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...

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

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)

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.)

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.

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 ...

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

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)

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

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.

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

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)

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

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)

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)

Progress in small angle neutron scattering activities in Malaysia

International Nuclear Information System (INIS)

Abdul Aziz Bin Mohamed; Azali Bin Muhamad; Shukri Bin Mohd

1999-01-01

The current status of SANS (Small Angle Neutron Scattering facility) activities in Malaysia has been presented. Many works need to be done for system improvement before the system can be confidently used as one of effective quality control tools in materials production and engineering sectors. (author)

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)

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.

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

Small-angle neutron scattering studies on water soluble complexes ...

Indian Academy of Sciences (India)

... by small-angle neutron scattering. SANS data showed a positive indication of the formation of RCP-SDS complexes. Even though the complete structure of the polyion complexes could not be ascertained, the results obtained give us the information on the local structure in these polymer-surfactant systems. The data were ...

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)

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.

Small-angle neutron scattering in materials science - an introduction

International Nuclear Information System (INIS)

Fratzl, P.

1996-01-01

The basic principles of the application of small-angle neutron scattering to materials research are summarized. The text focusses on the classical methods of data evaluation for isotropic and for anisotropic materials. Some examples of applications to the study of alloys, porous materials, composites and other complex materials are given. (author) 9 figs., 38 refs

Small-angle neutron scattering studies of nonionic surfactant: Effect

Indian Academy of Sciences (India)

Micellar solution of nonionic surfactant -dodecyloligo ethyleneoxide surfactant, decaoxyethylene monododecyl ether [CH3(CH2)11(OCH2CH2)10OH], C12E10 in D2O solution have been analysed by small-angle neutron scattering (SANS) at different temperatures (30, 45 and 60°C) both in the presence and absence of ...

A review on the study of polymer properties by Small Angle Neutron Scattering

International Nuclear Information System (INIS)

Seong, Baek Seok; Lee, Chang Hee; Sim, Hae Seop; Lee, Jung Sool; Kim, Hong Doo; Kim, Eu Gene; Cha, Kuk Heon

1998-05-01

This report contains concept of small angle neutron scattering , various design features and considerations of the small angle neutron spectrometer at HANARO, and recent trends of polymer studies by using this SANS technique with the installation of the spectrometer in near future. We, therefore, wish to review feasibility of small angle studies for polymer field at this spectrometer and to help possible beam time users for their experimental consideration. (author). 23 refs., 7 tabs., 23 figs

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

The challenge of observation on livings things by employing an ultra small-angle neutron scattering method

International Nuclear Information System (INIS)

Koizumi, Satoshi; Motokawa, Ryuhei; Iwase, Hiroki; Miyamoto, Nobuyoshi; Tanaka, Kazuhiro; Masui, Tomomi; Iida, You; Yue, Zhao; Chiba, Kaori; Kumada, Takayuki; Yamaguchi, Daisuke; Hashimoto, Takeji

2007-01-01

To address the question as to how small-angle scattering is effectively applied to the cell, i.e., a hierarchically ordered system comprising multi-components of macro and small molecules, the size of which ranges from 100 μm to several μm, we reconstructed SANS-J (pinhole small-angle neutron scattering spectrometer at research reactor JRR3, Tokai) to focusing and polarized neutron small-angle spectrometer (SANS-J-II), by employing focusing neutron lenses and high resolution photomultiplier. Consequently, an accessible minimum wave number q min was improved from 3x10 -3 A -1 to medium ultra-small angle scattering of 3x10 -4 A -1 . The focusing USANS method, thus developed, is crucial to fill the gap in wave number q between those covered by a double crystal method and by a conventional pin-hole method. (author)

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

Investigation of polydisperse, disordered, and fractal systems by small-angle x-ray and neutron scattering

International Nuclear Information System (INIS)

Schmidt, P.W.; Tang, Y.; Roell, A.; Steiner, M.; Hoehr, A.; Neumann, H.B.

1990-01-01

Small-angle x-ray and neutron scattering are useful methods for investigating the structure of materials on a scale from about 10 to 2000 A. Some experimental procedures and methods of data analysis for small-angle scattering are outlined, and the use of small-angle scattering for studies of polydisperse systems (i.e., systems of particles of different size) of independently scattering particles is reviewed. Some general properties of the small-angle scattering from mass and surface fractals are discussed, and some applications of these concepts in recent experimental studies are presented. Results obtained in calculations of the small-angle scattering from a model of a surface are summarized. (author) 3 figs., 18 refs

Characterization of alumina using small angle neutron scattering (SANS)

International Nuclear Information System (INIS)

Megat Harun Al Rashidn Megat Ahmad; Abdul Aziz Mohamed; Azmi Ibrahim; Che Seman Mahmood; Edy Giri Rachman Putra; Muhammad Rawi Muhammad Zin; Razali Kassim; Rafhayudi Jamro

2007-01-01

Alumina powder was synthesized from an aluminium precursor and studied using small angle neutron scattering (SANS) technique and complemented with transmission electron microscope (TEM). XRD measurement confirmed that the alumina produced was high purity and highly crystalline αphase. SANS examination indicates the formation of mass fractals microstructures with fractal dimension of about 2.8 on the alumina powder. (Author)

Small-Angle Neutron Scattering Study of Structural Changes in Temperature-Sensitive Microgel Colloids

NARCIS (Netherlands)

Stieger, M.A.; Richtering, W.; Pedersen, J.S.; Lindner, P.

2004-01-01

The structure of temperature-sensitive poly(N-isopropylacrylamide) microgels in dilute suspension was investigated by means of small-angle neutron scattering. A direct modeling expression for the scattering intensity distribution was derived which describes very well the experimental data at all

Small angle neutron scattering studies of mixed micelles of sodium

Indian Academy of Sciences (India)

The aqueous solutions of sodium cumene sulphonate (NaCS) and its mixtures with each of cetyl trimethylammonium bromide (CTAB) and sodium dodecyl sulphate (SDS) are characterized by small angle neutron scattering (SANS). NaCS when added to CTAB solution leads to the formation of long rod-shaped micelles with ...

Small-angle neutron-scattering studies of the magnetic phase diagram of MnSi

DEFF Research Database (Denmark)

Harris, P.; Lebech, B.; Hae Seop Shim

1995-01-01

The antiferromagnetic order of MnSi has been studied as function of temperature and applied magnetic field using small-angle neutron scattering. The results were analyzed using the three-dimensional resolution function and the scattering cross-section to model the diffraction data. Physical...

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.)

Small angle neutron scattering studies on the interaction of cationic

Indian Academy of Sciences (India)

The structure of the protein–surfactant complex of bovine serum albumin (BSA) and cationic surfactants has been studied by small angle neutron scattering. At low concentrations, the CTAB monomers are observed to bind to the protein leading to an increase in its size. On the other hand at high concentrations, surfactant ...

Investigation of metallic and ceramic materials by small-angle neutron scattering

NARCIS (Netherlands)

Smirnov, YI; Elyutin, NO

Small-angle neutron scattering measurements on a double-crystal spectrometer with perfect monochromator and analyzer crystals were used to follow microstructural changes in the aluminum alloy VD-17. refractory alloy ZhS-6, and dispersion-hardened zirconia-based ceramics with yttria additions. The

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)

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.)

Time-resolved small-angle neutron scattering study on soap-free emulsion polymerization

Energy Technology Data Exchange (ETDEWEB)

Motokawa, Ryuhei [Research Group of Soft Matter and Neutron Scattering, Advanced Science Research Center, Japan Atomic Energy Research Institute, Tokai, Ibaraki 319-1195 (Japan); Koizumi, Satoshi [Research Group of Soft Matter and Neutron Scattering, Advanced Science Research Center, Japan Atomic Energy Research Institute, Tokai, Ibaraki 319-1195 (Japan)]. E-mail: koizumi@neutrons.tokai.jaeri.go.jp; Hashimoto, Takeji [Research Group of Soft Matter and Neutron Scattering, Advanced Science Research Center, Japan Atomic Energy Research Institute, Tokai, Ibaraki 319-1195 (Japan); Nakahira, Takayuki [Department of Applied Chemistry and Biotechnology, Chiba University, Chiba-shi, Chiba 263-8522 (Japan); Annaka, Masahiko [Department of Chemistry, Kyushu University, Fukuoka 812-8581 (Japan)

2006-11-15

We investigated an aqueous soap-free emulsion polymerization process of Poly(N-isopropylacrylamide)-block-poly(ethylene glycol) by ultra-small-angle and time-resolved small-angle neutron scattering methods. The results indicate that the compartmentalization of chain end radicals into solid-like micelle cores crucially leads to the quasi-living behavior of the radical polymerization by prohibiting recombination process.

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)

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)

Small-angle neutron scattering and cyclic voltammetry study on electrochemically oxidized and reduced pyrolytic carbon

International Nuclear Information System (INIS)

Braun, A.; Kohlbrecher, J.; Baertsch, M.; Schnyder, B.; Koetz, R.; Haas, O.; Wokaun, A.

2004-01-01

The electrochemical double layer capacitance and internal surface area of a pyrolytic carbon material after electrochemical oxidation and subsequent reduction was studied with cyclic voltammetry and small-angle neutron scattering. Oxidation yields an enhanced internal surface area (activation), and subsequent reduction causes a decrease of this internal surface area. The change of the Porod constant, as obtained from small-angle neutron scattering, reveals that the decrease in internal surface area is not caused merely by a closing or narrowing of the pores, but by a partial collapse of the pore network

Small-angle scattering at a pulsed neutron source: comparison with a steady-state reactor

Energy Technology Data Exchange (ETDEWEB)

Borso, C S; Carpenter, J M; Williamson, F S; Holmblad, G L; Mueller, M H; Faber, J Jr; Epperson, J E; Danyluk, S S [Argonne National Lab., IL (USA)

1982-08-01

A time-of-flight small-angle diffractometer employing seven tapered collimator elements and a two-dimensional gas proportional counter was successfully utilized to collect small-angle scattering data from a solution sample of the lipid salt cetylpyridinium chloride, C/sub 21/H/sub 38/N/sup +/.Cl/sup -/, at the Argonne National Laboratory prototype pulsed spallation neutron source, ZING-P'. Comparison of the small-angle scattering observed from the same compound at the University of Missouri Research Reactor corroborated the ZING-P' results. The results are used to compare the neutron flux available from the ZING-P' source relative to the well characterized University of Missouri source. Calculations based on experimentally determined parameters indicated the time-averaged rate of detected neutrons at the ZING-P' pulsed spallation source to have been at least 33% higher than the steady-state count rate from the same sample. Differences between time-of-flight techniques and conventional steady-state techniques are discussed.

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)

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

Two-dimensional position-sensitive detectors for small-angle neutron scattering

International Nuclear Information System (INIS)

McElhaney, S.A.; Vandermolen, R.I.

1990-05-01

In this paper, various detectors available for small angle neutron scattering (SANS) are discussed, along with some current developments being actively pursued. A section has been included to outline the various methodologies of position encoding/decoding with discussions on trends and limitations. Computer software/hardware vary greatly from institute and experiment and only a general discussion is given to this area. 85 refs., 33 figs

Small-angle neutron scattering at pulsed sources compared to reactor sources

International Nuclear Information System (INIS)

Hjelm, R.P. Jr.; Seeger, P.A.; Thiyagarajan, P.

1990-01-01

Detailed comparisons of measurements made on small-angle neutron scattering instruments at pulsed spallation and reactor sources show that the results from the two types of instruments are comparable. It is further demonstrated that spallation instruments are preferable for measurements in the mid-momentum transfer domain or when a large domain is needed. 8 refs., 2 figs

Time-resolved small-angle neutron scattering of a micelle-to-vesicle transition

Energy Technology Data Exchange (ETDEWEB)

Egelhaaf, S U [Institut Max von Laue - Paul Langevin (ILL), 38 -Grenoble (France); Schurtenberger, P [Eidgenoessische Technische Hochschule, Zurich (Switzerland)

1997-04-01

Amphiphilic molecules spontaneously self-assemble in solution to form a variety of aggregates. Only limited information is available on the kinetics of the structural transitions as well as on the existence of non-equilibrium or metastable states. Aqueous mixtures of lecithin and bile salt are very interesting biological model-systems which exhibit a spontaneous transition from polymer-like mixed micelles to vesicles upon dilution. The small-angle neutron scattering (SANS) instrument D22, with its very high neutron flux and the broad range of scattering vectors covered in a single instrumental setting, allowed us for the first time to perform time-resolved scattering experiments in order to study the micelle-to-vesicle transition. The temporal evolution of the aggregate structures were followed and detailed information was obtained even on molecular length-scales. (author). 5 refs.

Studies in small angle scattering techniques

International Nuclear Information System (INIS)

Moellenbach, K.

1980-03-01

Small angle scattering of neutrons, X-rays and γ-rays are found among the spectroscopic methods developed in the recent years. Although these techniques differ from each other in many respects, e.g. radiation sources and technical equipment needed, their power to resolve physical phenomena and areas of application can be discussed in a general scheme. Selected examples are given illustrating the use of specific technical methods. Jahn-Teller driven structural phase transitions in Rare Earth zircons were studied with neutron scattering as well as small angle γ-ray diffraction. The study of neutron scattering from formations of magnetic domains in the Ising ferromagnet LiTbF 4 is a second example. Both these examples represent more than experimental test cases since the theoretical interpretations of the data obtained are discussed as well. As a last example the use of small angle scattering methods for the study of molecular biological samples is discussed. In particular the experimental procedures used in connection with scattering from aqueous solutions of proteins and protein complexes are given. (Auth.)

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.

Invisible detergents for structure determination of membrane proteins by small-angle neutron scattering

DEFF Research Database (Denmark)

Midtgaard, Søren Roi; Darwish, Tamim A.; Pedersen, Martin Cramer

2018-01-01

A novel and generally applicable method for determining structures of membrane proteins in solution via small-angle neutron scattering (SANS) is presented. Common detergents for solubilizing membrane proteins were synthesized in isotope-substituted versions for utilizing the intrinsic neutron sca...... solution structure determination of membrane proteins by SANS and subsequent data analysis available to non-specialists. This article is protected by copyright. All rights reserved....

Influence of multiple small-angle neutron scattering on diffraction peak broadening in ferritic steel

Czech Academy of Sciences Publication Activity Database

Woo, W.; Em, V.; Shin, E.; Mikula, Pavol; Ryukhtin, Vasyl

2015-01-01

Roč. 48, APR (2015), s. 350-356 ISSN 0021-8898 R&D Projects: GA ČR GB14-36566G; GA MŠk(CZ) LM2011019 Institutional support: RVO:61389005 Keywords : peak broadening * small-angle neutron scattering * neutron diffraction * magnetic domain Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.720, year: 2014

Small angle scattering of X radiation and slow neutrons in structural analyses of amorphous solids

International Nuclear Information System (INIS)

Kostorz, G.

1980-01-01

Small angle scattering of x radiation and slow neutrons allows to detect inhomogeneities of the dimension of ten to some thousands of Angstroem by the difference in the scattering length density. The progress made during recent years in the development of apparatusses has created the possibility of solving very complicated problems. A first outline shows that in separation processes as well as in investigating extended defects the method of small angle scattering may provide valuable contributions to the analysis of the non-crystalline state

Reversible membrane reorganizations during photosynthesis in vivo: revealed by small-angle neutron scattering

DEFF Research Database (Denmark)

Nagy, Gergely; Posselt, Dorthe; Kovacs, Laszlo

2011-01-01

In the present study, we determined characteristic repeat distances of the photosynthetic membranes in living cyanobacterial and eukaryotic algal cells, and in intact thylakoid membranes isolated from higher plants with time-resolved small-angle neutron scattering. This non-invasive technique...

Soller collimators for small angle neutron scattering

International Nuclear Information System (INIS)

Crawford, R.K.; Epperson, J.E.; Thiyagarajan, P.

1989-01-01

The neutron beam transmitted through the soller collimators on the SAD (Small Angle Diffractometer) instrument at IPNS (Intense Pulsed Neutron Source) showed wings about the main beam. These wings were quite weak, but were sufficient to interfere with the low-Q scattering data. General considerations of the theory of reflection from homogeneous absorbing media, combined with the results from a Monte Carlo simulation, suggested that these wings were due to specular reflection of neutrons from the absorbing material on the surfaces of the collimator blades. The simulations showed that roughness of the surface was extremely important, with wing background variations of three orders of magnitude being observed with the range of roughness values used in the simulations. Based on the results of these simulations, new collimators for SAD were produced with a much rougher 10 B-binder surface coating on the blades. These new collimators were determined to be significantly better than the original SAD collimators. This work suggests that any soller collimators designed for use with long wavelengths should be fabricated with such a rough surface coating, in order to eliminate (or at least minimize) the undesirable reflection effects which otherwise seem certain to occur. 4 refs., 6 figs

Small angle neutron scattering using a triple axis spectrometer

International Nuclear Information System (INIS)

Ahmed, F.U.; Goyal, P.S.; Kamal, L.; Yunus, S.M.; Datta, T.K.; Rahman, M.O.; Azad, A.K.; Begum, S.; Zakaria, A.K.

1994-01-01

SANS techniques has been developed on a triple axis neutron spectrometer at TRIGA Mark II (3 MW) research reactor, AERE, Savar, Dhaka, Bangladesh. Double crystal (with very small mosaic spread ∼ 1 min.) diffraction known as Bonse and Hart's method has been employed. Such a device is a useful tool for small angle scattering in the Q range between 10 -5 and 10 -1 Angstroms -1 and for real time experiments at short time scales. Therefore, large objects and large distance interparticle correlations can be easily investigated. The results of SANS' measurements using alumina (A1 2 0 3 ) sample are presented. The radius of gyration has been determined and the data has been fitted to the scattering function of a sphere. 9 refs., 6 figs.,

Dispersion forces and small-angle neutron scattering from liquid noble metals

International Nuclear Information System (INIS)

March, N.H.

1988-01-01

Maggs and Ashcroft [Phys. Rev. letts., 59,113 (1987)] have re-opened the question of the analogy between the cohesion of a molecular crystal, in which dispersion forces play a major role, and that in a metal crystal with polarizable ion cores. It is pointed out that small-angle neutron scattering from liquid noble metals could be used to test their predictions. (author)

Anomalous and resonance small-angle scattering

International Nuclear Information System (INIS)

Epperson, J.E.; Thiyagarajan, P.

1988-01-01

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

Informing the improvement of forest products durability using small angle neutron scattering

Science.gov (United States)

Nayomi Plaza Rodriguez; Sai Venkatesh Pingali; Shuo Qian; William T. Heller; Joseph E. Jakes

2016-01-01

A better understanding of how wood nanostructure swells with moisture is needed to accelerate the development of forest products with enhanced moisture durability. Despite its suitability to study nanostructures, small angle neutron scattering (SANS) remains an underutilized tool in forest products research. Nanoscale moisture-induced structural changes in intact and...

Small angle neutron scattering. Report of a coordinated research project 2000-2003

International Nuclear Information System (INIS)

2006-03-01

Small angle neutron scattering (SANS) is a powerful technique for studying macro structures like polymers, precipitates in metallurgical specimens, biological molecules, micelles and magnetic systems like ferrofluids. Neutron scattering has an advantage over X ray scattering (XSAXS) due to selective absorption and scattering cross section of neutrons across the periodic table. It is possible to develop and use a SANS instrument even with a medium flux reactor. The present CRP was aimed at the development of components like collimators, monochromators, position sensitive detectors (PSD) etc. for improving the throughput of the instrument and foster the effective utilization of research reactors, as well as to provide a link between developing and developed facilities. The CRP was launched with the first research coordination meeting (RCM) in 2000 to refine the project proposals and define the action plans and partnerships. There were eight research contracts and four research agreements. Good partnerships were established between various participants with collaborations among participants from various countries including those from developing and developed countries. The progress of the individual projects and team work under the CRP was evaluated and discussed during the second RCM and the action plan for the final phase was formulated. The results of the work done under the CRP were then reviewed in the final RCM held in Vienna, December 2003. This publication presents the results of the work carried out by the participants under the CRP at their respective institutions. The information will be useful for the users and operators of research reactors in developing an instrument and building collaborations for capacity building. The development of collimators, detector assemblies, utilization of the SANS for microstructural characterization of advanced materials , development and design of a ultra small angle neutron scattering (USANS) and proposals for a new SANS

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)

Structure of unilamellar vesicles: Numerical analysis based on small-angle neutron scattering data

International Nuclear Information System (INIS)

Zemlyanaya, E. V.; Kiselev, M. A.; Zbytovska, J.; Almasy, L.; Aswal, V. K.; Strunz, P.; Wartewig, S.; Neubert, R.

2006-01-01

The structure of polydispersed populations of unilamellar vesicles is studied by small-angle neutron scattering for three types of lipid systems, namely, single-, two-and four-component vesicular systems. Results of the numerical analysis based on the separated-form-factor model are reported

Improved performances of 36 m small-angle neutron scattering spectrometer BATAN in Serpong Indonesia

International Nuclear Information System (INIS)

Putra, Edy Giri Rachman; Bharoto; Santoso, Eddy; Ikram, Abarrul

2009-01-01

SMARTer, a 36 m small-angle neutron scattering (SANS) spectrometer owned by the National Nuclear Energy Agency of Indonesia (BATAN) was installed at the Neutron Scattering Laboratory (NSL) in Serpong, Indonesia. Lots of works on replacing, upgrading and improving the control system, experimental methods, data collection and reduction in the last two years have been carried out to optimize the performance of SMARTer. Some standard samples such as silver behenate, monodisperse polystyrene nanoparticle, porous silica and block copolymer PS-PEP film were measured for the inter-laboratory comparison.

A mechanical velocity selector for a small angle scattering instrument on a pulsed neutron source

International Nuclear Information System (INIS)

Meardon, B.H.; Stewart, R.J.; Williams, W.G.

1978-11-01

Design parameters and performance calculations are given for a straight-slot velocity selector which can be used for discriminating between elastic and inelastic scattering events in small angle scattering experiments on a pulsed neutron source. The selector has a high transmittance over the wavelength range 3 A 5%. (author)

Insights into the interactions among Surfactin, betaines, and PAM: surface tension, small-angle neutron scattering, and small-angle X-ray scattering study.

Science.gov (United States)

Xiao, Jingwen; Liu, Fang; Garamus, Vasil M; Almásy, László; Handge, Ulrich A; Willumeit, Regine; Mu, Bozhong; Zou, Aihua

2014-04-01

The interactions among neutral polymer polyacrylamide (PAM) and the biosurfactant Surfactin and four betaines, N-dodecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate (SDDAB), N-tetradecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate (STDAB), N-hexadecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate (SHDAB), and N-dodecyl-N,N-dimethyl-2-ammonio-acetate (C12BE), in phosphate buffer solution (PBS) have been studied by surface tension measurements, small-angle neutron scattering (SANS), small-angle X-ray scattering (SAXS), and rheological experiments. It has been confirmed that the length of alkyl chain is a key parameter of interaction between betaines and PAM. Differences in scattering contrast between X-ray and neutrons for surfactants and PAM molecules provide the opportunity to separately follow the changes of structure of PAM and surfactant aggregates. At concentrations of betaines higher than CMC (critical micelle concentration) and C2 (CMC of surfactant with the presence of polymer), spherical micelles are formed in betaines and betaines/PAM solutions. Transition from spherical to rod-like aggregates (micelles) has been observed in solutions of Surfactin and Surfactin/SDDAB (αSurfactin = 0.67 (molar fraction)) with addition of 0.8 wt % of PAM. The conformation change of PAM molecules only can be observed for Surfactin/SDDAB/PAM system. Viscosity values follow the structural changes suggested from scattering measurements i.e., gradually increases for mixtures PAM → Surfactin/PAM → Surfactin/SDDAB/PAM in PBS.

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

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.

Small-angle neutron scattering from poly(NIPA-co-AMPS) gels

DEFF Research Database (Denmark)

Travas-Sejdic, J.; Easteal, A.; Knott, R.

2000-01-01

was reversed; that is the lower cross-link density, the higher the scattered intensity. Therefore, the role of cross-links at high temperature was to suppress microphase separation. The fitting of the experimental data with the Rabin and Panyukov theory indicated qualitative agreement.......The microstructure of the poly( N-isopropylacrylamide-co-acrylamido- 2-methyl-1-propane sulphonic acid) gel, poly( NIPA-co-AMPS), was investigated as a function of temperature and cross-link density using the small angle neutron scattering technique. The sample temperature was varied in the range...... 30 to 55C. Two different behaviours of poly( NIPA-co-AMPS) gels were observed. At low temperature (30C), the magnitude of the scattered intensity increased with cross-link density suggesting that additional cross-links introduced more inhomogeneities in the gel network. At high temperatures the trend...

Small-angle neutron scattering at pulsed spallation sources

International Nuclear Information System (INIS)

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

1991-01-01

The importance of small-angle neutron scattering (SANS) in biological, chemical, physical and engineering research mandates that all intense neutron sources be equipped with SANS instruments. Four existing instruments at pulsed sources are described and the general differences between pulsed-source and reactor-based instrument designs are discussed. The basic geometries are identical, but dynamic range is generally achieved by using a broad band of wavelengths (with time-of-flight analysis) rather than by moving the detector. This allows optimization for maximum beam intensity at a given beam size over the full dynamic range with fixed collimation. Data-acquisition requirements at a pulsed source are more severe, requiring large fast histrograming memories. Data reduction is also more complex, as all wavelength-dependent and angle-dependent backgrounds and nonlinearities must be accounted for before data can be transformed to intensity vs momentum transfer (Q). A comparison is shown between the Los Alamos pulsed instrument and D11 (Institut Laue-Langevin) and examples from the four major topics of the conference are shown. The general conclusion is that reactor-based instruments remain superior at very low Q or if only a narrow range of Q is required, but that the current generation of pulsed-source instruments is competitive of moderate Q and may be faster when a wide range of Q is required. (orig.)

Structure investigations on Portland cement paste by small angle neutron scattering

International Nuclear Information System (INIS)

Dragolici, C.A.; Lin, A.

2004-01-01

Hydrated Portland cement is a very complex material. Cement paste consists of many crystalline and non-crystalline phases in various ranges of sizes (μm and nm scale). The crystalline phases are embedded in amorphous phases of hydration products. We investigated the structural changes of hydrating phases in a time interval up to 18 days, at Budapest Neutron Center's SANS spectrometer. The small angle neutron scattering of Portland cements prepared with a various water-to-cement ratios, gave us information about the microstructure changes in the material. Fractals were a suitable way for structure modelling. Some comments regarding the opportunity of using the most common models are pointed out. (authors)

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)

Neutron and synchrotorn x-ray small angle scattering instruments for applications in biology at the Brookhaven National Laboratory

International Nuclear Information System (INIS)

Schoenborn, B.P.; Wise, D.S.; Schneider, D.K.

1983-01-01

Facilities for small angle x-ray and neutron scattering are described, with emphasis on the characterization of the primary beam of the neutron instrument and the spectrometer control logic of the synchrotron instrument

Cylindrical aggregates of chlorophylls studied by small-angle neutron scatter

Energy Technology Data Exchange (ETDEWEB)

Worcester, D.L. [Univ. of Missouri, Columbus, MO (United States); Katz, J.J. [Argonne National Laboratory, IL (United States)

1994-12-31

Neutron small-angle scattering has demonstrated tubular chlorophyll aggregates formed by self-assembly of a variety of chlorophyll types in nonpolar solvents. The size and other properties of the tubular aggregates can be accounted for by stereochemical properties of the chlorophyll molecules. Features of some of the structures are remarkably similar to light harvesting chlorophyll complexes in vivo, particularly for photosynthetic bacteria. These nanotube chlorophyll structures may have applications as light harvesting biomaterials where efficient energy transfer occurs from an excited state which is highly delocalized.

MAGNETIC NEUTRON SCATTERING

Energy Technology Data Exchange (ETDEWEB)

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

2004-07-30

science, ranging from large-scale structures and dynamics of polymers and biological systems, to electronic properties of today's technological materials. Neutron scattering developed into a vast field, encompassing many different experimental techniques aimed at exploring different aspects of matter's atomic structure and dynamics. Modern magnetic neutron scattering includes several specialized techniques designed for specific studies and/or particular classes of materials. Among these are magnetic reflectometry aimed at investigating surfaces, interfaces, and multilayers, small-angle scattering for the large-scale structures, such as a vortex lattice in a superconductor, and neutron spin-echo spectroscopy for glasses and polymers. Each of these techniques and many others offer exciting opportunities for examining magnetism and warrant extensive reviews, but the aim of this chapter is not to survey how different neutron-scattering methods are used to examine magnetic properties of different materials. Here, we concentrate on reviewing the basics of the magnetic neutron scattering, and on the recent developments in applying one of the oldest methods, the triple axis spectroscopy, that still is among the most extensively used ones. The developments discussed here are new and have not been coherently reviewed. Chapter 2 of this book reviews magnetic small-angle scattering, and modern techniques of neutron magnetic reflectometry are discussed in Chapter 3.

Structure of polyacrylic acid and polymethacrylic acid solutions : a small angle neutron scattering study

OpenAIRE

Moussaid , A.; Schosseler , F.; Munch , J.; Candau , S.

1993-01-01

The intensity scattered from polyacrylic acid and polymethacrylic acid solutions has been measured by small angle neutron scattering experiemnts. The influence of polymer concentration, ionization degree, temperature and salt content has been investigated. Results are in qualitative agreement with a model which predicts the existence of microphases in the unstable region of the phase diagram. Quantitative comparison with the theory is performed by fitting the theoretical structure factor to t...

The Small-Angle Neutron Scattering Data Analysis of the Phospholipid Transport Nanosystem Structure

Science.gov (United States)

Zemlyanaya, E. V.; Kiselev, M. A.; Zhabitskaya, E. I.; Aksenov, V. L.; Ipatova, O. M.; Ivankov, O. I.

2018-05-01

The small-angle neutron scattering technique (SANS) is employed for investigation of structure of the phospholipid transport nanosystem (PTNS) elaborated in the V.N.Orekhovich Institute of Biomedical Chemistry (Moscow, Russia). The SANS spectra have been measured at the YuMO small-angle spectrometer of IBR-2 reactor (Joint Institute of Nuclear Research, Dubna, Russia). Basic characteristics of polydispersed population of PTNS unilamellar vesicles (average radius of vesicles, polydispersity, thickness of membrane, etc.) have been determined in three cases of the PTNS concentrations in D2O: 5%, 10%, and 25%. Numerical analysis is based on the separated form factors method (SFF). The results are discussed in comparison with the results of analysis of the small-angle X-ray scattering spectra collected at the Kurchatov Synchrotron Radiation Source of the National Research Center “Kurchatov Institute” (Moscow, Russia).

Small angle neutron scattering form polymer melts: structural investigation and phase behaviour

International Nuclear Information System (INIS)

Ertugrul, O.

2004-01-01

The Small-Angle Neutron Scattering (SANS) techniques have been used to study the structural properties and phase behavior of polymer melts. A model based on Random Phase Approximation (RPA) is proposed to predict the experimental data. By fitting the model to data we could be able to obtain radius of gyration (a measure of size of a polymer) and phase transition for the sample. (author)

Study of humic acids by small-angle X-ray and neutron scattering

International Nuclear Information System (INIS)

Timchenko, A.; Trubetskaya, O.; Kihara, H.

1999-01-01

Humic acids are an important component of natural ecological system and represent a polydisperse complex of natural biopolymers with molecular masses from several to hundreds kilodaltons. They are both a source of organic compounds and a protector against anthropogenic pollutions of biosphere. The aim of the report is to underline some possibilities of small-angle X-ray and neutron scattering to study HA and their fractions. (author)

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)

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)

Small Angle Neutron Scattering experiments on ``side-on fixed"" liquid crystal polyacrylates

Science.gov (United States)

Leroux, N.; Keller, P.; Achard, M. F.; Noirez, L.; Hardouin, F.

1993-08-01

Small Angle Neutron Scattering experiments were carried out on liquid crystalline “side-on fixed” polyacrylates : we observe that the polymer backbone adopts a prolate conformation in the nematic phase. Such anisotropy of the global backbone is larger for smaller spacer length. In every case we measure at low temperatures a large chain extension as previously described in polysiloxanes. Par diffusion des neutrons aux petits angles nous observons que la chaîne de polyacrylates “en haltère” adopte une conformation type prolate en phase nématique. Son anisotropie est d'autant plus grande que l'espaceur est plus court. Dans tous les cas, nous retrouvons à basse température la forte extension de la chaîne polymère qui fut d'abord révélée dans les polysiloxanes.

Structure of magnetic particles studied by small angle neutron scattering. [Magnetic colloid particles in stable liquid dispersion

Energy Technology Data Exchange (ETDEWEB)

Cebula, D J; Charles, S W; Popplewell, J

1981-03-01

The purpose of this note is to show how the use of small angle neutron scattering (SANS) can provide fundamental information on the structure of magnetic colloid particles in stable liquid dispersion. A more detailed account elaborating the use of the technique to provide fundamental information on interactions will appear later. This contribution contains some principal results on particle structure. The technique of SANS provides a very sensitive means of measuring particle size by measuring the scattered neutron intensity, I(Q), as a function of scattered wave vector, Q.

Structure investigations on Portland cement paste by small angle neutron scattering

International Nuclear Information System (INIS)

Dragolici, C. A.; Len, A.

2003-01-01

Portland cement pastes consist of many crystalline and non-crystalline phases in various ranges of sizes (nm and mm scale). The crystalline phases are embedded in amorphous phases of the hydration products. We investigated the structural changes of hydrating phases in the time interval of 1-30 days at Budapest Neutron Center's SANS diffractometer. The small angle neutron scattering of Portland cements prepared with a water-to-cement ratio from 0,3 to 0,8 gave us information about the microstructure changes in the material. Fractals were a suitable way for structure modelling. The variation of fractals size depending on the preparation-to-measurement time interval and water-to-cement ratio could be observed. (authors)

Comparison of X-ray and neutron small-angle scattering from an Al-Zn alloy

International Nuclear Information System (INIS)

Gerold, V.; Epperson, J.E.; Gerstenberg, K.W.

1978-01-01

The normalized integrated small-angle scattered intensity for Al-Zn alloys should be independent of whether the measurements are made with X-rays or neutrons. In order to check this, and thus the correction and standardization processes, the small-angle scattering from an Al-5.05 at.% Zn alloy containing GP zones was measured with these two types of radiation. The data were corrected and converted to absolute units with reference to the commonly accepted secondary standards: vanadium for the neutron data and polyethylene (Lupolen) for the X-ray data. The results are shown to differ by, at best, 6% if reasonable values for the change in atomic volume with alloy composition are taken into account. These findings are compared with those available from the literature, and the consistency is found to be somewhat lacking. Additional careful work is clearly needed to determine if the difficulty is traceable to the data correction or to the conversion to absolute units. (Auth.)

Small-angle neutron scattering at pulsed spallation sources

International Nuclear Information System (INIS)

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

1990-01-01

The importance of small-angle neutron scattering (SANS) in biological, chemical, physical, and engineering research mandates that all intense neutron sources be equipped with SANS instruments. Four existing instruments are described, and the general differences between pulsed-source and reactor-based instrument designs are discussed. The basic geometries are identical, but dynamic range is achieved by using a broad band of wavelengths (with time-of-flight analysis) rather than by moving the detector. This allows a more optimized collimation system. Data acquisition requirements at a pulsed source are more severe, requiring large, fast histogramming memories. Data reduction is also more complex, as all wave length-dependent and angle-dependent backgrounds and non-linearities must be accounted for before data can be transformed to intensity vs Q. A comparison is shown between the Los Alamos pulsed instrument and D-11 (Institute Laue-Langevin), and examples from the four major topics of the conference are shown. The general conclusion is that reactor-based instruments remain superior at very low Q or if only a narrow range of Q is required, but that the current generation of pulsed-source instruments is competitive at moderate Q and may be faster when a wide range of Q is required. In principle, a user should choose which facility to use on the basis of optimizing the experiment; in practice the tradeoffs are not severe and the choice is usually made on the basis of availability

Small-angle neutron scattering investigations of Co-doped iron oxide nanoparticles. Preliminary results

Science.gov (United States)

Creanga, Dorina; Balasoiu, Maria; Soloviov, Dmitro; Balasoiu-Gaina, Alexandra-Maria; Puscasu, Emil; Lupu, Nicoleta; Stan, Cristina

2018-03-01

Preliminary small-angle neutron scattering investigations on aqueous suspensions of several cobalt doped ferrites (CoxFe3-xO4, x=0; 0.5; 1) nanoparticles prepared by chemical co-precipitation method, are reported. The measurements were accomplished at the YuMO instrument in function at the IBR-2 reactor. Results of intermediary data treatment are presented and discussed.

Small angle neutron scattering study on star di-block copolymers

International Nuclear Information System (INIS)

Ertugrul, O.

2006-01-01

Determining structural properties, phase transitions and stability of polymer mixtures is very important to produce new materials with desired and interesting properties. Small Angle Neutron Scattering Technique (SANS) has been one of the most powerful and intensely used methods for the characterization of polymers for last decades, m this study, we use a model based on Gaussian Random Phase Approximation (RPA) to describe Star Di-block Copolymers (SDC) mixtures with homo-polymers. We could able to predict the miscibility and phase transitions of the various mixtures along with their structure factors, producing a thermodynamic picture of the system. Also the results suggest that scattering intensity will be dictated by the structure factor of the core or shell parts of star polymer only, which depends on the homo-polymer type of the mixture

Structure of fullerene aggregates in pyridine/water solutions by small-angle neutron scattering

International Nuclear Information System (INIS)

Aksenov, V.L.; Belushkin, A.V.; Avdeev, M.V.; Rosta, L.; Mihailovic, D.; Mrzel, A.; Serdyuk, I.N.; Timchenko, A.A.

2001-01-01

Results of small-angle neutron scattering experiments on fullerenes (C 60 ) in pyridine/water solutions are reported. They confirm conclusions of the previous studies, in particular, dynamic light scattering experiments. Aggregates with characteristic radius of about 20 nm are formed in the solutions. The contrast variation using different combinations of protonated/deuterated components (water and pyridine) of the solutions points to the small pyridine content inside the aggregates. This fact testifies that the aggregates consist of a massive fullerene core covered by a thin pyridine shell

Phase separation process in FeCr alloys studied by neutron small angle scattering

International Nuclear Information System (INIS)

Furusaka, Michihiro; Ishikawa, Yoshikazu; Yamaguchi, Sadae; Fujino, Yutaka.

1986-01-01

The very early stage as well as late stage of phase separation process in FeCr alloys (Fe-20, 30, 40, 60 at%Cr) have been studied by pulsed cold neutron small angle scattering instrument (SAN). At the early stage, scattering intensity I(q) obeys q -2 dependence at the high q side of the scattering function. The results are in accord with the theory of Langer et al. which takes into account nonlinear and thermal fluctuations effects. At the late stage where I(q) shows q -4 dependence, a dynamical scaling law holds, while it is not the case for the earlier stage. Phase diagram of FeCr system is also determined by critical scattering measurements. (author)

Studies performed on neutron-irradiated copper-doped iron specimens by means of neutron small-angle scattering

International Nuclear Information System (INIS)

Naraghi, M.

1978-01-01

By means of neutron small-angle scattering precipitation arising from heat-treatment and reactor irradiation in copper-alloyed iron specimens were studied. Copper content varried between 0 and 1.5%, irradiation temperature between 310 and 563K. The specimens had been cooled from the melt partly fast, partly slowely. By taking account of magnetic scattering and by investigating the azimuthal dependence of the total scattering it became possible to distinguish between copper precipitations and vacancy agglomerates. The most obvious effect in the slowly cooled specimens after irradiation with 2-10 19 fast neutrons per cm 2 at a temperature of 563 K is the existence of copper agglomerates with diameters of the order of magnitude of 5nm. Precipitation already occurs to a much lesser extent by the influence of temperature alone. Fast cooling from the melt or low irradiation temperature reduce precipitation during reactor irradiation. Moreover, there are indications on the formation of vacancy accumulations and dislocation rings, the latter especially in the fast cooled specimens. (orig.) [de

X-ray and neutron small-angle scattering studies of human serum lipoproteins

International Nuclear Information System (INIS)

Luzzati, V.; Tardieu, A.; Mateu, L.; Sardet, C.; Stuhrmann, H.B.; Aggerbeck, L.; Scanu, A.M.

1976-01-01

The paper describes an extended x-ray study of two types of human serum lipoproteins and a neutron study of one of them. The results are similar and to some extent complementary. Serum lipoproteins provide an excellent illustration of the wealth of information that can be obtained by a small-angle scattering approach to the structure of particles with non-uniform density distribution, by using solvents of variable density

Spin waves in full-polarized state of Dzyaloshinskii-Moriya helimagnets: Small-angle neutron scattering study

Science.gov (United States)

Grigoriev, S. V.; Sukhanov, A. S.; Altynbaev, E. V.; Siegfried, S.-A.; Heinemann, A.; Kizhe, P.; Maleyev, S. V.

2015-12-01

We develop the technique to study the spin-wave dynamics of the full-polarized state of the Dzyaloshinskii-Moriya helimagnets by polarized small-angle neutron scattering. We have experimentally proven that the spin-waves dispersion in this state has the anisotropic form. We show that the neutron scattering image displays a circle with a certain radius which is centered at the momentum transfer corresponding to the helix wave vector in helimagnetic phase ks, which is oriented along the applied magnetic field H . The radius of this circle is directly related to the spin-wave stiffness of this system. This scattering depends on the neutron polarization showing the one-handed nature of the spin waves in Dzyaloshinskii-Moriya helimagnets in the full-polarized phase. We show that the spin-wave stiffness A for MnSi helimagnet decreased twice as the temperature increases from zero to the critical temperature Tc.

Conformation of comb liquid crystal polymers by neutron small angle scattering

International Nuclear Information System (INIS)

Noirez, L.; Pepy, G.

1988-01-01

A review is made of the direct information obtained by small angle neutron scattering about the anisotropy of the components parallel and perpendicular to the orienting magnetic field of the radius of gyration of comb like liquid crystal polymers. The behaviour of the conformation versus temperature is reported for several samples. Until now all samples show an oblate conformation in the smectic phase and probably the whole range of the nematic phase. The results are compared with the available theoretical predictions

On Small-Angle Neutron Scattering from Microemulsion Droplets the Role of Shape Fluctuations

CERN Document Server

Lisy, V

2001-01-01

The form factor and intensity of static neutron scattering from microemulsion droplets are calculated. The droplet is modeled by a double-layered sphere consisting of a fluid core and a thin surfactant layer, immersed in another fluid. All the three components are incompressible and characterized by different scattering length densities. As distinct from previous descriptions of small-angle neutron scattering (SANS), we consistently take into account thermal fluctuations of the droplet shape, to the second order of the fluctuations of the droplet radius. The properties of the layer are described within Helfrich's concept of the elasticity of curved interfaces. It is shown that in many cases the account for the fluctuations is essential for the interpretation of SANS. Information about two elastic constants \\kappa and \\bar\\kappa (so far extracted from the experiments in the combination 2\\kappa+\\bar\\kappa) can be now simultaneously obtained from SANS for system in conditions of two-phase coexistence. As an illu...

Elucidation of density profile of self-assembled sitosterol + oryzanol tubules with small-angle neutron scattering

NARCIS (Netherlands)

Bot, A.; Gilbert, E.P.; Bouwman, W.G.; Sawalha, H.I.M.; Adel, den R.; Garamus, V.M.; Venema, P.; Linden, van der E.; Flöter, E.

2012-01-01

Small-angle neutron scattering (SANS) experiments have been performed on self-assembled tubules of sitosterol and oryzanol in triglyceride oils to investigate details of their structure. Alternative organic phases (deuterated and non-deuterated decane, limonene, castor oil and eugenol) were used to

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

A small angle neutron scattering study of mica based glass-ceramics with applications in dentistry

International Nuclear Information System (INIS)

Kilcoyne, S.H.; Bentley, P.M.; Al-Jawad, M.; Bubb, N.L.; Al-Shammary, H.A.O.; Wood, D.J.

2004-01-01

We are currently developing machinable and load-bearing mica-based glass-ceramics for use in restorative dental surgery. In this paper we present the results of an ambient temperature small angle neutron scattering (SANS) study of several such ceramics with chemical compositions chosen to optimise machinability and strength. The SANS spectra are all dominated by scattering from the crystalline-amorphous phase interface and exhibit Q -4 dependence (Porod scattering) indicating that, on a 100 A scale, the surface of the crystals is smooth

Novel tendencies in developing small-angle neutron scattering methods for studying the structure of biological macromolecules

International Nuclear Information System (INIS)

Serdyuk, I.

1995-01-01

In recent 20 years thermal neutron scattering has been acknowledged an important instrument for structural studies in molecular biology. The methods of neutron diffraction of high resolution, which are not discussed in this paper, have already permitted to obtain a detailed representation of the course of proteolytic reactions and have arisen a number of new problems connected with the localization of water molecules and the H-D exchange. The methods of low resolution widely used due to a relative simplicity of the experiment have been successfully applied for both solving structural problems per se and investigating the changes in the structure when macromolecules perform their biological functions. The most promising are novel experimental approaches: the triple isotopic substitution method and the method of spin dynamic polarization. These methods ensure solving structural problems at a higher resolution than the dimensions of the macromolecules studied. Installation of new experimental instruments makes neutron measurements more accessible, and development of direct methods for interpretation of experimental data using the apparatus of spherical harmonics opens new possibilities for small-angle neutron scattering making it a necessary element for interpretation of diffraction data of monocrystals of intricate biological macromolecules. The paper presents a brief account of the tendencies in theoretical development and practical use of small-angle scattering for studying biological macromolecules. Special attention is given to the studies carried out in the Laboratory of Neutron Physics on a unique pulse IBR-2 reactor. (author) 14 refs

Small angle neutron scattering analysis programs on the Rutherford Laboratory IBM 360/195 computers

International Nuclear Information System (INIS)

Knowles, K.J.; Johnson, M.W.

1980-06-01

The implementation and operation of the suite of programs used for the analysis of small angle neutron scattering data originally written at the ILL (Grenoble) is described. The programs make use of a circulating data file which is also described and may be used by a variety of data analysis programs. (author)

Small angle neutron scattering investigations of spin disorder in nanocomposite soft magnets

International Nuclear Information System (INIS)

Vecchini, C.; Moze, O.; Suzuki, K.; Cadogan, J.M.; Pranzas, K.; Michels, A.; Weissmueller, J.

2006-01-01

The technique of SANS (small angle neutron scattering) furnishes unique information on the characteristic magnetic length scales and local magnetic anisotropies at the nanoscale in nanocomposite ferromagnets. Such information is not presently available using any other microscopic technique. The basic principles and results of the technique will be presented with regard to a unique and unexpected observation of a dipole field controlled spin disorder in a prototypical soft nanocomposite ferromagnet of the Nanoperm type

Small-angle neutron scattering study of high-pressure sintered detonation nanodiamonds

Energy Technology Data Exchange (ETDEWEB)

Kidalov, S. V.; Shakhov, F. M., E-mail: fedor.shakhov@mail.ioffe.ru [Ioffe Physical-Technical Institute of the Russian Academy of Sciences (Russian Federation); Lebedev, V. T.; Orlova, D. N.; Grushko, Yu. S. [Russian Academy of Sciences, Konstantinov St. Petersburg Nuclear Physics Institute (Russian Federation)

2011-12-15

The structure of detonation diamonds sintered at a high pressure (7 GPa) and temperatures of 1200-1700 Degree-Sign C has been investigated by small-angle neutron scattering. It is shown that sintering leads to an increase in the particle size from 6 to 30 nm and established that this increase is due to the chainlike oriented attachment of particles. This study supplements the oriented-attachment model, which was suggested based on the X-ray diffraction spectra of detonation nanodiamonds (DNDs) sintered under the same conditions.

Small-angle neutron scattering study of micropore collapse in amorphous solid water.

Science.gov (United States)

Mitterdorfer, Christian; Bauer, Marion; Youngs, Tristan G A; Bowron, Daniel T; Hill, Catherine R; Fraser, Helen J; Finney, John L; Loerting, Thomas

2014-08-14

Vapor-deposited amorphous solid water (ASW) is the most abundant solid molecular material in space, where it plays a direct role in both the formation of more complex chemical species and the aggregation of icy materials in the earliest stages of planet formation. Nevertheless, some of its low temperature physics such as the collapse of the micropore network upon heating are still far from being understood. Here we characterize the nature of the micropores and their collapse using neutron scattering of gram-quantities of D2O-ASW of internal surface areas up to 230 ± 10 m(2) g(-1) prepared at 77 K. The model-free interpretation of the small-angle scattering data suggests micropores, which remain stable up to 120-140 K and then experience a sudden collapse. The exact onset temperature to pore collapse depends on the type of flow conditions employed in the preparation of ASW and, thus, the specific surface area of the initial deposit, whereas the onset of crystallization to cubic ice is unaffected by the flow conditions. Analysis of the small-angle neutron scattering signal using the Guinier-Porod model suggests that a sudden transition from three-dimensional cylindrical pores with 15 Å radius of gyration to two-dimensional lamellae is the mechanism underlying the pore collapse. The rather high temperature of about 120-140 K of micropore collapse and the 3D-to-2D type of the transition unraveled in this study have implications for our understanding of the processing and evolution of ices in various astrophysical environments.

III International Conference on Small Angle Neutron Scattering dedicated to the 80 anniversary of Yu.M. Ostanevich

International Nuclear Information System (INIS)

2017-01-01

Preface “Among the many well-known fundamental and applied consequences of neutron discovery, one of the first was the emergence of structural neutron diffraction - one of the methods for studying the spatial structure of condensed matter at the atomic level. Investigating the dynamics of biological macromolecules by neutron diffraction methods is an area that is almost untouched. We believe that also in this direction one should expect rapid progress.” Yu.M.Ostanevich and I.N.Serdyuk Uspekhi Fizicheskih Nauk (1982) More than 30 years after Ostanevich and Serdyuk reviewed the then 50 years from the neutron discovery, we are happy to support their statement and prediction by reporting on the further progress in the field of neutron scattering research. Frank Laboratory of Neutron Physics has organized the III International Conference on Small Angle Neutron Scattering (YuMO2016) that was – not coincidently – dedicated to the 80th anniversary of Ostanevich. Yuriy Mechislavovich Ostanevich (1936–1992) has had a determinative and crucial contribution to the construction of spectrometers at the pulsed reactor IBR in Dubna, Russia. He contributed in particular to the development of time-of-flight small-angle neutron scattering (SANS) technique, and the selection of advanced scientific areas for its application. The SANS instrument at the IBR-2 reactor is called YuMO in his honour. The Ostanevich’s leadership and outstanding scientific achievements in SANS studies of polyelectrolytes, small molecules, fractals, metallic glasses, macromolecules, polymers, etc., were recognized also by a number of awards including the State Prize of the Russian Federation in 2000. To this end of course, we should not forget mentioning the contribution of close collaborators of Ostanevich: Laszlo Cser, Josef Plestil as well as Alexander Kunchenko, Vadim Bezzabotnov and Nikolay Gorski. The YuMO2016 conference focused on providing opportunities to discuss various possibilities of

A small angle neutron scattering study of thermoplastic elastomer

Energy Technology Data Exchange (ETDEWEB)

Sutiarso,; Edy Giri, R Putra; Andon, Insani; Sudirman,; Sudaryanto, [Materials Science Research Centre, National Atomic Energy Agency, Jakarta (Indonesia)

1998-10-01

A bilateral scientific cooperation, in the small angle neutron scattering has been agreed upon between CIAE, China and BATAN, Indonesia as well as MINT Malaysia. As stated in the agreed proposal that the objective of this cooperation, in the initial stage (stage-1), was to have a regional intercomparison measurements of SANS instruments in order to determine their characteristic/performance. Therefore, this report is supposed to describe the progress in the SANS instrument development of each country involved during the period of 1996/97 and some activities related to the SANS instrument. Since, up to now, we have not yet received any progresses reported from either China or Malaysia, this report will describe the progress of SANS`s activities in BATAN only. (author)

User's guide for the small-angle neutron scattering facility

International Nuclear Information System (INIS)

Vlak, W.A.H.M.; Werkhoven, E.J.

1989-04-01

This report serves as a manual for the users of the small-angle neutron scattering instrument located at beamport HB3 of the High Flux Reactor in Petten. The main part of the text is devoted to the control of the facility and the data handling by means of a μVAX computer. Also, the various possibilities to access the facility across computer networks are discussed. A collection of menu-driven and command-driven programs, which utilize the flexibility of the VMS operating system without requiring detailed knowledge of the user about the computer environment, enables to control the instrument. For the convenience of the experienced user, who might wish to update or extend the software, a technical supplement is included. 15 figs.; 8 refs

Time-of-flight small-angle-neutron-scattering data reduction and analysis at LANSCE (Los Alamos Neutron Scattering Center) with program SMR

International Nuclear Information System (INIS)

Hjelm, R.P. Jr.; Seegar, P.A.

1989-01-01

A user-friendly, integrated system, SMR, for the display, reduction and analysis of data from time-of-flight small-angle neutron diffractometers is described. Its purpose is to provide facilities for data display and assessment and to provide these facilities in near real time. This allows the results of each scattering measurement to be available almost immediately, and enables the experimenter to use the results of a measurement as a basis for other measurements in the same instrument allocation. 8 refs., 11 figs

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

On small-angle neutron scattering from microemulsion droplets: the role of shape fluctuations

International Nuclear Information System (INIS)

Lisy, V.; Brutovsky, B.

2001-01-01

The form factor and intensity of static neutron scattering from microemulsion droplets are calculated. The droplet is modeled by a double-layered sphere consisting of a fluid core and a thin surfactant layer, immersed in another fluid. All the three components are incompressible and characterized by different scattering length densities. As distinct from previous descriptions of small-angle neutron scattering (SANS), we consistently take into account thermal fluctuations of the droplet shape, to the second order of the fluctuations of the droplet radius. The properties of the layer are described within Helfrich's concept of the elasticity of curved interfaces. It is shown that in many cases the account for the fluctuations is essential for the interpretation of SANS. Information about two elastic constants k and k bar (so far extracted from the experiments in the combination 2k + k bar) can be now simultaneously obtained from SANS for the system in conditions of two-phase coexistence. As an illustration, the theory is applied for the quantitative description of SANS experiments from the literature

Q resolution calculation of small angle neutron scattering spectrometer and analysis of form factor

International Nuclear Information System (INIS)

Chen Liang; Peng Mei; Wang Yan; Sun Liangwei; Chen Bo

2011-01-01

The calculational methods of Small Angle Neutron Scattering (SANS) spectrometer Q resolution function and its correlative Q standard difference were introduced. The effects of Q standard difference were analysed with the geometry lay out of spectrometer and the spread of neutron wavelength. The one dimension Q resolution Gaussian function were analysed. The form factor curve of ideal solid sphere and two different instrument arrangement parameter was convoluted respectively and the different smearing curve of form factor was obtained. The combination of using the Q resolution function to more accurately analysis SANS data. (authors)

Study on porosity of ceramic SiC using small angle neutron scattering

International Nuclear Information System (INIS)

Li Jizhou; Yang Jilian; Kang Jian; Ye Chuntang

1996-01-01

The mechanical properties of functional heat-resistant ceramics SiC are significantly influenced by the concentration and dimensions of pores. Small angle neutron scattering measurements for 3 SiC samples with different densities are performed on C1-2 SANS instrument of the University of Tokyo. Two groups of the neutron data are obtained using 8 and 16 m of secondary flight path, 1 and 0.7 nm of neutron wave lengths, respectively. After deduction of background measurement and transmission correction, both neutron data are linked up with each other. The patterns of neutron data of 3 samples with Q range from 0.028∼0.5 nm -1 are almost with axial symmetry, showing that the shape of pores is almost spherical. Using Mellin transform, size distributions of pores in 3 samples are obtained. The average size (∼19 nm) of pores for hot-pressed SiC sample with higher density is smaller than the others (∼ 21 nm). It seems to be the reason why the density of hot-pressed SiC sample is higher than not hot-pressed sample

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

Recent developments in X-ray and neutron small-angle scattering instrumentation and data analysis

International Nuclear Information System (INIS)

Schelten, J.

1978-01-01

The developments in instrumentation and data analysis that have occurred in the field of small-angle X-ray and neutron scattering since 1973 are reviewed. For X-rays, the cone camera collimation was invented, synchrotrons and storage rings were demonstrated to be intense sources of X-radiation, and one- and two-dimensional position-sensitive detectors were interfaced to cameras with both point and line collimation. For neutrons, the collimators and detectors on the Juelich and Grenoble machines were improved, new D11-type instruments were built or are under construction at several sites, double-crystal instruments were set up, and various new machines have been proposed. Significant progress in data analysis and evaluation has been made through application of mathematical techniques such as the use of spline functions, error minimization with constraints, and linear programming. Several special experiments, unusual in respect to the anisotropy of the scattering pattern, gravitational effects, moving scatterers, and dynamic fast time slicing, are discussed. (Auth.)

Structure of polyacrylic acid and polymethacrylic acid solutions: a small angle neutron scattering study

Energy Technology Data Exchange (ETDEWEB)

Moussaid, A. (Lab. d' Ultrasons et de Dynamique des Fluides Complexes, Univ. Louis Pasteur, 67 - Strasbourg (France)); Schosseler, F. (Lab. d' Ultrasons et de Dynamique des Fluides Complexes, Univ. Louis Pasteur, 67 - Strasbourg (France)); Munch, J.P. (Lab. d' Ultrasons et de Dynamique des Fluides Complexes, Univ. Louis Pasteur, 67 - Strasbourg (France)); Candau, S.J. (Lab. d' Ultrasons et de Dynamique des Fluides Complexes, Univ. Louis Pasteur, 67 - Strasbourg (France))

1993-04-01

The intensity scattered from polyacrylic acid and polymethacrylic acid solutions has been measured by small angle neutron scattering experiments. The influence of polymer concentration, ionization degree, temperature and salt content has been investigated. Results are in qualitative agreement with a model which predicts the existence of microphases in the unstable region of the phase diagram. Quantitative comparison with the theory is performed by fitting the theoretical structure factor to the experimental data. For a narrow range of ionization degrees nearly quantitative agreement with the theory is found for the polyacrylic acid system. (orig.).

Structure of polyacrylic acid and polymethacrylic acid solutions : a small angle neutron scattering study

Science.gov (United States)

Moussaid, A.; Schosseler, F.; Munch, J. P.; Candau, S. J.

1993-04-01

The intensity scattered from polyacrylic acid and polymethacrylic acid solutions has been measured by small angle neutron scattering experiemnts. The influence of polymer concentration, ionization degree, temperature and salt content has been investigated. Results are in qualitative agreement with a model which predicts the existence of microphases in the unstable region of the phase diagram. Quantitative comparison with the theory is performed by fitting the theoretical structure factor to the experimental data. For a narrow range of ionizaiton degrees nearly quantitative agreement with the theory is found for the polyacrylic acide system.

Neutron small-angle scattering study of phase decomposition in Au-Pt

International Nuclear Information System (INIS)

Singhal, S.P.; Herman, H.

1978-01-01

Isothermal decomposition of a Au-60 at.% Pt alloy, quenched from the solid as well as the liquid state, has been studied with the D11 neutron small-angle scattering spectrometer at ILL, Grenoble. An incident neutron wavelength of 6.7 A was used and measurements were carried out in the range of scattering vector [β=4π sin theta/lambda] from 2.8x10 -2 to 21x10 -2 A -1 . The preliminary results indicate that decomposition of this alloy at 550 0 C takes place by a spinodal mode, although deviations were observed from linear spinodal theory, even at very early times. Slower aging kinetics were observed in liquid-quenched alloy as compared with solid-quenched. Liquid quenching is more efficient in suppressing quench clustering than is solid quenching. However, liquid quenching yields an extremely fine-grained material, which thereby enhances discontinuous precipitation at grain boundaries, competing with decomposition in the bulk. A Rundman-Hilliard analysis was used for the early stages of the spinodal reaction to obtain an interdiffusion coefficient of the order of 10 -16 cm 2 s -1 at 550 0 C for the solid-quenched alloy. (Auth.)

Polymer boosting effect in the droplet phase studied by small-angle neutron scattering

CERN Document Server

Frielinghaus, H; Allgaier, J; Richter, D; Jakobs, B; Sottmann, T; Strey, R

2002-01-01

Small-angle neutron-scattering experiments were performed in order to obtain the six partial scattering functions of a droplet microemulsion containing water, decane, C sub 1 sub 0 E sub 4 surfactant and PEP sub 5 -PEO sub 8 sub 0. We systematically varied the contrast around the polymer contrast, where only the polymer becomes visible, and we also measured bulk and film contrasts. With the singular value decomposition method we could extract the desired six partial scattering functions from the 15 measured spectra. We find a sphere-shell-shell structure of the droplets, where the innermost sphere consists of oil, the middle shell of surfactant and the outer shell is a depletion zone where the polymer is almost not present. (orig.)

Effects of pressure and temperature on pore structure of ceramic synthesized from rice husk: A small angle neutron scattering investigation

Energy Technology Data Exchange (ETDEWEB)

Raut Dessai, R., E-mail: reshooin@yahoo.com [Department of Physics, Goa University, Taleigao Plateau, Goa 403 206 (India); Desa, J.A.E. [Department of Physics, Goa University, Taleigao Plateau, Goa 403 206 (India); Sen, D.; Mazumder, S. [Solid State Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India)

2013-07-05

Highlights: ► A porous ceramic has been prepared from silica obtained from rice husk. ► The ceramic has a hierarchical pore structure from micrometric to nano-metric. ► Small Angle Neutron Scattering data indicate nano-pore connectivity to micro-pores. ► Pore morphology can be tuned by compaction pressure and sintering temperature. -- Abstract: Ceramic powder has been synthesized from rice husk as the source of silica. In order to probe the evolution of its hierarchical mesoscopic and microscopic porous structure, the ceramic powder was compacted at different pressures and was sintered at different temperatures. A glassy ceramic to crystalline transition under thermal treatment (up to 1000 °C) was revealed by X-ray diffraction. Existence of pores in two widely separated length scales was indicated by small angle neutron scattering with the smaller ones having mass fractal arrangement. Although no significant change in small pore structure under thermal effect was indicated, a significant modification of the same has been revealed by small angle neutron scattering at different compaction pressures. Connectivity between the pores was ascertained from scattering experiments on the ceramic compact impregnated with heavy water. Scanning electron microscopy shows the microstructure to undergo appreciable coalescence of micrometric ceramic particles for sintering temperature and pressure changes.

Structure and dynamics of nonaqueous electrolyte solutions by small angle neutron scattering, brownian dynamics and primitive model theories

International Nuclear Information System (INIS)

Kunz, W.; Turq, P.

1990-01-01

The study of electrolyte solutions by small angle neutron scattering (static) of quasi-elastic neutron scattering (dynamics) gives new perspectives to the primitive model of electrolytes, for both static and dynamic properties of those systems. Whereas all properties can be interpreted by brownian dynamics, integral equations cannot be used at the present time to get transport coefficients in all cases. As regards the choice of the potentials at the McMillan Mayer level, specific Gurney terms for solvation are not needed for tetraalkylammonium salts. (orig.)

Small-angle neutron scattering from multilamellar lipid bilayers: Theory, model, and experiment

DEFF Research Database (Denmark)

Lemmich, Jesper; Mortensen, Kell; Ipsen, John Hjorth

1996-01-01

Small-angle neutron scattering data obtained from fully hydrated, multilamellar phospholipid bilayers with deuterated acyl chains of different length are presented and analyzed within a paracrystalline theory and a geometric model that permit the bilayer structure to be determined under conditions...... of temperature for the lamellar repeat distance, the hydrophobic bilayer thickness, as well as the thickness of the aqueous and polar head group region. In addition to these geometric parameters the analysis permits determination of molecular cross-sectional area, number of interlamellar water molecules, as well...

The very low angle detector for high-energy inelastic neutron scattering on the VESUVIO spectrometer

International Nuclear Information System (INIS)

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

2008-01-01

The Very Low Angle Detector (VLAD) bank has been installed on the VESUVIO spectrometer at the ISIS spallation neutron source. The new device allows for high-energy inelastic neutron scattering measurements, at energies above 1 eV, maintaining the wave vector transfer lower than 10A -1 . This opens a still unexplored region of the kinematical (q,ω) space, enabling new and challenging experimental investigations in condensed matter. This paper describes the main instrumental features of the VLAD device, including instrument design, detector response, and calibration procedure

The very low angle detector for high-energy inelastic neutron scattering on the VESUVIO spectrometer

Science.gov (United States)

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

2008-05-01

The Very Low Angle Detector (VLAD) bank has been installed on the VESUVIO spectrometer at the ISIS spallation neutron source. The new device allows for high-energy inelastic neutron scattering measurements, at energies above 1 eV, maintaining the wave vector transfer lower than 10Å-1. This opens a still unexplored region of the kinematical (q, ω) space, enabling new and challenging experimental investigations in condensed matter. This paper describes the main instrumental features of the VLAD device, including instrument design, detector response, and calibration procedure.

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.

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).

A verification scenario of nuclear plus interference scattering effects using neutron incident angle distribution to the wall in beam-injected deuterium plasmas

International Nuclear Information System (INIS)

Sugiyama, Shota; Matsuura, Hideaki; Uchiyama, Daisuke; Sawada, Daisuke; Watanabe, Tsuguhiro; Goto, Takuya; Mitarai, Osamu

2015-01-01

A verification scenario of knock-on tail formation in the deuteron distribution function due to nuclear plus interference scattering is presented by observing the incident angle distribution of neutrons in a vacuum vessel. Assuming a knock-on tail created in a "3He-beam-injected deuterium plasma, the incident angle distribution and energy spectra of the neutrons produced by fusion reactions between 1-MeV and thermal deuterons are evaluated. The relation between the neutron incident angle to the vacuum vessel and neutron energy is examined in the case of anisotropic neutron emission due to knock-on tail formation in neutral-beam-injected plasmas. (author)

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

Particle size distribution models of small angle neutron scattering pattern on ferro fluids

International Nuclear Information System (INIS)

Sistin Asri Ani; Darminto; Edy Giri Rachman Putra

2009-01-01

The Fe 3 O 4 ferro fluids samples were synthesized by a co-precipitation method. The investigation of ferro fluids microstructure is known to be one of the most important problems because the presence of aggregates and their internal structure influence greatly the properties of ferro fluids. The size and the size dispersion of particle in ferro fluids were determined assuming a log normal distribution of particle radius. The scattering pattern of the measurement by small angle neutron scattering were fitted by the theoretical scattering function of two limitation models are log normal sphere distribution and fractal aggregate. Two types of particle are detected, which are presumably primary particle of 30 Armstrong in radius and secondary fractal aggregate of 200 Armstrong with polydispersity of 0.47 up to 0.53. (author)

Small Angle Neutron Scattering (SANS) characterization of electrically conducting polyaniline nanofiber/polyimide nanocomposites

Energy Technology Data Exchange (ETDEWEB)

Hopkins, Alan R., E-mail: alan.r.hopkins@aero.org [Aerospace Corporation, Space Materials Lab, Micro/Nano Technology Dept, Polymers Section, M2/242, Los Angeles, CA 90009-2957 (United States); Tomczak, Sandra J. [AFRL/RZSM Materials Application Branch, Space and Missile Propulsion Division 10 East Saturn Blvd., Bldg. 8451, Edwards Air Force Base, CA 93524 (United States); Vij, Vandana [ERC. Inc., AFRL/PRSM, Edwards AFB, CA (United States); Jackson, Andrew J. [National Institute of Standards and Technology (NIST) Center for Neutron Research, 100 Bureau Drive, Stop 6102, Gaithersburg, MD 20899-6102 (United States)

2011-12-30

Nanocomposites of polyaniline nanofibers and polyimide were fabricated and studied using small angle neutron scattering (SANS). The immiscible nature of the conformationally dissimilar polyaniline nanofiber and polyimide host is established by a series of experiments involving neutron scattering. Based on these techniques, we conclude that the crystal structure of the polyimides is not disrupted, and that there is no mixing between the two components on a molecular level. The morphology of the conducting salt component was analyzed by SANS data and was treated by two common models: Debye-Bueche (D-B) and inverse power law (IPL). Due to deviations in the linear curve fitting over a large scattering range, neither the D-B nor the IPL model could be used to characterize the size and shape of all PANI-0.5-CSA (polyaniline camphor sulfonic acid doped polymer)/polyimide blend systems. At 1 and 2% concentration, the D-B model suggested salt domains between 20 and 70 A with fractal geometries implied by the IPL model. As salt concentrations increased to 5%, the structures were observed to change, but there is no simple structural model that provides a suitable basis for comparison.

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

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)

The very low angle detector for high-energy inelastic neutron scattering on the VESUVIO spectrometer

Energy Technology Data Exchange (ETDEWEB)

Perelli Cippo, E.; Gorini, G.; Tardocchi, M. [Dipartimento di Fisica ' G. Occhialini' , Universita degli Studi di Milano-Bicocca, Piazza della Scienza 3, 20126 Milano (Italy); Pietropaolo, A. [Dipartimento di Fisica ' G. Occhialini' , CNISM-Universita degli Studi di Milano-Bicocca, Piazza della Scienza 3, 20126 Milano (Italy); NAST Center - Nanoscienze-Nanotecnologie-Strumentazione, Universita degli Studi di Roma Tor Vergata, via della Ricerca Scientifica 1, 00133 Roma (Italy)], E-mail: antonino.pietropaolo@mib.infn.it; Andreani, C.; Senesi, R. [Dipartimento di Fisica and Centro NAST - Nanoscienze-Nanotecnologie-Strumentazione, Universita degli Studi di Roma Tor Vergata, via della Ricerca Scientifica 1, 00133 Roma (Italy); Rhodes, N.J.; Schooneveld, E.M. [ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire 0QX OX11 (United Kingdom)

2008-05-01

The Very Low Angle Detector (VLAD) bank has been installed on the VESUVIO spectrometer at the ISIS spallation neutron source. The new device allows for high-energy inelastic neutron scattering measurements, at energies above 1 eV, maintaining the wave vector transfer lower than 10A{sup -1}. This opens a still unexplored region of the kinematical (q,{omega}) space, enabling new and challenging experimental investigations in condensed matter. This paper describes the main instrumental features of the VLAD device, including instrument design, detector response, and calibration procedure.

Microstructural characterization of a modified 706-type Ni-Fe superalloy by small-angle neutron scattering and electron microscopy

Czech Academy of Sciences Publication Activity Database

Del Genovese, D.; Strunz, Pavel; Mukherji, D.; Gilles, R.; Rösler, J.

36A, - (2005), s. 3439-3450 ISSN 1073-5623 Institutional research plan: CEZ:AV0Z10480505 Keywords : superalloys * small-angle neutron scattering Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.232, year: 2005

Small-angle neutron scattering studies of the template-mediated crystallization of ZSM-5 type zeolite

International Nuclear Information System (INIS)

Iton, L.E.; Brun, T.O.; Epperson, J.E.

1988-03-01

Small-angle neutron scattering is a useful new approach to the study of zeolite crystallization from aluminosilicate gels and the action of template molecules. It has been applied to gels for synthesis of zeolite ZSM-5 using tetrapropylammonium ions as templates where the scattering length densities of the gel particles and their texture were determined using contrast variation methods. Gels formulated from soluble silicate incorporate template molecules promptly into an amorphous ''embryonic'' structure and crystallization ensues via a solid hydrogel transformation mechanism. Gels formulated from colloidal silica show different scattering behavior, and a liquid phase transport mechanism is inferred. 8 refs., 4 figs., 2 tabs

Small angle neutron and x-ray scattering studies of self-assembled nano structured materials

International Nuclear Information System (INIS)

Choi, Sung Min

2009-01-01

Full text: Small angle neutron and x-ray scattering are very powerful techniques to investigate nano structured materials. In this presentation, examples of nano structured materials investigated by neutron and x-ray scattering will be presented. Part I: The unique anisotropic physical properties of columnar discotic liquid crystals (DLCs) have attracted considerable interest for their potential applications as electronic devices. For many practical applications, however, it is crucial to obtain uniaxially oriented and highly ordered columnar superstructures of DLC molecules covering macroscopic area. Here, we present a simple and straight-forward approach to fabricate uniaxially oriented and highly ordered columnar superstructures of cobalt octa(n-decylthio) porphyrazine (CoS 1 0), a discotic supra-molecule, in bulk and on substrates [1] over a macroscopic length scale, utilizing an applied magnetic field and the interaction of CoS 1 0 with an OTS-functionalized substrate. The details of the oriented and ordered columnar nano-structures are investigated by SANS and GISAXS. Part II: Self-assembly of one-dimensional (1D) nanoparticles with metallic or semiconducting properties into highly ordered superstructures using various interactions has been of great interest as a route towards materials with new functionalities. Here, we report a new phase diagram of negatively charged 1D nanoparticle (cROD) and cationic liposome (CL) complexes in water which exhibit three different highly ordered phases [2]. Small angle neutron and x-ray scattering measurements show that the cROD-CL complexes exhibit three different highly ordered phases, intercalated lamellar, doubly intercalated lamellar and centered rectangular phases, depending on particle curvature and electrostatic interactions. The new phase diagram can be used to understand and design new highly ordered self-assemblies of 1D nanoparticles in soft matter which provide new functionalities. (author)

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)

Domain interaction in rabbit muscle pyruvate kinase. II. Small angle neutron scattering and computer simulation.

Science.gov (United States)

Consler, T G; Uberbacher, E C; Bunick, G J; Liebman, M N; Lee, J C

1988-02-25

The effects of ligands on the structure of rabbit muscle pyruvate kinase were studied by small angle neutron scattering. The radius of gyration, RG, decreases by about 1 A in the presence of the substrate phosphoenolpyruvate, but increases by about the same magnitude in the presence of the allosteric inhibitor phenylalanine. With increasing pH or in the absence of Mg2+ and K+, the RG of pyruvate kinase increases. Hence, there is a 2-A difference in RG between two alternative conformations. Length distribution analysis indicates that, under all experimental conditions which increase the radius of gyration, there is a pronounced increase observed in the probability for interatomic distance between 80 and 110 A. These small angle neutron scattering results indicate a "contraction" and "expansion" of the enzyme when it transforms between its active and inactive forms. Using the alpha-carbon coordinates of crystalline cat muscle pyruvate kinase, a length distribution profile was calculated, and it matches the scattering profile of the inactive form. These observations are expected since the crystals were grown in the absence of divalent cations (Stuart, D. I., Levine, M., Muirhead, H., and Stammers, D. K. (1979) J. Mol. Biol. 134, 109-142). Hence, results from neutron scattering, x-ray crystallographic, and sedimentation studies (Oberfelder, R. W., Lee, L. L.-Y., and Lee, J.C. (1984) Biochemistry 23, 3813-3821) are totally consistent with each other. With the aid of computer modeling, the crystal structure has been manipulated in order to effect changes that are consistent with the conformational change described by the solution scattering data. The structural manipulation involves the rotation of the B domain relative to the A domain, leading to the closure of the cleft between these domains. These manipulations resulted in the generation of new sets of atomic (C-alpha) coordinates, which were utilized in calculations, the result of which compared favorably with the

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

Spin-wave dynamics in Invar Fe65Ni35 studied by small-angle polarized neutron scattering

NARCIS (Netherlands)

Brück, E.H.; Grigoriev, S.V.; Deriglazov, V.V.; Okorokov, A.I.; Dijk van, N.H.; Klaasse, J.C.P.

2002-01-01

Abstract. Spin dynamics in Fe65Ni35 Invar alloy has been studied by left-right asymmetry of small-angle polarized neutron scattering below TC=485 K in external magnetic fields of H=0.05-0.25 T inclined relative to the incident beam. The spin-wave stiffness D and the damping & were obtained by

Analysis of the nano-scale structure of a natural clayey soil using the small angle neutron scattering method

International Nuclear Information System (INIS)

Itakura, T.; Bertram, W.K.; Hathaway, P.V.; Knott, R.B.

2001-01-01

The small angle neutron scattering method (SANS) was used to analyze the nano-structure of a natural clayey soil used for containment of industrial liquid wastes. A Tertiary clay deposit called the Londonderry clay was used to contain the wastes in a state-run landfill facility in NSW. A number of site assessments have been carried out at the site and continual efforts have been made to characterize interactions between soil materials and contaminants at the site. Hence, it is of research and practical interest to investigate the effects of deformation on the nano-scale structure of the soil. Experiments have been conducted to analyze the structure of reconstituted clayey soil samples that were subjected to uniaxial compression ranging from 200 kPa to 800 kPa. The small angle neutron scattering instrument was used to measure the scattering intensity of these samples at a scattering vector (q) range between 0.01 and 0.1 Angstroms -1 . The sector integration technique was used to analyse elliptical scattering patterns along the major and minor axes. A relation between stress, void ratio and nano-scale structure properties was then briefly discussed for use in assessing the performance of clayey soils as in situ barriers

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

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

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.)

Enhancement of graphic user interface data acquisition of small angle neutron scattering

International Nuclear Information System (INIS)

Abd Aziz Muhammad; Abd Jalil Abd Hamid

2004-01-01

This paper discusses the activities of the development of data acquisition software for PC, which capable of controlling instrument via IEEE-488 and graphic visualization for small angle neutron scattering (SANS) runs in DOS mode. With the help of outstanding free ware graphic library for DOS, this software has enhanced the efficiency of graphic visualization for SANSLab data acquisition. Featuring easy-to-use graphical user interface (GUI) and several other built-in tools for convenience, this software can be manipulated with the mouse or the keyboard. This software can be converted into an inexpensive data acquisition system for SANS. (Author)

A new small-angle neutron scattering spectrometer at China Mianyang research reactor

Energy Technology Data Exchange (ETDEWEB)

Peng, Mei, E-mail: pm740509@163.com; Sun, Liangwei; Chen, Liang; Sun, Guangai; Chen, Bo; Xie, Chaomei; Xia, Qingzhong; Yan, Guanyun; Tian, Qiang; Huang, Chaoqiang; Pang, Beibei; Zhang, Ying; Wang, Yun; Liu, Yaoguang; Kang, Wu; Gong, Jian

2016-02-21

A new pinhole small-angle neutron scattering (SANS) spectrometer, installed at the cold neutron source of the 20 MW China Mianyang Research Reactor (CMRR) in the Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, has been put into use since 2014. The spectrometer is equipped with a multi-blade mechanical velocity selector, a multi-beam collimation system, and a two-dimensional He-3 position sensitive neutron detector. The q-range of the spectrometer covers from 0.01 nm{sup −1} to 5.0 nm{sup −1}. In this paper, the design and characteristics of the SANS spectrometer are described. The q-resolution calculations, together with calibration measurements of silver behenate and a dispersion of nearly monodisperse poly-methyl-methacrylate nanoparticles indicate that our SANS spectrometer has a good performance and is now in routine service. - Highlights: • A new SANS spectrometer has been put into use since 2014 in China. • One MBR selector possesses a higher resolution compared with traditional selector is used. • The spectrometer has a good performance and is now in routinely service.

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

CERN Document Server

Gazeau, F; Dubois, E; Perzynski, R

2003-01-01

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

The neutron small-angle camera D11 at the high-flux reactor, Grenoble

International Nuclear Information System (INIS)

Ibel, K.

1976-01-01

The neutron small-angle scattering system at the high-flux reactor in Grenoble consists of three major parts: the supply of cold neutrons via bent neutron guides; the small-angle camera D11; and the data handling facilities. The camera D11 has an overall length of 80 m. The effective length of the camera is variable. The full length of the collimator before the fixed sample position can be reduced by movable neutron guides; the second flight path of 40 m full length contains detector sites in various positions. Thus a large range of momentum transfers can be used with the same relative resolution. Scattering angles between 5 x 10 -4 and 0.5 rad and neutron wavelengths from 0.2 to 2.0 nm are available. A large-area position-sensitive detector is used which allows simultaneous recording of intensities scattered at different angles; it is a multiwire proportional chamber. 3808 elements of 1 cm 2 are arranged in a two-dimensional matrix. (Auth.)

Characterization of Nanocellulose Using Small-Angle Neutron, X-ray, and Dynamic Light Scattering Techniques.

Science.gov (United States)

Mao, Yimin; Liu, Kai; Zhan, Chengbo; Geng, Lihong; Chu, Benjamin; Hsiao, Benjamin S

2017-02-16

Nanocellulose extracted from wood pulps using TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl radical)-mediated oxidation and sulfuric acid hydrolysis methods was characterized by small-angle neutron scattering (SANS), small-angle X-ray scattering (SAXS), and dynamic light scattering (DLS) techniques. The dimensions of this nanocellulose (TEMPO-oxidized cellulose nanofiber (TOCN) and sulfuric acid hydrolyzed cellulose nanocrystal (SACN)) revealed by the different scattering methods were compared with those characterized by transmission electron microscopy (TEM). The SANS and SAXS data were analyzed using a parallelepiped-based form factor. The width and thickness of the nanocellulose cross section were ∼8 and ∼2 nm for TOCN and ∼20 and ∼3 nm for SACN, respectively, where the fitting results from SANS and SAXS profiles were consistent with each other. DLS was carried out under both the V V mode with the polarizer and analyzer parallel to each other and the H V mode having them perpendicular to each other. Using rotational and translational diffusion coefficients obtained under the H V mode yielded a nanocellulose length qualitatively consistent with that observed by TEM, whereas the length derived by the translational diffusion coefficient under the V V mode appeared to be overestimated.

Small angle neutron scattering measurements of magnetic cluster sizes in magnetic recorging disks

CERN Document Server

Toney, M

2003-01-01

We describe Small Angle Neutron Scattering measurements of the magnetic cluster size distributions for several longitudinal magnetic recording media. We find that the average magnetic cluster size is slightly larger than the average physical grain size, that there is a broad distribution of cluster sizes, and that the cluster size is inversely correlated to the media signal-to-noise ratio. These results show that intergranular magnetic coupling in these media is small and they provide empirical data for the cluster-size distribution that can be incorporated into models of magnetic recording.

Study of chemically unfolded β-casein by means of small-angle neutron scattering

International Nuclear Information System (INIS)

Aschi, Adel; Gharbi, Abdelhafidh; Daoud, Mohamed; Douillard, Roger; Calmettes, Patrick

2007-01-01

β-casein is a flexible amphiphilic milk protein which forms an unfolded conformation in presence of very high denaturant concentrations. The structure of β-casein formed at the bulk was studied by small-angle neutron scattering (SANS). The value of the second virial coefficient of the protein solutions indicates that the interactions between the polypeptide chain and solvent are repulsive. The protein conformation is similar to an excluded volume chain. The corresponding values of the contour length, L, the statistical length, b and the apparent radius of the chain cross-section, R c are given

Membrane Structure Studies by Means of Small-Angle Neutron Scattering (SANS)

International Nuclear Information System (INIS)

Knott, R. B.

2008-01-01

summary of membrane structure will be followed by an outline of the neutron scattering techniques used to understand membrane structure and dynamics. The emphasis will be on the small angle neutron scattering technique since there is a very powerful instrument at Serpong, however brief mention of other techniques will be included to demonstrate how a multidisciplinary approach is usually required

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.

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.)

Solutions for implementing time-of-flight techniques in low-angle neutron scattering, as realized on the Low-Q Diffractometer at Los Alamos

International Nuclear Information System (INIS)

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

1992-01-01

The implementation of small-angle (Low-momentum transfer) neutron scattering at pulsed spallation sources, using time of flight methods, has meant the introduction of some new ideas in instrument design, data acquisition, data reduction and computer management of the experiment and the data. Here we recount some of the salient aspects of solutions for implementing time of fight small-angle neutron scattering instruments at pulsed sources, as realized on the Low-Q Diffractometer, LQD, at Los Alamos. We consider, fortlier, some of the problems that are yet to be solved, and take a short excursion into the future of SANS instrumentation at pulsed sources

Characterization of the dimensions of colloidal calcium carbonate dispersions in toluene with neutron small-angle scattering

International Nuclear Information System (INIS)

Vlak, W.A.H.M.; Dorrepaal, J.

1987-02-01

Calcium carbonate particles, stabilized by a surface layer, and dispersed in toluene are investigated with neutron small-angle scattering. Estimates for the dimensions of the core particle and the layer have been obtained: the layer thickness is 8.6 A and the core particle radius is 16.5 A. The limits within which these results are valid are indicated. (Auth.)

Project study of a small-angle neutron scattering apparatus

International Nuclear Information System (INIS)

Schedler, E.; Pollet, J.L.

1979-03-01

This design study deals with the set up of a low angle scattering apparatus in the HMI reactor hall in Berlin. The experiences of other institutes with facilities of a similar type, - especially with D11 and D17 of the ILL in Grenoble, the set up the KFA in Juelich and of the PTB in Braunschweig -, are included to a large extend. The aim of this paper is - to define the necessary boundary conditions for the construction (including: installation of a cold source, the beam line, the neutron guide pipe and an extention of the reactor hall), -to determine the properties of the planned apparatus, especially in comparison with D11, probably the most versatile instrument, - to make desitions for the design of the components, - to work out the detailed drawings for construction - to estimate the costs and the time necessary for construction, if industrial manufacturers set up the project. (orig.) [de

A microstructural comparison of two nuclear-grade martensitic steels using small-angle neutron scattering

Science.gov (United States)

Coppola, R.; Fiori, F.; Little, E. A.; Magnani, M.

1997-06-01

Results are presented of a small-angle neutron scattering (SANS) study on two 10-13% Cr martensitic stainless steels of interest for nuclear applications, viz. DIN 1.4914 (MANET specification, for fusion reactors) and AISI 410. The investigation has focussed principally on microstructural effects associated with the differences in chromium content between the two alloys. The size distribution functions determined from nuclear and magnetic SANS components for the two steels given identical heat treatments are in accord with an interpretation based on the presence of ˜ 1 nm size CCr aggregates in the microstructure. Much larger (˜ 10 nm) scattering inhomogeneities with different magnetic contrast are also present and tentatively identified as carbides.

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.

Kappa-casein micelles: structure, interaction and gelling studied by small-angle neutron scattering.

Science.gov (United States)

de Kruif, C G; May, R P

1991-09-01

Small-angle neutron scattering (SANS) measurements on dilute and concentrated dispersions of kappa-casein micelles in a buffer at pH = 6.7 were made using the D11 diffractometer in Grenoble. Results indicate that the micelles have a dense core with a fluffy outer layer. This outer layer appears to give rise to a steeply repulsive interaction on contact. In fact, the hard-sphere model best fits the measured scattering intensities. Adding chymosin to the dispersion initiated a fractal flocculation of the micelles and consecutively a coalescence of the micelles. This unexpected second process resembled that of spinodal demixing. The dispersion phase thus separates into a water and a protein phase on a time scale of hours. The observed phenomona contribute to the understanding of the cheese-making process.

Branch Point Withdrawal in Elongational Startup Flow by Time-Resolved Small Angle Neutron Scattering

KAUST Repository

Ruocco, N.

2016-05-27

We present a small angle neutron scattering (SANS) investigation of a blend composed of a dendritic polymer and a linear matrix with comparable viscosity in start-up of an elongational flow at Tg + 50. The two-generation dendritic polymer is diluted to 10% by weight in a matrix of a long well-entangled linear chains. Both components consist of mainly 1,4-cis-polyisoprene but differ in isotopic composition. The resulting scattering contrast is sufficiently high to permit time-resolved measurements of the system structure factor during the start-up phase and to follow the retraction processes involving the inner sections of the branched polymer in the nonlinear deformation response. The outer branches and the linear matrix, on the contrary, are in the linear deformation regime. The linear matrix dominates the rheological signature of the blend and the influence of the branched component can barely be detected. However, the neutron scattering intensity is predominantly that of the (branched) minority component so that its dynamics is clearly evident. In the present paper, we use the neutron scattering data to validate the branch point withdrawal process, which could not be unambiguously discerned from rheological measurements in this blend. The maximal tube stretch that the inner branches experience, before the relaxed outer arm material is incorporated into the tube is determined. The in situ scattering experiments demonstrate for the first time the leveling-off of the strain as the result of branch point withdrawal and chain retraction directly on the molecular level. We conclude that branch point motion in the mixture of architecturally complex polymers occurs earlier than would be expected in a purely branched system, presumably due to the different topological environment that the linear matrix presents to the hierarchically deep-buried tube sections. © 2016 American Chemical Society.

Branch Point Withdrawal in Elongational Startup Flow by Time-Resolved Small Angle Neutron Scattering

KAUST Repository

Ruocco, N.; Auhl, D.; Bailly, C.; Lindner, P.; Pyckhout-Hintzen, W.; Wischnewski, A.; Leal, L. G.; Hadjichristidis, Nikolaos; Richter, D.

2016-01-01

We present a small angle neutron scattering (SANS) investigation of a blend composed of a dendritic polymer and a linear matrix with comparable viscosity in start-up of an elongational flow at Tg + 50. The two-generation dendritic polymer is diluted to 10% by weight in a matrix of a long well-entangled linear chains. Both components consist of mainly 1,4-cis-polyisoprene but differ in isotopic composition. The resulting scattering contrast is sufficiently high to permit time-resolved measurements of the system structure factor during the start-up phase and to follow the retraction processes involving the inner sections of the branched polymer in the nonlinear deformation response. The outer branches and the linear matrix, on the contrary, are in the linear deformation regime. The linear matrix dominates the rheological signature of the blend and the influence of the branched component can barely be detected. However, the neutron scattering intensity is predominantly that of the (branched) minority component so that its dynamics is clearly evident. In the present paper, we use the neutron scattering data to validate the branch point withdrawal process, which could not be unambiguously discerned from rheological measurements in this blend. The maximal tube stretch that the inner branches experience, before the relaxed outer arm material is incorporated into the tube is determined. The in situ scattering experiments demonstrate for the first time the leveling-off of the strain as the result of branch point withdrawal and chain retraction directly on the molecular level. We conclude that branch point motion in the mixture of architecturally complex polymers occurs earlier than would be expected in a purely branched system, presumably due to the different topological environment that the linear matrix presents to the hierarchically deep-buried tube sections. © 2016 American Chemical Society.

Preparing Monodisperse Macromolecular Samples for Successful Biological Small-Angle X-ray and Neutron Scattering Experiments

Science.gov (United States)

Jeffries, Cy M.; Graewert, Melissa A.; Blanchet, Clément E.; Langley, David B.; Whitten, Andrew E.; Svergun, Dmitri I

2017-01-01

Small-angle X-ray and neutron scattering (SAXS and SANS) are techniques used to extract structural parameters and determine the overall structures and shapes of biological macromolecules, complexes and assemblies in solution. The scattering intensities measured from a sample contain contributions from all atoms within the illuminated sample volume including the solvent and buffer components as well as the macromolecules of interest. In order to obtain structural information, it is essential to prepare an exactly matched solvent blank so that background scattering contributions can be accurately subtracted from the sample scattering to obtain the net scattering from the macromolecules in the sample. In addition, sample heterogeneity caused by contaminants, aggregates, mismatched solvents, radiation damage or other factors can severely influence and complicate data analysis so it is essential that the samples are pure and monodisperse for the duration of the experiment. This Protocol outlines the basic physics of SAXS and SANS and reveals how the underlying conceptual principles of the techniques ultimately ‘translate’ into practical laboratory guidance for the production of samples of sufficiently high quality for scattering experiments. The procedure describes how to prepare and characterize protein and nucleic acid samples for both SAXS and SANS using gel electrophoresis, size exclusion chromatography and light scattering. Also included are procedures specific to X-rays (in-line size exclusion chromatography SAXS) and neutrons, specifically preparing samples for contrast matching/variation experiments and deuterium labeling of proteins. PMID:27711050

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

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.

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

A small-angle neutron scattering investigation of coke deposits on catalysts

International Nuclear Information System (INIS)

Acharya, D.R.; Hughes, R.; Allen, A.J.

1990-01-01

Small-angle neutron scattering (SANS) has been used to characterize a silica-alumina catalyst before and after coke deposition. The reaction used to deactivate the catalyst was the isomerization of xylenes. The results showed that, while most of the surface area in this type of catalyst resides in the ultrafine pores of diameters less than 1 nm occupying about 7% of the sample volume, there appears to be no coke deposition in these pores. The coke seems to coat the solid structures of 3.3-nm diameter which are of capillary shape. Such structures occupy about 6% of the sample volume. The coke was found to correspond to amonolayer of composition CH 0.3 with a density of 1660 kg/m 3

Proceedings of the International school and symposium on small angle scattering

International Nuclear Information System (INIS)

Borbely, S.; Rosta, L.

1999-04-01

The meeting was devoted to small angle neutron and X-ray scattering with regard to the wide interest for this method in various fields of basic and applied research. Scientists from European laboratories gave introductory talks to various subject fields related to small angle scattering (SAS) techniques or data analysis methods as well as topical research area e.g. soft condensed matter, biology or materials science. An important number of contributed talks were presented on neutron or X-ray scattering and even on combining both of them, demonstrating the very useful complementarity of these methods. Some other papers give nice examples of SAS experiments completed by results of other techniques such as NMRE of light scattering. The variety of presented contributions is a nice demonstration for the interdisciplinary use of small angle scattering from physics through biology, chemistry, materials science to engineering. 18 items are indexed separately for the INIS database. (K.A.)

Measuring module of spectrometer of neutron small angle scattering on the IBR pulse reactor

International Nuclear Information System (INIS)

Vagov, V.A.; Zhukov, G.P.; Kozlova, E.P.; Korobchenko, M.L.; Namsraj, Yu.; Ostanevich, Yu.M.; Savvateev, A.S.; Salamatin, I.M.; Sirotin, A.P.

1980-01-01

Equipment and software for experiments with neutron small angle scattering is described. It is intended for data acquisition, equipment control storage of collected data and their output to network of the Laboratory measuring centre. The set-up equipment includes: 9 neutron detectors with corresponding electronic apparatus, sample exchanging device, communication link, SM-3 type minicomputer of an extended configuration and some units of CAMAC electronic equipment. The software (MUR applied operatio system) is intended for the automatic performance of the given number of cycles of successive uniform runs of a given duration with the sample list at two possible filter positions. Besides, the MUR system contains test, debugging and service software. The software has been designed using the SANPO system means [ru

Development of new instrumentation for epithermal neutron scattering at very low angles

International Nuclear Information System (INIS)

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

2004-01-01

New perspectives for epithermal neutron spectroscopy are opened up by the recent developments of Resonance Detectors (RD) for inverse geometry time-of-flight spectrometers at pulsed neutron sources. The RD is based on the combination of an analyser foil used as neutron-to-gamma converter and a suitable photon detector. Here, we report on the state of the RD which is based on a YAP scintillator viewing a natural uranium analyser foil. The response of the YAP detector to the radiative capture γ emission from the uranium analyser foil has been characterized with a bi-parametric measurement of a reference Pb sample, which allowed simultaneous measurements of both neutron time-of-flight and γ pulse height (energy) spectra. The analysis of the γ pulse height and neutron time-of-flight spectra permitted to identify the signal and background components. These measurements showed that a significant improvement in the signal-to-background ratio can be achieved by setting a lower level discrimination on the photon energy at about 600keV. The first application of RD is the Very Low Angle Detector Bank (VLAD) which is planned to be installed in the next three years as an upgrade of the VESUVIO spectrometer, at the ISIS pulsed neutron source. VLAD will extend the (q,ω) kinematical to low wave vector transfers (q10A-1) coupled to high-energy transfers (-bar ω>1eV), which is still unexplored by neutron scattering experiments. The first measurements obtained on an ice sample with a VLAD prototype consisting of four RD units are presented here

Development of new instrumentation for epithermal neutron scattering at very low angles

Energy Technology Data Exchange (ETDEWEB)

Tardocchi, M. [INFM, UdR Milano-Bicocca and Dipartimento di Fisica ' G.Occhialini' , Universita degli Studi di Milano-Bicocca, Pizza Della Scienza 3, Milan 20126 (Italy)]. E-mail: marco.tardocchi@mib.infn.it; Pietropaolo, A. [Dipartimento di Fisica, Universita degli Studi di Roma Tor Vergata and INFM, UdR Roma Tor Vergata, Rome (Italy); Andreani, C. [Dipartimento di Fisica, Universita degli Studi di Roma Tor Vergata and INFM, UdR Roma Tor Vergata, Rome (Italy); Gorini, G. [INFM, UdR Milano-Bicocca and Dipartimento di Fisica ' G.Occhialini' , Universita degli Studi di Milano-Bicocca, Pizza Della Scienza 3, Milan 20126 (Italy); Perelli-Cippo, E. [INFM, UdR Milano-Bicocca and Dipartimento di Fisica ' G.Occhialini' , Universita degli Studi di Milano-Bicocca, Pizza Della Scienza 3, Milan 20126 (Italy); Rhodes, N.J. [Isis Facility, Rutherford Appleton Laboratory, Chilton, Didcot (United Kingdom); Schooneveld, E.M. [Isis Facility, Rutherford Appleton Laboratory, Chilton, Didcot (United Kingdom); Senesi, R. [Dipartimento di Fisica, Universita degli Studi di Roma Tor Vergata and INFM, UdR Roma Tor Vergata, Rome (Italy)

2004-12-11

New perspectives for epithermal neutron spectroscopy are opened up by the recent developments of Resonance Detectors (RD) for inverse geometry time-of-flight spectrometers at pulsed neutron sources. The RD is based on the combination of an analyser foil used as neutron-to-gamma converter and a suitable photon detector. Here, we report on the state of the RD which is based on a YAP scintillator viewing a natural uranium analyser foil. The response of the YAP detector to the radiative capture {gamma} emission from the uranium analyser foil has been characterized with a bi-parametric measurement of a reference Pb sample, which allowed simultaneous measurements of both neutron time-of-flight and {gamma} pulse height (energy) spectra. The analysis of the {gamma} pulse height and neutron time-of-flight spectra permitted to identify the signal and background components. These measurements showed that a significant improvement in the signal-to-background ratio can be achieved by setting a lower level discrimination on the photon energy at about 600keV. The first application of RD is the Very Low Angle Detector Bank (VLAD) which is planned to be installed in the next three years as an upgrade of the VESUVIO spectrometer, at the ISIS pulsed neutron source. VLAD will extend the (q,{omega}) kinematical to low wave vector transfers (q10A-1) coupled to high-energy transfers (-bar {omega}>1eV), which is still unexplored by neutron scattering experiments. The first measurements obtained on an ice sample with a VLAD prototype consisting of four RD units are presented here.

Small-angle neutron scattering study of D2O-alcohol solutions

International Nuclear Information System (INIS)

D'Arrigo, G.

1990-01-01

Small-angle neutron scattering (SANS) measurements have been carried out on heavy water solutions of ethanol, isopropyl alcohol, n-propyl alcohol, t-butyl alcohol and butoxyethanol between 5 and 37 0 C at the concentrations where ultrasonic attenuation exhibits peak values. The wavevector dependence and the absolute intensity of the scattered intensities were analysed according to a microscopic model of the solutions in terms of aggregated complexes. The results indicate that at 25 0 C there exist either alcohol 'micelle-like' structures or alcohol-heavy water complexes which increase on going from the lower to higher alcohol solutions. As temperature increases from 25 to 37 0 C a higher aggregation is observed in butyl alcohol and butoxyethanol solutions. This behaviour is attributed to the demixing tendency of these systems at high temperatures. On going from 25 to 5 0 C the aggregation increases again. This trend is associated with the anomalous behaviour of the specific heat and ultrasonic attenuation of these systems. The occurrence of a low-temperature phase transition suggested by these anomalies is supported by our results. (author)

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)

Study of chemically unfolded {beta}-casein by means of small-angle neutron scattering

Energy Technology Data Exchange (ETDEWEB)

Aschi, Adel [Laboratoire de Physique de la Matiere Molle, Faculte des Sciences de Tunis, Campus Universitaire, 1060, Tunis (Tunisia)]. E-mail: aschi13@yahoo.fr; Gharbi, Abdelhafidh [Laboratoire de Physique de la Matiere Molle, Faculte des Sciences de Tunis, Campus Universitaire, 1060, Tunis (Tunisia); Daoud, Mohamed [Service de Physique de l' Etat Condense. CEA Saclay. 91191 Gif-sur-Yvette cedex (France); Douillard, Roger [Equipe de Biochimie des Macromolecules Vegetales, Centre de Recherche Agronomique, 2Esplanade R. Garros, BP 224, 51686 Reims cedex 2 (France); Calmettes, Patrick [Laboratoire Leon Brillouin, CEA Saclay, 91191 Gif-sur-Yvette cedex (France)

2007-01-01

{beta}-casein is a flexible amphiphilic milk protein which forms an unfolded conformation in presence of very high denaturant concentrations. The structure of {beta}-casein formed at the bulk was studied by small-angle neutron scattering (SANS). The value of the second virial coefficient of the protein solutions indicates that the interactions between the polypeptide chain and solvent are repulsive. The protein conformation is similar to an excluded volume chain. The corresponding values of the contour length, L, the statistical length, b and the apparent radius of the chain cross-section, R{sub c} are given.

Validation of large-angle scattering data via shadow-bar experiment

Energy Technology Data Exchange (ETDEWEB)

Ohnishi, S., E-mail: ohnishi@nmri.go.jp [National Maritime Research Institute, 6-38-1, Shinkawa, Mitaka, Tokyo 181-0004 (Japan); Tamaki, S.; Murata, I. [Osaka University, 1-14-16-1, Yamadaoka, Suita-si, Osaka 565-0871 (Japan)

2016-11-15

Highlights: • An experiment to validate large-angle scattering cross section is conducted. • Pieces of Nb foil are set behind a shadow bar to obtain the {sup 92m}Nb production rates. • The results calculated using ENDF/B-VI library data exhibit a 57% overestimation. • The adjustment of cross section in large-angle region makes the C/E close to 1. - Abstract: An experiment emphasizing the influence of large-angle scattering on nuclear data was conducted, in which a Fe shadow bar and a Fe slab target were placed before a deuterium–tritium fusion (DT) neutron source. Two Nb foils were set on both sides of the shadow bar in order to monitor the neutron source intensity and to measure the neutrons scattered from the slab target. The {sup 93}Nb(n,2n){sup 92m}Nb reaction rate of the foil was measured following the DT neutron irradiation and calculated using the MCNP5 Monte Carlo radiation transportation code. The {sup 92m}Nb production rates calculated using data from the JEFF-3.1 and JENDL-4.0 libraries agreed with that measured in the experiment, while the result calculated using data from the ENDF/B-VI library exhibited a 57% overestimation. Because the sensitivity of the {sup 92m}Nb production rate to the scattering angular distribution was large in the angular region between scattering direction cosines of −0.9 and −0.4, the scattering angular distribution was adjusted in that region. This adjustment resulted in a calculation-to-experiment ratio close to 1, but had little influence on the existing integral benchmark experiment.

Small-angle neutron scattering and molecular dynamics structural study of gelling DNA nanostars

Energy Technology Data Exchange (ETDEWEB)

Fernandez-Castanon, J.; Bomboi, F. [Sapienza–Università di Roma, P.le A. Moro 5, 00185 Roma (Italy); Rovigatti, L. [Rudolf Peierls C.T.P., University of Oxford, 1 Keble Road, Oxford OX1 3NP (United Kingdom); Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna (Austria); Zanatta, M. [Dipartimento di Fisica, Università di Perugia, Via Pascoli, 06123 Perugia (Italy); CNR-ISC, UOS Sapienza–Università di Roma, I-00186 Roma (Italy); Paciaroni, A. [Dipartimento di Fisica, Università di Perugia, Via Pascoli, 06123 Perugia (Italy); Comez, L. [Dipartimento di Fisica, Università di Perugia, Via Pascoli, 06123 Perugia (Italy); IOM-CNR, UOS Perugia c/o Dipartimento di Fisica e Geologia, Università di Perugia, Via Pascoli, 06123 Perugia (Italy); Porcar, L. [Institut Laue-Langevin, 71 Avenue des Martyrs, CS 20156, 38042 Grenoble Cedex 9 (France); Jafta, C. J. [Helmholtz-Zentrum Berlin, Hahn-Meitner-Platz 1, 14109 Berlin (Germany); Fadda, G. C. [Laboratoire Léon Brillouin, LLB, CEA Saclay, 91191 Gif-sur-Yvette Cedex (France); Bellini, T. [Department of Medical Biotechnology and Translational Medicine, Università di Milano, I-20133 Milano (Italy); Sciortino, F., E-mail: francesco.sciortino@uniroma1.it [Sapienza–Università di Roma, P.le A. Moro 5, 00185 Roma (Italy); CNR-ISC, UOS Sapienza–Università di Roma, I-00186 Roma (Italy)

2016-08-28

DNA oligomers with properly designed sequences self-assemble into well defined constructs. Here, we exploit this methodology to produce bulk quantities of tetravalent DNA nanostars (each one composed of 196 nucleotides) and to explore the structural signatures of their aggregation process. We report small-angle neutron scattering experiments focused on the evaluation of both the form factor and the temperature evolution of the scattered intensity at a nanostar concentration where the system forms a tetravalent equilibrium gel. We also perform molecular dynamics simulations of one isolated tetramer to evaluate the form factor numerically, without resorting to any approximate shape. The numerical form factor is found to be in very good agreement with the experimental one. Simulations predict an essentially temperature-independent form factor, offering the possibility to extract the effective structure factor and its evolution during the equilibrium gelation.

Polyhydroxyalkanoate-based natural-synthetic hybrid copolymer films: A small-angle neutron scattering study

International Nuclear Information System (INIS)

Foster, L. John R.; Knott, Robert; Sanguanchaipaiwong, Vorapat; Holden, Peter J.

2006-01-01

Polyhydroxyalkanoates have attracted attention as biodegradable alternatives to conventional thermoplastics and as biomaterials. Through modification of their biosynthesis using Pseudomonas oleovorans, we have manipulated the material properties of these biopolyesters and produced a natural-synthetic hybrid copolymer of polyhydroxyoctanoate-block-diethylene glycol (PHO-b-DEG). A mixture of PHO and PHO-DEG were solvent cast from analytical grade chloroform and analysed using small-angle neutron scattering. A scattering pattern, easily distinguished above the background, was displayed by the films with a diffraction ring at q∼0.12 A -1 . This narrow ring of intensity is suggestive of a highly ordered system. Analysis of the diffraction pattern supported this concept and showed a d-spacing of approximately 50 A. In addition, conformation of the hybrid polymer chains can be manipulated to support their self-assembly into ordered microporous films

Small angle neutron scattering study of creep deformation and fracture of type 304 stainless steel

International Nuclear Information System (INIS)

Yoo, M.H.; Ogle, J.C.; Schneibel, J.H.; Swindeman, R.W.

1983-01-01

A small-angle neutron scattering (SANS) study has been performed to determine the size distribution of carbide precipitates that were formed during creep deformation in type 304 stainless steel. The hardening mechanism during primary creep by a fine dispersion of carbide particles in the matrix was confirmed by the SANS measurement and also by direct TEM observations. The size distribution of creep-induced cavities was also determined by SANS measurements after post-creep solution heat treatment. (author)

Small angle neutron scattering study of creep deformation and fracture of Type 304 stainless steel

International Nuclear Information System (INIS)

Yoo, M.H.; Ogle, J.C.; Schneibel, J.H.; Swindeman, R.W.

1982-01-01

A small-angle neutron scattering (SANS) study has been performed to determine the size distribution of carbide precipitates that were formed during creep deformation in Type 304 stainless steel. The hardening mechanism during primary creep by a fine dispersion of carbide particles in the matrix was confirmed by the SANS measurement and also by direct TEM observations. The size distribution of creep-induced cavities was also determined by SANS measurements after post-creep solution heat treatment

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)

Kinetics of the urea-induced dissociation of human plasma alpha-2-macroglobulin as measured by small-angle neutron scattering

DEFF Research Database (Denmark)

Sjöberg, B.; Pap, S.; Järnberg, S.-E.

1991-01-01

The kinetics of the urea-induced dissociation of human plasma alpha-2-macroglobulin into two half-molecular fragments was investigated at 21.0-degrees-C by using small-angle neutron scattering. The relative change in molecular mass that occurs upon dissociation was monitored by recording the forw...

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.

Assess the Intra-molecular Cavity in PAMAM Dendrimers by Small Angle Neutron Scattering

International Nuclear Information System (INIS)

Chen, Wei-Ren

2008-01-01

In this report, we present a contrast variation small angle neutron scattering (SANS) study of a series of neutral PAMAM dendrimer in aqueous solutions using three different generations (G4-6) at a concentration of about 10 mg/ml. Varying the solvent hydrogen-deuterium ratio, the scattering contributions from the water molecules and the constituent components of PAMAM dendrimer can be determined. Using an analytical model of the scattering cross section I(Q) incorporating the effect of water penetration, we have quantified the intra-molecular space of PAMAM dendrimer by evaluating the number of guest water molecules and we draw a direct comparison to computational predictions. As expected, the overall available internal cavity was seen to increase as a function of increasing dendrimer generation. However, the fraction of water accessible volume in the internal cavity of a dendrimer was found to remain invariant for the three generation PAMAM dendrimers studied in this report. We have also estimated the average water density inside a dendrimer, which is found to be higher than that of bulk water

Fractal Structures on Silica Aerogels Containing Titanium: A Small Angle Neutron Scattering Study

International Nuclear Information System (INIS)

Widya Sari; Dian Fitriyani; Abdul Aziz Mohamed; Noordin Ibrahim

2009-01-01

Full text: The fractal structure of silica aerogels containing titanium has been investigated by means of small-angle neutron scattering (SANS) technique. The SANS experiments were conducted using a 36 meter SANS BATAN spectrometer (SMARTer) in Serpong, Indonesia in the range of momentum transfer Q, 0.006 -1 ) < 0.3. The power-law for a fractal object scattering Q-D observed from all measured samples. The Fourier transform of pattern I(Q) a pair correlation model function was implemented in analyzing the structure factor from the power-law scattering profiles. The results are showing that the silica aerogels containing titanium has a mass fractal where its dimension DM is larger than the pure silica aerogels. The mass fractal dimension of silica aerogels containing titanium is relatively constant between 2.23 to 2.40 with the decrease of acid concentrations during a sol-gel process and formed a nanometer size of aggregate. Those fractal structures were simulated using a Delphi language and the results are presented in this paper. (author)

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)

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)

Joint small-angle X-ray and neutron scattering data analysis of asymmetric lipid vesicles

International Nuclear Information System (INIS)

Eicher, Barbara; Heberle, Frederick A.; Marquardt, Drew T.

2017-01-01

Low- and high-resolution models describing the internal transbilayer structure of asymmetric lipid vesicles have been developed. These models can be used for the joint analysis of small-angle neutron and X-ray scattering data. The models describe the underlying scattering length density/electron density profiles either in terms of slabs or through the so-called scattering density profile, previously applied to symmetric lipid vesicles. Both models yield structural details of asymmetric membranes, such as the individual area per lipid, and the hydrocarbon thickness of the inner and outer bilayer leaflets. The scattering density profile model, however, comes at a cost of increased computational effort but results in greater structural resolution, showing a slightly lower packing of lipids in the outer bilayer leaflet of ~120 nm diameter palmitoyloleoyl phosphatidylcholine (POPC) vesicles, compared to the inner leaflet. Here, analysis of asymmetric dipalmitoyl phosphatidylcholine/POPC vesicles did not reveal evidence of transbilayer coupling between the inner and outer leaflets at 323 K,i.e.above the melting transition temperature of the two lipids.

Small angle neutron scattering study of metallic alloys by a double crystal device

International Nuclear Information System (INIS)

Cser, L.; Kovacs, I.; Kroo, N.; Zsigmond, Gy.

1982-06-01

A double crystal small angle neutron scattering (SANS) device was built and a simple method for measuring the integrated SANS intensity was developed. The device and the method were tested and the possibility of future applications was demonstrated by measurements on different samples. The test measurements were performed on iron and teflon slabs of different thickness. On Fe-B metallic glasses a SANS intensity originating mainly from the multiple magnetic refraction at domain boundaries was observed. A very weak SANS intensity was found on turbine blades. The integrated SANS intensity was shown to correlate with the running time of the blades. Similar measurements were performed on artificially deformed steel samples. (author)

The small angle neutron scattering study on the segmented polyurethane

International Nuclear Information System (INIS)

Sudirman; Gunawan; Prasetyo, S.M.; Karo Karo, A.; Lahagu, I.M.; Darwinto, Tri

1999-01-01

The distance between hard segment (HS) and soft segment (SS) of segmented polyurethane have been determined using the Small Angle Neutron Scattering (SANS) technique. The segmented Polyurethanes (SPU) are linear multiblock copolymers, which include elastomer thermoplastic. SPU consist of hard segment and soft segment, each has tendency to make a group with similar type to form a domain. The soft segments used were polypropylene glycol (PPG) and 4,4 diphenylmethane diisocyanate (MDI), while l,4 butanediol (BD) was used as hard segment. The characteristic of SPU depends on its phase structure which is affected by several factors, such as type of chemical formula and the composition of the HS and SS, solvent as well as the synthesizing process. The samples used in this study were SPU56 and SPU68. Based on the appearance of SANS profile, it was obtained that domain distances are 12.32 nm for the SPU56 and 19 nm for the SPU68. (author)

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)

Gracing incidence small angle neutron scattering of incommensurate magnetic structures in MnSi thin films

Energy Technology Data Exchange (ETDEWEB)

Wiedemann, Birgit; Pfleiderer, Christian; Boeni, Peter [Physik Department, Technische Universitaet Muenchen (Germany); Zhang, Shilei; Hesjedal, Thorsten [Clarendon Laboratory, Department of Physics, University of Oxford (United Kingdom); Khaydukov, Yury; Soltwedel, Olaf; Keller, Thomas [Max-Planck-Institut fuer Festkoerperforschung (Germany); Max Planck Society, Outstation at FRM-II (Germany); Muehlbauer, Sebastian [Forschungsneutronenquelle Heinz Maier Leibnitz, Technische Universitaet Muenchen (Germany); Chacon, Alfonso [Physik Department, Technische Universitaet Muenchen (Germany); Forschungsneutronenquelle Heinz Maier Leibnitz, Technische Universitaet Muenchen (Germany)

2015-07-01

The topological stability of skyrmions in bulk samples of MnSi and the observation of spin transfer torque effects at ultra-low current densities have generated great interest in skyrmions in chiral magnets as a new route towards next generation spintronics devices. Yet, the formation of skyrmions in MBE grown thin films of MnSi reported in the literature is highly controversial. We report gracing incidence small angle neutron scattering (GISANS) of the magnetic order in selected thin films of MnSi grown by state of the art MBE techniques. In combination with polarised neutron reflectometry (PNR) and magnetisation measurements of the same samples our data provide direct reciprocal space information of the incommensurate magnetic order, clarifying the nature of magnetic phase diagram.

Investigation of digestion Kinetics in commercial starches using in-situ small-angle neutron scattering

International Nuclear Information System (INIS)

Blazek, Jaroslav; Gilbert, Elliot Paul

2009-01-01

Full text: The digestion of starch has been the subject of many investigations, mostly involving in vitro measurement of the susceptibility of starches to attack by different enzymes, rather than measuring actual digestibility in vivo. The rate and extent of amylolytic hydrolysis of granular starches is known to vary according to botanical origin. Granule characteristics considered to influence susceptibility to attack by alpha-amylase include crystallinity, granule size and available specific surface, amylose content, porosity, structural inhomogeneities and degree of integrity. Most in-vitro studies of granular starch digestion have been limited to samples for which aliquots have been removed from the reaction mixture at various time intervals and freeze-dried to be subsequently characterized using a range of techniques. It remains unclear whether sample preparation creates artefacts in the samples. In this study, we have studied the kinetics of starch digestion of several commercial granular starches by time-resolved small-angle neutron scattering using an in-situ digestion chamber allowing, for the first time, to follow structural changes of starch in the course of digestion directly in the digestion mixture. Additionally, samples before and after digestion were studied by x-ray diffraction, small-angle x-ray scattering, differential scanning calorimetry and microscopy. Microscopy revealed that studied starches, which varied in their amylose content and digestion kinetics, followed different modes of attack The multidisciplinary approach allowed the nanostructural changes detected by small-angle scattering in the course of enzymic breakdown to be correlated with changes in crystallinity and functional properties.

Small-angle neutron scattering study of the ultrastructure of chloroplast thylakoid membranes - Periodicity and structural flexibility of the stroma lamellae

DEFF Research Database (Denmark)

Posselt, Dorthe; Nagy, Gergely; Kirkensgaard, Jacob J. K.

2012-01-01

The multilamellar organization of freshly isolated spinach and pea chloroplast thylakoid membranes was studied using small-angle neutron scattering. A broad peak at similar to 0.02 angstrom(-1) is ascribed to diffraction from domains of ordered, unappressed stroma lamellae, revealing a repeat dis...

The application of small-angle neutron scattering to the study of mass transfer in clays

International Nuclear Information System (INIS)

Allen, A.J.; Baston, A.H.; Bourke, P.J.; Jefferies, N.L.

1990-01-01

An extensive study using small angle neutron scattering (SANS) has been made of the pore structures in London Clay and in Ca-montmorillonite. Using SANS contrast variation techniques, the accessibilities of the pores to D 2 O by diffusion and permeation have been studied. Characterisation of the accessibility to different parts of the pore structure is intended to provide input data for models of radionuclide transport through clay geological barriers, and to improve interpretation of laboratory experiments that measure sorption of radionuclides on clays. (author)

Power-law correlations and finite-size effects in silica particle aggregates studied by small-angle neutron scattering

DEFF Research Database (Denmark)

Freltoft, T.; Kjems, Jørgen; Sinha, S. K.

1986-01-01

Small-angle neutron scattering from normal, compressed, and water-suspended powders of aggregates of fine silica particles has been studied. The samples possessed average densities ranging from 0.008 to 0.45 g/cm3. Assuming power-law correlations between particles and a finite correlation length ξ......, the authors derive the scattering function S(q) from specific models for particle-particle correlation in these systems. S(q) was found to provide a satisfactory fit to the data for all samples studied. The fractal dimension df corresponding to the power-law correlation was 2.61±0.1 for all dry samples, and 2...

SANS [small-angle neutron scattering] evaluation of the RPA [random phase approximation] theory for binary homopolymer mixtures

International Nuclear Information System (INIS)

Bates, F.S.; Koehler, W.C.; Wignall, G.D.; Fetters, L.J.

1986-12-01

A well characterized binary mixture of normal (protonated) and perdeuterated monodisperse 1,2 polybutenes has been studied by small-angle neutron scattering (SANS). For scattering wavevectors q greater than the inverse radius-of-gyration R/sub g/ -1 , the SANS intensity is quantitatively predicted by the random phase approximation (RPA) theory of deGennes over all measured values of the segment-segment interaction parameter Chi. In the region (Chi s-Chi)Chi s -1 > 0.5 the interaction parameter determined using the RPA theory for q > R/sub g/ -1 is greater than that calculated from the zero-angle intensity based on an Ornstein-Zernike plot, where Chi s represents the limit of single phase stability. These findings indicate a correlation between the critical fluctuation length ξ and R/sub g/ which is not accounted for by the RPA theory

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.

Structure analyses of swollen rubber-filler systems by using contrast variation Small angle neutron scattering (SANS)

International Nuclear Information System (INIS)

Takenaka, Mikihito; Nishitsuji, Shotaro; Yamaguchi, Daisuke; Koizumi, Satoshi

2009-01-01

Full text: The polymer layers absorbed on silica particles in rubber-silica systems have investigated with contrast variation small-angle neutron scattering (SANS) method. The scattering intensities of specimens swollen by the solvents having various scattering length densities were measured. The contrast variation SANS for the specimens yielded partial scattering functions: the scattering function for polymer-polymer correlation SPP(q), the scattering function for silica- silica correlation SSS(q), and the scattering function for polymer- silica correlation SPS(q). The analyses of SSS(q) explored the hierarchical structures formed by silica particles. The analyses of SPS(q) and SSS(q) clarified the existence of dense polymer layers around silica aggregates. Several characteristic parameters are estimated from the analyses, such as the size of aggregates, the thickness of layers, the volume fractions of polymer of layers and matrix, and the correlation length of the matrix network. The contrast variation SANS is found to be a powerful tool of the analyses of the structures of the rubber-filler systems. (author)

Monomeric Amyloid Beta Peptide in Hexafluoroisopropanol Detected by Small Angle Neutron Scattering.

Directory of Open Access Journals (Sweden)

Bo Zhang-Haagen

Full Text Available Small proteins like amyloid beta (Aβ monomers are related to neurodegenerative disorders by aggregation to insoluble fibrils. Small angle neutron scattering (SANS is a nondestructive method to observe the aggregation process in solution. We show that SANS is able to resolve monomers of small molecular weight like Aβ for aggregation studies. We examine Aβ monomers after prolonged storing in d-hexafluoroisopropanol (dHFIP by using SANS and dynamic light scattering (DLS. We determined the radius of gyration from SANS as 1.0±0.1 nm for Aβ1-40 and 1.6±0.1 nm for Aβ1-42 in agreement with 3D NMR structures in similar solvents suggesting a solvent surface layer with 5% increased density. After initial dissolution in dHFIP Aβ aggregates sediment with a major component of pure monomers showing a hydrodynamic radius of 1.8±0.3 nm for Aβ1-40 and 3.2±0.4 nm for Aβ1-42 including a surface layer of dHFIP solvent molecules.

Study of the M23C6 precipitation in AISI 304 stainless steel by small angle neutron scattering

International Nuclear Information System (INIS)

Boeuf, A.; Caciuffo, R.G.M.; Institut Max von Laue - Paul Langevin, 38 - Grenoble; Ancona Univ.; Melone, S.; Puliti, P.; Rustichelli, F.; Institut Max von Laue - Paul Langevin, 38 - Grenoble; Ancona Univ.; Coppola, R.

1985-01-01

The results of some small-angle neutron scattering (SANS) experiments on M 23 C 6 (M=Fe, Cr) carbide precipitation in AISI 304 stainless steel, aged at different temperatures during different times, are presented. The total volume fraction, the total surface of precipitates per unit sample volume and the size distribution functions of the M 23 C 6 carbides were determined. (orig.)

The effect of pressure, isotopic (H/D) substitution, and other variables on miscibility in polymer-solvent systems. The nature of the demixing process; dynamic light scattering and small angle neutron scattering studies. Final report

International Nuclear Information System (INIS)

Van Hook, W.A.

2000-01-01

A research program examining the effects of pressure, isotope substitution and other variables on miscibility in polymer solvent systems is described. The techniques employed included phase equilibrium measurements and dynamic light scattering and small angle neutron scattering

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.

Study of α-crystallin structure by small-angle neutron scattering with contrast variation

International Nuclear Information System (INIS)

Krivandin, A.V.; Muranov, K.O.; Polyanskij, N.B.; Ostrovskij, M.A.; Murugova, T.N.; Kuklin, A.I.; Aksenov, V.L.

2010-01-01

The structure of the oligomeric protein α-crystallin from the bovine eye lens has been investigated by small-angle neutron scattering (SANS) by the contrast variation method (volume fraction of D 2 O was 0, 23, 68 and 90%). Experiments were carried out on YuMO spectrometer (IBR-2 reactor, JINR). From the SANS curves the match point for α-crystallin (43% D 2 O) and its average scattering length density at this point (2.4·10 10 cm -2 ) have been obtained. The radius of gyration and distance distribution functions for α-crystallin have been calculated as well. On the basis of these calculations it was concluded that α-crystallin has a homogeneous distribution of the scattering density in domains inaccessible for water penetration and all parts of this protein undergo a uniform deuteration. The latter indicates that all α-crystallin subunits have an equal accessibility for water and presumably for some other low molecular weight substances. These conclusions on the α-crystallin structure (a homogeneous distribution of the scattering density and an equal accessibility of all subunits for low molecular weight substances) should be taken into account in the time of elaboration of α-crystallin quaternary structure models

Structure of the capsid of Kilham rat virus from small-angle neutron scattering

International Nuclear Information System (INIS)

Wobbe, C.R.; Mitra, S.; Ramakrishnan, V.

1984-01-01

The structure of empty capsids of Kilham rat virus, an autonomous parvovirus with icosahedral symmetry, was investigated by small-angle neutron scattering. From the forward scatter, the molecular weight was determined to be 4.0 x 10(6), and from the Guinier region, the radius of gyration was found to be 105 A in D2O and 104 A in H 2 O. On the basis of the capsid molecular weight and the molecular weights and relative abundances of the capsid proteins, the authors propose that the capsid has a triangulation number of 1. Extended scattering curves and mathematical modeling revealed that the capsid consists of two shells of protein, the inner shell extending from 58 to 91 A in D2O and from 50 to 91 A in H 2 O and containing 11% of the capsid scattering mass, and the outer shell extending to 121 A in H 2 O and D2O. The inner shell appears to have a higher content of basic amino acids than the outer shell, based on its lower scattering density in D2O than in H 2 O. The authors propose that all three capsid proteins contribute to the inner shell and that this basic region serves DNA binding and partial charge neutralization functions

Small angle, quasielastic and inelastic neutron scattering from 0.85AgPO3-0.15PbI2 glass

International Nuclear Information System (INIS)

Malugani, J.P.; Tachez, M.; Mercier, R.

1987-01-01

A small angle neutron scattering (SANS) experiment and a quasielastic neutron scattering (QENS) experiment were performed on the fast ionic conductor 0.85AgPO 3 -0.15PbI 2 , which is a vitreous electrolyte. The SANS data show that the scattering obeys Guinier's law for Q -2 A; dispersed heterogeneities are present in the glass with a mean radius of gyration of 20 A. The QENS spectra show a quasielastic broadening of the elastic peak and a long tail up to 40 meV which is due to an inelastic distribution. The results seem to confirm the hypothesis on the structure of this glass: small 'clusters' of AgI with tetrahedral coordination are dispersed in the AgPO 3 host glass. In order to build these clusters, an exchange between Ag + and Pb 2+ is proposed. 18 refs.; 6 figs.; 2 tabs

Small angle neutron scattering study on a phase separation in a 3-component microemulsion system

International Nuclear Information System (INIS)

Seto, Hideki; Yokoi, Eiji; Komura, Shigehiro; Schwahn, Dietmar; Mortensen, Kell; Suzuki, Junichi; Funahashi, Satoru; Ito, Yuji.

1993-01-01

The mixture of three components, water, n-decane and 2-ethylhexylsulfosuccinate (AOT), is a well-known system that forms a 'water-in-oil' microemulsion at room temperature and decomposes with increasing temperature, thereby being associated with a critical phenomenon. Experimental results in previous literature, indicate that the phenomenon is interpreted to be that of the 3D-Ising, but we obtained the meanfield behavior of the susceptibility at 'near-critical region' by a small angle neutron scattering. The observed spinodal and binodal points were well explained assuming the van der Waals free energy expression. (author)

Investigation of the cluster structure in aqueous suspensions of nanodiamonds by small-angle neutron scattering

International Nuclear Information System (INIS)

Bulavin, L.A.; Tomchuk, O.V.; Avdeev, M.V.

2015-01-01

The paper presents the results of the structural study of various types of the water-detonation nanodiamond liquid systems, which are obtained by small-angle scattering of thermal neutrons. It was shown that in the mass fraction range (0.3/1.8) % the experimental spectra are well described by a two-level model of unified exponential/power-law approach. The resulting structural parameters allowed us to estimate the aggregation number in the studied systems. Sizes of the nanodiamond particles and their clusters are found as well as the fractal dimension of the latter

Fast, quantitative, and nondestructive evaluation of hydrided LWR fuel cladding by small angle incoherent neutron scattering of hydrogen

Energy Technology Data Exchange (ETDEWEB)

Yan, Y.; Qian, S.; Littrell, K.; Parish, C.M. [Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Plummer, L.K. [University of Oregon, Eugene, OR 97403 (United States)

2015-05-15

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

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.)

Modeling small angle scattering data using FISH

International Nuclear Information System (INIS)

Elliott, T.; Buckely, C.E.

2002-01-01

Full text: Small angle neutron scattering (SANS) and small angle x-ray scattering (SAXS) are important techniques for the characterisation of samples on the nanometer scale. From the scattered intensity pattern information about the sample such as particle size distribution, concentration and particle interaction can be determined. Since the experimental data is in reciprocal space and information is needed about real space, modeling of the scattering data to obtain parameters is extremely important and several paradigms are available. The use of computer programs to analyze the data is imperative for a robust description of the sample to be obtained. This presentation gives an overview of the SAS process and describes the data-modeling program FISH, written by R. Heenan 1983-2000. The results of using FISH to obtain the particle size distribution of bubbles in the aluminum hydrogen system and other systems of interest are described. Copyright (2002) Australian X-ray Analytical Association Inc

A novel application of small-angle scattering techniques: Quality assurance testing of virus quantification technology

International Nuclear Information System (INIS)

Kuzmanovic, Deborah A.; Elashvili, Ilya; O'Connell, Catherine; Krueger, Susan

2008-01-01

Small-angle scattering (SAS) techniques, like small-angle X-ray scattering (SAXS) and small-angle neutron scattering (SANS), were used to measure and thus to validate the accuracy of a novel technology for virus sizing and concentration determination. These studies demonstrate the utility of SAS techniques for use in quality assurance measurements and as novel technology for the physical characterization of viruses

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

Characterization of nanoparticles of lidocaine in w/o microemulsions using small-angle neutron scattering and dynamic light scattering

International Nuclear Information System (INIS)

Shukla, A.; Kiselev, M.A.; Hoell, A.; Neubert, R.H.H.

2004-01-01

Microemulsions (MEs) are of special interest because a variety of reactants can be introduced into the nanometer-sized aqueous domains, leading to materials with controlled size and shape. In the past few years, significant research has been conducted in the reverse ME-mediated synthesis of organic nanoparticles. In this study, a w/o ME medium was employed for the synthesis of lidocaine by direct precipitation in w/o microemulsion systems: water/isopropylpalmitat/Tween80/Span80. The particle size as well as the location of nanoparticles in the ME droplet were characterized by means of dynamic light scattering (DLS) and small angle neutron scattering (SANS). It is observed that lidocaine precipitated in the aqueous cores because of its insolubility in water. Hydrodynamic radius and gyration radius of microemulsion droplets were estimated as ∼15 nm and ∼4.50 nm from DLS and SANS respectively. Furthermore, different size parameters obtained by DLS and SANS experiments were compared. (author)

Characterization of nanoparticles of lidocaine in w/o microemulsions using small-angle neutron scattering and dynamic light scattering

Science.gov (United States)

Shukla, A.; Kiselev, M. A.; Hoell, A.; Neubert, R. H. H.

2004-08-01

Microemulsions (MEs) are of special interest because a variety of Reactants can be introduced into the nanometer-sized aqueous domains, leading to materials with controlled size and shape [1,2]. In the past few years, significant research has been conducted in the reverse ME-mediated synthesis of organic nanoparticles [3,4]. In this study, a w/o ME medium was employed for the synthesis of lidocaine by direct precipitation in w/o microemulsion systems: water/isopropylpalmitat/Tween80/Span80. The particle size as well as the location of nanoparticles in the ME droplet were characterized by means of dynamic light scattering (DLS) and small angle neutron scattering (SANS). It is observed that lidocaine precipitated in the aqueous cores because of its insolubility in water. Hydrodynamic radius and gyration radius of microemulsion droplets were estimated as ~15 nm and ~4.50 nm from DLS and SANS respectively. Furthermore, different size parameters obtained by DLS and SANS experiments were compared

Analysis by low-angle neutron scattering of the structure of the acetylcholine receptor from Torpedo californica in detergent solution

International Nuclear Information System (INIS)

Wise, D.S.; Karlin, A.; Schoenborn, B.P.

1979-01-01

The acetylcholine receptor from the electric tissue of Torpedo californica is a large, integral membrane protein containing four different types of polypeptide chains. In this paper the results of the use of low-angle neutron scattering to investigate the shape of the receptor-detergent complex and separately of its protein and detergent moieties are reported. By adjustment of the neutron-scattering density of the solvent with D 2 O to match that of one or the other of the moieties, its contribution to the scattering can be nearly, if not completely, eliminated. Neutron scattering from Triton X-100 micelles established that this detergent is contrast matched in 18% D 2 O. Scattering measurements on the receptor-detergent complex in this solvent yielded a radius of gyration of the acetylcholine receptor monomer of 46 +- 1 A. The radius of gyration and molecular volume (305,000 A 3 ) of the receptor is inconsistent with a compact spherical shape. These parameters are consistent with, for example, a prolate cylinder of dimensions (length x diameter) 150 x 50 A or an oblate cylinder, 25 x 130 A. More complex shapes are possible and in fact seem to be required to reconcile the present results with previous electron microscopic and x-ray analyses of receptor in membrane and with considerations of the function of the receptor in controlling ion permeability. The neutron-scattering data yield, in addition, an independent determination of the molecular weight of the receptor protein (240,000 +- 40,000), the extent of Triton X-100 binding in the complex (0.4 g/g protein), and from the extended scattering curve, an approximation to the shape of the receptor-Triton X-100 complex, namely an oblate ellipsoid of axial ratio 1:4

Small-angle neutron scattering study of activated carbon cloth and ammonium persulfate-modified activated carbon cloth: Effect of oxygen content

International Nuclear Information System (INIS)

Pendleton, Phillip; Chen Lin

2006-01-01

Small-angle neutron scattering (SANS) patterns of as-received, oxidized, and thermally reduced FM1/250 activated carbon cloth (ACC) samples are compared to determine the effects of surface chemistry on scattering. Porosity analyses show minimal effect on pore size distribution from oxidation, but an increase in micropore volume on heat treatment. SANS suggests an increase in localized order within the treated samples when compared with graphite cloth patterns. The ACC exhibits Porod scattering at q-ranges -1 ; the graphite cloth exhibits the same at q-ranges>1.0 nm -1 . A cylindrical model reproduces the scattering patterns in the micropore equivalent dimensions, q>0.5 nm -1

Interphase effects in dental nanocomposites investigated by small-angle neutron scattering.

Science.gov (United States)

Wilson, Kristen S; Allen, Andrew J; Washburn, Newell R; Antonucci, Joseph M

2007-04-01

Small-angle and ultrasmall-angle neutron scattering (SANS and USANS) were used to characterize silica nanoparticle dispersion morphologies and the interphase in thermoset dimethacrylate polymer nanocomposites. Silica nanoparticle fillers were silanized with varying mass ratios of 3-methacryloxypropyltrimethoxysilane (MPTMS), a silane that interacts with the matrix through covalent and H-bonding, and n-octyltrimethoxysilane (OTMS), a silane that interacts through weak dispersion forces. Interphases with high OTMS mass fractions were found to be fractally rough with fractal dimensions, D(s), between 2.19 and 2.49. This roughness was associated with poor interfacial adhesion and inferior mechanical properties. Mean interparticle distances calculated for composites containing 10 mass % and 25 mass % silica suggest that the nanoparticles treated with more MPTMS than OTMS may be better dispersed than OTMS-rich nanoparticles. The results indicate that the covalent bonding and H-bonding of MPTMS-rich nanoparticles with the matrix are necessary for preparing well-dispersed nanocomposites. In addition, interphases containing equal masses of MPTMS and OTMS may yield composites with overall optimal properties. Finally, the combined SANS/USANS data could distinguish the differences, as a function of silane chemistry, in the nanoparticle/silane and silane/matrix interfaces that affect the overall mechanical properties of the composites. (c) 2006 Wiley Periodicals, Inc.

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.)

Time-of-flight small-angle neutron scattering data reduction and analysis at LANSCE with program SMR

International Nuclear Information System (INIS)

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

1988-01-01

A user-friendly integrated system, SMR, for the display, reduction and analysis of data from time-of-flight small-angle neutron diffractometers is described. Its purpose is to provide facilities for data display and assessment, and to provide these facilities in near real time. This allows the results of each scattering measurement to be available almost immediately, and enables the user to use the results of a measurement as a basis for other measurements in the same time allocation of the instrument. 8 refs., 10 figs

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)

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

The design and q resolution of the small and wide angle neutron scattering instrument (TAIKAN) in J-PARC

International Nuclear Information System (INIS)

Takata, Shin-ichi; Suzuki, Jun-ichi; Shinohara, Takenao; Oku, Takayuki; Tominaga, Taiki; Nakatani, Takeshi; Inamura, Yasuhiro; Suzuya, Kentaro; Aizawa, Kazuya; Arai, Masatoshi; Ohishi, Kazuki; Iwase, Hiroki; Ito, Takayoshi; Otomo, Toshiya; Sugiyama, Masaaki

2015-01-01

The small and wide angle neutron scattering instrument (TAIKAN) is designed to cover the wide q range of 0.005 0.3 Å"-"1 with the other banks. The q resolution was compared with the values experimentally obtained from the widths of Bragg peaks of a standard sample, silver behenate. The results of the experiment were consistent with the theory. It was confirmed that TAIKAN was completed as was expected. (author)

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

International Nuclear Information System (INIS)

McCray, John; Navarre-Sitchler, Alexis; Mouzakis, Katherine; Heath, Jason E.; Dewers, Thomas A.; Rother, Gernot

2010-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2010-11-01

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

Small-angle neutron scattering and rheological analyses of nanoemulsion for cosmetics

International Nuclear Information System (INIS)

Kume, Takuji

2014-01-01

A stable nanoemulsion consisting of nanometer-sized oil droplets in water having a self-standing capability was prepared by high-pressure emulsification. Rheological measurements show that the nanoemulsion has a high viscosity and a yield stress. Small-angle neutron scattering (SANS) revealed the presence of an ordered crystal-like lattice structure in addition to spherical domains with a diameter of ca. 30 nm. Nonfluidity of nanoemulsion is ascribed to crystal-like lattice structure of nanodroplets. A mixed solution of 2-hydroxyethyl cellulose and the nanoemulsion has shear-thickening behavior (shear-induced gelation). Real-time SANS measurements with a Couette geometry as a function of shear rate (Rheo-SANS) revealed that a possible mechanism of gelation was proposed from the viewpoint of shear-induced percolation transition. Furthermore, mixtures of the nanoemulsion and poly(acrylic acid) solutions were opaque and kept the same interdomain distance and high viscosity. We estimated that it had phase-separated structure between nanoemulsion phase and poly(acrylic acid) solution phase. (author)

Small angle neutron scattering study of the gemini nonionic surfactant in heavy water solutions

International Nuclear Information System (INIS)

Rajewska, A

2012-01-01

The nonionic gemini surfactant α α'-[2,4,7,9-tetramethyl-5-decyne-4,7diyl]bis[ω hydroxyl-polyoxyethylene] (S-10) was investigated in heavy water solutions only for concentrations: 2.3%, 2.5%,3%, 3.4%, 4% and 5% at temperature 25 C with small angle neutron scattering (SANS) method. All of surfactants solutions were prepared using D 2 O (99.9% deuterated, Prikladnaia Chimia, St. Petersburg, Russia) as a solvent. The nonionic gemini surfactant S-10 was obtained from Air Products and Chemicals, Inc., and used without further purification. All SANS measurements were performed on V-4 SANS spectrometer at BENSC, Berlin (Germany). Neutrons were used in wavelength range of 0.02 - 4 nm - 1. For the measurements quartz cells of were used during experiment. Up to 14 such cells were placed in a holder. Results from experiment was calculated and evaluated with PCG 2.0 program from Graz University (Austria). In the investigated solutions two axis ellipsoidal micelles was observed.

Investigation of the cluster structure in aqueous suspensions of nanodiamonds by small-angle neutron scattering

Directory of Open Access Journals (Sweden)

L. A. Bulavin

2015-07-01

Full Text Available The paper presents the results of the structural study of various types of the water-detonation nanodiamond liquid systems, which are obtained by small-angle scattering of thermal neutrons. It was shown that in the mass fraction range (0.3 - 1.8 % the experimental spectra are well described by a two-level model of unified exponential/power-law approach. The resulting structural parameters allowed us to estimate the aggregation number in the studied systems. Sizes of the nanodiamond particles and their clusters are found as well as the fractal dimension of the latter.

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)

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

Small angle neutron scattering study on short and long chain phosphatidylcholine mixture in trehalose solution

Energy Technology Data Exchange (ETDEWEB)

Takahashi, Hiroshi [Department of Physics, Gunma University, Maebashi, Gunma (Japan)

2001-03-01

Trehalose protects cells and proteins against various stresses due to low temperatures or dryness. In order to clarify the molecular mechanism of cryoprotective function of trehalose, we have studied the interaction between trehalose and phosphatidylcholine (PC) which is a main lipid component of cell membranes. In this study, the structural change of a binary PC mixture by the presence of trehalose was investigated by means of small angle neutron scattering. The PC binary mixture studied contains dihexanoyl-PC (diC{sub 6}PC) and dihexadecy-PC (DHPC). The former has short hydrocarbon chains and the latter has long hydrocarbon chains. The scattering profiles from the DHPC/diC{sub 6}PC mixture were changed, depending on trehalose concentrations. This change can be interpreted as suggesting that the presence of trehalose reduces the interfacial area between water and PCs. (author)

X-ray magnetic circular dichroism and small angle neutron scattering studies of thiol capped gold nanoparticles

International Nuclear Information System (INIS)

de la Venta, J.; Bouzas, V.; Pucci, A.; Laguna-Marco, M.A.; Haskel, D.; te Velthuis, S.G.E; Hoffmann, A.; Lal, J.; Bleuel, M.; Ruggeri, G.; de Julian Fernandez, C.; Garcia, M.A.

2009-01-01

X-ray magnetic circular dichroism (XMCD) and Small Angle Neutron Scattering (SANS) measurements were performed on thiol capped Au nanoparticles (NPs) embedded into polyethylene. An XMCD signal of 0.8 · 10 -4 was found at the Au L 3 edge of thiol capped Au NPs embedded in a polyethylene matrix for which Superconducting Quantum Interference Device (SQUID) magnetometry yielded a saturation magnetization, M s , of 0.06 emu/g Au . SANS measurements showed that the 3.2 nm average-diameter nanoparticles are 28% polydispersed, but no detectable SANS magnetic signal was found with the resolution and sensitivity accessible with the neutron experiment. A comparison with previous experiments carried out on Au NPs and multilayers, yield to different values between XMCD signals and magnetization measured by SQUID magnetometer. We discuss the origin of those differences

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.)

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.)

V4: The Small Angle Scattering Instrument (SANS at BER II

Directory of Open Access Journals (Sweden)

Uwe Keiderling

2016-11-01

Full Text Available V4 is a small-angle neutron scatting instrument with an accessible range of scattering vector 0.01 nm-1 < Q < 8.5 nm-1. Outstanding features of the instrument are the polarized neutron option and the list mode data acquisition, allowing for time-resolved measurements with µs time resolution.

Spin-Echo Small Angle Neutron Scattering analysis of liposomes and bacteria

Science.gov (United States)

van Heijkamp, Léon F.; Sevcenco, Ana-Maria; Abou, Diane; van Luik, Remko; Krijger, Gerard C.; Hagedoorn, Peter-Leon; de Schepper, Ignatz M.; Wolterbeek, Bert; Koning, Gerben A.; Bouwman, Wim G.

2010-10-01

Two types of liposomes, commonly used in drug delivery studies, and E. coli bacteria, all prepared in H2O, were resuspended in D2O and measured with Small Angle Spin-Echo Neutron Scattering (SESANS). Modeling was performed using correlation functions for solid spheres and hollow spheres. The signal strength and curve shape were more indicative of hollow particles, indicating that the H2O-D2O exchange occurred too fast to be observed with the available time resolution. Fitting the particle diameter and membrane thickness of the hollow sphere model to the data, gave results which were in good agreement with Dynamic Light Scattering (DLS) data and literature, showing as a proof-of-principle that SESANS is able to investigate such systems. SESANS may become a good alternative to conventional tritium studies or a tool with which to study intracellular vesicle transport phenomena, with possible in vivo applications. Calculations show that a substantial change in numbers of a mixed system of small and large biological particles should be observable. A possible application is the destruction by external means of great numbers of liposomes in the presence of tumor cells for triggered drug release in cancer treatment. Since SESANS is both non-invasive and non-destructive and can handle relatively thick samples, it could be a useful addition to more conventional techniques.

The new 'BerSANS-PC' software for reduction and treatment of small angle neutron scattering data

International Nuclear Information System (INIS)

Keiderling, U.

2002-01-01

Measurements on small angle neutron scattering (SANS) instruments are typically characterized by a large number of samples, short measurement times for the individual samples, and a frequent change of visiting scientist groups. Besides this, recent advances in instrumentation have led to more frequent measurements of kinetic sequences and a growing interest in analyzing two-dimensional scattering data, these requiring special software tools that enable the users to extract physically relevant information from the scattering data with a minimum of effort. The new 'BerSANS-PC' data-processing software has been developed at the Hahn-Meitner-Institut (HMI) in Berlin, Germany, to meet these requirements and to support an efficiently working guest-user service. Comprising some basic functions of the 'BerSANS' program available at the HMI and other institutes in the past, BerSANS-PC is a completely new development for network-independent use on local PCs with a full-feature graphical interface. (orig.)

Search for small-angle neutron scattering in MnO at 1700K

International Nuclear Information System (INIS)

Routbort, J.L.; Epperson, J.E.; Klippert, T.E.; Goretta, K.C.

1986-01-01

A preliminary small-angle scattering (SANS) experiment has been performed on MnO single crystal at the Intense Pulsed Neutron Source. The experiment was preformed at 1700 0 K at oxygen partial pressures of 2.2 x 10 -4 , 1 x 10 2 , and 2 x 10 2 Pa, which resulted in deviations from stoichiometry of about 0.0015, 0.082, and 0.127. No statistically significant change in SANS was observed at this temperature with the pressure changes. Neither was any significant change observed in the wavelength-dependent sample transmission, also measured in-situ as a function of pressure. Therefore, either clustering of cation vacancies is negligible in MnO for these conditions, or the clusters are smaller than about 5 A. Of proposed cluster configurations, only the existence of the smallest (4:1, 6:2, or possible 8:3) appears to be consistent with these results

Investigation of Monodisperse Dendrimeric Polysaccharide Nanoparticle Dispersions Using Small Angle Neutron Scattering

Science.gov (United States)

Atkinson, John; Nickels, Jonathan; Papp-Szabo, Erzsi; Katsaras, John; Dutcher, John

2015-03-01

Phytoglycogen is a highly branched polysaccharide that is very similar to the energy storage molecule glycogen. We have isolated monodisperse phytoglycogen nanoparticles from corn and these particles are attractive for applications in the cosmetic, food and beverage, and biomedical industries. Many of these promising applications are due to the special interaction between the nanoparticles and water, which results in: (1) high solubility; (2) low viscosity and high stability in aqueous dispersions; and (3) a remarkable capacity to sequester and retain water. Our rheology measurements indicate that the nanoparticles behave like hard spheres in water, with the viscosity diverging for concentrations >25% (w/w). Because of this, aqueous suspensions of phytoglycogen provide an ideal platform for detailed testing of theories of colloidal glasses and jamming. To further explore the interaction of the phytoglycogen particles and water, we have performed small angle neutron scattering (SANS) measurements on the Extended Q-Range SANS (EQ-SANS) diffractometer at the Spallation Neutron Source at Oak Ridge National Laboratory. Measurements performed on phytoglycogen dispersions in mixtures of hydrogenated and deuterated water have allowed us to determine the particle size and average particle spacing as a function of the phytoglycogen concentration in the limits of dilute and concentrated dispersions.

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.

The investigation of Fe-Mn-based alloys with shape memory effect by small-angle scattering of polarized neutrons

International Nuclear Information System (INIS)

Kopitsa, G.P.; Runov, V.V.; Grigoriev, S.V.; Bliznuk, V.V.; Gavriljuk, V.G.; Glavatska, N.I.

2003-01-01

The small-angle polarized neutron scattering (SAPNS) technique has been used to study a nuclear and magnetic homogeneity in the distribution of both substituent (Si, Cr, Ni) and interstitial (C, N) alloying elements on the mesoscopic range in Fe-Mn-based alloys with shape memory effect (SME). The four groups of alloys with various basic compositions: FeMn 18 (wt%), FeMn 20 Si 6 , FeMn 20 Cr 9 N 0.2 and FeMn 17 Cr 9 Ni 4 Si 6 were investigated. It was found that the small-angle scattering of neutrons and depolarization on these alloys are very small altogether. The scattering did not exceed 1.5% from the incident beam and depolarization ∼2% for all samples. It means that these alloys are well nuclear and magnetically homogeneous on the scale of 10-1000 A. However, the difference in the homogeneity depending on the compositions still takes place. Thus, the adding of Si in FeMn 18 and FeMn 20 Cr 9 N 0.2 alloys improves the homogeneity pronouncedly. At once, the effect of the doping by C or N atoms on the homogeneity in FeMn 20 Si 6 and FeMn 17 Cr 9 Ni 4 Si 6 alloys is multivalued and depend on the presence of substitutional atoms (Ni and Cr). The capability of SAPNS as a method for the study of mesoscopic homogeneity in materials with SME and testing of the quality of their preparation is discussed

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)

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

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.

X-ray magnetic circular dichroism and small angle neutron scattering studies of thiol capped gold nanoparticles.

Energy Technology Data Exchange (ETDEWEB)

de la Venta, J.; Bouzas, V.; Pucci, A.; Laguna-Marco, M. A.; Haskel, D.; te Velthuis, S. G. E; Hoffmann, A.; Lal, J.; Bleuel, M.; Ruggeri, G.; de Julian Fernandez, C.; Garcia, M. A.; Univ.Complutense de Madrid; Inst. de Magnetismo Aplicado; Univ. of Pisa; Lab. di Magnetismo Molecolare

2009-01-01

X-ray magnetic circular dichroism (XMCD) and Small Angle Neutron Scattering (SANS) measurements were performed on thiol capped Au nanoparticles (NPs) embedded into polyethylene. An XMCD signal of 0.8 {center_dot} 10{sup -4} was found at the Au L{sub 3} edge of thiol capped Au NPs embedded in a polyethylene matrix for which Superconducting Quantum Interference Device (SQUID) magnetometry yielded a saturation magnetization, M{sub s}, of 0.06 emu/g{sub Au}. SANS measurements showed that the 3.2 nm average-diameter nanoparticles are 28% polydispersed, but no detectable SANS magnetic signal was found with the resolution and sensitivity accessible with the neutron experiment. A comparison with previous experiments carried out on Au NPs and multilayers, yield to different values between XMCD signals and magnetization measured by SQUID magnetometer. We discuss the origin of those differences.

X-ray magnetic circular dichroism and small angle neutron scattering study of thiol capped gold nanoparticles.

Energy Technology Data Exchange (ETDEWEB)

de la Venta, J.; Bouzas, V.; Pucci, A.; Laguna-Marco, M. A.; Haskel, D.; Pinel, E. F.; te Velthuis, S. G. E.; Hoffmann, A.; Lal, J.; Bleuel, M.; Ruggeri, G.; de Julian, C.; Garcia, M. A.; Univ. Complutense de Madrid; Inst. de Magnetismo Aplicado UCM; Univ. Pisa; Univ. di Padova

2009-11-01

X-ray magnetic circular dichroism (XMCD) and Small Angle Neutron Scattering (SANS) measurements were performed on thiol capped Au nanoparticles (NPs) embedded into polyethylene. An XMCD signal of 0.8 {center_dot} 10{sup -4} was found at the Au L{sub 3} edge of thiol capped Au NPs embedded in a polyethylene matrix for which Superconducting Quantum Interference Device (SQUID) magnetometry yielded a saturation magnetization, M{sub s}, of 0.06 emu/g{sub Au}. SANS measurements showed that the 3.2 nm average-diameter nanoparticles are 28% polydispersed, but no detectable SANS magnetic signal was found with the resolution and sensitivity accessible with the neutron experiment. A comparison with previous experiments carried out on Au NPs and multilayers, yield to different values between XMCD signals and magnetization measured by SQUID magnetometer. We discuss the origin of those differences.

Development of the Very Low Angle Detector (VLAD) for detection of epithermal neutrons at low momentum transfers

International Nuclear Information System (INIS)

Tardocchi, M.; Andreani, C.; Cremonesi, O.; Gorini, G.; Perelli-Cippo, E.; Pietropaolo, A.; Rhodes, N.; Schooneveld, E.; Senesi, R.

2006-01-01

New perspectives for epithermal neutron spectroscopy are opened up by the recent development of new instrumentation for inverse geometry time of flight spectrometers at pulsed neutron sources. One example is the Very Low Angle Detector (VLAD) bank which will be installed as an upgrade of the VESUVIO neutron spectrometer, at the ISIS pulsed neutron source. VLAD is developed for detecting epithermal neutrons in the 1-100 eV energy range at very low scattering angles (l deg. - 5 deg.). VLAD will extend the kinematical region covered by today's neutron scattering experiments to the region of low wave vector transfers ( -1 ) and high energy transfers (>1 eV). Accessing such kinematical region will allow new experimental studies in condensed matter systems. The neutron detection is based on Resonance Detectors (RD), which consist of the combination of a resonance foil used as neutron-to-gamma converter and a photon detector. The results obtained with a prototype VLAD detector confirm the potential of this kind of experiments at scattering angles as low as 2 deg. - 5 deg. GEANT4 simulations are used to address issues, such as detector cross talk, which arise with the construction of compact RD arrays

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

Characterization of Nano Sized Microstructures in Fe and Ni Base ODS Alloys Using Small Angle Neutron Scattering

International Nuclear Information System (INIS)

Han, Young-Soo; Jang, Jin-Sung; Mao, Xiaodong

2015-01-01

Ferritic ODS(Oxide-dispersion-strengthened) alloy is known as a primary candidate material of the cladding tubes of a sodium fast reactor (SFR) in the Generation IV research program. In ODS alloy, the major contribution to the enhanced high-temperature mechanical property comes from the existence of nano-sized oxide precipitates, which act as obstacles to the movement of dislocations. In addition for the extremely high temperature application(>950 .deg. C) of future nuclear system, Ni base ODS alloys are considered as candidate materials. Therefore the characterization of nano-sized microstructures is important for determining the mechanical properties of the material. Small angle neutron scattering (SANS) technique non-destructively probes structures in materials at the nano-meter length of scale (1 - 1000 nm) and has been a very powerful tool in a variety of scientific/engineering research areas. In this study, nano-sized microstructures were quantitatively analyzed by small angle neutron scattering. Quantitative microstructural information on nanosized oxide in ODS alloys was obtained from SANS data. The effects of the thermo mechanical treatment on the size and volume fraction of nano-sized oxides were analyzed. For 12Cr ODS alloy, the experimental A-ratio is two-times larger than the theoretical A-ratio., and this result is considered to be due to the imperfections included in YTaO 4 . For Ni base ODS alloy, the volume fraction of the mid-sized particles (- 30 nm) increases rapidly as hot extrusion temperature decreases

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.

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

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.

VLAD for epithermal neutron scattering experiments at large energy transfers

International Nuclear Information System (INIS)

Tardocchi, M; Gorini, G; Perelli-Cippo, E; Andreani, C; Imberti, S; Pietropaolo, A; Senesi, R; Rhodes, N R; Schooneveld, E M

2006-01-01

The Very Low Angle Detector (VLAD) bank will extend the kinematical region covered by today's epithermal neutron scattering experiments to low momentum transfer ( -1 ) together with large energy transfer 0 -4 0 . In this paper the design of VLAD is presented together with Montecarlo simulations of the detector performances. The results of tests made with prototype VLAD detectors are also presented, confirming the usefulness of the Resonance Detector for measurements at very low scattering angles

The application of density functional theory to the analysis of small-angle neutron scattering of concentrated microemulsion with nonionic surfactant

International Nuclear Information System (INIS)

Korneta, W.; Lopez Quintela, M.A.; Liz, L.

1993-09-01

The experimental results obtained by the static small-angle neutron scattering technique for the microemulsion consisting of 40% in volume of nonionic surfactant pentaethylene-glycol-4-octylphenylether, equal volumes of heavy water and decane, and additives (the salt KCl, the anionic surfactant SDS and butanol) are presented and discussed. The universal features of obtained scattering intensity plots are determined. The shape of the peak present in all scattering spectra was fitted by the universal function derived from the density functional theory. The persistence length of surfactant sheet used in many density functional theories of microemulsions is determined and the effect of different additives on this length is shown. (author). 10 refs, 2 figs

Time-resolved small angle neutron scattering measurements of asphaltene nanoparticle aggregation kinetics in incompatible crude oil mixtures

International Nuclear Information System (INIS)

Mason, Thomas G.; Lin, Min Y.

2003-01-01

We use time-resolved-small angle neutron scattering to study the kinetics of asphaltene nanoparticle aggregation in incompatible crude oil mixtures. We induce asphaltene aggregation by mixing asphaltene-rich Syrian crude oil (SACO) with a paraffinic British crude oil and observe the scattered neutron intensity, I, as a function of wave number, q, over times, t, ranging from twenty minutes to about a week. We observe a growth in I at low q as the nanoscale asphaltenes agglomerate into microscale aggregates and interpret this growth as an increase in surface scattering from the aggregates. We fit I(q,t) to an empirical model and measure the growth in the power-law exponent, α, associated with the low-q logarithmic slope of I(q). We define a time, τ α , associated with the first appearance of the aggregates when α>3; τ α increases as a function of the volume fraction, φ m , of SACO in the mixture. The surface scattering intensity initially increases and then saturates at long times when the aggregate structures no longer evolve at the length scales we probe. Based on this saturation, we define a time scale, τ I , which is larger than τ α but has essentially the same dependence on φ m . We interpret τ α (φ m ) and τ I (φ m ) in terms of a simple aggregation model based on diffusion-limited kinetics and a repulsive potential barrier that models the effective solvent quality

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

Investigations on the density fluctuations of deuterium in niobium and tantalum by means of energy resolving neutron small-angle scattering

International Nuclear Information System (INIS)

Muenzing, W.

1978-01-01

Density fluctuations of solved deuterium were measured by means of small angle scattering ob subthermal neutrons at deuterated niobium and tantalum single crystals between temperatures of 340 and 640 K. The concentrations were varied at the NbD between c = 0.10 and c = 0.53 (atomic ratio D-atom / Nb-atom). The center point was at the critical concentration of c = 0.31. In TaD there was only one concentration c = 0.14 (D-atoms / Ta-atoms) measured. At the critical point of Tsub(c) approx. 455 K no diverging critical scattering intensity was observed. (orig./HSI) [de

Biological Small Angle Scattering: Techniques, Strategies and Tips

Energy Technology Data Exchange (ETDEWEB)

Chaudhuri, Barnali [University at Buffalo (SUNY); Muñoz, Inés G. [Centro Nacional de Investigaciones Oncológicas Madrid, Madrid, Spain; Urban, Volker S. [ORNL; Qian, Shuo [ORNL

2017-12-01

This book provides a clear, comprehensible and up-to-date description of how Small Angle Scattering (SAS) can help structural biology researchers. SAS is an efficient technique that offers structural information on how biological macromolecules behave in solution. SAS provides distinct and complementary data for integrative structural biology approaches in combination with other widely used probes, such as X-ray crystallography, Nuclear magnetic resonance, Mass spectrometry and Cryo-electron Microscopy. The development of brilliant synchrotron small-angle X-ray scattering (SAXS) beam lines has increased the number of researchers interested in solution scattering. SAS is especially useful for studying conformational changes in proteins, highly flexible proteins, and intrinsically disordered proteins. Small-angle neutron scattering (SANS) with neutron contrast variation is ideally suited for studying multi-component assemblies as well as membrane proteins that are stabilized in surfactant micelles or vesicles. SAS is also used for studying dynamic processes of protein fibrillation in amyloid diseases, and pharmaceutical drug delivery. The combination with size-exclusion chromatography further increases the range of SAS applications.The book is written by leading experts in solution SAS methodologies. The principles and theoretical background of various SAS techniques are included, along with practical aspects that range from sample preparation to data presentation for publication. Topics covered include techniques for improving data quality and analysis, as well as different scientific applications of SAS. With abundant illustrations and practical tips, we hope the clear explanations of the principles and the reviews on the latest progresses will serve as a guide through all aspects of biological solution SAS.The scope of this book is particularly relevant for structural biology researchers who are new to SAS. Advanced users of the technique will find it helpful for

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

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.

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

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

The influence of C/Ta ratio on TaC precipitates in Co-Re base alloys investigated by small-angle neutron scattering

Czech Academy of Sciences Publication Activity Database

Karge, L.; Gilles, R.; Mukherji, D.; Strunz, Pavel; Beran, Přemysl; Hofmann, M.; Gavilano, J. L.; Keiderling, U.; Dolotko, O.; Kriele, A.; Neubert, A.; Rösler, J.; Petry, W.

2017-01-01

Roč. 132, JUN (2017), s. 354-366 ISSN 1359-6454 R&D Projects: GA ČR GB14-36566G Institutional support: RVO:61389005 Keywords : high temperature alloys * small-angle neutron scattering * precipitaiton * in-situ studies * phase transformation Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 5.301, year: 2016

Magnetic phase diagram of MnSi near critical temperature studied by neutron small angle scattering

International Nuclear Information System (INIS)

Ishikawa, Yoshikazu; Arai, Masatoshi

1984-01-01

The magnetic phase diagram of MnSi near the critical temperature T sub(N)=29.5K has been studied by neutron small angle scattering at KENS. It has been found that the anomalous new phase predicted by various methods to exist around at 28 K and 2 kOe is the paramagnetic phase where the magnetic correlations exhibit the same characteristics as those found at 29.5 K and zero magnetic field. This phenomenon, together with the sharp decrease of the magnetic phase boundary at T sub(N) and the substantial increase of the satellite Q vector at this temperature, has been found not to be interpreted by the current theories. (author)

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

Fine scale microstructure in cast and aged duplex stainless steels investigated by small angle neutron scattering

International Nuclear Information System (INIS)

Epperson, J.E.; Lin, J.S.; Spooner, S.

1986-02-01

Small angle neutron scattering (SANS) allows clustering phenomena to be studied in systems for which the constituent atoms do not differ greatly in atomic number. This investigation used SANS to characterize the fine scale microstructure in two cast and aged duplex stainless steels; aging times extended up to eight years. The steels differed in ferrite content by about a factor of two. The scattering at lowest q was dominated by magnetic scattering effects associated with the ferrite phase. In the range 0.025 less than or equal to q less than or equal to 0.2A -1 , additional scattering due to a precipitating phase rich in Ni and Si was observed. This scattering was rather intense and revealed a volume fraction of precipitate, in the ferrite, estimated to be 12 to 18% after long time aging. After about 70,000 hours at 400 0 C, there were about 10 18 precipitate particles per cm 3 some 50A in mean diameter, and they were distributed in a nonrandom manner, i.e., spatially, short-range-ordered. This investigation suggests that after aging some 70,000 hours at 400 0 C, the precipitate in the ferrite phase is undergoing Ostwald ripening. The present data are insufficient to indicate at what time this ripening process began

Shear- and magnetic-field-induced ordering in magnetic nanoparticle dispersion from small-angle neutron scattering

International Nuclear Information System (INIS)

Krishnamurthy, V.V.; Bhandar, A.S.; Piao, M.; Zoto, I.; Lane, A.M.; Nikles, D.E.; Wiest, J.M.; Mankey, G.J.; Porcar, L.; Glinka, C.J.

2003-01-01

Small-angle neutron scattering experiments have been performed to investigate orientational ordering of a dispersion of rod-shaped ferromagnetic nanoparticles under the influence of shear flow and static magnetic field. In this experiment, the flow and flow gradient directions are perpendicular to the direction of the applied magnetic field. The scattering intensity is isotropic in zero-shear-rate or zero-applied-field conditions, indicating that the particles are randomly oriented. Anisotropic scattering is observed both in a shear flow and in a static magnetic field, showing that both flow and field induce orientational order in the dispersion. The anisotropy increases with the increase of field and with the increase of shear rate. Three states of order have been observed with the application of both shear flow and magnetic field. At low shear rates, the particles are aligned in the field direction. When increasing shear rate is applied, the particles revert to random orientations at a characteristic shear rate that depends on the strength of the applied magnetic field. Above the characteristic shear rate, the particles align along the flow direction. The experimental results agree qualitatively with the predictions of a mean field model

Magnetic small-angle scattering of subthermal neutrons by internal stress fields in work-hardened nickel single crystals oriented for multiple glide

International Nuclear Information System (INIS)

Vorbrugg, W.; Schaerpf, O.

1975-01-01

The small-angle scattering of Ni single crystals with (111) and (100) axis orientation is measured by a photographic method in the work-hardened state after tensile deformation. Parameters are the external magnetic field H parallel to the axis (600 2 ]<=8,8), and the elastic stress tausub(el)(0<=tausub(el)<=tausub(pl)) applied to the deformed crystals during the experiments. The scattering is found to be anisotropic and characteristic for the chosen orientation. The quantitative photometric analysis shows that the parameters mentioned above only influence the intensity but not the distribution of the scattered neutrons. The scattering increases with the elastic stress and decreases with the magnetic field. In particular, in the unloaded state there is a linear relation between the scattered intensity and the plastic shear stress. (author)

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

Microstructural characterization of dental zinc phosphate cements using combined small angle neutron scattering and microfocus X-ray computed tomography

Czech Academy of Sciences Publication Activity Database

Viani, Alberto; Sotiriadis, Konstantinos; Kumpová, Ivana; Mancini, L.; Appavou, M.-S.

2017-01-01

Roč. 33, č. 4 (2017), s. 402-417 ISSN 0109-5641 R&D Projects: GA MŠk(CZ) LO1219 Keywords : zinc phosphate cements * small angle neutron scattering * X-ray micro-computed tomography * X-ray powder diffraction * zinc oxide * acid-base cements Subject RIV: JJ - Other Materials OBOR OECD: Composites (including laminates, reinforced plastics, cermets, combined natural and synthetic fibre fabrics Impact factor: 4.070, year: 2016 https://www.sciencedirect.com/science/article/pii/S0109564116305127

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

Small angle scattering methods to study porous materials under high uniaxial strain

Energy Technology Data Exchange (ETDEWEB)

Le Floch, Sylvie, E-mail: sylvie.le-floch@univ-lyon1.fr; Balima, Félix; Pischedda, Vittoria; Legrand, Franck; San-Miguel, Alfonso [Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon, 69622 Villeurbanne Cedex (France)

2015-02-15

We developed a high pressure cell for the in situ study of the porosity of solids under high uniaxial strain using neutron small angle scattering. The cell comprises a hydraulically actioned piston and a main body equipped with two single-crystal sapphire windows allowing for the neutron scattering of the sample. The sample cavity is designed to allow for a large volume variation as expected when compressing highly porous materials. We also implemented a loading protocol to adapt an existing diamond anvil cell for the study of porous materials by X-ray small angle scattering under high pressure. The two techniques are complementary as the radiation beam and the applied pressure are in one case perpendicular to each other (neutron cell) and in the other case parallel (X-ray cell). We will illustrate the use of these two techniques in the study of lamellar porous systems up to a maximum pressure of 0.1 GPa and 0.3 GPa for the neutron and X-ray cells, respectively. These devices allow obtaining information on the evolution of porosity with pressure in the pore dimension subdomain defined by the wave-numbers explored in the scattering process. The evolution with the applied load of such parameters as the fractal dimension of the pore-matrix interface or the apparent specific surface in expanded graphite and in expanded vermiculite is used to illustrate the use of the high pressure cells.

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.

Small-angle scattering studies of the fully hydrated phospholipid DPPC

Energy Technology Data Exchange (ETDEWEB)

Mason, P.C.; Gaulin, B.D. [Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, L8S 4M1 (CANADA); Epand, R.M. [Department of Biochemistry, McMaster University, Hamilton, Ontario, L8N 3Z5 (CANADA); Wignall, G.D.; Lin, J.S. [Center for Small-Angle Scattering Research, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

1999-01-01

Small-angle neutron and x-ray scattering studies have been carried out on fully hydrated dipalmitoylphosphatidylcholine (DPPC) multilamellar vesicles. This system is known to exhibit two distinct ripple (P{sub {beta}{sup {prime}}}) phases, which depend on sample history, at temperatures intermediate to its high-temperature liquid crystalline (L{sub {alpha}}), phase, and its low-temperature gel (L{sub {beta}{sup {prime}}}), phase. On cooling from the L{sub {alpha}} phase, the P{sub {beta}{sup {prime}}} phase displays a complex multipeak diffraction pattern that differs significantly from the diffraction pattern seen in the P{sub {beta}{sup {prime}}} phase obtained on warming from the L{sub {beta}{sup {prime}}} phase. Examining the P{sub {beta}{sup {prime}}} phase on cooling using small-angle neutron scattering and x-ray diffraction techniques leads to the conclusion that this phase is characterized by a long wavelength ripple ({lambda}{sub r}{approximately}330thinsp{Angstrom}) and a highly monoclinic unit cell ({gamma}{approximately}125{degree}). As the P{sub {beta}{sup {prime}}} phase is traversed in temperature, the ripple wavelength changes significantly while the monoclinicity remains unchanged. Ripples from the P{sub {beta}{sup {prime}}} phase are seen to persist into the L{sub {beta}{sup {prime}}} phase on cooling, leading to increased small-angle scattering characteristic of a disordered stacking of the lamellae. {copyright} {ital 1999} {ital The American Physical Society}

Investigation of coercivity mechanism in hot deformed Nd-Fe-B permanent magnets by small-angle neutron scattering

International Nuclear Information System (INIS)

Yano, M.; Manabe, A.; Shoji, T.; Kato, A.; Ono, K.; Harada, M.; Kohlbrecher, J.

2014-01-01

The magnetic reversal behaviors of single domain sized Nd-Fe-B permanent magnets, with and without isolation between the Nd 2 Fe 14 B grains, was clarified using small-angle neutron scattering (SANS). The SANS patterns obtained arose from changes in the magnetic domains and were analyzed using the Teubner–Stray model, a phenomenological correlation length model, to quantify the periodicity and morphology of the magnetic domains. The results indicated that the magnetic reversal evolved with the magnetic domains that had similar sized grains. The grain isolation enabled us to realize the reversals of single domains

Small-angle neutron scattering study of recombinant yeast-derived human hepatitis B virus surface antigen vaccine particle

Science.gov (United States)

Sato, M.; Ito, Y.; Kameyama, K.; Imai, M.; Ishikawa, N.; Takagi, T.

1995-02-01

The overall and internal structure of recombinant yeast-derived human hepatitis B virus surface antigen vaccine particles was investigated by small-angle neutron scattering using the contrast variation method. The vaccine is a nearly spherical particle, and its contrast-matching point was determined to be at about 24% D 2O content, indicating that a large part of the vaccine particle is occupied by lipids and carbohydrates from the yeast. The Stuhrmann plot suggests that the surface antigens exist predominantly in the peripheral region of the particle, which is favorable to the induction of anti-virus antibodies.

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.)

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

The study of the structural properties of very low viscosity sodium alginate by small-angle neutron scattering

Energy Technology Data Exchange (ETDEWEB)

Badita, C. R., E-mail: ramona@tandem.nipne.ro [Horia Hulubei National Institute of Physics and Nuclear Engineering, Reactorului 30, RO-077125, POB-MG6, Magurele-Bucharest, Romania, ramona@tandem.nipne.ro, daranghe@nipne.ro (Romania); University of Bucharest, Faculty of Physics, Atomiştilor 405, CP MG - 11, RO – 077125, Bucharest-Magurele (Romania); Aranghel, D., E-mail: daranghe@nipne.ro [Horia Hulubei National Institute of Physics and Nuclear Engineering, Reactorului 30, RO-077125, POB-MG6, Magurele-Bucharest, Romania, ramona@tandem.nipne.ro, daranghe@nipne.ro (Romania); Extreme Light Intrastructure Nuclear Physics (ELI-NP), Reactorului 30, RO-077125, POB-MG6, Magurele-Bucharest (Romania); Radulescu, A. [Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science, 85747 Garching (Germany); Anitas, E. M. [Horia Hulubei National Institute of Physics and Nuclear Engineering, Reactorului 30, RO-077125, POB-MG6, Magurele-Bucharest, Romania, ramona@tandem.nipne.ro, daranghe@nipne.ro (Romania); Joint Institute for Nuclear Research, 141980 Dubna, Moscow region (Russian Federation)

2016-03-25

Sodium alginate is a linear polymer extract from brown algae and it is used in the biomedical, food, cosmetics and pharmaceutical industries as solution property modifiers and gelling agents. But despite the extensive studies of the alginate gelation process, still some fundamental questions remain unresolved. The fractal behavior of very low viscosity sodium alginate solutions and their influence on the critical gelation of alginate induced by Ca{sup 2+} ions were investigated using Small-Angle Neutron Scattering (SANS) measurements. SANS data are interpreted using both standard linear plots and the Beaucage model. The scattering intensity is dependent by alginate concentration and Ca{sup 2+} concentration. From a critical concentration of 1.0 % w/w our polymer swelled forming spherical structures with rough surfaces. Also the addition of the salt induces the collapse and the appearance of the aggregation and clusters formation.

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

Small-angle neutron scattering investigation of polyurethane aged in dry and wet air

Directory of Open Access Journals (Sweden)

Q. Tian

2014-05-01

Full Text Available The microstructures of Estane 5703 aged at 70°C in dry and wet air have been studied by small-angle neutron scattering. The samples were swollen in deuterated toluene for enhancing the contrast. The scattering data show the characteristic domain structure of polyurethanes consisting of soft and hard segments. Debye-Anderson-Brumberger function used with hard sphere structure factor, and the Teubner-Strey model are used to analyze the two-phase domain structure of the polymer. The combined effects of temperature and humidity have a strong disruption effect on the microstructures of Estane. For the sample aged at 70°C in wet air for 1 month, the domain size, described by the correlation length, increases from 2.3 to 3.8 nm and their distance, expressed by hard-sphere interaction radius, increases from 8.4 to 10.6 nm. The structure development is attributed to degradation of polymer chains as revealed by gel permeation chromatography. The hydrolysis of ester links on polymer backbone at 70°C in the presence of water humidity is the main reason for the changes of the microstructure. These findings can contribute to developing predictive models for the safety, performance, and lifetime of polyurethanes.

Small angle neutron scattering and calorimetric studies of large unilamellar vesicles of the phospholipid dipalmitoylphosphatidylcholine

Energy Technology Data Exchange (ETDEWEB)

Mason, P.C.; Gaulin, B.D. [Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, L8S 4M1 (CANADA); Epand, R.M. [Department of Biochemistry, McMaster University, Hamilton, Ontario, L8N 3Z5 (CANADA); Wignall, G.D.; Lin, J.S. [Center for Small-Angle Scattering Research, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

1999-03-01

High-resolution differential scanning calorimetry (DSC) and small angle neutron scattering (SANS) experiments have been conducted on large unilamellar vesicles (LUV{close_quote}s) of the phospholipid dipalmitoylphosphatidylcholine (DPPC) in excess water. The DSC results indicate a phase transition at temperatures corresponding to the gel (L{sub {beta}{sup {prime}}}) to ripple (P{sub {beta}{sup {prime}}}) phase transition seen in multilamellar vesicles of DPPC while the SANS experiments provide direct evidence for the formation of the P{sub {beta}{sup {prime}}} phase in these systems. In addition, it is shown that SANS is an effective technique for extracting structural parameters such as vesicle radius and thickness in LUV model membrane systems. {copyright} {ital 1999} {ital The American Physical Society}

Small angle neutron scattering on an absolute intensity scale and the internal surface of diatom frustules from three species of differing morphologies

Czech Academy of Sciences Publication Activity Database

Garvey, C. J.; Strobl, M.; Percot, A.; Šaroun, Jan; Haug, J.; Vyverman, W.; Chepurnov, V. A.; Ferris, J. M.

2013-01-01

Roč. 42, č. 5 (2013), s. 395-404 ISSN 0175-7571 Institutional support: RVO:61389005 Keywords : biosilica * diffusion limited aggregation * small angle neutron scattering * Raman spectroscopy * infrared spectroscopy * Porod law * BET isotherm * biomineralisation Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.474, year: 2013 http://link.springer.com/content/pdf/10.1007%2Fs00249-013-0889-x.pdf

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)

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)

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

Neutron scattering investigations of the lipid bilayer structure pressure dependence

International Nuclear Information System (INIS)

Solovjov, D.V.; Gordelyij, V.Yi.; Gorshkova, Yu.Je.; Yivan'kov, O.Yi.; Koval'ov, Yu.S.; Kuklyin, A.Yi.; Solovjov, D.V.; Bulavyin, L.A.; Yivan'kov, O.Yi.; Nyikolajenko, T.Yu.; Kuklyin, A.Yi.; Gordelyij, V.Yi.; Gordelyij, V.Yi.

2012-01-01

Lipid bilayer structure investigation results obtained with small angle neutron scattering method at the Joint Institute for Nuclear Research IBR-2M nuclear reactor (Dubna, Russia) are presented. Experiment has been performed with small angle neutron scattering spectrometer YuMO, upgraded with the apparatus for performing PV-T measurements on the substance under investigation. D 2 O-1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) liquid system, presenting the model of natural live membrane, has been taken as the sample for investigations. The lipid bilayer spatial period was measured in experiment along with isothermal compressibility simultaneously at different pressures. It has been shown, that the bilayer structural transition from ripple (wavelike gel-phase) phase to liquid-crystal phase is accompanied with anomalous rise of isothermal compressibility, indicating occurrence of the phase transition.

Characterization of oligomerization of a peptide from the ebola virus glycoprotein by small-angle neutron scattering

International Nuclear Information System (INIS)

Egorov, V. V.; Gorshkov, A. N.; Murugova, T. N.; Vasin, A. V.; Lebedev, D. V.; Isaev-Ivanov, V. V.; Kiselev, O. I.

2016-01-01

Transmission electron microscopy (TEM) and small-angle neutron scattering (SANS) studies showed that model peptides QNALVCGLRQ (G33) and QNALVCGLRG (G31) corresponding to region 551–560 of the GP protein of the Sudan Ebola virus are prone to oligomerization in solution. Both peptides can form amyloid-like fibrills. The G33 peptide forms fibrils within one day of incubation, whereas the fibrillogenesis of the G31 peptide is observed only after incubation for several months. The possible role of the observed processes in the pathogenesis and the possibility of applying a combination of the TEM and SANS techniques to search for new compounds that are able to influence the protein oligomerization are discussed

Characterization of oligomerization of a peptide from the ebola virus glycoprotein by small-angle neutron scattering

Energy Technology Data Exchange (ETDEWEB)

Egorov, V. V., E-mail: vlaegur@omrb.pnpi.spb.ru [National Research Center “Kurchatov Institute”, Konstantinov Petersburg Nuclear Physics Institute (Russian Federation); Gorshkov, A. N. [Ministry of Health of the Russian Federation, Research Institute of Influenza (Russian Federation); Murugova, T. N. [Joint Institute for Nuclear Research (Russian Federation); Vasin, A. V. [Ministry of Health of the Russian Federation, Research Institute of Influenza (Russian Federation); Lebedev, D. V.; Isaev-Ivanov, V. V. [National Research Center “Kurchatov Institute”, Konstantinov Petersburg Nuclear Physics Institute (Russian Federation); Kiselev, O. I. [Ministry of Health of the Russian Federation, Research Institute of Influenza (Russian Federation)

2016-01-15

Transmission electron microscopy (TEM) and small-angle neutron scattering (SANS) studies showed that model peptides QNALVCGLRQ (G33) and QNALVCGLRG (G31) corresponding to region 551–560 of the GP protein of the Sudan Ebola virus are prone to oligomerization in solution. Both peptides can form amyloid-like fibrills. The G33 peptide forms fibrils within one day of incubation, whereas the fibrillogenesis of the G31 peptide is observed only after incubation for several months. The possible role of the observed processes in the pathogenesis and the possibility of applying a combination of the TEM and SANS techniques to search for new compounds that are able to influence the protein oligomerization are discussed.

Characterization of oligomerization of a peptide from the ebola virus glycoprotein by small-angle neutron scattering

Science.gov (United States)

Egorov, V. V.; Gorshkov, A. N.; Murugova, T. N.; Vasin, A. V.; Lebedev, D. V.; Isaev-Ivanov, V. V.; Kiselev, O. I.

2016-01-01

Transmission electron microscopy (TEM) and small-angle neutron scattering (SANS) studies showed that model peptides QNALVCGLRQ (G33) and QNALVCGLRG (G31) corresponding to region 551-560 of the GP protein of the Sudan Ebola virus are prone to oligomerization in solution. Both peptides can form amyloid-like fibrills. The G33 peptide forms fibrils within one day of incubation, whereas the fibrillogenesis of the G31 peptide is observed only after incubation for several months. The possible role of the observed processes in the pathogenesis and the possibility of applying a combination of the TEM and SANS techniques to search for new compounds that are able to influence the protein oligomerization are discussed.

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

Proceedings of the workshop on small angle scattering data analysis. Micelle related topics

Energy Technology Data Exchange (ETDEWEB)

Yamaguchi, Toshio [Fukuoka Univ. (Japan). Faculty of Science; Furusaka, Michihiro; Ohtomo, Toshiya [eds.

1996-02-01

This workshop was held on December 13 and 14, 1995 at National Laboratory for High Energy Physics. At the workshop, the purpose of the workshop was explained, and lectures were given on the research on superhigh molecular structure by small angle neutron scattering, the verification of the reliability of WINK data (absolute intensity), the analysis of WINK data, the new data program of SAN, small angle X-ray scattering data analysis program (SAXS), the basis of the analysis of micelle system, analysis software manual and practice program Q-I(Q) ver 1.0, various analysis methods for small angle scattering and contrast modulation method and others, the ordering of and the countermeasures to the problems of WINK, and the hereafter of KENS small angle scattering facility. How to treat the analysis related to micelle, how to save WINK and how to install the SAN/reflectometer are the matters to be discussed at the workshop. In this book, the summaries of the lectures are collected. (K.I.)

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.

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

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.

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)

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)

Small-angle neutron scattering investigation of the chain conformation of lamellar polystyrene/isoprene phase in solid state

International Nuclear Information System (INIS)

Constantinescu, L.M.

1994-01-01

Small-angle neutron scattering has been used in the study of chain conformation of lamellar styrene/isoprene block copolymers oriented in large single crystals. The radius of gyration of deuterated polystyrene chains around the normal to the interface has been measured. By comparing this direct evolution of the lateral dimension of the chains with the average chain separation given by the molecular area (the surface available at the interface for each covalent bond linking the blocks together) we characterized the transverse interpenetration degree of the chains. The polystyrene chains are displayed in simple strata own micro-domains, without an important interpenetration. (Author) 9 Figs., 2 Tabs., 25 Refs

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.

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)

Low-Resolution Structure of Detergent-Solubilized Membrane Proteins from Small-Angle Scattering Data.

Science.gov (United States)

Koutsioubas, Alexandros

2017-12-05

Despite the ever-increasing usage of small-angle scattering as a valuable complementary method in the field of structural biology, applications concerning membrane proteins remain elusive mainly due to experimental challenges and the relative lack of theoretical tools for the treatment of scattering data. This fact adds up to general difficulties encountered also by other established methods (crystallography, NMR) for the study of membrane proteins. Following the general paradigm of ab initio methods for low-resolution restoration of soluble protein structure from small-angle scattering data, we construct a general multiphase model with a set of physical constraints, which, together with an appropriate minimization procedure, gives direct structural information concerning the different components (protein, detergent molecules) of detergent-solubilized membrane protein complexes. Assessment of the method's precision and robustness is evaluated by performing shape restorations from simulated data of a tetrameric α-helical membrane channel (Aquaporin-0) solubilized by n-Dodecyl β-D-Maltoside and from previously published small-angle neutron scattering experimental data of the filamentous hemagglutinin adhesin β-barrel protein transporter solubilized by n-Octyl β-D-glucopyranoside. It is shown that the acquisition of small-angle neutron scattering data at two different solvent contrasts, together with an estimation of detergent aggregation number around the protein, permits the reliable reconstruction of the shape of membrane proteins without the need for any prior structural information. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

From free to bound water - progress in hydratisation for concrete, measured by means of neutron small angle scatter

International Nuclear Information System (INIS)

Hempel, M.; Haeussler, F.; Eichhorn, E.

1993-01-01

Neutron small angle scatter (NSAS) is suitable for characterising matrix non-homogeneousness in many materials. The description of amorphous materials (distribution of clusters, defect structures, boundary surfaces, e.g.: Between pores and the solid matrix etc.) is possible, in principle, by NSAS. This method is non-destructive to the extent that no pretreatment of samples is necessary, which significantly affects the microstructure to be examined. The process of NSAS itself produces no changes in the sample regarding the target of the examination. Thus the progress of hydratisation in concrete can be observed by successive NSAS measurements in time. (orig./HP) [de

The association effect of human serum albumin under different zinc ion concentrations studied by small angle of neutron scattering

International Nuclear Information System (INIS)

He Jian; Xu Yanping; Yang Tonghua; He Jintian; Li Lianzhi; Zhou Yongqia

1997-01-01

The microscopic parameters of the HSA-Zn 2+ , R g and I(0), are obtained directedly by small angle of neutron scattering (SANS) under different concentrations of zinc ion. Comparing with other relevant experimental results, e.g. equilibrium dialysis, we can determine and distinguish the apparent interactive subsequences into more detailed sub-actions, such as self-association, inter-association, disintegration and deconformation et al., or even certain combination of them, other than some indirect and microscopic results. Results obtained by SANS can qualitatively and readily interpret the characteristics from the viewpoint of microscopic process

Neutron scattering investigations of the lipid bilayer structure pressure dependence

Directory of Open Access Journals (Sweden)

D. V. Soloviov

2012-03-01

Full Text Available Lipid bilayer structure investigation results obtained with small angle neutron scattering method at the Joint Institute for Nuclear Research IBR-2M nuclear reactor (Dubna, Russia are presented. Experiment has been per-formed with small angle neutron scattering spectrometer YuMO, upgraded with the apparatus for performing P-V-T measurements on the substance under investigation. D2O-1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC liquid system, presenting the model of natural live membrane, has been taken as the sample for investiga-tions. The lipid bilayer spatial period was measured in experiment along with isothermal compressibility simulta-neously at different pressures. It has been shown, that the bilayer structural transition from ripple (wavelike gel-phase phase to liquid-crystal phase is accompanied with anomalous rise of isothermal compressibility, indicat-ing occurrence of the phase transition.

Small angle scattering from protein/sugar conjugates

Science.gov (United States)

Jackson, Andrew; White, John

2006-11-01

The Maillard reaction between free amine groups on proteins and sugars is well known. We have examined the effect of the reaction of the casein group of milk proteins with sugars on their nanoscale structure and aggregation. The small angle neutron scattering from beta casein and sodium caseinate and their sugar conjugates have been studied as a function of solution concentration. At high conjugate concentration (greater than ca. 5 mg/ml) the addition of sugar reduces supra-micellar aggregation of the protein whilst at lower concentration, where the protein is expected to be deaggregated already, little effect is seen. Guinier analysis of the scattering data show a radius of gyration of around 75 A˚ for beta casein in solution and around 80 A˚ for the sucrose conjugate.

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.)

Spin-wave dynamics in the helimagnet FeGe studied by small-angle neutron scattering

Science.gov (United States)

Siegfried, S.-A.; Sukhanov, A. S.; Altynbaev, E. V.; Honecker, D.; Heinemann, A.; Tsvyashchenko, A. V.; Grigoriev, S. V.

2017-04-01

We have studied the spin-wave stiffness of the Dzyaloshinskii-Moriya helimagnet FeGe in a temperature range from 225 K up to TC≈278.7 K by small-angle neutron scattering. The method we have used is based on [Grigoriev et al., Phys. Rev. B 92, 220415(R) (2015), 10.1103/PhysRevB.92.220415] and was extended here for the application in polycrystalline samples. We confirm the validity of the anisotropic spin-wave dispersion for FeGe caused by the Dzyaloshinskii-Moriya interaction. We have shown that the spin-wave stiffness A for the FeGe helimagnet decreases with a temperature as A (T ) =194 [1 -0.7 (T/TC) 4.2] meVÅ 2 . The finite value of the spin-wave stiffness A =58 meVÅ 2 at TC classifies the order-disorder phase transition in FeGe as being the first-order one.

3rd AINSE neutron scattering conference, Lucas Heights -AINSE Theatre

International Nuclear Information System (INIS)

1986-01-01

Abstracts of papers, the conference program and general information is included in the conference handbook. The program is divided into the following sessions: hydrogeneous and biological materials, industrial applications, phase transitions, magnetism, small angle neutron scattering and new developments

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.

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)

Analysis of the spatial structure of rigid polyphenylene dendrimers by small-angle neutron scattering

International Nuclear Information System (INIS)

Rosenfeldt, S.; Dingenouts, N.; Poetschke, D.; Ballauff, M.; Berresheim, A.J.; Muellen, K.; Lindner, P.; Saalwaechter, K.

2005-01-01

The analysis of the spatial structure of a rigid polyphenylene dendrimer G4-M of fourth generation by small-angle neutron scattering (SANS) is presented. This dendrimer is composed of phenyl units and is therefore devoid of any flexible unit. The scattering intensity of dilute solutions of the dendrimer was measured by SANS at different contrast which was adjusted by mixtures of protonated and deuterated toluene. Hence, the method of contrast variation could be applied and the data yield the scattering function extrapolated to infinite contrast. The comparison of this data with simulations demonstrates that the scaffold of the dendrimer is rigid as expected from its chemical structure. The positions of the various units setting up consecutive shells of the dendrimer are relatively well localized and the entire structure cannot be modeled in terms of spherically symmetric models. No backfolding of the terminal groups can occur and the model calculations demonstrate that higher generations of this dendritic scaffold must exhibit a dense shell and a congestion of the terminal groups. This finding is directly corroborated by recent solid-state NMR data. All results show that the rigid dendrimer investigated here presents the first example for a dendritic structure whose segment density does not have its maximum at the center. Rigid scaffolds are therefore the only way to achieve the goal of a 'dense-shell' dendrimer whereas flexible scaffolds leads invariably to the 'dense-core' case

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.)

Small angle neutron scattering modeling of copper-rich precipitates in steel

International Nuclear Information System (INIS)

Spooner, S.

1997-11-01

The magnetic to nuclear scattering intensity ratio observed in the scattering from copper rich precipitates in irradiated pressure vessel steels is much smaller than the value of 11.4 expected for a pure copper precipitate in iron. A model for precipitates in pressure vessel steels which matches the observed scattering typically incorporates manganese, nickel, silicon and other elements and it is assumed that the precipitate is non-magnetic. In the present work consideration is given to the effect of composition gradients and ferromagnetic penetration into the precipitate on the small angle scattering cross section for copper rich clusters as distinguished from conventional precipitates. The calculation is an extension of a scattering model for micelles which consist of shells of varying scattering density. A discrepancy between recent SANS scattering experiments on pressure vessel steels was found to be related to applied magnetic field strength. The assumption of cluster structure and its relation to atom probe FIM findings as well as the effects of insufficient field for magnetic saturation is discussed

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.)

Small angle neutron scattering studies of the vortex lattice in the UPt₃ mixed state: Direct structural evidence for the B->C transition

DEFF Research Database (Denmark)

Yaron, U.; Gammel, P.L.; Boebinger, G.S.

1997-01-01

Small angle neutron scattering studies of the flux line lattice (FLL) in UPt3 for fields H perpendicular to c provide direct microscopic evidence for the 5 kOe B --> C transition. We find a pronounced maximum in the longitudinal correlation length of the FLL at the transition and an abrupt change...

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

Light Scattering at Various Angles

Science.gov (United States)

Latimer, Paul; Pyle, B. E.

1972-01-01

The Mie theory of scattering is used to provide new information on how changes in particle volume, with no change in dry weight, should influence light scattering for various scattering angles and particle sizes. Many biological cells (e.g., algal cells, erythrocytes) and large subcellular structures (e.g., chloroplasts, mitochondria) in suspension undergo this type of reversible volume change, a change which is related to changes in the rates of cellular processes. A previous study examined the effects of such volume changes on total scattering. In this paper scattering at 10° is found to follow total scattering closely, but scattering at 45°, 90°, 135°, and 170° behaves differently. Small volume changes can cause very large observable changes in large angle scattering if the sample particles are uniform in size; however, the natural particle size heterogeneity of most samples would mask this effect. For heterogeneous samples of most particle size ranges, particle shrink-age is found to increase large angle scattering. PMID:4556610

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)

Comparison of the Behaviour of Polymers in Supercritical Fluids and Organic Solvents Via Small Angle Neutron Scattering

International Nuclear Information System (INIS)

Melnichenko, Y.B.; Kiran, E.; Heath, K.D.; Salaniwal, S.; Cochran, H.D.; Stamm, M.; Van Hook, W.A.; Wignall, G.D.

1999-01-01

Small-angle neutron scattering has been used to study the effect of temperature and pressure on the phase behavior of semidilute solutions of polymers dissolved in organic and supercritical solvents. Above the theta temperature (To), these systems exhibit a ''good solvent'' domain, where the molecules expand beyond the unperturbed dimensions in both organic solvents and in COZ. However, this transition can be made to occur at a critical ''theta pressure'' (PO) in CO2 and this represents a new concept in the physics of polymer-solvent systems. For T < To, and P < Po, the system enters the ''poor solvent'' domain where diverging concentration fluctuations prevent the chains from collapsing and allow them to maintain their unperturbed dimensions

Conformation of cyclic and linear polydimethylsiloxane in the melt a small-angle neutron-scattering study

CERN Document Server

Gagliardi, S; Dagger, A; Semlyen, A J

2002-01-01

In this study we report small-angle neutron-scattering measurements of cyclic and linear polydimethylsiloxane (PDMS) in the melt. It has been suggested that due to the presence of topological constraints, rings in the melt may be more compact than Gaussian chains. We show that the cyclic chains are partially collapsed and do not follow Gaussian statistics: the weight-average radius of gyration R sub g sub , sub w is found to be proportional to M sub w sup 0 sup . sup 5 sup 3 and M sub w sup 0 sup . sup 4 sup 0 in the case of linear and cyclic PDMS, respectively. The results are in agreement with recent computer simulations, which predict R sub g to be proportional to N sup 2 sup / sup 5 , where N is the degree of polymerisation. (orig.)

Anisotropic kernel p(μ → μ') for transport calculations of elastically scattered neutrons

International Nuclear Information System (INIS)

Stevenson, B.

1985-01-01

Literature in the area of anisotropic neutron scattering is by no means lacking. Attention, however, is usually devoted to solution of some particular neutron transport problem and the model employed is at best approximate. The present approach to the problem in general is classically exact and may be of some particular value to individuals seeking exact numerical results in transport calculations. For attempts neutrons originally directed toward the unit vector Omega, it attempts the evaluation of p(theta'), defined such that p(theta') d theta' is that fraction of scattered neutrons that emerges in the vicinity of a cone i.e., having been scattered to between angles theta' and theta' + d theta' with the axis of preferred orientation i; Omega makes an angle theta with i. The relative simplicity of the final form of the solution for hydrogen, in spite of the complicated nature of the limits involved, is a trade-off that truly is not necessary. The exact general solution presented here in integral form, has exceedingly simple limits, i.e., 0 ≤ theta' ≤ π regardless of the material involved; but the form of the final solution is extraordinarily complicated

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.

Small angle scattering from protein/sugar conjugates

International Nuclear Information System (INIS)

Jackson, Andrew; White, John

2006-01-01

The Maillard reaction between free amine groups on proteins and sugars is well known. We have examined the effect of the reaction of the casein group of milk proteins with sugars on their nanoscale structure and aggregation. The small angle neutron scattering from beta casein and sodium caseinate and their sugar conjugates have been studied as a function of solution concentration. At high conjugate concentration (greater than ca. 5mg/ml) the addition of sugar reduces supra-micellar aggregation of the protein whilst at lower concentration, where the protein is expected to be deaggregated already, little effect is seen. Guinier analysis of the scattering data show a radius of gyration of around 75A-bar for beta casein in solution and around 80A-bar for the sucrose conjugate

Small angle scattering from protein/sugar conjugates

Energy Technology Data Exchange (ETDEWEB)

Jackson, Andrew [Research School of Chemistry, Australian National University, Canberra, ACT 0200 (Australia)]. E-mail: ajj@nist.gov; White, John [Research School of Chemistry, Australian National University, Canberra, ACT 0200 (Australia)

2006-11-15

The Maillard reaction between free amine groups on proteins and sugars is well known. We have examined the effect of the reaction of the casein group of milk proteins with sugars on their nanoscale structure and aggregation. The small angle neutron scattering from beta casein and sodium caseinate and their sugar conjugates have been studied as a function of solution concentration. At high conjugate concentration (greater than ca. 5mg/ml) the addition of sugar reduces supra-micellar aggregation of the protein whilst at lower concentration, where the protein is expected to be deaggregated already, little effect is seen. Guinier analysis of the scattering data show a radius of gyration of around 75A-bar for beta casein in solution and around 80A-bar for the sucrose conjugate.

Inversion of the pahse diagram in polymer blends studied by small-angle neutron scattering

International Nuclear Information System (INIS)

Jinnai, Hiroshi; Hasegawa, Hirokazu; Hashimoto, Takeji; Han, C.C.

1993-01-01

The miscibility of an amorphous mixture of normal (protonated) polybutadiend (HPB) and perdeuterated polybutadiene (DPB) has been extensively studied and was characterized by an upper critical solution temperature (UCST). In this study the miscibility of HPB and DPB as a function of temperature was studied by small-angle neutron scattering (SANS). The vinyl component of the DPB was held constant at 16%, while the vinyl frantion of the HPB was varied from 17-80%. The binary interaction parameter, χ, was obtained. The mixtures of DPB and HPB with 17-39% vinyl show UCST behaviors; i.e., χ increases with decreasing temperature. The mixture of DPB and HPB with 52% vinyl was found to have almost no temperature dependence. However, the mixture of DPB and HPB with 65-80% show a lower critical solution temperature (LCST) behavior; i.e., χ increases with increasing temperature. This inversion of the phase diagram from UCST to LCST has never been observed. (author)

Quantitative analysis of inclusions in low carbon free cutting steel using small-angle X-ray and neutron scattering

International Nuclear Information System (INIS)

Oba, Yojiro; Koppoju, Suresh; Ohnuma, Masato; Kinjo, Yuki; Tomota, Yo; Morooka, Satoshi; Suzuki, Jun-ichi; Yamaguchi, Daisuke; Koizumi, Satoshi; Sato, Masugu; Shiraga, Tetsuo

2012-01-01

The microstructure of inclusions in low carbon free cutting steel without lead addition was investigated using small-angle X-ray scattering (SAXS) coupled with small-angle neutron scattering (SANS). The two-dimensional (2D) SAXS pattern shows clear scattering due to inclusions composed of large elongated particles aligned along the rolling direction, and small isotropic particles. From a comparison of the simulated and experimental 2D SAXS patterns, the shapes of the inclusions are regarded as ellipsoid for the larger inclusions and spherical for the smaller inclusions. The length of the minor axis in the large inclusion is 6.9 μm, while the diameter of the small inclusion is 0.50 μm. The aspect ratio of the large inclusion is estimated to be 3.8 in the lower q region, and is reduced slightly to 3.5 in the higher q region from the azimuthal plots. The results of an alloy contrast variation (ACV) analysis using both the SAXS and SANS data indicate that the chemical composition of the inclusions is almost NaCl-type manganese sulfide, and that the amount of iron sulfide is low. The volume fractions are 1.4% for the large inclusions and 0.2% for the small inclusions. This is consistent with the area fraction estimated using an optical microscope, and indicates that nearly all of the sulfur in the steel sample forms the manganese sulfide inclusions. (author)

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

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.

Assessment of firing conditions in old fired-clay bricks. The contribution of X-ray powder diffraction with the Rietveld method and small angle neutron scattering

Czech Academy of Sciences Publication Activity Database

Viani, Alberto; Sotiriadis, Konstantinos; Len, A.; Šašek, Petr; Ševčík, Radek

2016-01-01

Roč. 116, June (2016), s. 33-43 ISSN 1044-5803 R&D Projects: GA MŠk(CZ) LO1219 Keywords : fired- clay brick * Rietveld method * small angle neutron scattering * X-ray diffraction * firing temperature Subject RIV: AL - Art, Architecture, Cultural Heritage Impact factor: 2.714, year: 2016 http://www.sciencedirect.com/science/article/pii/S1044580316300870

Neutron scattering. Experiment manuals

International Nuclear Information System (INIS)

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

2012-01-01

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, the neutron polarization analyzer DNS, the neutron spin-echo spectrometer J-NSE, the small-angle neutron diffractometers KWS-1/-2, the very-small-angle neutron diffractometer with focusing mirror KWS-3, the resonance spin-echo spectrometer RESEDA, the reflectometer TREFF, the time-of-flight spectrometer TOFTOF. (HSI)

Theory of magnetic neutron small-angle scattering using the dynamical theory of diffraction instead of the Born approximation. I

International Nuclear Information System (INIS)

Schaerpf, O.

1978-01-01

Two ways are given for solving the problem of the dependence of the refraction on the direction of magnetization on both sides of the refractive boundary, one applying the Halpern magnetic scattering vector, the other applying the dynamical theory of diffraction. They lead to different results. Experimental investigation of refraction by magnetic boundaries shows no dependence of the angle of deflection on the relative angles of magnetization in adjacent domains. This behaviour is only described correctly by the dynamical theory, which far from Laue reflections leads to a treatment by the Schoedinger equation with a spin-dependent potential dependent on the average continuous homogenous magnetic induction, both for the law of refraction and for the precession of the spin. The results of this treatment are discussed as a consequence of the behaviour of the spin of the neutrons. This gives some insight about how and why, with refraction, the intensities of the direct and deflected beams depend on the magnetization directions in adjacent domains. The dynamical theory also shows that the Halpern magnetic scattering vector applies only with Laue or Bragg reflections and not with transmission far from those reflections. (Auth.)

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...

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.)

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)

The tetragonal-monoclinic transformations of zirconia studied by small angle neutron scattering and differential thermal analysis

International Nuclear Information System (INIS)

Li, Z.; Epperson, J.E.; Fang, Y.; Chan, S.K.

1992-08-01

The tetragonal-monoclinic transformations of zirconia have been studied on pristine single crystals and on their cycled crystallites. Two complementary techniques have been used. Small angle neutron scattering experiments were carried out to monitor the degree of completion of a transformation under equilibrium conditions for collections of 20--30 large crystals using the total internal and external surface area as an indicator. Differential thermal analysis experiments were carried out on smaller single-domain crystals of different sizes individually during heating and cooling to measure the rates of latent heat absorption and emission. The investigation establishes the upper limit of stability of the monoclinic phase, the lower limit of stability of the tetragonal phase, and the coexistence temperature between the two phases. The characteristics of the transformations are also inferred from these experiments

Characterisation of creep cavitation damage in a stainless steel pressure vessel using small angle neutron scattering

CERN Document Server

Bouchard, P J; Treimer, W

2002-01-01

Grain-boundary cavitation is the dominant failure mode associated with initiation of reheat cracking, which has been widely observed in austenitic stainless steel pressure vessels operating at temperatures within the creep range (>450 C). Small angle neutron scattering (SANS) experiments at the LLB PAXE instrument (Saclay) and the V12 double-crystal diffractometer of the HMI-BENSC facility (Berlin) are used to characterise cavitation damage (in the size range R=10-2000 nm) in a variety of creep specimens extracted from ex-service plant. Factors that affect the evolution of cavities and the cavity-size distribution are discussed. The results demonstrate that SANS techniques have the potential to quantify the development of creep damage in type-316H stainless steel, and thereby link microstructural damage with ductility-exhaustion models of reheat cracking. (orig.)

Analysis and simulation of a small-angle neutron scattering instrument on a 1 MW long pulse spallation source

International Nuclear Information System (INIS)

Olah, G.A.; Hjelm, R.P.; Lujan, M. Jr.

1996-01-01

We studied the design and performance of a small-angle neutron scattering (SANS) instrument for a proposed 1 MW, 60 Hz long pulsed spallation source at the Los Alamos Neutron Science Center (LANSCE). An analysis of the effects of source characteristics and chopper performance combined with instrument simulations using the LANSCE Monte Carlo instrument simulations package shows that the T 0 chopper should be no more than 5 m from the source with the frame overlap and frame definition choppers at 5.6 and greater than 7 m, respectively. The study showed that an optimal pulse structure has an exponential decaying tail with τ ∼ 750 μs. The Monte Carlo simulations were used to optimize the LPSS SANS, showing that an optimal length is 18 m. The simulations show that an instrument with variable length is best to match the needs of a given measurement. The performance of the optimized LPSS instrument was found to be comparable with present world standard instruments

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)

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)

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

Constant-q data representation in Neutron Compton scattering on the VESUVIO spectrometer

International Nuclear Information System (INIS)

Senesi, R.; Pietropaolo, A.; Andreani, C.

2008-01-01

Standard data analysis on the VESUVIO spectrometer at ISIS is carried out within the Impulse Approximation framework, making use of the West scaling variable y. The experiments are performed using the time-of-flight technique with the detectors positioned at constant scattering angles. Line shape analysis is routinely performed in the y-scaling framework, using two different (and equivalent) approaches: (1) fitting the parameters of the recoil peaks directly to fixed-angle time-of-flight spectra; (2) transforming the time-of-flight spectra into fixed-angle y spectra, referred to as the Neutron Compton Profiles, and then fitting the line shape parameters. The present work shows that scattering signals from different fixed-angle detectors can be collected and rebinned to obtain Neutron Compton Profiles at constant wave vector transfer, q, allowing for a suitable interpretation of data in terms of the dynamical structure factor, S(q,ω). The current limits of applicability of such a procedure are discussed in terms of the available q-range and relative uncertainties for the VESUVIO experimental set up and of the main approximations involved

Constant-q data representation in Neutron Compton scattering on the VESUVIO spectrometer

Energy Technology Data Exchange (ETDEWEB)

Senesi, R. [Dipartimento di Fisica, Universita degli Studi di Roma ' Tor Vergata' , Via della Ricerca Scientifica 1, 00133 Roma (Italy); Centro NAST, Nanoscienze and Nanotecnologie and Strumentazione, Universita degli Studi di Roma ' Tor Vergata' , Via della Ricerca Scientifica 1, 00133 Roma (Italy)], E-mail: roberto.senesi@roma2.infn.it; Pietropaolo, A.; Andreani, C. [Dipartimento di Fisica, Universita degli Studi di Roma ' Tor Vergata' , Via della Ricerca Scientifica 1, 00133 Roma (Italy); Centro NAST, Nanoscienze and Nanotecnologie and Strumentazione, Universita degli Studi di Roma ' Tor Vergata' , Via della Ricerca Scientifica 1, 00133 Roma (Italy)

2008-09-01

Standard data analysis on the VESUVIO spectrometer at ISIS is carried out within the Impulse Approximation framework, making use of the West scaling variable y. The experiments are performed using the time-of-flight technique with the detectors positioned at constant scattering angles. Line shape analysis is routinely performed in the y-scaling framework, using two different (and equivalent) approaches: (1) fitting the parameters of the recoil peaks directly to fixed-angle time-of-flight spectra; (2) transforming the time-of-flight spectra into fixed-angle y spectra, referred to as the Neutron Compton Profiles, and then fitting the line shape parameters. The present work shows that scattering signals from different fixed-angle detectors can be collected and rebinned to obtain Neutron Compton Profiles at constant wave vector transfer, q, allowing for a suitable interpretation of data in terms of the dynamical structure factor, S(q,{omega}). The current limits of applicability of such a procedure are discussed in terms of the available q-range and relative uncertainties for the VESUVIO experimental set up and of the main approximations involved.

Constant- q data representation in Neutron Compton scattering on the VESUVIO spectrometer

Science.gov (United States)

Senesi, R.; Pietropaolo, A.; Andreani, C.

2008-09-01

Standard data analysis on the VESUVIO spectrometer at ISIS is carried out within the Impulse Approximation framework, making use of the West scaling variable y. The experiments are performed using the time-of-flight technique with the detectors positioned at constant scattering angles. Line shape analysis is routinely performed in the y-scaling framework, using two different (and equivalent) approaches: (1) fitting the parameters of the recoil peaks directly to fixed-angle time-of-flight spectra; (2) transforming the time-of-flight spectra into fixed-angle y spectra, referred to as the Neutron Compton Profiles, and then fitting the line shape parameters. The present work shows that scattering signals from different fixed-angle detectors can be collected and rebinned to obtain Neutron Compton Profiles at constant wave vector transfer, q, allowing for a suitable interpretation of data in terms of the dynamical structure factor, S(q,ω). The current limits of applicability of such a procedure are discussed in terms of the available q-range and relative uncertainties for the VESUVIO experimental set up and of the main approximations involved.

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

Variation of solvent scattering-length density small-angle neutron scattering as a means of determining structure of composite materials

International Nuclear Information System (INIS)

Hjelm, R.P.; Wampler, W.; Gerspacher, M.

1994-01-01

As part of our work on the, structure of composite materials we have been exploring the use of small-angle neutron scattering using the method of contrast variation to dissect the component form, structure and distribution. This approach has resulted in a new look at very old problem reinforcement of elastomers by carbon black. Using this approach we studied an experimental high surface area (HSA) carbon black and a gel of ''HSA-bound'' rubber in cyclohexane/deuterocyclohexane mixtures. HSA in cyclohexane is found to be short rodlike particle aggregates. The aggregates have a shell-core structure with a high density graphitic outer shell and an inner core of lower density amorphous carbon. The core is continuous throughout the carbon black aggregate, making the aggregate a stiff, integral unit. Contrast variation of swollen composite gels shows that there are two length scales in the gel structure. Above 10 Angstrom, scattering from carbon black predominates, and below 10 Angstrom the scattering is from both carbon black and the elastomer. The HSA in the composite is completely embedded in polyisoprene. An estimate of the carbon black structure factor shows strong exclusion of neighboring aggregates, probably from excluded volume effects. The surface structure of the carbon black is unaltered by the interactions with elastomer and appears smooth over length scales above about 10 Angstrom. These results show that contrast variation can provide information on composite structure that is not available by other means. This information relates to the reinforcement mechanism of elastomers by carbon blacks

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

Accounting for thermodynamic non-ideality in the Guinier region of small-angle scattering data of proteins.

Science.gov (United States)

Scott, David J

2016-12-01

Hydrodynamic studies of the solution properties of proteins and other biological macromolecules are often hard to interpret when the sample is present at a reasonably concentrated solution. The reason for this is that solutions exhibit deviations from ideal behaviour which is manifested as thermodynamic non-ideality. The range of concentrations at which this behaviour typically is exhibited is as low as 1-2 mg/ml, well within the range of concentrations used for their analysis by techniques such as small-angle scattering. Here we discuss thermodynamic non-ideality used previously used in the context of light scattering and sedimentation equilibrium analytical ultracentrifugation and apply it to the Guinier region of small-angle scattering data. The results show that there is a complementarity between the radially averaged structure factor derived from small-angle X-ray scattering/small-angle neutron scattering studies and the second virial coefficient derived from sedimentation equilibrium analytical ultracentrifugation experiments.

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.

Modelling small-angle scattering data from complex protein-lipid systems

DEFF Research Database (Denmark)

Kynde, Søren Andreas Røssell

This thesis consists of two parts. The rst part is divided into five chapters. Chapter 1 gives a general introduction to the bio-molecular systems that have been studied. These are membrane proteins and their lipid environments in the form of phospholipid nanodiscs. Membrane proteins...... the techniques very well suited for the study of the nanodisc system. Chapter 3 explains two different modelling approaches that can be used in the analysis of small-angle scattering data from lipid-protein complexes. These are the continuous approach where the system of interest is modelled as a few regular...... combine the bene ts of each of the methods and give unique structural information about relevant bio-molecular complexes in solution. Chapter 4 describes the work behind a proposal of a small-angle neutron scattering instrument for the European Spallation Source under construction in Lund. The instrument...

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)

Small Angle Neutron Scattering Studies on Blends of Poly (Styrene-ran-Vinyl Phenol) with Liquid Crystalline Polyurethane

Science.gov (United States)

Mehta, Rujul

2005-03-01

Molecular composites, composed of uniformly dispersed rigid-rod liquid crystalline polymer (LCP) molecules in a flexible amorphous polymer matrix, have remained hitherto elusive due to a scarcity of miscible systems containing a LCP and an amorphous polymer. The production of such a blend, with an experimentally accessible miscibility window, has become possible by modifying the architecture of the flexible polymer, so as to induce favorable intermolecular hydrogen bonding. Specifically, liquid crystalline polyurethanes (LCPU) are found to be miscible with a copolymer of styrene and vinyl phenol; with optimum hydrogen bonding between the carbonyl groups of the urethane linkages and the hydroxyl groups present in the styrenic matrix. Availability of a truly miscible molecular composite presents a unique opportunity of studying the confirmation of polymer chains containing rigid-rods that are uniformly dispersed in a flexible coil matrix. A system consisting of the LCPU and the deuterated styrenic copolymer containing 20% vinyl phenol is examined by Small Angle Neutron Scattering at the National Center for Neutron Research at Gaithersburg and Technology, and the Institute of Solid State Research (IFF) at Jülich. Scattering curves for neat dPS-VPh did not fit the Debye-Bueche model; indicating complex structure. A two correlation length Debye-Bueche model was considered to accommodate for this nonlinear behavior. This model utilizes four fitting parameters, including two correlation lengths a1 and a2, corresponding to a Debye-Bueche model and Guinier model.

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.

Properties of surfactant films in water-in-CO2 microemulsions obtained by small-angle neutron scattering.

Science.gov (United States)

Yan, Ci; Sagisaka, Masanobu; James, Craig; Rogers, Sarah; Alexander, Shirin; Eastoe, Julian

2014-12-01

The formation, stability and structural properties of normal liquid phase microemulsions, stabilized by hydrocarbon surfactants, comprising water and hydrocarbon oils can be interpreted in terms of the film bending rigidity (energy) model. Here, this model is tested for unusual water-in-CO2 (w/c) microemulsions, formed at high pressure with supercritical CO2 (sc-CO2) as a solvent and fluorinated surfactants as stabilizers. Hence, it is possible to explore the generality of this model for other types of microemulsions. High Pressure Small-Angle Neutron Scattering (HP-SANS) has been used to study w/c microemulsions, using contrast variation to highlight scattering from the stabilizing fluorinated surfactant films: these data show clear evidence for spherical core-shell structures for the microemulsion droplets. The results extend understanding of w/c microemulsions since previous SANS studies are based only on scattering from water core droplets. Here, detailed structural parameters for the surfactant films, such as thickness and film bending energy, have been extracted from the core-shell SANS profiles revealed by controlled contrast variation. Furthermore, at reduced CO2 densities (∼0.7gcm(-3)), elongated cylindrical droplet structures have been observed, which are uncommon for CO2 microemulsions/emulsions. The implications of the presence of cylindrical micelles and droplets for applications of CO2, and viscosity enhancements are discussed. Copyright © 2014 Elsevier Inc. All rights reserved.

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

Dissolution and growth of precipitates under electron irradiation in an Al-11.8 at % Zn alloy by small angle neutron scattering

International Nuclear Information System (INIS)

Baig, M.R.

1995-01-01

Dissolution and growth of precipitates in a room temperature aged Al-11.8 at % Zn alloy have been studied under electron irradiation using small angle neutron scattering (SANS). A series of electron irradiations were performed on each sample and SANS measurements were made on each irradiation. In general for low doses the results show an initial decrease in the magnitude of the scattering, but associated with an increase in the precipitate size. This is followed on prolonged irradiation by an increase in the magnitude of the scattering with a continued increase in precipitate size. It is believed, that at low doses some precipitate grow in size but others may dissolve in the matrix, which then becomes supersaturated. With the enhanced rate of diffusion as a result of the irradiation, the remaining precipitates grow rapidly. As the supersaturation reduces, a coarsening mechanism takes over, via a radiation enhanced diffusion mechanism

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)

Nucleon-nucleon scattering studies at small angles at COSY-ANKE

Energy Technology Data Exchange (ETDEWEB)

Bagdasarian, Zara [Forschungszentrum Juelich, Juelich (Germany); Tbilisi State University, Tbilisi (Georgia); Collaboration: ANKE-Collaboration

2015-07-01

The most accepted approach to describe nucleon-nucleon (NN) interaction is the partial wave analysis (PWA). The SAID database and analysis program comprise various experimental observables at different energies over the full angular range and express them in the partial waves. The goal of the experiments held at COSY-Juelich is to provide SAID with new valuable measurements. Scattering data was taken at small angles for six beam energies between 0.8 and 2.4 GeV with polarized proton beam incident on both proton and deuteron unpolarized targets using the ANKE spectrometer. First, the results of the proton-proton (pp) scattering analyzing power and cross section are presented. While pp data closes a very important gap at small angles in the database, proton-neutron (pn) data is a crucial contribution to the almost non-explored pn database above 800 MeV. Therefore, the talk will mainly concentrate on the proton-deuteron (pd) scattering studies, which includes the overview of the older COSY experiments with polarized deuteron beam, and the abovementioned new experiment with polarized proton beam and unpolarized deuteron target. The presentation will show the most recent results of the analyzing powers of pd elastic and pn scattering.

Core-shell structure of Miglyol/poly(D,L-lactide)/Poloxamer nanocapsules studied by small-angle neutron scattering.

Science.gov (United States)

Rübe, Andrea; Hause, Gerd; Mäder, Karsten; Kohlbrecher, Joachim

2005-10-03

The contrast variation technique in small angle neutron scattering (SANS) was used to investigate the inner structure of nanocapsules on the example of poly(D,L-lactide) (PLA) nanocapsules. The determination of the PLA and Poloxamer shell thickness was the focus of this study. Highest sensitivity on the inner structure of the nanocapsules was obtained when the scattering length density of the solvent was varied between the one of the Miglyol core and the PLA shell. According to the fit data the PLA shell thickness was 9.8 nm. The z-averaged radius determined by SANS experiments correlated well with dynamic light scattering (DLS) results, although DLS values were systematically slightly higher than the ones measured by SANS. This could be explained by taking into account the influence of Poloxamer attached to the nanocapsules surface. For a refined fit model with a second shell consisting of Poloxamer, SANS values and DLS values fitted well with each other. The characterization method presented here is significant because detailed insights into the nanocapsule and the Poloxamer shell were gained for the first time. This method could be used to develop strategies for the optimization of the shell properties concerning controlled release and to study changes in the shell structure during degradation processes.

SMALL-ANGLE NEUTRON SCATTERING CONTRIBUTION TO DEVELOPMENT OF SOME NOVEL MATERIALS

Czech Academy of Sciences Publication Activity Database

Strunz, Pavel; Mukherji, D.; Petrenec, Martin; Gilles, R.; Schumacher, G.; Pigozzi, G.; Keiderling, U.; Geue, T.; Gasser, U.; Šaroun, Jan; Rösler, J.

2013-01-01

Roč. 20, č. 2 (2013), s. 67-69 ISSN 1211-5894. [Struktura 2013 - Kolokvium Krystalografické společnosti. Češkovice (Blansko), 09.09.2013-13.09.2013] R&D Projects: GA ČR(CZ) GAP204/11/1453; GA MŠk(XE) LM2011019 Institutional support: RVO:68081723 ; RVO:61389005 Keywords : neutron scattering * superalloy * temperature dependence Subject RIV: BM - Solid Matter Physics ; Magnetism; JL - Materials Fatigue, Friction Mechanics (UFM-A)

Experimental verification of a method to create a variable energy neutron beam from a monoenergetic, isotropic source using neutron elastic scatter and time of flight

Energy Technology Data Exchange (ETDEWEB)

Whetstone, Zachary D., E-mail: zacwhets@umich.edu; Flaska, Marek, E-mail: mflaska@umich.edu; Kearfott, Kimberlee J., E-mail: kearfott@umich.edu

2016-08-11

An experiment was performed to determine the neutron energy of near-monoergetic deuterium–deuterium (D–D) neutrons that elastically scatter in a hydrogenous target. The experiment used two liquid scintillators to perform time of flight (TOF) measurements to determine neutron energy, with the start detector also serving as the scatter target. The stop detector was placed 1.0 m away and at scatter angles of π/6, π/4, and π/3 rad, and 1.5 m at a scatter angle of π/4 rad. When discrete 1 ns increments were implemented, the TOF peaks had estimated errors between −21.2 and 3.6% relative to their expected locations. Full widths at half-maximum (FWHM) ranged between 9.6 and 20.9 ns, or approximately 0.56–0.66 MeV. Monte Carlo simulations were also conducted that approximated the experimental setup and had both D–D and deuterium–tritium (DT) neutrons. The simulated results had errors between −17.2 and 0.0% relative to their expected TOF peaks when 1 ns increments were applied. The largest D–D and D–T FWHMs were 26.7 and 13.7 ns, or approximately 0.85 and 4.98 MeV, respectively. These values, however, can be reduced through manipulation of the dimensions of the system components. The results encourage further study of the neutron elastic scatter TOF system with particular interest in application to active neutron interrogation to search for conventional explosives.

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

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.

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

Structure determination of AgPO3 and (AgPO3)0.5(AgI)0.5 glasses by neutron diffraction and small angle neutron scattering

International Nuclear Information System (INIS)

Tachez, M.; Mercier, R.; Malugani, J.P.; Chieux, P.

1987-01-01

Neutron diffraction and small angle neutron scattering (SANS) were performed on AgPO 3 and (AgPO 3 ) 0.5 (AgI) 0.5 glasses. AgPO 3 glass is made up of long chains of PO 4 tetrahedra joined together by Ag atoms. When silver iodide is added, the radial distribution function shows a large peak at 2.83 A, due to Ag-I interactions. AgI does not modify the network forming unit. The existence of small clusters is confirmed by analysing the coordination number of Ag-I pairs obtained by subtracting the experimental structure function of the AgPO 3 glass from that of the corresponding AgI-doped glasses. A rough estimation of their size is given by SANS experiments. Not all the AgI pairs are involved in AgI cluster units. The compatibility of the results obtained with recent structural investigations by non diffractometric techniques is examined. 23 refs.; 5 figs.; 3 tabs

Possible magnetism in vortex cores of superconducting TmNi{sub 2}B{sub 2}C studied by small angle neutron scattering

Energy Technology Data Exchange (ETDEWEB)

Abrahamsen, Asger Bech

2003-11-01

The compound TmNi{sub 2}B{sub 2}C has previously been studied by Small Angle Neutron Scattering(SANS) with the applied field along the crystalline c-axis and a very rich phase diagram in terms of flux line lattices(FLL) with different symmetries have been observed. One of the FLL transitions is coincident with a magnetic phase transition between two spin density waves. In this thesis additional SANS studies of the FLL phases in TmNi{sub 2}B{sub 2}C are reported and an interpretation of the phase diagram in the paramagnetic region is presented. It is suggested that the square FLL observed is stable in between two transition lines determined by two different length scales. The lower transition field is reached when the distance between the flux lines becomes comparable to the non-locality radius resulting from non-local electrodynamics, whereas the upper transition field is determined from the crossover from intermediate to high flux line density where the vortex cores start to overlap and the superconducting order parameter is suppressed in between the flux lines. A detailed examination of the intensity of the neutron diffraction spots caused by scattering on the flux line lattice in TmNi{sub 2}B{sub 2}C is presented and analyzed on the basis of the form factor of an isolated flux line. This analysis can not provide a good explanation for the observed scattering and it is suggested that the scattering from the Tm ions must be considered. One can argue that the moments of the Tm ions are modulated by the flux line lattice, because the Ruderman-Kittel- Kasuya-Yosida(RKKY) interaction between the Tm ions might be different inside the vortex cores than outside in the superconducting phase. A calculation of the neutron scattering cross section of such a magnetic flux line lattice has been performed and compared to the SANS data. This offers a qualitative explanation of some of the observations, but future work is needed to perform a more quantitative comparison. (au)

Porosity of the Marcellus Shale: A contrast matching small-angle neutron scattering study

Science.gov (United States)

Bahadur, Jitendra; Ruppert, Leslie F.; Pipich, Vitaliy; Sakurovs, Richard; Melnichenko, Yuri B.

2018-01-01

Neutron scattering techniques were used to determine the effect of mineral matter on the accessibility of water and toluene to pores in the Devonian Marcellus Shale. Three Marcellus Shale samples, representing quartz-rich, clay-rich, and carbonate-rich facies, were examined using contrast matching small-angle neutron scattering (CM-SANS) at ambient pressure and temperature. Contrast matching compositions of H2O, D2O and toluene, deuterated toluene were used to probe open and closed pores of these three shale samples. Results show that although the mean pore radius was approximately the same for all three samples, the fractal dimension of the quartz-rich sample was higher than for the clay-rich and carbonate-rich samples, indicating different pore size distributions among the samples. The number density of pores was highest in the clay-rich sample and lowest in the quartz-rich sample. Contrast matching with water and toluene mixtures shows that the accessibility of pores to water and toluene also varied among the samples. In general, water accessed approximately 70–80% of the larger pores (>80 nm radius) in all three samples. At smaller pore sizes (~5–80 nm radius), the fraction of accessible pores decreases. The lowest accessibility to both fluids is at pore throat size of ~25 nm radii with the quartz-rich sample exhibiting lower accessibility than the clay- and carbonate-rich samples. The mechanism for this behaviour is unclear, but because the mineralogy of the three samples varies, it is likely that the inaccessible pores in this size range are associated with organics and not a specific mineral within the samples. At even smaller pore sizes (~generally follows that of water; however, in the smallest pores (~<2.5 nm radius), accessibility to toluene decreases, especially in the clay-rich sample which contains about 30% more closed pores than the quartz- and carbonate-rich samples. Results from this study show that mineralogy of producing intervals

Reports of the study group for neutron scattering

International Nuclear Information System (INIS)

1982-01-01

This report covers the activities from July 1980 to December 1981. Within this period, the project for reactor extension (including a thermal neutron source and a hall for the neutron guide), was worked out in detail. Like the Fritz-Haber Institute, the Institute for Crystallography of Tuebingen University decided to send a number of guest-scientists for studies at the Hahn-Meitner Institute on a permanent basis. The HMI also organized the 5th International Conference on Small-Angle Scattering, held in Berlin in October 1980. The scientific research work was mainly concerned with magnetic systems, molecular crystals, and the determination of electron densities. (orig.)

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

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.

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

Small-angle neutron scattering study of the n-decane effect on the bilayer thickness in extruded unilamellar dioleoylphosphatidylcholine liposomes.

Science.gov (United States)

Uhríková, D; Balgavý, P; Kucerka, N; Islamov, A; Gordeliy, V; Kuklin, A

2000-12-15

Dioleoylphosphatidylcholine (DOPC) and n-decane were mixed and hydrated afterwards in an excess of heavy water at 1 wt.% of DOPC. From this dispersion, unilamellar liposomes were prepared by extrusion through polycarbonate filter with 500-A pores. Small-angle neutron scattering (SANS) was conducted on these liposomes. From the Kratky-Porod plot ln[I(Q)Q2] vs. Q2 of SANS intensity I(Q) in the range of scattering vectors Q corresponding to the interval 0.001 A(-2) < or = Q2 < or = 0.006 A(-2), the liposome bilayer radius of gyration Rg and the bilayer thickness parameter d(g) = 12(0.5)Rg were obtained. The values of d(g) indicated that the bilayer thickness is within the experimental error constant up to n-decane/DOPC approximately 0.5 molar ratio, and then increases by 2.4 +/- 1.3 A up to n-decane/DOPC = 1.2 molar ratio.

Magnetization reversal of a Nd-Cu-infiltrated Nd-Fe-B nanocrystalline magnet observed with small-angle neutron scattering

Energy Technology Data Exchange (ETDEWEB)

Saito, Kotaro, E-mail: kotaro.saito@kek.jp; Ono, Kanta [Institute of Materials Structure Science, High Energy Accelerator Research Organization, 1-1 Oho, 305-0803 Tsukuba (Japan); Ueno, Tetsuro [Elements Strategy Initiative Center for Magnetic Materials, National Institute for Materials Science, 1-2-1 Sengen, 305-0047 Tsukuba (Japan); Yano, Masao; Shoji, Tetsuya; Sakuma, Noritsugu; Manabe, Akira; Kato, Akira [Toyota Motor Corporation, Toyota, Aichi 471-8571 (Japan); Harada, Masashi [Toyota Central R and D Labs, Inc., Aichi 480-1192 (Japan); Keiderling, Uwe [Helmholtz-Zentrum Berlin für Materialien and Energie, 14109 Berlin (Germany)

2015-05-07

The magnetization reversal process of Nd-Fe-B nanocrystalline magnets infiltrated with Nd-Cu alloy was examined using small-angle neutron scattering (SANS). The magnetic-field dependence of SANS intensity revealed a qualitative difference between Nd-Cu-infiltrated samples and as-deformed samples. Insufficient magnetic isolation along the direction perpendicular to the nominal c-axis is expected from comparable SANS intensities for different ranges of q values along this direction. For small q values near the coercivity field, Nd-Cu-infiltrated samples show a noticeable reduction in SANS intensity along the nominal c-axis, which is parallel to the external magnetic field. This indicates less spatial fluctuation of magnetic moments in Nd-Cu-infiltrated samples, owing to magnetically isolated Nd{sub 2}Fe{sub 14}B grains.

Magnetization reversal of a Nd-Cu-infiltrated Nd-Fe-B nanocrystalline magnet observed with small-angle neutron scattering

International Nuclear Information System (INIS)

Saito, Kotaro; Ono, Kanta; Ueno, Tetsuro; Yano, Masao; Shoji, Tetsuya; Sakuma, Noritsugu; Manabe, Akira; Kato, Akira; Harada, Masashi; Keiderling, Uwe

2015-01-01

The magnetization reversal process of Nd-Fe-B nanocrystalline magnets infiltrated with Nd-Cu alloy was examined using small-angle neutron scattering (SANS). The magnetic-field dependence of SANS intensity revealed a qualitative difference between Nd-Cu-infiltrated samples and as-deformed samples. Insufficient magnetic isolation along the direction perpendicular to the nominal c-axis is expected from comparable SANS intensities for different ranges of q values along this direction. For small q values near the coercivity field, Nd-Cu-infiltrated samples show a noticeable reduction in SANS intensity along the nominal c-axis, which is parallel to the external magnetic field. This indicates less spatial fluctuation of magnetic moments in Nd-Cu-infiltrated samples, owing to magnetically isolated Nd 2 Fe 14 B grains

Early stages of spinodal decomposition in Fe-Cr resolved by in-situ small-angle neutron scattering

Science.gov (United States)

Hörnqvist, M.; Thuvander, M.; Steuwer, A.; King, S.; Odqvist, J.; Hedström, P.

2015-02-01

In-situ, time-resolved small-angle neutron scattering (SANS) investigations of the early stages of the spinodal decomposition process in Fe-35Cr were performed at 773 and 798 K. The kinetics of the decomposition, both in terms of characteristic distance and peak intensity, followed a power-law behaviour from the start of the heat treatment (a'= 0.10-0.11 and a″ = 0.67-0.86). Furthermore, the method allows tracking of the high-Q slope, which is a sensitive measure of the early stages of decomposition. Ex-situ SANS and atom probe tomography were used to verify the results from the in-situ investigations. Finally, the in-situ measurement of the evolution of the characteristic distance at 773 K was compared with the predictions from the Cahn-Hilliard-Cook model, which showed good agreement with the experimental data (a'= 0.12-0.20 depending on the assumed mobility).

Spin-resolved unpolarized neutron off-specular scattering for magnetic multilayer studies

CERN Document Server

Lauter, H J; Toperverg, B P; Romashev, L; Ustinov, V; Kravtsov, E; Vorobiev, A; Major, J; Nikonov, O A

2002-01-01

The capabilities of the method of using unpolarized neutron off-specular scattering for investigation of magnetic structures in exchange-coupled magnetic multilayers are thoroughly examined. It is demonstrated that strong anomalies in spin-flip selective scattering processes originating from magnetic fluctuations enables a straightforward determination of the coupling angle between the magnetization direction of successive Fe layers in Fe/Cr multilayers. A complete quantitative 2-dimensional data analysis of specular and off-specular scattering has been employed to provide detailed information on the lateral and transverse magnetization arrangement in the multilayer. (orig.)

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

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.)

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.

Scattering angle-based filtering via extension in velocity

KAUST Repository

Kazei, Vladimir; Tessmer, Ekkehart; Alkhalifah, Tariq

2016-01-01

The scattering angle between the source and receiver wavefields can be utilized in full-waveform inversion (FWI) and in reverse-time migration (RTM) for regularization and quality control or to remove low frequency artifacts. The access to the scattering angle information is costly as the relation between local image features and scattering angles has non-stationary nature. For the purpose of a more efficient scattering angle information extraction, we develop techniques that utilize the simplicity of the scattering angle based filters for constantvelocity background models. We split the background velocity model into several domains with different velocity ranges, generating an

Scattering angle-based filtering via extension in velocity

KAUST Repository

Kazei, Vladimir

2016-09-06

The scattering angle between the source and receiver wavefields can be utilized in full-waveform inversion (FWI) and in reverse-time migration (RTM) for regularization and quality control or to remove low frequency artifacts. The access to the scattering angle information is costly as the relation between local image features and scattering angles has non-stationary nature. For the purpose of a more efficient scattering angle information extraction, we develop techniques that utilize the simplicity of the scattering angle based filters for constantvelocity background models. We split the background velocity model into several domains with different velocity ranges, generating an