; Morris, J.V.; Sankey, D.P.C.; Cozzika, G.; Feltesse, J.; Perez, E.; Schoeffel, L.; Cvach, J.; Reimer, P.; Zalesak, J.; Dainton, J.B.; Gabathuler, E.; Greenshaw, T.; Klein, M.; Kluge, T.; Kretzschmar, J.; Laycock, P.; Maxfield, S.J.; Mehta, A.; Patel, G.D.; Rahmat, A.J.; Daum, K.; Meyer, H.; Delvax, J.; Wolf, E.A. de; Favart, L.; Hreus, T.; Janssen, X.; Marage, P.; Mozer, M.U.; Roland, B.; Roosen, R.; Sykora, T.; Mechelen, P. van; Diaconu, C.; Hoffmann, D.; Sauvan, E.; Trinh, T.N.; Vallee, C.; Dodonov, V.; Povh, B.; Egli, S.; Hildebrandt, M.; Horisberger, R.; Falkiewicz, A.; Goerlich, L.; Mikocki, S.; Milcewicz-Mika, I.; Nowak, G.; Sopicki, P.; Turnau, J.; Glushkov, I.; Henschel, H.; Hiller, K.H.; Kostka, P.; Lange, W.; Naumann, T.; Piec, S.; Grab, C.; Zimmermann, T.; Henderson, R.C.W.; Sloan, T.; Hennekemper, E.; Herbst, M.; Jung, A.W.; Krueger, K.; Lendermann, V.; Schultz-Coulon, H.C.; Urban, K.; Herrera, G.; Lopez-Fernandez, R.; Joensson, L.; Osman, S.; Kapichine, M.; Lytkin, L.; Makankine, A.; Morozov, A.; Nikitin, D.; Palichik, V.; Spaskov, V.; Tchoulakov, V.; Landon, M.P.J.; Rizvi, E.; Thompson, G.; Traynor, D.; Martyn, H.U.; Mueller, K.; Nowak, K.; Robmann, P.; Straumann, U.; Truoel, P.; Radescu, V.; Sauter, M.; Schoening, A.; South, D.; Wegener, D.; Stella, B.; Tsakov, I.

    2010-01-01

    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 2 2 , Bjorken scaling variable 1.5 .10 -4 -2 , longitudinal momentum fraction 0.32 L T 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. (orig.)

  7. Measurement of the scattering cross section of slow neutrons on liquid parahydrogen from neutron transmission

    Science.gov (United States)

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

    2015-05-01

    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/σ d Ω 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 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 nonequilibrium 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.

  8. Lecture notes of the Introductory course to the European Conference on Neutron Scattering, ECNS'99

    International Nuclear Information System (INIS)

    Kadar, G.; Rosta, L.

    1999-01-01

    The aim of this volume of Lecture Notes is to form and confirm a tradition of Introductory Courses in relation to the European Conferences on Neutron Scattering. The structure of the Lecture Notes is as follows: a general block of introduction of mainly experimental character is presented, then traditional diffraction methods are discussed. Some aspects of small angle neutron scattering and reflectometry are discussed, and in a final block the well-known techniques of inelastic neutron scattering is outlined. 12 items are indexed separately for the INIS database. (K.A.)

  9. Study for correction of neutron scattering in the calibration of the albedo individual monitor from the Neutron Laboratory (LN), IRD/CNEN-RJ, Brazil

    International Nuclear Information System (INIS)

    Freitas, B.M.; Silva, A.X. da

    2014-01-01

    The Instituto de Radioprotecao e Dosimetria (IRD) runs a neutron individual monitoring service with albedo type monitor and thermoluminescent detectors (TLD). Moreover the largest number of workers exposed to neutrons in Brazil is exposed to 241 Am-Be fields. Therefore a study of the response of albedo dosemeter due to neutron scattering from 241 Am-Be source is important for a proper calibration. In this work, it has been evaluated the influence of the scattering correction in two distances at the Low Scattering Laboratory of the Neutron Laboratory of the Brazilian National Laboratory (Lab. Nacional de Metrologia Brasileira de Radiacoes Ionizantes) in the calibration of that albedo dosemeter for a 241 Am-Be source. (author)

  10. Inelastic scattering of 1-2.5 MeV neutrons by 235U and 238U nuclei

    International Nuclear Information System (INIS)

    Kornilov, N.V.; Kagalenko, A.B.; Baryba, V.Ya.; Balitskij, A.V.; Androsenko, A.A.; Androsenko, P.A.

    1993-07-01

    The inelastic scattering cross-sections of 1-2.5 MeV neutrons for 235 U and 238 0 nuclei were measured. A detailed description is given of the data processing procedures used, and the methods for determining the neutron flux in the sample. The Monte Carlo method was used to calculate the corrections for multiple neutron scattering and neutron flux attenuation in the sample. Pursuant to an analysis of the fission neutron spectra, we concluded that the systematic error level of the results is ± 3.27%. The results of these cross-section and spectrum measurements for inelastically scattered neutrons are compared with results from other sources and existing evaluations, the possible causes of the divergences for neutrons with an energy level of less than 1 MeV are analysed, and suggestions are put forward for future research work. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-07-15

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

  12. Applications of neutron scattering to the study of magnetic materials

    International Nuclear Information System (INIS)

    Koehler, W.C.

    1976-01-01

    The types of interactions that neutrons undergo with condensed matter are reviewed and those properties of neutrons that make them an ideal probe for the study of magnetism on a microscopic scale are discussed. Following a very brief survey of experimental methods, a few illustrative examples of specific investigations are described in sufficient detail to illustrate the power of the techniques. Views as to the future directions that may be taken by neutron scattering are presented

  13. Fast-neutron total and scattering cross sections of elemental palladium

    International Nuclear Information System (INIS)

    Smith, A.B.; Guenther, P.T.; Whalen, J.F.

    1982-06-01

    Neutron total cross sections of palladium are measured from approx. = 0.6 to 4.5 MeV with resolutions of approx. = 30 to 70 keV at intervals of less than or equal to 50 keV. Differential neutron elastic- and inelastic-scattering cross sections are measured from 1.4 to 3.85 MeV at intervals of 50 to 100 keV and at 10 to 20 scattering angles distributed between approx. = 20 and 160 0 . The experimental results are compared with respective quantities given in ENDF/B-V and used to deduce an optical potential that provides a good description of the measured values

  14. Data reduction for neutron scattering from plutonium samples. Final report

    International Nuclear Information System (INIS)

    Seeger, P.A.

    1997-01-01

    An experiment performed in August, 1993, on the Low-Q Diffractometer (LQD) at the Manual Lujan Jr. Neutron Scattering Center (MLNSC) was designed to study the formation and annealing of He bubbles in aged 239 Pu metal. Significant complications arise in the reduction of the data because of the very high total neutron cross section of 239 Pu, and also because the sample are difficult to make uniform and to characterize. This report gives the details of the data and the data reduction procedures, presents the resulting scattering patterns in terms of macroscopic cross section as a function of momentum transfer, and suggests improvements for future experiments

  15. Fast-neutron total and scattering cross sections of elemental palladium

    Energy Technology Data Exchange (ETDEWEB)

    Smith, A.B.; Guenther, P.T.; Whalen, J.F.

    1982-06-01

    Neutron total cross sections of palladium are measured from approx. = 0.6 to 4.5 MeV with resolutions of approx. = 30 to 70 keV at intervals of less than or equal to 50 keV. Differential neutron elastic- and inelastic-scattering cross sections are measured from 1.4 to 3.85 MeV at intervals of 50 to 100 keV and at 10 to 20 scattering angles distributed between approx. = 20 and 160/sup 0/. The experimental results are compared with respective quantities given in ENDF/B-V and used to deduce an optical potential that provides a good description of the measured values.

  16. Neutron-proton elastic scattering at high energies

    Energy Technology Data Exchange (ETDEWEB)

    Saleem, M.; Fazal-e-Aleem (Punjab Univ., Lahore (Pakistan). Dept. of Physics)

    1980-09-06

    The most recent measurements of the differential and total cross sections of neutron-proton elastic scattering from 70 to 400 GeV/c have been explained by using rho as a simple pole and pomeron as a dipole. The predictions are also made regarding the energy dependence of dip and bump structure in angular distribution.

  17. Inelastic scattering of neutrons by spin waves in terbium

    DEFF Research Database (Denmark)

    Bjerrum Møller, Hans; Houmann, Jens Christian Gylden

    1966-01-01

    Measurements of spin-wave dispersion relations for magnons propagating in symmetry directions in ferromagnetic Tb; it is first experiment to give detailed information on magnetic excitations in heavy rare earths; Tb was chosen for these measurements because it is one of few rare-earth metals which...... does not have very high thermal-neutron capture cross section, so that inelastic neutron scattering experiments can give satisfactory information on magnon dispersion relations....

  18. Opportunities for research program development at LANSCE (Los Alamos Neutron Scattering Center

    International Nuclear Information System (INIS)

    Bowman, C.D.

    1989-01-01

    The availability of intense neutron beams from facilities associated with the Proton Storage Ring and LANSCE has stimulated the development of neutron research well beyond the mainstream of neutron scattering. A description of this extended program is given along with prospects for further growth. 23 refs., 11 figs., 4 tabs

  19. Measurement of leading neutron production in deep-inelastic scattering at HERA

    Energy Technology Data Exchange (ETDEWEB)

    Aaron, F.D.; Alexa, C.; Rotaru, M.; Stoicea, G. [National Inst. for Physics and Nuclear Engineering, Bucharest (Romania); Andreev, V.; Belousov, A.; Eliseev, A.; Fomenko, A.; Gogitidze, N.; Lebedev, A.; Loktionova, N.; Malinovski, E.; Rusakov, S.; Shtarkov, L.N.; Soloviev, Y.; Vazdik, Y. [Lebedev Physical Inst., Moscow (Russian Federation); Antunovic, B.; Bartel, W.; Brandt, G.; Campbell, A.J.; Cholewa, A.; Deak, M.; Eckerlin, G.; Elsen, E.; Felst, R.; Fischer, D.J.; Fleischer, M.; Gayler, J.; Ghazaryan, S.; Glazov, A.; Gouzevitch, M.; Grell, B.R.; Haidt, D.; Helebrant, C.; Jung, H.; Katzy, J.; Kleinwort, C.; Knutsson, A.; Kraemer, M.; Krastev, K.; Kutak, K.; Levonian, S.; Lipka, K.; List, J.; Marti, L.; Meyer, A.B.; Meyer, H.; Meyer, J.; Niebuhr, C.; Nikiforov, A.; Olsson, J.E.; Pahl, P.; Panagoulias, I.; Papadopoulou, T.; Pitzl, D.; Placakyte, R.; Schmitt, S.; Sefkow, F.; Staykova, Z.; Steder, M.; Sunar, D.; Vargas Trevino, A.; Vinokurova, S.; Driesch, M. von den; Wissing, C.; Wuensch, E. [DESY, Hamburg (Germany); Backovic, S.; Dubak, A.; Lastovicka-Medin, G.; Picuric, I.; Raicevic, N. [Univ. of Montenegro, Faculty of Science, Podgorica (ME); Baghdasaryan, A.; Volchinski, V.; Zohrabyan, H. [Yerevan Physics Inst. (Armenia); Barrelet, E. [Universites Paris VI et VII, CNRS/IN2P3, LPNHE, Paris (France); Begzsuren, K.; Ravdandorj, T.; Tseepeldorj, B. [Mongolian Academy of Sciences, Inst. of Physics and Technology, Ulaanbaatar (Mongolia); Bizot, J.C.; Brisson, V.; Delcourt, B.; Jacquet, M.; Li, G.; Pascaud, C.; Tran, T.H.; Zhang, Z.; Zomer, F. [Univ. Paris-Sud, CNRS/IN2P3, LAL, Orsay (France); Boudry, V.; Moreau, F.; Specka, A. [Ecole Polytechnique, CNRS/IN2P3, LLR, Palaiseau (France); Bozovic-Jelisavcic, I.; Mudrinic, M.; Pandurovic, M.; Smiljanic, I. [Vinca Inst. of Nuclear Sciences, Belgrade (RS); Bracinik, J.; Kenyon, I.R.; Newman, P.R.; Shaw-West, R.N.; Thompson, P.D. [Univ. of Birmingham, School of Physics and Astronomy (United Kingdom)] [and others

    2010-08-15

    The production of leading neutrons, where the neutron carries a large fraction x{sub 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 {sup -1}. The semi-inclusive cross section is measured in the phase space defined by the photon virtuality 6neutron transverse momentum p{sub T} <0.2 GeV. The leading neutron structure function, F{sub 2}{sup LN(3)}(Q{sup 2},x,x{sub L}), and the fraction of deep-inelastic scattering events containing a leading neutron are studied as a function of Q{sup 2}, x and x{sub L}. Assuming that the pion exchange mechanism dominates leading neutron production, the data provide constraints on the shape of the pion structure function. (orig.)

  20. Hydrogen potential in β-V2H studied by deep inelastic neutron scattering

    International Nuclear Information System (INIS)

    Hempelmann, R.; Price, D.L.; Reiter, G.; Richter, D.

    1989-02-01

    Two complementary techniques of deep inelastic neutron scattering were used to study hydrogen in β-V 2 H: (i) by means of neutron vibrational spectroscopy we measured hydrogen vibrations up to the fourteenth order; from these data we derived the effective single-particle potential, the shape of which is a parabola with a flattened bottom, and the hydrogen wave functions. (ii) By means of neutron Compton scattering we determined the kinetic of energy of the hydrogen; the value agrees with that calculated from the vibrational ground-state wave function. 6 refs., 5 figs

  1. On determination of the dynamics of hydrocarbon molecules on catalyst's surfaces by means of neutron scattering

    International Nuclear Information System (INIS)

    Stockmeyer, R.

    1976-01-01

    The intensity distribution of slow neutrons scattered by adsorbed hydrocarbon molecules contains information on the dynamics of the molecules. In this paper the scattering law for incoherently scattering molecules is derived taking into account the very different mobility perpendicular and parallel to the surface. In contrast to the well known scattering law of threedimensionally diffusing particles the scattering law for twodimensional diffusion diverges logarithmically at zero energy transfer. Conclusions relevant to the interpretation of neutron scattering data are discussed. (orig.) [de

  2. DNS: Diffuse scattering neutron time-of-flight spectrometer

    Directory of Open Access Journals (Sweden)

    Yixi Su

    2015-08-01

    Full Text Available DNS is a versatile diffuse scattering instrument with polarisation analysis operated by the Jülich Centre for Neutron Science (JCNS, Forschungszentrum Jülich GmbH, outstation at the Heinz Maier-Leibnitz Zentrum (MLZ. Compact design, a large double-focusing PG monochromator and a highly efficient supermirror-based polarizer provide a polarized neutron flux of about 107 n cm-2 s-1. DNS is used for the studies of highly frustrated spin systems, strongly correlated electrons, emergent functional materials and soft condensed matter.

  3. Neutron diffuse scattering in magnetite due to molecular polarons

    International Nuclear Information System (INIS)

    Yamada, Y.; Wakabayashi, N.; Nicklow, R.M.

    1980-01-01

    A detailed neutron diffuse scattering study has been carried out in order to verify a model which describes the property of valence fluctuations in magnetite above T/sub V/. This model assumes the existence of a complex which is composed of two excess electrons and a local displacement mode of oxygens within the fcc primitive cell. The complex is called a molecular polaron. It is assumed that at sufficiently high temperatures there is a random distribution of molecular polarons, which are fluctuating independently by making hopping motions through the crystal or by dissociating into smaller polarons. The lifetime of each molecular polaron is assumed to be long enough to induce an instantaneous strain field around it. Based on this model, the neutron diffuse scattering cross section due to randomly distributed dressed molecular polarons has been calculated. A precise measurement of the quasielastic scattering of neutrons has been carried out at 150 K. The observed results definitely show the characteristics which are predicted by the model calculation and, thus, give evidence for the existence of the proposed molecular polarons. From this standpoint, the Verwey transition of magnetite may be viewed as the cooperative ordering process of dressed molecular polarons. Possible extensions of the model to describe the ordering and the dynamical behavior of the molecular polarons are discussed

  4. Dynamics of crystalline acetanilide: Analysis using neutron scattering and computer simulation

    Science.gov (United States)

    Hayward, R. L.; Middendorf, H. D.; Wanderlingh, U.; Smith, J. C.

    1995-04-01

    The unusual temperature dependence of several optical spectroscopic vibrational bands in crystalline acetanilide has been interpreted as providing evidence for dynamic localization. Here we examine the vibrational dynamics of crystalline acetanilide over a spectral range of ˜20-4000 cm-1 using incoherent neutron scattering experiments, phonon normal mode calculations and molecular dynamics simulations. A molecular mechanics energy function is parametrized and used to perform the normal mode analyses in the full configurational space of the crystal i.e., including the intramolecular and intermolecular degrees of freedom. One- and multiphonon incoherent inelastic neutron scattering intensities are calculated from harmonic analyses in the first Brillouin zone and compared with the experimental data presented here. Phonon dispersion relations and mean-square atomic displacements are derived from the harmonic model and compared with data derived from coherent inelastic neutron scattering and neutron and x-ray diffraction. To examine the temperature effects on the vibrations the full, anharmonic potential function is used in molecular dynamics simulations of the crystal at 80, 140, and 300 K. Several, but not all, of the spectral features calculated from the molecular dynamics simulations exhibit temperature-dependent behavior in agreement with experiment. The significance of the results for the interpretation of the optical spectroscopic results and possible improvements to the model are discussed.

  5. Recent high-accuracy measurements of the 1S0 neutron-neutron scattering length

    International Nuclear Information System (INIS)

    Howell, C.R.; Chen, Q.; Gonzalez Trotter, D.E.; Salinas, F.; Crowell, A.S.; Roper, C.D.; Tornow, W.; Walter, R.L.; Carman, T.S.; Hussein, A.; Gibbs, W.R.; Gibson, B.F.; Morris, C.; Obst, A.; Sterbenz, S.; Whitton, M.; Mertens, G.; Moore, C.F.; Whiteley, C.R.; Pasyuk, E.; Slaus, I.; Tang, H.; Zhou, Z.; Gloeckle, W.; Witala, H.

    2000-01-01

    This paper reports two recent high-accuracy determinations of the 1 S 0 neutron-neutron scattering length, a nn . One was done at the Los Alamos National Laboratory using the π - d capture reaction to produce two neutrons with low relative momentum. The neutron-deuteron (nd) breakup reaction was used in other measurement, which was conducted at the Triangle Universities Nuclear Laboratory. The results from the two determinations were consistent with each other and with previous values obtained using the π - d capture reaction. The value obtained from the nd breakup measurements is a nn = -18.7 ± 0.1 (statistical) ± 0.6 (systematic) fm, and the value from the π - d capture experiment is a nn = -18.50 ± 0.05 ± 0.53 fm. The recommended value is a nn = -18.5 ± 0.3 fm. (author)

  6. Analysis of inelastic neutron scattering results on model compounds ...

    Indian Academy of Sciences (India)

    Vibrational spectroscopy; nitrogenous bases; inelastic neutron scattering. PACS No. ... obtain good quality, high resolution results in this region. Here the .... knowledge of the character of each molecular transition as well as the calculated.

  7. Neutron scattering studies of Mn12-acetate

    International Nuclear Information System (INIS)

    Robinson, R.A.

    2000-01-01

    Full text: The S=10 magnetic molecule Mn 12 -acetate, which crystallises into a tetragonal crystal structure, has attracted substantial recent attention by virtue of its low temperature bulk magnetic properties, which give evidence for resonant quantum tunnelling of the magnetisation. We report a full neutron crystal structure including positions of all protons/deuterons, including the solvated water and acetic acid, a polarised-neutron study of the real space magnetisation, which confirms a simple magnetic-structure model for the molecule, albeit with reduced Mn moments, and inelastic neutron scattering data containing both the excitations within the 21-fold degenerate S=10 manifold, and those from S=10 to the S=9 manifolds. Both manifolds are split by uniaxial magnetic anisotropy, and we report coefficients for 2nd and 4th-order terms in the magnetic Hamiltonian

  8. Diffuse neutron scattering study of Cu2−xSe

    DEFF Research Database (Denmark)

    Cava, R. J.; Andersen, Niels Hessel; Clausen, Kurt Nørgaard

    1986-01-01

    We have measured the diffuse neutron scattering in the hkk plane for Cu2Se and Cu1.8Se at 180°C and 51°C, respectively, in the cubic antifluorite type phase. The diffuse scattering shows significant structure, indicative of correlated short range mobile ion ordering. The short range order is foun...

  9. Experimental technique of small angle neutron scattering

    International Nuclear Information System (INIS)

    Xia Qingzhong; Chen Bo

    2006-03-01

    The main parts of Small Angle Neutron Scattering (SANS) spectrometer, and their function and different parameters are introduced from experimental aspect. Detailed information is also introduced for SANS spectrometer 'Membrana-2'. Based on practical experiments, the fundamental requirements and working condition for SANS experiments, including sample preparation, detector calibration, standard sample selection and data preliminary process are described. (authors)

  10. Small-angle neutron scattering from colloidal dispersions

    International Nuclear Information System (INIS)

    Ottewill, R.H.

    1991-01-01

    A survey is given of recent work on the use of small-angle neutron scattering to examine colloidal dispersions. Particular attention is given to the determination of particle size and polydispersity, the determination of particle morphology and the behaviour of concentrated colloidal dispersions, both at rest and under the influence of an applied shear field. (orig.)

  11. Neutron scattering instrumentation for biology at spallation neutron sources

    Energy Technology Data Exchange (ETDEWEB)

    Pynn, R. [Los Alamos National Laboratory, NM (United States)

    1994-12-31

    Conventional wisdom holds that since biological entities are large, they must be studied with cold neutrons, a domain in which reactor sources of neutrons are often supposed to be pre-eminent. In fact, the current generation of pulsed spallation neutron sources, such as LANSCE at Los Alamos and ISIS in the United Kingdom, has demonstrated a capability for small angle scattering (SANS) - a typical cold- neutron application - that was not anticipated five years ago. Although no one has yet built a Laue diffractometer at a pulsed spallation source, calculations show that such an instrument would provide an exceptional capability for protein crystallography at one of the existing high-power spoliation sources. Even more exciting is the prospect of installing such spectrometers either at a next-generation, short-pulse spallation source or at a long-pulse spallation source. A recent Los Alamos study has shown that a one-megawatt, short-pulse source, which is an order of magnitude more powerful than LANSCE, could be built with today`s technology. In Europe, a preconceptual design study for a five-megawatt source is under way. Although such short-pulse sources are likely to be the wave of the future, they may not be necessary for some applications - such as Laue diffraction - which can be performed very well at a long-pulse spoliation source. Recently, it has been argued by Mezei that a facility that combines a short-pulse spallation source similar to LANSCE, with a one-megawatt, long-pulse spallation source would provide a cost-effective solution to the global shortage of neutrons for research. The basis for this assertion as well as the performance of some existing neutron spectrometers at short-pulse sources will be examined in this presentation.

  12. Investigations of homologous disaccharides by elastic incoherent neutron scattering and wavelet multiresolution analysis

    Energy Technology Data Exchange (ETDEWEB)

    Magazù, S.; Migliardo, F. [Dipartimento di Fisica e di Scienze della Terra dell’, Università degli Studi di Messina, Viale F. S. D’Alcontres 31, 98166 Messina (Italy); Vertessy, B.G. [Institute of Enzymology, Hungarian Academy of Science, Budapest (Hungary); Caccamo, M.T., E-mail: maccamo@unime.it [Dipartimento di Fisica e di Scienze della Terra dell’, Università degli Studi di Messina, Viale F. S. D’Alcontres 31, 98166 Messina (Italy)

    2013-10-16

    Highlights: • Innovative multiresolution wavelet analysis of elastic incoherent neutron scattering. • Elastic Incoherent Neutron Scattering measurements on homologues disaccharides. • EINS wavevector analysis. • EINS temperature analysis. - Abstract: In the present paper the results of a wavevector and thermal analysis of Elastic Incoherent Neutron Scattering (EINS) data collected on water mixtures of three homologous disaccharides through a wavelet approach are reported. The wavelet analysis allows to compare both the spatial properties of the three systems in the wavevector range of Q = 0.27 Å{sup −1} ÷ 4.27 Å{sup −1}. It emerges that, differently from previous analyses, for trehalose the scalograms are constantly lower and sharper in respect to maltose and sucrose, giving rise to a global spectral density along the wavevector range markedly less extended. As far as the thermal analysis is concerned, the global scattered intensity profiles suggest a higher thermal restrain of trehalose in respect to the other two homologous disaccharides.

  13. Inelastic Neutron Scattering Investigations of the Magnetic Excitations

    DEFF Research Database (Denmark)

    Feile, R; Kjems, Jørgen; Hauser, A.

    1984-01-01

    The magnetic excitations perpendicular to the antiferromagnetic chains in CsVX3 (X = Cl, Br, I) have been measured in the ordered state by inelastic neutron scattering. The dispersion relations and intensity distributions are those expected for ordinary spin waves in a triangular xy-model....

  14. Neutron transport in two dissimilar media anisotropic scattering

    International Nuclear Information System (INIS)

    Burkart, A.R.; Ishiguro, Y.; Siewert, C.E.

    1976-01-01

    The elementary solution of the one-speed neutron-transport equation with linearly anisotropic scattering are used in conjunction with Chandrasekhar's invariance principles to solve in a concise manner the Milne problem for two adjoining half-spaces and the critical reactor problem for a reflected slab

  15. A mechanical rotator for neutron scattering measurements

    International Nuclear Information System (INIS)

    Thaler, A.; Northen, E.; Aczel, A. A.; MacDougall, G. J.

    2016-01-01

    We have designed and built a mechanical rotation system for use in single crystal neutron scattering experiments at low temperatures. The main motivation for this device is to facilitate the application of magnetic fields transverse to a primary training axis, using only a vertical cryomagnet. Development was done in the context of a triple-axis neutron spectrometer, but the design is such that it can be generalized to a number of different instruments or measurement techniques. Here, we discuss some of the experimental constraints motivating the design, followed by design specifics, preliminary experimental results, and a discussion of potential uses and future extension possibilities.

  16. Scattering of neutrons by catalase: a study of molecules, subunits, and tubules

    International Nuclear Information System (INIS)

    Randall, J.; Starling, D.; Baldwin, J.P.; Ibel, K.

    1976-01-01

    The paper deals with small-angle scattering of neutrons by catalase tetramers, dimers, and monomers and with neutron diffraction by helical assemblies of tetramers in the form of tubules. A preliminary study of catalase is described

  17. Studies of Water by Scattering of Slow Neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Skoeld, K; Pilcher, E; Larsson, K E

    1964-01-15

    The quasielastic scattering peak in light water at room temperature has been studied with neutrons of energy {approx} 5x10{sup -3} eV. The width and shape of the peak has been determined by the time-of-flight technique at two scattering angles. If it is assumed that the broad inelastic spectrum is due to scattering by a monoatomic gas of mass 18, it is found that the quasielastic scattering is in good agreement with the predictions by the continuous diffusion model. Inelastic spectra were recorded up to 13x10{sup -3} eV. Indications of two discrete energy transfers (8 and 14x10{sup -4} eV) are observed in the 90 deg run. The results are discussed and compared with earlier observations.

  18. Small-angle neutron scattering studies of sodium butyl benzene

    Indian Academy of Sciences (India)

    Na-NBBS), in aqueous solutions is investigated by small-angle neutron scattering (SANS). Nearly ellipsoidal aggregates of Na-NBBS at concentrations well above its minimum hydrotrope concentration were detected by SANS. The hydrotrope ...

  19. Neutron scattering investigation of magnetic excitations at high energy transfers

    International Nuclear Information System (INIS)

    Loong, C.K.

    1984-01-01

    With the advance of pulsed spallation neutron sources, neutron scattering investigation of elementary excitations in magnetic materials can now be extended to energies up to several hundreds of MeV. We have measured, using chopper spectrometers and time-of-flight techniques, the magnetic response functions of a series of d and f transition metals and compounds over a wide range of energy and momentum transfer. In PrO 2 , UO 2 , BaPrO 3 and CeB 6 we observed crystal-field transitions between the magnetic ground state and the excited levels in the energy range from 40 to 260 MeV. In materials exhibiting spin-fluctuation or mixed-valent character such as Ce 74 Th 26 , on the other hand, no sharp crystal-field lines but a broadened quasielastic magnetic peak was observed. The line width of the quasielastic component is thought to be connected to the spin-fluctuation energy of the 4f electrons. The significance of the neutron scattering results in relation to the ground state level structure of the magnetic ions and the spin-dynamics of the f electrons is discussed. Recently, in a study of the spin-wave excitations in itinerant magnetic systems, we have extended the spin-wave measurements in ferromagnetic iron up to about 160 MeV. Neutron scattering data at high energy transfers are of particular interest because they provide direct comparison with recent theories of itinerant magnetism. 26 references, 7 figures

  20. High energy neutron recoil scattering from liquid 4He

    International Nuclear Information System (INIS)

    Holt, R.S.; Needham, L.M.; Paoli, M.P.

    1987-10-01

    The neutron recoil scattering from liquid 4 He at 4.2 K and 1.6 K has been observed for a momentum transfer of 150 A -1 using the Electron Volt Spectrometer on the pulsed neutron source, ISIS. The experiment yielded mean atomic kinetic energy values = 14.8 +- 3 K at 4.2 K and = 14.6 +- 3.2 K at 1.6 K in good agreement with values obtained at lower momentum transfers. (author)

  1. Development of Cold Neutron Scattering Kernels for Advanced Moderators

    International Nuclear Information System (INIS)

    Granada, J. R.; Cantargi, F.

    2010-01-01

    The development of scattering kernels for a number of molecular systems was performed, including a set of hydrogeneous methylated aromatics such as toluene, mesitylene, and mixtures of those. In order to partially validate those new libraries, we compared predicted total cross sections with experimental data obtained in our laboratory. In addition, we have introduced a new model to describe the interaction of slow neutrons with solid methane in phase II (stable phase below T = 20.4 K, atmospheric pressure). Very recently, a new scattering kernel to describe the interaction of slow neutrons with solid Deuterium was also developed. The main dynamical characteristics of that system are contained in the formalism, the elastic processes involving coherent and incoherent contributions are fully described, as well as the spin-correlation effects.

  2. Summary of coherent neutron scattering length

    International Nuclear Information System (INIS)

    Rauch, H.

    1981-07-01

    Experimental values of neutron-nuclei bound scattering lengths for some 354 isotopes and elements and the various spin-states are compiled in a uniform way together with their error bars as quoted in the original literature. Recommended values are also given. The definitions of the relevant quantities presented in the data tables and the basic principles of measurements are explained in the introductory chapters. The data is also available on a magnetic tape

  3. Time-of-flight small-angle scattering spectrometers on pulsed neutron sources

    International Nuclear Information System (INIS)

    Ostanevich, Yu.M.

    1987-01-01

    The operation principles, constructions, advantages and shortcomings of known time-of-flight small angle neutron scattering (TOF SANS) spectrometers built up with pulsed neutron sources are reviewed. The most important characteristics of TOF SANS apparatuses are rather a high luminosity and the possibility for the measurement in an extremely wide range of scattering vector at a single exposure. This is achieved by simultaneous employment of white beam, TOF technique for wave length-scan and the commonly known angle-scan. However, the electronic equipment, data-matching programs, and the measurement procedure, necessary for accurate normalization of experimental data and their transformation into absolute cross-section scale, they all become more complex, as compared with those for SANS apparatuses operating on steady-state neutron sources, where only angle-scan is used

  4. Time collimation for elastic neutron scattering instrument at a pulsed source

    International Nuclear Information System (INIS)

    Aksenov, V.L.; Nikitenko, Yu.V.

    1996-01-01

    Conditions for carrying out elastic neutron scattering experiments using the time-of-flight technique are considered. It is shown that the employment of time dependent neutron beam collimation in the source-sample flight path increases the luminosity of the spectrometer under certain resolution restrictions. 3 refs., 8 figs

  5. Neutron scattering and HPLC study on L-ascorbic acid and its degradation

    International Nuclear Information System (INIS)

    Bellocco, E.; Barreca, D.; Lagana, G.; Leuzzi, U.; Migliardo, F.; Torre, R. La; Galli, G.; Galtieri, A.; Minutoli, L.; Squadrito, F.

    2008-01-01

    The present paper shows a systematic dynamic and kinetic study on L-ascorbic acid and its degradation at high temperature. The neutron scattering study allows, through the behavior of quasi-elastic neutron scattering (QENS) spectra, to characterize the diffusive dynamics of L-ascorbic acid in water mixtures. Ascorbic acid undergoes degradation process at high temperature, but the presence of trehalose in solution markedly avoids ascorbic acid loss enhancing its t 1/2 (half life time), as determined by high performance liquid chromatography (HPLC)

  6. Spin-wave and critical neutron scattering from chromium

    DEFF Research Database (Denmark)

    Als-Nielsen, Jens Aage; Axe, J.D.; Shirane, G.

    1971-01-01

    Chromium and its dilute alloys are unique examples of magnetism caused by itinerant electrons. The magnetic excitations have been studied by inelastic neutron scattering using a high-resolution triple-axis spectrometer. Spin-wave peaks in q scans at constant energy transfer ℏω could, in general...

  7. Diffuse neutron scattering from anion-excess strontium chloride

    DEFF Research Database (Denmark)

    Goff, J.P.; Clausen, K.N.; Fåk, B.

    1992-01-01

    The defect structure and diffusional processes have been studied in the anion-excess fluorite (Sr, Y)Cl2.03 by diffuse neutron scattering techniques. Static cuboctahedral clusters found at ambient temperature break up at temperatures below 1050 K, where the anion disorder is highly dynamic. The a...

  8. Neutron scattering-instrumentation at the upgraded research reactor BER II

    International Nuclear Information System (INIS)

    1991-01-01

    The Berlin Neutron Scattering Centre (BENSC) is a newly created special department of the Hahn-Meitner-Institut, in the framework of which the BER II neutron beam reactor is made available to external users. BENSC is devoted to development, continuous modernisation and maintenance of the scientific instrumets at the BER II and to the support of their users. (orig./HSI)

  9. Anomalous scattering of neutrons in spin-polarized media

    International Nuclear Information System (INIS)

    Bashkin, E.P.

    1989-01-01

    A new exchange mechanism of inelastic scattering with spin flip for slow neutrons propagating through a spin-polarized medium is studied. The scattering is accompanied by emission or absorption of thermal fluctuations of the transverse magnetization of the medium; the weakly damped Larmor precession of nuclear spins in the external magnetic field plays the main role in these fluctuations. Under the conditions of giant opalescence the effect is enormous and the corresponding cross sections are significantly greater than the standard elastic scattering cross sections. Thus in the case of 29 Si↑ and 3 He↑ under typical experimental conditions the cross sections of these inelastic processes are of the order of 10 5 -10 6 b

  10. X-ray and neutron scattering studies of complex confined fluids

    International Nuclear Information System (INIS)

    Sinha, S. K.

    1999-01-01

    We review recent X-ray and neutron scattering studies of the structure and dynamics of confined complex fluids. This includes the study of polymer conformations and binary fluid phase transitions in porous media using Small Angle Neutron scattering, and the use of synchrotrons radiation to study ordering and fluctuation phenomena at solid/liquid and liquid/air interfaces. Ordering of liquids near a solid surface or in confinement will be discussed, and the study, via specular and off-specular X-ray reflectivity, of capillary wave fluctuations on liquid polymer films. Finally, we shall discuss the use of high-brilliance beams from X-ray synchrotrons to study via photon correlation spectroscopy the slow dynamics of soft condensed matter systems

  11. Neutron scattering differential cross sections of carbon and bismuth at 37 MeV

    International Nuclear Information System (INIS)

    Zhou Zuying; Tang Hongqing; Qi Bujia; Zhou Chenwei; Du Yanfeng; Xia Haihong; Walter, R.L.; Tornow, W.; Howell, C.; Braun, R.; Roper, C.; Chen Zemin; Chen Zhengpeng; Chen Yingtang

    1997-01-01

    Elastic differential cross sections of 37 MeV neutrons scattered from carbon and bismuth were measured in the angular range 11 to 160 degrees by means of the multi-detector TOF facility. The 37 MeV neutrons were produced via the T(d,n) 4 He reaction in a tritium gas target. The pulsed 20 MeV deuteron beam was provided by the HI-13 tandem accelerator. The angular distribution of scattered neutrons from carbon and bismuth were measured in the angular range 11 degree to 145 degree and 11 degree to 160 degree respectively in steps of about 3 degree

  12. Resolution of the VESUVIO spectrometer for High-energy Inelastic Neutron Scattering experiments

    Energy Technology Data Exchange (ETDEWEB)

    Imberti, S. [Universita degli Studi di Roma Tre, Dipartimento di Fisica ' E.Amaldi' , Rome (Italy) and CNR-INFM, Rome (Italy)]. E-mail: silvia.imberti@roma2.infn.it; Andreani, C. [Universita degli Studi di Roma Tor Vergata, Dipartimento di Fisica, Roma 60133 (Italy); CNR-INFM, Rome (Italy); Garbuio, V. [Universita degli Studi di Roma Tor Vergata, Dipartimento di Fisica, Roma 60133 (Italy); CNR-INFM, Rome (Italy); Gorini, G. [Universita degli Studi di Milano-Bicocca, Dipartimento di Fisica ' G.Occhialini' , Milan (Italy); CNR-INFM, Milan (Italy); Pietropaolo, A. [Universita degli Studi di Roma Tor Vergata, Dipartimento di Fisica, Roma 60133 (Italy); CNR-INFM, Rome (Italy); Senesi, R. [Universita degli Studi di Roma Tor Vergata, Dipartimento di Fisica, Roma 60133 (Italy); CNR-INFM, Rome (Italy); Tardocchi, M. [Universita degli Studi di Milano-Bicocca, Dipartimento di Fisica ' G.Occhialini' , Milan (Italy); CNR-INFM, Milan (Italy)

    2005-11-01

    New perspectives for epithermal neutron spectroscopy have been opened up as a result of the development of the Resonance Detector and its use on inverse geometry time-of-flight spectrometers at spallation sources. A special application of the Resonance Detector is the Very Low Angle Detector Bank (VLAD) for the VESUVIO spectrometer at ISIS, operating in the angular range 1 deg. <2{theta}<5 deg. This equipment allows High-energy Inelastic Neutron Scattering (HINS) measurements to be performed in the (q,{omega}) kinematical region at low wavevector (q<10A{sup -1}) and high energy (unlimited) transfer -bar {omega}>500meV, a regime so far inaccessible to experimental studies on condensed matter systems. The HINS measurements complement the Deep Inelastic Neutron Scattering (DINS) measurements performed on VESUVIO in the high wavevector q(20A{sup -1}1eV), where the short-time single-particle dynamics can be sampled. This paper will revise the main components of the resolution for HINS measurements of VESUVIO. Instrument performances and examples of applications for neutron scattering processes at high energy and at low wavevector transfer are discussed.

  13. Scattering length measurements from radiative pion capture and neutron-deuteron breakup

    International Nuclear Information System (INIS)

    Gibson, B.F.; Tornow, W.; Carman, T.S.

    1997-07-01

    The neutron-neutron and neutron-proton 1 S 0 scattering lengths a nn and a np , respectively, were determined simultaneously from the neutron-deuteron breakup reaction. Their comparison with the recommended values obtained from two body reactions gives a measure of the importance of three-nucleon force effects in the three-nucleon continuum. In order to check on the result obtained for a nn from the two-body π - -d capture reaction, a new measurement was performed at LANL. Preliminary results of the three experiments are given

  14. Thermal diffuse scattering in angular-dispersive neutron diffraction

    International Nuclear Information System (INIS)

    Popa, N.C.; Willis, B.T.M.

    1998-01-01

    The theoretical treatment of one-phonon thermal diffuse scattering (TDS) in single-crystal neutron diffraction at fixed incident wavelength is reanalysed in the light of the analysis given by Popa and Willis [Acta Cryst. (1994), (1997)] for the time-of-flight method. Isotropic propagation of sound with different velocities for the longitudinal and transverse modes is assumed. As in time-of-flight diffraction, there exists, for certain scanning variables, a forbidden range in the one-phonon TDS of slower-than-sound neutrons, and this permits the determination of the sound velocity in the crystal. A fast algorithm is given for the TDS correction of neutron diffraction data collected at a fixed wavelength: this algorithm is similar to that reported earlier for the time-of-flight case. (orig.)

  15. Neutron-optical effects at very cold neutrons scattering on the spherical particles of different sizes

    International Nuclear Information System (INIS)

    Grinev, V.G.; Kudinova, O.I.; Novokshonova, L.A.; Kuznetsov, S.P.; Udovenko, A.I.; Shelagin, A.V.

    2006-01-01

    Very cold neutrons (VCN) with the wavelength λ > 4.0 ran are convenient tool for investigating the super molecular structures of different nature. Using a Born approximation (BA) to the analysis of dependencies on the wavelength of the VCN scattering cross sections, it is possible to obtain information about average sizes (R) and concentrations of the scattering particles with R∼ λ. However, with an increasing the sizes of scatterers the conditions for BA applicability can be disrupted. In this work we investigated the possibilities of BA, eikonal and geometric-optical approximations for the analysis of VCN scattering on the spherical particles with R ≥ λ

  16. New neutron-based isotopic analytical methods; An explorative study of resonance capture and incoherent scattering

    NARCIS (Netherlands)

    Perego, R.C.

    2004-01-01

    Two novel neutron-based analytical techniques have been treated in this thesis, Neutron Resonance Capture Analysis (NRCA), employing a pulsed neutron source, and Neutron Incoherent Scattering (NIS), making use of a cold neutron source. With the NRCA method isotopes are identified by the

  17. Progress report on JAERI-ORNL cooperative neutron scattering research

    International Nuclear Information System (INIS)

    Iizumi, Masashi

    1985-08-01

    One year activities done under the JAERI-DOE(ORNL) cooperative neutron scattering program are summarized. This period just followed the completion of the wide-angle neutron diffractometer dedicated to the cooperative research. The report contains results of the performance test of the instrument and early research activities. The latter part includes the time-resolved measurements of the transition kinetics in tin and Ni-Mn alloy as well as the single-crystal diffraction by the flat-cone method. (author)

  18. Fast-neutron scattering cross sections of elemental zirconium

    International Nuclear Information System (INIS)

    Smith, A.B.; Guenther, P.T.

    1982-12-01

    Differential neturon-elastic-scattering cross sections of elemental zirconium are measured from 1.5 to 4.0 MeV at intervals of less than or equal to 200 keV. Inelastic-neutron-scattering cross sections corresponding to the excitation of levels at observed energies of: 914 +- 25, 1476 +- 37, 1787 +- 23, 2101 +- 26, 2221 +- 17, 2363 +- 14, 2791 +- 15 and 3101 +- 25 keV are determined. The experimental results are interpreted in terms of the optical-statistical model and are compared with corresponding quantities given in ENDF/B-V

  19. A Neutron Scattering Study of Collective Excitations in Superfluid Helium

    DEFF Research Database (Denmark)

    Graf, E. H.; Minkiewicz, V. J.; Bjerrum Møller, Hans

    1974-01-01

    Extensive inelastic-neutron-scattering experiments have been performed on superfluid helium over a wide range of energy and momentum transfers. A high-resolution study has been made of the pressure dependence of the single-excitation scattering at the first maximum of the dispersion curve over...... of the multiexcitation scattering was also studied. It is shown that the multiphonon spectrum of a simple Debye solid with the phonon dispersion and single-excitation cross section of superfluid helium qualitatively reproduces these data....

  20. Neutron scattering and HPLC study on L-ascorbic acid and its degradation

    Energy Technology Data Exchange (ETDEWEB)

    Bellocco, E. [Department of Organic and Biological Chemistry, University of Messina, Messina (Italy)], E-mail: bellocco@isengard.unime.it; Barreca, D.; Lagana, G.; Leuzzi, U. [Department of Organic and Biological Chemistry, University of Messina, Messina (Italy); Migliardo, F.; Torre, R. La; Galli, G. [Department of Physics, University of Messina, Messina (Italy); Galtieri, A. [Department of Organic and Biological Chemistry, University of Messina, Messina (Italy); Minutoli, L.; Squadrito, F. [Department of Clinical and Experimental Medicine and Pharmacology, University of Messina, Messina (Italy)

    2008-04-18

    The present paper shows a systematic dynamic and kinetic study on L-ascorbic acid and its degradation at high temperature. The neutron scattering study allows, through the behavior of quasi-elastic neutron scattering (QENS) spectra, to characterize the diffusive dynamics of L-ascorbic acid in water mixtures. Ascorbic acid undergoes degradation process at high temperature, but the presence of trehalose in solution markedly avoids ascorbic acid loss enhancing its t{sub 1/2} (half life time), as determined by high performance liquid chromatography (HPLC)

  1. Bose condensation in 4He and neutron scattering

    International Nuclear Information System (INIS)

    Silver, R.N.

    1997-01-01

    The discovery of superfluidity in liquid 4 He below T λ = 2.17 K, and its phenomenological characterization since then, has been one of the great success stories of condensed matter physics. The relation of superfluidity to the behavior of atoms was conjectured by F. London in 1938. Superfluidity is a manifestation of the Bose condensation of helium atoms, the extensive occupation of the zero momentum state. Ever since 4 He has been the paradigm in the search for Bose condensates in other systems. At the Pune meeting scientists have heard exciting new evidence for Bose condensates of laser cooled alkali atoms in magnetic traps, of excitons in Cu 2 O, and possibly pre-formed Cooper pairs of electrons in the high T c perovskite superconductors. There remains the holy-grail of forming a Bose condensate in spin-polarized hydrogen. In the current excitement for new types of Bose condensates, and new phenomena such as atom lasers, it may be useful to recall the older story of the experimental verification of a relation between superfluidity and Bose condensation in 4 He. This topic has been investigated over many years by neutron scattering experiments and quantum many-body theory. The authors goal is to illustrate the difficulties of establishing the existence of a Bose condensate in a strongly interacting system, even though its macroscopic effects are manifest. The author assumes readers have access to a review by Silver and Sokol which emphasizes the neutron scattering theory through 1990 and a review by Snow and Sokol of the deep inelastic neutron scattering (DINS) experiments through 1995

  2. A neutron scattering study of triblock copolymer micelles

    Energy Technology Data Exchange (ETDEWEB)

    Gerstenberg, M.C.

    1997-11-01

    The thesis describes the neutron scattering experiments performed on poly(ethylene oxide)/poly(propylene oxide)/poly(ethylene oxide) triblock copolymer micelles in aqueous solution. The studies concern the non-ionic triblock copolymer P85 which consists of two outer segments of 25 monomers of ethylene oxide attached to a central part of 40 monomers of propylene oxide. The amphiphilic character of P85 leads to formation of various structures in aqueous solution such as spherical micelles, rod-like structures, and a BCC liquid-crystal mesophase of spherical micelles. The present investigations are centered around the micellar structures. In the first part of this thesis a model for the micelle is developed for which an analytical scattering form factor can be calculated. The micelle is modeled as a solid sphere with tethered Gaussian chains. Good agreement was found between small-angle neutron scattering experiments and the form factor of the spherical P85 micelles. Above 60 deg. C some discrepancies were found between the model and the data which is possibly due to an elongation of the micelles. The second part focuses on the surface-induced ordering of the various micellar aggregates in the P85 concentration-temperature phase diagram. In the spherical micellar phase, neutron reflection measurements indicated a micellar ordering at the hydrophilic surface of quartz. Extensive modeling was performed based on a hard sphere description of the micellar interaction. By convolution of the distribution of hard spheres at a hard wall, obtained from Monte Carlo simulations, and the projected scattering length density of the micelle, a numerical expression was obtained which made it possible to fit the data. The hard-sphere-hard-wall model gave an excellent agreement in the bulk micellar phase. However, for higher concentrations (25 wt % P85) close to the transition from the micellar liquid into a micellar cubic phase, a discrepancy was found between the model and the

  3. A neutron scattering study of triblock copolymer micelles

    International Nuclear Information System (INIS)

    Gerstenberg, M.C.

    1997-11-01

    The thesis describes the neutron scattering experiments performed on poly(ethylene oxide)/poly(propylene oxide)/poly(ethylene oxide) triblock copolymer micelles in aqueous solution. The studies concern the non-ionic triblock copolymer P85 which consists of two outer segments of 25 monomers of ethylene oxide attached to a central part of 40 monomers of propylene oxide. The amphiphilic character of P85 leads to formation of various structures in aqueous solution such as spherical micelles, rod-like structures, and a BCC liquid-crystal mesophase of spherical micelles. The present investigations are centered around the micellar structures. In the first part of this thesis a model for the micelle is developed for which an analytical scattering form factor can be calculated. The micelle is modeled as a solid sphere with tethered Gaussian chains. Good agreement was found between small-angle neutron scattering experiments and the form factor of the spherical P85 micelles. Above 60 deg. C some discrepancies were found between the model and the data which is possibly due to an elongation of the micelles. The second part focuses on the surface-induced ordering of the various micellar aggregates in the P85 concentration-temperature phase diagram. In the spherical micellar phase, neutron reflection measurements indicated a micellar ordering at the hydrophilic surface of quartz. Extensive modeling was performed based on a hard sphere description of the micellar interaction. By convolution of the distribution of hard spheres at a hard wall, obtained from Monte Carlo simulations, and the projected scattering length density of the micelle, a numerical expression was obtained which made it possible to fit the data. The hard-sphere-hard-wall model gave an excellent agreement in the bulk micellar phase. However, for higher concentrations (25 wt % P85) close to the transition from the micellar liquid into a micellar cubic phase, a discrepancy was found between the model and the

  4. The SCANDAL facility - How to measure elastic neutron scattering in the 50-130 MeV range

    International Nuclear Information System (INIS)

    Klug, Joakim

    2001-01-01

    The interest in neutrons of energies above 20 MeV is growing rapidly, since new applications are being developed or have been identified. Transmutation of nuclear waste and cancer therapy with neutron beams are two research fields that would benefit from new neutron scattering data at these energies. A facility for detection of scattered neutrons in the energy interval 50-130 MeV, SCANDAL (SCAttered Nucleon Detection AssembLy), has been developed and installed at the neutron beam facility of the The Svedberg Laboratory in Uppsala. It can be used to study the (n,n), (n,p) and (n,d) reactions. This thesis describes the layout of the setup, the experimental procedure, and data analysis principles. The performance of the spectrometer is illustrated with measurements of the (n,p) and (n,n) reactions on 1 H and 12 C. In addition, the neutron beam facility is described in some detail

  5. Research performed at the ET-RR-1 reactor using the neutron scattering equipment

    International Nuclear Information System (INIS)

    Adib, M.; Maayouf, R.M.A.; Abdel-Kawy, A.

    1990-02-01

    This report represents the results of studies and measurements, performed at the ET-RR-1 reactor, using the neutron scattering equipment supplied by the IAEA according to the technical assistance project EGY/1/11/10. The results of these studies, starting in 1980 and continuing to date, are discussed; the use of the equipment, both as a neutron monochromator and fixed scattering angle spectrometer, is also assessed. (author). 19 refs, 17 figs

  6. The polarized neutron small-angle scattering instrument at BENSC Berlin

    International Nuclear Information System (INIS)

    Keller, T.; Krist, T.; Danzig, A.; Keiderling, U.; Mezei, F.; Wiedenmann, A.

    2000-01-01

    A polarized neutron beam has been installed at the small-angle neutron-scattering instrument V4 at BENSC Berlin. The main component of this new option is a 1.8 m long cavity transmission polarizer. The advantages of this device compared to the conventional bender polarizers are: (i) high transmission (35% of unpolarized beam at λ=6 A); (ii) the polarization is better than 93% in the wavelength band 4 A 3 O 4 particles embedded in a glass matrix) are presented and compared to a measurement with unpolarized neutrons

  7. Incoherent quasielastic neutron scattering from plastic crystals

    International Nuclear Information System (INIS)

    Bee, M.; Amoureux, J.P.

    1980-01-01

    The aim of this paper is to present some applications of a method indicated by Sears in order to correct for multiple scattering. The calculations were performed in the particular case of slow neutron incoherent quasielastic scattering from organic plastic crystals. First, an exact calculation (up to second scattering) is compared with the results of a Monte Carlo simulation technique. Then, an approximation is developed on the basis of a rotational jump model which allows a further analytical treatment. The multiple scattering is expressed in terms of generalized structure factors (which can be regarded as self convolutions of first order structure factors taking into account the instrumental geometry) and lorentzian functions the widths of which are linear combinations of the jump rates. Three examples are given. Two of them correspond to powder samples while in the third we are concerned with the case of a single crystalline slab. In every case, this approximation is shown to be a good approach to the multiple scattering evaluation, its main advantage being the possibility of applying it without any preliminary knowledge of the correlation times for rotational jumps. (author)

  8. A national facility for small angle neutron scattering

    International Nuclear Information System (INIS)

    Buyers, W.J.L.; Katsaras, J.; Mellors, W.; Potter, M.M.; Powell, B.M.; Rogge, R.B.; Root, J.H.; Tennant, D.C.; Tun, Z.

    1995-01-01

    A world-class small angle neutron scattering (SANS) facility is proposed for Canada. It will provide users from the fields of biology, chemistry, physics, materials science and engineering with a uniquely powerful tool for investigating microstructural properties whose length scales lie in the optical to atomic range. (author). 7 refs

  9. Neutron scattering and the 1994 Nobel Physics Prize

    International Nuclear Information System (INIS)

    Sun Xiangdong

    1995-01-01

    Neutron scattering is an efficient method for detecting the microstructure of matter by which we can study, for example, details of the phonon spectrum in solids, and the isotopic effect. Bertram N. Brockhouse and Clifford G. Shull earned the Nobel Physics Prize in 1994 for their significant contributions in this domain

  10. Benchmarking the inelastic neutron scattering soil carbon method

    Science.gov (United States)

    The herein described inelastic neutron scattering (INS) method of measuring soil carbon was based on a new procedure for extracting the net carbon signal (NCS) from the measured gamma spectra and determination of the average carbon weight percent (AvgCw%) in the upper soil layer (~8 cm). The NCS ext...

  11. A national facility for small angle neutron scattering

    Energy Technology Data Exchange (ETDEWEB)

    Buyers, W J.L.; Katsaras, J; Mellors, W; Potter, M M; Powell, B M; Rogge, R B; Root, J H; Tennant, D C; Tun, Z [Atomic Energy of Canada Ltd., Chalk River, ON (Canada). Chalk River Nuclear Labs.; Epand, R; Gaulin, B D [McMaster Univ., Hamilton, ON (Canada)

    1995-09-15

    A world-class small angle neutron scattering (SANS) facility is proposed for Canada. It will provide users from the fields of biology, chemistry, physics, materials science and engineering with a uniquely powerful tool for investigating microstructural properties whose length scales lie in the optical to atomic range. (author). 7 refs.

  12. A diffuse neutron scattering study of clustering in copper-nickel alloys

    International Nuclear Information System (INIS)

    Vrijen, J.

    1977-01-01

    The amount of clustering in Cu-Ni alloys in thermal equilibrium at several temperatures between 400degC and 700degC and ranging in composition between 20 and 80 atomic percent Ni has been determined by means of diffuse neutron scattering. A rough calculation of the excess elastic energy due to alloying Cu with Ni shows that the contribution of size effects to the configurational energy is asymmetric in the composition with its maximum located between 60 and 70 atomic percent Ni. This asymmetry is caused by different elastic constants for Cu and Ni and it might explain part of the asymmetry of clustering in Cu-Ni and its temperature dependence. With the help of the measured cluster parameters, the magnetic diffuse neutron scattering cross-sections of several differently clustered compositions in Cu-Ni could be interpreted, both well inside the ferromagnetic phase and in the transition region between ferromagnetism and superparamagnetism. Giants moments have been observed. Non-equilibrium distributions and their changes during relaxing towards equilibrium have been investigated by measuring the time-evolution of the diffuse scattering. The relaxation of the null matrix (composition without Bragg reflections for neutron scattering) has been measured at five temperatures between 320degC and 450degC. The results of these relaxations were compared with a few available kinetic models

  13. Determination of the scattered radiation at the Neutron Calibration Laboratory of IPEN, SP, Brazil

    International Nuclear Information System (INIS)

    Alvarenga, Tallyson; Valeriano, Caio C.S.; Caldas, Linda V.E.; Federico, Claudio A.

    2016-01-01

    With the increased use of techniques using neutron radiation, there has been a considerable growth in the number of detectors for this kind of radiation. A neutron calibration laboratory with neutron radiation ("2"4"1AmBe) was designed. In practical situations of this type of laboratory, one of the main problems is related to the knowledge of scattered radiation. In order to evaluate this scattered radiation, simulations were carried out without the presence of structural elements and with the complete room. Fourteen measuring points were evaluated in different directions at various distances. (author)

  14. Ultra-small-angle neutron scattering. History, developments and applications

    International Nuclear Information System (INIS)

    Koizumi, Satoshi; Yamaguchi, Daisuke

    2011-01-01

    Ultra-small-angle neutron scattering (USANS), which is a scattering method observing in a q-region of q=10 -3 nm -1 , was initiated by double crystal (Bonse-Hart) method. Recently, a focusing USANS method was developed by combining a pin-hole type spectrometer and focusing lenses. These two methods, which are complementary to each other, were employed to achieve wide q-observations on microbial cellulose, actin cytoskeleton, tire, and membrane-electrolyte assembly of fuel cell. (author)

  15. Combination of epithermal and inelastic neutron scattering methods to locate coal and oil-shale zones

    International Nuclear Information System (INIS)

    Schultz, W.E.

    1976-01-01

    A pulsed neutron generator of the deuterium-tritium reaction type irradiates earth formations in the vicinity of a borehole with 14 MeV neutrons. Gamma rays produced by the inelastic scattering of the fast neutrons are observed in four energy regions of the gamma ray energy spectrum corresponding to the inelastic scattering of neutrons by carbon, oxygen, silicon, and calcium. The carbon/oxygen, calcium/silicon, and carbon plus oxygen gamma rays are found and combined with a separately derived hydrogen index log to determine the quality of coal-bearing formations or oil-shale regions. The hydrogen index curve is found preferably by a dual-spaced detector epithermal neutron porosity logging technique or from a conventional thermal neutron gamma ray log

  16. Measurement of the angular distribution of neutron-proton scattering at 10 MeV

    International Nuclear Information System (INIS)

    Haight, R.C.; Bateman, F.B.; Grimes, S.M.; Brient, C.E.; Massey, T.N.; Wasson, O.A.; Carlson, A.D.; Zhou, H.

    1995-01-01

    The relative angular distribution of neutrons scattered from protons was measured at an incident neutron energy of 10 MeV at the Ohio University Accelerator Laboratory. An array of 11 detector telescopes at laboratory angles of 0 to 60 degrees was used to detect recoil protons from neutron interactions with a CH 2 (polypropylene) target. Data for 7 of these telescopes were obtained with one set of electronics and are presented here. These data, from 108 to 180 degrees for the center-of-mass scattering angles, have a small slope which agrees better with angular distributions predicted by the Arndt phase shifts than with the ENDF/B-VI angular distribution

  17. Studies of magnetism with inelastic scattering of cold neutrons

    International Nuclear Information System (INIS)

    Jacrot, B.

    1964-01-01

    Inelastic scattering of cold neutrons can be used to study some aspects of magnetism: spins waves, exchange integrals, vicinity of Curie point. After description of the experimental set-up, several experiments, in the fields mentioned above, are analysed. (author) [fr

  18. Model-based design evaluation of a compact, high-efficiency neutron scatter camera

    Science.gov (United States)

    Weinfurther, Kyle; Mattingly, John; Brubaker, Erik; Steele, John

    2018-03-01

    This paper presents the model-based design and evaluation of an instrument that estimates incident neutron direction using the kinematics of neutron scattering by hydrogen-1 nuclei in an organic scintillator. The instrument design uses a single, nearly contiguous volume of organic scintillator that is internally subdivided only as necessary to create optically isolated pillars, i.e., long, narrow parallelepipeds of organic scintillator. Scintillation light emitted in a given pillar is confined to that pillar by a combination of total internal reflection and a specular reflector applied to the four sides of the pillar transverse to its long axis. The scintillation light is collected at each end of the pillar using a photodetector, e.g., a microchannel plate photomultiplier (MCP-PM) or a silicon photomultiplier (SiPM). In this optically segmented design, the (x , y) position of scintillation light emission (where the x and y coordinates are transverse to the long axis of the pillars) is estimated as the pillar's (x , y) position in the scintillator "block", and the z-position (the position along the pillar's long axis) is estimated from the amplitude and relative timing of the signals produced by the photodetectors at each end of the pillar. The neutron's incident direction and energy is estimated from the (x , y , z) -positions of two sequential neutron-proton scattering interactions in the scintillator block using elastic scatter kinematics. For proton recoils greater than 1 MeV, we show that the (x , y , z) -position of neutron-proton scattering can be estimated with < 1 cm root-mean-squared [RMS] error and the proton recoil energy can be estimated with < 50 keV RMS error by fitting the photodetectors' response time history to models of optical photon transport within the scintillator pillars. Finally, we evaluate several alternative designs of this proposed single-volume scatter camera made of pillars of plastic scintillator (SVSC-PiPS), studying the effect of

  19. Influence of the effective mass of water molecule on thermal neutron scattering

    International Nuclear Information System (INIS)

    Markovic, M.

    1981-01-01

    The influence of the effective water molecule mass on the thermal neutron scattering on the nucleus of the hydrogen atom has been investigated. Besides the actual water molecule mass (M = 18) the investigations have been carried out with its two effective values (M1 = 16 and M2 = 20). The differential and total cross sections have been calculated for the incident thermal neutron energy E o = 1 eV. Investigation results show different prominence of the quantum effects and for M2 the appearance of peaks in the quasielastic scattering. (author)

  20. The single-angle neutron scattering facility at Pelindaba

    International Nuclear Information System (INIS)

    Hofmeyr, C.; Mayer, R.M.; Tillwick, D.L.; Starkey, J.R.

    1978-05-01

    The small-angle neutron scattering facility at the SAFARI-1 reactor is described in detail, and with reference to theoretical and practical design considerations. Inexpensive copper microwave guides used as a guide-pipe for slow neutrons provided the basis for a useful though comparatively simple facility. The neutron-spectrum characteristics of the final facility in different configurations of the guide-pipe (both S and single-curved) agree wel with expected values based on results obtained with a test facility. The design, construction, installation and alignment of various components of the facility are outlined, as well as intensity optimisation. A general description is given of experimental procedures and data-aquisition electronics for the four-position sample holder and counter array of up to 18 3 He detectors and a beam monitor [af

  1. Neutron scattering studies of the dynamics of biopolymer-water systems using pulsed-source spectrometers

    Energy Technology Data Exchange (ETDEWEB)

    Middendorf, H.D. [Univ. of Oxford (United Kingdom); Miller, A. [Stirling Univ., Stirling (United Kingdom)

    1994-12-31

    Energy-resolving neutron scattering techniques provide spatiotemporal data suitable for testing and refining analytical models or computer simulations of a variety of dynamical processes in biomolecular systems. This paper reviews experimental work on hydrated biopolymers at ISIS, the UK Pulsed Neutron Facility. Following an outline of basic concepts and a summary of the new instrumental capabilities, the progress made is illustrated by results from recent experiments in two areas: quasi- elastic scattering from highly hydrated polysaccharide gels (agarose and hyaluronate), and inelastic scattering from vibrational modes of slightly hydrated collagen fibers.

  2. Neutron scattering studies of the dynamics of biopolymer-water systems using pulsed-source spectrometers

    International Nuclear Information System (INIS)

    Middendorf, H.D.; Miller, A.

    1994-01-01

    Energy-resolving neutron scattering techniques provide spatiotemporal data suitable for testing and refining analytical models or computer simulations of a variety of dynamical processes in biomolecular systems. This paper reviews experimental work on hydrated biopolymers at ISIS, the UK Pulsed Neutron Facility. Following an outline of basic concepts and a summary of the new instrumental capabilities, the progress made is illustrated by results from recent experiments in two areas: quasi- elastic scattering from highly hydrated polysaccharide gels (agarose and hyaluronate), and inelastic scattering from vibrational modes of slightly hydrated collagen fibers

  3. The analysis of nano structures based on small angle scattering of neutrons

    International Nuclear Information System (INIS)

    Len, Adel; Fuzi, Janos; Rosta, Laszlo; Harmat, Peter

    2014-01-01

    The paper describes the technology of small angle neutron scattering from neutron beam cooling to beam focusing and image processing. The applicability of the method is illustrated by sodium bubble analysis in tungsten, and investigation of the the effect of microbial transglutamase on casein micellas.

  4. Neutron scattering study of the magnetism in a nanocrystalline/amorphous material

    International Nuclear Information System (INIS)

    Rosov, N.

    1995-01-01

    Recently developed nanocrystalline magnetic systems are of considerable interest fundamentally as well as technologically. One such material is Fe 73.5 B 9 Si 13.5 Cu 1 Nb 3 , which can be produced by heat treating the amorphous precursor. This forms a noncrystalline phase with typical dimension of 350 angstrom as determined by neutron diffraction. Small angle neutron scattering (SANS) has been employed to investigate the properties of the nanocrystallized material over the temperature range from 10 K to 725 K, a regime where no significant structural changes are expected to occur. In zero field and low temperature (10 K) the authors obtained an isotropic scattering pattern. The application of a relatively modest field to sweep out the domains changed the scattering to a butterfly wings pattern typical of patterns dominated by magnetic elastic intensity. Up to 450 K this pattern changed only modestly, while for substantially higher temperatures the ratio of inelastic to elastic scattering increased rapidly as the magnetic phase transition of the intergranular component (≅ 575 K) was approached. Triple axis inelastic measurements showed that the majority of the magnetic inelastic scattering was from the nanocrystalline phase

  5. Neutron scattering study of the magnetism in a nanocrystalline/amorphous material

    Energy Technology Data Exchange (ETDEWEB)

    Rosov, N. [National Inst. of Standards and Technology, Gaithersburg, MD (United States). Reactor Radiation Div.; Lynn, J.W. [National Inst. of Standards and Technology, Gaithersburg, MD (United States). Reactor Radiation Div.]|[Univ. of Maryland, College Park, MD (United States). Dept. of Physics; Fish, G.E. [Allied Signal Inc., Morristown, NJ (United States)

    1995-12-31

    Recently developed nanocrystalline magnetic systems are of considerable interest fundamentally as well as technologically. One such material is Fe{sub 73.5}B{sub 9}Si{sub 13.5}Cu{sub 1}Nb{sub 3}, which can be produced by heat treating the amorphous precursor. This forms a noncrystalline phase with typical dimension of 350 {angstrom} as determined by neutron diffraction. Small angle neutron scattering (SANS) has been employed to investigate the properties of the nanocrystallized material over the temperature range from 10 K to 725 K, a regime where no significant structural changes are expected to occur. In zero field and low temperature (10 K) the authors obtained an isotropic scattering pattern. The application of a relatively modest field to sweep out the domains changed the scattering to a butterfly wings pattern typical of patterns dominated by magnetic elastic intensity. Up to 450 K this pattern changed only modestly, while for substantially higher temperatures the ratio of inelastic to elastic scattering increased rapidly as the magnetic phase transition of the intergranular component ({approx_equal} 575 K) was approached. Triple axis inelastic measurements showed that the majority of the magnetic inelastic scattering was from the nanocrystalline phase.

  6. Small angle neutron scattering study of nano sized microstructure in Fe-Cr ODS steels for gen IV in-core applications.

    Science.gov (United States)

    Han, Young-Soo; Mao, Xiadong; Jang, Jinsung

    2013-11-01

    The nano-sized microstructures in Fe-Cr oxide dispersion strengthened steel for Gen IV in-core applications were studied using small angle neutron scattering. The oxide dispersion strengthened steel was manufactured through hot isostatic pressing with various chemical compositions and fabrication conditions. Small angle neutron scattering experiments were performed using a 40 m small angle neutron scattering instrument at HANARO. Nano sized microstructures, namely, yttrium oxides and Cr-oxides were quantitatively analyzed by small angle neutron scattering. The yttrium oxides and Cr-oxides were also observed by transmission electron microscopy. The microstructural analysis results from small angle neutron scattering were compared with those obtained by transmission electron microscopy. The effects of the chemical compositions and fabrication conditions on the microstructure were investigated in relation to the quantitative microstructural analysis results obtained by small angle neutron scattering. The volume fraction of Y-oxide increases after fabrication, and this result is considered to be due to the formation of non-stochiometric Y-Ti-oxides.

  7. Enhancing the performances of a resonance detector spectrometer for deep inelastic neutron scattering measurements

    International Nuclear Information System (INIS)

    Filabozzi, A.; Pace, E.; Pietropaolo, A.

    2012-01-01

    The possibility is explored to sum up neutron Compton profiles at different scattering angles in deep inelastic neutron scattering measurements within the Resonance Detector (RD) configuration to enhance the statistics for a more reliable extraction of the momentum distribution of the constituents in the target. The RD configuration allows to select the energy of the scattered neutrons up to several tens of electron Volt, thus accessing energy and wave vector transfers well above 1 eV and 30 Å −1 , respectively. In the high-q/ω regime, the final state effects could be considered as negligible, as shown in a series of simulations using a Monte Carlo method with different inverse geometry instrument setups. The simulations show that it could be possible to conceive an instrument set up where the RD configuration allows the proper summation of several spectra at different scattering angles, providing a good separation of the proton recoil signal from that of the heavier atoms, thus avoiding the cell subtraction by fitting procedure.

  8. Incoherent neutron scattering functions for random jump diffusion in bounded and infinite media

    International Nuclear Information System (INIS)

    Hall, P.L.; Ross, D.K.

    1981-01-01

    The incoherent neutron scattering function for unbounded jump diffusion is calculated from random walk theory assuming a gaussian distribution of jump lengths. The method is then applied to calculate the scattering function for spatially bounded random jumps in one dimension. The dependence on momentum transfer of the quasi-elastic energy broadenings predicted by this model and a previous model for bounded one-dimensional continuous diffusion are calculated and compared with the predictions of models for diffusion in unbounded media. The one-dimensional solutions can readily be generalized to three dimensions to provide a description of quasi-elastic scattering of neutrons by molecules undergoing localized random motions. (author)

  9. Magnetic scattering of neutrons by atoms

    International Nuclear Information System (INIS)

    Stassis, C.; Deckman, H.W.

    1976-01-01

    The magnetic scattering of neutrons by an atom or ion possessing both a spin and orbital magnetic moment is examined. For an atom in the 1sup(n) electronic configuration the magnetic scattering amplitude is determined by matrix elements of even-order electric and odd-order magnetic multipoles, whose order of multipolarity k is less than or equal to 21 + 1. The calculation of the matrix elements of these multipoles is separated into evaluating radial matrix elements and matrix elements of the Racah tensors Wsup(0,k) and Wsup(1,k') where k is an even integar less than or equal to 21. The calculation of the matrix elements of these tensors is considerably simplified by selection rules based on the groups Sp(41 + 2), R(21 + 1), R(3) and in the case of f-electrons, the special group G 2 . It is shown that, in the case of elastic scattering by an atom or an ion whose state is a single Russell-Saunders state, the magnetic scattering amplitude can be written in the conventional form p(q)qsub(m).sigma. General expressions for the amplitude p(q) as well as the elastic magnetic form factor are obtained. The evaluation of the coherent magnetic scattering amplitude by an atom in a magnetic field is discussed, and the small-q approximation to the elastic magnetic scattering is considered. The formation is illustrated for the important case of d- and f-electrons. The generalization of the formalism to the case of mixed atomic configurations is examined in some detail. (author)

  10. Neutron-scattering cross section of the S=1/2 Heisenberg triangular antiferromagnet

    DEFF Research Database (Denmark)

    Lefmann, K.; Hedegård, P.

    1994-01-01

    In this paper we use a Schwinger-boson mean-field approach to calculate the neutron-scattering cross section from the S = 1/2 antiferromagnet with nearest-neighbor isotropic Heisenberg interaction on a two-dimensional triangular lattice. We investigate two solutions for T = 0: (i) a state with lo...... no elastic, but a set of broader dispersive spin excitations around kappa almost-equal-to (1/2, 0) and around kappa almost-equal-to (1/3, 1/3) for omega/E(g) = 2.5-4. It should thus be possible to distinguish these two states in a neutron-scattering experiment.......In this paper we use a Schwinger-boson mean-field approach to calculate the neutron-scattering cross section from the S = 1/2 antiferromagnet with nearest-neighbor isotropic Heisenberg interaction on a two-dimensional triangular lattice. We investigate two solutions for T = 0: (i) a state with long......-range order resembling the Neel state and (ii) a resonating valence bond or ''spin liquid'' state with an energy gap, E(g) almost-equal-to 0.17J, for the elementary excitations (spinons). For solution (ii) the neutron cross section shows Bragg rods at kappa = K = (1/3, 1/3), whereas solution (ii) shows...

  11. Inelastic neutron scattering method in hard coal quality monitoring

    International Nuclear Information System (INIS)

    Cywicka-Jakiel, T.; Loskiewicz, J.; Tracz, G.

    1994-07-01

    Nuclear methods in mining industry and power generation plants are nowadays very important especially because of the need for optimization of combustion processes and reduction of environmental pollution. On-line analysis of coal quality not only economic benefits but contribute to environmental protection too. Neutron methods especially inelastic scattering and PGNAA are very useful for analysis of coal quality where calorific valve, ash and moisture content are the most important. Using Pu-Be or Am-Be isotopic sources and measuring carbon 4.43 MeV γ-rays from neutron inelastic scattering: 12 C(n,n'γ) 12 C we can evaluate calorific valve in hard coals with precision better than in PGNAA method. This is mainly because of large cross-section for inelastic scattering and the strong correlation between carbon content and calorific value shown in the paper for different coal basins. The influence of moisture on 4.43 MeV carbon γ-rays in considered in the paper in theoretical and experimental aspects and appropriate formula is introduced. Also the possibilities of determine ash, moisture, Cl, Na and Si in coal are shown. (author). 11 refs, 15 figs

  12. Inelastic neutron scattering method in hard coal quality monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Cywicka-Jakiel, T.; Loskiewicz, J.; Tracz, G. [Institute of Nuclear Physics, Cracow (Poland)

    1994-07-01

    Nuclear methods in mining industry and power generation plants are nowadays very important especially because of the need for optimization of combustion processes and reduction of environmental pollution. On-line analysis of coal quality not only economic benefits but contribute to environmental protection too. Neutron methods especially inelastic scattering and PGNAA are very useful for analysis of coal quality where calorific valve, ash and moisture content are the most important. Using Pu-Be or Am-Be isotopic sources and measuring carbon 4.43 MeV {gamma}-rays from neutron inelastic scattering: {sup 12}C(n,n`{gamma}){sup 12}C we can evaluate calorific valve in hard coals with precision better than in PGNAA method. This is mainly because of large cross-section for inelastic scattering and the strong correlation between carbon content and calorific value shown in the paper for different coal basins. The influence of moisture on 4.43 MeV carbon {gamma}-rays in considered in the paper in theoretical and experimental aspects and appropriate formula is introduced. Also the possibilities of determine ash, moisture, Cl, Na and Si in coal are shown. (author). 11 refs, 15 figs.

  13. Albedo analytical method for multi-scattered neutron flux calculation in cavity

    International Nuclear Information System (INIS)

    Shin, Kazuo; Selvi, S.; Hyodo, Tomonori

    1986-01-01

    A simple formula which describes multi-scattered neutron flux in a spherical cavity was derived based on the albedo concept. The formura treats a neutron source which has an arbitrary energy-angle distribution and is placed at any point in the cavity. The derived formula was applied to the estimation of neutron fluxes in two cavities, i.e. a spherical concrete cell with a 14-MeV neutron source at the center and the ''YAYOI'' reactor cavity with a pencil beam of reactor neutrons. The results of the analytical formula agreed very well with the reference data in the both problems. It was concluded that the formula is applicable to estimate the neutron fluxes in a spherical cell except for special cases that tangential source neutrons are incident to the cavity wall. (author)

  14. Fast-neutron elastic-scattering cross sections of elemental tin

    International Nuclear Information System (INIS)

    Budtz-Jorgensen, C.; Guenther, P.T.; Smith, A.

    1982-07-01

    Broad-resolution neutron-elastic-scattering cross sections of elemental tin are measured from 1.5 to 4.0 MeV. Incident-energy intervals are approx. 50 keV below 3.0 MeV and approx. 200 keV at higher energies. Ten to twenty scattering angles are used, distributed between approx. 20 and 160 0 . The experimental results are used to deduce the parameters of a spherical optical-statistical model and they are also compared with corresponding values given in ENDF/B-V

  15. Molecular simulation study to examine the possibility of detecting collective motion in protein by inelastic neutron scattering

    International Nuclear Information System (INIS)

    Yasumasa, Joti; Nobuhiro, Go; Akio, Kitao; Nobuhiro, Go

    2003-01-01

    Inelastic and quasielastic neutron scattering gives the information on the dynamics of biological macromolecules. The combination of computer simulation with neutron scattering experiments allows us to characterize a wide range of dynamical phenomena in condensed phase bio-molecular systems. In this work, the dynamic structure factors in (Q,ω)-space were calculated by using the results of bio-molecular simulations. From the simulated inelastic neutron scattering spectra, we discuss the (Q,ω)-range and the resolution of a detector needed to observe function-related protein dynamics. (authors)

  16. Neutron scattering studies of crude oil viscosity reduction with electric field

    Science.gov (United States)

    Du, Enpeng

    Small-angle neutron scattering (SANS) is a very powerful laboratory technique for micro structure research which is similar to the small angle X-ray scattering (SAXS) and light scattering for microstructure investigations in various materials. In small-angle neutron scattering (SANS) technique, the neutrons are elastically scattered by changes of refractive index on a nanometer scale inside the sample through the interaction with the nuclei of the atoms present in the sample. Because the nuclei of all atoms are compact and of comparable size, neutrons are capable of interacting strongly with all atoms. This is in contrast to X-ray techniques where the X-rays interact weakly with hydrogen, the most abundant element in most samples. The SANS refractive index is directly related to the scattering length density and is a measure of the strength of the interaction of a neutron wave with a given nucleus. It can probe inhomogeneities in the nanometer scale from 1nm to 1000nm. Since the SANS technique probes the length scale in a very useful range, this technique provides valuable information over a wide variety of scientific and technological applications, including chemical aggregation, defects in materials, surfactants, colloids, ferromagnetic correlations in magnetism, alloy segregation, polymers, proteins, biological membranes, viruses, ribosome and macromolecules. Quoting the Nobel committee, when awarding the prize to C. Shull and B. Brockhouse in 1994: "Neutrons tell you where the atoms are and what the atoms do". At NIST, there is a single beam of neutrons generated from either reactor or pulsed neutron source and selected by velocity selector. The beam passes through a neutron guide then scattered by the sample. After the sample chamber, there are 2D gas detectors to collect the elastic scattering information. SANS usually uses collimation of the neutron beam to determine the scattering angle of a neutron, which results in an even lower signal-to-noise ratio for

  17. Low-angle polarized neutron and X-ray scattering from magnetic nanolayers and nanostructures

    CERN Document Server

    Paul, Amitesh

    2017-01-01

    This research monograph presents the latest results related to the characterization of low dimensional systems. Low-angle polarized neutron scattering and X-ray scattering at grazing incidence are used as the two main techniques to explore various physical phenomena of these systems. Special focus is put on systems like thin film transition metal and rare-earth layers, oxide heterostructures, hybrid systems, self-assembled nanostructures and self-diffusion.  Readers will gain in-depth knowledge about the usage of specular scattering and off-specular scattering techniques. Investigation of in-plane and out-of-plane structures and magnetism with vector magnetometric information is illustrated comprehensively. The book caters to a wide audience working in the field of nano-dimensional magnetic systems and the neutron and X-ray reflectometry community in particular.

  18. Scattering length measurements from radiative pion capture and neutron-deuteron breakup

    Energy Technology Data Exchange (ETDEWEB)

    Tornow, W.; Chen, Q. [Duke Univ., Durham, NC (United States). Dept. of Physics; Carman, T.S. [Lawrence Livermore National Lab., CA (United States). Program for Climate Model Diagnosis and Intercomparison] [and others

    1998-03-02

    The neutron-neutron and neutron-proton {sup 1}S{sub 0} scattering lengths a{sub nn} and a{sub np}, respectively, were determined simultaneously from the neutron-deuteron breakup reaction. Their comparison with the recommended values obtained from ``two-body`` reactions gives a measure of the importance of three-nucleon force effects in the three-nucleon continuum. In order to check on the result obtained for a{sub nn} from the ``two-body`` {pi}{sup -}-d capture reaction, a new measurement was performed at LANL. Preliminary results of the three experiments are given. (orig.). 5 refs.

  19. An automated analysis workflow for optimization of force-field parameters using neutron scattering data

    Energy Technology Data Exchange (ETDEWEB)

    Lynch, Vickie E.; Borreguero, Jose M. [Neutron Data Analysis & Visualization Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831 (United States); Bhowmik, Debsindhu [Computational Sciences & Engineering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831 (United States); Ganesh, Panchapakesan; Sumpter, Bobby G. [Center for Nanophase Material Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831 (United States); Computational Sciences & Engineering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831 (United States); Proffen, Thomas E. [Neutron Data Analysis & Visualization Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831 (United States); Goswami, Monojoy, E-mail: goswamim@ornl.gov [Center for Nanophase Material Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831 (United States); Computational Sciences & Engineering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831 (United States)

    2017-07-01

    Graphical abstract: - Highlights: • An automated workflow to optimize force-field parameters. • Used the workflow to optimize force-field parameter for a system containing nanodiamond and tRNA. • The mechanism relies on molecular dynamics simulation and neutron scattering experimental data. • The workflow can be generalized to any other experimental and simulation techniques. - Abstract: Large-scale simulations and data analysis are often required to explain neutron scattering experiments to establish a connection between the fundamental physics at the nanoscale and data probed by neutrons. However, to perform simulations at experimental conditions it is critical to use correct force-field (FF) parameters which are unfortunately not available for most complex experimental systems. In this work, we have developed a workflow optimization technique to provide optimized FF parameters by comparing molecular dynamics (MD) to neutron scattering data. We describe the workflow in detail by using an example system consisting of tRNA and hydrophilic nanodiamonds in a deuterated water (D{sub 2}O) environment. Quasi-elastic neutron scattering (QENS) data show a faster motion of the tRNA in the presence of nanodiamond than without the ND. To compare the QENS and MD results quantitatively, a proper choice of FF parameters is necessary. We use an efficient workflow to optimize the FF parameters between the hydrophilic nanodiamond and water by comparing to the QENS data. Our results show that we can obtain accurate FF parameters by using this technique. The workflow can be generalized to other types of neutron data for FF optimization, such as vibrational spectroscopy and spin echo.

  20. Using Java to visualize and manipulate large arrays of neutron scattering data

    International Nuclear Information System (INIS)

    Mikkelson, D.; Worlton, T.; Chatterjee, A.; Hammonds, J.; Chen, D.

    2000-01-01

    The Intense Pulsed Neutron Source at Argonne National Laboratory is a world class pulsed neutron source with thirteen instruments designed to characterize materials using time-of-flight neutron scattering techniques. For each instrument, a collimated pulse of neutrons is directed to a material sample. The neutrons are scattered by the sample and detected by arrays of detectors. The type, number and arrangement of detectors vary widely from instrument to instrument, depending on which properties of materials are being studied. In all cases, the faster, higher energy neutrons reach the detectors sooner than the lower energy neutrons. This produces a time-of-flight spectrum at each detector element. The time-of-flight spectrum produced by each detector element records the scattering intensity at hundreds to thousands of discrete time intervals. Since there are typically between two hundred and ten thousand distinct detector elements, a single set of raw data can include millions of points. Often many such datasets are collected for a single sample to determine the effect of different conditions on the microscopic structure and dynamics of the sample. In this project, Java was used to construct a portable highly interactive system for viewing and operating on large collections of time-of-flight spectra. Java performed surprisingly well in handling large amounts of data quickly was fast enough even with standard PC hardware. Although Java may not be the choice at this time for applications where computational efficiency is the primary refinement, any disadvantages in this case were outweighed by the advantages of a clean object oriented language with a portable set of GUI components. The authors anticipate that Java will prove useful for scientific computing and data visualization in situations where portability, case of use and effective use of software development manpower are critical