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1

LANSCE | Lujan Neutron Scattering Center  

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

Lujan Center Data Management Lujan Neutron Scattering Center Logo The Lujan Center within LANSCE utilizes a pulsed source and has a complement of 15 instruments. It maintains a...

2

Manuel Lujan Jr. Neutron Scattering Center Los Alamos Neutron...  

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

2013 LANSCE School on Neutron Scattering Geosciences & Materials in Extreme Environments Manuel Lujan Jr. Neutron Scattering Center Los Alamos Neutron Science Center Los Alamos...

3

LANSCE | Lujan Neutron Scattering Center  

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

Department of Energy, National Office of Science Department of Energy, National Office of Science science.energy.gov Department of Energy, National Nuclear Security Administration nnsa.energy.gov Lujan Neutron Scattering Center Logo Lujan Center Mission The Lujan Center delivers science by exploiting the unique characteristics of intense beams of pulsed neutrons for academia, national security, and industry. Lujan Center Vision The Lujan Center will operate a world class user program in the service of the nation. Lujan Center scientists will be recognized for their leadership and innovation in neutron scattering. Lujan Center at LANSCE The Lujan Center is one of five user facilities supported by the LANSCE accelerator which is stewarded. Funding to operate 10 instruments in a national user program is provided by the Department of Energy's Office of

4

Call issued for Lujan Neutron Scattering Center proposals  

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

Call issued for Lujan Neutron Scattering Center proposals Call issued for Lujan Neutron Scattering Center proposals The Lujan Neutron Scattering Center invites proposals addressing...

5

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...

6

At Los Alamos's Lujan Neutron Scattering Center, crystallographer...  

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

showing off the revealing properties of neutrons February 27, 2014 At Los Alamos's Lujan Neutron Scattering Center, crystallographer Olivier Gourdon shows visiting researchers...

7

Neutron Scattering Facilities 1982  

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

NEUTRON SOURCES NEUTRON SOURCES Types of Sources U.S. Sources Available for Users Plans for the Future The Neutron Scattering Society of America (NSSA) SNS/ANL School on Neutron and x-Ray Scattering, June 2011 Jim Rhyne Lujan Neutron Scattering Center Los Alamos National Lab. What do we need to do neutron scattering? * Neutron Source - produces neutrons * Diffractometer or Spectrometer - Allows neutrons to interact with sample - Sorts out discrete wavelengths by monochromator (reactor) or by time of flight (pulse source) - Detectors pick up neutrons scattered from sample * Analysis methods to determine material properties * Brain power to interpret results Sources of neutrons for scattering * Nuclear Reactor - Neutrons produced from fission of 235 U - Fission spectrum neutrons

8

LANSCE School on Neutron Scattering:  

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

11 th LANSCE School on Neutron Scattering: Materials at the Mesoscale Lujan Center Los Alamos Neutron Science Center Los Alamos National Laboratory lansce.lanl.govneutronschool...

9

Los Alamos Neutron Science Center  

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

LINAC Outreach Affiliations Visiting LANSCE Facilities Isotope Production Facility Lujan Neutron Scattering Center MaRIE Proton Radiography Ultracold Neutrons Weapons Neutron...

10

11th LANSCE School on Neutron Scattering | About the School  

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

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

11

Neutron Scattering Facilities  

Science Journals Connector (OSTI)

The past history, present performance and future prospects for neutron scattering facilities will be discussed. Special features of neutron scattering techniques applicable to biological problems will be ... . Th...

D. L. Price

1996-01-01T23:59:59.000Z

12

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

13

Neutron Scattering Tutorials | Neutron Science | ORNL  

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

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

14

Neutron scattering  

Science Journals Connector (OSTI)

... likely to be able to contribute to many different branches of chemistry and secondly because neutron ...neutronscattering ...

A. J. Leadbetter

1977-12-01T23:59:59.000Z

15

Neutron-Neutron Scattering Length  

Science Journals Connector (OSTI)

The final-state interaction of the two neutrons from the reaction ?-+d?2n+? has a pronounced and distinctive effect on the momentum spectrum of the outgoing particles. In particular, the neutron spectrum is sharply peaked in the neighborhood of 2 Mev, with a shape that is quite sensitive to the strength of the nn interaction. In the region of this peak, the relative neutron-neutron momentum is so small that the nn interaction is completely characterized by its scattering length. Hence it is proposed that a measurement of the shape of the neutron spectrum from this reaction may provide a convenient means of measuring the neutron-neutron scattering length. Neutron spectra are calculated in an impulse approximation, for several assumed values of the scattering length. It appears from their shapes that, in this way, present neutron-detection techniques should be capable of determining the scattering length to within 25%.

Kirk W. McVoy

1961-03-01T23:59:59.000Z

16

Neutron Scattering  

Science Journals Connector (OSTI)

... Magnetic Neutron Diffraction By Yurii A. Izyumov and Ruslan P. Ozerov. Translated from the Russian. ... York; Heydon: London, June 1970.) 350s; $37.50; 150 DM.

G. L. SQUIRES

1970-12-05T23:59:59.000Z

17

Neutron scattering  

Science Journals Connector (OSTI)

... statements that the EMBL outstation in Grenoble "[has an] uncertain future" and that "neutrons have not turned out to be particularly useful for biologists" in Peter Newmark's ... on the European Molecular Biology Laboratory (Nature 338, 724; 1989) require some comment.Neutron ...

S. CUSACK; B. JACROT; R. LEBERMAN; R. MAY; P. TlMMINS; G. ZACCAI

1989-06-01T23:59:59.000Z

18

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

19

11th LANSCE School on Neutron Scattering | Lecturers  

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

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

20

Neutron Scattering User Program | Neutron Science | ORNL  

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

User Program SHARE Neutron Scattering Can Benefit Your Research Neutron scattering has applications in almost every technical and scientific field, from biology and chemistry to...

Note: This page contains sample records for the topic "neutron scattering center" 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

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

22

Proton-Neutron Scattering  

Science Journals Connector (OSTI)

Using Glauber multiple-scattering theory, the missing-mass spectrum for protons scattered off a deuterium target is computed. The relatively clean separation of the single- and double-scattering peaks offers the possibility of determining the high-energy proton-neutron differential cross section.

N. Straumann and C. Wilkin

1970-03-02T23:59:59.000Z

23

Neutron Scattering Software  

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

Software Software A new portal for neutron scattering has just been established at neutronsources.org. The information contained here in the Neutron Scattering Web has been transferred to the new site. We will leave the current content here for archival purposes but no new content will be added. We encourage everyone interested in neutron scattering to take full advantage of this exciting new resource for our community. Neutronsources.org Data Formats NeXus: Neutron and X-ray Data Format Crystallographic Binary Format (CBF/imgCIF) Hierarchical Data Format (HDF) Data Analysis and Visualization Data Analysis for Neutron Scattering Experiments (DANSE): distributed data analysis project Large Array Manipulation Program (LAMP): IDL-based data analysis and visualization

24

Scattering of Slow Neutrons  

Science Journals Connector (OSTI)

1 September 1937 research-article Scattering of Slow Neutrons M. Goldhaber G. H. Briggs The Royal Society is collaborating with JSTOR to digitize, preserve, and extend access to Proceedings...

1937-01-01T23:59:59.000Z

25

Inelastic Neutron Scattering Instrumentation  

Science Journals Connector (OSTI)

Abstract Inelastic neutron scattering spectroscopy spans an enormous energy range, which is equivalent to a wide range of timescales. It is convenient to divide the whole energy range into three sectors, while recognising that there is significant overlap between them. In the lowest energy range, 10meV the applications are principally quasielastic scattering and tunneling spectroscopy. The second range, 01000meV covers the regions of vibrational spectroscopy and magnetic excitations. The highest range above 1000meV is the province of neutron Compton scattering. The instrumentation used in each of these energy regimes is described.

S.F. Parker

2014-01-01T23:59:59.000Z

26

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

27

Neutron Scattering Conference Archive  

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

Conference Archive Conference Archive A new portal for neutron scattering has just been established at neutronsources.org. The information contained here in the Neutron Scattering Web has been transferred to the new site. We will leave the current content here for archival purposes but no new content will be added. We encourage everyone interested in neutron scattering to take full advantage of this exciting new resource for our community. Neutronsources.org 2000 | 2001 | 2002 | 2003 | 2004 | 2005 | 2006 | 2007 | 2008 | 2009 | 2010 | 2011 | 2012 2000 June 12-14, 2000 Workshop on "New Opportunities for Better User Group Software (NOBUGS III)" Location Daresbury Laboratory, Cheshire, UK Contact Mark Enderby, Daresbury Laboratory Email M.J.Enderby@dl.ac.uk URL http://nobugs.dl.ac.uk/

28

Neutron-Neutron Quasifree Scattering  

Science Journals Connector (OSTI)

The reaction D(n ,2n)p has been measured at Einc=14.1 MeV, ?n (3)=?n(4)=30?, ?=180?, and the results are compared with the predictions of two separable-potential models. Neutron-proton and proton-proton quasifree scattering from nucleon + deuteron reactions at 14 MeV are also compared with the predictions of the same models. The upper limit of 2 mb/sr2 is determined for the reaction D(n,n?)d.

Ivo Slaus; J. W. Sunier; G. Thompson; J. C. Young; J. W. Verba; D. J. Margaziotis; P. Doherty; R. T. Cahill

1971-03-29T23:59:59.000Z

29

Neutron Scattering Methods in Chemistry  

Science Journals Connector (OSTI)

Starting with basic properties of the neutron, this chapter reviews the most important neutron scattering methods that provide valuable information for a ... wide, from standard methods of crystallography to neutron

L. Pusztai

2011-01-01T23:59:59.000Z

30

Neutron Science Center  

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

to have rare opportunity to tour Neutron Science Center May 10, 2011 LANL Rosenfest will celebrate life of LANSCE founder Louis Rosen and offer tour LOS ALAMOS, New Mexico, May 10,...

31

Magnetic neutron scattering (invited)  

Science Journals Connector (OSTI)

The application of neutron scattering techniques to magnetic problems is reviewed. We will first discuss diffraction techniques used to solve magnetic structures as well as to measure magnetic form factors order parameters critical phenomena and the scattering from low?dimensional systems. We will also discuss inelastic scattering techniques including polarized beam methods utilized to determine the spin dynamics of various materials. Information will be provided about the types of spectrometers available at the user?oriented national facilities located at Argonne National Laboratory Brookhaven National Laboratory Los Alamos National Laboratory The National Institute of Standards and Technology and Oak Ridge National Laboratory as well as the spectrometers at the Missouri University Research Reactor.

J. W. Lynn

1994-01-01T23:59:59.000Z

32

The Manuel Lujan, Jr. Neutron Scattering Center (LANSCE) experiment reports 1992 run cycle. Progress report  

SciTech Connect (OSTI)

This year was the fifth in which LANSCE ran a formal user program. A call for proposals was issued before the scheduled run cycles, and experiment proposals were submitted by scientists from universities, industry, and other research facilities around the world. An external program advisory committee, which LANSCE shares with the Intense Pulsed Neutron Source (IPNS), Argonne National Laboratory, examined the proposals and made recommendations. At LANSCE, neutrons are produced by spallation when a pulsed, 800-MeV proton beam impinges on a tungsten target. The proton pulses are provided by the Clinton P. Anderson Meson Physics Facility (LAMPF) accelerator and an associated Proton Storage Ring (PSR), which can alter the intensity, time structure, and repetition rate of the pulses. The LAMPF protons of Line D are shared between the LANSCE target and the Weapons Neutron Research (WNR) facility, which results in LANSCE spectrometers being available to external users for unclassified research about 80% of each annual LAMPF run cycle. Measurements of interest to the Los Alamos National Laboratory may also be performed and may occupy up to an additional 20% of the available beam time. These experiments are reviewed by an internal program advisory committee. One hundred sixty-seven proposals were submitted for unclassified research and twelve proposals for research of a programmatic interest to the Laboratory; six experiments in support of the LANSCE research program were accomplished during the discretionary periods. Oversubscription for instrument beam time by a factor of three was evident with 839 total days requested and only 371 available for allocation.

DiStravolo, M.A. [comp.

1993-09-01T23:59:59.000Z

33

Scattering of Neutrons by Lead  

Science Journals Connector (OSTI)

... THE University of Cambridge cyclotron and neutron velocity selector have been used for studying the ... velocity selector have been used for studying the scattering of ...

R. LATHAM; J. M. CASSELS

1948-02-21T23:59:59.000Z

34

Neutron Scattering Methods in Chemistry  

Science Journals Connector (OSTI)

Before going into details of the scattering of neutrons in condensed phases, some of this elementary particle should be recalled, as these characteristics play a central role in the scattering process.

2003-01-01T23:59:59.000Z

35

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 (more)

Chtangeev, Maxim B

2005-01-01T23:59:59.000Z

36

Simultaneous Neutron Scattering and Raman Scattering  

Science Journals Connector (OSTI)

The capability to make simultaneous neutron and Raman scattering measurements at temperatures between 1.5 and 450 K has been developed. The samples to be investigated are attached to...

Adams, Mark A; Parker, Stewart F; Fernandez-Alonso, Felix; Cutler, David J; Hodges, Christopher; King, Andrew

2009-01-01T23:59:59.000Z

37

Direct Measurement of Neutron?Neutron Scattering  

Science Journals Connector (OSTI)

In order to resolve long?standing discrepancies in indirect measurements of the neutron?neutron scattering length ann and contribute to solving the problem of the charge symmetry of the nuclear force the collaboration DIANNA (Direct Investigation of ann Association) plans to measure the neutron?neutron scattering cross section ? nn . The key issue of our approach is the use of the through?channel in the Russia reactor YAGUAR with a peak neutron flux of 1018 /cm2/s. The proposed experimental setup is described. Results of calculations are presented to connect ? nn with the nn?collision detector count rate and the neutron flux density in the reactor channel. Measurements of the thermal neutron fields inside polyethylene converters show excellent prospects for the realization of the direct nn?experiment.

E. I. Sharapov; C. D. Bowman; B. E. Crawford; W. I. Furman; C. R. Howell; B. G. Levakov; V. I. Litvin; W. I. Lychagin; A. E. Lyzhin; E. P. Magda; G. E. Mitchell; G. V. Muzichka; G. V. Nekhaev; Yu. V. Safronov; V. N. Shvetsov; S. L. Stephenson; A. V. Strelkov; W. Tornow

2003-01-01T23:59:59.000Z

38

Inelastic neutron scattering study on bioprotectant systems  

Science Journals Connector (OSTI)

...22 December 2005 Inelastic neutron scattering study on bioprotectant systems...UK We collected inelastic neutron scattering (INS) spectra of homologous...vibrational properties|neutron scattering| 1. Introduction In recent...

2005-01-01T23:59:59.000Z

39

Neutron scattering from adsorbed polymer layers  

Science Journals Connector (OSTI)

Neutron scattering from adsorbed polymer layers ... Small-Angle Neutron Scattering Study of Cyclic Poly(ethylene glycol) Adsorption on Colloidal Particles ... Small-Angle Neutron Scattering Study of Cyclic Poly(ethylene glycol) Adsorption on Colloidal Particles ...

Terence Cosgrove; Timothy G. Heath; Keith Ryan; Trevor L. Crowley

1987-11-01T23:59:59.000Z

40

Inelastic Neutron Scattering from Glass Formers  

Science Journals Connector (OSTI)

......research-article Articles Inelastic Neutron Scattering from Glass Formers U. Buchenau...transition. Coherent inelastic neutron scattering data indicate a mixture of...Supplement No. 126, 1997 Inelastic Neutron Scattering from Glass Formers U. BUCHENAU......

U. Buchenau

1997-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "neutron scattering center" 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

Quasiclassical Approximation for Slow Neutron Scattering  

Science Journals Connector (OSTI)

......Approximation for Slow Neutron Scattering Takeo Nishigori Department...formula for the differential scattering cross section of a slow neutron is derived along the line...of Spherical Rotors and Neutron Scattering Juichiro Hama and Tuto......

Takeo Nishigori

1970-06-01T23:59:59.000Z

42

Neutron scattering in concrete and wood  

Science Journals Connector (OSTI)

......Article Computational techniques Neutron scattering in concrete and wood A. Facure...library were used to simulate the neutron scattering in barriers of conventional...of the barrier thickness on neutron scattering factors is also being studied......

A. Facure; A. X. Silva; R. C. Falco; V. R. Crispim

2006-09-01T23:59:59.000Z

43

Neutron Scattering in ORNL'S Calibration Facility  

Science Journals Connector (OSTI)

......Dosimetry Article Neutron Scattering in ORNL'S Calibration...C. Francis Room scattering corrections for several common neutron detectors in a new...and enclosed room scattering situations are compared...good. A personnel neutron spectrometer was......

J.C. Liu; C.S. Sims; W.H. Casson; H. Murakami; C. Francis

1991-01-01T23:59:59.000Z

44

Calculations of neutron spectra after neutronneutron scattering  

Science Journals Connector (OSTI)

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

B E Crawford; S L Stephenson; C R Howell; G E Mitchell; W Tornow; W I Furman; E V Lychagin; A Yu Muzichka; G V Nekhaev; A V Strelkov; E I Sharapov; V N Shvetsov

2004-01-01T23:59:59.000Z

45

Search for: "neutron scattering" | DOE PAGES  

Office of Scientific and Technical Information (OSTI)

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

46

Intermediate Scattering Function in Slow Neutron Scattering  

Science Journals Connector (OSTI)

The conditions under which the so-called intermediate scattering function occurring in the theory of slow neutron scattering and in the theory of the Mssbauer effect can be written in the form exp[-?2?(t)] have been explicitly stated; the intermediate scattering function is then factorizable into two parts; the part referred to in the paper as the displacement part gives on Fourier transformation a real space-time function which, quite unambiguously, has the meaning usually attributed to the Van Hove Gs(x,t) function; the other part arises out of the nucleus recoiling against the neutron. It is shown that for systems in thermal equilibrium, the recoil part can be expressed in terms of the displacement part. This relation enables one to take care of the recoil part in case a classical approximation is made for the dynamics of the scattering system.

A. Rahman

1963-05-15T23:59:59.000Z

47

Low-Angle Neutron Scattering  

Science Journals Connector (OSTI)

A set of techniques that can be used to find the size of a particle in solution or to find the size or spacing of internal regions that can be distinguished by different neutron scattering power, such as the prot...

Jan W. Gooch

2011-01-01T23:59:59.000Z

48

Scattering of Neutrons by Protons  

Science Journals Connector (OSTI)

... IT is known that hydrogen shows a large scattering cross-section for slow ... cross-section for slow neutrons. On the usual assumption that the forces between proton and ...

M. GOLDHABER

1936-05-16T23:59:59.000Z

49

Incoherent Neutron Scattering by Polycrystals  

Science Journals Connector (OSTI)

General expressions are given for the first terms in the expansion in powers of the neutron to nuclear mass ratio of the total cross section for incoherent scattering of neutrons by polycrystals. Special limiting cases of these expressions had been published earlier.

G. Placzek

1957-02-15T23:59:59.000Z

50

Thermal Neutron Scattering  

Science Journals Connector (OSTI)

... of its title. It is not for the nuclear physicist, nor even for the neutron physicist, but for the student of solids and liquids. "Thermal ... physicist, but for the student of solids and liquids. "Thermal neutron ...

G. E. BACON

1968-11-09T23:59:59.000Z

51

Neutron scattering and ribosomes  

Science Journals Connector (OSTI)

... the complexity of intra-ribosomal interactions. This is however by no means the case with neutron ...neutronscattering ...

Richard Brimacombe

1977-06-23T23:59:59.000Z

52

NXS 2010 - Neutron Scattering School  

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

2-26, 2010 2-26, 2010 Argonne National Laboratory, Argonne, IL Oak Ridge National Laboratory, Oak Ridge, TN NXS2010 Travel Airport Shuttles Departure Flights Schedule Participants Lectures Lecturers Lecture Notes/Videos Experiments Schedule, Desc, Groups Student Presentations ANL Facilities APS Facility ANL Map ANL Visitor's Guide ORNL Facilities HFIR Facility SNS Facility HFIR/SNS Map Access Requirements ANL ORNL Rad Worker Training Study Guide Wireless Networks ANL ORNL Safety & Security Rules ANL ORNL NSSA New Initiatives NSSA Weblink Contacts ANL ORNL 12th National School on Neutron & X-ray Scattering 2009 Neutron Scattering School participants 2010 National School Participants Students share their thoughts about NXS 2010. Purpose: The main purpose of the National School on Neutron and X-ray Scattering is to educate graduate students on the utilization of major neutron and x-ray facilities. Lectures, presented by researchers from academia, industry, and national laboratories, will include basic tutorials on the principles of scattering theory and the characteristics of the sources, as well as seminars on the application of scattering methods to a variety of scientific subjects. Students will conduct four short experiments at Argonne's Advanced Photon Source and Oak Ridge's Spallation Neutron Source and High Flux Isotope Reactor facilities to provide hands-on experience for using neutron and synchrotron sources.

53

Neutron-Neutron Scattering at Low Energies  

Science Journals Connector (OSTI)

This paper investigates the information contained in a neutron-neutron scattering experiment at low energies which could be performed by colliding beams coming from an underground nuclear explosion. The significance of such an experiment is discussed from the point of view of a check on charge symmetry and charge independence, and it is found that because of the electromagnetic complications in proton-proton scattering, and because of the proton-neutron mass difference, the knowledge of neutron-neutron scattering would be of considerable value. The functional form of the experimental data which is most convenient for analysis and the approximate relative magnitude of the terms is investigated, and it is concluded that for the kind of experiment which is envisaged (measuring cross sections to 10% from 20 keV to 2 MeV) only two parameters should be kept in the effective-range expansion. The connection between the number and distribution of energies at which the cross section is measured and the error on the individual measurements, on the one hand, and the accuracy of the effective-range parameters deduced from the experiments, on the other, is given explicitly and is found also to depend on the absolute magnitude of the scattering length. The results show that ten 10% measurements, suitably distributed between 20 keV and 2 MeV, can determine the sign of the scattering length to four standard deviations, the magnitude of the effective range to 50-70%, and the magnitude of the scattering length to about 3%. Finally, the relationship between the variation of the effective-range parameters and the corresponding variation in the parameters of the scattering potential is studied, and it is found that, while this relationship is strongly shape-dependent, a small change in the potential parameters, in any case, results in a large change in the scattering length, but a small one in the effective range. Numerical relationships show that, even in the worst case, the variation in the scattering length is about eight times the variation in the potential parameter. It is concluded that a 10% experiment at 20 energies between 20 keV and 2 MeV would be able to get information on the potential parameters sufficiently accurately so that charge-dependent or charge-symmetry violating effects could be detected.

Michael J. Moravcsik

1964-11-09T23:59:59.000Z

54

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

55

Los Alamos Neutron Science Center  

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

Neutron Science Center gets capacity boost December 2, 2010 Los Alamos National Security funds upgrade to key facility LOS ALAMOS, New Mexico, December 2, 2010-The National Nuclear...

56

Scattering of Fast Neutrons by Boron  

Science Journals Connector (OSTI)

The cross section of boron for the scattering of fast neutrons through angles greater than 30 was measured at neutron energies between 0.2 and 3 Mev.

H. H. Barschall; M. E. Battat; W. C. Bright

1946-10-01T23:59:59.000Z

57

NXS 2013 - Neutron Scattering School  

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

5th National School on Neutron and X-Ray Scattering 5th National School on Neutron and X-Ray Scattering August 10-24, 2013 Argonne National Laboratory, Argonne, IL Oak Ridge National Laboratory, Oak Ridge, TN NXS2013 Schedule Participants Image Gallery Travel Info Thank you Lectures Lecture Notes/Videos Experiments ANL Facilities ANL Map (jpg) ANL Map (pdf) ANL Visitor's Guide ORNL Facilities HFIR Facility SNS Facility HFIR/SNS Map Wireless Networks ORNL Safety & Security Rules ORNL NSSA Weblink Contacts ANL ORNL 2013 NXS School Participants 2013 NXS Participants. NXS interveiws 2013 Click the image to download the video. Video Interviews: Participants answer questions about their experiences at NXS 2011. Your feedback about lectures and experiments is important for evaluating this year's Neutron and X-ray Scattering School and for making improvements for future participants. We sincerely hope that each of you will complete the survey by the end of the school.

58

Thermal neutron scattering  

Science Journals Connector (OSTI)

... and liquids. They have just the right wavelength for atomic physics; and, as nuclear scattering takes place effectively at a point, one can use the ... takes place effectively at a point, one can use the scattered intensity to disentangle the motion of atoms. The momentum transfer dependence of ithe ...

D. V. Bugg

1979-06-14T23:59:59.000Z

59

Neutron scattering at high pressure  

Science Journals Connector (OSTI)

Neutron scattering spectra at pressures up to 30 kilobar in the temperature range 3004 K have been obtained with a compact clamped type apparatus. The pressure cell geometry by allowing the detection of neutronsscattered in a plane makes it compatible with operation on crystal spectrometers both for elastic and inelastic scattering. The instrument is light (4.5 kg) and easy to move. An external diameter of 68 mm makes the pressure cell adaptable to standard cryostats or furnaces.

D. Bloch; J. Paureau; J. Voiron; G. Parisot

1976-01-01T23:59:59.000Z

60

Scattering of Neutrons by Deuterons  

Science Journals Connector (OSTI)

The elastic scattering of neutrons by deuterons is considered for energies small enough so that only the l=0 part of the incident wave is different from the corresponding part of a plane wave. The Breit-Feenberg Hamiltonian is used, assuming the same potential between all pairs of particles. Any possible polarization of the deuteron by the neutron is neglected, although the individual particles in the deuteron are taken into account by an approximate method. This method is capable of including exchange between the two neutrons. When the exchange term is included, the theory gives a cross section for thermal neutrons two to three times greater than observed; the cross section for 2.5 Mev neutrons is slightly greater than observed.

L. I. Schiff

1937-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "neutron scattering center" 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

Neutron Scattering Methods of Investigating Clay Systems  

Science Journals Connector (OSTI)

Of the techniques surveyed in the present proceedings, neutron scattering is probably the least familiar to clay ... a rather simple account of the theory of neutron scattering, while the third section describes ...

D. Keith Ross; Peter L. Hall

1980-01-01T23:59:59.000Z

62

10th LANSCE School on Neutron Scattering  

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

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

63

11th LANSCE School on Neutron Scattering  

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

11th LANSCE School on Neutron Scattering LANSCE 11th LANSCE School on Neutron Scattering Home Abstract Lecturers Hands-On Experiments Free Day About the School Sponsors FAQ's...

64

Neutron scattering reaps Nobel for physics  

Science Journals Connector (OSTI)

... through its joint award to Bertrand Brockhouse and Clifford Shull for their work in developing neutron inelastic ... inelastic scattering and ...

Philip Ball

1994-10-20T23:59:59.000Z

65

Scattering of Neutrons by Protons  

Science Journals Connector (OSTI)

... THEORETICAL investigations of the interaction of protons and neutrons have been given by Wigner, Heisenberg and Major ana. A very valuable check on ... ana. A very valuable check on their conclusions is provided by the study of the scattering cross-section of the hydrogen nucleus for ...

E. T. BOOTH; C. HURST

1936-12-12T23:59:59.000Z

66

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.

67

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

68

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

69

Polarization Analysis of Thermal-Neutron Scattering  

Science Journals Connector (OSTI)

A triple-axis neutron spectrometer with polarization-sensitive crystals on both the first and third axes is described. The calculation of polarized-neutron scattering cross sections is presented in a form particularly suited to apply to this instrument. Experimental results on nuclear incoherent scattering, paramagnetic scattering, Bragg scattering, and spin-wave scattering are presented to illustrate the possible applications of neutron-polarization analysis.

R. M. Moon; T. Riste; W. C. Koehler

1969-05-10T23:59:59.000Z

70

Small-angle neutron scattering and neutron reflectometry  

Science Journals Connector (OSTI)

Diffraction methods, interpreted loosely, could be applied to the techniques of wide-angle X-ray scattering, small-angle X-ray scattering, electron diffraction, small-angle neutron scattering, small-angle light s...

R. W. Richards

1993-01-01T23:59:59.000Z

71

NEUTRON: a program for computing phonon extinction rules of inelastic neutron scattering and thermal diffuse scattering experiments  

Science Journals Connector (OSTI)

NEUTRON is a program for the determination of phonon extinction rules in inelastic neutron scattering experiments.

Kirov, A.K.

2003-07-19T23:59:59.000Z

72

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

73

Spin Waves and Neutron Scattering  

Science Journals Connector (OSTI)

A review is given of the problems in this field and of the possibilities opened up by the fact that neutron scattering gives access to the time?dependent spin?correlation function in magnets over virtually the whole range of q t and T. New experimental results are given in connection with magnon energy linewidth and renormalization and some data are presented for the spin?wave stiffness of bcc 3d transition?metal alloys as a function of electron concentration showing effects explained by the electronic density?of?states curve. It is pointed out that the ground?state fluctuations of magnets give rise to effects in the formulas for neutron scattering.

R. D. Lowde

1965-01-01T23:59:59.000Z

74

Scattering of Neutrons in Polycrystals  

Science Journals Connector (OSTI)

Although elastic and first-order inelastic cross sections for a neutron against a Debye crystal have already been determined, expressions for higher order inelastic collisions have not been calculated, and would be very complex for the Debye model. The calculation of the total inelastic cross section involving the emission of an arbitrarily large number of phonons is here presented for a neutron against an Einstein polycrystal. The result, as one would expect, is essentially the same as that given by Fermi for amorphous scatterers, except at high neutron energies where we have calculated the cross section for the ejection of the struck nucleus from its lattice. The coherent elastic cross section is also determined; it is important for energies as high as 1 volt, and does not differ appreciably from that previously calculated for a Debye crystal. The total cross section, the sum of the coherent and incoherent parts, is compared with the experimental data on beryllium.

R. J. Finkelstein

1947-11-15T23:59:59.000Z

75

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

Office of Science (SC) Website

Neutron Scattering Neutron Scattering Materials Sciences and Engineering (MSE) Division MSE Home About Research Areas Energy Frontier Research Centers (EFRCs) DOE Energy Innovation Hubs BES Funding Opportunities The Computational Materials and Chemical Sciences Network (CMCSN) Theoretical Condensed Matter Physics Scientific Highlights Reports and Activities Principal Investigators' Meetings BES Home Research Areas Neutron Scattering Print Text Size: A A A RSS Feeds FeedbackShare Page This activity supports basic research on the fundamental interactions of neutrons with matter to achieve an understanding of the atomic, electronic, and magnetic structures and excitations of materials and their relationship to materials properties. Major emphasis is on the application of neutron scattering, spectroscopy, and imaging for materials research, primarily at

76

Neutron scattering above 25 MeV with monoenergetic neutrons  

Science Journals Connector (OSTI)

Technical problems encountered in measuring elastic and inelastic neutron scattering at kinetic energies well above 25 MeV are considered by extrapolating from experience with lower energy neutrons. It is concluded that all of the techniques required for a high?quality systematic study of neutron scatteringwith the notable exception of a suitable accelerator facilityare at hand.

Roger W. Finlay

1985-01-01T23:59:59.000Z

77

Neutron-Proton Scattering at Small Angles  

Science Journals Connector (OSTI)

24 May 1955 research-article Neutron-Proton Scattering at Small Angles...Thresher R. G. P. Voss R. Wilson Neutron-proton scattering has been measured from 6 to 61 5 degrees c.m. for neutrons of effective energy 105 3 and 137 5...

1955-01-01T23:59:59.000Z

78

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

79

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...

80

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

Note: This page contains sample records for the topic "neutron scattering center" 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

Neutron Scattering Experiment on Solid 3He  

Science Journals Connector (OSTI)

Magnetic neutron scattering probes the order parameter symmetry and magnitude ... as well as exchange parameters in a critical scattering experiment above the ordering temperature. Therefore we propose an experim...

Stephan Schttl; Konrad Siemensmeyer; Vitaliy Boyko

2002-01-01T23:59:59.000Z

82

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

83

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"

84

Rotational Correlation Function of Spherical Rotors and Neutron Scattering  

Science Journals Connector (OSTI)

......Function of Spherical Rotors and Neutron Scattering Juichiro Hama Tuto Nakamura...Correlation Effect on the Slow Neutron Scattering by Polyatomic Molecules with...A. , Kowalska A. Thermal Neutron Scattering-Egelstaff P. A., ed......

Juichiro Hama; Tuto Nakamura

1971-12-01T23:59:59.000Z

85

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

86

Neutron Scattering from Liquid Helium at Large Momentum Transfer  

Science Journals Connector (OSTI)

......letter Letters to the Editor Neutron Scattering from Liquid Helium at Large...Vol. 46 (1971), No. 1 Neutron Scattering from Liquid Helium at Large...Feynman diagram for the elastic scattering of a neutron from liquid helium, where......

Sigenobu Sunakawa; Kazuo Okajima; Kiyohisa Matsuda

1971-07-01T23:59:59.000Z

87

Slow Neutron Scattering and Space-Time Correlation Functions  

Science Journals Connector (OSTI)

......research-article Articles Slow Neutron Scattering and Space-Time Correlation...Osaka The cross section for neutron scattering is studied in the light of...Quasi-Classical Theory of Slow Neutron Scattering Takeo Nishigori and Sigenobu......

Sigenobu Sunakawa; Shuichiro Yamasaki; Takeo Nishigori

1967-06-01T23:59:59.000Z

88

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

89

Quasi-Classical Theory of Slow Neutron Scattering  

Science Journals Connector (OSTI)

......Quasi-Classical Theory of Slow Neutron Scattering Takeo Nishigori Sigenobu...quasi-classical formula of the scattering cross section of a slow neutron is proposed. The formula...Approximation for Slow Neutron Scattering Takeo Nishigori References......

Takeo Nishigori; Sigenobu Sunakawa

1969-03-01T23:59:59.000Z

90

Neutron scattering study of human serum low density lipoprotein  

Science Journals Connector (OSTI)

Neutron scattering study of human serum low density...human serum have been determined by neutron scattering. From measurements in various H2O...protein emerging from the lipid core. Neutron scattering study of human serum low density...

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

1975-01-01T23:59:59.000Z

91

Neutron scattering studies of materials under pressure  

Science Journals Connector (OSTI)

A review of experimental techniques used in the study of materials under applied pressure by neutron scattering is given along with a discussion of the amount of information that can be obtained from various pressure conditions. Some experimental results are presented to illustrate both the feasibility and the interest of elastic and inelastic neutron scattering measurements of materials under pressure.

C. Vettier

1982-01-01T23:59:59.000Z

92

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

Office of Science (SC) Website

Neutron Scattering Facilities Neutron Scattering Facilities Scientific User Facilities (SUF) Division SUF Home About User Facilities X-Ray Light Sources Neutron Scattering Facilities Nanoscale Science Research Centers Electron-Beam Microcharacterization Centers Accelerator & Detector Research & Development Principal Investigators' Meetings Scientific Highlights Construction Projects BES Home User Facilities Neutron Scattering Facilities Print Text Size: A A A RSS Feeds FeedbackShare Page This activity supports the operation of three DOE neutron scattering facilities, which are unique and effective tools for probing the structure of matter. Neutron scattering is particularly well-suited for determining the atomic positions of both light and heavy atoms in a solid and thermal fluctuations in these positions. In addition the neutron

93

A beam swinger for neutron scattering  

Science Journals Connector (OSTI)

A conceptual design is presented for a system that provides for varying the angle of incidence of neutron flux on a scattering target. This makes possible the use of long flight paths for time?of?flight spectroscopy of scattered neutrons. The system is also applicable to measurements of neutron induced charged particle reactions. Special emphasis is placed on the energy range of 50200 MeV.

C. D. Goodman

1985-01-01T23:59:59.000Z

94

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

95

2012 LANSCE Neutron Scattering School | Los Alamos National Laboratory  

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

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

96

2012 LANSCE Neutron Scattering School | Los Alamos National Laboratory  

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

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

97

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...

98

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

99

Neutron Scattering on Frustrated Magnets  

Science Journals Connector (OSTI)

Frustration denotes the inability of a system to satisfy all pairwise interactions and enables a large variety of fascinating ground states that depend on the very details of the interactions involved. The focus will be on neutron scattering studies of spinel compounds AB 2 X 4 . It is well known that the B?site ions form a pyrochlore lattice with inherent strong geometric frustration (GF). Among these compounds heavy fermion?like behaviour of LiV 2 O 4 and new kinds of magneto?elastic coupling phenomena in chromate spinels will be considered. Recently also the A?site spinels has been shown to be subject to strong frustration effects not only for the spin sector but also for the orbital and structural degrees of freedom. Corresponding ordering phenomena in MAl 2 O 4 ( M ?=? Mn Fe Co ) will be discussed.

A. Krimmel; V. Tsurkan; A. Loidl; H. Mutka; M. M. Koza

2008-01-01T23:59:59.000Z

100

Measurement of Lattice Vibrations in Vanadium by Neutron Scattering  

Science Journals Connector (OSTI)

The energy spectrum of slow neutrons inelastically scattered by vanadium metal has been measured by the time-of-flight technique. The neutrons gain energy by absorbing quanta of lattice vibration energy (phonons). As the nuclear scattering amplitude of vanadium is incoherent, the energy distribution of scattered neutrons is directly related to the frequency distribution of lattice vibrations. The measured neutron energy spectrum, as well as the derived frequency distribution, shows a clearly resolved double peak. This structure, which is distinctly different from the simple Debye distribution, but expected on the basis of detailed calculations, has heretofore not been amenable to direct measurement. The measured frequency distribution is compared with calculations for a body-centered cubic lattice by the Born-von Krmn theory and qualitative agreement is obtained. A more exact comparison awaits measurement of the elastic constants of vanadium.

C. M. Eisenhauer; I. Pelah; D. J. Hughes; H. Palevsky

1958-02-15T23:59:59.000Z

Note: This page contains sample records for the topic "neutron scattering center" 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

Slow Neutron Scattering by the Titanium Isotopes  

Science Journals Connector (OSTI)

Neutron diffraction studies are reported on isotopically enriched samples of TiO2 from which are evaluated the coherent scattering amplitudes of the titanium isotopes. Scattering amplitudes of +0.48, +0.33, -0.58, +0.08, and +0.5510-12 cm were established for the titanium isotopes of mass 46, 47, 48, 49, and 50, respectively. The major isotope Ti48 is thus responsible for the anomalous scattering amplitude, -0.3410-12 cm, characteristic of the normal element. Pronounced nuclear scattering resonance effects on the observed neutron scattering are suggested to occur for most of the isotopes.

C. G. Shull; M. K. Wilkinson; M. H. Mueller

1960-05-01T23:59:59.000Z

102

Neutron Scattering by Liquid Neon  

Science Journals Connector (OSTI)

A theory for neutron scattering by a semiclassical system, which is appropriate for liquid neon, is described. The theory is based on a generalized mean-field approximation involving the polarization potential and the screened response function, similarly to what has been done previously for argon and helium. The screened response function is assumed to be a sum of Gaussian functions weighted by the momentum-distribution function. The polarization potential and the width of the Gaussians are determined by the zeroth and third moments of the scattering law. The momentum distribution has the MaxwellBoltzmann form, but includes quantum corrections to order ?2. The quantum-mechanical zero-point energy is found to increase the kinetic energy per particle to a value of about 30% greater than the classical equipartition value. Calculations have been done for wave-vector transfers in the range 0.75-5.5 times the wave vector at the principal maximum in the static-structure factor, and the theoretical line shapes have been folded with the resolution function for the experiments of Buyers et al. Comparison of the position of the maximum, full width at half-maximum, and line shapes with the experimental results gives good agreement.

W. C. Kerr and K. S. Singwi

1973-03-01T23:59:59.000Z

103

Quasiclassical Theory of Neutron Scattering  

Science Journals Connector (OSTI)

A Wigner representation is used for expressing the thermal average occurring in the Van Hove formalism for slow-neutron scattering from macroscopic systems. For quadratic and lower-degree potentials, results in closed form may be obtained, and in general, an asymptotic series expansion in powers of ? is still possible for the incoherent part of the differential cross section for quasiclassical systems. The lead term of this asymptotic expansion results in an expression relating the cross section to a four-dimensional Fourier inversion of the classical space-time distribution Gsc(r,t), and hence to the classical motions of the atoms in the scattering system. Correction terms of O(?2) have been obtained explicitly and found to be small for systems at ordinary temperatures. It is shown that (at least to order ?2) the results obey the constraint of detailed balance and satisfy the Placzek moments. It is also shown that because of the contact nature of the Fermi pseudopotential, the exact classical limit (??0) for any system is the ideal-gas result. In principle, the results can be extended to all orders of ?2. No similar asymptotic expansion appears to exist, however, for the coherent cross section. The analysis is then used for deriving other existing prescriptions and for examining their implications and range of validity.

M. Rosenbaum and P. F. Zweifel

1965-01-25T23:59:59.000Z

104

Electroweak bremsstrahlung from neutron-neutron scattering  

Science Journals Connector (OSTI)

Background: Nucleon-nucleon (NN) bremsstrahlung processes NN? (nn?, np?, and pp?) have been extensively investigated. Neutrino-pair bremsstrahlung processes from nucleon-nucleon scattering NN?? (nn??, np??, and pp??) have recently attracted attention in studies of neutrino emission in neutron stars. The calculated NN?? cross sections (or emissivities) are found to be sensitive to the two-nucleon dynamical model used in the calculations. Purpose and Method: A realistic one-boson-exchange (ROBE) model for NN interactions is used to construct the electroweak bremsstrahlung amplitudes using the well-known nucleon electromagnetic and weak interaction vertices. The constructed nn? and nn?? amplitudes are investigated by applying them to calculate nn? and nn?? cross sections, respectively. Results: (i) The 190-MeV ROBE nn? cross sections agree well with those calculated using the TuTts amplitude, but they are in disagreement with those calculated using the Low amplitude. (ii) The calculated nn?? cross sections using the ROBE amplitude at the neutrino-pair energy ? = 1 MeV are in quantitative agreement with those calculated by Timmermans et al. [Phys. Rev. C 65, 064007 (2002)], who used the leading-order term of the soft neutrino-pair bremsstrahlung amplitude. Conclusions: The nn? amplitude in the ROBE approach, which obeys the soft-photon theorem, has a predictive power similar to that of the TuTts amplitude. The nn?? amplitude in the ROBE approach, which is consistent with the soft neutrino-pair bremsstrahlung theorem, has a predictive power similar to that of the soft neutrino-pair bremsstrahlung amplitude of Timmermans et al. in the low neutrino-pair energy region.

Yi Li; M. K. Liou; W. M. Schreiber

2009-09-22T23:59:59.000Z

105

Total Neutron Scattering in Vitreous Silica  

Science Journals Connector (OSTI)

The structure of Corning superpure vitreous silica glass has been investigated with neutrons. A new method of analysis using variable neutron wavelengths and the measurement of total scattering cross sections from transmission experiments is developed and the results are compared with those from differential x-ray scattering. The total neutron scattering method permits a simple and direct structure analysis with resolution apparently superior to x-rays. The preliminary results compare well in a first approximation analysis with the basic structure model of Warren and others and in addition the neutron-determined atomic radial distribution curve exhibits some finer details than the x-ray results. Thermal inelastic scattering of neutrons was corrected for in an approximate way.

R. J. Breen; R. M. Delaney; P. J. Persiani; A. H. Weber

1957-01-15T23:59:59.000Z

106

Neutron scattering instrumentation at reactor based installations  

Science Journals Connector (OSTI)

During the past decade neutron scattering techniques have been applied to an increasingly wide range of scientific problems. Concurrently a number of substantial improvements of neutron scattering instrumentation have occurred to stimulate this trend. In this article several such developments which have occurred at reactor?based installations are described. Individual spectrometer components which are discussed in some detail include: neutron?optical devices such as guide tubes supermirrors and multilayer systems; neutronmonochromators with optimum reflectivity mosaic and focusing characteristics; position?sensitive detectors of several types; and equipment required for neutronpolarizationanalysis. Several novel spectrometers which have enhanced the role of neutron scattering during the past ten years are also described. These include spectrometers for small?angle scattering backscattering and neutron spin echo. An extensive bibliography is included which covers both early and more recent developments.

Roger Pynn

1984-01-01T23:59:59.000Z

107

LANSCE | Lujan Center | Highlights | Neutron Reflectometry (NR...  

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

of the crystallinity of the sample (single crystal, polycrystalline, or amorphous). Neutron scattering is a unique tool to study such nanolayered composites because the...

108

Neutron-Proton Scattering near 180 at 93 Mev  

Science Journals Connector (OSTI)

A measurement has been made with neutrons of 93-Mev effective energy of the angular distribution of n-p scattering near 180 in the center-of-mass system. The results show that the magnitude of the cross section approaches the 180 point smoothly, without any sudden increase.

W. Selove; K. Strauch; F. Titus

1953-11-01T23:59:59.000Z

109

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.

110

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

111

Scattering of Fast Neutrons by Magnesium  

Science Journals Connector (OSTI)

Angular distributions for the scattering of fast neutrons by magnesium have been obtained for incident neutron energies of 2.0, 3.0, 4.0, and 5.0 Mev. The results for the elastic scattering have been compared with optical model calculations. The results for the inelastic scattering have been compared with calculations based on Hauser-Feshbach theory, and with direct interaction predictions. Over the range of conditions investigated, compound nucleus formation appears to be the dominant mechanism for the inelastic scattering.

D. B. Thomson; L. Cranberg; J. S. Levin

1962-03-15T23:59:59.000Z

112

Neutron Scattering and Ordering of Nuclear Spins  

Science Journals Connector (OSTI)

The ordering of nuclear spins takes place at extremely low temperatures because of the weakness of the interactions between their magnetic moments. Neutron scattering is the traditional and unique method to ... (...

M. Steiner

2004-06-01T23:59:59.000Z

113

Neutron scattering experiments on partially disordered materials  

Science Journals Connector (OSTI)

Neutron scattering methods to characterize intercalation compounds of layered conducting compounds are presented. It is shown that complex structural and chemical processes exist which must be understood before an in depth study of selected systems can be started.

C. Riekel

1982-01-01T23:59:59.000Z

114

Low-Energy Neutron-Neutron Scattering Parameters  

Science Journals Connector (OSTI)

A precise evaluation of the spectrum in the reaction ?-+D?2n+?, including final-state interactions is presented with a view of determining the neutron-neutron scattering length. Approximations of previous calculations are examined and avoided where their effect is found to be significant. Sufficiently accurate experiments should be capable of distinguishing this parameter to an error of 1 F.

Myron Bander

1964-06-08T23:59:59.000Z

115

Neutron scattering from ?-Ce at epithermal neutron energies  

Science Journals Connector (OSTI)

Neutron scattering data, using neutrons of incident energies as high as 2...?-Ce and ?-Ce-like systems such as CeRh2, CeNi2, CeFe2, CeRu2, and many others that point clearly to the substantially localized 4f elec...

A. P. Murani

2008-10-01T23:59:59.000Z

116

Multiple-scattering effects on smooth neutron-scattering spectra  

Science Journals Connector (OSTI)

Elastic and inelastic incoherent neutron-scattering experiments are simulated for simple models: a rigid solid (as used for normalization), a glass (with a smooth distribution of harmonic vibrations), and a viscous liquid (described by schematic mode-coupling equations). In cases where the input scattering law factorizes into a wave-number-dependent amplitude and a frequency-dependent spectral distribution, the latter is only weakly affected by multiple scattering, whereas the former is severely distorted.

Joachim Wuttke

2000-11-01T23:59:59.000Z

117

Diffuse Neutron Scattering from Crystal Imperfections [and Discussion  

Science Journals Connector (OSTI)

...1980 research-article Diffuse Neutron Scattering from Crystal Imperfections...years has been the small angle scattering centred on 000. Examples are...comparison with small angle neutron scattering, much less work has been done...

1980-01-01T23:59:59.000Z

118

Neutron scattering studies of carbon nanotubes  

Science Journals Connector (OSTI)

We report on neutron scattering studies of single wall carbon nanotubes (SWNT). Small angle scattering was used to investigate the structure of SWNT suspensions. Diffraction data were compared to calculations on finite-size bundles of SWNT in order to estimate the distribution of tube diameters. Lastly we present an inelastic neutron scattering study of the density of phonon states in SWNT. In the frequency range of intramolecular modes the measured spectrum is found to be in good agreement with that calculated on an isolated (10 10) nanotube.

E. Anglaret; S. Rols; J. L. Sauvajol

1999-01-01T23:59:59.000Z

119

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.

Professor Simon Billinge

2011-06-17T23:59:59.000Z

120

11th LANSCE School on Neutron Scattering | About the School  

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

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

Note: This page contains sample records for the topic "neutron scattering center" 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

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

122

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

123

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

124

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

125

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...

126

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

127

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

128

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

129

Appendix - Neutron Scattering Lengths and Cross Sections  

Science Journals Connector (OSTI)

Abstract In this appendix, we present an updated table of neutron scattering lengths and cross sections for most of the known nuclides, based on preexisting works. We include the coherent and incoherent scattering lengths, as well as the spin-dependent scattering lengths b+ and b?, in cases where this information is available. Also presented are the scattering coherent, incoherent, total, and absorption cross sections. We present an overview of the fundamental theory of the magnitudes to which the table is referred, and also a summary of the main experimental techniques used in determining these magnitudes.

Javier Dawidowski; Jos Rolando Granada; Javier Roberto Santisteban; Florencia Cantargi; Luis Alberto Rodrguez Palomino

2013-01-01T23:59:59.000Z

130

Neutron Scattering Data Vickie Lynch, Jose Borreguero-Calvo,  

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

Discovery in Neutron Scattering Data Vickie Lynch, Jose Borreguero-Calvo, Mark Hagen & Thomas Proffen Neutron Data Analysis & Visualization Division Galen Shipman & Bobby Sumpter...

131

Neutron Sciences - Neutron Scattering Dynamics in Polymer Family  

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

Neutron scattering characterizes dynamics in polymer family Neutron scattering characterizes dynamics in polymer family Research Contact: Christine Gerstl December 2012, Written by Agatha Bardoel Understanding the interplay between structure and dynamics is the key to obtaining tailor-made materials. In the last few years, a large effort has been devoted to characterizing and relating the structure and dynamic properties in families of polymers with alkyl side groups. Now researchers have used quasielastic neutron scattering to investigate the hydrogen dynamics in poly(alkylene oxide)s with different side-chain lengths at temperatures below, as well as above, the glass transition. The combination of techniques and instruments used is bringing a more complete understanding of multiple contributions to system dynamics. The results

132

Fast-Neutron Scattering from Germanium  

Science Journals Connector (OSTI)

Elastic and inelastic neutron scattering cross sections of natural germanium were measured in the incident neutron energy range 0.3-1.5 MeV with incident energy resolutions of ?20 keV. Neutron-velocity and ?-ray spectroscopic methods were employed to resolve the scattering to individual low-lying states. The results were interpreted in terms of the optical model and the statistical compound-nucleus model including effects due to fluctuations and correlations of resonance widths. Measured cross sections for inelastic scattering to a number of excited states in even Ge isotopes were reasonably well described by the statistical model of Hauser and Feshbach without corrections for width fluctuations and correlations.

D. Lister and A. B. Smith

1969-07-20T23:59:59.000Z

133

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

134

Neutron Scattering Application of Polarized Solid Target in Materials Research  

SciTech Connect (OSTI)

Neutron scattering is one of the most important tools for materials research. However, neutrons are very expensive to produce. Even with the best sources, such as the newly completed Spallation Neutron Source at the Oak Ridge National Laboratory, most neutron scattering experiments are still flux limited. One way to improve the experimental data is polarized neutron scattering from polarized solid target: the strong spin-dependent neutron scattering cross-section can increase the coherent scattering and decrease the incoherent scattering at the same time, thereby significantly enhancing the signal to noise ratio. Hydrogen, abundant in most soft condensed matters, has a strong spin-dependent scattering cross-section. Early applications of polarized neutron scattering in biological soft condensed matters have already demonstrated the huge potential of this technique. Here we describe the polarized target program at the SNS. The program is under active construction and is aimed at serving neutron scattering at the SNS.

Zhao, Jinkui [ORNL

2008-09-01T23:59:59.000Z

135

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.

136

Aqueous Solutions and Neutron Scattering  

Science Journals Connector (OSTI)

The application of neutron diffraction techniques to aqueous solutions is described, and a framework involving the use of isotopic substitution is set up to illustrate the scope of the method. Specific applications described include a study of glassy ...

G. W. Neilson; J. E. Enderby

1996-01-25T23:59:59.000Z

137

Neutron scattering in Mineral Sciences:  

Science Journals Connector (OSTI)

...de WWW page: http://www.kfa-juelich.de FRG-1 Geesthacht (D) Type: Swimming Pool Cold Neutron Source. Flux: 8...Div. Wfn-Neutronscattering, GKSS Research Centre, 21502 Geesthacht, Germany Telephone: 49 (0) 4152 87 1316 / 2503 Fax: 49...

Romano RINALDI

138

Characterization of Metallurgical Chars by Small Angle Neutron Scattering  

Science Journals Connector (OSTI)

Characterization of Metallurgical Chars by Small Angle Neutron Scattering ... Small angle scattering measures the intensity I(q) of scattered neutrons as a function of scattering angle ? from the input beam, or alternatively, as a function of the scattering vector q:? q = |q| = (4?/?) sin(?/2), where ? is the wavelength of the incident wave. ...

I. Snook; I. Yarovsky; H. J. M. Hanley; M. Y. Lin; D. Mainwaring; H. Rogers; P. Zulli

2002-08-06T23:59:59.000Z

139

Neutron Scattering in Ortho- and Parahydrogen  

Science Journals Connector (OSTI)

The cross section for the scattering of cold neutrons by parahydrogen is sensitive to the range of the forces in the triplet state. To facilitate the determination of the range from such measurements, expressions have been obtained for the dependence of the ortho and para cross sections on neutron energy and hydrogen temperature. The interpretation of transmission measurements is complicated by the existence of radiative capture, which is comparable in importance to scattering in parahydrogen. The different energy dependence of the two processes should permit an accurate determination of the individual cross sections.

Morton Hamermesh and Julian Schwinger

1947-05-15T23:59:59.000Z

140

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

Note: This page contains sample records for the topic "neutron scattering center" 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

Neutron scattering length of lithium and boron and their isotopes  

Science Journals Connector (OSTI)

Coherent neutron scattering lengths and free cross sections were measured in order to determine the spin dependent scattering lengths of the isotopes of Li and B.

L. Koester; K. Knopf; W. Waschkowski

1983-01-01T23:59:59.000Z

142

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

143

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

144

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

145

Rotational motion in plastic quinuclidine : Results from quasielastic neutron scattering  

E-Print Network [OSTI]

563 Rotational motion in plastic quinuclidine : Results from quasielastic neutron scattering C. 2014 Results of incoherent quasielastic neutron scattering experiments on quinuclidine, C7Hl3N, in its

Boyer, Edmond

146

Aspherical refractive lenses for small-angle neutron scattering  

Science Journals Connector (OSTI)

This paper discusses the testing and simulation of aspherical neutron lenses as focusing elements for small-angle neutron scattering and their transparency with respect to thermal diffuse scattering.

Frielinghaus, H.

2009-06-20T23:59:59.000Z

147

11th LANSCE School on Neutron Scattering | Lecturers  

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

they lead to new knowledge of existing materials or novel materials concepts. Examples of Neutron scattering, X-ray scattering and neutron or X-ray tomography will be shown which...

148

Study of neutron scattering contribution on Hp(10) and H*(10) calibration in the Brazilian National Low Scattering Laboratory  

Science Journals Connector (OSTI)

......Dosimetry (Neudos 12) Study of neutron scattering contribution on H p(10...22783-127 RJ, Brazil The neutron scattering at the Low Scattering Laboratory...of this work is to study the neutron scattering contribution for the quantities......

B. M. Freitas; W. W. Pereira; K. C. S. Patro; E. S. Fonseca; C. L. P. Mauricio

2014-10-01T23:59:59.000Z

149

Neutron scattering, a powerful tool to study clay minerals  

Science Journals Connector (OSTI)

Abstract Of the techniques used to study clay minerals, neutron scattering has become more familiar to clay scientists over the past decade. A brief account of neutron scattering theory is given in this review, followed by a description of measurements that can be made using neutron diffraction and neutron scattering spectroscopy, and especially quasi-elastic neutron scattering. Then recent examples of the application of neutron scattering methods to the study of clay minerals are presented, and finally the potential advantages of such experimental results when combined to molecular dynamics are discussed. To conclude, the potential perspectives that the European Spallation Source brings to this subject are pointed out.

Murillo L. Martins; Will P. Gates; Laurent Michot; Eric Ferrage; Virginie Marry; Heloisa N. Bordallo

2014-01-01T23:59:59.000Z

150

Off-specular scattering in neutron reflectometry  

SciTech Connect (OSTI)

When neutrons are scattered at small angles from planar, laterally homogeneous, stratified media, only specular (mirror like) reflection is observed. Sample inhomogeneities, such as interfacial roughness or voids, give rise to off-specular scattering which has been observed in many experiments with neutrons and x-rays. The easiest way to describe this scattering theoretically is based on the distorted-wave Born approximation (DWBA), which uses the neutron wavefunctions that describe reflection from a smooth surface as the basis functions for perturbation theory. From the DWBA one may obtain a number of qualitative results which are supported by experiment. Examples include the Yoneda fringes observed in reflection experiments with microscopically rough surfaces and the constant-q{sub z} fringes observed for multilayers with correlated, rough interfaces. One must, however, use the DWBA with care. When the correlation range within the reflecting interfaces is large--for example, when a surface is composed of misoriented facets--the approximation breaks down. Some authors have also reported a lack of quantitative agreement between versions of the DWBA calculations and the scattering observed with microscopically rough surfaces. A remarkable feature of neutron (or x-ray) reflectometry is the length scales that are probed within reflecting surfaces. These range from a few hundred Angstroms up to several microns, allowing neutron scattering to probe objects of a size normally visible by optical microscopy! The intent of this paper is to provide a simple description of scattering from rough surfaces that is accessible to a wide audience. Mathematical completeness is sacrificed in favor of intuitive arguments and experimental examples.

Pynn, R.; Baker, S.M.; Smith, G.; Fitzsimmons, M. [Los Alamos National Lab., NM (United States). Manuel Lujan Jr. Neutron Scattering Center

1995-03-01T23:59:59.000Z

151

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

152

Neutron scattering of transuranium materials  

SciTech Connect (OSTI)

A number of neutron experiments on transuranium materials are reviewed. Purpose of these experiments, which range from studies of crystal fields in the oxides to excitations in PuSb, is to increase our understanding of the 5f electron behavior across the first half of the actinide series. Comparisons are made with the more familiar uranium analogues.

Lander, G.H.

1986-01-01T23:59:59.000Z

153

Novel Neutron Detector for n-n Scattering Length Measurement.  

E-Print Network [OSTI]

??The neutron-neutron (n-n) scattering length is a fundamental parameter in nuclear physics; however, measurements are plagued with large uncertainties caused by neutron detector cross talk. (more)

Wilcox, Eva

2005-01-01T23:59:59.000Z

154

NEUTRON SCATTERING EVIDENCE FOR A SPIN-PEIERLS  

E-Print Network [OSTI]

NEUTRON SCATTERING EVIDENCE FOR A SPIN-PEIERLS GROUND STATE IN (TMTTF)2PF6 J.P. POUGET, P. FOURY results · magnetic caracterisation of the samples used · neutron scattering detection of the SP;elastic neutron scattering evidence of SP superlattice reflexions in (TMTTF)2PF6 (H12) Laboratoire Léon

Paris-Sud 11, Université de

155

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

156

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

157

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

158

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

159

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.

160

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

Note: This page contains sample records for the topic "neutron scattering center" 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

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

162

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

163

Neutron Scattering Society of America Purpose and New Initiatives  

E-Print Network [OSTI]

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

164

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.

165

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

166

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

167

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

168

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

169

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

170

Los Alamos Neutron Science Center gets capacity boost  

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

Neutron Science Center capacity boost Los Alamos Neutron Science Center gets capacity boost The facility can simulate the effects of hundreds or thousands of years of...

171

Study of Liquid Dynamics by Neutron Scattering  

Science Journals Connector (OSTI)

This paper reviews the information about the collective motions of atoms in liquids which can be obtained from neutron scattering experiments with particular attention to the rare gases and liquid metals. The current status of the theoretical interpretation is examined. Coherent neutron scattering from a monatomic liquid gives directly the spectrum of the correlation function for density fluctuations in the system for wavelengths in the range 110 . The results have a dual interpretation. On the one hand they may be understood in terms of a viscoelastic theory which takes into account the microscopic structure of the liquid; on the other hand fluctuations at these wavelengths may be interpreted in terms of vibrational modes as in an amorphous solid. The paper attempts to reconcile these two points of view. Qualitative differences between liquidargon and the liquid metals are discussed with reference to the connection between the neutron results and the microscopic properties of these liquids.

P. Schofield

1969-01-01T23:59:59.000Z

172

Test of time reversal symmetry with resonance neutron scattering  

Science Journals Connector (OSTI)

Discussions for using thermal neutron scattering from nuclei for symmetry measurements stem from past experiments which have observed large parity violating effects in neutron scattering. The proposed LAMPF II proton storage ring spallation neutron source is a vast improvement over the neutron source used in the parity measurements. A proposal for a time reversal symmetry measurement at the LAMPF II facility is presented. (AIP)

J. David Bowman

1986-01-01T23:59:59.000Z

173

13 - X-ray and Neutron Scattering  

Science Journals Connector (OSTI)

Abstract This chapter describes the use of neutrons and X-rays as probes in the study of structural and dynamic properties of metallic materials. Crystalline materials are characterized by their diffraction peaks related to their average crystallographic structure. In real crystals, locally displaced atoms and chemically (or isotopically for neutrons) different species may lead not only to changes of peak shapes and positions, but also to additional (diffuse) scattering between Bragg peak, including scattering around the primary beam (small-angle scattering). All these features can be used to extract information about the state of a sample, its compositional and structural variations on a scale depending on the scattering, in static and time-resolved kinetic studies. Energy-resolved scattering also offers an insight into solid-state dynamics on a microscopic scale. Some of the most important methods will be described and illustrated by instructive examples. The presentation offers a combined view of neutron and X-ray scattering, with the necessary simplifications dictated by space limitations. The special properties of thermal neutrons and of hard X-rays (now widely available at synchrotron radiation sources), their mutual combination, and combinations with other methods, in particular electron microscopy, offer ample opportunity to better understand and control materials properties. After a brief introduction to scattering from real crystals and some general ideas about long-range strains and Bragg peaks, the vicinity of Bragg peaks (displacement scattering at large scattering angles), the scattering far away from Bragg peaks (chemical heterogeneities, short-range order), and, in greater detail, small-angle scattering (which is not sensitive to the extent of crystallinity, but to nanoscale variations of chemical composition and of magnetization, precipitation) will be described, along with classical and more recent applications related to short-range ordering and precipitation in bulk and nanostructured alloys. Some other fields are only briefly addressed (grazing-incidence studies of surfaces, radiography, absorption spectroscopies, coherent X-rays). The final section offers some information on the influence of defects on lattice dynamics and on (slow) diffusive motion in materials.

Gernot Kostorz

2014-01-01T23:59:59.000Z

174

A More Informative Approach for Characterization of Polymer Monolithic Phases: Small Angle Neutron Scattering/Ultrasmall Angle Neutron Scattering  

Science Journals Connector (OSTI)

A More Informative Approach for Characterization of Polymer Monolithic Phases: Small Angle Neutron Scattering/Ultrasmall Angle Neutron Scattering ... Scattered neutrons were detected with a 64 cm 64 cm two-dimensional position sensitive detector with 128 128 pixels and 0.5 cm resolution per pixel. ...

Kathleen M. Ford; Brian G. Konzman; Judith F. Rubinson

2011-11-08T23:59:59.000Z

175

Scattering of Slow Neutrons by a Liquid  

Science Journals Connector (OSTI)

The differential cross section for coherent scattering of thermal neutrons by a liquid is given in general by the Fourier transform of a time-displaced radial density function. It is suggested here that, to an adequate degree of approximation, this time-displaced function can be expressed as a convolution of the ordinary radial density function with a self-diffusion function describing the wandering of an atom from an arbitrary initial position. The neutron scattering cross section then becomes the product of the Fourier transforms of these two functions. One of the transforms is the differential cross section for x-ray scattering and describes interference effects, the other governs the energy changes upon scattering. In this development the scatterer can be treated either quantum mechanically or classically. Recoil effects are not provided by the classical treatment, but this is a significant deficiency only in liquids of low atomic weight. Several models for calculating the self-diffusion function are considered, and from these it is suggested that a Gaussian function with a time-dependent width is a reasonable approximation for the case of a simple liquid. The principal features of the width are deduced. Quantization of the scatterer effects the width at small times. At large times the width depends only on the coefficient of self-diffusion of the liquid, and inelastic scattering is suggested as a means of determining this coefficient, as well as other features of atomic movement. The accuracy of the static approximation for determining liquid structures by neutron diffraction is assessed by considering the typical case of liquid lead near its melting point, and is found to be moderately good. The extension of the entire formalism to the case of polyatomic liquids is outlined.

George H. Vineyard

1958-06-01T23:59:59.000Z

176

Protein crystallography with spallation neutrons: the user facility at Los Alamos Neutron Science Center  

Science Journals Connector (OSTI)

The protein crystallography user facility at the neutron spallation source run by Los Alamos Neutron Science Center is described.

Langan, P.

2004-01-17T23:59:59.000Z

177

Neutron scattering on deformed nuclei  

Science Journals Connector (OSTI)

Measurements of neutron elastic and inelastic differential cross sections around 14 MeV for 9Be C 181 Ta 232Th 238U and 239Pu have been analyzed using a coupled channel (CC) formalism for deformed nuclei and phenomenological global optical model potentials (OMP). For the actinide targets these results are compared with the predictions of a semi?microscopic calculation using Jeukenne Lejeune and Mahaux (JLM) microscopic OMP and a deformed ground state nuclear density. The overall agreement between calculations and the measurements is reasonably good even for the very light nuclei where the quality of the fits is better than those obtained with spherical OMP.

L. F. Hansen; R. C. Haight; B. A. Pohl; C. Wong; Ch. Lagrange

1985-01-01T23:59:59.000Z

178

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.

179

Method of analysis of multiphonon and multiple-scattering effects in inelastic neutron scattering experiments  

Science Journals Connector (OSTI)

We present experimental results of inelastic neutron scattering experiments on a TiZr alloy, together ... measurements. A method of analysis of inelastic neutron scattering experiments is proposed, aimed at obta...

J. Dawidowski; G.J. Cuello; M. Koza; J.J. Blostein; G. Aurelio

2002-12-01T23:59:59.000Z

180

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

Note: This page contains sample records for the topic "neutron scattering center" 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

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

182

Neutron-Proton and Neutron-Carbon Scattering Amplitudes  

Science Journals Connector (OSTI)

Measurements of the n-p and n-C coherent atomic scattering amplitudes are described. The results aH=-3.7400.003 fm and aC=6.6480.003 fm were obtained by reflection measurements on seventeen various liquid mirrors with the neutron gravity refractometer, for which a more accurate method of evaluation is given. The mirrors were composed of the elements hydrogen, carbon, and chlorine. The atomic scattering amplitude of chlorine was found to be aCl=9.5800.002 fm. The new aH is of importance for describing the n-p system.

L. Koester and W. Nistler

1971-10-04T23:59:59.000Z

183

Neutron scattering in almost-classical liquids  

Science Journals Connector (OSTI)

A theory of quantum corrections for thermal-neutron scattering in almost-classical liquids is developed that goes beyond the usual quasiclassical approximations, which take only detailed balance and translational recoil into account, by also including quantum effects in the structure and dynamics of the liquid itself. The method that we use is similar to one which we have recently developed for calculating corrections for final-state interactions in deep-inelastic neutron scattering. In the present application the method requires an expansion of the moments of the dynamic structure factor in powers of ?2. We show that the required expansions can conveniently be obtained by an extension of a method due originally to Nelkin.

V. F. Sears

1985-04-01T23:59:59.000Z

184

Inelastic neutron scattering from confined molecular oxygen  

Science Journals Connector (OSTI)

Inelastic neutron-scattering measurements were carried out on condensed bulk and confined molecular oxygen. The phase transitions of the oxygen confined in cylindrical pores with diameter of ?94? are suppressed below their bulk temperatures or in the case of the lowest-temperature transition to the ? phase are suppressed entirely. This last observation is possibly due to the low latent heat of transition for this transition. Both elastic and inelastic neutron-scattering data indicate a mixing of oxygen crystal phases upon confinement. Magnetic ordering fluctuations in the ? phase are found to have similar energy-dependent profiles for confined and bulk excitations showing that the magnetic correlation function decay is unaffected by the finite crystal size in confinement.

Duncan Kilburn; Paul E. Sokol; Craig M. Brown

2008-12-29T23:59:59.000Z

185

Neutron Scattering by an Anharmonic Crystal  

Science Journals Connector (OSTI)

Baym's treatment of coherent scattering of slow neutrons by a crystal is examined and modified to include effects due to the cubic-anharmonic term in the lattice potential to second order in the coupling constant. Corrections to the Debye-Waller factor and to the "one-phonon" resonance peak are obtained, which appear to be negligible (?0.01%) for the case of a Bravais lattice and certainly <1% in other cases.

B. V. Thompson

1963-08-15T23:59:59.000Z

186

Fragility by elastic incoherent neutron scattering  

Science Journals Connector (OSTI)

The present work furnishes an operative definition for the fragility degree by using elastic incoherent neutron scattering (EINS). Such a definition is based on the relation between viscosity a macroscopic quantity and the atomic mean-square displacement which refers to a nanoscopic property. This procedure has been used to analyze a set of glass-forming systems and it allows to obtain a linear dependence of the fragility parameter M obtained by EINS on the fragility parameter m obtained by viscosity measurements.

S. Magaz; G. Maisano; F. Migliardo

2004-01-01T23:59:59.000Z

187

Neutron scattering reveals extremely slow cell water in a Dead Sea organism  

Science Journals Connector (OSTI)

Neutron scattering reveals extremely slow cell water...from the Dead Sea, was studied by neutron scattering. The water in centrifuged cell pellets...marismortui cells by measuring neutron scattering in deuterium-labeled cells. Neutron...

Moeava Tehei; Bruno Franzetti; Kathleen Wood; Frank Gabel; Elisa Fabiani; Marion Jasnin; Michaela Zamponi; Dieter Oesterhelt; Giuseppe Zaccai; Margaret Ginzburg; Ben-Zion Ginzburg

2007-01-01T23:59:59.000Z

188

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

189

Magnetism and magnetic materials probed with neutron scattering  

Science Journals Connector (OSTI)

Abstract Neutron scattering techniques are becoming increasingly accessible to a broader range of scientific communities, in part due to the onset of next-generation, high-power spallation sources, high-performance, sophisticated instruments and data analysis tools. These technical advances also advantageously impact research into magnetism and magnetic materials, where neutrons play a major role. In this Current Perspective series, the achievements and future prospects of elastic and inelastic neutron scattering, polarized neutron reflectometry, small angle neutron scattering, and neutron imaging, are highlighted as they apply to research into magnetic frustration, superconductivity and magnetism at the nanoscale.

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

2014-01-01T23:59:59.000Z

190

Slow-Neutron Scattering by Molecules  

Science Journals Connector (OSTI)

The operator formalism in slow-neutron scattering theory introduced by Wick and by Zemach and Glauber is considered in an approximation in which molecular rotational and vibrational effects are explicitly separated. The combined effects of rotation and translation are treated in terms of the Sachs-Teller "mass-tensor" concept, which is rederived on the basis of a rigid molecule Hamiltonian and extended to include interference effects. Only elastic vibrational transitions from the ground vibrational state are considered. The applicable neutron energy range is restricted to values large compared to the rotational level separation but below the vibrational threshold.The method is applicable to the calculation of differential as well as total scattering cross sections and to molecules of arbitrary structure. Expressions in closed form for these cross sections are obtained through use of an approximate procedure for averaging over molecular orientations. In the case of hydrogenous molecules, where direct scattering is dominant, the scattering by a given nucleus is described in terms of two parameters, viz., an effective nuclear mass for rotation and translation, and a vibrational constant. The relative simplicity of the method is illustrated in the calculation of the differential and total cross sections of CH4 and the total cross section of H2. Agreement of these calculations with experiment and with other calculations is good.

T. J. Krieger and M. S. Nelkin

1957-04-15T23:59:59.000Z

191

Slow-Neutron Scattering by Rotators. II  

Science Journals Connector (OSTI)

The methods developed in a previous paper for extending the neutron scattering formalism of Zemach and Glauber to any type of molecular rotator have been employed to derive generalized forms of the differential cross sections for rotator scattering. A mass-ratio expansion for the treatment of the high-energy limit is illustrated on the classical cross section and then employed in the treatment of the more general quantum-mechanical expression for the differential cross section. The results apply to an arbitrarily asymmetric rotator. The very low energy approximation is carried out for the symmetric rotator, and the procedure is compared with the explicit summing of the partial cross sections for individual rotational transitions. The inelastic correction to the static approximation for interference scattering is calculated to an accuracy of first order in the mass ratios for the case of the symmetric rotator.

Howard C. Volkin

1960-02-15T23:59:59.000Z

192

Theory of coherent neutron scattering by hydrogen-bonded ferroelectrics at low temperatures. I. General expression for inelastic coherent scattering of slow neutrons and effective thermal factors  

Science Journals Connector (OSTI)

The differential cross section for inelastic coherent scattering of slow neutrons scattered by hydrogen-bonded ferroelectrics at low temperatures...

S. Stamenkovi?

1972-12-01T23:59:59.000Z

193

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

194

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

195

11th LANSCE School on Neutron Scattering | School Abstract  

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

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

196

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...

197

11th LANSCE School on Neutron Scattering | Registration  

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

11th LANSCE School on Neutron Scattering | Application Full Name: First: * Middle (optional): Last: * Field of Study: * Educational Status: Graduate Student Postdoc Other...

198

Scattering of Slow Neutrons by Water  

Science Journals Connector (OSTI)

The motions of hydrogen atoms in water are considered in terms of the H2O molecule at the basic dynamical unit. Vibrations, hindered rotations, and translations of the molecule are included. For the numerical calculations, the hindrance of the translations is neglected, and the hindered rotations are replaced by a torsional oscillation with a single energy, h?=0.06 ev. When certain approximations are made in the average over molecular orientation, this model allows for the computation of differential and total slow-neutron cross sections. The computed cross sections are in good agreement with most of the available slow-neutron scattering data. The features of the high-resolution experiments directly associated with the hindrance of the molecular translations in the liquid are not reproduced.

Mark Nelkin

1960-07-15T23:59:59.000Z

199

Inelastic Neutron Scattering in F19  

Science Journals Connector (OSTI)

The energies and yields of the ? rays following inelastic neutron scattering in F19 have been studied as a function of neutron bombarding energy up to 2.2 Mev. In this range four ? rays only, of energies 1111.5 kev, 1962 kev, 1.2400.015 Mev and 1.3710.016 Mev, have been found. The first two correspond to the first two excited states of F19. The second pair of ? rays appear, from the threshold curves, to arise from F19 levels at 1.430.03 and 1.550.03 Mev respectively. The alternative of a 1.35-Mev level and the decay scheme are discussed.

Joan M. Freeman

1955-09-01T23:59:59.000Z

200

Neutron-Proton Interaction: The Scattering of Neutrons by Protons  

Science Journals Connector (OSTI)

The inadequacy of present theories of proton-neutron interaction is shown in work in which 730 proton tracks produced by collisions of fast neutrons with hydrogen nuclei have been studied and measured to determine the distribution-in-angle. The recoils have been observed in three gaseous media; hydrogen, ethylene and hydrogen sulphide, by the use of a sylphon-type Wilson chamber and two cameras mounted in such a way as to give two views of each recoil, thus enabling a stereoscopic projection and a direct measurement of the angle of scattering to be made for each track. In this way it is found that the intensity distribution of recoil protons shows a maximum in the neighborhood of 25. The distribution referred to unit solid angle in each angle interval exhibits a sharp maximum at 0 in close agreement with the work of Kurie, but in contradiction to those who have believed the scattering to be of the classical type. Various factors, both geometrical and statistical, which may lead to distortion of the angular distribution are cited, and it is shown that their effect is taken into account in these experiments, but not necessarily in those of the other workers. The contradictions in the results reported at present in the literature are assumed to arise from these factors. The bearing of the distribution found in these experiments on the neutron-proton inter-action is considered in the light of the modern nuclear theories and evidence is deduced for an exchange or some other type of interaction at energies lower than predicted on the basis of these theories. The mechanism favored by both the classical and quantum theories, namely elastic collision of like spheres, is inadequate to explain the distribution. The present distribution is found to be consistent with Fermi's explanation for the efficiency of hydrogen nuclei in slowing fast neutrons, but indicates an even higher efficiency.

William D. Harkins; Martin D. Kamen; Henry W. Newson; David M. Gans

1936-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "neutron scattering center" 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.
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to obtain the most current and comprehensive results.


201

Neutron Scattering from Star Polymers in a Matrix of Homopolymers  

Science Journals Connector (OSTI)

Neutron Scattering from Star Polymers in a Matrix of Homopolymers ... Benoit, H. On the effect of Branching and Polydispersity on the Angular Distribution of the Light Scattered by Gaussian Coils. ...

Mehmet Tombako?lu; A. Ziya Akcasu

1997-12-01T23:59:59.000Z

202

Phonon Transport and Thermodynamics Probed with Neutron Scattering...  

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

Phonon Transport and Thermodynamics Probed with Neutron Scattering Oct 22 2014 10:00 AM - 11:00 AM Olivier Delaire, Scattering and Thermophysics Group, MSTD, ORNL, Oak Ridge...

203

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

2007-09-04T23:59:59.000Z

204

Analysis of neutron scattering components inside a room with concrete walls  

Science Journals Connector (OSTI)

Abstract This paper describes the scattering corrections needed when neutron detectors are calibrated with a neutron point source at the center of a calibration room. The independence of scattering value from the geometric shape of the room was studied, which for more confidence in this case, two sets of rooms with same inner surface area were evaluated. The parameters that relate the air scattering part (A) and room-return part (R) with the additional contribution from scattered neutrons have been calculated for neutrons whose energy goes from 10?8 to 20MeV. These parameters were calculated using Monte Carlo method for 150, 200, 300, 407, 500, 800 and 1000cm-radius spherical cavity containing air. In the calculations, monoenergetic neutron sources were placed at the center of cavity, and then neutron fluences were determined at several distances of source to detector along the spherical cavity radius. The parameter R has been fitted as a function of surface area (or radius) of spherical room, and the related coefficient has been calculated for 16 monoenergetic neutron sources. It may produce a reasonable estimate (with difference scattering in any geometry of a calibration room.

Rahim Khabaz

2015-01-01T23:59:59.000Z

205

Scattering of Fast Neutrons by Helium  

Science Journals Connector (OSTI)

Measurements have been made of the angular distribution of helium recoils for incident neutrons of energies from 0.6 to 1.6 Mev. The distribution curves also permit estimates of the total cross section in this energy range. The results confirm the existence of a cross-section peak of about 6.810-24 cm2 around 1 Mev and indicate, under the assumption of s- and p-wave scattering only, that the peak is double. But preliminary attempts to fit the data to Bloch's detailed theory of s- and p-scattering with a split p-level have not been successful, and the sign of the postulated splitting is not established.

T. A. Hall and P. G. Koontz

1947-08-01T23:59:59.000Z

206

Glassy Dynamics of Polystyrene by Quasielastic Neutron Scattering  

Science Journals Connector (OSTI)

Glassy Dynamics of Polystyrene by Quasielastic Neutron Scattering ... The ratio of coherent to total scattered intensities(25) has also been included on the rhs-axis of Figure 3 (crosses). ... It is introduced as the long-time limit of the intermediate scattering function and it is related to the region of the space accessible to the scatters. ...

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

2011-03-28T23:59:59.000Z

207

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

208

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

209

The Scattering of Thermal Neutrons by Deuterons  

Science Journals Connector (OSTI)

The cross section for the scattering of very slow neutrons by deuterons is calculated by numerical methods. Polarization is completely neglected and the wave equation for the process is set up in such a form as to take correctly into account exchange effects between the incident neutron and the neutron initially in the deuteron. This wave equation is then replaced by an integral equation the solution of which is correctly symmetrized and has the right asymptotic value to describe the scattering process. The numerical integration is performed by replacing the integral equation by a finite set of simultaneous linear algebraic equations. The work is greatly simplified by the use of a sum of two Gauss functions to approximate the ground state deuteron wave function. It is assumed throughout this paper that the interactions between like and unlike particles are equal and are of the general form Vij=-[(1-g-g1-g2)Pij+gPijQij+g1+g2Qij]J(rij), where the symbols have their usual meanings and where J(rij) is a Gauss function. The calculation is carried out for two sets of g's. For the first set, g1=g2=0, g=0.2, the cross section is found to be equal to 4.5710-24 cm2, and for the second set of g's, g2=2, g=0.22-g2, g1=0.25-0.8g2, the value of the cross section is found to be equal to 6.9110-24 cm2. The experimental value is at least 20 percent smaller than the first of these values.

Lloyd Motz and Julian Schwinger

1940-07-01T23:59:59.000Z

210

Elastic neutron scattering studies at 96 MeV for transmutation  

Science Journals Connector (OSTI)

......POSTER Presentations Elastic neutron scattering studies at 96 MeV for transmutation...University, Japan Elastic neutron scattering from 12C, 14N, 16O, 28Si...a nuclear target. Elastic neutron scattering is of utmost importance for......

M. sterlund; J. Blomgren; M. Hayashi; P. Mermod; L. Nilsson; S. Pomp; A. hrn; A. V. Prokofiev; U. Tippawan

2007-08-01T23:59:59.000Z

211

Neutron scattering in concrete and wood: Part IIoblique incidence  

Science Journals Connector (OSTI)

......Scientific and Technical Notes Neutron scattering in concrete and wood: Part...radiotherapy rooms. (b) Geometry of neutron scattering simulations. Another empirical...due to capture gamma rays. NEUTRON SCATTERING-MONTE CARLO SIMULATION RESULTS......

A. Facure; A. X. Silva; J. C. Rivera; R. C. Falco

2008-02-01T23:59:59.000Z

212

Concentration dependence of vibrational properties of bioprotectant/water mixtures by inelastic neutron scattering  

Science Journals Connector (OSTI)

...water mixtures by inelastic neutron scattering S Magazu 1 * F Migliardo 1...LaboratoryChilton, Didcot,OX11 0QX, UK Neutron scattering has been demonstrated to be...to investigate by inelastic neutron scattering (INS) the vibrational behaviour...

2007-01-01T23:59:59.000Z

213

Atomic-scale dynamics inside living cells explored by neutron scattering  

Science Journals Connector (OSTI)

...inside living cells explored by neutron scattering Marion Jasnin * * jasnin...specific usefulness of the neutron scattering technique to get insight into...cell types and organelles. neutron scattering|living cell|molecular dynamics...

2009-01-01T23:59:59.000Z

214

Neutron scattering studies and modeling of high mobility group 14 core nucleosome complex  

Science Journals Connector (OSTI)

Neutron scattering studies and modeling of high mobility...were studied by use of small-angle neutron scattering techniques. By varying the H2O...occurring in active nucleosomes. Neutron scattering studies and modeling of high mobility...

E C Uberbacher; J K Mardian; R M Rossi; D E Olins; G J Bunick

1982-01-01T23:59:59.000Z

215

Scattering of Slow Neutrons from Propane Gas  

Science Journals Connector (OSTI)

Measurements of the partial differential neutron scattering cross sections for room-temperature propane gas are reported. These measurements were made at incident energies of 0.0101, 0.0254, 0.0736, and 0.102 ev at seven scattering angles between 16.3 and 84.7 using the Materials Testing Reactor phased chopper velocity selector. The data are converted to the scattering-law presentation and compared with three theoretical calculations: (a) The ideal gas, using an effective mass obtained from an average of the mass tensors for the three types of H atoms in propane, gives poor agreement. (b) The Krieger-Nelkin approximation, which includes the effect of zero-point vibrations, gives limited agreement for energy transfer less than 0.5kBT at intermediate momentum transfers. At large momentum transfers where vibrational effects become important it underestimates the cross section. (c) A modification of the Krieger-Nelkin theory that includes the effects of single-quantum transitions from the three lowest vibrational states gives better agreement. The discrepancies still present at large momentum and energy transfers are attributed to an uncertainty in the methyl-group barrier height for the three lowest energy modes, to the harmonic oscillator approximation for these modes, and to the approximate molecular orientation averaging used in the calculation.

K. A. Strong; G. D. Marshall; R. M. Brugger; P. D. Randolph

1962-02-01T23:59:59.000Z

216

Rotational motion of molecules and neutron scattering  

Science Journals Connector (OSTI)

The differential neutron scattering cross section for scattering from a rigid rotating molecule in a general isotropic medium (condensed or gas state of matter) is presented. It is based on a model which assumes the complete rotational motion to consist of a damped form of free rotations and of damped librations respectively. The two phases of rotation are assumed to be coupled to microscopic density fluctuations in the medium in such a way that densities larger than the average allow only damped librations whereas densities lower than the average allow only damped rotations. The cross section is derived with the aid of a step function formalism first used by Singwi and Sjlander. Further use is made of Sears' earlier work on rotational scattering cross sections. The resulting cross section describes the molecular motions in a range of conditions from free rotations to undamped libration including all possible intermediate damped motions. The model differs from those created earlier insofar as the rotational diffusion is not necessarily described as a motion consisting of free rotations over smaller or larger angles interrupted by brief collisions. The collisions may in the present model be replaced by shorter or longer periods of libration. Numerical calculations of the Fourier transform S 1(?) of the first rotational relaxation function F 1(t) is performed using explicit models for the librational and rotational relaxation functions and for such a choice of numerical constants that the results should describe various hypothetical rotational motions of the methane molecule.

K. E. Larsson

1973-01-01T23:59:59.000Z

217

Los Alamos Neutron Science Center | National Nuclear Security...  

National Nuclear Security Administration (NNSA)

Neutron Science Center | National Nuclear Security Administration People Mission Managing the Stockpile Preventing Proliferation Powering the Nuclear Navy Emergency Response...

218

XII SoNS School of Neutron Scattering  

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

XII School of Neutron Scattering (SoNS) XII School of Neutron Scattering (SoNS) "Francesco Paolo Ricci" "Introduction to the theory and techniques of neutron scattering and applications to Cultural Heritage" 30 April - 9 May 2014 A Course within the International School of Solid State Physics ETTORE MAJORANA FOUNDATION AND CENTRE FOR SCIENTIFIC CULTURE, Erice (I) Application deadline: 1 st April 2014 Application is now open for the XII School of Neutron Scattering (SoNS) "Francesco Paolo Ricci": Introduction to the theory and techniques of neutron scattering and applications to Cultural Heritage. The school will be held at the ETTORE MAJORANA FOUNDATION AND CENTRE FOR SCIENTIFIC CULTURE, Erice (Sicily, I) as a specialized course within the International School of Solid State Physics (Director: Giorgio Benedek), between the 30

219

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

220

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

Note: This page contains sample records for the topic "neutron scattering center" 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.


221

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...

222

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...

223

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...

224

The Neutron-Proton and Neutron-Carbon Scattering Cross Sections for Fast Neutrons  

Science Journals Connector (OSTI)

An experimental investigation of the total scattering cross section of hydrogen and carbon for neutrons of energies 0.35 to 6.0 Mev is reported. Neutrons of discrete energies were produced by particle bombardment of lithium, carbon, and heavy water targets. Transmissions of cyclohexane (C6H12) and graphite scatterers under conditions of good geometry were measured. Results for ?s(H) are compared with the theoretical interpretations of Bohm and Richman in a later paper and to the experimental results of D. Frisch at lower energies in a companion paper. It is estimated that ?s(H) and ?s(C) are determined to approximately five percent.

Carl L. Bailey; William E. Bennett; Thor Bergstralth; Richard G. Nuckolls; Hugh T. Richards; John H. Williams

1946-11-01T23:59:59.000Z

225

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

226

Elastic neutron-scattering experiments at the Geesthacht Neutron Facility (GeNF)  

Science Journals Connector (OSTI)

The Geesthacht Neutron Facility (GeNF) comprises experimental facilities for elastic neutron scattering for materials research and engineering problems as well as for environmental research purposes at the research reactor FRG-1. The experimental facilities for elastic neutron-scattering experiments at GeNF, most of which can be optimally used with polarized neutrons, will be presented. They are open to national and international users from universities and other research institutes at no cost.

R Kampmann; R Wagner

1997-01-01T23:59:59.000Z

227

Coherent neutron scattering response from glassy glycerol  

Science Journals Connector (OSTI)

We report on inelastic neutron scattering measurements of fully deuterated glassy glycerol at temperatures between 15 K to 180 K. Incident energies of 40 and 100 meV and momentum transfers up to ?12 A?-1 were used. Analysis of the static structure factor calculated as the zeroth-frequency moment of S(Q,?) enabled us to derive valuable structural information on the intra- and intermolecular correlations. Generalized frequency distributions are derived from the spectra and are used to calculate the relevant thermodynamic properties of the material using a quasiharmonic approximation. Estimates are also made for the first order anharmonic effects. Some wave-vector-dependent effects, such as the reduced frequency moments of S(Q,?) are also evaluated, and their physical meaning discussed in some detail. 1996 The American Physical Society.

J. Dawidowski; F. J. Bermejo; R. Fayos; R. Fernndez Perea; S. M. Bennington; A. Criado

1996-05-01T23:59:59.000Z

228

Differential Neutron Scattering Cross Sections and Average Neutron Parameters of Tin Isotopes  

Science Journals Connector (OSTI)

The differential cross sections of elastically scattered neutrons were measured for tin isotopes at the...o, s 1/2 1 , S 1/3 ...

V. G. Nikolenko; A. B. Popov; G. S. Samosvat

1983-01-01T23:59:59.000Z

229

Neutron Scattering Investigations on a Bimodal Polymer Gel  

Science Journals Connector (OSTI)

As these clusters are both large and chemically different from the surrounding polymer, they scatter strongly at small values of q, thereby giving rise to the feature described by the length ?2. ... For gels swollen in octane, the scattered light and the smallest angle neutron response are dominated by scattering from aggregates of polymd. ...

Anne-Marie Hecht; Ferenc Horkay; Erik Geissler

2001-05-26T23:59:59.000Z

230

Foams As Viewed by Small-Angle Neutron Scattering  

Science Journals Connector (OSTI)

Foams As Viewed by Small-Angle Neutron Scattering ... For wet foams, we met other difficulties, common to any strongly scattering system:? a part of the scattered beam is collected in the central cells along with the transmitted beam; this can spoil the transmission measurements. ...

Monique A. V. Axelos; Franois Bou

2003-07-04T23:59:59.000Z

231

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

232

Scattering of Fast Neutrons in Pb and Ag  

Science Journals Connector (OSTI)

The total cross section for neutron scattering in lead and silver has been measured using monoenergetic neutrons with energies which were varied from 12.9 to 16.2 Mev. The total cross section in silver becomes smaller as the energy is increased, while the cross section in lead is greater at the higher neutron energies. In the case of lead there appears to be a broad maximum in the cross section curve at a neutron energy of 16 Mev.

T. W. Bonner; F. Alba; A. Fernndez; M. Mazari

1955-02-15T23:59:59.000Z

233

Neutron scattering observation of solitons (invited)  

Science Journals Connector (OSTI)

It has been suggested that in systems with strong fluctuations as around a critical point strongly nonlinear effects should occur. The simplest possible equation for nonlinear dynamics is the sine?Gordon equation. This equation can be applied to the dynamics of a 1?D?ferromagnetic chain with planar anisotropy in a symmetry?breaking field (magnetic field perpendicular to the chain direction). The dynamics of such a system consist of two types of elementary excitations: nonlinear modes (solitons and breathers) and linear modes (spin waves). The thermodynamics for the nonlinear modes are the same as for a gas of noninteracting relativistic quasi?particles. In the frame of that picture the dynamic structure factor for an inelastic neutron scattering experiment can be calculated for the relativistic case and it appears that inelastic n?scattering is the most direct way for the observation of solitons. Experimental results obtained for CsNiF3 are discussed and compared with the theoretical results. These experimental results show that nonlinear modes are indeed an essential part of the dynamics of that system.

1979-01-01T23:59:59.000Z

234

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.

Polosatkin, Sergey; Dolgov, Alexander

2014-01-01T23:59:59.000Z

235

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

236

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

237

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

Science Journals Connector (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.

F. Grazzi; A. Scherillo; M. Zoppi

2009-01-01T23:59:59.000Z

238

Modern Techniques for Inelastic Thermal Neutron Scattering Analysis  

Science Journals Connector (OSTI)

Abstract A predictive approach based on ab initio quantum mechanics and/or classical molecular dynamics simulations has been formulated to calculate the scattering law, S ( ? ? , ? ) , and the thermal neutron scattering cross sections of materials. In principle, these atomistic methods make it possible to generate the inelastic thermal neutron scattering cross sections of any material and to accurately reflect the physical conditions of the medium (i.e, temperature, pressure, etc.). In addition, the generated cross sections are free from assumptions such as the incoherent approximation of scattering theory and, in the case of solids, crystalline perfection. As a result, new and improved thermal neutron scattering data libraries have been generated for a variety of materials. Among these are materials used for reactor moderators and reflectors such as reactor-grade graphite and beryllium (including the coherent inelastic scattering component), silicon carbide, cold neutron media such as solid methane, and neutron beam filters such as sapphire and bismuth. Consequently, it is anticipated that the above approach will play a major role in providing the nuclear science and engineering community with its needs of thermal neutron scattering data especially when considering new materials where experimental information may be scarce or nonexistent.

A.I. Hawari

2014-01-01T23:59:59.000Z

239

ISOTOPESuses, demand, and supply NIST Center for Neutron Research  

E-Print Network [OSTI]

Laboratory Neutron reflectometry study of the conformation of HIV Nef bound to lipid membranes #12;Ultra ColdISOTOPESuses, demand, and supply NIST Center for Neutron Research Rob Dimeo, Director at #12;We CENTER FOR NEUTRON RESEARCH ENGINEERING LABORATORY INFORMATIONTECHNOLOGY LABORATORY MATERIAL MEASUREMENT

Dimeo, Robert M.

240

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.

Note: This page contains sample records for the topic "neutron scattering center" 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

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

242

Concepts in spin echo small-angle neutron scattering  

Science Journals Connector (OSTI)

Two-dimensional spin echo small-angle neutron scattering experiments are proposed for the direct measurement of the vector-length distribution function. Interpretation of the correlation function from one-dimensional experiments is also presented.

Zhao, J.

2001-09-25T23:59:59.000Z

243

11th LANSCE School on Neutron Scattering | FAQ's  

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

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

244

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

245

A case study of computational differentiation applied to neutron scattering  

Science Journals Connector (OSTI)

In a neutron scattering application, an unconstrained nonlinear minimization problem is used for the fitting of model parameters to experimental data. Automatic differentiation enables, in a completely mechanical fashion, algorithmic changes by switching ...

Christian H. Bischof; H. Martin Bcker; Dieter an Mey

2000-10-01T23:59:59.000Z

246

A focusing-geometry small-angle neutron scattering instrument with a magnetic neutron lens  

Science Journals Connector (OSTI)

A focusing-geometry small-angle neutron scattering (FSANS) instrument with a magnetic neutron lens based on an extended Halbach-type sextupole magnet has been constructed and tested. A minimum value of the measurable range, , of ?-1 could be achieved by the FSANS instrument using a neutron wavelength ? with for the full width at half maximum.

Oku, T.

2007-02-23T23:59:59.000Z

247

Coherent Neutron Scattering Amplitudes of Krypton and Xenon, and the Electron-Neutron Interaction  

Science Journals Connector (OSTI)

The coherent scattering amplitudes of krypton and xenon for thermal neutrons have been measured by a comparison method involving reflection of a neutron beam from liquid mirrors. The results were (7.680.19)10-13 cm for krypton and (5.100.17)10-13 cm for xenon. When these results are used with the scattering measurements of Hamermesh, Ringo, and Wattenberg, one obtains (3900800) ev for the electron-neutron interaction.

M. F. Crouch; V. E. Krohn; G. R. Ringo

1956-06-01T23:59:59.000Z

248

Neutron Scattering Investigation on Quantum Spin System SrCu2(BO3)2  

Science Journals Connector (OSTI)

......research-article Articles Neutron Scattering Investigation on Quantum Spin...review the zero field inelastic neutron scattering results obtained by using both the thermal and cold neutron triple axis instrument. The......

Kazuhisa Kakurai; Katsuyuki Nukui; Naofumi Aso; Masakazu Nishi; Hiroaki Kadowaki; Hiroshi Kageyama; Yutaka Ueda; L.-P. Regnault; O. Cpas

2005-05-01T23:59:59.000Z

249

International Conference on Surface X-ray and Neutron Scattering (SXNS-11)  

SciTech Connect (OSTI)

The 11th International Surface X-ray and Neutron Scattering (SXNS) Conference was held on July 13-17, 2010, on the Northwestern University (NU) campus, in Evanston Illinois and hosted by the NU Materials Research Science and Engineering Center. This biennial conference brought together a community of 164 attendees from 16 countries. The field now makes use of a broad range of new experimental capabilities that have been made possible through the development of increasingly brilliant X-ray and neutron sources around the world, including third generation synchrotron sources, neutron reactor and spallation sources, as well as the recent development of X-ray lasers.

Michael J. Bedzyk

2011-06-17T23:59:59.000Z

250

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

251

Neutron Scattering Instrumentation for Biology at Spallation Neutron Sources  

Science Journals Connector (OSTI)

Conventional wisdom holds that since biological entities are large, they must be studied with cold neutrons, a domain in which reactor sources of neutrons are often supposed to be pre-eminent. ... fact, the curre...

Roger Pynn

1996-01-01T23:59:59.000Z

252

The Scattering of Neutrons by Ortho- and Parahydrogen  

Science Journals Connector (OSTI)

Calculations have been performed which indicate that experiments on the scattering of neutrons by ortho- and parahydrogen would enable one to determine the sign of the singlet state binding energy and the range of the neutron-proton interaction, in addition to providing direct information concerning the spin dependence of the neutron-proton interaction. A dependence of the neutron-proton interaction upon the relative spin orientation of the particles will manifest itself in a marked difference between the slow neutron scattering cross sections of orthohydrogen (parallel proton spins) and parahydrogen (anti-parallel proton spins). Neutrons with energy less than 0.068 ev, incident upon para-H2 in its ground state (J=0,v=0,S=0), may be either elastically scattered, or inelastically scattered with excitation of the molecule to the ground state of the ortho system (J=1,v=0,S=1). This latter process, requiring 0.023 ev, occurs only if the neutron-proton interaction is spin dependent. When the neutron energy is less than 0.045 ev, the cross section for the scattering of neutrons by ortho-H2 in its ground state will be the sum of the elastic scattering cross section and the cross section for the inelastic process in which the molecule is converted to a para-H2 molecule in its ground state, with the neutron taking up the excess energy. The cross sections of these four processes have been calculated, assuming an interaction range of 210-13 cm and a virtual singlet state of the deuteron. For liquid-air temperature neutrons (3kT2=0.012 ev), ?para(0.012)=0.2110-24 cm2, while ?ortho(0.012)=6510-24 cm2. The cross sections for neutrons at ordinary temperatures (3kT2=0.037 ev), however, are ?para(0.037)=1910-24 cm2, and ?ortho(0.037)=5010-24 cm2. Therefore, if the present concept of the neutron-proton interaction is valid, one would expect the following results: (a) The ortho-scattering cross section for liquid air neutrons should be about 300 times the corresponding para-scattering cross section. (b) The para-scattering cross section for ordinary thermal neutrons should be roughly 100 times the para-scattering cross section for liquid air neutrons. For a real singlet state, however, these ratios are of the order of one. The elastic para-scattering cross section is quite sensitive to the value of the range of interaction if the singlet state is virtual. For example, the value of this cross section at liquid air neutron temperatures with zero range of interaction is 1.7510-24 cm2, as compared with 0.2610-24 cm2 for an interaction range of 210-13 cm. Hence, from a measurement of the para elastic scattering cross section for homogeneous neutrons at some energy less than 0.023 ev, the range of interaction in the triplet state may be inferred with some degree of accuracy. A discussion of the influence of intermolecular forces on the previous results is given.

Julian Schwinger and E. Teller

1937-08-15T23:59:59.000Z

253

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

254

Polymeric Hydrate?Inhibitor Adsorption Measured by Neutron Scattering  

Science Journals Connector (OSTI)

18 Measured scattering from the empty sample cell Ic and background Ib is subtracted via the formula which accounts for attenuation of the scattered intensities by both cell and sample according to their measured neutron transmissions Tc and Ts, respectively. ... Because the solvated and adsorbed polymer scatter incoherently, the solution scattering term may be simply added to the others in eq 2. We model this scattering as the Debye-like structure factor due to Beaucage,22 where q* = q/[erf(kqRg/?6)]3 with k ? 1.06. ...

Jeffrey L. Hutter; H. E. King, Jr.; Min Y. Lin

2000-03-09T23:59:59.000Z

255

Advanced neutron irradiation system using Texas A&M University Nuclear Science Center Reactor  

E-Print Network [OSTI]

was installed in the irradiation cell of the Texas A&M University Nuclear Science Center Reactor (NSCR). By increasing the thickness of the lead-bismuth alloy, the neutron spectra were shifted into lower energies by the scattering interactions of fast...

Jang, Si Young

2005-11-01T23:59:59.000Z

256

Neutron scattering techniques as a tool for nondestructive testing  

Science Journals Connector (OSTI)

Neutron scattering techniques such as neutron diffraction, Small-Angle Neutron Scattering (SANS) and Neutron Reflectivity (NREF) are very powerful tools for the nondestructive study of materials. The corresponding experimental facilities at a Greek research reactor and demonstrative experiments of their employment in the nondestructive testing of materials are presented. Neutron diffraction was applied in the study of irradiation effects on SiCf /SiC composites in view of their application to future fusion reactors. SiC materials are important in the aerospace industry and their oxidation at high temperatures was investigated by NREF. Finally, a SANS study of the precipitation of the aerospace Al-8.9at%Li alloy is presented.

G. Apostolopoulos; K. Mergia; A.G. Youtsos

2009-01-01T23:59:59.000Z

257

Neutron Production, Neutron Facilities and Neutron Instrumentation  

Science Journals Connector (OSTI)

...Mexico, 87545, U.S.A, e-mail: sven@lanl.gov Hans-Georg Priesmeyer Geesthacht Neutron Scattering Facility, GKSS Research Center, 21502 Geesthacht, Germany, e-mail: hans-georg.priesmeyer@gkss.de NEUTRON GENERATION The...

Sven C. Vogel; Hans-Georg Priesmeyer

258

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

259

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.

260

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

Note: This page contains sample records for the topic "neutron scattering center" 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

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

262

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

263

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

264

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.

265

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.

266

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

267

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

268

SciTech Connect: Neutron inelastic scattering in natural Pb as...  

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

Article: Neutron inelastic scattering in natural Pb as a background in neutrinoless double-beta decay experiments Citation Details In-Document Search Title: Neutron inelastic...

269

Paramagnetic neutron scattering from Ni (invited)  

Science Journals Connector (OSTI)

New polarized beammeasurements have been carried out in the paramagnetic phase of 6 0Ni in order to enlarge the (q ?) range previously studied by Steinsvoll e t a l. Magnetic scattering has been detected up to halfway to the zone boundary. The results can be successfully interpreted in terms of a diffusive?type scattering function over an unexpected wide (q ?) range qneutron data are also compared with the predictions of the very recent band model by Callaway. Finally we point out important similarities and differences in the paramagnetic scattering from localized systems such as EuO and itinerant systems and discuss the universality of the paramagnetic scattering function.

P. Bni; G. Shirane

1985-01-01T23:59:59.000Z

270

The Scattering of 4.5- and 5.5-Mev Neutrons by Deuterons  

Science Journals Connector (OSTI)

By bombarding a thin deuterium gas target with deuterons 4.5- and 5.5-Mev neutrons were produced. Deuterons recoiling from neutron collisions in (a) a thin heavy paraffin scatterer and (b) a gas sample were detected by a double coincidence counter telescope. The angular distribution of recoiling deuterons, measured from 0 to 60 in the laboratory system, shows a sharp maximum for neutron scattering at 180 with a minimum at approximately 110 in the center-of-mass system. The ratio of the differential cross section at 180 to that at 110 is 5:1 for both energies. The experimental curves are compared with the theory of Buckingham and Massey.

E. Wantuch

1951-10-15T23:59:59.000Z

271

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

272

A Bayesian approach to removal of incoherent scattering from neutron total-scattering data  

Science Journals Connector (OSTI)

A Bayesian approach for subtraction of incoherent scattering from neutron total-scattering data has been developed and implemented in an open-source software package. The approach has been tested using both simulated and experimental data collected on different types of samples.

Gagin, A.

2014-11-28T23:59:59.000Z

273

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

274

Neutron scattering studies of lac repressor  

Science Journals Connector (OSTI)

... 1. Two parameters were obtained from the Guinier plots-a radius of gyration of excess scattering length density, RG, and the ... length density, RG, and the scattered intensity extrapolated to zero angle (//C)o, which is related to the MW ...

M. Charlier; J. C. Maurizot; G. Zaccai

1980-07-24T23:59:59.000Z

275

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

276

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

277

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

278

Conformational Changes in Sindbis Virus Induced by Decreased pH Are Revealed by Small-Angle Neutron Scattering  

Science Journals Connector (OSTI)

...Are Revealed by Small-Angle Neutron Scattering Lilin He a b Amanda Piper c...Oak Ridge, Tennessee, USA b Neutron Scattering Sciences Division, Oak Ridge...we employed small-angle neutron scattering with contrast variation to...

Lilin He; Amanda Piper; Flora Meilleur; Raquel Hernandez; William T. Heller; Dennis T. Brown

2011-12-07T23:59:59.000Z

279

The Structure of Sindbis Virus Produced from Vertebrate and Invertebrate Hosts as Determined by Small-Angle Neutron Scattering  

Science Journals Connector (OSTI)

...Determined by Small-Angle Neutron Scattering Published ahead of print on...Raleigh, North Carolina 27695 3 Neutron Scattering Sciences Division, Oak Ridge...determined by small-angle neutron scattering (SANS), a nondestructive...

Lilin He; Amanda Piper; Flora Meilleur; Dean A. A. Myles; Raquel Hernandez; Dennis T. Brown; William T. Heller

2010-03-10T23:59:59.000Z

280

Neutron scattering: a tool to detect in vivo thermal stress effects at the molecular dynamics level in micro-organisms  

Science Journals Connector (OSTI)

...Research articles 1004 30 31 68 Neutron scattering: a tool to detect in vivo...conditions was measured by neutron scattering experiments coupled with microbiological...experiments indicated that the neutron scattering method provides a promising...

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "neutron scattering center" 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

Doppler shift anisotropy in small angle neutron scattering  

Science Journals Connector (OSTI)

The two-dimensional patterns in our small angle neutron scattering (SANS) experiments from rapidly moving aerosols are anisotropic. To test the kinematic theory of two-body scattering that describes the anisotropy, we conducted SANS experiments using a constant source of D2O aerosol with droplets moving at ?440 m/s, and varied the neutron velocity from 267 to 800 m/s. The theoretically predicted anisotropy of the laboratory scattering intensities agrees well with the experimental results. Based on an analysis of the scattering intensity in the Guinier region, we also determined the particle velocity. The results are in very good agreement with independent velocity estimates based on supersonic flow measurements.

B. E. Wyslouzil; G. Wilemski; J. L. Cheung; R. Strey; J. Barker

1999-10-01T23:59:59.000Z

282

Neutron and X-Ray Scattering - Argonne National Laboratories, Materials  

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

Home Home Neutron and X-Ray Scattering Neutron and X-ray Scattering Science Recent advances in neutron and x-ray scattering instrumentation at major DOE facilities such as the Spallation Neutron Source and Advanced Photon Source provide unprecedented insights into complex phenomena in bulk and interfacial materials. The vision of our group is to harness the complementarity of neutrons and x-rays to study how materials respond on a range of length and time scales to phase competition, so that we can learn to control emergent behavior and generate functional properties in energy-related materials. We use neutrons and x-rays to investigate the structure and dynamics of bulk and interfacial materials with properties that are useful for energy applications, such as superconductivity, magnetism and thermoelectricity. Phase competition can generate or enhance such properties, but it is extremely challenging to characterize fluctuations in the competing order, whether in bulk disordered materials, or artificial heterostructures. Our goal is to utilize efficient techniques that we have been developing for measuring nanoscale phase fluctuations, both static and dynamic, to enable the rational design of new materials for energy within MSD.

283

Correlated Motions in Glasses Studied by Coherent Inelastic Neutron Scattering  

Science Journals Connector (OSTI)

Coherent inelastic neutron scattering provides detailed information about the correlated atomic displacements in the vibrational modes of a glass. As an example, we show the wave-vector dependence of the scattering function of vitreous SiO2 corresponding to different peaks in the one-phonon density of states. Pending the availability of results from computer simulations, we give a qualitative comparison with the Sen-Thorpe model.

J. M. Carpenter and D. L. Price

1985-02-04T23:59:59.000Z

284

Neutron reflectivity and small angle neutron scattering: An introduction and perspective on recent progress  

Science Journals Connector (OSTI)

Abstract In recent years both neutron reflectivity, NR, and small angle neutron scattering, SANS, have been applied to the study of increasingly complex surface and interfacial properties. The methodology and advantages of using these neutron scattering techniques to probe surfaces and interfaces will be briefly outlined. Some recent examples of surfactant, polymer and polymersurfactant adsorption at the airwater, liquidsolid, and liquidliquid planar interfaces are highlighted. These are contrasted by some examples of the nature of adsorption on colloidal sol particles and emulsion droplets.

Jeffrey Penfold; Robert K. Thomas

2014-01-01T23:59:59.000Z

285

A molecular beam epitaxy facility for in situ neutron scattering  

SciTech Connect (OSTI)

A molecular beam epitaxy (MBE) facility has been built to enable in situ neutron scattering measurements during growth of epitaxial layers. While retaining the full capabilities of a research MBE chamber, this facility has been optimized for polarized neutron reflectometry measurements. Optimization includes a compact lightweight portable design, a neutron window, controllable magnetic field, deposition across a large 76 mm diameter sample with exceptional flux uniformity, and sample temperatures continuously controllable from 38 to 1375 K. A load lock chamber allows for sample insertion, storage of up to 4 samples, and docking with other facilities. The design and performance of this chamber are described here.

Dura, J. A.; LaRock, J. [NIST Center for Neutron Research, 100 Bureau Dr. MS 6102, Gaithersburg, Maryland 20899 6102 (United States)

2009-07-15T23:59:59.000Z

286

Neutron-deuteron scattering calculation for evaluated neutron data libraries  

Science Journals Connector (OSTI)

In the low-energy regime, differential cross sections for n + d elastic scattering are not well described in existing nuclear data libraries, such as ENDF/B-VII.0. Supporting experimental data in this energy regi...

J. P. Svenne; L. Canton; K. S. Kozier

2008-12-01T23:59:59.000Z

287

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

288

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

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

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

289

The Scattering of Slow Neutrons by Ortho- and Paradeuterium  

Science Journals Connector (OSTI)

Information relating to the spin dependence of the neutron-deuteron interaction can be obtained from slow neutron scattering experiments in ortho- and paradeuterium. Theoretical formulae have been derived for the cross sections of the various transitions among the molecular rotational levels, which involve the scattering amplitudes a32 and a12 for the two spin states of the neutron-deuteron system. In particular, numerical results are given for the first few transitions originating from the ground levels of the ortho- and para-systems with neutron energies not exceeding 0.05 ev. The influence of the thermal motion of the molecule is described, and explicit formulae are given for the important transitions occurring at small neutron energies, on the assumption that the D2 is in gaseous form at low temperature. The ratio of the ortho- and para-cross sections, under these conditions, is examined in its dependence upon the ratio of the scattering amplitudes. If the scattering amplitudes are of the same sign, the cross-section ratio is never greater than 1.31 and attains this magnitude only for small values of a32 relative to a12. If, however, the amplitudes are of opposite sign, this ratio can be as large as 1.75 and always exceeds 1.11. This experiment measures only the magnitudes of the amplitude combinations (2a32+a12) and (a32-a12), but not their signs, and thus leaves a fourfold ambiguity in interpretation. The possibility is discussed of determining the sign of (2a32+a12) by scattering experiments in HD. It is pointed out that the sign of (a32-a12) cannot be fixed by any experiment in which the deuteron spin is unoriented in space. An alternative experimental method, involving the depolarization of neutrons, is mentioned.

M. Hamermesh and Julian Schwinger

1946-03-01T23:59:59.000Z

290

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

291

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

292

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

293

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

294

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

295

THE JOURNAL OF CHEMICAL PHYSICS 139, 175102 (2013) Dynamic neutron scattering from conformational dynamics. II. Application  

E-Print Network [OSTI]

#12;THE JOURNAL OF CHEMICAL PHYSICS 139, 175102 (2013) Dynamic neutron scattering from; accepted 12 September 2013; published online 1 November 2013) Neutron scattering experiments directly probe.1063/1.4824071] I. INTRODUCTION Dynamic neutron scattering is a direct probe of the inter- nal, conformational

296

The thermal denaturation of DNA studied with neutron scattering Andrew Wildes,1  

E-Print Network [OSTI]

The thermal denaturation of DNA studied with neutron scattering Andrew Wildes,1 Nikos characterized using neutron scattering. A Bragg peak from B-form fibre DNA has been measured as a function techniques have proved to be excellent probes8 . We have used neutron scattering to measure the tem- perature

Boyer, Edmond

297

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

298

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

299

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

300

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

Note: This page contains sample records for the topic "neutron scattering center" 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

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

302

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.

303

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

304

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

305

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

306

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

307

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.

308

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

309

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

310

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.

311

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

312

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

E-Print Network [OSTI]

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

Boyer, Edmond

313

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, Université de

314

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

315

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

316

Neutron scattering effects on fusion ion temperature measurements.  

SciTech Connect (OSTI)

To support the nuclear fusion program at Sandia National Laboratories (SNL), a consistent and verifiable method to determine fusion ion temperatures needs to be developed. Since the fusion temperature directly affects the width in the spread of neutron energies produced, a measurement of the neutron energy width can yield the fusion temperature. Traditionally, the spread in neutron energies is measured by using time-of-flight to convert a spread in neutron energies at the source to a spread in time at detector. One potential obstacle to using this technique at the Z facility at SNL is the need to shield the neutron detectors from the intense bremsstrahlung produced. The shielding consists of eight inches of lead and the concern is that neutrons will scatter in the lead, artificially broaden the neutron pulse width and lead to an erroneous measurement. To address this issue, experiments were performed at the University of Rochester's Laboratory for Laser Energetics, which demonstrated that a reliable ion temperature measurement can be achieved behind eight inches of lead shielding. To further expand upon this finding, Monte Carlo N-Particle eXtended (MCNPX) was used to simulate the experimental geometric conditions and perform the neutron transport. MCNPX was able to confidently estimate results observed at the University of Rochester.

Ziegler, Lee (Bechtel/Nevada, Las Vegas, NV); Starner, Jason R.; Cooper, Gary Wayne; Ruiz, Carlos L.; Franklin, James Kenneth (Ktech Corporation, Albuquerque, NM); Casey, Daniel T.

2006-06-01T23:59:59.000Z

317

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

318

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

319

Public to have rare opportunity to tour Neutron Science Center  

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

Rosenfest: celebrate Louis Rosen, tour LANSCE Rosenfest: celebrate Louis Rosen, tour LANSCE Public to have rare opportunity to tour Neutron Science Center Tour attendees can expect to see many facets of the LANSCE, including areas along the linear accelerator beam line, the control room area, and one or more experimental areas. May 10, 2011 Aerial View of Neutron Science Center Aerial View of Neutron Science Center Contact James Rickman Communicatons Office (505) 665-9203 Email LANL Rosenfest will celebrate life of LANSCE founder Louis Rosen and offer tour LOS ALAMOS, New Mexico, May 10, 2011-Members of the public will have an unusual opportunity to tour the Los Alamos Neutron Science Center from 1 to 5 p.m. on Friday, May 20, 2011, as part of Rosenfest, a celebration of LANSCE founder Louis Rosen and the remarkable facility he conceived. In

320

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

2009-06-06T23:59:59.000Z

Note: This page contains sample records for the topic "neutron scattering center" 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.


321

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

322

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

323

Small angle neutron scattering and small angle X-ray scattering studies of platinum-loaded carbon foams  

Science Journals Connector (OSTI)

The morphology of carbon nanofoam samples comprising platinum nanoparticles dispersed in the matrix was characterized by small angle neutron scattering (SANS) and small angle X-ray scattering (SAXS) techniques. R...

P. U. Sastry; V. K. Aswal; A. G. Wagh

2008-11-01T23:59:59.000Z

324

Temperature dependence of the dynamic scattering function in glycerol studied by quasi-elastic slow neutron scattering  

Science Journals Connector (OSTI)

Microscopic dynamics of glycerol across the liquidglass transition has been studied by incoherent slow neutron scattering performed at temperatures from 400?K to ... data are analyzed in terms of the dynamic scattering

I. Padureanu; R.E. Lechner; D. Aranghel; A. Radulescu; A. Desmedt

2002-12-01T23:59:59.000Z

325

Rotational dynamics of hydration water in dicalcium silicate by quasielastic neutron scattering  

Science Journals Connector (OSTI)

Quasielastic neutron scattering (QENS) has been used to investigate the single-particle dynamics of interfacial water in dicalcium silicate (C2S)/water paste. Our previous neutron-scattering studies on interfacial water have focused attention on the translational dynamics of the center of mass of water molecules. In this paper, we have collected QENS data on a wider range of wave-vector transfer so that both translational and rotational motions of water molecules are detected. The data have been analyzed by models for translation and rotation we recently proposed for supercooled water. The evolution of the parameters describing the relaxational dynamics of water embedded in the C2S matrix is given at temperature T=303?K as a function of the curing time.

A. Faraone; S.-H. Chen; E. Fratini; P. Baglioni; L. Liu; C. Brown

2002-04-08T23:59:59.000Z

326

Introduction to Neutron and X-Ray Scattering  

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

Scattering Studies of Thin Scattering Studies of Thin Polymer Films Introduction to Neutron and X-Ray Scattering Sunil K. Sinha UCSD/LANL Acknowledgements: Prof. R.Pynn( Indiana U.) Prof. M.Tolan (U. Dortmund) Wilhelm Conrad Röntgen 1845-1923 1895: Discovery of X-Rays 1901 W. C. Röntgen in Physics for the discovery of x-rays. 1914 M. von Laue in Physics for x-ray diffraction from crystals. 1915 W. H. Bragg and W. L. Bragg in Physics for crystal structure determination. 1917 C. G. Barkla in Physics for characteristic radiation of elements. 1924 K. M. G. Siegbahn in Physics for x-ray spectroscopy. 1927 A. H. Compton in Physics for scattering of x-rays by electrons. 1936 P. Debye in Chemistry for diffraction of x-rays and electrons in gases.

327

CORELLI: the Elastic Diffuse Scattering Spectrometer at SNS | ORNL Neutron  

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

The Elastic Diffuse Scattering Spectrometer The Elastic Diffuse Scattering Spectrometer CORELLI The CORELLI instrument. CORELLI is a statistical chopper spectrometer with energy discrimination. It's designed and optimized to probe complex disorder in crystalline materials through diffuse scattering of single-crystal samples. The momentum transfer ranges from 0.5 to 12 Å-1, and the energy of incident neutrons ranges from 10 to 200 meV. This instrument combines the high efficiency of white-beam Laue diffraction with energy discrimination by modulating the beam with a statistical chopper. A cross-correlation method is used to reconstruct the elastic signal from the modulated data. Accurate modeling of the short-range order associated with the diffuse scattering requires measurements over large volumes of three-dimensional reciprocal space, with sufficient momentum

328

Precision neutron-interferometric measurement of the coherent neutron-scattering length in silicon  

Science Journals Connector (OSTI)

The neutron-interferometry (NI) technique provides a precise and direct way to measure the bound, coherent scattering lengths b of low-energy neutrons in solids, liquids, or gases. The potential accuracy of NI to measure b has not been fully realized in past experiments, due to systematic sources of error. We have used a method which eliminates two of the main sources of error to measure the scattering length of silicon with a relative standard uncertainty of 0.005%. The resulting value, b=4.1507(2) fm, is in agreement with the current accepted value, but has an uncertainty five times smaller.

A. Ioffe; D. L. Jacobson; M. Arif; M. Vrana; S. A. Werner; P. Fischer; G. L. Greene; F. Mezei

1998-08-01T23:59:59.000Z

329

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

330

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

331

Neutron scattering by rough surfaces at grazing incidence  

Science Journals Connector (OSTI)

There are a number of calculations in the literature of the effect of statistical surface roughness on the specular and diffuse scattering of neutrons and x rays which impinge on surfaces at grazing incidence. These calculations do not agree with one another and in some cases lack internal consistency. In this paper I show that these discrepancies can be resolved within the distorted-wave Born approximation. The result I obtain for the specular reflectivity is the widely used version of Nevot and Croce, while that for the diffuse scattering is the same as a recent calculation by Sinha, Sirota, Garoff, and Stanley. The approximations made by Nevot and Croce are clearly revealed by the distorted-wave Born approximation. A simple numerical algorithm is proposed for the calculation of diffuse scattering from a surface whose roughness is self-affine, and the form of the scattering is calculated for a range of parameters within this model. The calculation of diffusion scattering is extended in this paper to the case of films with rough surfaces. Correlation between roughness at the two film surfaces is considered and shown to be important for the description of neutron reflectivity data obtained with a thin film of titanium deposited on a sapphire substrate.

Roger Pynn

1992-01-01T23:59:59.000Z

332

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

2005-07-22T23:59:59.000Z

333

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

334

[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

335

Los Alamos Neutron Science Center gets capacity boost  

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

Neutron Science Center capacity boost Neutron Science Center capacity boost Los Alamos Neutron Science Center gets capacity boost The facility can simulate the effects of hundreds or thousands of years of cosmic-ray-induced neutrons in a single hour. December 2, 2010 Los Alamos National Laboratory sits on top of a once-remote mesa in northern New Mexico with the Jemez mountains as a backdrop to research and innovation covering multi-disciplines from bioscience, sustainable energy sources, to plasma physics and new materials. Los Alamos National Laboratory sits on top of a once-remote mesa in northern New Mexico with the Jemez mountains as a backdrop to research and innovation covering multi-disciplines from bioscience, sustainable energy sources, to plasma physics and new materials. Contact

336

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

337

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

338

Neutron scattering studies of spin?glass alloys  

Science Journals Connector (OSTI)

Neutron diffraction investigations of binary alloys such as Cu?Mn beginning with the earliest reported measurements in 1957 show no evidence of any long range magnetic order except for the broad short range order peaks at the (1 1/2 0) type positions attributed to both atomic and magnetic short range ordering in alloys containing more than about 1015 at.% Mn. The current interest in spin glasses is focused on the theoretical possibility of a magnetic phase transition to the spin glass state in the dilute random substitutional alloys. Recently neutron scatteringmeasurements have been attempted to study the dynamics of spins in the alloys with a view to understanding the nature of the processes leading to the spin glass state. Small angle neutron scatteringmeasurements on Au?Fe alloys with Fe concentrations below the percolation threshold for ferromagnetism show a series of q?dependent maxima in the total scattering intensity suggesting a continuum of freezing temperatures. Other measurements employing energy analysis by the time?of?flight technique at somewhat larger qs on the same and other alloys such as Cu?Mn Pd?Mn show a broad quasi?elastic paramagnetic spectrum at high temperatures whose energy width decreases with decreasing temperature apparently goes through a minimum especially at the higher qs but always remains finite as T?0 K. The intensity of the quasi?elastic scattering however diminishes progressively below some temperature with a simultaneous continuous increase of the elastic peak intensity. Although the implications of the recent phase transition theories of spin glasses to the dynamics of spins at finite scattering vectors are not entirely clear the present neutron scattering results appear not inconsistent with the alternative picture of a continuous process of freezing of spins occurring at least over a finite temperature range.

A. P. Murani

1978-01-01T23:59:59.000Z

339

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

340

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

Note: This page contains sample records for the topic "neutron scattering center" 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.


341

Neutron scattering investigations on methyl group dynamics in polymers.  

E-Print Network [OSTI]

Among the different dynamical processes that take place in polymers, methyl group rotation is perhaps the simplest one, since all the relevant interactions on the methyl group can be condensed in an effective mean-field one-dimensional potential. Recent experimental neutron scattering results have stimulated a new revival of the interest on methyl group dynamics in glasses and polymer systems. The existence of quantum rotational tunnelling of methyl groups in polymers was expected for a long time but only very recently (1998), these processes have been directly observed by high-resolution neutron scattering techniques. This paper revises and summarizes the work done on this topic over last ten years by means of neutron scattering. It is shown that the results obtained in many chemically and structurally different polymers can be consistently described in the whole temperature range from the quantum tunnelling limit to the classical hopping regime as well as in the librational spectrum, in terms of the Rotation Rate Distribution Model (RRDM), which was first proposed in 1994. This model introduces a distribution of potential barriers for methyl group rotation, which is associated to the disorder present in any structural glass. The molecular and structural origin of the barrier distribution in polymers is discussed on the basis of a huge collection of investigations reported in the literature, including recent fully atomistic molecular dynamics simulations.

Juan Colmenero; Angel J. Moreno; Angel Alegra

2005-01-01T23:59:59.000Z

342

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

343

Theory of Neutron Scattering by Conduction Electrons in a Metal and on the Collective-Electron Model of a Ferromagnet  

Science Journals Connector (OSTI)

...research-article Theory of Neutron Scattering by Conduction Electrons in...are studied for the magnetic scattering of slow neutrons by metallic electrons whose...current contribute to the scattering. With the aid of certain...

1956-01-01T23:59:59.000Z

344

Neutron-Proton and Neutron-Neutron Scattering at High Energies  

Science Journals Connector (OSTI)

The phase method and the Born approximation is used to calculate the cross sections of high energy neutrons scattered by protons and neutrons. Various exchange theories are considered for both, central and tensor forces of rectangular and Yukawa well shape.For the tensor case the phase method leads to general formulas for the differential and total cross sections in terms of real phase shifts. The reality of the phase shifts is a direct consequence of the use of the asymptotic form of the eigenfunctions of the tensor force Hamiltonian. The differential cross section in this case also contains the "amounts of admixture" which measure the coupling of states of different orbital angular momentum which have the same total angular momentum and the same parity. The real phase shifts and the amounts of admixture are derived from a variational principle. The total cross sections thus obtained are within a few percent of the exact values. The Born approximation is not satisfactory at 100 Mev.At this energy, tensor forces of a rectangular well shape with Rarita-Schwinger constants yield 0.2113, 0.1497, and 0.1271 barns for the n-p cross section, and 0.2566, 0.1381, and 0.0359 barns for the n-n cross section, in the neutral, charged, and symmetrical exchange theory, respectively. The observed n-p cross section at 90 Mev, 0.0830.004 barns, agrees best with the theoretical value of ?0.080 barns at 100 Mev, derived from a tensor interaction potential of equal amounts of neutral and charged exchange. It is concluded, however, that a Yukawa tensor potential of the symmetrical exchange type can be in agreement with the experiments, if relativistic corrections of the n-p cross section at 100 Mev are negative and of the order of 5-10 percent. The differential cross section needs considerably larger corrections unless a different tensor force range is used.

F. Rohrlich and J. Eisenstein

1949-03-01T23:59:59.000Z

345

The evanescent neutron wave diffractometer: On the way to surface sensitive neutron scattering  

Science Journals Connector (OSTI)

A novel experimental technique to observe the Bragg scattering of evanescent neutronwaves is presented. The so?called EVA diffractometer installed at the high?flux reactor of the Institut Laue?Langevin allows the identification of neutron scattering from single crystalsurfaces. We discuss the experimental setup intensity and resolution considerations and some first Bragg scattering signals from evanescent neutronwaves excited at CaF2 InP and MnF2single crystalsurfaces. The experimental results are discussed within the framework of the so?called distorted wave Born approximation and within a dynamical scattering theory. The limitations of both theoretical approaches to describe the Bragg scattering of evanescent neutronwaves are indicated. ?

H. Dosch; K. Al Usta; A. Lied; W. Drexel; J. Peisl

1992-01-01T23:59:59.000Z

346

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

347

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

348

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

349

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

350

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

351

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

352

Neutron-Proton Scattering at 156$\\,\\pm \\,$3 MeV  

Science Journals Connector (OSTI)

8 July 1952 research-article Neutron-Proton Scattering at 156 3 MeV T. C. Randle A. E. Taylor E. Wood The angular distribution for neutron-proton scattering at 156 3 MeV has been determined for centre-of-mass scattering angles between...

1952-01-01T23:59:59.000Z

353

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.

354

A High Count Rate Neutron Beam Monitor for Neutron Scattering Facilities  

SciTech Connect (OSTI)

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

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

2013-01-01T23:59:59.000Z

355

LANSCE | Lujan Center | Highlights | In situ neutron diffraction study of  

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

In situ neutron diffraction study of CO clathrate hydrate In situ neutron diffraction study of CO clathrate hydrate The structure of a CO clathrate hydrate has been studied for the first time using high-P low-T neutron diffraction. Clathrate Rietveld analysis shows that lattice parameter a (SII cubic clathrate structure) increases with increasing temperature. CO molecules are positionally disordered and off-centered in both large and small cages. Each large cage is occupied by two CO molecules while each small cage is occupied by one CO. A representative neutron diffraction pattern of SII CO clathrate hydrate. Variation of lattice parameter a of CO SII clathrate hydrate as a function of temperature. A representative neutron diffraction pattern of SII CO clathrate hydrate. Variation of lattice parameter a of CO SII clathrate hydrate as a function of temperature.

356

Chapter Three - Magnetic Exchange Phenomena Probed by Neutron Scattering  

Science Journals Connector (OSTI)

Abstract Neutron scattering techniques are powerful tools for investigation of magnetic materials and magnetic exchange interactions on the nanoscale. Owing to the weak interaction of the neutron, results are representative of the bulk and not only comprised of surface properties. Nevertheless, due to the high atomic and magnetic contrast, high interface sensitivity is easily achieved. This chapter will review the applicability of neutron scattering techniques to the investigation magnetic exchange interactions based on two examples, interlayer exchange coupling and exchange bias in metallic multilayers. PNR will be employed to study the magnetic state of a Cu0.94Mn0.06/Co multilayer showing a temperature-dependent coupling originating from the dilute magnetic impurities. Exchange bias within mono-stoichiometric FePt3 thin films based on chemical order modulation will be investigated with PNR and diffraction techniques to elucidate the magnetic ordering on nanometer and atomic length scales. During the individual discussion of the phenomena, both interlayer exchange coupling and exchange bias will be reviewed.

Thomas Saerbeck

2014-01-01T23:59:59.000Z

357

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;

358

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

359

Small-angle neutron scattering analysis of a water-based magnetic fluid with charge stabilization: contrast variation and scattering of polarized neutrons  

Science Journals Connector (OSTI)

The nuclear and magnetic scattering contributions in small-angle scattering experiments on a diluted water-based magnetic fluid are separated by the contrast variation technique and scattering of polarized neutrons. The significant difference found in the nuclear and magnetic apparent particle sizes is related to different nuclear and magnetic correlation lengths in the system.

Avdeev, M.V.

2009-10-30T23:59:59.000Z

360

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

2005-10-11T23:59:59.000Z

Note: This page contains sample records for the topic "neutron scattering center" 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.


361

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

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

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

362

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

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

areas of materials at the mesoscale. They will use several instruments utlizing different neutron scattering and complementary techniques. Featured Instruments (tentative) HIPPO:...

363

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

Broader source: Energy.gov [DOE]

Application of Neutron Imaging and Scattering to Fluid Flow and Fracture in EGS Environments presentation at the April 2013 peer review meeting held in Denver, Colorado.

364

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...

365

Parity Violation in Neutron Deuteron Scattering in Pionless Effective Field Theory.  

E-Print Network [OSTI]

??In this dissertation the parity violating neutron deuteron scattering amplitudes are calculated using pionless effective field theory to leading order. The five low energy parity (more)

Vanasse, Jared James

2012-01-01T23:59:59.000Z

366

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

367

Neutron-scattering investigation of molecular reorientations in solid cubane  

Science Journals Connector (OSTI)

We have studied the reorientations of the cube-shaped molecule cubane (C8H8) in its solid phase using quasielastic neutron-scattering techniques both below and above the molecular orientational phase-transition temperature Tp=394 K. In the orientationally ordered phase, just below Tp, the elastic incoherent structure factor (EISF) extracted from neutron time-of-flight measurements indicates that cubane undergoes ? jumps about the molecular fourfold axis. In the disordered phase we find that the EISF excludes isotropic and free uniaxial rotational motions of the molecule. Instead our data suggest cubane undergoes uncorrelated ? jumps about the fourfold axis (as in the ordered phase) and 2?/3 jumps about the threefold axis.

T. Yildirim; P. M. Gehring; D. A. Neumann; P. E. Eaton; T. Emrick

1999-07-01T23:59:59.000Z

368

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

369

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

370

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

371

X-ray and neutron scattering from nano-mgantic clusters | The...  

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

X-ray and neutron scattering from nano-mgantic clusters The student will participate in hands on X-ray scattering experiments on bio-inspired inorganic materials (i.e., magnetic...

372

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

373

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

374

Incoherent Neutron Scattering and the Dynamics of Confined Polycarbonate Films  

Science Journals Connector (OSTI)

Incoherent elastic neutron scattering measurements are performed on thin (75 to 1015 ?) polycarbonate films supported on Si wafers. We find that the mean-square atomic displacement ?u2? is diminished by thin film confinement. For film thicknesses comparable to the unperturbed dimensions of the macromolecule, we observe two characteristic crossover temperatures in ?u2? as a function of temperature T, one above and the other below the bulk Tg. Furthermore, the harmonic force constant ?, defined by the low temperature dependence of ?u2? (i.e., ??kBT/?u2?), increases as the film thickness decreases. These observations suggest that the atoms are more strongly localized in the thin supported films.

C. L. Soles; J. F. Douglas; W.-l. Wu; R. M. Dimeo

2002-01-02T23:59:59.000Z

375

Contrast variation in spin-echo small angle neutron scattering  

Science Journals Connector (OSTI)

The use of contrast variation in spin-echo small angle neutron scattering (SESANS) experiments is discussed for the case of colloidal structural investigation. On the basis of calculations for several model systems, we find that the contrast variation SESANS technique, in terms of the measured SESANS correlation function G(z), is not sensitive to the structural characteristics of colloidal suspensions consisting of particles with uniform scattering length density profiles. However, its ability to resolve structural heterogeneity, at both intra-colloidal and inter-colloidal length scales, is clearly demonstrated. The prospect of using this new technique to investigate structural information that is difficult to probe in other ways is also explored.

Xin Li; Bin Wu; Yun Liu; Roger Pynn; Chwen-Yang Shew; Gregory S Smith; Kenneth W Herwig; J Lee Robertson; Wei-Ren Chen; Li Liu

2012-01-01T23:59:59.000Z

376

Deuterium Labeling and Neutron Scattering for Structural Biology  

SciTech Connect (OSTI)

Neutron scattering applications in structural biology are strongly enhanced by deuterium labeling either of the aqueous solvent or of the macromolecules themselves, or both. In protein crystallography deuteration of the solvent and protein allows a clear visualization of hydrogen sites (deuterium atoms) as well as increasing signal/noise in the diffraction data. This allows crystals as small as 0.1 mm{sup 3} to be used. In small angle scattering and reflectometry deuteration of the aqueous solvent allows one to exploit manipulate the contrast between different components complexes such as proteins, nucleic acids or lipids. In the case of multi-protein complexes the in vivo deuteration of individual protein sub-units allows an even more sophisticated contrast variation to be performed.

Timmins, Peter [Institut Laue-Langevin, BP 156, 6 rue Jules Horowitz 38042 Grenoble Ceclex 9 (France)

2008-03-17T23:59:59.000Z

377

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

378

Structural and dynamical studies of superacids and superacidic solutions using neutron and high energy X-ray scattering.  

E-Print Network [OSTI]

?? The diffusive motions of the Brnsted superacid, hydrogen fluoride, have been studied using quasielastic neutron scattering. Neutron and high energy X-ray diffraction measurements on (more)

Molaison, Jamie John

2006-01-01T23:59:59.000Z

379

| Los Alamos National Laboratory | Total Scattering Developments forTotal Scattering Developments for  

E-Print Network [OSTI]

Laboratory | Total Scattering at the Lujan Center Neutron Powder Diffractometer (NPDF) High-Intensity Powder. Shoemaker, et al., Reverse Monte Carlo neutron scattering study of disordered crystalline materials neutron| Los Alamos National Laboratory | Total Scattering Developments forTotal Scattering Developments

Magee, Joseph W.

380

Neutron scattering and magnetic studies of ferrihydrite nanoparticles  

Science Journals Connector (OSTI)

Magnetic properties of two-line ferrihydrite (FeOOD?nD2O) nanoparticles with an average size ?4 nm are investigated using neutron scattering and magnetometry. Comparison of the neutron scattering and x-ray diffraction patterns identifies the (002) peak at Q=1.3 -1 as predominantly magnetic. The intensity of this peak, measured from 10 to 450 K, decreases almost linearly with temperature until 350 K, becoming temperature independent above 350 K. From this, TN?350 K is identified to be the ordering temperature of the core spins of the nanoparticles. The width of the line is temperature independent, yielding a magnetic coherence length?particle size. The temperature variations (5300 K) of the initial susceptibility ? for the field-cooled (FC) and zero-field-cooled (ZFC) cases yield a peak at Tp(m)?65 K, below which ?(FC)>?(ZFC). For T>Tp(m), the variation of ?-1 vs T is analyzed in terms of the model of El-Hilo et al., involving particle-size distribution and interparticle interactions, and substantial interparticle interactions are inferred. Following the observations in ferritin, the field dependence of the magnetization M for T>Tp(m) is analyzed in terms of the modified Langevin variation: M=MoL(?pH/kT)+?aH, where ?p is the magnetic moment/particle. The fit at 100 K yields ?p?250 ?B, consistent with the theoretical estimates based on uncompensated surface spins of Fe3+.

M. S. Seehra; V. S. Babu; A. Manivannan; J. W. Lynn

2000-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "neutron scattering center" 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

Inelastic neutron scattering study of a quantum spin trimer  

Science Journals Connector (OSTI)

We present an inelastic neutron scattering (INS) study of the excitation spectrum of a quantum S=1?2 equilateral Heisenberg trimer, Cu3(O2C16H23)61.2C6H12. The magnetic properties of the system can be described by an ensemble of independent equilateral triangles of S=1?2 Cu2+ ions. With antiferromagnetic Heisenberg coupling, the ground state of each trimer is a degenerate pair of S=1?2 doublets, with a quartet S=3?2 excited state. Previous bulk measurements led to an estimate for the excitation energy of 28meV. Here, we report INS measurements that can provide a direct measurement of magnetic excitation energies. These measurements are challenging since inter- and intramolecular vibrational modes associated with the organic ligands are at frequencies similar to the magnetic excitations. Measurements on a nonmagnetic compound with the same ligands as well as the temperature dependence of the neutron scattering cross section are used to identify the vibrational modes. This leads to an identification of the magnetic excitation energy as being approximately 37meV at T=10K, with a gradual softening with increasing temperature.

M. B. Stone; F. Fernandez-Alonso; D. T. Adroja; N. S. Dalal; D. Villagrn; F. A. Cotton; S. E. Nagler

2007-06-25T23:59:59.000Z

382

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

383

Direct proof of a "more-than-single-layered" peptidoglycan architecture of Escherichia coli W7: a neutron small-angle scattering study.  

Science Journals Connector (OSTI)

...sacculus obtained by using a small-angle neutron scattering technique. A comparison of the hydrogenated...used as a measurement for background in the neutron scattering studies. Neutron scattering data collection and evaluation. Small...

H Labischinski; E W Goodell; A Goodell; M L Hochberg

1991-01-01T23:59:59.000Z

384

Small-Angle Neutron Scattering Studies of the Conformation of Myeloma Protein MOPC315 and its Fab Fragment, and the Interaction with a Monovalent Dinitrophenyl Hapten  

Science Journals Connector (OSTI)

...research-article Small-Angle Neutron Scattering Studies of the Conformation...fixation. Small-angle neutron scattering studies of the conformation...Fragments Myeloma Proteins Neutrons Protein Conformation Scattering, Radiation The Royal Society...

1981-01-01T23:59:59.000Z

385

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

E-Print Network [OSTI]

The scattering of slow neutron beams provides unique, non-destructive, 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 15 meV, which renders the moderator volume transparent to the neutron energies of most interest for scattering studies, is therefore especially interesting and important. We have placed an upper bound on 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 Nati...

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

2014-01-01T23:59:59.000Z

386

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"

387

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

388

Quasielastic Neutron Scattering in the High-Field Phase of a Haldane Antiferromagnet  

Science Journals Connector (OSTI)

Inelastic neutron scattering experiments on the Haldane-gap quantum antiferromagnet Ni(C5D14N2)2-N3(PF6) are performed in magnetic fields below and above the critical field Hc at which the gap closes. Quasielastic neutron scattering is found for H>Hc, indicating topological excitations in the high-field phase.

A. Zheludev; Z. Honda; Y. Chen; C. L. Broholm; K. Katsumata; S. M. Shapiro

2002-02-05T23:59:59.000Z

389

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

390

Ultra-small-angle neutron scattering from dense micrometre-sized colloidal systems: data evaluation and comparison with static light scattering  

Science Journals Connector (OSTI)

Application of the GIFT method works well for evaluation of both neutron and light scattering data, but multiple scattering must be kept negligible. The advantage of light scattering is the fast data acquisition, while USANS covers a wider q range.

Innerlohinger, J.

2006-03-12T23:59:59.000Z

391

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

392

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

393

Neutron-transmuted carbon-14 in neutron-irradiated GaN: Compensation of DX-like center  

SciTech Connect (OSTI)

The transmuted-C related luminescence and net carrier concentration are studied by combining photoluminescence, liquid scintillation, and Raman scattering. GaN single crystal films grown by metalorganic-vapor-phase epitaxy are irradiated with fast and thermal neutrons at fluxes of 3.9 10{sup 13} cm{sup ?2}s{sup ?1} and 8.15 10{sup 13} cm{sup ?2}s{sup ?1}, respectively. Irradiation time is 48 hours. The calculated {sup 72}Ge and {sup 14}C concentrations are 1.24 10{sup 18} cm{sup ?3} and 1.13 10{sup 18} cm{sup ?3}, respectively. The transmuted {sup 14}C is detected by the liquid scintillation method to survey ?-rays emitted in the process of {sup 14}C decays from {sup 14}N. Tritium ({sup 3}H) is also emitted by a (n,t) reaction of {sup 14}N due to the neutron irradiation above 4.5 MeV. Photoluminescence relating to C, DX-like center of Ge and yellow luminescence band are observed in 1000 C annealed NTD-GaN. The free electron concentration estimated from Raman scattering is 4.97 10{sup 17} cm{sup ?3}. This value is lower than that from the transmuted Ge concentration, suggesting the compensation due to the transmuted {sup 14}C acceptors.

Ida, T.; Oga, T.; Kuriyama, K. [College of Engineering and Research Center of Ion Beam Technology, Hosei University Koganei, Tokyo 184-8584 (Japan); Kushida, K. [Departments of Arts and Sciences, Osaka Kyoiku University Kashiwara, Osaka 582-8582 (Japan); Xu, Q.; Fukutani, S. [Research Reactor Institute, Kyoto University Kumatori, Osaka 590-0494 (Japan)

2013-12-04T23:59:59.000Z

394

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

395

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.

396

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

397

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

398

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

399

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.

400

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

Note: This page contains sample records for the topic "neutron scattering center" 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

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.

402

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

403

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

404

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.

405

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

406

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

407

Inelastic neutron scattering from single crystal Zn under high pressure  

Science Journals Connector (OSTI)

Inelastic neutron-scattering experiments have been performed for single crystals of Zn under pressures up to 8.8 GPa at 300 K. The phonon modes q/qmax=?=0.075 and ?=0.10 were measured in the transverse acoustic branch ?3, where q=0 corresponds with the elastic constant C44. The phonon energy showed a substantial hardening with increasing pressure. The experimental data below 6.8 GPa for ?=0.075 yield a constant Grneisen mode ?i=-ln?i/lnV of 2.25 in good agreement with a previous calculation [H. Ledbetter, Phys. Status Solidi B 181, 81 (1994)]. Above 6.8 GPa, there is a very rapid increase of ?i which is indicative of the presence of a giant Kohn anomaly. This rapid divergence at high pressure indicates that a phonon softening may occur at pressures higher than 8.8 GPa caused by the collapse of the giant Kohn anomaly via an electronic topological transition (ETT). In an earlier Mssbauer Zn study at 4 K [W. Potzel et al., Phys. Rev. Lett. 74, 1139 (1994)], a drastic drop of the Lamb-Mssbauer factor was observed at 6.6 GPa, which was interpreted as being due to phonon softening, indicating this ETT had occurred. This paper also compares the compressibility data for single crystal Zn and Zn powder using neutron scattering. The results were found to be similar to an earlier x-ray Zn powder experiment [O. Schulte et al., High Pressure Res. 6, 169 (1991)]. 1996 The American Physical Society.

J. G. Morgan; R. B. Von Dreele; P. Wochner; S. M. Shapiro

1996-07-01T23:59:59.000Z

408

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

409

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

410

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

411

E-Print Network 3.0 - activ-87 fast neutron Sample Search Results  

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

2106533431 Large Scale Experimental Facilities at RRL Nuclear Research Reactor 5 MW power Neutron... Scattering Facilities Neutron diffractometer, ... Source: National Center for...

412

LANSCE | Lujan Center | Industrial Users  

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

Industrial Users The Lujan Neutron Scattering Center offers a diverse set of capabilities and instruments for industrial projects. Industrial users are invited to contact the Lujan...

413

Proton Angular Distribution for 90 Mev Neutron-proton Scattering  

E-Print Network [OSTI]

PROTON SCATTERING James Hadley, Cecil E. Leith, and HerbertPRarON SCATTERING James Hadley, Cecil E. Leith, and Herbert

Hadley, James

2010-01-01T23:59:59.000Z

414

Nanoscale Science Research Centers (NSRCs) | U.S. DOE Office...  

Office of Science (SC) Website

(SUF) Division SUF Home About User Facilities User Facilities Dev X-Ray Light Sources Neutron Scattering Facilities Nanoscale Science Research Centers (NSRCs) Center for...

415

Center for Integrated Nanotechnologies (CINT) | U.S. DOE Office...  

Office of Science (SC) Website

(SUF) Division SUF Home About User Facilities User Facilities Dev X-Ray Light Sources Neutron Scattering Facilities Nanoscale Science Research Centers (NSRCs) Center for...

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

Neutron Scattering Study of Vermiculite?Poly(vinyl methyl ether) Mixtures  

Science Journals Connector (OSTI)

Neutrons scattered by the gel samples were recorded on a two-dimensional area detector, software coded as 128 128 pixels, situated 1.5 m behind the samples, covering the approximate q range between 0.2 and 2 nm-1, where the wavenumber q is defined by the equation with ? being the scattering angle. ... The quartz sample cells used were practically transparent to neutrons at the wavelength utilized on the SANS-J, and the small angle neutron scattering from D2O was of low intensity and completely unstructured over the q range studied. ...

H. Jinnai; M. V. Smalley; T. Hashimoto; S. Koizumi

1996-03-06T23:59:59.000Z

418

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

419

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

420

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

SciTech Connect (OSTI)

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

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

2008-03-17T23:59:59.000Z

Note: This page contains sample records for the topic "neutron scattering center" 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.


421

The pore structure of the Argonne coals as interpreted from contrast matching small angle neutron scattering  

Science Journals Connector (OSTI)

Contrast matching small angle neutron scattering has been performed on a series of Argonne coals using H2O/D2O mixtures using short contact times between the coal and liquid. Calculations of the neutron scattering densities of the coals based on their formulae and helium densities are discussed. The results of the CM-SANS are given and it is shown that the scattering from the scattering from the non-contrast-matched samples is unreliable. It is shown that porosity in coals is effectively determined by the presence of water and that porosity levels decrease with increasing rank.

P.J. Hall; S.D. Brown; J.M. Calo

2000-01-01T23:59:59.000Z

422

National School on Neutron and X-Ray Scattering Held at APS&IPNS  

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

August 14th, 2000 National School on Neutron and X-Ray Scattering Held at APS & IPNS During the two-week period of August 14-26, 2000 Argonne National Laboratory once again hosted...

423

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

Science Journals Connector (OSTI)

The directional properties of electron-proton spin interaction in an external magnetic field give rise to an anisotropic distribution of the intensity of polarized neutron scattering from dynamically polarized protons of radical molecules in solution.

Stuhrmann, H.B.

2007-11-01T23:59:59.000Z

424

National School on Neutron and X-ray Scattering | Argonne National...  

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

Questions Program Details NX School Partners Contact education@anl.gov National School on Neutron & X-ray Scattering June 14-28, 2014 About the School The main purpose of the...

425

Neutron-Scattering Evidence for a Spin-Peierls Ground State in (TMTTF)2PF6  

Science Journals Connector (OSTI)

(TMTTF)2X, with X=PF6, exhibits, at TSP..., a spin-Peierls transition. Below TSP elastic neutron scattering measurements performed on large protonated and deuterated...SP decreases by 30% while the charge orderin...

J.-P. Pouget; P. Foury-Leylekian; D. Le Bolloch

2006-02-01T23:59:59.000Z

426

Analysis of randomly oriented structures by grazing-incidence small-angle neutron scattering  

Science Journals Connector (OSTI)

A formalism is presented which allows the quantitative evaluation of grazing-incidence small-angle neutron scattering patterns from randomly oriented one-dimensional paracrystal domains with lamellar structure.

Korolkov, D.

2012-03-15T23:59:59.000Z

427

Small Angle Neutron Scattering Characterization of the Porous Structure of Carbons Prepared Using Inorganic Templates  

Science Journals Connector (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 ...

Giselle Sand; P. Thiyagarajan; Kathleen A. Carrado; Randall E. Winans

1999-01-20T23:59:59.000Z

428

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

429

Dynamic radial distribution function from inelastic neutron scattering  

Science Journals Connector (OSTI)

A real-space, local dynamic structure function g(r,?) is defined from the dynamic structure function S(Q,?), which can be measured using inelastic neutron scattering. At any particular frequency ?, S(Q,?) contains Q-dependent intensity oscillations which reflect the spatial distribution and relative displacement directions for the atoms vibrating at that frequency. Information about local and dynamic atomic correlations is obtained from the Fourier transform of these oscillations g(r,?) at the particular frequency. g(r,?) can be formulated such that the elastic and frequency-summed limits correspond to the average and instantaneous radial distribution function, respectively, and is thus called the dynamic radial distribution function. As an example, the dynamic radial distribution function is calculated for fcc nickel in a model which considers only the harmonic atomic displacements due to phonons. The results of these calculations demonstrate that the magnitude of the atomic correlations can be quantified and g(r,?) is a well-defined correlation function. This leads to a simple prescription for investigating local lattice dynamics.

R. J. McQueeney

1998-05-01T23:59:59.000Z

430

Incoherent neutron scattering from multi-element materials  

Science Journals Connector (OSTI)

The differences and distinguishing characteristics of incoherent scattering vis--vis diffuse coherent scattering due to atomic disorder are delineated and demonstrated experimentally.

Glinka, C.J.

2011-04-02T23:59:59.000Z

431

95 MeV neutron scattering on hydrogen, deuterium, carbon, and oxygen  

Science Journals Connector (OSTI)

Three neutron-deuteron scattering experiments at 95 MeV have been performed recently at The Svedberg Laboratory in Uppsala. Subsets of the results of these experiments have been reported in two short articles, showing clear evidence for three-nucleon force effects. In this paper, we present a more detailed description of the experimental methods as well as further discussion of the results. In addition to neutron-deuteron scattering data, neutron-proton and C12(n,n) elastic scattering data have been measured for normalization purposes, and O16(n,n) data have been obtained for the first time at this energy. It was possible to extract C12(n,n') and O16(n,n') inelastic scattering cross sections to excited states below 12 MeV excitation energy. The inelastic scattering data (for both carbon and oxygen) are shown to have a significant impact on the determination of nuclear recoil kerma coefficients.

P. Mermod; J. Blomgren; C. Johansson; A. hrn; M. sterlund; S. Pomp; B. Bergenwall; J. Klug; L. Nilsson; N. Olsson; U. Tippawan; P. Nadel-Turonski; O. Jonsson; A. Prokofiev; P.-U. Renberg; Y. Maeda; H. Sakai; A. Tamii; K. Amos; R. Crespo; A. Moro

2006-11-27T23:59:59.000Z

432

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

433

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

434

Neutron Scattering and Diffraction Studies of Fluids and Fluid-Solid Interactions  

Science Journals Connector (OSTI)

...structure, such as porous glasses (e.g., Vycor), xerogels, aerogels, and rocks. At the other end, there are materials characterized...Frielinghaus H (2006) Adsorption of supercritical CO2 in aerogels as studied by small-angle neutron scattering and neutron...

David R. Cole; Kenneth W. Herwig; Eugene Mamontov; John Z. Larese

435

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

436

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

437

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

E-Print Network [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 software engineers and scientists at the ISIS Neutron and Muon Facility and the Oak Ridge National Laboratory. The objectives, functionality and novel design aspects of Mantid are described.

Arnold, O; Borreguero, J M; Buts, A; Campbell, S I; Chapon, L; Doucet, M; Draper, N; Leal, R Ferraz; Gigg, M A; Lynch, V E; Markvardsen, A; Mikkelson, D J; Mikkelson, R L; Miller, R; Palmen, K; Parker, P; Passos, G; Perring, T G; Peterson, P F; Ren, S; Reuter, M A; Savici, A T; Taylor, J W; Taylor, R J; Tolchenov, R; Zhou, W; Zikovsky, J

2014-01-01T23:59:59.000Z

438

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

439

NEUTRON SCATTERING STUDY OF METHYL GROUP ROTATION IN SOLID PARA-AZOXYANISOLE (PAA)  

E-Print Network [OSTI]

587 NEUTRON SCATTERING STUDY OF METHYL GROUP ROTATION IN SOLID PARA-AZOXYANISOLE (PAA) H. HERVET diffusion incohérente de neutrons, que dans le PAA solide les groupes méthyle sont animés d'un mouvement de that the methyl groups in solid PAA undergo random rotational motion around their three-fold axis

Paris-Sud XI, Université de

440

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

SciTech Connect (OSTI)

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

Hjelm, R.P.

1998-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "neutron scattering center" 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

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, in the case of a_{nn}=+18.22 fm, the result of 275(3) s^{-1} (135(3) s^{-1}) is obtained, when the di-neutron system in the final state is unbound (bound). The muon capture mu + 3He --> nu_mu + 3H is also analyzed, and the total capture rate is found to be 1494(15) s^{-1}, 1491(16) s^{-1}, 1488(18) s^{-1}, and 1475(16) s^{-1} for a_{nn}=-18.95 fm, -16.0 fm, -22.0 fm, and +18.22 fm, respectively. All the theoretical uncertainties are due to the fitting procedure and radiative corrections. Our results seem to exclude the possibility of constraining a negative a_{nn} with an uncertainty of less than ~ +/-3 fm through an accurate determination of the muon capture rates. However, a comparison with the already available experimental data discourages the possibility of a bound di-neutron state (positive a_{nn}).

L. E. Marcucci; R. Machleidt

2014-09-15T23:59:59.000Z

442

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

443

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.

444

Uranium Monochalcogenides: Magnetic Form Factor and Magnetic Neutron Scattering  

Science Journals Connector (OSTI)

Fig. R.66. UY. (A) Magnetic form factor. The radial ?j i? integrals, which contribute to the neutron magnetic fo...

R. Tro?

2009-01-01T23:59:59.000Z

445

Improved Technique of Hydrogen Content Analysis by Slow Neutron Scattering  

DOE R&D Accomplishments [OSTI]

A slow-neutron-transmission method fro determining the H content of fluorcarbons is described (G.Y.)

Rainwater, L. J.; Havens, W. W. Jr.

1945-02-28T23:59:59.000Z

446

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

447

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

448

Fast Proton Hopping Detection in Ice Ih by Quasi-Elastic Neutron Scattering  

Science Journals Connector (OSTI)

Quasi-elastic neutron scattering was employed on samples of HCl-doped polycrystalline ice Ih. The analysis of the scattering signal provides the excess proton hopping time, ?hop, in the temperature range of 140195 K. The hopping time strongly depends on ...

Itay Presiado; Jyotsana Lal; Eugene Mamontov; Alexander I. Kolesnikov; Dan Huppert

2011-05-04T23:59:59.000Z

449

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

450

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

451

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

452

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

2007-02-19T23:59:59.000Z

453

Spin-echo small-angle neutron scattering in neutron reflectometry  

Science Journals Connector (OSTI)

A new method to perform neutron reflectometry measurements is discussed, based on Larmor precession of polarized neutrons in the spin-echo mode.

Rekveldt, M.T.

2003-11-15T23:59:59.000Z

454

Calculation of neutron-${}^3$He scattering up to 30 MeV  

E-Print Network [OSTI]

Microscopic calculations of four-body collisions become very challenging in the energy regime above the threshold for four free particles. The neutron-${}^3$He scattering is an example of such process with elastic, rearrangement, and breakup channels. We aim to calculate observables for elastic and inelastic neutron-${}^3$He reactions up to 30 MeV neutron energy using realistic nuclear force models. We solve the Alt, Grassberger, and Sandhas (AGS) equations for the four-nucleon transition operators in the momentum-space framework. The complex-energy method with special integration weights is applied to deal with the complicated singularities in the kernel of AGS equations. We obtain fully converged results for the differential cross section and neutron analyzing power in the neutron-${}^3$He elastic scattering as well as the total cross sections for inelastic reactions. Several realistic potentials are used, including the one with an explicit $\\Delta$ isobar excitation. There is reasonable agreement between t...

Deltuva, A

2014-01-01T23:59:59.000Z

455

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

456

NIST SP 1168 NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY NIST CENTER FOR NEUTRON RESEARCH  

E-Print Network [OSTI]

membrane as determined by neutron reflectometry. See the highlight article by Zan et al. on p.12. #12NIST SP 1168 #12;NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY ­ NIST CENTER FOR NEUTRON RESEARCH FOR NEUTRON RESEARCH DISCLAIMER Certain commercial entities, equipment, or materials may be identified

457

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

458

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

459

Improvement of data treatment in small-angle neutron scattering  

Science Journals Connector (OSTI)

General equations are given for background subtraction of SANS treatment, which account for large scattering angles () and allow the extraction of the scattering due to the sample when the later is inside a container that displays a spurious scattering signal. Several calibration methods to determine the inherent sample backgrounds are also described.

Br?let, A.

2007-01-12T23:59:59.000Z

460

Center for Nanophase Materials Sciences (CNMS) | U.S. DOE Office...  

Office of Science (SC) Website

(SUF) Division SUF Home About User Facilities User Facilities Dev X-Ray Light Sources Neutron Scattering Facilities Nanoscale Science Research Centers (NSRCs) Center for...

Note: This page contains sample records for the topic "neutron scattering center" 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.


461

Center for Functional Nanomaterials (CFN) | U.S. DOE Office of...  

Office of Science (SC) Website

(SUF) Division SUF Home About User Facilities User Facilities Dev X-Ray Light Sources Neutron Scattering Facilities Nanoscale Science Research Centers (NSRCs) Center for...

462

Center for Nanoscale Materials (CNM) | U.S. DOE Office of Science...  

Office of Science (SC) Website

(SUF) Division SUF Home About User Facilities User Facilities Dev X-Ray Light Sources Neutron Scattering Facilities Nanoscale Science Research Centers (NSRCs) Center for...

463

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]

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

Danon, Yaron

464

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

E-Print Network [OSTI]

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

465

Characterization of Magnetic Materials by Means of Neutron Scattering  

Science Journals Connector (OSTI)

The neutron is an elementary particle with a particular combination of properties that makes it uniquely versatile as a condensed matter probe. These properties are: (1) ...

G. Ehlers; F. Klose

2006-01-01T23:59:59.000Z

466

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

467

Measurements of neutron dose equivalent for a proton therapy center using uniform scanning proton beams  

SciTech Connect (OSTI)

Purpose: Neutron exposure is of concern in proton therapy, and varies with beam delivery technique, nozzle design, and treatment conditions. Uniform scanning is an emerging treatment technique in proton therapy, but neutron exposure for this technique has not been fully studied. The purpose of this study is to investigate the neutron dose equivalent per therapeutic dose, H/D, under various treatment conditions for uniform scanning beams employed at our proton therapy center. Methods: Using a wide energy neutron dose equivalent detector (SWENDI-II, ThermoScientific, MA), the authors measured H/D at 50 cm lateral to the isocenter as a function of proton range, modulation width, beam scanning area, collimated field size, and snout position. They also studied the influence of other factors on neutron dose equivalent, such as aperture material, the presence of a compensator, and measurement locations. They measured H/D for various treatment sites using patient-specific treatment parameters. Finally, they compared H/D values for various beam delivery techniques at various facilities under similar conditions. Results: H/D increased rapidly with proton range and modulation width, varying from about 0.2 mSv/Gy for a 5 cm range and 2 cm modulation width beam to 2.7 mSv/Gy for a 30 cm range and 30 cm modulation width beam when 18 Multiplication-Sign 18 cm{sup 2} uniform scanning beams were used. H/D increased linearly with the beam scanning area, and decreased slowly with aperture size and snout retraction. The presence of a compensator reduced the H/D slightly compared with that without a compensator present. Aperture material and compensator material also have an influence on neutron dose equivalent, but the influence is relatively small. H/D varied from about 0.5 mSv/Gy for a brain tumor treatment to about 3.5 mSv/Gy for a pelvic case. Conclusions: This study presents H/D as a function of various treatment parameters for uniform scanning proton beams. For similar treatment conditions, the H/D value per uncollimated beam size for uniform scanning beams was slightly lower than that from a passive scattering beam and higher than that from a pencil beam scanning beam, within a factor of 2. Minimizing beam scanning area could effectively reduce neutron dose equivalent for uniform scanning beams, down to the level close to pencil beam scanning.

Zheng Yuanshui; Liu Yaxi; Zeidan, Omar; Schreuder, Andries Niek; Keole, Sameer [ProCure Proton Therapy Center, 5901 West Memorial Road, Oklahoma City, Oklahoma 73142 (United States); INTEGRIS Cancer Insititute, 5911 West Memorial Road, Oklahoma City, Oklahoma 73142 (United States); ProCure Proton Therapy Center, 5901 West Memorial Road, Oklahoma City, Oklahoma 73142 (United States); ProCure Treatment Centers, 420 North Walnut Street, Bloomington, Indiana 47404 (United States); ProCure Proton Therapy Center, 5901 West Memorial Road, Oklahoma City, Oklahoma 73142 (United States)

2012-06-15T23:59:59.000Z

468

Structured water in polyelectrolyte dendrimers: Understanding small angle neutron scattering results through atomistic simulation  

SciTech Connect (OSTI)

Based on atomistic molecular dynamics (MD) simulations, the small angle neutron scattering (SANS) intensity behavior of a single generation-4 (G4) polyelectrolyte polyamidoamine (PAMAM) starburst dendrimer is investigated at different levels of molecular protonation. The SANS form factor, P(Q), and Debye autocorrelation function, (r), are calculated from the equilibrium MD trajectory based on a mathematical approach proposed in this work which provides a link between the neutron scattering experiment and MD computation. The simulations enable scattering calculations of not only the hydrocarbons, but also the contribution to the scattering length density fluctuations caused by structured, confined water within the dendrimer. Based on our computational results, we question the validity of using radius of gyration RG for microstructure characterization of a polyelectrolyte dendrimer from the scattering perspective.

Chen, Wei-Ren [ORNL; Do, Changwoo [ORNL; Hong, Kunlun [ORNL; Liu, Emily [Rensselaer Polytechnic Institute (RPI); Liu, Yun [National Institute of Standards and Technology (NIST); Porcar, L. [National Institute of Standards and Technology (NIST); Smith, Gregory Scott [ORNL; Wu, Bin [ORNL; Egami, T [University of Tennessee, Knoxville (UTK); Smith, Sean C [ORNL

2012-01-01T23:59:59.000Z

469

A Polarized Neutron Scattering Study of the Normal Phase in YBa2Cu3O6.95  

Science Journals Connector (OSTI)

Polarized neutron scattering with polarization analysis has revealed negligible magnetic scattering up to 30 meV in the normal...2Cu3O6.95 indicating the absence of local moments.

T. J. Smith; K. H. Andersen; U. Beck; H. Capellmann

1999-02-01T23:59:59.000Z

470

Metal-black scattering centers to enhance light harvesting by thin-film solar cells  

E-Print Network [OSTI]

Metal-black scattering centers to enhance light harvesting by thin-film solar cells Deep Panjwania as scattering centers to increase the effective optical thickness of thin-film solar cells. The particular type. Gold-black was deposited on commercial thin-film solar cells using a thermal evaporator in nitrogen

Peale, Robert E.

471

Neutron Scattering at 2.2 Mev by Time of Flight  

Science Journals Connector (OSTI)

A millimicrosecond time-of-flight technique has been applied to a study of the scattering of 2.2-Mev neutrons from targets of Fe, Pb206, and Y. The 3-Mev phase-focused proton beam from the BNL 18-inch cyclotron was used to produce high-intensity neutron pulses in the T(p,n)He3 reaction. The angular distributions of the elastically scattered neutrons have been measured for the above targets. The angular distributions of the inelastically scattered neutrons from the 0.845-Mev level in Fe56 and from the 0.803-Mev level in Pb206 have been carefully studied, and were found to be symmetric about ?c.m.=90. The angular distributions of the inelastically scattered neutrons from levels at 1.34 and 1.43 Mev in Pb206 and from levels at 0.913 and 1.53 Mev in Y have been measured, and also appear to be symmetric about ?c.m.=90. The inelastic scattering from Pb206 shows evidence for a new level at 1.15 Mev.

H. H. Landon; A. J. Elwyn; G. N. Glasoe; S. Oleksa

1958-11-15T23:59:59.000Z

472

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

473

Slow-Neutron Scattering Cross-Sections of Magnesium  

Science Journals Connector (OSTI)

... of magnesium has been measured using the arrangement shown in Fig. 1, which selects neutrons in the energy-range 0*5-1,000 eV. The number of ... in the energy-range 0*5-1,000 eV. The number of neutrons ...

P. A. EGELSTAFF; R. JACKSON

1953-08-29T23:59:59.000Z

474

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

475

Neutron-proton and neutron-neutron quasifree scattering in the n-d breakup reaction at 26 MeV  

Science Journals Connector (OSTI)

The regions of neutron-proton and neutron-neutron quasifree scattering (QFS) have been investigated in the n-d breakup reaction at 26 MeV, measuring absolute cross sections with an accuracy of a few percent. The data were analyzed by means of detailed Monte Carlo simulations based on rigorous three-body calculations with realistic nucleon-nucleon potentials. For n-p QFS, good agreement between theory and experiment was found. In contrast, for n-n QFS the experimentally determined cross section is almost 20% larger than the theoretical predictions.

A. Siepe; J. Deng; V. Huhn; L. Wtzold; Ch. Weber; W. von Witsch; H. Wita?a; W. Glckle

2002-03-04T23:59:59.000Z

476

Geek-Up[1.28.2011]: Neutron Scattering and Full-Spectrum Solar Cells |  

Broader source: Energy.gov (indexed) [DOE]

.28.2011]: Neutron Scattering and Full-Spectrum Solar .28.2011]: Neutron Scattering and Full-Spectrum Solar Cells Geek-Up[1.28.2011]: Neutron Scattering and Full-Spectrum Solar Cells January 28, 2011 - 5:11pm Addthis Detector tanks for the new SANS instruments at the High Flux Isotope Reactor. The Bio-SANS detector is on the right. Source: ORNL Detector tanks for the new SANS instruments at the High Flux Isotope Reactor. The Bio-SANS detector is on the right. Source: ORNL Niketa Kumar Niketa Kumar Public Affairs Specialist, Office of Public Affairs Oak Ridge National Lab and North Carolina State University scientists are helping to develop medicines that will block the spread of viruses. Using the Bio-SANS instrument at ORNL's High Flux Isotope Reactor, these researchers are studying how viruses change their structure as they move

477

Magnetic excitations in Dy/Y superlattices as seen via inelastic neutron scattering  

Science Journals Connector (OSTI)

Measurements of the spin excitations propagating normal to the interfaces in Dy/Y superlattices using neutron inelastic scattering are presented. For a given magnon momentum, a neutron-scattering spectrum shows multiple peaks at different energies, which indicates discrete energy spectra. The results are compared with theoretical calculations developed here to describe magnetic excitations in rare-earth superlattices. The theory accounts for Ruderman-Kittel-Kasuya-Yosida (RKKY) and Dzyaloshinsky-Moriya interactions in incommensurate helicoidal structures and achieves a quantitative agreement with the experimental data. This work demonstrates that neutron inelastic scattering can be used for systematic studies of the exchange interactions and spin dynamics in nanomagnetic systems over wide areas of the Brillouin zone.

A. T. D. Grnwald; A. R. Wildes; W. Schmidt; E. V. Tartakovskaya; J. Kwo; C. Majkrzak; R. C. C. Ward; A. Schreyer

2010-07-23T23:59:59.000Z

478

Probing spin frustration in high-symmetry magnetic nanomolecules by inelastic neutron scattering  

Science Journals Connector (OSTI)

Low temperature inelastic neutron scattering studies have been performed to characterize the low energy magnetic excitation spectrum of the magnetic nanomolecule {Mo72Fe30}. This unique highly symmetric cluster features spin frustration and is one of the largest discrete magnetic molecules studied to date by inelastic neutron scattering. The 30s=5?2 FeIII ions, embedded in a spherical polyoxomolybdate molecule, occupy the vertices of an icosidodecahedron and are coupled via nearest-neighbor antiferromagnetic interactions. The overall energy scale of the excitation and the gross features of the temperature dependence of the observed neutron scattering are explained by a quantum model of the frustrated spin cluster. However, no satisfactory theoretical explanation is yet available for the observed magnetic field dependence.

V. O. Garlea; S. E. Nagler; J. L. Zarestky; C. Stassis; D. Vaknin; P. Kgerler; D. F. McMorrow; C. Niedermayer; D. A. Tennant; B. Lake; Y. Qiu; M. Exler; J. Schnack; M. Luban

2006-01-23T23:59:59.000Z

479

EQ-SANS: the Extended Q-Range Small-Angle Neutron Scattering Diffractometer  

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

The Extended Q-Range Small-Angle Neutron Scattering Diffractometer at SNS The Extended Q-Range Small-Angle Neutron Scattering Diffractometer at SNS Extended Q-Range Small Angle Diffractometer EQ-SANS detector array The EQ-SANS Diffractometer is designed to study non-crystalline, nano-sized materials in solid, liquid, or gas forms such as polymers, micelles, proteins, and other large biological molecular complexes in solution. It offers high neutron flux, high wavelength resolution (precision), and wide Q-coverage. EQSANS is located on beam line 6, viewing the top-downstream, coupled supercritical hydrogen moderator. It has a curved multichannel beam bender to avoid the direct line of sight of the moderator, which cleans out the background from the prompt neutron pulse quite effectively. The cutoff wavelength of the optics is ~1.5 Å. Above this minimum wavelength, the

480

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

Note: This page contains sample records for the topic "neutron scattering center" 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.


481

Neutron scattering study of two-magnon states in the quantum magnet copper nitrate  

Science Journals Connector (OSTI)

We report measurements of the two-magnon states in a dimerized antiferromagnetic chain material, copper nitrate [Cu(NO3)2?2.5D2O]. Using inelastic neutron scattering we have measured the one- and two-magnon excitation spectra in a large single crystal. The data are in excellent agreement with a perturbative expansion of the alternating Heisenberg Hamiltonian from the strongly dimerized limit. The expansion predicts a two-magnon bound state for q?(2n+1)?d which is consistent with the neutron scattering data.

D. A. Tennant; C. Broholm; D. H. Reich; S. E. Nagler; G. E. Granroth; T. Barnes; K. Damle; G. Xu; Y. Chen; B. C. Sales

2003-02-27T23:59:59.000Z

482

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

483

Neutron scattering measurements of separation and shape of proteins in 30S ribosomal subunit of Escherichia coli: S2-S5, S5-S8, S3-S7  

Science Journals Connector (OSTI)

Neutron scattering measurements of separation and shape...Engelman P B Moore B P Schoenborn Neutron scattering measurements done on E. coli 30S...information about these proteins from the neutron scattering profiles is demonstrated. The method...

D M Engelman; P B Moore; B P Schoenborn

1975-01-01T23:59:59.000Z

484

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

485

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

486

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

487

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

488

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

489

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

490

Neutron-scattering evidence for a spin-Peierls ground state in ,,TMTTF...2PF6 P. Foury-Leylekian,1  

E-Print Network [OSTI]

Neutron-scattering evidence for a spin-Peierls ground state in ,,TMTTF...2PF6 P. Foury-Leylekian,1 by elastic neutron scattering. The 1 2 , 1 2 , 1 2 superstructure reflection associated with the SP

Paris-Sud 11, Université de

491

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

492

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.

493

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

494

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

2011-04-10T23:59:59.000Z

495

Tests of time reversal in neutron?nucleus scattering  

Science Journals Connector (OSTI)

Experiments to test time?reversal invariance are discussed. The experiments are based on observables constructed from the momentum and spin vectors of epithermal neutrons and from the spin of an aligned or polarized target. It is shown that the proposed tests are detailed balance tests of time?reversal invariance. The status of the experiments is briefly reviewed.

J. David Bowman

1988-01-01T23:59:59.000Z

496

Neutron Scattering Study of Colloidal Interactions in an Adsorbing Polymer Solution  

E-Print Network [OSTI]

Neutron Scattering Study of Colloidal Interactions in an Adsorbing Polymer Solution X. Ye and P in the colloidal suspension partition themselves between the bulk solution and the adsorbed state. The free polymer of the attraction is suppressed considerably by the adsorbed polymer chains on the colloidal surfaces. It is found

Tong, Penger

497

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

498

The General-Purpose Small-Angle Neutron Scattering Diffractometer at HFIR -  

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

General-Purpose Small-Angle Neutron Scattering Diffractometer at HFIR General-Purpose Small-Angle Neutron Scattering Diffractometer at HFIR Instrument scientist Ken Littrell at GP-SANS. Instrument scientist Ken Littrell at GP-SANS. The General-Purpose Small-Angle Neutron Scattering Diffractometer (GP-SANS) instrument is optimized for providing information about structure and interactions in materials in the size range of 0.5 - 200 nm. It has a cold neutron flux on sample and capabilities comparable to those of the best SANS instruments worldwide, including a wide range of neutron wavelengths λ 5 - 30 Å, resolution Δλ ⁄ λ 9=45%, and a 1m2 area detector with 5 × 5mm2 pixel resolution with a maximum counting capability of up to 2.5 kHz. The sample-to-detector distance can be varied from 1 to 20 m, and the detector can be offset horizontally by up to 45 cm, allowing

499

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

500

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