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Note: This page contains sample records for the topic "angle neutron scattering" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


1

SANS -Small Angle Neutron Scattering Tcnica de difrao  

E-Print Network [OSTI]

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

Loh, Watson

2

E-Print Network 3.0 - angle neutron scattering Sample Search...  

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

neutron scattering Search Powered by Explorit Topic List Advanced Search Sample search results for: angle neutron scattering Page: << < 1 2 3 4 5 > >> 1 Exceptional tools for...

3

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

E-Print Network [OSTI]

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

Dubin, Paul D.

4

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

E-Print Network [OSTI]

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

Boyer, Edmond

5

Radiation damage studies using small-angle neutron scattering  

SciTech Connect (OSTI)

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

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

1996-12-31T23:59:59.000Z

6

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

E-Print Network [OSTI]

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

Boyer, Edmond

7

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

E-Print Network [OSTI]

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

Boyer, Edmond

8

Comparison of collimation systems for small-angle neutron scattering  

SciTech Connect (OSTI)

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

Seeger, P.A.

1985-01-01T23:59:59.000Z

9

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

E-Print Network [OSTI]

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

Boyer, Edmond

10

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

E-Print Network [OSTI]

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

Wang, Howard "Hao"

11

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

E-Print Network [OSTI]

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

Kilpatrick, Peter K.

12

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

E-Print Network [OSTI]

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

Boyer, Edmond

13

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

E-Print Network [OSTI]

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

Chen, Sow-Hsin

14

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

E-Print Network [OSTI]

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

Liu, Dazhi

15

Time-Resolved Small-Angle Neutron Scattering Study of Polyethylene Crystallization from Solution  

E-Print Network [OSTI]

Time-Resolved Small-Angle Neutron Scattering Study of Polyethylene Crystallization from Solution-resolved small-angle neutron scattering (TR-SANS), the crystal- lization kinetics of polyethylene from deuterated of polyethylene crystallization from xylene solutions. One unique feature of this experimentation is that both

Wang, Howard "Hao"

16

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

E-Print Network [OSTI]

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

Langowski, Jörg

17

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

E-Print Network [OSTI]

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

Kofinas, Peter

18

Study, by neutron small angle scattering, of addition of an electrolyte to reversed micellar solution  

E-Print Network [OSTI]

L-455 Study, by neutron small angle scattering, of addition of an electrolyte to reversed micellar the size of reversed micelles of the ternary system Aerosol OT-n-heptane-water by small angle neutron, highly soluble in hydro- carbon substances, which may give reversed micelles in the presence of water

Paris-Sud XI, Université de

19

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

E-Print Network [OSTI]

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

Boyer, Edmond

20

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

E-Print Network [OSTI]

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

Nagle, John F.

Note: This page contains sample records for the topic "angle neutron scattering" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

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

E-Print Network [OSTI]

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

Sylvain Desert; Vincent Thevenot; Julian Oberdisse; Annie Brulet

2007-06-12T23:59:59.000Z

22

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

E-Print Network [OSTI]

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

Langowski, Jörg

23

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

E-Print Network [OSTI]

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

Sutter, Marc

2006-10-25T23:59:59.000Z

24

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

E-Print Network [OSTI]

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

25

Effect of the concentration of inhomogeneities on the multiple small-angle neutron scattering  

SciTech Connect (OSTI)

The interference effects manifested during multiple small-angle neutron scattering (MSANS) on a chaotically arranged close-packed ensemble of scatterers have been studied. MSANS measurements have been performed for mixtures of Al and Ti-Zr alloy powders. It is shown that the results can be satisfactorily described based on a theory that takes into account spatial correlations in the arrangement of powder grains.

Abov, Yu. G.; Dzheparov, F. S.; Elyutin, N. O.; Lvov, D. V., E-mail: lvov@itep.ru; Tyulyusov, A. N. [Institute for Theoretical and Experimental Physics (Russian Federation)] [Institute for Theoretical and Experimental Physics (Russian Federation)

2013-03-15T23:59:59.000Z

26

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

SciTech Connect (OSTI)

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

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

1996-12-31T23:59:59.000Z

27

Characterization of porous materials using combined small-angle X-ray and neutron scattering techniques  

SciTech Connect (OSTI)

A combination of ultra small angle X-ray scattering (USAXS) and ultra small angle neutron scattering (USANS) is used to characterize porous materials. The analysis methods yield quantitative information, including the mean skeletal chord length, mean pore chord length, skeletal density, and composition. A mixed cellulose ester (MCE) membrane with a manufacturer-labeled pore size of 0.1 {mu}m was used as a model to elucidate the specifics of the method. Four approaches describing four specific scenarios (different known parameters and form of the scattering data) are compared. Pore chords determined using all four approaches are in good agreement with the scanning electron microscopy estimates but are larger than the manufacturer's nominal pore size. Our approach also gives the average chord of the skeletal solid (struts) of the membrane, which is also consistent for all four approaches. Combined data from USAXS and USANS gives the skeletal density and the strut composition.

Hu, Naiping; Borkar, Neha; Kohls, Doug; Schaefer, Dale W. (UCIN)

2014-09-24T23:59:59.000Z

28

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

E-Print Network [OSTI]

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

29

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

E-Print Network [OSTI]

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

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

2012-09-20T23:59:59.000Z

30

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

SciTech Connect (OSTI)

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

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

2010-11-01T23:59:59.000Z

31

Small angle neutron scattering analysis of novel carbons for lithium secondary batteries.  

SciTech Connect (OSTI)

Small angle neutron scattering analyses of carbonaceous materials used as anodes in lithium ion cells have been performed. The carbons have been synthesized using pillared clays (PILCs) as inorganic templates. Pillared clays are layered silicates whose sheets have been permanently propped open by sets of thermally stable molecular props. The calcined PILC was loaded with five different organic precursors and heated at 700 C under nitrogen. When the inorganic pillars were removed by acid treatment, carbon sheets are produced with holes. The fitting of the data in the high q region suggested that the carbon sheets have voids with radii ranging from 4 to 8 {angstrom}. Similar radii were obtained for the PILC and PILC/organic precursor, which suggests that the carbon was well distributed in the clay prior to pyrolysis.

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

1998-01-14T23:59:59.000Z

32

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

SciTech Connect (OSTI)

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

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

1997-09-01T23:59:59.000Z

33

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

E-Print Network [OSTI]

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

Jacqueline Appell; Christian Ligoure; Gregoire Porte

2004-06-30T23:59:59.000Z

34

Small angle neutron scattering characterization of the porous structure of carbons prepared using inorganic templates  

SciTech Connect (OSTI)

Small angle neutron scattering (SANS) was used for the characterization of the microstructure of carbons derived from organic-loaded inorganic template materials that are used as anodes in lithium ion cells. Pillared clays (PILC), layered silicates whose sheets have been permanently propped open by sets of thermally stable molecular props, were used as a template to load the organic precursors. Five organic precursors, namely pyrene, styrene, pyrene/trioxane copolymer, ethylene, and propylene, were used to load the PILC. Pyrolysis was carried out at 700 C under nitrogen atmosphere. From SANS, information has been derived about the pore radius, mass fractal dimension, and the cutoff length (above which the fractal property breaks down) on each carbon. In general, the pore radius ranges from 4 to 11 {angstrom}, and the mass fractal dimension varies in the range from 2.5 to 2.9. Contrast-match SANS studies of carbons wetted in 84% deuterated toluene indicate that a significant amount of pores in carbon from pyrene are not accessible to the solvent, while most of the porous network of carbon from propylene is accessible.

Sandi, G.; Thiyagarajan, P.; Carrado, K.A.; Winans, R.E. [Argonne National Lab., IL (United States)] [Argonne National Lab., IL (United States)

1999-02-01T23:59:59.000Z

35

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

E-Print Network [OSTI]

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

Maria Sotiropoulou; Julian Oberdisse; Georgios Staikos

2006-04-03T23:59:59.000Z

36

Concept for a Time-of-Flight Small Angle Neutron Scattering Instrument at the European Spallation Source  

E-Print Network [OSTI]

A new Small Angle Neutron Scattering instrument is proposed for the European Spallation Source. The pulsed source requires a time-of-flight analysis of the gathered neutrons at the detector. The optimal instrument length is found to be rather large, which allows for a polarizer and a versatile collimation. The polarizer allows for studying magnetic samples and incoherent background subtraction. The wide collimation will host VSANS and SESANS options that increase the resolution of the instrument towards um and tens of um, respectively. Two 1m2 area detectors will cover a large solid angle simultaneously. The expected gains for this new instrument will lie in the range between 20 and 36, depending on the assessment criteria, when compared to up-to-date reactor based instruments. This will open new perspectives for fast kinetics, weakly scattering samples, and multi-dimensional contrast variation studies.

S. Jaksch; D. Martin-Rodriguez; A. Ostermann; J. Jestin; S. Duarte Pinto; W. G. Bouwman; J. Uher; R. Engels; G. Kemmerling; R. Hanslik; H. Frielinghaus

2014-03-11T23:59:59.000Z

37

Nanostructure in block copolymer solutions: Rheology and small-angle neutron scattering  

SciTech Connect (OSTI)

Triblock copolymers composed of poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO) present an amphiphilic character in aqueous solutions. Since PPO is less hydrophilic than PEO and since their solubilities decrease when the temperature increases, the copolymers self-assemble spontaneously, forming micelles at moderate temperatures. For higher temperatures or concentrations, the copolymers or the micelles are ordered because of repulsive interactions and form lyotropic liquid crystalline phases. These are phases of very great viscosity with the aspect of gels, and transitions between different crystalline phases can occur at fixed concentration during an increase of temperature. We studied solutions of three different copolymers. The first two have a star structure. They are both composed of four branches (EO){sub x}(PO){sub y} fixed on an ethylene diamine, but differ by the values of x and y. Their commercial name is Tetronic 908 (x=114, y=21) and Tetronic 704 (x=16, y=18). The third copolymer (EO){sub 37}(PO){sub 56}(EO){sub 37} is linear and is known under the name of Pluronic P105. The measurements of the shear complex elastic modulus according to the temperature is used to determine the temperatures of the different transitions. Then, small-angle neutron scattering on samples under flow and true crystallographic arguments make it possible to identify the nature of the crystalline phases. For the systems studied, we show that the branched copolymers form only one type of liquid crystalline phase, which is bcc for the T908 and lamellar for the T704. For the linear copolymer, it is possible to identify three transitions: micellar solution to hexagonal phase, hexagonal phase to body-centered cubic phase, and finally body-centered cubic phase to lamellar phase.

Habas, Jean-Pierre; Pavie, Emmanuel; Perreur, Christelle; Lapp, Alain; Peyrelasse, Jean [Laboratoire de Physico-Chimie des Polymeres UMR 5067, Universite de Pau et des Pays de l'Adour, Avenue de l'Universite, 64000 Pau (France); Laboratoire Leon Brillouin CEA Saclay, 91191 Gif-sur-Yvette Cedex (France); Laboratoire de Physico-Chimie des Polymeres UMR 5067, Universite de Pau et des Pays de l'Adour, Avenue de l'Universite, 64000 Pau (France)

2004-12-01T23:59:59.000Z

38

Neutron Small Angle Scattering on Liquid Helium in the temperature Range 1.5-4.2 K  

E-Print Network [OSTI]

The small angle neutron scattering from liquid helium at saturated vapour pressure in the temperature range from 1.5 to 4.2 K was measured with the instrument D22 of the ILL Grenoble at a wavelength of 4.6 angstrom. The zero angle cross section is monotonically decreasing with decreasing temperature and does not show any singularity at the lambda-point. On the other handd, we observe a change of the slope of the temperature dependence of thw second momentum of the pair correlation function at the lambda-point that reflects the transition of liquid to the superfluid state.

Yu. M. Tsipenyuk; R. P. May

2002-07-11T23:59:59.000Z

39

angle light scattering: Topics by E-print Network  

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

Biological tissues tend Kim, Arnold D. 11 Static light scattering and small-angle neutron scattering study on aggregated recombinant gelatin in aqueous solution University...

40

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

E-Print Network [OSTI]

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

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

2005-08-05T23:59:59.000Z

Note: This page contains sample records for the topic "angle neutron scattering" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

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

SciTech Connect (OSTI)

The magnetic reversal behaviors of single domain sized Nd-Fe-B permanent magnets, with and without isolation between the Nd{sub 2}Fe{sub 14}B grains, was clarified using small-angle neutron scattering (SANS). The SANS patterns obtained arose from changes in the magnetic domains and were analyzed using the TeubnerStray 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.

Yano, M., E-mail: masao-yano-aa@mail.toyota.co.jp; Manabe, A.; Shoji, T.; Kato, A. [Advanced Material Engineering Division, Toyota Motor Corporation, Susono 410-1193 (Japan); Ono, K. [High Energy Accelerator Research Organization (KEK), Tsukuba 305-0801 (Japan); Harada, M. [Toyota Central R and D Labs, Inc., Aichi 480-1192 (Japan); Kohlbrecher, J. [Laboratory for Neutron Scattering, Paul Scherrer Institut, 5232 Villigen PSI (Switzerland)

2014-05-07T23:59:59.000Z

42

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

E-Print Network [OSTI]

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

Jeremy Causse; Julian Oberdisse; Jacques Jestin; Serge Lagerge

2010-12-04T23:59:59.000Z

43

E-Print Network 3.0 - angle scattering studies Sample Search...  

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

Search Sample search results for: angle scattering studies Page: << < 1 2 3 4 5 > >> 1 Neutron Scattering in Polymer Micelle Characterization Summary: scattering Small Angle...

44

Microemulsion nanocomposites: phase diagram, rheology and structure using a combined small angle neutron scattering and reverse Monte Carlo approach  

E-Print Network [OSTI]

The effect of silica nanoparticles on transient microemulsion networks made of microemulsion droplets and telechelic copolymer molecules in water is studied, as a function of droplet size and concentration, amount of copolymer, and nanoparticle volume fraction. The phase diagram is found to be affected, and in particular the percolation threshold characterized by rheology is shifted upon addition of nanoparticles, suggesting participation of the particles in the network. This leads to a peculiar reinforcement behaviour of such microemulsion nanocomposites, the silica influencing both the modulus and the relaxation time. The reinforcement is modelled based on nanoparticles connected to the network via droplet adsorption. Contrast-variation Small Angle Neutron Scattering coupled to a reverse Monte Carlo approach is used to analyse the microstructure. The rather surprising intensity curves are shown to be in good agreement with the adsorption of droplets on the nanoparticle surface.

Nicolas Puech; Serge Mora; Ty Phou; Gregoire Porte; Jacques Jestin; Julian Oberdisse

2010-12-04T23:59:59.000Z

45

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

SciTech Connect (OSTI)

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

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

1996-12-31T23:59:59.000Z

46

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

E-Print Network [OSTI]

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

Nagle, John F.

47

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

E-Print Network [OSTI]

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

48

MAGNETIC NEUTRON SCATTERING  

SciTech Connect (OSTI)

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

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

2004-07-30T23:59:59.000Z

49

Imaging with Scattered Neutrons  

E-Print Network [OSTI]

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

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

2006-10-30T23:59:59.000Z

50

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

SciTech Connect (OSTI)

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

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

1996-12-31T23:59:59.000Z

51

Design of the Small Angle Neutron Scattering instrument at the Indiana University Low Energy Neutron Source| Applications to the study of nanostructured materials.  

E-Print Network [OSTI]

?? The Low Energy Neutron Source (LENS) located at the Indiana University Cyclotron Facility (IUCF) is a prototypical long-pulse accelerator-based neutron source. The Small Angle (more)

Remmes, Nicholas B.

2008-01-01T23:59:59.000Z

52

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

SciTech Connect (OSTI)

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

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

2014-01-01T23:59:59.000Z

53

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

SciTech Connect (OSTI)

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

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

2008-01-01T23:59:59.000Z

54

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

E-Print Network [OSTI]

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

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

2004-10-12T23:59:59.000Z

55

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

SciTech Connect (OSTI)

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

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

2006-01-01T23:59:59.000Z

56

E-Print Network 3.0 - angle scattering techniques Sample Search...  

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

angle ... Source: Ecole Polytechnique, Centre de mathmatiques Collection: Mathematics 2 Neutron Scattering in Polymer Micelle Characterization Summary: - Nondestructive technique...

57

Digenetic Changes in Macro- to Nano-Scale Porosity in the St. Peter Sandstone:L An (Ultra) Small Angle Neutron Scattering and Backscattered Electron Imagining Analysis  

SciTech Connect (OSTI)

Small- and Ultra-Small Angle Neutron Scattering (SANS and USANS) provide powerful tools for quantitative analysis of porous rocks, yielding bulk statistical information over a wide range of length scales. This study utilized (U)SANS to characterize shallowly buried quartz arenites from the St. Peter Sandstone. Backscattered electron imaging was also used to extend the data to larger scales. These samples contain significant volumes of large-scale porosity, modified by quartz overgrowths, and neutron scattering results show significant sub-micron porosity. While previous scattering data from sandstones suggest scattering is dominated by surface fractal behavior over many orders of magnitude, careful analysis of our data shows both fractal and pseudo-fractal behavior. The scattering curves are composed of subtle steps, modeled as polydispersed assemblages of pores with log-normal distributions. However, in some samples an additional surface-fractal overprint is present, while in others there is no such structure, and scattering can be explained by summation of non-fractal structures. Combined with our work on other rock-types, these data suggest that microporosity is more prevalent, and may play a much more important role than previously thought in fluid/rock interactions.

Anovitz, Lawrence {Larry} M [ORNL; Cole, David [Ohio State University; Rother, Gernot [ORNL; Allard Jr, Lawrence Frederick [ORNL; Jackson, Andrew [NIST Center for Neutron Research (NCRN), Gaithersburg, MD; Littrell, Ken [ORNL

2013-01-01T23:59:59.000Z

58

Application of small-angle neutron scattering to the study of forces between magnetically chained monodisperse ferrofluid emulsion droplets  

SciTech Connect (OSTI)

The optical magnetic chaining technique (MCT) developed by Leal-Calderon, Bibette and co-workers in the 1990 s allows precise measurements of force profiles between droplets in monodisperse ferrofluid emulsions. However, the method lacks an in-situ determination of droplet size and therefore requires the combination of separately acquired measurements of droplet chain periodicity versus an applied magnetic field from optical Bragg scattering and droplet diameter inferred from dynamic light scattering (DLS) to recover surface force-distance profiles between the colloidal particles. Compound refractive lens (CRL) focussed small-angle scattering (SANS) MCT should result in more consistent measurements of droplet size (form factor measurements in the absence of field) and droplet chaining period (from structure factor peaks when the magnetic field is applied); and, with access to shorter length scales, extend force measurements to closer approaches than possible by optical measurements. We report on CRL-SANS measurements of monodisperse ferrofluid emulsion droplets aligned in straight chains by an applied field perpendicular to the incident beam direction. Analysis of the scattering from the closely spaced droplets required algorithms that carefully treated resolution and its effect on mean scattering vector magnitudes in order to determine droplet size and chain periods to sufficient accuracy. At lower applied fields scattering patterns indicate structural correlations transverse to the magnetic field direction due to the formation of intermediate structures in early chain growth.

Jain, Dr Nirmesh [University of Sydney, Australia] [University of Sydney, Australia; Liu, Dr C K [Institute of Materials research and Engineering, A-STAR, Singapore] [Institute of Materials research and Engineering, A-STAR, Singapore; Hawkett, Dr B. S. [University of Sydney, Australia] [University of Sydney, Australia; Warr, G. G. [University of Sydney, Australia] [University of Sydney, Australia; Hamilton, William A [ORNL] [ORNL

2014-01-01T23:59:59.000Z

59

Lujan Neutron Scattering Center  

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

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

60

Neutron scattering and models: Titanium  

SciTech Connect (OSTI)

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

Smith, A.B.

1997-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "angle neutron scattering" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Diffusion and adsorption of methane confined in nanoporous carbon aerogel: a combined quasi-elastic and small-angle neutron scattering study  

SciTech Connect (OSTI)

The diffusion of methane confined in nano-porous carbon aerogel with the average pore size 48 {angstrom} and porosity 60% was investigated as a function of pressure at T = 298 K using quasi-elastic neutron scattering (QENS). The diffusivity of methane shows a clear effect of confinement: it is about two orders of magnitude lower than in bulk at the same thermodynamic conditions and is close to the diffusivity of liquid methane at 100 K (i.e. {approx} 90 K below the liquid-gas critical temperature T{sub C} {approx} 191 K). The diffusion coefficient (D) of methane initially increases with pressure by a factor of {approx}2.5 from 3.47 {+-} 0.41 x 10{sup -10} m{sup 2} s{sup -1} at 0.482 MPa to D = 8.55 {+-} 0.33 x 10{sup -10} m{sup 2} s{sup -1} at 2.75 MPa and starts to decrease at higher pressures. An explanation of the observed non-monotonic behavior of the diffusivity in the confined fluid is based on the results of small-angle neutron scattering experiments of the phase behavior of methane in a similar carbon aerogel sample. The initial increase of the diffusion coefficient with pressure is explained as due to progressive filling of bigger pores in which molecular mobility in the internal pore volume is less affected by the sluggish liquid-like molecular mobility in the adsorbed phase. Subsequent decrease of D, is associated with the effect of intermolecular collisions, which result in a lower total molecular mobility with pressure, as in the bulk state. The results are compared with the available QENS data on the methane diffusivity in zeolites, metal organic frameworks, and porous silica as well as with the molecular dynamics simulations of methane in nano-porous carbons and silica zeolites.

Mavila Chathoth, Suresh [ORNL; Mamontov, Eugene [ORNL; Melnichenko, Yuri B [ORNL; Zamponi, Michaela M [ORNL

2010-01-01T23:59:59.000Z

62

E-Print Network 3.0 - angle neutron diffractometer Sample Search...  

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

(300 - 2000 K) X-ray reflectometer (under installation) Small and Ultra Small Angle Neutron Scattering... (at)ipta.demokritos.gr 2106503712 2106533431 Large Scale...

63

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

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

The Heusler-derived multiferroic alloy Ni50?xCoxMn??Sn?? has recently been shown to exhibit, at just above room temperature, a highly reversible martensitic phase transformation with an unusually large magnetization change. In this work the nature of the magnetic ordering above and below this transformation has been studied in detail in the critical composition range x = 68 via temperature-dependent (5600 K) magnetometry and small-angle neutron scattering (SANS). We observe fairly typical paramagnetic to long-range-ordered ferromagnetic phase transitions on cooling to 420430 K, with the expected critical spin fluctuations, followed by first-order martensitic phase transformations to a nonferromagnetic state below 360390 K. The static magnetization reveals complex magnetism in this low-temperature nonferromagnetic phase, including a Langevin-like field dependence, distinct spin freezing near 60 K, and significant exchange bias effects, consistent with superparamagnetic blocking of ferromagnetic clusters of nanoscopic dimensions. We demonstrate that these spin clusters, whose existence has been hypothesized in a variety of martensitic alloys exhibiting competition between ferromagnetic and antiferromagnetic exchange interactions, can be directly observed by SANS. The scattering data are consistent with a liquidlike spatial distribution of interacting magnetic clusters with a mean center-to-center spacing of 12 nm. Considering the behavior of the superparmagnetism, cooling-field and temperature-dependent exchange bias, and magnetic SANS, we discuss in detail the physical form and origin of these spin clusters, their intercluster interactions, the nature of the ground-state magnetic ordering in the martensitic phase, and the implications for our understanding of such alloy systems.

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

2012-04-01T23:59:59.000Z

64

Neutron Scattering Stiudies  

SciTech Connect (OSTI)

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

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

2007-04-18T23:59:59.000Z

65

Small Angle X-Ray Scattering Detector  

DOE Patents [OSTI]

A detector for time-resolved small-angle x-ray scattering includes a nearly constant diameter, evacuated linear tube having an end plate detector with a first fluorescent screen and concentric rings of first fiber optic bundles for low angle scattering detection and an annular detector having a second fluorescent screen and second fiber optic bundles concentrically disposed about the tube for higher angle scattering detection. With the scattering source, i.e., the specimen under investigation, located outside of the evacuated tube on the tube's longitudinal axis, scattered x-rays are detected by the fiber optic bundles, to each of which is coupled a respective photodetector, to provide a measurement resolution, i.e., dq/q, where q is the momentum transferred from an incident x-ray to an x-ray scattering specimen, of 2% over two (2) orders of magnitude in reciprocal space, i.e., qmax/qmin approx=lO0.

Hessler, Jan P.

2004-06-15T23:59:59.000Z

66

Temperature Dependent Neutron Scattering Sections for Polyethylene  

E-Print Network [OSTI]

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

Roger E. Hill; C. -Y. Liu

2003-09-05T23:59:59.000Z

67

Neutron Scattering Tutorials | Neutron Science | ORNL  

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

4 A. J. Schultz Single-Crystal Diffraction PDF Video V. S. Urban Small-Angle Scattering PDF Video NOTE: the windows media plugin may be required to view these videos with Firefox....

68

E-Print Network 3.0 - angle scattering restraints Sample Search...  

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

Characterization of Assemblies from Summary: , San Francisco 2001), small-angle X-ray and neutron scattering (KochQB3 et al., 2003), site... subcomplex) are first purified by...

69

Small Angle X-Ray Scattering Detector  

DOE Patents [OSTI]

A detector for time-resolved small-angle x-ray scattering includes a nearly constant diameter, evacuated linear tube having an end plate detector with a first fluorescent screen and concentric rings of first fiber optic bundles for low angle scattering detection and an annular detector having a second fluorescent screen and second fiber optic bundles concentrically disposed about the tube for higher angle scattering detection. With the scattering source, i.e., the specimen under investigation, located outside of the evacuated tube on the tube's longitudinal axis, scattered x-rays are detected by the fiber optic bundles, to each of which is coupled a respective photodetector, to provide a measurement resolution, i.e., dq/q, where q is the momentum transferred from an incident x-ray to an x-ray scattering specimen, of 2% over two (2) orders of magnitude in reciprocal space, i.e., q.sub.max /q.sub.min.congruent.100.

Hessler, Jan P. (Downers Grove, IL)

2004-06-15T23:59:59.000Z

70

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

E-Print Network [OSTI]

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

71

Microsoft Word - Milestone_Report-12-2012-Small-Angle_Neutron...  

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

Water Reactor Sustainability Program: Milestone M3LW-13OR0402012, Report on Small-Angle Neutron Scattering Experiments of Irradiated RPV Materials Prepared by M. A. Sokolov, K....

72

Neutron Scattering at 25 Teslas: MagLab Completes Conical Bore...  

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

central field with a unique conical warm bore with 30 degree opening angles suitable for neutron scattering experiments. Development and fabrication of this Conical Bore Resistive...

73

RisR1125(EN) Neutron Scattering  

E-Print Network [OSTI]

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

74

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

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

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

75

Neutron-deuteron elastic scattering and three-nucleon force  

E-Print Network [OSTI]

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

Chtangeev, Maxim B

2005-01-01T23:59:59.000Z

76

Neutron-deuteron breakup and quasielastic scattering  

E-Print Network [OSTI]

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

Ohlson, Alice Elisabeth

2009-01-01T23:59:59.000Z

77

Measurements of the Thermal Neutron Scattering Kernel  

E-Print Network [OSTI]

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

Danon, Yaron

78

Neutron Scattering Studies of Correlated Electron Systems  

E-Print Network [OSTI]

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

Boothroyd, Andrew

79

Requirements, possible alternatives & international NEUTRON SCATTERING  

E-Print Network [OSTI]

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

Dimeo, Robert M.

80

SMB, Small Angle X-Ray Scattering  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 -the Mid-Infrared0 ResourceAwards SAGE Awards ,#2446Small Angle X-Ray Scattering

Note: This page contains sample records for the topic "angle neutron scattering" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Structure Transition in PSS/Lysozyme Complexes: A Chain-Conformation-Driven Process, as Directly Seen by Small Angle Neutron Scattering  

E-Print Network [OSTI]

Measurements of chain conformation in proteins/polyelectrolytes complexes (lysozyme and PSSNa) show that the crossover observed between an open structure -a chain network crosslinked by the proteins, and a globular one - dense globules of ~ 10 nm aggregated in a fractal way, results from a conformation modification prior to the transition. Before showing this, we have widened the parameters range for the observation of the transition. We had shown before that the two structures can be formed depending on chain length (for a given [PSS]/[lysozyme] ratio): gel for large chains, globules for short chains. We show here that the crossover between these two regimes can also be reached as a function of chains concentration or salinity of the buffer. Since all these crossover parameters act on chains overlapping concentration c*, we reinforce the idea of a transition from the dilute to the semi-dilute regime, but c* is shifted compared to pure PSS solutions. In order to understand this, we have measured by SANS the conformation of a single chain of PSS in presence of proteins within the complexes. This is achieved by a specific labeling trick where we take advantage of the fact that lysozyme and hydrogenated PSS chains have the same neutron scattering length density. In the gel structure, the PSS chains keep a wormlike structure as in pure solutions, but their persistence length is strongly reduced, from 50 {\\AA} without proteins to 20 {\\AA} in average with lysozyme. With this value of 20 {\\AA}, we calculate new overlapping thresholds (concentration, mass, ionic strength) in agreement with observed ones. In a second stage, after the globular structure is formed, the PSS chains get a third conformation, no longer wormlike, but more collapsed, within the globules.

Jrmie Gummel; Fabrice Cousin; Franois Bou

2009-03-30T23:59:59.000Z

82

Simulation-guided optimization of small-angle analyzer geometry in the neutron backscattering spectrometer SPHERES  

SciTech Connect (OSTI)

The resolution of neutron backscattering spectrometers deteriorates at small scattering angles where analyzers deviate from exact backscattering. By reducing the azimuth angle range of the analyzers, the resolution can be improved with little loss of peak intensity. Measurements at the spectrometer SPHERES are in excellent agreement with simulations, which proves the dominance of geometric effects.

Wuttke, Joachim; Zamponi, Michaela [Forschungszentrum Jlich GmbH, Jlich Centre for Neutron Science at MLZ, Lichtenbergstrae 1, 85747 Garching (Germany)] [Forschungszentrum Jlich GmbH, Jlich Centre for Neutron Science at MLZ, Lichtenbergstrae 1, 85747 Garching (Germany)

2013-11-15T23:59:59.000Z

83

Analyzing Power Measurement for Forward Angle N-P Scattering at 790 Mev  

E-Print Network [OSTI]

nature of one of the experiments. The present measure- M=a+c(o', n+o2 n)+m(tr& n)(oz n), in which e& and o2 are the neutron and proton spin operators, respectively, and n is the unit vector normal to the scattering plane. The analyzing power A (or... (Received 20 November 1989) A measurement of the analyzing power for n-p scattering has been made at center-of-mass angles, 8.8, 15.0', and 20.7' with a nearly monoenergetic polarized neutron beam peaked at 790 MeV. These angles represent an acceptance...

Glass, G.; Bhatia, T. S.; Hiebert, John C.; Kenefick, R. A.; Nath, S.; Northcliffe, L. C.; Johnson, K. F.; Spinka, H.; Stanek, R.; Rawool, M. W.; Faucett, J. A.; Jeppersen, R. H.; Tripard, G. E.; Newsom, C. R.

1990-01-01T23:59:59.000Z

84

Scattered neutron tomography based on a neutron transport problem  

E-Print Network [OSTI]

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

Scipolo, Vittorio

2005-11-01T23:59:59.000Z

85

Neutron-deuteron breakup and quasielastic scattering .  

E-Print Network [OSTI]

??Quasielastic scattering and deuteron breakup in the 200 MeV region is studied by impinging a pulsed neutron beam on a deuterium target at the Weapons (more)

Ohlson, Alice Elisabeth

2009-01-01T23:59:59.000Z

86

26 Tesla DC Magnet for Neutron Scattering  

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

Previously, DC Magnets located at Neutron-Scattering Beamlines were commercially-manufactured superconducting magnets and limited to 17 T. A few pulsed magnet systems have been...

87

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

E-Print Network [OSTI]

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

Nagle, John F.

88

Electron-neutron scattering and transport properties of neutron stars  

E-Print Network [OSTI]

We show that electrons can couple to the neutron excitations in neutron stars and find that this can limit their contribution to the transport properties of dense matter, especially the shear viscosity. The coupling between electrons and neutrons is induced by protons in the core, and by ions in the crust. We calculate the effective electron-neutron interaction for the kinematics of relevance to the scattering of degenerate electrons at high density. We use this interaction to calculate the electron thermal conductivity, electrical conductivity, and shear viscosity in the neutron star inner crust, and in the core where we consider both normal and superfluid phases of neutron-rich matter. In some cases, particularly when protons are superconducting and neutrons are in their normal phase, we find that electron-neutron scattering can be more important than the other scattering mechanisms considered previously.

Bertoni, Bridget; Rrapaj, Ermal

2014-01-01T23:59:59.000Z

89

Fully portable, highly flexible dilution refrigerator systems for neutron scattering  

E-Print Network [OSTI]

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

Boyer, Edmond

90

UNIVERSITY OF CALIFORNIA Inelastic Neutron Scattering Study of the  

E-Print Network [OSTI]

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

Lawrence, Jon

91

Implementation of the control and data acquisition system for a small angle neutron scattering spectrometer according to the "Juelich-Munich standard"  

E-Print Network [OSTI]

In Forschungszentrum Juelich the control and data acquisition systems for several neutron spectrometers are being built. Because some of these spectrometers will be commissioned to the new research reactor FRM-II at the technical university of Munich, there was a joint effort with the instrumentation group of the FRM-II to establish the "Juelich-Munich standard", which is basically a collection of tools and devices which are used for the implementation of the spectrometers. This includes: Siemens S7 PLCs for all axis movement issues, PROFIBUS DP for the connection of slow control equipment in the front end, TACO Middleware running on PC-Systems with Linux, python for scripting and Qt for the implementation of GUIs. The paper describes the implementation the control and data acquisition system of the KWS-1, the first experiment built according to the above standard

H. Kleines; M. Drochner; H. Loevenich; M. Wagener; F. Suxdorf; F. -J. Kayser; K. Zwoll; L. Schaetzler; J. Heinen; M. Heiderich; D. Schwahn; J. Neuhaus; J. Krueger

2002-10-24T23:59:59.000Z

92

Proton Angular Distribution for 90 Mev Neutron-proton Scattering  

E-Print Network [OSTI]

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

Hadley, James

2010-01-01T23:59:59.000Z

93

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

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

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

94

A New Polyethylene Scattering Law Determined Using Inelastic Neutron Scattering  

SciTech Connect (OSTI)

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

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

2013-01-01T23:59:59.000Z

95

BUILDING A NETWORK FOR NEUTRON SCATTERING EDUCATION  

SciTech Connect (OSTI)

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

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

2008-10-01T23:59:59.000Z

96

The Neutron Scattering Society www.neutronscattering.org  

E-Print Network [OSTI]

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

Chen, Sow-Hsin

97

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

E-Print Network [OSTI]

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

Hall, Christopher

98

Neutron and X-ray Scattering Study of Magnetic Manganites  

E-Print Network [OSTI]

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

Boothroyd, Andrew

99

Neutron scattering at high pressure D. B. McWhan  

E-Print Network [OSTI]

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

Paris-Sud XI, Université de

100

E-Print Network 3.0 - alamos neutron scattering Sample Search...  

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

neutron scattering Search Powered by Explorit Topic List Advanced Search Sample search results for: alamos neutron scattering Page: << < 1 2 3 4 5 > >> 1 Neutron Scattering Society...

Note: This page contains sample records for the topic "angle neutron scattering" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Neutron Scattering Tutorials | Neutron Science | ORNL  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the Contributions andDataNational Library of1, 2007Transmission toBeamNDiscoveryNeutron

102

Neutron Interactions: Q-Equation, Elastic Scattering  

E-Print Network [OSTI]

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

unknown authors

103

Neutron scattering measurements at intermediate energies  

E-Print Network [OSTI]

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

N. Olsson; J. Blomgren; E. Ramstrom

104

Neutron Compton scattering from hydrogen and perovskite oxide interfaces.  

E-Print Network [OSTI]

??In this thesis we investigate two independent topics: neutron Compton scattering from hydrogen and perovskite oxide interfaces. Part one is an investigation of the scattering (more)

Lemon, Christopher P.

2010-01-01T23:59:59.000Z

105

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

E-Print Network [OSTI]

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

Boothroyd, Andrew

106

Cold neutron scattering in imperfect deuterium crystals  

E-Print Network [OSTI]

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

Andrzej Adamczak

2010-12-10T23:59:59.000Z

107

Attosecond neutron Compton scattering from protons  

E-Print Network [OSTI]

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

C. Aris Chatzidimitriou-Dreismann

2007-02-01T23:59:59.000Z

108

The Neutron Scattering Society www.neutronscattering.org  

E-Print Network [OSTI]

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

Homes, Christopher C.

109

Thirteenth National School on Neutron and X-ray Scattering  

E-Print Network [OSTI]

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

110

Neutron Scattering Society of America Purpose and New Initiatives  

E-Print Network [OSTI]

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

Pennycook, Steve

111

ORNL Neutron Scattering School May 30 -June 5, 2009  

E-Print Network [OSTI]

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

Pennycook, Steve

112

Nitrogen Contamination in Elastic Neutron Scattering Songxue Chi,ab  

E-Print Network [OSTI]

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

Lynn, Jeffrey W.

113

LANSCE School on Neutron Scattering: Materials at the Mesoscale  

E-Print Network [OSTI]

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

114

A Java-based Science Portal for Neutron Scattering Experiments  

E-Print Network [OSTI]

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

Vazhkudai, Sudharshan

115

Tenth National School on Neutron and X-ray Scattering  

E-Print Network [OSTI]

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

Pennycook, Steve

116

Sixteenth National School on Neutron and X-ray Scattering  

E-Print Network [OSTI]

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

Pennycook, Steve

117

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

E-Print Network [OSTI]

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

Boyer, Edmond

118

Fourteenth National School on Neutron and X-ray Scattering  

E-Print Network [OSTI]

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

Pennycook, Steve

119

National School on Neutron and X-ray Scattering  

E-Print Network [OSTI]

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

120

National School on Neutron and X-ray Scattering  

E-Print Network [OSTI]

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

Pennycook, Steve

Note: This page contains sample records for the topic "angle neutron scattering" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

TUTORIAL / ARTICLE DIDACTIQUE Neutron scattering study of the classical  

E-Print Network [OSTI]

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

Ryan, Dominic

122

Twelfth National School on Neutron and X-ray Scattering  

E-Print Network [OSTI]

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

Pennycook, Steve

123

Neutron Scattering Experiment Automation with Python  

SciTech Connect (OSTI)

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

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

2010-01-01T23:59:59.000Z

124

Neutron scattering and extra short range interactions  

E-Print Network [OSTI]

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

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

2007-11-14T23:59:59.000Z

125

Total Cross Sections for Neutron Scattering  

E-Print Network [OSTI]

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

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

1994-10-19T23:59:59.000Z

126

Small-angle scattering instruments on a 1 MW long pulse spallation source  

SciTech Connect (OSTI)

Two small-angle neutron scattering instruments have been designed and optimized for installation at a 1 MW long pulse spallation source. The first of these instruments allows access to length scales in materials from 10 to 400 {angstrom}, and the second instrument from 40 to 1200 {angstrom}. Design characteristics were determined and optimization was done using the MCLIB Monte Carlo instrument simulation package. The code has been {open_quote}benchmarked{close_quote} by simulating the {open_quote}as-built{close_quote} D11 spectrometer at ILL and a performance comparison of the three instruments was made. Comparisons were made by evaluating the scattered intensity for {delta} scatterers at different Q values for various instrument configurations needed to span a Q-range of 0.0007 - 0.44 {angstrom}{sup {minus}1}.

Olah, G.A.; Hjelm, R.P.; Seeger, P.A.

1995-12-01T23:59:59.000Z

127

A new method for analyzing collimation angle of neutron Soller collimator  

E-Print Network [OSTI]

A new method for analyzing collimation angle of neutron Soller collimator is described. Gaussian distribution formula is used to define the angle distribution function of neutron source and neutron transmission function of Soller collimator. A relationship between FWHM of collimator rocking curve and collimation angle is derived.

Jian-Bo Gao; Yun-Tao Liu; Dong-Feng Chen

2015-03-18T23:59:59.000Z

128

A new method for analyzing collimation angle of neutron Soller collimator  

E-Print Network [OSTI]

A new method for analyzing collimation angle of neutron Soller collimator is described. Gaussian distribution formula is used to define the angle distribution function of neutron source and neutron transmission function of Soller collimator. A relationship between FWHM of collimator rocking curve and collimation angle is derived.

Gao, Jian-Bo; Chen, Dong-Feng

2015-01-01T23:59:59.000Z

129

On the kinematics and resolution of spectrometers for neutron Brillouin scattering  

SciTech Connect (OSTI)

Neutron Brillouin scattering involves measurement of excitations at smaller Q values than in currently customary. We outline the kinematic constraints on scattering angle and incident energy for excitations with both linear dispersion (sound waves) and parabolic dispersion (ferromagnetic spin waves), and discuss the resolution characteristics of the chopper spectrometer proposed for LANSCE which should be suitable for such studies. In particular, we demonstrate that longitudinal resolution focusing can be exploited both in neutron energy gain and in neutron energy loss. 13 refs., 8 figs., 1 tab.

Robinson, R.A.

1988-01-01T23:59:59.000Z

130

Instrumentation development for neutron scattering at high pressure  

E-Print Network [OSTI]

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

Fang, Junwei

2012-11-29T23:59:59.000Z

131

Instrumentation development for neutron scattering at high pressure.  

E-Print Network [OSTI]

??Neutron scattering at extremes of pressure is a powerful tool for studying the response of structural and magnetic properties of materials on microscopic level to (more)

Fang, Junwei

2012-01-01T23:59:59.000Z

132

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

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

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

133

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

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

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

134

Transverse Beam Spin Asymmetries at Backward Angles in Elastic Electron-Proton and Quasi-elastic Electron-Deuteron Scattering  

E-Print Network [OSTI]

We have measured the beam-normal single-spin asymmetries in elastic scattering of transversely polarized electrons from the proton, and performed the first measurement in quasi-elastic scattering on the deuteron, at backward angles (lab scattering angle of 108 degrees) for Q2 = 0.22 GeV^2/c^2 and 0.63 GeV^2/c^2 at beam energies of 362 MeV and 687 MeV, respectively. The asymmetry arises due to the imaginary part of the interference of the two-photon exchange amplitude with that of single photon exchange. Results for the proton are consistent with a model calculation which includes inelastic intermediate hadronic (piN) states. An estimate of the beam-normal single-spin asymmetry for the scattering from the neutron is made using a quasi-static deuterium approximation, and is also in agreement with theory.

The G0 Collaboration; D. Androi?; D. S. Armstrong; J. Arvieux; S. L. Bailey; D. H. Beck; E. J. Beise; J. Benesch; F. Benmokhtar; L. Bimbot; J. Birchall; P. Bosted; H. Breuer; C. L. Capuano; Y. -C. Chao; A. Coppens; C. A. Davis; C. Ellis; G. Flores; G. Franklin; C. Furget; D. Gaskell; M. T. W. Gericke; J. Grames; G. Guillard; J. Hansknecht; T. Horn; M. K. Jones; P. M. King; W. Korsch; S. Kox; L. Lee; J. Liu; A. Lung; J. Mammei; J. W. Martin; R. D. McKeown; A. Micherdzinska; M. Mihovilovic; H. Mkrtchyan; M. Muether; S. A. Page; V. Papavassiliou; S. F. Pate; 10 S. K. Phillips; P. Pillot; M. L. Pitt; M. Poelker; B. Quinn; W. D. Ramsay; J. -S. Real; J. Roche; P. Roos; J. Schaub; T. Seva; N. Simicevic; G. R. Smith; D. T. Spayde; M. Stutzman; R. Suleiman; V. Tadevosyan; W. T. H. van Oers; M. Versteegen; E. Voutier; W. Vulcan; S. P. Wells; S. E. Williamson; S. A. Wood; B. Pasquini; M. Vanderhaeghen

2011-06-16T23:59:59.000Z

135

Deeply Virtual Compton Scattering off the neutron  

E-Print Network [OSTI]

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

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

2007-12-12T23:59:59.000Z

136

Electron Scattering From High-Momentum Neutrons in Deuterium  

SciTech Connect (OSTI)

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

A.V. Klimenko; S.E. Kuhn

2005-10-12T23:59:59.000Z

137

Electron Scattering From High-Momentum Neutrons in Deuterium  

E-Print Network [OSTI]

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

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

2005-10-12T23:59:59.000Z

138

Cross sections for neutron-deuteron elastic scattering in the energy range 135250 MeV  

E-Print Network [OSTI]

We report new measurements of the neutron-deuteron elastic scattering cross section at energies from 135 to 250 MeV and center-of-mass angles from 80[degrees] to 130[degrees]. Cross sections for neutron-proton elastic ...

Ertan, E.

139

Enhanced reaction rates in NDP analysis with neutron scattering  

SciTech Connect (OSTI)

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

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

2014-04-15T23:59:59.000Z

140

Anomalous neutron Compton scattering from molecular hydrogen  

SciTech Connect (OSTI)

Application of neutron Compton scattering, which operates in the attosecond time scale, to (a) the equimolar H{sub 2}-D{sub 2} mixture and (b) the mixed-isotope system HD (liquids, both at 20 K), reveals a strong anomalous shortfall (about 30%) of the ratio R={sigma}{sub H}/{sigma}{sub D} of H and D cross sections. This striking effect is similar to that observed in liquid H{sub 2}O-D{sub 2}O mixtures [C. A. Chatzidimitriou-Dreismann et al., Phys. Rev. Lett. 79, 2839 (1997)]. Crucially, the shortfall of R is equal in both samples (a) and (b). This result demonstrates that quantum exchange correlations of identical nuclei play no significant role in this effect, thus refuting corresponding theoretical models claiming its interpretation. In contrast, our findings are consistent with alternative theoretical models, in which attosecond dynamics of electronic degrees of freedom (via violation of the Born-Oppenheimer approximation) is considered to participate significantly in the dynamics of an elementary neutron-proton (-deuteron) scattering process. Possible implications for attosecond chemical dynamics, e.g., the onset of bond breaking, are mentioned.

Chatzidimitriou-Dreismann, C.A.; Krzystyniak, M. [Institute of Chemistry, Stranski Laboratory, Technical University of Berlin, D-10623 Berlin (Germany); Abdul-Redah, T. [Physics Laboratory, The University of Kent at Canterbury, Canterbury, Kent CT2 7NR (United Kingdom)

2005-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "angle neutron scattering" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Using multi-angle scattered sound to size fish swimbladders Jules S. Jaffe  

E-Print Network [OSTI]

Using multi-angle scattered sound to size fish swimbladders Jules S. Jaffe Jaffe, J. S. 2006. Using multi-angle scattered sound to size fish swimbladders. e ICES Journal of Marine Science, 63: 1397e1404 a simple one-dimensional model of scatter from a fish swimbladder, an expression is derived that predicts

Jaffe, Jules

142

Analysis of neutron scattering data: Visualization and parameter estimation  

SciTech Connect (OSTI)

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

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

1998-09-01T23:59:59.000Z

143

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

SciTech Connect (OSTI)

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

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

2012-01-01T23:59:59.000Z

144

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

E-Print Network [OSTI]

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

Deepshikha Choudhury; Andreas Nogga; Daniel R. Phillips

2007-06-11T23:59:59.000Z

145

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

Office of Science (SC) Website

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

146

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

Office of Science (SC) Website

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

147

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

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

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

148

Quantum Monte Carlo calculations of neutron-alpha scattering  

E-Print Network [OSTI]

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

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

2006-12-09T23:59:59.000Z

149

E-Print Network 3.0 - angle scattering revision Sample Search...  

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

and scattering, effective index, surface autocovariance, and correlation... . The phenomenology is complex, including specular and diffuse reflection, high-angle forward...

150

Deterministic Multigroup Modeling of Thermal Effect on Neutron Scattering by Heavy Nuclides.  

E-Print Network [OSTI]

??The principal physical phenomenon underlying the computation of neutron spectra is the nuclear reaction in which neutrons lose or gain energy, i.e., the neutron scattering (more)

Ghrayeb, Shadi

2013-01-01T23:59:59.000Z

151

Liquid Argon Cryogenic Detector Calibration by Inelastic Scattering of Neutrons  

E-Print Network [OSTI]

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

Sergey Polosatkin; Evgeny Grishnyaev; Alexander Dolgov

2014-07-10T23:59:59.000Z

152

Toward a Taxonomy of the Denatured State: Small Angle Scattering Studies of Unfolded Proteins  

SciTech Connect (OSTI)

Despite the critical role the unfolded state plays in defining protein folding kinetics and thermodynamics (Berg et al., 2002; Dunker, 2002; Shortle, 2002; Wright and Dyson, 2002), our understanding of its detailed structure remains rather rudimentary; the heterogeneity of the unfolded ensemble renders difficult or impossible its study by traditional, atomic-level structural methods. Consequently, recent years have seen a significant expansion of small-angle X-ray and neutron scattering (SAXS and SANS, respectively) techniques that provide direct, albeit rotationally and time-averaged, measures of the geometric properties of the unfolded ensemble. These studies have reached a critical mass, allowing us for the first time to define general observations regarding the nature of the geometry - and possibly the chemistry and physics - of unfolded proteins.

Millett, I.S.; Doniach, S.; Plaxco, K.W. (Stanford); (UCSB)

2005-02-15T23:59:59.000Z

153

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

E-Print Network [OSTI]

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

Paris-Sud XI, Université de

154

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

SciTech Connect (OSTI)

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

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

2009-09-15T23:59:59.000Z

155

Compton Scattering from the Deuteron and Extracted Neutron Polarizabilities  

E-Print Network [OSTI]

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

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

2003-06-13T23:59:59.000Z

156

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

E-Print Network [OSTI]

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

A. Nogga; C. Hanhart

2005-11-02T23:59:59.000Z

157

Dynamic Properties of Materials: Phonons from Neutron Scattering  

E-Print Network [OSTI]

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

Cope, Elizabeth Ruth

2010-01-01T23:59:59.000Z

158

NEUTRON SPECTROSCOPY BY DOUBLE SCATTER AND ASSOCIATED PARTICLE TECHNIQUES.  

SciTech Connect (OSTI)

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

DIOSZEGI,I.

2007-10-28T23:59:59.000Z

159

Angle-resolved scattering spectroscopy of explosives using an external cavity quantum cascade laser  

SciTech Connect (OSTI)

Investigation of angle-resolved scattering from solid explosives residues on a car door for non-contact sensing geometries. Illumination with a mid-infrared external cavity quantum cascade laser tuning between 7 and 8 microns was detected both with a sensitive single point detector and a hyperspectral imaging camera. Spectral scattering phenomena were discussed and possibilities for hyperspectral imaging at large scattering angles were outlined.

Suter, Jonathan D.; Bernacki, Bruce E.; Phillips, Mark C.

2012-04-01T23:59:59.000Z

160

Cross sections for neutron-deuteron elastic scattering in the energy range 135-250 MeV  

E-Print Network [OSTI]

We report new measurements of the neutron-deuteron elastic scattering cross section at energies from 135 to 250 MeV and center-of-mass angles from $80^\\circ$ to $130^\\circ$. Cross sections for neutron-proton elastic scattering were also measured with the same experimental setup for normalization purposes. Our $nd$ cross section results are compared with predictions based on Faddeev calculations including three-nucleon forces, and with cross sections measured with charged particle and neutron beams at comparable energies.

E. Ertan; T. Akdogan; M. B. Chtangeev; W. A. Franklin; P. A. M. Gram; M. A. Kovash; J. L. Matthews; M. Yuly

2012-11-22T23:59:59.000Z

Note: This page contains sample records for the topic "angle neutron scattering" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Entangling neutrons via successive scattering from a substrate  

E-Print Network [OSTI]

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

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

2008-07-10T23:59:59.000Z

162

Origin of the intensity deficit in neutron Compton scattering  

SciTech Connect (OSTI)

Neutron Compton scattering measurements in a variety of materials have shown a relative deficit in the total signal from hydrogen compared to deuterium and heavier ions. We show here that a breakdown in the Born-Oppenheimer approximation in the final states of the scattering process leads to such a deficit and may be responsible for the effect.

Reiter, G.F.; Platzman, P.M. [Physics Department, University of Houston, Houston, Texas 77204-5506 (United States); Bell Laboratories, Lucent Technologies, Murray Hill, New Jersey 07974-0636 (United States)

2005-02-01T23:59:59.000Z

163

Realization of adiabatic Aharonov-Bohm scattering with neutrons  

E-Print Network [OSTI]

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

Erik Sjqvist; Martin Almquist; Ken Mattsson; Zeynep Nilhan Grkan; Bjrn Hessmo

2015-03-08T23:59:59.000Z

164

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

SciTech Connect (OSTI)

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

Saenboonruang, Kiadtisak [Virginia U., JLAB

2013-05-31T23:59:59.000Z

165

E-Print Network 3.0 - angle quasi-elastic scattering Sample Search...  

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

Force Academy, University of New South Wales Collection: Physics ; Materials Science 2 Neutron scattering study of the quasi-elastic spectral width in CeMg, CeMg3 and NdMg3...

166

2010 American Conference on Neutron Scattering (ACNS 2010)  

SciTech Connect (OSTI)

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

Billinge, Simon

2011-06-17T23:59:59.000Z

167

Effects of droplet fluctuations on the scattering of neutrons and light by microemulsions  

E-Print Network [OSTI]

Beginning from the first neutron spin-echo study of the shape fluctuations of microemulsion droplets [J.S. Huang, S.T. Milner, B. Farago, and D. Richter, Phys. Rev. Lett. 59, 2600 (1987)] these experiments are incorrectly interpreted in the literature. This is due to an inappropriate account for the fluctuations and the erroneous application of the original theory to the experiments (see [V. Lisy and B. Brutovsky, Czech. J. Phys. 50, 239 (2000)]). In the presented work both these shortcomings are corrected. We develop the theory of static and dynamic light and neutron scattering from droplet microemulsions. The fluids inside and out of the droplets are separated by a surfactant layer of arbitrary thickness. The scattering functions consistently take into account thermal fluctuations of the shapes of such double-layered spheres to the second order in the changes of their radius. The relaxation times and correlation functions of the fluctuations are found within the Helfrich's theory of interfacial elasticity. The theory is applied to the quantitative description of small-angle neutron scattering, neutron spin-echo spectroscopy and dynamic light scattering experiments. Basic characteristics of the microemulsions, extracted from the fits to the experimental data, significantly differ from those determined in the original works. We include into the consideration the viscosity of the surface layer and give its estimation for the octane-C10E5- water microemulsion.

V. Lisy; B. Brutovsky

2000-10-26T23:59:59.000Z

168

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

E-Print Network [OSTI]

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

Montfrooij, Wouter

169

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

E-Print Network [OSTI]

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

Nagle, John F.

170

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

E-Print Network [OSTI]

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

Boothroyd, Andrew

171

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

E-Print Network [OSTI]

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

Danon, Yaron

172

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

E-Print Network [OSTI]

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

Johnson, Peter D.

173

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

E-Print Network [OSTI]

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

Liu, Jian

2008-01-01T23:59:59.000Z

174

Investigation of microstructure of disordered colloidal systems by small-angle scattering  

E-Print Network [OSTI]

Small-angle scattering (SAS) has been widely applied to study the microstructure of colloidal systems. Although colloids cover a wide range of materials, in general they can simply be viewed as basic building particles ...

Chiang, Wei-Shan

2014-01-01T23:59:59.000Z

175

Nondispersive neutron focusing method beyond the critical angle of mirrors  

DOE Patents [OSTI]

This invention extends the Kirkpatrick-Baez (KB) mirror focusing geometry to allow nondispersive focusing of neutrons with a convergence on a sample much larger than is possible with existing KB optical schemes by establishing an array of at least three mirrors and focusing neutrons by appropriate multiple deflections via the array. The method may be utilized with supermirrors, multilayer mirrors, or total external reflection mirrors. Because high-energy x-rays behave like neutrons in their absorption and reflectivity rates, this method may be used with x-rays as well as neutrons.

Ice, Gene E. (Oak Ridge, TN)

2008-10-21T23:59:59.000Z

176

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

E-Print Network [OSTI]

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

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

2014-12-12T23:59:59.000Z

177

The Algebraic Approach to the Phase Problem for Neutron Scattering  

E-Print Network [OSTI]

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

A. Cervellino; S. Ciccariello

2004-01-27T23:59:59.000Z

178

Multiple-scattering effects on incoherent neutron scattering in glasses and viscous liquids  

E-Print Network [OSTI]

Incoherent neutron scattering experiments are simulated for simple dynamic models: a glass (with a smooth distribution of harmonic vibrations) and a viscous liquid (described by schematic mode-coupling equations). In most situations multiple scattering has little influence upon spectral distributions, but it completely distorts the wavenumber-dependent amplitudes. This explains an anomaly observed in recent experiments.

Joachim Wuttke

2000-04-25T23:59:59.000Z

179

Constraints on new interactions from neutron scattering experiments  

E-Print Network [OSTI]

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

Yu. N. Pokotilovski

2006-01-19T23:59:59.000Z

180

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

E-Print Network [OSTI]

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

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

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "angle neutron scattering" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Improved di-neutron cluster model for 6He scattering  

E-Print Network [OSTI]

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

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

2007-03-01T23:59:59.000Z

182

Identification and rejection of scattered neutrons in AGATA  

E-Print Network [OSTI]

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

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

2013-06-12T23:59:59.000Z

183

Optimizing Moderator Dimensions for Neutron Scattering at the Spallation Neutron Source  

SciTech Connect (OSTI)

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

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

2013-01-01T23:59:59.000Z

184

Scattered Neutron Tomography Based on A Neutron Transport Inverse Problem  

SciTech Connect (OSTI)

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

William Charlton

2007-07-01T23:59:59.000Z

185

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

SciTech Connect (OSTI)

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

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

2014-01-01T23:59:59.000Z

186

Virtual experiments: Combining realistic neutron scattering instrument and sample simulations  

SciTech Connect (OSTI)

A new sample component is presented for the Monte Carlo, ray-tracing program, McStas, which is widely used to simulate neutron scattering instruments. The new component allows the sample to be described by its material dynamic structure factor, which is separated into coherent and incoherent contributions. The effects of absorption and multiple scattering are treated and results from simulations and previous experiments are compared. The sample component can also be used to treat any scattering material which may be close to the sample and therefore contaminates the total, measured signal.

Farhi, E. [Institut Laue Langevin, BP 156, 38042 Grenoble Cedex 9 (France)], E-mail: farhi@ill.fr; Hugouvieux, V. [INRA, UR1268 Biopolymeres Interactions Assemblages, F-44300 Nantes (France); Johnson, M.R. [Institut Laue Langevin, BP 156, 38042 Grenoble Cedex 9 (France); Kob, W. [Laboratoire des Colloides, Verres et Nanomateriaux, Universite Montpellier II, place E. Bataillon, 34095 Montpellier Cedex 5 (France)

2009-08-01T23:59:59.000Z

187

Neutron-Proton High-Energy Charge Exchange Scattering  

E-Print Network [OSTI]

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

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

2002-04-18T23:59:59.000Z

188

Neutron Scattering Studies of Cuprates and Iron Pnictides.  

E-Print Network [OSTI]

??Presented within are neutron scattering studies of several different high temperature superconducting materials: BaFe1.9Ni0.1As2 [Barium Iron Nickel Arsenic], BaFe1.85Ni0.15As2 [Barium Iron Nickel Arsenic], Ba0.67K0.33Fe2As2 [Barium (more)

Liu, Mengshu

2014-01-01T23:59:59.000Z

189

Time Reversal Invariance Violation in Neutron Deuteron Scattering  

E-Print Network [OSTI]

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

Young-Ho Song; Rimantas Lazauskas; Vladimir Gudkov

2011-04-15T23:59:59.000Z

190

A workshop on enhanced national capability for neutron scattering  

SciTech Connect (OSTI)

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

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

2009-01-01T23:59:59.000Z

191

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

E-Print Network [OSTI]

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

Paris-Sud XI, Universit de

192

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

E-Print Network [OSTI]

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

193

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

E-Print Network [OSTI]

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

Boyer, Edmond

194

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

E-Print Network [OSTI]

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

Glyde, Henry R.

195

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

E-Print Network [OSTI]

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

196

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

E-Print Network [OSTI]

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

Utah, University of

197

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

E-Print Network [OSTI]

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

198

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

E-Print Network [OSTI]

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

Kemner, Ken

199

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

E-Print Network [OSTI]

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

Tuscia, Università Degli Studi Della

200

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

E-Print Network [OSTI]

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

Glyde, Henry R.

Note: This page contains sample records for the topic "angle neutron scattering" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

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

E-Print Network [OSTI]

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

202

2015 LaCNS Neutron Scattering Seed Funding Request for White Papers  

E-Print Network [OSTI]

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

203

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

E-Print Network [OSTI]

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

204

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

E-Print Network [OSTI]

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

Tuscia, Università Degli Studi Della

205

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

E-Print Network [OSTI]

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

Glyde, Henry R.

206

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

SciTech Connect (OSTI)

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

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

2012-01-01T23:59:59.000Z

207

Neutron Scattering Studies of Vortex Matter in Type-II Superconductors  

SciTech Connect (OSTI)

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

Xinsheng Ling

2012-02-02T23:59:59.000Z

208

Optimizing moderator dimensions for neutron scattering at the spallation neutron source  

SciTech Connect (OSTI)

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

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

2013-12-15T23:59:59.000Z

209

Optimizing Neutron Thermal Scattering Effects in very High Temperature Reactors  

SciTech Connect (OSTI)

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

Hawari, Ayman; Ougouag, Abderrafi

2014-07-08T23:59:59.000Z

210

From Nuclei to Micro-structure: investigating intermediate length scales by small angle laser light scattering  

E-Print Network [OSTI]

Hard spheres are a well recognized model system of statistical physics and soft condensed matter. Their crystallization behaviour has been intensively studied at the structural length scale by Bragg light scattering and/or high resolution microscopy. We here present an improved light scattering apparatus capable to perform simultaneous measurements in the Bragg scattering regime and in the small angle regime. We give an account of its construction and demonstrate its performance for several examples of hard sphere and attractive hard sphere suspensions. Comparison of small angle to Bragg data allows a calibration of the sequence of events in time. We show how important complementary information can be gained from the small angle studies e.g. on the immediate environment of the growing crystals or the global scale crystallite distribution. We further demonstrate that processes occurring on larger length scales have a significant influence on the crystallization kinetics and the final micro-structure.

Richard Beyer; Markus Franke; Hans Joachim Schpe; Eckhard Bartsch; Thomas Palberg

2014-12-02T23:59:59.000Z

211

10th LANSCE School on Neutron Scattering  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLasDelivered‰PNGExperience hands-on halloweenReliable solar:210th LANSCE School on Neutron

212

2009 International Conference on Neutron Scattering (ICNS 2009)  

SciTech Connect (OSTI)

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

Gopal Rao, PhD; Donna Gillespie

2010-08-05T23:59:59.000Z

213

X-ray small-angle scattering from sputtered CeO{sub 2}/C bilayers  

SciTech Connect (OSTI)

Surface and interface morphology of cerium oxide/carbon bilayers used as thin-film catalysts is studied by grazing-incidence small-angle x-ray scattering, scanning electron microscopy, and atomic-force microscopy, and the dependence of the structural parameters on the thicknesses of the constituting layers is investigated. The applicability of x-ray scattering and its advantages over standard analytical methods are discussed.

Haviar, S.; Dubau, M.; Khalakhan, I.; Vorokhta, M.; Matolinova, I.; Matolin, V. [Department of Surface and Plasma Science, Faculty of Mathematics and Physics Charles University, V Holesovickach 2, 180 00, Prague 8 (Czech Republic); Vales, V.; Endres, J.; Holy, V. [Department of Condensed Matter Physics, Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, 121 16 Prague 2 (Czech Republic); Buljan, M. [Institute Ruder Boskovic, Bijenicka 54, 10000 Zagreb (Croatia); Bernstorff, S. [Sincrotrone ELETTRA, 34149 Basovizza, Trieste (Italy)

2013-01-14T23:59:59.000Z

214

Complete Monte Carlo Simulation of Neutron Scattering Experiments  

SciTech Connect (OSTI)

In the far past, it was not possible to accurately correct for the finite geometry and the finite sample size of a neutron scattering set-up. The limited calculation power of the ancient computers as well as the lack of powerful Monte Carlo codes and the limitation in the data base available then prevented a complete simulation of the actual experiment. Using e.g. the Monte Carlo neutron transport code MCNPX [1], neutron scattering experiments can be simulated almost completely with a high degree of precision using a modern PC, which has a computing power that is ten thousand times that of a super computer of the early 1970s. Thus, (better) corrections can also be obtained easily for previous published data provided that these experiments are sufficiently well documented. Better knowledge of reference data (e.g. atomic mass, relativistic correction, and monitor cross sections) further contributes to data improvement. Elastic neutron scattering experiments from liquid samples of the helium isotopes performed around 1970 at LANL happen to be very well documented. Considering that the cryogenic targets are expensive and complicated, it is certainly worthwhile to improve these data by correcting them using this comparatively straightforward method. As two thirds of all differential scattering cross section data of {sup 3}He(n,n){sup 3}He are connected to the LANL data, it became necessary to correct the dependent data measured in Karlsruhe, Germany, as well. A thorough simulation of both the LANL experiments and the Karlsruhe experiment is presented, starting from the neutron production, followed by the interaction in the air, the interaction with the cryostat structure, and finally the scattering medium itself. In addition, scattering from the hydrogen reference sample was simulated. For the LANL data, the multiple scattering corrections are smaller by a factor of five at least, making this work relevant. Even more important are the corrections to the Karlsruhe data due to the inclusion of the missing outgoing self-attenuation that amounts to up to 15%.

Drosg, M. [Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Wien (Austria)

2011-12-13T23:59:59.000Z

215

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

SciTech Connect (OSTI)

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

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

2011-10-01T23:59:59.000Z

216

Neutron Brillouin scattering in a metallic glass  

SciTech Connect (OSTI)

The dispersion of collective modes in a metallic glass (Mg{sub 70}Zn{sub 30}) measured earlier at the thermal neutron time-of-flight spectrometer IN4 of the HFR of the ILL could be extended towards lower momentum transfers down to the first pseudo-Brillouin zone for the first time. This extension to momentum transfer not accessible up to now was possible using the highly resolving time-of-flight spectrometer HET of the new spallation source ISIS. In the region of overlap the two parts of the dispersion determined with different samples of the same metallic glass on different instruments agree very well. Also the earlier discrepancies with the dispersion determined for this metallic glass from a computer simulation could be nearly completely eliminated due to a more recent and more complete investigations of this glass.

Suck, J.B. (Kernforschungszentrum Karlsruhe GmbH (Germany). Inst. fuer Nukleare Festkoerperphysik); Egelstaff, P.A. (Guelph Univ., ON (Canada). Dept. of Physics); Robinson, R.A.; Sivia, D.S. (Los Alamos National Lab., NM (United States)); Taylor, A.D. (Rutherford Appleton Lab., Chilton (United Kingdom))

1991-01-01T23:59:59.000Z

217

Causality bounds for neutron-proton scattering  

E-Print Network [OSTI]

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

Serdar Elhatisari; Dean Lee

2012-07-25T23:59:59.000Z

218

Resonant Cyclotron Scattering and Comptonization in Neutron Star Magnetospheres  

E-Print Network [OSTI]

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

Maxim Lyutikov; Fotis P. Gavriil

2006-02-10T23:59:59.000Z

219

Solid phases of spatially nanoconfined oxygen: A neutron scattering study  

SciTech Connect (OSTI)

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

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

2014-01-14T23:59:59.000Z

220

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

E-Print Network [OSTI]

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

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221

Scanning angle Raman spectroscopy: Investigation of Raman scatter enhancement techniques for chemical analysis  

SciTech Connect (OSTI)

This thesis outlines advancements in Raman scatter enhancement techniques by applying evanescent fields, standing-waves (waveguides) and surface enhancements to increase the generated mean square electric field, which is directly related to the intensity of Raman scattering. These techniques are accomplished by employing scanning angle Raman spectroscopy and surface enhanced Raman spectroscopy. A 1064 nm multichannel Raman spectrometer is discussed for chemical analysis of lignin. Extending dispersive multichannel Raman spectroscopy to 1064 nm reduces the fluorescence interference that can mask the weaker Raman scattering. Overall, these techniques help address the major obstacles in Raman spectroscopy for chemical analysis, which include the inherently weak Raman cross section and susceptibility to fluorescence interference.

Meyer, Matthew W. [Ames Laboratory

2013-03-14T23:59:59.000Z

222

Accurate Development of Thermal Neutron Scattering Cross Section Libraries  

SciTech Connect (OSTI)

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

Hawari, Ayman; Dunn, Michael

2014-06-10T23:59:59.000Z

223

Nucleon semimagic numbers and low-energy neutron scattering  

E-Print Network [OSTI]

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

D. A. Zaikin; I. V. Surkova

2010-04-09T23:59:59.000Z

224

Light propagation in tissues with forward-peaked and large-angle scattering  

E-Print Network [OSTI]

-angle scattering makes it difficult to solve the radiative transport equation, we present a method to construct to inhomogene- ities. The radiative transport equation is a partial differential-integral equation. Analytical of the sev- eral independent variables in the radiative transport equation. Biological tissues tend

Kim, Arnold D.

225

Scientific opportunities with advanced facilities for neutron scattering  

SciTech Connect (OSTI)

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

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

1984-01-01T23:59:59.000Z

226

Novel Boron-10-based detectors for Neutron Scattering Science  

E-Print Network [OSTI]

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

Piscitelli, Francesco

2015-01-01T23:59:59.000Z

227

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

E-Print Network [OSTI]

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

Weston, Ken

228

BIOISIS: Biological Macromolecules by Small Angle X-ray Scattering (SAXS)  

DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

BIOISIS is an open access database dedicated to the study of biological macromolecules by small angle X-ray scattering (SAXS). BIOISIS aims to become the complete source for the deposition, distribution and maintenance of small angle X-ray scattering data and technologies. The database is designed around the concept of an experiment and relates a specific experiment to a set of genes, organisms, computational models and experimental data. As of May 2012, BIOSIS contains 7,118 genes covering four different organisms. Forty-two modeled structures are available. Clicking on a structures reveals scattering curves, experimental conditions, and experimental values. The data are collected at Beamline 12.3.1 of the Advanced Light Source (ALS).[Copied with editing from http://www.bioisis.net/about

Tainer, John (Scripps Research Institute); Hura, Greg (LBNL); Rambo, Robert P. (LBNL)

229

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

SciTech Connect (OSTI)

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

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

1995-12-31T23:59:59.000Z

230

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

E-Print Network [OSTI]

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

Kemner, Ken

231

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

E-Print Network [OSTI]

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

V. A. Abramovsky; N. V. Radchenko

2011-07-30T23:59:59.000Z

232

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

E-Print Network [OSTI]

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

Danon, Yaron

233

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

E-Print Network [OSTI]

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

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

2005-06-02T23:59:59.000Z

234

Measurement of the Wolfenstein parameters for proton-proton and proton-neutron scattering at 500 MeV  

SciTech Connect (OSTI)

Using liquid hydrogen and liquid deuterium targets respectively, forward angle (ten degrees to sixty degrees in the center of Mass) free proton-proton and quasielastic proton-proton and proton-neutron triple scattering data at 500 MeV have been obtained using the high resolution spectrometer at the Los Alamos Meson Physics Facility. The data are in reasonable agreement with recent predictions from phase shift analyses, indicating that the proton-nucleon scattering amplitudes are fairly well determined at 500 MeV. 32 references.

Marshall, J.A.

1984-07-01T23:59:59.000Z

235

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

E-Print Network [OSTI]

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

236

Large-angle elastic and inelastic scattering of Pi(+) and Pi(-) from (28)Si and (40)Ca. Master's thesis  

SciTech Connect (OSTI)

Differential cross sections were measured for Pi(+) and Pi(-) elastic scattering of Calcium 40 and Silicon 28 at incident pion energies ranging from 100 to 260 MeV at a scattering angle of 175 degs. Differential cross sections were also measured for Pi(+) and Pi(-) inelastic scattering to the 2(+), 1.78 MeV, 4(+), 4.62 MeV, and 3(-) 6.88 MeV states of 28Si at incident pion energies of 130, 180, and 226 MeV and scattering angles between 115 and 175{degrees} in 6{degrees} increments. The data are compared to previously obtained forward angle data through 120{degrees} and agree quite well. The data show a generally flat angular dependence for angles greater than 100{degrees}. Several theoretical codes are reviewed for their ability to predict large angle scattering. Coordinate-space and momentum-space models generally thought to be sufficient for predicting forward angle scattering have proved to be inappropriate for use at large angles. A new phenomenological delta-hole model, currently under modification, shows a greatly enhanced ability to predict scattering at back angles.

Snell, M.P.

1989-05-01T23:59:59.000Z

237

Small angle X-ray scattering study of coal soot formation  

SciTech Connect (OSTI)

The objective of this study is to examine, by small angle X-ray scattering (SAXS), the formation of soot from individual coal particle combustion in a methane flat flame burner. The SAXS instrument at the Basic Energy Sciences Synchrotron Radiation Center (BESSRC) at the Advanced Photon Source (APS) can be used to observe both the formation of spherules and clusters since it can access length scales of 6--6000 {angstrom}. The high X-ray flux enables rapid acquisition of scattering data of various regions of the flame. SAXS data reveal particle size, shape, surface areas, and surface roughness.

Winans, R. E.; Parker, J. T.; Seifert, S.; Fletcher, T. H.

2000-02-14T23:59:59.000Z

238

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

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

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

239

X-ray and neutron scattering studies on some nanoscale structures in molecular biology.  

E-Print Network [OSTI]

??Scattering of X-rays and neutrons has been applied to the study of nanostructures with interesting biological functions. The systems studied were the protein calmodulin and (more)

Ikonen, Teemu

2007-01-01T23:59:59.000Z

240

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

E-Print Network [OSTI]

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

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

2009-05-12T23:59:59.000Z

Note: This page contains sample records for the topic "angle neutron scattering" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Lambda-Neutron Scattering Lengths from Radiative K-minus Capture  

E-Print Network [OSTI]

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

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

2000-01-02T23:59:59.000Z

242

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

E-Print Network [OSTI]

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

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

2010-11-26T23:59:59.000Z

243

X-ray and neutron scattering studies of magnetic critical fluctuations in holmium  

SciTech Connect (OSTI)

We describe measurements of the magnetic critical fluctuations of holmium by x-ray scattering techniques. The x-ray results are compared to those obtained in neutron scattering experiments performed on the same sample.

Thurston, T.R.; Helgesen, G.; Gibbs, D.; Shirane, G. [Brookhaven National Lab., Upton, NY (United States); Hill, J.P. [Brookhaven National Lab., Upton, NY (United States)]|[Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Physics; Gaulin, B.D. [Brookhaven National Lab., Upton, NY (United States)]|[McMaster Univ., Hamilton, ON (Canada). Dept. of Physics

1993-04-01T23:59:59.000Z

244

X-ray and neutron scattering studies of magnetic critical fluctuations in holmium  

SciTech Connect (OSTI)

We describe measurements of the magnetic critical fluctuations of holmium by x-ray scattering techniques. The x-ray results are compared to those obtained in neutron scattering experiments performed on the same sample.

Thurston, T.R.; Helgesen, G.; Gibbs, D.; Shirane, G. (Brookhaven National Lab., Upton, NY (United States)); Hill, J.P. (Brookhaven National Lab., Upton, NY (United States) Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Physics); Gaulin, B.D. (Brookhaven National Lab., Upton, NY (United States) McMaster Univ., Hamilton, ON (Canada). Dept. of Physics)

1993-01-01T23:59:59.000Z

245

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

Office of Science (SC) Website

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched5 IndustrialIsadore Perlman, 1960 The ErnestLouisMichael J.|Neutron Scattering

246

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

E-Print Network [OSTI]

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

Danon, Yaron

247

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

E-Print Network [OSTI]

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

Schirmacher, Walter

248

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

E-Print Network [OSTI]

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

Pennycook, Steve

249

Quark Structure of the Nucleon and Angular Asymmetry of Proton-Neutron Hard Elastic Scattering  

E-Print Network [OSTI]

We investigate an asymmetry in the angular distribution of hard elastic proton-neutron scattering with respect to 90deg center of mass scattering angle. We demonstrate that the magnitude of the angular asymmetry is related to the helicity-isospin symmetry of the quark wave function of the nucleon. Our estimate of the asymmetry within the quark-interchange model of hard scattering demonstrates that the quark wave function of a nucleon based on the exact SU(6) symmetry predicts an angular asymmetry opposite to that of experimental observations. On the other hand the quark wave function based on the diquark picture of the nucleon produces an asymmetry consistent with the data. Comparison with the data allowed us to extract the relative sign and the magnitude of the vector and scalar diquark components of the quark wave function of the nucleon. These two quantities are essential in constraining QCD models of a nucleon. Overall, our conclusion is that the angular asymmetry of a hard elastic scattering of baryons provides a new venue in probing quark-gluon structure of baryons and should be considered as an important observable in constraining the theoretical models.

Carlos G. Granados; Misak M. Sargsian

2009-07-29T23:59:59.000Z

250

Wide angle x-ray scattering of proteins : effect of beam exposure on protein integrity.  

SciTech Connect (OSTI)

Wide-angle X-ray scattering patterns from proteins in solution contain information relevant to the determination of protein fold. At relevant scattering angles, however, these data are weak, and the degree to which they might be used to categorize the fold of a protein is unknown. Preliminary work has been performed at the BioCAT insertion-device beamline at the Advanced Photon Source which demonstrates that one can collect X-ray scattering data from proteins in solution to spacings of at least 2.2 {angstrom} (q = 2.8 {angstrom}-1). These data are sensitive to protein conformational states, and are in good agreement with the scattering predicted by the program CRYSOL using the known three-dimensional atomic coordinates of the protein. An important issue in the exploitation of this technique as a tool for structural genomics is the extent to which the high intensity of X-rays available at third-generation synchrotron sources chemically or structurally damage proteins. Various data-collection protocols have been investigated demonstrating conditions under which structural degradation of even sensitive proteins can be minimized, making this technique a viable tool for protein fold categorization, the study of protein folding, unfolding, protein-ligand interactions and domain movement.

Fischetti, R. F.; Rodi, D. J.; Mirza, A.; Makowski, L.; Illinois Inst. of Tech.

2003-01-01T23:59:59.000Z

251

E-Print Network 3.0 - angle diffractometer sans Sample Search...  

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

< 1 2 3 4 5 > >> 1 Technical ParametersSNS Primary Parameters Summary: -Range Small-Angle Neutron Scattering Diffractometer (EQ-SANS) 7 BD Water Engineering Materials...

252

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

E-Print Network [OSTI]

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

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

1999-08-11T23:59:59.000Z

253

Neutron observables from inclusive lepton scattering on nuclei  

SciTech Connect (OSTI)

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

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

2010-07-15T23:59:59.000Z

254

Neutron Polarisabilities from Deuteron Compton Scattering in \\chiEFT  

E-Print Network [OSTI]

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

Harald W. Griesshammer

2007-10-15T23:59:59.000Z

255

FINAL REPORT: DOE CONTRACT NUMBER FG0205ER64026 Biological Neutron Scattering: A Collaboration with the Oak Ridge Center for Structural Molecular Biology  

SciTech Connect (OSTI)

The overarching goal of this project was to promote applications of small-angle scattering in structural molecular biology by providing model examples of cutting edge applications that demonstrate the unique capabilities and potential of the DOE national user facilities at Oak Ridge, especially the newly commissioned BioSANS. The approach taken was three-fold: (1) to engage in high impact collaborative research projects that would benefit from small-angle neutron scattering to both demonstrate the power of the technique while expanding the potential user community; (2) to provide access to scattering facilities established at the University of Utah to as broad a set of researchers as possible to increase the expertise in small-angle scattering generally; and (3) to develop new methods and tools for small-angle scattering. To these ends, three major research collaborations were pursued that resulted in a significant body of published work where neutron scattering and contrast variation played a major role. These major collaborations involved studies of protein complexes involved in (1) bacterial transcription regulation and adaptive response (a DOE/BER priority area); (2) regulation of cardiac muscle; and (3) neuronal disorders. In addition, to broaden the impact of the project, smaller collaborative efforts were supported that used either small-angle X-ray or neutron scattering. Finally, the DOE supported facilities at the University of Utah were made available to researchers on a service basis and a number of independent groups took advantage of this opportunity. In all of this work, there was an emphasis on the training of students and post docs in scattering techniques, and a set of publications (a book chapter, a review, and an encyclopedia article) were produced to guide the non-specialist potential user of scattering techniques in successful applications of the techniques. We also developed a suite of user friendly web-based computational tools currently being accessed world-wide by researchers as an aid in neutron scattering data interpretation. In all, these collaborative projects and resulted in 29 original refereed journal articles published between 2005 and 2010 and engaged groups from at least 14 Universities (10 US, 4 international) and 3 National Laboratories (2 US, 1 international). An important final initiative from this project was to begin a process for international community agreement on a set of standards for the publication of biomolecular small-angle scattering data. This initiative is being championed with the International Union of Crystallography and has engaged a number of Journal Editors and is a very important step in the maturing of this now burgeoning field.

Jill Trewhella

2011-01-12T23:59:59.000Z

256

ON QUASI-ELASTIC SCATTERING OF SLOW NEUTRONS IN MOLECULAR LIQUIDS  

E-Print Network [OSTI]

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

Boyer, Edmond

257

Virtual Compton scattering and neutral pion electroproduction in the resonance region up to the deep inelastic region at backward angles  

E-Print Network [OSTI]

We have made the first measurements of the virtual Compton scattering (VCS) process via the H(e, e'p)? exclusive reaction in the nucleon resonance region, at backward angles. Results are presented for the W-dependence at ...

Zhou, Z. -L.

258

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

E-Print Network [OSTI]

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

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

2014-10-03T23:59:59.000Z

259

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

E-Print Network [OSTI]

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

Goodman, Wayne

260

Measurement of the analysing power in proton-proton elastic scattering at small angles  

E-Print Network [OSTI]

The proton analysing power in $\\vec{p}p$ elastic scattering has been measured at small angles at COSY-ANKE at 796 MeV and five other beam energies between 1.6 and 2.4 GeV using a polarised proton beam. The asymmetries obtained by detecting the fast proton in the ANKE forward detector or the slow recoil proton in a silicon tracking telescope are completely consistent. Although the analysing power results agree well with the many published data at 796 MeV, and also with the most recent partial wave solution at this energy, the ANKE data at the higher energies lie well above the predictions of this solution at small angles. An updated phase shift analysis that uses the ANKE results together with the World data leads to a much better description of these new measurements.

Z. Bagdasarian; D. Chiladze; S. Dymov; A. Kacharava; G. Macharashvili; S. Barsov; R. Gebel; B. Gou; M. Hartmann; I. Keshelashvili; A. Khoukaz; P. Kulessa; A. Kulikov; A. Lehrach; N. Lomidze; B. Lorentz; R. Maier; D. Mchedlishvili; S. Merzliakov; S. Mikirtychyants; M. Nioradze; H. Ohm; M. Papenbrock; D. Prasuhn; F. Rathmann; V. Serdyuk; V. Shmakova; R. Stassen; H. Stockhorst; I. I. Strakovsky; H. Strher; M. Tabidze; A. Tschner; S. Trusov; D. Tsirkov; Yu. Uzikov; Yu. Valdau; C. Wilkin; R. L. Workman

2014-10-28T23:59:59.000Z

Note: This page contains sample records for the topic "angle neutron scattering" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Neutron inelastic-scattering cross sections of /sup 232/Th, /sup 233/U, /sup 235/U, /sup 238/U, /sup 239/Pu and /sup 240/Pu. [LMFBR  

SciTech Connect (OSTI)

Differential-neutron-emission cross sections of /sup 232/Th, /sup 233/U, /sup 235/U, /sup 238/U, /sup 239/Pu and /sup 240/Pu are measured between approx. = 1.0 and 3.5 MeV with the angle and magnitude detail needed to provide angle-integrated emission cross sections to approx. < 3% accuracies. Emitted-neutron resolutions are quantitatively defined and vary from approx. = 0.1 to 0.35 MeV. The experimental results are corrected for fisson-neutron contributions to obtain pseudo-elastic-neutron-scattering cross sections which, together with the neutron total cross sections, define the non-elastic cross sections to within well specified energy resolutions. These results imply inelastic-neutron-scattering cross sections which are compared with comparable quantities derived from ENDF/B-V. Good general agreement is noted for /sup 232/Th, /sup 233/U, /sup 235/U and /sup 238/U inelastic-scattering values, poor agreement is observed for /sup 240/Pu, and a serious discrepancy exists in the case of /sup 239/Pu.

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

1982-01-01T23:59:59.000Z

262

Running of the QED coupling in small-angle Bhabha scattering at LEP  

E-Print Network [OSTI]

Using the OPAL detector at LEP, the running of the effective QED coupling alpha(t) is measured for space-like momentum transfer, 2 \\leq -t \\leq 6 GeV^2, from the angular distribution of small-angle Bhabha scattering. This is currently the most significant direct observation of the running of the QED coupling in a single experiment and the first clear evidence of the hadronic contribution to the running in the space-like region. Our result is in good agreement with standard evaluations of alpha(t), based on data in the time-like region.

G. Abbiendi

2005-05-18T23:59:59.000Z

263

Time Resolved Collapse of a Folding Protein Observed with Small Angle X-Ray Scattering  

SciTech Connect (OSTI)

High-intensity, ''pink'' beam from an undulator was used in conjunction with microfabricated rapid-fluid mixing devices to monitor the early events in protein folding with time resolved small angle x-ray scattering. This Letter describes recent work on the protein bovine {beta} -lactoglobulin where collapse from an expanded to a compact set of states was directly observed on the millisecond time scale. The role of chain collapse, one of the initial stages of protein folding, is not currently understood. The characterization of transient, compact states is vital in assessing the validity of theories and models of the folding process.

Pollack, L.; Tate, M. W.; Finnefrock, A. C.; Kalidas, C.; Trotter, S.; Darnton, N. C.; Lurio, L.; Austin, R. H.; Batt, C. A.; Gruner, S. M. (and others)

2001-05-21T23:59:59.000Z

264

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

E-Print Network [OSTI]

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

V. P. Levashev

2008-12-22T23:59:59.000Z

265

Neutron and synchrotron radiation scattering by nonpolar magnetic fluids  

SciTech Connect (OSTI)

The complex approach (which comprises different physical methods, including neutron and synchrotron radiation scattering) is justified in the structural analysis of magnetic fluids (MFs). Investigations of MFs based on nonpolar organic solvents with magnetite nanoparticles (2-20 nm in size) coated by various monocarboxylic acids have been performed. It is shown that the use of saturated linear acids with various alkyl chain (C12-C18) lengths instead of unsaturated oleic acid (alkyl chain C18 with a kink in the middle due to the double bond in the cis-configuration) in the classical stabilization procedure for the given type of magnetic fluids leads to a decrease in the mean size and polydispersity of nanoparticles in the final systems.

Aksenov, V. L., E-mail: aksenov@kiae.ru [National Research Center Kurchatov Institute (Russian Federation); Avdeev, M. V. [Joint Institute for Nuclear Research (Russian Federation); Shulenina, A. V. [Moscow State University (Russian Federation); Zubavichus, Y. V.; Veligzhanin, A. A. [National Research Center Kurchatov Institute (Russian Federation); Rosta, L. [Hungarian Academy of Sciences, Research Institute for Solid State Physics and Optics (Hungary); Garamus, V. M. [Helmholtz-Zentrum Geesthacht (Germany); Vekas, L. [Romanian Academy, Timisoara Division, Laboratory of Magnetic Fluids, Center of Fundamental and Advanced Technical Research (Romania)

2011-09-15T23:59:59.000Z

266

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

E-Print Network [OSTI]

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

Crowther, Paul

267

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

E-Print Network [OSTI]

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

Miller, William H.

268

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

E-Print Network [OSTI]

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

Danon, Yaron

269

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

E-Print Network [OSTI]

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

Turro, Nicholas J.

270

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

E-Print Network [OSTI]

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

271

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

E-Print Network [OSTI]

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

272

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

E-Print Network [OSTI]

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

Doster, Wolfgang

273

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

E-Print Network [OSTI]

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

Tuscia, Università Degli Studi Della

274

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

E-Print Network [OSTI]

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

Kuhl, Tonya L.

275

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

E-Print Network [OSTI]

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

276

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

E-Print Network [OSTI]

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

Pennycook, Steve

277

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

E-Print Network [OSTI]

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

C. R. Howell

2008-05-08T23:59:59.000Z

278

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

SciTech Connect (OSTI)

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

Hussler, Wolfgang [Heinz Maier-Leibnitz Zentrum, Technische Universitt Mnchen, D-85748 Garching, Germany and Physik-Department E21, Technische Universitt Mnchen, D-85748 Garching (Germany); Kredler, Lukas [Physik-Department E21, Technische Universitt Mnchen, D-85748 Garching (Germany)

2014-05-15T23:59:59.000Z

279

Muon capture on deuteron and the neutron-neutron scattering length  

E-Print Network [OSTI]

The muon capture reaction mu + 2H --> nu_mu + n + n is studied with nuclear potentials and charge-changing weak currents, derived within chiral effective field theory. The next-to-next-to-next-to leading order (N3LO) chiral potential with cutoff parameter Lambda=500 MeV is used, but the low-energy constant (LEC) determining the neutron-neutron S-wave scattering length (a_{nn}) is varied so as to obtain four different values, which are a_{nn}=-18.95 fm, -16.0 fm, -22.0 fm, and +18.22 fm. The first value is the present empirical one, while the last one is chosen such as to lead to a di-neutron bound system with a binding energy of 139 keV. The LEC's c_D and c_E, present in the three-nucleon potential and axial-vector current (c_D), are constrained to reproduce the A=3 binding energies and the triton Gamow-Teller matrix element. The muon capture rate on the deuteron in the doublet hyperfine initial state is found to be 399(3) s^{-1} for a_{nn}=-18.95 and -16.0 fm; and 400(3) s^{-1} for a_{nn}=-22.0 fm. However, ...

Marcucci, L E

2014-01-01T23:59:59.000Z

280

The prediction of Neutron Elastic Scattering from Tritium for E(n) = 6-14 MeV  

SciTech Connect (OSTI)

In a recent report Navratil et al. evaluated the angle-integrated cross section and the angular distribution for 14-MeV n+T elastic scattering by inferring these cross sections from accurately measured p+3He angular distributions. This evaluation used a combination of two theoretical treatments, based on the no-core shell model and resonating-group method (NCSM/RGM) and on the R-matrix formalism, to connect the two charge-symmetric reactions n+T and p+{sup 3}He. In this report we extend this treatment to cover the neutron incident energy range 6-14 MeV. To do this, we evaluate angle-dependent correction factors for the NCSM/RGM calculations so that they agree with the p+{sup 3}He data near 6 MeV, and using the results found earlier near 14 MeV we interpolate these correction factors to obtain correction factors throughout the 6-14 MeV energy range. The agreement between the corrected NCSM/RGM and R-Matrix values for the integral elastic cross sections is excellent ({+-}1%), and these are in very good agreement with total cross section experiments. This result can be attributed to the nearly constant correction factors at forward angles, and to the evidently satisfactory physics content of the two calculations. The difference in angular shape, obtained by comparing values of the scattering probability distribution P({mu}) vs. {mu}(the cosine of the c.m. scattering angle), is about {+-}4% and appears to be related to differences in the two theoretical calculations. Averaging the calculations yields P({mu}) values with errors of {+-}2 1/2 % or less. These averaged values, along with the corresponding quantities for the differential cross sections, will form the basis of a new evaluation of n+T elastic scattering. Computer files of the results discussed in this report will be supplied upon request.

Anderson, J D; Dietrich, F S; Luu, T; McNabb, D P; Navratil, P; Quaglioni, S

2010-06-14T23:59:59.000Z

Note: This page contains sample records for the topic "angle neutron scattering" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Waveguide detection of right-angle-scattered light in flow cytometry  

DOE Patents [OSTI]

A transparent flow cell is used as an index-guided optical waveguide. A detector for the flow cell but not the liquid stream detects the Right-Angle-Scattered (RAS) Light exiting from one end of the flow cell. The detector(s) could view the trapped RAS light from the flow cell either directly or through intermediate optical light guides. If the light exits one end of the flow cell, then the other end of the flow cell can be given a high-reflectivity coating to approximately double the amount of light collected. This system is more robust in its alignment than the traditional flow cytometry systems which use imaging optics, such as microscope objectives.

Mariella, Jr., Raymond P. (Danville, CA)

2000-01-01T23:59:59.000Z

282

Towards weighing individual atoms by high-angle scattering of electrons  

E-Print Network [OSTI]

We consider theoretically the energy loss of electrons scattered to high angles when assuming that the primary beam can be limited to a single atom. We discuss the possibility of identifying the isotopes of light elements and of extracting information about phonons in this signal. The energy loss is related to the mass of the much heavier nucleus, and is spread out due to atomic vibrations. Importantly, while the width of the broadening is much larger than the energy separation of isotopes, only the shift in the peak positions must be detected if the beam is limited to a single atom. We conclude that the experimental case will be challenging but is not excluded by the physical principles as far as considered here. Moreover, the initial experiments demonstrate the separation of gold and carbon based on a signal that is related to their mass, rather than their atomic number.

Argentero, G; Kotakoski, J; Eder, F R; Meyer, J C

2015-01-01T23:59:59.000Z

283

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

E-Print Network [OSTI]

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

Chen, Sow-Hsin

2010-01-01T23:59:59.000Z

284

Theoretical modeling for neutron elastic scattering angular distribution in the fast energy range  

SciTech Connect (OSTI)

One of the major issues of neutron scattering modeling in the fast energy range is the contribution of compound elastic and inelastic scattering to the total scattering process. The compound component may become large at very low energies where the angular distribution becomes 90-degree symmetric in the center-of-mass system. Together with the shape elastic component, the elastic scattering gives slightly forward-peaked angular distributions in the fast energy range. This anisotropic angular distribution gives high sensitivities to many important nuclear reactor characteristics, such as criticality and neutron shielding. In this talk we describe how the anisotropic angular distributions are calculated within the statistical model framework, including the case where strongly coupled channels exist, by combining the coupled-channels theory with the Hauser-Feshbach model. This unique capability extension will have significant advantages in understanding the neutron scattering process for deformed nuclei, like uranium or plutonium, on which advanced nuclear energy applications center.

Kawano, Toshihiko [Los Alamos National Laboratory

2010-12-07T23:59:59.000Z

285

Probing Matter Radii of Neutron-Rich Nuclei by Antiproton Scattering  

E-Print Network [OSTI]

We propose to use antiprotons to investigate the sizes of stable and neutron-rich exotic nuclei by measurements of the $\\pbar A$ absorption cross section along isotopic chains in inverse kinematics. The expected effects are studied theoretically in a microscopic model. The $\\pbar U$ optical potentials are obtained by folding free space $\\pbar N$ scattering amplitudes with HFB ground state densities and solving the scattering equations by direct integration. The mass dependence of absorption cross sections is found to follow closely the nuclear root-mean-square radii. The total absorption cross section is shown to be a superposition of cross sections describing partial absorption on neutrons and protons, respectively. Thus measuring the differential cross sections for absorption on neutrons and protons will give information on their respective distributions. In neutron-rich nuclei the outer neutron layer shields the absorption on the protons giving access to investigations of antiproton-neutron interactions in matter.

H. Lenske; P. Kienle

2005-02-21T23:59:59.000Z

286

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

E-Print Network [OSTI]

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

H1 Collaboration

2010-01-04T23:59:59.000Z

287

The MOLLER Experiment: An Ultra-Precise Measurement of the Weak Mixing Angle Using Mller Scattering  

E-Print Network [OSTI]

The physics case and an experimental overview of the MOLLER (Measurement Of a Lepton Lepton Electroweak Reaction) experiment at the 12 GeV upgraded Jefferson Lab are presented. A highlight of the Fundamental Symmetries subfield of the 2007 NSAC Long Range Plan was the SLAC E158 measurement of the parity-violating asymmetry $A_{PV}$ in polarized electron-electron (M{\\o}ller) scattering. The proposed MOLLER experiment will improve on this result by a factor of five, yielding the most precise measurement of the weak mixing angle at low or high energy anticipated over the next decade. This new result would be sensitive to the interference of the electromagnetic amplitude with new neutral current amplitudes as weak as $\\sim 10^{-3}\\cdot G_F$ from as yet undiscovered dynamics beyond the Standard Model. The resulting discovery reach is unmatched by any proposed experiment measuring a flavor- and CP-conserving process over the next decade, and yields a unique window to new physics at MeV and multi-TeV scales, complementary to direct searches at high energy colliders such as the Large Hadron Collider (LHC). The experiment takes advantage of the unique opportunity provided by the upgraded electron beam energy, luminosity, and stability at Jefferson Laboratory and the extensive experience accumulated in the community after a round of recent successfully completed parity-violating electron scattering experiments

MOLLER Collaboration; J. Benesch; P. Brindza; R. D. Carlini; J-P. Chen; E. Chudakov; S. Covrig; M. M. Dalton; A. Deur; D. Gaskell; A. Gavalya; J. Gomez; D. W. Higinbotham; C. Keppel; D. Meekins; R. Michaels; B. Moffit; Y. Roblin; R. Suleiman; R. Wines; B. Wojtsekhowski; G. Cates; D. Crabb; D. Day; K. Gnanvo; D. Keller; N. Liyanage; V. V. Nelyubin; H. Nguyen; B. Norum; K. Paschke; V. Sulkosky; J. Zhang; X. Zheng; J. Birchall; P. Blunden; M. T. W. Gericke; W. R. Falk; L. Lee; J. Mammei; S. A. Page; W. T. H. van Oers; K. Dehmelt; A. Deshpande; N. Feege; T. K. Hemmick; K. S. Kumar; T. Kutz; R. Miskimen; M. J. Ramsey-Musolf; S. Riordan; N. Hirlinger Saylor; J. Bessuille; E. Ihloff; J. Kelsey; S. Kowalski; R. Silwal; G. De Cataldo; R. De Leo; D. Di Bari; L. Lagamba; E. NappiV. Bellini; F. Mammoliti; F. Noto; M. L. Sperduto; C. M. Sutera; P. Cole; T. A. Forest; M. Khandekar; D. McNulty; K. Aulenbacher; S. Baunack; F. Maas; V. Tioukine; R. Gilman; K. Myers; R. Ransome; A. Tadepalli; R. Beniniwattha; R. Holmes; P. Souder; D. S. Armstrong; T. D. Averett; W. Deconinck; W. Duvall; A. Lee; M. L. Pitt; J. A. Dunne; D. Dutta; L. El Fassi; F. De Persio; F. Meddi; G. M. Urciuoli; E. Cisbani; C. Fanelli; F. Garibaldi; K. Johnston; N. Simicevic; S. Wells; P. M. King; J. Roche; J. Arrington; P. E. Reimer; G. Franklin; B. Quinn; A. Ahmidouch; S. Danagoulian; O. Glamazdin; R. Pomatsalyuk; R. Mammei; J. W. Martin; T. Holmstrom; J. Erler; Yu. G. Kolomensky; J. Napolitano; K. A. Aniol; W. D. Ramsay; E. Korkmaz; D. T. Spayde; F. Benmokhtar; A. Del Dotto; R. Perrino; S. Barkanova; A. Aleksejevs; J. Singh

2014-12-03T23:59:59.000Z

288

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

SciTech Connect (OSTI)

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

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

1990-10-01T23:59:59.000Z

289

16th National School on Neutron and X-ray Scattering  

ScienceCinema (OSTI)

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

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

2014-07-23T23:59:59.000Z

290

16th National School on Neutron and X-ray Scattering  

SciTech Connect (OSTI)

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

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

2014-07-02T23:59:59.000Z

291

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

E-Print Network [OSTI]

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

Brown, Michael F.

292

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

E-Print Network [OSTI]

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

Nagle, John F.

293

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

E-Print Network [OSTI]

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

Pennycook, Steve

294

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

E-Print Network [OSTI]

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

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

2003-05-21T23:59:59.000Z

295

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

E-Print Network [OSTI]

conditions, the nuclear polarization in non-magnetic substances is given by the Curie law : P = C of thermal neutrons by nuclei con- tains a spin-dependent part. In the present state of nuclear theory. In analogy to magnetic scattering, the influence of the nuclear spin-dependent scattering on a pola- rized

Boyer, Edmond

296

Breakdown of the Born-Oppenheimer description explains neutron Compton-scattering anomaly  

SciTech Connect (OSTI)

Several neutron Compton scattering experiments reveal an apparent drop of the proton cross section when the collision time {tau}{sub q} is around 1 fs. Such small {tau}{sub q} corresponds to a large energy spread of the proton wave packet after collision, allowing it to access excited electronic levels. This nonadiabatic excitation of electrons leads to a distortion of the shape of the neutron scattering response function with some redistribution of intensity at energies higher than the nuclear recoil energy and a slight shift of the main neutron intensity peak to lower energies.

Gidopoulos, Nikitas I. [ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxon, OX11 0QX (United Kingdom)

2005-02-01T23:59:59.000Z

297

Dynamics of water in prussian blue analogues: Neutron scattering study  

SciTech Connect (OSTI)

Dynamics of crystal water in Prussian blue (PB), Fe(III){sub 4}[Fe(II)(CN){sub 6}]{sub 3}.14H{sub 2}O and its analogue Prussian green (PG), ferriferricynaide, Fe(III){sub 4}[Fe(III)(CN){sub 6}]{sub 4}.16H{sub 2}O have been investigated using Quasielastic Neutron Scattering (QENS) technique. PB and its analogue compounds are important materials for their various interesting multifunctional properties. It is known that crystal water plays a crucial role towards the multifunctional properties of Prussian blue analogue compounds. Three structurally distinguishable water molecules: (i) coordinated water molecules at empty nitrogen sites, (ii) non-coordinated water molecules in the spherical cavities, and (iii) at interstitial sites exist in PB. Here spherical cavities are created due to the vacant sites of Fe(CN){sub 6} units. However, PG does not have any such vacant N or Fe(CN){sub 6} units, and only one kind of water molecules, exists only at interstitial sites. QENS experiments have been carried out on both the compounds in the temperature range of 260360?K to elucidate the dynamical behavior of different kinds of water molecules. Dynamics is found to be much more pronounced in case of PB, compared to PG. A detailed data analysis showed that localized translational diffusion model could describe the observed data for both PB and PG systems. The average diffusion coefficient is found to be much larger in the PB than PG. The obtained domain of dynamics is found to be consistent with the geometry of the structure of the two systems. Combining the data of the two systems, a quantitative estimate of the dynamics, corresponding to the water molecules at different locations is made.

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

2014-07-21T23:59:59.000Z

298

Pulsed-neutron monochromator  

DOE Patents [OSTI]

In one aspect, the invention is an improved pulsed-neutron monochromator of the vibrated-crystal type. The monochromator is designed to provide neutron pulses which are characterized both by short duration and high density. A row of neutron-reflecting crystals is disposed in a neutron beam to reflect neutrons onto a common target. The crystals in the row define progressively larger neutron-scattering angles and are vibrated sequentially in descending order with respect to the size of their scattering angles, thus generating neutron pulses which arrive simultaneously at the target. Transducers are coupled to one end of the crystals to vibrate them in an essentially non-resonant mode. The transducers propagate transverse waves in the crystal which progress longitudinally therein. The waves are absorbed at the undriven ends of the crystals by damping material mounted thereon. In another aspect, the invention is a method for generating neutron pulses characterized by high intensity and short duration.

Mook, H.A. Jr.

1984-01-01T23:59:59.000Z

299

Pulsed-neutron monochromator  

DOE Patents [OSTI]

In one aspect, the invention is an improved pulsed-neutron monochromator of the vibrated-crystal type. The monochromator is designed to provide neutron pulses which are characterized both by short duration and high density. A row of neutron-reflecting crystals is disposed in a neutron beam to reflect neutrons onto a common target. The crystals in the row define progressively larger neutron-scattering angles and are vibrated sequentially in descending order with respect to the size of their scattering angles, thus generating neutron pulses which arrive simultaneously at the target. Transducers are coupled to one end of the crystals to vibrate them in an essentially non-resonant mode. The transducers propagate transverse waves in the crystal which progress longitudinally therein. The wave are absorbed at the undriven ends of the crystals by damping material mounted thereon. In another aspect, the invention is a method for generating neutron pulses characterized by high intensity and short duration.

Mook, Jr., Herbert A. (Oak Ridge, TN)

1985-01-01T23:59:59.000Z

300

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

E-Print Network [OSTI]

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

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

1996-07-19T23:59:59.000Z

Note: This page contains sample records for the topic "angle neutron scattering" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Elastic and inelastic neutron scattering cross sections for fission reactor applications  

SciTech Connect (OSTI)

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

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

2013-04-19T23:59:59.000Z

302

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

E-Print Network [OSTI]

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

ZEUS Collaboration; S. Chekanov

2007-03-09T23:59:59.000Z

303

Studies of protein structure in solution and protein folding using synchrotron small-angle x-ray scattering  

SciTech Connect (OSTI)

Synchrotron small angle x-ray scattering (SAXS) has been applied to the structural study of several biological systems, including the nitrogenase complex, the heat shock cognate protein (hsc70), and lysozyme folding. The structural information revealed from the SAXS experiments is complementary to information obtained by other physical and biochemical methods, and adds to our knowledge and understanding of these systems.

Chen, Lingling

1996-04-01T23:59:59.000Z

304

A new chopper spectrometer for neutron Brillouin scattering and low-angle neutron inelastic scattering: PHAROS (Phase 1)  

SciTech Connect (OSTI)

Phase I of PHAROS, the new chopper spectrometer at LANSCE, is described in detail. The main components are a water moderator, a 60-Hz double-bladed T-zero chopper, a 600Hz magnetic-bearing Fermi chopper, a 6m-long vacuum vessel with thin aluminium-alloy vacuum window and a 1.2m{sup 2} array of linear position-sensitive detectors.

Robinson, R.A.; Nutter, M.; Ricketts, R.L.; Larson, E.; Sandoval, J.P.; Lysaght, P.; Olivier, B.J.

1993-05-01T23:59:59.000Z

305

A new chopper spectrometer for neutron Brillouin scattering and low-angle neutron inelastic scattering: PHAROS (Phase 1)  

SciTech Connect (OSTI)

Phase I of PHAROS, the new chopper spectrometer at LANSCE, is described in detail. The main components are a water moderator, a 60-Hz double-bladed T-zero chopper, a 600Hz magnetic-bearing Fermi chopper, a 6m-long vacuum vessel with thin aluminium-alloy vacuum window and a 1.2m[sup 2] array of linear position-sensitive detectors.

Robinson, R.A.; Nutter, M.; Ricketts, R.L.; Larson, E.; Sandoval, J.P.; Lysaght, P.; Olivier, B.J.

1993-01-01T23:59:59.000Z

306

A study of neutron-deuteron scattering in configuration space  

E-Print Network [OSTI]

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

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

2006-10-09T23:59:59.000Z

307

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

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

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

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

2012-03-15T23:59:59.000Z

308

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

E-Print Network [OSTI]

We report the first measurement of the parity-violating asymmetry A_PV in the elastic scattering of polarized electrons from 208Pb. A_PV is sensitive to the radius of the neutron distribution (Rn). The result A_PV = 0.656 \\pm 0.060 (stat) \\pm 0.014 (syst) ppm corresponds to a difference between the radii of the neutron and proton distributions Rn - Rp = 0.33 +0.16 -0.18 fm and provides the first electroweak observation of the neutron skin which is expected in a heavy, neutron-rich nucleus.

S. Abrahamyan; Z. Ahmed; H. Albataineh; K. Aniol; D. S. Armstrong; W. Armstrong; T. Averett; B. Babineau; A. Barbieri; V. Bellini; R. Beminiwattha; J. Benesch; F. Benmokhtar; T. Bielarski; W. Boeglin; A. Camsonne; M. Canan; P. Carter; G. D. Cates; C. Chen; J. -P. Chen; O. Hen; F. Cusanno; M. M. Dalton; R. De Leo; K. de Jager; W. Deconinck; P. Decowski; X. Deng; A. Deur; D. Dutta; A. Etile; D. Flay; G. B. Franklin; M. Friend; S. Frullani; E. Fuchey; F. Garibaldi; E. Gasser; R. Gilman; A. Giusa; A. Glamazdin; J. Gomez; J. Grames; C. Gu; O. Hansen; J. Hansknecht; D. W. Higinbotham; R. S. Holmes; T. Holmstrom; C. J. Horowitz; J. Hoskins; J. Huang; C. E. Hyde; F. Itard; C. -M. Jen; E. Jensen; G. Jin; S. Johnston; A. Kelleher; K. Kliakhandler; P. M. King; S. Kowalski; K. S. Kumar; J. Leacock; J. Leckey IV; J. H. Lee; J. J. LeRose; R. Lindgren; N. Liyanage; N. Lubinsky; J. Mammei; F. Mammoliti; D. J. Margaziotis; P. Markowitz; A. McCreary; D. McNulty; L. Mercado; Z. -E. Meziani; R. W. Michaels; M. Mihovilovic; N. Muangma; C. Muoz-Camacho; S. Nanda; V. Nelyubin; N. Nuruzzaman; Y. Oh; A. Palmer; D. Parno; K. D. Paschke; S. K. Phillips; B. Poelker; R. Pomatsalyuk; M. Posik; A. J. R. Puckett; B. Quinn; A. Rakhman; P. E. Reimer; S. Riordan; P. Rogan; G. Ron; G. Russo; K. Saenboonruang; A. Saha; B. Sawatzky; A. Shahinyan; R. Silwal; S. Sirca; K. Slifer; P. Solvignon; P. A. Souder; M. L. Sperduto; R. Subedi; R. Suleiman; V. Sulkosky; C. M. Sutera; W. A. Tobias; W. Troth; G. M. Urciuoli; B. Waidyawansa; D. Wang; J. Wexler; R. Wilson; B. Wojtsekhowski; X. Yan; H. Yao; Y. Ye; Z. Ye; V. Yim; L. Zana; X. Zhan; J. Zhang; Y. Zhang; X. Zheng; P. Zhu

2012-01-13T23:59:59.000Z

309

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

E-Print Network [OSTI]

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

Deepshikha Shukla; Andreas Nogga; Daniel R. Phillips

2008-12-01T23:59:59.000Z

310

Neutron scattering-modern techniques and their scientific impact  

E-Print Network [OSTI]

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

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

311

Measurement Of Neutron Radius In Lead By Parity Violating Scattering Flash ADC DAQ  

SciTech Connect (OSTI)

This dissertation reports the experiment PREx, a parity violation experiment which is designed to measure the neutron radius in {sup 208}Pb. PREx is performed in hall A of Thomas Jefferson National Accelerator Facility from March 19th to June 21st. Longitudionally polarized electrons at energy 1 GeV scattered at and angle of {theta}{sub lab} = 5.8 {degrees} from the Lead target. Beam corrected pairty violaing counting rate asymmetry is (A{sub corr} = 594 50(stat) 9(syst))ppb at Q{sup 2} = 0.009068GeV {sup 2}. This dissertation also presents the details of Flash ADC Data Acquisition(FADC DAQ) system for Moller polarimetry in Hall A of Thomas Jefferson National Accelerator Facility. The Moller polarimeter measures the beam polarization to high precision to meet the specification of the PREx(Lead radius experiment). The FADC DAQ is part of the upgrade of Moller polarimetery to reduce the systematic error for PREx. The hardware setup and the results of the FADC DAQ analysis are presented

Ahmed, Zafar [Christopher Newport U.

2012-06-01T23:59:59.000Z

312

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

SciTech Connect (OSTI)

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

Dai, Pengcheng

2014-02-18T23:59:59.000Z

313

Combining Single-Molecule Optical Trapping and Small-Angle X-Ray Scattering Measurements to Compute the Persistence Length of a Protein  

E-Print Network [OSTI]

and purification For small-angle x-ray scattering and circular dichroism ER/K a-helix sequences from the myosin VICombining Single-Molecule Optical Trapping and Small-Angle X-Ray Scattering Measurements to Compute. In this study, we quantify this flexibility in terms of persistence length, namely the length scale over which

Spudich, James A.

314

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

E-Print Network [OSTI]

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

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

2012-12-12T23:59:59.000Z

315

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

E-Print Network [OSTI]

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

Beaucage, Gregory

316

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

E-Print Network [OSTI]

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

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

2010-07-11T23:59:59.000Z

317

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

SciTech Connect (OSTI)

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

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

2014-02-15T23:59:59.000Z

318

Study on generating of thermal neutron scattering cross sections for LiH  

SciTech Connect (OSTI)

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

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

2013-07-01T23:59:59.000Z

319

Measurement of Feynman-x Spectra of Photons and Neutrons in the Very Forward Direction in Deep-Inelastic Scattering at HERA  

E-Print Network [OSTI]

Measurements of normalised cross sections for the production of photons and neutrons at very small angles with respect to the proton beam direction in deep-inelastic $ep$ scattering at HERA are presented as a function of the Feynman variable $x_F$ and of the centre-of-mass energy of the virtual photon-proton system $W$. The data are taken with the H1 detector in the years 2006 and 2007 and correspond to an integrated luminosity of $131 \\mathrm{pb}^{-1}$. The measurement is restricted to photons and neutrons in the pseudorapidity range $\\eta>7.9$ and covers the range of negative four momentum transfer squared at the positron vertex $6scattering models and of models for hadronic interactions of high energy cosmic rays are compared to the measured cross sections.

H1 Collaboration

2014-04-01T23:59:59.000Z

320

Coherent Scattering Investigations at the Spallation Neutron Source: a Snowmass White Paper  

SciTech Connect (OSTI)

The Spallation Neutron Source (SNS) at Oak Ridge National Laboratory, Tennessee, provides an intense flux of neutrinos in the few tens-of-MeV range, with a sharply-pulsed timing structure that is beneficial for background rejection. In this white paper, we describe how the SNS source can be used for a measurement of coherent elastic neutrino-nucleus scattering (CENNS), and the physics reach of different phases of such an experimental program (CSI: Coherent Scattering Investigations at the SNS).

Akimov, D. [Moscow Engineering Physics Institute (MEPhI), Russia] Moscow Engineering Physics Institute (MEPhI), Russia; Bernstein, A. [Lawrence Livermore National Laboratory (LLNL)] Lawrence Livermore National Laboratory (LLNL); BarbeauP., [Duke University; Barton, P. J. [Lawrence Berkeley National Laboratory (LBNL)] Lawrence Berkeley National Laboratory (LBNL); Bolozdynya, A. [Moscow Engineering Physics Institute (MEPhI), Russia] Moscow Engineering Physics Institute (MEPhI), Russia; Cabrera-Palmer, B. [Sandia National Laboratories (SNL)] Sandia National Laboratories (SNL); Cavanna, F. [Yale University] Yale University; Cianciolo, Vince [ORNL] ORNL; Collar, J. [University of Chicago, Enrico Fermi Institute] University of Chicago, Enrico Fermi Institute; Cooper, R. J. [Indiana University] Indiana University; Dean, D. J. [Oak Ridge National Laboratory (ORNL)] Oak Ridge National Laboratory (ORNL); Efremenko, Yuri [University of Tennessee (UTK) and Oak Ridge National Laboratory (ORNL)] University of Tennessee (UTK) and Oak Ridge National Laboratory (ORNL); Etenko, A. [Moscow Engineering Physics Institute (MEPhI), Russia] Moscow Engineering Physics Institute (MEPhI), Russia; Fields, N. [University of Chicago, Enrico Fermi Institute] University of Chicago, Enrico Fermi Institute; Foxe, M. [Pennsylvania State University, University Park, PA] Pennsylvania State University, University Park, PA; Figueroa-Feliciano, E. [Massachusetts Institute of Technology (MIT)] Massachusetts Institute of Technology (MIT); Fomin, N. [University of Tennessee, Knoxville (UTK)] University of Tennessee, Knoxville (UTK); Gallmeier, F. [Oak Ridge National Laboratory (ORNL)] Oak Ridge National Laboratory (ORNL); Garishvili, I. [University of Tennessee, Knoxville (UTK)] University of Tennessee, Knoxville (UTK); Gerling, M. [Sandia National Laboratories (SNL)] Sandia National Laboratories (SNL); Green, M. [University of North Carolina, Chapel Hill] University of North Carolina, Chapel Hill; Greene, Geoffrey [University of Tennessee, Knoxville (UTK)] University of Tennessee, Knoxville (UTK); Hatzikoutelis, A. [University of Tennessee, Knoxville (UTK)] University of Tennessee, Knoxville (UTK); Henning, Reyco [University of North Carolina, Chapel Hill] University of North Carolina, Chapel Hill; Hix, R. [University of Tennessee (UTK) and Oak Ridge National Laboratory (ORNL)] University of Tennessee (UTK) and Oak Ridge National Laboratory (ORNL); Hogan, D. [University of California-Berkeley] University of California-Berkeley; Hornback, D. [University of Tennessee (UTK) and Oak Ridge National Laboratory (ORNL)] University of Tennessee (UTK) and Oak Ridge National Laboratory (ORNL); Jovanovic, I. [Pennsylvania State University, University Park, PA] Pennsylvania State University, University Park, PA; Hossbach, T. [Pacific Northwest National Laboratory (PNNL)] Pacific Northwest National Laboratory (PNNL); Iverson, Erik B [ORNL] ORNL; Klein, S. R. [Lawrence Berkeley National Laboratory (LBNL)] Lawrence Berkeley National Laboratory (LBNL); Khromov, A. [Moscow Engineering Physics Institute (MEPhI), Russia] Moscow Engineering Physics Institute (MEPhI), Russia; Link, J. [Virginia Polytechnic Institute and State University] Virginia Polytechnic Institute and State University; Louis, W. [Los Alamos National Laboratory (LANL)] Los Alamos National Laboratory (LANL); Lu, W. [Oak Ridge National Laboratory (ORNL)] Oak Ridge National Laboratory (ORNL); Mauger, C. [Los Alamos National Laboratory (LANL)] Los Alamos National Laboratory (LANL); Marleau, P. [Sandia National Laboratories (SNL)] Sandia National Laboratories (SNL); Markoff, D. [North Carolina Central University, Durham] North Carolina Central University, Durham; Martin, R. D. [University of South Dakota] University of South Dakota; Mueller, Paul Edward [ORNL] ORNL; Newby, J. [Oak Ridge National Laboratory (ORNL)] Oak Ridge National Laboratory (ORNL); Orrell, John L. [Pacific Northwest National Laboratory (PNNL)] Pacific Northwest National Laboratory (PNNL); O'Shaughnessy, C. [University of North Carolina, Chapel Hill] University of North Carolina, Chapel Hill

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "angle neutron scattering" from the National Library of EnergyBeta (NLEBeta).
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321

Incoherent Quasielastic Neutron Scattering Study of Molecular dynamics of 4-n-cyano-4'-octylbiphenyl  

E-Print Network [OSTI]

We report incoherent quasielastic neutron scattering experiments on the thermotropic liquid crystal 4-n-cyano-4'-octylbiphenyl. The combination of time-of-flight and backscattering data allows analyzing the intermediate scattering function over about three decades of relaxation times. Translational diffusion and uniaxial molecular rotations are clearly identified as the major relaxation processes in respectively the nanosecond and picosecond time scales. The comparison with literature data obtained by other techniques is discussed.

Ronan Lefort; Denis Morineau; Rgis Gugan; Claude Ecolivet; Mohammed Guendouz; Jean-Marc Zanotti; Bernhard Frick

2008-04-10T23:59:59.000Z

322

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

E-Print Network [OSTI]

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

Franz Gross; Alfred Stadler

2008-08-21T23:59:59.000Z

323

Electric dipole response of 208Pb from proton inelastic scattering: constraints on neutron skin thickness and symmetry energy  

E-Print Network [OSTI]

The electric dipole (E1) response of 208Pb has been precisely determined by measuring Coulomb excitation induced by proton scattering at very forward angles. The electric dipole polarizability, defined as inverse energy-weighted sum rule of the E1 strength, has been extracted as 20.1+-0.6 fm^3. The data can be used to constrain the neutron skin thickness of 208Pb to 0.168(+-0.009)_expt(+-0.013)_theo(+-0.021)_est fm, where the subscript "expt" refers to the experimental uncertainty, "theor" to the theoretical confidence band and "est" to the uncertainty associated with the estimation of the symmetry energy at the saturation density. In addition, a constraint band has been extracted in the plane of the symmetry energy (J) and its slope parameter (L) at the saturation density.

A. Tamii; P. von Neumann-Cosel; I. Poltoratska

2013-10-02T23:59:59.000Z

324

Accurate small and wide angle x-ray scattering profiles from atomic models of proteins and nucleic acids  

SciTech Connect (OSTI)

A new method is introduced to compute X-ray solution scattering profiles from atomic models of macromolecules. The three-dimensional version of the Reference Interaction Site Model (RISM) from liquid-state statistical mechanics is employed to compute the solvent distribution around the solute, including both water and ions. X-ray scattering profiles are computed from this distribution together with the solute geometry. We describe an efficient procedure for performing this calculation employing a Lebedev grid for the angular averaging. The intensity profiles (which involve no adjustable parameters) match experiment and molecular dynamics simulations up to wide angle for two proteins (lysozyme and myoglobin) in water, as well as the small-angle profiles for a dozen biomolecules taken from the BioIsis.net database. The RISM model is especially well-suited for studies of nucleic acids in salt solution. Use of fiber-diffraction models for the structure of duplex DNA in solution yields close agreement with the observed scattering profiles in both the small and wide angle scattering (SAXS and WAXS) regimes. In addition, computed profiles of anomalous SAXS signals (for Rb{sup +} and Sr{sup 2+}) emphasize the ionic contribution to scattering and are in reasonable agreement with experiment. In cases where an absolute calibration of the experimental data at q = 0 is available, one can extract a count of the excess number of waters and ions; computed values depend on the closure that is assumed in the solution of the OrnsteinZernike equations, with results from the KovalenkoHirata closure being closest to experiment for the cases studied here.

Nguyen, Hung T. [BioMaPS Institute for Quantitative Biology, Rutgers University, Piscataway, New Jersey 08854 (United States); Pabit, Suzette A.; Meisburger, Steve P.; Pollack, Lois [School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853 (United States); Case, David A., E-mail: case@biomaps.rutgers.edu [BioMaPS Institute for Quantitative Biology, Rutgers University, Piscataway, New Jersey 08854 (United States); Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854 (United States)

2014-12-14T23:59:59.000Z

325

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

E-Print Network [OSTI]

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

Malgorzata Kasprzak

2004-07-26T23:59:59.000Z

326

Small angle x-ray scattering study of fluctuations in 1-propanol-water and 2-propanol-water systems  

SciTech Connect (OSTI)

Small-angle x-ray scattering (SAXS) measurements have been carried out on the 1-propanol (NPA)-water system and on the 2-propanol (IPA)-water system at 20{degree}C. In the NPA-water system, the zero angle intensity, the concentration fluctuation, the Kirkwood-Buff parameters, and Debye's correlation lengths have been determined at various concentrations. In the IPA-water system, the zero angle intensity and Debye's correlation lengths have also been determined. In both the NPA-water and IPA-water systems, all obtained parameters have maxima at about 0.2 of the mole fraction of alcohol. In terms of these parameters, the mixing state of the NPA-water and IPA-water systems is discussed and compared with that of the TBA-water system.

Hayashi, Hisashi; Nishikawa, Keiko; Iijima, Takao (Gakushuin Univ., Tokyo (Japan))

1990-10-18T23:59:59.000Z

327

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

E-Print Network [OSTI]

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

328

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

E-Print Network [OSTI]

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

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

2014-11-28T23:59:59.000Z

329

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

E-Print Network [OSTI]

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

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

2012-10-02T23:59:59.000Z

330

Anomalous small angle x-ray scattering studies of amorphous metal-germanium alloys  

SciTech Connect (OSTI)

This dissertation addresses the issue of composition modulation in sputtered amorphous metal-germanium thin films with the aim of understanding the intermediate range structure of these films as a function of composition. The investigative tool used in this work is anomalous small-angle X-ray scattering (ASAXS). The primary focus of this investigation is the amorphous iron-germanium (a-Fe{sub x}Ge{sub 100-x}) system with particular emphasis on the semiconductor-rich regime. Brief excursions are made into the amorphous tungsten-germanium (a-W{sub x}Ge{sub 100-x}) and the amorphous molybdenum-germanium (a-Mo{sub x}Ge{sub 100-x}) systems. All three systems exhibit an amorphous structure over a broad composition range extending from pure amorphous germanium to approximately 70 atomic percent metal when prepared as sputtered films. Across this composition range the structures change from the open, covalently bonded, tetrahedral network of pure a-Ge to densely packed metals. The structural changes are accompanied by a semiconductor-metal transition in all three systems as well as a ferromagnetic transition in the a-Fe{sub x}Ge{sub 100-x} system and a superconducting transition in the a-Mo{sub x}Ge{sub 100-x} system. A long standing question, particularly in the a-Fe{sub x}Ge{sub 100-x} and the a-Mo{sub x}Ge{sub 100-x} systems, has been whether the structural changes (and therefore the accompanying electrical and magnetic transitions) are accomplished by homogeneous alloy formation or phase separation. The application of ASAXS to this problem proves unambiguously that fine scale composition modulations, as distinct from the simple density fluctuations that arise from cracks and voids, are present in the a-Fe{sub x}Ge{sub 100-x}, a-W{sub x}Ge{sub 100-x}, and a-Mo{sub x}Ge{sub 100-x} systems in the semiconductor-metal transition region. Furthermore, ASAXS shows that germanium is distributed uniformly throughout each sample in the x<25 regime of all three systems.

Rice, M.

1993-12-01T23:59:59.000Z

331

Neutron Scattering Society of America Purpose and New Initiatives  

E-Print Network [OSTI]

Science Prize, and the Outstanding Student Research Prize Hosts information booths and displays at major of correlated electron physics in magnets, metals and superconductors, and for science-drive is the NSSA? NSSA is an organization of scientists and engineers with a common interest in using neutron

332

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

E-Print Network [OSTI]

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

Pinghan Chu

2014-03-06T23:59:59.000Z

333

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

E-Print Network [OSTI]

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

M Steiner; D A Tennant; P Smeibidl

334

Structure of Flame-Made Silica Nanoparticles by Ultra-Small-Angle X-ray Scattering  

E-Print Network [OSTI]

by thermophoretic sampling and microscopy that provided consistent results with light scattering with respect thermophoretically collected samples and image analysis of t

Beaucage, Gregory

335

E-Print Network 3.0 - angle elastic scattering Sample Search...  

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

of Physics and Astronomy, Texas A&M University - Commerce Collection: Physics 17 Subcritical scattering from buried elastic shells Irena Lucifredi and Henrik Schmidt Summary:...

336

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

E-Print Network [OSTI]

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

337

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

E-Print Network [OSTI]

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

Pennycook, Steve

338

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

E-Print Network [OSTI]

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

Turro, Nicholas J.

339

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

E-Print Network [OSTI]

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

Paris-Sud XI, Université de

340

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

E-Print Network [OSTI]

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

Pennycook, Steve

Note: This page contains sample records for the topic "angle neutron scattering" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

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

E-Print Network [OSTI]

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

Downs, Robert T.

342

Importance of Compton scattering to radiation spectra of isolated neutron stars  

E-Print Network [OSTI]

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

V. Suleimanov; K. Werner

2006-12-22T23:59:59.000Z

343

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

E-Print Network [OSTI]

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

Pennycook, Steve

344

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

E-Print Network [OSTI]

The production of leading neutrons, where the neutron carries a large fraction x_L of the incoming proton's longitudinal momentum, is studied in deep-inelastic positron-proton scattering at HERA. The data were taken with the H1 detector in the years 2006 and 2007 and correspond to an integrated luminosity of 122 pb^{-1}. The semi-inclusive cross section is measured in the phase space defined by the photon virtuality 6 < Q^2 < 100 GeV^2, Bjorken scaling variable 1.5x10^{-4} < x < 3x10^{-2}, longitudinal momentum fraction 0.32 < x_L < 0.95 and neutron transverse momentum p_T < 0.2 GeV. The leading neutron structure function, F_2^{LN(3)}(Q^2,x,x_L), and the fraction of deep-inelastic scattering events containing a leading neutron are studied as a function of Q^2, x and x_L. Assuming that the pion exchange mechanism dominates leading neutron production, the data provide constraints on the shape of the pion structure function.

Aaron, F D; Alimujiang, K; Andreev, V; Antunovic, B; Backovic, S; Baghdasaryan, A; Barrelet, E; Bartel, W; Begzsuren, K; Belousov, A; Bizot, J C; Boudry, V; Bozovic-Jelisavcic, I; Bracinik, J; Brandt, G; Brinkmann, M; Brisson, V; Bruncko, D; Bunyatyan, A; Buschhorn, G; Bystritskaya, L; Campbell, A J; Cantun Avila, K B; Cerny, K; Cerny, V; Chekelian, V; Cholewa, A; Contreras, J G; Coughlan, J A; Cozzika, G; Cvach, J; Dainton, J B; Daum, K; Deak, M; Delcourt, B; Delvax, J; De Wolf, E A; Diaconu, C; Dodonov, V; Dossanov, A; Dubak, A; Eckerlin, G; Efremenko, V; Egli, S; Eliseev, A; Elsen, E; Falkiewicz, A; Favart, L; Fedotov, A; Felst, R; Feltesse, J; Ferencei, J; Fischer, D.-J; Fleischer, M; Fomenko, A; Gabathuler, E; Gayler, J; Ghazaryan, Samvel; Glazov, A; Glushkov, I; Goerlich, L; Gogitidze, N; Gouzevitch, M; Grab, C; Greenshaw, T; Grell, B R; Grindhammer, G.; Habib, S; Haidt, D; Helebrant, C; Henderson, R C W; Hennekemper, E; Henschel, H; Herbst, M; Herrera, G; Hildebrandt, M; Hiller, K H; Hoffmann, D; Horisberger, R; Hreus, T; Jacquet, M; Janssen, X; Jonsson, L; Jung, Andreas Werner; INSPIRE-00183962; Jung, H; Kapichine, M; Katzy, J; Kenyon, I R; Kiesling, C; Klein, M; Kleinwort, C; Kluge, T; Knutsson, A; Kogler, R; Kostka, P; Kraemer, M; Krastev, K; Kretzschmar, J; Kropivnitskaya, A; Kruger, K; Kutak, K; Landon, M P J; Lange, W; Lastovicka-Medin, G; Laycock, P; Lebedev, A; Lendermann, V; Levonian, S; Li, G; Lipka, K; Liptaj, A; List, B; List, J; Loktionova, N; Lopez-Fernandez, R; Lubimov, V; Lytkin, L; Makankine, A; Malinovski, E; Marage, P; Marti, Ll; Martyn, H.-U.; Maxfield, S J; Mehta, A; Meyer, A B; Meyer, H; Meyer, H; Meyer, J; Mikocki, S; Milcewicz-Mika, I; Moreau, F; Morozov, A; Morris, J V; Mozer, Matthias Ulrich; Mudrinic, M; Muller, K; Murin, P; Naumann, Th; Newman, P R; Niebuhr, C; Nikiforov, A; Nikitin, D; Nowak, G; Nowak, K; Olsson, J E; Osman, S; Ozerov, D; Pahl, P; Palichik, V; Panagoulias, I; Pandurovic, M; Papadopoulou, Th; Pascaud, C; Patel, G D; Pejchal, O; Perez, E; Petrukhin, A; Picuric, I; Piec, S; Pitzl, D; Placakyte, R; Pokorny, B; Polifka, R; Povh, B; Radescu, V; Rahmat, A J; Raicevic, N; Raspiareza, A; Ravdandorj, T; Reimer, P; Rizvi, E; Robmann, P; Roland, B; Roosen, R; Rostovtsev, A; Rotaru, M; Ruiz Tabasco, J E; Rusakov, S; Salek, D; Sankey, D P C; Sauter, M; Sauvan, E; Schmitt, S; Schoeffel, L; Schoning, A; Schultz-Coulon, H.-C; Sefkow, F; Shaw-West, R N; Shtarkov, L N; Shushkevich, S; Sloan, T; Smiljanic, Ivan; Soloviev, Y; Sopicki, P; South, D; Spaskov, V; Specka, Arnd E; Staykova, Z; Steder, M; Stella, B; Stoicea, G; Straumann, U.; Sunar, D; Sykora, T; Tchoulakov, V; Thompson, G; Thompson, P D; Toll, T; Tomasz, F; Tran, T H; Traynor, D; Trinh, T N; Truol, P; Tsakov, I; Tseepeldorj, B; Turnau, J; Urban, K; Valkarova, A; Vallee, C; Van Mechelen, P; Vargas Trevino, A; Vazdik, Y; Vinokurova, S; Volchinski, V; von den Driesch, M; Wegener, D; Wissing, Ch; Wunsch, E; Zacek, J; Zalesak, J; Zhang, Z; Zhokin, A; Zimmermann, T; Zohrabyan, H; Zomer, F

2010-01-01T23:59:59.000Z

345

A promising concept for using near-surface measuring angles in angle-resolved x-ray photoelectron spectroscopy considering elastic scattering effects  

SciTech Connect (OSTI)

The increasing number of applications of very thin films requires both reliable thin-layer and interface characterization. A powerful method for characterization in the nanometer thickness range is the angle-resolved x-ray photoelectron spectroscopy (ARXPS). This is a nondestructive depth-profiling method, which can provide elemental content as well as chemical information. Two of the drawbacks of ARXPS are, that it requires dedicated mathematical modeling and that, at least up until now, its use has been restricted away from near-surface angles. In this paper we present a method for the mathematical description of a few, hitherto unaccounted, measurement effects in order to improve the simulations of ARXPS data for complex surface structures. As an immediate application, we propose a simple algorithm to consider the effects of elastic scattering in the standard ARXPS data interpretation, which in principle would allow the use of the whole angular range for the analysis; thus leading to a significant increase in the usable information content from the measurements. The potential of this approach is demonstrated with model calculations for a few thin film examples.

Oswald, S.; Oswald, F. [IFW Dresden, Postfach 270116, D-01171 Dresden (Germany)

2011-02-01T23:59:59.000Z

346

Comparison of discrete and continuous thermal neutron scattering treatments in MCNP5  

SciTech Connect (OSTI)

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

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

2012-07-01T23:59:59.000Z

347

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

SciTech Connect (OSTI)

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

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

2014-01-01T23:59:59.000Z

348

Virtual Compton scattering and neutral pion electroproduction in the resonance region up to the deep inelastic region at backward angles  

SciTech Connect (OSTI)

We have made the first measurements of the virtual Compton scattering (VCS) process via the H(e,e'p)? exclusive reaction in the nucleon resonance region, at backward angles. Results are presented for the W-dependence at fixed Q2=1 GeV2, and for the Q2-dependence at fixed W near 1.5 GeV. The VCS data show resonant structures in the first and second resonance regions. The observed Q2-dependence is smooth. The measured ratio of H(e,e'p)? to H(e,e'p)?0 cross sections emphasizes the different sensitivity of these two reactions to the various nucleon resonances. Finally, when compared to Real Compton Scattering (RCS) at high energy and large angles, our VCS data at the highest W (1.8-1.9 GeV) show a striking Q2-independence, which may suggest a transition to a perturbative scattering mechanism at the quark level.

Laveissiere, Geraud; Degrande, Natalie; Jaminion, Stephanie; Jutier, Christophe; Todor, Luminita; Di Salvo, Rachele; Van Hoorebeke, L.; Alexa, L.C.; Anderson, Brian; Aniol, Konrad; Arundell, Kathleen; Audit, Gerard; Auerbach, Leonard; Baker, F.; Baylac, Maud; Berthot, J.; Bertin, Pierre; Bertozzi, William; Bimbot, Louis; Boeglin, Werner; Brash, Edward; Breton, Vincent; Breuer, Herbert; Burtin, Etienne; Calarco, John; Cardman, Lawrence; Cavata, Christian; Chang, C.; Chang, C.C.; Chang, C.; Chang, C.C.; Chang, C.; Chang, C.C.; Chang, C.; Chang, C.C.; Chen, Jian-Ping; Chudakov, Eugene; Cisbani, Evaristo; Dale, Daniel; De Jager, Cornelis; De Leo, Raffaele; Deur, Alexandre; D'Hose, Nicole; Dodge, Gail; Domingo, John; Elouadrhiri, Latifa; Epstein, Martin; Ewell, Lars; Finn, John; Fissum, Kevin; Fonvieille, Helene; Fournier, Guy; Frois, Bernard; Frullani, Salvatore; Furget, Christophe; Gao, Haiyan; Gao, Juncai; Garibaldi, Franco; Gasparian, Ashot; Gilad, Shalev; Gilman, Ronald; Glamazdin, Oleksandr; Glashausser, Charles; Gomez, Javier; Gorbenko, Viktor; Grenier, Philippe; Guichon, Pierre; Hansen, Jens-Ole; Holmes, Richard; Holtrop, Maurik; Howell, Calvin; Huber, Garth; Hyde, Charles; Incerti, Sebastien; Iodice, Mauro; Jardillier, Johann; Jones, Mark; Kahl, William; Kamalov, Sabit; Kato, Seigo; Katramatou, A.T.; Kelly, James; Kerhoas, Sophie; Ketikyan, Armen; Khayat, Mohammad; Kino, Kouichi; Kox, Serge; Kramer, Laird; Kumar, Krishna; Kumbartzki, Gerfried; Kuss, Michael; Leone, Antonio; LeRose, John; Liang, Meihua; Lindgren, Richard; Liyanage, Nilanga; Lolos, George; Lourie, Robert; Madey, Richard; Maeda, Kazushige; Malov, Sergey; Manley, D.; Marchand, Claude; Marchand, Dominique; Margaziotis, Demetrius; Markowitz, Pete; Marroncle, Jacques; Martino, Jacques; McCormick, Kathy; McIntyre, Justin; Mehrabyan, Surik; Merchez, Fernand; Meziani, Zein-Eddine; Michaels, Robert; Miller, Gerald; Mougey, Jean; Nanda, Sirish; Neyret, Damien; Offermann, Edmond; Papandreou, Zisis; Perdrisat, Charles; Perrino, R.; Petratos, Gerassimos; Platchkov, Stephane; Pomatsalyuk, Roman; Prout, David; Punjabi, Vina; Pussieux, Thierry; Quemener, Gilles; Ransome, Ronald; Ravel, Oliver; Real, Jean-Sebastien; Renard, F.; Roblin, Yves; Rowntree, David; Rutledge, Gary; Rutt, Paul; Saha, Arunava; Saito, Teijiro; Sarty, Adam; Serdarevic, A.; Smith, T.; Smirnov, G.; Soldi, K.; Sorokin, Pavel; Souder, Paul; Suleiman, Riad; Templon, Jeffrey; Terasawa, Tatsuo; Tiator, Lothar; Tieulent, Raphael; Tomasi-Gustaffson, E.; Tsubota, Hiroaki; Ueno, Hiroaki; Ulmer, Paul; Urciuoli, Guido; Van De Vyver, R.; van der Meer, Rob; Vernin, Pascal; Vlahovic, B.; Voskanyan, Hakob; Voutier, Eric; Watson, J.W.; Weinstein, Lawrence; Wijesooriya, Krishni; Wilson, R.; Wojtsekhowski, Bogdan; Zainea, Dan; Zhang, Wei-Ming; Zhao, Jie; Zhou, Z.-L.

2009-01-01T23:59:59.000Z

349

Discrimination of gamma rays due to inelastic neutron scattering in AGATA  

E-Print Network [OSTI]

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

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

2009-06-10T23:59:59.000Z

350

Discrimination of gamma rays due to inelastic neutron scattering in AGATA  

E-Print Network [OSTI]

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

A. Ata; A. Kaskas A; S. Akkoyun A; M. Senyi?git A; T. Hyk A; S. O. Kara A; J. Nyberg B

351

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

E-Print Network [OSTI]

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

V. Suleimanov; K. Werner

2007-02-15T23:59:59.000Z

352

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

SciTech Connect (OSTI)

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

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

2009-01-01T23:59:59.000Z

353

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

SciTech Connect (OSTI)

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

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

2014-01-01T23:59:59.000Z

354

Influence of the Environment Fluctuations on Incoherent Neutron Scattering Functions  

E-Print Network [OSTI]

In extending the conventional dynamic models, we consider a simple model to account for the environment fluctuations of particle atoms in a protein system and derive the elastic incoherent structure factor (EISF) and the incoherent scattering correlation function C(Q,t) for both the jump dynamics between sites with fluctuating site interspacing and for the diffusion inside a fluctuating sphere. We find that the EISF of the system (or the normalized elastic intensity) is equal to that in the absence of fluctuations averaged over the distribution of site interspacing or sphere radius a. The scattering correlation function is $C(Q,t)=\\sum_{n} \\psi(t)$, where the average is taken over the Q-dependent effective distribution of relaxation rates \\lambda_n(a) and \\psi(t) is the correlation function of the length a. When \\psi(t)=1, the relaxation of C(Q,t) is exponential for the jump dynamics between sites (since \\lambda_n(a) is independent of a) while it is nonexponential for diffusion inside a sphere.

D. J. Bicout

2001-04-09T23:59:59.000Z

355

Observation of acoustic umklapp-phonons in water-stabilized DNA by neutron scattering  

SciTech Connect (OSTI)

We have investigated static and dynamic properties of wet-spun DNA fibers in their C, A, and B conformations using the thermal neutron scattering. Over-damped and underdamped longitudinal acoustic umklapp phonons are observed in the vicinity of a hydration-dependent two-dimensional sheet of diffuse scattering perpendicular to the helix axis. A quantitative analysis of this mode is presented for the B-DNA sample in terms of a harmonic one-dimensional liquid, i.e., taking into account all orders of fluctuations. The resulting effective dispersion does not extrapolate to zero frequency at the position of the sheet.

Grimm, H.; Stiller, H.; Majkrzak, C.F.; Rupprecht, A.; Dahlborg, U.

1987-10-12T23:59:59.000Z

356

Transverse Beam Spin Asymmetries in Forward-Angle Elastic Electron-Proton Scattering  

SciTech Connect (OSTI)

We have measured the beam-normal single-spin asymmetry in elastic scattering of transversely polarized 3 GeV electrons from unpolarized protons at Q{sup 2}=0.15, 0.25 (GeV/c){sup 2}. The results are inconsistent with calculations solely using the elastic nucleon intermediate state and generally agree with calculations with significant inelastic hadronic intermediate state contributions. A{sub n} provides a direct probe of the imaginary component of the 2{gamma} exchange amplitude, the complete description of which is important in the interpretation of data from precision electron-scattering experiments.

Armstrong, D. S.; Averett, T.; Bailey, S. L.; Finn, J. M.; Griffioen, K. A.; Moffit, B.; Phillips, S. K.; Secrest, J.; Sulkosky, V. [Department of Physics, College of William and Mary, Williamsburg, Virginia 23187 (United States); Arvieux, J.; Bimbot, L.; Guler, H.; Lenoble, J.; Marchand, D.; Morlet, M.; Ong, S.; Van de Wiele, J. [Institut de Physique Nucleaire d'Orsay, CNRS/IN2P3, Universite Paris Sud, Orsay (France); Asaturyan, R.; Mkrtchyan, H.; Stepanyan, S. [Yerevan Physics Institute, Yerevan 375036 (Armenia)] (and others)

2007-08-31T23:59:59.000Z

357

Quantum correlations in bulk properties of solids obtained from neutron scattering  

E-Print Network [OSTI]

We demonstrate that inelastic neutron scattering technique can be used to indirectly detect and measure the macroscopic quantum correlations quantified by both entanglement and discord in a quantum magnetic material, VODPO4 . 1D2O. The amount of quantum correlations is obtained 2 by analyzing the neutron scattering data of magnetic excitations in isolated V4+ spin dimers. Our quantitative analysis shows that the critical temperature of this material can reach as high as Tc = 82.5 K, where quantum entanglement drops to zero. Significantly, quantum discord can even survive at Tc = 300 K and may be used in room temperature quantum devices. Taking into account the spin-orbit (SO) coupling, we also predict theoretically that entanglement can be significantly enhanced and the critical temperature Tc increases with the strength of spin-orbit coupling.

Ben-Qiong Liu; Lian-Ao Wu; Guo-Mo Zeng; Jian-Ming Song; Wei Luo; Yang Lei; Guang-Ai Sun; Bo Chen; Shu-Ming Peng

2014-07-02T23:59:59.000Z

358

NEUTRON SCATTERING STUDIES OF THE FRUSTRATED ANTIFERROMAGNETIC PYROCHLORE SYSTEM Tb2Sn2-xTixO7.  

E-Print Network [OSTI]

?? The following dissertation shows the results of a series of inelastic neutron scattering experiments on the geometrically frustrated pyrochlore system Tb2Sn2-xTixO7 for x=0, 0.1, (more)

Zhang, Jimin

2013-01-01T23:59:59.000Z

359

AN EFFICIENT PARALLEL GPU EVALUATION OF SMALL ANGLE X-RAY SCATTERING PROFILES  

E-Print Network [OSTI]

the scat- tering curve from a condensation of a gas of "dummy beads" to an experi-ray Scattering (SAXS) provides information on the excess electron density of the sample versus the surrounding of the experiment. For this procedure to be successful, an efficient procedure for both sampling protein structures

Hamelryck, Thomas

360

Low-energy neutron-12C analyzing powers: Results from a multichannel algebraic scattering theory  

E-Print Network [OSTI]

Analyzing powers in low-energy neutron scattering from 12C are calculated in an algebraic momentum-space coupled-channel formalism (MCAS). The results are compared with recently obtained experimental data. The channel-coupling potentials have been defined previously to reproduce the total cross section and sub-threshold bound states of the compound system. Without further adjustment, good agreement with data for the analyzing powers is obtained.

J. P. Svenne; K. Amos; S. Karataglidis; D. van der Knijff; L. Canton; G. Pisent

2005-10-29T23:59:59.000Z

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361

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

SciTech Connect (OSTI)

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

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

2014-09-08T23:59:59.000Z

362

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

SciTech Connect (OSTI)

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

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

2014-01-01T23:59:59.000Z

363

Self-similar multiscale structure of lignin revealed by neutron scattering and molecular dynamics simulation  

SciTech Connect (OSTI)

Lignin, a major polymeric component of plant cell walls, forms aggregates in vivo and poses a barrier to cellulosic ethanol production. Here, neutron scattering experiments and molecular dynamics simulations reveal that lignin aggregates are characterized by a surface fractal dimension that is invariant under change of scale from ~1 1000 . The simulations also reveal extensive water penetration of the aggregates and heterogeneous chain dynamics corresponding to a rigid core with a fluid surface.

Petridis, Loukas [ORNL; Pingali, Sai Venkatesh [ORNL; Urban, Volker S [ORNL; Heller, William T [ORNL; O'Neill, Hugh Michael [ORNL; Foston, Marcus [Georgia Institute of Technology; Ragauskas, A J [Georgia Institute of Technology; Smith, Jeremy C [ORNL

2011-01-01T23:59:59.000Z

364

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

E-Print Network [OSTI]

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

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

365

Neutrino-nucleus coherent scattering as a probe of neutron density distributions  

E-Print Network [OSTI]

Neutrino-nucleus coherent elastic scattering provides a theoretically appealing way to measure the neutron part of nuclear form factors. Using an expansion of form factors into moments, we show that neutrinos from stopped pions can probe not only the second moment of the form factor (the neutron radius) but also the fourth moment. Using simple Monte Carlo techniques for argon, germanium, and xenon detectors of 3.5 tonnes, 1.5 tonnes, and 300 kg, respectively, we show that the neutron radii can be found with an uncertainty of a few percent when near a neutrino flux of $3\\times10^{7}$ neutrinos/cm$^{2}$/s. If the normalization of the neutrino flux is known independently, one can determine the moments accurately enough to discriminate among the predictions of various nuclear energy functionals.

Kelly Patton; Jonathan Engel; Gail C. McLaughlin; Nicolas Schunck

2012-07-03T23:59:59.000Z

366

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

E-Print Network [OSTI]

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

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

2011-02-21T23:59:59.000Z

367

Deeply virtual compton scattering from the neutron with CLAS and CLAS12  

SciTech Connect (OSTI)

Generalised Parton Distributions (GPDs) offer an insight into the three-dimensional structure of the nucleon and its internal dynamics, relating the longitudinal momentum of quarks to their transverse position. A very effective means of accessing GPDs is via measurements of cross-sections and polarisation-asymmetries in Deeply Virtual Compton Scattering (DVCS). In particular, the beam-spin asymmetry (BSA) in DVCS from the neutron is especially sensitive to angular momentum of the up- and down-quarks, and its measurement therefore has potential to shed important light on the puzzle of nucleon spin. We present a preliminary extraction of BSA from a recent experiment using a 6 GeV electron beam and the CLAS detector at Jefferson Laboratory and introduce the Central Neutron Detector to be integrated with CLAS12 for the exclusive measurement of neutron DVCS at 11 GeV, made possible by the Jefferson Lab upgrade.

Sokhan, Daria [Glasgow University, Glasgow, Scotland (United Kingdom)

2014-01-01T23:59:59.000Z

368

Polarized Deep Inelastic Scattering Off the "Neutron" From Gauge/String Duality  

E-Print Network [OSTI]

We investigate deep inelastic scattering off the polarized "neutron" using gauge/string duality. The "neutron" corresponds to a supergravity mode of the neutral dilatino. Through introducing the Pauli interaction term into the action in $\\textrm{AdS}_{5}$ space, we calculate the polarized deep inelastic structure functions of the "neutron" in supergravity approximation at large t' Hooft coupling $\\lambda$ and finite $x$ with $\\lambda^{-1/2}\\ll xneutron" are power suppressed at the same order as the ones of the "proton." Especially, we find the Burkhardt-Cottingham-like sum rule, which is satisfied in the work by Gao and Xiao, is broken due to the Pauli interaction term. We also illustrate how such a Pauli interaction term can arise naturally from higher dimensional fermion-graviton coupling through the usual Kaluza-Klein reduction.

Jian-Hua Gao; Zong-Gang Mou

2010-05-25T23:59:59.000Z

369

Method for improving the angular resolution of a neutron scatter camera  

DOE Patents [OSTI]

An instrument that will directly image the fast fission neutrons from a special nuclear material source wherein the neutron detection efficiency is increased has been described. Instead of the previous technique that uses a time-of-flight (TOF) between 2 widely spaced fixed planes of neutron detectors to measure scatter neutron kinetic energy, we now use the recoil proton energy deposited in the second of the 2 scatter planes which can now be repositioned either much closer together or further apart. However, by doubling the separation distance between the 2 planes from 20 cm to a distance of 40 cm we improved the angular resolution of the detector from about 12.degree. to about 10.degree.. A further doubling of the separation distance to 80 cm provided an addition improvement in angular resolution of the detector to about 6.degree. without adding additional detectors or ancillary electronics. The distance between planes also may be dynamically changed using a suitable common technique such as a gear- or motor-drive to toggle between the various positions. The angular resolution of this new configuration, therefore, is increased at the expanse of detection sensitivity. However, the diminished sensitivity may be acceptable for those applications where the detector is able to interrogate a particular site for an extended period.

Mascarenhas, Nicholas; Marleau, Peter; Gerling, Mark; Cooper, Robert Lee; Mrowka, Stanley; Brennan, James S.

2012-12-25T23:59:59.000Z

370

Transverse Beam Spin Asymmetries in Forward-Angle Elastic Electron-Proton Scattering  

SciTech Connect (OSTI)

We have measured the beam-normal single-spin asymmetry in elastic scattering of transversely-polarized 3 GeV electrons from unpolarized protons at Q^2 values of 0.15 and 0.25 (GeV/c)^2 with results of A_n = -4.06 +- 0.99(stat) +- 0.63(syst) and A_n = -4.82 +- 1.87(stat) +- 0.98(syst) ppm. These results are inconsistent with calculations solely using the elastic nucleon intermediate state, and generally agree with calculations with significant inelastic hadronic intermediate state contributions. A_n provides a direct probe of the imaginary component of the two-photon exchange amplitude, the complete description of which is important in the interpretation of data from precision electron-scattering experiments.

David Armstrong; Francois Arvieux; Razmik Asaturyan; Todd Averett; Stephanie Bailey; Guillaume Batigne; Douglas Beck; Elizabeth Beise; Jay Benesch; Louis Bimbot; James Birchall; Angela Biselli; Peter Bosted; Elodie Boukobza; Herbert Breuer; Roger Carlini; Robert Carr; Nicholas Chant; Yu-Chiu Chao; Swapan Chattopadhyay; Russell Clark; Silviu Covrig; Anthony Cowley; Daniel Dale; Charles Davis; Willie Falk; John Finn; Tony Forest; Gregg Franklin; Christophe Furget; David Gaskell; Joseph Grames; Keith Griffioen; Klaus Grimm; Benoit Guillon; Hayko Guler; Lars Hannelius; Richard HASTY; Alice Hawthorne Allen; Tanja Horn; Kathleen Johnston; Mark Jones; Peter Kammel; Reza Kazimi; Paul King; Ameya Kolarkar; Elie Korkmaz; Wolfgang Korsch; Serge Kox; Joachim Kuhn; Jeff Lachniet; Lawrence Lee; Jason Lenoble; Eric Liatard; Jianglai Liu; Berenice Loupias; Allison Lung; Dominique Marchand; Jeffery Martin; Kenneth McFarlane; David McKee; Robert McKeown; Fernand Merchez; Hamlet Mkrtchyan; Bryan Moffit; M. Morlet; Itaru Nakagawa; Kazutaka Nakahara; Retief Neveling; Silvia Niccolai; S. Ong; Shelley Page; Vassilios Papavassiliou; Stephen Pate; Sarah Phillips; Mark Pitt; Benard Poelker; Tracy Porcelli; Gilles Quemener; Brian Quinn; William Ramsay; Aamer Rauf; Jean-Sebastien Real; Julie Roche; Philip Roos; Gary Rutledge; Jeffery Secrest; Neven Simicevic; Gregory Smith; Damon Spayde; Samuel Stepanyan; Marcy Stutzman; Vince Sulkosky; Vincent Sulkosky; Vince Sulkosky; Vincent Sulkosky; Vardan Tadevosyan; Raphael Tieulent; Jacques Van de Wiele; Willem van Oers; Eric Voutier; William Vulcan; Glen Warren; Steven Wells; Steven Williamson; Stephen Wood; Chen Yan; Junho Yun; Valdis Zeps

2007-08-01T23:59:59.000Z

371

Monitoring simultaneously the growth of nanoparticles and aggregates by in situ ultra-small-angle x-ray scattering  

SciTech Connect (OSTI)

Ultra-small-angle x-ray scattering can provide information about primary particles and aggregates from a single scattering experiment. This technique is applied in situ to flame aerosol reactors for monitoring simultaneously the primary particle and aggregate growth dynamics of oxide nanoparticles in a flame. This was enabled through the use of a third generation synchrotron source (Advanced Photon Source, Argonne IL, USA) using specialized scattering instrumentation at the UNICAT facility which is capable of simultaneously measuring nanoscales to microscales (1 nm to 1 {mu}m). More specifically, the evolution of primary-particle diameter, mass-fractal dimension, geometric standard deviation, silica volume fraction, number concentration, radius of gyration of the aggregate, and number of primary particles per aggregate are measured along the flame axis for two different premixed flames. All these particle characteristics were derived from a single and nonintrusive measurement technique. Flame temperature profiles were measured in the presence of particles by in situ Fourier transform infrared spectroscopy and thermophoretic sampling was used to visualize particle growth with height above the burner as well as in the radial direction.

Kammler, Hendrik K.; Beaucage, Gregory; Kohls, Douglas J.; Agashe, Nikhil; Ilavsky, Jan [Particle Technology Laboratory, Department of Mechanical and Process Engineering, ETH Zurich, ML F23, CH-8092 Zurich (Switzerland); Department of Chemical and Materials Engineering, University of Cincinnati, 540 Engineering Research Center, Cincinnati, Ohio 45221-0012 (United States); UNICAT, Advanced Photon Source, Building 438D, 9700 South Cass Avenue, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

2005-03-01T23:59:59.000Z

372

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

E-Print Network [OSTI]

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

Boyer, Edmond

373

Proton elastic scattering from tin isotopes at 295 MeV and systematic change of neutron density distributions  

E-Print Network [OSTI]

Cross sections and analyzing powers for proton elastic scattering from $^{116,118,120,122,124}$Sn at 295 MeV have been measured for a momentum transfer of up to about 3.5 fm$^{-1}$ to deduce systematic changes of the neutron density distribution. We tuned the relativistic Love-Franey interaction to explain the proton elastic scattering of a nucleus whose density distribution is well known. Then, we applied this interaction to deduce the neutron density distributions of tin isotopes. The result of our analysis shows the clear systematic behavior of a gradual increase in the neutron skin thickness of tin isotopes with mass number.

S. Terashima; H. Sakaguchi; H. Takeda; T. Ishikawa; M. Itoh; T. Kawabata; T. Murakami; M. Uchida; Y. Yasuda; M. Yosoi; J. Zenihiro; H. P. Yoshida; T. Noro; T. Ishida; S. Asaji; T. Yonemura

2008-02-02T23:59:59.000Z

374

X-ray Dust Scattering at Small Angles: The Complete Halo around GX13+1  

E-Print Network [OSTI]

The exquisite angular resolution available with Chandra should allow precision measurements of faint diffuse emission surrounding bright sources, such as the X-ray scattering halos created by interstellar dust. However, the ACIS CCDs suffer from pileup when observing bright sources, and this creates difficulties when trying to extract the scattered halo near the source. The initial study of the X-ray halo around GX13+1 using only the ACIS-I detector done by Smith, Edgar & Shafer (2002) suffered from a lack of sensitivity within 50'' of the source, limiting what conclusions could be drawn. To address this problem, observations of GX13+1 were obtained with the Chandra HRC-I and simultaneously with the RXTE PCA. Combined with the existing ACIS-I data, this allowed measurements of the X-ray halo between 2-1000''. After considering a range of dust models, each assumed to be smoothly distributed with or without a dense cloud along the line of sight, the results show that there is no evidence in this data for a dense cloud near the source, as suggested by Xiang et al. (2005). Finally, although no model leads to formally acceptable results, the Weingartner & Draine (2001) and nearly all of the composite grain models from Zubko, Dwek & Arendt (2004) give poor fits.

Randall K. Smith

2008-05-04T23:59:59.000Z

375

Small-angle x-ray scattering measurements of the microstructure of liquid helium mixtures adsorbed in aerogel  

SciTech Connect (OSTI)

Small-angle x-ray scattering (SAXS) was used to measure the microstructure of isotopic mixtures of {sup 3}He and {sup 4}He adsorbed into silica aerogels as a function of temperature and {sup 3}He concentration. The SAXS measurements could be well described by the formation of a nearly pure film of {sup 4}He which separates from the bulk mixture onto the aerogel strands and which thickens with decreasing temperature. Previous observations of a superfluid {sup 3}He-rich phase are consistent with superfluidity existing within this film phase. Observed differences between different density aerogels are explained in terms of the depletion of {sup 4}He from the bulk mixture due to film formation.

Lurio, L. B.; Mulders, N.; Paetkau, M.; Chan, M. H. W.; Mochrie, S. G. J. [Department of Physics, Northern Illinois University, DeKalb, Illinois 60115 (United States); Department of Physics, University of Delaware, Newark, Delaware 19716 (United States); Department of Physics and Astronomy, Okanagan College, British Columbia V1Y4X8 (Canada); Department of Physics, Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Department of Physics, Yale University, New Haven, Connecticut 06511 (United States)

2007-07-15T23:59:59.000Z

376

Liquid 1-propanol studied by neutron scattering, near-infrared, and dielectric spectroscopy  

SciTech Connect (OSTI)

Liquid monohydroxy alcohols exhibit unusual dynamics related to their hydrogen bonding induced structures. The connection between structure and dynamics is studied for liquid 1-propanol using quasi-elastic neutron scattering, combining time-of-flight and neutron spin-echo techniques, with a focus on the dynamics at length scales corresponding to the main peak and the pre-peak of the structure factor. At the main peak, the structural relaxation times are probed. These correspond well to mechanical relaxation times calculated from literature data. At the pre-peak, corresponding to length scales related to H-bonded structures, the relaxation times are almost an order of magnitude longer. According to previous work [C. Gainaru, R. Meier, S. Schildmann, C. Lederle, W. Hiller, E. Rssler, and R. Bhmer, Phys. Rev. Lett. 105, 258303 (2010)] this time scale difference is connected to the average size of H-bonded clusters. The relation between the relaxation times from neutron scattering and those determined from dielectric spectroscopy is discussed on the basis of broad-band permittivity data of 1-propanol. Moreover, in 1-propanol the dielectric relaxation strength as well as the near-infrared absorbance reveal anomalous behavior below ambient temperature. A corresponding feature could not be found in the polyalcohols propylene glycol and glycerol.

Sillrn, P.; Matic, A.; Karlsson, M. [Department of Applied Physics, Chalmers University of Technology, SE-412 96 Gteborg (Sweden)] [Department of Applied Physics, Chalmers University of Technology, SE-412 96 Gteborg (Sweden); Koza, M.; Maccarini, M.; Fouquet, P. [Institut Laue Langevin, 6, rue Jules Horowitz, BP 156, 38042 Grenoble Cedex 9 (France)] [Institut Laue Langevin, 6, rue Jules Horowitz, BP 156, 38042 Grenoble Cedex 9 (France); Gtz, M.; Bauer, Th.; Gulich, R.; Lunkenheimer, P.; Loidl, A. [Experimental Physics V, University of Augsburg, 86135 Augsburg (Germany)] [Experimental Physics V, University of Augsburg, 86135 Augsburg (Germany); Mattsson, J. [School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT (United Kingdom)] [School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT (United Kingdom); Gainaru, C.; Vynokur, E.; Schildmann, S.; Bauer, S.; Bhmer, R. [Fakultt fr Physik, Technische Universitt Dortmund, 44221 Dortmund (Germany)] [Fakultt fr Physik, Technische Universitt Dortmund, 44221 Dortmund (Germany)

2014-03-28T23:59:59.000Z

377

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

E-Print Network [OSTI]

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

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

2012-09-04T23:59:59.000Z

378

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

E-Print Network [OSTI]

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

Kazuhiro Tominaga; Motoyuki Saijo; Kei-ichi Maeda

1999-09-20T23:59:59.000Z

379

Search for Anomalous Scattering of keV Neutrons from H2O-D2O Mixtures R. Moreh,1,2,* R. C. Block,2  

E-Print Network [OSTI]

Search for Anomalous Scattering of keV Neutrons from H2O-D2O Mixtures R. Moreh,1,2,* R. C. Block,2 (Received 20 January 2005; published 12 May 2005) We measured the neutron scattering intensities from pure Linac and the final energy of the scattered neutrons was fixed at 24.3 keV using a 20 cm thick pure iron

Danon, Yaron

380

Independent measurement of the neutrino mixing angle theta(13) via neutron capture on hydrogen at Daya Bay  

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

A new measurement of the ?13 mixing angle has been obtained at the Daya Bay Reactor Neutrino Experiment via the detection of inverse beta decays tagged by neutron capture on hydrogen. The antineutrino events for hydrogen capture are distinct from those for gadolinium capture with largely different systematic uncertainties, allowing a determination independent of the gadolinium-capture result and an improvement on the precision of the ?13 measurement. With a 217-day antineutrino data set obtained with six antineutrino detectors and from six 2.9 GWth reactors, the rate deficit observed at the far hall is interpreted as sin22?13=0.0830.018 in the three-flavor oscillation model. When combined with the gadolinium-capture result from Daya Bay, we obtain sin22?13=0.0890.008 as the final result for the six-antineutrino-detector configuration of the Daya Bay experiment.

Jaffe D. E.; Jaffe, D.E., et al. Daya Bay Collaboration

2014-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "angle neutron scattering" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Neutron Transmission, Capture, and Scattering Measurements at the Gaerttner LINAC Center Y. Danon, L. Liu, E.J. Blain, A.M. Daskalakis, B.J. McDermott, K. Ramic, C.R. Wendorff  

E-Print Network [OSTI]

Neutron Transmission, Capture, and Scattering Measurements at the Gaerttner LINAC Center Y. Danon . As the energy of the neutrons increases to the keV region neutron resonance scattering becomes dominant compared to capture, and scattered neutrons can penetrate the 10 B4C liner of the NaI capture detector and get

Danon, Yaron

382

Exploration of deeply virtual Compton scattering on the neutron in the Hall A of Jefferson Laboratory  

SciTech Connect (OSTI)

Generalized Parton Distributions (GPDs) are universal functions which provide a comprehensive description of hadron properties in terms of quarks and gluons. Deeply Virtual Compton Scattering (DVCS) is the simplest hard exclusive process involving GPDs. In particular, the DVCS on the neutron is mostly sensitive to E, the less constrained GPD, wich allows to access to the quark angular momentum. The first dedicated DVCS experiment on the neutron ran in the Hall A of Jefferson Lab in fall 2004. The high luminosity of the experiment and the resulting background rate recquired specific devices which are decribed in this document. The analysis methods and the experiment results, leading to preliminary constraints on the GPD E, are presented.

Malek Mazouz

2006-12-08T23:59:59.000Z

383

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

SciTech Connect (OSTI)

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

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

2012-03-05T23:59:59.000Z

384

Deep Inelastic Scattering from A=3 Nuclei and the Neutron Structure Function  

SciTech Connect (OSTI)

We present a comprehensive analysis of deep inelastic scattering from {sup 3}He and {sup 3}H, focusing in particular on the extraction of the free neutron structure function, F{sup n}{sub 2}. Nuclear corrections are shown to cancel to within 1-2% for the isospin-weighted ratio of {sup 3}He to {sup 3}H structure functions, which leads to more than an order of magnitude improvement in the current uncertainty on the neutron to proton ratio F{sup 2n}{sub 2}/F{sup p}{sub 2} at large x. Theoretical uncertainties originating tom the nuclear wave function, including possible non-nucleonic components, are evaluated. Measurement of the {sup 3}He and {sup 3}H structure functions will, in addition, determine the magnitude of the EMC effect in all A [lte] 3 nuclei.

I. Afnan; F. Bissey; J. Gomez; A. Katramatou; S. Liuti; W. Melnitchouk; G. Petratos; A.W. Thomas

2003-03-01T23:59:59.000Z

385

X-ray and neutron scattering studies of the Rb?MnF? and Cu???xMgx̳GeO? in an external magnetic field  

E-Print Network [OSTI]

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

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

2001-01-01T23:59:59.000Z

386

Deeply virtual Compton scattering on longitudinally polarized protons and neutrons at CLAS  

E-Print Network [OSTI]

This paper focuses on a measurement of deeply virtual Compton scattering (DVCS) performed at Jefferson Lab using a nearly-6-GeV polarized electron beam, two longitudinally polarized (via DNP) solid targets of protons (NH3) and deuterons (ND3) and the CEBAF Large Acceptance Spectrometer. Here, preliminary results for target-spin asymmetries and double (beam-target) asymmetries for proton DVCS, as well as a very preliminary extraction of beam-spin asymmetry for neutron DVCS, are presented and linked to Generalized Parton Distributions.

Silvia Niccolai; for the CLAS Collaboration

2012-07-13T23:59:59.000Z

387

Deeply virtual Compton scattering on longitudinally polarized protons and neutrons at CLAS  

SciTech Connect (OSTI)

This paper focuses on a measurement of deeply virtual Compton scattering (DVCS) performed at Jefferson Lab using a nearly-6-GeV polarized electron beam, two longitudinally polarized (via DNP) solid targets of protons (NH{sub 3}) and deuterons (ND{sub 3}) and the CEBAF Large Acceptance Spectrometer. Here, preliminary results for target-spin asymmetries and double (beam-target) asymmetries for proton DVCS, as well as a very preliminary extraction of beam-spin asymmetry for neutron DVCS, are presented and linked to Generalized Parton Distributions.

Silvia Niccolai

2012-04-01T23:59:59.000Z

388

Observation of spin-wave dispersion in Nd-Fe-B magnets using neutron Brillouin scattering  

SciTech Connect (OSTI)

The low-energy spin-wave dispersion in polycrystalline Nd-Fe-B magnets was observed using neutron Brillouin scattering (NBS). Low-energy spin-wave excitations for the lowest acoustic spin-wave mode were clearly observed. From the spin-wave dispersion, we were able to determine the spin-wave stiffness constant D{sub sw} (100.0??4.9?meV.{sup 2}) and the exchange stiffness constant A (6.6 0.3 pJ/m)

Ono, K., E-mail: kanta.ono@kek.jp; Inami, N.; Saito, K.; Takeichi, Y.; Kawana, D.; Yokoo, T.; Itoh, S. [Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801 (Japan); Yano, M.; Shoji, T.; Manabe, A.; Kato, A. [Toyota Motor Corporation, Toyota, Aichi 471-8571 (Japan); Kaneko, Y. [Toyota Central R and D Labs. Inc., Aichi 480-1192 (Japan)

2014-05-07T23:59:59.000Z

389

Neutron-Proton Scattering in the Context of the $d^*$(2380) Resonance  

E-Print Network [OSTI]

New data on quasifree polarized neutron-proton scattering, in the region of the recently observed $d^*$ resonance structure, have been obtained by exclusive and kinematically complete high-statistics measurements with WASA at COSY. This paper details the determination of the beam polarization, checks of the quasifree character of the scattering process, on all obtained $A_y$ angular distributions and on the new partial-wave analysis, which includes the new data producing a resonance pole in the $^3D_3$-$^3G_3$ coupled partial waves at ($2380\\pm10 - i40\\pm5$) MeV -- in accordance with the $d^*$ dibaryon resonance hypothesis. The effect of the new partial-wave solution on the description of total and differential cross section data as well as specific combinations of spin-correlation and spin-transfer observables available from COSY-ANKE measurements at $T_d$ = 2.27 GeV is discussed.

P. Adlarson; W. Augustyniak; W. Bardan; M. Bashkanov; F. S. Bergmann; M. Ber?owski; H. Bhatt; M. Bscher; H. Caln; I. Ciepa?; H. Clement; D. Coderre; E. Czerwi?ski; K. Demmich; E. Doroshkevich; R. Engels; A. Erven; W. Erven; W. Eyrich; P. Fedorets; K. Fhl; K. Fransson; F. Goldenbaum; P. Goslawski; A. Goswami; K. Grigoryev; C. --O. Gullstrm; F. Hauenstein; L. Heijkenskjld; V. Hejny; M. Hodana; B. Histad; N. Hsken; A. Jany; B. R. Jany; L. Jarczyk; T. Johansson; B. Kamys; G. Kemmerling; F. A. Khan; A. Khoukaz; D. A. Kirillov; S. Kistryn; H. Kleines; B. K?os; M. Krapp; W. Krzemie?; P. Kulessa; A. Kup??; K. Lalwani; D. Lersch; B. Lorentz; A. Magiera; R. Maier; P. Marciniewski; B. Maria?ski; M. Mikirtychiants; H. --P. Morsch; P. Moskal; H. Ohm; I. Ozerianska; E. Perez del Rio; N. M. Piskunov; P. Podkopa?; D. Prasuhn; A. Pricking; D. Pszczel; K. Pysz; A. Pyszniak; C. F. Redmer; J. Ritman; A. Roy; Z. Rudy; S. Sawant; S. Schadmand; T. Sefzick; V. Serdyuk; R. Siudak; T. Skorodko; M. Skurzok; J. Smyrski; V. Sopov; R. Stassen; J. Stepaniak; E. Stephan; G. Sterzenbach; H. Stockhorst; H. Strher; A. Szczurek; A. Tschner; A. Trzci?ski; R. Varma; G. J. Wagner; M. Wolke; A. Wro?ska; P. Wstner; P. Wurm; A. Yamamoto; L. Yurev; J. Zabierowski; M. J. Zieli?ski; A. Zink; J. Z?oma?czuk; P. {?}upra?ski; M. {?}urek; R. L. Workman; W. J. Briscoe; I. I. Strakovsky

2014-08-21T23:59:59.000Z

390

Neutron-Proton Scattering in the Context of the $d^*$(2380) Resonance  

E-Print Network [OSTI]

New data on quasifree polarized neutron-proton scattering, in the region of the recently observed $d^*$ resonance structure, have been obtained by exclusive and kinematically complete high-statistics measurements with WASA at COSY. This paper details the determination of the beam polarization, checks of the quasifree character of the scattering process, on all obtained $A_y$ angular distributions and on the new partial-wave analysis, which includes the new data producing a resonance pole in the $^3D_3$-$^3G_3$ coupled partial waves at ($2380\\pm10 - i40\\pm5$) MeV -- in accordance with the $d^*$ dibaryon resonance hypothesis. The effect of the new partial-wave solution on the description of total and differential cross section data as well as specific combinations of spin-correlation and spin-transfer observables available from COSY-ANKE measurements at $T_d$ = 2.27 GeV is discussed.

Adlarson, P; Bardan, W; Bashkanov, M; Bergmann, F S; Ber?owski, M; Bhatt, H; Bscher, M; Caln, H; Ciepa?, I; Clement, H; Coderre, D; Czerwi?ski, E; Demmich, K; Doroshkevich, E; Engels, R; Erven, A; Erven, W; Eyrich, W; Fedorets, P; Fhl, K; Fransson, K; Goldenbaum, F; Goslawski, P; Goswami, A; Grigoryev, K; Gullstrm, C --O; Hauenstein, F; Heijkenskjld, L; Hejny, V; Hodana, M; Histad, B; Hsken, N; Jany, A; Jany, B R; Jarczyk, L; Johansson, T; Kamys, B; Kemmerling, G; Khan, F A; Khoukaz, A; Kirillov, D A; Kistryn, S; Kleines, H; K?os, B; Krapp, M; Krzemie?, W; Kulessa, P; Kup??, A; Lalwani, K; Lersch, D; Lorentz, B; Magiera, A; Maier, R; Marciniewski, P; Maria?ski, B; Mikirtychiants, M; Morsch, H --P; Moskal, P; Ohm, H; Ozerianska, I; del Rio, E Perez; Piskunov, N M; Podkopa?, P; Prasuhn, D; Pricking, A; Pszczel, D; Pysz, K; Pyszniak, A; Redmer, C F; Ritman, J; Roy, A; Rudy, Z; Sawant, S; Schadmand, S; Sefzick, T; Serdyuk, V; Siudak, R; Skorodko, T; Skurzok, M; Smyrski, J; Sopov, V; Stassen, R; Stepaniak, J; Stephan, E; Sterzenbach, G; Stockhorst, H; Strher, H; Szczurek, A; Tschner, A; Trzci?ski, A; Varma, R; Wagner, G J; Wolke, M; Wro?ska, A; Wstner, P; Wurm, P; Yamamoto, A; Yurev, L; Zabierowski, J; Zieli?ski, M J; Zink, A; Z?oma?czuk, J; {?}upra?ski, P; {?}urek, M; Workman, R L; Briscoe, W J; Strakovsky, I I

2014-01-01T23:59:59.000Z

391

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

E-Print Network [OSTI]

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

Dean Lee; Thomas Schaefer

2005-09-07T23:59:59.000Z

392

Structure of low-density nanoporous dielectrics revealed by low-vacuum electron microscopy and small-angle x-ray scattering  

SciTech Connect (OSTI)

We use low-vacuum scanning electron microscopy to image directly the ligament and pore size and shape distributions of representative aerogels over a wide range of length scales ({approx} 10{sup 0}-10{sup 5} nm). The images are used for unambiguous, real-space interpretation of small-angle scattering data for these complex nanoporous systems.

Kucheyev, S O; Toth, M; Baumann, T F; Hamza, A V; Ilavsky, J; Knowles, W R; Thiel, B L; Tileli, V; van Buuren, T; Wang, Y M; Willey, T M

2006-06-05T23:59:59.000Z

393

Electron Boltzmann kinetic equation averaged over fast electron bouncing and pitch-angle scattering for fast modeling of electron cyclotron resonance discharge  

E-Print Network [OSTI]

cyclotron resonance ECR heating. Typically, the operating gas pressures in ECR reactors range from 10 5Electron Boltzmann kinetic equation averaged over fast electron bouncing and pitch-angle scattering for fast modeling of electron cyclotron resonance discharge I. Kaganovich,1,* M. Misina,2, S. V. Berezhnoi

Kaganovich, Igor

394

Excess wing in glass-forming glycerol and LiCl-glycerol mixtures detected by neutron scattering  

E-Print Network [OSTI]

The relaxational dynamics in glass-forming glycerol and glycerol mixed with LiCl is in-vestigated using different neutron scattering techniques. The performed neutron spin-echo experiments, which extend up to relatively long relaxation-time scales of the order of 10 ns, should allow for the detection of contributions from the so-called excess wing. This phenomenon, whose microscopic origin is controversially discussed, arises in a variety of glass formers and, until now, was almost exclusively investigated by dielectric spectros-copy and light scattering. Here we show that the relaxational process causing the excess wing also can be detected by neutron scattering, which directly couples to density fluctua-tions.

S. Gupta; N. Arend; P. Lunkenheimer; A. Loidl; L. Stingaciu; N. Jalarvo; E. Mamontov; M. Ohl

2014-03-08T23:59:59.000Z

395

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

E-Print Network [OSTI]

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

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

2013-04-03T23:59:59.000Z

396

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

E-Print Network [OSTI]

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

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

2015-02-05T23:59:59.000Z

397

Neutron Scattering Facility for Characterization of CRESST and EURECA Detectors at mK Temperatures  

E-Print Network [OSTI]

CRESST (Cryogenic Rare Event Search with Superconducting Thermometers) is an experiment located at the Gran Sasso underground laboratory and aimed at the direct detection of dark matter in the form of WIMPs. The setup has just completed a one year commissioning run in 2007 and is presently starting a physics run with an increased target mass. Scintillating $\\mathrm{CaWO_4}$ single crystals, operated at temperatures of a few millikelvin, are used as target to detect the tiny nuclear recoil induced by a WIMP. The powerful background identification and rejection of $\\alpha$, e$^{-}$ and $\\gamma$ events is realized via the simultaneous measurement of a phonon and a scintillation signal generated in the $\\mathrm{CaWO_4}$ crystal. However, neutrons could still be misidentified as a WIMP signature. Therefore, a detailed understanding of the individual recoil behaviour in terms of phonon generation and scintillation light emission due to scattering on Ca, O or W nuclei, respectively, is mandatory. The only setup which allows to perform such measurements at the operating temperature of the CRESST detectors has been installed at the Maier-Leibnitz-Accelerator Laboratory in Garching and is presently being commissioned. The design of this neutron scattering facility is such that it can also be used for other target materials, e.g. $\\mathrm{ZnWO_4}$, $\\mathrm{PbWO_4}$ and others as foreseen in the framework of the future multitarget tonne-scale experiment EURECA (European Underground Rare Event Calorimeter Array).

J. -C. Lanfranchi; C. Ciemniak; C. Coppi; F. von Feilitzsch; A. Gtlein; H. Hagn; C. Isaila; J. Jochum; M. Kimmerle; S. Pfister; W. Potzel; W. Rau; S. Roth; K. Rottler; C. Sailer; S. Scholl; I. Usherov; W. Westphal

2008-10-01T23:59:59.000Z

398

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

E-Print Network [OSTI]

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

unknown authors

399

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

SciTech Connect (OSTI)

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

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

2013-07-28T23:59:59.000Z

400

Sub-second Morphological Changes in Nafion during Water Uptake Detected by Small-Angle X-Ray Scattering  

SciTech Connect (OSTI)

The ability of Nafion membrane to absorb water rapidly and create a network of hydrated interconnected water domains provides this material with an unmatched ability to conduct ions through a chemically and mechanically robust membrane. The morphology and composition of these hydrated membranes significantly affects their transport properties and performance. This work demonstrates that differences in interfacial interactions between the membranes exposed to vapor or liquid water can cause significant changes in kinetics of water uptake. In-situ small-angle X-ray scattering (SAXS) experiments captured the rapid swelling of the membrane in liquid water with nanostructure rearrangement on the order of seconds. For membranes in contact with water vapor, morphological changes are four-orders-of-magnitude slower than in liquid water, suggesting that interfacial resistance limits the penetration of water into the membrane. Also, upon water absorption from liquid water, a structural rearrangement from a distribution of spherical and cylindrical domains to exclusively cylindrical-like domains is suggested. These differences in water-uptake kinetics and morphology provide a new perspective into Schroeders Paradox, which dictates different water contents for vaporand liquid-equilibrated ionomers at unit activity. The findings of this work provide critical insights into the fast kinetics of water absorption of Nafion membrane, which can aid in the design of energy conversion devices that operate under frequent changes in environmental conditions.

Kusoglu, Ahmet; Modestino, Miguel A.; Hexemer, Alexander; Segalman, Rachel A.; Weber, Adam Z.

2011-09-30T23:59:59.000Z

Note: This page contains sample records for the topic "angle neutron scattering" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Protein Folding Dynamics Detected By Time-Resolved Synchrotron X-ray Small-Angle Scattering Technique  

SciTech Connect (OSTI)

The polypeptide collapse is an essential dynamics in protein folding. To understand the mechanism of the collapse, in situ observation of folding by various probes is necessary. The changes in secondary and tertiary structures in the folding process of globular proteins, whose chain lengths are less than 300 polypeptides, were observed by circular dichrosim and intrinsic fluorescence spectroscopies, respectively. On the other hand, those in protein compactness could be only detected by using time-resolved synchrotron x-ray small-angle scattering technique. The observed dynamics for several proteins with different topologies suggested a common folding mechanism termed 'collapse and search' dynamics, in which the polypeptide collapse precedes the formation of the native contact formation. In 'collapse and search' dynamics, the most outstanding feature lied in the compactness of the initial intermediates. The collapsed intermediates demonstrated the scaling relationship between radius of gyration (Rg) and chain length with a scaling exponent of 0.35 {+-} 0.11, which is close to the value (1/3) predicted by mechano-statistical theory for the collapsed globules of polymers in poor solvent. Thus, it was suggested that the initial collapse is caused by the coil-globule transition of polymers. Since the collapse is essential to the folding of larger proteins, further investigations on the collapse likely lead to an important insight into the protein folding phenomena.

Fujisawa, Tetsuro; Takahashi, Satoshi [RIKEN Harima Institute, SPring-8 Center, Laboratory for Biometal Science, Hyogo 679-5148 (Japan); Institute for Protein Research, Osaka University Suita Osaka 565-0871/CREST, JST (Japan)

2007-03-30T23:59:59.000Z

402

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

E-Print Network [OSTI]

Your access to the Oak Ridge National Laboratory (ORNL) is approved beginning Sunday, June 20, 2010, Neutron Scattering Science User Office Oak Ridge National Laboratory ORNL Neutron Scattering School June 20-25, 2010 Oak Ridge National Laboratory Oak Ridge, Tennessee #12;

Pennycook, Steve

403

Response to 'Comment on 'Elastic incoherent neutron scattering operating by varying instrumental energy resolution: Principle, simulations, and experiments of the resolution elastic neutron scattering (RENS)'' [Rev. Sci. Instrum. 83, 107101 (2012)  

SciTech Connect (OSTI)

Recently [S. Magazu et al., Rev. Sci. Instrum. 82, 105115 (2011)] we have proposed a new method for characterizing, by neutron scattering, the dynamical properties of complex material systems, such as, the ones of interest in the biophysical field. This approach called Resolution Elastic Neutron Scattering, in short RENS, is based on the detection of the elastically scattered neutron intensity as a function of the instrumental energy resolution. By experimental, theoretical, and numerical findings, we have pointed out that an inflection point occurs in the elastic intensity when the system relaxation time approaches the instrumental energy resolution time. This approach, differently from quasi-elastic neutron scattering (QENS), gives the chance to evaluate the system relaxation times without using pre-defined models that can be wrong and/or misleading. Here, we reply to a Comment on the above-mentioned main paper in which Wuttke proposes a different approach to evaluate the above-mentioned inflection point; on this regard, it should be noticed that the existence of the inflection point, which is the main topic of our work, is not questioned and that the approach proposed by Wuttke in the Comment, although valid for a class of dynamical processes, is not applicable when different and distinct processes occur simultaneously at different time scale.

Magazu, Salvatore; Migliardo, Federica; Benedetto, Antonio [Dipartimento di Fisica, Universita di Messina, C.da Papardo n Degree-Sign 31, P.O. Box 55, Vill. S. Agata 98166 Messina (Italy)

2012-10-15T23:59:59.000Z

404

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

SciTech Connect (OSTI)

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

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

2007-11-01T23:59:59.000Z

405

National School on Neutron and X-ray Scattering Argonne National Laboratory and Oak Ridge National Laboratory  

E-Print Network [OSTI]

National School on Neutron and X-ray Scattering Argonne National Laboratory and Oak Ridge National Laboratory June 12-26, 2010 Schedule for Saturday, June 12, 2010 School participants arrive at Argonne and check in at the Argonne Guest House, Building 460. 3:00 PM until 8:00 PM - Registration and informal get

Pennycook, Steve

406

National School on Neutron and X-ray Scattering Oak Ridge National Laboratory and Argonne National Laboratory  

E-Print Network [OSTI]

National School on Neutron and X-ray Scattering Oak Ridge National Laboratory and Argonne National Laboratory May 30-June 14, 2009 Air Travel Arrangements The Argonne Division of Educational Programs has made to Argonne - June 8 through and including June 13, 2009 Daily bus transportation will be provided for School

Pennycook, Steve

407

A cryogenic high pressure cell for inelastic neutron scattering measurements of quantum fluids and solids  

SciTech Connect (OSTI)

We present our new development of a high pressure cell for inelastic neutron scattering measurements of helium at ultra-low temperatures. The cell has a large sample volume of ~140 cm3, and a working pressure of ~70 bar, with a relatively thin wall-thickness (1.1 mm) - thanks to the high yield strength aluminum used in the design. Two variants of this cell have been developed; one with permanently joined components using electron-beam welding and explosion welding, methods that have little or no impact on the global heat treatment of the cell, and another with modular and interchangeable components, which include a capacitance pressure gauge, that can be sealed using traditional indium wire technique. The performance of the cell has been tested in recent measurements on superfluid liquid helium near the solidification line.

Carmichael, Justin R [ORNL; Omar Diallo, Souleymane [ORNL

2013-01-01T23:59:59.000Z

408

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

SciTech Connect (OSTI)

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

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

2014-06-01T23:59:59.000Z

409

Inelastic neutron scattering of a quantum translator-rotator encapsulated in a closed fullerene cage: Isotope effects and translation-rotation coupling in H2@C60 and HD@C60  

E-Print Network [OSTI]

Inelastic neutron scattering of a quantum translator-rotator encapsulated in a closed fullerene, New York 10027, USA Received 1 July 2010; published 20 August 2010 We report an inelastic neutron-scattering inelastic neutron scattering INS ,6 and specific heat7 inves- tigations have recently been reported

Turro, Nicholas J.

410

Mass fractal characteristics of wet sonogels as determined by small-angle x-ray scattering and differential scanning calorimetry  

SciTech Connect (OSTI)

Low density silica sonogels were prepared from acid sonohydrolysis of tetraethoxysilane. Wet gels were studied by small-angle x-ray scattering (SAXS) and differential scanning calorimetry (DSC). The DSC tests were carried out under a heating rate of 2 deg. C/min from -120 deg. C up to 30 deg. C. Aerogels were obtained by CO{sub 2} supercritical extraction and characterized by nitrogen adsorption and SAXS. The DSC thermogram displays two distinct endothermic peaks. The first, a broad peak extending from about -80 deg. C up to practically 0 deg. C, was associated to the melting of ice nanocrystals with a crystal size distribution with 'pore' diameter ranging from 1 or 2 nm up to about 60 nm, as estimated from Thomson's equation. The second, a sharp peak with onset temperature close to 0 deg. C, was attributed to the melting of macroscopic crystals. The DSC incremental 'nanopore' volume distribution is in reasonable agreement with the incremental pore volume distribution of the aerogel as determined from nitrogen adsorption. No macroporosity was detected by nitrogen adsorption, probably because the adsorption method applies stress on the sample during measurement, leading to a underestimation of pore volume, or because often positive curvature of the solid surface is in aerogels, making the nitrogen condensation more difficult. According to the SAXS results, the solid network of the wet gels behaves as a mass fractal structure with mass fractal dimension D=2.20{+-}0.01 in a characteristic length scale below {xi}=7.9{+-}0.1 nm. The mass fractal characteristics of the wet gels have also been probed from DSC data by means of an earlier applied modeling for generation of a mass fractal from the incremental ''pore'' volume distribution curves. The results are shown to be in interesting agreement with the results from SAXS.

Vollet, D. R.; Donatti, D. A.; Ibanez Ruiz, A.; Gatto, F. R. [Departamento de Fisica, Unesp-Univerisdade Estadual Paulista, IGCE, P.O. Box 178 CEP 13500-970 Rio Claro, SP (Brazil)

2006-07-01T23:59:59.000Z

411

Mass fractal characteristics of silica sonogels as determined by small-angle x-ray scattering and nitrogen adsorption  

SciTech Connect (OSTI)

A sample series of silica sonogels was prepared using different water-tetraethoxysilane molar ratio (r{sub w}) in the gelation step of the process in order to obtain aerogels with different bulk densities after the supercritical drying. The samples were analyzed by means of small-angle x-ray-scattering (SAXS) and nitrogen-adsorption techniques. Wet sonogels exhibit mass fractal structure with fractal dimension D increasing from {approx}2.1 to {approx}2.4 and mass-fractal correlation length {xi} diminishing from {approx}13 nm to {approx}2 nm, as r{sub w} is changed in the nominal range from 66 to 6. The process of obtaining aerogels from sonogels and heat treatment at 500 deg. C, in general, increases the mass-fractal dimension D, diminishes the characteristic length {xi} of the fractal structure, and shortens the fractal range at the micropore side for the formation of a secondary structured particle, apparently evolved from the original wet structure at a high resolution level. The overall mass-fractal dimension D of aerogels was evaluated as {approx}2.4 and {approx}2.5, as determined from SAXS and from pore-size distribution by nitrogen adsorption, respectively. The fine structure of the 'secondary particle' developed in the obtaining of aerogels could be described as a surface-mass fractal, with the correlated surface and mass-fractal dimensions decreasing from {approx}2.4 to {approx}2.0 and from {approx}2.7 to {approx}2.5, respectively, as the aerogel bulk density increases from 0.25 (r{sub w}=66) up to 0.91 g/cm{sup 3} (r{sub w}=6)

Donatti, D.A.; Vollet, D.R.; Ibanez Ruiz, A.; Mesquita, A.; Silva, T.F.P. [Unesp-Universidade Estadual Paulista, IGCE, Departamento de Fisica, P.O. Box 178 CEP, 13500-970 Rio Claro, Sao Paulo (Brazil)

2005-01-01T23:59:59.000Z

412

Nanoparticle shape reconstruction by solving the direct and inverse small-angle scattering problems for a unit potential localized inside a torus  

SciTech Connect (OSTI)

The simplest doubly connected surface of revolution (torus) is used as an example to demonstrate the possibility of stable reconstruction a three-dimensional homogeneous body defined by a unit potential U(r) using a spherically averaged small-angle scattering (SAS) curve I(s). Annealing Monte Carlo simulations are performed without using prior information about nanoparticle shape and size. Exact and approximate expressions are obtained for the form factor of a torus. It is shown graphically that the exact and approximate SAS form-factor curves agree for an experimentally accessible scattering region. Examples are given.

Amarantov, S. V. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)], E-mail: amarantov_s@mail.ru

2009-04-15T23:59:59.000Z

413

The reflection of very cold neutrons from diamond powder nanoparticles  

E-Print Network [OSTI]

We study possibility of efficient reflection of very cold neutrons (VCN) from powders of nanoparticles. In particular, we measured the scattering of VCN at a powder of diamond nanoparticles as a function of powder sample thickness, neutron velocity and scattering angle. We observed extremely intense scattering of VCN even off thin powder samples. This agrees qualitatively with the model of independent nanoparticles at rest. We show that this intense scattering would allow us to use nanoparticle powders very efficiently as the very first reflectors for neutrons with energies within a complete VCN range up to $10^{-4}$ eV.

V. V. Nesvizhevsky; E. V. Lychagin; A. Yu. Muzychka; A. V. Strelkov; G. Pignol; K. V. Protasov

2008-05-17T23:59:59.000Z

414

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

SciTech Connect (OSTI)

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

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

2012-03-15T23:59:59.000Z

415

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

SciTech Connect (OSTI)

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

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

1995-12-31T23:59:59.000Z

416

Characterization of a Thermo Scientific D711 D-T Neutron Generator Located in a Low-Scatter Facility  

SciTech Connect (OSTI)

A dosimetry experiment used to measure the neutron flux and spectrum of a D-T neutron generator is presented. The D-T generator at Pacific Northwest National Laboratory is installed in the middle of a large room to minimize scatter of neutrons back to the sample. The efficacy of maintaining a pure fast neutron field for the sample is investigated. Twenty-one positions within 13 cm of the neutron source contained foils or wires of Fe, Ni, Al with additional Au, and In monitors at some locations. Spectral adjustment of the neutron flux at each position based on measured reaction rates and theoretical Monte Carlo calculations show that at least 99.1% of the spectrum lies above 110 keV for all measured positions, and neutrons above 14 MeV can account for as much as 91% at locations along the axis of the generator and close to the source. The 14 MeV component drops to 77% in radial positions far from the source. The largest total flux observed was 8.29E+08 n/cm2-s (1.4%) in the center of the cooling cap, although additional experiments have shown this value could be as high as 1.20E+09 n/cm2-s.

Hayes, John W.; Finn, Erin C.; Greenwood, Lawrence R.; Wittman, Richard S.

2014-03-21T23:59:59.000Z

417

Role of Triple Phonon Excitations on Large Angle Quasi-elastic Scattering of {sup 54}Cr+{sup 208}Pb System  

SciTech Connect (OSTI)

We study the large angle quasi-elastic scattering of {sup 54}Cr+{sup 208}Pb system in terms of the full-order coupled-channels formalism. We especially investigate the role of single, double and triple phonon excitations on quasi-elastic scattering cross section as well as quasi-elastic barrier distribution of this system for which the experimental data have been measured. It is shown that the triple phonon excitations both in {sup 54}Cr and {sup 208}Pb nuclei seem to be needed by the present coupled-channels calculations in order to reproduce the experimental data of quasi-elastic cross section and barrier distribution for the {sup 54}Cr+{sup 208}Pb system. We also show that the standard value of the surface diffuseness parameter for the nuclear potential a = 0.63 fm, is preferred by the experimental quasi-elastic scattering data for this system.

Zamrun, Muhammad F. [Department of Physics, University of Malaya, Kuala Lumpur 50603 (Malaysia); Jurusan Fisika FMIPA, Universitas Haluoleo, Kendari, Sulawesi Tenggara 93232 (Indonesia); Kasim, Hasan Abu [Department of Physics, University of Malaya, Kuala Lumpur 50603 (Malaysia)

2011-03-30T23:59:59.000Z

418

Neutron interferometric measurement of the scattering length difference between the triplet and singlet states of n-$^3$He  

E-Print Network [OSTI]

We report a determination of the n-$^3$He scattering length difference $\\Delta b^{\\prime} = b_{1}^{\\prime}-b_{0}^{\\prime} = $ ($-5.411$ $\\pm$ $0.031$ (statistical) $\\pm$ $0.039$ (systematic)) fm between the triplet and singlet states using a neutron interferometer. This revises our previous result $\\Delta b^{\\prime} = $ (-5.610 $\\pm$ $0.027$ (statistical) $\\pm$ $0.032$ (systematic) fm obtained using the same technique in 2008. This revision is due to a re-analysis of the 2008 experiment that includes a more robust treatment of the phase shift caused by magnetic field gradients near the $^3$He cell. Furthermore, we more than doubled our original data set from 2008 by acquiring six months of additional data in 2013. Both the new data set and a re-analysis of the older data are in good agreement. Scattering lengths of low Z isotopes are valued for use in few-body nuclear effective field theories, provide important tests of modern nuclear potential models and in the case of $^3$He aid in the interpretation of neutron scattering from quantum liquids. The difference $\\Delta b^{\\prime}$ was determined by measuring the relative phase shift between two incident neutron polarizations caused by the spin-dependent interaction with a polarized $^3$He target. The target $^3$He gas was sealed inside a small, flat windowed glass cell that was placed in one beam path of the interferometer. The relaxation of $^3$He polarization was monitored continuously with neutron transmission measurements. The neutron polarization and spin flipper efficiency were determined separately using $^3$He analyzers and two different polarimetry analysis methods. A summary of the measured scattering lengths for n-$^3$He with a comparison to nucleon interaction models is given.

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

2014-09-30T23:59:59.000Z

419

Solution Structure of the 128 kDa Enzyme I Dimer from Escherichia coli and Its 146 kDa Complex with HPr Using Residual Dipolar Couplings and Small- and Wide-Angle X-ray Scattering  

SciTech Connect (OSTI)

The solution structures of free Enzyme I (EI, {approx}128 kDa, 575 x 2 residues), the first enzyme in the bacterial phosphotransferase system, and its complex with HPr ({approx}146 kDa) have been solved using novel methodology that makes use of prior structural knowledge (namely, the structures of the dimeric EIC domain and the isolated EIN domain both free and complexed to HPr), combined with residual dipolar coupling (RDC), small- (SAXS) and wide- (WAXS) angle X-ray scattering and small-angle neutron scattering (SANS) data. The calculational strategy employs conjoined rigid body/torsion/Cartesian simulated annealing, and incorporates improvements in calculating and refining against SAXS/WAXS data that take into account complex molecular shapes in the description of the solvent layer resulting in a better representation of the SAXS/WAXS data. The RDC data orient the symmetrically related EIN domains relative to the C{sub 2} symmetry axis of the EIC dimer, while translational, shape, and size information is provided by SAXS/WAXS. The resulting structures are independently validated by SANS. Comparison of the structures of the free EI and the EI-HPr complex with that of the crystal structure of a trapped phosphorylated EI intermediate reveals large ({approx}70-90{sup o}) hinge body rotations of the two subdomains comprising the EIN domain, as well as of the EIN domain relative to the dimeric EIC domain. These large-scale interdomain motions shed light on the structural transitions that accompany the catalytic cycle of EI.

Schwieters, Charles D.; Suh, Jeong-Yong; Grishaev, Alexander; Ghirlando, Rodolfo; Takayama, Yuki; Clore, G. Marius (NIH)

2010-09-17T23:59:59.000Z

420

Neutron scattering in molecular liquids: Influence of orientational degrees of freedom and the prepeak in a fragile glass former  

E-Print Network [OSTI]

The intermediate scattering function S(q,t) for neutron scattering is expanded with respect to a complete set of correlation functions which describe the dynamical correlations in a molecular liquid. For the static ns-structure factor S(q) of a system of diatomic molecules the results of the expansion are compared with the exact results from a MD-imulation and it is shown that the Sears-expansion, which is commonly used to interpret such data, fails in the supercooled regime. The representation for S(q) is used to draw conclusions about the q-dependence and especially the origin of the prepeak.

Christoph Theis; Rolf Schilling

1998-08-07T23:59:59.000Z

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421

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

E-Print Network [OSTI]

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

Kenji Fukukawa; Yoshikazu Fujiwara

2011-02-15T23:59:59.000Z

422

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

E-Print Network [OSTI]

Scattering of 64 eV to 3 keV Neutrons from Polyethylene and Graphite and the Coherence Length intensity ratios from polyethylene (CH2) relative to graphite (C) at several discrete final energies

Danon, Yaron

423

The ground state of the spin-1/2 kagom lattice antiferromagnet : neutron scattering studies of the zinc-paratacamite mineral family  

E-Print Network [OSTI]

The magnetic properties of the geometrically frustrated quantum magnets clinoatacamite, Cu2(OH)3Cl, and herbertsmithite, ZnCu3(OH)6Cl2, are studied by means of neutron scattering measurements as well as specific heat, ...

Helton, Joel Strader

2009-01-01T23:59:59.000Z

424

The importance of the nucleon-nucleon correlations for the eta alpha S-wave scattering length, and the pi-eta mixing angle in the low-energy eta alpha scattering length model  

E-Print Network [OSTI]

Using the new set of dd --> eta alpha near threshold experimental data, the estimate of the importance of the nucleon-nucleon correlations for the eta alpha S-wave scattering length in the multiple scattering theory is obtained using the low-energy scattering length model. The contribution turns out to be much bigger then previously believed. The pi-eta mixing angle is extracted using the experimental data on the dd --> eta alpha and dd --> pi alpha processes. The model is dominated by the subthreshold extrapolation recipe for the eta alpha scattering amplitudes. When the recipe is chosen the model is completely insensitive to the eta alpha parameters for the subthreshold value of the eta cm momentum of p_{eta}^2 = -(0.46)^2 fm^{-2}. Provided that the subthreshold extrapolation recipe is correct, a good estimate of the pi-eta mixing angle is obtained, if the experimental cross sections for the dd --> pi alpha reaction at the corresponding deuteron input energy are taken from the literature.

S. Ceci; D. Hrupec; A. Svarc

2001-04-12T23:59:59.000Z

425

Multi-component modeling of quasielastic neutron scattering from phospholipid membranes  

SciTech Connect (OSTI)

We investigated molecular motions in the 0.3350 ps time range of D{sub 2}O-hydrated bilayers of 1-palmitoyl-oleoyl-sn-glycero-phosphocholine and 1,2-dimyristoyl-sn-glycero-phosphocholine in the liquid phase by quasielastic neutron scattering. Model analysis of sets of spectra covering scale lengths from 4.8 to 30 revealed the presence of three types of motion taking place on well-separated time scales: (i) slow diffusion of the whole phospholipid molecules in a confined cylindrical region; (ii) conformational motion of the phospholipid chains; and (iii) fast uniaxial rotation of the hydrogen atoms around their carbon atoms. Based on theoretical models for the hydrogen dynamics in phospholipids, the spatial extent of these motions was analysed in detail and the results were compared with existing literature data. The complex dynamics of protons was described in terms of elemental dynamical processes involving different parts of the phospholipid chain on whose motions the hydrogen atoms ride.

Wanderlingh, U., E-mail: uwanderlingh@unime.it; DAngelo, G.; Branca, C.; Trimarchi, A.; Rifici, S.; Finocchiaro, D. [Dipartimento di Fisica e Scienze della Terra, University of Messina, I-98166 Messina (Italy)] [Dipartimento di Fisica e Scienze della Terra, University of Messina, I-98166 Messina (Italy); Conti Nibali, V. [Institute for Physical Chemistry II, Ruhr-University Bochum, Bochum (Germany)] [Institute for Physical Chemistry II, Ruhr-University Bochum, Bochum (Germany); Crupi, C. [IPCF-V.le F. Stagno DAlcontres, n. 37, Messina 98158 (Italy)] [IPCF-V.le F. Stagno DAlcontres, n. 37, Messina 98158 (Italy); Ollivier, J. [Institut Laue-Langevin, 6 rue J. Horowitz, BP 156, F-38042 Grenoble (France)] [Institut Laue-Langevin, 6 rue J. Horowitz, BP 156, F-38042 Grenoble (France); Middendorf, H. D. [Clarendon Laboratory, University of Oxford, Oxford (United Kingdom)] [Clarendon Laboratory, University of Oxford, Oxford (United Kingdom)

2014-05-07T23:59:59.000Z

426

Status report on the analysis of inelastic neutron scattering from carbon, iron, yttrium and lead at 96 MeV  

E-Print Network [OSTI]

This work is part of an effort to provide more experimental data for the (n,n'x) reaction. The experiments were carried out at The Svedberg Laboratory in Uppsala, Sweden, at the quasi-mono-energetic neutron beam of 96 MeV, before the facility was upgraded in 2004. Using an extended data analysis of data primarily intended for measuring elastic neutron scattering only, it was found to be possible to extract information on the inelastic scattering from several nuclei. In the preliminary data analysis, an iterative forward-folding technique was applied, in which a physically reasonable trial spectrum was folded with the response function of the detector system and the output was compared to the experimental data. As a result, double-differential cross sections and angular distributions of inelastic neutron scattering from 12-C, 56-Fe, 89-Y and 208-Pb could be obtained. In this paper, a status update on the efforts to improve the description of the detector response function is given.

C. Gustavsson; C. Hellesen; S. Pomp; A. hrn; J. Blomgren; U. Tippawan

2013-03-27T23:59:59.000Z

427

Validation of angle-resolved polarized light scattering spectroscopy as a diagnostic tool for pre-cancer detection  

E-Print Network [OSTI]

Light scattering spectroscopy has emerged as a valuable diagnostic tool for cancer diagnoses in the past ten years. The interaction of light with cellular structures brings out information about morphological changes ...

Kalashnikov, Maxim M

2009-01-01T23:59:59.000Z

428

Angular distributions of neutron-nucleus collisions  

SciTech Connect (OSTI)

We derive the total and the differential cross sections with respect to angle for neutron-induced reactions from an analytical model having a simple functional form to demonstrate the quantitative agreement with the measured cross sections. The energy dependence of the neutron-nucleus interaction cross sections are estimated successfully for energies ranging from 5 to 600 MeV. In this work, the effect of the imaginary part of the nuclear potential is treated more appropriately compared to our earlier work. The angular distributions for neutron scattering also agree reasonably well with the experimental data at forward angles.

Mukhopadhyay, Tapan; Lahiri, Joydev; Basu, D. N. [Variable Energy Cyclotron Centre, 1/AF Bidhan Nagar, Kolkata 700 064 (India)

2011-06-15T23:59:59.000Z

429

Neutron reflecting supermirror structure  

DOE Patents [OSTI]

An improved neutron reflecting supermirror structure comprising a plurality of stacked sets of bilayers of neutron reflecting materials. The improved neutron reflecting supermirror structure is adapted to provide extremely good performance at high incidence angles, i.e. up to four time the critical angle of standard neutron mirror structures. The reflection of neutrons striking the supermirror structure at a high critical angle provides enhanced neutron throughput, and hence more efficient and economical use of neutron sources.

Wood, James L. (Drayton Plains, MI)

1992-01-01T23:59:59.000Z

430

Neutron reflecting supermirror structure  

DOE Patents [OSTI]

An improved neutron reflecting supermirror structure comprising a plurality of stacked sets of bilayers of neutron reflecting materials. The improved neutron reflecting supermirror structure is adapted to provide extremely good performance at high incidence angles, i.e. up to four time the critical angle of standard neutron mirror structures. The reflection of neutrons striking the supermirror structure at a high critical angle provides enhanced neutron throughput, and hence more efficient and economical use of neutron sources. 2 figs.

Wood, J.L.

1992-12-01T23:59:59.000Z

431

HFIR Experiment Facilities | ORNL Neutron Sciences  

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

Scattering Neutron Scattering Facilities at HFIR The fully instrumented HFIR will eventually include 15 state-of-the-art neutron scattering instruments, seven of which will be...

432

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

E-Print Network [OSTI]

scattering, Resonance, Time-of-flight, Depleted uranium, LINAC experiment DOI: 10.3938/jkps.55.1389 I the neutron time-of-flight (TOF) method and a 6 Li scintillation detector. Two different thickness depleted uranium samples, 169 and 362 g of 7.62 ? 7.62 cm2 , were used in the experiments. The spectra of scattered

Danon, Yaron

433

The G0 Experiment: Apparatus for Parity-Violating Electron Scattering Measurements at Forward and Backward Angles  

E-Print Network [OSTI]

In the G0 experiment, performed at Jefferson Lab, the parity-violating elastic scattering of electrons from protons and quasi-elastic scattering from deuterons is measured in order to determine the neutral weak currents of the nucleon. Asymmetries as small as 1 part per million in the scattering of a polarized electron beam are determined using a dedicated apparatus. It consists of specialized beam-monitoring and control systems, a cryogenic hydrogen (or deuterium) target, and a superconducting, toroidal magnetic spectrometer equipped with plastic scintillation and aerogel Cerenkov detectors, as well as fast readout electronics for the measurement of individual events. The overall design and performance of this experimental system is discussed.

G0 Collaboration; D. Androic; D. S. Armstrong; J. Arvieux; R. Asaturyan; T. D. Averett; S. L. Bailey; G. Batigne; D. H. Beck; E. J. Beise; J. Benesch; F. Benmokhtar; L. Bimbot; J. Birchall; A. Biselli; P. Bosted; H. Breuer; P. Brindza; C. L. Capuano; R. D. Carlini; R. Carr; N. Chant; Y. -C. Chao; R. Clark; A. Coppens; S. D. Covrig; A. Cowley; D. Dale; C. A. Davis; C. Ellis; W. R. Falk; H. Fenker; J. M. Finn; T. Forest; G. Franklin; R. Frascaria; C. Furget; D. Gaskell; M. T. W. Gericke; J. Grames; K. A. Griffioen; K. Grimm; G. Guillard; B. Guillon; H. Guler; K. Gustafsson; L. Hannelius; J. Hansknecht; R. D. Hasty; A. M. Hawthorne Allen; T. Horn; T. M. Ito; K. Johnston; M. Jones; P. Kammel; R. Kazimi; P. M. King; A. Kolarkar; E. Korkmaz; W. Korsch; S. Kox; J. Kuhn; J. Lachniet; R. Laszewski; L. Lee; J. Lenoble; E. Liatard; J. Liu; A. Lung; G. A. MacLachlan; J. Mammei; D. Marchand; J. W. Martin; D. J. Mack; K. W. McFarlane; D. W. McKee; R. D. McKeown; F. Merchez; M. Mihovilovic; A. Micherdzinska; H. Mkrtchyan; B. Moffit; M. Morlet; M. Muether; J. Musson; K. Nakahara; R. Neveling; S. Niccolai; D. Nilsson; S. Ong; S. A. Page; V. Papavassiliou; S. F. Pate; S. K. Phillips; P. Pillot; M. L. Pitt; M. Poelker; T. A. Porcelli; G. Quemener; B. P. Quinn; W. D. Ramsay; A. W. Rauf; J. -S. Real; T. Ries; J. Roche P. Roos; G. A. Rutledge; J. Schaub; J. Secrest; T. Seva; N. Simicevic; G. R. Smith; D. T. Spayde; S. Stepanyan; M. Stutzman; R. Suleiman; V. Tadevosyan; R. Tieulent; J. van de Wiele; W. T. H. van Oers; M. Versteegen; E. Voutier; W. F. Vulcan; S. P. Wells; G. Warren; S. E. Williamson; R. J. Woo; S. A. Wood; C. Yan; J. Yun; V. Zeps

2011-03-03T23:59:59.000Z

434

Simulation of the shape of chaperonins using the small-angle x-ray scattering curves and torus form factor  

SciTech Connect (OSTI)

The inverse scattering problem has been solved for protein complexes whose surfaces can be described by a set of the simplest doubly connected surfaces in the uniform approximation (a scattering potential inside the molecule is a constant). Solutions of two proteins-well-known GroEL bacterial chaperonin and poor-studied bacteriophage chaperonin, which is a product of 146 gene (gp146)-were taken for the experiment. The shapes of protein complexes have been efficiently reconstructed from the experimental scattering curves. The shell method, the method of the rotation of amino acid sequences with the use of the form factor of an amino acid, and the method of seeking the model parameters of a protein complex with the preliminarily obtained form factor of the model have been used to reconstruct the shape of these particles.

Amarantov, S. V., E-mail: amarantov_s@mail.ru [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Naletova, I. N. [Moscow State University, Belozerskii Institute of Molecular Biology and Bioorganic Chemistry (Russian Federation); Kurochkina, L. P. [Russian Academy of Sciences, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry (Russian Federation)

2011-08-15T23:59:59.000Z

435

The G0 Experiment: Apparatus for Parity-Violating Electron Scattering Measurements at Forward and Backward Angles  

E-Print Network [OSTI]

In the G0 experiment, performed at Jefferson Lab, the parity-violating elastic scattering of electrons from protons and quasi-elastic scattering from deuterons is measured in order to determine the neutral weak currents of the nucleon. Asymmetries as small as 1 part per million in the scattering of a polarized electron beam are determined using a dedicated apparatus. It consists of specialized beam-monitoring and control systems, a cryogenic hydrogen (or deuterium) target, and a superconducting, toroidal magnetic spectrometer equipped with plastic scintillation and aerogel Cerenkov detectors, as well as fast readout electronics for the measurement of individual events. The overall design and performance of this experimental system is discussed.

Androic, D; Arvieux, J; Asaturyan, R; Averett, T D; Bailey, S L; Batigne, G; Beck, D H; Beise, E J; Benesch, J; Benmokhtar, F; Bimbot, L; Birchall, J; Biselli, A; Bosted, P; Breuer, H; Brindza, P; Capuano, C L; Carlini, R D; Carr, R; Chant, N; Chao, Y -C; Clark, R; Coppens, A; Covrig, S D; Cowley, A; Dale, D; Davis, C A; Ellis, C; Falk, W R; Fenker, H; Finn, J M; Forest, T; Franklin, G; Frascaria, R; Furget, C; Gaskell, D; Gericke, M T W; Grames, J; Griffioen, K A; Grimm, K; Guillard, G; Guillon, B; Guler, H; Gustafsson, K; Hannelius, L; Hansknecht, J; Hasty, R D; Allen, A M Hawthorne; Horn, T; Ito, T M; Johnston, K; Jones, M; Kammel, P; Kazimi, R; King, P M; Kolarkar, A; Korkmaz, E; Korsch, W; Kox, S; Kuhn, J; Lachniet, J; Laszewski, R; Lee, L; Lenoble, J; Liatard, E; Liu, J; Lung, A; MacLachlan, G A; Mammei, J; Marchand, D; Martin, J W; Mack, D J; McFarlane, K W; McKee, D W; McKeown, R D; Merchez, F; Mihovilovic, M; Micherdzinska, A; Mkrtchyan, H; Moffit, B; Morlet, M; Muether, M; Musson, J; Nakahara, K; Neveling, R; Niccolai, S; Nilsson, D; Ong, S; Page, S A; Papavassiliou, V; Pate, S F; Phillips, S K; Pillot, P; Pitt, M L; Poelker, M; Porcelli, T A; Quemener, G; Quinn, B P; Ramsay, W D; Rauf, A W; Real, J -S; Ries, T; Roos, J Roche P; Rutledge, G A; Schaub, J; Secrest, J; Seva, T; Simicevic, N; Smith, G R; Spayde, D T; Stepanyan, S; Stutzman, M; Suleiman, R; Tadevosyan, V; Tieulent, R; van de Wiele, J; van Oers, W T H; Versteegen, M; Voutier, E; Vulcan, W F; Wells, S P; Warren, G; Williamson, S E; Woo, R J; Wood, S A; Yan, C; Yun, J; Zeps, V

2011-01-01T23:59:59.000Z

436

New Measurement of Compton Scattering from the Deuteron and an Improved Extraction of the Neutron Electromagnetic Polarizabilities  

E-Print Network [OSTI]

The electromagnetic polarizabilities of the nucleon are fundamental properties that describe its response to external electric and magnetic fields. They can be extracted from Compton-scattering data --- and have been, with good accuracy, in the case of the proton. In contradistinction, information for the neutron requires the use of Compton scattering from nuclear targets. Here we report a new measurement of elastic photon scattering from deuterium using quasimonoenergetic tagged photons at the MAX IV Laboratory in Lund, Sweden. These first new data in more than a decade effectively double the world dataset. Their energy range overlaps with previous experiments and extends it by 20 MeV to higher energies. An analysis using Chiral Effective Field Theory with dynamical \\Delta(1232) degrees of freedom shows the data are consistent with and within the world dataset. After demonstrating that the fit is consistent with the Baldin sum rule, extracting values for the isoscalar nucleon polarizabilities and combining them with a recent result for the proton, we obtain the neutron polarizabilities as \\alpha_n = [11.55 +/- 1.25(stat) +/- 0.2(BSR) +/- 0.8(th)] X 10^{-4} fm^3 and \\beta_n = [3.65 -/+ 1.25(stat) +/- 0.2(BSR) -/+ 0.8(th)] X 10^{-4} fm3, with \\chi^2 = 45.2 for 44 degrees of freedom.

L. S. Myers; J. R. M. Annand; J. Brudvik; G. Feldman; K. G. Fissum; H. W. Griehammer; K. Hansen; S. S. Henshaw; L. Isaksson; R. Jebali; M. A. Kovash; M. Lundin; J. A. McGovern; D. G. Middleton; A. M. Nathan; D. R. Phillips; B. Schrder; S. C. Stave

2014-11-13T23:59:59.000Z

437

Comments to the problem of experimental determination of the neutron-electron scattering length and its theoretical interpretation  

E-Print Network [OSTI]

We discuss the experimental data on the n,e-scattering length bne and the values of mean square charge radius of the neutron obtained from them. It is shown that the accumulated during the last 50 years most significant experimental estimates of the bne are not contradictory and lead to the average value =-0.1178+-0.0037 fm^2. Assuming that all the authors have underestimated the errors of their measurements by a factor of 1.7, the combined fit of all available experimental data would lead to Chi^2~1 per degree of freedom. Different modern theoretical predictions of are considered. They are found to be in a good agreement with the obtained experimental value . However the existing theoretical description of the structure of neutron does not provide a value of with a sufficient accuracy.

A. B. Popov; T. Yu. Tretyakova

2008-12-30T23:59:59.000Z

438

Investigation of the role of neutron transfer in the fusion of 32,34S with 197Au,208Pb using quasi-elastic scattering  

E-Print Network [OSTI]

Excitation functions for quasi-elastic scattering have been measured at backward angles for the systems 32,34S+197Au and 32,34S+208Pb for energies spanning the Coulomb barrier. Representative distributions, sensitive to the low energy part of the fusion barrier distribution, have been extracted from the data. For the fusion reactions of 32,34S with 197Au couplings related to the nuclear structure of 197Au appear to be dominant in shaping the low energy part of the barrier distibution. For the system 32S+208Pb the barrier distribution is broader and extends further to lower energies, than in the case of 34S+208Pb. This is consistent with the interpretation that the neutron pick-up channels are energetically more favoured in the 32S induced reaction and therefore couple more strongly to the relative motion. It may also be due to the increased collectivity of 32S, when compared with 34S.

T. J. Schuck; H. Timmers; M. Dasgupta

2002-07-22T23:59:59.000Z

439

Phonon self-energy and origin of anomalous neutron scattering spectra in SnTe and PbTe thermoelectrics  

SciTech Connect (OSTI)

The anharmonic lattice dynamics of rock-salt thermoelectric compounds SnTe and PbTe are investigated with inelastic neutron scattering (INS) and first-principles calculations. The experiments show that, surprisingly, although SnTe is closer to the ferroelectric instability, phonon spectra in PbTe exhibit a more anharmonic character. This behavior is reproduced in first-principles calculations of the temperature-dependent phonon self-energy. Our simulations reveal how the nesting of phonon dispersions induces prominent features in the self-energy, which account for the measured INS spectra and their temperature dependence. We establish that the phase-space for three-phonon scattering processes, rather than just the proximity to the lattice instability, is the mechanism determining the complex spectrum of the transverse-optical ferroelectric mode.

Li, Chen [ORNL] [ORNL; Ma, Jie [ORNL] [ORNL; May, Andrew F [ORNL] [ORNL; Cao, Huibo [ORNL] [ORNL; Christianson, Andrew D [ORNL] [ORNL; Ehlers, Georg [ORNL] [ORNL; Singh, David J [ORNL] [ORNL; Sales, Brian C [ORNL] [ORNL; Delaire, Olivier A [ORNL] [ORNL

2014-01-01T23:59:59.000Z

440

New insight into the properties of proton conducting oxides from neutron total scattering  

SciTech Connect (OSTI)

In recent years there has been a growing interest in searching for new proton conducting materials that could be successfully used in medium temperature solid oxide fuel cells (SOFC). In particular, proton conducting oxides have been the subject of a massive research activity. Among the most promising oxide the acceptor doped cerates appears to be those most appealing in view of practical applications. A relevant aspect of these materials is the investigation of the local distortion of the structure arising from water incorporation. This kind of study is of great help in defining how the structure changes in order to accommodate the proton which is usually thought to enter the structure in form of hydroxyl group where the oxygen vacancy results from the acceptor doping on the Ce site. Atomistic simulation work confirmed that the preferential location of dopant ions is on the Ce site. To the best of our knowledge the only experimental work addressing the role of dopant and water incorporation on the local structure of V-doped cerates is a X-ray absorption spectroscopy (XAS) work carried out by Longo and coworkers at the Y K-edge. The main conclusion of that work was the observation that Y-doping induces a distortion of the parent BaCe0{sub 3} structure resulting in a significantly distorted Y local environment. However, local structure information derived from XAS study does not provide a direct structural information and depends strongly upon the model used to calcualte theoretical {chi}(k) which is not unique. Moreover, the XAS analysis usually provide significant information only up to the second shell. As a consequence, a more reliable and useful technique to investigate the local arrangement in these proton conducting oxides appears to be the Pair Distribution Function (PDF) analysis derived from total neutron scattering measurements. In the present work we investigated the pure BaCeO{sub 3} and the acceptor doped BaCe{sub 0.90}Y{sub 0.10}O{sub 2.85} compounds. In both cases the samples have been measured at room temperature and after being exposed to dry and wet air (humidification attained through bubbling air in D{sub 2}O). Aim of this work is to look at the effect of Y-doping and water doping on the local structure of the above mentioned samples.

Proffen, Thomas E [Los Alamos National Laboratory; Kim, Hyunjeong [Los Alamos National Laboratory; Malavasi, Lorenzo [U PAVIA, ITALY; Flor, Giorgio [U PAVIA, ITALY

2008-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "angle neutron scattering" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

A Survey of Students from the National School on Neutron and X-ray Scattering: Communication Habits and Preferences  

SciTech Connect (OSTI)

Oak Ridge National Laboratory (ORNL) offers the scientific community unique access to two types of world-class neutron sources at a single site - the Spallation Neutron Source (SNS) and the High Flux Isotope Reactor (HFIR). The 85-MW HFIR provides one of the highest steady-state neutron fluxes of any research reactor in the world. And the SNS is one of the world's most intense pulse neutron beams. Management of these resources is the responsibility of the Neutron Sciences Directorate (NScD). NScD started conducting the National School on Neutron and X-ray Scattering (NXS) in conjunction with the Advanced Photon Source (APS) at Argonne National Laboratory in 2007. This survey was conducted to determine the most effective ways to reach students with information about what SNS and HFIR offer the scientific community, including content and communication vehicles. The emphasis is on gaining insights into compelling messages and the most effective channels, e.g., Web sites and social media, for communicating with students about neutron science The survey was conducted in two phases using a classic qualitative investigation to confirm language and content followed by a survey designed to quantify issues, assumptions, and working hypotheses. Phase I consisted of a focus group in late June 2010 with students attending NXS. The primary intent of the group was to inform development of an online survey. Phase two consisted of an online survey that was developed and pre-tested in July 2010 and launched on August 9, 2010 and remained in the field until September 9, 2010. The survey achieved an overall response rate of 48% for a total of 157 completions. The objective of this study is to determine the most effective ways to reach students with information about what SNS and HFIR offer the scientific community, including content and communication vehicles. The emphasis is on gaining insights into compelling messages and the most effective channels, e.g., Web sites, social media, for communicating with students about neutron science.

Bryant, Rebecca [Bryant Research, LLC

2010-12-01T23:59:59.000Z

442

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

E-Print Network [OSTI]

measurements, our structural modelling is confirmed using contrast-variation SANS. #12;2 INTRODUCTION be addressed. Tel.: +33 (0)4 67 14 46 20. Fax: +33 (0)4 6714 33 04. E-mail: slagerge@univ-montp2.fr ABSTRACT We by an emulsification failure and a resolubilization is found. We have measured the microstructure by SANS

Boyer, Edmond

443

Ray tracing flux calculation for the small and wide angle x-ray scattering diffraction station at the SESAME synchrotron radiation facility  

SciTech Connect (OSTI)

The calculation for the optics of the synchrotron radiation small and wide angle x-ray scattering beamline, currently under construction at SESAME is described. This beamline is based on a cylindrically bent germanium (111) single crystal with an asymmetric cut of 10.5 deg., followed by a 1.2 m long rhodium coated plane mirror bent into a cylindrical form. The focusing properties of bent asymmetrically cut crystals have not yet been studied in depth. The present paper is devoted to study of a particular application of a bent asymmetrically cut crystal using ray tracing simulations with the SHADOW code. These simulations show that photon fluxes of order of 1.09x10{sup 11} photons/s will be available at the experimental focus at 8.79 keV. The focused beam dimensions will be 2.2 mm horizontal full width at half maximum (FWHM) by 0.12 mm vertical (FWHM).

Salah, Wa'el [Synchrotron-light for Experimental Science and Application in the Middle East (SESAME), P.O. Box 7, Allan 19252 (Jordan); Department of Physics, The Hashemite University, Zarqa 13115 (Jordan); Sanchez del Rio, M. [European Synchrotron Radiation Facility, Bp 220, 38043 Grenoble Cedex (France); Hoorani, H. [Synchrotron-light for Experimental Science and Application in the Middle East (SESAME), P.O. Box 7, Allan 19252 (Jordan)

2009-09-15T23:59:59.000Z

444

Role of Anharmonic Vibration on Heavy-ion Fusion Reaction and Large Angle Quasi-elastic Scattering of {sup 16}O+{sup 144}Sm  

SciTech Connect (OSTI)

We study the effects of double quadrupole and octupole phonon excitations of {sup 144}Sm nucleus on heavy-ion fusion reaction and large angle quasi-elastic scattering for {sup 16}O+{sup 144}Sm reaction using the coupled-channels approach. We explicitly taken into account the anharmonicites of nuclear vibrations using the sdf-interacting boson model. It is shown that the anhamronicities play an essential role in reproducing the experimental data of the fusion cross section as well as the fusion barrier distribution for this system. Also the quasi-elastic cross section is well reproduced in this way. However, the quasi-elastic barrier distribution has a high distinct peak which is smeared out in the experimental data. Our study indicates that the fusion and quasi-elastic barrier distribution for {sup 16}O+{sup 144}Sm system cannot be accounted for simultaneously with the standard coupled-channels formalism.

Muhammad, Zamrun F. [Jurusan Fisika, FMIPA Universitas Haluoleo, Kendari, Sulawesi Tenggara, 93232 (Indonesia); Hagino, K. [Department of Physics, Tohoku University, Sendai, 980-8576 (Japan)

2009-07-10T23:59:59.000Z

445

Neutron scattering investigation of the magnetic order in single crystalline BaFe2As2  

SciTech Connect (OSTI)

The magnetic structure of BaFe{sub 2}As{sub 2} was determined from polycrystalline neutron diffraction measurements soon after the ThCr{sub 2}Si{sub 2}-type FeAs-based superconductors were discovered. Both the moment direction and the in-plane antiferromagnetic wavevector are along the longer a-axis of the orthorhombic unit cell. There is only one combined magnetostructural transition at {approx}140 K. However, a later single-crystal neutron diffraction work reported contradicting results. Here, we show neutron diffraction results from a single-crystal sample, grown by a self-flux method, that support the original polycrystalline work.

Bao, Wei [Los Alamos National Laboratory; Qiu, Y [NIST; Kofu, M [UNIV OF VA; Lee, S - H [UNIV OF VA; Chang, S [NIST; Wu, T [HEFEI NAT. LAB.; Wu, G [HEFEI NAT. LAB; Chen, X H [HEFEI NAT. LAB

2008-01-01T23:59:59.000Z

446

Neutron scattering residual stress measurements on gray cast iron brake discs  

SciTech Connect (OSTI)

Neutron diffraction was used to investigate the effects of a heat treatment designed to remove internal residual stresses in brake discs. It is believed that residual stresses may change the rate of deformation of the discs during severe braking conditions when the disc temperature is increased significantly. Neutron diffraction was used to map out residual strain distributions in a production disc before and after a stress-relieving heat treatment. Results from these neutron diffraction experiments show that some residual strains were reduced by as much as 400 microstrain by stress relieving. 5 refs., 5 figs., 1 tab.

Spooner, S.; Payzant, E.A.; Hubbard, C.R. [and others

1996-11-01T23:59:59.000Z

447

Crystal Structures and Small-angle X-ray Scattering Analysis of UDP-galactopyranose Mutase from the Pathogenic Fungus Aspergillus fumigatus  

SciTech Connect (OSTI)

UDP-galactopyranose mutase (UGM) is a flavoenzyme that catalyzes the conversion of UDP-galactopyranose to UDP-galactofuranose, which is a central reaction in galactofuranose biosynthesis. Galactofuranose has never been found in humans but is an essential building block of the cell wall and extracellular matrix of many bacteria, fungi, and protozoa. The importance of UGM for the viability of many pathogens and its absence in humans make UGM a potential drug target. Here we report the first crystal structures and small-angle x-ray scattering data for UGM from the fungus Aspergillus fumigatus, the causative agent of aspergillosis. The structures reveal that Aspergillus UGM has several extra secondary and tertiary structural elements that are not found in bacterial UGMs yet are important for substrate recognition and oligomerization. Small-angle x-ray scattering data show that Aspergillus UGM forms a tetramer in solution, which is unprecedented for UGMs. The binding of UDP or the substrate induces profound conformational changes in the enzyme. Two loops on opposite sides of the active site move toward each other by over 10 {angstrom} to cover the substrate and create a closed active site. The degree of substrate-induced conformational change exceeds that of bacterial UGMs and is a direct consequence of the unique quaternary structure of Aspergillus UGM. Galactopyranose binds at the re face of the FAD isoalloxazine with the anomeric carbon atom poised for nucleophilic attack by the FAD N5 atom. The structural data provide new insight into substrate recognition and the catalytic mechanism and thus will aid inhibitor design.

Dhatwalia, Richa; Singh, Harkewal; Oppenheimer, Michelle; Karr, Dale B.; Nix, Jay C.; Sobrado, Pablo; Tanner, John J. (Missouri); (LBNL); (VPI-SU)

2012-05-14T23:59:59.000Z

448

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

SciTech Connect (OSTI)

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

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

2014-01-01T23:59:59.000Z

449

MAGNON SCATTERING OF SLOW NEUTRONS ON A PYRRHOTITE SINGLE CRYSTAL By ADAM WANIC,  

E-Print Network [OSTI]

. It was carried out in Vinca using neutrons f rom the Yugoslavian heavy water moderated TVRS reactor on the supply of parti- cular samples. However, before a variety of large artificial crystals becomes accessible

Paris-Sud XI, Université de

450

Neutron inelastic scattering and reactions in natural Pb as a background in neutrinoless double-beta-decay experiments  

E-Print Network [OSTI]

Inelastic neutron scattering and reactions on Pb isotopes can result in gamma rays near the signature endpoint energy in a number of double-beta decay isotopes. In particular, there are gamma-ray transitions in Pb-206,207,208 that might produce energy deposits at the 76-Ge Q value in Ge detectors used for double-beta decay searches. The levels that produce these gamma rays can be excited by (n,n'gamma) or (n,xngamma) reactions, but the cross sections are small and previously unmeasured. This work uses the pulsed neutron beam at the Los Alamos Neutron Science Center to directly measure reactions of interest to double-beta decay experiments. The cross section on natural Pb to produce the 2041-keV gamma ray from Pb-206 is measured to be 3.6 +/- 0.7 (stat.) +/- 0.3 (syst.) mb at ~9.6 MeV. The cross section on natural Pb to produce the 3062-keV gamma ray from Pb-207 and Pb-208 is measured to be 3.9 +/- 0.8 (stat.) +/- 0.4 (syst.) mb at the same energy. We report cross sections or place upper limits on the cross sections for exciting some other levels in Pb that have transition energies corresponding to Q value in other double-beta decay isotopes.

V. E. Guiseppe; M. Devlin; S. R. Elliott; N. Fotiades; A. Hime; D. -M. Mei; R. O. Nelson; D. V. Perepelitsa

2009-09-24T23:59:59.000Z

451

Spin rotation and birefringence effect for a particle in a high energy storage ring and measurement of the real part of the coherent elastic zero-angle scattering amplitude, electric and magnetic polarizabilities  

E-Print Network [OSTI]

In the present paper the equations for the spin evolution of a particle in a storage ring are analyzed considering contributions from the tensor electric and magnetic polarizabilities of the particle. Study of spin rotation and birefringence effect for a particle in a high energy storage ring provides for measurement as the real part of the coherent elastic zero-angle scattering amplitude as well as tensor electric and magnetic polarizabilities. We proposed the method for measurement the real part of the elastic coherent zero-angle scattering amplitude of particles and nuclei in a storage ring by the paramagnetic resonance in the periodical in time nuclear pseudoelectric and pseudomagnetic fields.

V. G. Baryshevsky; A. A. Gurinovich

2005-06-14T23:59:59.000Z

452

Measurement of the differential neutron-deuteron scattering cross section in the energy range from 100 keV to 600 keV using a proportional counter  

E-Print Network [OSTI]

The angular distribution of neutron-deuteron scattering was investigated using the proportional counter P2 simultaneously as scattering target and detector for the recoil deuterons. The measurements were carried out using monoenergetic neutrons in the energy range from 150 keV to 500 keV. Various techniques were employed to reduce distortions of the experimental pulse-height distribution by photon-induced events. The experimental data were compared with realistic simulations which were carried out using different evaluated data sets. This comparison allows to conclude on inconsistencies in the evaluations.

Nolte, R; Plompen, A; Rttger, S

2014-01-01T23:59:59.000Z

453

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

SciTech Connect (OSTI)

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

Kim, Min Gyu [Ames Laboratory

2012-08-28T23:59:59.000Z

454

"Optical" Spin Rotation Phenomenon and Spin Filtering of Antiproton (Proton, Deuteron) Beams in a Pseudomagnetic Field of a Polarized Target: the Possibility of Measuring the Real Part of the Coherent Zero-angle Scattering Amplitude  

E-Print Network [OSTI]

It is shown that in the experiments dedicated for producing of polarized beams of antiprotons during their passage through a polarized gas target placed in a storage ring it is possible to measure not only spin-dependent total cross-sections of antiproton scattering by the proton (deuteron), but also the spin-dependent real part of the coherent zero-angle scattering amplitude in the process of production of a polarized beam of antiprotons.

V. G. Baryshevsky

2011-01-17T23:59:59.000Z

455

Structure of light neutron-rich nuclei and mechanism of elastic proton scattering  

SciTech Connect (OSTI)

Differential cross sections for elastic p{sup 6}He, p{sup 8}Li, and p{sup 9}Li scattering at two energies of 70 and 700 MeV per nucleon were calculated within the Glauber theory of multiple diffractive scattering. Threeparticle wave functions ({alpha}-n-n for {sup 6}He, {alpha}-t-n for {sup 8}Li, and {sup 7}Li-n-n for {sup 9}Li) were used for realistic potentials of intercluster interactions. The sensitivity of elastic scattering to proton-nucleus interaction and to the structure of nuclei was explored. In particular, the dependence of the differential cross section on the contribution of higher order collisions, on scattering on the core and peripheral nucleons, and on the contribution of small wave-function components and their asymptotic behavior was determined. A comparison with available experimental data and with the results of calculations within different formalisms was performed.

Ibraeva, E. T., E-mail: ibr@inp.kz [National Nuclear Center of the Republic of Kazakhstan, Institute of Nuclear Physics (Kazakhstan); Zhusupov, M. A. [Al-Farabi Kazakh National University (Kazakhstan); Imambekov, O. [National Nuclear Center of the Republic of Kazakhstan, Institute of Nuclear Physics (Kazakhstan)

2011-11-15T23:59:59.000Z

456

Scattering of particles by neutron stars: Time-evolutions for axial perturbations  

E-Print Network [OSTI]

The excitation of the axial quasi-normal modes of a relativistic star by scattered particles is studied by evolving the time dependent perturbation equations. This work is the first step towards the understanding of more complicated perturbative processes, like the capture or the scattering of particles by rotating stars. In addition, it may serve as a test for the results of the full nonlinear evolution of binary systems.

V. Ferrari; K. D. Kokkotas

2000-08-23T23:59:59.000Z

457

Fast neutron scattering on Gallium target at 14.8 MeV  

E-Print Network [OSTI]

Benchmarking of evaluated nuclear data libraries was performed for $\\sim 14.8$ MeV neutrons on Gallium targets. The experiments were performed at China Institute of Atomic Energy(CIAE). Solid samples of natural Gallium (3.2 cm and 6.4 cm thick) were bombarded by $\\sim 14.8$ MeV neutrons and leakage neutron energy spectra were measured at 60$^{\\circ}$ and 120$^{\\circ}$. The measured spectra are rather well reproduced by MCNP-4C simulations with the CENDL-3.1, ENDF/B-VII and JENDL-4.0 evaluated nuclear data libraries, except for the inelastic contributions around $E_{n} = 10-13$ MeV. All three libraries significantly underestimate the inelastic contributions. The inelastic contributions are further studied, using the Talys simulation code and the experimental spectra are reproduced reasonably well in the whole energy range by the Talys calculation, including the inelastic contributions.

R. Han; R. Wada; Z. Chen; Y. Nie; X. Liu; S. Zhang; P. Ren; B. Jia; G. Tian; F. Luo; W. Lin; J. Liu; F. Shi; M. Huang; X. Ruan; J. Ren; Z. Zhou; H. Huang; J. Bao; K. Zhang; B. Hu

2014-11-03T23:59:59.000Z

458

Fast neutron scattering on Gallium target at 14.8 MeV  

E-Print Network [OSTI]

Benchmarking of evaluated nuclear data libraries was performed for $\\sim 14.8$ MeV neutrons on Gallium targets. The experiments were performed at China Institute of Atomic Energy(CIAE). Solid samples of natural Gallium (3.2 cm and 6.4 cm thick) were bombarded by $\\sim 14.8$ MeV neutrons and leakage neutron energy spectra were measured at 60$^{\\circ}$ and 120$^{\\circ}$. The measured spectra are rather well reproduced by MCNP-4C simulations with the CENDL-3.1, ENDF/B-VII and JENDL-4.0 evaluated nuclear data libraries, except for the inelastic contributions around $E_{n} = 10-13$ MeV. All three libraries significantly underestimate the inelastic contributions. The inelastic contributions are further studied, using the Talys simulation code and the experimental spectra are reproduced reasonably well in the whole energy range by the Talys calculation, including the inelastic contributions.

Han, R; Chen, Z; Nie, Y; Liu, X; Zhang, S; Ren, P; Jia, B; Tian, G; Luo, F; Lin, W; Liu, J; Shi, F; Huang, M; Ruan, X; Ren, J; Zhou, Z; Huang, H; Bao, J; Zhang, K; Hu, B

2014-01-01T23:59:59.000Z

459

Coupling of the hydration water dynamics and the internal dynamics of actin detected by quasielastic neutron scattering  

SciTech Connect (OSTI)

Highlights: ? Quasielastic neutron scattering spectra of F-actin and G-actin were measured. ? Analysis of the samples in D{sub 2}O and H{sub 2}O provided the spectra of hydration water. ? The first layer hydration water around F-actin is less mobile than around G-actin. ? This difference in hydration water is in concert with the internal dynamics of actin. ? Water outside the first layer behaves bulk-like but influenced by the first layer. -- Abstract: In order to characterize dynamics of water molecules around F-actin and G-actin, quasielastic neutron scattering experiments were performed on powder samples of F-actin and G-actin, hydrated either with D{sub 2}O or H{sub 2}O, at hydration ratios of 0.4 and 1.0. By combined analysis of the quasielastic neutron scattering spectra, the parameter values characterizing the dynamics of the water molecules in the first hydration layer and those of the water molecules outside of the first layer were obtained. The translational diffusion coefficients (D{sub T}) of the hydration water in the first layer were found to be 1.2 10{sup ?5} cm{sup 2}/s and 1.7 10{sup ?5} cm{sup 2}/s for F-actin and G-actin, respectively, while that for bulk water was 2.8 10{sup ?5} cm{sup 2}/s. The residence times were 6.6 ps and 5.0 ps for F-actin and G-actin, respectively, while that for bulk water was 0.62 ps. These differences between F-actin and G-actin, indicating that the hydration water around G-actin is more mobile than that around F-actin, are in concert with the results of the internal dynamics of F-actin and G-actin, showing that G-actin fluctuates more rapidly than F-actin. This implies that the dynamics of the hydration water is coupled to the internal dynamics of the actin molecules. The D{sub T} values of the water molecules outside of the first hydration layer were found to be similar to that of bulk water though the residence times are strongly affected by the first hydration layer. This supports the recent observation on intracellular water that shows bulk-like behavior.

Fujiwara, Satoru, E-mail: fujiwara.satoru@jaea.go.jp [Quantum Beam Science Directorate, Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan)] [Quantum Beam Science Directorate, Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Plazanet, Marie [Laboratoire Interdisciplinaire de Physique, Universit Joseph Fourier de Grenoble and CNRS (UMR5588), BP87, 38402 Saint Martin d'Hres Cedex 9 (France)] [Laboratoire Interdisciplinaire de Physique, Universit Joseph Fourier de Grenoble and CNRS (UMR5588), BP87, 38402 Saint Martin d'Hres Cedex 9 (France); Oda, Toshiro [RIKEN SPring-8 Center, RIKEN Harima Institute, Sayo, Hyogo 679-5148 (Japan)] [RIKEN SPring-8 Center, RIKEN Harima Institute, Sayo, Hyogo 679-5148 (Japan)

2013-02-15T23:59:59.000Z

460

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

E-Print Network [OSTI]

National School on Neutron and X-ray Scattering Oak Ridge National Laboratory June 12-26, 2010 Oak ------------------------------------------------------------------------------- SCHEDULE FOR SATURDAY, JUNE 19, 2010 School participants arrive in Oak Ridge, TN and check in at the Comfort Inn. Dinner hosted by Oak Ridge National Laboratory

Pennycook, Steve