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1

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

2

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; José Rolando Granada; Javier Roberto Santisteban; Florencia Cantargi; Luis Alberto Rodríguez Palomino

2013-01-01T23:59:59.000Z

3

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

4

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

5

Kaonic hydrogen atom and kaon-proton scattering length  

E-Print Network [OSTI]

Kaonic hydrogen is studied with various realistic potentials in an accurate numerical approach based on Sturmian functions. The kaon-proton scattering length extracted from the 1s energy shift of the kaonic hydrogen by applying the Deser-Trueman formula is severely inconsistent with the one derived by directly solving the scattering Schoedinger equation. We pay special attention to the recent measurement of the energy shift and decay width of the 1s kaonic hydrogen state by the DEAR Collaboration. After taking into account the large discrepancy between the extracted and directly-evaluated scattering lengths, we found theoretical predictions of most chiral SU(3) based models for the kaonic hydrogen decay width are consistent with the DEAR data. We warn the SIDDHARTA collaboration that it may not be reasonable to extract kaon-nucleon scattering lengths, by using the Coulomb-interaction corrected Deser-Truemab formula, from the planned measurement of kaonic hydrogen.

Y. Yan

2009-05-29T23:59:59.000Z

6

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

7

Optical Scattering Lengths in Large Liquid-Scintillator Neutrino Detectors  

E-Print Network [OSTI]

For liquid-scintillator neutrino detectors of kiloton scale, the transparency of the organic solvent is of central importance. The present paper reports on laboratory measurements of the optical scattering lengths of the organic solvents PXE, LAB, and Dodecane which are under discussion for next-generation experiments like SNO+, Hanohano, or LENA. Results comprise the wavelength range from 415 to 440nm. The contributions from Rayleigh and Mie scattering as well as from absorption/re-emission processes are discussed. Based on the present results, LAB seems to be the preferred solvent for a large-volume detector.

Michael Wurm; Franz von Feilitzsch; Marianne Goeger-Neff; Martin Hofmann; Tobias Lachenmaier; Timo Lewke; Teresa Marrodan Undagoitita; Quirin Meindl; Randoplh Moellenberg; Lothar Oberauer; Walter Potzel; Marc Tippmann; Sebastian Todor; Christoph Traunsteiner; Juergen Winter

2010-04-06T23:59:59.000Z

8

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

9

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

10

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

11

Scattering lengths in SU(2) gauge theory with two fundamental fermions  

E-Print Network [OSTI]

We investigate non perturbatively scattering properties of Goldstone Bosons in an SU(2) gauge theory with two Wilson fermions in the fundamental representation. Such a theory can be used to build extensions of the Standard Model that unifies Technicolor and pseudo Goldstone composite Higgs models. The leading order contribution to the scattering amplitude of Goldstone bosons at low energy is given by the scattering lengths. In the context of technicolor extensions of the Standard Model the scattering lengths are constrained by WW scattering measurements. We first describe our setup and in particular the expected chiral symmetry breaking pattern. We then discuss how to compute them on the lattice and give preliminary results using finite size methods.

R. Arthur; V. Drach; M. Hansen; A. Hietanen; C. Pica; F. Sannino

2014-12-15T23:59:59.000Z

12

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

13

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

E-Print Network [OSTI]

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

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

2014-12-02T23:59:59.000Z

14

Decoherence of trapped bosons by buffer gas scattering: What length scales matter?  

E-Print Network [OSTI]

We ask and answer a basic question about the length scales involved in quantum decoherence: how far apart in space do two parts of a quantum system have to be, before a common quantum environment decoheres them as if they were entirely separate? We frame this question specifically in a cold atom context. How far apart do two populations of bosons have to be, before an environment of thermal atoms of a different species (`buffer gas') responds to their two particle numbers separately? An initial guess for this length scale is the thermal coherence length of the buffer gas; we show that a standard Born-Markov treatment partially supports this guess, but predicts only inverse-square saturation of decoherence rates with distance, and not the much more abrupt Gaussian behavior of the buffer gas's first-order coherence. We confirm this Born-Markov result with a more rigorous theory, based on an exact solution of a two-scatterer scattering problem, which also extends the result beyond weak scattering. Finally, however, we show that when interactions within the buffer gas reservoir are taken into account, an abrupt saturation of the decoherence rate does occur, exponentially on the length scale of the buffer gas's mean free path.

Lukas Gilz; Luis Rico-Pérez; James R. Anglin

2014-02-13T23:59:59.000Z

15

Determination of the eta'-proton scattering length in free space  

E-Print Network [OSTI]

Taking advantage of both the high mass resolution of the COSY-11 detector and the high energy resolution of the low-emittance proton-beam of the Cooler Synchrotron COSY we determine the excitation function for the pp --> pp eta' reaction close-to-threshold. Combining these data with previous results we extract the scattering length for the eta'-proton potential in free space to be Re(a_{p eta'}) = 0+-0.43 fm and Im(a_{p eta'}) = 0.37(+0.40)(-0.16) fm.

E. Czerwinski; P. Moskal; M. Silarski; S. D. Bass; D. Grzonka; B. Kamys; A. Khoukaz; J. Klaja; W. Krzemien; W. Oelert; J. Ritman; T. Sefzick; J. Smyrski; A. Taschner; M. Wolke; M. Zielinski

2014-07-17T23:59:59.000Z

16

1186 IEEE TRANSACTIONS ON ELECTRON DEVICES, VOL. 46, NO. 6, JUNE 1999 A Simple Hole Scattering Length Model for the  

E-Print Network [OSTI]

assumption of an energy independent scattering length . This assumption is accurate for the electron acoustic of the hole energy. This result now makes it possible to solve the Boltzmann transport equation to obtain phonon scattering with the quasi-elastic approximation. Based on this assumption they obtained simple

Kumar, M. Jagadesh

17

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

18

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

E-Print Network [OSTI]

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

Danon, Yaron

19

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

20

Acoustic scattering by axisymmertic finite-length bodies with application to fish : measurement and modeling  

E-Print Network [OSTI]

This thesis investigates the complexities of acoustic scattering by finite bodies in general and by fish in particular through the development of an advanced acoustic scattering model and detailed laboratory acoustic ...

Reeder, D. Benjamin (Davis Benjamin), 1966-

2002-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "1-to-2-ft lengths scattered" 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

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

E-Print Network [OSTI]

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

Spudich, James A.

22

The importance of the nucleon-nucleon correlations for the eta alpha S-wave scattering length, and the pi-eta mixing angle in the low-energy eta alpha scattering length model  

E-Print Network [OSTI]

Using the new set of dd --> eta alpha near threshold experimental data, the estimate of the importance of the nucleon-nucleon correlations for the eta alpha S-wave scattering length in the multiple scattering theory is obtained using the low-energy scattering length model. The contribution turns out to be much bigger then previously believed. The pi-eta mixing angle is extracted using the experimental data on the dd --> eta alpha and dd --> pi alpha processes. The model is dominated by the subthreshold extrapolation recipe for the eta alpha scattering amplitudes. When the recipe is chosen the model is completely insensitive to the eta alpha parameters for the subthreshold value of the eta cm momentum of p_{eta}^2 = -(0.46)^2 fm^{-2}. Provided that the subthreshold extrapolation recipe is correct, a good estimate of the pi-eta mixing angle is obtained, if the experimental cross sections for the dd --> pi alpha reaction at the corresponding deuteron input energy are taken from the literature.

S. Ceci; D. Hrupec; A. Svarc

2001-04-11T23:59:59.000Z

23

E-Print Network 3.0 - atomic scattering length Sample Search...  

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

Bromley, Michael - Physics Department, San Diego State University Collection: Physics 3 Neutron Scattering in Polymer Micelle Characterization Summary: highly effective probe...

24

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

25

Neutron interferometric measurement of the scattering length difference between the triplet and singlet states of n-$^3$He  

E-Print Network [OSTI]

We report a determination of the n-$^3$He scattering length difference $\\Delta b^{\\prime} = b_{1}^{\\prime}-b_{0}^{\\prime} = $ ($-5.411$ $\\pm$ $0.031$ (statistical) $\\pm$ $0.039$ (systematic)) fm between the triplet and singlet states using a neutron interferometer. This revises our previous result $\\Delta b^{\\prime} = $ (-5.610 $\\pm$ $0.027$ (statistical) $\\pm$ $0.032$ (systematic) fm obtained using the same technique in 2008. This revision is due to a re-analysis of the 2008 experiment that includes a more robust treatment of the phase shift caused by magnetic field gradients near the $^3$He cell. Furthermore, we more than doubled our original data set from 2008 by acquiring six months of additional data in 2013. Both the new data set and a re-analysis of the older data are in good agreement. Scattering lengths of low Z isotopes are valued for use in few-body nuclear effective field theories, provide important tests of modern nuclear potential models and in the case of $^3$He aid in the interpretation of neutron scattering from quantum liquids. The difference $\\Delta b^{\\prime}$ was determined by measuring the relative phase shift between two incident neutron polarizations caused by the spin-dependent interaction with a polarized $^3$He target. The target $^3$He gas was sealed inside a small, flat windowed glass cell that was placed in one beam path of the interferometer. The relaxation of $^3$He polarization was monitored continuously with neutron transmission measurements. The neutron polarization and spin flipper efficiency were determined separately using $^3$He analyzers and two different polarimetry analysis methods. A summary of the measured scattering lengths for n-$^3$He with a comparison to nucleon interaction models is given.

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

2014-09-30T23:59:59.000Z

26

Neutron interferometric measurement of the scattering length difference between the triplet and singlet states of n-$^3$He  

E-Print Network [OSTI]

We report a determination of the n-$^3$He scattering length difference $\\Delta b^{\\prime} = b_{1}^{\\prime}-b_{0}^{\\prime} = $ ($-5.411$ $\\pm$ $0.031$ (statistical) $\\pm$ $0.039$ (systematic)) fm between the triplet and singlet states using a neutron interferometer. This revises our previous result $\\Delta b^{\\prime} = $ (-5.610 $\\pm$ $0.027$ (statistical) $\\pm$ $0.032$ (systematic) fm obtained using the same technique in 2008. This revision is due to a re-analysis of the 2008 experiment that includes a more robust treatment of the phase shift caused by magnetic field gradients near the $^3$He cell. Furthermore, we more than doubled our original data set from 2008 by acquiring six months of additional data in 2013. Both the new data set and a re-analysis of the older data are in good agreement. Scattering lengths of low Z isotopes are valued for use in few-body nuclear effective field theories, provide important tests of modern nuclear potential models and in the case of $^3$He aid in the interpretation of neu...

Huber, M G; Chen, W C; Gentile, T R; Hussey, D S; Black, T C; Pushin, D A; Shahi, C B; Wietfeldt, F E; Yang, L

2014-01-01T23:59:59.000Z

27

Determination of the s-Wave Scattering Length and the C6 van der Waals Coefficient of Yb174 via Photoassociation Spectroscopy  

Science Journals Connector (OSTI)

We report photoassociation spectroscopy of Yb174 for the S01-P11 transition at 1???K, where only the s-wave scattering state contributes to the spectra. The wave function of the s-wave scattering state is obtained from the photoassociation efficiency, and we determine that the C6 potential coefficient is 2300±250??a.u. and the s-wave scattering length is 5.53±0.11??nm. Based on these parameters, we discuss the scattering properties of s- and d-wave states.

K. Enomoto; M. Kitagawa; K. Kasa; S. Tojo; Y. Takahashi

2007-05-16T23:59:59.000Z

28

Comments to the problem of experimental determination of the neutron-electron scattering length and its theoretical interpretation  

E-Print Network [OSTI]

We discuss the experimental data on the n,e-scattering length bne and the values of mean square charge radius of the neutron obtained from them. It is shown that the accumulated during the last 50 years most significant experimental estimates of the bne are not contradictory and lead to the average value =-0.1178+-0.0037 fm^2. Assuming that all the authors have underestimated the errors of their measurements by a factor of 1.7, the combined fit of all available experimental data would lead to Chi^2~1 per degree of freedom. Different modern theoretical predictions of are considered. They are found to be in a good agreement with the obtained experimental value . However the existing theoretical description of the structure of neutron does not provide a value of with a sufficient accuracy.

A. B. Popov; T. Yu. Tretyakova

2008-12-30T23:59:59.000Z

29

Determination of iron-ligand bond lengths in horse heart met- and deoxymyoglobin using multiple-scattering XAFS analyses  

SciTech Connect (OSTI)

XAFS data in the range 0 {le} k {le} 14.5 {angstrom}{sup {minus}1} have been obtained from frozen aqueous solutions (10 K) of horse heart myoglobin (Mb) in the Fe(III) (aqua-met) and Fe(II) (deoxy) forms. The structures of the Fe sites have been refined using both single-scattering (SS) and multiple-scattering (MS) analyses. The XAFS MS analyses yield more precise Fe-ligand bond lengths (estimated error 0.02--0.03 {angstrom}) than those determined crystallographically (estimated errors {ge} 0.1 {angstrom}). For met-Mb, the MS analysis results in an average Fe-N(pyrrole) distance of 2.05 {angstrom}, an Fe-N(imidazole) distance of 2.17 {angstrom}, and an Fe-O(aqua) distance of 2.08 {angstrom}. For deoxy-Mb, the MS analysis results in Fe-N(pyrrole) and Fe-N(imidazole) distances of 2.06 and 2.16 {angstrom}, respectively. The final XAFS R values are 18.8% and 17.8% for met- and deoxy-Mb, respectively. The robustness of the refinements was tested by varying the starting models, constraints, restraints, and k ranges.

Rich, A.M.; Armstrong, R.S.; Ellis, P.J.; Freeman, H.C.; Lay, P.A. [Univ. of Sydney, New South Wales (Australia). School of Chemistry] [Univ. of Sydney, New South Wales (Australia). School of Chemistry

1998-11-02T23:59:59.000Z

30

Scattering length of the ground-state MgMg collision E. Tiesinga, S. Kotochigova, and P. S. Julienne  

E-Print Network [OSTI]

can be magneto- optically trapped. This offers many possible applications of cold Mg atoms for ultra coefficients. At temperatures below 5 mK ground state Mg collisions are in the s-wave scattering regime

Kotochigova, Svetlana

31

Determination of iron-ligand bond lengths in ferric and ferrous horse heart cytochrome c using multiple-scattering analyses of XAFS data  

SciTech Connect (OSTI)

Cytochrome c (cyt c) is a small heme protein (MW 12 384) that functions as a biological electron-transfer agent. It consists of a single polypeptide chain and a prosthetic heme group and provides a pathway for the transfer of electrons from cyt c reductase to cyt c oxidase in the mitochondrial respiratory chain (oxidative phosphorylation). The protein participates in oxidation-reduction reactions with the heme iron alternating between the oxidized (ferric, Fe{sup III}) state and the reduced (ferrous, Fe{sup II}) state. X-ray absorption fine structure (XAFS) data were obtained from frozen aqueous solutions (10 K) of horse heart ferri- and ferrocyt c. Models of the structure about the Fe center were refined to optimize the fit between the observed XAFS in the range 0 {le} k {le} 16.3 {angstrom}{sup {minus}1} and the XAFS calculated using both single-scattering (SS) and multiple-scattering (MS) calculations. The bond lengths obtained are more accurate and precise than those determined previously for cyt c from various species using X-ray crystallography. The Fe-N bond lengths are 1.98--1.99 {angstrom} for both oxidation states of cyt c. The Fe-S bond of derricyt c (2.33 {angstrom}) is significantly longer than that of ferrocyt c (2.29 {angstrom}). The small changes in the bond lengths are consistent with the small reorganizational energy required for the fast electron-transfer reaction of cyt c.

Cheng, M.C.; Rich, A.M.; Armstrong, R.S.; Ellis, P.J.; Lay, P.A.

1999-12-13T23:59:59.000Z

32

Scattering  

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

Scattering Print Scattering Print When a crystalline sample is illuminated with x-rays, the x-rays are scattered (diffracted) into very specific directions with various intensities. Detectors are used to measure this "diffraction pattern," which is then processed by computers to deduce the arrangement of atoms within the crystal. Hard x-rays have wavelengths comparable to the distance between atoms. Essentially everything we know about the atomic structure of materials is based on results from x-ray and neutron diffraction. From advanced ceramics to catalysts, from semiconductor technology to the frontiers of medicine, and from new magnetic materials and devices to framework compounds used to sequester radioactive waste, crystallography using hard x-ray diffraction techniques at synchrotron radiation facilities plays a crucial role in our ability to understand and control the world in which we live.

33

Scattering  

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

Scattering Print Scattering Print When a crystalline sample is illuminated with x-rays, the x-rays are scattered (diffracted) into very specific directions with various intensities. Detectors are used to measure this "diffraction pattern," which is then processed by computers to deduce the arrangement of atoms within the crystal. Hard x-rays have wavelengths comparable to the distance between atoms. Essentially everything we know about the atomic structure of materials is based on results from x-ray and neutron diffraction. From advanced ceramics to catalysts, from semiconductor technology to the frontiers of medicine, and from new magnetic materials and devices to framework compounds used to sequester radioactive waste, crystallography using hard x-ray diffraction techniques at synchrotron radiation facilities plays a crucial role in our ability to understand and control the world in which we live.

34

Determination of the S-Wave Pi Pi Scattering Lengths From a Study of K - to Pi - Pi0 Pi0 Decays  

SciTech Connect (OSTI)

We report the results from a study of the full sample of {approx}6.031 x 10{sup 7} K{sup {+-}} {yields} {pi}{sup {+-}}{pi}{sup 0}{pi}{sup 0} decays recorded by the NA48/2 experiment at the CERN SPS. As first observed in this experiment, the {pi}{sup 0}{pi}{sup 0} invariant mass (M{sub 00}) distribution shows a cusp-like anomaly in the region around M{sub 00} = 2m{sub +}, where m{sub +} is the charged pion mass. This anomaly has been interpreted as an effect due mainly to the final state charge exchange scattering process {pi}{sup +}{pi}{sup -} {yields} {pi}{sup 0}{pi}{sup 0} in K{sup {+-}} {yields} {pi}{sup {+-}}{pi}{sup +}{pi}{sup -} decay. Fits to the M{sub 00} distribution using two different theoretical formulations provide the presently most precise determination of a{sub 0} - a{sub 2}, the difference between the {pi}{pi} S-wave scattering lengths in the isospin I = 0 and I = 2 states. Higher-order {pi}{pi} rescattering terms, included in the two formulations, allow also an independent, though less precise, determination of a{sub 2}.

Batley, J.R.; Culling, A.J.; Kalmus, G.; /Cambridge U.; Lazzeroni, C.; /Cambridge U. /Birmingham U.; Munday, D.J.; /Cambridge U.; Slater, M.W.; /Cambridge U. /Birmingham U.; Wotton, S.A.; /Cambridge U.; Arcidiacono, R.; /CERN /Turin U. /INFN, Turin; Bocquet, G.; /CERN; Cabibbo, N.; /CERN /Rome U. /INFN, Rome; Ceccucci, A.; /CERN; Cundy, D.; /CERN /Turin, Cosmo-Geofisica Lab; Falaleev, V.; Fidecaro, M.; Gatignon, L.; Gonidec, A.; Kubischta, W.; /CERN; Norton, A.; /CERN /Ferrara U. /INFN, Ferrara; Maier, A.; Patel, M.; Peters, A.; /CERN /Dubna, JINR /Pisa, Scuola Normale Superiore /Dubna, JINR /Dubna, JINR /Birmingham U. /Dubna, JINR /CERN /Dubna, JINR /Dubna, JINR /Sofiya U. /Dubna, JINR /Dubna, JINR /Dubna, JINR /INFN, Perugia /Dubna, JINR /Dubna, JINR /Northwestern U. /Dubna, JINR /Chicago U., EFI /Marseille, CPPM /Chicago U., EFI /Edinburgh U. /George Mason U. /Edinburgh U. /Ferrara U. /INFN, Ferrara /Florence U. /INFN, Florence /Florence U. /INFN, Florence /Pisa, Scuola Normale Superiore /INFN, Florence /Modena U. /INFN, Florence /INFN, Florence /Urbino U. /INFN, Florence /Mainz U., Inst. Phys. /Bonn U. /Mainz U., Inst. Phys. /Northwestern U. /SLAC /Northwestern U. /Northwestern U. /Royal Holloway, U. of London /Northwestern U. /Northwestern U. /UCLA /Perugia U. /INFN, Perugia /Frascati /Perugia U. /INFN, Perugia /INFN, Perugia /INFN, Pisa /Pisa, Scuola Normale Superiore /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa U. /INFN, Pisa /Barcelona, IFAE /Pisa U. /INFN, Pisa /DSM, DAPNIA, Saclay /DSM, DAPNIA, Saclay /CERN /DSM, DAPNIA, Saclay /Siegen U. /INFN, Turin /Turin U. /INFN, Turin /Bern U. /Turin U. /INFN, Turin /CERN /Turin U. /INFN, Turin /Madrid, CIEMAT /Vienna, OAW

2012-03-29T23:59:59.000Z

35

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

36

Diffuse Scattering  

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

Diffuse Scattering Diffuse Scattering * Anticipatory (trick) question: If you have an x-ray or neutron detector looking at a small sample volume, which will scatter more x- rays or neutrons into the detector 1 atom 100 atoms or 1000 atoms? X-ray or neutron beam Answer: Depends! Diffuse Scattering Gene E. Ice Materials Science and Technology Division Oak Ridge National Laboratory, USA National School on Neutron and X-ray Scattering ORNL/SNS June 2011 Presentation concentrates year graduate-level course into 1 hour * Skip mathematical complexities * Expose to range of applications * Develop intuition for length scales * Talk like x-ray/neutron scattering guru - Reciprocal space - Debye Temperature - Laue monotonic - Krivoglaz defects of 1st/2nd kinds! Great for cocktail parties or impressing attractive strangers-

37

Energy loss, range, path length, time-of-flight, straggling, multiple scattering, and nuclear interaction probability: In two parts. Part 1. For 63 compounds Part 2. For elements 1 ? Z ? 92  

Science Journals Connector (OSTI)

Extensive tables have been prepared of the mean energy loss, pathlength, range, multiple scattering, pathlength straggling, time-of-flight, and nonelastic collision probability for protons of energy from 1 keV through 10 GeV in all elements having atomic number from 1 through 92, and in many compounds and mixtures. Emphasis has been placed on obtaining accurate results, particularly in the difficult low-energy and high-atomic-number regions. The accuracies of all proton range-energy parameters are tabulated. The energy loss below 20 keV was found by normalizing theoretical expressions for the ionization, excitation, and nuclear contributions to known values at 20 keV. The energy loss between 20 keV and 1.0 MeV was obtained by statistically evaluating the accuracy of the available experimental information and then performing least-squares curve fits. Above 1.0 MeV, the Bethe equation with all necessary corrections was used. New values of the adjusted ionization potentials were determined by least-squares-fitting the Bethe equation to all available energy-loss data. The polarization effect was calculated in detail for each material. Path-lengths were calculated by integrating the reciprocal of the energy losses. Ranges were obtained by use of multiple Coulomb scattering theory. The straggling calculations include electronic, elastic nuclear, and charge exchange effects. The literature search was completed in June 1979. Keys for the references used for each element are collected in Table 12. A comparison of the calculational methods used here and in other recent proton range-energy tables is presented in Table 14.

Joseph F. Janni

1982-01-01T23:59:59.000Z

38

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

39

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

40

B Decay Length  

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

Threshold Decay Length Threshold Decay Length Data from 292 B events are in an Excel spreadsheet that looks like this table. To find the threshold decay length: Sort the data by descending decay lengths, dt. Run Event No. B Mass GeV/c2 ptB GeV/c dt cm Velocity v/c Lab Lifetime sec Rest Lifetime sec Bin 65160 642324 5.277 7.966 0.388 66500 89978 5.274 20.508 0.940 Get the data. Make a histogram of decay lengths. Rather than graphing all the lengths as individual points, physicists group the data. They consider the range of the data and divide it into "bins" of equal size. A histogram is a graph of the number of events in each bin vs. the bin range. We are looking for the smallest decay length that fits the exponential curve. This will indicate the length of the decay as detemined by that experimental run.

Note: This page contains sample records for the topic "1-to-2-ft lengths scattered" 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

Myofilament length dependent activation  

SciTech Connect (OSTI)

The Frank-Starling law of the heart describes the interrelationship between end-diastolic volume and cardiac ejection volume, a regulatory system that operates on a beat-to-beat basis. The main cellular mechanism that underlies this phenomenon is an increase in the responsiveness of cardiac myofilaments to activating Ca{sup 2+} ions at a longer sarcomere length, commonly referred to as myofilament length-dependent activation. This review focuses on what molecular mechanisms may underlie myofilament length dependency. Specifically, the roles of inter-filament spacing, thick and thin filament based regulation, as well as sarcomeric regulatory proteins are discussed. Although the 'Frank-Starling law of the heart' constitutes a fundamental cardiac property that has been appreciated for well over a century, it is still not known in muscle how the contractile apparatus transduces the information concerning sarcomere length to modulate ventricular pressure development.

de Tombe, Pieter P.; Mateja, Ryan D.; Tachampa, Kittipong; Mou, Younss Ait; Farman, Gerrie P.; Irving, Thomas C. (IIT); (Loyola)

2010-05-25T23:59:59.000Z

42

Thermodynamics of irregular scattering  

Science Journals Connector (OSTI)

It is pointed out that scaling (multifractal) properties of chaotic repellers underlying irregular scattering in two-degrees-of-freedom systems can be deduced by measuring simple length scales generated hierarchically along a straight line taken far away from the interaction region, or on the Poincaré plane, and analyzing them in the spirit of the thermodynamic formalism. The method is easier to apply than a periodic orbit analysis.

Zoltán Kovács and Tamás Tél

1990-04-02T23:59:59.000Z

43

Planck-Length Phenomenology  

E-Print Network [OSTI]

This author's recent proposal of interferometric tests of Planck-scale-related properties of space-time is here revisited from a strictly phenomenological viewpoint. The results announced previously are rederived using elementary dimensional considerations. The dimensional analysis is then extended to the other two classes of experiments (observations of neutral kaons at particle accelerators and observations of the gamma rays we detect from distant astrophysical sources) which have been recently considered as opportunities to explore "foamy" properties of space-time. The emerging picture suggests that there is an objective and intuitive way to connect the sensitivities of these three experiments with the Planck length. While in previous studies the emphasis was always on some quantum-gravity scenario and the analysis was always primarily aimed at showing that the chosen scenario would leave a trace in a certain class of doable experiments, the analysis here reported takes as starting point the experiments and, by relating in a direct quantitative way the sensitivities to the Planck length, provides a model-independent description of the status of Planck-length phenomenology.

Giovanni Amelino-Camelia

2000-08-04T23:59:59.000Z

44

Scattering lengths for collisions of hydrogen and deuterium atoms  

E-Print Network [OSTI]

Chu,X. Jamieson,M.J. Dalgarno,A. Journal of Physics B: Atomic, Molecular and Optical Physics, Vol. 36 pp L415-L418

Chu, X.; Jamieson, M.J.

45

Scattering lengths for collisions between sodium and potassium atoms  

E-Print Network [OSTI]

Venturi,V. Jamieson,M.J. Cote,R. Journal of Physics B: Atomic, Molecular and Optical Physics, Vol. 34 pp 4339-4347

Venturi, V.

46

Energy-Length Rule  

E-Print Network [OSTI]

Lorentz ordering (causality) implies the following rule: for any given energy p0 of a system there is a certain interval c0 on x0 so that their product is the Lorentz ordering constant L It means p0c0 = L. The constant L=hc. Hence Planck constant h in a similar way as c are both consequences of Lorentz metric. The basic ideas are: 1. Lorentz metric implies that x0 must represent a length like the other components of x in X 2. The dual metric space X* is well defined since the Lorentz metric tensor is not singular. The components of the vectors p in X*are interpreted as representing energy. The properties of the physical systems that are direct consequences of the detailed structure of X and X*, and so expressed through the Lorentz Limit L are presented.

Alexandru C Mihul; Eleonora A Mihul

2006-08-25T23:59:59.000Z

47

Branch length distribution in TREF fractionated polyethylene Ramnath Ramachandran a  

E-Print Network [OSTI]

Branch length distribution in TREF fractionated polyethylene Ramnath Ramachandran a , Gregory Keywords: Polyethylene Branching Neutron scattering a b s t r a c t Commercial polyethylene is typically and catalyst activity. Further, processing of polyethylene after polymerization may also result in changes

Beaucage, Gregory

48

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

49

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

50

Emergent gravity by tuning the effective Planck length in Bose-Einstein Condensate  

E-Print Network [OSTI]

We show that at lowest energy nonlocal interactions, the tuning of s-wave scattering length can enable a systematic control over the quantum pressure term in a Bose-Einstein condensate (BEC). We derive the equation for the massless free excitations in an analogue curved space-time by controlling the effective Planck length. Our controlled derivation indicates a breakdown of this dynamics at length scales comparable to effective Planck length. We also specify the correction that one has to take into account at a larger length scale in a flat space-time due to the emergent gravity at intermediate length scales.

Sarkar, Supratik

2014-01-01T23:59:59.000Z

51

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.

52

Comparing Membrane Simulations to Scattering Experiments: Introducing the SIMtoEXP Software  

E-Print Network [OSTI]

of biomembrane simulations with experimental X-ray and neutron scattering data. It has the following features: (1 the electron density e(z) and neutron scattering length density m(z) profiles along the z direction (i.e., nor simulation Á X-ray scattering Á Neutron scattering Á Computer software Introduction It is well recognized

Nagle, John F.

53

Intron Length and Codon Usage  

Science Journals Connector (OSTI)

...The correlation was shown between the length of introns and the codon usage of the coding sequences of the corresponding ... longer introns show the higher bias of codon usage. It is most pronounced in baker's...

Alexander E. Vinogradov

2001-01-01T23:59:59.000Z

54

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

55

Time resolved side scatter diagnostics at NOVA  

SciTech Connect (OSTI)

Side scattering of the radiation during the interaction of a laser beam with the long scale length plasma in hohlraum is a difficult problem of relevance to the viability of ICF. It is important to measure the absolute amount of the laser side scatter as well as the angular distribution of that scatter. The OSA diagnostics has been implemented on NOVA to measure these quantities. We have implemented a fiber-optically coupled streak camera to measure the temporally and angularly resolved side scatter radiation at 351 nm at 9 different angles. Filtered PIN diodes were positioned at 31 various angles in the E-field planed and B-field plane of the incident probe beam to sample and measure the scattered radiation at the 351 nm wavelength of the probe. The diode data was used to calibrate the Brillouin power received by the 9 strategically located fiber optic channels. This presentation will describe the OSA and associated diagnostics.

Kyrala, G.A.; Evans, S.C.; Jimerson, J.R.; Fernandez, J.C.

1996-06-01T23:59:59.000Z

56

Positronium scattering from Kr and Xe at low energies  

Science Journals Connector (OSTI)

The scattering of orthopositronium from Kr and Xe is investigated with the fixed core stochastic variational method. The scattering lengths for Ps-Kr and Ps-Xe scattering in the fixed core approximation are 3.18a0 and 3.82a0, respectively. Inclusion of core-polarization potentials leads to a significant reduction in the scattering lengths. The Ps-Kr and Ps-Xe scattering lengths were 1.98a0 and 2.29a0 for polarization potentials that were tuned to an average of the model electron-atom and positron-atom scattering lengths for the respective atoms. Other choices of the polarization potential resulted in scattering lengths that could be larger by 0.3a0 or smaller by 0.8a0. The pick-off annihilation parameter 1Zeff has also been computed as part of the analysis. The present values of 1Zeff are about 3 to 10 times smaller than the accepted experimental values since short-range electron-positron correlations were ignored when the annihilation matrix element was evaluated.

J. Mitroy and M. W. J. Bromley

2003-03-17T23:59:59.000Z

57

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

58

Coherence length of neutron superfluids  

Science Journals Connector (OSTI)

The coherence length of superfluid neutron matter is calculated from the microscopic BCS wave function of a Cooper pair in momentum space making use of recent nucleon-nucleon potential models and including polarization (RPA) effects. We find as our main result that the coherence length is proportional to the Fermi momentum to pairing gap ratio, in good agreement with simple estimates used in the literature, with a nearly interaction independent constant of proportionality. Our calculations can be applied to the problem of inhomogeneous superfluidity of hadronic matter in the crust of a neutron star.

F. V. De Blasio; M. Hjorth-Jensen; Ø. Elgarøy; L. Engvik; G. Lazzari; M. Baldo; H.-J. Schulze

1997-10-01T23:59:59.000Z

59

Rearrangement and annihilation in antihydrogen-atom scattering  

SciTech Connect (OSTI)

I review some results for annihilation and rearrangement processes in low-energy antihydrogen-hydrogen and antihydrogen-helium scattering. For the strong nuclear force results using a {delta}-function potential are compared to a scattering length approach. It is found that the {delta}-function potential does not give correct annihilation cross sections in the case of antihydrogen-helium scattering. Problem associated with the use of the Born-Oppenheimer approximation for rearrangement calculations are reviewed.

Jonsell, Svante [Department of Physics, Swansea University, Singleton Park, Swansea SA2 8PP (United Kingdom)

2008-08-08T23:59:59.000Z

60

[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

Note: This page contains sample records for the topic "1-to-2-ft lengths scattered" 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

Coherence lengths and neutron optics  

Science Journals Connector (OSTI)

The dynamical diffraction of divergent beams and its application to neutron interferometry are considered. The coherence properties of thermal neutrons are studied, and it is shown that the extreme anisotropy of dynamically diffracted wave packets should be included in the discussion of coherence lengths. Finally, the mechanism leading to a nondispersive phase shift is investigated.

D. Petrascheck

1987-05-01T23:59:59.000Z

62

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

63

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

64

Data hiding using run length matching  

Science Journals Connector (OSTI)

This paper proposes two data hiding methods based on run length matching encoding. All of the proposed methods use the location of accumulated run length values where it compares the run length of the cover data with that of the secret data. The run length matching (RLM) method uses the run length table, which is constructed from the cover data and secret data. The reduced run length matching (RRLM) method calculates the difference value before making the run length encoding table. The experimental results demonstrate that RLM and RRLM have their own strengths with respect to different types of data and run length encoding value matching.

Ki-Hyun Jung; Kee-Young Yoo

2009-01-01T23:59:59.000Z

65

On Coherence Lengths of Wave Packets  

Science Journals Connector (OSTI)

......research-article Articles A60 A64 On Coherence Lengths of Wave Packets Kenzo Ishikawa...University, Sapporo 060-0810, Japan The coherence lengths of one-particle states described...finite spatial size that we call the coherence length. The coherence lengths in the......

Kenzo Ishikawa; Yutaka Tobita

2009-11-01T23:59:59.000Z

66

Calculations of neutron spectra after neutron–neutron scattering  

Science Journals Connector (OSTI)

A direct neutron–neutron 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 proton–proton 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 spectrum—Maxwellian plus epithermal tail. The shape of the neutron spectrum after scattering is appreciably different from the initial spectrum, due to collisions between thermal–thermal and thermal–epithermal neutrons. At the same time, the integral over the Maxwellian part of the realistic scattering spectrum differs by only about 6 per cent from that of a pure Maxwellian nn-scattering spectrum.

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

67

Nano-wires with surface disorder: Giant localization lengths and quantum-to-classical crossover  

E-Print Network [OSTI]

We investigate electronic quantum transport through nano-wires with one-sided surface roughness. A magnetic field perpendicular to the scattering region is shown to lead to exponentially diverging localization lengths in the quantum-to-classical crossover regime. This effect can be quantitatively accounted for by tunneling between the regular and the chaotic components of the underlying mixed classical phase space.

J. Feist; A. Bäcker; R. Ketzmerick; S. Rotter; B. Huckestein; J. Burgdörfer

2006-09-14T23:59:59.000Z

68

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

69

Bound States and Scattering Resonances Induced by Spatially Modulated Interactions  

Science Journals Connector (OSTI)

We study the two-body problem with a spatially modulated interaction potential using a two-channel model, in which the interchannel coupling is provided by an optical standing wave and its strength modulates periodically in space. As the modulation amplitudes increase, there will appear a sequence of bound states. Part of them will cause a divergence of the effective scattering length, defined through the phase shift in the asymptotic behavior of scattering states. We also discuss how the local scattering length, defined through short-range behavior of scattering states, modulates spatially in different regimes. These results provide a theoretical guideline for a new control technique in the cold atom toolbox, in particular, for alkaline-earth(-like) atoms where the inelastic loss is small.

Ran Qi and Hui Zhai

2011-04-20T23:59:59.000Z

70

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

71

Low-Energy Pion-Nucleon Scattering Phase Shifts  

Science Journals Connector (OSTI)

Low-energy pion-nucleon scattering phase shifts have been calculated using a model which includes only N, N*, ?, and ? intermediate states. This remarkably simple model yields good agreement with phase shifts determined from experimental data. There are two adjustable parameters in the model. The even s-wave scattering length fixes one of these, and the other is determined by the ?-nucleon magnetic moment coupling. The phase shifts are not sensitive to the choice of this coupling.

Binayak Dutta-Roy; I. Richard Lapidus; Menasha J. Tausner

1969-05-25T23:59:59.000Z

72

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 Mössbauer 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

73

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

74

Nonlinear X-ray Compton Scattering  

E-Print Network [OSTI]

X-ray scattering is a weak linear probe of matter. It is primarily sensitive to the position of electrons and their momentum distribution. Elastic X-ray scattering forms the basis of atomic structural determination while inelastic Compton scattering is often used as a spectroscopic probe of both single-particle excitations and collective modes. X-ray free-electron lasers (XFELs) are unique tools for studying matter on its natural time and length scales due to their bright and coherent ultrashort pulses. However, in the focus of an XFEL the assumption of a weak linear probe breaks down, and nonlinear light-matter interactions can become ubiquitous. The field can be sufficiently high that even non-resonant multiphoton interactions at hard X-rays wavelengths become relevant. Here we report the observation of one of the most fundamental nonlinear X-ray-matter interactions, the simultaneous Compton scattering of two identical photons producing a single photon at nearly twice the photon energy. We measure scattered...

Fuchs, Matthias; Chen, Jian; Ghimire, Shambhu; Shwartz, Sharon; Kozina, Michael; Jiang, Mason; Henighan, Thomas; Bray, Crystal; Ndabashimiye, Georges; Bucksbaum, P H; Feng, Yiping; Herrmann, Sven; Carini, Gabriella; Pines, Jack; Hart, Philip; Kenney, Christopher; Guillet, Serge; Boutet, Sebastien; Williams, Garth; Messerschmidt, Marc; Seibert, Marvin; Moeller, Stefan; Hastings, Jerome B; Reis, David A

2015-01-01T23:59:59.000Z

75

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

76

Scattering of Skyrmions  

E-Print Network [OSTI]

In this paper, we present a detailed study of Skyrmion-Skyrmion scattering for two $B=1$ Skyrmions in the attractive channel where we observe two different scattering regimes. For large separation, the scattering can be approximated as interacting dipoles. We give a qualitative estimate when this approximation breaks down. For small separations we observe an additional short-range repulsion which is qualitatively similar to monopole scattering. We also observe the interesting effect of "rotation without rotating" whereby two Skyrmions, whose orientations remain constant while well-separated, change their orientation after scattering. We can explain this effect by following preimages through the scattering process, thereby measuring which part of an in-coming Skyrmion forms part of an out-going Skyrmion. This leads to a new way of visualising Skyrmions. Furthermore, we consider spinning Skyrmions and find interesting trajectories.

David Foster; Steffen Krusch

2014-12-30T23:59:59.000Z

77

Muon-proton Scattering  

E-Print Network [OSTI]

A recent proposal to measure the proton form factor by means of muon-proton scattering will use muons which are not ultrarelativistic (and also not nonrelativistic). The usual equations describing the scattering cross section use the approximation that the scattered lepton (usually an electron) is ultrarelativistic, with v/c approximately equal to 1. Here the cross section is calculated for all values of the energy. It agrees with the standard result in the appropriate limit.

E. Borie

2012-07-24T23:59:59.000Z

78

Environment scattering in GADRAS.  

SciTech Connect (OSTI)

Radiation transport calculations were performed to compute the angular tallies for scattered gamma-rays as a function of distance, height, and environment. Green's Functions were then used to encapsulate the results a reusable transformation function. The calculations represent the transport of photons throughout scattering surfaces that surround sources and detectors, such as the ground and walls. Utilization of these calculations in GADRAS (Gamma Detector Response and Analysis Software) enables accurate computation of environmental scattering for a variety of environments and source configurations. This capability, which agrees well with numerous experimental benchmark measurements, is now deployed with GADRAS Version 18.2 as the basis for the computation of scattered radiation.

Thoreson, Gregory G.; Mitchell, Dean James; Theisen, Lisa Anne; Harding, Lee T.

2013-09-01T23:59:59.000Z

79

Scattering Solar Thermal Concentrators  

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

is a rendering of a scattering solar concentrator. Light collected by a cylindrical Fresnel lens is focused within a curved glass "guide" sheet, where it is redirected into...

80

Diffusivity determination in bulk materials on nanometric length scales using neutron reflectometry  

Science Journals Connector (OSTI)

An approach based on neutron reflectometry and isotope heterostructures is presented in order to determine self-diffusivities in bulk materials on small length scales of 1–10 nm. The method is demonstrated for lithium self-diffusion in LiNbO3 single crystals at low temperatures of 200 and 250?°C using 6LiNbO3 (amorphous film)/natLiNbO3 (single crystal) structures for analysis. Lithium diffusivities are derived from neutron reflectivity patterns in good agreement with results obtained by secondary ion mass spectrometry on the same type of samples but on larger length scales up to 90 nm, as given in literature. In addition, neutron reflectivity simulations were performed in order to investigate the influence of diffusion length and scattering length density on the quality of the results. The limitation of the method is discussed.

E. Hüger; J. Rahn; J. Stahn; T. Geue; H. Schmidt

2012-06-04T23:59:59.000Z

Note: This page contains sample records for the topic "1-to-2-ft lengths scattered" 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

The Fiber Optic Multiplexed Upgraded Thomson Scattering Diagnostic for the ISTTOK Tokamak  

E-Print Network [OSTI]

The Fiber Optic Multiplexed Upgraded Thomson Scattering Diagnostic for the ISTTOK Tokamak M. P by different length optical fibers used to relay the scattered light to a single spectrometer. 2. Thomson vessel and opposite to the collection lenses. Figure 1 shows the present two fiber optic Thomson

82

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

83

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

84

The Doppler Effect in the Molecular Scattering of Radiation  

Science Journals Connector (OSTI)

... the irregular alterations in the wave-length of the scattered radiation produced (in accordance with Doppler's principle) by the thermal movements of the molecules. There is one interesting feature ... ) by the thermal movements of the molecules. There is one interesting feature of the Doppler ...

C. V. RAMAN

1919-05-01T23:59:59.000Z

85

Effect of Minimal lengths on Electron Magnetism  

E-Print Network [OSTI]

We study the magnetic properties of electron in a constant magnetic field and confined by a isotropic two dimensional harmonic oscillator on a space where the coordinates and momenta operators obey generalized commutation relations leading to the appearance of a minimal length. Using the momentum space representation we determine exactly the energy eigenvalues and eigenfunctions. We prove that the usual degeneracy of Landau levels is removed by the presence of the minimal length in the limits of weak and strong magnetic field.The thermodynamical properties of the system, at high temperature, are also investigated showing a new magnetic behavior in terms of the minimal length.

Khireddine Nouicer

2007-07-13T23:59:59.000Z

86

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

87

Coherence length of the KY(WO4)2 single crystal  

Science Journals Connector (OSTI)

The coherence scattering lengths of a KY(WO4)2 single crystal in the directions parallel and perpendicular to the growth directions were estimated from the broadening of X-ray reflections. Qualitative analysis of the shape of the diffracted peaks and the intensity distribution in reciprocal space maps indicated the presence of dislocations and volume defects, which introduced a negative dilation into the crystal host.

Shalimov, A.

2008-05-15T23:59:59.000Z

88

Property:Length(m) | Open Energy Information  

Open Energy Info (EERE)

Length(m) Length(m) Jump to: navigation, search This is a property of type String, and provides a complied list of the lengths of various hydrodynamic testing facilities. Pages using the property "Length(m)" Showing 25 pages using this property. (previous 25) (next 25) 1 1.5-ft Wave Flume Facility + 45.1 + 10-ft Wave Flume Facility + 63.4 + 11-ft Wave Flume Facility + 77.4 + 2 2-ft Flume Facility + 61.0 + 3 3-ft Wave Flume Facility + 45.1 + 5 5-ft Wave Flume Facility + 63.4 + 6 6-ft Wave Flume Facility + 105.2 + A Alden Large Flume + 24.4 + Alden Small Flume + 17.1 + Alden Tow Tank + 30.5 + Alden Wave Basin + 33.5 + B Breakwater Research Facility + 121.9 + Bucknell Hydraulic Flume + 9.8 + C Carderock Circulating Water Channel + 18.3 + Carderock Large Cavitation Tunnel + 13.1 +

89

A length operator for canonical quantum gravity  

E-Print Network [OSTI]

We construct an operator that measures the length of a curve in four-dimensional Lorentzian vacuum quantum gravity. We work in a representation in which a $SU(2)$ connection is diagonal and it is therefore surprising that the operator obtained after regularization is densely defined, does not suffer from factor ordering singularities and does not require any renormalization. We show that the length operator admits self-adjoint extensions and compute part of its spectrum which like its companions, the volume and area operators already constructed in the literature, is purely discrete and roughly is quantized in units of the Planck length. The length operator contains full and direct information about all the components of the metric tensor which faciliates the construction of a new type of weave states which approximate a given classical 3-geometry.

T. Thiemann

1996-06-29T23:59:59.000Z

90

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, ± 10 meV the applications are principally quasielastic scattering and tunneling spectroscopy. The second range, 0–1000 meV covers the regions of vibrational spectroscopy and magnetic excitations. The highest range above 1000 meV 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

91

Scattering Solar Thermal Concentrators  

Broader source: Energy.gov [DOE]

"This fact sheet describes a scattering solar thermal concentrators project awarded under the DOE's 2012 SunShot Concentrating Solar Power R&D award program. The team, led by the Pennsylvania State University, is working to demonstrate a new, scattering-based approach to concentrating sunlight that aims to improve the overall performance and reliability of the collector field. The research team aims to show that scattering solar thermal collectors are capable of achieving optical performance equal to state-of-the-art parabolic trough systems, but with the added benefits of immunity to wind-load tracking error, more efficient land use, and utilization of stationary receivers."

92

Viscosity and Light Scattering in Critical Mixtures  

Science Journals Connector (OSTI)

Simultaneous measurements of both viscosity and light scattering are performed on two critical mixtures. The first one is a triethylamine-water solution, which exhibits a lower consolute point, the second one a methanol-ciclohexane mixture with an upper consolute point. It is found that the singular behavior of viscosity cannot be fitted by a simple power law, nor by a logarithmic one, in the entire range of temperature. The asymptotic behavior, however, tends to become logarithmic as the critical temperature is approached. The simultaneous observation of scattered light allows one to exclude the intervention of spurious processes, like a breaking of correlations because of impurities. In addition, it is shown that the correlation length seems to depend mainly on the reduced temperature, irrespective of the system under examination.

S. Ballaro'; G. Maisano; P. Migliardo; F. Wanderlingh

1972-10-01T23:59:59.000Z

93

EXPONENTIAL GALAXY DISKS FROM STELLAR SCATTERING  

SciTech Connect (OSTI)

Stellar scattering off of orbiting or transient clumps is shown to lead to the formation of exponential profiles in both surface density and velocity dispersion in a two-dimensional non-self gravitating stellar disk with a fixed halo potential. The exponential forms for both nearly flat rotation curves and near-solid-body rotation curves. The exponential does not depend on initial conditions, spiral arms, bars, viscosity, star formation, or strong shear. After a rapid initial development, the exponential saturates to an approximately fixed scale length. The inner exponential in a two-component profile has a break radius comparable to the initial disk radius; the outer exponential is primarily scattered stars.

Elmegreen, Bruce G. [IBM Research Division, T.J. Watson Research Center, 1101 Kitchawan Road, Yorktown Heights, NY 10598 (United States)] [IBM Research Division, T.J. Watson Research Center, 1101 Kitchawan Road, Yorktown Heights, NY 10598 (United States); Struck, Curtis, E-mail: bge@watson.ibm.com, E-mail: curt@iastate.edu [Department of Physics and Astronomy, Iowa State University, Ames, IA 50011 (United States)] [Department of Physics and Astronomy, Iowa State University, Ames, IA 50011 (United States)

2013-10-01T23:59:59.000Z

94

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

95

HS: Scattering --June 24, 1997 TIME--DEPENDENT SCATTERING THEORY  

E-Print Network [OSTI]

completeness, which was stated precisely in the early days of scattering theory [Jauch], [Hack]. The challenge

96

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

97

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

98

Compton Scattering of  

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

Compton Scattering of Picosecond Electron and CO2 beams T. Hirose (TMU) @BNL user meeting, Jan. 31, 2002 JapanUS cooperation in high energy physics (Supported by JSPS from 1998)...

99

Fracture Properties From Seismic Scattering  

E-Print Network [OSTI]

Fractures scatter seismic energy and this energy can be analyzed to provide information about fracture

Burns, Daniel R.

2007-01-01T23:59:59.000Z

100

Scattering from Materials BRENT FULTZ  

E-Print Network [OSTI]

by scattering methods using x-rays, electrons, neutrons, and -rays. Coherent elastic scattering, for example by inelastic neutron scattering to understand the reasons for differences in vibrational entropy of different and local distortions around impurity atoms. The field of inelastic neutron scattering is a broad one

Note: This page contains sample records for the topic "1-to-2-ft lengths scattered" 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

S-wave scattering lengths and effective ranges for collisions of ground state Be atoms  

E-Print Network [OSTI]

Jamieson,M.J. Cheung,A.S.C. Ouerdane,H. Jeung,G.H. Geum,N. Journal of Physics B, Volume 40 pp 3497-3504

Jamieson, M.J.

102

Scattering length density profile of Ni film under controlled corrosion: A study in neutron reflectometry  

Science Journals Connector (OSTI)

We report the density depth profile of an as-deposited Ni film and density profile for the same film after controlled electrochemical corrosion by chloride ions, measured by unpolarized neutron reflectometry. The...

Surendra Singh; A. K. Poswal; S. K. Ghosh; Saibal Basu

2008-11-01T23:59:59.000Z

103

Scattering of near-zero-energy electrons and positrons by H2  

Science Journals Connector (OSTI)

The parameters for S-wave elastic scattering of near-zero-energy electrons and positrons by H2 molecules are calculated using the stabilization method with explicitly correlated Gaussians. The confined variational method is applied to optimize the Gaussians to describe the short-range interaction of incident e± with H2 in the fixed-nuclei approximation. For e+-H2 scattering the scattering length of previous work [Phys. Rev. Lett. 103, 223202 (2009)] is substantially improved. More importantly, for e?-H2 scattering, from first principles, the scattering length is computed as a function of the internuclear distance. In the case that the two nuclei are at the equilibrium distance the results are in a good agreement with values derived from fitting experimental total and diffusion cross sections to the modified effective range theory.

J.-Y. Zhang; Y.-J. Yang; Y. Qian; Z.-C. Yan; U. Schwingenschlögl

2014-04-15T23:59:59.000Z

104

Inheritance of Cotton Fiber Length and Strength  

E-Print Network [OSTI]

. Frequency distribution of upper half mean length (UHML) in the P1, P2, F1, BC1P1, BC1P2, and F2 generations for the parental combination of ELS33 (P1) x SID84 (P2) in 2010 and 2011. ..................................................... 63 Figure 4.... Frequency distribution of upper half mean length (UHML) in the P1, P2, F1, BC1P1, BC1P2, and F2 generations for the parental combination of ELS33 (P1) x HS624 (P2) in 2010 and 2011. ................................................................. 64...

Joy, Kolbyn Seth

2014-04-23T23:59:59.000Z

105

Crystal diffraction lens with variable focal length  

DOE Patents [OSTI]

A method and apparatus for altering the focal length of a focusing element of one of a plurality of pre-determined focal lengths by changing heat transfer within selected portions of the element by controlled quantities is disclosed. Control over heat transfer is accomplished by manipulating one or more of a number of variables, including: the amount of heat or cold applied to surfaces; type of fluids pumped through channels for heating and cooling; temperatures, directions of flow and rates of flow of fluids; and placement of channels. 19 figures.

Smither, R.K.

1991-04-02T23:59:59.000Z

106

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/

107

Defect Scattering in Graphene  

Science Journals Connector (OSTI)

Irradiation of graphene on SiO2 by 500 eV Ne and He ions creates defects that cause intervalley scattering as is evident from a significant Raman D band intensity. The defect scattering gives a conductivity proportional to charge carrier density, with mobility decreasing as the inverse of the ion dose. The mobility decrease is 4 times larger than for a similar concentration of singly charged impurities. The minimum conductivity decreases proportional to the mobility to values lower than 4e2/?h, the minimum theoretical value for graphene free of intervalley scattering. Defected graphene shows a diverging resistivity at low temperature, indicating insulating behavior. The results are best explained by ion-induced formation of lattice defects that result in midgap states.

Jian-Hao Chen; W. G. Cullen; C. Jang; M. S. Fuhrer; E. D. Williams

2009-06-12T23:59:59.000Z

108

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

109

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

110

On the flat length of injective modules  

Science Journals Connector (OSTI)

......that I has a projective resolution of length n + m and hence pdRI n + m. Therefore, spli R n + m, as needed. The second inequality...n - 1. Proof. Let I be an injective left R-module. Then pdRI spli R n and hence Corol- lary 2.12 implies that fdRI n......

Ioannis Emmanouil; Olympia Talelli

2011-10-01T23:59:59.000Z

111

The Impact of Query Length and Document Length on Book Search Effectiveness  

E-Print Network [OSTI]

search is an important track at INEX ­ books are generally much larger documents than the scientificThe Impact of Query Length and Document Length on Book Search Effectiveness Mingfang Wu, Falk for the Evaluation of XML retrieval (INEX) book search track in 2008, specifically the book retrieval task. Book

Wu, Mingfang

112

Length dependence of the Raman spectra of carbon nanotubes  

E-Print Network [OSTI]

DNA-wrapping technology, combined with size-exclusion chromatography, have made possible the sorting of carbon nanotubes according to length. In particular, length sorted nanotube samples, with finite lengths approaching ...

Zare, Aurea Tucay

2009-01-01T23:59:59.000Z

113

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...

114

Coherence length tunable semiconductor laser with optical feedback  

Science Journals Connector (OSTI)

We report the experimental results to continuously tune the coherence length of a semiconductor laser using an optical feedback scheme. The coherence length can be controlled by...

Wang, Yuncai; Kong, Lingqin; Wang, Anbang; Fan, Linlin

2009-01-01T23:59:59.000Z

115

Property:Length (m) | Open Energy Information  

Open Energy Info (EERE)

(m) (m) Jump to: navigation, search Property Name Length (m) Property Type Number Pages using the property "Length (m)" Showing 25 pages using this property. (previous 25) (next 25) M MHK Technologies/AirWEC + 0 + MHK Technologies/CurrentStar + 30.5 + MHK Technologies/Deep Green + 4 + MHK Technologies/Deep water capable hydrokinetic turbine + 5 + MHK Technologies/Electric Buoy + 10 + MHK Technologies/European Pico Pilot Plant + 20 + MHK Technologies/Evopod E35 + 12.5 + MHK Technologies/Float Wave Electric Power Station + 12 + MHK Technologies/Floating anchored OTEC plant + 60 + MHK Technologies/HyPEG + 50 + MHK Technologies/HydroGen 10 + 4.5 + MHK Technologies/Hydroflo + 7 + MHK Technologies/ITRI WEC + 6 + MHK Technologies/IVEC Floating Wave Power Plant + 150 +

116

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

117

Critical length limiting super-low friction  

E-Print Network [OSTI]

Since the demonstration of super-low friction (superlubricity) in graphite at nanoscale, one of the main challenges in the field of nano- and micro-mechanics was to scale this phenomenon up. A key question to be addressed is to what extent superlubricity could persist, and what mechanisms could lead to its failure. Here, using an edge-driven Frenkel-Kontorova model, we establish a connection between the critical length above which superlubricity disappears and both intrinsic material properties and experimental parameters. A striking boost in dissipated energy with chain length emerges abruptly due to a high-friction stick-slip mechanism caused by deformation of the slider leading to a local commensuration with the substrate lattice. We derived a parameter-free analytical model for the critical length that is in excellent agreement with our numerical simulations. Our results provide a new perspective on friction and nano-manipulation and can serve as a theoretical basis for designing nano-devices with super-low friction, such as carbon nanotubes.

Ming Ma; Andrea Benassi; Andrea Vanossi; Michael Urbakh

2015-01-02T23:59:59.000Z

118

Performance prediction for short plant length systems  

Science Journals Connector (OSTI)

Plant length dependent performance is commonly observed when performing feedforward active noise control for broadband disturbances. This is primarily due to high levels of low?frequency noise and limited coherence between input and error sensors. These types of systems present trade?offs in choosing between performance output power requirements and plant length. An additional design opportunity exists in terms of balancing the levels of cancellation achieved over frequency. The selection of an error signal emphasis filter determining the frequency dependence of the cost function being minimized by the controller adaptation can be of critical importance. While several explanations for this type of behavior have been offered little work has been presented for quantifying performance limitations. A method based on calculation of Lagrange multipliers is presented for determining the optimal power limited solution of an FIR filter?based controller. This provides a useful tool for predicting the effects of emphasis filter design actuator limitations and plant length on performance. This prediction method and the associated trade?offs are illustrated using data from an HVAC fan.

Steven R. Popovich

1996-01-01T23:59:59.000Z

119

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

120

Diffuse scattering of hard x rays from rough surfaces  

Science Journals Connector (OSTI)

The diffuse scattering of hard x rays from rough solid surfaces has been measured and described quantitatively in terms of an improved distorted-wave Born approximation. The rough surface is characterized by the rms roughness ?, the height-height correlation length ?, and the roughness exponent h. The value for ? is in excellent agreement with that deduced from reflectivity. The significance of the parameters ?, ?, and h is tested by comparison with the results obtained from scanning force mircoscopy.

Wolfgang Weber and Bruno Lengeler

1992-09-15T23:59:59.000Z

Note: This page contains sample records for the topic "1-to-2-ft lengths scattered" 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

Relativistic scattering coherence  

Science Journals Connector (OSTI)

Wave propagation through inhomogeneous, turbulent media is investigated for the case where the signal and inhomogeneities move relativistically. Although in classical treatments the mean-square angular deviations grow as the path length, this is found not to be true relativistically. Special attention is given to the problem of light propagating through a cosmological background of gravitational waves.

Eric V. Linder

1986-09-15T23:59:59.000Z

122

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

123

Molecular-beam scattering  

SciTech Connect (OSTI)

The molecular-beam technique has been used in three different experimental arrangements to study a wide range of inter-atomic and molecular forces. Chapter 1 reports results of a low-energy (0.2 kcal/mole) elastic-scattering study of the He-Ar pair potential. The purpose of the study was to accurately characterize the shape of the potential in the well region, by scattering slow He atoms produced by expanding a mixture of He in N/sub 2/ from a cooled nozzle. Chapter 2 contains measurements of the vibrational predissociation spectra and product translational energy for clusters of water, benzene, and ammonia. The experiments show that most of the product energy remains in the internal molecular motions. Chapter 3 presents measurements of the reaction Na + HCl ..-->.. NaCl + H at collision energies of 5.38 and 19.4 kcal/mole. This is the first study to resolve both scattering angle and velocity for the reaction of a short lived (16 nsec) electronic excited state. Descriptions are given of computer programs written to analyze molecular-beam expansions to extract information characterizing their velocity distributions, and to calculate accurate laboratory elastic-scattering differential cross sections accounting for the finite apparatus resolution. Experimental results which attempted to determine the efficiency of optically pumping the Li(2/sup 2/P/sub 3/2/) and Na(3/sup 2/P/sub 3/2/) excited states are given. A simple three-level model for predicting the steady-state fraction of atoms in the excited state is included.

Vernon, M.F.

1983-07-01T23:59:59.000Z

124

Long Length Contaminated Equipment Maintenance Plan  

SciTech Connect (OSTI)

The purpose of this document is to provide the maintenance requirements of the Long Length Contaminated Equipment (LLCE) trailers and provide a basis for the maintenance frequencies selected. This document is applicable to the LLCE Receiver trailer and Transport trailer assembled by Mobilized Systems Inc. (MSI). Equipment used in conjunction with, or in support of, these trailers is not included. This document does not provide the maintenance requirements for checkout and startup of the equipment following the extended lay-up status which began in the mid 1990s. These requirements will be specified in other documentation.

ESVELT, C.A.

2000-02-01T23:59:59.000Z

125

TREKisM At Length Issue 2  

E-Print Network [OSTI]

. "Triskelian Fledgeling" — by Vel Jaeger "Kelvan Exile" — by Vel Jaeger 111. Romulan Astronomy — by Robert S. Sayes 113c Trek-M's Speak their Minds on ST:TMP 121. A Glance Backwards - reactions to TaL I (first issue of TREKisM at Length) 122. Trivia Quizes #3...\\un Speck run. "fynjrur^run. -Storu Ipu1- 'The^dds" UYena T^fc* Ink.nc l'*- bjj rafrick La\\fena ^aq Kidd LuckICKU ©/980' -14- 0N CONVENTIONAL OCCASIONS The following Is a conglomeration of reports, Interviews, and reminiscences from TREKisM members...

Multiple Contributors

1981-01-01T23:59:59.000Z

126

TREKiSM At Length Issue 5  

E-Print Network [OSTI]

Trek IV! SHALOM PAX PEACE to us all in 1986 Table of Contents TITLE AUTHOR ARTIST PAGE I. DATA ENTRIES FROST ON THE TYPEWRITER V.L. Thorn LaVena Kay Kldd 2 "Trek Omen" V.L. Thorn 6 (originally appeared In TREKisM #26) JAMES T. KIRK vs THE COMPUTER... appeared in TREKisM at Length III) TALES FROM THE VULCAN HEARTH Karen C. Hunter 53 HOW THE VULCANS LOST THEIR WINGS 54 THE SKY GOD'S DAUGHTER 56 THE GIFT OF THE GODS LaVena Kay Kldd 57 "Sul Generis" V.L. Thorn 58 "Cat-Kin" Emily Ross 60 (originally appeared...

Multiple Contributors

1988-01-01T23:59:59.000Z

127

TrekISM At Length Issue 3  

E-Print Network [OSTI]

Length III is published by the Star Trek Special Interest Group LSIGJ of Mensa. Copyright (c) 1983..., 1701 W. Third St, Brooklyn NY 11223. \\S In January Paramount STAR TREK new produc Star Trek' no time wa two-and-a- of TREKisM interested said in an Thank you, never ceas the contin eternally ixgmqp^ion of 19 P i c t u r II. A er, Ha...

Multiple Contributors

1983-01-01T23:59:59.000Z

128

LHC Predictions from an extended theory with Elastic, Inelastic, and Path Length Fluctuating Energy Loss  

E-Print Network [OSTI]

We present the LHC predictions for the WHDG model of radiative, elastic, and path length fluctuating energy loss. We find the pT dependence of RAA is qualitatively very different from AWS-based energy loss extrapolations to the LHC; the large pT reach of the year one data at the LHC should suffice to distinguish between the two. We also discuss the importance of requiring a first elastic scatter before any medium-induced elastic or radiative loss occurs, a necessary physical effect not considered in any previous models.

William A. Horowitz

2007-02-27T23:59:59.000Z

129

Imaging at All Length and Time Scales  

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

Thematic Workshop Summary: Imaging at All Length and Time Scales Thematic Workshop Summary: Imaging at All Length and Time Scales Organizers: K amel F ezzaa ( APS), M arc D e G raef ( Carnegie M ellon U niversity), N athan G uisinger ( CNM) The a bility t o u nderstand, m odify, a nd c ontrol s ystems i n a v ariety o f e nvironments a cross m ultiple t ime and l ength s cales i s c entral t o m any f undamental c ontemporary r esearch a nd e ngineering c hallenges. Success i n t hese e fforts h inges o n t he a bility t o i mage n ot o nly t he s tructure i n s ystems, b ut a lso t he electronic, m agnetic, o ptical a nd c hemical p roperties a nd b ehavior a ssociated w ith t his s tructure. T he APS, C NM a nd E MC p ossess a d iverse a nd c omplementary a rray o f i maging, m icroscopy a nd s pect--- roscopy p latforms t o p ush t his f rontier o f m ultiscale a nd t ime---resolved i nvestigation.

130

Modeling tip zones to predict the throw and length characteristics of faults  

SciTech Connect (OSTI)

A map of faults in a 60 km{sup 2} area of the southern North Sea has been produced from three-dimensional seismic data. The faults shown on the map obey power-law cumulative-frequency distributions for throw (power-law exponent, D, {approx} 2.7) and length (D {approx} 1.1). Simulations have been carried out to correct for sampling biases in the data and to make predictions of the throw the data and to make predictions of the throw and length scaling characteristics of the faults. The most important bias is caused by poor resolution of the small displacement tip zones of faults. The raw data show considerable scatter in their length: throw ratios, but they more closely fit a linar relationship if a length of 500 m is added to each fault, thereby making up for the zones near the fault tips with throws ({approx} 15 m) below seismic resolution. Further variability in the data may be caused by such geological factors as fault interaction. Tip lengths have been extended to simulate the actual fault pattern in the study area. Maps produced by this procedure can be used to estimate the true connectivity of the fault network. Extending the faults results in greater connectivity than shown by the raw data, which may cause greater compartmentalization of the rock mass. This greater compartmentalization has implications for hydrocarbon exploitation if the faults are sealing. A problem with the model, however, is that it does not deal effectively with the interaction of subparallel, noncoplanar faults. To test the reliability of the procedure, we analyzed exposure-scale faults in Somerset, United Kingdom, where the tips are well constrained. Both length-throw relationships and map-pattern connectivity for the simulated fault networks agree closely with the actual data.

Pickering, G.; Sanderson, D.J.; Bull, J.M. [Univ. of Southampton (United Kingdom)] [and others

1997-01-01T23:59:59.000Z

131

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

132

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

133

Raman scattering in crystals  

SciTech Connect (OSTI)

A tutorial presentation is given of Raman scattering in crystals. The physical concepts are emphasized rather than the detailed mathematical formalism. Starting with an introduction to the concepts of phonons and conservation laws, the effects of photon-phonon interactions are presented. This interaction concept is shown for a simple cubic crystal and is extended to a uniaxial crystal. The correlation table method is used for determining the number and symmetry of the Raman active modes. Finally, examples are given to illustrate the relative ease of using this group theoretical method and the predictions are compared with measured Raman spectra. 37 refs., 17 figs., 6 tabs.

Edwards, D.F.

1988-09-30T23:59:59.000Z

134

Magnetic x-ray scattering at the M{sub 5} absorption edge of Ho  

SciTech Connect (OSTI)

Magnetic x-ray scattering from thin Ho-metal films at M{sub 5} resonance reveals atomic scattering lengths up to 200r{sub 0}--i.e., of the same order of magnitude as predicted theoretically by Hannon et al. [Phys. Rev. Lett. 61, 1245 (1988)]. The photon-energy dependence of first- and second-order magnetic satellites allows a straightforward identification of circular and linear dichroic contributions. A direct comparison to magnetic neutron scattering demonstrates the potential of the method for studies of complex magnetic structures in ultrathin films and highly diluted materials.

Ott, H.; Schierle, E.; Grigoriev, A. Yu.; Kaindl, G.; Weschke, E. [Institut fuer Experimentalphysik, Freie Universitaet Berlin, Arnimallee 14, D-14195 Berlin-Dahlem (Germany); Schuessler-Langeheine, C. [Institut fuer Experimentalphysik, Freie Universitaet Berlin, Arnimallee 14, D-14195 Berlin-Dahlem (Germany); II. Physikalisches Institut, Universitaet zu Koeln, Zuelpicher Str. 77, D-50937 Koeln (Germany); Leiner, V. [Institut fuer Experimentalphysik/Festkoerperphysik, Ruhr-Universitaet Bochum, D-44780 Bochum (Germany); Institut fuer Werkstoffforschung, WFN, GKSS Forschungszentrum, D-21502 Geesthacht (Germany); Zabel, H. [Institut fuer Experimentalphysik/Festkoerperphysik, Ruhr-Universitaet Bochum, D-44780 Bochum (Germany)

2006-09-01T23:59:59.000Z

135

Length of cell division/mitosis  

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

Length of cell division/mitosis Length of cell division/mitosis Name: Mrs. Goeheler Location: N/A Country: N/A Date: N/A Question: We are a 5/6 grade class at Lake Louise in Palatine. We are studying cell division- mitosis. We would like to know how long this process takes? Can you please help us with this question? thanks for your help. Replies: For cells that are actively growing and dividing (say, for instance, human skin cells - fibroblasts- that are grown in culture dishes) the entire cell cycle takes about 20-24 hours. The cell cycle is usually described as having four "phases". In the G1 phase, the cell grows and also senses whether the environment is right to go on to divide. The d decision to divide is made in G1 phase. The second phase is S phase, where the DNA of the cell is copied (replicated). It's called S because this is the phase where DNA Synthesis occurs. The third phase is called G2. Here, the cell grows more, makes sure that all of its chromosomes are fully copied, and gets ready to divide. The fourth phase is M phase, where mitosis and cell division occurs. M phase usually takes about 1 hour; G1 phase is variable (depending on growth conditions); S phase usually takes about 6-8 hours, and G2 is normally 2-5 S phase usually takes about 6-8 hours, and G2 is normally 2-5 hours. Just how this cycle is regulated - and how the "decisions" are made - is a very hot topic in cell biology research these days. You're on to something big and exciting here!

136

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

137

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...

138

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...

139

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

140

Book review Light Scattering Reviews 4: Single Light Scattering and  

E-Print Network [OSTI]

-monograph on the use of space-time Green functions in the description of the diffusive radiation transport in active equation of the radiative transfer theory in the classical style of the ``Soviet'' school of radiativeBook review Light Scattering Reviews 4: Single Light Scattering and Radiative Transfer, A

Note: This page contains sample records for the topic "1-to-2-ft lengths scattered" 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

Queue-length synchronization in communication networks  

Science Journals Connector (OSTI)

We study the synchronization in the context of network traffic on a 2-d communication network with local clustering and geographic separations. The network consists of nodes and randomly distributed hubs where the top five hubs ranked according to their coefficient of betweenness centrality (CBC) are connected by random assortative and gradient mechanisms. For multiple message traffic, messages can trap at the high CBC hubs, and congestion can build up on the network with long queues at the congested hubs. The queue lengths are seen to synchronize in the congested phase. Both complete and phase synchronization are seen, between pairs of hubs. In the decongested phase, the pairs start clearing and synchronization is lost. A cascading master-slave relation is seen between the hubs, with the slower hubs (which are slow to decongest) driving the faster ones. These are usually the hubs of high CBC. Similar results are seen for traffic of constant density. Total synchronization between the hubs of high CBC is also seen in the congested regime. Similar behavior is seen for traffic on a network constructed using the Waxman random topology generator. We also demonstrate the existence of phase synchronization in real internet traffic data.

Satyam Mukherjee and Neelima Gupte

2009-05-14T23:59:59.000Z

142

Light scattering for aerogel characterization  

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

for aerogel characterization for aerogel characterization Title Light scattering for aerogel characterization Publication Type Journal Article Year of Publication 1998 Authors Hunt, Arlon J. Journal Journal of Non-Crystalline Solids Volume 225 Pagination 303-306 Keywords aerogel, light scattering, microstructure Abstract Light scattering is a useful tool to evaluate aerogel clarity, study its structure, pore size, mechanical strain, and examine the modes of sol-gel evolution that determine its microstructure. Ultraviolet-visible transmission spectroscopy can be used to study the wavelength dependent scattering to readily compare aerogels of differing origins, thickness, and to evaluate effects of residual contaminants. Infrared reflectance measurements can be used to determine the effective real and imaginary indices of refraction of porous aerogel materials for material property and radiant heat transfer studies. Measurements of scattering at a fixed angle can be used for quality control, to evaluate sources of scattering, and study inhomogeneities. Measurement of the Mueller matrix (describing the 16-element angle-dependent transformation of intensity and polarization of incident to scattered light) provides information about the anisotropy, large pore fraction, induced stresses, microstructure and inhomogeneities in the aerogel. The time evolution of scattering before and after gel formation gives information.

143

Effective scattering coefficient of the cerebral spinal fluid in adult head models for diffuse optical imaging  

E-Print Network [OSTI]

correct radiative transport equation (RTE); however, it is commonly assumed that scattering lengths must. Boas An efficient computation of the time-dependent forward solution for photon transport in a head of the brain. The diffusion approximation to photon transport is much faster to simulate than the physically

144

Superlinear growth of Rayleigh scattering-induced intensity noise in single-mode fibers  

E-Print Network [OSTI]

Rayleigh scattering generates intensity noise close to an optical carrier that propagates in a single-mode optical fiber. This noise degrades the performance of optoelectronic oscillators and RF-photonic links. When using a broad linewidth laser, we previously found that the intensity noise power scales linearly with optical power and fiber length, which is consistent with guided entropy mode Rayleigh scattering (GEMRS), a third order nonlinear scattering process, in the spontaneous limit. In this work, we show that this behavior changes significantly with the use of a narrow linewidth laser. Using a narrow linewidth laser, we measured the bandwidth of the intensity noise plateau to be 10 kHz. We found that the scattered noise power scales superlinearly with fiber length up to lengths of 10 km in the frequency range of 500 Hz to 10 kHz, while it scales linearly in the frequency range of 10 Hz to 100 Hz. These results suggest that the Rayleigh-scattering-induced intensity noise cannot be explained by third-ord...

Cahill, James P; Zhou, Weimin; Menyuk, Curtis R; Carter, Gary M

2015-01-01T23:59:59.000Z

145

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

146

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

147

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

148

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

149

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. Falcão; V. R. Crispim

2006-09-01T23:59:59.000Z

150

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

151

s-wave-scattering resonances induced by dipolar interactions of polar molecules  

Science Journals Connector (OSTI)

We show that the s-wave-scattering resonances induced by dipolar interactions in polar molecular gases have a universal large and positive effective range, which is very different from Feshbach resonances previously realized in cold atoms before, where the effective range is either negligible or negative. Such a difference has important consequences in many-body physics. At a high-temperature regime, a positive effective range gives rise to a stronger repulsive interaction energy for positive scattering length, and a weaker attractive interaction energy for negative scattering length. At low temperatures, we study a polaron problem formed by a single-impurity molecule, and we find that the polaron binding energy increases at the BEC side and decreases at the BCS side. All these effects are opposite to narrow Feshbach resonances, where the effective range is negative.

Zhe-Yu Shi, Ran Qi, and Hui Zhai

2012-02-27T23:59:59.000Z

152

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

SciTech Connect (OSTI)

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

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

2014-09-24T23:59:59.000Z

153

Estimates of wave front distortion from measurements of scattering by model random media and calf liver  

Science Journals Connector (OSTI)

An expression based on a perturbation method is employed to estimate the correlation of path length difference in a plane normal to the direction of wave propagation from measurements of ultrasonic scattering by model random media and calf liver. The expression gives the correlation function of path length difference in terms of an integral of the correlation function of the medium variations or an equivalent integral of the power spectrum of medium variations both for a scattering angle of zero degrees. Power spectra derived from measurements of average differential scattering cross section over a spatial?frequency window are used to fit analytic functions that extend over all spatial frequencies. The results for the windowed and unwindowed data yield correlation functions and corresponding power spectra that are used to estimate the correlation function of path length difference. The results suggest that the correlation length in calf liver is less than 100 ?m and that a root?mean?square path length variation of about 20 ?m results from propagation through a 100?mm calf liver path.

Robert C. Waag; Diane Dalecki; Wallace A. Smith

1989-01-01T23:59:59.000Z

154

What Does a Scattering Pattern Tell US?  

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

Space sample light image Image Space lens Angular Space Q 4p sin(q) l Fourier Transform Scattering Pattern Fourier Transform Phase Problem Scattering Pattern Fourier...

155

Microwave scattering from laser spark in air  

SciTech Connect (OSTI)

In this paper, microwave Mie scattering from a laser-induced plasma in atmospheric air is computed. It shows that the scattered microwave transitions from coherent Rayleigh scattering to Mie scattering based on the relative transparency of the laser-induced plasma at the microwave frequency. The microwave penetration in the plasma alters from total transparency to partial shielding due to the sharp increase of the electron number density within the avalanche ionization phase. The transition from Rayleigh scattering to Mie scattering is verified by both the temporal evolution of the scattered microwave and the homogeneity of polar scattering plots.

Sawyer, Jordan; Zhang Zhili [Mechanical, Aerospace and Biomedical Engineering, University of Tennessee, Knoxville, Tennessee 37996 (United States); Shneider, Mikhail N. [Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544 (United States)

2012-09-15T23:59:59.000Z

156

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...

157

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...

158

Timelike Compton Scattering at Jlab  

SciTech Connect (OSTI)

It is demonstrated, that with exclusive final state, data from electron scattering experiments that are recorded with loose trigger requirements can be used to analyze photoproduction reactions. A preliminary results on Timelike Compton Scattering using the electroproduction data from the CLAS detector at Jefferson Lab are presented. In particular, using final state (pe{sup -}e{sup +}) photoproduction of vector mesons and timelike photon is studied. Angular asymmetries in Timelike Compton Scattering region is compared with model predictions in the framework of Generalized Parton Distribution.

Paremuzyan, Rafayel G. [Institut de Physique Nucleaire, Orsay (France)

2014-01-01T23:59:59.000Z

159

Pitch-angle scattering of energetic particles with adiabatic focusing  

E-Print Network [OSTI]

Understanding turbulent transport of charged particles in magnetized plasmas often requires a model for the description of random variations in the particle's pitch angle. The Fokker-Planck coefficient of pitch-angle scattering, which is used to describe scattering parallel to the mean magnetic field, is therefore of central importance. Whereas quasi-linear theory assumes a homogeneous mean magnetic field, such a condition is often not fulfilled, especially for high-energy particles. Here, a new derivation of the quasi-linear approach is given that is based on the unperturbed orbit found for an adiabatically focused mean magnetic field. The results show that, depending on the ratio of the focusing length and the particle's Larmor radius, the Fokker-Planck coefficient is significantly modified but agrees with the classical expression in the limit of a homogeneous mean magnetic field.

Tautz, R C; Dosch, A

2014-01-01T23:59:59.000Z

160

LENGTH OF BEAMLINES AND WIDTH OF THE LS-37  

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

LENGTH OF BEAMLINES AND WIDTH OF THE LENGTH OF BEAMLINES AND WIDTH OF THE LS-37 November 10, 1985 G. K. Shenoy G. S. Knapp EXPERIMENTAL HALL AT A 6-GeV SYNCHROTRON FACILITY The width of the experimental hall at a 6-GeV facility is closely related to the length of the beamlines. This note addresses this aspect in some de tail. In general, no two beamlines will have identical lengths or the placement of various optical elements. Hence fixing the beamline lengths prior to their assignment to specific experiments is difficult. In spite of this fact, a few general conclusions are made. 1. At least 25m of all the beamlines will be behind the shielding wall. Within this length many beamline components can be accommodated as shown in Fig. 1. 2. For most beamlines on bending magnets (BM), the first optical element will

Note: This page contains sample records for the topic "1-to-2-ft lengths scattered" 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

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

162

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

163

Posters Radiation Singularities, Multiple Scattering  

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

mean C 1 0.75 and Levy index 1.35 (as empirically observed) and apply to it the Radiative Transfer Equation in the perfect scattering case. We have analytical and numerical...

164

Hadronic scattering of charmed mesons  

E-Print Network [OSTI]

The scattering cross sections of charm mesons with hadrons such as the pion, rho meson, and nucleon are studied in an effective Lagrangian. In heavy ion collisions, rescattering of produced charm mesons by hadrons affects the invariant mass spectra...

Lin, ZW; Ko, Che Ming; Zhang, B.

2000-01-01T23:59:59.000Z

165

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

166

Chaotic Scattering and Self-Organization in Spheromak Sustainment  

Science Journals Connector (OSTI)

Flux core spheromak sustainment by electrostatic helicity injection is studied in resistive MHD. The geometry has magnetized electrodes at the ends held at a potential difference V. For V>Vc the central current column is kink unstable. The nonlinear state with V just above Vc has a large volume of flux surfaces, with rotational transform provided by the helical kinking of the column. As V increases the kink becomes stronger, the tori are destroyed, and the field lines exhibit chaotic scattering. The distribution of field line lengths L, related to confinement and parallel current density, is studied. At larger V or larger Lundquist number S, a limit cycle appears.

John M. Finn; Carl R. Sovinec; Diego del-Castillo-Negrete

2000-11-20T23:59:59.000Z

167

Polarized lepton-nucleon scattering  

SciTech Connect (OSTI)

Deep inelastic polarized lepton-nucleon scattering is reviewed in three lectures. The first lecture covers the polarized deep inelastic scattering formalism and foundational theoretical work. The second lecture describes the nucleon spin structure function experiments that have been performed up through 1993. The third lecture discusses implication of the results and future experiments aimed at high-precision measurements of the nucleon spin structure functions.

Hughes, E.

1994-02-01T23:59:59.000Z

168

Neutron scattering at high pressure  

Science Journals Connector (OSTI)

Neutron scattering spectra at pressures up to 30 kilobar in the temperature range 300–4 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

169

SQUID magnetometry from nanometer to centimeter length scales  

E-Print Network [OSTI]

length scales . . . . . . . Josephson Junction and SQUIDin nanoscale weak link josephson junction oscillators. Phys.cation by unbiased Josephson junctions. Journ. Appl. Phys. ,

Hatridge, Michael Jonathan

2010-01-01T23:59:59.000Z

170

Measurements of the Vertical Coherence Length in Neutron Interferometry  

SciTech Connect (OSTI)

The study and use of macroscopic quantum coherence requires long coherence lengths. Here we describe an approach to measuring the vertical coherence length in neutron interferometry, along with improvements to the NIST interferometer that led to a measured coherence length of 790 A. The measurement is based on introducing a path separation and measuring the loss in contrast as this separation is increased. The measured coherence length is consistent with the momentum distribution of the neutron beam. Finally, we demonstrate that the loss in contrast with beam displacement in one leg of the interferometer can be recovered by introducing a corresponding displacement in the second leg.

Pushin, D. A.; Cory, D. G. [Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts (United States); Arif, M. [National Institute of Standards and Technology, Gaithersburg, Maryland (United States); Huber, M. G. [Department of Physics, Tulane University, New Orleans, Louisiana (United States)

2008-06-27T23:59:59.000Z

171

Scattering of Protons by Deuterons  

Science Journals Connector (OSTI)

Utilizing a scattering chamber based upon the successful design used by Herb, Kerst, Parkinson, and Plain (HKPP) in the measurement of proton-proton scattering, experimental data on the scattering of protons by deuterons have been obtained. The incident protons were accelerated by the 3.5-Mev Wisconsin generator ("long tank") which was used by the Manhattan Project at Los Alamos, New Mexico. The geometry, and the current and pressure measurements were checked by comparing the measurements of proton-proton scattering at 2.1 Mev with the work of HKPP. Results on proton-deuteron scattering at 0.825, 1.51, 2.08, 2.53, 3.00, and 3.49 Mev were obtained. The absolute cross sections per unit solid angle show the presence at all energies studied of higher order waves. A minimum in the scattering is observed near 90° at the low energies; the minimum shifts to larger angles with increasing energy. The cross sections at all angles decrease with increasing energy but the ratio of the cross section at 150° to the minimum increases gradually from 2.3 at 1.51 Mev to 3.0 at 3.49 Mev. The present results at 825 kev do not show the large anomaly found by Tuve, Heydenburg, and Hafstad at 830 kev.

R. Sherr; J. M. Blair; H. R. Kratz; C. L. Bailey; R. F. Taschek

1947-10-15T23:59:59.000Z

172

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

173

Analytic Expressions for the Statistics of the Primitive-Path Length in Entangled Polymers  

Science Journals Connector (OSTI)

An analytic expression is proposed for the primitive-path length of entangled polymer chains. The expression is derived from statistical mechanics of a chain that is a random walk with randomly scattered entanglements. The only parameters are the number of Kuhn steps in the chain and a dimensionless parameter ? that contains information about the entanglement density and Kuhn step size. The expression is found to compare very favorably with numerical results recently found from examining topological constraints in microscopic simulations. The comparison also predicts well the plateau modulus of polyethylene, suggesting that the slip-link model is a viable intermediate in the search for true ab initio rheology predictions. Since the expression is analytic, it can be used to make predictions where the simulations cannot reach, and hence is applicable for coarse graining.

Renat N. Khaliullin and Jay D. Schieber

2008-05-05T23:59:59.000Z

174

Explanation of the Random Lengths Framing Lumber Composite Price  

E-Print Network [OSTI]

Explanation of the Random Lengths Framing Lumber Composite Price May 10, 2006 The Random Lengths Framing Lumber Composite is a broad measure of price behavior in the U.S. framing lumber market) Western U.S., 2) Southern U.S., and 3) Canada. Thus, 33% of the Composite is comprised of Southern Pine

175

Microtubule length dependence of motor traffic in cells  

E-Print Network [OSTI]

In living cells, motor proteins, such as kinesin and dynein can move processively along microtubule (MT), and also detach from or attach to MT stochastically. Experiments have found that, the traffic of motor might be jammed, and various theoretical models have been designed to understand this traffic jam phenomenon. But previous studies mainly focus on motor attachment/detachment rate dependent properties. Recent experiment of Leduc {\\it et al.} found that the traffic jam formation of motor protein kinesin depends also on the length of MT [Proc. Natl. Acad. Sci. U.S.A. {\\bf 109}, 6100-6105 (2012)]. In this study, the MT length dependent properties of motor traffic will be analyzed. We found that MT length has one {\\it critical value} $N_c$, traffic jam occurs only when MT length $N>N_c$. The jammed length of MT increases with total MT length, while the non-jammed MT length might not change monotonically with the total MT length. The critical value $N_c$ increases with motor detachment rate from MT, but decreases with motor attachment rate to MT.

Yunxin Zhang

2012-05-18T23:59:59.000Z

176

Scaling of fracture length and distributed damage Vladimir Lyakhovsky  

E-Print Network [OSTI]

Scaling of fracture length and distributed damage Vladimir Lyakhovsky The Institute of Earth space scaling except linear relations between fracture length and displacements and thus the determination theoretically of the strength of a body or structure directly. Self-similarity of a fracture

Lyakhovsky, Vladimir

177

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

178

Electromagnetic wave scattering by Schwarzschild black holes  

E-Print Network [OSTI]

We analyze the scattering of a planar monochromatic electromagnetic wave incident upon a Schwarzschild black hole. We obtain accurate numerical results from the partial wave method for the electromagnetic scattering cross section, and show that they are in excellent agreement with analytical approximations. The scattering of electromagnetic waves is compared with the scattering of scalar, spinor and gravitational waves. We present a unified picture of the scattering of all massless fields for the first time.

Luís C. B. Crispino; Sam R. Dolan; Ednilton S. Oliveira

2009-05-20T23:59:59.000Z

179

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.

180

Scattering apodizer for laser beams  

DOE Patents [OSTI]

A method is disclosed for apodizing a laser beam to smooth out the production of diffraction peaks due to optical discontinuities in the path of the laser beam, such method comprising introduction of a pattern of scattering elements for reducing the peak intensity in the region of such optical discontinuities, such pattern having smoothly tapering boundaries in which the distribution density of the scattering elements is tapered gradually to produce small gradients in the distribution density, such pattern of scattering elements being effective to reduce and smooth out the diffraction effects which would otherwise be produced. The apodizer pattern may be produced by selectively blasting a surface of a transparent member with fine abrasive particles to produce a multitude of minute pits. In one embodiment, a scattering apodizer pattern is employed to overcome diffraction patterns in a multiple element crystal array for harmonic conversion of a laser beam. The interstices and the supporting grid between the crystal elements are obscured by the gradually tapered apodizer pattern of scattering elements.

Summers, Mark A. (Livermore, CA); Hagen, Wilhelm F. (Livermore, CA); Boyd, Robert D. (Livermore, CA)

1985-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "1-to-2-ft lengths scattered" 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

Scattering apodizer for laser beams  

DOE Patents [OSTI]

A method is disclosed for apodizing a laser beam to smooth out the production of diffraction peaks due to optical discontinuities in the path of the laser beam, such method comprising introduction of a pattern of scattering elements for reducing the peak intensity in the region of such optical discontinuities, such pattern having smoothly tapering boundaries in which the distribution density of the scattering elements is tapered gradually to produce small gradients in the distribution density, such pattern of scattering elements being effective to reduce and smooth out the diffraction effects which would otherwise be produced. The apodizer pattern may be produced by selectively blasting a surface of a transparent member with fine abrasive particles to produce a multitude of minute pits. In one embodiment, a scattering apodizer pattern is employed to overcome diffraction patterns in a multiple element crystal array for harmonic conversion of a laser beam. The interstices and the supporting grid between the crystal elements are obscured by the gradually tapered apodizer pattern of scattering elements.

Summers, M.A.; Hagen, W.F.; Boyd, R.D.

1984-01-01T23:59:59.000Z

182

Coherence lengths for three-dimensional superconductors in the BCS-Bose picture  

Science Journals Connector (OSTI)

Following an approach similar to that of Miyake or Randeria, Duan, and Shieh in two dimensions, we study a three-dimensional many-fermion gas at zero temperature interacting via some short-ranged two-body potential. To accommodate a possible singularity (e.g., the Coulomb repulsion) in the interaction, the potential is eliminated in favor of the two-body scattering t-matrix, the low-energy form of which is expressible in terms of the s-wave scattering length as. The BCS gap equation for s-wave pairing is then solved simultaneously with the number equation in order to self-consistently obtain the zero-temperature BCS gap ? as well as the chemical potential ? as functions of the dimensionless coupling variable ??kFas, where kF is the Fermi momentum. Results are valid for arbitrary coupling strength, and in the weak coupling limit reproduce the standard BCS results. Finally, root-mean-square pair sizes are obtained as a function of ? and compared with experimental values.

R. M. Carter; M. Casas; J. M. Getino; M. de Llano; A. Puente; H. Rubio; D. M. van der Walt

1995-12-01T23:59:59.000Z

183

Coherence length of cosmic background radiation enlarges the attenuation length of the ultra-high energy proton  

E-Print Network [OSTI]

It is pointed out that an agreement of the one particle energy spectrum of the cosmic background radiation (CMBR) with Plank distribution of 2.725 [K] does not give a strong constraint on the coherence length of CMBR if the mean free path of CMBR is very long. The coherence length in this situation is estimated as a few times of $k_BT$. Due to this finite coherence length, the attenuation length of ultra-high energy cosmic rays (UHECR) is reduced in the $\\Delta $ resonance region,i.e., around $10^{20}$ [eV]. The small attenuation length makes the suppression of the flux of cosmic rays in this energy region less prominent than the naive estimation

Kenzo Ishikawa; Yutaka Tobita

2008-01-21T23:59:59.000Z

184

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.

185

Nuclear-resonant electron scattering  

Science Journals Connector (OSTI)

We investigate nuclear-resonant electron scattering as occurring in the two-step process of nuclear excitation by electron capture (NEEC) followed by internal conversion. The nuclear excitation and decay are treated by a phenomenological collective model in which nuclear states and transition probabilities are described by experimental parameters. We present capture rates and resonant strengths for a number of heavy-ion collision systems considering various scenarios for the resonant electron-scattering process. The results show that for certain cases resonant electron scattering can have significantly larger resonance strengths than NEEC followed by the radiative decay of the nucleus. We discuss the impact of our findings on the possible experimental observation of NEEC.

Adriana Pálffy and Zoltán Harman

2008-04-04T23:59:59.000Z

186

Ramsauer-Townsend effect for electron scattering from gaseous CF4 molecules  

Science Journals Connector (OSTI)

Quantum scattering calculations are carried out down to very low energy for collisions of electrons with CF4 molecules in the gas phase. The interaction forces are obtained from ab initio data for the static interaction and through model potentials for the exchange and correlation-polarization effects. A numerical analysis is performed to evaluate the partial wave convergence behavior over the whole energy range, to assess the reliability of modified effective range theory close to zero energy, and to extract the value and the sign of the scattering length. A comparison with experiments and earlier calculations in the low-energy domain is also presented.

F. A. Gianturco and K. Willner

2007-06-27T23:59:59.000Z

187

Scattering, Inverse Scattering and Resonances in R Plamen Stefanov  

E-Print Network [OSTI]

Apr 18, 2013 ... material comes from the books and the lecture notes of Melrose [9] ... A few remarks about the Stationary Scattering Theory vi .... density on the unit sphere. .... Remember, we need a kernel that is a tempered function of ? for ? ...

2013-04-18T23:59:59.000Z

188

SCATTERING MATRICES AND SCATTERING GEODESICS OF LOCALLY SYMMETRIC SPACES  

E-Print Network [OSTI]

variables d'#19;energie. D#19;e#12;nissons pour cela les g#19;eod#19;esiques de scattering de l'une telle g#19;eod#19;esique le temps qu'elle passe dans un domaine compact #12;x#19;e. Nous prouvons que

Zworski, Maciej

189

Structural stability of transparent conducting films assembled from length purified single-wall carbon nanotubes  

SciTech Connect (OSTI)

Single-wall carbon nanotube (SWCNT) films show significant promise for transparent electronics applications that demand mechanical flexibility, but durability remains an outstanding issue. In this work, thin membranes of length purified single-wall carbon nanotubes (SWCNTs) are uniaxially and isotropically compressed by depositing them on prestrained polymer substrates. Upon release of the strain, the topography, microstructure, and conductivity of the films are characterized using a combination of optical/fluorescence microscopy, light scattering, force microscopy, electron microscopy, and impedance spectroscopy. Above a critical surface mass density, films assembled from nanotubes of well-defined length exhibit a strongly nonlinear mechanical response. The measured strain dependence reveals a dramatic softening that occurs through an alignment of the SWCNTs normal to the direction of prestrain, which at small strains is also apparent as an anisotropic increase in sheet resistance along the same direction. At higher strains, the membrane conductivities increase due to a compression-induced restoration of conductive pathways. Our measurements reveal the fundamental mode of elasto-plastic deformation in these films and suggest how it might be suppressed.

J. M. Harris; G. R. S. Iyer; D. O. Simien; J. A. Fagan; J. Y. Huh; J. Y. Chung; S. D. Hudson; J. Obrzut; J. F. Douglas; C. M. Stafford; E. K. Hobbie

2011-01-01T23:59:59.000Z

190

Hydrogen atom in momentum space with a minimal length  

E-Print Network [OSTI]

A momentum representation treatment of the hydrogen atom problem with a generalized uncertainty relation,which leads to a minimal length ({\\Delta}X_{i})_{min}= \\hbar \\sqrt(3{\\beta}+{\\beta}'), is presented. We show that the distance squared operator can be factorized in the case {\\beta}'=2{\\beta}. We analytically solve the s-wave bound-state equation. The leading correction to the energy spectrum caused by the minimal length depends on \\sqrt{\\beta}. An upper bound for the minimal length is found to be about 10^{-9} fm.

Djamil Bouaziz; Nourredine Ferkous

2010-09-05T23:59:59.000Z

191

Coherence Length of Cold Exciton Gases in Coupled Quantum Wells  

Science Journals Connector (OSTI)

A Mach-Zehnder interferometer with spatial and spectral resolution was used to probe spontaneous coherence in cold exciton gases, which are implemented experimentally in the ring of indirect excitons in coupled quantum wells. A strong enhancement of the exciton coherence length is observed at temperatures below a few Kelvin. The increase of the coherence length is correlated with the macroscopic spatial ordering of excitons. The coherence length at the lowest temperature corresponds to a very narrow spread of the exciton momentum distribution, much smaller than that for a classical exciton gas.

Sen Yang, A. T. Hammack, M. M. Fogler, L. V. Butov, and A. C. Gossard

2006-10-31T23:59:59.000Z

192

INSTRUMENTS-METHODS-36 Absorption and scattering lengths of high density silica aerogels with n = 1.07  

E-Print Network [OSTI]

angles could be the use of silica aerogels as radiator. Simultaneously, an aerogel ?erenkov counter is

L. Debenjak; P. Achenbach; J. Pochodzalla; T. Saito

193

Measurements of photon scattering lengths in scintillator and a test of the linearity of light yield as a function of  

E-Print Network [OSTI]

neutrinoless double beta decay and measure solar neutrinos and geoneutrinos. The type of particle by ap- proximately 9500 PMTs. For detections of neutrinoless double beta decay, the liquid scintillator double beta decay, low energy solar neutrinos, geo- neutrinos and supernova neutrinos using scintillation

Washington at Seattle, University of - Department of Physics, Electroweak Interaction Research Group

194

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.

195

Coherent scattering function in the reptation model: Analysis beyond asymptotic limits  

Science Journals Connector (OSTI)

We calculate the coherent dynamical scattering function Sc(q,t;N) of a flexible chain of length N, diffusing through an ordered background of topological obstacles. As an instructive generalization, we also calculate the scattering function Sc(q,t;M,N) for the central piece of length M<~N of the chain. Using the full reptation model, we treat global creep, tube length fluctuations, and internal relaxation within a consistent and unified approach. Our theory concentrates on the universal aspects of reptational motion, and our results in all details show excellent agreement with our simulations of the Evans-Edwards model, provided we allow for a phenomenological prefactor which accounts for nonuniversal effects of the microstructure of the Monte Carlo chain, present for short times. Previous approaches to the coherent structure function can be analyzed as special limits of our theory. First, the effects of internal relaxation can be isolated by studying the limit N??, M fixed. The results do not support the model of a “Rouse chain in a tube.” We trace this back to the nonequilibrium initial conditions of the latter model. Second, in the limit of long chains (M=N??) and times large compared to the internal relaxation time (t/N2??), our theory reproduces the results of the primitive chain model. This limiting form applies only to extremely long chains, and for chain lengths accessible in practice, effects of, e.g., tube length fluctuations are not negligible.

Lothar Schäfer, Ute Ebert, and Artur Baumgärtner

2002-06-21T23:59:59.000Z

196

Full-length Ebola glycoprotein accumulates in the endoplasmic reticulum  

Science Journals Connector (OSTI)

The Filoviridae family comprises of Ebola and Marburg viruses, which are known to ... pathogens. The envelope glycoprotein (GP) of Ebola virus, which mediates entry into target cells ... with full-length and muci...

Suchita Bhattacharyya; Thomas J Hope

2011-01-01T23:59:59.000Z

197

Word length and frequency as determinants of stuttering  

Science Journals Connector (OSTI)

Word length and Frequency were independently varied to assess their effect on stuttering frequency. The list of test words contained ... low, medium of high frequency of occurrence. Stuttering frequency of 31 you...

I. M. Schlesinger; Rachel Melkman; Ron Levy

1966-06-01T23:59:59.000Z

198

Fact #615: March 22, 2010 Average Vehicle Trip Length  

Broader source: Energy.gov [DOE]

According to the latest National Household Travel Survey, the average trip length grew to over 10 miles in 2009, just slightly over the 9.9 mile average in 2001. Trips to work in 2009 increased to...

199

Cholesteric helical pitch of near persistence length DNA  

Science Journals Connector (OSTI)

Cholesteric helical pitch of near persistence length DNA ... We report measurements of the cholesteric pitch and twist elastic constant (K22) in monodisperse suspensions of the rodlike virus filamentous bacteriophage fd. ...

David H. Van Winkle; Michael W. Davidson; Wan Xu Chen; Randolph L. Rill

1990-09-01T23:59:59.000Z

200

Complete Variable-Length \\Fix-Free" Codes David Gillman  

E-Print Network [OSTI]

Complete Variable-Length \\Fix-Free" Codes David Gillman Institute for Mathematics & Its-free codes Supported by NSF grant 9212184-CCR and Darpa contract N00014-92-J-1799. Email address: gillman

Rivest, Ronald L.

Note: This page contains sample records for the topic "1-to-2-ft lengths scattered" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Inferring the Rate-Length Law of Protein Folding  

E-Print Network [OSTI]

We investigate the rate-length scaling law of protein folding, a key undetermined scaling law in the analytical theory of protein folding. We demonstrate that chain length is a dominant factor determining folding times, and that the unambiguous determination of the way chain length corre- lates with folding times could provide key mechanistic insight into the folding process. Four specific proposed laws (power law, exponential, and two stretched exponentials) are tested against one an- other, and it is found that the power law best explains the data. At the same time, the fit power law results in rates that are very fast, nearly unreasonably so in a biological context. We show that any of the proposed forms are viable, conclude that more data is necessary to unequivocally infer the rate-length law, and that such data could be obtained through a small number of protein folding experiments on large protein domains.

Lane, Thomas J

2013-01-01T23:59:59.000Z

202

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

203

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

204

Pauli Principle and Pion Scattering  

DOE R&D Accomplishments [OSTI]

It is pointed out that if the Pauli principle is taken into account in the discussion of pion scattering by complex nuclei (as it ought, of course, to be) some rather implausible consequences of some earlier treatments of this problem can be avoided. (auth)

Bethe, H. A.

1972-10-00T23:59:59.000Z

205

Treatment options for tank farms long-length contaminated equipment  

SciTech Connect (OSTI)

This study evaluated a variety of treatment and disposal technologies for mixed waste (MW) meeting the following criteria: 1. Single-Shell and Double-Shell Tank System (tank farms) equipment and other debris; 2. length greater than 12 feet; and contaminated with listed MW from the tank farms. This waste stream, commonly referred to as tank farms long-length contaminated equipment (LLCE), poses a unique and costly set of challenges during all phases of the waste management lifecycle.

Josephson, W.S.

1995-10-16T23:59:59.000Z

206

Self-aligned submicron gate length gallium arsenide MESFET  

E-Print Network [OSTI]

SELF-ALIGNED SUBMICRON GATE LENGTH GALLIUM ARSENIDE MESFET A Thesis by HSIEN-CHING HUANG Submitted to the Graduate College of Texas ASSAM University in partial fulfillment of the requirement for the degree ol' MASTER OF SCIENCE May 1987... Major Subject: Electrical Engineering SELF-ALIGNED SUBMICRON GATE LENGTH GALLIUM ARSENIDE MESFET A Thesis by HSIEN-CHING HUANG Approved as to style and content by: Mark. H. Weichold (Chairman of Committee) Donald L. Parker (Member) dali L...

Huang, Hsien-Ching

2012-06-07T23:59:59.000Z

207

Hydrogen-atom spectrum under a minimal-length hypothesis  

E-Print Network [OSTI]

The energy spectrum of the Coulomb potential with minimal length commutation relations $[X_i, P_j] = i\\hbar\\{\\delta_{ij}(1+\\beta P^2) + \\beta'P_iP_j\\}$ is determined both numerically and perturbatively for arbitrary values of $\\beta'/\\beta$ and angular momenta $\\ell$. The constraint on the minimal length scale from precision hydrogen spectroscopy data is of order of a few GeV$\

Sandor Benczik; Lay Nam Chang; Djordje Minic; Tatsu Takeuchi

2005-07-08T23:59:59.000Z

208

Three-dimensional reconstruction of liquid phases in disordered mesopores using in situ small-angle scattering  

Science Journals Connector (OSTI)

In situ synchrotron small-angle X-ray scattering is used to investigate wetting transitions of liquids confined in disordered mesoporous materials. A plurigaussian stochastic model is proposed, which enables one to analyze the data in terms of changing interface areas, contact angle and triple-line length.

Gommes, C.J.

2013-03-14T23:59:59.000Z

209

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...

210

Characterization of Light Scattering in Transparent Polycrystalline Laser Ceramics  

E-Print Network [OSTI]

promotes the identification of bulk scattering and defectsfailure. Previously, identification of bulk scatter in PLMaccurate identification and characterization of bulk scatter

Sharma, Saurabh

2013-01-01T23:59:59.000Z

211

Antenna mechanism of length control of actin cables  

E-Print Network [OSTI]

Actin cables are linear cytoskeletal structures that serve as tracks for myosin-based intracellular transport of vesicles and organelles in both yeast and mammalian cells. In a yeast cell undergoing budding, cables are in constant dynamic turnover yet some cables grow from the bud neck toward the back of the mother cell until their length roughly equals the diameter of the mother cell. This raises the question: how is the length of these cables controlled? Here we describe a novel molecular mechanism for cable length control inspired by recent experimental observations in cells. This antenna mechanism involves three key proteins: formins, which polymerize actin, Smy1 proteins, which bind formins and inhibit actin polymerization, and myosin motors, which deliver Smy1 to formins, leading to a length-dependent actin polymerization rate. We compute the probability distribution of cable lengths as a function of several experimentally tuneable parameters such as the formin-binding affinity of Smy1 and the concentration of myosin motors delivering Smy1. These results provide testable predictions of the antenna mechanism of actin-cable length control.

Lishibanya Mohapatra; Bruce L. Goode; Jane Kondev

2014-11-15T23:59:59.000Z

212

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

213

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...

214

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...

215

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 Schöttl; Konrad Siemensmeyer; Vitaliy Boyko…

2002-01-01T23:59:59.000Z

216

Coherent scattering from a free gas  

E-Print Network [OSTI]

We investigate decoherence in atom interferometry due to scattering from a background gas and show that the supposition that residual coherence is due to near-forward scattering is incorrect. In fact, the coherent part is ...

Sanders, Scott N.

217

Purdue University :: College of Science :: Scattering, Imaging ...  

E-Print Network [OSTI]

... inverse scattering in media of low regularity, highly discontinuous and random media - structured matrix based methods, and massively parallel algorithms

218

Scattering Anisotropies in n-Type Silicon  

Science Journals Connector (OSTI)

Measurements have been made of magnetoresistance effects in several relatively pure samples of n-type silicon for the purpose of obtaining information on scattering anisotropies. The results indicate that the ratios of relaxation times parallel and perpendicular to a constant-energy-spheroid axis in the six-valley conduction band of silicon are ?II???23 for acoustic-mode intravalley lattice scattering and ?II??>1 for ionized-impurity scattering. Intervalley lattice scattering, important at higher temperatures, is isotropic.

Donald Long and John Myers

1960-10-01T23:59:59.000Z

219

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

220

Magnetic field dependence of the coherence length and penetration depth of MgB2 single crystals T. Klein,1,2 L. Lyard,1 J. Marcus,1 Z. Holanova,1 and C. Marcenat3  

E-Print Network [OSTI]

Magnetic field dependence of the coherence length and penetration depth of MgB2 single crystals T with a phenomenological Ginzburg-Landau model introducing field dependent parameters i.e., penetration depth and which scattering form factor, and muon spin relaxation rate. DOI: 10.1103/PhysRevB.73.184513 PACS number s : 74

Boyer, Edmond

Note: This page contains sample records for the topic "1-to-2-ft lengths scattered" 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

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.

222

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

223

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

224

Studies in Small Angle Scattering Techniques  

E-Print Network [OSTI]

. Knud Møllenbach Abstract. Small angle scattering of neutrons, x-rays and y-rays are found among scattering as well as small angle y-ray diffraction. The study of neutron scat- tering from formations limit of the neutron diffractometer 20 3. SMALL ANGLE SCATTERING INSTRUMENTS 22 3.1. The double crystal

225

Feature Article NEXAFS microscopy and resonant scattering  

E-Print Network [OSTI]

and conven- tional electron, X-ray and neutron scattering. We provide an overview of these synchrotron based and derivative struc- tures, ranging from spectroscopy to mechanical analysis and neutron scattering [9,10]. SomeFeature Article NEXAFS microscopy and resonant scattering: Composition and orientation probed

Hitchcock, Adam P.

226

| 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.

227

Absorption and scattering images of heterogeneous scattering media can be simultaneously reconstructed  

E-Print Network [OSTI]

Absorption and scattering images of heterogeneous scattering media can be simultaneously designed phantom experimental study aimed to provide solid evidence that both absorption and scattering the important absorption­scattering cross-talk issue. In this regard, we develop a simple normalizing scheme

Khan, Taufiquar R.

228

Neutron-Proton Scattering below 20 MeV  

Science Journals Connector (OSTI)

Critical examination and analysis of existing n-p scattering data below 20 MeV reveal that they provide quantitative information only about the S-wave scattering lengths and effective ranges, which are found to be at=5.396±0.011 F; as=-23.678±0.028 F; rt=1.726±0.014 F; rs=2.51±0.11±0.043 F; where the second error quoted for rs is a conservative estimate of the uncertainty due to departures from the shape-independent approximation. The correlations in error are ??at?as?=-0.7828?at?as; ??at?rs?=-0.8547?at?rs; ??as?rs?=0.7029?as?rs. An estimate of the contribution to the total cross section from scattering in higher angular momentum states, based on model calculations, p-p phases, and the cos? term in the differential cross section, allows the deviation from the shape-independent approximation to be computed at 14.1 and 19.665 MeV from total cross-section measurements. It is shown on theoretical grounds that this must come almost entirely from the S01 state, and extreme limits to this variation are established. The value found is close to zero at both energies, in accord with theoretical expectations, but the uncertainty is so large that it barely excludes the extreme limits. Some qualitative evidence for or against the existence of the long-range one pion exchange interaction in this state could be obtained by improving the experiments below 5 MeV, but the uncertainty arising from the non-S wave scattering precludes any but qualitative results. It is shown that this uncertainty cannot be removed by improved measurement of the differential cross section because 8 independent pieces of experimental information are required. We conclude that the energy variation of the S waves below 20 MeV cannot be measured without recourse to experiments which separate the spin states of the particles, such as spin-correlation, triple scattering, polarized-beam polarized-target, etc. If some information is taken from p-p scattering and some from theory, a single such measurement in each system might suffice; this minimal program is briefly discussed.

H. Pierre Noyes

1963-06-01T23:59:59.000Z

229

Property:Maximum Wave Length(m) | Open Energy Information  

Open Energy Info (EERE)

Wave Length(m) Wave Length(m) Jump to: navigation, search Property Name Maximum Wave Length(m) Property Type String Pages using the property "Maximum Wave Length(m)" Showing 18 pages using this property. A Alden Small Flume + Variable + Alden Wave Basin + 1.8 + C Carderock Maneuvering & Seakeeping Basin + 12.2 + Carderock Tow Tank 2 + 12.2 + Carderock Tow Tank 3 + 12.2 + D Davidson Laboratory Tow Tank + 15.2 + DeFrees Large Wave Basin + 64 + DeFrees Small Wave Basin + 30 + H Haynes Wave Basin + 10.7 + L Lakefront Tow Tank + 22 + M MIT Tow Tank + 4.6 + O OTRC Wave Basin + 25 + Ohmsett Tow Tank + 18 + R Richmond Field Station Tow Tank + 2 + S SAFL Channel + 6.6 + Sandia Lake Facility + 4.57 + Sheets Wave Basin + 10 + Ship Towing Tank + 6 + Retrieved from "http://en.openei.org/w/index.php?title=Property:Maximum_Wave_Length(m)&oldid=597351

230

Isotropic-nematic phase behavior of length polydisperse hard rods  

E-Print Network [OSTI]

The isotropic-nematic phase behavior of length polydisperse hard rods with arbitrary length distributions is calculated. Within a numerical treatment of the polydisperse Onsager model using the Gaussian trial function Ansatz we determine the onset of isotropic-nematic phase separation, coming from a dilute isotropic phase and a dense nematic phase. We focus on parent systems whose lengths can be described by either a Schulz or a `fat-tailed' log-normal distribution with appropriate lower and upper cutoff lengths. In both cases, very strong fractionation effects are observed for parent polydispersities larger than roughly 50 %. In these regimes, the isotropic and nematic phases are completely dominated by respectively the shortest and the longest rods in the system. Moreover, for the log-normal case, we predict triphasic isotropic-nematic-nematic equilibria to occur above a certain threshold polydispersity. By investigating the properties of the coexisting phases across the coexistence region for a particular set of cutoff lengths we explicitly show that the region of stable triphasic equilibria does not extend up to very large parent polydispersities but closes off at a consolute point located not far above the threshold polydispersity. The experimental relevance of the phenomenon is discussed.

H. H. Wensink; G. J. Vroege

2003-04-18T23:59:59.000Z

231

Two Permanently Congruent Rods May Have Different Proper Lengths  

E-Print Network [OSTI]

We scrutinize congruence as one of the basic definitions of equality in geometry and pit it against physics of Special Relativity. We show that two non-rigid rods permanently kept congruent during their common expansion or compression may have different instantaneous proper lengths (when measured at the same time of their respective reference clocks) if they have different mass distributions over their lengths. Alternatively, their proper lengths can come out equal only when measured at different but strictly correlated moments of time of their respective clocks. The derived expression for the ratio of instantaneous proper lengths of two permanently congruent changing objects explicitly contains information about the objects mass distribution. The same is true for the ratio of readings of the two reference clocks, for which the instantaneous measurements of respective proper lengths produce the same result. In either case the characteristics usually considered as purely kinematic depend on mass distribution, which is a dynamic property. This is a spectacular demonstration of dynamic aspect of geometry already in the framework of Special Relativity.

Moses Fayngold

2008-07-06T23:59:59.000Z

232

Patch-repetition correlation length in glassy systems  

E-Print Network [OSTI]

We obtain the patch-repetition entropy Sigma within the Random First Order Transition theory (RFOT) and for the square plaquette system, a model related to the dynamical facilitation theory of glassy dynamics. We find that in both cases the entropy of patches of linear size l, Sigma(l), scales as s_c l^d+A l^{d-1} down to length-scales of the order of one, where A is a positive constant, s_c is the configurational entropy density and d the spatial dimension. In consequence, the only meaningful length that can be defined from patch-repetition is the cross-over length xi=A/s_c. We relate xi to the typical length-scales already discussed in the literature and show that it is always of the order of the largest static length. Our results provide new insights, which are particularly relevant for RFOT theory, on the possible real space structure of super-cooled liquids. They suggest that this structure differs from a mosaic of different patches having roughly the same size.

Chiara Cammarota; Giulio Biroli

2012-01-10T23:59:59.000Z

233

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

234

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

235

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 +0.55×10-12 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, -0.34×10-12 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

236

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

237

Cable length optimization for trawl fuel consumption reduction  

Science Journals Connector (OSTI)

A numerical method for optimization of the cable lengths in trawls with respect to the ratio between the estimated trawl drag and the predicted catch efficiency is developed and applied. The trawl cables of interest are warps, bridles, headline and footrope. The optimization algorithm applies an ordered sequential process changing one cable length at the time. It is assumed in the predictions that the catch efficiency of the trawl is proportional with the trawl mouth area. In a case study optimizing a bottom trawl used on a research vessel by applying the new method it is predicted that it would be possible to reduce the ratio between trawl drag and catch efficiency by up to 46% by optimizing the cable lengths. Thus this would enable a considerable reduction in fuel consumption to catch a specific amount of fish. Moreover, we predict an increase in the value of the trawl mouth area leading to better catching efficiency without increase in otter door drag.

Ramez Khaled; Daniel Priour; Jean-Yves Billard

2013-01-01T23:59:59.000Z

238

Conservation of bond lengths in strained Ge-Si layers  

Science Journals Connector (OSTI)

The combined techniques of x-ray-absorption fine structure and x-ray diffraction have been used to study the strain and bond distortions in epitaxial Ge-Si on Si(001). In a 31% Ge, 340-Å pseudomorphic Ge-Si film, the Ge-Ge and Ge-Si first-neighbor bond lengths have been found to be 2.44±0.02 and 2.38±0.02 Å, respectively. The lattice parameter perpendicular to the Ge-Si/Si(001) interface has been found to be a?=5.552±0.002 Å, in agreement with the predictions of macroscopic elastic theory. These results show that the bond-length strain in the epitaxial layer appears in the second and higher coordination shells, rather than in the nearest-neighbor bond lengths, which remain the same as in unstrained Ge-Si. A microscopic model is presented that accounts for these findings.

J. C. Woicik; C. E. Bouldin; M. I. Bell; J. O. Cross; D. J. Tweet; B. D. Swanson; T. M. Zhang; L. B. Sorensen; C. A. King; J. L. Hoyt; P. Pianetta; J. F. Gibbons

1991-01-15T23:59:59.000Z

239

Pumping current of a Luttinger liquid with finite length  

E-Print Network [OSTI]

We study transport properties in a Tomonaga-Luttinger liquid in the presence of two time-dependent point like weak impurities, taking into account finite-length effects. By employing analytical methods and performing a perturbation theory, we compute the backscattering pumping current (I_bs) in different regimes which can be established in relation to the oscillatory frequency of the impurities and to the frequency related to the length and the renormalized velocity (by the electron-electron interactions) of the charge density modes. We investigate the role played by the spatial position of the impurity potentials. We also show how the previous infinite length results for I_bs are modified by the finite size of the system.

Sebastián Franchino Viñas; Pablo Pisani; Mariano Salvay

2012-03-16T23:59:59.000Z

240

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. Patrão; E. S. Fonseca; C. L. P. Mauricio

2014-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "1-to-2-ft lengths scattered" 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

Material Effects and Detector Response Corrections for Bunch Length Measurements  

SciTech Connect (OSTI)

A typical diagnostic used to determine the bunch length of ultra-short electron bunches is the auto-correlation of coherent transition radiation. This technique can produce artificially short bunch length results due to the attenuation of low frequency radiation if corrections for the material properties of the Michelson interferometer and detector response are not made. Measurements were taken using FTIR spectroscopy to determine the absorption spectrum of various materials and the response of a Molectron P1-45 pyroelectric detector. The material absorption data will be presented and limitations on the detector calibration discussed.

Zacherl, W.; Blumenfeld, I.; Berry, M.; Decker, F.-J.; Hogan, M.J.; Ischebeck, R.; Iverson, R.; Kirby, N.; Siemann, R.; Walz, D.; /SLAC; Clayton, C.E.; Huang, C.; Joshi, C.; Lu, W.; Marsh, K.A.; Mori, W.B.; Zhou, M.; /UCLA; Katsouleas, T.C.; Muggli, P.; Oz, E.; /Southern California U.

2007-06-28T23:59:59.000Z

242

Chaos in a well : Effects of competing length scales  

E-Print Network [OSTI]

A discontinuous generalization of the standard map, which arises naturally as the dynamics of a periodically kicked particle in a one dimensional infinite square well potential, is examined. Existence of competing length scales, namely the width of the well and the wavelength of the external field, introduce novel dynamical behaviour. Deterministic chaos induced diffusion is observed for weak field strengths as the length scales do not match. This is related to an abrupt breakdown of rotationally invariant curves and in particular KAM tori. An approximate stability theory is derived wherein the usual standard map is a point of ``bifurcation''.

R. Sankaranarayanan; A. Lakshminarayan; V. B. Sheorey

2000-05-17T23:59:59.000Z

243

Behavior of sigma(gamma p) at Large Coherence Lengths  

E-Print Network [OSTI]

Various parametrizations of sigma(gamma p) are tried out on the small-x fixed target and HERA data. A two-Pomeron type parametrization is found to give the best reproduction of the data. The data indicate that the value of lambda(eff) for parametrizations of the form sigma(gamma p)~l^lambda(eff) approaches a constant value at high Q^2. The extrapolated values of sigma(gamma p) to very long coherence lengths are found to cross in some parametrizations for l>10^7 fm, indicating the possibility that sigma(gamma p) becomes Q^2 independent at large values of the coherence length l.

Allen Caldwell

2008-02-06T23:59:59.000Z

244

Temporal coherence length of light in semiclassical field theory models  

SciTech Connect (OSTI)

The following work is motivated by the conceptual problems associated with the wave-particle duality and the notion of the photon. Two simple classical models for radiation from individual emitters are compared, one based on sines with random phasejumps, another based on pulse trains. The sum signal is calculated for a varying number of emitters. The focus lies on the final signal's statistical features quantified by means of the temporal coherence function and the temporal coherence length. We show how these features might be used to experimentally differentiate between the models. We also point to ambiguities in the definition of the temporal coherence length.

Jagielski, Borys; Lein, Johanne; Inge Vistnes, Arnt [Quantum Optics Laboratory, Department of Physics, University of Oslo, P.O. Box 1048 Blindern, 0316 Oslo (Norway)

2011-03-28T23:59:59.000Z

245

Past and Future Blurring at Fundamental Length Scale  

SciTech Connect (OSTI)

We obtain the {kappa}-deformed versions of the retarded and advanced Green functions and show that their causality properties are blurred in a time interval of the order of a length parameter q=1/(2{kappa}). The functions also indicate a smearing of the light cone. These results favor the interpretation of q as a fundamental length scale below which the concept of a point in space-time should be substituted by the concept of a fuzzy region of radius q, as proposed long ago by Heisenberg.

Neves, M. J. [Centro Brasileiro de Pesquisas Fisicas, Rua Dr. Xavier Sigaud 150, Urca, Rio de Janeiro, RJ, 22290-180 (Brazil); Farina, C.; Cougo-Pinto, M. V. [Instituto de Fisica, UFRJ, CP 68528, Rio de Janeiro, RJ, 21941-972 (Brazil)

2010-11-19T23:59:59.000Z

246

Measurements of magnetic screening lengths in superconducting Nb thin films by polarized neutron reflectometry  

Science Journals Connector (OSTI)

Polarized neutron reflectivity measurements have been performed on two polycrystalline niobium films grown on silicon substrates. The samples were characterized with x-ray diffraction and reflection, electrical resistivity, and unpolarized neutron reflection measurements. For the film of 310 nm thickness, polarized neutron reflectivity measurements were carried out on both the Si side as well as the vacuum side, and we found that substantially higher quality data could be obtained from the Si side due to the enhanced contrast between the weak diamagnetic scattering and the nuclear scattering from the films. A large number of interference fringes from the waves reflected from the front and back surfaces of the film could be observed, attesting to the high quality and flatness of the sample. The vacuum-Nb interface had a surface roughness of ??3.4 nm, while the Nb-Si interface was nearly atomically smooth. We also carried out an experiment on a 300 nm-thick film of YBa2Cu3O7, but the roughness was so severe that no interference fringes could be observed, and reliable measurements of ? could not be obtained. The magnetic screening length for the Nb films was measured to be ?=110±2 nm for the sample with an electron mean free path l=10 nm, and ?=55±2 nm for the sample with l=35 nm. Taking into account the effects of crystalline defects and impurities, we obtain the intrinsic London penetration depth in superconducting Nb to be ?L=43±8 nm at T=4.5 K. This result is in good agreement with that of Felcher et al.

Huai Zhang; J. W. Lynn; C. F. Majkrzak; S. K. Satija; J. H. Kang; X. D. Wu

1995-10-01T23:59:59.000Z

247

LENGTH-SCALE DEPENDENT CRACK-GROWTH Lars Pilgaard Mikkelsen  

E-Print Network [OSTI]

length scale is present a large influence on the local stress field is expected. In addition, for strong: Interface Design of Polymer Matrix Composites ­ Mechanics, Chemistry, Modelling and Manufacturing Editors: B is modeled for an elastic-plastic material loading in pure mode I. In addition, the strain gradient dependent

248

TRANSGENIC COTTON WITH IMPROVED FIBER MICRONAIRE, STRENGTH, AND LENGTH AND  

E-Print Network [OSTI]

483 TRANSGENIC COTTON WITH IMPROVED FIBER MICRONAIRE, STRENGTH, AND LENGTH AND INCREASED FIBER. Keating, N. G. Srinivas, C. Wu and A. S. Holaday Texas Tech University Lubbock, TX G. J. Jividen Cotton Incorporated Raleigh, NC Abstract We set out to use genetic engineering to make cotton crop yield and fiber

Strauss, Richard E.

249

ATP Hydrolysis Stimulates Large Length Fluctuations in Single Actin Filaments  

E-Print Network [OSTI]

ATP Hydrolysis Stimulates Large Length Fluctuations in Single Actin Filaments Evgeny B. Stukalin is investigated theoretically using a stochastic model that takes into account the hydrolysis of ATP filaments. It is found that the ATP hydrolysis has a strong effect on dynamic properties of single actin

250

Tuning a short coherence length Josephson junction through a  

E-Print Network [OSTI]

Tuning a short coherence length Josephson junction through a metal-insulator transition J. K University, Josephson Junction talk, 2001 #12;Josephson Tunnel Junctions · A Superconductor maintaining nonhysteretic behavior. J. K. Freericks, Georgetown University, Josephson Junction talk, 2001 S N

Freericks, Jim

251

Dynamic core length in saturated core fault current limiters  

Science Journals Connector (OSTI)

A saturated core fault current limiter (SCFCL) is a non-linear core-reactor where the core is saturated by an external superconducting DC bias source to achieve a low core permeability at nominal AC currents. Fault current levels in the AC coils de-saturate the core and transform it to a higher permeability state, hence limiting the fault current. In this work we describe the transition between saturated and de-saturated states in three SCFCL configurations. The 'effective core length', Leff, of the SCFCL, defined as the length of the de-saturated AC core limb, is introduced for exploring this transition as a function of the current, I, in the AC coil. Practically, Leff allows one to see the SCFCL as an inductor with a variable core length, allowing calculations of the impedance of the SCFCL over the whole range of operating currents. The Leff(I) curve is further used to calculate the dynamics of the demagnetization factor in a SCFCL. We show that the strong change in the magnetic induction of a SCFCL at high current is the result of both increasing the effective core length and decreasing the demagnetization factor. The method and results presented here serve as an important tool for comparing between various SCFCL concepts not only by comparing their impedance values at the extreme fault and nominal current conditions but also by providing an insight into the full de-saturation process.

Y Nikulshin; Y Wolfus; A Friedman; Y Yeshurun

2013-01-01T23:59:59.000Z

252

Document Normalization Revisited Cosine Pivoted Document Length Normalization has  

E-Print Network [OSTI]

submitted results to the TREC-10 web track. 2. Calibrating the Slope for Ad Hoc Task Using pivoted documentDocument Normalization Revisited Abstract Cosine Pivoted Document Length Normalization has reached for the document collection degrades average precision by as much as 20%. 1. Introduction The cosine measure

253

Introduction Fracture at small length scales is a concern  

E-Print Network [OSTI]

Introduction Fracture at small length scales is a concern in many advanced technologies. Micro. These constrained geometries localize cracking so that fracture may not compromise the structural integrity functions. For example, lo- calized fracture of a dielectric film adjacent to a conducting line

Suo, Zhigang

254

DATA AVAILABILITY, LANDINGS, AND LENGTH TRENDS OF CALIFORNIA'S ROCKFISH  

E-Print Network [OSTI]

the 1980- 1989 data to fork length using standard conversion factors from Echeverria and Lenarz (1984). For those species which did not have conversion factors, conversion factors from a similarly shaped species factors from Echeverria and Lenarz (1984). For the few species where conversions were not available

255

IE 361 Module 15 The Average Run Length Concept  

E-Print Network [OSTI]

IE 361 Module 15 The Average Run Length Concept Reading: Section 3.5 of Statistical Quality Assurance Methods for Engineers Prof. Steve Vardeman and Prof. Max Morris Iowa State University Vardeman Electric set of alarm rules to a control charting scheme? The most e¤ective means known for making

Vardeman, Stephen B.

256

Multiphonon Raman scattering in graphene  

Science Journals Connector (OSTI)

We report on multiphonon Raman scattering in graphene samples. Higher-order combination modes involving three and four phonons are observed in single-layer, bilayer, and few-layer graphene samples prepared by mechanical exfoliation. The intensity of the higher-order phonon modes (relative to the G peak) is highest in single-layer graphene and decreases with increasing layers. In addition, all higher-order modes are observed to upshift in frequency almost linearly with increasing graphene layers, betraying the underlying interlayer van der Waals interactions.

Rahul Rao; Derek Tishler; Jyoti Katoch; Masa Ishigami

2011-09-12T23:59:59.000Z

257

Completeness for sparse potential scattering  

SciTech Connect (OSTI)

The present paper is devoted to the scattering theory of a class of continuum Schrödinger operators with deterministic sparse potentials. We first establish the limiting absorption principle for both modified free resolvents and modified perturbed resolvents. This actually is a weak form of the classical limiting absorption principle. We then prove the existence and completeness of local wave operators, which, in particular, imply the existence of wave operators. Under additional assumptions on the sparse potential, we prove the completeness of wave operators. In the context of continuum Schrödinger operators with sparse potentials, this paper gives the first proof of the completeness of wave operators.

Shen, Zhongwei, E-mail: zzs0004@auburn.edu [Department of Mathematics and Statistics, Auburn University, Auburn, Alabama 36849 (United States)] [Department of Mathematics and Statistics, Auburn University, Auburn, Alabama 36849 (United States)

2014-01-15T23:59:59.000Z

258

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

259

Determination of interfacial roughness using X-ray scattering  

SciTech Connect (OSTI)

Crystal truncation rod (CTR) scattering is shown to be a powerful technique for determining interfacial roughness non-destructively. By measuring the decay of scattering away from a Bragg reflection in the surface direction an rms roughness of the surface or interface can be extracted. The authors obtain rms roughness values with an accuracy of {+-} 0.1 {angstrom}. Sensitivity to lateral length scale roughness ranges from the wavelength of the x-rays to between 1,000--10,000 {angstrom} depending on the instrument function and the specific truncation rod. The influence of different cleans, as well as the thermal oxidation process, on the Si-SiO{sub 2} interface is investigated. A hot water treatment prior to the thermal oxidation is shown to roughen the Si-SiO{sub 2} interface. CTR scattering results also show a smoothing of the interface as a result of the oxidation process even for as little as 60 {angstrom} of thermal oxidation. Comparison between AFM and CTR scattering gives a consistent picture of the relative roughness of the wafers, although the absolute numbers do not agree. The differences in the absolute values can be explained by the lateral roughness scale that the two techniques measure, indicating that it is at periodicities below {approx} 100 {angstrom} that the increased roughness observed by the x-ray is found. Crystal truncation rods are shown to be perpendicular to the surface and not along the crystallographic axes of a miscut crystal. It is shown that for a crystal terminated by a regular step array both an atomistic and a continuum description of CTR scattering give identical results. Furthermore, the atomistic approach is used to show that a diamond cubic surface with a miscut is inherently rough. Even for a small miscut the tilt of the CTR with respect to the crystallographic axes results in complications for measuring the rod intensity. The authors present schemes for determining the exact position of the CTR in reciprocal space and for measuring the miscut of a single crystal. These methods were applied to the measurement of CTR intensities of silicon(001) wafers with miscuts of 0.1 and 4 degrees.

Munkholm, A.

1997-05-01T23:59:59.000Z

260

Evaluation of the relationship between fracture conductivity, fracture fluid production, and effective fracture length  

E-Print Network [OSTI]

Low-permeability gas wells often produce less than predicted after a fracture treatment. One of the reasons for this is that fracture lengths calculated after stimulation are often less than designed lengths. While actual fracture lengths may...

Lolon, Elyezer P.

2006-04-12T23:59:59.000Z

Note: This page contains sample records for the topic "1-to-2-ft lengths scattered" 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

Small Angle X-Ray Scattering Detector  

DOE Patents [OSTI]

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

Hessler, Jan P.

2004-06-15T23:59:59.000Z

262

Thomson scattering measurements in atmospheric plasma jets  

Science Journals Connector (OSTI)

Electron temperature and electron density in a dc plasma jet at atmospheric pressure have been obtained using Thomson laser scattering. Measurements performed at various scattering angles have revealed effects that are not accounted for by the standard scattering theory. Differences between the predicted and experimental results suggest that higher order corrections to the theory may be required, and that corrections to the form of the spectral density function may play an important role.

G. Gregori; J. Schein; P. Schwendinger; U. Kortshagen; J. Heberlein; E. Pfender

1999-02-01T23:59:59.000Z

263

Polarization of Nucleons Elastically Scattered by Nuclei  

Science Journals Connector (OSTI)

The polarization of 424-Mev nucleons elastically scattered by nuclei is calculated by a method which is similar to the Born approximation, but in which the phase shifts of the incident plane wave due to the scattering potential is taken into consideration. A qualitative agreement with the experimental result is obtained if one uses the well parameters determined by Riesenfeld and Watson. Poor agreement at the diffraction minimum may be attributed to the existence of inelastic scattering in the experimental data.

Keiichi Nishimura

1958-06-01T23:59:59.000Z

264

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

265

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 Å-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 (5–300 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

266

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 Maxwell—Boltzmann 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

267

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

268

Pion scattering and nuclear dynamics  

SciTech Connect (OSTI)

A phenomenological optical-model analysis of pion elastic scattering and single- and double-charge-exchange scattering to isobaric-analog states is reviewed. Interpretation of the optical-model parameters is briefly discussed, and several applications and extensions are considered. The applications include the study of various nuclear properties, including neutron deformation and surface-fluctuation contributions to the density. One promising extension for the near future would be to develop a microscopic approach based on powerful momentum-space methods brought to existence over the last decade. In this, the lowest-order optical potential as well as specific higher-order pieces would be worked out in terms of microscopic pion-nucleon and delta-nucleon interactions that can be determined within modern meson-theoretical frameworks. A second extension, of a more phenomenological nature, would use coupled-channel methods and shell-model wave functions to study dynamical nuclear correlations in pion double charge exchange. 35 refs., 11 figs., 1 tab.

Johnson, M.B.

1988-01-01T23:59:59.000Z

269

INVERSE SCATTERING PROBLEMS WITH MULTI-FREQUENCIES ...  

E-Print Network [OSTI]

variational problem is studied for the direct scattering; an energy estimate is given ..... It follows from Green's formula and the adjoint problem (2.23) that we have.

2015-01-25T23:59:59.000Z

270

Fast methods for inverse wave scattering problems  

E-Print Network [OSTI]

Inverse wave scattering problems arise in many applications including computerized/diffraction tomography, seismology, diffraction/holographic grating design, object identification from radar singals, and semiconductor ...

Lee, Jung Hoon, Ph. D. Massachusetts Institute of Technology

2008-01-01T23:59:59.000Z

271

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...

272

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

273

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

274

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

275

Granular Structure Determined by Terahertz Scattering  

E-Print Network [OSTI]

Light-scattering in the terahertz region is demonstrated for granular matter. A quantum-cascade laser is used in a benchtop setup to determine the angle-dependent scattering of spherical grains as well as coffee powder and sugar grains. For the interpretation of the form factors for the scattering from single particles one has to go beyond the usual Rayleigh-Gans-Debye theory and apply calculations within Mie theory. In addition to single scattering also collective correlations can be identified and extracted as a static structure factor.

Philip Born; Nick Rothbart; Matthias Sperl; Heinz-Wilhelm Hübers

2013-12-23T23:59:59.000Z

276

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. Böni; G. Shirane

1985-01-01T23:59:59.000Z

277

Development of KSTAR Thomson scattering system  

SciTech Connect (OSTI)

To measure the electron temperature (T{sub e}) and electron density (n{sub e}) profiles in the Korean Superconducting Tokamak Advanced Research (KSTAR) device for the KSTAR third campaign (September 2010), we designed and installed a Thomson scattering system. The KSTAR Thomson scattering system is designed as a tangential Thomson scattering system and utilizes the N-, L-, and B-ports. The N-port is designed for the collection optics with a cassette system, the L-port is the laser input port, and the B-port is the location of the beam dump. In this paper, we will describe the final design of the KSTAR Thomson scattering system.

Lee, J. H.; Oh, S. T.; Wi, H. M. [National Fusion Research Institute, Gwahangno 113, Daejeon 305-333 (Korea, Republic of)

2010-10-15T23:59:59.000Z

278

U-261: Novell GroupWise Internet Agent "Content-Length" Integer...  

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

1: Novell GroupWise Internet Agent "Content-Length" Integer Overflow Vulnerability U-261: Novell GroupWise Internet Agent "Content-Length" Integer Overflow Vulnerability September...

279

Broadband and statistical characterization of echoes from random scatterers : application to acoustic scattering by marine organisms  

E-Print Network [OSTI]

The interpretation of echoes collected by active remote-sensing systems, such as sonar and radar, is often ambiguous due to the complexities in the scattering processes involving the scatterers, the environment, and the ...

Lee, Wu-Jung

2013-01-01T23:59:59.000Z

280

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 Ti–Zr 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

Note: This page contains sample records for the topic "1-to-2-ft lengths scattered" 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

Communication: The length and time scales of water's glass transitions  

E-Print Network [OSTI]

Using a model for the equilibrium dynamics of supercooled water, I derive the average length and time scales that govern the nonequilibrium relaxation behavior of amorphous ice prepared by rapid cooling. Upon cooling, water falls out of equilibrium whereby the temperature dependence of water's relaxation time is shown to change from super-Arrhenius to Arrhenius. A consequence of this crossover is that the location of water's glass transition temperature depends logarithmically on cooling rate. Accompanying the change in temperature dependence is the emergence of a dynamical length-scale, the size of which depends on the cooling rate and varies between angstroms and 10s of nanometers. Elucidating this protocol dependence on the properties of amorphous ice clarifies a number of previous experimental observations.

Limmer, David T

2013-01-01T23:59:59.000Z

282

Electron Bunch Length Measurement for LCLS at SLAC  

SciTech Connect (OSTI)

At Stanford Linear Accelerator Center (SLAC) a Bunch Length Measurement system has been developed to measure the length of the electron bunch for its new Linac Coherent Light Source (LCLS). This destructive measurement uses a transverse-mounted RF deflector (TCAV) to vertically streak the electron beam and an image taken with an insertable screen and a camera. The device control software was implemented with the Experimental Physics and Industrial Control System (EPICS) toolkit. The analysis software was implemented in Matlab{trademark} using the EPICS/Channel Access Interface for Scilab{trademark} and Matlab{trademark} (labCA). This architecture allowed engineers and physicists to develop and integrate their control and analysis without duplication of effort.

Zelazny, M.; Allison, S.; Chevtsov, Sergei; Emma, P.; Kotturi, K.d.; Loos, H.; Peng, S.; Rogind, D.; Straumann, T.; /SLAC

2007-10-04T23:59:59.000Z

283

Alternatives Generation Analysis Long Length Contaminated Equipment Removal System Storage  

SciTech Connect (OSTI)

The long length contaminated equipment was designed and built to aid in the remote removal and transport of highly radioactive, contaminated equipment from various locations in the tank farms to disposal. The equipment has been stored in an open lay-down yard area, exposed to the elements for the past year and a half. The possible alternatives available to provide shelter for the equipment are investigated.

BOGER, R.M.

1999-08-13T23:59:59.000Z

284

ATP hydrolysis stimulates large length fluctuations in single actin filaments  

E-Print Network [OSTI]

Polymerization dynamics of single actin filaments is investigated theoretically using a stochastic model that takes into account the hydrolysis of ATP-actin subunits, the geometry of actin filament tips, the lateral interactions between the monomers as well as the processes at both ends of the polymer. Exact analytical expressions are obtained for a mean growth velocity and for dispersion in length fluctuations. It is found that the ATP hydrolysis has a strong effect on dynamic properties of single actin filaments. At high concentrations of free actin monomers the mean size of unhydrolyzed ATP-cap is very large, and the dynamics is governed by association/dissociation of ATP-actin subunits. However, at low concentrations the size of the cap becomes finite, and the dissociation of ADP-actin subunits makes a significant contribution to overall dynamics. Actin filament length fluctuations reach the maximum at the boundary between two dynamic regimes, and this boundary is always larger than the critical concentration. Random and vectorial mechanisms of hydrolysis are compared, and it is found that they predict qualitatively similar dynamic properties. The possibility of attachment and detachment of oligomers is also discussed. Our theoretical approach is successfully applied to analyze the latest experiments on the growth and length fluctuations of individual actin filaments.

Evgeny B. Stukalin; Anatoly B. Kolomeisky

2005-07-27T23:59:59.000Z

285

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

286

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

287

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

288

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

289

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

E-Print Network [OSTI]

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

unknown authors

290

Neutrino Beams for Scattering Experiment  

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

Options for Neutrino Scattering Measurements Options for Neutrino Scattering Measurements Draft Skeleton Table Beam Characteristics K2K CERN AD FNAL Debuncher FNAL Booster NuMI LE NuMI ME NuMI HE Peak E(nu) (GeV) X X ~2.5 1 3.5 7.5 13 Maximum E(nu) (GeV) (->1% peak rate) X X 8.9 3 50 50+ 50+ Nu(mu) CC Rate (per ton-year) X 1.4 0 5,000 210,000 1,100,000 2,000,000 Nubar(mu) CC Rate (per ton-year) X 3.4 ~18 (Time Separated) ~360 (Prompt) 1,000 21,000 32,000 20,000 Nu(e) CC Rate (per ton-year) X 0 0 1 2,300 9,500 12,000 Nubar(e) CC Rate (per ton-year) X 0.4 ~18 (Time Separated) 0.5 630 660 600 Flux uncertainty X X 10% 10% 20% 20% 20% QE events / 100 ton-years X 169 nubar(mu) 47 nu(mu) 17 nubar(e) 525 nubar(e) 500,000 nu(mu) 100,000 nu(mu) X X X Floor space (m**2) X X New Hall New Hall 20 x 2.5 20 x 2.5 20 x 2.5 Run Type X X Parasitic Parasitic Parasitic Parasitic Parasitic

291

Giant resonance study by 6li scattering  

E-Print Network [OSTI]

above 35 MeV. Other processes give a large physical background at high excitation energy in ? inelastic scattering, which makes it difficult to extract strength distributions in this range. As an isoscalar projectile (N=Z), 6Li scattering could...

Chen, Xinfeng

2009-05-15T23:59:59.000Z

292

CP violation in neutrino–photon scattering  

Science Journals Connector (OSTI)

It is shown that effects of CP violation arise in neutrino–photon scattering. Several CP-violating ?? reactions are considered within the Standard Model and predictions for some observables are made. It is emphasized that neutrino–photon scattering may provide an experimental tool for testing the scale dependence of CP violation.

I Alikhanov

2014-01-01T23:59:59.000Z

293

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

294

Neutrino proton scattering and the isosinglet term  

SciTech Connect (OSTI)

Elastic neutrino proton scattering is sensitive to the SU(3) axial isosinglet term which is in turn dependent on the strangeness content of the proton. The uncertainties in the analysis of a neutrino proton elastic scattering experiment are discussed, and an experiment which is insensitive to many of the difficulties of the previous experiment is described.

White, D.H.

1990-01-01T23:59:59.000Z

295

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

296

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

297

Theory of Brillouin scattering from opaque media  

Science Journals Connector (OSTI)

The general theory of Brillouin scattering from the surfaces of opaque media is developed using a total field solution approach. Acoustical modes appropriate to a stress-free surface are found from solutions to the acoustical-wave equation and boundary conditions for a finite isotropic medium. Two light-scattering mechanisms, namely, the surface corrugation and bulk elasto-optical effects, were analyzed by deriving optical fields which satisfy both the acousto-optically driven wave equation and the electromagnetic boundary conditions. The special case for a metal of scattering by acoustically created conductivity fluctuations was also investigated in a similar way. The Brillouin spectrum was obtained by summing the scattering from the individual acoustical modes over the density of phonon states. Excellent agreement was obtained with experiment for Brillouin scattering from the metals gallium (liquid) and aluminum (solid).

N. L. Rowell and G. I. Stegeman

1978-09-15T23:59:59.000Z

298

Determination of Low-Energy Parameters of Neutron--Proton Scattering on the Basis of Modern Experimental Data from Partial-Wave Analyses  

E-Print Network [OSTI]

The triplet and singlet low-energy parameters in the effective-range expansion for neutron--proton scattering are determined by using the latest experimental data on respective phase shifts from the SAID nucleon--nucleon database. The results differ markedly from the analogous parameters obtained on the basis of the phase shifts of the Nijmegen group and contradict the parameter values that are presently used as experimental ones. The values found with the aid of the phase shifts from the SAID nucleon--nucleon database for the total cross section for the scattering of zero-energy neutrons by protons, $\\sigma_{0}=20.426 $b, and the neutron--proton coherent scattering length, $f=-3.755 $fm, agree perfectly with the experimental cross-section values obtained by Houk, $\\sigma_{0}=20.436\\pm 0.023 $b, and experimental scattering-length values obtained by Houk and Wilson, $f=-3.756\\pm 0.009 $fm, but they contradict cross-section values of $\\sigma_{0}=20.491\\pm 0.014 $b according to Dilg and coherent-scattering-length values of $f=-3.7409\\pm 0.0011 $fm according to Koester and Nistler.

V. A. Babenko; N. M. Petrov

2007-04-08T23:59:59.000Z

299

Quantitative study of two- and three-dimensional strong localization of matter waves by atomic scatterers  

SciTech Connect (OSTI)

We study the strong localization of atomic matter waves in a disordered potential created by atoms pinned at the nodes of a lattice, for both three-dimensional (3D) and two-dimensional (2D) systems. The localization length of the matter wave, the density of localized states, and the occurrence of energy mobility edges (for the 3D system), are numerically investigated as a function of the effective scattering length between the atomic matter wave and the pinned atoms. Both positive and negative matter wave energies are explored. Interesting features of the density of states are discovered at negative energies, where maxima in the density of bound states for the system can be interpreted in terms of bound states of a matter wave atom with a few pinned atomic scatterers. In 3D we found evidence of up to three mobility edges, one at positive energies, and two at negative energies, the latter corresponding to transitions between extended and localized bound states. In 2D, no mobility edge is found, and a rapid exponential-like increase of the localization length is observed at high energy.

Antezza, Mauro; Castin, Yvan; Hutchinson, David A. W. [Laboratoire Kastler Brossel, Ecole Normale Superieure, CNRS and UPMC, 24 rue Lhomond, F-75231 Paris (France); Jack Dodd Centre for Quantum Technology, Department of Physics, University of Otago, Dunedin 9016 (New Zealand)

2010-10-15T23:59:59.000Z

300

Quantitative study of two- and three-dimensional strong localization of matter waves by atomic scatterers  

Science Journals Connector (OSTI)

We study the strong localization of atomic matter waves in a disordered potential created by atoms pinned at the nodes of a lattice, for both three-dimensional (3D) and two-dimensional (2D) systems. The localization length of the matter wave, the density of localized states, and the occurrence of energy mobility edges (for the 3D system), are numerically investigated as a function of the effective scattering length between the atomic matter wave and the pinned atoms. Both positive and negative matter wave energies are explored. Interesting features of the density of states are discovered at negative energies, where maxima in the density of bound states for the system can be interpreted in terms of bound states of a matter wave atom with a few pinned atomic scatterers. In 3D we found evidence of up to three mobility edges, one at positive energies, and two at negative energies, the latter corresponding to transitions between extended and localized bound states. In 2D, no mobility edge is found, and a rapid exponential-like increase of the localization length is observed at high energy.

Mauro Antezza; Yvan Castin; David A. W. Hutchinson

2010-10-07T23:59:59.000Z

Note: This page contains sample records for the topic "1-to-2-ft lengths scattered" 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

Technology development for gene discovery and full-length sequencing  

SciTech Connect (OSTI)

In previous years, with support from the U.S. Department of Energy, we developed methods for construction of normalized and subtracted cDNA libraries, and constructed hundreds of high-quality libraries for production of Expressed Sequence Tags (ESTs). Our clones were made widely available to the scientific community through the IMAGE Consortium, and millions of ESTs were produced from our libraries either by collaborators or by our own sequencing laboratory at the University of Iowa. During this grant period, we focused on (1) the development of a method for preferential cloning of tissue-specific and/or rare transcripts, (2) its utilization to expedite EST-based gene discovery for the NIH Mouse Brain Molecular Anatomy Project, (3) further development and optimization of a method for construction of full-length-enriched cDNA libraries, and (4) modification of a plasmid vector to maximize efficiency of full-length cDNA sequencing by the transposon-mediated approach. It is noteworthy that the technology developed for preferential cloning of rare mRNAs enabled identification of over 2,000 mouse transcripts differentially expressed in the hippocampus. In addition, the method that we optimized for construction of full-length-enriched cDNA libraries was successfully utilized for the production of approximately fifty libraries from the developing mouse nervous system, from which over 2,500 full-ORF-containing cDNAs have been identified and accurately sequenced in their entirety either by our group or by the NIH-Mammalian Gene Collection Program Sequencing Team.

Marcelo Bento Soares

2004-07-19T23:59:59.000Z

302

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

303

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

304

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

305

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

306

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

307

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

308

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

309

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

310

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

311

Varying properties along lengths of temperature limited heaters  

DOE Patents [OSTI]

A system for heating a subsurface formation is described. The system includes an elongated heater in an opening in the formation. The elongated heater includes two or more portions along the length of the heater that have different power outputs. At least one portion of the elongated heater includes at least one temperature limited portion with at least one selected temperature at which the portion provides a reduced heat output. The heater is configured to provide heat to the formation with the different power outputs. The heater is configured so that the heater heats one or more portions of the formation at one or more selected heating rates.

Vinegar, Harold J. (Bellaire, TX); Xie, Xueying (Houston, TX); Miller, David Scott (Katy, TX); Ginestra, Jean Charles (Richmond, TX)

2011-07-26T23:59:59.000Z

312

Dynamic optical properties in graphene: Length versus velocity gauge  

SciTech Connect (OSTI)

The dynamic optical properties of graphene are theoretically investigated in both length gauge and velocity gauge in the presence of ultrafast optical radiation field. The two gauges present different results of dynamic photo-induced carriers and optical conductance due to distinct dependencies on electric field and non-resonant optical absorption, while the two gauges give identical results in the steady state time. It shows that the choice of gauge affects evidently the dynamic optical properties of graphene. The velocity gauge represents an outcome of a real physical experiment.

Dong, H. M.; Han, K., E-mail: han6409@263.net [Department of Physics, China University of Mining and Technology, Xuzhou 221116 (China); Xu, W. [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China); Department of Physics, Yunnan University, Kunming 650091 (China)

2014-02-14T23:59:59.000Z

313

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

SciTech Connect (OSTI)

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

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

2014-01-01T23:59:59.000Z

314

Mask roughness induced LER: geometric model at long correlation lengths  

SciTech Connect (OSTI)

Collective understanding of how both the resist and line-edge roughness (LER) on the mask affect the final printed LER has made significant advances. What is poorly understood, however, is the extent to which mask surface roughness couples to image plane LER as a function of illumination conditions, NA, and defocus. Recently, progress has been made in formulating a simplified solution for mask roughness induced LER. Here, we investigate the LER behavior at long correlation lengths of surface roughness on the mask. We find that for correlation lengths greater than 3/NA in wafer dimensions and CDs greater than approximately 0.75/NA, the previously described simplified model, which remains based on physical optics, converges to a 'geometric regime' which is based on ray optics and is independent of partial coherence. In this 'geometric regime', the LER is proportional to the mask slope error as it propagates through focus, and provides a faster alternative to calculating LER in contrast to either full 2D aerial image simulation modeling or the newly proposed physical optics model. Data is presented for both an NA = 0.32 and an NA = 0.5 imaging system for CDs of 22-nm and 50-nm horizontal-line-dense structures.

McClinton, Brittany M.; Naulleau, Patrick P.

2011-02-11T23:59:59.000Z

315

On the microscopic origin of light scattering in tissue  

Science Journals Connector (OSTI)

Understanding the nature of light scattering within tissue is a crucial issue for development of medical imaging techniques. Microscopic measurements of static light-scattering...

Kaplan, Peter; Weissman, Jesse; Hancewicz, Tom; Popp, Alois; Weitz, David

316

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...

317

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

318

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...

319

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...

320

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

Note: This page contains sample records for the topic "1-to-2-ft lengths scattered" 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

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...

322

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...

323

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

324

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...

325

Incoherent neutron scattering from multi-element materials  

Science Journals Connector (OSTI)

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

Glinka, C.J.

2011-04-02T23:59:59.000Z

326

Transport and noise properties of Si nanowire channels with different lengths before and after gamma radiation treatment  

SciTech Connect (OSTI)

The transport properties of Si nanowire (NW) structures fabricated on the basis of silicon on insulator (SOI) wafers were studied using noise spectroscopy before and after treatment with small doses of gamma radiation. The total resistance obtained from the I-V characteristics of Si NW structures scaled perfectly with length. Normalized flicker noise demonstrated 1/L{sup 2} dependence, which is a characteristic of dominant noise contribution from near-contact regions. The behavior changed to 1/L dependence after a small dose (1×10{sup 4} Gy) of gamma radiation treatment. Comparison of the random telegraph signal (RTS) noise parameters in the samples with small lengths before and after the treatment revealed a decrease in RTS amplitude and a shift to a lower frequency range after gamma irradiation. These results confirmed that the main changes in the samples were related to strain relaxation near-contact regions. In addition, such treatment resulted in a considerable decrease in the scattering data of device parameters.

Li, Jing; Vitusevich, Svetlana; Pud, Sergii; Sydoruk, Viktor; Offenhäusser, Andreas [Peter Grünberg Institute, Forschungszentrum Jülich (Germany); Petrychuk, Mykhailo [Taras Shevchenko National University, Kiev (Ukraine); Danilchenko, Boris [Institute of Physics, NASU, Kiev (Ukraine)

2013-12-04T23:59:59.000Z

327

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

328

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

329

The I=2 ?? S-wave Scattering Phase Shift from Lattice QCD  

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

The ?+?+ s-wave scattering phase-shift is determined below the inelastic threshold using Lattice QCD. Calculations were performed at a pion mass of m? ? 390 MeV with an anisotropic nf = 2+1 clover fermion discretization in four lattice volumes, with spatial extent L ? 2.0, 2.5, 3.0 and 3.9 fm, and with a lattice spacing of bs ? 0.123 fm in the spatial direction and bt bs/3.5 in the time direction. The phase-shift is determined from the energy-eigenvalues of ?+?+ systems with both zero and non-zero total momentum in the lattice volume using Luscher's method. Our calculations are precise enough to allow for a determination of the threshold scattering parameters, the scattering length a, the effective range r, and the shape-parameter P, in this channel and to examine the prediction of two-flavor chiral perturbation theory: m?2 a r = 3+O(m?2/??2). Chiral perturbation theory is used, with the Lattice QCD results as input, to predict the scattering phase-shift (and threshold parameters) at the physical pion mass. Our results are consistent with determinations from the Roy equations and with the existing experimental phase shift data.

Beane, S R; Detmold, W; Lin, H W; Luu, T C; Orginos, K; Parreno, A; Savage, M J; Torok, A; Walker-Loud, A

2012-02-16T23:59:59.000Z

330

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

331

Nuclear level density as a tool for probing the inelastic scattering of 6He  

E-Print Network [OSTI]

The cross sections are calculated for the both elastic and inelastic scattering of 6He from 12C and 4He. A phenomenological optical potential is used to describe the elastic scattering. 4He is taken as spherical and inelastic couplings to the first excited states of 6He and 12C are described with collective rotational model and coupled-channels method. Deformation lengths for 6He and 12C are determined from semi-classical nuclear level density model by using Laplace-like formula for the nuclear level density parameter. The comparison of the predicted and the measured cross sections are presented to test the applicability of nuclear level density model to the light exotic nuclei reactions. Good agreement is achieved between the predicted and measured cross sections.

Bora Canbula; Halil Babacan

2014-10-23T23:59:59.000Z

332

Spin observables in nucleon-nucleus scattering  

SciTech Connect (OSTI)

The curse of inelastic nucleon scattering and charge exchange has always been the enormous complexity of the nucleon-nucleon (N-N) interaction. This complexity, however, can also be viewed as the ultimate promise of nucleons as probes of nuclear structure. Given an adequate theoretical basis, inelastic nucleon scattering is capable of providing information not obtainable with other probes. Recently a revolution of experimental technique has taken place that makes it desirable to re-examine the question of what physics is ultimately obtainable from inelastic nucleon scattering. It is now feasible to perform complete polarization transfer (PT) experiments for inelastic proton scattering with high efficiency and excellent energy resolution. Programs to measure PT obsevables are underway at several laboratories, and results are beginning to appear. Objectives of this presentation are to examine how such experiments are done, and what physics is presently obtained and may ultimately be learned from them.

Moss, J.M.

1982-01-01T23:59:59.000Z

333

What Does a Scattering Pattern Tell US?  

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

e iwt Phase difference Phase difference S e i (ri Q) A(DK) fi A(Q) Fourier Transform ( ri ) DK Q 4p sin(q) l Lensless Imaging Sample Space Scattering Space sample...

334

Scattering theory without large-distance asymptotics  

E-Print Network [OSTI]

In conventional scattering theory, to obtain an explicit result, one imposes a precondition that the distance between target and observer is infinite. With the help of this precondition, one can asymptotically replace the Hankel function and the Bessel function with the sine functions so that one can achieve an explicit result. Nevertheless, after such a treatment, the information of the distance between target and observer is inevitably lost. In this paper, we show that such a precondition is not necessary: without losing any information of distance, one can still obtain an explicit result of a scattering rigorously. In other words, we give an rigorous explicit scattering result which contains the information of distance between target and observer. We show that at a finite distance, a modification factor --- the Bessel polynomial --- appears in the scattering amplitude, and, consequently, the cross section depends on the distance, the outgoing wave-front surface is no longer a sphere, and, besides the phase...

Liu, Tong; Dai, Wu-Sheng

2014-01-01T23:59:59.000Z

335

A New Treatment of Rough Surface Scattering  

Science Journals Connector (OSTI)

...1996 research-article A New Treatment of Rough Surface Scattering C. Macaskill P...narrow beam at a randomly rough surface where the height distribution...is Gaussian. The field at the surface is assumed to satisfy a Dirichlet...

1996-01-01T23:59:59.000Z

336

Orthopositronium-orthopositronium scattering at medium energies  

SciTech Connect (OSTI)

The scattering of ortho-positronium (o-Ps) atoms has been investigated using the first Born approximation (FBA) and Born-Oppenheimer (B-O) model at medium energies. The angle integrated total elastic cross sections of o-Ps-o-Ps scattering have been reported. Apart from this, the inelastic cross sections for discrete excitations (principal quantum number, n{<=}3) of the single and both the Ps atoms as well as single and double Ps atom ionization have also been obtained. We have also predicted the total cross section of o-Ps-o-Ps scattering by adding all these partial cross sections. The first Born and B-O scattering amplitudes have also been evaluated using partial wave technique. It has been noticed that odd values of the partial wave B-O amplitude vanishes for even parity transitions and vice versa. To the best of our knowledge, this feature has not been noticed for other systems.

Chakraborty, Sumana; Ghosh, A.S. [Department of Theoretical Physics, Indian Association for the Cultivation of Science, Jadavpur, Kolkata-700 032 (India); Kumari, Kiran [Department of Physics, R N College, Hajipur (Vaishali), B R A Bihar University, Muzaffarpur, Bihar (India)

2005-08-15T23:59:59.000Z

337

Bragg scattering measurement of atmospheric plasma decay  

Science Journals Connector (OSTI)

The decay processes of the plasma layers generated by two intersecting microwave pulses in 1 torr dry air are investigated by Bragg scattering method. The results of measurement show that the electrons decay i...

Y. S. Zhang; S. P. Kuo

1991-04-01T23:59:59.000Z

338

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

339

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

340

Scattering Properties of Oriented Hexagonal Ice Crystals  

E-Print Network [OSTI]

To interpret the data from spaceborn lidar measurements, one must have a basic understanding of the backscattering of oriented ice particles. The conventional raytracing method is not applicable to the scattering of light by oriented particles...

Zhang, Feng

2010-01-14T23:59:59.000Z

Note: This page contains sample records for the topic "1-to-2-ft lengths scattered" 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

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

342

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

343

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

344

Doppler effect in light scattering in liquids  

Science Journals Connector (OSTI)

The present work deals with the study of the state of polarisation of the three components observed in the spectrum of monochromatic light scattered by liquid formic and acetic acids, when examined with a Fabr...

B. V. Raghavendra Rao

1936-06-01T23:59:59.000Z

345

On the analysis of small?angle scattering with elliptical azimuthal symmetry  

Science Journals Connector (OSTI)

Inhomogeneities which have azimuthal symmetry around some unique axis exhibit small?angle neutron scattering with elliptical symmetry. It is not necessary that these inhomogeneities have an ellipsoidal shape. The model of Debye e t a l. has been generalized to incorporate an anisotropic correlation length having this symmetry. A method is given for fitting two?dimensional intensity data to this model. This is illustrated by data taken for sections of slate and shale rock cut normal to the direction of the bedding planes and which exhibit both large? and small?pore anisotropies.

Peter L. Hall; D. F. R. Mildner

1983-01-01T23:59:59.000Z

346

MEASUREMENTS OF INTRA-BEAM SCATTERING GROWTH TIMES WITH GOLD BEAM BELOW TRANSITION IN RHIC.  

SciTech Connect (OSTI)

While RHIC is filled with beam, bunches are stored for up to several minutes at the injection energy before acceleration starts. In gold operation, the RHIC injection energy is below transition. A bunch length increase, and correspondingly an increase in the longitudinal emittance, can lead to particle loss during transition crossing and rebucketing into the storage buckets. The longitudinal growth of gold beams in RHIC at injection is dominated by intra-beam scattering. Measurements of longitudinal growth times are presented and compared with computations.

FISCHER,W.; BAI,M.; BLASKIEWICZ,M.; BRENNAN,J.M.; CAMERON,P.; CONNOLLY,R.; LEHRACH,A.; PARZEN,G.; TEPIKIAN,S.; ZENO,K.; VAN ZEIJTS,J.

2001-06-18T23:59:59.000Z

347

Convective equilibrium and mixing-length theory for stellarator reactors  

SciTech Connect (OSTI)

In high ..beta.. stellarator and tokamak reactors, the plasma pressure gradient in some regions of the plasma may exceed the critical pressure gradient set by ballooning instabilities. In these regions, convective cells break out to enhance the transport. As a result, the pressure gradient can rise only slightly above the critical gradient and the plasma is in another state of equilibrium - ''convective equilibrium'' - in these regions. Although the convective transport cannot be calculated precisely, it is shown that the density and temperature profiles in the convective region can still be estimated. A simple mixing-length theory, similar to that used for convection in stellar interiors, is introduced in this paper to provide a qualitative description of the convective cells and to show that the convective transport is highly efficient. A numerical example for obtaining the density and temperature profiles in a stellarator reactor is given.

Ho, D.D.M.; Kulsrud, R.M.

1985-09-01T23:59:59.000Z

348

Light absorption cell combining variable path and length pump  

DOE Patents [OSTI]

A device for use in making spectrophotometric measurements of fluid samples. In particular, the device is a measurement cell containing a movable and a fixed lens with a sample of the fluid therebetween and through which light shines. The cell is connected to a source of light and a spectrophotometer via optic fibers. Movement of the lens varies the path length and also pumps the fluid into and out of the cell. Unidirectional inlet and exit valves cooperate with the movable lens to assure a one-way flow of fluid through the cell. A linear stepper motor controls the movement of the lens and cycles it from a first position closer to the fixed lens and a second position farther from the fixed lens, preferably at least 10 times per minute for a nearly continuous stream of absorption spectrum data.

Prather, William S. (2419 Dickey Rd., Augusta, GA 30906)

1993-01-01T23:59:59.000Z

349

Light absorption cell combining variable path and length pump  

DOE Patents [OSTI]

A device is described for use in making spectrophotometric measurements of fluid samples. In particular, the device is a measurement cell containing a movable and a fixed lens with a sample of the fluid there between and through which light shines. The cell is connected to a source of light and a spectrophotometer via optic fibers. Movement of the lens varies the path length and also pumps the fluid into and out of the cell. Unidirectional inlet and exit valves cooperate with the movable lens to assure a one-way flow of fluid through the cell. A linear stepper motor controls the movement of the lens and cycles it from a first position closer to the fixed lens and a second position farther from the fixed lens, preferably at least 10 times per minute for a nearly continuous stream of absorption spectrum data. 2 figures.

Prather, W.S.

1993-12-07T23:59:59.000Z

350

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

351

Coherent Neutrino Scattering and Stellar Collapse  

Science Journals Connector (OSTI)

Freedman has shown that coherency and the neutral current theory of neutrinos imply a scattering cross section for neutrinos off heavy nuclei proportional to the square of the atomic weight. The collapse of an iron-core star produces a hot neutron star surrounded by a thin iron layer. Because of the large scattering rate in the outer layer, neutrinos from the hot neutron core are able to accelerate the iron layer to above escape velocity.

James R. Wilson

1974-04-15T23:59:59.000Z

352

Quantum Energy Regression using Scattering Transforms  

E-Print Network [OSTI]

We present a novel approach to the regression of quantum mechanical energies based on a scattering transform of an intermediate electron density representation. A scattering transform is a deep convolution network computed with a cascade of multiscale wavelet transforms. It possesses appropriate invariant and stability properties for quantum energy regression. This new framework removes fundamental limitations of Coulomb matrix based energy regressions, and numerical experiments give state-of-the-art accuracy over planar molecules.

Hirn, Matthew; Mallat, Stephane

2015-01-01T23:59:59.000Z

353

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 50–200 MeV.

C. D. Goodman

1985-01-01T23:59:59.000Z

354

Inverse scattering with non-overdetermined data  

E-Print Network [OSTI]

Let $A(\\beta,\\alpha,k)$ be the scattering amplitude corresponding to a real-valued potential which vanishes outside of a bounded domain $D\\subset \\R^3$. The unit vector $\\alpha$ is the direction of the incident plane wave, the unit vector $\\beta$ is the direction of the scattered wave, $k>0$ is the wave number. The governing equation for the waves is $[\

A. G. Ramm

2009-06-17T23:59:59.000Z

355

Small Angle X-Ray Scattering Detector  

DOE Patents [OSTI]

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

Hessler, Jan P. (Downers Grove, IL)

2004-06-15T23:59:59.000Z

356

Toward improved photon-atom scattering predictions  

SciTech Connect (OSTI)

Photon-atom scattering is important in a variety of applications, but scattering from a composite system depends on the accurate characterization of the scattering from an isolated atom or ion. We have been examining the validity of simpler approximations of elastic scattering in the light of second-order S-matrix theory. Partitioning the many-body amplitude into Rayleigh and Delbrueck components, processes beyond photoionization contribute. Subtracted cross sections for bound-bound atomic transitions, bound pair annihilation, and bound pair production are required in anomalous scattering factors for: (1) convergence of the dispersion integral; (2) agreement with predictions of the more sophisticated S-matrix approach; (3) satisfying the Thomas-Reiche-Kuhn sum rule. New accurate tabulations of anomalous scattering factors have been prepared for all Z, for energies 0--10,000 keV, within the independent particle approximation (IPA) using a Dirac-Slater model of the atom. Separately, experimental atomic photoabsorption threshold information has been used to modify these IPA predictions for improved comparison with experiment.

Kissel, L.

1994-10-21T23:59:59.000Z

357

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

358

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

359

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

360

The Linear Sampling Method in Inverse Electromagnetic Scattering  

E-Print Network [OSTI]

Scatterer: Two Balls . . . . . . . . 50 3.5.2 The Teapot . . . . . . . . . . . . . . . . . . . . . . . 52 3

Cakoni, Fioralba

Note: This page contains sample records for the topic "1-to-2-ft lengths scattered" 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

Statistical Assessment of Variability of Terminal Restriction Fragment Length Polymorphism Analysis Applied to Complex Microbial Communities  

Science Journals Connector (OSTI)

...communities. The statistical analysis was carried out at successive...batch bubble column reactor inoculated with activated...length polymorphism data analysis. Appl. Environ. Microbiol...length polymorphism analysis. Environ. Microbiol...F. Widmer. 2008. Reliability for detecting composition...

Pierre Rossi; François Gillet; Emmanuelle Rohrbach; Nouhou Diaby; Christof Holliger

2009-09-11T23:59:59.000Z

362

Length measurement of a moving rod by a single observer without assumptions concerning its magnitude  

E-Print Network [OSTI]

We extend the results presented by Weinstein concerning the measurement of the length of a moving rod by a single observer, without making assumptions concerning the distance between the moving rod and the observer who measures its length.

Bernhard Rothenstein; Ioan Damian

2005-07-03T23:59:59.000Z

363

Fact #728: May 21, 2012 Average Trip Length is Less Than Ten Miles  

Broader source: Energy.gov [DOE]

The average trip length (one-way) is 9.7 miles according to the 2009 Nationwide Personal Transportation Survey. Trip lengths vary by the purpose of the trip. Shopping and family/personal business...

364

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

365

Patterns of authors' information scattering: towards a causal explanation of information scattering from a scholarly information-seeking behavior perspective  

Science Journals Connector (OSTI)

This study primarily aims to reveal the worldwide patterns of authors' information scattering through illustrating the possible differences among authors based on subject, country, geographic region, institution, economic and scientific level factors. ... Keywords: Authors' patterns of information scattering, Bradford's law, Information scattering, Information scattering explanation, Scholarly information-seeking behavior, Scholarly journal usage

Zahed Bigdeli; Morteza Kokabi; Gholam Reza Rajabi; Ali Gazni

2013-07-01T23:59:59.000Z

366

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

367

Absorption and Scattering When we have both variations in both absorption and scattering, the solution to the  

E-Print Network [OSTI]

Chapter 6 Absorption and Scattering When we have both variations in both absorption and scattering of absorption and scatttering. 6.1 Simulation Results For the following simulationsthe forward data were of the simulation. #12;Absorption and Scattering 107 We have reconstructed images of scattering and absorption

368

A Simple Biomass-Based Length-Cohort Analysis for Estimating Biomass and Fishing Mortality  

E-Print Network [OSTI]

, Washington 98115, USA Abstract.--A biomass-based length-cohort analysis (LCA) was examined for its compared two LCA methods--(1) a numbers-based LCA that relies on catch numbers at length as input data and (2) a new biomass-based LCA that relies on catch biomass at length--by applying both to simulated

369

THE DISTRIBUTION OF THE COMBINED LENGTH OF SPANNED CYCLES IN A  

E-Print Network [OSTI]

THE DISTRIBUTION OF THE COMBINED LENGTH OF SPANNED CYCLES IN A RANDOM PERMUTATION By YANNAI A of the combined length L = L(, M) of all cycles of that contain at least one element of M. We give a simple-MAIL: ratio@math.huji.ac.il URL: http://www.ratio.huji.ac.il/ #12;The Distribution of the Combined Length

Hart, Sergiu

370

The use of multiple-scattering data to enhance small-angle neutron scattering experiments  

Science Journals Connector (OSTI)

It is shown that SANS patterns from specimens of different thicknesses but otherwise identical not only provide information on the shape and size of the scattering entity but also give absolute values of the scattering contrast between particles responsible for SANS and the matrix. No separate calibration of the incident beam is required.

Sabine, T.M.

1999-05-01T23:59:59.000Z

371

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

372

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

373

Resonant impurity scattering and electron-phonon scattering in the electrical resistivity of Cr thin films  

E-Print Network [OSTI]

Resonant impurity scattering and electron-phonon scattering in the electrical resistivity of Cr The resistivity as a function of temperature from 0.6 to 300 K for epitaxial and polycrystalline Cr thin films residual resistivity up to 400 cm and a minimum at low temperatures below 100 K . This is strong

Hellman, Frances

374

Length Scale of Leidenfrost Ratchet Switches Droplet Directionality  

SciTech Connect (OSTI)

Arrays of tilted pillars with characteristic heights spanning from hundreds of nanometers to tens of micrometers were created using wafer level processing and used as Leidenfrost ratchets to control droplet directionality. Dynamic Leidenfrost droplets on the ratchets with nanoscale features were found to move in the direction of the pillar tilt while the opposite directionality was observed on the microscale ratchets. This remarkable switch in the droplet directionality can be explained by varying contributions from the two distinct mechanisms controlling droplet motion on Leidenfrost ratchets with nanoscale and microscale features. In particular, asymmetric wettability of dynamic Leidenfrost droplets upon initial impact appears to be the dominant mechanism determining their directionality on tilted nanoscale pillar arrays. By contrast, asymmetric wetting does not provide a strong enough driving force compared to the forces induced by asymmetric vapour flow on arrays of much taller tilted microscale pillars. Furthermore, asymmetric wetting plays a role only in the dynamic Leidenfrost regime, for instance when droplets repeatedly jump after their initial impact. The point of crossover between the two mechanisms coincides with the pillar heights comparable to the values of the thinnest vapor layers still capable of cushioning Leidenfrost droplets upon their initial impact. The proposed model of the length scale dependent interplay between the two mechanisms points to the previously unexplored ability to bias movement of dynamic Leidenfrost droplets and even switch their directionality.

Agapov, Rebecca L [ORNL; Boreyko, Jonathan B [ORNL; Briggs, Dayrl P [ORNL; Srijanto, Bernadeta R [ORNL; Retterer, Scott T [ORNL; Collier, Pat [ORNL; Lavrik, Nickolay V [ORNL

2014-01-01T23:59:59.000Z

375

Thermal management of long-length HTS cable systems  

SciTech Connect (OSTI)

Projections of electric power production suggest a major shift to renewables, such as wind and solar, which will be in remote locations where massive quantities of power are available. One solution for transmitting this power over long distances to load centers is direct current (dc), high temperature superconducting (HTS) cables. Electric transmission via dc cables promises to be effective because of the low-loss, highcurrent- carrying capability of HTS wire at cryogenic temperatures. However, the thermal management system for the cable must be carefully designed to achieve reliable and energyefficient operation. Here we extend the analysis of a superconducting dc cable concept proposed by the Electric Power Research Institute (EPRI), which has one stream of liquid nitrogen flowing in a cryogenic enclosure that includes the power cable, and a separate return tube for the nitrogen. Refrigeration stations positioned every 10 to 20 km cool both nitrogen streams. Both go and return lines are contained in a single vacuum/cryogenic envelope. Other coolants, including gaseous helium and gaseous hydrogen, could provide potential advantages, though they bring some technical challenges to the operation of long-length HTS dc cable systems. A discussion of the heat produced in superconducting cables and a system to remove the heat are discussed. Also, an analysis of the use of various cryogenic fluids in long-distance HTS power cables is presented.

Demko, Jonathan A [ORNL; Hassenzahl, William V [ORNL

2011-01-01T23:59:59.000Z

376

Inclusion of Scatter in HADES: Final Report  

SciTech Connect (OSTI)

Covert nuclear attack is one of the foremost threats facing the United States and is a primary focus of the War on Terror. The Domestic Nuclear Detection Office (DNDO), within the Department of Homeland Security (DHS), is chartered to develop, and improve domestic systems to detect and interdict smuggling for the illicit use of a nuclear explosive device, fissile material or radiologica1 material. The CAARS (Cargo Advanced Automated Radiography System) program is a major part of the DHS effort to enhance US security by harnessing cutting-edge technologies to detect radiological and nuclear threats at points of entry to the United States. DNDO has selected vendors to develop complete radiographic systems. It is crucial that the initial design and testing concepts for the systems be validated and compared prior to the substantial efforts to build and deploy prototypes and subsequent large-scale production. An important aspect of these systems is the scatter which interferes with imaging. Monte Carlo codes, such as MCNP (X-5 Monte Carlo Team, 2005 Revision) allow scatter to be calculatied, but these calculations are very time consuming. It would be useful to have a fast scatter estimation algorithm in a fast ray tracing code. We have been extending the HADES ray-tracing radiographic simulation code to model vendor systems in a flexible and quick fashion and to use this tool to study a variety of questions involving system performance and the comparative value of surrogates. To enable this work, HADES has been linked to the BRL-CAD library (BRL-CAD Open Source Project, 2010), in order to enable the inclusion of complex CAD geometries in simulations, scanner geometries have been implemented in HADES, and the novel detector responses have been included in HADES. A major extension of HADES which has been required by this effort is the inclusion of scatter in these radiographic simulations. Ray tracing codes generally do not easily allow the inclusion of scatter, because these codes define a source and a grid of detector pixels and only compute the attenuation along rays between these points. Scatter is an extremely complex set of processes which can involve rays which change directions many times between the source and detector. Scatter from outside the field of view of the imaging system, as well as within the field of view, can have an important role in image formation. In this report, we will describe how we implemented a treatment of scatter in HADES. We begin with a discussion of how we define scatter in Section 2, followed by a description of how single Compton scatter is now included in HADES in Section 3. In Section 4 we report a set of verification tests against MCNP and tests of how the technique scales with image size, number of scatters allowed and number of processors used in the calculations. In Section 5, we describe how we plan to extend this approach to other forms of scatter and conclude in Section 6. It should be emphasized that the purpose of this report is to show that a form of scatter has been implemented in HADES and has been verified against MCNP. Validation, the process of comparing simulation and experiment, is a future task.

Aufderheide, M B

2010-12-20T23:59:59.000Z

377

Proton-Proton Scattering at 5 Mev  

Science Journals Connector (OSTI)

A scattering chamber has been constructed which employs a number of radial slit units arranged at various angles with respect to the collimated beam of protons. A photographic plate is placed behind each slit unit and the tracks of protons which are scattered into the plate can be counted. To obtain cross sections from this apparatus the number of tracks per unit area must be determined. Protons were scattered from hydrogen gas at approximately 1.5-cm Hg pressure. Advantages of the design were relatively simple geometry, data obtained simultaneously at all angles, almost complete freedom from impurity-scattering, and short cyclotron running times. The differential cross sections were measured for 5.07-Mev protons from 14° to 150° in the center-of-mass system. The results indicate an S-wave phase shift of 54.5±0.6° and a repulsive P-wave phase shift of 0.05±0.09°. They are therefore quite consistent with pure S-wave scattering.

K. B. Mather

1951-04-15T23:59:59.000Z

378

Scattering theory without large-distance asymptotics  

E-Print Network [OSTI]

In conventional scattering theory, to obtain an explicit result, one imposes a precondition that the distance between target and observer is infinite. With the help of this precondition, one can asymptotically replace the Hankel function and the Bessel function with the sine functions so that one can achieve an explicit result. Nevertheless, after such a treatment, the information of the distance between target and observer is inevitably lost. In this paper, we show that such a precondition is not necessary: without losing any information of distance, one can still obtain an explicit result of a scattering rigorously. In other words, we give an rigorous explicit scattering result which contains the information of distance between target and observer. We show that at a finite distance, a modification factor --- the Bessel polynomial --- appears in the scattering amplitude, and, consequently, the cross section depends on the distance, the outgoing wave-front surface is no longer a sphere, and, besides the phase shift, there is an additional phase (the argument of the Bessel polynomial) appears in the scattering wave function.

Tong Liu; Wen-Du Li; Wu-Sheng Dai

2014-03-22T23:59:59.000Z

379

Liquid 1-propanol studied by neutron scattering, near-infrared, and dielectric spectroscopy  

SciTech Connect (OSTI)

Liquid monohydroxy alcohols exhibit unusual dynamics related to their hydrogen bonding induced structures. The connection between structure and dynamics is studied for liquid 1-propanol using quasi-elastic neutron scattering, combining time-of-flight and neutron spin-echo techniques, with a focus on the dynamics at length scales corresponding to the main peak and the pre-peak of the structure factor. At the main peak, the structural relaxation times are probed. These correspond well to mechanical relaxation times calculated from literature data. At the pre-peak, corresponding to length scales related to H-bonded structures, the relaxation times are almost an order of magnitude longer. According to previous work [C. Gainaru, R. Meier, S. Schildmann, C. Lederle, W. Hiller, E. Rössler, and R. Böhmer, Phys. Rev. Lett. 105, 258303 (2010)] this time scale difference is connected to the average size of H-bonded clusters. The relation between the relaxation times from neutron scattering and those determined from dielectric spectroscopy is discussed on the basis of broad-band permittivity data of 1-propanol. Moreover, in 1-propanol the dielectric relaxation strength as well as the near-infrared absorbance reveal anomalous behavior below ambient temperature. A corresponding feature could not be found in the polyalcohols propylene glycol and glycerol.

Sillrén, P.; Matic, A.; Karlsson, M. [Department of Applied Physics, Chalmers University of Technology, SE-412 96 Göteborg (Sweden)] [Department of Applied Physics, Chalmers University of Technology, SE-412 96 Göteborg (Sweden); Koza, M.; Maccarini, M.; Fouquet, P. [Institut Laue Langevin, 6, rue Jules Horowitz, BP 156, 38042 Grenoble Cedex 9 (France)] [Institut Laue Langevin, 6, rue Jules Horowitz, BP 156, 38042 Grenoble Cedex 9 (France); Götz, M.; Bauer, Th.; Gulich, R.; Lunkenheimer, P.; Loidl, A. [Experimental Physics V, University of Augsburg, 86135 Augsburg (Germany)] [Experimental Physics V, University of Augsburg, 86135 Augsburg (Germany); Mattsson, J. [School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT (United Kingdom)] [School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT (United Kingdom); Gainaru, C.; Vynokur, E.; Schildmann, S.; Bauer, S.; Böhmer, R. [Fakultät für Physik, Technische Universität Dortmund, 44221 Dortmund (Germany)] [Fakultät für Physik, Technische Universität Dortmund, 44221 Dortmund (Germany)

2014-03-28T23:59:59.000Z

380

HIGH BRILLIANCE X-RAY SCATTERING FOR  

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

BRILLIANCE X-RAY SCATTERING FOR BRILLIANCE X-RAY SCATTERING FOR LIFE SCIENCES (LIX) Group Leader: Lin Yang Proposal Team: O. Bilsel 1 , B. Hsiao 2 , H. Huang 3 , T. Irving 4 , A. Menzel 5 , L. Pollack 6 , C. Riekel 7 , J. Rubert 8 , H. Tsuruta 9 , L. Yang 10 1 University of Massachusetts, 2 Stony Brook University, 3 Rice University, 4 IIT, 5SLS, 6 Cornell University, 7 European Synchrotron Radiation Facility, 8 NEU, 9 Stanford Synchrotron Radiation Lightsource, 10 Brookhaven National Laboratory TECHNIQUES AND CAPABILITIES APPLICATIONS ADDITIONAL INFORMATION * Energy range 2-20keV using undulator source. Simultaneous SAXS/WAXS to cover 0.003-3Å -1 at 12keV with 1 micron spot size * Time-resolved solution scattering with resolution of (1) microseconds to milliseconds using continuous-flow mixing (5µm x 10µm spot size) and (2) milliseconds using stopped-

Note: This page contains sample records for the topic "1-to-2-ft lengths scattered" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
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381

Argonne CNM Highlight: Light Scattering by Nanoparticles  

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

Light Scattering by Nanoparticles: Understanding Confinement of Light for Nanophotonics Applications through Near-Field Scanning Optical Microscopy Light Scattering by Nanoparticles: Understanding Confinement of Light for Nanophotonics Applications through Near-Field Scanning Optical Microscopy Schematic of the apertureless near-field optical microscope Schematic of the apertureless near-field optical microscope. The optical scattering from the AFM probe tip provides the subdiffraction-limited optical field information. One of the motivations of nanoscience is to achieve sufficient control over photon propagation in nanostructures so as to effectively replace the electron with the photon in all-optical integrated circuits. The much greater speed and bandwidth of light pulses versus electrons promise new capabilities and size reduction of photon based “electronics.” Arrays of metal nanoparticles are currently considered a leading candidate for photon

382

Scattering Workshop May 16-17, 2006  

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

Workshop on Synchrotron X-ray Scattering Techniques in Materials and Workshop on Synchrotron X-ray Scattering Techniques in Materials and Environmental Sciences: Theory and Application. group shot on the steps of bldg 41 (Click image for a hi-res version) Date: May 16 (Lectures) May 17 (Hands-on practical session) Location: SSRL Overview: Modern synchrotron-based X-ray scattering (SR-XRS) techniques offer the ability to probe nano- and atomic-scale structures and order/disorder relationships that critically govern the properties of advanced technological and environmental materials. The high collimation, intensity, and tunability of SR allow the investigation of a wide range of materials, including thin films and interfaces, nanoparticles, amorphous materials, solutions, hydrated and disordered bacteriogenic minerals, and

383

Proton-Proton Scattering at 5 Mev  

Science Journals Connector (OSTI)

The differential cross section for the scattering of protons by protons has been measured at an energy of 4.96±0.08 Mev, at angles from 12.5° to 55° in the laboratory system. The scattering medium was hydrogen gas at a pressure of approximately 5 cm of Hg. The scattered or recoil protons were detected by nuclear track photographic plates. Approximately 10,000 proton tracks were counted at each angle of observation. An estimate indicates the error of each individual cross section to be about two percent. Because the observations at each angle are made simultaneously, the relative accuracy from one angle to another is smaller and amounts to about 1.3 percent.

R. E. Meagher

1950-06-15T23:59:59.000Z

384

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

385

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

386

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

387

Off-resonance atomic Bragg scattering  

SciTech Connect (OSTI)

We performed extensive measurements on the scattering efficiency of atomic Bragg scattering on a standing light wave up to sixth order and developed a two-state Demkov model to explain the results. Using an effective 2N-photon coupling between the original and the reflected momentum states and the assumption of a mostly adiabatic transfer we derived the scattering probability. This probability has two factors: an oscillating part which represents the well-known Pendelloesung oscillation and a part that is peaked in the energy difference between the two momentum states. This last part describes the tolerance on the Bragg condition for angular misalignment. Comparison of the measurements and numerical simulations with this model shows good agreement.

Jansen, M. A. H. M.; Domen, K. F. E. M.; Beijerinck, H. C. W.; Leeuwen, K. A. H. van [Eindhoven University of Technology, P.O. Box 513, 5600MB Eindhoven (Netherlands)

2007-11-15T23:59:59.000Z

388

Scattering and; Delay, Scale, and Sum Migration  

SciTech Connect (OSTI)

How do we see? What is the mechanism? Consider standing in an open field on a clear sunny day. In the field are a yellow dog and a blue ball. From a wave-based remote sensing point of view the sun is a source of radiation. It is a broadband electromagnetic source which, for the purposes of this introduction, only the visible spectrum is considered (approximately 390 to 750 nanometers or 400 to 769 TeraHertz). The source emits an incident field into the known background environment which, for this example, is free space. The incident field propagates until it strikes an object or target, either the yellow dog or the blue ball. The interaction of the incident field with an object results in a scattered field. The scattered field arises from a mis-match between the background refractive index, considered to be unity, and the scattering object refractive index ('yellow' for the case of the dog, and 'blue' for the ball). This is also known as an impedance mis-match. The scattering objects are referred to as secondary sources of radiation, that radiation being the scattered field which propagates until it is measured by the two receivers known as 'eyes'. The eyes focus the measured scattered field to form images which are processed by the 'wetware' of the brain for detection, identification, and localization. When time series representations of the measured scattered field are available, the image forming focusing process can be mathematically modeled by delayed, scaled, and summed migration. This concept of optical propagation, scattering, and focusing have one-to-one equivalents in the acoustic realm. This document is intended to present the basic concepts of scalar scattering and migration used in wide band wave-based remote sensing and imaging. The terms beamforming and (delayed, scaled, and summed) migration are used interchangeably but are to be distinguished from the narrow band (frequency domain) beamforming to determine the direction of arrival of a signal, and seismic migration in which wide band time series are shifted but not to form images per se. Section 3 presents a mostly graphically-based motivation and summary of delay, scale, and sum beamforming. The model for incident field propagation in free space is derived in Section 4 under specific assumptions. General object scattering is derived in Section 5 and simplified under the Born approximation in Section 6. The model of this section serves as the basis in the derivation of time-domain migration. The Foldy-Lax, full point scatterer scattering, method is derived in Section 7. With the previous forward models in hand, delay, scale, and sum beamforming is derived in Section 8. Finally, proof-of-principle experiments are present in Section 9.

Lehman, S K

2011-07-06T23:59:59.000Z

389

Method for compression of data using single pass LZSS and run-length encoding  

DOE Patents [OSTI]

A method used preferably with LZSS-based compression methods for compressing a stream of digital data. The method uses a run-length encoding scheme especially suited for data strings of identical data bytes having large run-lengths, such as data representing scanned images. The method reads an input data stream to determine the length of the data strings. Longer data strings are then encoded in one of two ways depending on the length of the string. For data strings having run-lengths less than 18 bytes, a cleared offset and the actual run-length are written to an output buffer and then a run byte is written to the output buffer. For data strings of 18 bytes or longer, a set offset and an encoded run-length are written to the output buffer and then a run byte is written to the output buffer. The encoded run-length is written in two parts obtained by dividing the run length by a factor of 255. The first of two parts of the encoded run-length is the quotient; the second part is the remainder. Data bytes that are not part of data strings of sufficient length are written directly to the output buffer.

Berlin, G.J.

1994-01-01T23:59:59.000Z

390

Vehicle Technologies Office: Fact #622: May 10, 2010 Average Length of  

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

2: May 10, 2010 2: May 10, 2010 Average Length of Light Vehicle Ownership to someone by E-mail Share Vehicle Technologies Office: Fact #622: May 10, 2010 Average Length of Light Vehicle Ownership on Facebook Tweet about Vehicle Technologies Office: Fact #622: May 10, 2010 Average Length of Light Vehicle Ownership on Twitter Bookmark Vehicle Technologies Office: Fact #622: May 10, 2010 Average Length of Light Vehicle Ownership on Google Bookmark Vehicle Technologies Office: Fact #622: May 10, 2010 Average Length of Light Vehicle Ownership on Delicious Rank Vehicle Technologies Office: Fact #622: May 10, 2010 Average Length of Light Vehicle Ownership on Digg Find More places to share Vehicle Technologies Office: Fact #622: May 10, 2010 Average Length of Light Vehicle Ownership on AddThis.com...

391

Vehicle Technologies Office: Fact #728: May 21, 2012 Average Trip Length is  

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

8: May 21, 2012 8: May 21, 2012 Average Trip Length is Less Than Ten Miles to someone by E-mail Share Vehicle Technologies Office: Fact #728: May 21, 2012 Average Trip Length is Less Than Ten Miles on Facebook Tweet about Vehicle Technologies Office: Fact #728: May 21, 2012 Average Trip Length is Less Than Ten Miles on Twitter Bookmark Vehicle Technologies Office: Fact #728: May 21, 2012 Average Trip Length is Less Than Ten Miles on Google Bookmark Vehicle Technologies Office: Fact #728: May 21, 2012 Average Trip Length is Less Than Ten Miles on Delicious Rank Vehicle Technologies Office: Fact #728: May 21, 2012 Average Trip Length is Less Than Ten Miles on Digg Find More places to share Vehicle Technologies Office: Fact #728: May 21, 2012 Average Trip Length is Less Than Ten Miles on AddThis.com...

392

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

393

In-situ small-angle X-ray scattering study of the precipitation behavior in a Fe-25 at.%Co-9 at.%Mo alloy  

SciTech Connect (OSTI)

Fe-Co-Mo alloys show extraordinary mechanical properties which make them potential candidates for various high-performance applications. In the present study, for the first time, the precipitation behavior in a Fe-25 at.%Co-9 at.%Mo alloy was studied by small-angle X-ray scattering using high-energy synchrotron radiation. The specimens were isothermally aged in an in-situ furnace. The small-angle X-ray scattering patterns showed scaling behavior and were evaluated by employing a model function from the literature. This approach provides information about the characteristic length scale and the volume fraction of the precipitates in the alloy.

Zickler, Gerald A. [Department of Physical Metallurgy and Materials Testing, Montanuniversitaet Leoben, Franz-Josef-Strasse 18, A-8700 Leoben (Austria); Christian Doppler Laboratory for Early Stages of Precipitation, Montanuniversitaet Leoben, Franz-Josef-Strasse 18, A-8700 Leoben (Austria)], E-mail: gerald.zickler@mu-leoben.at; Eidenberger, Elisabeth [Department of Physical Metallurgy and Materials Testing, Montanuniversitaet Leoben, Franz-Josef-Strasse 18, A-8700 Leoben (Austria); Leitner, Harald [Department of Physical Metallurgy and Materials Testing, Montanuniversitaet Leoben, Franz-Josef-Strasse 18, A-8700 Leoben (Austria); Christian Doppler Laboratory for Early Stages of Precipitation, Montanuniversitaet Leoben, Franz-Josef-Strasse 18, A-8700 Leoben (Austria); Stergar, Erich; Clemens, Helmut [Department of Physical Metallurgy and Materials Testing, Montanuniversitaet Leoben, Franz-Josef-Strasse 18, A-8700 Leoben (Austria); Staron, Peter; Lippmann, Thomas; Schreyer, Andreas [GKSS Research Center Geesthacht, Max-Planck-Strasse 1, D-21502 Geesthacht (Germany)

2008-12-15T23:59:59.000Z

394

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

395

Scattering theory with localized non-Hermiticities  

SciTech Connect (OSTI)

In the context of the recent interest in solvable models of scattering mediated by non-Hermitian Hamiltonians (cf. H. F. Jones, Phys. Rev. D 76, 125003 (2007)) we show that the well-known variability of the ad hoc choice of the metric {theta} which defines the physical Hilbert space of states can help us to clarify several apparent paradoxes. We argue that with a suitable {theta}, a fully plausible physical picture of the scattering can be recovered. Quantitatively, our new recipe is illustrated on an exactly solvable toy model.

Znojil, Miloslav [Nuclear Physics Institute ASCR, 250 68 Rez (Czech Republic)

2008-07-15T23:59:59.000Z

396

Quantum-entanglement-initiated super Raman scattering  

SciTech Connect (OSTI)

It has now been possible to prepare a chain of ions in an entangled state and thus the question arises: How will the optical properties of a chain of entangled ions differ from say a chain of independent particles? We investigate nonlinear optical processes in such chains. Since light scattering is quite a versatile technique to probe matter, we explicitly demonstrate the possibility of entanglement-produced super Raman scattering. Our results suggest the possibility of similar enhancement factors in other nonlinear processes like four-wave mixing.

Agarwal, G. S. [Department of Physics, Oklahoma State University, Stillwater, Oklahoma 74078 (United States)

2011-02-15T23:59:59.000Z

397

[Inelastic electron scattering from surfaces]. [Progress report  

SciTech Connect (OSTI)

This program uses ab-initio and multiple scattering to study surface dynamical processes; high-resolution electron-energy loss spectroscopy is used in particular. Off-specular excitation cross sections are much larger if electron energies are in the LEED range (50--300 eV). The analyses have been extended to surfaces of ordered alloys. Phonon eigenvectors and eigenfrequencies were used as inputs to electron-energy-loss multiple scattering cross section calculations. Work on low-energy electron and positron holography is mentioned.

Not Available

1993-10-01T23:59:59.000Z

398

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

399

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

400

Electromagnetic wave scattering by small bodies  

E-Print Network [OSTI]

A reduction of the Maxwell's system to a Fredholm second-kind integral equation with weakly singular kernel is given for electromagnetic (EM) wave scattering by one and many small bodies. This equation is solved asymptotically as the characteristic size of the bodies tends to zero. The technique developed is used for solving the many-body EM wave scattering problem by rigorously reducing it to solving linear algebraic systems, completely bypassing the usage of integral equations. An equation is derived for the effective field in the medium, in which many small particles are embedded. A method for creating a desired refraction coefficient is outlined.

A. G. Ramm

2008-04-21T23:59:59.000Z

Note: This page contains sample records for the topic "1-to-2-ft lengths scattered" 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

Hydrodynamic simulations of long-scale-length two-plasmon-decay experiments at the Omega Laser Facility  

SciTech Connect (OSTI)

Direct-drive-ignition designs with plastic CH ablators create plasmas of long density scale lengths (L{sub n} {>=} 500 {mu}m) at the quarter-critical density (N{sub qc}) region of the driving laser. The two-plasmon-decay (TPD) instability can exceed its threshold in such long-scale-length plasmas (LSPs). To investigate the scaling of TPD-induced hot electrons to laser intensity and plasma conditions, a series of planar experiments have been conducted at the Omega Laser Facility with 2-ns square pulses at the maximum laser energies available on OMEGA and OMEGA EP. Radiation-hydrodynamic simulations have been performed for these LSP experiments using the two-dimensional hydrocode draco. The simulated hydrodynamic evolution of such long-scale-length plasmas has been validated with the time-resolved full-aperture backscattering and Thomson-scattering measurements. draco simulations for CH ablator indicate that (1) ignition-relevant long-scale-length plasmas of L{sub n} approaching {approx}400 {mu}m have been created; (2) the density scale length at N{sub qc} scales as L{sub n}({mu}m) Asymptotically-Equal-To (R{sub DPP} Multiplication-Sign I{sup 1/4}/2); and (3) the electron temperature T{sub e} at N{sub qc} scales as T{sub e}(keV) Asymptotically-Equal-To 0.95 Multiplication-Sign {radical}(I), with the incident intensity (I) measured in 10{sup 14} W/cm{sup 2} for plasmas created on both OMEGA and OMEGA EP configurations with different-sized (R{sub DPP}) distributed phase plates. These intensity scalings are in good agreement with the self-similar model predictions. The measured conversion fraction of laser energy into hot electrons f{sub hot} is found to have a similar behavior for both configurations: a rapid growth [f{sub hot} Asymptotically-Equal-To f{sub c} Multiplication-Sign (G{sub c}/4){sup 6} for G{sub c} < 4] followed by a saturation of the form, f{sub hot} Asymptotically-Equal-To f{sub c} Multiplication-Sign (G{sub c}/4){sup 1.2} for G{sub c} {>=} 4, with the common wave gain is defined as G{sub c}=3 Multiplication-Sign 10{sup -2} Multiplication-Sign I{sub qc}L{sub n}{lambda}{sub 0}/T{sub e}, where the laser intensity contributing to common-wave gain I{sub qc}, L{sub n}, T{sub e} at N{sub qc}, and the laser wavelength {lambda}{sub 0} are, respectively, measured in [10{sup 14} W/cm{sup 2}], [{mu}m], [keV], and [{mu}m]. The saturation level f{sub c} is observed to be f{sub c} Asymptotically-Equal-To 10{sup -2} at around G{sub c} Asymptotically-Equal-To 4. The hot-electron temperature scales roughly linear with G{sub c}. Furthermore, to mitigate TPD instability in long-scale-length plasmas, different ablator materials such as saran and aluminum have been investigated on OMEGA EP. Hot-electron generation has been reduced by a factor of 3-10 for saran and aluminum plasmas, compared to the CH case at the same incident laser intensity. draco simulations suggest that saran might be a better ablator for direct-drive-ignition designs as it balances TPD mitigation with an acceptable hydro-efficiency.

Hu, S. X.; Michel, D. T.; Edgell, D. H.; Froula, D. H.; Follett, R. K.; Goncharov, V. N.; Myatt, J. F.; Skupsky, S.; Yaakobi, B. [Laboratory for Laser Energetics, University of Rochester, 250 E. River Road, Rochester, New York 14623 (United States)

2013-03-15T23:59:59.000Z

402

Critical fluctuations in MnSi near T{sub C}: A polarized neutron scattering study  

SciTech Connect (OSTI)

Results of polarized neutron small angle scattering in MnSi, a cubic itinerant magnet, near T{sub c}=28.8 K are presented and analyzed. The diffuse scattering intensity looks like half-moons oriented along the incident neutron polarization. The sum of the intensities for two opposite polarizations form an anisotropic ring with weak spots, which below T{sub c} transform into the Bragg peaks originating from the helical structure. These results are in semiquantitative agreement with the mean-field calculations based on the Bak-Jensen model that takes into account the hierarchy of the interactions: the exchange interaction, the isotropic Dzyaloshinskii-Moriya (DM) interaction and the weak anisotropic exchange (AE) interaction. The DM interaction is responsible for the scattering intensity concentrated in the half-moons. The AE interaction provides the anisotropy so that the correlation length diverges along [111] only. The corresponding critical exponent is {nu}=0.62(1). The exponent of the Bragg intensity due to the helical structure at T

Grigoriev, S.V.; Maleyev, S.V.; Okorokov, A.I.; Chetverikov, Yu.O. [Petersburg Nuclear Physics Institute, Gatchina, St. Petersburg 188300 (Russian Federation); Georgii, R.; Boeni, P.; Lamago, D. [ZWE FRM-II/E21, Technische Universitaet Muenchen, 85747 Garching (Germany); Eckerlebe, H.; Pranzas, K. [GKSS Forschungszentrum, 21502 Geesthacht (Germany)

2005-10-01T23:59:59.000Z

403

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

404

Nonrelativistic Description of Nucleon-Nucleus Scattering  

SciTech Connect (OSTI)

Within the three-dimensional semiclassical approximation, an analytic expression is obtained for the amplitude of proton-nucleus scattering at intermediate energies of incident protons. The method for deriving this amplitude is based on the use of the high-energy approximation with distorted waves. In view of the short-range character of proton-nucleon interaction, the process of proton-nucleus scattering is represented as a series of single scattering events occurring on each individual nucleon. With the aid of the proposed mathematical formalism, a recursion relation is derived that makes it possible to express the nuclear form factor obtained within the distorted-wave method in terms of the sum of an infinite Born series. Parameters that characterize the distributions of protons and neutrons in the spherical nuclei {sup 40}Ca, {sup 48}Ca, {sup 90}Zr, and {sup 208}Pb and which include the width of the surface layer of nucleons and the root-mean-square radii of the proton-, neutron-, and nucleon-density distributions are determined from an analysis of the measured cross sections for the elastic scattering of 1-GeV protons, a modified Fermi function being employed for the nucleon-density distribution.

Mirabutalybov, M.M. [Azerbaijan State Petroleum Academy, pr. Azadlyg 20, Baku, 370010 (Azerbaijan)

2004-12-01T23:59:59.000Z

405

Compton Scattering Sources and Applications at LLNL  

SciTech Connect (OSTI)

We report the design and current status of a monoenergetic laser-based Compton scattering 0.5-2.5 MeV {gamma}-ray source. Previous nuclear resonance fluorescence results and future linac and laser developments for the source are presented.

Albert, Felicie; Anderson, S. G.; Anderson, G.; Bayramian, A.; Betts, S. M.; Cross, R. R.; Ebbers, C. A.; Gibson, D. J.; Marsh, R. A.; Messerly, M.; Shverdin, M. Y.; Wu, S. S.; Hartemann, F. V.; Scarpetti, R.; Siders, C. W.; Barty, C. P. J. [Lawrence Livermore National Laboratory, NIF and Photon Science, 7000 East Avenue, Livermore, CA, 94550 (United States)

2010-11-04T23:59:59.000Z

406

Rutherford Scattering MIT Department of Physics  

E-Print Network [OSTI]

Rutherford Scattering MIT Department of Physics (Dated: September 1, 2013) This is an experiment on the web site. SUGGESTED PROGRESS CHECK FOR END OF 2nd SESSION Plot the rate of alpha particle observations, an alpha particle traversing a thin gold film should experience many small angle deflections as it passes

Seager, Sara

407

The Phase of the Scattering Matrix  

E-Print Network [OSTI]

Vacuum polarization in external fields is treated by way of calculating - exactly and then perturbatively - the phase of the quantum scattering matrix in the Shale-Stinespring approach to field theory. The link between the Shale-Stinespring method and the Epstein-Glaser renormalization procedure is highlighted.

Gracía-Bondía, José M

2000-01-01T23:59:59.000Z

408

Fiber optic probe for light scattering measurements  

DOE Patents [OSTI]

This invention is comprised of a fiber optic probe and a method for using the probe for light scattering analyses of a sample. The probe includes a probe body with an inlet for admitting a sample into an interior sample chamber, a first optical fiber for transmitting light from a source into the chamber, and a second optical fiber for transmitting light to a detector such as a spectrophotometer. The interior surface of the probe carries a coating that substantially prevents non-scattered light from reaching the second fiber. The probe is placed in a region where the presence and concentration of an analyte of interest are to be detected, and a sample is admitted into the chamber. Exciting light is transmitted into the sample chamber by the first fiber, where the light interacts with the sample to produce Raman-scattered light. At least some of the Raman- scattered light is received by the second fiber and transmitted to the detector for analysis. Two Raman spectra are measured, at different pressures. The first spectrum is subtracted from the second to remove background effects, and the resulting sample Raman spectrum is compared to a set of stored library spectra to determine the presence and concentration of the analyte.

Nave, S.E.; Livingston, R.R.; Prather, W.S.

1993-01-01T23:59:59.000Z

409

Rapid Research Note Raman Scattering in Resonance  

E-Print Network [OSTI]

-uniformity in the ternary alloy InGaN [4, 5]. However, resonance Raman scattering at bound excitons as reported for CdS doped 220 mm thick GaN film grown by hydride vapor phase epitaxy. Sapphire (0001) with a sputtered Zn

Nabben, Reinhard

410

Multiparameter light scattering for rapid virus identification  

SciTech Connect (OSTI)

An instrument for making multiparameter light scattering (MLS) measurements from viral suspensions has been described. Calibration methods and a technique for the correction of artifacts were also presented. This measurement technique may have broad applications in cell biology in general and in virology in particular. It may be possible to use MLS to identify viruses directly from clinical specimens. 8 references, 7 figures.

Salzman, G.C.; Grace, W.K.; McGregor, D.M.; Gregg, C.T.

1984-01-01T23:59:59.000Z

411

Focusing on moving targets through scattering samples  

E-Print Network [OSTI]

. http://dx.doi.org/10.1364/OPTICA.1.000227 1. INTRODUCTION Focusing light through highly scattering-2536/14/040227-06$15/0$15.00 © 2014 Optical Society of America Research Article Vol. 1, No. 4 / October 2014 / Optica 227 #12

Yang, Changhuei

412

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

413

SCATTERING BEHAVIOR OF TRANSITIONAL SHOCK WAVES  

E-Print Network [OSTI]

SCATTERING BEHAVIOR OF TRANSITIONAL SHOCK WAVES Kevin R. Zumbrun Bradley J. Plohr Dan Marchesin September, 1991 Abstract. We study the stability and asymptotic behavior of transitional shock waves as solutions of a parabolic system of conservation laws. In contrast to classical shock waves, transitional

New York at Stoney Brook, State University of

414

Fiber optic probe for light scattering measurements  

DOE Patents [OSTI]

A fiber optic probe and a method for using the probe for light scattering analyses of a sample. The probe includes a probe body with an inlet for admitting a sample into an interior sample chamber, a first optical fiber for transmitting light from a source into the chamber, and a second optical fiber for transmitting light to a detector such as a spectrophotometer. The interior surface of the probe carries a coating that substantially prevents non-scattered light from reaching the second fiber. The probe is placed in a region where the presence and concentration of an analyte of interest are to be detected, and a sample is admitted into the chamber. Exciting light is transmitted into the sample chamber by the first fiber, where the light interacts with the sample to produce Raman-scattered light. At least some of the Raman-scattered light is received by the second fiber and transmitted to the detector for analysis. Two Raman spectra are measured, at different pressures. The first spectrum is subtracted from the second to remove background effects, and the resulting sample Raman spectrum is compared to a set of stored library spectra to determine the presence and concentration of the analyte.

Nave, Stanley E. (Evans, GA); Livingston, Ronald R. (Aiken, SC); Prather, William S. (Augusta, GA)

1995-01-01T23:59:59.000Z

415

Microscopic prescriptions for elastic and inelastic scattering  

SciTech Connect (OSTI)

New prescriptions are presented for the single scattering approximations for the optical potential and distorted-wave impulse approximation transition amplitudes. They are based on the application of systematics observed in the behavior of off-shell T matrices calculated from realistic potential models.

Redish, E.F.; Stricker-Bauer, K.

1987-04-01T23:59:59.000Z

416

Doppler Effect in Light-Scattering  

Science Journals Connector (OSTI)

... the subject classically, the result to be expected is obvious: there should be a Doppler broadening of the incident spectral line, varying with the angle of observation, and determined ... should persist in the scattered light in the same position with no change except a Doppler broadening.

C. V. RAMAN

1931-10-10T23:59:59.000Z

417

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

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

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

418

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...

419

Absorption and scattering by long and randomly oriented linear chains of spheres  

E-Print Network [OSTI]

experimental measurements absorption and scattering cross-C. Bohren and D. Huffman, Absorption and Scattering of LightScattering and absorption of light by nonspherical

Lee, Euntaek; Pilon, Laurent

2013-01-01T23:59:59.000Z

420

Probing Pulsar Winds Using Inverse Compton Scattering  

E-Print Network [OSTI]

We investigate the effects of inverse Compton scattering by electrons and positrons in the unshocked winds of rotationally-powered binary pulsars. This process can scatter low energy target photons to produce gamma rays with energies from MeV to TeV. The binary radio pulsars PSR B1259-63 and PSR J0045-73 are both in close eccentric orbits around bright main sequence stars which provide a huge density of low energy target photons. The inverse Compton scattering process transfers momentum from the pulsar wind to the scattered photons, and therefore provides a drag which tends to decelerate the pulsar wind. We present detailed calculations of the dynamics of a pulsar wind which is undergoing inverse Compton scattering, showing that the deceleration of the wind of PSR B1259-63 due to `inverse Compton drag' is small, but that this process may confine the wind of PSR J0045-73 before it attains pressure balance with the outflow of its companion star. We calculate the spectra and light curves of the resulting inverse Compton emission from PSR B1259-63 and show that if the size of the pulsar wind nebula is comparable to the binary separation, then the gamma-ray emission from the unshocked wind may be detectable by atmospheric Cerenkov detectors or by the new generation of satellite-borne gamma-ray detectors such as INTEGRAL and GLAST. This mechanism may therefore provide a direct probe of the freely-expanding regions of pulsar winds, previously thought to be invisible.

Lewis Ball; J. G. Kirk

1999-08-18T23:59:59.000Z

Note: This page contains sample records for the topic "1-to-2-ft lengths scattered" 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

SunShot Initiative: Scattering Solar Thermal Concentrators  

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

Scattering Solar Thermal Scattering Solar Thermal Concentrators to someone by E-mail Share SunShot Initiative: Scattering Solar Thermal Concentrators on Facebook Tweet about SunShot Initiative: Scattering Solar Thermal Concentrators on Twitter Bookmark SunShot Initiative: Scattering Solar Thermal Concentrators on Google Bookmark SunShot Initiative: Scattering Solar Thermal Concentrators on Delicious Rank SunShot Initiative: Scattering Solar Thermal Concentrators on Digg Find More places to share SunShot Initiative: Scattering Solar Thermal Concentrators on AddThis.com... Concentrating Solar Power Systems Components Competitive Awards CSP Research & Development Thermal Storage CSP Recovery Act Baseload CSP SunShot Multidisciplinary University Research Initiative CSP Heat Integration for Baseload Renewable Energy Deployment

422

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

423

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...

424

Inverse scattering by a continuation method with initial guesses from ...  

E-Print Network [OSTI]

Sep 5, 2007 ... b Department of Mathematics and Statistics, Louisiana Tech University, ... The present paper focuses on the inverse scattering problem. ..... Example 1: (a) the true scatterer; (b) the initial guess; and (c) the final reconstruction.

2007-10-11T23:59:59.000Z

425

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

426

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

427

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

428

Anisotropic light scattering of individual sickle red blood cells  

E-Print Network [OSTI]

We present the anisotropic light scattering of individual red blood cells (RBCs) from a patient with sickle cell disease (SCD). To measure light scattering spectra along two independent axes of elongated-shaped sickle RBCs ...

Kim, Youngchan

429

Bright-White Beetle Scales Optimise Multiple Scattering of Light  

E-Print Network [OSTI]

Whiteness arises from diffuse and broadband reflection of light typically achieved through optical scattering in randomly structured media. In contrast to structural colour due to coherent scattering, white appearance ...

Burresi, Matteo

430

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

431

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...

432

Elastic scattering of Dirac fermions on Schwarzschild black holes  

E-Print Network [OSTI]

Approximative analytic solutions of the Dirac equation in the Schwarzschild geometry are used for building the partial wave analysis of the Dirac fermions scattered by black holes. The analytic expressions of the differential cross section and induced polarization degree are derived in terms of scattering angle, mass of the black-hole, energy and mass of the fermion. We perform a graphical study of differential cross section analysing the forward/backward scattering (known also as glory scattering) and the polarization degree as functions of scattering angle. The graphical analysis shows the presence of oscillations in scattering intensity around forward/backward directions, phenomena known as spiral scattering. In addition, we find that the scattering probability increases significantly for fermions with large angular momentum. The energy dependence of the differential cross section is also established by using analytical and graphical methods.

Ion I. Cotaescu; Cosmin Crucean; Ciprian A. Sporea

2014-10-08T23:59:59.000Z

433

Incoherent x-ray scattering in single molecule imaging  

E-Print Network [OSTI]

Imaging of the structure of single proteins or other biomolecules with atomic resolution would be enormously beneficial to structural biology. X-ray free-electron lasers generate highly intense and ultrashort x-ray pulses, providing a route towards imaging of single molecules with atomic resolution. The information on molecular structure is encoded in the coherent x-ray scattering signal. In contrast to crystallography there are no Bragg reflections in single molecule imaging, which means the coherent scattering is not enhanced. Consequently, a background signal from incoherent scattering deteriorates the quality of the coherent scattering signal. This background signal cannot be easily eliminated because the spectrum of incoherently scattered photons cannot be resolved by usual scattering detectors. We present an ab initio study of incoherent x-ray scattering from individual carbon atoms, including the electronic radiation damage caused by a highly intense x-ray pulse. We find that the coherent scattering pa...

Slowik, Jan Malte; Dixit, Gopal; Jurek, Zoltan; Santra, Robin

2014-01-01T23:59:59.000Z

434

Inter-filament Attractions Narrow the Length Distribution of Actin Filaments  

E-Print Network [OSTI]

We show that the exponential length distribution that is typical of actin filaments under physiological conditions dramatically narrows in the presence of (i) crosslinker proteins (ii) polyvalent counterions or (iii) depletion mediated attractions. A simple theoretical model shows that in equilibrium, short-range attractions enhance the tendency of filaments to align parallel to each other, eventually leading to an increase in the average filament length and a decrease in the relative width of the distribution of filament lengths.

David Biron; Elisha Moses; Itamar Borukhov; S. A. Safran

2004-06-13T23:59:59.000Z

435

Measuring short electron bunch lengths using coherent smith-purcell radiation  

DOE Patents [OSTI]

A method is provided for directly determining the length of sub-picosecond electron bunches. A metallic grating is formed with a groove spacing greater than a length expected for the electron bunches. The electron bunches are passed over the metallic grating to generate coherent and incoherent Smith-Purcell radiation. The angular distribution of the coherent Smith-Purcell radiation is then mapped to directly deduce the length of the electron bunches.

Nguyen, Dinh C. (Los Alamos, NM)

1999-01-01T23:59:59.000Z

436

Persistence-Length Renormalization of Polymers in a Crowded Environment of Hard Disks  

E-Print Network [OSTI]

The most conspicuous property of a semiflexible polymer is its persistence length, defined as the decay length of tangent correlations along its contour. Using an efficient stochastic growth algorithm to sample polymers embedded in a quenched two-dimensional hard-disk fluid, we find apparent wormlike chain statistics with a renormalized persistence length. We identify a universal form of the disorder renormalization that suggests itself as a quantitative measure of molecular crowding.

Sebastian Schöbl; Sebastian Sturm; Wolfhard Janke; Klaus Kroy

2014-10-22T23:59:59.000Z

437

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

SciTech Connect (OSTI)

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

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

2013-01-01T23:59:59.000Z

438

Stimulated scattering in laser driven fusion and high energy density physics experiments  

SciTech Connect (OSTI)

In laser driven fusion and high energy density physics experiments, one often encounters a k?{sub D} range of 0.15?scattering (SRS) is active (k is the initial electron plasma wave number and ?{sub D} is the Debye length). Using particle-in-cell simulations, the SRS reflectivity is found to scale as ? (k?{sub D}){sup ?4} for k?{sub D} ? 0.3 where electron trapping effects dominate SRS saturation; the reflectivity scaling deviates from the above for k?{sub D}?scattering processes are found to be unimportant under conditions relevant to ignition experiments at the National Ignition Facility (NIF). Large-scale simulations of the hohlraum plasma show that the SRS wavelength spectrum peaks below 600?nm, consistent with most measured NIF spectra, and that nonlinear trapping in the presence of plasma gradients determines the SRS spectral peak. Collisional effects on SRS, stimulated Brillouin scattering (SBS), LDI, and re-scatter, together with three dimensional effects, are examined. Effects of collisions are found to include de-trapping as well as cross-speckle electron temperature variation from collisional heating, the latter of which reduces gain, introduces a positive frequency shift that counters the trapping-induced negative frequency shift, and affects SRS and SBS saturation. Bowing and breakup of ion-acoustic wavefronts saturate SBS and cause a dramatic, sharp decrease in SBS reflectivity. Mitigation of SRS and SBS in the strongly nonlinear trapping regime is discussed.

Yin, L., E-mail: lyin@lanl.gov; Albright, B. J.; Rose, H. A.; Montgomery, D. S.; Kline, J. L.; Finnegan, S. M.; Bergen, B.; Bowers, K. J. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Kirkwood, R. K.; Milovich, J. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

2014-09-15T23:59:59.000Z

439

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; François Boué

2003-07-04T23:59:59.000Z

440

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

Note: This page contains sample records for the topic "1-to-2-ft lengths scattered" 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

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

442

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

443

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

444

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

445

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.

446

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

447

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

448

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

449

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

450

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

451

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.

452

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

453

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

454

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

455

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

456

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

457

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

458

Recent Results in Diffractive ep Scattering at HERA  

E-Print Network [OSTI]

Recent Results in Diffractive ep Scattering at HERA Introduction to diffraction in ep Exclusive Diffraction in ep Scattering Matthew Beckingham 2 Diffraction Lepton-hadron (-p) or hadron-hadron (p to interpret in (p)QCD? #12;Lake Louise 06 Diffraction in ep Scattering Matthew Beckingham 3 Diffraction

459

Small Angle X-ray Scattering (SAXS) Laboratory Learning Experiences  

E-Print Network [OSTI]

.A. & Svergun D.I. (1987). Structure Analysis by Small-Angle X-Ray and Neutron Scattering. NY: Plenum PressSmall Angle X-ray Scattering (SAXS) Laboratory Learning Experiences o - Use of small angle X-ray scattering instrumentation o - Programs that you will use SAXS (BRUKER AXS) PRIMUS (Konarev, Volkov, Koch

Meagher, Mary

460

Anisotropic light scattering of individual sickle red blood cells  

E-Print Network [OSTI]

Anisotropic light scattering of individual sickle red blood cells Youngchan Kim John M. Higgins blood cells (RBCs) from a patient with sickle cell disease (SCD). To measure light scattering spectra: red blood cell; sickle cell disease; light scattering; quantita- tive phase microscopy. Paper 11736L

Suresh, Subra

Note: This page contains sample records for the topic "1-to-2-ft lengths scattered" 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

Wavelength-dependent scattering in spectroscopic optical coherence tomography  

E-Print Network [OSTI]

Wavelength-dependent scattering in spectroscopic optical coherence tomography Chenyang Xu, P. Scott of light scattering spectroscopy (LSS) and the spatial localization of optical coherence tomography (OCT.4500) Optical coherence tomography; (290.0290) Scattering; (300.0300) Spectroscopy References and links 1. A

Bhargava, Rohit

462

ccsd00002835, Light scattering from cold rolled aluminum surfaces  

E-Print Network [OSTI]

ccsd­00002835, version 2 ­ 14 Sep 2004 Light scattering from cold rolled aluminum surfaces Damien Camille Soula , 31400 Toulouse, France We present experimental light scattering measurements from aluminum scattering measurements of an s-polarized electromagnetic wave (632.8 nanometers) from a rough aluminum alloy

463

Similarity between positronium-atom and electron-atom scattering  

E-Print Network [OSTI]

We employ the impulse approximation for description of positronium-atom scattering. Our analysis and calculations of Ps-Kr and Ps-Ar collisions provide theoretical explanation of the similarity between the cross sections for positronium scattering and electron scattering for a range of atomic and molecular targets observed by S. J. Brawley et al. [Science 330, 789 (2010)].

Fabrikant, I I

2015-01-01T23:59:59.000Z

464

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

465

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 liquid–glass 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

466

Neutron scattering study of the hydration hull of DNA by H/sub 2/O/D/sub 2/O-exchange  

SciTech Connect (OSTI)

Films of highly oriented DNA (A-, B-, and C-conformation) were investigated by neutron scattering. Diffuse sheets corresponding to a one-dimensionally periodic ''water-DNA'' structure are identified close to the intersection of the helix direction with the structure factor maximum of bulk water. The correlation length in this structure is strongly influenced by its commensurability with the axial translation H per nucleotide. The fiber or lateral chain interaction is enhanced in the commensurate case. 10 refs., 3 figs.

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

1988-01-01T23:59:59.000Z

467

Nonperturbative NN scattering in {sup 3}S{sub 1}–{sup 3}D{sub 1} channels of EFT(??)  

SciTech Connect (OSTI)

The closed-form T matrices in the {sup 3}S{sub 1}–{sup 3}D{sub 1} channels of EFT(??) for NN scattering with the potentials truncated at order O(Q{sup 4}) are presented with the nonperturbative divergences parametrized in a general manner. The stringent constraints imposed by the closed form of the T matrices are exploited in the underlying theory perspective and turned into virtues in the implementation of subtractions and the manifestation of power counting rules in nonperturbative regimes, leading us to the concept of EFT scenario. A number of scenarios of the EFT description of NN scattering are compared with PSA data in terms of effective range expansion and {sup 3}S{sub 1} phase shifts, showing that it is favorable to proceed in a scenario with conventional EFT couplings and sophisticated renormalization in order to have large NN scattering lengths. The informative utilities of fine tuning are demonstrated in several examples and naturally interpreted in the underlying theory perspective. In addition, some of the approaches adopted in the recent literature are also addressed in the light of EFT scenario. -- Highlights: •Closed-form unitary T matrices for NN scattering are obtained in EFT(??). •Nonperturbative properties inherent in such closed-form T matrices are explored. •Nonperturbative renormalization is implemented through exploiting these properties. •Unconventional power counting of couplings is shown to be less favored by PSA data. •The ideas about nonperturbative renormalization here might have wider applications.

Yang, Ji-Feng, E-mail: jfyang@phy.ecnu.edu.cn

2013-12-15T23:59:59.000Z

468

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

469

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

E-Print Network [OSTI]

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

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

2014-03-11T23:59:59.000Z

470

Multiple Scattering Measurements in the MICE Experiment  

SciTech Connect (OSTI)

The international Muon Ionization Cooling Experiment (MICE), under construction at RAL, will test a prototype cooling channel for a future Neutrino Factory or Muon Collider. The cooling channel aims to achieve, using liquid hydrogen absorbers, a 10% reduction in transverse emittance. The change in 4D emittance will be determined with an accuracy of 1% by measuring muons individually. Step IV of MICE will make the first precise emittance-reduction measurements of the experiment. Simulation studies using G4MICE, based on GEANT4, find a significant difference in multiple scattering in low Z materials, compared with the standard expression quoted by the Particle Data Group. Direct measurement of multiple scattering using the scintillating-fibre trackers is found to be possible, but requires the measurement resolution to be unfolded from the data.

Carlisle, T.; Cobb, J.; /Oxford U.; Neuffer, D.; /Fermilab

2012-05-01T23:59:59.000Z

471

Optical theorem and elastic nucleon scattering  

E-Print Network [OSTI]

In the theoretical analysis of high-energy elastic nucleon scattering one starts commonly from the description based on the validity of optical theorem, which allows to derive the value of total cross section directly from the experimentally measured t-dependence of elastic differential cross section. It may be shown, however, that this theorem has been derived on the basis of one assumption that might be regarded perhaps as acceptable for long-range (e.g., Coulomb) forces but must be denoted as quite unacceptable for finite-range hadron forces. Consequently, the conclusions leading to the increase of total cross section with energy at higher collision energies must be newly analyzed. The necessity of new analysis concerns also the derivation of elastic scattering t-dependence at very low transverse momenta from measured data.

Milos V. Lokajicek; Vojtech Kundrat

2009-06-22T23:59:59.000Z

472

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 6.8×10-24 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

473

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 1–10 Å. 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

474

Raman scattering from sp2 carbon clusters  

Science Journals Connector (OSTI)

Raman spectra of B ion-implanted glassy carbon (GC) and hydrogenated amorphous carbon (a-C:H) films have been measured as a function of polarization direction of the scattered light and excitation wavelength. Raman bands of GC implanted heavily with a fluence of more than 5×1015 B ions/cm2 and a-C:H films show a frequency-independent depolarization ratio, suggesting the existence of sp2 carbon clusters in these samples. It was found that Raman spectra of GC implanted heavily with a fluence of more than 5×1015 B ions/cm2 varied with the excitation wavelength. From a comparative study of the heavily implanted GC and a-C:H films, the variation of the Raman spectra with the excitation wavelength observed for the heavily implanted GC is interpreted in terms of ?-?* resonant Raman scattering from sp2 carbon clusters having various sizes.

M. Yoshikawa; N. Nagai; M. Matsuki; H. Fukuda; G. Katagiri; H. Ishida; A. Ishitani; I. Nagai

1992-09-15T23:59:59.000Z

475

Scattering off an SO(10) cosmic string  

Science Journals Connector (OSTI)

The scattering of fermions from the Abelian string arising during the phase transition SO(10)?SU(5)×Z2 induced by the Higgs field in the 126 representation is studied. Elastic cross sections and baryon-number-violating cross sections due to the coupling to gauge fields in the core of the string are computed by both a first-quantized method and a perturbative second-quantized method. The elastic cross sections are found to be Aharonov-Bohm-type. However, there is a marked asymmetry between the scattering cross sections for left- and right-handed fields. The catalysis cross sections are small, depending on the grand unified scale. If cosmic strings were observed our results could help tie down the underlying gauge group.

Anne-Christine Davis and Rachel Jeannerot

1995-08-15T23:59:59.000Z

476

Adiabatic Approximation, Semiclassical Scattering, and Unidirectional Invisibility  

E-Print Network [OSTI]

The transfer matrix of a possibly complex and energy-dependent scattering potential can be identified with the $S$-matrix of a two-level time-dependent non-Hermitian Hamiltonian H(t). We show that the application of the adiabatic approximation to H(t) corresponds to the semiclassical description of the original scattering problem. In particular, the geometric part of the phase of the evolving eigenvectors of H(t) gives the pre-exponential factor of the WKB wave functions. We use these observations to give an explicit semiclassical expression for the transfer matrix. This allows for a detailed study of the semiclassical unidirectional reflectionlessness and invisibility. We examine concrete realizations of the latter in the realm of optics.

Ali Mostafazadeh

2014-01-17T23:59:59.000Z

477

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

478

Brillouin scattering study of molten zinc chloride  

Science Journals Connector (OSTI)

Polarized and depolarized Brillouin scattering experiments on molten ZnCl2 were performed between 300 and 600 °C in different geometries. VV spectra measured in backscattering and small angle scattering were analyzed with conventional viscoelastic theory using either a Debye or a Cole-Davidson model for the memory function. We also analyzed in the same way the temperature dependence of the transverse Brillouin lines detected in a 90° VH geometry. We show that the Cole-Davidson memory function yields a consistent interpretation of all the spectra. The resulting shear and longitudinal relaxation times are equal within their error bars, and are about 2.5 times smaller than the ? relaxation time previously determined. The static shear viscosity values deduced from the analysis of the propagating transverse waves agree, at all temperatures, with the measured viscosity values.

C. Dreyfus; M. J. Lebon; F. Vivicorsi; A. Aouadi; R. M. Pick; H. Z. Cummins

2001-03-29T23:59:59.000Z

479

Fixed target electroweak and hard scattering physics  

SciTech Connect (OSTI)

The possibilities for future physics and experiments involving weak and electromagnetic interactions, neutrino oscillations, general hard scattering and experiments involving nuclear targets were explored. The studies were limited to the physics accessible using fixed target experimentation. While some of the avenues explored turn out to be relatively unrewarding in the light of competition elsewhere in the world, there are a number of positive conclusions reached about experimentation in the energy range available to the Main Injector and Tevatron. Some of the experiments would benefit from the increased intensity available from the Tevatron utilizing the Main Injector, while some require this increase. Finally, some of the experiments would use the Main Injector low energy, high intensity extracted beams directly. A program of electroweak and hard scattering experiments at fixed target energies retains the potential for important contributions to physics. The key to major parts of this program would appear to be the existence of the Main Injector. 115 refs, 17 figs.

Brock, R. (Michigan State Univ., East Lansing, MI (USA)); Brown, C.N.; Montgomery, H.E. (Fermi National Accelerator Lab., Batavia, IL (USA)); Corcoran, M.D. (eds.) (Rice Univ., Houston, TX (USA))

1990-02-01T23:59:59.000Z

480

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?Å 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

Note: This page contains sample records for the topic "1-to-2-ft lengths scattered" 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

Pumping angular momentum by driven chaotic scattering  

E-Print Network [OSTI]

Chaotic scattering with an internal degree of freedom and the possibility to generate directed transport of angular momentum is studied in a specific model, a magnetic dipole moving in a periodically modulated magnetic field confined to a compact region in space. We show that this system is an irregular scatterer in large parts of its parameter space. If in addition all spatio-temporal symmetries are broken, directed transport of mass as well as angular momentum occurs. The sensitive parameter dependence of the corresponding currents includes frequent sign reversals. Zeros of either quantity entail the exclusive occurrence of the other and thus give rise in particular to angular-momentum separation without mass transport as a classical analogue of spin-polarized currents.

T. Dittrich; F. L. Dubeibe

2008-04-29T23:59:59.000Z

482

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

483

Recent results from COMPASS muon scattering measurements  

SciTech Connect (OSTI)

A sample of recent results in muon scattering measurements from the COMPASS experiment at CERN will be reviewed. These include high energy processes with longitudinally polarised proton and deuteron targets. High energy polarised measurements provide important constraints for studying the nucleon spin structure and thus permit to test the applicability of the theoretical framework of factorisation theorems and perturbative QCD. Specifically, latest results on longitudinal quark polarisation, quark helicity densities and gluon polarisation will be reviewed.

Capozza, Luigi [Irfu/SPhN - CEA Saclay, 91190 Gif-sur-Yvette (France); Collaboration: COMPASS Collaboration

2012-10-23T23:59:59.000Z

484

Scatter factors assessment in microbeam radiation therapy  

SciTech Connect (OSTI)

Purpose: The success of the preclinical studies in Microbeam Radiation Therapy (MRT) paved the way to the clinical trials under preparation at the Biomedical Beamline of the European Synchrotron Radiation Facility. Within this framework, an accurate determination of the deposited dose is crucial. With that aim, the scatter factors, which translate the absolute dose measured in reference conditions (2 x 2 cm{sup 2} field size at 2 cm-depth in water) to peak doses, were assessed. Methods: Monte Carlo (MC) simulations were performed with two different widely used codes, PENELOPE and GEANT4, for the sake of safety. The scatter factors were obtained as the ratio of the doses that are deposited by a microbeam and by a field of reference size, at the reference depth. The calculated values were compared with the experimental data obtained by radiochromic (ISP HD-810) films and a PTW 34070 large area chamber. Results: The scatter factors for different microbeam field sizes assessed by the two MC codes were in agreement and reproduced the experimental data within uncertainty bars. Those correction factors were shown to be non-negligible for the future MRT clinical settings: an average 30% lower dose was deposited by a 50 {mu}m microbeam with respect to the reference conditions. Conclusions: For the first time, the scatter factors in MRT were systematically studied. They constitute an essential key to deposit accurate doses in the forthcoming clinical trials in MRT. The good agreement between the different calculations and the experimental data confirms the reliability of this challenging micrometric dose estimation.

Prezado, Y.; Martinez-Rovira, I.; Sanchez, M. [Laboratoire Imagerie et Modelisation en Neurobiologie et Cancerologie IMNC-UMR 8165, Centre National de la Recherche Scientifique (CNRS), Campus Universitaire, Bat. 440, 15 rue Georges Clemenceau, 91406 Orsay Cedex (France); Institut de Tecniques Energetiques, Universitat Politecnica de Catalunya, Diagonal 647, E-08028 Barcelona (Spain) and ID17 Biomedical Beamline, European Synchrotron Radiation Facility (ESRF), 6 Rue Jules Horowitz, B.P. 220, 38043 Grenoble Cedex (France); Servicio de Radiofisica, Complejo Hospitalario de Santiago de Compostela, Rua Choupana S/N, 15706 Santiago de Compostela (Spain)

2012-03-15T23:59:59.000Z

485

Pionic atoms and low energy elastic scattering  

SciTech Connect (OSTI)

A fit to pionic atom data is used to determine four of the parameters of the low energy pion-nucleus optical potential, while the other parameters are taken from theory. The resulting potential is used to predict elastic scattering from 30 --50 MeV pions. The effects of extrapolating the parameters to 50 MeV with a simple energy dependence are examined.

Stricker, K.; Carr, J.A.; McManus, H.

1980-11-01T23:59:59.000Z

486

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. Magazù; G. Maisano; F. Migliardo

2004-01-01T23:59:59.000Z

487

Finite Rank Perturbations, Scattering Matrices and Inverse Problems  

E-Print Network [OSTI]

In this paper the scattering matrix of a scattering system consisting of two selfadjoint operators with finite dimensional resolvent difference is expressed in terms of a matrix Nevanlinna function. The problem is embedded into an extension theoretic framework and the theory of boundary triplets and associated Weyl functions for (in general nondensely defined) symmetric operators is applied. The representation results are extended to dissipative scattering systems and an explicit solution of an inverse scattering problem for the Lax-Phillips scattering matrix is presented.

Jussi Behrndt; Mark M. Malamud; Hagen Neidhardt

2009-02-20T23:59:59.000Z

488

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

489

Volume Scattering?Strength Profiles in the Northeast Pacific Ocean  

Science Journals Connector (OSTI)

A technique is described that permits the determination of the acoustic scattering strength of the ocean volume in terms of depth frequency and time. A pod of charges is lowered together with a hydrophone to various depths in the ocean and by observing the amount of scattered energy produced by detonating units of the explosive charge pod a profile of good resolution of the scattering strength versus depths obtained. The broad?band acoustic characteristics of the charges permit the spectral characteristics of the scattered returns to be determined. Observations made over an extended time period yield the time dependence of scattering. Measurements made in the northeast Pacific Ocean are given.

J. A. Scrimger; R. G. Turner

1969-01-01T23:59:59.000Z

490

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

491

Seismic scattering in the subduction zone of the Middle America region  

E-Print Network [OSTI]

vi 4 Scattering of seismic waves in heterogenousvii 6 Evaluation of seismic scattering usingan alternative seismic network . .

Dominguez, Luis Antonio

2012-01-01T23:59:59.000Z

492

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

493

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 Sjölander. 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

494

Variational Principles for Scattering Processes. I  

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A systematic treatment is presented of the application of variational principles to the quantum theory of scattering.Starting from the time-dependent theory, a pair of variational principles is provided for the approximate calculation of the unitary (collision) operator that describes the connection between the initial and final states of the system. An equivalent formulation of the theory is obtained by expressing the collision operator in terms of an Hermitian (reaction) operator; variational principles for the reaction operator follow. The time-independent theory, including variational principles for the operators now used to describe transitions, emerges from the time-dependent theory by restricting the discusson to stationary states. Specialization to the case of scattering by a central force field establishes the connection with the conventional phase shift analysis and results in a variational principle for the phase shift.As an illustration, the results of Fermi and Breit on the scattering of slow neutrons by bound protons are deduced by variational methods.

B. A. Lippmann and Julian Schwinger

1950-08-01T23:59:59.000Z

495

Power Controlled Minimum Frame Length Scheduling in TDMA Wireless Networks with  

E-Print Network [OSTI]

Power Controlled Minimum Frame Length Scheduling in TDMA Wireless Networks with Sectored Antennas controlled min- imum frame length scheduling for TDMA wireless networks. Given a set of one-hop transmission scheduling and power control was first addressed by Tamer and Ephremides in [1, 2]. Given a set of one

Arabshahi, Payman

496

DOI: 10.1002/cphc.201400055 Effects of Adsorbate Coverage and Bond-Length Disorder  

E-Print Network [OSTI]

DOI: 10.1002/cphc.201400055 Effects of Adsorbate Coverage and Bond-Length Disorder on the d the effects of bond-length disorder and adsorbate coverage (CO and H2) on the d-band center of 1.25 nm size Pt catalysts supported on carbon. We found that the decrease in adsorbate coverage at elevated temperatures

Frenkel, Anatoly

497

Video Description Length Guided Constant Quality Video Coding with Bitrate Constraint  

E-Print Network [OSTI]

Video Description Length Guided Constant Quality Video Coding with Bitrate Constraint Lei Yang propose a new video encoding strategy -- Video description length guided Constant Quality video coding with Bitrate Constraint (V-CQBC), for large scale video transcoding systems of video charing websites

Tomkins, Andrew

498

Bloat control and generalization pressure using the minimum description length principle for a  

E-Print Network [OSTI]

Bloat control and generalization pressure using the minimum description length principle to achieve these objectives based on the Minimum Description Length (MDL) principle. This principle solutions that are bigger than necessary, contradicting the Occam's razor principle [7] which says that "the

Bacardit, Jaume

499

Bloat control and generalization pressure using the minimum description length principle for a  

E-Print Network [OSTI]

Bloat control and generalization pressure using the minimum description length principle propose a method to achieve these objectives based on the Minimum Description Length (MDL) principle. This principle is a metric which combines in a smart way the accuracy and the complexity of a theory (rule set

Bacardit, Jaume

500

Copper CMP Planarization Length -MRS 2001 -April 19th , 2001 Paul Lefevre Page 1  

E-Print Network [OSTI]

Copper CMP Planarization Length - MRS 2001 - April 19th , 2001 ­ Paul Lefevre ­ Page 1 DIRECT MEASUREMENT OF PLANARIZATION LENGTH FOR COPPER CHEMICAL MECHANICAL POLISHING (CMP) PROCESSES USING A LARGE; Michael Gostein, Philips Analytical, Natick, MA; John Nguyen, SpeedFam-IPEC, Phoenix, AZ. #12;Copper CMP

Boning, Duane S.