A Monte Carlo algorithm for computing spin echo small angle neutron scattering correlation functions in real space: Hard sphere liquids

2010 ◽  
Vol 132 (4) ◽  
pp. 044906 ◽  
Author(s):  
Chwen-Yang Shew ◽  
Wei-Ren Chen
Keyword(s):  
Monte Carlo ◽  
Neutron Scattering ◽  
Small Angle ◽  
Correlation Functions ◽  
Hard Sphere ◽  
Small Angle Neutron Scattering ◽  
Spin Echo ◽  
Real Space ◽  
Monte Carlo Algorithm ◽  
Hard Sphere Liquids

Structural transitions of hard-sphere colloids studied by spin-echo small-angle neutron scattering

2003 ◽  
Vol 36 (6) ◽  
pp. 1417-1423 ◽  
Author(s):  
Timofei Krouglov ◽  
Wim G. Bouwman ◽  
Jeroen Plomp ◽  
M. Theo Rekveldt ◽  
Gert Jan Vroege ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Hard Sphere ◽  
Small Angle Neutron Scattering ◽  
Crystalline State ◽  
Spin Echo ◽  
Colloidal Suspensions ◽  
Real Space ◽  
Concentrated Suspension ◽  
Dilute Suspension

The structure of hard-sphere colloidal suspensions is measured at different concentrations using the recently developed spin-echo small-angle neutron scattering (SESANS) technique. It is shown that SESANS measures real-space correlations ranging from the size of a single particle for a dilute suspension to several particle diameters for a concentrated suspension, glass and crystalline state.

Structure of hard-sphere colloid observed in real space by spin-echo small-angle neutron scattering

2005 ◽  
Vol 357 (3-4) ◽  
pp. 452-455 ◽  
Author(s):  
Timofey Kruglov ◽  
Wim G. Bouwman ◽  
Jeroen Plomp ◽  
M. Theo Rekveldt ◽  
Gert Jan Vroege ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Hard Sphere ◽  
Small Angle Neutron Scattering ◽  
Spin Echo ◽  
Real Space

scholarly journals Spin-echo small-angle neutron scattering (SESANS) studies of diblock copolymer nanoparticles

Soft Matter ◽  
2019 ◽  
Vol 15 (1) ◽  
pp. 17-21
Author(s):  
Gregory N. Smith ◽  
Victoria J. Cunningham ◽  
Sarah L. Canning ◽  
Matthew J. Derry ◽  
J. F. K. Cooper ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Diblock Copolymer ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Spin Echo ◽  
Real Space ◽  
Polymer Nanoparticles ◽  
High Contrast ◽  
Concentrated Dispersions

Concentrated dispersions of polymer nanoparticles with high contrast can be studied using SESANS in real space.

Model calculations for the spin-echo small-angle neutron-scattering correlation function

2003 ◽  
Vol 36 (1) ◽  
pp. 109-116 ◽  
Author(s):  
Oktay Uca ◽  
Wim G. Bouwman ◽  
M. Theo Rekveldt
Keyword(s):  
Correlation Function ◽  
Neutron Scattering ◽  
Small Angle ◽  
Structure Factor ◽  
Small Angle Neutron Scattering ◽  
Spin Echo ◽  
Random Systems ◽  
Real Space ◽  
Exact Expression ◽  
Model Calculations

Spin-echo small-angle neutron scattering (SESANS) is a new kind of SANS technique enabling measurements to be made directly in real space from a range of a few nanometres up to micrometres. In this paper it is shown by calculations on models that SESANS measures correlations directly. Furthermore, the effect of polydispersity and structure factor has been studied. An exact expression for the correlation function has been derived in the case of random systems, such as fractal systems.

Analysis of spin-echo small-angle neutron scattering measurements

2008 ◽  
Vol 41 (5) ◽  
pp. 868-885 ◽  
Author(s):  
Robert Andersson ◽  
Léon F. van Heijkamp ◽  
Ignatz M. de Schepper ◽  
Wim G. Bouwman
Keyword(s):  
Correlation Function ◽  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Spin Echo ◽  
Pair Correlation ◽  
Real Space ◽  
Density Correlation ◽  
Measurement Models ◽  
Space Technique

Spin-echo small-angle neutron scattering (SESANS) is, in contrast to conventional small-angle neutron scattering (SANS), a real-space technique. SESANS measures the projection of the density–density correlation function of a sample, rather than, as in SANS, its Fourier transform. This paper introduces a toolkit for interpretion and analysis of a SESANS measurement. Models that are used in SANS are discussed and translated into a SESANS formalism. These models can be used to analyse and fit the data obtained by SESANS. Dilute, concentrated, random, fractal and anisotropic density distributions are considered. Numerical methods used to calculate the projection from numerical data are presented, either by using Fourier transformation orviathe real-space pair correlation function.

Spin-echo small-angle neutron scattering for dense systems of spheres

2005 ◽  
Vol 38 (5) ◽  
pp. 721-726 ◽  
Author(s):  
Timofey Kruglov
Keyword(s):  
Small Angle ◽  
Correlation Functions ◽  
Hard Sphere ◽  
Small Angle Neutron Scattering ◽  
Spin Echo ◽  
Spherical Particles ◽  
Correlation Lengths ◽  
Angle Scattering ◽  
Hard Sphere Liquid ◽  
Single Sphere

This paper presents (spin-echo) SANS correlation functions describing small-angle scattering on dense systems of spherical particles. (Spin-echo) small-angle correlation functions and associated correlation lengths for a single sphere, a dumbbell, excluded volume and structure are introduced. It is shown that the correlation length is proportional to the cumulative scattering probability. This approach is applied to a hard-sphere liquid.

Spin echo modulated small-angle neutron scattering using superconducting magnetic Wollaston prisms

2016 ◽  
Vol 49 (1) ◽  
pp. 55-63 ◽  
Author(s):  
Fankang Li ◽  
Steven R. Parnell ◽  
Hongyu Bai ◽  
Wencao Yang ◽  
William A. Hamilton ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Spin Echo ◽  
Test Sample ◽  
Neutron Spin ◽  
Neutron Polarization ◽  
Magnetic Components

The spin echo modulated small-angle neutron scattering technique has been implemented using two superconducting magnetic Wollaston prisms at a reactor neutron source. The density autocorrelation function measured for a test sample of colloidal silica in a suspension agrees with that obtained previously by other neutron scattering methods on an identically prepared sample. The reported apparatus has a number of advantages over competing technologies: it should allow larger length scales (up to several micrometres) to be probed; it has very small parasitic neutron scattering and attenuation; the magnetic fields within the device are highly uniform; and the neutron spin transport across the device boundaries is very efficient. To understand quantitatively the results of the reported experiment and to guide future instrument development, Monte Carlo simulations are presented, in which the evolution of the neutron polarization through the apparatus is based on magnetic field integrals obtained from finite-element simulations of the various magnetic components. The Monte Carlo simulations indicate that the polarization losses observed in the experiments are a result of instrumental artifacts that can be easily corrected in future experiments.

Concepts in spin echo small-angle neutron scattering

2001 ◽  
Vol 34 (5) ◽  
pp. 639-645 ◽  
Author(s):  
Jinkui Zhao
Keyword(s):  
Distribution Function ◽  
Correlation Function ◽  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Spin Echo ◽  
Length Distribution ◽  
Real Space ◽  
Vector Length ◽  
One Dimensional

Two-dimensional spin echo small-angle neutron scattering experiments that measure the vector-length distribution function, or pair-distance distribution function, in real space are discussed. The proposed diffractometer uses two cylindrically symmetric magnetic fields with conically shaped front and end faces to enable experiments in two dimensions. It also features a π/2 neutron spin flipper to make the effective analyzing direction of the analyzer perpendicular to the polarizing direction of the polarizer. The theoretical aspect of one-dimensional spin echo small-angle neutron scattering experiments is also explored. The relationship between the correlation function from one-dimensional experiments and the vector-length distribution function is established, and interpretation of this correlation function in real space is presented.

Real-space interpretation of spin-echo small-angle neutron scattering

2003 ◽  
Vol 36 (1) ◽  
pp. 117-124 ◽  
Author(s):  
Timofei Krouglov ◽  
Ignatz M. de Schepper ◽  
Wim G. Bouwman ◽  
M. Theo Rekveldt
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Spin Echo ◽  
Scattering Length ◽  
Structural Parameters ◽  
Pair Correlation ◽  
Real Space ◽  
Radius Of Gyration ◽  
Solid Spheres

Spin-echo small-angle neutron scattering (SESANS) is a novel real-space scattering technique. SESANS measures a correlation-like functionG(Z), the meaning of which was unknown until now. Here a direct real-space interpretation ofG(Z) through the particle scattering density and pair correlation function is given. One-dimensional and two-dimensional SESANS are compared. The case of non-interacting particles is considered in detail with an explicit geometrical interpretation. General methods for the calculation of structural parameters, such as the total scattering length and the radius of gyration, are developed. Analytical expressions ofG(Z) for non-interacting solid spheres, hollow spheres and Gaussian coils are derived. The case of solid spheres is compared with experimental data.

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